Evaluation of Solar Disinfection of E. coli Under Sub-Saharan Field Conditions Using a 25 Litre Borosilicate Glass Batch Reactor Fitted with a Compound Parabolic Collector.

The bacterial inactivation efficacy of a solar water disinfection (SODIS) reactor consisting of a 25L borosilicate glass tube fitted with a compound parabolic collector (BGTR-CPC) was assessed under equatorial weather conditions in Uganda. The SODIS BGTR-CPC was tested over a 17-month period in Sub-Saharan conditions in Kampala, Uganda. The BGTR-CPC was filled with natural water from a nearby protected well. A wild strain of Escherichia coli isolated from local natural water was added to the reactor to give a starting population of between 105 and 107 CFU/100ml. This spiked water was exposed to natural sunlight. Satisfactory bacterial inactivation (log10 reduction values \u3e6 units or inactivation to below the limit of detection (/100ml.)) was observed for 11 of 13 experiments. Rainfall and overcast/cloudy conditions were factors on both of the occasions when incomplete inactivation was observed. In conclusion, the use of CPC SODIS technology is suitable for treating drinking water both at household level and institutional level in Sub-Saharan and other similar tropical climates if careful consideration of the cloud cover and rainfall is taken into account

Fish farming in Tanzania: the availability and nutritive value of local feed ingredients

An investigative field survey was performed to gather baseline data on locally available feed ingredients and fish farming practices in different regions of Tanzania. More than 80% of respondents relied on locally available feed ingredients as a major feed supplement for their cultured fish, with maize bran being the most commonly used feed ingredient in all regions. Crude protein content in most analyzed local feed ingredients was medium-high, while crude fat content was high in some animal and agricultural by-products, and medium-low in other ingredients. Most respondents were males and the majority of fish farms were owned by individuals. Earthen pond was the most common fish farming system in all regions except Dar es Salaam. Semi-intensively mixed-sex tilapia monoculture was the dominating fish farming practice. The results of the survey presented provide a good platform for future development of culture systems and feeding strategies for tilapia in Tanzania

Local selection in the presence of high levels of gene flow: Evidence of heterogeneous insecticide selection pressure across Ugandan Culex quinquefasciatus populations

Background: Culex quinquefasciatus collected in Uganda, where no vector control interventions directly targeting this species have been conducted, was used as a model to determine if it is possible to detect heterogeneities in selection pressure driven by insecticide application targeting other insect species. Methodology/Principal findings: Population genetic structure was assessed through microsatellite analysis, and the impact of insecticide pressure by genotyping two target-site mutations, Vgsc-1014F of the voltage-gated sodium channel target of pyrethroid and DDT insecticides, and Ace1-119S of the acetylcholinesterase gene, target of carbamate and organophosphate insecticides. No significant differences in genetic diversity were observed among populations by microsatellite markers with HE ranging from 0.597 to 0.612 and low, but significant, genetic differentiation among populations (FST = 0.019, P = 0.001). By contrast, the insecticide-resistance markers display heterogeneous allelic distributions with significant differences detected between Central Ugandan (urban) populations relative to Eastern and Southwestern (rural) populations. In the central region, a frequency of 62% for Vgsc-1014F, and 32% for the Ace1-119S resistant allele were observed. Conversely, in both Eastern and Southwestern regions the Vgsc-1014F alleles were close to fixation, whilst Ace1-119S allele frequency was 12% (although frequencies may be underestimated due to copy number variation at both loci). Conclusions/Significance: Taken together, the microsatellite and both insecticide resistance target-site markers provide evidence that in the face of intense gene flow among populations, disjunction in resistance frequencies arise due to intense local selection pressures despite an absence of insecticidal control interventions targeting Culex

Plus- and Minus-End Directed Microtubule Motors Bind Simultaneously to Herpes Simplex Virus Capsids Using Different Inner Tegument Structures

Many viruses depend on host microtubule motors to reach their destined intracellular location. Viral particles of neurotropic alphaherpesviruses such as herpes simplex virus 1 (HSV1) show bidirectional transport towards the cell center as well as the periphery, indicating that they utilize microtubule motors of opposing directionality. To understand the mechanisms of specific motor recruitment, it is necessary to characterize the molecular composition of such motile viral structures. We have generated HSV1 capsids with different surface features without impairing their overall architecture, and show that in a mammalian cell-free system the microtubule motors dynein and kinesin-1 and the dynein cofactor dynactin could interact directly with capsids independent of other host factors. The capsid composition and surface was analyzed with respect to 23 structural proteins that are potentially exposed to the cytosol during virus assembly or cell entry. Many of these proteins belong to the tegument, the hallmark of all herpesviruses located between the capsid and the viral envelope. Using immunoblots, quantitative mass spectrometry and quantitative immunoelectron microscopy, we show that capsids exposing inner tegument proteins such as pUS3, pUL36, pUL37, ICP0, pUL14, pUL16, and pUL21 recruited dynein, dynactin, kinesin-1 and kinesin-2. In contrast, neither untegumented capsids exposing VP5, VP26, pUL17 and pUL25 nor capsids covered by outer tegument proteins such as vhs, pUL11, ICP4, ICP34.5, VP11/12, VP13/14, VP16, VP22 or pUS11 bound microtubule motors. Our data suggest that HSV1 uses different structural features of the inner tegument to recruit dynein or kinesin-1. Individual capsids simultaneously accommodated motors of opposing directionality as well as several copies of the same motor. Thus, these associated motors either engage in a tug-of-war or their activities are coordinately regulated to achieve net transport either to the nucleus during cell entry or to cytoplasmic membranes for envelopment during assembly

Nutritional quality of the major fish feed ingredients and commercial fish feeds from different sources in East Africa for Nile tilapia cage culture

Aquaculture has grown at a slower pace in Sub-Saharan African countries mainly due to constraints in high-quality feed supply. Improvement of productivity and profitability requires close examination and evaluation of nutritional quality and economic feasibility of feed for both semi-intensive and intensive aquaculture. Consequently, the present study was conducted to evaluate the nutritional quality and costs of nutrients of ingredients as they are affected by shifting from one point in supply chainto another, and as they are transformed from one form to another. Additionally, commercial fish feeds were evaluated. The study involved taking samples from landing sites and oil extraction plants, milling factories, stores and shops from different parts of East Africa and analysis of proximate composition. It also involved evaluation of cost per unit of protein and energy. The results of the present study revealed that there was serious adulteration from one point in the supply chain to another and from one physical form to another. The main adulteration materials most probably were sand. As a result of this adulteration, the composition of the commercial fish feeds were substantially below the target values and the tagged prices were hence not considerate to their quality. It is therefore recommended that in order to get fairy accurately formulated feeds that are made for intensive fish farms, ingredients should be sourced from landing sites and oil plants for animal protein (fish meal) and plant protein respectively. Nevertheless, feed ingredients sourced from stores and shops can be used for semi-intensive aquaculture where complete formulated feeds are not necessary. However, it should be noted that these feed ingredients from stores and shops are more expensive than those sourced from landing sites andoil plants and therefore even the economic performance of semi-intensive aquaculture may be affected if feed components of questionable quality from stores and shops are used

A study of the bacteriological quality of roof-harvested rainwater and an evaluation of SODIS as a suitable treatment technology in rural Sub-Saharan Africa

Harvested rainwater (HRW) is of great socio-economic importance particularly in areas where water sources are scarce or polluted. This case study was carried out in a rural area of Southern Uganda where the community has limited access to safe drinking water. The aims of the project were to investigate the quality of harvested rainwater over a year long period covering wet and dry seasons and to investigate the use of solar waterdisinfection (SODIS) as a water treatment technology. Fifty households using roof HRW were selected. The systems used included catchment ponds, metallic, concrete and plastic tanks. All households used the HRW for drinking. The raw HRW was analysed for temperature, pH and total dissolved solids (TDS) and for the presence of the bacterial indicators of faecal pollution – Escherichia coli, faecal enterococci and Clostridium perfringens. Results indicated that while the HRW met the required physiochemical drinking water standards, the majority of samples from all types of system showed levels of microbiological contamination indicating that the water was unsafe for drinking without treatment. The use of SODIS to treat the water was investigated using 2 Liter PET bottles and was shown to be an effective treatment technology

Achieving production and conservation simultaneously in tropicalagricultural landscapes

Increasing population size and demand for food in the developing world is driving the intensification ofagriculture, often threatening the biodiversity within the farmland itself and in the surrounding land-scape. This paper quantifies bird and tree species richness, tree carbon and farmer’s gross income, andinteractions between these four variables, across an agricultural gradient in central Uganda. We showedthat higher cultivation intensities in farmed landscapes resulted in increased income but also a declinein species richness of birds and trees, and reductions in tree carbon storage. These declines were particu-larly marked with a shift from high intensity smallholder mixed cropping to plantation style agriculture.This was especially evident for birds where significant declines only occurred in plantations. Small scalefarming will likely continue to be a key source of cash income for the rural populations, and ensuring‘sustained agricultural growth’ within such systems while minimising negative impacts on biodiversityand other key ecosystem services will be a major future challenge

Herpes Simplex Virus Type 1 Gene UL14: Phenotype of a Null Mutant and Identification of the Encoded Protein

Herpes simplex virus type 1 (HSV-1) gene UL14 is located between divergently transcribed genes UL13 and UL15 and overlaps the promoters for both of these genes. UL14 also exhibits a substantial overlap of its coding region with that of UL13. It is one of the few HSV-1 genes for which a phenotype and protein product have not been described. Using mass spectrometric and immunological approaches, we demonstrated that the UL14 protein is a minor component of the virion tegument of 32 kDa which is expressed late in infection. In infected cells, the UL14 protein was detected in the nucleus at discrete sites within electron-dense nuclear bodies and in the cytoplasm initially in a diffuse distribution and then at discrete sites. Some of the UL14 protein was phosphorylated. A mutant with a 4-bp deletion in the central region of UL14 failed to produce the UL14 protein and generated small plaques. The mutant exhibited an extended growth cycle at low multiplicity of infection and appeared to be compromised in efficient transit of virus particles from the infected cell. In mice injected intracranially, the 50% lethal dose of the mutant was reduced more than 30,000-fold. Recovery of the mutant from the latently infected sacral ganglia of mice injected peripherally was significantly less than that of wild-type virus, suggesting a marked defect in the establishment of, or reactivation from, latent infection