511 research outputs found

    PRELIMINARY BASELINE SURVEY OF AVIFAUNAL DIVERSITY IN JIMMA ZONE, SOUTH-WESTERN ETHIOPIA

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    Multidimensional poverty, which is deeply-rooted within least-developed African countries like Ethiopia, is forcing local people to heavily rely on natural resources for their subsistent livelihoods. As a result, remaining wilderness areas in tropical Africa which support huge but little known biological diversity, are subject to extensive habitat loss, fragmentation and degradation in turn causing loss of plant and animal species and ecosystem services provided by them. Coffee forest fragment within the Jimma Zone of Ethiopia cannot be expected to be an exception to such scenario. Taking this persistent problem into consideration, we carried out a preliminary survey of bird biodiversity in selected areas of Jimma Zone during a short term bird ringing training held from Sept. 30 to Oct. 20, 2008. The main objective of the survey was to identify and document bird species of Jimma Zone, Southwestern Ethiopia, for further in-debth ornithological studies. Survey data were collected through exhaustive observations in and around 10 coffee forest fragments in Garuke, one fragment in Eladale, one urban area site in Jimma town and in scrubland vegetation around Gilgel Ghibe hydropower reservoir, Jimma Zone, Southwestern Ethiopia. In addition, five mist-nets were employed to capture understory forest birds in two purposively selected coffee forest fragments. Mist nets were opened at 5:50 A.M. and checked every 30 minutes until they were closed at 12:00 A.M. Over 196 bird species were identified during this survey and of these, 41 individuals belonging to 20 species were captured in Garuke and 23 individuals of 9 bird species in Eladale. Montane white-eye (Zosterops poliogastrus) followed by Olive sunbird (Nectarinia olivacea), Abyssinian slaty-flycatcher (Melaenornis chocolatinus) and Rupell’s robinchat (Cossypha semirufa) were the most frequently captured bird species. Of the sites surveyed, Gilgel Ghibe hydropower reservoir had strikingly highest bird species diversity. We approached the reservoir almost in a constant site near Bulbul Kebele (the smallest administrative unit in Ethiopia) and recorded over 115 bird species within about 300 meters distance! We learnt that this area was an important and most appropriate site to see a number of migrant and resident species as well as to undertake future bird ringing activities. We believe that the result of this survey will contribute much for the preparation of a comprehensive bird species checklist for Jimma Zone that could serve as important baseline information for more focused future ornithological investigations in the area so as to promote bird conservation through ecotourism activities and improve the livelihood of local people

    Ancient pigs reveal a near-complete genomic turnover following their introduction to Europe

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    Archaeological evidence indicates that pig domestication had begun by ∼10,500 y before the present (BP) in the Near East, and mitochondrial DNA (mtDNA) suggests that pigs arrived in Europe alongside farmers ∼8,500 y BP. A few thousand years after the introduction of Near Eastern pigs into Europe, however, their characteristic mtDNA signature disappeared and was replaced by haplotypes associated with European wild boars. This turnover could be accounted for by substantial gene flow from local European wild boars, although it is also possible that European wild boars were domesticated independently without any genetic contribution from the Near East. To test these hypotheses, we obtained mtDNA sequences from 2,099 modern and ancient pig samples and 63 nuclear ancient genomes from Near Eastern and European pigs. Our analyses revealed that European domestic pigs dating from 7,100 to 6,000 y BP possessed both Near Eastern and European nuclear ancestry, while later pigs possessed no more than 4% Near Eastern ancestry, indicating that gene flow from European wild boars resulted in a near-complete disappearance of Near East ancestry. In addition, we demonstrate that a variant at a locus encoding black coat color likely originated in the Near East and persisted in European pigs. Altogether, our results indicate that while pigs were not independently domesticated in Europe, the vast majority of human-mediated selection over the past 5,000 y focused on the genomic fraction derived from the European wild boars, and not on the fraction that was selected by early Neolithic farmers over the first 2,500 y of the domestication process

    Improving early warning systems for agricultural resilience in Africa

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    Extreme climate events can undermine agriculture and rural development. Even in years when extreme events do not occur, the uncertainty that results from climate-related risk is an impediment to sustainable intensification of agriculture and adoption of climate-smart agricultural production practices. In an era of more frequent and more extreme weather events and climate shocks, enhanced early warning systems provide a key opportunity to curb erosion of development progress in rural sectors. This Info Note sets out recommendations to African policy makers for strengthening existing early warning systems and developing new systems in Africa

    Noradrenergic α1 Receptor Antagonist Treatment Attenuates Positive Subjective Effects of Cocaine in Humans: A Randomized Trial

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    Preclinical research implicates dopaminergic and noradrenergic mechanisms in mediating the reinforcing effects of drugs of abuse, including cocaine. The objective of this study was to evaluate the impact of treatment with the noradrenergic α(1) receptor antagonist doxazosin on the positive subjective effects of cocaine.Thirteen non-treatment seeking, cocaine-dependent volunteers completed this single-site, randomized, placebo-controlled, within-subjects study. In one study phase volunteers received placebo and in the other they received doxazosin, with the order counterbalanced across participants. Study medication was masked by over-encapsulating doxazosin tablets and matched placebo lactose served as the control. Study medication treatment was initiated at 1 mg doxazosin or equivalent number of placebo capsules PO/day and increased every three days by 1 mg. After receiving 4 mg doxazosin or equivalent number of placebo capsules participants received masked doses of 20 and 40 mg cocaine IV in that order with placebo saline randomly interspersed to maintain the blind.Doxazosin treatment was well tolerated and doxazosin alone produced minimal changes in heart rate and blood pressure. During treatment with placebo, cocaine produced dose-dependent increases in subjective effect ratings of "high", "stimulated", "like cocaine", "desire cocaine", "any drug effect", and "likely to use cocaine if had access" (p<.001). Doxazosin treatment significantly attenuated the effects of 20 mg cocaine on ratings of "stimulated", "like cocaine", and "likely to use cocaine if had access" (p<.05). There were trends for doxazosin to reduce ratings of "stimulated", "desire cocaine", and "likely to use cocaine if had access" (p<.10).Medications that block noradrenergic α₁ receptors, such as doxazosin, may be useful as treatments for cocaine dependence, and should be evaluated further.Clinicaltrials.gov NCT01062945

    Seasonal surface drainage of sloping farmland : a review of its hydrogeomorphic impacts

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    The combination of runoff-generating areas (saturated soils) and overland flow concentration in features such as drainage ditches makes sloping farmland vulnerable to soil erosion. The establishment of drainage ditches aims at draining the excess of water from the farmland, particularly in areas where soils are saturated in the rainy season. The hydrogeomorphic impacts on the farmland itself and on downstream areas need however also to be studied. Off site, downstream problems comprise higher peak discharges, leading to gully initiation, an increase in sediment load, and flooding problems. On-site problems such as the development of the drainage ditches into (ephemeral) gullies are less documented, although they may be important, as illustrated in the Lake Tana Basin (Ethiopia). The similarities and interactions between ephemeral gully channels and drainage ditches have to be considered to better understand all effects of drainage. Drainage ditches are a potential source of conflict between farmers with different interests and power, as well as between upstream and downstream users. A case study on drainage ditches on sloping farmlands in the Lake Tana Basin showed that nine out of ten catchments had drainage densities by ditches ranging from 53 to 510 m ha−1. Drainage ditches were constructed with an average top width of 27 (±9) cm. A significant correlation was found between stone bund density (physical conservation structures) and ditch drainage density (R = −0·72), in line with the Ethiopian government's ban on drainage ditches in farmlands where stone bunds have been constructed

    Potentials of 3D extrusion‐based printing in resolving food processing challenges: A perspective review

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    Three-dimensional (3D) printing has promising application potentials in improving food product manufacturing, increasingly helping in simplifying the supply chain, as well as expanding the utilization of food materials. To further understand the current situation of 3D food printing in providing food engineering solutions with customized design, the authors checked recently conducted reviews and considered the extrusion-based type to deserve additional literature synthesis. In this perspective review, therefore, we scoped the potentials of 3D extrusion-based printing in resolving food processing challenges. The evolving trends of 3D food printing technologies, fundamentals of extrusion processes, food printer, and printing enhancement, (extrusion) food systems, algorithm development, and associated food rheological properties were discussed. The (extrusion) mechanism in 3D food printing involving some essentials for material flow and configuration, its uniqueness, suitability, and printability to food materials, (food material) types in the extrusion-based (3D food printing), together with essential food properties and their dynamics were also discussed. Additionally, some bottlenecks/concerns still applicable to extrusion-based 3D food printing were brainstormed. Developing enhanced calibrating techniques for 3D printing materials, and designing better methods of integrating data will help improve the algorithmic representations of printed foods. Rheological complexities associated with the extrusion-based 3D food printing require both industry and researchers to work together so as to tackle the (rheological) shifts that make (food) materials unsuitable.info:eu-repo/semantics/publishedVersio
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