40 research outputs found
Bundled CSA/CIS for AICCRA Ghana Project (Platform creation)
Esoko engaged ten (10) agents to profile farmers in AiCCRA operational areas. Based on the profiling, Esoko was able to create a network of 256,981, exceeding the target by 6,981 (2.79%). These farmers were provided with CIS/CSA technologie
Reliability and Statistical Power: How Measurement Fallibility Affects Power and Required Sample Sizes for Several Parametric and Nonparametric Statistics
The relationship between reliability and statistical power is considered, and tables that account for reduced reliability are presented. A series of Monte Carlo experiments were conducted to determine the effect of changes in reliability on parametric and nonparametric statistical methods, including the paired samples dependent t test, pooled-variance independent t test, one-way analysis of variance with three levels, Wilcoxon signed-rank test for paired samples, and Mann-Whitney-Wilcoxon test for independent groups. Power tables were created that illustrate the reduction in statistical power from decreased reliability for given sample sizes. Sample size tables were created to provide the approximate sample sizes required to achieve given levels of statistical power based for several levels of reliability
Creation of Network on the Esoko platform to monitor beneficiaries and information dissemination
Esoko was able to create a network of 256,981 and provided them with Climate Information Services and Climate Smart Agriculture (CIS-CSA)
Correlation of Horizontal Cephalic Index and Cranial Parameters in Iranian Medical Students
Cranial parameters and cephalic indices are used to evaluate the racial and gender differences. The aim of this study was to assess the cephalic indices, to classify the type of cranium and to determine the relationship between the horizontal cephalic index and cranial parameters among Iranian medical students. This study was done on 200 medical students (100 males and 100 females) with an age range of 18-30-year-old. Head length, head breadth, and auricular height were measured by using a standard spreading caliper. Then cephalic indices were calculated for the classification of cranial type. The linear regression was used for examining the relationship between the horizontal cephalic index and head length, head breadth and auricular height. The results of this study showed that the mean of the horizontal, vertical, and transverse cephalic index in total students were 83.51±6.85, 85.58±5.85 and 102.77±6.35 cm, respectively. According to this result, the predominant head shapes in total students were brachycephalic, hypsicephalic and acrocephalic types. In this study, there was a strongly negative correlation between horizontal cephalic index with head length (r=-0.744, P=0.000), moderate positive correlation between horizontal cephalic index with head breadth (r=0.512, P=0.000) and weakly negative correlation between horizontal cephalic index with auricular height (r=-0.205, P=0.004). The data of the present study can be beneficial in craniofacial reconstruction, clinical diagnosis, and forensic applications
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Assessment of the phytochemical composition and antimicrobial properties of Tapinanthus bangwensis leaves hosted by the branches of Persea americana
Abstract Background Medicinal plants represent a valuable source for new effective and safe antimicrobial drugs making them an alternative therapy. Existing antimicrobial agents are costly and mostly associated with possible side effects. The aim of the present study therefore, was to assess the antimicrobial property and phytochemical composition of hydroethanolic extract of Tapinanthus bangwensis leaves and its fractions. Method T. bangwensis leaves (harvested from its host plant, Persea americana) was extracted by cold maceration with 70% ethanol and further fractionated with different organic solvents using the solvent partitioning method to obtain the crude extract, petroleum ether, chloroform, ethyl acetate and the resulting aqueous fractions. The phytochemical constituents of the extracts were screened and quantified. Also, the TLC of the extracts were analyzed to serve as a fingerprint. Using the agar diffusion and broth dilution methods, the antimicrobial properties of the extracts were assessed. Results The study showed that the hydroethanolic (70%) crude extract of T. bangwensis leaves and its fractions contain phenolic compounds, flavonoids, saponins, phytosterols and reducing sugars. The phytoconstituents were well extracted into the ethyl acetate fraction than the other fractions evidenced in the high levels (p < 0.0001) of saponins (66.47 ± 1.72% w/w), phenolic compounds (77.75 ± 1.06 mg/100 mg GAE) and flavonoids (44.34 ± 0.06 mg/100 mg QE) contents. From the antimicrobial studies, all the microorganisms tested exhibited varying degrees of susceptibility to the extracts with MIC values between 0.78 to 12.5 mg/mL. The crude extract of T. bangwensis leaves, its ethyl acetate and chloroform fractions also exhibited lethal antimicrobial activity with MLC between 6.25 to 50 mg/mL. Conclusion The crude extract of T. bangwensis leaves and its fractions demonstrated antimicrobial properties against Escherichia coli, Staphylococcus aureus, Staphylococcus saprophyticus and Candida albicans, thereby representing a potential source of natural antimicrobial agent. Further study is required to identify and isolate antimicrobial compounds from the plant for the development of the natural bioactive antimicrobial agents
Klebsiella pneumoniae survives within macrophages by avoiding delivery to lysosomes
Klebsiella pneumoniae is an important cause of community-acquired and nosocomial pneumonia. Evidence indicates that Klebsiella might be able to persist intracellularly within a vacuolar compartment. This study was designed to investigate the interaction between Klebsiella and macrophages. Engulfment of K.pneumoniae was dependent on host cytoskeleton, cell plasma membrane lipid rafts and the activation of phosphoinositide 3-kinase (PI3K). Microscopy studies revealed that K.pneumoniae resides within a vacuolar compartment, the Klebsiella-containing vacuole (KCV), which traffics within vacuoles associated with the endocytic pathway. In contrast to UV-killed bacteria, the majority of live bacteria did not co-localize with markers of the lysosomal compartment. Our data suggest that K.pneumoniae triggers a programmed cell death in macrophages displaying features of apoptosis. Our efforts to identify the mechanism(s) whereby K.pneumoniae prevents the fusion of the lysosomes to the KCV uncovered the central role of the PI3K-Akt-Rab14 axis to control the phagosome maturation. Our data revealed that the capsule is dispensable for Klebsiella intracellular survival if bacteria were not opsonized. Furthermore, the environment found by Klebsiella within the KCV triggered the down-regulation of the expression of cps. Altogether, this study proves evidence that K.pneumoniae survives killing by macrophages by manipulating phagosome maturation that may contribute to Klebsiella pathogenesis. Prevailing belief states that the human pathogens Klebsiella pneumoniae is an extracellular pathogen. However, in this work, we demonstrate that K. pneumoniae co-opts the maturation of the phagosome manipulating a PI3K-AKT-RAB14 signalling cascade. Here, we also demonstrate that by preventing the activation of this cascade, the macrophages eliminate intracellular Klebsiella. © 2015 John WileyM.I.M.-L. was financially supported by the Instituto de Salud Carlos III (grant CM09/000123). Part of this work was supported by grant PS09-00130 from Instituto de Salud Carlos III to J.G. and by grants from Biomedicine Program (SAF2009-07885 and SAF2012-39841), Ministerio de EconomĂa y Competitividad (Spain), Govern Illes Balears (Competitive group Ref: 46/2011) and Queen's University Belfast start-up funds to J.A.B. This research was also supported by a Marie Curie FP7 Integration Grant (U-KARE; PCIG13-GA-2013-618162) to J.A.B. within the 7th European Union Framework Programme. CIBERES is an initiative from Instituto de Salud Carlos III.Peer Reviewe