4,323 research outputs found
Assessment of farmer preferences for cattle traits in smallholder cattle production systems of Kenya and Ethiopia
The urgent need to improve livestock productivity in sub.Saharan Africa in order to keep pace with expected increases in demand for meat and milk is very topical. Breed improvement provides key entry points for increasing productivity in cattle populations. However, there are tendencies for genetic improvement programs to focus on single, market driven traits such as milk or meat production in isolation of environmental constraints and broader livestock system functions which cattle perform in developing countries. This potentially leads to genotypes that are not well adapted to the environment and not capable of performing the multiple roles that cattle assume in smallholder systems. In developing countries, many important functions of livestock are embedded in non-tradeable traits that are neither captured in economic analysis nor considered in livestock improvement programs. This study employs Participatory Rural Appraisal (PRA) ranking techniques and conjoint analysis to evaluate preferences of cattle keepers in pastoral and agro-pastoral systems of selected sites in Kenya and Ethiopia for various cattle traits. These systems are characterized by low input management and prevalence of various cattle diseases. Trypanosomosis is a serious disease constraint in Ghibe valley of Ethiopia and some of the pastoral areas in Kenya. The results indicate that farmer preferences for cattle traits are influenced by various factors including production system characteristics, infrastructural constraints and environmental conditions, especially in relation to disease prevalence and availability of cattle feeds. In the crop-livestock systems of Ghibe valley in Ethiopia, preferred cattle traits include trypanotolerance, reproductive potential and fitness to traction. Milk production is a less important trait. On the other hand, in the pastoral and agropastoral systems of Kenya, important traits include trypanotolerance, reproductive potential, coat colour and watering needs
Evolution of habitat and environment of red deer (Cervus elaphus) during the Lateglacial and early Holocene in eastern France using stable isotope composition ( d13C, d15N, d18O) of archaeological bones.
International audienceRed deer (Cervus elaphus) is a flexible species that survived the significant climatic and environmental change toward warming temperature and forested landscape of the Late-glacial to early Holocene transition (ca. 17–6 ka cal BP). To investigate the conditions of ethological adaptation of red deer at that time, isotopic analysis of carbon, nitrogen, sulfur in collagen (δ13Ccoll, δ15Ncoll, δ34Scoll) and of oxygen in phosphate (δ18Op) were performed on red deer from archaeological sites of the French Jura and the western Alps. Fifty out of eighty two samples benefited from direct AMS radiocarbon dating, which confirmed the few number of red deer record during the cold Younger Dryas oscillation (ca. 12.8–11.6 ka cal BP) in Western Europe. The French Jura red deer showed a significant decrease in their δ13Ccoll values and increase in their δ15Ncoll values in the early Holocene compared to the Late-glacial, which is most likely due to the change in environment from open areas with low pedogenic activity to warm dense forests with increasing soil maturity. In contrast, the stable δ13Ccoll and δ15Ncoll values over time in the western Alps were thought to indicate a change to higher altitude for the red deer habitat in this mountainous region. A decrease of the δ18Op values between the Late-glacial and the early Holocene was observed in the western Alps red deer, in contrast to the expected increase with rising temperature which was indeed confirmed for the French Jura red deer. The multi-isotope results pointed to open areas home range at higher altitude for the Alps red deer in the Holocene compared to the previous period. The similarity of the δ34Scoll patterns with those of the δ15Ncoll suggested the primarily influence of soil activity on the 34S abundances recorded by red deer in a purely terrestrial context. Red deer of the French Jura on one hand and of the western Alps on the other hand showed different adaptive response to the global warming of the early Holocene, with an ethological change in the first case and a change in home range in the second case
Model of Enterpreneurship and Social-cultural and Market Orientation of Small Business Owners in Poland
In the development of SMEs in Poland crucial meaning is legislation, steadily adapted to EU regulations, especially to the European Charter for Small Enterprises. Research conducted in Poland by many authors provide data for doing so, to confirm the hypothesis that among small businesses a vital role in shaping their work situation did not continue to play the market mechanisms and orientations, but mainly socio-cultural factors.W rozwoju MŚP w Polsce podstawowe znaczenie mają również uregulowania prawne, systematycznie dostosowywane do regulacji unijnych, zwłaszcza zaś do Europejskiej Karty Małych Przedsiębiorstw. Badania prowadzone w Polsce przez wielu autorów dostarczają danych ku temu, by potwierdzić tezę, że wśród drobnych przedsiębiorców decydującą rolę w kształtowaniu ich sytuacji pracy odgrywają nadal nie mechanizmy i orientacje rynkowe, ale przede wszystkim czynniki społeczno-kulturowe
A Full Characterization of Quantum Advice
We prove the following surprising result: given any quantum state rho on n
qubits, there exists a local Hamiltonian H on poly(n) qubits (e.g., a sum of
two-qubit interactions), such that any ground state of H can be used to
simulate rho on all quantum circuits of fixed polynomial size. In terms of
complexity classes, this implies that BQP/qpoly is contained in QMA/poly, which
supersedes the previous result of Aaronson that BQP/qpoly is contained in
PP/poly. Indeed, we can exactly characterize quantum advice, as equivalent in
power to untrusted quantum advice combined with trusted classical advice.
Proving our main result requires combining a large number of previous tools --
including a result of Alon et al. on learning of real-valued concept classes, a
result of Aaronson on the learnability of quantum states, and a result of
Aharonov and Regev on "QMA+ super-verifiers" -- and also creating some new
ones. The main new tool is a so-called majority-certificates lemma, which is
closely related to boosting in machine learning, and which seems likely to find
independent applications. In its simplest version, this lemma says the
following. Given any set S of Boolean functions on n variables, any function f
in S can be expressed as the pointwise majority of m=O(n) functions f1,...,fm
in S, such that each fi is the unique function in S compatible with O(log|S|)
input/output constraints.Comment: We fixed two significant issues: 1. The definition of YQP machines
needed to be changed to preserve our results. The revised definition is more
natural and has the same intuitive interpretation. 2. We needed properties of
Local Hamiltonian reductions going beyond those proved in previous works
(whose results we'd misstated). We now prove the needed properties. See p. 6
for more on both point
Thriving or surviving? The isotopic record of the Wrangel Island woolly mammoth population
The world's last population of woolly mammoths (Mammuthus primigenius) lived on Wrangel Island persisting well into the Holocene, going extinct at ca. 4000 cal BP. According to the frequency of 'radiocarbon dated mammoth remains from the island, the extinction appears fairly abrupt. This study investigates the ecology of the Wrangel Island mammoth population by means of carbon, nitrogen and sulfur isotope analyses. We report new isotope data on 77 radiocarbon dated mammoth specimens from Wrangel Island and Siberia, and evaluate them in relation to previously published isotope data for Pleistocene mammoths from Beringia and lower latitude Eurasia, and the other insular Holocene mammoth population from St. Paul Island. Contrary to prior suggestions of gradual habitat deterioration, the nitrogen isotope values of the Wrangel Island mammoths do not support a decline in forage quality/quantity, and are in fact very similar to their north Beringian forebears right to the end. However, compared to Siberian mammoths, those from Wrangel Island show a difference in their energy economy as judged by the carbon isotope values of structural carbonate, possibly representing a lower need of adaptive strategies for survival in extreme cold. Increased mid-Holocene weathering of rock formations in the central mountains is suggested by sulfur isotope values. Scenarios related to water quality problems stemming from increased weathering, and a possibility of a catastrophic starvation event as a cause of, or contributing factor in their demise are discussed. (C) 2019 The Authors. Published by Elsevier Ltd.Peer reviewe
Economic analysis of crossbreeding programmes in sub-Saharan Africa: A conceptual framework and Kenyan case study
Conventional economic evaluations of crossbreeding programmes have overestimated their benefits by ignoring subsidies, the increased costs of management such as veterinary support services, and the higher levels of risk and socio-environmental costs associated with the loss of the indigenous genotypes. A conceptual evaluation framework is developed and applied to Kenyan dairy farmers. Results suggest that at the national level crossbreeding has had a positive impact on Kenyan society's welfare, although taking into account important social cost components substantially lowers the net benefits. Farm-level performance is, however, little improved under certain production systems by replacing the indigenous zebu with exotic breeds
Synthesis of new DPP-4 inhibitors based on a novel tricyclic scaffold
A novel molecular scaffold has been synthesized and its synthesis and incorporation into new analogues of biologically active molecules will be discussed. A comparison of the inhibitory activity of these compounds to the known type-2 diabetes compound (sitagliptin) against dipeptidyl peptidase-4 (DPP-4) will be shown
Web platform for geospatial information: aplications for GeoPECUS project.
The aim of this article is to describe and report how the GeoPECUS project is using the standards and rules established by the Brazilian National SDI to publish and organize the geospatial data produced by the PECUS Research Network.Coordenador: Roberto Giolo de Almeida. II SIGEE. Disponível em . Acesso em: 06 dez. 2016
TSH-CHECK-1 test: diagnostic accuracy and potential application to initiating treatment for hypothyroidism in patients on anti-tuberculosis drugs.
Thyroid-stimulating hormone (TSH) promotes expression of thyroid hormones which are essential for metabolism, growth, and development. Second-line drugs to treat tuberculosis (TB) can cause hypothyroidism by suppressing thyroid hormone synthesis. Therefore, TSH levels are routinely measured in TB patients receiving second-line drugs, and thyroxin treatment is initiated where indicated. However, standard TSH tests are technically demanding for many low-resource settings where TB is prevalent; a simple and inexpensive test is urgently needed
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