An HIV-1 Nef genotype that diminishes immune control mediated by protective human leucocyte antigen alleles

Objectives: Certain human leucocyte antigen (HLA)-B alleles (protective alleles) associate with durable immune control of HIV-1, but with substantial heterogeneity in the level of control. It remains elusive whether viral factors including Nef-mediated immune evasion function diminish protective allele effect on viral control. / Design: The naturally occurring non-Ser variant at position 9 of HIV-1 subtype C Nef has recently exhibited an association with enhanced HLA-B downregulation function and decreased susceptibility to recognition by CD8+ T cells. We therefore hypothesized this Nef genotype leads to diminished immune control mediated by protective HLA alleles. / Methods: Nef sequences were isolated from HIV-1 subtype C-infected patients harboring protective alleles and several Nef functions including downregulation of HLA-A, HLA-B, CD4, and SERINC5 were examined. Association between Nef non-Ser9 and plasma viral load was examined in two independent South African and Botswanan treatment-naïve cohorts. / Results: Nef clones isolated from protective allele+ individuals encoding Nef non-Ser9 variant exhibited greater ability to downregulate HLA-B when compared with the Ser9 variant, while other Nef functions including HLA-A, CD4, and SERINC5 downregulation activity were unaltered. By analyzing a cohort of South African participants chronically infected with subtype C HIV-1, Nef non-Ser9 associated with higher plasma viral load in patients harboring protective alleles. Corroboratively, the Nef non-Ser9 correlated with higher plasma viral load in an independent cohort in Botswana. / Conclusion: Taken together, our study identifies the Nef genotype, non-Ser9 that subverts host immune control in HIV-1 subtype C infection

Boys are more stunted than girls in Sub-Saharan Africa: a meta-analysis of 16 demographic and health surveys

BACKGROUND: Many studies in sub-Saharan Africa have occasionally reported a higher prevalence of stunting in male children compared to female children. This study examined whether there are systematic sex differences in stunting rates in children under-five years of age, and how the sex differences in stunting rates vary with household socio-economic status. METHODS: Data from the most recent 16 demographic and health surveys (DHS) in 10 sub-Saharan countries were analysed. Two separate variables for household socio-economic status (SES) were created for each country based on asset ownership and mothers' education. Quintiles of SES were constructed using principal component analysis. Sex differentials with stunting were assessed using Student's t-test, chi square test and binary logistic regressions. RESULTS: The prevalence and the mean z-scores of stunting were consistently lower amongst females than amongst males in all studies, with differences statistically significant in 11 and 12, respectively, out of the 16 studies. The pooled estimates for mean z-scores were -1.59 for boys and -1.46 for girls with the difference statistically significant (p < 0.001). The stunting prevalence was also higher in boys (40%) than in girls (36%) in pooled data analysis; crude odds ratio 1.16 (95% CI 1.12–1.20); child age and individual survey adjusted odds ratio 1.18 (95% CI 1.14–1.22). Male children in households of the poorest 40% were more likely to be stunted compared to females in the same group, but the pattern was not consistent in all studies, and evaluation of the SES/sex interaction term in relation to stunting was not significant for the surveys. CONCLUSION: In sub-Saharan Africa, male children under five years of age are more likely to become stunted than females, which might suggest that boys are more vulnerable to health inequalities than their female counterparts in the same age groups. In several of the surveys, sex differences in stunting were more pronounced in the lowest SES groups

CEREBRAL VENOUS SINUS THROMBOSIS: A REPORT OF TWO CASES

Cerebral venous sinus thrombosis is an uncommon yet potentially life threatening condition which is often under-diagnosed or misdiagnosed because of the variability of the clinical signs and symptoms. The imaging findings are often subtle thus the need for a high index of suspicion. The superior sagittal and transverse sinuses are the most frequently involved. The correct diagnosis of cerebral venous thrombosis relies on neuroimaging studies. The two cases reported highlight the fact that the radiologistmay be the first clinician to suspect and diagnose this condition. This ultimately affects prognosis as early diagnosis and treatment reduces morbidity and mortality

The effect of habitat type on population distribution and abundance of Rothschilds Giraffe (Giraffa camelopardalis rothschildi) in Ruma National Park and Mwea National Reserve in Kenya

The Rothschilds giraffe is currently listed as vulnerable by the International Union for Conservation of Nature (IUCN). This is attributed to the loss of habitat due to human activities. This study examined the effect of habitat type on population structure and distribution of Rothschilds giraffe in Ruma National Park (RNP) and Mwea National Reserve (MNR) in Kenya. The study employed road transects to collect data on the number, age class and sex distribution in three habitat types, open, medium and closed. Data was collected along three road transects of equal lengths measuring 14.2 km in each site (RNP and MNR) for comparison. A driving speed of 20 km per hour was maintained along each transect for standardization of survey effort and a maximum giraffe detection rate. Photographic capture of the coat patterns of the right side of all the giraffes sighted within 500 m from the transect was done for identification of age classes. The field visits were replicated 12 times for each transect giving 36 replications for each site spread equally through wet and dry seasons from March 2017 to November 2018. The effect of habitat type on population structure and distribution was analysed using ANOVA and Tukey HSD to test for significant differences. T-test was used to compare the mean population size of giraffe across the wet and dry seasons. Coat pattern analysis for age class identification was done using WildID software. The findings indicated that MNR had more males to females compared to RNP that registered more females and calves. Habitat type had a significant effect on the distribution of giraffes. The giraffe population showed a preference for medium habitat types. The findings are key for the management of habitat quality for giraffe populations at the interface where conservation areas overlap with human land use

Carbon Sequestration in Agroforestry Systems Between Conservation Agriculture and Conventional Practice in the Asal Area of Machakos County, Kenya

Dryland ecosystems have always been prone to relatively high vegetation and general environmental degradation; translating to changes in soil physical and chemical properties and massive carbon losses. Despite their vast surface area, Carbon sequestration therein still remains low. However, this low carbon means they are less saturated and therefore a tremendous potential therein to sequester more Carbon. Conservation agriculture with trees (CAWT) presents an opportunity to reduce the degradation and enhance the carbon stocks. This study was set to compare the biomass productivity and carbon sequestration potential of agroforestry between conventional and conservation agriculture practice. The&nbsp; study was carried out as part of ongoing experimentation established in short rain (SR) season of 2012 by the World Agroforestry Centre in a trial site at the Agricultural Training Centre (ATC) in Machakos county, Kenya. The trials adopted a split plot arranged in a randomized complete block design with two farming systems (conventional and conservation agriculture) as the main blocks, 7 treatments and three replicates, summing to a total of 42 plots. In the fields, two shrub species (Calliandra calothyrsus Meissn. and Gliricidia sepium Jacq.) were planted in three different spacing (1.5x1 m, 3x1 m, 4.5x1 m) for maize-legume intercrops. Trees were harvested by coppicing, weighed and leaf/twig samples taken for determination of biomass, which was then converted to Carbon using a conversion factor 0.5. The data was statistically analyzed using ANOVA and means separated using LSD at p &lt;0.05. Results showed significant increase in carbon sequestration under conservation agriculture (p &lt;0.001), with a yearly sequestration potential of between 12.8 and 24 Mg C/ha/yr compared to 11.6-23 Mg C/ha/yr for conventional practice. Calliandra also sequestered more carbon than Gliricidia. CAWT is therefore concluded to be a feasible way of increasing carbon stocks in the drylands

Ultrastructure of the gastro intestinal tract of healthy Japanese quail (Coturnix japonica) using light and scanning electron microscopy

The Japanese quail (Coturnix japonica) are popular both as an alternative protein source and as a model of choice for scientific research in several disciplines. There is limited published information on the histological features of the intestinal tract of Japanese quail. The only comprehensive reference is a book published in 1969. This study aims to fill that niche by providing a reference of general histological features of the Japanese quail, covering all the main sections of the intestinal tract. Both light and scanning electron microscope (SEM) images are presented. Results showed that the Japanese quail intestinal tract is very similar to that of the chicken with the exception of the luminal koilin membrane of the gizzard. Scanning electron microscopic photomicrographs show that in the Japanese quail koilin vertical rods are tightly packed together in a uniform manner making a carpet-like appearance. This differs in chicken where the conformations of vertical rods are arranged in clusters. © 2018 Chinese Association of Animal Science and Veterinary Medicin

Integrating common and rare genetic variation in diverse human populations.

Despite great progress in identifying genetic variants that influence human disease, most inherited risk remains unexplained. A more complete understanding requires genome-wide studies that fully examine less common alleles in populations with a wide range of ancestry. To inform the design and interpretation of such studies, we genotyped 1.6 million common single nucleotide polymorphisms (SNPs) in 1,184 reference individuals from 11 global populations, and sequenced ten 100-kilobase regions in 692 of these individuals. This integrated data set of common and rare alleles, called 'HapMap 3', includes both SNPs and copy number polymorphisms (CNPs). We characterized population-specific differences among low-frequency variants, measured the improvement in imputation accuracy afforded by the larger reference panel, especially in imputing SNPs with a minor allele frequency o