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It is well established that milk composition is affected by the breed and genotype of a cow. The present study investigated the relationship between the proportion of exotic genes and milk composition in Tanzanian crossbred dairy cows. Milk samples were collected from 209 animals kept under smallholder production systems in Rungwe and Lushoto districts of Tanzania. The milk samples were analyzed for the content of components including fat, protein, casein, lactose, solids-not-fat (SNF), and the total solids (TS) through infrared spectroscopy using Milko-Scan FT1 analyzer (Foss Electric, Denmark). Hair samples for DNA analysis were collected from individual cows and breed composition determined using 150,000 single nucleotide polymorphism (SNP) markers. Cows were grouped into four genetic classes based on the proportion of exotic genes present: 25–49, 50–74, 75–84, and >84%, to mimic a backcross to indigenous zebu breed, F1, F2, and F3 crosses, respectively. The breed types were defined based on international commercial dairy breeds as follows: RG (Norwegian Red X Friesian, Norwegian Red X Guernsey, and Norwegian Red X Jersey crosses); RH (Norwegian Red X Holstein crosses); RZ (Norwegian Red X Zebu and Norwegian Red X N’Dama crosses); and ZR (Zebu X GIR, Zebu X Norwegian Red, and Zebu X Holstein crosses). Results obtained indicate low variation in milk composition traits between genetic groups and breed types. For all the milk traits except milk total protein and casein content, no significant differences (p < 0.05) were observed among genetic groups. Protein content was significantly (p < 0.05) higher for genetic group 75–84% at 3.4 ± 0.08% compared to 3.18 ± 0.07% for genetic group >84%. Casein content was significantly lower for genetic group >84% (2.98 ± 0.05%) compared to 3.18 ± 0.09 and 3.16 ± 0.06% for genetic group 25–49 and 75–84%, respectively (p < 0.05). There was no significant difference (p < 0.05) between breed types with respect to milk composition traits. These results suggest that selection of breed types to be used in smallholder systems need not pay much emphasis on milk quality differences as most admixed animals would have similar milk composition profiles. However, a larger sample size would be required to quantify any meaningful differences between groups.

Background: Increased resistance against antimicrobial medication used to combat bacterial infection necessitates the need for alternative medication. Objective: This study seeks to evaluate the antimicrobial potential and phytochemical profiles of 10 medicinal plants collected from Chuka, Tharaka-Nithi County of Kenya. Plant samples were collected, dried, pulverised into fine powders and extracted with distilled water. Methodology: Qualitative phytochemical screening and disc-agar diffusion methods were used according to standard method to determine phytochemical profile and antimicrobial activity of the aqueous extracts against four bacterial strains and a fungus. Results: Phytochemical investigation revealed the presence of terpenoids, tannins and reducing sugars in all the plants except one. Saponins were found to be present in Albizia anthelmintica, Entada leptostachya, Raponae rhododendroides and Warbugia ugandensis. Steroids were present in seven plants while alkaloids were present in five. Albizia anthelmintica, E. leptostachya and W. ugandensis extracts were active against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans. Escherichia coli was the most susceptible bacteria against all the plant extracts tested, except Harrisonia abyssinica. Vernonia lasiopus and Uvariodendron anisatum were the least active extracts. Susceptibility against E. coli and C. albicans was significantly comparable to benzathine penicillin and streptomycin. Conclusion: The type of ailments the plants are claimed to treat can be attributed to the presence of various classes of phytochemicals. In conclusion, the plants evaluated were found to be active against the microorganisms tested.

Background: Natural phytoconstituents produced by plants for their sustenance have been reported to reduce disease. Objectives: This study determined the phytoconstituents, antioxidant and antimicrobial activity of crude methanolic extracts of Entada leptostachya and Prosopis juliflora extracts. Methodology: Antioxidant activity was determined using 2,2-diphenyl-1-picrylhydrazyl and β-carotene assays; the total phenolic and flavonoid were estimated using Folin–Ciocalteau and aluminium chloride, whereas antimicrobial activity was determined using the zone of inhibition method. Results: Screening of the extracts revealed the presence of terpenoids, flavonoids, saponins and phenols. Fourier transform infrared spectra of the extracts revealed presence of hydrogen bonded –OH functional group. E. leptostachya barks had the highest antioxidant activity followed by P. juliflora roots, E. leptostachya roots and P. juliflora leaves [μg/mL]. Prosopis juliflora (roots) had the highest bleaching effect, whereas E. leptostachya (barks) had the lowest bleaching effect. The total flavonoids were determined to be 0.15 ± 0.02 mg/g, 1.18 ± 0.18 mg/g, 0.39 ± 0.05 mg/g and 0.64 ± 0.03 mg/g for E. leptostachya roots, E. leptostachya barks, P. juliflora leaves and P. juliflora roots extracts, respectively. The total phenols were determined to be 0.93 ± 0.18 mg/g, 2.69 ± 0.41 mg/g, 0.62 ± 0.08 mg/g and 0.62 ± 0.08 mg/g for E. leptostachya roots, E. leptostachya barks, P. juliflora roots and P. juliflora leaves extracts. All plant extracts exhibited moderate activity against the growth of selected microorganisms. Conclusion: Antimicrobial and antioxidant activity of the two plants was as a result of secondary metabolites found in the crude extracts.

Anthracnose disease of avocado contributes to a huge loss of avocado fruits due to postharvest rot in Kenya. The causal agent of this disease has not been clear but presumed to be Colletotrichum gloeosporioides as reported in other regions where avocado is grown. The fungus mainly infects fruits causing symptoms such as small blackish spots, “pepper spots,” and black spots with raised margin which coalesce as infection progresses. Due to economic losses associated with the disease and emerging information of other species of fungi as causal agents of the disease, this study was aimed at identifying causal agent(s) of the disease. A total of 80 fungal isolates were collected from diseased avocado fruits in Murang’a County, the main avocado growing region in Kenya. Forty-six isolates were morphologically identified as Colletotrichum spp. based on their cultural characteristics, mainly whitish, greyish, and creamish colour and cottony/velvety mycelia on the top side of the culture and greyish cream with concentric zonation on the reverse side. Their spores were straight with rounded end and nonseptate. Thirty-four isolates were identified as Pestalotiopsis spp. based on their cultural characteristics: whitish grey mycelium with black fruiting structure on the upper side and greyish black one on the lower side and septate spores with 3-4 septa and 2 or 3 appendages at one end. Further molecular studies using ITS indicated Colletotrichum gloeosporioides, Colletotrichum boninense, and Pestalotiopsis microspora as the causal agents of anthracnose disease in avocado. However, with this being the first report, there is a need to conduct further studies to establish whether there is coinfection or any interaction thereof.

The genetic diversity of African pigs, whether domestic or wild has not been widely studied and there is very limited published information available. Available data suggests that African domestic pigs originate from different domestication centers as opposed to international commercial breeds. We evaluated two domestic pig populations in Western Kenya, in order to characterize the genetic diversity, breed composition and admixture of the pigs in an area known to be endemic for African swine fever (ASF). One of the reasons for characterizing these specific populations is the fact that a proportion of indigenous pigs have tested ASF virus (ASFv) positive but do not present with clinical symptoms of disease indicating some form of tolerance to infection. Pigs were genotyped using either the porcine SNP60 or SNP80 chip. Village pigs were sourced from Busia and Homabay counties in Kenya. Because bush pigs (Potamochoerus larvatus) and warthogs (Phacochoerus spp.) are known to be tolerant to ASFv infection (exhibiting no clinical symptoms despite infection), they were included in the study to assess whether domestic pigs have similar genomic signatures. Additionally, samples representing European wild boar and international commercial breeds were included as references, given their potential contribution to the genetic make-up of the target domestic populations. The data indicate that village pigs in Busia are a non-homogenous admixed population with significant introgression of genes from international commercial breeds. Pigs from Homabay by contrast, represent a homogenous population with a "local indigenous' composition that is distinct from the international breeds, and clusters more closely with the European wild boar than African wild pigs. Interestingly, village pigs from Busia that tested negative by PCR for ASFv genotype IX, had significantly higher local ancestry (>54%) compared to those testing positive, which contained more commercial breed gene introgression. This may have implication for breed selection and utilization in ASF endemic areas. A genome wide scan detected several regions under preferential selection with signatures for pigs from Busia and Homabay being very distinct. Additionally, there was no similarity in specific genes under selection between the wild pigs and domestic pigs despite having some broad areas under similar selection signatures. These results provide a basis to explore possible genetic determinants underlying tolerance to infection by ASFv genotypes and suggests multiple pathways for genetically mediated ASFv tolerance given the diversity of selection signatures observed among the populations studied.

The nonsense mediated RNA decay (NMD) pathway safeguards the integrity of the transcriptome by targeting mRNAs with premature translation termination codons (PTCs) for degradation. It also regulates gene expression by degrading a large number of non-mutant RNAs (including mRNAs and noncoding RNAs) that bear NMD-inducing features. Consequently, NMD has been shown to influence development, cellular response to stress, and clinical outcome of many genetic diseases. Small molecules that can modulate NMD activity provide critical tools for understanding the mechanism and physiological functions of NMD, and they also offer potential means for treating certain genetic diseases and cancer. Therefore, there is an intense interest in identifying small-molecule NMD inhibitors or enhancers. It was previously reported that both inhibition of NMD and treatment with the AMPK-selective inhibitor Compound C (CC) induce autophagy in human cells, raising the possibility that CC may be capable of inhibiting NMD. Here we show that CC indeed has a NMD-inhibitory activity. Inhibition of NMD by CC is, however, independent of AMPK activity. As a competitive ATP analog, CC does not affect the kinase activity of SMG1, an essential NMD factor and the only known kinase in the NMD pathway. However, CC treatment down-regulates the protein levels of several NMD factors. The induction of autophagy by CC treatment is independent of ATF4, a NMD target that has been shown to promote autophagy in response to NMD inhibition. Our results reveal a new activity of CC as a NMD inhibitor, which has implications for its use in basic research and drug development.

Colletotrichum gloeosporioides is a serious postharvest pathogen of avocado fruits worldwide. Kenya lacks any registered fungicides for the management of the disease. Nevertheless, farmers commonly use commercially available fungicides such as Bayleton 25WP (Triadimefon 250 g/Kg), Milraz 76WP (Propineb 70% and Cymoxanil 6%), and Copper oxychloride 500WP for disease management. The efficacy of these fungicides against C. gloeosporioides is not known. The purpose of this study was therefore to test the inhibitory effect of these fungicides against 46 C. gloeosporioides isolates from avocado fruits collected from varieties grown at different agroecological zones in Murang’a County, a popular avocado-growing region in Kenya. Mycelial growth rate and sporulation for each isolate were measured in vitro on PDA plates amended with different concentrations of the fungicides. Plates were arranged in a completely randomized design with three replications per treatment. All fungicides were effective in vitro but there were significant differences in sensitivity among isolates. Bayleton had the highest mycelial inhibition followed by Milraz, while copper oxychloride had the lowest mycelial inhibition rates, ranging from 81% to 88%. However, copper oxychloride was more effective in inhibiting sporulation. The inhibitory effect of each fungicide was concentration-dependent, where twice the recommended concentration had the highest inhibitory effect, followed by the recommended concentration. Our results show that the fungicides used by farmers against C. gloeosporioides, the causal agent for anthracnose, are effective. We, however, recommend further field tests in different avocado-growing areas so as to validate their efficacy against various isolates and under different environments.

: Introduction: Many HIV‐positive individuals in Africa have advanced disease when initiating antiretroviral therapy (ART) so have high risks of opportunistic infections and death. The REALITY trial found that an enhanced‐prophylaxis package including fluconazole reduced mortality by 27% in individuals starting ART with CD4 Methods: The REALITY trial enrolled from June 2013 to April 2015. A decision‐analytic model was developed to estimate the cost‐effectiveness of six management strategies in individuals initiating ART in the REALITY trial countries. Strategies included standard‐prophylaxis, enhanced‐prophylaxis, standard‐prophylaxis with fluconazole; and three CrAg testing strategies, the first stratifying individuals to enhanced‐prophylaxis (CrAg‐positive) or standard‐prophylaxis (CrAg‐negative), the second to enhanced‐prophylaxis (CrAg‐positive) or enhanced‐prophylaxis without fluconazole (CrAg‐negative) and the third to standard‐prophylaxis with fluconazole (CrAg‐positive) or without fluconazole (CrAg‐negative). The model estimated costs, life‐years and quality‐adjusted life‐years (QALY) over 48 weeks using three competing mortality risks: cryptococcal meningitis; tuberculosis, serious bacterial infection or other known cause; and unknown cause. Results: Enhanced‐prophylaxis was cost‐effective at cost‐effectiveness thresholds of US$300 and US$500 per QALY with an incremental cost‐effectiveness ratio (ICER) of US$157 per QALY in the CD4 Conclusions: The REALITY enhanced‐prophylaxis package in individuals with advanced HIV starting ART reduces morbidity and mortality, is practical to administer and is cost‐effective. Efforts should continue to ensure that components are accessed at lowest available prices., Introduction In low‐ and middle‐income settings, more than a third of HIV‐positive individuals starting antiretroviral therapy (ART) present with advanced disease (CD4 ≤ 200 cells/mm[sup.3]); over half of these have [...]

The Plasmodium falciparum in vitro culture system is critical for genotypic and phenotypic analyses of the parasites. For genotypic analysis, the genomic DNA can be obtained directly from the patient blood sample or from culture adapted parasites whereas for phenotypic analysis, immediate ex vivo or in vitro culture adapted parasites are used. However, parasite biology studies have not investigated whether culture adaptation process affects genotypic and/or phenotypic characteristics of the parasites in short- or long-term cultures. Here, we set out to study the dynamics and stability of parasite genetic and phenotypic profiles as field isolate parasites were adapted in continuous cultures. Parasites collected from three different patients presenting with uncomplicated malaria were adapted and maintained in drug-free continuous cultures. Aliquots from the continuous cultures were collected every 24-48 hours for analyses. Each aliquot was treated as a separate parasite sample. For genetic analysis, microsatellite (MS) typing and single nucleotide polymorphism (SNP) analyses of 23 drug resistance markers were done. The 50% inhibitory concentrations (IC50) for some of the samples were also established for four antimalarial drugs. Samples from each patient (parasite-line) were compared as they were passed through the continuous culture. Data revealed genotypic and phenotypic profiles for the three parasite-lines fluctuated from one generation to the next with no specific pattern or periodicity. With few exceptions, multilocus analysis revealed samples from each parasite-line had high genetic diversity with unique haplotypes. Interestingly, changes in MS and SNP profiles occurred simultaneously. The difference in the IC50s of samples in each parasite-line reached statistical significance. However, phenotypic changes did not correspond or correlate to genotypic changes. Our study revealed parasite genetic and phenotypic characteristics fluctuates in short- and long-term cultures, which indicates parasite genetic information obtained even in short cultures is likely to be different from the natural infection parasites.

Large-scale schistosomiasis control programs are implemented in regions with diverse social and economic environments. A key epidemiological feature of schistosomiasis is its small-scale heterogeneity. Locally profiling disease dynamics including risk factors associated with its transmission is essential for designing appropriate control programs. To determine spatial distribution of schistosomiasis and its drivers, we examined schoolchildren in Kwale, Kenya.We conducted a cross-sectional study of 368 schoolchildren from six primary schools. Soil-transmitted helminths and Schistosoma mansoni eggs in stool were evaluated by the Kato-Katz method. We measured the intensity of Schistosoma haematobium infection by urine filtration. The geometrical mean intensity of S. haematobium was 3.1 eggs/10 ml urine (school range, 1.4-9.2). The hookworm geometric mean intensity was 3.2 eggs/g feces (school range, 0-17.4). Heterogeneity in the intensity of S. haematobium and hookworm infections was evident in the study area. To identify factors associated with the intensity of helminth infections, we utilized negative binomial generalized linear mixed models. The intensity of S. haematobium infection was associated with religion and socioeconomic status (SES), while that of hookworm infection was related to SES, sex, distance to river and history of anthelmintic treatment.Both S. haematobium and hookworm infections showed micro-geographical heterogeneities in this Kwale community. To confirm and explain our observation of high S. haematobium risk among Muslims, further extensive investigations are necessary. The observed small scale clustering of the S. haematobium and hookworm infections might imply less uniform strategies even at finer scale for efficient utilization of limited resources.

Malaria causes about half a million deaths annually, with Plasmodium falciparum being responsible for 90% of all the cases. Recent reports on artemisinin resistance in Southeast Asia warrant urgent discovery of novel drugs for the treatment of malaria. However, most bioactive compounds fail to progress to treatments due to safety concerns. Drug repositioning offers an alternative strategy where drugs that have already been approved as safe for other diseases could be used to treat malaria. This study screened approved drugs for antimalarial activity using an in silico chemogenomics approach prior to in vitro verification. All the P. falciparum proteins sequences available in NCBI RefSeq were mined and used to perform a similarity search against DrugBank, TTD and STITCH databases to identify similar putative drug targets. Druggability indices of the potential P. falciparum drug targets were obtained from TDR targets database. Functional amino acid residues of the drug targets were determined using ConSurf server which was used to fine tune the similarity search. This study predicted 133 approved drugs that could target 34 P. falciparum proteins. A literature search done at PubMed and Google Scholar showed 105 out of the 133 drugs to have been previously tested against malaria, with most showing activity. For further validation, drug susceptibility assays using SYBR Green I method were done on a representative group of 10 predicted drugs, eight of which did show activity against P. falciparum 3D7 clone. Seven had IC50 values ranging from 1 μM to 50 μM. This study also suggests drug-target association and hence possible mechanisms of action of drugs that did show antiplasmodial activity. The study results validate the use of proteome-wide target similarity approach in identifying approved drugs with activity against P. falciparum and could be adapted for other pathogens.

To compare the vaginal microbiota of women engaged in high-risk sexual behaviour (sex work) with women who are not engaged in high-risk sexual behaviour. Diverse vaginal microbiota, low in Lactobacillus species, like those in bacterial vaginosis (BV), are associated with increased prevalence of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV) acquisition. Although high-risk sexual behaviour increases risk for STIs, the vaginal microbiota of sex workers is understudied.A retrospective cross-sectional study was conducted comparing vaginal microbiota of women who are not engaged in sex work (non-sex worker controls, NSW, N = 19) and women engaged in sex work (female sex workers, FSW, N = 48), using Illumina sequencing (16S rRNA, V3 region).Bacterial richness and diversity were significantly less in controls, than FSW. Controls were more likely to have Lactobacillus as the most abundant genus (58% vs. 17%; P = 0.002) and composition of their vaginal microbiota differed from FSW (PERMANOVA, P = 0.001). Six microbiota clusters were detected, including a high diversity cluster with three sub-clusters, and 55% of women with low Nugent Scores fell within this cluster. High diversity was observed by 16S sequencing in FSW, regardless of Nugent Scores, suggesting that Nugent Score may not be capable of capturing the diversity present in the FSW vaginal microbiota.High-risk sexual behaviour is associated with diversity of the vaginal microbiota and lack of Lactobacillus. These factors could contribute to increased risk of STIs and HIV in women engaged in high-risk sexual behaviour.

Harvesting stage of sweet sorghum (Sorghum bicolor L. Moench) cane is an important aspect in the content of sugar for production of industrial alcohol. Four sweet sorghum genotypes were evaluated for harvesting stage in a randomized complete block design. In order to determine sorghum harvest growth stage for bioethanol production, sorghum canes were harvested at intervals of seven days after anthesis. The genotypes were evaluated at different stages of development for maximum production of bioethanol from flowering to physiological maturity. The canes were crushed and juice fermented to produce ethanol. Measurements of chlorophyll were taken at various stages as well as panicles from the harvested canes. Dried kernels at 14% moisture content were also weighed at various stages. Chlorophyll, grain weight, absolute ethanol volume, juice volume, cane yield, and brix showed significant (p=0.05) differences for genotypes as well as the stages of harvesting. Results from this study showed that harvesting sweet sorghum at stages IV and V (104 to 117 days after planting) would be appropriate for production of kernels and ethanol. EUSS10 has the highest ethanol potential (1062.78 l ha−1) due to excellent juice volume (22976.9 l ha−1) and EUSS11 (985.26 l ha−1) due to its high brix (16.21).

In various surveys, presence of measurement errors has led to misleading results in estimation of various population parameters. This study indicates the effects of measurement errors on estimates of population total and population variance when samples are drawn using systematic sampling technique from a stratified population. A finite population was generated through simulation. The population was then stratified into four strata followed by generation of ten samples in each of them using systematic sampling technique. In each stratum a sample was picked at random. The findings of this work indicated that systematic errors affected the accuracy of the estimates by overestimating both the population total and the population variance. Random errors only added variability to the data but their effect on the estimates of the population total and population variance was not that profound.

Hoseah M Akala, Angela O Achieng, Fredrick L Eyase, Dennis W Juma, Luiser Ingasia, Agnes C Cheruiyot, Charles Okello, Duke Omariba, Eunice A Owiti, Catherine Muriuki, Redemptah Yeda, Ben Andagalu, Jacob D Johnson, Edwin Kamau Global Emerging Infections Surveillance Program, United States Army Medical Research Unit-Kenya, Kenya Medical Research Institute, Walter Reed Project, Kisumu and Nairobi, Kenya Background: The renewed malaria eradication efforts require an understanding of the seasonal patterns of frequency of polymorphic variants in order to focus limited funds productively. Although cross-sectional studies in holoendemic areas spanning a single year could be useful in describing parasite genotype status at a given point, such information is inadequate in describing temporal trends in genotype polymorphisms. For Plasmodium falciparum isolates from Kisumu District Hospital, Plasmodium falciparum chloroquine-resistance transporter gene (Pfcrt-K76T) and P. falciparum multidrug resistance gene 1 (PfMDR1-N86Y), were analyzed for polymorphisms and parasitemia changes in the 53 months from March 2008 to August 2012. Observations were compared with prevailing climatic factors, including humidity, rainfall, and temperature. Methods: Parasitemia (the percentage of infected red blood cells per total red blood cells) was established by microscopy for P. falciparum malaria-positive samples. P. falciparum DNA was extracted from whole blood using a Qiagen DNA Blood Mini Kit. Single nucleotide polymorphism identification at positions Pfcrt-K76T and PfMDR1-N86Y was performed using real-time polymerase chain reaction and/or sequencing. Data on climatic variables were obtained from http://www.tutiempo.net/en/. Results: A total of 895 field isolates from 2008 (n=169), 2009 (n=161), 2010 (n=216), 2011 (n=223), and 2012 (n=126) showed large variations in monthly frequency of PfMDR1-N86Y and Pfcrt-K76T as the mutant genotypes decreased from 68.4%±15% and 38.1%±13% to 29.8%±18% and 13.3%±9%, respectively. The mean percentage of parasitemia was 2.61%±1.01% (coefficient of variation 115.86%; n=895). There was no correlation between genotype or parasitemia and climatic factors. Conclusion: This study shows variability in the frequency of Pfcrt-K76T and PfMDR1-N86Y polymorphisms during the study period, bringing into focus the role of cross-sectional studies in describing temporal genotype trends. The lack of correlation between genotypes and climatic changes, especially precipitation, emphasizes the cost of investment in genotype change. Keywords: PfMDR1-N86Y, Pfcrt-K76T, polymorphism, parasitemia

Delineation of aquatic plants and estimation of its surface extent are crucial to the efficient control of its proliferation, and this information can be derived accurately with fine resolution remote sensing products. However, small swath and low observation frequency associated with them may be prohibitive for application to large water bodies with rapid proliferation and dynamic floating aquatic plants. The information can be derived from products with large swath and high observation frequency, but with coarse resolution; and the quality of so derived information must be eventually assessed using finer resolution data. In this study, we evaluate two methods: Normalized Difference Vegetation Index (NDVI) slicing and maximum likelihood in terms of delineation; and two methods: Gutman and Ignatov’s NDVI-based fractional cover retrieval and linear spectral unmixing in terms of area estimation of aquatic plants from 300 m Medium Resolution Imaging Spectrometer (MERIS) data, using as reference results obtained with 30 m Landsat-7 ETM+. Our results show for delineation, that maximum likelihood with an average classification accuracy of 80% is better than NDVI slicing at 75%, both methods showing larger errors over sparse vegetation. In area estimation, we found that Gutman and Ignatov’s method and spectral unmixing produce almost the same root mean square (RMS) error of about 0.10, but the former shows larger errors of about 0.15 over sparse vegetation while the latter remains invariant. Where an endmember spectral library is available, we recommend the spectral unmixing approach to estimate extent of vegetation with coarse resolution data, as its performance is relatively invariant to the fragmentation of aquatic vegetation cover.

The appraisal of crop water requirements (CWR) is crucial for the management of water resources, especially in arid and semi-arid regions where irrigation represents the largest consumer of water, such as the Doukkala area, western Morocco. Simple and (semi) empirical approaches have been applied to estimate CWR: the first one is called Kc-NDVI method, based on the correlation between the Normalized Difference Vegetation Index (NDVI) and the crop coefficient (Kc); the second one is the analytical approach based on the direct application of the Penman-Monteith equation with reflectance-based estimates of canopy biophysical variables, such as surface albedo (r), leaf area index (LAI) and crop height (hc). A time series of high spatial resolution RapidEye (REIS), SPOT4 (HRVIR1) and Landsat 8 (OLI) images acquired during the 2012/2013 agricultural season has been used to assess the spatial and temporal variability of crop evapotranspiration ETc and biophysical variables. The validation using the dual crop coefficient approach (Kcb) showed that the satellite-based estimates of daily ETc were in good agreement with ground-based ETc, i.e., R2 = 0.75 and RMSE = 0.79 versus R2 = 0.73 and RMSE = 0.89 for the Kc-NDVI, respective of the analytical approach. The assessment of irrigation performance in terms of adequacy between water requirements and allocations showed that CWR were much larger than allocated surface water for the entire area, with this difference being small at the beginning of the growing season. Even smaller differences were observed between surface water allocations and Irrigation Water Requirements (IWR) throughout the irrigation season. Finally, surface water allocations were rather close to Net Irrigation Water Requirements (NIWR).

Temporal variability analysis of rainfall and river discharges is useful in determining the likelihood of the occurrence of extreme events such as drought or flooding for the purposes of developing policies to mitigate their effects. This study investigated the temporal variability of rainfall and discharges into Lake Nakuru, Kenya using meteorological drought indicators and hydrological drought indicators from 1981 to 2018. The standardized precipitation index (SPI) and standardized precipitation evaporation index (SPEI) were used to characterize meteorological drought, while the streamflow drought index (SDI) was used to characterize hydrological drought. A SWAT model was applied for the prediction of streamflow on five tributaries of Lake Nakuru (Njoro, Ngosur, Nderit, Larmudiac, and Makalia Rivers). The model was successfully calibrated on Njoro River at the upstream of river gauging station 2FCO5 from 1984 to 1996, and the parameters were validated from 1997 to 2007. The SUFI-2 algorithm was applied in SWATCup to perform the calibration of the model. The model performance was considered satisfactory in daily time step (NSE = 0.58, R2 = 0.58 during calibration and NSE = 0.52, R2 = 0.68 during validation). The average annual water balance revealed that out of 823 mm received annual precipitation, 154 mm was surface runoff and 178 mm was the annual average water yield. The average annual actual evapotranspiration (ET) was 607 mm. The results for the temporal variation of the SPI and SDI for the five subcatchments indicated that the drought events identified by the 12-month SPI/SPEI were almost all identified by the 12-month SDI. At the catchment scale, SPI showed an equal distribution of wet and dry periods, with 50.00% of positive anomalies and 50.00% of negative anomalies being observed from 1981 to 2018, while SDI observes a high frequency of dry periods (52.63%) and a lower frequency of wet periods (47.37%). There is a higher frequency of wet periods compared to dry periods for both indices from 2009 to 2010 at 60.00% and 40.00% for SPI and 90.00% and 10.00% for SDI, respectively. Both indices observed that 1984 and 2000 were severely dry years (SPI/SPEI < −2.00), while 2018 was severely wet (SPI/SPEI > 2.00). The results for the variability in rainfall and streamflow indices revealed that the last 10 years (2009−2018) were wetter than the period from 1981 to 2008.

Genetically determined artemisinin resistance in Plasmodium falciparum has been described in Southeast Asia. The relevance of recently described Kelch 13-propeller mutations for artemisinin resistance in Sub-Saharan Africa parasites is still unknown. Southeast Asia parasites have low genetic diversity compared to Sub-Saharan Africa, where parasites are highly genetically diverse. This study attempted to elucidate whether genetics provides a basis for discovering molecular markers in response to artemisinin drug treatment in P. falciparum in Kenya. The genetic diversity of parasites collected pre- and post- introduction of artemisinin combination therapy (ACT) in western Kenya was determined. A panel of 12 microsatellites and 91 single nucleotide polymorphisms (SNPs) distributed across the P. falciparum genome were genotyped. Parasite clearance rates were obtained for the post-ACT parasites. The 12 microsatellites were highly polymorphic with post-ACT parasites being significantly more diverse compared to pre-ACT (p < 0.0001). The median clearance half-life was 2.55 hours for the post-ACT parasites. Based on SNP analysis, 15 of 90 post-ACT parasites were single-clone infections. Analysis revealed 3 SNPs that might have some causal association with parasite clearance rates. Further, genetic analysis using Bayesian tree revealed parasites with similar clearance phenotypes were more closely genetically related. With further studies, SNPs described here and genetically determined response to artemisinin treatment might be useful in tracking artemisinin resistance in Kenya.

The genotype and environment interaction influences the selection criteria of sorghum (Sorghum bicolor) genotypes. Eight sweet sorghum genotypes were evaluated at five different locations in two growing seasons of 2014. The aim was to determine the interaction between genotype and environment on cane, juice, and ethanol yield and to identify best genotypes for bioethanol production in Kenya. The experiments were conducted in a randomized complete block design replicated three times. Sorghum canes were harvested at hard dough stage of grain development and passed through rollers to obtain juice that was then fermented to obtain ethanol. Cane, juice, and ethanol yield was analyzed using the additive main effect and multiplication interaction model (AMMI) and genotype plus genotype by environment (GGE) biplot. The combined analysis of variance of cane and juice yield of sorghum genotypes showed that sweet sorghum genotypes were significantly (P

The study explained a model of employee social responsibility (ESR) as an antecedent to corporate competitiveness. It hypothesizes that ESR has significant effect on employee competitiveness (EC). Questionnaires were administered to a sample of 700 employees selected from a population of 5,595 from 20 classified hotels in the coastal region of Kenya using proportionate and systematic random sampling methods. Structural equation model was used for model specification and hypotheses testing. Confirmatory factor analysis was performed on six and four constructs representing ESR and EC, respectively. Overall, a negative effect of ESR on EC was found with un-standardized β estimates = −.516; SE = .071, p = .000. Accordingly, increase in employee corporate social responsibility (CSR) is associated with decline in EC. This was potentially paradoxical because employees demonstrated job and organization commitment and retention intention despite poor ESR practices.

The synthesis and characterization of zinc(II) and copper(II) complexes of embelin (1), C17H26O4, are described. Zinc(II) and copper(II) ions reacted with (1) (an orange compound) in a 1:2 ratio to yield purple and green complexes, respectively. IR analysis of the two complexes showed that the metal ions were co-ordinated through the carbonyl and the hydroxyl oxygen atoms. Elemental analyses (AAS and C, H, N) of the complexes gave values that are consistent with six co-ordinate octahedral geometry about the metal ions. Molecular formulae, ZnC34H50N2O14 and CuC34H54O10 for the zinc(II) and copper(II) complexes are proposed.

Single Nucleotide Polymorphisms (SNPs) in the Pfmdr1, and Pfcrt, genes of Plasmodium falciparum may confer resistance to a number of anti-malaria drugs. Pfmdr1 86Y and haplotypes at Pfcrt 72-76 have been linked to chloroquine (CQ) as well as amodiaquine (AQ) resistance. mefloquine (MQ) and lumefantrine (LU) sensitivities are linked to Pfmdr1 86Y. Additionally, Pfcrt K76 allele carrying parasites have shown tolerance to LU. We investigated the association between Pfmdr1 86/Pfcrt 72-76 and P. falciparum resistance to CQ, AQ, MQ and LU using field samples collected during 2008-2011 from malaria endemic sites in western Kenya. Genomic DNA from these samples was genotyped to examine SNPs and haplotypes in Pfmdr1 and Pfcrt respectively. Additionally, immediate ex vivo and in vitro drug sensitivity profiles were assessed using the malaria SYBR Green I fluorescence-based assay. We observed a rapid but steady percent increase in wild-type parasites with regard to both Pfmdr1 and Pfcrt between 2008 and 2011 (p

There is an urgent need to improve our understanding of the mucosal immuno-pathogenesis of HIV acquisition in the female genital tract, particularly in high-risk women such as female sex workers (FSWs). Cervical biopsy samples offer technical advantages over cytobrush sampling, but there are concerns that this might increase HIV acquisition, particularly if healing is slow and/or women do not abstain from sex during healing.Cervical biopsy samples and cervico-vaginal swabs for co-infection diagnostics, prostate specific antigen (PSA) and immune studies were collected from 59 women, including HIV seropositive and HIV-exposed seronegative (HESN) FSWs as well as lower risk women from Nairobi, Kenya. A clinical-demographic questionnaire was administered and women were instructed to avoid sexual intercourse, douching and the insertion of tampons for 14 days. All participants underwent a repeat exam to assess healing within the 14 days, and had HIV diagnostics at six months. Cervical sampling was well tolerated, and 82% of participants had healed macroscopically by 5 days. Both self-report and PSA screening suggested high levels of compliance with pre- and post-procedure abstinence. Delayed healing was associated with vulvovaginal candidiasis (VVC) and HESN status. At six-month follow up all low-risk and HESN participants remained HIV seronegative.Cervical biopsy sampling is a safe and well-tolerated method to obtain cervical biopsies in this context, particularly if participants with VVC are excluded. As healing could be delayed up to 11 days, it is important to support (both financially and with rigorous counseling) a period of post-procedure abstinence to minimize HIV risk.

The need of developing systems that address traffic matters such as traffic control and accidents has led to the development of a number of techniques, methods and tools to address road usability issues. Many automated models have been proposed and applied in different scenarios such as road oddities. Despite of the advantages of these models the major problem of road accidents continue to pose problem globally. This has created the need to come up with more user-effective approaches to address road accidents. Main objective of this research therefore is to identify and address the gap in Location Based Services (LBS). A model that combines RFID and GPS technology to provide Location Based Services via audio alerts to drivers as they approach black spots is presented. The model provides location based services to drivers as they approach black spots causing them to adjust their driving accordingly (i.e. speeding, overtaking). Since LBS technologies have different limitations, most researchers have focused on addressing accuracy limitation by proposing hybrid technologies. Accuracy requirement varies depending on application area. The analysis of the different technologies revealed that in vehicle transportation medium accuracy is effective. This research focused on availability aspect which is a key requirement in LBS. To achieve this a model made up of RFID & GPS is formulated. Higher availability of significant alerts at black spots is registered through simulation as compared to alerts when the technologies are applied separately. Black spot accidents are therefore managed due to safer driving around black spots. This can lead to reduction in exposure to accidents, likelihood of occurrence and impact in the event of an incident. Usability metrics is used to determine effectiveness of the model. [ABSTRACT FROM AUTHOR]

Background: Coronavirus disease 2019 (COVID-19) is a rapidly escalating pandemic that has spread to many parts of the world. As such, there is urgent need to identify predictors of clinical severity in COVID-19 patients. This may be useful for early identification of patients who may require life-saving interventions. In this meta-analysis, we evaluated whether malignancies are associated with a significantly enhanced odds of COVID-19 severity and mortality.Method: A systematic search of literature was conducted between November 1, 2019, to May 26th, 2020 on PubMed and China National Knowledge Infrastructure (CNKI) to identify studies reporting data on cancers in patients with or without severe COVID-19 were included. The primary outcome of interest was the association between malignancies and COVID-19 severity, while the secondary outcome was the association between malignancies and COVID-19 mortality. Data were pooled into a meta-analysis to estimate pooled odds ratio (OR) with 95% confidence interval (95% CI) for either outcome.Results: A total of 20 studies (n = 4549 patients) were included. Overall, malignancies were found to be associated with significantly increased odds of COVID-19 severity (OR = 2.17; 95% CI 1.47-3.196; p < 0.001) and mortality (OR = 2.39; 95% CI 1.18-4.85; p = 0.016). No heterogeneity was observed for both outcomes (Cochran's Q = 6.558, p = 0.922, I2 = 0% and Cochran's Q = 2.91, p = 0.71, I2 = 0% respectively).Conclusion: Malignancies were significantly associated with a 2-fold increase in the odds of developing severe COVID-19 disease, as well as mortality. Larger studies are needed to corroborate these findings. These patients should be closely monitored for any signs of unfavorable disease progression. [ABSTRACT FROM AUTHOR]

Dolichos (Lablab purpureus L.) is a drought tolerant legume used as food/feed and improvement of soil fertility. The production of dolichos in Kenya, Nakuru County is however limited by insect pests like bean aphids, pod borers and whiteflies. Field studies were conducted to determine the effect of cropping systems (dolichos monocrop and maize-dolichos intercrop) and field margin vegetation on bean aphids and their natural enemies. The experiment was conducted in Njoro (high field margin vegetation) and Rongai (low field margin vegetation) during May-December 2019 and March-November 2020 cropping seasons. Bean aphid percent incidence, severity of damage and abundance was assessed at seedling, early vegetative, late vegetative and flowering dolichos growth stages. The populations of natural enemies in the plots and field margin vegetation were monitored using pan traps and sweep nets. Species diversity and composition of the field margin vegetation was determined using a quadrat. Results showed that location and cropping system had significant effects on bean aphid infestations. A high bean aphid incidence (38.13%) was observed in Njoro compared to Rongai (31.10%). Dolichos monocrop had significantly higher bean aphid infestation (51.63%) than the maize-dolichos intercrop system (24.62%). A highly diverse Shannon-weaver index was observed in Rongai (1.90) compared to Njoro (1.67). Dolichos monocrop had a more diverse Shannon-weaver index (1.8) than the maizedolichos intercrop system (1.7). Rongai had the most abundant annual and perennial field margin vegetation species. The field margin species richness and diversity were higher in Rongai (81%) than in Njoro (54%). The findings of this study have demonstrated that a maize-dolichos intercrop in Rongai can reduce bean aphid damage in dolichos. [ABSTRACT FROM AUTHOR]

The aim of this study was to determine the prevalence and anatomic features of major tracheobronchial anomalies. Major electronic databases were systematically searched to identify eligible studies. Data were extracted and pooled into a meta-analysis. The primary outcome was the prevalence of major tracheobronchial anomalies, specifically tracheal bronchus (TB) and accessory cardiac bronchus (ACB). Secondary outcomes included the origin and types of TB and ACB. A total of 27 studies (n = 119,695 patients) were included. A TB was present in 0.99% (95% confidence interval, 0.67 to 1.37) of patients, and an ACB was present in 0.14% (95% confidence interval, 0.09 to 0.20). The overall prevalence of TB was higher in imaging than in operative studies (1.81% vs 0.82%). It was also higher in pediatric (2.55%) than in adult studies (0.50%). Patients with other congenital anomalies were 15 times more likely to have a TB (odds ratio 14.89; 95% confidence interval, 7.09 to 31.22). The most common origin of TBs was from the trachea (81.42%), primarily from the right side (96.43%). The most common origin of ACBs was from the intermediate bronchus (74.32%). The ACBs terminated as blind-ending diverticulum in two thirds of cases. Major tracheobronchial anomalies are present in approximately 1% of the population, although the prevalence is higher among pediatric patients and patients with accompanying congenital anomalies. Although rare, major tracheobronchial anomalies can be associated with significant respiratory morbidities and present challenges during airway management in surgical and critical care patients. Establishing a preoperative diagnosis of these variations is essential for planning and implementing an appropriate airway management strategy to minimize attendant complications. [Display omitted] [ABSTRACT FROM AUTHOR]

The adoption of the Arusha Protocol for the Protection of New Varieties of Plants (Arusha Protocol) in 2015 created a harmonized regional legal mechanism for the protection of plant breeders' rights (PBRs) in the African Regional Intellectual Property Organization (ARIPO) member states. Regrettably, the Arusha Protocol, which is to enter into force after the requisite ratifications, reaffirms the often criticized International Convention for the Protection of New Varieties of Plants of 1991 (UPOV 1991) in its extensive limitation of the traditional farmers' rights to freely save, replant and exchange seeds of protected plant varieties, while liberally conceptualizing PBRs. The stated farmers' rights are essential for the food security of the developing ARIPO member states, as their agriculture is predominantly characterized by impoverished small-scale farmers who rely on informal seed exchanges. On that basis, this article is premised on the view that the legal regime for plant varieties protection established under the Arusha Protocol is inappropriate for ARIPO members as it fails to balance breeders' and farmers' rights in a manner that promotes food security. It proceeds to evaluate the appropriate approach that can suitably balance breeders' and farmers' rights for the purposes of promoting food security in Africa. [ABSTRACT FROM AUTHOR]

Depot medroxyprogesterone acetate (DMPA) is the most common hormonal contraceptive used by women in sub-Saharan Africa, however, it has been epidemiologically associated with HIV infections. To assess whether DMPA has an effect on the number and activation of HIV target cells, this study assessed the levels and phenotype of blood- and mucosal-derived HIV target cells among women using DMPA. Thirty-five HIV uninfected women from the Pumwani Sex Worker cohort from Nairobi, Kenya were enrolled in the study (15 using DMPA and 20 not using hormonal contraception). Blood (plasma and peripheral blood mononuclear cells) and cervicovaginal (lavage, cervical cells, and ectocervical biopsies) samples were collected. Cellular phenotype and activation status were determined by flow cytometry, cytokine levels were assessed by bead array and image analysis assessed cell number and phenotype in situ. In blood, the proportion of HIV target cells and activated T cells was lower in DMPA users versus those not using hormonal contraceptives. However, analysis of cervical mononuclear cells showed that DMPA users had elevated levels of activated T cells (CD4+CD69+) and expressed lower levels of the HIV co-receptor CCR5 on a per cell basis, while tissue samples showed that in the ectocervix, DMPA users had a higher proportion of CD4+CCR5+ T cells. This study demonstrates that DMPA users had higher levels of activated T cells and HIV target cells in the genital tract. The increased pool of mucosal HIV target cells provides new biological information about the potential impact of DMPA on HIV susceptibility. [ABSTRACT FROM AUTHOR]