This was a prospective study involving 27 patients with moderate symptoms of benign prostatic hyperplasia (BPH) treated continuously with 5 mg of finasteride daily for one year. There was improvement in clinical BPH symptoms in 22 patients (81.48%), increase in urinary flow rates by a mean of 2.2 mls/sec in 20 patients (74.07%) and a mean decrease in prostate volume of 20.9% in 25 patients (92.59%) comparable to the findings of the other investigators. No patient on finasteride therapy developed acute urinary retention suggesting reduced risk. The reversal in BPH progression stems from the ability of finasteride to reduce prostate volume thus relieving urinary obstruction and to decrease BPH symptoms and increase urinary flow rates. Finasteride therapy was well tolerated in this study. No adverse effect was observed except impotence in one patient (3.7%) and loss of libido in another patient (3.7%). For symptomatic relief in men with moderate obstructive symptoms of BPH, finasteride should be considered an effective alternative to watchful waiting. These findings warrant further investigations and may signal a positive change in the role of medical therapy in the future long term management of BPH.

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Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:"Times New Roman"; mso-bidi-theme-font:minor-bidi;} Olfactory acuity differs among animal species depending on age and dependence on smell. However, the attendant functional anatomy has not been elucidated. We sought to determine the functional structure of the olfactory mucosa in suckling and adult dog and sheep. Mucosal samples harvested from ethmoturbinates were analyzed qualitatively and quantitatively. In both species, the olfactory mucosa comprised olfactory, supporting and basal cells, and a lamina propria containing bundles of olfactory cell axons, Bowman’s glands and vascular elements. The olfactory cells terminated apically with an expanded knob, from which cilia projected in a radial fashion from its base and in form of a tuft from its apex in the dog and the sheep respectively. Olfactory cilia per knob weremorenumerous in the dog (19±3) compared to the sheep (7±2) (p < 0.05). In the dog, axonal bundles exhibited one to two centrally located capillaries and the bundles were of greater diameters (73.3±10.3_m) than those of the sheep (50.6±6.8_m), which had no capillaries. From suckling to adulthood in the dog, the packing density of the olfactory and supporting cells increased by 22.5% and 12.6% respectively. Surprisingly in the sheep, the density of the olfactory cells decreased by 26.2% while that of the supportive cells showed no change. Overall epithelial thickness reached 72.5±2.9_m in the dog and 56.8±3.1_m in the sheep. These observations suggest that the mucosa is better structurally refined during maturation in the dog than in the sheep.

From cadaver dissections of the recurrent motor branch of the median nerve, we determined the exact relationship of its terminal branches at the base of the thumb. This enabled us to surgically approach the first carpometacarpal joint directly on the volar aspect for management of Bennett's fractures in 18 consecutive patients.

As compared with the different surgical approaches advocated and commonly used, the direct volar approach affords clear direct exposure of the intra-articular fracture at the base of the thumb so aiding appropriate reduction and fixation of the fracture. The proposed approach is safe and requires minimal dissection or soft tissue resection. The results were excellent and no case of nerve injury was encountered.

Records were available for 197 patients with malignant lymphomas (MLs) aged 13 years and above seen at Kenyatta National Hospital (KNH) between the years 1973 and 1986. There were 110 cases of Hodgkin's disease (HD) and 87 cases of non-Hodgkin's lymphomas (NHLs). The distribution of the two groups according to sex and histologic sub-types was not significantly different. HD patients were on average significantly younger than NHL patients (28.8 years versus 41.1 years). Over 70% of both HD and NHL cases presented in stages III and IV and the distribution of the groups according to stage of disease was not statistically significant. There was no significant correlation between stage of disease at diagnosis and histologic subtypes for either group. Losses to follow-up were high in both groups. Female sex was associated with longer periods of follow-up in both groups, being statistically significant for HD and not so for NHLs. Age was not correlated with duration of follow-up for NHLS whereas for HD cases, older age (above 53 years) was associated with shortened follow-up periods. The mortality rate was higher in NHLs than in HD cases.

Separation of midgut membrane proteins from the tick, Ambylomma variegatum, using a nonionic detergent (Triton X-114), resulted in two protein fractions, namely DET (detergent) and AQ (aqueous). In immunoblotting analysis with polyclonal antibodies against these fractions, 4 proteins (Mr approximately 27,000, 67,000, 86,000 and 95,000,) and 2 proteins (M, approximately 54,000 and 67,000) were detected in the DET and AQ fractions, respectively. Three of the DET fraction proteins Mr approximately 27,000, 67,000 and 95,000 were glycosylated since they bound to the lectin, concanavalin A. In 2-dimensional gel electrophoresis, the AQ and DET fraction proteins were found to be acidic in nature. In a series of bioassay experiments, rabbits were first immunised with both DET and AQ fractions and then infested with ticks. The egg batch weights of these ticks were reduced by 50% compared to control ticks. Furthermore, there was a significant reduction in the hatchability of eggs laid by ticks fed on rabbits previously immunised with both DET (14%) and AQ (33%) fractions. Based on the egg hatchability, the reproductive capacity of ticks was reduced by 77 and 48% by DET and AQ fractions, respectively.

Five plasters and one fiberglass casting bandages available on the Kenyan market were evaluated for breaking strength and resistance to abrasion. Under the test conditions, scotch cast was found to be 2.6 times stronger than the strongest plaster of Paris preparation when the load per unit thickness was compared and was significantly different from the plaster casts in terms of maximum load (p=0.0001). Among the plaster products, there were significant statistical differences (p=0.029) in maximum strength with Helm and Plasrum-gyps withstanding the greatest load. Scotchcast was the most resistant to abrasion while among the plaster product, Salvaplast and POP-Nairobi Enterprises showed satisfactory resistance Heal, Plasrun-gyps and Veronese proved least resistant under the testing conditions.

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Every reducible operator can be decomposed into normal and completely non-normal operators.
Unfortunately, there are several non normal operators which are irreducible. However, every operator
whose self-commutator is bounded, is reducible. Berger-Shaw inequality implies boundedness
of the trace of the self-commutator for hyponormal operators. In this paper, the Berger-Shaw
inequality is studied for n-Power normal, n-power quasinormal and w-hyponormal operators.

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PEST MANAGEMENT PRACTICES AND COMPLIANCE TO MARKET STANDARDS AMONG FRENCH BEAN FARMERS

Bernard Ouma, James Muthomi, John Nderitu2 and Faith Toroitich
Department of Plant Science and Crop Protection, University of Nairobi, P. O. Box 30197-00100, Nairobi, Kenya
2. Mount Kenya University, P. O. Box 342-01000, Thika, Kenya
Abstract
The EU commission increased to 10% sampling and pesticide residue analysis of French beans and peas imported from Kenya. This resulted in a 25% dip in bean sales in January 2013. This study aimed at determining pest management strategies used by small scale French bean farmers. A survey to determine farmers’ pest management practices was done in Embu east and Mwea east district, where 32 and 38 farmers were from Embu east and Mwea east, respectively. The farmers considered French beans farming as an important source of income, and up to 50% of the farmers had been in French beans production for a period of three years and more. Most of farmers in the study area entirely relied on synthetic pesticides for pest and disease control. White fly was the major insect pest while rust was the major disease as identified by the majority of farmers. Less than 30% of the farmers were involved in the implementation of GLOBALGAP, with 3.1% of the farmers being certified. The findings showed that farmer’s pest management practices were incompatible with good agricultural practices and export market standards. There is a need to sensitize farmers on the use of alternative pest management strategies and requirements of the export market standards.
Key words: French beans, export market requirements, maximum residue levels, Global G.A.P

Staphylococcus aureus cause diseases both in humans and animals. These diseases range from mild to fatal infections thus necessitating development of a specific molecular method for detection of pathogenic S. aureus.

The human beta-2 adrenergic receptor (beta2AR) is responsible for the binding of endogenous catecholamines and their exogenously administered agonists and antagonists. Three functional polymorphisms in codons 16, 27 and 164 have been described which have clinical importance for several diseases, including asthma, hypertension, heart failure, cystic fibrosis and obesity, as well as response to beta-agonist therapy. These were evaluated in 726 individuals from 8 distinct ethnic populations (Chinese, Filipino, Southwest Asian, Saudi, Ghanaian, Kenyan, Sudanese, and European from Scotland). The results show that most haplotypes are shared among all populations, yet there are marked differences in their frequency distributions geographically. The genetic distance tree is different from standard human population distance trees, implying a different mode of evolution for this locus than that for human population gene-flow history. The multilocus frequency differences between the observed clusters of populations correspond to historical haplotype groupings that have been found to be functionally different with respect to multiple medically related phenotypes. Further studies are needed to see if functional relationships are the same across populations.

The factors responsible for the explosive spread of human immunodeficiency virus type 1 (HIV-1) in sub-Saharan Africa continue to be identified and debated. One of the most controversial factors has been male circumcision. This cross-sectional study was conducted to measure the association between circumcision status and infection with HIV-1 among men with genital ulcer disease. Eight hundred and ten men participated in the study, of whom 190 (23%) were HIV-1-positive. A logistic regression model adjusted for behavioral and historical showed that HIV-1 positivity was independently associated with being uncircumcised (adjusted odds ratio [OR], 4.8; 95% confidence interval [CI], 3.3-7.2) and with a history of urethral discharge (adjusted OR, 2.0; 95% CI, 1.4-2.8). This association could not be explained by measures of sexual exposure to HIV-1 among this population. Male circumcision should be considered as an intervention strategy for AIDS control.

A clinical, radiological, histological, and geographical study of carcinoma of the esophagus in Kenya is reported. It was found that this cancer is diagnosed more often in males than in females, with a ration of 8:1 (Kenya Cancer Registry). The most common age in males and females is 50 to 59 years. The regions of the esophagus most commonly involved are the middle and lower thirds, in almost equal proportions. An unexplained tendency for the tumor to be poorly differentiated towards the lower third is noted. In addition a review on the possible etiological factors is presented.

This study was conducted to evaluate the control of trypanosomosis in camels in Turkana district of Kenya using participatory approaches. Lapur division of the district was conveniently selected as the study area considering logistics and security concerns. Four main animal camps (adakars) formed the study units. Key informants from each adakar were selected for participatory research processes. Participatory mapping, semi-structured interviews, pair-wise comparisons and matrix scoring were the participatory methods employed. Five camel diseases in order of their importance, were identified, namely, camel trypanososmosis, tick infestation, non-specific diarrhoea, mange and harmorrhagic septicaemia. Twelve groups of the lay key informants agreed well on the presenting signs of theses diseases. Although trypanocides were considered by the informants to be reasonably available, the most preferred method for the control of camel trypanosomosis was the use of indigenous remedies. These indigenous remedies included the oral administration to sick camels with variety of herbs mixed with soups from goat, wildcat, bird or donkey meat. The results from this study revealed that camel trypanosomosis is an important disease in Turkana district. The prices of the available modern trypanocides in the management of camel trypanosomosis appeared to hamper the effective control of the disease. However, the efficacy of the widely used indigenous remedies remains undetermined.

Four thousand nine hundred and seventy-one trypanosomosis-surveillance records from an open population of Orma Boran cattle raised under natural trypanosomosis challenge in Galana Ranch, Kenya between the years 1990 and 2000 were analysed. The objective of the analysis was to identify epidemiological factors that influenced time-to-treatment of trypanosomosis cases. Under the surveillance programme, blood was being examined fortnightly for trypanosomosis using buffy coat technique. Infected animals were treated when their packed cell volumes (PCV) fell to 25% or lower. The number of days between the first diagnosis and treatment of trypanosomosis cases was obtained from the difference between diagnosis and treatment dates. Days-to-treatment clustered around the screening periods; therefore, time-to-treatment was represented by a series of time points 0-8 at 14-day intervals. Factors postulated to affect the outcome (time-to-treatment) were age of an animal at time of diagnosis, sex, number of trypanosome infections, trypanosome species and season of the year. Five animal generations were generated from birth dates and treated as nuisance parameters. Conditional logistic regression and Cox proportional hazards models were fitted to the data, the former to analyse factors that influenced treatment after time 0 (outcome dichotomised as time 0 or >0) and the latter to analyse factors that influenced time-to-treatment for cases that were treated after time 0, excluding all cases treated on time 0. The majority of the cases (89.5%) were treated on the same day of diagnosis. Trypanosome infections were more likely to be treated after time 0 in dry than in wet season. Similarly, the rate of treatment was lower in the dry than the wet season. An increase in number of previous trypanosome infections reduced the odds of an animal being treated after time 0. Animals that had been exposed to many infections before had higher rates of treatment than those that had minimal experiences. We offer possible reasons for these observations and conclude that selection of animals for breeding purposes in programmes geared towards improving trypanotolerance should take into consideration the environmental factors that affect classification of an animal as being resistant or susceptible.

Despite the many thousands of research studies published every year,
evidence for making clinical decisions is often lacking. The main problem is that
the evidence available is generated in conditions very different from those that
prevail in routine clinical practice and with patients who are different. This is
particularly a problem for low and middle income countries as most evidence is
generated in high income countries.
A group of clinicians, researchers, and policy makers met at Bellagio in Italy to
consider how more relevant evidence might be generated. One answer is to
conduct more pragmatic trials—those undertaken in routine clinical practice.
The group thought that this might best be achieved by developing “learning
health systems” in low and middle income countries.
Learning health systems develop in communities that include clinicians,
patients, researchers, improvement specialists, information technology
specialists, managers, and policy makers and have a governance system that
gives a voice to all those in the community. The systems focus on improving
outcomes for patients, use a common dataset, and promote quality
improvement and pragmatic research. Plans have been developed to create at
least two learning systems in Africa.

Kent papers in POlitics and International Relations, Series 4, No. 4.

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Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin:0in; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:"Times New Roman","serif";} Products of gene modification have vast implications. Creating public awareness and disseminating information on the subject seeks to demystify some of the widely held falsehoods regarding genetically modified products. This is an informative, thorough and easy to understand guidebook that aims to enlighten and debunk some of the commonly held misconceptions on products of gene modification and to give the reader a better understanding of the role genetic modification will play. The review sheds light on the safety, and application of these products in medicine, the food industry and other areas, especially those where genetic modification may represent a cheap, faster, credible, viable alternative in achieving sustainable development among resource-poor communities.

Kent papers in POlitics and International Relations, Series 4, No. 4.

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Journal of Eastern African Literary and Cultural Studies

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Journal of Eastern African Literary and Cultural Studies

{ BACKGROUND & AIMS: Oxidative stress has been implicated in the pathophysiology of chronic pancreatitis (CP). We evaluated the effects of antioxidant supplementation on pain relief, oxidative stress and antioxidant status in patients with CP. METHODS: In a placebo-controlled double blind trial, consecutive patients with CP were randomized to groups that were given placebo or antioxidants for 6 months. The primary outcome measure was pain relief, and secondary outcome measures were analgesic requirements, hospitalization, and markers of oxidative stress (thiobarbituric acid-reactive substances [TBARS]) and antioxidant status (ferric-reducing ability of plasma [FRAP]). RESULTS: Patients (age 30.5 +/- 10.5 years, 86 male, 35 alcoholic and 92 with idiopathic CP) were assigned to the placebo (n = 56) or antioxidant groups (n = 71). After 6 months, the reduction in the number of painful days per month was significantly higher in the antioxidant group compared with the placebo group (7.4 +/- 6.8 vs 3.2 +/- 4, respectively; P < .001; 95% CI, 2.07, 6.23). The reduction in the number of analgesic tablets per month was also higher in the antioxidant group (10.5 +/- 11.8 vs 4.4 +/- 5.8 respectively; P = .001; 95% CI, 2.65, 9.65). Furthermore, 32% and 13% of patients became pain free in the antioxidant and placebo groups, respectively (P = .009). The reduction in the level of TBARS and increase in FRAP were significantly higher in the antioxidant group compared with the placebo group (TBARS: placebo 1.2 +/- 2.7 vs antioxidant 3.5 +/- 3.4 nmol/mL; P = .001; 95% CI 0.96, 3.55; FRAP: placebo -5.6 +/- 154.9 vs antioxidant 97.8 +/- 134.9 muMFe(+2) liberated

Nine patients with acute liver failure due to Plasmodium falciparum liver injury admitted to the Rajgarhia Liver Unit of the All-India Institute of Medical Sciences during 1982-84 are presented. The liver was palpable in all the patients, and eight had splenomegaly. Investigations revealed mild to moderate abnormality in liver function tests. All were negative for the markers of acute infection due to hepatitis A and B viruses. Blood film examination showed P. falciparum alone in seven and along with P. vivax in the remaining two patients. Liver histology, which was identical in all eight patients where liver biopsy was done, showed centrizonal necrosis and hyperplastic Kupffer cells loaded with malarial pigment. All the patients recovered with specific anti-malarial and supportive treatment. Our observations suggest that malaria due to P. falciparum may present as jaundice and encephalopathy which stimulates acute hepatic failure due to fulminant hepatitis.

Nine patients with acute liver failure due to Plasmodium falciparum liver injury admitted to the Rajgarhia Liver Unit of the All-India Institute of Medical Sciences during 1982-84 are presented. The liver was palpable in all the patients, and eight had splenomegaly. Investigations revealed mild to moderate abnormality in liver function tests. All were negative for the markers of acute infection due to hepatitis A and B viruses. Blood film examination showed P. falciparum alone in seven and along with P. vivax in the remaining two patients. Liver histology, which was identical in all eight patients where liver biopsy was done, showed centrizonal necrosis and hyperplastic Kupffer cells loaded with malarial pigment. All the patients recovered with specific anti-malarial and supportive treatment. Our observations suggest that malaria due to P. falciparum may present as jaundice and encephalopathy which stimulates acute hepatic failure due to fulminant hepatitis.

Hepatitis G virus (HGV)/GB virus-C (GBV-C) has been identified as a blood-borne agent with disputed pathogenicity. This virus belongs to the flaviviridae with a distant relationship to hepatitis C virus (HCV). Genetically divergent HGV isolates have been reported from different parts of the world. This study describes the prevalence of HGV in multitransfused thalassaemic children in India and genomic sequence variations in 11 HGV isolates from the same geographical location. Hepatitis G virus RNA was detected in 39.7% multitransfused thalassaemic children. The seroprevalence of hepatitis B virus (HBV) and HCV was 23.8% and 17.1%, respectively, and 11.4% had dual infection. The nucleotide sequence of a 166 bp HGV genomic segment from the putative capsid-envelope region (nucleotide; nt 578-743) from 11 Indian isolates was compared to the sequences available in the nucleotide databases. The isolates from India were 81.3-94.5% homologous to the isolates from other parts of the world. On phylogenetic analysis, it was observed that HGV isolates from India may belong to two genetically divergent types.

BACKGROUND/AIMS: Seizure activity in patients with acute liver failure (ALF) may increase cerebral oxygen requirements and worsen cerebral edema. Recently, prophylactic phenytoin has been recommended to suppress sub-clinical seizure activity evident on electroencephalographic monitoring. To determine the clinical utility of prophylactic phenytoin therapy in patients with ALF. METHODS: Forty two patients with ALF were randomized. Twenty two patients were given prophylactic phenytoin and 22 patients acted as controls. The baseline clinical and biochemical features were similar in the two groups and patients with > or =2 poor prognostic variables were equally represented. RESULTS: Sixteen patients in the phenytoin group, and 15 in the control group developed cerebral edema (P=0.38). Mechanical ventilation was required in 10 and 12 patients in the phenytoin and control groups, respectively, (P=0.77). Seizures occurred in 5 (22.7%) control patients and 5 (25%) phenytoin treated patients (P=0.86). Fourteen (70%) patients randomized to phenytoin and 15 (68.2%) control patients died (P=0.89). CONCLUSIONS: Seizure was common in patients with ALF. Prophylactic use of phenytoin did not prevent cerebral edema, seizures or need for mechanical ventilation, and did not improve survival.

BACKGROUND AND AIMS: In acute liver failure (ALF), the brain is exposed to high levels of ammonia. Human studies defining the clinical significance of ammonia in ALF are lacking. This prospective study evaluated the relationship of arterial ammonia levels at admission to complications and survival among patients with ALF. METHODS: Eighty consecutive ALF patients admitted from March 2001 to December 2003 were followed up until death or complete recovery. All had arterial ammonia estimation at admission (enzymatic method). Logistic regression analysis was performed to identify independent predictors of mortality. RESULTS: Forty two (52.5%) patients died. Non-survivors had significantly higher median ammonia levels than survivors (174.7 v 105.0 micromol/l; p<0.001). An arterial ammonia level of > or = 124 micromol/l was found to predict mortality with 78.6% sensitivity and 76.3% specificity, and had 77.5% diagnostic accuracy. Patients with higher ammonia levels also developed more complications, including deeper encephalopathy (p = 0.055), cerebral oedema (p = 0.020), need for ventilation (p<0.001), and seizures (p = 0.006). Logistic regression analysis showed that pH, presence of cerebral oedema, and arterial ammonia at admission were independent predictors of mortality (odds ratios 6.6, 12.6, and 10.9, respectively). Incorporating these variables, a score predicting mortality risk at admission was derived: 2.53 + 2.91 ammonia + 2.41 oedema + 1.40 pH, where ammonia is scored as 0 (if <124 micromol/l) or 1 (if > or =124 micromol/l); oedema is scored as 0 (absent) or 1(present); and pH is scored as 1 (if < or =7.40) or 0 (if >7.40). Levels of partial pressure of ammonia were equally correlated with outcome. CONCLUSION: Arterial ammonia at presentation is predictive of outcome and can be used for risk stratification. Ammonia lowering therapies in patients with ALF should be evaluated.

Pregnant patients with acute liver failure (ALF) are believed to have a worse outcome than nonpregnant women and men with ALF. However objective data supporting this supposition are scant. Therefore, the current study compared the outcome, complications, and causes of ALF among pregnant women and girls with age-matched nonpregnant women and girls and men and boys with ALF. One thousand fifteen consecutive ALF patients in the reproductive age group, admitted at the All India Institute of Medical Sciences, New Delhi, from January 1986 to December 2006, were included in the study. A total of 249 (38.5%) women were pregnant. They were compared with 341 nonpregnant women and girls and 425 men and boys, aged 15 to 45 years. The mortality rate of pregnant women and girls (53.8%) was similar to age-matched nonpregnant women and girls (57.2%), and men and boys (57.9%); P = 0.572.The clinical and biochemical features, disease severity, and complications were also similar in the three groups. A significantly higher proportion of ALF was attributable to hepatitis E virus (HEV) among women and girls who were pregnant (59.4%), as compared with both nonpregnant women and girls (30.4%), and men and boys (23.1%); P < 0.001. However, the outcome of HEV-related ALF was independent of the sex and pregnancy status of the patients (P = 0.103). Mortality in HEV-ALF and non-HEV-ALF patients in pregnant women and girls was 51% (74/145) and 54.7% (52/95)(P > 0.1), respectively. The outcome of pregnant ALF patients was also unrelated to the trimester of pregnancy. The mortality of non-HEV-related ALF among the pregnant women and girls (54.7%), age-matched nonpregnant women and girls (61.7%), and men and boys (62.8%) were also similar (P > 0.1). Conclusion: The mortality of pregnant patients with ALF is similar to that of nonpregnant women and girls and men and boys and is independent of the cause or trimester. Pregnancy per se should not be regarded as a poor prognostic factor for a patient with ALF. (HEPATOLOGY 2008.).

BACKGROUND: Although artesunate and mefloquine have been used as monotherapies in the treatment of malaria in Kenya for a long time, there is insufficient data on the clinical outcome when used as combination therapy in this population. OBJECTIVE: To derive data on the efficacy and safety profile of artesunate-mefloquine combination in the treatment of uncomplicated Plasmodium falciparum malaria in Kenya. DESIGN: An open label single arm clinical trial. SETTING: Bungoma district Hospital. Study area was Bungoma District of Kenya, an endemic area of malaria. The study was conducted between January 2004 and April 2004. SUBJECTS: A total of 200 males and females with uncomplicated plasmodium falciparum malaria weighing 35kg and above were recruited in the study. RESULTS: In the evaluable patient population the day 28 cure rate was 98.4% while day 14 and 7 cure rates were 98.4% and 99.2% respectively. There was rapid relief of symptoms the median time of fever clearance was one day and the most common drug related adverse events were headache dizziness and asthenia. There was no significant derangement in the haematological, biochemical and ECG parameters in the patients on treatment. CONCLUSION: Artesunate-mefloquine combination given simultaneously was found to be highly effective and safe in the treatment of uncomplicated malaria.

OBJECTIVE: To record the costs of hospital care for HIV-positive and -negative patients in Nairobi, and identify costs paid by patients per admission. DESIGN: Cost data were collected on inpatients enrolled in a linked clinical study using standardized costing methods. SETTING: Kenyatta National Hospital, Nairobi's main district hospital. PATIENTS: Consecutive adult medical admissions to one ward over 14 weeks who consented to enrollment; tertiary referrals were excluded. MAIN OUTCOME MEASURE: Average length of stay and cost per patient admission. RESULTS: The hospital costs of 398 patients (163 HIV positive; 33 with clinical AIDS) were analysed. The mean length of stay was 9.3 days and the mean cost per patient admission was US$163. There was no significant difference in costs or mean lengths of stay between HIV-positive and -negative groups, nor were the costs and lengths of stay for clinical AIDS patients significantly different to those for HIV-positive patients without AIDS. The patient charges paid to the hospital per admission, recorded for 344 patients, were on average US$61; and did not differ by HIV status. CONCLUSION: The similar cost patterns for inpatient care irrespective of HIV status or clinical AIDS probably reflects the limited provision of care beyond basic clinical services. Length of stay rather than differing treatment regimes thus appears to be the main cost driver. Private costs of medical care were high and were likely to pressurize households. When resources are limited, the introduction of new, more costly therapies needs careful planning. The study provides cost information for planning care services in resource-poor settings.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

Meningococcal meningitis has been recognised as serious problem for almost 200 years. In Africa the disease occurs in epidemics periodically during the hot and dry weather in the "meningitis belt" and in east Africa, which is outside this belt the epidemics tend to occur during the cold and dry months. The infection is mainly transmitted from person to person by nasopharyngeal carriers in crowded places like refugee camps and army barracks. The rural/urban migration, the basic structural conditions of housing in squatter settlements and slums together with an overcrowded transport system have also contributed to the transmission of meningococcal meningitis. The earlier treatment of meningococcal meningitis was by the way of repeated CSF drainage. The first important advance in the treatment was intrathecal injection of antimeningococcal serum. A major break through in the treatment was the introduction of sulphonamides which was the preferred treatment until emergence of resistance to sulphonamides in mid 1960's. Penicillin remains the drug of choice currently. Mass immunisation of selected communities using polyvalent A and C polysaccharide vaccine is a useful control measure. Chemoprophylaxis is generally not recommended during epidemics. Given the current population densities and rural/urban migration together with financial constraints, future epidemic in Kenya may be more explosive unless strict surveillance programmes are maintained.

Meningococcal meningitis has been recognised as serious problem for almost 200 years. In Africa the disease occurs in epidemics periodically during the hot and dry weather in the "meningitis belt" and in east Africa, which is outside this belt the epidemics tend to occur during the cold and dry months. The infection is mainly transmitted from person to person by nasopharyngeal carriers in crowded places like refugee camps and army barracks. The rural/urban migration, the basic structural conditions of housing in squatter settlements and slums together with an overcrowded transport system have also contributed to the transmission of meningococcal meningitis. The earlier treatment of meningococcal meningitis was by the way of repeated CSF drainage. The first important advance in the treatment was intrathecal injection of antimeningococcal serum. A major break through in the treatment was the introduction of sulphonamides which was the preferred treatment until emergence of resistance to sulphonamides in mid 1960's. Penicillin remains the drug of choice currently. Mass immunisation of selected communities using polyvalent A and C polysaccharide vaccine is a useful control measure. Chemoprophylaxis is generally not recommended during epidemics. Given the current population densities and rural/urban migration together with financial constraints, future epidemic in Kenya may be more explosive unless strict surveillance programmes are maintained.

A 33-year old female patient presented with recurrent polyneuropathy during two consecutive pregnancies and recovered completely after spontaneous abortion the first time and after a normal delivery the second time. The patient has had a tubal ligation since then and has remained well up to date.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

BACKGROUND: Anthrax is an ancient disease affecting animals and humans. Sporadic cases of anthrax and small epidemics have been seen from time to time in different parts of the world and in Africa. However many clinicians are not very familiar with the various presentations and management of anthrax. It is relevant for the health care workers to re-familiarise themselves with all aspects of anthrax, with the impending threat of bioterrorism. OBJECTIVE: To familiarise healthcare workers on all aspects of anthrax. STUDY SELECTION: To describe epidemiology pathogenesis, clinical features, management and prevention of anthrax including measures to take when weapons grade anthrax is suspected. DATA SYNTHESIS: Three forms of the disease are recognised, cutaneous, inhalational and intestinal. Cutaneous anthrax is the most common form. Inhalation anthrax is the most severe form of anthrax. The treatment of anthrax in most cases is penicillin, however with the threat of bioterrorism, intentional releases of anthrax spores in the environment has caused much concern. Weapons grade anthrax of more virulent strain and resistant to commonly used antibiotics is possible. CONCLUSION: In view of the different clinical presentations and outcomes it is important that health care workers re-familiarise themselves with the disease and in the event of bioterrorism are able to take appropriate measures.

Rat bite fever has not been reported from Kenya previously. A case of 17 year old Kenyan male who was diagnosed to have rat bite fever after a bite of domestic rat is described. The history, clinical features and demonstration of spirillum like organisms from a thick blood film suggest infection due to spirillum minus. The patient recovered completely after a course of penicillin and gentamicin.

BACKGROUND: Although artesunate and mefloquine have been used as monotherapies in the treatment of malaria in Kenya for a long time, there is insufficient data on the clinical outcome when used as combination therapy in this population. OBJECTIVE: To derive data on the efficacy and safety profile of artesunate-mefloquine combination in the treatment of uncomplicated Plasmodium falciparum malaria in Kenya. DESIGN: An open label single arm clinical trial. SETTING: Bungoma district Hospital. Study area was Bungoma District of Kenya, an endemic area of malaria. The study was conducted between January 2004 and April 2004. SUBJECTS: A total of 200 males and females with uncomplicated plasmodium falciparum malaria weighing 35kg and above were recruited in the study. RESULTS: In the evaluable patient population the day 28 cure rate was 98.4% while day 14 and 7 cure rates were 98.4% and 99.2% respectively. There was rapid relief of symptoms the median time of fever clearance was one day and the most common drug related adverse events were headache dizziness and asthenia. There was no significant derangement in the haematological, biochemical and ECG parameters in the patients on treatment. CONCLUSION: Artesunate-mefloquine combination given simultaneously was found to be highly effective and safe in the treatment of uncomplicated malaria.

PIP: Features of the laboratory diagnosis of malaria are described. Microscope equipment is absolutely essential. Clinical symptoms are inadequate for the proper diagnosis of malaria. Screening for malaria involves identification of all cases where high fever is present in endemic areas. Diagnosis is complicated because many people take antimalarial drugs which reduce the chances of detecting malarial parasites. Confirmation should be made before treatment is administered. A thick blood slide can be quickly and cheaply taken without much training of health personnel. The disadvantage of thick stains is the difficulty in identifying "plasmodium" strains. When a thin smear with Giemsa and Leishmanin stain is used, a light infection may be missed. Thin smears require trained personnel and time, which in peak seasons may be impractical. Urinary tract and viral infections may be confused with malaria. Evidence of parasites can be discerned from thick stains. Modern assay techniques are also available. There are enzyme linked immunosorbent assays (ELISA) and immunofluorescent assay techniques (IFAT), which are frequently used in large scale seroepidemiological studies. DNA probes have the limitation of radioisotope handling problems. Acridine orange fluorescent microscopy with capillary centrifuged blood is a technique which improves the viability of Giemsa stain procedures. This technique is desirable because of the sensitivity and speed of diagnosis. The quantitative buddy coat (GBC) technique is superior to Giemsa stained thick blood film in identifying malaria, but it is not reliable with mixed infections. Advanced techniques are not readily available in local settings. The recommendation is to continue use of thick or thin blood film and trained health personnel. Laboratory results must be interpreted in the context of when the flood film was prepared, prior drug administration, and clinical manifestations.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

PIP: Malaria is the most prevalent and devastating public health problem in Africa despite much research and control effort over the last two decades. In most parts of Africa, individuals should take 200 mg of Proguanil daily together with chloroquine 5 mg/kg per week as prophylaxis. Pregnant women and individuals with underlying disease such as sickle cell making them susceptible to severe or complicated malaria, however, should take just 200 mg Proguanil daily. In hard-core multi-drug resistance areas, mefloquine 250 mg once weekly together with chloroquine 300 mg weekly is recommended as prophylaxis. Since no anti-malarial drug confers absolute protection against infection, however, using mosquito nets impregnated with permethrin, insecticides, and mosquito repellents is also advocated for those at high risk of severe malaria. The need also exists to treat cases of malaria when prevention is unsuccessful. Chloroquine in total dose 25 mg/Kg over three days is the first choice treatment of uncomplicated malaria in 4-aminoquinoline sensitive areas. Amodiaquine 25 mg/Kg over three days is the second line treatment, while pyrimethamine/sulphonamide combinations are useful in areas where there is resistance to 4-aminoquinalines. Finally, quinine 10 mg/kg every eight hours for seven days is the treatment of choice for severe and complicated malaria.

Blackwater fever was an important cause of morbidity and mortality in the beginning of this century particularly in West and Central Africa. There has been a marked reduction in the incidence of blackwater fever since 1950 and only sporadic cases occur nowadays. At the Kenyatta National Hospital, three cases of blackwater fever have been seen in the past four years whereas not a single case had been reported between 1975 and 1988. Two of the patients fit into the classical description of blackwater fever and one was possibly due to drug induced haemolysis in a G6PD deficiency patient.

Between June and December 1992 forty AIDS patients as defined by the CDC criteria, admitted to the medical wards of the Kenyatta National Hospital, were studied to determine the prevalence and pattern of peripheral neuropathy. Their mean age was 33 +/- 3 years with a range of 16 to 55 years. Clinical and laboratory assessment were carried out both to confirm peripheral neuropathy and exclude other causes of peripheral neuropathy apart from AIDS. All the patients had nerve conduction and electromyographic studies done. Eighteen patients were asymptomatic while fourteen had both signs and symptoms. The commonest symptom was painful paresthesiae of the limbs (35%) while the commonest sign was loss of vibration sense (60%). When symptoms, signs, and electrophysiological studies were combined, all the patients fitted the definition of peripheral neuropathy. The commonest type of peripheral neuropathy was distal symmetrical peripheral neuropathy (DSPN) (37.5%). PIP: In Kenya, physicians evaluated 40 AIDS patients admitted to Kenyatta National Hospital during June-December 1992 to determine the prevalence and types of peripheral neuropathy in AIDS patients. 75% were 21-40 years old. 18 (45%) of the 40 AIDS patients had symptoms of peripheral neuropathy. Symptoms included increased sensitivity to stimulation (43%), hyperpathia (15%), and muscle or limb weakness (13%). 26 AIDS patients had signs of peripheral neuropathy, especially impaired sense of vibration (60%). 14 of these patients had both signs and symptoms. Electromyographic and nerve conduction velocity revealed peripheral neuropathy in 16 (40%) AIDS patients. The types of peripheral neuropathy included distal symmetrical peripheral neuropathy (37.5%), polyneuropathy, and mononeuritis multiplex. When the symptoms, signs, and electroneurophysiological test findings were considered, all 40 AIDS patients had evidence of peripheral neuropathy.

Recent publications have demonstrated that the protease caspase-1 is responsible for the processing of pro-interleukin 18 (IL-18) into the active form. Studies on cell lines and murine macrophages have shown that the bacterial invasion factor SipB activates caspase-1, triggering cell death. Thus, we investigated the role of SipB in the activation and release of IL-18 in human alveolar macrophages (AM), which are the first line of defense against inhaled pathogens. Under steady-state conditions, AM are a more important source of IL-18 than are dendritic cells (DC) and monocytes. Cytokine production by AM and DC was compared after both types of cells had been infected with a virulent strain of Salmonella enterica serovar Typhimurium and an isogenic sipB mutant, which were used as an infection model. Infection with virulent Salmonella led to marked cell death with features of apoptosis while both intracellular activation and release of IL-18 were demonstrated. In contrast, the sipB mutant did not induce such cell death or the release of active IL-18. The specific caspase-1 inhibitor Ac-YVAD-CMK blocked the early IL-18 release in AM infected with the virulent strain. However, the type of Salmonella infection did not differentially regulate IL-18 gene expression. We concluded that the bacterial virulence factor SipB plays an essential posttranslational role in the intracellular activation of IL-18 and the release of the cytokine in human AM.

Recent publications have demonstrated that the protease caspase-1 is responsible for the processing of pro-interleukin 18 (IL-18) into the active form. Studies on cell lines and murine macrophages have shown that the bacterial invasion factor SipB activates caspase-1, triggering cell death. Thus, we investigated the role of SipB in the activation and release of IL-18 in human alveolar macrophages (AM), which are the first line of defense against inhaled pathogens. Under steady-state conditions, AM are a more important source of IL-18 than are dendritic cells (DC) and monocytes. Cytokine production by AM and DC was compared after both types of cells had been infected with a virulent strain of Salmonella enterica serovar Typhimurium and an isogenic sipB mutant, which were used as an infection model. Infection with virulent Salmonella led to marked cell death with features of apoptosis while both intracellular activation and release of IL-18 were demonstrated. In contrast, the sipB mutant did not induce such cell death or the release of active IL-18. The specific caspase-1 inhibitor Ac-YVAD-CMK blocked the early IL-18 release in AM infected with the virulent strain. However, the type of Salmonella infection did not differentially regulate IL-18 gene expression. We concluded that the bacterial virulence factor SipB plays an essential posttranslational role in the intracellular activation of IL-18 and the release of the cytokine in human AM.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

21) S. Derese, A. Yenesew, J.O. Midiwo, Heydenreich and M.G. Peter. (). ..

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the most dominant soil types are of limited agricultural productivity due to crusting and compaction. The occurrence of soil crusting and compaction is attributed to seasonal rainfall characteristics, physical soil properties and bad tillage practices. Soil crusting and compaction decreases rainwater infiltration and increases surface runoff. Increased and concentrated surface runoff water flow causes severe soil erosion. The objective of this study was to examine the hydrological effects of different tillage practices with and without farmyard manure on infiltration, surface runoff and soil loss of crusting and compacting soils under field and laboratory conditions in semi arid Kenya. Field investigations on infiltration, soil moisture, surface runoff, soil loss, soil bulk density and soil shear strength covered two rainy seasons (short and long rains) and were done on a Chromic Luvisol. The field treatments were zero and conventional tillage, and two farmyard manure applications (5 and 10 Mg/ha). Laboratory investigations on infiltration, time to runoff, surface runoff, soil loss and penetration resistance were conducted under simulated rainfall on four Luvisols for sixty days with the same farmyard manure (5 and 10 Mg/ha) treatments. A regression analysis and a one way ANOVA revealed significant (P<0.05) differences between soil types and treatments. The results obtained showed significant effects of conventional and zero tillage and farmyard manure on infiltration and soil moisture, time to runoff, surface runoff and soil loss. Soil crusting and compaction significantly influenced the hydrological responses of all soil types and treatments. These responses were attributed to seasonal rainfall events of varying amounts, intensities and duration and treatment differences in soil surface conditions and aggregation. Farmyard manure (FYM) application enhanced infiltration and reduced soil crusting and compaction, and surface runoff during the initial stages of the rainy season. But in the mid-stages of the rainy season, the effects of FYM on soil aggregation diminished and resulted in an increase in soil loss. At the end of the rainy season, when soil crusts had formed, some significant decrease in soil loss with FYM treatments was observed. Conventional tillage without farmyard manure led to high surface runoff and soil loss in these structurally unstable soils. Zero tillage performed poorly under these soil conditions because of high soil crusting and compaction, low rainwater infiltration and subsequent increase in surface runoff.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop productivity. Model simulation of the stochastic behaviour of dry and wet spells and rainsums provides some insights into: the differences in rainfall characteristics within an agricultural watershed; and distribution and reliability of seasonal rainfall for various uses. The longest dry spell analysis is of practical relevance to the selection of the best conservation practices (including conservation tillage) for soil and water management whilst the largest rainsum analysis can be used to determine the watershed runoff volume and discharges that would assist in the design of flood and erosion control structures, and the design of runoff water catchment systems (RWCS), which are essential for supplementary irrigation in semi arid Kenya. This study adopted an agro-hydrologic systems approach to the mitigation of agricultural drought at micro, meso and macro scale levels within an agricultural watershed. This approach had its premise that many agricultural drought problems in unstable ecosystems are best solved through farmers interventions at the micro scale level, conservation planning at the meso scale level and resource management at the macro scale level. Thus, the adopted agro-hydrologic systems approach is holistic and aimed at optimizing soil and water management in hydrologically defined geographical areas. The three levels of agricultural drought mitigation should be hierarchical and must consider all factors influencing the hydrologic and hydraulic properties of dominant soils in semi arid Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop performance and yield. The objective of this study was to stochastically simulate the behaviour of dry and wet spells and rainsums in Iiuni watershed, Kenya. The stochastic behaviour of the longest dry and wet spells (runs) and largest rainsums were simulated using a Markov (order 1) model. There were eight raingauge stations within the watershed. The entire analysis was carried out using probability parameters, i.e. mean, variance, simple and conditional probabilities of dry and rain days. An analysis of variance test (ANOVA) was used to establish significant differences in rainfall characteristics between the eight stations. An analysis of the number of rain days and rainfall amount per rain day was done on a monthly basis to establish the distribution and reliability of seasonal rainfall. The graphical comparison of simulated cumulative distribution functions (cdfs) of the longest spells and largest rainsums showed Markovian dependence or persistence. The longest dry spells could extend to 24 days in the long rainy season and 12 in the short rainy season. At 50% (median) probability level, the largest rainsums were 91 mm for the long rainy season and 136 mm for the short rainy season. The short rains were more reliable for crop production than the long rains. The Markov model performed well and gave adequate simulations of the spells and rainsums under semi arid conditions.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop productivity. Model simulation of the stochastic behaviour of dry and wet spells and rainsums provides some insights into: the differences in rainfall characteristics within an agricultural watershed; and distribution and reliability of seasonal rainfall for various uses. The longest dry spell analysis is of practical relevance to the selection of the best conservation practices (including conservation tillage) for soil and water management whilst the largest rainsum analysis can be used to determine the watershed runoff volume and discharges that would assist in the design of flood and erosion control structures, and the design of runoff water catchment systems (RWCS), which are essential for supplementary irrigation in semi arid Kenya. This study adopted an agro-hydrologic systems approach to the mitigation of agricultural drought at micro, meso and macro scale levels within an agricultural watershed. This approach had its premise that many agricultural drought problems in unstable ecosystems are best solved through farmers interventions at the micro scale level, conservation planning at the meso scale level and resource management at the macro scale level. Thus, the adopted agro-hydrologic systems approach is holistic and aimed at optimizing soil and water management in hydrologically defined geographical areas. The three levels of agricultural drought mitigation should be hierarchical and must consider all factors influencing the hydrologic and hydraulic properties of dominant soils in semi arid Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop performance and yield. The objective of this study was to stochastically simulate the behaviour of dry and wet spells and rainsums in Iiuni watershed, Kenya. The stochastic behaviour of the longest dry and wet spells (runs) and largest rainsums were simulated using a Markov (order 1) model. There were eight raingauge stations within the watershed. The entire analysis was carried out using probability parameters, i.e. mean, variance, simple and conditional probabilities of dry and rain days. An analysis of variance test (ANOVA) was used to establish significant differences in rainfall characteristics between the eight stations. An analysis of the number of rain days and rainfall amount per rain day was done on a monthly basis to establish the distribution and reliability of seasonal rainfall. The graphical comparison of simulated cumulative distribution functions (cdfs) of the longest spells and largest rainsums showed Markovian dependence or persistence. The longest dry spells could extend to 24 days in the long rainy season and 12 in the short rainy season. At 50% (median) probability level, the largest rainsums were 91 mm for the long rainy season and 136 mm for the short rainy season. The short rains were more reliable for crop production than the long rains. The Markov model performed well and gave adequate simulations of the spells and rainsums under semi arid conditions.

In semi arid Kenya, the most dominant soil types are of limited agricultural productivity due to crusting and compaction. The occurrence of soil crusting and compaction is attributed to seasonal rainfall characteristics, physical soil properties and bad tillage practices. Soil crusting and compaction decreases rainwater infiltration and increases surface runoff. Increased and concentrated surface runoff water flow causes severe soil erosion. The objective of this study was to examine the hydrological effects of different tillage practices with and without farmyard manure on infiltration, surface runoff and soil loss of crusting and compacting soils under field and laboratory conditions in semi arid Kenya. Field investigations on infiltration, soil moisture, surface runoff, soil loss, soil bulk density and soil shear strength covered two rainy seasons (short and long rains) and were done on a Chromic Luvisol. The field treatments were zero and conventional tillage, and two farmyard manure applications (5 and 10 Mg/ha). Laboratory investigations on infiltration, time to runoff, surface runoff, soil loss and penetration resistance were conducted under simulated rainfall on four Luvisols for sixty days with the same farmyard manure (5 and 10 Mg/ha) treatments. A regression analysis and a one way ANOVA revealed significant (P<0.05) differences between soil types and treatments. The results obtained showed significant effects of conventional and zero tillage and farmyard manure on infiltration and soil moisture, time to runoff, surface runoff and soil loss. Soil crusting and compaction significantly influenced the hydrological responses of all soil types and treatments. These responses were attributed to seasonal rainfall events of varying amounts, intensities and duration and treatment differences in soil surface conditions and aggregation. Farmyard manure (FYM) application enhanced infiltration and reduced soil crusting and compaction, and surface runoff during the initial stages of the rainy season. But in the mid-stages of the rainy season, the effects of FYM on soil aggregation diminished and resulted in an increase in soil loss. At the end of the rainy season, when soil crusts had formed, some significant decrease in soil loss with FYM treatments was observed. Conventional tillage without farmyard manure led to high surface runoff and soil loss in these structurally unstable soils. Zero tillage performed poorly under these soil conditions because of high soil crusting and compaction, low rainwater infiltration and subsequent increase in surface runoff.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop productivity. Model simulation of the stochastic behaviour of dry and wet spells and rainsums provides some insights into: the differences in rainfall characteristics within an agricultural watershed; and distribution and reliability of seasonal rainfall for various uses. The longest dry spell analysis is of practical relevance to the selection of the best conservation practices (including conservation tillage) for soil and water management whilst the largest rainsum analysis can be used to determine the watershed runoff volume and discharges that would assist in the design of flood and erosion control structures, and the design of runoff water catchment systems (RWCS), which are essential for supplementary irrigation in semi arid Kenya. This study adopted an agro-hydrologic systems approach to the mitigation of agricultural drought at micro, meso and macro scale levels within an agricultural watershed. This approach had its premise that many agricultural drought problems in unstable ecosystems are best solved through farmers interventions at the micro scale level, conservation planning at the meso scale level and resource management at the macro scale level. Thus, the adopted agro-hydrologic systems approach is holistic and aimed at optimizing soil and water management in hydrologically defined geographical areas. The three levels of agricultural drought mitigation should be hierarchical and must consider all factors influencing the hydrologic and hydraulic properties of dominant soils in semi arid Kenya.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop performance and yield. The objective of this study was to stochastically simulate the behaviour of dry and wet spells and rainsums in Iiuni watershed, Kenya. The stochastic behaviour of the longest dry and wet spells (runs) and largest rainsums were simulated using a Markov (order 1) model. There were eight raingauge stations within the watershed. The entire analysis was carried out using probability parameters, i.e. mean, variance, simple and conditional probabilities of dry and rain days. An analysis of variance test (ANOVA) was used to establish significant differences in rainfall characteristics between the eight stations. An analysis of the number of rain days and rainfall amount per rain day was done on a monthly basis to establish the distribution and reliability of seasonal rainfall. The graphical comparison of simulated cumulative distribution functions (cdfs) of the longest spells and largest rainsums showed Markovian dependence or persistence. The longest dry spells could extend to 24 days in the long rainy season and 12 in the short rainy season. At 50% (median) probability level, the largest rainsums were 91 mm for the long rainy season and 136 mm for the short rainy season. The short rains were more reliable for crop production than the long rains. The Markov model performed well and gave adequate simulations of the spells and rainsums under semi arid conditions.

In semi arid Kenya, the most dominant soil types are of limited agricultural productivity due to crusting and compaction. The occurrence of soil crusting and compaction is attributed to seasonal rainfall characteristics, physical soil properties and bad tillage practices. Soil crusting and compaction decreases rainwater infiltration and increases surface runoff. Increased and concentrated surface runoff water flow causes severe soil erosion. The objective of this study was to examine the hydrological effects of different tillage practices with and without farmyard manure on infiltration, surface runoff and soil loss of crusting and compacting soils under field and laboratory conditions in semi arid Kenya. Field investigations on infiltration, soil moisture, surface runoff, soil loss, soil bulk density and soil shear strength covered two rainy seasons (short and long rains) and were done on a Chromic Luvisol. The field treatments were zero and conventional tillage, and two farmyard manure applications (5 and 10 Mg/ha). Laboratory investigations on infiltration, time to runoff, surface runoff, soil loss and penetration resistance were conducted under simulated rainfall on four Luvisols for sixty days with the same farmyard manure (5 and 10 Mg/ha) treatments. A regression analysis and a one way ANOVA revealed significant (P<0.05) differences between soil types and treatments. The results obtained showed significant effects of conventional and zero tillage and farmyard manure on infiltration and soil moisture, time to runoff, surface runoff and soil loss. Soil crusting and compaction significantly influenced the hydrological responses of all soil types and treatments. These responses were attributed to seasonal rainfall events of varying amounts, intensities and duration and treatment differences in soil surface conditions and aggregation. Farmyard manure (FYM) application enhanced infiltration and reduced soil crusting and compaction, and surface runoff during the initial stages of the rainy season. But in the mid-stages of the rainy season, the effects of FYM on soil aggregation diminished and resulted in an increase in soil loss. At the end of the rainy season, when soil crusts had formed, some significant decrease in soil loss with FYM treatments was observed. Conventional tillage without farmyard manure led to high surface runoff and soil loss in these structurally unstable soils. Zero tillage performed poorly under these soil conditions because of high soil crusting and compaction, low rainwater infiltration and subsequent increase in surface runoff.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop productivity. Model simulation of the stochastic behaviour of dry and wet spells and rainsums provides some insights into: the differences in rainfall characteristics within an agricultural watershed; and distribution and reliability of seasonal rainfall for various uses. The longest dry spell analysis is of practical relevance to the selection of the best conservation practices (including conservation tillage) for soil and water management whilst the largest rainsum analysis can be used to determine the watershed runoff volume and discharges that would assist in the design of flood and erosion control structures, and the design of runoff water catchment systems (RWCS), which are essential for supplementary irrigation in semi arid Kenya. This study adopted an agro-hydrologic systems approach to the mitigation of agricultural drought at micro, meso and macro scale levels within an agricultural watershed. This approach had its premise that many agricultural drought problems in unstable ecosystems are best solved through farmers interventions at the micro scale level, conservation planning at the meso scale level and resource management at the macro scale level. Thus, the adopted agro-hydrologic systems approach is holistic and aimed at optimizing soil and water management in hydrologically defined geographical areas. The three levels of agricultural drought mitigation should be hierarchical and must consider all factors influencing the hydrologic and hydraulic properties of dominant soils in semi arid Kenya.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop performance and yield. The objective of this study was to stochastically simulate the behaviour of dry and wet spells and rainsums in Iiuni watershed, Kenya. The stochastic behaviour of the longest dry and wet spells (runs) and largest rainsums were simulated using a Markov (order 1) model. There were eight raingauge stations within the watershed. The entire analysis was carried out using probability parameters, i.e. mean, variance, simple and conditional probabilities of dry and rain days. An analysis of variance test (ANOVA) was used to establish significant differences in rainfall characteristics between the eight stations. An analysis of the number of rain days and rainfall amount per rain day was done on a monthly basis to establish the distribution and reliability of seasonal rainfall. The graphical comparison of simulated cumulative distribution functions (cdfs) of the longest spells and largest rainsums showed Markovian dependence or persistence. The longest dry spells could extend to 24 days in the long rainy season and 12 in the short rainy season. At 50% (median) probability level, the largest rainsums were 91 mm for the long rainy season and 136 mm for the short rainy season. The short rains were more reliable for crop production than the long rains. The Markov model performed well and gave adequate simulations of the spells and rainsums under semi arid conditions.

In semi arid Kenya, episodes of agricultural droughts of varying severity and duration occur. The occurrence of these agricultural droughts is associated with seasonal rainfall variability and can be reflected by seasonal soil moisture deficits that significantly affect crop productivity. Model simulation of the stochastic behaviour of dry and wet spells and rainsums provides some insights into: the differences in rainfall characteristics within an agricultural watershed; and distribution and reliability of seasonal rainfall for various uses. The longest dry spell analysis is of practical relevance to the selection of the best conservation practices (including conservation tillage) for soil and water management whilst the largest rainsum analysis can be used to determine the watershed runoff volume and discharges that would assist in the design of flood and erosion control structures, and the design of runoff water catchment systems (RWCS), which are essential for supplementary irrigation in semi arid Kenya. This study adopted an agro-hydrologic systems approach to the mitigation of agricultural drought at micro, meso and macro scale levels within an agricultural watershed. This approach had its premise that many agricultural drought problems in unstable ecosystems are best solved through farmers interventions at the micro scale level, conservation planning at the meso scale level and resource management at the macro scale level. Thus, the adopted agro-hydrologic systems approach is holistic and aimed at optimizing soil and water management in hydrologically defined geographical areas. The three levels of agricultural drought mitigation should be hierarchical and must consider all factors influencing the hydrologic and hydraulic properties of dominant soils in semi arid Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

This paper reviews some research studies on tillage methods influencing soil and moisture conservation in the eastern African countries of Kenya, Tanzania, Malawi and Ethiopia during the past four decades. Most of these studies were conducted in marginal rainfall (semi arid ) areas and on shallow soils of various textures (sandy clay loam, sandy clay, clay and loam). The studies were meant to establish the effects of tillage and residue management practices on physico-chemical soil properties (i.e. structure, bulk density, soil moisture and organic matter contents), runoff and infiltration. This review emphasizes the importance of appropriate tillage and residue management methods (contour bunds and terraces, minimum tillage, tied ridging, mulching and conventional tillage) in providing soil conditions favourable for soil moisture conservation and subsequent crop performance and yield on smallholder farms.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

In semi arid Kenya, the occurrence of flush floods and soil erosion on agricultural watersheds is attributed to intense rainstorm events of short duration. Thus when agricultural watersheds have no erosion control structures in place, the generation of direct runoff would increase with cultivation. Of the two components of runoff namely, runoff volume and peak runoff discharge, the consideration of peak runoff discharge rate is critical to the design of effective hydraulic structures for controlling floods and soil erosion. In order to accurately predict a watershed's peak runoff discharge, it is important to select a model that is deterministic and yet simple to use. The model should be able to consider the time distribution of runoff response as influenced by Watershed characteristics. The time to peak runoff discharge is largely influenced by the time of concentration. The time of concentration depends on the shape, size and relief of the watershed. In Iiuni Watershed, the Nash model, a parsimonious deterministic model, was selected to predict peak runoff discharges. This model uses the instantaneous unit hydrograph principle to simulate the direct runoff hydrographs and estimate peak runoff discharge. The Nash model was applied using input parameters derived from the watershed's rainfall-runoff characteristics. The results obtained showed that the Nash model was good in predicting peak runoff discharges. This statistic of comparison, R2 (coefficient of efficiency) for the model was above 70% for the model which is indicative of good model prediction of peak runoff discharge (Nash and Sutcliffe, 1970). From this analysis, the Nash model is recommended for the estimation of peak runoff discharge from un-gauged agricultural watersheds in Kenya.

Cohen CR, Gichui J, Rukaria R, Sinei SS, Gaur LK, Brunham RC. Departments of Obstetrics and Gynecology, University of Washington, Box 356460, Seattle, WA 98195, USA. crcohen@u.washington.edu OBJECTIVE: To understand immunogenetic mechanisms of Chlamydia trachomatis infection and tubal scarring. METHODS: We measured and compared previously significant human leukocyte antigen (HLA) class II DQ alleles, their linked DRB genes, and polymorphisms in selected cytokine genes (tumor necrosis factor alpha-308 promoter; transforming growth factor beta1-10 and -25 codons; interleukin 10-1082, -819, and -592 promoters; interleukin 6-174 promoter; and interferon gamma+874 codon 1) among Kenyan women with confirmed tubal infertility with and without C trachomatis microimmunofluorescence antibody. RESULTS: Two class II alleles, HLA-DR1*1503 and DRB5*0101, were detected less commonly in C trachomatis microimmunofluorescence seropositive women than in C trachomatis microimmunofluorescence seronegative women with infertility (0% versus 20%; odds ratio [OR] 0.05; 95% confidence interval [CI] 0, 0.7, and 6% versus 26%; OR 0.2; 95% CI 0.02, 1.0, respectively). These alleles are commonly linked as a haplotype at the DRB locus. This finding could not be explained through linkage disequilibrium with the other studied HLA or cytokine genes. CONCLUSION: These alleles may lead to an immunologically mediated mechanism of protection against C trachomatis infection and associated tubal damage, or alternatively increase risk for tubal scarring due to another cause. PMID: 12636945 [PubMed - indexed for MEDLINE]

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Kenya is a country of marked environmental and ethnic diversity. A study of osteogenic sarcoma occurring in Kenya from 1968 to 1978 revealed 251 cases, representing between 89% and 100% of the predicted number. Variations in age, sex and anatomical location were within classical limits. However, the incidence of osteogenic sarcoma amongst the Central Bantu was significantly higher than predicted (P less than 0.0001), whilst the incidence among the Western Bantu was significantly lower (P less than 0.002), despite their similar ethnic origins. Two geographically dissimilar areas likewise exhibited significant differences in incidence. The Eastern province showed a higher incidence (P less than 0.02), whereas the Nyanza Province (P less than 0.001) and the adjacent Western Province (P less than 0.005) showed a lower than predicted incidence. These observations suggest that in Kenya a geomedical variable affects the incidence of osteogenic sarcoma and that genetic variation has no effect on incidence.

The Educational Mission of the Church: An African Perspective

Kenya is a country of marked environmental and ethnic diversity. A study of osteogenic sarcoma occurring in Kenya from 1968 to 1978 revealed 251 cases, representing between 89% and 100% of the predicted number. Variations in age, sex and anatomical location were within classical limits. However, the incidence of osteogenic sarcoma amongst the Central Bantu was significantly higher than predicted (P less than 0.0001), whilst the incidence among the Western Bantu was significantly lower (P less than 0.002), despite their similar ethnic origins. Two geographically dissimilar areas likewise exhibited significant differences in incidence. The Eastern province showed a higher incidence (P less than 0.02), whereas the Nyanza Province (P less than 0.001) and the adjacent Western Province (P less than 0.005) showed a lower than predicted incidence. These observations suggest that in Kenya a geomedical variable affects the incidence of osteogenic sarcoma and that genetic variation has no effect on incidence.

Cohen CR, Gichui J, Rukaria R, Sinei SS, Gaur LK, Brunham RC. Departments of Obstetrics and Gynecology, University of Washington, Box 356460, Seattle, WA 98195, USA. crcohen@u.washington.edu OBJECTIVE: To understand immunogenetic mechanisms of Chlamydia trachomatis infection and tubal scarring. METHODS: We measured and compared previously significant human leukocyte antigen (HLA) class II DQ alleles, their linked DRB genes, and polymorphisms in selected cytokine genes (tumor necrosis factor alpha-308 promoter; transforming growth factor beta1-10 and -25 codons; interleukin 10-1082, -819, and -592 promoters; interleukin 6-174 promoter; and interferon gamma+874 codon 1) among Kenyan women with confirmed tubal infertility with and without C trachomatis microimmunofluorescence antibody. RESULTS: Two class II alleles, HLA-DR1*1503 and DRB5*0101, were detected less commonly in C trachomatis microimmunofluorescence seropositive women than in C trachomatis microimmunofluorescence seronegative women with infertility (0% versus 20%; odds ratio [OR] 0.05; 95% confidence interval [CI] 0, 0.7, and 6% versus 26%; OR 0.2; 95% CI 0.02, 1.0, respectively). These alleles are commonly linked as a haplotype at the DRB locus. This finding could not be explained through linkage disequilibrium with the other studied HLA or cytokine genes. CONCLUSION: These alleles may lead to an immunologically mediated mechanism of protection against C trachomatis infection and associated tubal damage, or alternatively increase risk for tubal scarring due to another cause. PMID: 12636945 [PubMed - indexed for MEDLINE]

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Critics of bicarbonate therapy for life-threatening lactic acidosis have argued that the treatment is not only ineffective but that it also worsens morbidity and mortality. We critically examine the six major arguments used to condemn alkali treatment. We highlight the shortcomings of frequently cited uncontrolled human studies, experiments in animals, and in-vitro chemical analyses not clearly related to the human condition. The damaging hemodynamic effects of acidemia, which centralizes blood volume while depressing myocardial contraction (thereby causing hemodynamic collapse), are discussed and offered in support of alkali therapy. We also emphasize the extreme sensitivity of patients with acidosis to further small decreases in serum bicarbonate concentration or increases in arterial PCO2. In short, we have found no basis by which to condemn the use of alkali and believe that those who have scorned its use have yet to demonstrate its danger clearly. Until that time, sodium bicarbonate should remain the standard of therapy for this life-threatening condition.

Twenty-one adult patients with severe diabetic ketoacidosis entered a randomized prospective protocol in which variable doses of sodium bicarbonate, based on initial arterial pH (6.9 to 7.14), were administered to 10 patients (treatment group) and were withheld from 11 patients (control group). During treatment, there were no significant differences in the rate of decline of glucose or ketone levels or in the rate of increase in pH or bicarbonate levels in the blood or cerebrospinal fluid in either group. Similarly, there were no significant differences in the time required for the plasma glucose level to reach 250 mg/dL, blood pH to reach 7.3, or bicarbonate level to reach 15 meq/L. We conclude that in severe diabetic ketoacidosis (arterial pH 6.9 to 7.14), the administration of bicarbonate does not affect recovery outcome variables as compared with those in a control group.

Ethnopharmacological relevance: Traditional medicines play an important role in the management of chronically painful and debilitating joint conditions, particularly in the rural Africa. However, their potential use as sources of medicines has not been fully exploited. The present study was carried to find the medicinal plants traditionally used to manage chronic joint pains in Machakos and Makueni counties in Kenya. Materials and methods: To obtain this ethnobotanical information, 30 consenting traditional herbal med-ical practitioners were interviewed exclusively on medicinal plant use in the management of chronic joint pains, in a pre-planned workshop. Results and discussion: In this survey, a total of 37 plants belonging to 32 genera and 23 families were cited as being important for treatment of chronic joint pains. The most commonly cited plant species were Pavetta crassipes K. Schum, Strychnos henningsii Gilg., Carissa spinarum L., Fagaropsis hildebrandtii (Engl.) Milve-Redh. and Zanthoxylum chalybeum Engl. Acacia mellifera (Vahl) Benth., Amaranthus albus L., Balanites glabra Mildbr. & Schltr., Grewia fallax K. Schum., Lactuca capensis, Launaea cornuta (Oliv. & Hiern) O. Jeffrey, Lippia kituiensis Vatke, Pappea capensis Eckl. & Zeyh. and Pennisetum glaucum (L.) R. Br. are documented for the first time as being important in the management of chronic joint pains. Conclusions: The findings of this study show that a variety of medicinal plants are used in the management of chronic joint pains and the main mode of administration is oral. Keywords: Ethnobotanical survey; Medicinal plants; Chronic joint pains; Rheumatoid arthritis; Akamba; Machakos-Kenya

Abstract—Seven biflavones, amentoflavone, bilobetin, sequoiaflavone, ginkgetin, sciadopitysin, 7,4',7',4"-
tetra-O-methylamentoflavone, and diooflavone (amentoflavone hexamethyl ether), were identified from
extracts of the cycad genus Dioon. The biflavones were identified by direct comparison with authentic
samples using m.m.p., co-chromatography in 3 solvents, and NMR studies of the acetates. This is the first
time amentoflavone hexamethyl ether has been identified as a natural product. After surveying numerous
species of the Cycadales, no evidence could be obtained for the occurrence of biflavones glycosides or of biflavones base upon any other nucleus than apeginin.

Biflavanoid patterns of leaves of 82 species of the order Cycadales comprising 3 families and 10
genera have been determined. The biflavanoidswere Identified byTLC, UV, NMR and MS studies. Pattern differences between species, when detected, involve the position or degree of methylation of the base compounds. On the other hand, differences in the biflavanoid patterns at the generic and family levels were sufficient to support taxonomic relationships. Thus, the absence of hinokiflavone and its derivatives clearly distinguish the Zamiaceae from the Cycadaceae and Stangeriaceae. The complete absence of biflavanoids in the latter family suggests an advanced evolutionary condition, but morphologically, this family has the most fern-like characters, and therefore has been considered by previous workers to be the most primitive of the cycads.

OBJECT: The angles of arterial bifurcations are governed by principles of work minimization (optimality principle). This determines the relationship between the angle of a bifurcation and the radii of the vessels. Nevertheless, the model is predicated on an absence of significant communication between these branches. The circle of Willis changes this relationship because the vessels proximal to the ring of vessels have additional factors that determine work minimization compared with more distal branches. This must have an impact on understanding of the relationship between shear stress and aneurysm formation. The authors hypothesized that normal bifurcations of cerebral arteries beyond the circle of Willis would follow optimality principles of minimum work and that the presence of aneurysms would be associated with deviations from optimum bifurcation geometry. Nevertheless, the vessels participating in (or immediately proximal to) the circle of Willis may not follow the geometric model as it is generally applied and this must also be investigated. METHODS: One hundred seven bifurcations of the middle cerebral artery (MCA), distal internal carotid artery (ICA), and basilar artery (BA) were studied in 55 patients. The authors analyzed three-dimensional reconstructions of digital subtraction angiography images with respect to vessel radii and bifurcation angles. The junction exponent (that is, a calculated measure of the division of flow at the bifurcation) and the difference between the predicted optimal and observed branch angles were used as measures of deviation from the geometry thought best to minimize work. The mean junction exponent for MCA bifurcations was 2.9 +/- 1.2 (mean +/- standard deviation [SD]), which is close to the theoretical optimum of 3, but it was significantly smaller (p {\textless} 0.001; 1.7 +/- 0.8, mean +/- SD) for distal ICA bifurcations. In a multilevel multivariate logistic regression analysis, only the observed branch angles were significant independent predictors for the presence of an aneurysm. The odds ratio (OR) (95% confidence interval) for the presence of an aneurysm was 3.46 (1.02-11.74) between the lowest and highest tertile of the observed angle between the parent vessel and the largest branch. The corresponding OR for the smallest branch was 48.06 (9.7-238.2). CONCLUSIONS: The bifurcation beyond the circle of Willis (that is, the MCA) closely approximated optimality principles, whereas the bifurcations within the circle of Willis (that is, the distal ICA and BA) did not. This indicates that the confluence of hemodynamic forces plays an important role in the distribution of work at bifurcations within the circle of Willis. In addition, the observed branch angles were predictors for the presence of aneurysms.

The data revolution has increased data demands for leveraging on Big Data in the production of statistics. The paper assesses the adoption of Big Data in research institutes in Kenya. Data were collected from 64 data practitioners based in the 24 research institutes that have a mandate to produce and analyse official statistics. The paper establishes the risks and challenges of using Big Data in statistics, identifies the determinants of adoption of Big Data in statistics and validates the relevance of a Technology Adoption Model (TAM) for predicting the adoption. It is the conclusion that there are immense opportunities for Big Data in statistics if the associated risks and challenges are addressed and the identified key determinants prioritized to promote the adoption.

This study focussed on big data and competitive advantage in commercial banks and insurance companies in Nairobi, Kenya and was dependent on the following objectives: To establish the extent of application of big data analytics in commercial banks and insurance companies in Nairobi; to determine the relationship between big data analytics and competitive advantage of commercial banks and insurance companies in Nairobi; to establish the challenges of big data analytics in commercial banks and insurance companies in Nairobi. A descriptive survey was employed for the purpose of data collection for this research. The population targeted for this study was commercial banks and insurance companies in Nairobi, Kenya. There are 42 commercial banks and 49 insurance companies in Nairobi. A sample of 20 commercial banks and 25 insurance companies was undertaken due to the limited time allocated for data collection and analysis. The sample was selected based on a judgmental basis taking into account the companies’ use of big data analytics. This research used primary data collected using structured questionnaires. The respondents were managers dealing with company strategies and/ or information and technology managers in the selected companies. The data was analyzed using frequencies, percentages, mean, and standard deviation and regression techniques. The study found that companies in the financial industry specifically commercial banks and insurance firms have invested in data storage facilities and advanced tools in the area of business intelligence for reporting and analysing consumer/ client behaviour. These tools allow the companies to anticipate consumer needs more effectively, in addition to optimizing their operations. The addition of big data analytics systems in the companies’ daily routines enables them to gain higher levels of insight in the big data environment thus enabling more effective decision making. There are challenges in management of big data that if addressed can help organizations appreciate the full potential of big data tools and various analytics especially in aspects of competitive advantage. This study, through a thorough analysis of its findings concludes that the big data revolution has found a place in the commercial banking and insurance industry in Nairobi, and that the trend is on the rise as these companies continue to discover the valuable data with tremendous potential they have had in their storage for decades.

Digitalization is transforming governments across the globe. At the national level, down to regional and multiple departments in the public institutions, unprecedented change is occurring exponentially as a result of massive digitalization. Digitalization is compelling governments at all levels to embrace voluminous data and institute appropriate multi-channel platforms to support digital transformation. While this is the case, most governments have been caught unprepared thwarting maximum benefits spurred by digitalization. Inherently, the social media and e-participation tools for generating huge amount of data have convoluted most governments’ appetite in Big Data management. This situation is further compounded with the slow pace of adoption of these technological tools by citizens and the public sectors. For enhanced e-citizen satisfaction and engagement, as well as e-participation processes, public institutions need to promote engagement and collaboration. In view of advancing benefits to their citizens, public institutions need to institute appropriate measures to collect citizen’s data. The information collected is vital for public institutions in actualizing what services the citizens want. Using literature reviews and cases, the authors examine Big Data benefits in counties and propose a Big Data model to improve efficiency of e-governance services and productivity in county governments. The authors demonstrate Big Data framework has the aptitude of molding citizen’s opinion in county decision making process. Better use of e-technologies is shown in the proposed model which illustrates sharing resources among various data analytics sources. Our proposed framework based on Big Data analytics is a viable initiative to progress effectiveness and productivity, strengthen citizen engagement and participation and encourage decision-making in e-governance services delivery in the counties.

Ogutu EO. A 10-year (1976-1986) retrospective study was done on 30 cases with histological diagnosis of pancreatic carcinoma. The male to female ratio was 1.3:1 and the peak incidence was in the 6th and 7th decades. The head of the pancreas was involved in 96% of cases while solid adenocarcinoma of duct cell origin accounted for 73.3% of cases, followed by anaplastic carcinoma (23.3%). The commonest complications were distinct metastasis (86.6%), obstructive jaundice (73.3%) and upper gastrointestinal bleed (13.6%).

research theories for high school students

research theories for high school students

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Abstract
Hemorrhage is the main cause of Maternal Mortality (MM) (27%) followed by hypertensive disorders and sepsis (12%). Septic abortion is considered an intermediate risk factor for the development of Massive Obstetric Hemorrhage (MOH). The algorithm for the management of postpartum hemorrhage due to uterine atony that includes systematic pelvic devascularization has been described, but this management is really planned for resolution of the pregnancy after the 20th week of gestation, since an HMO due to abortion is un usual. We present the case of a 21-year-old patient who self-medicates a prostaglandin analog at 2 months of pregnancy, achieving only a threat of abortion, goes to the emergency room 3 months later with a diagnosis of septic shock, USG and MRI are performed with altered results, only of hepatomegaly, delayed abortion of 8 weeks of evolution and gestational trophoblastic disease. Emergency MVA was performed due to profuse bleeding, placement of a Bakri balloon and clamping of the uterine arteries without results, for which an emergency exploratory laparotomy (LAPE) was performed with ligation of the anterior trunk of the internal iliac artery, being a successful procedure, without the need for Obstetric Hysterectomy (HO). The patient is managed in intensive care and in the end the diagnosis of TSG is ruled out. Bilateral Hypogastric Artery Ligation (BHAL) in the case of Massive Obstetric Hemorrhage (MOH) secondary to delivery or cesarean section is commonly used, however it is not a technique to report when bleeding is secondary to abortion. In these cases, it is also a viable, successful, fertility-preserving surgical procedure, and an alternative to Obstetric Hysterectomy (OH) when other less invasive methods such as uterine artery clamping or Bakri balloon have failed.

The superior cerebellar artery is the most consistent branch of the basilar artery and arises near the bifurcation of the basilar artery. A bilateral origin of the superior cerebellar arteries from the posterior cerebral arteries has been rarely reported in the literature. Reporting variations in brain vessels is important for neurosurgeons to safely and confidently treat pathologies in this region. We report on a specimen with a bilateral origin to the superior cerebellar artery from the posterior cerebral artery and discuss the embryogenesis of this rare variation.

A nineteen year old Kenyan male presented with a twelve month history of rapidly progressing painless swelling of both testicles. Pre-operative clinical and laboratory evaluation resulted in clinical suspicion of bilateral testicular tumour confirmed by ultrasonography. Bilateral inguinal orchidectomy was effected and histology confirmed bilateral primary malignant lymphoma of the testis in a nineteen year old regarded as a rare and unusual presentation.

The human body louse, Pediculus humanus, showed eighteen midgut proteins ranging between 12 and 117 kDa, when analysed by SDS-PAGE electrophoresis. Seven of them (12 kDa, 17 kDa, 29 kDa, 35 kDa, 40 kDa, 55 kDa and 97 kDa) were major bands based on their intensity of staining. The immunization of rabbits with a midgut extract elicited the production of protective polyclonal antibodies. These antibodies reacted strongly with all major midgut proteins as well as with 63 kDa and 117 kDa proteins when tested by the Western blot technique. The analysis of the proteins revealed that the 12 kDa, 25 kDa, 29 kDa, 35 kDa, 45 kDa, 87 kDa and 97 kDa proteins are glycosylated and none of them contained a lipid moiety. By electroelution, the proteins of 35 kDa and 63 kDa were purified. On trypsinization, the proteins of 35 kDa and 63 kDa produced four major fragments (F1, F2, F3, and F4) when resolved on a 18% SDS-PAGE. The F1 fragment of the 35 kDa protein reacted with the polyclonal antibodies by the immunoblot technique.

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The 24-hr LD50 of colchicine in newborn rats is 0.24 mg/kg, which is about 1/10 that observed in the adult. The 24-hr LD50 of colchicine was relatively constant in rats over 25 days of age. In an attempt to determine the mechanism of the increased sensitivity of the newborn rat to the toxic action of colchicine, the distribution of 3H after the administration of 3H-colchicine (0.1 mg/kg) was measured in 10- and 35-day-old rats. The concentration of 3H was higher in all tissues of the newborn than the adult after ip administration, suggesting an immaturity in the pathway for colchicine elimination. After iv administration, radioactivity disappeared much more slowly from the plasma of the newborn rat than from the adult. This was due to a lower capacity of the liver of the newborn to concentrate colchicine and to excrete it into the bile. Development of the hepatic excretory mechanism responsible for excretion of colchicine occurred at the same age as did the increase in LD50. These results suggest that colchicine is more toxic in the newborn because the drug remains in the body for a longer time due to immaturity of the liver excretory process.

isolated from preterm neonates during the outbreak of gastroenteritis in hospital in Nairobi, Kenya, were resistance to trimethoprin-sulfathoxaxole, Chloramphenicol, oxytetracycline and ampicilin, but only a few strains were resistant to cefazolin, cefamandole, cefataximine, amikacin and nalidixic acid. Fourteen different antimicrobial resistance patterns were observed in the 229 strains of E.coli analyzed. Eighty-two percent of the EPEC strains belonged to two resistance patterns. There was no consistent relationship between palsmid profile group and antimicrobial resistance pattern, although one resistance pattern was more frequently observed in EAF-positive strins belonging to the dominant plasmid profile group. Nine percent of the EPEC strins were resistant to gentamicin compared to 37% in the non-EPEC group. No correlation was observed between administration of gentamicin and percentage of resistant strains isolated. None of the nine neonates receiving gentamicin died during the outbreak. Gentamicin resistance was observed in E.coli strains from six out of these nine neonates. Five out of fourteen neonates who received other antimicrobials, or no antibiotic at all, died. Key words: Enteropathogenic Escherichia Coli; antimicrobial resistance;

Lipophorin was isolated from the haemolymph of adult tsetse fly, Glossina morsitans morsitans, by ultracentrifugation in a potassium bromide density gradient. 2. The tsetse fly lipophorin (Mr congruent to 600,000) has a density of congruent to 1.11 g/ml and consists of two apoproteins, apolipophorin-I (apoLp-I, Mr congruent to 250,000) and apolipophorin-II (apoLp-II, Mr congruent to 80,000), both of which are glycosylated as shown by staining with periodate-Schiff reagent. The protein complex is composed of 49% protein and 51% lipids. 3. The finding of lipophorin in tsetse fly haemolymph suggests that, although these flies primarily utilize proline for their energy needs, there is an active transport mechanism for the supply of lipid requirements.