433 research outputs found

    Will Small-Scale Dairy Producers in Kenya Disappear Due to Economies of Scale in Production?

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    There is growing policy concern regarding the competitiveness of small-scale livestock production in the wake of the contemporary livestock revolution in many developing countries. In Kenya, this debate has focused on economies of scale and the undue influence of policy distortions on promoting the scaling up of dairy farms. This paper seeks to investigate economies of scale in Kenyan dairy in terms of relative profit efficiency at different levels of output, and identify policy and technology options to help small-scale farmers develop solutions to the challenges of competition. Data were collected from 204 dairy producers of different farm sizes in rural Kiambu and Thika, and urban Nairobi districts and a stochastic frontier model approach was used to analyze the determinants of profitability and inefficiency. Unit profitability per farm ranged between US0.13−US0.13 - US0.16 per liter of milk with no significant variation across scales of farm. However, at all given levels of scale of farm, inefficiency significantly contributed to variability in profitability across farms. Scale had no significant effect on efficiency, confirming the relative competitiveness of small-scale dairy producers. Dairy farmers with commercial poultry achieved higher relative profit efficiency as poultry waste was fed to cattle. Rural location relative to Nairobi also increased efficiency. Linking rural areas and major market centre with good roads, strengthening of farmers' co-operative societies and exploring use of cheaper raw materials in the manufacture of concentrate feeds may strengthen the competitive position small dairy farms versus large ones.Dairy Production, Stochastic Production Frontier, Efficiency, Profitability, Livestock Production/Industries, C21, Q12,

    SPATIAL ANALYSIS OF SOIL FERTILITY MANAGEMENT USING INTEGRATED HOUSEHOLD AND GIS DATA FROM SMALLHOLDER KENYAN FARMS

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    Although soil fertility is recognized as a primary constraint to agricultural production in developing countries, use of fertilizer in Sub-Saharan Africa is declining. Smallholder farmers still rely heavily on livestock manure for soil fertility management. To explore the determinants of soil fertility management practices, including both the use of cattle manure and inorganic fertilizer, data are used from a sample of 3,330 geo-referenced farm households across Central and Western Kenya. A bivariate probit model is applied to jointly examine the use of the two technologies. Particular attention is given to measures of location related to market access and agroclimate, which in the adoption literature have typically been addressed using crude proxies. To avoid such proxies, GIS-derived variables are integrated into the household decision model. Their use also allows the spatial prediction of uptake based on parameter estimates. The results show clearly the derived-demand nature of soil fertility services, based on markets for farm outputs. They also illustrate that supply of manure for soil fertility amendments is conditioned by demand for livestock products, especially milk. The integration of GIS-derived variables is shown to better estimate the effects of location than the usual measures employed, and offers scope to wider use in technology adoption research.spatial analysis, soil fertility, market access, technology adoption., Farm Management, Land Economics/Use, Q12, Q16,

    Atomistic Simulation of Graphene-Polyurethane Nanocomposite for Use in Ballistic Applications

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    Exposure to high impact velocity is the principle limiting factor of material performance in ballistic applications for use in civilian and defense industries. Graphene has emerged as a material of scientific interest due to its exceptional mechanical and thermal properties. When incorporated appropriately in a polymer matrix, graphene can significantly improve properties of polymers at small loading, while preserving the integrity of the polymer. Graphene based polymer nanocomposites provide a novel approach for material design for ballistic applications. The reliability of graphene/polymer nanocomposites on end use applications depends on understanding the effect of structure-property relationship of nanocomposite. A first approach to engineering nanocomposite for ballistic applications requires thorough understanding of physical properties change with incorporation of nanofillers in polymer matrix. One significant class of properties tremendously affected by inclusion of nanofiller is thermodynamic properties. Therefore, a first investigative study, we explore non-linear elastic behavior of graphene using first principle method, specifically Density-Functional Theory (DFT), and atomistic simulation. Using DFT, we calculated the equation of state (EOS) and elastic constants of graphene. The results are in agreement with experimental and other theoretical studies using DFT. However, accuracy of atomistic simulations is limited by empirical potentials. Nevertheless, general anisotropic, non-linear mechanical behavior of graphene is evident on both approaches. Additionally we use molecular dynamics (MD) simulations to study effect of graphene nanofiller on thermo‑mechanical properties of polyurethane. We have calculated thermodynamic, structural and mechanical properties of the amorphous polyurethane and its graphene nanocomposite. Our results show significant enhancement of thermal-mechanical properties. The final part of this dissertation, we used non-equilibrium molecular dynamics (NEMD) simulations to investigate dynamic response behavior of polyurethane and its graphene nanocomposite. Calculation of Hugoniot states of polyurethane agrees with experimental studies. However, a phase change phenomenon observed in experimental work was not visible in the present work. This is due to bond breaking and formation, which is a clear characterization of phase changes. Graphene-polyurethane nanocomposites demonstrate similar shock wave propagation illustrating characteristics of impeding shock wave when subjected to different particle velocities. This is due to graphene inducing stress concentrations in the composite, which may increase yield strength

    Utilization of community-based outpatient addiction treatment programmes in Kenya

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    This paper examines a number of outpatient addictions treatment programmes developed in various regions of Kenya. The uptake of outpatient services at four sites between 2007 and 2010 has been examined. A field-based follow-up survey was administered to determine abstinence rates among clients who participated in treatment. Factors involved in recovery outcomes are discussed. Utilization of outpatient addictions treatment and retention in services increased over the three-year period, and field-based follow up with clients showed 42% abstinence rates. Key Words: Outpatient treatment, Alcohol, Drug, Addiction recovery, HIV, Keny

    Nutrient flows and balances in intensive crop-dairy production systems in the Kenya highlands

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    Sustainability of their agricultural systems is essential for many tropical countries where the majority of the people depend upon agriculture for their livelihoods. In the short term economic sustainability is the main factor influencing viability of an agricultural system and of the farms which form its production units. In the long-term, however, economic viability will depend upon the nutrient status of a system. In common with much of the eastern African highlands, Kiambu district in central Kenya has high and increasing pressure on its land and farmers are responding by steadily intensifying their farming systems. This paper addresses the hypothesis that where ruminant livestock are present in intensifying smallholder cropping systems, they make a positive contribution to the nutrient status of the smallholder system. For 21 crop-dairy farms representative of the major smallholder-farming systems in the central highlands of Kenya, annual nutrient balances were determined in a longitudinal study. The farms were visited twice a week; data on all farm inputs and outputs were collected, based on farmer recall. Measures of livestock feed inputs were collected fortnightly. Estimates of nutrient gains and losses in the soil resulting from erosion, leaching, denitrification, volatilisation and N fixation were taken from the literature. Using these data, annual nutrient balances per hectare were estimated for N, P and K. The majority of the sample farms had balanced nutrient flows or were in positive balance for N, P and K overall because of positive flows to the dairy sub-unit, which counterbalanced the outflows from the crop sub-unit. The dairy unit contributed significantly, principally through feed purchases, particularly concentrates for lactating cows. Napier grass and crop residues were also purchased, and large quantities of roadside grass were collected from outside the farms. On the majority of the farms the nutrients returned to the cropping land as manure (which consisted of faeces, bedding material and feed refusals) contributed more nutrients than inorganic fertilisers. It is concluded that the dairy cattle played a major role in contributing nutrient in-flows into these intensive smallholder farms, as well as providing the household’s regular source of income through milk sales

    Taxonomic revision of the Afrotropical Agabus raffrayi species group with the description of four new species (Coleoptera, Dytiscidae)

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    We revise the Afrotropical Agabus raffrayi species group, motivated by the discovery of new diversity in Kenya and South Africa. Whilst Agabus is mainly a holarctic genus, the Agabus raffrayi group is restricted to high altitude regions of eastern Africa and temperate parts of South Africa, from where we describe the southernmost Agabus in the world. The following new species are introduced: Agabus anguluverpus sp. nov. from Mount Kenya in central Kenya, Agabus austellus sp. nov. a widespread species in South Africa, Agabus riberae sp. nov. from the Kamiesberg and northeastern Cederberg ranges in the Northern and Western Cape Provinces of South Africa and Agabus agulhas sp. nov. from the Agulhas Plain, Western Cape Province, South Africa. We provide a distribution map, a determination key for males, quantitative measurements of diagnostic characters, habitus photos and detailed photos of male genitalia for all described species in the group, as well as images of diagnostic characters and habitats. The presence or absence of an elongated section between the subapical broadening and the base of the apical and subapical teeth of the male aedeagus is a useful novel character, first revealed by our study. In contrast with the most recent revision of Afrotropical Agabus, we show that Agabus ruwenzoricus Guignot, 1936 is restricted to eastern Africa; South African records of this species having been based on misidentifications, no species of the group being common to southern and eastern Africa. We speculate that the raffrayi group may display phylogenetic niche conservatism, being restricted, as an originally temperate taxon, to higher elevations in tropical eastern Africa, but occurring at lower altitudes in temperate South Africa

    Targeting dairy interventions in Kenya: a guide for development planners, researchers and extension workers

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    This easy-to-use guide to effective targeting of selected dairy interventions in Kenya is intended for use by anyone involved in dairy farming in the country, such as development planners, researchers, service providers, suppliers of dairy inputs and extension workers. The guide answers the question often faced by these workers: where is their proposed intervention most likely to be adopted? Using a combination of Geographical Information Systems (GIS) mapping methods and economic regression techniques, this guide shows where and under what circumstances dairy technologies are most likely to succeed. The guide is divided into three sections. The first section deals with concepts, rationale and methodologies for targeting dairy interventions. It also explains, with examples, how to use the guide. The second section presents the targeting maps for various dairy interventions. A total of eleven dairy interventions are considered in this guide. For each, a map shows relative probability of adoption together with a description of the innovation and background information. Also presented are the socio-economic, biophysical and agro-climatic characteristics that predispose uptake of each intervention. The third section presents some policy-relevant research results in three topical areas: Cost of milk production; Evaluation and assessment of alternative milk preservation techniques; and Employment generation in the dairy marketing chain

    The extent of and factors associated with self-reported overdose and self-reported receipt of naloxone among people who inject drugs (PWID) in England, Wales and Northern Ireland.

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    BACKGROUND: Overdose is a major cause of death among PWID, and for opioid overdoses naloxone administration can reduce harm. However, globally there is limited national level data on the extent of non-fatal overdose and naloxone uptake. The first national level data on the extent of self-reported overdose and self-reported receipt of naloxone among UK PWID, providing a baseline to monitor the impact of the recent policy change regarding naloxone availability, is presented. METHODS: Data on self-reported overdose and receipt of naloxone during the preceding year for 2013-2014 from a national survey of PWID was analysed. Participants who reported injecting during the preceding year were included. RESULTS: Participants (3850) were predominantly male (75%); mean age was 36 years. The most commonly injected drugs were: heroin (91%), crack (45%) and amphetamine (29%). 15% (591) reported overdosing during the preceding year. There were no differences in the proportion reporting overdose by age or gender, but overdose was more common among those who: injected multiple drugs; recently ceased addiction treatment; injected with used needles/syringes; ever had transactional sex; had used a sexual health clinic or emergency department and lived in Wales or Northern Ireland. Among those reporting an overdose during the preceding year, a third reported two to four overdoses and 7.5% five or more overdoses; half reported receiving naloxone. Those reporting naloxone receipt in the preceding year were more likely to: live in Wales or Northern Ireland; ever received used needles/syringes; ever been imprisoned; and less likely to have injected two drug types. CONCLUSION: These data provide a baseline for monitoring the impact of the 2015 UK policy change to improve take-home naloxone access. Interventions tackling overdose should promote naloxone awareness and access, and target those who; are poly-drug injectors, have ceased treatment, share needles/syringes and whose drug use links to sexual activity

    Nutrients limiting soybean (glycine max l) growth in acrisols and ferralsols of western Kenya

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    Low soybean yields in western Kenya have been attributed to low soil fertility despite much work done on nitrogen (N) and phosphorus (P) nutrition leading to suspicion of other nutrient limitations. To investigate this, a nutrient omission trial was set up in the greenhouse at the University of Eldoret-Kenya to diagnose the nutrients limiting soybean production in Acrisols from Masaba central and Butere sub-Counties, and Ferralsols from Kakamega (Shikhulu and Khwisero sub-locations) and Butula sub-Counties and to assess the effect of liming on soil pH and soybean growth. The experiment was laid out in a completely randomized design with ten treatments viz; positive control (complete), negative control (distilled water), complete with lime, complete with N, minus macronutrients P, potassium (K), calcium (Ca), magnesium (Mg) and sulphur (S) and with, micro-nutrients boron (B), molybdenum (Mo), manganese (Mn), copper (Cu) and zinc (Zn) omitted. Visual deficiency symptoms observed included interveinal leaf yellowing in Mg omission and N addition and dark green leaves in P omission. Nutrients omission resulted in their significantly low concentration in plant tissues than the complete treatment. Significantly (P≀ 0.05) lower shoot dry weights (SDWs) than the complete treatment were obtained in different treatments; omission of K and Mg in Masaba and Shikhulu, Mg in Khwisero, K in Butere and, P, Mg and K in Butula. Nitrogen significantly improved SDWs in soils from Kakamega and Butula. Liming significantly raised soil pH by 9, 13 and 11% from 4.65, 4.91 and 4.99 in soils from Masaba, Butere and Butula respectively and soybean SDWs in soils from Butere. The results show that, poor soybean growth was due to K, Mg and P limitation and low pH in some soils. The results also signify necessity of application of small quantities of N for initial soybean use
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