724 research outputs found

    General Samora Yenus: Profile, Sudanese award, Expert comment

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    Unless otherwise indicated, all text posts are original productions of HornAffairs. If you copy and re-publish this post, you shall include a link to this page as well as a clear reference to HornAffairs and to the author.Sudanese President Al-Bashir honoured General Samora Yenus, the Chief of Staff of the Ethiopian National Defence Forces (ENDF), with the highest military medal, the Order of the two Niles. The former rebel commander, Samora, has been in charge of the army’s military commitment in the region and the continent for a decade and a half. According to the UK’s Professor Ann Fitz-Gerald, the Sudanese military medal award “has significance for Sudan, Ethiopia and the wider Horn of Africa region”

    Photodetachment of cold OH- in a multipole ion trap

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    The absolute photodetachment cross section of OH- anions at a rotational and translational temperature of 170K is determined by measuring the detachment-induced decay rate of the anions in a multipole radio-frequency ion trap. In comparison with previous results, the obtained cross section shows the importance of the initial rotational state distribution. Using a tomography scan of the photodetachment laser through the trapped ion cloud, the derived cross section is model-independent and thus features a small systematic uncertainty. The tomography also yields the column density of the OH- anions in the 22-pole ion trap in good agreement with the expected trapping potential of a large field free region bound by steep potential walls.Comment: Phys. Rev. Lett., in pres

    Structural, optical and electrical properties of electron beam evaporated TiOxNy films as selective solar absorber coatings

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    Titanium oxinitride (TiOxNy) solar absorber coatings were deposited at different oxygen partial pressures onto Cu, Si and glass substrates using electron beam evaporation technique. XRD diffraction patterns evidenced (111), (200) and (220) orientation of TiNx phase. The preferred orientation of the films changed with oxygen partial pressure. XPS revealed the intensity of both Ti 2P3/2 and Ti 2P1/2 increases as a function of oxygen flow, and also shifted towards higher binding energy, indicating more oxidized state of Ti species than that of TiO2 due to incorporation of nitrogen atoms. Formation of uniformly distributed spherical like particles and an increase in surface roughness of the TiOxNy films were observed as a function of oxygen partial pressure as depicted from SEM and AFM, respectively. Ellipsometric and resistivity measurements showed a shift from metallic to semiconductor behaviour of the TiOxNy films as oxygen flow changed. A solar absorptance value of 0.94 in the solar spectrum region and a low thermal emittance value of 0.05 were achieved for the TiOxNy solar absorber coatings prepared at the oxygen partial pressure of 7.5x10-5 Torr due to both interference and intrinsic absorption. This study confirmed that a single layer of TiOxNy film can be a good candidate as selective solar absorber

    Intercontinental spread of Asian-origin H7 avian influenza viruses by captive bird trade in 1990's

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    Wild bird migration and illegal trade of infected poultry, eggs, and poultry products have been associated with the spread of avian influenza viruses (AIV). During 1992–1996, H7N1 and H7N8 low pathogenic AIV (LPAIV) were identified from captive wild birds; such as Pekin robin (Leiothrix lutea), magpie robin (Copsychus saularis), flycatcher sp. (genus Empidonax), a species of softbill and parakeet, sun conure (Aratinga solstitialis), painted conure (Pyrrhura picta), fairy bluebird (Irena puella), and common iora (Aegithina tiphia), kept in aviaries or quarantine stations in England, The Netherlands, Singapore and the United States (U.S.). In this study, we sequenced these H7 viruses isolated from quarantine facilities and aviaries using next-generation sequencing and conducted a comparative phylogenetic analysis of complete genome sequences to elucidate spread patterns. The complete genome sequencing and phylogenetic analysis suggested that H7 viruses originated from a common source, even though they were obtained from birds in distant geographical regions. All H7N1 and H7N8 viruses were LPAIV, except a H7N1 highly pathogenic AIV (HPAIV), A/Pekin robin/California/30412/1994(H7N1) virus. Our results support the continued need for regulation of the captive wild bird trade to reduce the risk of introduction and dissemination of both LPAIV and HPAIV throughout the world

    Rangeland forage availability and management in times of drought – A case study of pastoralists in Afar, Ethiopia

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    This research article published by Elsevier, 2017Many Eastern African rangelands comprise marginal land, where climatic conditions are poor, access rights are increasingly limited, and land degradation is progressing. We conducted participatory land use mapping and vegetation assessment to identify the most important rangeland locations and their condition in Afar, Ethiopia. Further, we conducted 79 interviews across six villages to assess pastoralist adaptation strategies during drought times. In the dry season, livestock feed resources represented rangelands far away from the village (in 76% of the cases) while 50% and 40% of pastoralists also used cake concentrates and crop residues, respectively. During the wet season, rangeland resources close to villages, albeit with rather low herbaceous cover (<25%), contributed 80% to livestock forage. In times of severe drought, migrating with livestock was the most common (70%) adaptation, in combination with purchasing feed (50%) while <40% of the pastoralists sold or slaughtered animals. Afar pastoralists applied little conservation and mitigation methods, most commonly they removed livestock pressure to allow the pasture to recover. Overall, pastoralists in Afar still strongly depended on natural rangelands and their resources. Hence, to manage these sustainably a monitoring scheme must urgently be established for investigating rangeland quality and resilience to drought and grazing pressure

    Dengue fever outbreaks in Eritrea, 2005-2015: a case for strengthening surveillance, control and reporting

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    BACKGROUND: The geographic distribution and burden of dengue is increasing globally. This study aims to evaluate dengue outbreaks and to substantiate the need for strengthened surveillance, reporting and control in Eritrea. METHODS: Data from two cross-sectional dengue epidemic investigations in 2005 and 2010 were analyzed. Samples were tested for dengue virus-specific IgM and IgG antibodies using capture enzyme-linked immunosorbent assays. Dengue vectors' breeding attributes were characterized and epidemic risk indices determined. National routine surveillance weekly reports from 2005 to the second quarter of 2015 were analyzed for spatiotemporal trends. RESULTS: Dengue outbreaks increased in Eritrea from 2005 to 2015 with clinical presentation varying markedly among patients. The house and container indices for Aedes aegypti were 40 and 39.6 % respectively, with containers having A. aeqypti varying significantly (P < 0.04). Serum from 33.3 % (n = 15) and 88 % (n = 26) of clinical dengue cases in Aroget sub-Zoba (district) of Gash Barka Zoba (region) contained anti-DENV IgM antibody in 2005 and 2006, respectively. The national surveillance data from 2005 to 2015 indicate an overall spatiotemporal increase of dengue fever. CONCLUSIONS: The increase in dengue outbreaks has been confirmed in Eritrea and necessitates strengthening of surveillance and health worker and laboratory capacity, as well as targeted vector control interventions

    Phase transformation-induced superconducting aluminium-silicon alloy rings

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    The development of a materials platform that exhibits both superconducting and semiconducting properties is an important endeavour for a range of emerging quantum technologies. We investigate the formation of superconductivity in nanowires fabricated with silicon-on-insulator (SOI). Aluminium from deposited contact electrodes is found to interdiffuses with the Si nanowire structures to form an Al-Si alloy along the entire length of the predefined nanowire device over micron length scales at temperatures well below that of the Al-Si eutectic. The resultant transformed nanowire structures are layered in geometry with a continuous Al-Si alloy wire sitting on the buried oxide of the SOI and a residual Si cap sitting on top of the wire. The phase transformed material is conformal with any predefined device patterns and the resultant structures are exceptionally smooth-walled compared to similar nanowire devices formed by silicidation processes. The superconducting properties of a mesoscopic AlSi ring formed on a SOI platform are investigated. Low temperature magnetoresistance oscillations, quantized in units of the fluxoid, h/2e, are observed.Comment: 11 pages, 9 figure

    Traditional values of virginity and sexual behaviour in rural Ethiopian youth: results from a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Delaying sexual initiation has been promoted as one of the methods of decreasing risks of HIV among young people. In traditional countries, such as Ethiopia, retaining virginity until marriage is the norm. However, no one has examined the impact of this traditional norm on sexual behaviour and risk of HIV in marriage. This study examined the effect of virginity norm on having sex before marriage and sexual behaviour after marriage among rural Ethiopian youth.</p> <p>Methods</p> <p>We did a cross-sectional survey in 9 rural and 1 urban area using a probabilistic sample of 3,743 youth, 15–24 years of age. Univariate analysis was used to assess associations between virginity norm and gender stratified by area, and between sexual behaviour and marital status. We applied Kaplan-Meier and Cox regression analysis to estimate age at sexual debut and assessed the predictors of premarital sex among the never-married using SPSS.</p> <p>Results</p> <p>We found that maintaining virginity is still a way of securing marriage for girls, especially in rural areas; the odds of belief and intention to marry a virgin among boys was 3–4 times higher among rural young males. As age increased, the likelihood of remaining a virgin decreased. There was no significant difference between married and unmarried young people in terms of number of partners and visiting commercial sex workers. Married men were twice more likely to have multiple sexual partners than their female counterparts. A Cox regression show that those who did not believe in traditional values of preserving virginity (adjusted hazard ratio [AHR] = 2.91 [1.92–4.40]), alcohol drinkers (AHR = 2.91 [1.97–4.29]), Khat chewers (AHR = 2.36 [1.45–3.85]), literates (AHR = 18.01 [4.34–74.42]), and the older age group (AHR = 1.85 [1.19–2.91]) were more likely to have premarital sex than their counterparts.</p> <p>Conclusion</p> <p>Although virginity norms help delay age at sexual debut among rural Ethiopian youth, and thus reduces vulnerability to sexually transmitted infections and HIV infection, vulnerability among females may increase after marriage due to unprotected multiple risky sexual behaviours by spouses. The use of preventive services, such as VCT before marriage and condom use in marriage should be part of the HIV/AIDS prevention and control strategies.</p
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