633 research outputs found

    Seasonality, water quality trends and biological responses in four streams in the Cairngorm Mountains, Scotland

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    The chemical composition and invertebrate communities found in four streams in the Cairngorms, Scotland, were monitored between 1985-1997. Stream waters were mildly acidic (mean pH ca. 6.5), with low alkalinity (mean acid neutralising capacity varying from 35-117 meq l<sup>-1</sup>) and low ionic strength. Subtle differences in the chemistry of each stream were reflected in their invertebrate faunas. Strong seasonality in water chemistry occurred, with the most acid, low alkalinity waters observed during the winter and early spring. This was particularly marked during snowmelt between January and April. In contrast, summer flows were usually groundwater dominated and characterised by higher alkalinity and higher concentrations of most other weathering-derived solutes. Seasonality was also clear in the invertebrate data, with Canonical Correspondence Analysis (CCA) separating seasonal samples along axes related to water temperature and discharge characteristics. Inter-annual hydrological and chemical differences were marked, particularly with respect to the winter period. Invertebrate communities found in each of the streams also varied from year to year, with spring communities significantly more variable (<i>P</i><0.01) than other seasons (quantified using Euclidean distance on CCA ordinations). <br>Hydrochemical trends over the study period were analysed using a seasonal Kendall test, LOcally WEighted Scatterplot Smoothing (LOWESS) and graphical techniques. These indicated that a reduction in sulphate concentrations in stream water is occurring, consistent with declining levels of atmospheric deposition. This may be matched by increases in pH and declining calcium concentrations, though available evidence is inconclusive. Other parameters, such as chloride, total organic carbon and zinc, reveal somewhat random patterns, probably reflecting irregular variations in climatic factors and/or atmospheric deposition. Previous studies have shown that the stream invertebrate communities have remained stable over this period (i.e. no significant linear trends) and show no evidence of acid-related impoverishment. Thus, over longer timescales invertebrates in these streams appear robust to the short-term (seasonal and inter-annual) environmental variability and long-term (decadal) chemical changes identified.</p> <p style='line-height: 20px;'><b>Keywords: </b>hydrochemistry, hydrology, trends, macroinvertebrates, uplands, Cairngorms, acidificatio

    Age structure, dispersion and diet of a population of stoats (Mustela erminea) in southern Fiordland during the decline phase of the beechmast cycle

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    The dispersion, age structure and diet of stoats (Mustela erminea) in beech forest in the Borland and Grebe Valleys, Fiordland National Park, were examined during December and January 2000/01, 20 months after a heavy seed-fall in 1999. Thirty trap stations were set along a 38-km transect through almost continuous beech forest, at least 1 km apart. Mice were very scarce (nights, C/100TN) along two standard index lines placed at either end of the transect, compared with November 1999 (>60/100TN), but mice were detected (from footprints in stoat tunnels) along an 8 km central section of the transect (stations 14-22). Live trapping with one trap per station (total 317.5 trap nights) in December 2000 caught 2 female and 23 male stoats, of which 10 (including both females) were radio collared. The minimum range lengths of the two females along the transect represented by the trap line were 2.2 and 6.0 km; those of eight radio-tracked males averaged 2.9 Ā± 1.7 km. Stations 14-22 tended to be visited more often, by more marked individual stoats, than the other 21 stations. Fenn trapping at the same 30 sites, but with multiple traps per station (1333.5 trap nights), in late January 2001 collected carcasses of 35 males and 28 females (including 12 of the marked live-trapped ones). Another two marked males were recovered dead. The stoat population showed no sign of chronic nutritional stress (average fat reserve index = 2.8 on a scale of 1-4 where 4 = highest fat content); and only one of 63 guts analysed was empty. Nevertheless, all 76 stoats handled were adults with 1-3 cementum annuli in their teeth, showing that reproduction had failed that season. Prey categories recorded in descending frequency of occurrence were birds, carabid beetle (ground beetle), weta, possum, rat, and mouse. The frequencies of occurrence of mice and birds in the diet of these stoats (10% and 48%, respectively) were quite different from those in stoats collected in Pig Creek, a tributary of the Borland River (87%, 5%), 12 months previously when mice were still abundant. Five of the six stoat guts containing mice were collected within 1 km of stations 14-22

    Simulation studies related to the particle identification by the forward and backward RICH detectors at Electron Ion Collider

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    The Electron-Ion collider (EIC) will be the ultimate facility to study the dynamics played by the colored quarks and gluons to the emergence of the global phenomenology of the nucleons and nuclei as described by Quantum Chromodynamics. The physics programs will greatly rely on efficient particle identification (PID) in both the forward and the backward regions. The forward and the backward RICHes of the EIC have to be able to cover wide acceptance and momentum ranges; in the forward region a dual radiator RICH (dRICH) is foreseen and in the backward region a proximity-focusing RICH can be foreseen to be employed. The geometry and the performance studies of the dRICH have been performed as prescribed in the EIC Yellow Report using the ATHENA software framework. This part of our work reports the effort following the call for EIC detector proposal the studies related to the forward and the backward RICHes performance. In the forward region, dRICH performance showed a pion-kaon separation from around 1 GeV/c to 50 GeV/c at a three sigma level; the proximity focusing RICH (pfRICH) foreseen for the backward region can reach three sigma separation up to 3 GeV/c for e/Ļ€\pi and up to 10 GeV/c for Ļ€\pi/K mass hypothesis.Comment: 4 pages, 8 figure

    Organizational guidance for the care of patients with head-and-neck cancer in Ontario.

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    Background: At the request of the Head and Neck Cancers Advisory Committee of Ontario Health (Cancer Care Ontario), a working group and expert panel of clinicians with expertise in the management of head-and-neck cancer developed the present guideline. The purpose of the guideline is to provide advice about the organization and delivery of health care services for adult patients with head-and-neck cancer. Methods: This document updates the recommendations published in the Ontario Health (Cancer Care Ontario) 2009 organizational guideline Results: To ensure that all patients have access to the highest standard of care available in Ontario, the guideline establishes the minimum requirements to maintain a head-and-neck disease site program. Recommendations are made about the membership of core and extended provider teams, minimum skill sets and experience of practitioners, cancer centre-specific and practitioner-specific volumes, multidisciplinary care requirements, and unique infrastructure demands. Conclusions: The recommendations contained in this document offer guidance for clinicians and institutions providing care for patients with head-and-neck cancer in Ontario, and for policymakers and other stakeholders involved in the delivery of health care services for head-and-neck cancer

    Genetic Factors Leading to Chronic Epsteinā€“Barr Virus Infection and Nasopharyngeal Carcinoma in South East China: Study Design, Methods and Feasibility

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    Nasopharyngeal carcinoma (NPC) is a complex disease caused by a combination of Epstein-Barr virus chronic infection, the environment and host genes in a multi-step process of carcinogenesis. The identity of genetic factors involved in the development of chronic Epstein-Barr virus infection and NPC remains elusive, however. Here, we describe a two-phase, population-based, case-control study of Han Chinese from Guangxi province, where the NPC incidence rate rises to a high of 25-50 per 100,000 individuals. Phase I, powered to detect single gene associations, enrolled 984 subjects to determine feasibility, to develop infrastructure and logistics and to determine error rates in sample handling. A microsatellite screen of Phase I study participants, genotyped for 319 alleles from 34 microsatellites spanning an 18-megabase region of chromosome 4 (4p15.1-q12), previously implicated by a linkage analysis of familial NPC, found 14 alleles marginally associated with developing NPC or chronic immunoglobulin A production (p = 0.001-0.03). These associations lost significance after applying a correction for multiple tests. Although the present results await confirmation, the Phase II study population has tripled patient enrolment and has included environmental covariates, offering the potential to validate this and other genomic regions that influence the onset of NPC

    Implementing integrated measurements of essential biodiversity variables at a national scale

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    Funding: the Strategic Science Investment Funding for Crown Research Institutes from the Ministry of Business, Innovation and Employment.1. There is a global need for observation systems that deliver regular, timely data on state and trends in biodiversity, but few have been implemented, and fewer still at national scales. We describe the implementation of measurement of Essential Biodiversity Variables (EBVs) on an 8 km Ɨ 8 km grid throughout New Zealand, with multiple components of biodiversity (vegetation, birds, and some introduced mammals) measured simultaneously at each sample point. 2. Between 2011 and 2017, all public land was sampled nationally (ca. 1,350 points) and some private land (ca. 500 points). Synthetic appraisals of the state of New Zealand's biodiversity, not possible previously, can be derived from the first measurement of species distribution, population abundance, and taxonomic diversity EBVs. 3. Native bird counts (all species combined) were about 2.5 times greater per sample point in natural forests and shrublands than in nonā€woody ecosystems, and native bird counts exceeded those of nonā€native birds across all natural forests and shrublands. 4. Nonā€native plants, birds, and mammals are invasive throughout, but highā€rainfall forested regions are least invaded, and historically deforested rain shadow regions are most invaded. 5. National reporting of terrestrial biodiversity across New Zealand's public land is established and becoming normalised, in the same manner as national and international reporting of human health and education statistics. The challenge is extending coverage across all private land. Repeated measurements of these EBVs, which began in 2017, will allow defensible estimates of biodiversity trends.Publisher PDFPeer reviewe
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