301 research outputs found

    O stars and Wolf-Rayet stars

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    Basic information is given about O and Wolf-Rayet stars indicating how these stars are defined and what their chief observable properties are. Part 2 of the volume discussed four related themes pertaining to the hottest and most luminous stars. Presented are: an observational overview of the spectroscopic classification and extrinsic properties of O and Wolf-Rayet stars; the intrinsic parameters of luminosity, effective temperature, mass, and composition of the stars, and a discussion of their viability; stellar wind properties; and the related issues concerning the efforts of stellar radiation and wind on the immediate interstellar environment are presented

    A swarm in July : Beekeeping perspectives on the Old English Wid Ymbe charm

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    Inscribed in the margins of an eleventh-century manuscript1 of Bede's Ecclesiastical History of the English People and crowded beneath a Latin prayer is a brief bit of advice for beekeepers in the event of a swarm (ymbe), a natural phenomenon in which a substantial portion of an older bee colony migrates en masse with a queen to establish a new colony. The following analysis of this enigmatic text has been inspired largely by three features central to John Miles Foley's vast body of work: interdisciplinarity, collaboration, and comparative research. While the eight lines of alliterative verse that constitute the greater portion of this swarm charm have assured its standing within canonical Old English literature, its insights into traditional apiary practices of Anglo-Saxon England make it equally appropriate subject matter for studies in folklore or even animal science. It is precisely such unlikely intersections that have long served as foci for the transdisciplinary work of John Foley, and it is thus that we now choose it as the subject of analysis for a volume in his honor.2Issue title: Festschrift for John Miles Foley. This article belongs to a special issue of Oral Tradition published in honor of John Miles Foley's 65th birthday and 2011 retirement. The surprise Festschrift, guest-edited by Lori and Scott Garner entirely without his knowledge, celebrates John's tremendous impact on studies in oral tradition through a series of essays contributed by his students from the University of Missouri-Columbia (1979-present) and from NEH Summer Seminars that he has directed (1987-1996). Quotation marks removed to ensure alphabetical order. Title difference as follows; "A Swarm in July" : Beekeeping Perspectives on the Old English Wid Ymbe Char

    Croatian genetic heritage: Y-chromosome story

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    The aim of this article is to offer a concise interpretation of the scientific data about the topic of Croatian genetic heritage that was obtained over the past 10 years. We made a short overview of previously published articles by our and other groups, based mostly on Y-chromosome results. The data demonstrate that Croatian human population, as almost any other European population, represents remarkable genetic mixture. More than 3/4 of the contemporary Croatian men are most probably the offspring of Old Europeans who came here before and after the Last Glacial Maximum. The rest of the population is the offspring of the people who were arriving in this part of Europe through the southeastern route in the last 10 000 years, mostly during the neolithization process. We believe that the latest discoveries made with the techniques for whole-genome typing using the array technology, will help us understand the structure of Croatian population in more detail, as well as the aspects of its demographic history

    The Strathclyde Prosthetic Foot : a high performance prosthetic foot for low income countries

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    In the developing world there are ~1-2 amputees per 10000 people1. An amputation can cause significant financial strainsand social exclusion. The anatomical foot provides shock absorption and energy return; this needs to be recreated in the prosthetic foot. The Strathclyde Foot is a dynamic, inexpensive foot for the developing world with a durable, cosmetic rubber casing

    Hand-rearing, release and survival of african penguin chicks abandoned before independence by moulting parents

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    The African penguin Spheniscus demersus has an ‘Endangered’ conservation status and a decreasing population. Following abandonment, 841 African penguin chicks in 2006 and 481 in 2007 were admitted to SANCCOB (Southern African Foundation for the Conservation of Coastal Birds) for hand-rearing from colonies in the Western Cape, South Africa, after large numbers of breeding adults commenced moult with chicks still in the nest. Of those admitted, 91% and 73% respectively were released into the wild. There were veterinary concerns about avian malaria, airsacculitis and pneumonia, feather-loss and pododermatitis (bumblefoot). Post-release juvenile (0.32, s.e. = 0.08) and adult (0.76, s.e. = 0.10) survival rates were similar to African penguin chicks reared after oil spills and to recent survival rates recorded for naturally-reared birds. By December 2012, 12 birds had bred, six at their colony of origin, and the apparent recruitment rate was 0.11 (s.e. = 0.03). Hand-rearing of abandoned penguin chicks is recommended as a conservation tool to limit mortality and to bolster the population at specific colonies. The feasibility of conservation translocations for the creation of new colonies for this species using hand-reared chicks warrants investigation. Any such programme would be predicated on adequate disease surveillance programmes established to minimise the risk of disease introduction to wild birds

    The direct synthesis of hydrogen peroxide from H<sub>2</sub> and O<sub>2</sub> using Pd-Ni/TiO<sub>2</sub> catalysts

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    The direct synthesis of hydrogen peroxide (H2O2) from molecular H2 and O2 offers an attractive solution to decentralised production compared to the anthraquinone process. Herein we evaluate the performance of a 0.5%Pd-4.5%Ni/TiO2 catalyst in batch and flow reactor systems using water as a solvent at ambient temperature which makes synthesising high H2O2 concentrations challenging. Catalyst activity was observed to be stable to prolonged use in multiple batch experiments or in a flow system, with selectivities towards H2O2 of 97% and 85% respectively. This study was carried out in the absence of halide or acid additives that are typically used to inhibit sequential H2O2 degradation reactions showing that this Pd-Ni catalyst has potential to produce H2O2 selectivel

    Rethinking human responses to sea-level rise : the Mesolithic occupation of the Channel Islands

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    This work provides new insights into human responses to and perceptions of sea-level rise at a time when the landscapes of north-west Europe were radically changing. These issues are investigated through a case study focused on the Channel Islands. We report on the excavation of two sites, Canal du Squez in Jersey and Lihou (GU582) in Guernsey, and the study of museum collections across the Channel Islands. We argue that people were drawn to this area as a result of the dynamic environmental processes occurring and the opportunities these created. The evidence suggests that the area was a particular focus during the Middle Mesolithic, when Guernsey and Alderney were already islands and while Jersey was a peninsula of northern France. Insularisation does not appear to have created a barrier to occupation during either the Middle or Final Mesolithic, indicating the appearance of lifeways increasingly focused on maritime voyaging and marine resources from the second half of the 9th millennium BC onwards.PostprintPeer reviewe

    High Viral Diversity and Mixed Infections in Cerebral Spinal Fluid From Cases of Varicella Zoster Virus Encephalitis.

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    BACKGROUND: Varicella zoster virus (VZV) may cause encephalitis, both with and without rash. Here we investigate whether viruses recovered from the central nervous system (CNS; encephalitis or meningitis) differ genetically from those recovered from non-CNS samples. METHODS: Enrichment-based deep sequencing of 45 VZV genomes from cerebral spinal fluid (CSF), plasma, bronchoalveolar lavage (BAL), and vesicles was carried out with samples collected from 34 patients with and without VZV infection of the CNS. RESULTS: Viral sequences from multiple sites in the same patient were identical at the consensus level. Virus from vesicle fluid and CSF in cases of meningitis showed low-level diversity. By contrast, plasma, BAL, and encephalitis had higher numbers of variant alleles. Two CSF-encephalitis samples had high genetic diversity, with variant frequency patterns typical of mixed infections with different clades. CONCLUSIONS: Low viral genetic diversity in vesicle fluid is compatible with previous observations that VZV skin lesions arise from single or low numbers of virions. A similar result was observed in VZV from cases of VZV meningitis, a generally self-limiting infection. CSF from cases of encephalitis had higher diversity with evidence for mixed clade infections in 2 cases. We hypothesize that reactivation from multiple neurons may contribute to the pathogenesis of VZV encephalitis.Action Medical research GN2424 This work was supported by a UK MRC New Investigator Award to D. P. D; UCL/UCLH BRC (J. B.); Action Medical Research (grant number GN2424 to C. J. H); Swedish Research Council (P. N. and T. B.). The work was also support by an NIHR Fellowship (grant number DRF-2013-06-168 to F. M.), the Meningitis Research Foundation (grant number 0904.0), an NIHR Programme Grant in Applied Research (grant number RP-PG-0108-10048 to T. S.), and the NIHR Health Protection Research Unit in Emerging and Zoonotic Infections, University of Liverpool

    Mitochondrial DNA signals of late glacial recolonization of Europe from near Eastern refugia

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    Human populations, along with those of many other species, are thought to have contracted into a number of refuge areas at the height of the last Ice Age. European populations are believed to be, to a large extent, the descendants of the inhabitants of these refugia, and some extant mtDNA lineages can be traced to refugia in Franco-Cantabria (haplogroups H1, H3, V, and U5b1), the Italian Peninsula (U5b3), and the East European Plain (U4 and U5a). Parts of the Near East, such as the Levant, were also continuously inhabited throughout the Last Glacial Maximum, but unlike western and eastern Europe, no archaeological or genetic evidence for Late Glacial expansions into Europe from the Near East has hitherto been discovered. Here we report, on the basis of an enlarged whole-genome mitochondrial database, that a substantial, perhaps predominant, signal from mitochondrial haplogroups J and T, previously thought to have spread primarily from the Near East into Europe with the Neolithic population, may in fact reflect dispersals during the Late Glacial period, ?19–12 thousand years (ka) ago.<br/
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