1,084 research outputs found

    A randomized triple blind trial to assess the effect of an anthelmintic programme for working equids in Morocco

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    <p>Abstract</p> <p>Background</p> <p>Gastro-intestinal parasitism has been identified as a significant cause of disease in working equids in many countries. This randomized triple-blind trial was designed to assess the impact of an anthelmintic treatment programme (using oral ivermectin and fenbendazole) comparing treated and placebo control populations of working donkeys, mules and horses in field conditions in Morocco. In particular, we assessed animal body weight and condition score, together with a questionnaire-based owner evaluation of number of subjective animal health parameters. Faecal worm egg count was also measured.</p> <p>Results</p> <p>239 animals completed the full study, 130 in the treatment group and 109 in the control group. Although the average animal weight increased during the study, this change was not significantly different between the two groups. Animals in the treatment group had a significantly lower strongyle worm egg count and increased in body condition score compared to animals in the control group at each examination during the study period. Owners of animals in the treatment group reported improvement in health and work ability and a beneficial effect on pruritus during the early period of the study. These differences in owner perception between treatment groups had disappeared in the latter stages of the study.</p> <p>Conclusion</p> <p>This study demonstrated that a routine anthelmintic treatment programme of three treatments annually can have a significant effect on faecal worm egg count. There may be beneficial consequences for the animal health and productivity. Further research on other populations of working equids in different environments would facilitate the objective planning of effective parasite control strategies for specific situations and provide better understanding of the likely clinical benefits of such programmes.</p

    Urban associations: class, culture and the enlightened spirit, Derby c.1700-c.1900

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    Essentially an urban biography, this thesis is a social history of Derby’s transformation during the eighteenth and nineteenth centuries. It emphasises the distinctive status of Derby as a county town and examines the synergy of its associative culture, sustained economic growth, thriving knowledge economy and the influence of both elite and plebeian leadership. In analysing the town’s industrial revolution and socio-cultural evolution, the thesis addresses the relative neglect of the historical literature in identifying Derby as a nationally important urban centre. In so doing, new light is shed on the timing and nature of the industrial revolution and adds to the debate on the role played by urban associations in shaping class identity and what Joel Mokyr has referred to as the ‘enlightened economy’. Issues relating to hierarchies and associations, aspirations and ambitions, are at the heart of the study. The paradoxical characteristics of the associational world are highlighted in promoting both social cohesion and fragmentation. The nature of power, control and self-determination is explored within the context of industrialisation and the town’s cultural awakening. Wealth creation and social emulation, patronage and the corporate culture of the Midland Railway are shown to be significant factors in forging a ‘creative community’ of industrialists, intellectuals and artists. A strong bourgeois elite created an ‘urban renaissance’ and a ‘knowledge economy’, whilst union action, co-operation and an emerging radical agenda forged a self-determined and politically ambitious workforce. The challenges of industrialisation and social change were met through the collegiality of vibrant and diverse associations. This resulted in the ‘little State’ of Derby rising up the urban hierarchy to become a provincial capital

    Structure of an Enclosed Dimer Formed by the Drosophila Period Protein

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    Period (PER) is the major transcription inhibitor in metazoan circadian clocks and lies at the center of several feedback loops that regulate gene expression. Dimerization of Drosophila PER influences nuclear translocation, repressor activity, and behavioral rhythms. The structure of a central, 346-residue PER fragment reveals two associated PAS (Per-Arnt-Sim) domains followed by a protruding α-helical extension (αF). A closed, pseudosymmetric dimer forms from a cross handshake interaction of the N-terminal PAS domain with αF of the opposing subunit. Strikingly, a shift of αF against the PAS ÎČ-sheet generates two alternative subunit interfaces in the dimer. Taken together with a previously reported PER structure in which αF extends, these data indicate that αF unlatches to switch association of PER with itself to its partner Timeless. The variable positions of the αF helix provide snapshots of a helix dissociation mechanism that has relevance to other PAS protein systems. Conservation of PER interaction residues among a family of PAS-AB-containing transcription factors suggests that contacts mediating closed PAS-AB dimers serve a general function

    Managing for change: October 11, 1989

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    Bi-weekly newsletter of University Hospital's Change Project, provided to managers at the hospital

    Exploring Halo Substructure with Giant Stars: Spectroscopy of Stars in the Galactic Anticenter Stellar Structure

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    To determine the nature of the recently discovered, ring-like stellar structure at the Galactic anticenter, we have collected spectra of a set of presumed constituent M giants selected from the 2MASS point source catalog. Radial velocities have been obtained for stars spanning ~100 degrees, exhibiting a trend in velocity with Galactic longitude and an estimated dispersion of 20 +/- 4 km/sec. A mean metallicity [Fe/H] = -0.4 +/- 0.3 measured for these stars combines with previous evidence from the literature to suggest a population with a significant metallicity spread. In addition, a curious alignment of at least four globular clusters of lower mean metallicity is noted to be spatially and kinematically consistent with this stellar distribution. We interpret the M giant sample position and velocity variation with Galactic longitude as suggestive of a satellite galaxy currently undergoing tidal disruption in a non-circular, prograde orbit about the Milky Way.Comment: (1) University of Virginia, 4 pages, 3 figures, accepted for publication in The Astrophysical Journal Letter

    The Geography of Scientific Productivity: Scaling in U.S. Computer Science

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    Here we extract the geographical addresses of authors in the Citeseer database of computer science papers. We show that the productivity of research centres in the United States follows a power-law regime, apart from the most productive centres for which we do not have enough data to reach definite conclusions. To investigate the spatial distribution of computer science research centres in the United States, we compute the two-point correlation function of the spatial point process and show that the observed power-laws do not disappear even when we change the physical representation from geographical space to cartogram space. Our work suggests that the effect of physical location poses a challenge to ongoing efforts to develop realistic models of scientific productivity. We propose that the introduction of a fine scale geography may lead to more sophisticated indicators of scientific output.Comment: 6 pages, 3 figures; minor change

    Spacetime as a Feynman diagram: the connection formulation

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    Spin foam models are the path integral counterparts to loop quantized canonical theories. In the last few years several spin foam models of gravity have been proposed, most of which live on finite simplicial lattice spacetime. The lattice truncates the presumably infinite set of gravitational degrees of freedom down to a finite set. Models that can accomodate an infinite set of degrees of freedom and that are independent of any background simplicial structure, or indeed any a priori spacetime topology, can be obtained from the lattice models by summing them over all lattice spacetimes. Here we show that this sum can be realized as the sum over Feynman diagrams of a quantum field theory living on a suitable group manifold, with each Feynman diagram defining a particular lattice spacetime. We give an explicit formula for the action of the field theory corresponding to any given spin foam model in a wide class which includes several gravity models. Such a field theory was recently found for a particular gravity model [De Pietri et al, hep-th/9907154]. Our work generalizes this result as well as Boulatov's and Ooguri's models of three and four dimensional topological field theories, and ultimately the old matrix models of two dimensional systems with dynamical topology. A first version of our result has appeared in a companion paper [gr-qc\0002083]: here we present a new and more detailed derivation based on the connection formulation of the spin foam models.Comment: 32 pages, 2 figure

    Association Between Chronic Hepatitis C Virus Infection and Myocardial Infarction Among People Living With HIV in the United States.

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    Hepatitis C virus (HCV) infection is common among people living with human immunodeficiency virus (PLWH). Extrahepatic manifestations of HCV, including myocardial infarction (MI), are a topic of active research. MI is classified into types, predominantly atheroembolic type 1 MI (T1MI) and supply-demand mismatch type 2 MI (T2MI). We examined the association between HCV and MI among patients in the Centers for AIDS Research (CFAR) Network of Integrated Clinical Systems, a US multicenter clinical cohort of PLWH. MIs were centrally adjudicated and categorized by type using the Third Universal Definition of Myocardial Infarction. We estimated the association between chronic HCV (RNA+) and time to MI while adjusting for demographic characteristics, cardiovascular risk factors, clinical characteristics, and history of injecting drug use. Among 23,407 PLWH aged ≄18 years, there were 336 T1MIs and 330 T2MIs during a median of 4.7 years of follow-up between 1998 and 2016. HCV was associated with a 46% greater risk of T2MI (adjusted hazard ratio (aHR)&nbsp;=&nbsp;1.46, 95% confidence interval (CI): 1.09, 1.97) but not T1MI (aHR&nbsp;=&nbsp;0.87, 95% CI: 0.58, 1.29). In an exploratory cause-specific analysis of T2MI, HCV was associated with a 2-fold greater risk of T2MI attributed to sepsis (aHR&nbsp;=&nbsp;2.01, 95% CI: 1.25, 3.24). Extrahepatic manifestations of HCV in this high-risk population are an important area for continued research

    Manacled to Identity: Cosmopolitanism, Class, and ‘The Culture Concept’ in Stephen Crane

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    This article begins with a close reading of Stephen Crane’s short story ‘Manacled’ from 1900, which situates this rarely considered short work within the context of contemporary debates about realism. I then proceed to argue that many of the debates raised by the tale have an afterlife in our own era of American literary studies, which has frequently focused on questions of ‘identity’ and ‘culture’ in its reading of realism and naturalism to the exclusion of the importance of cosmopolitan discourses of diffusion and exchange across national borders. I then offer a brief reading of Crane’s novel George’s Mother, which follows Walter Benn Michaels in suggesting that the recent critical attention paid to particularities of cultural difference in American studies have come to conflate ideas of class and social position with ideas of culture in ways that have ultimately obscured the presence of genuine historical inequalities in US society. In order to challenge this critical commonplace, I situate Crane’s work within a history of transatlantic cosmopolitanism associated with the ideas of Franz Boas and Matthew Arnold to demonstrate the ways in which Crane’s narratives sought out an experience of the universal within their treatments of the particular
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