30 research outputs found

    Digital Knowledge of Kenyan Succulent Flora and Priorities for Future Inventory and Documentation

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    Biodiversity inventory in Kenya has been ongoing for about a century and a half, coinciding with the arrival of naturalists from Europe, America, and elsewhere outside Africa. Since the first collections in the mid-to-late 1800s, there has been a steady increase of plant surveys, frequency of inventory, and discovery of new species that have considerably increased knowledge of faunal and floristic elements. However, as in all other countries, such historical biological collection activities are more often than not, ad hoc, resulting in gaps in knowledge of species and their habitats. While Kenya is relatively rich botanically, with a succulent flora of about 428 taxa, it is apparent that the list is understated owing to, among other factors, difficulty of preparing herbarium material and restricted access to some sites. This study investigated completeness of geographic knowledge of succulent plants in Kenya, with the aim of establishing species distribution patterns and identifying gaps that will guide and justify priority setting for future work on the group. Species data were filtered from the general BRAHMS database at the East African Herbarium and cleaned via an iterative series of inspections and visualizations designed to detect and document inconsistencies in taxonomic concepts, geographic coordinates, and dates of collection. Eight grid squares fulfilled criteria for completeness of inventory: one in the city of Mombasa, one in the Kulal–Nyiro complex, one in Garissa, one in Baringo, and four grid squares in the Nairobi–Nakuru–Laikipia area. Poorly-known areas, mostly in the west, north, and north-eastern regions of the country, were extremely isolated from well-known sites, both geographically and environmentally. These localities should be prioritised for future inventory as they are likely to yield species new to science, species new to the national flora, and/or contribute new knowledge on habitats. To avoid inconsistencies and data leakage, biodiversity inventory and documentation needs streamlining to generate standardised metadata that should be digitised to enhance access and synthesis

    A new class of hybrid secretion system is employed in Pseudomonas amyloid biogenesis

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    Gram-negative bacteria possess specialised biogenesis machineries that facilitate the export of amyloid subunits for construction of a biofilm matrix. The secretion of bacterial functional amyloid requires a bespoke outer-membrane protein channel through which unfolded amyloid substrates are translocated. Here, we combine X-ray crystallography, native mass spectrometry, single-channel electrical recording, molecular simulations and circular dichroism measurements to provide high-resolution structural insight into the functional amyloid transporter from Pseudomonas, FapF. FapF forms a trimer of gated ÎČ-barrel channels in which opening is regulated by a helical plug connected to an extended coil-coiled platform spanning the bacterial periplasm. Although FapF represents a unique type of secretion system, it shares mechanistic features with a diverse range of peptide translocation systems. Our findings highlight alternative strategies for handling and export of amyloid protein sequences

    Nutritional characterisation of low-income households of Nairobi: socioeconomic, livestock and gender considerations and predictors of malnutrition from a cross-sectional survey

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    Background: In sub-Saharan Africa, urban informal settlements are rapidly expanding, leading to overcrowding and constituting challenging environments for food and water supplies, health and nutrition. The study objectives were to characterise and compare two low-income areas of Nairobi according to socioeconomic (including livestock and gender) indicators and the nutritional status of non-pregnant women of reproductive age and 1 to 3 year-old children; and to investigate socioeconomic predictors of malnutrition in these areas. Methods: In this cross-sectional survey 205 low-income households in deprived areas of Dagoretti and Korogocho (Nairobi) were randomly selected. Socioeconomic data were collected via an interviewer-administered questionnaire. Maternal and child dietary data were collected by a 24-h dietary recall. Maternal and child anthropometric and haemoglobin measurements were taken. Chi-square, t-test and Wilcoxon-Mann–Whitney test were used to compare groups and multivariable linear regression to assess predictors of malnutrition. Results: Dagoretti consistently showed better socioeconomic indicators including: income, education and occupation of household head, land ownership, housing quality and domestic asset ownership. Animal ownership was more than twice as high in Dagoretti as in Korogocho (53.0 % vs 22.9 % of households; p-value < 0.0001). A double burden of malnutrition existed: 41.5 % of children were stunted, and 29.0 % of women were overweight. In addition, 74.0 % of the children and 25.9 % of the women were anaemic, and were at risk of inadequate intakes for a number of micronutrients. Nutritional status and nutrient intakes were consistently better in Dagoretti than Korogocho; height-for-age (0.47 Z-scores higher; p-value = 0.004), the minimum dietary diversity (80.0 % vs 57.7 % in children, p-value = 0.001) and intakes of several nutrients were significantly higher. Positive predictors of maternal nutritional status were income, age and not having a premature delivery. Positive predictors of child nutritional status were area, household head education, mother not being married, female animal ownership and child’s sex (female). Conclusions: Malnutrition is prevalent in these settings, which could be partly due to low nutrient intakes, and to socioeconomic factors (including poverty), thus requiring comprehensive approaches that include increased accessibility and affordability of nutrient-dense foods. This study indicates that differences among low-income areas may need consideration for prioritisation and design of interventions

    Modular Process Risk Models For Better Management Of Cryptosporidium parvum – An Emerging Zoonotic Pathogen

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    Cryptosporidium parvum is an emerging disease which is of particular concern because of its ability to contaminate milk, food-crops and water sources; to persist in the environment; to survive water treatment including chlorination; and to cause serious and sometimes fatal disease in children and the immuno-compromised. Understanding of disease epidemiology is rapidly advancing but uncertainties remain especially concerning the relative importance of zoonotic and anthroponotic transmission. A study is being carried out in Dagoretti in Nairobi to evaluate the contribution of urban dairying to disease burden and some preliminary results related to the risk analysis component are reported in this paper. The study is being carried in a population of around 1,000 urban cattle-keepers and their neighbours, with data collected at cow, farm, household and environmental levels. This paper details the construction, analysis and interpretation of process diagrams in order to show spatial and temporal linkages between pathogen, reservoir host, environment and populations. We show how by incorporating and modelling pathogen survival information, process diagrams allow greater understanding of the risk of disease and better targeting of interventions to successfully manage Cryptosporidium parvum in urban Kenya.Cryptosporidium parvum est une maladie Ă©mergente particuliĂšrement prĂ©occupante Ă  cause de sa capacitĂ© Ă  contaminer le lait, les cultures vivriĂšres et les sources d'eau. Il peut aussi persister dans l'environnement et survivre mĂȘme aprĂšs l'Ă©puration de l'eau, dont la javĂ©llisation. C. parvum peut provoquer une grave maladie, parfois mortelle chez les enfants et les personnes immunodĂ©ficitaires. La comprĂ©hension de l'Ă©pidĂ©miologie de la maladie avance vite ; cependant, des incertitudes demeurent surtout en ce qui concerne l'importance relative de la transmission zoonotique et anthroponotique. Une Ă©tude est conduite Ă  Dagoretti, Nairobi, pour dĂ©terminer la contribution des produits laitiers urbains au problĂšme de la maladie ; et quelques rĂ©sultats prĂ©liminaires relatifs a l'analyse des risques sont prĂ©sentĂ©s dans cet article. L'enquĂȘte est menĂ©e auprĂšs d'une population d'environ 1000 Ă©leveurs et de leurs voisins, Ă  l'aide de donnĂ©es recueillies sur les vaches, les fermes, les mĂ©nages et le milieu. Le prĂ©sent article Ă©voque en dĂ©tail la conception, l'analyse et l'interprĂ©tation des diagrammes de processus, afin d'indiquer les liens spatiaux et temporels entre le pathogĂšne, l'hĂŽte-rĂ©servoir, le milieu et la population. Nous montrons comment par l'incorporation et la modĂ©lisation des informations sur la survie du pathogĂšne, les diagrammes de processus permettent d'avoir une meilleure comprĂ©hension du risque de la maladie et un meilleur choix des interventions pour gĂ©rer avec succĂšs le Cryptosporidium parvum en milieu urbain au Kenya.Bulletin of Animal Health and Production in Africa Vol. 56 (1) 2008: pp. 13-1

    Assessment of benefits and risks in wastewater reuse for agriculture in urban and peri-urban areas of Nairobi including outputs from the feedback workshop : technical project report

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    Mycotoxins in Poultry Feed and Feed Ingredients from Sub-Saharan Africa and Their Impact on the Production of Broiler and Layer Chickens: A Review

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    The poultry industry in sub-Saharan Africa (SSA) is faced with feed insecurity, associated with high cost of feeds, and feed safety, associated with locally produced feeds often contaminated with mycotoxins. Mycotoxins, including aflatoxins (AFs), fumonisins (FBs), trichothecenes, and zearalenone (ZEN), are common contaminants of poultry feeds and feed ingredients from SSA. These mycotoxins cause deleterious effects on the health and productivity of chickens and can also be present in poultry food products, thereby posing a health hazard to human consumers of these products. This review summarizes studies of major mycotoxins in poultry feeds, feed ingredients, and poultry food products from SSA as well as aflatoxicosis outbreaks. Additionally reviewed are the worldwide regulation of mycotoxins in poultry feeds, the impact of major mycotoxins in the production of chickens, and the postharvest use of mycotoxin detoxifiers. In most studies, AFs are most commonly quantified, and levels above the European Union regulatory limits of 20 mu g/kg are reported. Trichothecenes, FBs, ZEN, and OTA are also reported but are less frequently analyzed. Co-occurrences of mycotoxins, especially AFs and FBs, are reported in some studies. The effects of AFs on chickens' health and productivity, carryover to their products, as well as use of mycotoxin binders are reported in few studies conducted in SSA. More research should therefore be conducted in SSA to evaluate occurrences, toxicological effects, and mitigation strategies to prevent the toxic effects of mycotoxins
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