Genetic homogeneity among Ugandan isolates of Xanthomonas campestris pv. musacearum revealed by randomly amplified polymorphic DNA analysis

The Random Amplification of Polymorphic DNA (RAPD) analysis was used to detect the genetic diversity among Ugandan isolates of Xanthomonas campestris pv. musacearum (Xcm), the causal agent of banana Xanthomonas wilt (BXW) disease. Seven random primers were used because of their ability to amplify reproducible and reliable fingerprints generated between 6 - 12 amplicons each from the Xcm isolates obtained from central core of pseudostems, peduncles, fruit peelings, sap, nectar,insects’ bodies and bacterial oozes. Regardless of the source and geographical origin, similar fingerprints were generated from the tested isolates. Using a similarity coefficient of 58%, the unweighted pair group method with arithmetic averaging (UPGMA) analysis did not reveal anysignificant differences in clustering, with exception of a single isolate that had unique fingerprints. Prior to the genetic analysis, all the isolates compared showed no significant difference (P = 0.92) with regardto incubation period for appearance of symptoms and the severity of symptoms in pathogenicity test. Thus, our data indicates that the population of Xcm in Uganda is clonal, that is, one uniform populationbeing spread fast and efficiently, suggesting that there is a low likelihood of the current population to rapidly evolve, in the near future, into more virulent strains to overcome any resistance deployed

The survival of Xanthomonas Campestris PV.musacearum in soil and plant debris

No Abstract

Performance Investigations of the Charging and Discharging Processes in a 3-Tank Thermal Energy Storage System

The paper presents a 3 tank thermal energy storage system. The system consists of cold oil reservoir, heat storage tank, and a residual drainage tank. Cold oil flows by gravity into a heating chamber and after being heated to the required temperature, a mechanical thermostat opens allowing the hot oil to flow into a heat storage tank. The storage tank was discharged through the cooking unit by boiling 0.5 litres of water. The used oil flowed by gravity to the drainage tank. The discharge flow rates of 0.5, 2.1, 2.8 and 6.5 g/s were considered. A charging efficiency of 51.3% and overall discharging efficiency range of 15.3 34.7% were achieved. Charging efficiency increased when the source was embedded in the storage tank. The instantaneous discharge power had a peak value for each flow rate. The adopted cooking unit had a thermal transfer efficiency range of 34.7 57.6%. A method for sizing oil based TES systems was proposed and illustrated based on the obtained discharge results. Keywords:     3-tank, sizing, discharging, efficiency, thermal energ

farmers knowledge and practices in the management of insect pests of leafy amaranth in kenya

Abstract Amaranth (Amaranthus L.) species are grown for their grain or leaves and contribute to farmers' livelihoods and nutritional food security. Leafy amaranth (LA) is consumed widely as a vegetable in Kenya. An assessment of current farmers' knowledge of pest management practices provides information about future educational needs. Six-hundred LA farmers were interviewed, focus group discussions with farmers, and interviews with key informants were completed in four Kenyan counties. The majority (71%) of survey respondents grew LA on less than 0.25 acre (<0.1 ha) and 59.2% were female. Constraints of LA production differed by counties surveyed. Farmers indicated insects and birds were important in Kiambu and Kisumu counties, whereas in Vihiga and Kisii, capital, markets, and land area for production were important. Farmers stated and ranked importance of the insects they observed during LA production. Eighty-seven percent stated aphids (Hemiptera: Aphididae), as a major pest and 96.8% ranked aphids as the number-one insect pest of LA in all four counties. Two other pests of LA included cotton leafworm, Spodoptera littoralis (Lepidoptera: Noctuidae) (0.8%) and spider mites, Tetranychus spp (Trombidiformes; Tetranychidae) (0.7%). Forty-two percent of all LA farmers managed aphids, with 34% using synthetic insecticides and 8% using nonsynthetic methods. Biological controls and host-plant resistance were not mentioned. Educational programs that train farmers about integrated pest management (IPM) in LA production are needed. Future research should determine successful IPM strategies for aphids on LA to reduce insecticide use and improve sustainability and nutritional food security for small-landholder farmers and consumers

Neonatal Circumcision for HIV Prevention: Cost, Culture, and Behavioral Considerations

Seth Kalichman discusses a new study that finds neonatal circumcision in Rwanda to be a cost-saving HIV prevention strategy

The Emergence of HIV Transmitted Resistance in Botswana: “When Will the WHO Detection Threshold Be Exceeded?”

BACKGROUND: The Botswana antiretroviral program began in 2002 and currently treats 42,000 patients, with a goal of treating 85,000 by 2009. The World Health Organization (WHO) has begun to implement a surveillance system for detecting transmitted resistance that exceeds a threshold of 5%. However, the WHO has not determined when this threshold will be reached. Here we model the Botswana government's treatment plan and predict, to 2009, the likely stochastic evolution of transmitted resistance. METHODS: We developed a model of the stochastic evolution of drug-resistant strains and formulated a birth-death Master equation. We analyzed this equation to obtain an analytical solution of the probabilistic evolutionary trajectory for transmitted resistance, and used treatment and demographic data from Botswana. We determined the temporal dynamics of transmitted resistance as a function of: (i) the transmissibility (i.e., fitness) of the drug-resistant strains that may evolve and (ii) the rate of acquired resistance. RESULTS: Transmitted resistance in Botswana will be unlikely to exceed the WHO's threshold by 2009 even if the rate of acquired resistance is high and the strains that evolve are half as fit as the wild-type strains. However, we also found that transmission of drug-resistant strains in Botswana could increase to ∼15% by 2009 if the drug-resistant strains that evolve are as fit as the wild-type strains. CONCLUSIONS: Transmitted resistance will only be detected by the WHO (by 2009) if the strains that evolve are extremely fit and acquired resistance is high. Initially after a treatment program is begun a threshold lower than 5% should be used; and we advise that predictions should be made before setting a threshold. Our results indicate that it may be several years before the WHO's surveillance system is likely to detect transmitted resistance in other resource-poor countries that have significantly less ambitious treatment programs than Botswana

Multi-centred mixed-methods PEPFAR HIV care & support public health evaluation: study protocol

BACKGROUND: A public health response is essential to meet the multidimensional needs of patients and families affected by HIV disease in sub-Saharan Africa. In order to appraise current provision of HIV care and support in East Africa, and to provide evidence-based direction to future care programming, and Public Health Evaluation was commissioned by the PEPFAR programme of the US Government. METHODS/DESIGN: This paper described the 2-Phase international mixed methods study protocol utilising longitudinal outcome measurement, surveys, patient and family qualitative interviews and focus groups, staff qualitative interviews, health economics and document analysis. Aim 1) To describe the nature and scope of HIV care and support in two African countries, including the types of facilities available, clients seen, and availability of specific components of care [Study Phase 1]. Aim 2) To determine patient health outcomes over time and principle cost drivers [Study Phase 2]. The study objectives are as follows. 1) To undertake a cross-sectional survey of service configuration and activity by sampling 10% of the facilities being funded by PEPFAR to provide HIV care and support in Kenya and Uganda (Phase 1) in order to describe care currently provided, including pharmacy drug reviews to determine availability and supply of essential drugs in HIV management. 2) To conduct patient focus group discussions at each of these (Phase 1) to determine care received. 3) To undertake a longitudinal prospective study of 1200 patients who are newly diagnosed with HIV or patients with HIV who present with a new problem attending PEPFAR care and support services. Data collection includes self-reported quality of life, core palliative outcomes and components of care received (Phase 2). 4) To conduct qualitative interviews with staff, patients and carers in order to explore and understand service issues and care provision in more depth (Phase 2). 5) To undertake document analysis to appraise the clinical care procedures at each facility (Phase 2). 6) To determine principle cost drivers including staff, overhead and laboratory costs (Phase 2). DISCUSSION: This novel mixed methods protocol will permit transparent presentation of subsequent dataset results publication, and offers a substantive model of protocol design to measure and integrate key activities and outcomes that underpin a public health approach to disease management in a low-income setting