Modeling the support factor (P) as a function of socio-economic factors for improved erosion prediction on the hillslopes of Lake Victoria Basin of Uganda

A major challenge to erosion prediction using the Universal Soil Loss Equation (USLE) is the uncertainty in parametrizing the support factor (P). This P factor is usually regarded as 1 in areas with no structural management practices. However, in agrarian landscapes which are dominated with agronomic management practices, the P factor is difficult to parameterize. Moreover, the agronomic practices are usually the most simplest and affordable soil and water conservation technologies for mitigating runoff and soil losses in many developing countries. Our objective was to model the support factor (P) as a function of socio-economic factors for adoption of management practices in order to improve erosion prediction. Our methodology involved four (4) steps; namely, (a) estimating potential erosion using RUSLE; (b) establishing the socio-economic for adoption of management practices using Probit regression analysis; (c) integrating socio-economic factors with biophysical parameters to form a Systems Dynamic (SD) model for soil erosion; and (d) validating the Systems Dynamic (SD) model at watershed level using empirical data and RUSLE as the baseline model.  Validation results showed that on Acric Ferralsols at slope gradient 10-15% the potential erosion as predicted by RUSLE model ranged between 120-140 t ha-1yr-1.  On the other hand, soil loss as predicted from the Systems Dynamic (SD) model, based on the same slope gradient and soil condition as the case in RUSLE, ranged between 11-50 t ha-1yr-1. This accounted for about 67-90% decrease in soil loss. Model outputs were calibrated and validated by field data measured using Un-bound runoff plots (Gerlach Troughs). The results showed that in sole banana soil loss increased step-wise with increasing gradient in the measured and predicted data (P < 0.05); while in sole coffee contradicting results were achieved. We concluded that modelling the support factor (P) as a function of socio-economic factors provides a pragmatic solution to the uncertainty in its parameterization. Generalizing the support factor (P) as one (1) even in areas with agronomic management technology tends to over-estimate the risk of soil erosion. Thus, it can potentially stand out as a dis-incentive that undermines farmers’ efforts to mitigate runoff and soil loss in degraded watersheds. Key words: 1. Erosion, 2. Geo information science, 3. System Dynamics, 4. Support factor, 5. Uganda Funding was by SIDA SAREC Project 377 under Makerere University for the period 2016-2022. DOI: 10.7176/JEES/13-3-06 Publication date: May 30th 202

Interceptor® long-lasting insecticidal net: phase III evaluation over three years of household use and calibration with Phase II experimental hut outcomes.

BACKGROUND: Long-lasting insecticidal nets (LN) are an effective tool for malaria prevention. The World Health Organization Pesticide Evaluation Scheme has established evaluation criteria to facilitate registration for public use. A household randomised trial was conducted in Tanzania according to WHOPES Phase III procedures to evaluate the alpha-cypermethrin coated Interceptor® LN (BASF) over three years' use. Outcomes were calibrated against results of Phase II experimental hut trials. METHODS: Interceptor LN (200 mg/m(2) alpha-cypermethrin) and conventionally treated nets CTN (40 mg/m(2) alpha-cypermethrin) were randomly distributed to 934 households. At 6-monthly intervals, household surveys recorded net use, durability, adverse effects, user acceptance and washing practices. Concurrently, 30 nets of each type were collected and tested for knock-down and kill of Anopheles gambiae mosquitoes in cone and tunnel bioassays. Alpha-cypermethrin content of nets was assessed annually. RESULTS: At 12 months 97% of Interceptor LN met the efficacy criteria by cone or tunnel test; this pass rate declined to 90% at 24 months and 87% at 36 months. In contrast only 63% of CTN met the efficacy criteria at 12 months, 14 % at 24 months and 0% at 36 months. The alpha-cypermethrin content at 36 months on Interceptor LN was 20% (42 ± 13 mg/m(2)) of the initial content but on CTNs only 4% (1.3 ± 1.6 mg/m(2)) remained. Interceptor LN was reported to be used year-round and washed 4.3 times/year. A few recalled facial tingling during the first days of use but this did not deter usage. The average number of holes at 36 months was 18, hole area per net was 229 cm(2) and hole index was 332. Insecticide content and cone bioefficacy of LN and CTN after 36 months' use were similar to that of LN and CTN used in earlier Phase II hut trials, but while the 20 times washed LN tested in experimental huts gave adequate personal protection the 20 times washed CTN did not. CONCLUSIONS: More than 80% Interceptor LN fulfilled the WHOPES Phase III criteria at 36 months and thus the LLIN was granted full WHO recommendation. Phase III outcomes at 36 months were anticipated by Phase II outcomes after 20 standardized washes

Factors Associated with Colonization of Streptococcus Pneumoniae among Under-fives Attending Clinic in Mwanza City, Tanzania

Streptococcus pneumoniae is a known cause of severe invasive bacterial infection leading to morbidity and mortality among children in sub-Saharan Africa. Nasopharyngeal colonization of S.pneumoniae is a critical step towards invasive disease progression. The objective of this study was to investigate the magnitude of nasopharyngeal carriage of S. pneumoniae and its associated factors in Mwanza, Tanzania. Children underfives attending Reproductive and Child Health (RCH) clinics in Mwanza, Tanzania clinics were enrolled and investigated for nasopharyngeal carriage of S. pneumoniae. Demographic and clinical data were collected using standardized data collection tool. Nasopharyngeal swabs were taken and processed as per standard laboratory procedures. S. pneumoniae isolates were identified using conventional methods. Antimicrobial susceptibility testing was performed using the disc diffusion method as described by Clinical Laboratory Standard Institute. Among 350 children enrolled in the study, 172 (49.1) were females and 309 (88.3%) were below 2 years of age. A total of 253 (72.3%) children had received at least one dose of pneumococcal vaccine (Prevanar 13) whereas 83 (23.7%) had used antibiotics at median duration of 5 days in the past 14 days. Out of 350 underfives, 43 (12.3%) were found to carry S. pneumoniae in their nasopharynx. Children with chronic diseases and those at school were 3.4 and 4.4 times more at risk to be carriers of S. pneumoniae than their counterpart group (OR; 3.4 (CI(1.0-11.6) 95%, p=0.05) and OR; 4.4 (CI (1.2-15.7) 95%, p=0.023), respectively. Number of children at home, positive HIV status and someone smoking showed association with S. pneumoniae carriage but the differences were not statistically significant. The resistance levels of S. pneumoniae to penicillin, co-trimoxazole and erythromycin were 40%, 88.2% and 41.7%, respectively. However all of the S. pneumoniae isolates were found to be 100% sensitive to ciprofloxacin. A high nasopharyngeal carriage of penicillin resistant S. pneumoniae is observed in Mwanza, Tanzania despite a good coverage of pneumococcal vaccination. The carriage is significantly associated with schooling and presence chronic diseases. Continuous surveillance of penicillin resistant strains coupled with serotyping of the isolates is highly recommended to determine the influence of the pneumococcal vaccination

TESS asteroseismology of the known red-giant host stars HD 212771 and HD 203949

International audienc

Megakaryopoiesis impairment through acute innate immune signaling activation by azacitidine

Publisher Copyright: © 2022 Okoye-Okafor et al.Thrombocytopenia, prevalent in the majority of patients with myeloid malignancies, such as myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML), is an independent adverse prognostic factor. Azacitidine (AZA), a mainstay therapeutic agent for stem cell transplant–ineligible patients with MDS/AML, often transiently induces or further aggravates disease-associated thrombocytopenia by an unknown mechanism. Here, we uncover the critical role of an acute type-I interferon (IFN-I) signaling activation in suppressing megakaryopoiesis in AZA-mediated thrombocytopenia. We demonstrate that megakaryocytic lineage-primed progenitors present IFN-I receptors and, upon AZA exposure, engage STAT1/SOCS1-dependent downstream signaling prematurely attenuating thrombopoietin receptor (TPO-R) signaling and constraining megakaryocytic progenitor cell growth and differentiation following TPO-R stimulation. Our findings directly implicate RNA demethylation and IFN-I signal activation as a root cause for AZA-mediated thrombocytopenia and suggest mitigation of TPO-R inhibitory innate immune signaling as a suitable therapeutic strategy to support platelet production, particularly during the early phases of AZA therapy.Peer reviewe

Functional drug screening reveals anticonvulsants as enhancers of mTOR-independent autophagic killing of Mycobacterium tuberculosis through inositol depletion.

Mycobacterium tuberculosis (MTB) remains a major challenge to global health made worse by the spread of multidrug resistance. We therefore examined whether stimulating intracellular killing of mycobacteria through pharmacological enhancement of macroautophagy might provide a novel therapeutic strategy. Despite the resistance of MTB to killing by basal autophagy, cell-based screening of FDA-approved drugs revealed two anticonvulsants, carbamazepine and valproic acid, that were able to stimulate autophagic killing of intracellular M. tuberculosis within primary human macrophages at concentrations achievable in humans. Using a zebrafish model, we show that carbamazepine can stimulate autophagy in vivo and enhance clearance of M. marinum, while in mice infected with a highly virulent multidrug-resistant MTB strain, carbamazepine treatment reduced bacterial burden, improved lung pathology and stimulated adaptive immunity. We show that carbamazepine induces antimicrobial autophagy through a novel, evolutionarily conserved, mTOR-independent pathway controlled by cellular depletion of myo-inositol. While strain-specific differences in susceptibility to in vivo carbamazepine treatment may exist, autophagy enhancement by repurposed drugs provides an easily implementable potential therapy for the treatment of multidrug-resistant mycobacterial infection

Genomic identification of a novel co-trimoxazole resistance genotype and its prevalence amongst Streptococcus pneumoniae in Malawi.

OBJECTIVES: This study aimed to define the molecular basis of co-trimoxazole resistance in Malawian pneumococci under the dual selective pressure of widespread co-trimoxazole and sulfadoxine/pyrimethamine use. METHODS: We measured the trimethoprim and sulfamethoxazole MICs and analysed folA and folP nucleotide and translated amino acid sequences for 143 pneumococci isolated from carriage and invasive disease in Malawi (2002-08). RESULTS: Pneumococci were highly resistant to both trimethoprim and sulfamethoxazole (96%, 137/143). Sulfamethoxazole-resistant isolates showed a 3 or 6 bp insertion in the sulphonamide-binding site of folP. The trimethoprim-resistant isolates fell into three genotypic groups based on dihydrofolate reductase (encoded by folA) mutations: Ile-100-Leu (10%), the Ile-100-Leu substitution together with a residue 92 substitution (56%) and those with a novel uncharacterized resistance genotype (34%). The nucleotide sequence divergence and dN/dS of folA and folP remained stable from 2004 onwards. CONCLUSIONS: S. pneumoniae exhibit almost universal co-trimoxazole resistance in vitro and in silico that we believe is driven by extensive co-trimoxazole and sulfadoxine/pyrimethamine use. More than one-third of pneumococci employ a novel mechanism of co-trimoxazole resistance. Resistance has now reached a point of stabilizing evolution. The use of co-trimoxazole to prevent pneumococcal infection in HIV/AIDS patients in sub-Saharan Africa should be re-evaluated

Dead or alive: animal sampling during Ebola hemorrhagic fever outbreaks in humans

There are currently no widely accepted animal surveillance guidelines for human Ebola hemorrhagic fever (EHF) outbreak investigations to identify potential sources of Ebolavirus (EBOV) spillover into humans and other animals. Animal field surveillance during and following an outbreak has several purposes, from helping identify the specific animal source of a human case to guiding control activities by describing the spatial and temporal distribution of wild circulating EBOV, informing public health efforts, and contributing to broader EHF research questions. Since 1976, researchers have sampled over 10,000 individual vertebrates from areas associated with human EHF outbreaks and tested for EBOV or antibodies. Using field surveillance data associated with EHF outbreaks, this review provides guidance on animal sampling for resource-limited outbreak situations, target species, and in some cases which diagnostics should be prioritized to rapidly assess the presence of EBOV in animal reservoirs. In brief, EBOV detection was 32.7% (18/55) for carcasses (animals found dead) and 0.2% (13/5309) for live captured animals. Our review indicates that for the purposes of identifying potential sources of transmission from animals to humans and isolating suspected virus in an animal in outbreak situations, (1) surveillance of free-ranging non-human primate mortality and morbidity should be a priority, (2) any wildlife morbidity or mortality events should be investigated and may hold the most promise for locating virus or viral genome sequences, (3) surveillance of some bat species is worthwhile to isolate and detect evidence of exposure, and (4) morbidity, mortality, and serology studies of domestic animals should prioritize dogs and pigs and include testing for virus and previous exposure