Occurrence of equilibrium and non equilibrium system dynamics in semiarid environments present serious management challenges. In these areas, resource management strategies are increasingly based on equilibrium rather than non equilibrium dynamics that assume simple system dynamics and strong coupling of animal-plant responses. This management approach underlies increasing trends of range degradation and low livestock productivity in these environments. To reverse these trends dictates greater understanding and alignment of grazing resource extraction strategies in space and time to prevailing system dynamics behaviour. In this study, range use patterns by free ranging herds under agropastoral herding were studied in two cycles of four consecutive grazing periods, in semiarid southeastern Kenya. The bites count and herd locations per area methods were used. While grazing thresholds in the system were derived from biweekly sward biomass measured by the quadrant technique in the growing period and stocking rates applied to a growth-consumption rate model. The analysis tested the responsiveness of the agropastoral herding strategies to the predominant system dynamics in the area. In this environment, high rainfall variability ranging from 71 to 98% is experienced across years and seasons, pointing to non-equilibrium dynamics in the system. The agropastoralists practiced seasonal range use and tracking strategies. During the dry season, areas of concentrated drainage; river valleys, bottomlands and ephemeral drainage ways absorbed a greater grazing load, taking 57.1 to 60% of the grazing time by the animals. In contrast, areas of limited moisture concentration, the open sandy/clay plains, were mainly exploited in the wet season and accounted for 52.6 to 55.6% of the grazing time. The agropastoralists tracked forage availability through use of multispecies livestock (cattle, goats and sheep) that exploited different grazing resources in space and time. These range use patterns and strategies tend to stabilize nutrient and energy flow to livestock and thus productivity throughout the seasons. Based on the growth-consumption rate model, grazing thresholds in the system are achieved at 13800, 13000, 4000 and 12300, 4600 and 12000, and 5600 and 11000 kgha-1 of grass biomass at, 2.5, 5, 7, 8 and 10 TLUha-1, respectively. 7 TLUha-1 represent the upper stocking rate limit in the system during the growing period. In this system, resource use strategies are in line with the predominantly non-equilibrium system behaviour. However, sedentary land use interventions and limiting farm sizes that restrict livestock mobility and negatively affect grazing resource diversity will undermine system stability and sustainable livestock production in the area.

Key words: Agropastoralists, range use, system dynamics.

Habitat utilization patterns and feeding interaction of free ranging agropastoral herds
were investigated in two cycles of four consecutive grazing periods, in a semiarid environment,
southeastern Kenya. The bites count and herd locations per area methods were used. During the dry
season, areas of concentrated drainage; river valleys, bottomlands and ephemeral drainage ways
absorbed a greater feeding load, taking 57.1 to 60% of the grazing time by the animals. In contrast,
areas of limited moisture concentration, the open sandy/clay plains, were mainly exploited in the wet
season and accounted for 52.6 to 55.6% of the grazing time. The trophic interaction patterns indicated
that goats and cattle had a seasonal mean diet overlap index of less than 0.5 for all forage classes.
Sheep and cattle, and sheep and goats had a seasonal mean diet overlap index of greater than 0.5 on
grass and forbs, and browse and forbs, respectively. This indicated that during periods of resource
scarcity, sheep and cattle or sheep and goats could become competitive feeders for same feed resources.
Grazing management strategies aimed at even distribution of grazing pressure and enhancing
complementary trophic interactions could be central to sustainable livestock production in such
environments.
KEYWORDS
Agropastoralists. Range Use. Animal Trophic Interactions

The pharmacokinetics of antipyrine were studied in 12 healthy volunteers and 10 patients of Kenya African origin with Hodgkin's lymphoma. The half-life of antipyrine was 12.2 +/- 1.3 h (mean + s.d.), while the apparent volume of distribution (V) was 0.67 +/- 0.11 l kg-1 (mean +/- s.d.) and the total body clearance was 40.7 +/- 3.2 ml kg-1 h-1 (mean +/- s.d.) in the healthy volunteers. The antipyrine half-life in the patients with advanced Hodgkin's lymphoma was 17.1 +/- 2.7 h (mean +/- s.d.). The apparent volume of distribution was 0.72 +/- 0.14 l kg-1 (mean +/- s.d.) which was larger than in healthy volunteers (P less than 0.05). The total body clearance was 30.3 +/- 9.4 ml kg-1 h-1 (mean + s.d.) and this was reduced compared with that in healthy volunteers (P less than 0.02). After cytotoxic therapy the half-life in the patients with advanced Hodgkin's lymphoma was significantly decreased to 8.3 +/- 1.3 h (mean +/- s.d.) (P less than 0.07), and the apparent volume of distribution was reduced to 0.65 +/- 0.07 l kg-1 (mean +/- s.d.) (P less than 0.05) while the total body clearance increased to 52.8 +/- 5.5 ml kg-1 h-1 (mean +/- s.d.) (P less than 0.01).

Prolonged labour causes maternal and perinatal morbidity and mortality. Its sequela include obstructed labour, uterine rupture, maternal exhaustion, postpartum haemorrhage, puerperal sepsis, obstetric fistula, stillbirths, birth asphyxia and neonatal sepsis. These complications can be reduced by using the partograph to assess the progress of labour. The Ministry of Health, Kenya has adopted this tool for labour management in the country and the standardised partograph is recommended for use in all delivery units. Objective: To determine the utilisation of the partograph in the management of labour in selected health facilities in Kenya. Design: A descriptive cross sectional study. Setting: Nine health facilities -ranging from a tertiary hospital to health centre, including public private and faith based facilities in four provinces in Kenya. Results: All facilities apart from Pumwani Maternity Hospital and one health centre were using the partograph. The correct use was low, the knowledge on the use of the tool was average and there was minimal formal training being provided. Staff shortage was listed as the most common cause of not using the tool. Contractions were recorded 30-80%, foetal heart rate 53-90% and cervical dilatation 70-97%. Documentation of state of the liquor, moulding and descent as well as maternal parameters such as pulse, and blood pressure and urinalysis were minimally recorded. Supplies for monitoring labour such as fetoscopes and blood pressure machines were in short supply and sometimes not functional. Overall, the poor usage was contributed to staff shortages, lack of knowledge especially on interpretation of findings, negative attitudes, conflict between providers as to their roles in filling the partograph, and senior staff themselves not acting as role models with regards to the use, advocacy and implementation of the partograph. Conclusion: The partograph was available in most units. However, accurate recording of parameters to monitor the foetus, the mother and progress of labour as recommended was mostly not done. Shortage of staff, lack of knowledge, lack of team work, lack of supplies and negative attitude among healthcare providers were some of the obstacles noted to hamper partograph use.

Prolonged labour causes maternal and perinatal morbidity and mortality. Its sequela include obstructed labour, uterine rupture, maternal exhaustion, postpartum haemorrhage, puerperal sepsis, obstetric fistula, stillbirths, birth asphyxia and neonatal sepsis. These complications can be reduced by using the partograph to assess the progress of labour. The Ministry of Health, Kenya has adopted this tool for labour management in the country and the standardised partograph is recommended for use in all delivery units. Objective: To determine the utilisation of the partograph in the management of labour in selected health facilities in Kenya. Design: A descriptive cross sectional study. Setting: Nine health facilities -ranging from a tertiary hospital to health centre, including public private and faith based facilities in four provinces in Kenya. Results: All facilities apart from Pumwani Maternity Hospital and one health centre were using the partograph. The correct use was low, the knowledge on the use of the tool was average and there was minimal formal training being provided. Staff shortage was listed as the most common cause of not using the tool. Contractions were recorded 30-80%, foetal heart rate 53-90% and cervical dilatation 70-97%. Documentation of state of the liquor, moulding and descent as well as maternal parameters such as pulse, and blood pressure and urinalysis were minimally recorded. Supplies for monitoring labour such as fetoscopes and blood pressure machines were in short supply and sometimes not functional. Overall, the poor usage was contributed to staff shortages, lack of knowledge especially on interpretation of findings, negative attitudes, conflict between providers as to their roles in filling the partograph, and senior staff themselves not acting as role models with regards to the use, advocacy and implementation of the partograph. Conclusion: The partograph was available in most units. However, accurate recording of parameters to monitor the foetus, the mother and progress of labour as recommended was mostly not done. Shortage of staff, lack of knowledge, lack of team work, lack of supplies and negative attitude among healthcare providers were some of the obstacles noted to hamper partograph use.

Objectives: To conduct a rapid assessment of cataract surgical services in Embu District.
Design: Community based survey
Setting: Embu district of the Eastern Province of Kenya
Subjects: 85 clusters selected by systematic method. Each cluster had 40 people aged >50
years.
Results: The prevalence of blindness in people aged >50 years in Embu district is 2.0% (95%CI: 1.5%-2.5%). Cataract is the commonest cause of blindness (39.7%; 95%CI: 38.9%-40.5%). The Cataract surgical coverage for cataract blind persons is 65.7 %. The outcome of cataract surgery with IOL is good in 39.5% of all the operated eyes and improved to 53.5% with best correction/VA with pinhole. Most of the cataract operations are done in voluntary/charity hospitals (47.4%) and in government hospitals (44.9%). The main barriers to utilization of cataract surgical services in the district are lack of awareness and cost of surgery.
Conclusions: Most of the cataract blind patients (65.7%) have assess to surgical services. The proportion of cataract surgeries resulting in good surgical outcomes is low.
Recommendations: There is need to improve the outcome of cataract surgery in Embu through continuing skills update courses for existing staff, supply of biometry equipment and vitrectomy machine plus establishing a cataract audit system. Collaboration between the Government and charitable eye care institutions should be strengthened because they are equal partners in delivery of cataract surgical services in the district. There is need to initiate community eye health promotion activities and cost-containment strategies in order to break the barriers to utilization of surgical services.

Objectives: To conduct a rapid assessment of cataract surgical services in Embu District.

Design: Community based survey Setting: Embu district of the Eastern Province of Kenya

Subjects: 85 clusters selected by systematic method. Each cluster had 40 people aged >50 years.

Conclusions: The prevalence of blindness in people aged >50 years in Embu district is 2.0% (95%CI: 1.5%-2.5%). Cataract is the commonest cause of blindness (39.7%; 95%CI: 38.9%-40.5%). The Cataract surgical coverage for cataract blind persons is 65.7 %. The outcome of cataract surgery with IOL is good in 39.5% of all the operated eyes and improved to 53.5% with best correction/VA with pinhole. Most of the cataract operations are done in voluntary/charity hospitals (47.4%) and in government hospitals (44.9%). The main barriers to utilization of cataract surgical services in the district are lack of awareness and cost of surgery.

Conclusions: Most of the cataract blind patients (65.7%) have assess to surgical services. The proportion of cataract surgeries resulting in good surgical outcomes is low.

Recommendations: There is need to improve the outcome of cataract surgery in Embu
through continuing skills update courses for existing staff, supply of biometry equipment and vitrectomy machine plus establishing a cataract audit system. Collaboration between the Government and charitable eye care institutions should be strengthened because they are equal partners in delivery of cataract surgical services in the district. There is need to initiate community eye health promotion activities and cost-containment strategies in order to break the barriers to utilization of surgical services.

BACKGROUND:
Prolonged labour causes maternal and perinatal morbidity and mortality. Its sequela include obstructed labour, uterine rupture, maternal exhaustion, postpartum haemorrhage, puerperal sepsis, obstetric fistula, stillbirths, birth asphyxia and neonatal sepsis. These complications can be reduced by using the partograph to assess the progress of labour. The Ministry of Health, Kenya has adopted this tool for labour management in the country and the standardised partograph is recommended for use in all delivery units.

OBJECTIVE:
To determine the utilisation of the partograph in the management of labour in selected health facilities in Kenya.

DESIGN:
A descriptive cross sectional study.

SETTING:
Nine health facilities -ranging from a tertiary hospital to health centre, including public private and faith based facilities in four provinces in Kenya.

RESULTS:
All facilities apart from Pumwani Maternity Hospital and one health centre were using the partograph. The correct use was low, the knowledge on the use of the tool was average and there was minimal formal training being provided. Staff shortage was listed as the most common cause of not using the tool. Contractions were recorded 30-80%, foetal heart rate 53-90% and cervical dilatation 70-97%. Documentation of state of the liquor, moulding and descent as well as maternal parameters such as pulse, and blood pressure and urinalysis were minimally recorded. Supplies for monitoring labour such as fetoscopes and blood pressure machines were in short supply and sometimes not functional. Overall, the poor usage was contributed to staff shortages, lack of knowledge especially on interpretation of findings, negative attitudes, conflict between providers as to their roles in filling the partograph, and senior staff themselves not acting as role models with regards to the use, advocacy and implementation of the partograph.

CONCLUSION:
The partograph was available in most units. However, accurate recording of parameters to monitor the foetus, the mother and progress of labour as recommended was mostly not done. Shortage of staff, lack of knowledge, lack of team work, lack of supplies and negative attitude among healthcare providers were some of the obstacles noted to hamper partograph use.

In designing HIY-l vaccine efficacy trials, it will be important to accounrfor changes in HIY -1 incidence, especially changes over time and while participating in riskreduction programs. Methods: Data from an open cohort of female prostitutes in Mombasa, Kenya were analyzed. Individuals were censored after 3 years of follow-up or at HIY -J seroconversion. Models of HIY -J and sexually transmitted disease incidence and sexual risk behaviors over time were constructed using generalized estimating equations. Annual HIV -1 incidence for the entire cohort was calculated. Results: The risk of HIY -J infection declined I O-fold during 3 years of follow-up (from 17.4 to 1.7 cases per 100 person-years for the first and last six months of follow-up, respectively, p

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We report the population structure analysis of Theiteiia orientalis types (Ikeda. Buffcli and Chitose). the causative agent of theileriosis in cattle and its cohorts, using ITSl and ITS2 spacers by fragment genotyping. We utilized primers flanking the two ribosomal RNA internal transcribed spacers (ITS I and ITS2). Due to varying degrees of sequence polymorphism in the ITS regions found within and between species. we exploited the insertions and or deletions in these regions which resulted in different fragment sizes. On the basis of fragment size polymorphism. we could discriminate the three commonly found types of T. orientalis. ITSl was capable of discriminating all three types (lkeda-251 bp, Chitose- 274 bp and Buffeli-269 bp) in one single reaction by fragment genotyping.In contrast. using ITS2.Ikeda (133-bp) a more pathogenic type was distinguishable from Buffeli/Chitose (139-bp). When compared with previous PCR detection method using. ITSI and ITS2 genotyping was found to be more sensitive method with high specificity in population analysis and can be deployed in molecular epidemiology studies

Visual acuity was assessed in 28 human infants who had been deprived of all patterned visual input by cataracts in one or both eyes until they were treated at 1 week to 9 months of age. Immediately after treatment, acuity was no better than that of normal newborns. Acuity improved significantly over the next month, with some improvement apparent after as little as 1 hour of visual input. Unlike findings at older ages, the pattern of results was the same for eyes treated for monocular and for binocular deprivation. The results indicate that patterned visual input is necessary for the postnatal improvement of human visual acuity and that the onset of such input initiates rapid functional development.

This paper presents the radiometric survey results of the Mrima-Kiruku high
background radiation (HBR) anomaly complex of south coastal Kenya. Utilizing a portable γ-
ray spectrometer consisting of a 2.0 l NaI (Tl) backpack detector integrated with GPS to
perform the relevant in-situ radiometric measurements, a novel geospatial gating method
was devised to represent the measurements. The goal of this study was to assess radiation
exposure and associated natural radioactivity levels in the complex and to compare the

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We conducted a controlled, prospective trial to evaluate the effectiveness of rapidly infusing sodium bicarbonate (NaHCO3) and salt-poor albumin into high-risk, premature infants in the first 2 hours of life. Fifty-three infants, randomized into one of four treatment groups, received 8 ml. per kilogram of a solution containing either (A) glucose in water, (B) salt-poor albumin, (C) NaHCO3, or (D) a combination of albumin and NaHCO3. After the initial infusion, the babies received no colloid or alkali solutions until 4 hours of age. We managed them supportively with warmth, appropriate oxygen administration, isotonic fluid infusion, and close monitoring. Among the infants who received alkali, 14 of 26 acquired the respiratory distress syndrome (RDS), 11 died, and four had intracranial hemorrhage. Among babies who received no alkali, RDS occurred in 11 of 27, 5 died, and none had intracranial hemorrhage. These results do not support the common practice of rapidly infusing NaHCO3 into high-risk, premature infants, and they suggest that the early management of such infants needs renewed critical evaluation.

We conducted a controlled, prospective trial to evaluate the effectiveness of rapidly infusing sodium bicarbonate (NaHCO3) and salt-poor albumin into high-risk, premature infants in the first 2 hours of life. Fifty-three infants, randomized into one of four treatment groups, received 8 ml. per kilogram of a solution containing either (A) glucose in water, (B) salt-poor albumin, (C) NaHCO3, or (D) a combination of albumin and NaHCO3. After the initial infusion, the babies received no colloid or alkali solutions until 4 hours of age. We managed them supportively with warmth, appropriate oxygen administration, isotonic fluid infusion, and close monitoring. Among the infants who received alkali, 14 of 26 acquired the respiratory distress syndrome (RDS), 11 died, and four had intracranial hemorrhage. Among babies who received no alkali, RDS occurred in 11 of 27, 5 died, and none had intracranial hemorrhage. These results do not support the common practice of rapidly infusing NaHCO3 into high-risk, premature infants, and they suggest that the early management of such infants needs renewed critical evaluation.

We conducted a controlled, prospective trial to evaluate the effectiveness of rapidly infusing sodium bicarbonate (NaHCO3) and salt-poor albumin into high-risk, premature infants in the first 2 hours of life. Fifty-three infants, randomized into one of four treatment groups, received 8 ml. per kilogram of a solution containing either (A) glucose in water, (B) salt-poor albumin, (C) NaHCO3, or (D) a combination of albumin and NaHCO3. After the initial infusion, the babies received no colloid or alkali solutions until 4 hours of age. We managed them supportively with warmth, appropriate oxygen administration, isotonic fluid infusion, and close monitoring. Among the infants who received alkali, 14 of 26 acquired the respiratory distress syndrome (RDS), 11 died, and four had intracranial hemorrhage. Among babies who received no alkali, RDS occurred in 11 of 27, 5 died, and none had intracranial hemorrhage. These results do not support the common practice of rapidly infusing NaHCO3 into high-risk, premature infants, and they suggest that the early management of such infants needs renewed critical evaluation.

In sub-Saharan Africa, where the effects of human immunodeficiency virus type 1 (HIV-1) have been most devastating, there are multiple subtypes of this virus. The distribution of different subtypes within African populations is generally not linked to particular risk behaviors. Thus, Africa is an ideal setting in which to examine the diversity and mixing of viruses from different subtypes on a population basis. In this setting, it is also possible to address whether infection with a particular subtype is associated with differences in disease stage. To address these questions, we analyzed the HIV-1 subtype, plasma viral loads, and CD4 lymphocyte levels in 320 women from Nairobi, Kenya. Subtype was determined by a combination of heteroduplex mobility assays and sequence analyses of envelope genes, using geographically diverse subtype reference sequences as well as envelope sequences of known subtype from Kenya. The distribution of subtypes in this population was as follows: subtype A, 225 (70.3%); subtype D, 65 (20.5%); subtype C, 22 (6.9%); and subtype G, 1 (0.3%). Intersubtype recombinant envelope genes were detected in 2.2% of the sequences analyzed. Given that the sequences analyzed represented only a small fraction of the proviral genome, this suggests that intersubtype recombinant viral genomes may be very common in Kenya and in other parts of Africa where there are multiple subtypes. The plasma viral RNA levels were highest in women infected with subtype C virus, and women infected with subtype C virus had significantly lower CD4 lymphocyte levels than women infected with the other subtypes. Together, these data suggest that women in Kenya who are infected with subtype C viruses are at more advanced stages of immunosuppression than women infected with subtype A or D. There are at least two models to explain the data from this cross-sectional study; one is that infection with subtype C is associated with a more rapid disease progression, and the second is that subtype C represents an older epidemic in Kenya. Discriminating between these possibilities in a longitudinal study will be important for increasing our understanding of the role of specific subtypes in the transmission and pathogenesis of HIV-1.

Nuclear forensics (NF) is an analytical methodology that involves analysis of intercepted nuclear and radiological materials (NRM) so as to establish their nuclear attribution. The critical challenge in NF currently is the lack of suitable microanalytical methodologies for direct, rapid, minimally invasive detection and quantification of NF signatures. Laser-induced breakdown spectroscopy (LIBS) has the potential to overcome these limitations with the aid of machine-learning (ML) techniques. In this paper, we report the development of ML-enabled LIBS methodology for rapid NF analysis and attribution in support of nuclear security. The atomic uranium lines at 385.464 nm, 385.957 nm, and 386.592 nm were identified as NF signatures of uranium for rapid qualitative detection of trace uranium concealed in organic binders and uranium-bearing mineral ores. The limit of detection of uranium using LIBS was determined to be 34 ppm. A multivariate calibration strategy for the quantification of trace uranium in cellulose and uranium-bearing mineral ores was developed using an artificial neural network (ANN, a feed forward back-propagation algorithm) and spectral feature selection: (1) uranium lines (348 nm to 455 nm), (2) uranium lines (380 nm to 388 nm), and (3) subtle uranium peaks (UV range). The model utilizing category 2 was able to predict the 48 ppm of uranium with a relative error prediction (REP) of 10%. The calibration model utilizing subtle uranium peaks, that is, category 3, could predict uranium in the pellets prepared from certified reference material (CRM) IAEA-RGU-1, with an REP of 6%. This demonstrates the power of ANN to model noisy LIBS spectra for trace quantitative analysis. The calibration model we developed predicted uranium concentrations in the uranium-bearing mineral ores in the range of 54–677 ppm. Principal component analysis (PCA) was performed on the LIBS spectra (200–980 nm) utilizing feature selection of the uranium-bearing samples collected from different regions of Kenya clustered into groups related to their geographic origins. The PCA loading spectrum revealed that the groupings of these samples were mainly due to rare earth elements, namely, cerium, dysprosium, praseodymium, promethium, neodymium, and samarium. ML-enabled LIBS therefore has utility in field NF analysis and attribution of uranium in NRM under concealed conditions.

Nuclear forensics (NF) is an analytical methodology that involves analysis of intercepted nuclear and radiological materials (NRM) so as to establish their nuclear attribution. The critical challenge in NF currently is the lack of suitable microanalytical methodologies for direct, rapid, minimally invasive detection and quantification of NF signatures. Laser-induced breakdown spectroscopy (LIBS) has the potential to overcome these limitations with the aid of machine-learning (ML) techniques. In this paper, we report the development of ML-enabled LIBS methodology for rapid NF analysis and attribution in support of nuclear security. The atomic uranium lines at 385.464 nm, 385.957 nm, and 386.592 nm were identified as NF signatures of uranium for rapid qualitative detection of trace uranium concealed in organic binders and uranium-bearing mineral ores. The limit of detection of uranium using LIBS was determined to be 34 ppm. A multivariate calibration strategy for the quantification of trace uranium in cellulose and uranium-bearing mineral ores was developed using an artificial neural network (ANN, a feed forward back-propagation algorithm) and spectral feature selection: (1) uranium lines (348 nm to 455 nm), (2) uranium lines (380 nm to 388 nm), and (3) subtle uranium peaks (UV range). The model utilizing category 2 was able to predict the 48 ppm of uranium with a relative error prediction (REP) of 10%. The calibration model utilizing subtle uranium peaks, that is, category 3, could predict uranium in the pellets prepared from certified reference material (CRM) IAEA-RGU-1, with an REP of 6%. This demonstrates the power of ANN to model noisy LIBS spectra for trace quantitative analysis. The calibration model we developed predicted uranium concentrations in the uranium-bearing mineral ores in the range of 54–677 ppm. Principal component analysis (PCA) was performed on the LIBS spectra (200–980 nm) utilizing feature selection of the uranium-bearing samples collected from different regions of Kenya clustered into groups related to their geographic origins. The PCA loading spectrum revealed that the groupings of these samples were mainly due to rare earth elements, namely, cerium, dysprosium, praseodymium, promethium, neodymium, and samarium. ML-enabled LIBS therefore has utility in field NF analysis and attribution of uranium in NRM under concealed conditions.

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.

In an effort to identify an immunological basis for natural resistance to HIV-1 infection, we have examined serum antibody responses to HLA class I antigens in female prostitutes of the Nairobi Sex Workers Study. Anti-HLA antibodies are known to block HIV infectivity in vitro and can be protective against SIV challenge in macaques immunized with purified class I HLA. Thus, it was postulated that broadly cross-reactive alloantibodies recognizing common HLA alleles in the client population might contribute to the prevention of heterosexual transmission of HIV. In fact, 12% of the women were found to have serum IgG antibodies against class I alloantigens. However, this alloantibody did not correlate with the HIV status of the women and was found in a similar proportion of HIV-positive and HIV-resistant women. The observed levels of alloantibody did not increase with HIV infection in susceptible individuals, suggesting that potential antigenic mimicry between HIV and host HLA class I antigens does not significantly increase levels of anti-class I antibodies. The lack of correlation between serum anti-allo-class I HLA antibodies and the risk of sexual transmission indicates that this humoral immune response is unlikely to be the natural mechanism behind the HIV-resistance phenotype of persistently HIV-seronegative women. This result, however, does not preclude the further investigation of alloimmunization as an artificial HIV immunization strategy.

J Infect Dis. 1995 Mar;171(3):686-9.
Rapid progression to disease in African sex workers with human immunodeficiency virus type 1 infection.
Anzala OA, Nagelkerke NJ, Bwayo JJ, Holton D, Moses S, Ngugi EN, Ndinya-Achola JO, Plummer FA.
Source
Department of Medical Microbiology, University of Nairobi, Kenya.
Erratum in
 J Infect Dis 1996 Jun;173(6):1529.
Abstract
From a cohort of female sex workers in Nairobi, Kenya, 163 women were observed to seroconvert to human immunodeficiency virus type 1 (HIV-1) and followed to study progression to HIV-1-related disease. The effect of several covariables on disease progression was studied using a Weibull proportional hazards model. The Weibull survival model was fitted to the observed incubation times. Estimates of the median duration to CDC stage IV-A and IV-C disease were 3.5 and 4.4 years, respectively. Condom use before seroconversion was associated with a reduced risk of CDC stage IV-A disease (relative risk = .64, P < .05). The incubation time of HIV-1-related disease is extremely short in this population.
Comment in
 The following popper user interface control may not be accessible. Tab to the next button to revert the control to an accessible version.
Destroy user interface controlRapid progression to human immunodeficiency virus type 1 disease. [J Infect Dis. 1996]
PMID:
7876618
[PubMed - indexed for MEDLINE]

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.

BACKGROUND: There is indirect evidence that HIV-1 exposure does not inevitably lead to persistent infection. Heterogeneity in susceptibility to infection could be due to protective immunity. The objective of this study was to find out whether in highly HIV-1-exposed populations some individuals are resistant to infection. METHODS: We did an observational cohort study of incident HIV-1 infection-among 424 initially HIV-1-seronegative prostitutes in Nairobi, Kenya, between 1985 and 1994. 239 women seroconverted to HIV-1 during the study period. Exponential, Weibull, and mixture survival models were used to examine the effect of the duration of follow-up on incidence of HIV-1 infection. The influence of the duration of exposure to HIV-1 through prostitution on seroconversion risk was examined by Cox proportional hazards modelling, with control for other known or suspected risk factors for incident HIV-1 infection. HIV-1 PCR with env, nef, and vif gene primers was done on 43 persistently seronegative prostitutes who remained seronegative after 3 or more years of follow-up. FINDINGS: Modelling of the time to HIV-1 seroconversion showed that the incidence of HIV-1 seroconversion decreased with increasing duration of exposure, which indicates that there is heterogeneity in HIV-1 susceptibility or acquired immunity to HIV-1. Each weighted year of exposure through prostitution resulted in a 1.2-fold reduction in HIV-1 seroconversion risk (hazard ratio 0.83 [95% CI 0.79-0.88], p < 0.0001). Analyses of epidemiological and laboratory data, show that persistent seronegativity is not explained by seronegative HIV-1 infection or by differences in risk factors for HIV-1 infection such as safer sexual behaviours or the incidence of other sexually transmitted infections. Interpretation: We conclude that a small proportion of highly exposed individuals, who may have natural protective immunity to HIV-1, are resistant to HIV-1. PIP: A cohort study conducted in 1985-94 among 424 prostitutes from Nairobi, Kenya, who were initially human immunodeficiency virus (HIV)-1 seronegative, tended to provide support for the observation that some individuals in highly exposed populations may be resistant to infection. During the 10-year study period, 239 of these women seroconverted. The overall HIV-1 incidence was 42/100 person-years. After the first 2 years of follow up, in which the majority of seroconversions occurred, HIV-1 prevalence reached a plateau and then began a steep decline. To determine whether the risk of HIV-1 infection declined over time as a result of the selection of resistance, incidence rates among women with less than 3 years' versus more than 3 years' duration of prostitution were compared for 1989-93. An increasing protective effect for each seronegative year of exposure was observed. The estimated cumulative protective effect for women practicing prostitution from 1984-93 and remaining seronegative, compared to women who entered prostitution in 1994, was over 100-fold. To rule out the possibility that the decrease in seroconversion with duration of exposure reflected differences in sexual behavior or immunity to sexually transmitted diseases that facilitate HIV transmission, Cox proportional hazards modelling was performed. The weighted duration of prostitution was independently associated with a decreased risk of seroconversion. Each weighted year of exposure resulted in a 1.2-fold decrease in risk. Women who seroconverted were more likely to report 1 or more regular partners and to use condoms with these partners than their counterparts who remained seronegative. Elucidation of the protective mechanisms and the factors mediating the development of immunity against HIV-1 could be important to HIV-1 vaccine research.

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A quick and suitable method for staining Leishmania donovani and other blood protozoa is described. The method, which could have wide applications, is a modification of Field's staining technique as used for malaria parasites. It uses the same stains in a different order. The method has been tried on smears containing malaria and trypanosomes, and the results were good. It is very cheap and requires no special apparatus or training

Trachoma is the leading cause of infectious blindness worldwide. Though trachoma can be treated with antibiotics (active trachoma) or surgery (trachomatous trichiasis), it is still endemic in most parts of Ethiopia. Despite the prevalence of this infectious disease in different parts of the country, district level data is lacking. This study was thus conducted to assess the prevalence estimate of trachoma and its risk factors in Kersa District, Southwest Ethiopia. METHODS: A community based cross sectional Rapid Assessment of Trachoma was conducted using a WHO guideline. Six sub-districts were selected from Kersa District based on primary high risk assessment and from each sub-district; 21-27 households were randomly selected. Active trachoma for children aged 1-9 years, trachomatous trichiasis for people above 15 years old and environmental risk factors for trachoma were assessed. Data were analyzed using SPSS version 16. RESULTS: The overall prevalence estimate of active trachoma was 25.2% (95% CI: 20.7-30.4%). Forty three percent of children had unclean faces, 11.5% of households had water source at more than half hour walking distance, 18.2% did not have functional latrine, and 95.3% of the households had solid waste disposal within a distance of 20 meters. Households with environmental risk factors were at an increased risk to active trachoma, but the association was not statistically significant (p>0.05). The prevalence estimate of trachomatous trichiasis inclusive of "trachoma suspects" was 4.5%. CONCLUSION: Trachoma is endemic in Kersa District with active trachoma being a public health problem in the studied sub-districts. Hence, SAFE strategy should be implemented.

Trachoma is the leading cause of infectious blindness worldwide. Though trachoma can be treated with antibiotics (active trachoma) or surgery (trachomatous trichiasis), it is still endemic in most parts of Ethiopia. Despite the prevalence of this infectious disease in different parts of the country, district level data is lacking. This study was thus conducted to assess the prevalence estimate of trachoma and its risk factors in Kersa District, Southwest Ethiopia. METHODS: A community based cross sectional Rapid Assessment of Trachoma was conducted using a WHO guideline. Six sub-districts were selected from Kersa District based on primary high risk assessment and from each sub-district; 21-27 households were randomly selected. Active trachoma for children aged 1-9 years, trachomatous trichiasis for people above 15 years old and environmental risk factors for trachoma were assessed. Data were analyzed using SPSS version 16. RESULTS: The overall prevalence estimate of active trachoma was 25.2% (95% CI: 20.7-30.4%). Forty three percent of children had unclean faces, 11.5% of households had water source at more than half hour walking distance, 18.2% did not have functional latrine, and 95.3% of the households had solid waste disposal within a distance of 20 meters. Households with environmental risk factors were at an increased risk to active trachoma, but the association was not statistically significant (p>0.05). The prevalence estimate of trachomatous trichiasis inclusive of "trachoma suspects" was 4.5%. CONCLUSION: Trachoma is endemic in Kersa District with active trachoma being a public health problem in the studied sub-districts. Hence, SAFE strategy should be implemented.

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Experience can dramatically alter the responses of cortical neurons. During a critical period in the development of visual cortex, these changes are extremely rapid, taking place in 2 d or less. Anatomical substrates of these changes have long been sought, primarily in alterations in the principal visual input from the thalamus, but the significant changes that have been found take 1 week. Recent results indicate that the initial physiological changes in the cortical circuit take place outside of the primary input layer. We now find that rapid plasticity of binocular responses in the upper layers of cortex is mirrored by similarly rapid anatomical changes in the horizontal connections between ocular dominance columns in the upper layers, which reorganize within 2 d.

Visual acuity was assessed in 28 human infants who had been deprived of all patterned visual input by cataracts in one or both eyes until they were treated at 1 week to 9 months of age. Immediately after treatment, acuity was no better than that of normal newborns. Acuity improved significantly over the next month, with some improvement apparent after as little as 1 hour of visual input. Unlike findings at older ages, the pattern of results was the same for eyes treated for monocular and for binocular deprivation. The results indicate that patterned visual input is necessary for the postnatal improvement of human visual acuity and that the onset of such input initiates rapid functional development.

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 Communications channel coding that achieves capacity is implemented and solution suggested for selection of the optimal design parameter to achieve capacity:Rate or reliability of channels.

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The study assessed the value of currently-available data on the rates of caesarean section as an indicator of safe-motherhood programmes. Data, collected through the routine health information system of the Ministry of Health, Kenya, were used for analyzing the available process indicators. The methodology of this study illustrates both usefulness and limitations of readily-available healthcare information. The rate of hospital-based caesarean section was 6.3% of all births (range 0.3-37%), whereas the rate of population-based caesarean section was 0.95% (range 0.1%-4%). The rate of population-based caesarean section indicates a significant unmet need for obstetric care in the rural areas and may be a useful tool for monitoring progress on safe-motherhood initiatives in poor settings. Rates of population-based caesarean section are low in Kenya, especially in the rural areas. The rate of caesarean section may be a valuable process indicator for identifying the gaps in obstetric care and may be used for advocating improvements for healthcare to the relevant authorities.

PMID: 679868 [PubMed - indexed for MEDLINE]

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In sub-Saharan Africa, where the effects of human immunodeficiency virus type 1 (HIV-1) have been most devastating, there are multiple subtypes of this virus. The distribution of different subtypes within African populations is generally not linked to particular risk behaviors. Thus, Africa is an ideal setting in which to examine the diversity and mixing of viruses from different subtypes on a population basis. In this setting, it is also possible to address whether infection with a particular subtype is associated with differences in disease stage. To address these questions, we analyzed the HIV-1 subtype, plasma viral loads, and CD4 lymphocyte levels in 320 women from Nairobi, Kenya. Subtype was determined by a combination of heteroduplex mobility assays and sequence analyses of envelope genes, using geographically diverse subtype reference sequences as well as envelope sequences of known subtype from Kenya. The distribution of subtypes in this population was as follows: subtype A, 225 (70.3%); subtype D, 65 (20.5%); subtype C, 22 (6.9%); and subtype G, 1 (0.3%). Intersubtype recombinant envelope genes were detected in 2.2% of the sequences analyzed. Given that the sequences analyzed represented only a small fraction of the proviral genome, this suggests that intersubtype recombinant viral genomes may be very common in Kenya and in other parts of Africa where there are multiple subtypes. The plasma viral RNA levels were highest in women infected with subtype C virus, and women infected with subtype C virus had significantly lower CD4 lymphocyte levels than women infected with the other subtypes. Together, these data suggest that women in Kenya who are infected with subtype C viruses are at more advanced stages of immunosuppression than women infected with subtype A or D. There are at least two models to explain the data from this cross-sectional study; one is that infection with subtype C is associated with a more rapid disease progression, and the second is that subtype C represents an older epidemic in Kenya. Discriminating between these possibilities in a longitudinal study will be important for increasing our understanding of the role of specific subtypes in the transmission and pathogenesis of HIV-1.

Review of the management of neonatal infections is done with the aim of guiding the clinician on appropriate therapy. Minimum investigations should include a white blood cell count including the L:T ratio and a blood culture. The bulk of infections at Kenyatta National Hospital newborn unit are caused by Klebsiela, Citrobacter and Staphylococcus aureus. During the 1990's considerable resistance to gentamicin has developed. Currently, cephalosporins chloramphenicol have the best sensitivity pattern. The diagnosis must be carefully verified at different stages of treatment to ensure that only those requiring antimicrobial therapy get it. Indiscriminate use is thus avoided. This in turn minimises development of antibiotic resistant organisms. Failure of response to antimicrobials sometimes means a non infectious cause of illness or poor supportive management. Continuous surveillance is recommended with emphasis on primary prevention of infection as well as cross infections.

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Background: Good diabetes mellitus (diabetes) and diabetic retinopathy (DR) management depends on the strength of the health system, prompting us to conduct a health system assessment for diabetes and DR in Kenya. We used diabetes and DR as tracer conditions to assess the strengths and weaknesses in the health system, and potential interventions to strengthen the health system. In this paper, we report on the need and relevance of integration to strengthen diabetes and DR care. This theme emerged from the health system assessment.

Methods: Using a mixed methods study design, we collected data from service providers in diabetes clinics and eye clinics in three counties, from key informants at national and county level, and from documents review.

Results: There is interest in integration of diabetes and DR services to address discontinuity of care. We report the findings describing the context of integration, why integration is a goal and how these services can be integrated. We use the results to develop a conceptual framework for implementation.

Conclusions: The principal rationale for integrated service provision is to address service gaps and to prevent complications of diabetes and DR. The stakeholder interest and the existing infrastructure can be leveraged to improve these health outcomes.

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A cross sectional study of 115 patients admitted at the Department of Orthopedics, Kenyatta National Hospital, Nairobi, Kenya was carried out to determine the prevalence and antibiotic susceptibility of Staphylococcus aureus isolated from infected wounds. The prevalence of Staphylococcus aureus was 33.0 %. The drugs tested and their corresponding sensitivity was amoxycillin (13.2 %), co-amoxyclav (39.5 %), oxacillin (55.3 %), erythromycin (44.7 %), gentamicin (60.5 %), ciprofloxacin (62.2 %), minocycline (86.8 %), cefuroxime (57.9 %), and clidamycin (84.2 %). These results show the sensitivity profile of Staphylococcus aureus and can be used to choose suitable drugs in the management of wounds for hospitalized patients.

Staphylococcus aureus strains were isolated from 183 of 300 raw milk samples collected at the Kenya Co-operative Creamery (Dandora). 97 of these 183 trains were assayed for the production of enterotoxin A, B, C and D. Seventy two (74.2%) of these were found to produce either a single or a combination of enterotoxins. Raw milk is a potential source of enterotoxigenic S. aureus in milk and milk products, especially if there is defective pasteurisation.

Staphylococcus aureus strains were isolated from 183 of 300 raw milk samples collected at the Kenya Cooperative Creamery (Dandora). Ninety seven percent of the 183 strains isolated  were assayed for the production of enterotoxin A, B, C and D. Seventy two (74.2 %) of these were found to produce either a single or a combination of enterotoxins. Raw milk is a potential source of enterotoxigenic S. aureus in milk and milk products especially if there is defective pasteurization.

Towers are typical structures that can be found in many urban and rural landscapes the world over. From their basic design, they are usually exposed to severe environmental loads. It is therefore prudent to carry out periodic maintenance that includes checking that they are correctly aligned. This paper describes a method that was used for the re-alignment of a guyed tower in Limuru, Kenya. Angular and distance observations, made from two observation points detected a vertical misalignment that was larger than the acceptable tolerance of An iterative re-alignment procedure was then applied, resulting in an acceptable final misalignment of

The identification of five novel compounds, pseudo-erythromycin A-6,9-hemiketal, 8,9-anhydro-pseudo-erythromycin A-6,9-hemiketal, 8,9-anhydro-pseudo-N-demethylerythromycin A-6,9-hemiketal, 5-O-beta-D-desosaminylerythronolide A and 15-nor-erythromycin C, in mother liquor concentrates of Streptomyces erythraeus is described. The pseudo-erythromycin derivatives are characterized by a 12-membered macrocyclic ring as a result of C13––C11 trans-lactonization. The five compounds have very little antimicrobial activity.

According to the millennium assessment report, during the last century, global drylands have experienced anthropogenic induced climate changes that are predicted to continue and even to accelerate during the present century. The traditional pastoralist spatial domains are facing unprecedented changes due to population growth, urban sprawl and an appetite for land not anticipated by the planners who designated such lands as trust lands. A case in point is Kajiado district which has seen most community owned land blocks subdivided and tenure changed to private especially in areas surrounding It is therefore not only the pastoralists that are finding their roaming area constricted but also the wild animals. A recent court case to protect the migratory corridors of wild animals is a good example. In fact there are more wild animals among these communities than are confined in parks in Kenya. With the inevitable land use changes, and their impacts on livelihoods and environment, this paper explores the literature on the interaction of environmental conservation amid global warming and the potential role of biogas in mitigating the livelihood and vulnerability associated with it. Further, the technology helps manage green house gases and has potential for using the clean development mechanism to raise carbon credits which could be ploughed back in propping the livelihoods of rural communities. The paper highlights the preconditions of successful biogas interventions which include partial or complete confinement of animals in zero grazing units alongside improvement/change of animal breeds to more economically viable ones. However, this raises the greater question whether the radical change of livelihood approaches is at all viable? Key words: Global warming, livelihoods, conservation, biogas, carbon markets

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Previous investigators have reported an increase in numbers of amacrine synapses in the inner plexiform layer (IPL) of the rat retina following light deprivation, and an increase in amacrine along with a decrease in bipolar synapses following light damage. Since there are several points of disagreement between the published reports on this subject we undertook a more detailed study of the effects of light deprivation and light damage on the retina. Four groups of eight male albino rat pups (14 days old) were raised for eight weeks under different conditions: (1) unsutured, bright light reared (UB); (2) bilaterally lid-sutured, bright light reared (SB); (3) unsutured, low light reared (UL); and (4) bilaterally lid-sutured, dark reared (SD). The intensity of the light given the UL group was equated with that striking the corneas of the SB group. Light microscopy showed that the retinas of the SB as well as the UB groups had almost complete degeneration of the outer retinal layers, indicating that even low intensity light, when continuous, causes severe retinal damage. The SD group was thicker in many of the retinal layers compared to the UL (control) group. Electron microscopy revealed that there were no significant changes in the incidences of any type of synapse in the IPL following light deprivation or light damage when averaged over total depth. This is in contradiction to the reports of other investigators. However, when the IPL was analyzed by levels, the incidence of amacrine-ganglion synapses was signficantly greater (p less than 0.05) in groups UB and SD, but only in the outer third of the IPL. Thus, extensive postnatal plasticity of IPL synapses in the rat retina did not occur under our experimental conditions. We found, at best, only limited effects which were confined to the amacrine-ganglion synapses.

The Eastern Africa coast has been a complex contact theatre between overseas peoples and the local population. These interconnections have over time produced mixed identities and cultural adaptation processes, expression, and transmission which are foundations of present-day Eastern Africa histories. The musician – historian’s account reflects the coastal identities as not simply painful and isolated historical creations upon a place, but also a part of global processes of cultural productions and affirmation. Through YouTube video, the coastal musician retells the coast’s history thereby preserving memory and lessons leant. The creative artist unveils the history – in an effort to gain inspiration from a cultural and commercial identity formation process. This paper, through Vitali Maembe’s YouTube music video, Little Town Bagamoyo, seeks to highlight the narrative that music exposes in retelling East African coast

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In their study of South African women's intravaginal practices and risk of human immunodeficiency virus (HIV) infection, Myer et al. (1) found a significant association between intravaginal practices and HIV serostatus at baseline but not during follow-up. Their results contrast with those from our prospective study of the effect of vaginal washing on HIV acquisition among women in Mombasa, Kenya (2). Compared with women who did not perform vaginal washing, we found an increased risk of HIV acquisition among women who used water (adjusted hazard ratio (HR) = 2.64, 95 percent confidence interval (CI): 1.00, 6.79) or soap (adjusted HR = 3.84, 95 percent CI: 1.51, 9.77) to clean inside the vagina (2). These findings were significant after adjustment for multiple potentially confounding factors

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Summing multipliers is an important class of operators in the geometric theory of general Banach spaces. They are particularly useful in the study of the structure of the classical spaces. The work done by Grothendieck and Pietsch provides a good basis for the study of this class of operators. The topic of this study is Aspects on (p,q)-summing multipliers. (p,q)-summing multipliers are sequences of bounded linear operators mapping weakly p-summable sequences into strongly q-summable sequences. This study is concerned with using the concepts of absolute and p-summing multipliers to characterize the space of all (p,q)-summing multipliers. In particular we show that the space of all (p, q)-summing multipliers is complete. This is accomplished through a detailed study of the concepts of the summing operators and absolute and p-summing multipliers

This integrative review on the teaching of reading in Kenyan primary schools provides a foundation for the growing movement there to improve reading education. In gathering sources for this review, we took an inclusive historical stance. Thus, we did not dismiss research reports that lacked traditional indicators of quality such as being published in peer-reviewed journals. We used multiple methods to find relevant research and associated documents, including two trips to Kenya. The review is organized by six topics: (a) language of instruction, (b) reading instruction, (c) reading materials, (d) reading culture, (e) assessment, and (f) teacher development. The review concludes with six proposals for policymakers, educational researchers, and teacher educators for the development of reading instruction based on what we learned in reviewing the literature. The first proposals are intended specifically to address the teaching of reading in Kenya, but they may be relevant to other sub-Saharan nations. The final proposal encourages others to conduct similar reviews to make possible a handbook of reading in Africa.

Normal 0 false false false MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui) } /* 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-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"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Macrophytes have been shown to perform important ecological roles in Lake Naivasha. Consequently, various studies regarding the impact of biotic factors on the macrophytes have been advanced but related studies on environmental parameters have lagged behind. In an attempt to address this gap, sampling on floating species and submergents was carried out in eight sampling sites in 2003 to investigate how they were influenced by a set of environmental factors. Soil texture (sandy sediments; P < 0.05, regression coefficient = - 0.749) and wind were the most important environmental parameters influencing the distribution and abundance of floating macrophytes. Combination of soil texture and lake-bed slope explained the most (86.3%) variation encountered in the submergents. Continuous translocation of the floating dominant water hyacinth to the western parts by wind has led to displacement of the submergents from those areas. In view of these findings, the maintenance and preservation of the steep Crescent Lake basin whose substratum is dominated by sand thus hosting most submergents remain important, if the whole functional purpose of the macrophytes is to be sustained.

Normal 0 false false false MicrosoftInternetExplorer4 st1:*{behavior:url(#ieooui) } /* 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-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"; mso-ansi-language:#0400; mso-fareast-language:#0400; mso-bidi-language:#0400;} Macrophytes have been shown to perform important ecological roles in Lake Naivasha. Consequently, various studies regarding the impact of biotic factors on the macrophytes have been advanced but related studies on environmental parameters have lagged behind. In an attempt to address this gap, sampling on floating species and submergents was carried out in eight sampling sites in 2003 to investigate how they were influenced by a set of environmental factors. Soil texture (sandy sediments; P < 0.05, regression coefficient = - 0.749) and wind were the most important environmental parameters influencing the distribution and abundance of floating macrophytes. Combination of soil texture and lake-bed slope explained the most (86.3%) variation encountered in the submergents. Continuous translocation of the floating dominant water hyacinth to the western parts by wind has led to displacement of the submergents from those areas. In view of these findings, the maintenance and preservation of the steep Crescent Lake basin whose substratum is dominated by sand thus hosting most submergents remain important, if the whole functional purpose of the macrophytes is to be sustained.

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Green manure plants are increasingly being adopted for soil fertility improvement especially in low-input agriculture. Information on their reaction to plant parasitic nematodes is, however, scanty. Green manure plants, Calliandra calothyrsus, Canavalia ensiformis, Chenopodium quinoa, Crotalaria juncea, Desmodium uncinartum, Gliricidia sepium, Leucaena leucocephala, Mucuna pruriens, Tephrosia purpurea, 1ithonia diversifolia and Vicia villosa, were evaluated to determine their reaction to root knot nematodes in glasshouse and field experiments. Sesbania sesban and Tagetes minuta were included as susceptible and resistant checks, respectively. In the glasshouse, 15 em-diameter pots were each filled with steam-sterilised soil infested with 10,000 eggs and juveniles (J2) of Meloidogyne javanica. The field experiment was conducted in a field naturally infested with Meloidogyne javanica and M. incognita. Ninety days after soil infestation, galling and egg masses were quantified using a scale of 1-9. Second stage juveniles (J2) were also extracted from 250 cm3 soil. Differences in galling and egg masses were significant (p=0.05) among the green manure plants evaluated. The plants could be grouped into three categories with V. villosa, and T purpurea being rated as susceptible. Calliandra calothyrsus, C quinoa and C. ensifomis were moderately resistant while C. juncea, D. uncinartum, G. sepium, L leucocephala, M. pruriens, and T. diversifolia were rated as resistant. Root knot-nematode resistant green manure plants should, therefore, be recommended in areas where the nematodes are constraint to crop production Key words: Calliandra calothyrsus, Canavalia ensiformis, Chenopodium quinoa, Crotalaria juncea, Desmodium uncinartum, Gliricidia sepium, Leucaena leucocephala, Meloidogyne javanica, M. incognita, Mucuna pruriens, Tephrosia purpurea, 1ithonia diversifolia and Vicia vil/osa.

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Fusarium wilt caused by Fusarium udum Butler, is an economically important disease of pigeonpea (Cajanus cajan (L.) Mill). Information on the mechanisms of resistance to this disease in pigeonpea is limited. To study the role of vascular occlusion in wilt resistance, isolates of F.udum were inoculated onto resistant and susceptible varieties of pigeonpea and observed under light and transmission electron microscopes. The presence of F. udum in wilt susceptible plants was characterized by mycelia and conidia in the xylem vessels, plugging in some vessels, disintegration of xylem parenchyma cells in the infected areas, and the formation of cavities due to heavy colonization in the pith cortex vascular bundle. Resistance to F. udum in the roots and stems of wilt resistant plants was associated with low fungal colonization and high occlusion due to tyloses and gels in the xylem vessels. There were significant differences (P = 0:05) in the number of xylem vessels occluded by tyloses in resistant and susceptible plants with a maximum of 22.5% and 8.0% occlusion, respectively. It is probable that tyloses and gels formed as a result of F. udum interaction in wilt resistant plants are part of a resistance mechanism. Key words: Fusarium wilt,cajanus cajan, resistance, tylose, vascular occlusion

The late blight resistance and yield characteristics of 32 potato genotypes were studied at KARI-Tigoni between 2006 and 2007 under natural late blight inoculums pressure. Foliar late blight resistance was assessed on the basis of area under disease progress curve (AUDPC) whereas the relative area under disease progress curve (RAUDPC) was used to classify the genotypes into five late blight resistance groupings (resistant, moderately resistant, intermediate, moderately susceptible and susceptible). Tuber yields for individual cultivars ranged from 5.87 to 60.70 t/ha. The correlation between foliar late blight and total tuber blight was weak but that between foliar late blight and total tuber yield was negative and significant. On the basis of RAUDPC, it was possible to classify 26 of the 32 cultivars into distinct resistance classes. Cultivars Kenya Karibu, Tana Kimande, Kihoro, Kenya Sifa and Kenya Karibu (white flowers) were rated as resistant. The most susceptible cultivars were Kerr’s Pink, Ngure, Desiree, Romano and Pimpenel. Any of the resistant or susceptible varieties can be used as checks in evaluating germplasm for late blight tolerance.

A survey of bactenal wilt (BW) incidence was carried out in three potato producing districts of Kenya, namely, Nyeri, Nyandarua, and Meru in 1997. The survey was carried out in 30 randomly selected farms in each district. Incidence of BW was highest (18.8%) in Nyeri district, intermediate (16.7%) in Meru and lowest (10.4%) in . Nyandarua. A significant and negative correlation (p=O.05; r = -0.34) between bacterial wilt incidence and altitude was observed. Fifteen potato cultivars, Nyayo, Desiree CIP-800048, Roslin Tana, Kerrs pinkLB-5, Golof (Dutch Robjin), B53, Tigoni CIP-381381.13, Rutuku CIP-720097, AsanteCIP-381381.20, Kenya DhamanaCIP- 800228, Mauritius Clone (89•016), .: KP93739.26, KP92633.26, and Cruza148 CIP-72011 were subsequently evaluated for their reaction to Ralstonia solanacearum in artificial and natural infections in the greenhouse and in the field. Although none of the cultivars appeared resistant, there were significant (p=0.05) differencesir bacterial wilt incidence and severity among the cultivars. Cultivars Kenya Dhamana, Mauritius and Cruza(Cllt- 720118) had low bacterial wilt severity and incidence and were rated tolerant, whereas the other cultivars were rated moderately susceptible or very susceptible.

The wide pathogenic variability occurring in Phaeoisariopsis griseola, the causal agent of angular leaf spot of common bean (Phaseolus vulgaris L.), dictates that new sources of resistance be continuously identified. This study was undertaken to determine the reaction of selected bean genotypes to different races of P. griseola in order to identify potential sources of resistance to angular leaf spot. Selected bean genotypes from Eastern and Central Africa Bean Research Network (ECABREN) and National Dryland Farming Research Centre (NDFRC), Katumani in Kenya were separately inoculated with forty-four races of P. griseola and evaluated for disease development under greenhouse conditions. The genotypes included small- and large-seeded types. None of the genotypes was resistant to all the races, indicating a high complexity of the pathogen population. Thirteen genotypes were resistant (disease score 1 to 3) or moderately resistant (score 4 to 6) to at least 40 of the races. Small-seeded bean genotypes ECAB 0754 and ECAB 0617 were resistant or moderately resistant to all races except Mesoamerican race 33-39 and Afro-Andean race 58-18, respectively. Genotype ECAB 0754 exhibited the highest level of resistance, with an average disease severity of 1.1%. All the resistant or moderately resistant genotypes were of the smallseeded bean types which are commercially less popular. The commonly grown large-seeded genotypes were generally susceptible. Among the bean genotypes evaluated, the small-seeded pintos and browns/yellows possessed high levels of resistance. The results of this study indicate that different bean genotypes have varying levels of resistance to angular leaf spot that can be pyramided into appropriate background to provide durable resistance.

Pathogenicity tests were performed on 11 genotypes of Coffea arabica using single-isolate suspensions of Colletotrichum Kahawae obtained from 90 monoconidial isolates. The objective of this study was to estimate the proportion of pathogenic variation corresponding 10 differences in aggressiveness and virulence (races). A large part of the variation in the pathogen population was due to aggressiveness. The differential effects were too small to suggest conclusively that races exist. This paper discusses the possible causes for the observed small differential interaction and suggests breeding strategies that not only prevent possible adaptation of the pathogen to resistant varieties but also limit variation for resistance due to differences in aggressiveness of the pathogen.

Fifty seven maize lines comprising 23 open pollinated, 30 hybrids and 4 inbreed lines were evaluated for resistance to Turcicum leaf blight both under greenhouse and field conditions. For greenhouse evaluation, the genotypes were inoculated with mixed inoculum derived from seven pathogenic isolates of Exserohilum turcicum whereas in the field trial, natural inoculum was relied upon. The parameters assessed were incubation period, disease incidence, disease severity, lesion density and grain yield. The scale used for disease severity in the greenhouse ranged from 0-6 whereas in the field evaluation, assessment was done using a 0-5 scale based on the proportionate leaf area affected by the disease. The maize genotypes evaluated showed a great variation in terms of lesion density, disease incidence and disease severity. Four lines namely SC Duma 41, H614D, H625, HR-KIB-04A-1-5 consistently rated as resistant with disease severity scores of less than 1, while IR-KIB-03B-19-4, PH1, IR-KIB-03B-19-2, PH4, ZIMLINE/KAT BG-25 and SYNIRO 1 showed a high level of susceptibility with severity scores of higher than 3. The maize genotypes were categorized into three groups namely tolerant, moderately tolerant and susceptible. Fifty three percent of the lines were moderately tolerant while 17 and 30% were tolerant and susceptible, respectively. The susceptible lines produced elliptical gray necrotic sporulating lesions while the lesions were chlorotic and small to medium in size in tolerant genotypes. This study is a clear demonstration of the existence of levels of tolerance in maize genotypes which can be utilized in the management of northern leaf blight.

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Objective: Sweet potato virus disease (SPVD) is highly devastating and diseased plants produce little or no yield. Efficient methods to control the disease are not available and conventional breeding forresistance has had limited success. Breeding for resistance through genetic engineering offers an alternative solution for the control of SPVD. The objective of this study was to select transformed sweet potato lines and evaluate their reaction to virus inoculation under controlled conditions. Methodology and results: Seven hundred and eight sweet potato lines that were putatively transformed with the coat protein (CP), replicase and inverted repeat of the CP genes of sweet potato feathery mottle virus (SPFMV) were characterized. Leaves of 597 (84.3%) were unbleached following treatment with 1% (w/v) kanamycin solution whereas those of 111 (15.7%) lines turned yellow. Kanamycin-resistant lines were graft-inoculated with sweet potato scions infected with SPVD and of the 597 lines, only 20 did not display symptoms. In PCR, amplified DNA fragments of 450 bp were realised in 7 out of the 20 transgenic lines tested using specific primers to the CP, replicase and inverted repeat of the CP genes. The confirmed transgenic lines were evaluated after inoculation with SPFMV, sweet potato chlorotic stunt virus (SPCSV) and a combination of the two under screen house conditions. Ten transgenic sweet potato lines remained symptomless and were virus-free when serologically tested by nitro-cellulose membrane (NCM) -ELISA. Results from triple antibody sandwich (TAS)-ELISA demonstrated that virus accumulation was suppressed in 7 transgenic lines as compared to the non-transgenic control plants two months after inoculation, indicating that the plants were relatively protected.Conclusion and application of findings: This study indicates some form of protection exists against SPVD in plants that were transformed with SPFMV-derived genes. Further experimentation in the field is needed to fully determine the efficacy of the transgenes in conferring resistance to SPVD.

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3 plants of each cultivar were raised in pots filled with sterile soil, 451 bean cultivars were tested in all. Inoculum was prepared from 30-day-old plants of P. vulgaris. Seedlings of test varieties were inoculated when 2 weeks old, the inoculum consisted of 14 virus isolates ground in 0.01 m phosphate buffer, pH 7.3 and manually inoculated onto primary leaves of seedlings dusted with 500 mesh carborundum. A cultivar was rated resistant if no systemic infection could be detected and susceptible if it became systemically infected or if the presence of the virus in inoculated leaves of plants without systemic symptoms was demonstrated by virus indexing. Only 68 showed some resistance. The other 383 were found susceptible, with 77 of them expressing systemic necrosis, the remainder showing mosaic symptoms

To document the histopathological pattern and distribution of reactive localised inflammatory hyperplastic lesions of the oral mucosa diagnosed at the University of Nairobi Dental Hospital over a 14 year period. DESIGN: A retrospective, cross-sectional descriptive study. SETTING: Division of Oral Pathology and Oral Medicine, histopathology laboratory, School of Dental Sciences, University of Nairobi. SUBJECTS: A total of 3135 oral biopsies were accessioned in the oral diagnostic histopathological Laboratory registry over a period of 14 years from March 1991 to December 2005. RESULTS: Three hundred and thirty three cases were histopathologically diagnosed as reactive inflammatory hyperplasias of the oral mucosa. This constituted 10.6% of the total oral biopsy specimens analysed during this period. Fibrous epulis was the most common histological sub-type with 129 cases (38.7%) followed by pyogenic granuloma with 94 (28.3%) cases. Six (1.8%) cases were peripheral giant cell granuloma and three cases (0.9%) were those of denture irritation hyperplasia. The age distribution ranged from 2 to 78 years (mean = 30.5 years) with a peak at 20-29 years. Gender distribution showed that 107 (32%) cases occurred in males and 226 (68%) cases females. Similar trends were observed in most of the histological sub-types. Fibrous epulis occurred in 41 male (31.8%) cases and in 88 (68.2%) females with an age range of 2 to 78 years (mean = 30.5 years). As for the pyogenic granuloma, 26 (27.7%) lesions occurred in males and 68 (72.3%) in females with an age range of 2 to 75 years (mean = 30.1 years). Among all the histopathological sub-types it was shown that 223 (67.0%) cases were fibrous, 104 (31.2%) vascular and six (1.8%) peripheral giant cell granuloma. Gingival lesions were the most common with 257 (77.2%) cases followed by 28 (8.4%) in the tongue, 16 (4.8%) lips, 15 (4.5%) cheek, six (1.8%) palate and the rest on the floor of the mouth and other mucosal sites. The duration of these lesions was recorded in 182 (54.7%) cases and ranged from 1 week to 16 years (mean = 1.8 years). Only 15 (4.5%) cases were reported to have recurred and all of them were gingival lesions. CONCLUSION: The present study has shown that the prevalence of reactive localised inflammatory hyperplasia (RLIHs) of the oral mucosa was 10.6% with fibrous epulis and pyogenic granuloma having been the most common histopathological sub-types predominantly affecting females. Although RLIHs are distinguished on clinical or histopatholocal grounds, it is important to appreciate that they are variations of the same basic process

To document the histopathological pattern and distribution of reactive localised inflammatory hyperplastic lesions of the oral mucosa diagnosed at the University of Nairobi Dental Hospital over a 14 year period. DESIGN: A retrospective, cross-sectional descriptive study. SETTING: Division of Oral Pathology and Oral Medicine, histopathology laboratory, School of Dental Sciences, University of Nairobi. SUBJECTS: A total of 3135 oral biopsies were accessioned in the oral diagnostic histopathological Laboratory registry over a period of 14 years from March 1991 to December 2005. RESULTS: Three hundred and thirty three cases were histopathologically diagnosed as reactive inflammatory hyperplasias of the oral mucosa. This constituted 10.6% of the total oral biopsy specimens analysed during this period. Fibrous epulis was the most common histological sub-type with 129 cases (38.7%) followed by pyogenic granuloma with 94 (28.3%) cases. Six (1.8%) cases were peripheral giant cell granuloma and three cases (0.9%) were those of denture irritation hyperplasia. The age distribution ranged from 2 to 78 years (mean = 30.5 years) with a peak at 20-29 years. Gender distribution showed that 107 (32%) cases occurred in males and 226 (68%) cases females. Similar trends were observed in most of the histological sub-types. Fibrous epulis occurred in 41 male (31.8%) cases and in 88 (68.2%) females with an age range of 2 to 78 years (mean = 30.5 years). As for the pyogenic granuloma, 26 (27.7%) lesions occurred in males and 68 (72.3%) in females with an age range of 2 to 75 years (mean = 30.1 years). Among all the histopathological sub-types it was shown that 223 (67.0%) cases were fibrous, 104 (31.2%) vascular and six (1.8%) peripheral giant cell granuloma. Gingival lesions were the most common with 257 (77.2%) cases followed by 28 (8.4%) in the tongue, 16 (4.8%) lips, 15 (4.5%) cheek, six (1.8%) palate and the rest on the floor of the mouth and other mucosal sites. The duration of these lesions was recorded in 182 (54.7%) cases and ranged from 1 week to 16 years (mean = 1.8 years). Only 15 (4.5%) cases were reported to have recurred and all of them were gingival lesions. CONCLUSION: The present study has shown that the prevalence of reactive localised inflammatory hyperplasia (RLIHs) of the oral mucosa was 10.6% with fibrous epulis and pyogenic granuloma having been the most common histopathological sub-types predominantly affecting females. Although RLIHs are distinguished on clinical or histopatholocal grounds, it is important to appreciate that they are variations of the same basic process

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This report concerns an outbreak that occurred during July/August 1997. Ten pigs from a herd of 181 pigs in a medium-scale, semi-closed piggery in Kiambu District, Kenya, contracted the clinical disease. The main clinical findings in affected pigs included: fever (40.5-41.8 degrees C), prostration, inappetence, dog-sitting posture, abortion, erythema and raised, firm to the touch and easily palpated light pink to dark purple diamond-shaped to square/rectangular spots on the skin around the belly and the back. Based on the pathognomonic skin lesions, a clinical diagnosis of swine erysipelas was made. The diagnosis was confirmed by the isolation of Erysipelothrix rhusiopathiae organisms from the blood and skin biopsies taken from the affected pigs. Response to treatment with a combination of procaine penicillin and dihydrostreptomycin at the dosage rate of 20,000 IU/kg body weight (based on procaine penicillin) for 3 days was good and all the affected pigs recovered fully. The farm was placed under quarantine to prevent spread of the disease

This article reveals that the concept of education as a process of growth is a difficult one. Philosophers are, therefore, justified in being weary when pondering over its meaning, both in theory and practice. By way of conclusion, the article appreciates the complexities inherent in the growth theory of education, summarizing its major strength and weaknesses. Then it cautions educational planners and practitioners to be weary when, and if, they translate the theory into practice, so that they utilize the strengths inherent in the theory whilst paying attention to the dangers of its inherent weaknesses.

Cities around the world are undergoing rapid urbanization, resulting in the growth of informal settlements or slums. These informal settlements lack basic services, including sanitation, and are associated with joblessness, low-income levels, and insecurity. Families living in such settlements may turn to a variety of strategies to improve their livelihoods and household food security, including urban agriculture. However, given the lack of formal sanitation services in most of these informal settlements, residents are frequently exposed to a number of environmental risks, including biological and chemical contaminants. In the Kibera slums of Nairobi, Kenya, households practice a form of urban agriculture called sack gardening, or vertical gardening, where plants such as kale and Swiss chard are planted into large sacks filled with soil. Given the nature of farming in slum environments, farmers and consumers of this produce in Kibera are potentially exposed to a variety of environmental contaminants due to the lack of formal sanitation systems. Our research demonstrates that perceived and actual environmental risks, in terms of contamination of food crops from sack gardening, are not the same. Farmers perceived exposure to biological contaminants to be the greatest risk to their food crops, but we found that heavy metal contamination was also significant risk. By demonstrating this disconnect between risk perception and actual risk, we wish to inform debates about how to appropriately promote urban agriculture in informal settlements, and more generally about the trade-offs created by farming in urban spaces

Contamination of cereals with Fusarium species is one of the major sources of mycotoxins in food and feed. Quantification of biomass of Fusarium species is essential to understand the interactions of individual species in disease development. In this study quantitative real-time PCR assays based on the elongation factor 1 α (EF1α) gene for the 11 Fusarium species F. graminearum, F. culmorum, F. poae, F. langsethiae, F. sporotrichioides, F. equiseti, F. tricinctum, F. avenaceum, F. verticillioides, F. subglutinans and F. proliferatum were developed and tested on 24 wheat and 24 maize field samples. The assays were found to be specific and sensitive. Generally, the results from the quantitative real-time PCR assays corresponded well with mycotoxin data of the field samples

BackgroundRecently, a transgenic rabbit with rhodopsin Pro 347 Leu mutation was generated as a model of retinitis pigmentosa (RP), which is characterized by a gradual loss of vision due to photoreceptor degeneration. The purpose of the current study is to noninvasively visualize and assess time-dependent changes in the retinal structures of a rabbit model of retinal degeneration by using speckle noise-reduced spectral-domain optical coherence tomography (SD-OCT).Methodology/Principal FindingsWild type (WT) and RP rabbits (aged 4–20 weeks) were investigated using SD-OCT. The total retinal thickness in RP rabbits decreased with age. The thickness of the outer nuclear layer (ONL) and between the external limiting membrane and Bruch's membrane (ELM–BM) were reduced in RP rabbits around the visual streak, compared to WT rabbits even at 4 weeks of age, and the differences increased with age. However, inner nuclear layer (INL) thickness in RP rabbits did not differ from that of WT during the observation period. The ganglion cell complex (GCC) thickness in RP rabbits increased near the optic nerve head but not around the visual streak in the later stages of the observation period. Hyper-reflective change was widely observed in the inner segments (IS) and outer segments (OS) of the photoreceptors in the OCT images of RP rabbits. Ultrastructural findings in RP retinas included the appearance of small rhodopsin-containing vesicles scattered in the extracellular space around the photoreceptors.Conclusions/SignificanceIn the current study, SD-OCT provided the pattern of photoreceptor degeneration in RP rabbits and the longitudinal changes in each retinal layer through the evaluation of identical areas over time. The time-dependent changes in the retinal structure of RP rabbits showed regional and time-stage variations. In vivo imaging of RP rabbit retinas by using SD-OCT is a powerful method for characterizing disease dynamics and for assessing the therapeutic effects of experimental interventions.

Towers are typical structures that can be found in many urban and rural landscapes the world over. From their basic design, they are usually exposed to severe environmental loads. It is therefore prudent to carry out periodic maintenance that includes checking that they are correctly aligned. This paper describes a method that was used for the re-alignment of a guyed tower in Limuru, Kenya. Angular and distance observations, made from two observation points detected a vertical misalignment that was larger than the acceptable tolerance of l/400. An iterative re-alignment procedure was then applied, resulting in an acceptable final misalignment of 1 / 520.

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A cross sectional study of 115 patients admitted at the Department of Orthopedics, Kenyatta National Hospital, Nairobi, Kenya was carried out to determine the prevalence and antibiotic susceptibility of Staphylococcus aureus isolated from infected wounds. The prevalence of Staphylococcus aureus was 33.0 %. The drugs tested and their corresponding sensitivity was amoxycillin (13.2 %), co-amoxyclav (39.5 %), oxacillin (55.3 %), erythromycin (44.7 %), gentamicin (60.5 %), ciprofloxacin (62.2 %), minocycline (86.8 %), cefuroxime (57.9 %), and clidamycin (84.2 %). These results show the sensitivity profile of Staphylococcus aureus and can be used to choose suitable drugs in the management of wounds for hospitalized patients.

This paper evaluates the potential of Jatropha curcas Linnaeus (Jatropha) as an alternative source of energy for rural households. The plant is said to have potential to diversify rural incomes, reclaim unproductive lands, reduce importation of fossil fuels, and consequently accumulation of green house gases in the atmosphere. A cost benefit analysis was employed to evaluate the feasibility of producing Jatropha as a biodiesel feedstock in relation to other crops in Kwale district. An IRR of 11 percent, BCR of 0.62 and a NPV of (28267.56) showed that production of Jatropha is not feasible at the moment. However we conclude that the plant has a potential to achieve its intended purpose if there is coordination in research and development along the Jatropha value chain and if technical and financial support is accorded to actors at the production level of the chain.

This paper evaluates the potential of Jatropha curcas Linnaeus (Jatropha) as an alternative source of energy for rural households. The plant is said to have potential to diversify rural incomes, reclaim unproductive lands, reduce importation of fossil fuels, and consequently accumulation of green house gases in the atmosphere. A cost benefit analysis was employed to evaluate the feasibility of producing Jatropha as a biodiesel feedstock in relation to other crops in Kwale district. An IRR of 11 percent, BCR of 0.62 and a NPV of (28267.56) showed that production of Jatropha is not feasible at the moment. However we conclude that the plant has a potential to achieve its intended purpose if there is coordination in research and development along the Jatropha value chain and if technical and financial support is accorded to actors at the production level of the chain.

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Asiatic acid (AA) is a pentacyclic triterpene found in Centella asiatica. In the present study, the mechanism of anticancer effect of AA on skin cancer was investigated. AA decreased viability and induced apoptosis in human melanoma SK-MEL-2 cells in a time- and dose-dependent manner. AA also markedly increased intracellular reactive oxygen species (ROS) level and enhanced the expression of Bax but not Bcl-2 protein in the cells. In addition, AA-induced activation of caspase-3 activity in a dose-dependent manner. Pretreatment with Trolox, an antioxidant, significantly blocked the induction of Bax and activation of caspase-3 in AA-treated cells. Furthermore, Ac-DEVD-CHO, a specific caspase-3 inhibitor, and Trolox prevented the AA-induced apoptosis. AA did not elevate p53 nuclear protein levels that are present in a mutant form in SK-MEL-2 cells. These results suggest that AA-induced apoptosis may be mediated through generation of ROS, alteration of Bax/Bcl-2 ratio and activation of caspase-3, but p53-independent. These results further suggest that AA may be a good candidate for the therapeutic intervention of human skin cancer.

{ Morphometric dimensions of diaghragma sellae influence the extent of instrumentation and tumour exposure in the hypophyseal fossa, and the degree of compression of visual fibres from an expanding pituitary tumor. The dimensions show inter-population variations but data from Africans is scarcely available in literature. We aimed to investigate the morphometric dimensions of diaghragma sellae in an adult Kenyan population. One hundred and forty wet open crania (96 males, 44 females) obtained from the Department of Human Anatomy, University of Nairobi were studied. The shape of diaphragma sellae was classified as round or elliptical (elliptical was further classified as coronal elliptical or sagittal elliptical). The sagittal and coronal dimensions of the sellae were also determined. The diaphragma sellae was round in 60% of cases, coronal elliptical in 34% and sagittal elliptical in 6%. It was significantly wider in females than males (10.26+2.61mm vs 8.37+1.82mm respectively)

Tala Quarrry in African Geoscience Review Vol. 9 Number 4 pp. 385-396.  

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Tunica adventitia was previously considered an inert fibrous layer only involved in nutritional and physical
support of the arterial wall. Recent studies reveal that it is an important dynamic layer actively involved
in the regulation of vascular structure, function, response to injury and disease processes especially
atherosclerosis. Many anatomical studies on arteries, however, still make only peripheral reference to it,
without elucidating its detailed structure. Knowledge of the latter is important in understanding
pathobiology and interventional approaches to atherosclerosis. This review, therefore, aims at
consolidating contemporary literature on the structure and clinical significance of the arterial tunica
adventitia. Google literature search was done using the key words tunica adventitia combined with:
artery, aorta, cells, cell types, collagen, elastic fibres, vasa vasora, lymphatics, nerves, atherosclerosis.
There is overwhelming evidence that the tunica adventitia comprises multiple types of collagen and
elastic fibres arranged in various directions, a wide variety of cells including fibroblasts, smooth muscle,
pericytes, myofibroblasts, leukocytes, mononuclear phagocytic, defence, mesenchymal stem and mast
cells; vasa vasora including microvasculature, lymphatics and neural elements. The exact cellular, fibre
composition and orientation vary between various arteries and regions of the same vessel. Its
components are involved in the initiation, progression and complications of atherosclerosis. In conclusion,
the tunica adventitia is an active dynamic layer which, besides mechanical and nutritive functions; has
metabolic, regulatory and defence roles that are critical in arterial homeostasis and atherosclerosis.
Vascular studies should always include detailed analysis of the biology of the tunica adventitia.

A bisquinaldine, 1,6-bis-(6-amino-2-methyl-4-quinolylamino) hexane, was tested against Trypanosoma brucei ssp. in goats and against T. brucei, T. congolense and T. vivax in mice. At doses of 25 and 100 mg kg-1, the drug protected goats for at least 90 days against blood challenge with T. brucei ssp. Fifty to sixty per cent of goats challenged 180 days after treatment were protected, but all goats challenged 270 days after treatment became infected. In mice, bisquinaldine also had a marked effect on T. brucei, but only a minimal effect on T. vivax and no apparent effect on T. congolense. No drug toxicity was noted in mice even at doses of 2000 mg kg-1. Both a short-term (25 and 100 mg kg-1) and long term (100 mg kg-1) toxicity was apparent in goats treated with bisquinaldine.

A model for the establishment of a four-dimensional regional geodetic reference datum is presented. Starting from the three-dimensional integrated geodetic network model, formulations for the establishment of a four-dimensional regional datum are developed. Astronomic latitudes, astronomic longitudes, gravity values, gravity potential differences, gravity differences, and GPS-vectors are considered as observables. The estimated parameters defining the datura are point coordinates, deflections of the vertical and geoidai undulations, and velocities and accelerations on the positional coordinates. The network datum is considered observed over several epochs with parameters estimated from previous epochs being introduced into later epochs as stochastic prior information parameters.