66 research outputs found
Performance evaluation of hybrid thin layer solar tunnel-windmill dryer in the drying of brined and non-brined Tafi (Siganussutor) Fish
Studies were carried out to evaluate the performance of hybrid solar tunnel-windmill dryer in thin layer drying of brined and non-brined Tafi (Siganus spp.) fish. The fish were, eviscerated, and split into pieces of approximately 6cm by 4cm by 5mm was soaked in brine at 0 and 5% concentrations. The samples were dried in the dryer for 44 hours. The moisture content of the drying fish was evaluated by the AOAC oven drying procedure. In addition, analysis was carried out to establish the best thin layer drying model that describes the drying of fish in the hybrid wind-solar tunnel dryer. The moisture content of the drying fish was found to reduce linearly from 4.2 and 3.9kg/kg (db), respectively for brined and non-brined fish to 0.8kg/kg (db). A two way Students t-test did not establish any significant difference in the drying of salted and unsalted fish (tstat=1.4032, tcrit, 5%=2.0687). Further, the page thin layer drying model was found to be the best model describing the thin layer drying of Tafi fish in the hybrd solar tunnel-windmill dryer (R2=0.9655 and 0.09434; RMSE=0.0539 and 0.0840 for unsalted; c2=0.0032 and 0.0077, for salted and unsalted fish, respectively). These results provide useful information in the modelling and design of solar drying systems for the drying of Tafi fish
Key limitations of fish feeds, feed management practices, and opportunities in Kenya’s aquaculture enterprise
Profitability is key in fish farming, just as it is to any other enterprise. For the farmers to actualize high-profit margins, it is imperative to have access to well-balanced nutritive and cost-effective feeds, backed by sound on-farm feed management practices. This paper audits Kenya’s fish feed industry and the on-going on-farm feed management practices, and emerging opportunities for fish farmers. The development of fish feed quality standards has boosted the aquaculture sector in Kenya, providing them hope that farmers will access high quality fish feeds. Much of the fish feed currently being used in Kenya is produced on-farm or by small-scale fish feed manufacturers within the East African region, while a few are imported directly from overseas countries, notably Israel, Netherlands, Mauritius and Denmark. Fish feeds produced by small-scale manufacturers are not closely monitored by quality standard agencies and not surprising that a majority are of poor quality. The improvement in the quality of these feeds is likely to lead to increased productivity and profitability because they are cheaper and readily available to fish farmers, compared to imported fish feeds. Besides feed quality, feed management practices markedly impact both the growth and economic performance of fish production. Adopting appropriate feed management strategies, therefore, is instrumental in the maximization of fish production and economic returns. Research has demonstrated several strategies for best feed management practices, which have not hitherto, been adopted by fish farmers in Kenya. Farmers have mainly focused on the mode of delivery of feeds to the fish. Furthermore, promoting natural pond productivity and supplementary feeding is still a common practice in the East African region. Provision of species-specific feeds and targeting the nutritional requirements of the different life stages of fish is still a major issue, although some local companies like Unga Farm Care (EA) have come up with a size and species-specific feed for catfish such as Fugo catfish®. To improve access to such information, public-private partnerships should be developed and, programmes that utilize the local media platforms such as extension service outlets must also be encouraged. Feed quality checks can also be carried out amongst fish feed suppliers. Lastly, farmers should be trained in various fish feed aspects like formulation, transportation and storage to sustain a steady fish feed supply and save on associated feed costs
Genetic diversity study of Kenyan cassava germplasm using simple sequence repeats
Cassava (Manihot esculenta Cranzt) is an important food security crop for resource poor rural communities particularly in Africa. Little is however known about molecular diversity of Kenyan cassava germplasm. This led to a study whose objective was to identify genetic constitution of cassava accessions from different regions of Kenya using molecular tools. Seven pairs of micro satellite (SSR) primers previously developed from cassava were used to detect polymorphic 21 alleles in a sample of 69 accessions. The cluster analysis of similarity matrix obtained at 68% with SSR data showed that the 69 accessions were grouped into five marker based groups. This study proved that SSRs could be used to identify cassava accessions as well as in the assessment of level of genetic relatedness among accessions.Keywords: Cassava, simple sequence repeat (SSR) markers, genetic diversity
Functional olfactory evolution in Drosophila suzukii and the subgenus Sophophora
Comparative analysis of multiple genomes has been used extensively to examine the evolution of chemosensory receptors across the genus Drosophila. However, few studies have delved into functional characteristics, as most have relied exclusively on genomic data alone, especially for non-model species. In order to increase our understanding of olfactory evolution, we have generated a comprehensive assessment of the olfactory functions associated with the antenna and palps for Drosophila suzukii as well as several other members of the subgenus Sophophora, thus creating a functional olfactory landscape across a total of 20 species. Here we identify and describe several common elements of evolution, including consistent changes in ligand spectra as well as relative receptor abundance, which appear heavily correlated with the known phylogeny. We also combine our functional ligand data with protein orthologue alignments to provide a high-throughput evolutionary assessment and predictive model, where we begin to examine the underlying mechanisms of evolutionary changes utilizing both genetics and odorant binding affinities. In addition, we document that only a few receptors frequently vary between species, and we evaluate the justifications for evolution to reoccur repeatedly within only this small subset of available olfactory sensory neurons
Standardisation: bolstering positive attitudes towards endangered language varieties? Evidence from implicit attitudes
Should first-line empiric treatment strategies cover coagulase-negative staphylococcal infections in severely malnourished or HIV-infected children in Kenya?
BACKGROUND:
Bloodstream infection is a common cause of morbidity in children aged andlt;5 years in developing countries. In studies reporting bacteremia in Africa, coagulase-negative Staphylococci (CoNS) are commonly isolated. However, it is currently unclear whether children who are highly susceptible to infection because of severe acute malnutrition (SAM) or HIV should be treated with antimicrobials specifically to cover CoNS. We aimed to determine the clinical significance of CoNS amongst children admitted to a rural hospital in Kenya in relation to nutritional and HIV status.
METHODS:
Systematically collected clinical and microbiological surveillance data from children aged 6-59 months admitted to Kilifi County Hospital (2007-2013) were analysed. Multivariable regression was used to test associations between CoNS isolation from blood cultures and SAM (MUAC andlt;11.5cm or nutritional oedema (kwashiorkor)), and HIV serostatus; and among children with SAM or HIV, associations between CoNS isolation and mortality, duration of hospitalization and clinical features.
RESULTS:
CoNS were isolated from blood culture in 906/13,315 (6.8%) children, of whom 135/906 (14.9%) had SAM and 54/906 (6.0%) were HIV antibody positive. CoNS isolation was not associated with SAM (MUACandlt;11.5cm (aOR 1.11, 95% CI 0.88-1.40) or kwashiorkor (aOR 0.84, 95% CI 0.48-1.49)), or a positive HIV antibody test (aOR 1.25, 95% CI 0.92-1.71). Among children with SAM or a positive HIV antibody test, CoNS isolation was not associated with mortality or prolonged hospitalization.
CONCLUSION:
In a large, systematic study, there was no evidence that antimicrobial therapy should specifically target CoNS amongst children with SAM or HIV-infection or exposure
COVID-19 vaccines under the international health regulations – we must use the WHO international certificate of vaccination or prophylaxis
The
first vaccines against SARS-CoV-2 have now received
emergency use authorization by the U.S. Food and Drug
Administration (FDA), European Medicines Agency (EMA) and
national authorities in China, India, UK, and Russia; and are rapidly
being distributed in more than 30 countries since the end of the
2020. So far vaccines are being used by the respective countries
after national approval based on promising efficacy reports and
safety data, however, data on some of these vaccines have not yet
been published in international peer-reviewed journals. The World
Health Organization (WHO) has a role in “pre-qualifying” COVID
vaccines, but WHO pre-qualification may not be necessary to
record the use of immunization or prophylaxis in WHO Interna-
tional Certificate of Vaccination or Prophylaxis (ICVP, aka Carte
Jaune or Yellow Card) as this has not been the case with other
vaccines which may not be WHO prequalified. Every dose of any
COVID vaccine should be entered in the WHO Yellow Card.http://www.elsevier.com/locate/ijidam2022Veterinary Tropical Disease
Genome sequence of the tsetse fly (Glossina morsitans):Vector of African trypanosomiasis
Tsetse flies are the sole vectors of human African trypanosomiasis throughout sub-Saharan Africa.
Both sexes of adult tsetse feed exclusively on blood and contribute to disease transmission. Notable
differences between tsetse and other disease vectors include obligate microbial symbioses, viviparous
reproduction, and lactation. Here, we describe the sequence and annotation of the 366-megabase
Glossina morsitans morsitans genome. Analysis of the genome and the 12,308 predicted
protein-encoding genes led to multiple discoveries, including chromosomal integrations of bacterial
(Wolbachia) genome sequences, a family of lactation-specific proteins, reduced complement of
host pathogen recognition proteins, and reduced olfaction/chemosensory associated genes. These
genome data provide a foundation for research into trypanosomiasis prevention and yield important
insights with broad implications for multiple aspects of tsetse biology.IS
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Patterns of antibiotic use, pathogens, and prediction of mortality in hospitalized neonates and young infants with sepsis: A global neonatal sepsis observational cohort study (NeoOBS).
BACKGROUND: There is limited data on antibiotic treatment in hospitalized neonates in low- and middle-income countries (LMICs). We aimed to describe patterns of antibiotic use, pathogens, and clinical outcomes, and to develop a severity score predicting mortality in neonatal sepsis to inform future clinical trial design. METHODS AND FINDINGS: Hospitalized infants <60 days with clinical sepsis were enrolled during 2018 to 2020 by 19 sites in 11 countries (mainly Asia and Africa). Prospective daily observational data was collected on clinical signs, supportive care, antibiotic treatment, microbiology, and 28-day mortality. Two prediction models were developed for (1) 28-day mortality from baseline variables (baseline NeoSep Severity Score); and (2) daily risk of death on IV antibiotics from daily updated assessments (NeoSep Recovery Score). Multivariable Cox regression models included a randomly selected 85% of infants, with 15% for validation. A total of 3,204 infants were enrolled, with median birth weight of 2,500 g (IQR 1,400 to 3,000) and postnatal age of 5 days (IQR 1 to 15). 206 different empiric antibiotic combinations were started in 3,141 infants, which were structured into 5 groups based on the World Health Organization (WHO) AWaRe classification. Approximately 25.9% (n = 814) of infants started WHO first line regimens (Group 1-Access) and 13.8% (n = 432) started WHO second-line cephalosporins (cefotaxime/ceftriaxone) (Group 2-"Low" Watch). The largest group (34.0%, n = 1,068) started a regimen providing partial extended-spectrum beta-lactamase (ESBL)/pseudomonal coverage (piperacillin-tazobactam, ceftazidime, or fluoroquinolone-based) (Group 3-"Medium" Watch), 18.0% (n = 566) started a carbapenem (Group 4-"High" Watch), and 1.8% (n = 57) a Reserve antibiotic (Group 5, largely colistin-based), and 728/2,880 (25.3%) of initial regimens in Groups 1 to 4 were escalated, mainly to carbapenems, usually for clinical deterioration (n = 480; 65.9%). A total of 564/3,195 infants (17.7%) were blood culture pathogen positive, of whom 62.9% (n = 355) had a gram-negative organism, predominantly Klebsiella pneumoniae (n = 132) or Acinetobacter spp. (n = 72). Both were commonly resistant to WHO-recommended regimens and to carbapenems in 43 (32.6%) and 50 (71.4%) of cases, respectively. MRSA accounted for 33 (61.1%) of 54 Staphylococcus aureus isolates. Overall, 350/3,204 infants died (11.3%; 95% CI 10.2% to 12.5%), 17.7% if blood cultures were positive for pathogens (95% CI 14.7% to 21.1%, n = 99/564). A baseline NeoSep Severity Score had a C-index of 0.76 (0.69 to 0.82) in the validation sample, with mortality of 1.6% (3/189; 95% CI: 0.5% to 4.6%), 11.0% (27/245; 7.7% to 15.6%), and 27.3% (12/44; 16.3% to 41.8%) in low (score 0 to 4), medium (5 to 8), and high (9 to 16) risk groups, respectively, with similar performance across subgroups. A related NeoSep Recovery Score had an area under the receiver operating curve for predicting death the next day between 0.8 and 0.9 over the first week. There was significant variation in outcomes between sites and external validation would strengthen score applicability. CONCLUSION: Antibiotic regimens used in neonatal sepsis commonly diverge from WHO guidelines, and trials of novel empiric regimens are urgently needed in the context of increasing antimicrobial resistance (AMR). The baseline NeoSep Severity Score identifies high mortality risk criteria for trial entry, while the NeoSep Recovery Score can help guide decisions on regimen change. NeoOBS data informed the NeoSep1 antibiotic trial (ISRCTN48721236), which aims to identify novel first- and second-line empiric antibiotic regimens for neonatal sepsis. TRIAL REGISTRATION: ClinicalTrials.gov, (NCT03721302)
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The burden of bacterial antimicrobial resistance in the WHO African region in 2019: a cross-country systematic analysis
Background
A critical and persistent challenge to global health and modern health care is the threat of antimicrobial resistance (AMR). Previous studies have reported a disproportionate burden of AMR in low-income and middle-income countries, but there remains an urgent need for more in-depth analyses across Africa. This study presents one of the most comprehensive sets of regional and country-level estimates of bacterial AMR burden in the WHO African region to date.
Methods
We estimated deaths and disability-adjusted life-years (DALYs) attributable to and associated with AMR for 23 bacterial pathogens and 88 pathogen–drug combinations for countries in the WHO African region in 2019. Our methodological approach consisted of five broad components: the number of deaths in which infection had a role, the proportion of infectious deaths attributable to a given infectious syndrome, the proportion of infectious syndrome deaths attributable to a given pathogen, the percentage of a given pathogen resistant to an antimicrobial drug of interest, and the excess risk of mortality (or duration of an infection) associated with this resistance. These components were then used to estimate the disease burden by using two counterfactual scenarios: deaths attributable to AMR (considering an alternative scenario where infections with resistant pathogens are replaced with susceptible ones) and deaths associated with AMR (considering an alternative scenario where drug-resistant infections would not occur at all). We obtained data from research hospitals, surveillance networks, and infection databases maintained by private laboratories and medical technology companies. We generated 95% uncertainty intervals (UIs) for final estimates as the 25th and 975th ordered values across 1000 posterior draws, and models were cross-validated for out-of-sample predictive validity.
Findings
In the WHO African region in 2019, there were an estimated 1·05 million deaths (95% UI 829 000–1 316 000) associated with bacterial AMR and 250 000 deaths (192 000–325 000) attributable to bacterial AMR. The largest fatal AMR burden was attributed to lower respiratory and thorax infections (119 000 deaths [92 000–151 000], or 48% of all estimated bacterial pathogen AMR deaths), bloodstream infections (56 000 deaths [37 000–82 000], or 22%), intra-abdominal infections (26 000 deaths [17 000–39 000], or 10%), and tuberculosis (18 000 deaths [3850–39 000], or 7%). Seven leading pathogens were collectively responsible for 821 000 deaths (636 000–1 051 000) associated with resistance in this region, with four pathogens exceeding 100 000 deaths each: Streptococcus pneumoniae, Klebsiella pneumoniae, Escherichia coli, and Staphylococcus aureus. Third-generation cephalosporin-resistant K pneumoniae and meticillin-resistant S aureus were shown to be the leading pathogen–drug combinations in 25 and 16 countries, respectively (53% and 34% of the whole region, comprising 47 countries) for deaths attributable to AMR.
Interpretation
This study reveals a high level of AMR burden for several bacterial pathogens and pathogen–drug combinations in the WHO African region. The high mortality rates associated with these pathogens demonstrate an urgent need to address the burden of AMR in Africa. These estimates also show that quality and access to health care and safe water and sanitation are correlated with AMR mortality, with a higher fatal burden found in lower resource settings. Our cross-country analyses within this region can help local governments to leverage domestic and global funding to create stewardship policies that target the leading pathogen–drug combinations.
Funding
Bill & Melinda Gates Foundation, Wellcome Trust, and Department of Health and Social Care using UK aid funding managed by the Fleming Fund
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