711 research outputs found

    First record of an Odontaspidid shark in Ascension Island waters

    Get PDF
    The occurrence of the poorly understood shark species Odontapsis ferox is reported at an oceanic seamount in the central south Atlantic, within the Exclusive Economic Zone of Ascension Island. The presence of the species at this location is confirmed by the discovery of a tooth embedded in scientific equipment, and footage of at least one animal on autonomous underwater video. The new record of this shark species at this location demonstrates the knowledge gaps which still exist at many remote, oceanic structures and their candidacy for status as important conservation areas.info:eu-repo/semantics/publishedVersio

    Field-calibrated model of melt, refreezing, and runoff for polar ice caps : Application to Devon Ice Cap

    Get PDF
    Acknowledgments R.M.M. was supported by the Scottish Alliance for Geoscience, Environment and Society (SAGES). The field data collection contributed to the validation of the European Space Agency Cryosat mission and was supported by the Natural Sciences and Engineering Research Council, Canada, the Meteorological Service of Canada (CRYSYS program), the Polar Continental Shelf Project (an agency of Natural Resources Canada), and by UK Natural Environment Research Council consortium grant NER/O/S/2003/00620. Support for D.O.B. was provided by the Canadian Circumpolar Institute and the Climate Change Geoscience Program, Earth Sciences Sector, Natural Resources Canada (ESS contribution 20130371). Thanks are also due to the Nunavut Research Institute and the communities of Resolute Bay and Grise Fjord for permission to conduct fieldwork on Devon Ice Cap. M.J. Sharp, A. Gardner, F. Cawkwell, R. Bingham, S. Williamson, L. Colgan, J. Davis, B. Danielson, J. Sekerka, L. Gray, and J. Zheng are thanked for logistical support and field assistance during the data collection. We thank Ruzica Dadic, two other anonymous reviewers, and the Editor, Bryn Hubbard, for their helpful comments on an earlier version of this paper and which resulted in significant improvements.Peer reviewedPublisher PD

    Reducing waste : repair, recondition, remanufacture or recycle?

    Get PDF
    Between 1980 and 1997, municipal waste in OECD countries increased by around 40%. This paper outlines the very real negative effects of this increase and then introduces the two main European Union policies that have been established to address this problem: a landfill directive and legislation on extended producer responsibility (EPR). The paper then describes and compares the four alternative strategies to reducing end-of-life waste within the context of extended producer responsibility: namely repairing, reconditioning, remanufacturing or recycling. It also introduces a more robust definition of remanufacturing, validated by earlier research, which differentiates it from repair and reconditioning. From a consideration of the different factors involved, it concludes that remanufacturing may well be the best strategy. This is because it enables the embodied energy of virgin production to be maintained, preserves the intrinsic added value of the product for the manufacturer and enables the resultant products to be sold as new with updated features if necessary

    Posterior segment eye disease in sub-Saharan Africa: review of recent population-based studies.

    Get PDF
    OBJECTIVE: To assess the burden of posterior segment eye diseases (PSEDs) in sub-Saharan Africa (SSA). METHODS: We reviewed published population-based data from SSA and other relevant populations on the leading PSED, specifically glaucoma, diabetic retinopathy and age-related macular degeneration, as causes of blindness and visual impairment in adults. Data were extracted from population-based studies conducted in SSA and elsewhere where relevant. RESULTS: PSEDs, when grouped or as individual diseases, are a major contributor to blindness and visual impairment in SSA. PSED, grouped together, was usually the second leading cause of blindness after cataract, ranging as a proportion of blindness from 13 to 37%. CONCLUSIONS: PSEDs are likely to grow in importance as causes of visual impairment and blindness in SSA in the coming years as populations grow, age and become more urban in lifestyle. African-based cohort studies are required to help estimate present and future needs and plan services to prevent avoidable blindness

    A versatile chemical method for the formation of macroporous transition metal alloys from cyanometalate coordination polymers †

    Get PDF
    A facile two-step synthetic route to macroporous metal and metal alloy frameworks from hydrogel-forming coordination polymers known as cyanogels is described. The polymerization of a chlorometalate and cyanometalate in aqueous solution results in the formation of a cyanogel that will auto-reduce at elevated temperatures to form metal alloys under an inert atmosphere. Cyanogels are versatile precursors to macroporous metals due to the large number of metal alloy systems that can be produced. This synthetic route is advantageous due to the production of uncontaminated final products of refractory metals at low temperatures. Transient reactive liquid sintering is shown to be the physical process through which macroporous metal forms from the cyanogel precursor

    Liver Parasites and Body Condition in Relation to Environmental Contaminants in Caribou (Rangifer tarandus) from Labrador, Canada

    Get PDF
    Over the last several decades, elders and hunters of the Innu Nation in Labrador, Canada, have expressed concerns over perceived declines in environmental health and the integrity of country food, including caribou. The primary objective of this study was to determine links between specific health parameters and contaminants found in caribou from the George River herd. Twenty-seven caribou killed by local Innu hunters between February and December 2001 were evaluated for gross and microscopic pathology, body condition, liver parasitology, and contaminant levels in kidney and fat. Overall, the sampled caribou appeared to be in adequate body condition for the time of year, and no clinically significant lesions were found. Concentrations of selenium, metals (Hg, Cd, and Pb), 20 organochlorine pesticides (HCB, a-HCH, g-HCH, aldrin, dieldrin, methoxychlor, mirex, a- and b-endosulfan, heptachlor, heptachlor epoxide, g-CHL, cis-CHL, trans-nonachlor, and o,p'- and p,p'-DDD, DDE, DDT), and 24 PCB congeners were within the ranges reported for caribou in Canada. In general, contaminant levels were relatively low, with the exception of cadmium in kidneys (geometric mean: 6.5 μg/g wet weight; range: 1.5–44.0 μg/g). Two types of liver parasites were found: the liver fluke Fascioloides magna (prevalence: 78%; geometric mean abundance: 4.2 flukes/caribou) and a tapeworm larva consistent with Taenia hydatigena (prevalence: 50%; geometric mean abundance: 0.6 larvae/caribou). Using multiple variable regression analysis, we found renal concentrations of cadmium to be positively associated, and selenium to be negatively associated, with F. magna abundance.Ces dernières décennies, les aînés et les chasseurs de la nation montagnaise du Labrador, au Canada, ont exprimé des inquiétudes au sujet du déclin de la santé de l’environnement et de l’intégrité de la nourriture provenant de la campagne, telle que le caribou. L’objectif principal de cette étude consistait à déterminer les liens qui existent entre certains paramètres de santé précis et les contaminants se trouvant dans le caribou du troupeau de la rivière George. Vingt-sept caribous ayant été tués par les chasseurs montagnais de la région entre les mois de février et de décembre 2001 ont subi des examens pathologiques macroscopiques et microscopiques, en plus d’avoir été évalués pour en déterminer l’état du corps, la parasitologie du foie et les taux de contaminants dans le foie et le gras. Dans l’ensemble, l’état des corps de caribous échantillonnés semblait adéquat pour cette période de l’année et aucune lésion clinique importante n’a été signalée. Les concentrations de sélénium, de métaux (Hg, Cd et Pb), de 20 pesticides organochlorés (HCB, a-HCH, g-HCH, aldrine, dieldrine, méthoxychlore, mirex, a- et b-endosulfane, heptachlore, heptachlorépoxyde, g-CHL, cis-CHL, trans-nonachlore ainsi que o,p'- et p,p'-DDD, DDE, DDT) et de 24 congénères de PCB s’établissaient dans les étendues signalées pour le caribou au Canada. En général, les niveaux de contaminants étaient relativement faibles, à l’exception du cadmium se trouvant dans les reins (moyenne géometrique : 6,5 μg/g poids humide; étendue : 1,5–44,0 mg/g). Deux types de parasites du foie ont été trouvés : la douve Fascioloides magna (prévalence : 78 %; abondance moyenne géométrique : 4,2 douves/caribou) et un cestode du genre Taenia hydatigena (prévalence : 50 %; abondance moyenne géométrique : 0,6 larves/caribou). Nous avons également réalisé une analyse de régression à variables multiples qui nous a permis de constater que les concentrations de cadmium sont positivement associées et celles de sélénium sont négativement associées à l’abondance de F. magna

    The tip-link antigen, a protein associated with the transduction complex of sensory hair cells, is protocadherin-15

    Get PDF
    Sound and acceleration are detected by hair bundles, mechanosensory structures located at the apical pole of hair cells in the inner ear. The different elements of the hair bundle, the stereocilia and a kinocilium, are interconnected by a variety of link types. One of these links, the tip link, connects the top of a shorter stereocilium with the lateral membrane of an adjacent taller stereocilium and may gate the mechanotransducer channel of the hair cell. Mass spectrometric and Western blot analyses identify the tip-link antigen, a hitherto unidentified antigen specifically associated with the tip and kinocilial links of sensory hair bundles in the inner ear and the ciliary calyx of photoreceptors in the eye, as an avian ortholog of human protocadherin-15, a product of the gene for the deaf/blindness Usher syndrome type 1F/DFNB23 locus. Multiple protocadherin-15 transcripts are shown to be expressed in the mouse inner ear, and these define four major isoform classes, two with entirely novel, previously unidentified cytoplasmic domains. Antibodies to the three cytoplasmic domain-containing isoform classes reveal that each has a different spatiotemporal expression pattern in the developing and mature inner ear. Two isoforms are distributed in a manner compatible for association with the tip-link complex. An isoform located at the tips of stereocilia is sensitive to calcium chelation and proteolysis with subtilisin and reappears at the tips of stereocilia as transduction recovers after the removal of calcium chelators. Protocadherin-15 is therefore associated with the tip-link complex and may be an integral component of this structure and/or required for its formatio
    corecore