1,285 research outputs found

    Effect of cleaning /disinfection strategies on helminth infections in finishing pigs

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    Ascaris suum is the most prevalent helminth on organic pig farms (Carstensen et al., 2002) and is transmitted mainly via the faeces. The use of anthelmintics does not fit in the organic principles and preventive measures are promoted. This project focused on assessing the efficacy of a cleaning protocol for the dunging area of pens on Ascaris s. transmission to pigs. In 4 batches with 8 identical pens for 15 pigs each (n=480 pigs) 6 pigs per pen were orally infected with Ascaris s. The other pigs can be earliest infected at 10 weeks and half of the pens were thoroughly cleaned at that time. Affected livers and egg counts in the manure had to show if this cleaning protocol keeps the non infected animals free of Ascaris s. The results show no effect of the cleaning protocol on the non infected pigs. These pigs had 57% damaged livers in both treatment and 50% had positive egg counts in the manure. The conclusion is that pen hygiene does not contribute to a reduction of Ascaris s. infections

    Effect of rooting area and drinker in the outdoor run on behaviour and Ascaris infection of organic pigs

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    Hygiene is often a problem on the outdoor runs of growing organic pigs. Manure and urine are mainly excreted outside, but spread all over the run. Reduc-ing the dirty surface may improve well being, reduce ammonia emission, improve hygiene and reduce labour and parasite infections. The presence of a rooting area and of a drinker on the outdoor run were tested in a 2x2 factorial design. The pens with the rooting areas had a higher number of pigs on the outdoor run than the pens without a rooting area (1.6 vs 1.2 pigs). This was caused by more pigs in area 2 and 3. At higher temperatures there were more pigs outside, except in the root-ing area: this was popular at all temperatures. A rooting area resulted in a cleaner outdoor area, however in some cases the root-ing area became a dunging area. An extra outdoor drinker leads to a cleaner area around the drinker, but to a dirtier indoor area. No difference in Ascaris infection was found between the four treatment combinations

    Narrow absorption features in the co-added XMM-Newton RGS spectra of isolated Neutron Stars

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    We co-added the available XMM-Newton RGS spectra for each of the isolated X-ray pulsars RX\,J0720.4−-3125, RX\,J1308.6+2127 (RBS\,1223), RX\,J1605.3+3249 and RX\,J1856.4−-3754 (four members of the "Magnificent Seven") and the "Three Musketeers" Geminga, PSR\,B0656+14 and PSR\,B1055-52. We confirm the detection of a narrow absorption feature at 0.57 keV in the co-added RGS spectra of RX\,J0720.4−-3125 and RX\,J1605.3+3249 (including most recent observations). In addition we found similar absorption features in the spectra of RX\,J1308.6+2127 (at 0.53 keV) and maybe PSR\,B1055-52 (at 0.56 keV). The absorption feature in the spectra of RX\,J1308.6+2127 is broader than the feature e.g. in RX\,J0720.4−-3125. The narrow absorption features are detected with 2σ\sigma to 5.6σ\sigma significance. Although very bright and frequently observed, there are no absorption features visible in the spectra of RX\,J1856.4−-3754 and PSR\,B0656+14, while the co-added XMM-Newton RGS spectrum of Geminga has not enough counts to detect such a feature. We discuss a possible origin of these absorption features as lines caused by the presence of highly ionised oxygen (in particular OVII and/or OVI at 0.57 keV) in the interstellar medium and absorption in the neutron star atmosphere, namely the absorption features at 0.57 keV as gravitational redshifted (grg_{r}=1.17) OVIII.Comment: 14 pages, 10 figures and 10 tables. Accepted for publication by MNRAS (Sep 12th, 2011

    On the Putative Detection of z>0 X-ray Absorption Features in the Spectrum of Markarian 421

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    In a series of papers, Nicastro et al. have reported the detection of z>0 OVII absorption features in the spectrum of Mrk421 obtained with the Chandra Low Energy Transmission Grating Spectrometer (LETGS). We evaluate this result in the context of a high quality spectrum of the same source obtained with the Reflection Grating Spectrometer (RGS) on XMM-Newton. The data comprise over 955ks of usable exposure time and more than 26000 counts per 50 milliAngstrom at 21.6 Angstroms. We concentrate on the spectrally clean region (21.3 < lambda < 22.5 Angstroms) where sharp features due to the astrophysically abundant OVII may reveal an intervening, warm--hot intergalactic medium (WHIM). We do not confirm detection of any of the intervening systems claimed to date. Rather, we detect only three unsurprising, astrophysically expected features down to the Log(N_i)~14.6 (3 sigma) sensitivity level. Each of the two purported WHIM features is rejected with a statistical confidence that exceeds that reported for its initial detection. While we can not rule out the existence of fainter, WHIM related features in these spectra, we suggest that previous discovery claims were premature. A more recent paper by Williams et al. claims to have demonstrated that the RGS data we analyze here do not have the resolution or statistical quality required to confirm or deny the LETGS detections. We show that our careful analysis resolves the issues encountered by Williams et al. and recovers the full resolution and statistical quality of the RGS data. We highlight the differences between our analysis and those published by Williams et al. as this may explain our disparate conclusions.Comment: 19 pages/7 figures/4 tables. 060424 submitted to ApJ 060522 re-submitted following ApJ reques

    The Prosopography of Ebla - G

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    Tarificación y provisiones

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    Esta publicación constituye un material de apoyo para la impartición y estudio de la asignatura Matemática Actuarial del Máster de Ciencias Actuariales y Financieras de la Universidad de Barcelona (UB). Tiene su origen en la experiencia de las autoras dentro de la asignatura Matemática Actuarial No Vida de la ya extinta Licenciatura de segundo ciclo en Ciencias Actuariales y Financieras de la UB y recoge parte del material incluido en la publicación que se utilizaba en dicha asignatura, Claramunt, M.M. y Costa, T. (2003). Matemática Actuarial No Vida. Un enfoque práctico. Colección de Publicaciones del Departamento de Matemática Económica, Financiera y Actuarial de la Universidad de Barcelona, n. 63. La publicación se estructura en dos partes.La primera, con dos capítulos, se dedica a los sistemas de tarificación, profundizando en los sistemas conocidos como Bonus-Malus que cumplen las propiedades necesarias para ser analizados mediante cadenas de Markov. La segunda, incluye el cálculo de provisiones en los seguros no-vida, haciendo hincapié en los modelos estocásticos que proporcionan no sólo una estimación puntual de dichas provisiones, sino también del error que lleva asociado y en determinados casos, incluso permiten obtener toda la distribución para dichas provisiones. En todos los temas, la publicación incluye, junto con los desarrollos teóricos, numerosos ejemplos prácticos solucionados analíticamente y con el lenguaje de programación R ([R Development Core Team (2017)])), utilizando paquetes ya existentes y programas de elaboración propia. También se incluyen enunciados de ejercicios sin resolver

    Reducing children's aggressive and oppositional behaviors in the schools: Preliminary results on the effectiveness of a social-cognitive group intervention program

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    This study examined the effects of a social-cognitive group intervention program for children with oppositional and aggressive behaviors. Forty-two children aged between 9 and 12 years who clearly displayed behavior problems at school were treated with this program. A cross-over design was used in which one group of children first received treatment and then assigned to a waiting period, whereas the other group of children first waited and subsequently received treatment. Treatment effects were assessed by means of standardized instruments completed by children, parents, and teachers. Results demonstrate that the social-cognitive intervention yielded a significant reduction of behavior problems and an increase of social-cognitive skills as compared to the waiting list control condition. Further, a follow-up assessment of the children who were initially treated indicate that the intervention effects were retained over a three-month period. Finally, some support was found for the theoretical underpinnings of the social-cognitive intervention program. More specifically, a greater increase in social-cognitive skills was to some extent associated with a larger reduction of behavior problems

    Polymorphism at the apical membrane antigen 1 locus reflects the world population history of Plasmodium vivax

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    <p>Abstract</p> <p>Background</p> <p>In malaria parasites (genus <it>Plasmodium</it>), <it>ama-1 </it>is a highly polymorphic locus encoding the Apical Membrane Protein-1, and there is evidence that the polymorphism at this locus is selectively maintained. We tested the hypothesis that polymorphism at the <it>ama-1 </it>locus reflects population history in <it>Plasmodium vivax</it>, which is believed to have originated in Southeast Asia and is widely geographically distributed. In particular, we tested for a signature of the introduction of <it>P. vivax </it>into the New World at the time of the European conquest and African slave trade and subsequent population expansion.</p> <p>Results</p> <p>One hundred and five ama<it>-1 </it>sequences were generated and analyzed from samples from six different Brazilian states and compared with database sequences from the Old World. Old World populations of <it>P. vivax </it>showed substantial evidence of population substructure, with high sequence divergence among localities at both synonymous and nonsynonymous sites, while Brazilian isolates showed reduced diversity and little population substructure.</p> <p>Conclusion</p> <p>These results show that genetic diversity in <it>P. vivax </it>AMA-1 reflects population history, with population substructure characterizing long-established Old World populations, whereas Brazilian populations show evidence of loss of diversity and recent population expansion.</p> <p>Note</p> <p>Nucleotide sequence data reported is this paper are available in the GenBank™ database under the accession numbers <ext-link ext-link-type="gen" ext-link-id="EF031154">EF031154</ext-link> – <ext-link ext-link-type="gen" ext-link-id="EF031216">EF031216</ext-link> and <ext-link ext-link-type="gen" ext-link-id="EF057446">EF057446</ext-link> – <ext-link ext-link-type="gen" ext-link-id="EF05487">EF057487</ext-link></p

    The relationship between primary school leaders' utilization of distributed leadership and teachers' capacity to change

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    Although it is generally known that distributed leadership is relevant for reinforcing teachers' capacity to change, how leadership roles are distributed among teachers largely depends on how principals perceive distributed leadership. Specifying principals' perceptions and how these are related to teachers' capacity to change leads to theories about the knowledge and beliefs of leaders with regard to distributed leadership that are crucial for achieving educational change as a team. Combining questionnaire data from 787 Dutch primary school teachers and interview data from 58 principals in a parallel mixed methods design, this study shows differences in how school leaders distribute leadership roles. In addition, the results indicate that several aspects of teachers' capacity to change, namely, joint work, collegial support, knowledge sharing, self-efficacy and their internalization of school goals, are more present in schools in which school leaders distribute leadership among teachers than in schools in which they do not
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