Description
In an attempt to synthesize carvotacetone analogues, new 3-O-benzyl-carvotacetone (10) and previously reported 3-hydroxy-2-isopropyl-5-methyl-p-benzoquinone (11) were synthesized from piperitone (7). In this work, we describe the synthesis of 10 and other analogues from 7. Luche reduction of 7 to cis-piperitol (8), followed by benzylation yielded 3-O-benzyl-piperitol (9). Riley oxidation of 9 afforded corresponding ketone 10, 11 and 3-benzyloxy-4-isopropylcyclohex-1-enecarbaldehyde (12). Structures of these compounds were determined based on NMR, IR and LC-MS spectral data. Compound 11, exhibited antiplasmodial activities against chloroquine-sensitive (D6) and resistant (W2) strains of Plasmodium falciparum with IC50 values of 0.697 and 0.653 µg/mL, respectively. In addition, compound 11 was active against Cryptococcus neoformans with an IC50 value of 3.11 µg/mL, compared to reference …

Chalcones, flavanones and other flavonoids have been shown to have varied anti-plasmodium activity. In this work, chalcones were synthesized from corresponding flavanones  extracted from Senecio roseiflorus, Erythina abysinica and Polygonum senegalense, using conventional organic reagents and green chemistry approach.Dihydrochalcones were converted to homoisoflavones using the Kostanecki reaction. Characterization and bioassay on the synthetic derivatives was also undertaken.

Background. The host immune response against mucosally-acquired pathogens may be influenced by the mucosal immune milieu during acquisition. Since Neisseria gonorrhoeae can impair dendritic cell and T cell immune function, we hypothesized that co-infection during HIV acquisition would impair subsequent systemic T-cell responses.   Methods. Monthly screening for sexually transmitted infections (STIs) was performed in high risk, HIV seronegative Kenyan female sex workers as part of an HIV prevention trial. Early HIV-specific CD8+ T cell responses and subsequent HIV viral load set point were assayed in participants acquiring HIV, and were correlated with the presence of prior genital infections during HIV acquisition.   Results. Thirty-five participants acquired HIV during follow up, and 16/35 (46%) had a classical STI at the time of acquisition. N. gonorrhoeae co-infection was present during HIV acquisition in 6/35 (17%), and was associated with an increased breadth and magnitude of systemic HIV-specific CD8+ T-cell responses, using both interferon- (IFNg) and MIP-1 beta (MIP1b) as an output. No other genital infections were associated with differences in HIV-specific CD8+ T cell response, and neither N. gonorrhoeae nor other genital infections were associated with differences in HIV plasma viral load at set point.   Conclusion. Unexpectedly, genital N. gonorrhoeae infection during heterosexual HIV acquisition was associated with substantially enhanced HIV-specific CD8+ T-cell responses, although not with differences in HIV viral load set point. This may have implications for the development of mucosal HIV vaccines and adjuvants.

The paper shows that in the analysis of a queuing system with fixed-size batch arrivals, there emerges a set of polynomials which are a generalization of Chebyshev polynomialsof the second kind. The paper uses these polynomials in assessing the transient behaviour of the overflow (equivalently call blocking) probability in the system. A key figure to noteis the proportion of the overflow (or blocking) probability resident in the transient component,which is shown in the results to be more significant at the beginning of the transient and naturally decays to zero in the limit of large t. The results also show that the significanceof transients is more pronounced in cases of lighter loads, but lasts longer for heavier loads.

The traditional approach to creativity (using methods such as brainstorming, C-sketch, morphological charts, scamper, etc.) calls upon the designer to look inward for inspiration. TRIZ, on other hand, invites the designer to use a ready pool of knowledge for inspiration. TRIZ does not discount the use of the traditional approaches. On the contrary, TRIZ ensures that design teams use these traditional methods in a systematically directed manner by carrying out intelligent idea generation in areas where other people have solved a similar general design problem. The main focus of this paper is to look at systematic creativity methods, such as TRIZ, from a learning styles perspective. Three learning styles dominant in the engineering education literature are explored: MBTI, Kolb and Felder-Silverman. For each it was found that the tasks required of each of the TRIZ steps matches a broader range of engineering student learning styles, than the sole use of brainstorming.

This paper examines some of the reasons for the low success rate in gully control and argues that a more careful examination of each situation and a greater understanding of the processes at work could lead to more successful interventions. It outlines a systematic evaluation of a gully erosion problem and analysis of the options for control or reclamation. Evaluation should involve assessment of the causes of gully formation, gully morphology, gully erosion/sedimentation processes, soil characteristics, land use in the vicinity, and catchment characteristics.

I have picked this evaluation because it focuses on the special needs of migrant female sex workers (FSWs), in particular those in Sub-Saharan Africa, where the prevalence of sexually transmitted infections (STls) and HIV is high and the health infrastructure is insufficient to respond to these problems. In addition, migrant FSWs might initially be too afraid to immediately seek medical help in the 'new country' due to the fear of being apprehended for real or perceived reasons. By the same token, they might not have access to male or female condoms, but may have a high incidence of partner change and unprotected sex. Fear of stigma and discrimination might also keep them away from appropriate services.

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Despite significant increases in global health investment and the availability of low-cost, efficacious interventions to prevent mother-to-child HIV transmission (pMTCT) in low- and middle-income countries with high HIV burden, the translation of scientific advances into effective delivery strategies has been slow, uneven and incomplete. As a result, pediatric HIV infection remains largely uncontrolled. A five-step, facility-level systems analysis and improvement intervention (SAIA) was designed to maximize effectiveness of pMTCT service provision by improving understanding of inefficiencies (step one: cascade analysis), guiding identification and prioritization of low-cost workflow modifications (step two: value stream mapping), and iteratively testing and redesigning these modifications (steps three through five). This protocol describes the SAIA intervention and methods to evaluate the intervention's impact on reducing drop-offs along the pMTCT cascade.

Description: This book describes four types of indigenous water retention structures used in East Africa. These structures are the Berkad tank, the Charco dam, sand wiers and hillside water retention ditches.

This report is an attempt to impress on managers of building projects the relevance and importance of the systems approach to management in their field. To achieve this aim the report has started by examining some common theoretical models of management and their inherent shortcomings in the management of complex problems such as building projects. The complexity of building projects is demonstrated throuqh a discussion of their resource markets which are found to be highly differentiated yet interdependent. The building process itself is made up of different activities which often require different skills, materials and facilities. As a consequence, a wide range of participants are involved in building projects. This raises the need to coordinate their inputs. The systems approach and its concepts which are most relevant to building project management is discussed. Its place in project management is illustrated with parallels drawn from districts which form the case studies for the research. ~. Among" the most important concepts discussed is the environment. It is the framework of forces within which construction activity takes place. The extent of the environment of a project depends on its resources requirements. Various aspects of the environment affect the execution of building projects. The environment is usually turbulent and projects are vulnerable to the turbulence. The functions of the managerial system of a project are considered in detail. They include the planning; securing and bringing together various inputs in amounts and modes which best suit the requirements of a project. It resolves disputes among project participants and controls the interaction between the project and its environment. In so doing the project is shielded from harmful environmental effects while the environment is protected from the harmful products of a project. Two case studies reveal that project management in districts is disjointed and suffers from technical, managerial, and logistic problems. There is poor coordination between and among participants and projects. Resources are not adequately planned and controlled. Procedures are constrained by bureaucracy and shortage of facilities. A major conclusion of the study is that the organization structure within which building projects are managed is not suitable for the tasks involved in building. The inappropriateness-is largely, the result of Iack of channels for speedy communciation within the structure and the rigidity of the structure especially with regard to the expenditure of authority. The recommendations that are given aim to make the authority structure more flexible to allow a faster rate of discharging duties while at the same time disallowing wasteful operations which result from poor planning and control.

ABSTRACTObjective: Dental wastes are material that has been utilized in dental clinics, which are no longerwanted for use and therefore discarded. Improper disposal of these dental wastes can cause harmto the dentist, the people in immediate vicinity of the dentist, waste handlers and general publicand the environment through production of toxins or as by products of the destruction process.This study aims to determine the knowledge, attitudes and practice on management of dentalwastes among dental practitioners in Nairobi, Kenya.Methods: Descriptive cross-sectional study of 70 dental practitioners practicing in Nairobi,Kenya.Results: A total of 50 dental practitioners were included in the study. Majority had graduatedbetween 1991-1995. 47.5% had only a bachelors degree, 25% had masters 7.5% had PhD and12.5% had postgraduate diploma. Forty five percent of the respondents indicated they haveattended training on management of dental waste while 89.5% had been attending continuousdental education. Forty-two percent of the respondents worked in public institution while the restwere in private practice. Only 48.7% of the practitioners were aware of the existence of wastemanagement guidelines. Only 64% felt it was important to follow the set guidelines, 5% thought itwas tedious, 2% said they were not practical and the rest were not interested in the guidelines.Eighty-two percent of the respondents said that amalgam was toxic if disposed improperly withonly 10.7% indicating pollution to be a consequence of improper disposal of amalgam. Seventysevenpercent of the respondents did not know the hazardous effects of improper disposal ofamalgam. Only half of the respondents stored waste amalgam under water, 25% said they did notknow how to dispose amalgam. All (100%) knew about occurrence of cross-infection withimproper disposal of bloody waste but only 56.1% said they incinerated bloody body waste while24.4% disposed off bloody waste with general waste 35.7% of the respondents indicated thatsharps were hazardous if improperly disposed. Only 52.4% incinerated their pathological wasted.On expired drugs, 7.3% disposed them off as part of general wastes.Conclusion: There is need for continuous professional development on waste management amongdentists in Kenya.