650 research outputs found

    Wood fuel Utilization Patterns and Cooking Devices Efficiency Analysis for Likia Residents, Njoro Kenya

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    Over 2.6 billion people of the world’s population prepare their food and heat their homes with coal and the traditional biomass fuel. Wood fuel continues to be used as a major source of energy without a replacement program and is partly the cause of wide spread deforestation at an alarming rate of about 13 million hectares per year. Crucial to slowing the loss of the vegetation is promoting alternative sources of energy and/or using fuel efficient devices. This study examined the efficiency of cooking devices and the wood fuel consumption patterns among the rural population sampled from Kenya in Likia village near Njoro, so as to determine the more efficient cooking device and corresponding wood fuel. Initially, a survey was carried out capturing baseline data on the wood fuel utilization patterns and Split Plot in Randomized Complete Block Experimental Design used to select an efficient heating device where heating devices were a sub plot factor and the sources of energy as main plot factor to study the efficiencies of the devices. The results showed that wood fuel was the major source of cooking energy among the study population, and there were significant differences in the efficiencies of the devices due to the fuel type, the devices and interaction between the fuel and the devices. Among the recommendations made include the need to promote on-farm forestry specifically for wood fuel and timber production; effective management of natural forests, creating awareness about the key ecological services provided by forest ecosystems and delayed possible deforestation; promotion of energy saving stoves, the improvement of biomass briquette burning properties alongside the design of stoves for briquette use. Ultimately these results are expected to contribute to the slowing down of deforestation of the Mau Forest which is major water catchment for East Africa with overflow benefits to the Sudan and Egypt and promote sustainable uses of forest resources. Keywords: Wood fuel, Cooking devices, Efficienc

    Evaluation of tandem repeats for MLVA typing of Streptococcus uberis isolated from bovine mastitis

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    BACKGROUND: Streptococcus uberis is a common cause of bovine mastitis and recommended control measures, based on improved milking practice, teat dipping and antibiotic treatment at drying-off, are poorly efficient against this environmental pathogen. A simple and efficient typing method would be helpful in identifying S.uberis sources, virulent strains and cow to cow transmission. The potential of MLVA (Multiple Loci VNTR Analysis; VNTR, Variable Number of Tandem Repeats) for S. uberis mastitis isolates genotyping was investigated. RESULTS: The genomic sequence of Streptococcus uberis (strain 0104J) was analyzed for potential variable number tandem repeats (VNTRs). Twenty-five tandem repeats were identified and amplified by PCR with DNA samples from 24 S. uberis strains. A set of seven TRs were found to be polymorphic and used for MLVA typing of 88 S. uberis isolates. A total of 82 MLVA types were obtained with 22 types among 26 strains isolated from the milk of mastitic cows belonging to our experimental herd, and 61 types for 62 epidemiologically unrelated strains, i.e. collected in different herds and areas. CONCLUSION: The MLVA method can be applied to S. uberis genotyping and constitutes an interesting complement to existing typing methods. This method, which is easy to perform, low cost and can be used in routine, could facilitate investigations of the epidemiology of S. uberis mastitis in dairy cows

    Repertoire of Escherichia coli agonists sensed by innate immunity receptors of the bovine udder and mammary epithelial cells

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    Escherichia coli is a frequent cause of clinical mastitis in dairy cows. It has been shown that a prompt response of the mammary gland after E. coli entry into the lumen of the gland is required to control the infection, which means that the early detection of bacteria is of prime importance. Yet, apart from lipopolysaccharide (LPS), little is known of the bacterial components which are detected by the mammary innate immune system. We investigated the repertoire of potential bacterial agonists sensed by the udder and bovine mammary epithelial cells (bMEC) during E. coli mastitis by using purified or synthetic molecular surrogates of bacterial agonists of identified pattern-recognition receptors (PRRs). The production of CXCL8 and the influx of leucocytes in milk were the readouts of reactivity of stimulated cultured bMEC and challenged udders, respectively. Quantitative PCR revealed that bMEC in culture expressed the nucleotide oligomerization domain receptors NOD1 and NOD2, along with the Toll-like receptors TLR1, TLR2, TLR4, and TLR6, but hardly TLR5. In line with expression data, bMEC proved to react to the cognate agonists C12-iE-DAP (NOD1), Pam3CSK4 (TLR1/2), Pam2CSK4 (TLR2/6), pure LPS (TLR4), but not to flagellin (TLR5). As the udder reactivity to NOD1 and TLR5 agonists has never been reported, we tested whether the mammary gland reacted to intramammary infusion of C12-iE-DAP or flagellin. The udder reacted to C12-iE-DAP, but not to flagellin, in line with the reactivity of bMEC. These results extend our knowledge of the reactivity of the bovine mammary gland to bacterial agonists of the innate immune system, and suggest that E. coli can be recognized by several PRRs including NOD1, but unexpectedly not by TLR5. The way the mammary gland senses E. coli is likely to shape the innate immune response and finally the outcome of E. coli mastitis

    RELATIONSHIP BETWEEN HUMAN RESOURCE AND SUSTAINABILITY OF FREE DAY SECONDARY EDUCATION; A SURVEY OF IMENTI NORTH SUB-COUNTY, KENYA

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    This study aimed at establishing the relationship between Human resource and sustainability of public day secondary schools in Imenti North Sub-County, Meru County. The study had the following objectives; the influence of salary, management leadership, incentives, training and development and their relationship with sustainability of public day secondary schools in Kenya. This study sought to test the hypothesis that; salary, management leadership, incentives, training and development affect sustainability of free day secondary schools. The study adopted descriptive and explorative research design since its main aim is to explain human resource variables that affect sustainability of public day secondary schools in Kenya. The target population was 29 public day secondary schools in Imenti North sub-County. The respondents were selected using stratified random sampling to identify sample schools and simple random sampling to select respondents from the identified strata. The sample respondents comprised of 12 principals, 61 HODs and 136 teachers totaling 173 respondents. Data was collected using structured open ended, closed ended and unstructured questionnaire. Reliability was tested by test–retest method using Cronbach's alpha correlation coefficient which was used to test the correlations between the items. Correlation coefficient of above 0.7 was obtained and was deemed acceptable for the study. Data was analyzed by use of descriptive statistics and logistic regression. Descriptive statistics and multiple logistic regression was used to test the cause and effect relationship between the dependent and independent variables under the study. All the hypothesis was tested at 5% level of significance or 95% confidence level. The analyzed data is presented in frequency tables, pie charts and bar graphs. It is expected that the results of the study will assist education stakeholders and the Ministry of education to address human resource challenges that affect sustainability of public day secondary schools in Kenya.JEL: J24, O15, H75, I25 Article visualizations

    Establishment of Cowpeas in Bermudagrass Sod

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    Last updated: 6/1/200

    Effect of actual and accelerated ageing on microstructure evolution and mechanical properties of a 2024-T351 aluminium alloy

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    This paper presents an investigation on the effects of ageing on the microstructure and the corresponding physical and mechanical properties of a 2024 aluminium alloy used in a civil transport aircraft wing structure in order to assess the residual resistance of the end of a service life. More precisely, heat treatments are applied in order to simulate thermal ageing actually endured by the structure during service. The results of characterisation of microstructural, physical and mechanical properties are compared not only to the data obtained on a pristine alloy, but also to the results obtained on coupons of a similar alloy coming from the teardown of an A320 aircraft using the same experimental procedure. The main findings are that, during a service life, no significant modification in fatigue resistance is noticed despite of changes in the precipitation structure

    Petrography and Geochemistry of the Rocks in Lodwar, Kenya and their Influences on Groundwater Quality

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    Rock geochemistry influences groundwater quality and the aquifer processes of an area. The geology of the study area comprises quartzo-feldspathic gneiss and biotite gneiss of the Precambrian basement, sedimentary Turkana Grits and Holocene sediments, Tertiary volcanics comprising nepheline phonolites and augite basalts, alluvial deposits along the banks of major streams and laggas (ephemeral streams), and Quaternary sands that blanket much of the area. This paper evaluates the influence of rock chemistry on groundwater quality in Lodwar area. Conventional petrography and geochemistry techniques involving measurement of major elements using X-ray fluorescence (XRF) and trace elements using and X-ray diffraction (XRD) in 69 rock samples to evaluate their mineralogical compositions. The major rock-forming in rocks of the study area include pyroxenes, olivine, kaolinite, siderite, fluorite calcite and dolomite. These minerals release major ions to groundwater through weathering, leaching, oxidation, dissolution and precipitation, and ion exchange reactions during rock-water interactions. The rocks in study area have generally low amounts of Na and K with modal values < 2.00 wt%, suggesting other sources of Na+ and K+ ions in groundwater. In contrast, Ca, Mg, Al, Fe and Mn are released to groundwater from rocks, as shown by high modal compositions of individual elements and associated oxides. The higher concentrations of Na+, K+, Ca2+ and Mg2+ in the groundwater of the Turkana Grit aquifer relative to the grit rock samples suggest a long history of dissolution and recycling of the groundwater. The ratio SiO2:Al2O3 was found to be greater than 8.0 implying a high degree of maturity of the grits. The results presented by this study show that geological factors and processes have location-specific influence on groundwater quality and should be considered in aquifer water quality studies and supply development across Africa’s vast ASAL regions

    Differential response of bovine mammary epithelial cells to Staphylococcus aureus or Escherichia coli agonists of the innate immune system

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    Mastitis caused by Escherichia coli and Staphylococcus aureus is a major pathology of dairy cows. To better understand the differential response of the mammary gland to these two pathogens, we stimulated bovine mammary epithelial cells (bMEC) with either E. coli crude lipopolysaccharide (LPS) or with S. aureus culture supernatant (SaS) to compare the transcriptomic profiles of the initial bMEC response. By using HEK 293 reporter cells for pattern recognition receptors, the LPS preparation was found to stimulate TLR2 and TLR4 but not TLR5, Nod1 or Nod2, whereas SaS stimulated TLR2. Biochemical analysis revealed that lipoteichoic acid, protein A and alpha-hemolysin were all present in SaS, and bMEC were found to be responsive to each of these molecules. Transcriptome profiling revealed a core innate immune response partly shared by LPS and SaS. However, LPS induced expression of a significant higher number of genes and the fold changes were of greater magnitude than those induced by SaS. Microarray data analysis suggests that the activation pathways and the early chemokine and cytokine production preceded the defense and stress responses. A major differential response was the activation of the type I IFN pathway by LPS but not by SaS. The higher upregulation of chemokines (Cxcl10, Ccl2, Ccl5 and Ccl20) that target mononuclear leucocytes by LPS than by SaS is likely to be related to the differential activation of the type I IFN pathway, and could induce a different profile of the initial recruitment of leucocytes. The MEC responses to the two stimuli were different, as LPS was associated with NF-kappaB and Fas signaling pathways, whereas SaS was associated with AP-1 and IL-17A signaling pathways. It is noteworthy that at the protein level secretion of TNF-alpha and IL-1beta was not induced by either stimulus. These results suggest that the response of MEC to diffusible stimuli from E. coli and S. aureus contributes to the onset of the response with differential leucocyte recruitment and distinct inflammatory and innate immune reactions of the mammary gland to infection

    Investigating the contribution of IL-17A and IL-17F to the host response during Escherichia coli mastitis

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    Mastitis remains a major disease of cattle with a strong impact on the dairy industry. There is a growing interest in understanding how cell mediated immunity contributes to the defence of the mammary gland against invading mastitis causing bacteria. Cytokines belonging to the IL-17 family, and the cells that produce them, have been described as important modulators of the innate immunity, in particular that of epithelial cells. We report here that expression of IL-17A and IL-17F genes, encoding two members of the IL-17 family, are induced in udder tissues of cows experimentally infected with Escherichia coli. The impact of IL-17A on the innate response of bovine mammary epithelial cells was investigated using a newly isolated cell line, the PS cell line. We first showed that PS cells, similar to primary bovine mammary epithelial cells, were able to respond to agonists of TLR2 and to LPS, provided CD14 was added to the culture medium. We then showed that secretion of CXCL8 and transcription of innate immunity related-genes by PS cells were increased by IL-17A, in particular when these cells were stimulated with live E. coli bacteria. Together with data from the literature, these results support the hypothesis that IL-17A and IL-17 F could play an important role in mediating of host-pathogen interactions during mastitis
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