450 research outputs found

    The effects of human land use on the winter habitat of the recovering Carcross woodland caribou herd in suburban Yukon Territory, Canada

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    Carcross woodland caribou (Rangifer tarandus caribou) numbers are increasing as a result of an intensive management and recovery program initiated in 1993. In the last 13 years, three overlapping First Nation land claim agreements were settled resulting in a complicated array of private and public land management authorities on this winter range, situated in the Whitehorse periphery. Twelve years of VHF radio-collar data (1994-2005) and 5 years of GPS radio-collar data (2000-2005) for female caribou were assessed to determine winter concentration areas and important winter habitats. We contrasted locations from 11 GPS radio-collared caribou with land cover classes, derived from classified Landsat 7 imagery, to evaluate the distribution and abundance of preferred habitats within this winter range. We found significant use of Open Needle Leaf lichen vegetation classes and avoidance of the relatively more abundant Closed Needle Leaf class. Our resource selection function model validated the preference for Open Needle Leaf Lichen and determined that caribou were spaced significantly further from an estimate of the human Zone of Influence (ZOI) than was expected from random locations. While our assessment determined that 64% of the winter range was located outside of either private lands or land influenced by human activity, key winter vegetation classes were under-represented within this area. If caribou are to successfully recover on this landscape and persist through time it is essential to manage, through meaningful participation among land management authorities, the remaining caribou habitat for environmental rather than human consumptive values

    The status of Rangifer tarandus caribou in Yukon, Canada

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    This paper summarizes the population trends as well as research and management programs for woodland caribou {Rangifer tarandus caribou) in Yukon. Most herds are stable although not all are counted regularly and systematic monitoring of herds remains an essential need. Over the past decade the Southern Lakes, Aishihik, and Finlayson herds have been well studied and provide valuable models for guiding Yukon management programs. Over harvest and the spread of agriculture, forestry and mining are ongoing human activities are of concern to caribou managers

    Zarządzanie jakością w komercyjnej placówce ochrony zdrowia

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    Podstawę zapewnienia wysokiej jakości usług zdrowotnych stanowi rozbudowany system certyfikacji. Z jednej strony powinien się on przejawiać powszechnym wymogiem akredytacji podmiotów świadczących usługi zdrowotne, a z drugiej – koniecznością ubiegania się o kontrakty długofalowe z płatnikami instytucjonalnymi. Autor omawia różne systemy certyfikacji i analizuje możliwość ich zastosowania w placówkach ochrony zdrowia. Podkreśla, że certyfikacja – niezależnie od wybranego systemu – powinna wiązać się ze stałym poszukiwaniem metod podnoszenia jakości dla pacjenta, a zwłaszcza na poszukiwaniu i wdrażaniu pozytywnych wzorców szczególnie wysokiej jakości

    Rola glonów glebowych w inicjalnych etapach rozwoju gleby na zanieczyszczonych obszarach piaszczystych

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    Research to evaluate the role of the soil algae in the initiation of pedogenesis in sandy areas and to establish the mineral, chemical and organic composition of soil-algal crusts was done. The investigations area is located in southern Poland in a landscape of drift sand (Bledowska Desert) formed as a result of medieval deforestation related to Ag, Pb and Fe mining activities. Fifteen species of algae (Cyanophyta, Chlorophyta and Heterokontophyta) were identified. In the soil-algal crusts, Corg contents ranged from 0.35-2.23%, Pavail from 9-34 mg · kg–1 and Nt was variable. In investigated area the ground on which soil algae developed was acidic (pH 4.4-5.7 in KCl). Among mineral components in the crust, phases rich in Fe and K dominated (776.5(±2.3) - 2803(±31) mg · kg–1 and 230.5(±3.7) - 696(±22) mg · kg–1, respectively) and elevated concentrations of Zn, Mn and Pb occurred. Soil-crust organic matter includes aliphatic and aromatic compounds, carbohydrate derivatives, phenols, furan and pyrene structures. N compounds have significant contribution in composition of soil-algal crusts - the algae are main source of organic matter in this stage of soil formation. It could accelerate the regeneration of disturbed ecological systems

    Ocena pobrania z dietą wybranych składników mineralnych przez młodzież w wieku 13-15 lat w zależności od płci oraz miejsca zamieszkania

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    Absorption of minerals compound by the investigated population aged 13-15 depending on gender and place of residenceIntroduction.The life period between 11-19 years of age is defined as the adolescence (phase), which is a period of intense growth and development, during which the organism ultimately heads for achieving a biological, psychological and social maturity. During this period, proper nutrition is an essential factor in the harmonious development of the young organism and to achieve a high health potential.The aim.The aim of this study was to evaluate the absorption of minerals compound by the investigated population depending on gender and place of residence.Material and methods.The evaluation was performed by 24 hours diet recall in randomly selected schools in Krakow and Skawina area. The content of mineral compounds (Na, K, Ca, P, Mg, Fe, Zn, Cu) consumed by the subjects was assessed by the use of the "Dieta 2.0" software.Results. It were discovered a numerous irregularities in consumption of selected minerals, including significant calcium deficiency, and also the excess of sodium in the diet. Calcium deficiency combined the excess of phosphorus can adversely affect the achievement of the peak bone mass and increase the risk of osteoporosis in later stages of life. Also demonstrated high sodium and low potassium intakes could contribute to the development of cardiovascular disease

    Hydroxyapatite/Silver Nanoparticles Powders as Antimicrobial Agent for Bone Replacements

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    This paper reports a superficial morphological modification of the hydroxyapatite grains obtained by in situ deposition of Ag nanoparticles on natural origin calcium phosphate powder. Ceramic material was prepared in three stage bone treatment, including hydrolysis with a lactic acid, pre-calcination, and proper calcination. Subsequently, the Ag nanoparticles were synthesized by chemical reduction of Ag+ by sodium borohydride in a solution of polyvinylpyrrolidone and in presence of hydroxyapatite. Such-prepared materials were investigated with X-ray diffraction, Fourier-transformed infrared spectroscopy, atomic absorption spectrometry and scanning electron microscopy with energy dispersive spectroscopy. Furthermore, Ca/P molar ratio was calculated and microbiological tests were performed to investigate materials antimicrobial activity. The appearance of Ag nanoparticles located on phosphate surface was confirmed by SEM analysis, and no chemical bonding with hydroxyapatite was recorded by IR and XRD techniques. Additionally, the biological assessment revealed bactericidal effect on Escherichia coli and Staphylococcus aureus, while slightly affected on Enterococcus faecalis viability. This work is licensed under a Creative Commons Attribution 4.0 International License

    The Ability to Maintain Attention during Visuomotor Task Performance in Handball Players and Non-Athletes

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    One of the important aspects of attentional processes in sport performance is sustained attention during task execution. The objective of this study was to analyze the ability to maintain attention during a serial reaction time task performance in expert handball players (n = 12) and non-athletes (n = 12). Participants p erform a FitLight TrainerTM (Fitlight Sports Corp., Canada) test protocol configured by the PDA controller which consisted of 10 series of simple motor reaction task to visual stimuli appearing on 8 wireless light discs. Each of the 10 series included 22 reactions. Ability to maintain attention was determined by analyzing the variability in results during testing, e.g. the total time of test execution and the average reaction time to visual stimulus in each subsequent series. The main finding in our study was that Non-athletes in comparison to Athletes had: (1) longer total time of test execution; (2) longer reaction time; (3) and higher variability in results during task performance. The results indicate a higher level of ability to maintain attention in handball players

    Yield criteria for glaciotectonically deformed deposits

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    Most glaciotectonically deformed deposits, including varved clays and glacial tills, are characterised by cracks and fissures. This paper presents a method for describing the yield criteria for glacitectonically deformed cohesive deposits using a model of cracked geomaterial with isotropic or anisotropic matrix. The general representation of the limit conditions for anisotropic materials in plane-strain is used to determine the yield criterion. The yield criterion represents a convex, piece-wise surface in the three-dimensional stress space revealing explicitly global, plastic properties of the materials considered. An example of using proposed yield criteria to solve a bearing capacity problem of a strip foundation constructed on a glaciotectonically cracked layer is presented. The lower and upper-bound estimates of limit loads on the strip footing are given. The limit state analysis presented in this paper can be used to solve many other geotechnical engineering problems, for example, the stability of slopes and reinforced walls or the bearing capacity of pile foundations

    Synthesis and characterization of polymer-based coatings modified with bioactive ceramic and bovine serum albumin

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    This study involves the synthesis of hydroxyapatite and describes the preparation and characterization of polymer coatings based on poly(ethylene glycol) diacrylate and poly(ethylene glycol) and modified with bovine serum albumin and hydroxyapatite. Hydroxyapatite was obtained by wet chemical synthesis and characterized by X-ray diffraction and FTIR spectroscopy, and its Ca/P molar ratio was determined (1.69 ± 0.08). The ceramic and bovine serum albumin were used in the preparation of composite materials with the polymeric matrix. The chemical composition of coatings was characterized with FTIR spectroscopy, and their morphology was recorded with SEM imaging. Moreover, the measurements of surface roughness parameters and stereometric research were performed. The prepared coatings were subjected to in vitro studies in simulated body fluid and artificial saliva. Changes in chemical composition and morphology after immersion were examined with FTIR spectroscopy and SEM imaging. Based on the conducted research, it can be stated that applied modifiers promote the biomineralization process. The roughness analysis confirmed prepared materials were characterized by the micrometer-scale topography. The materials morphology and roughness, and the morphology of the newly formed apatite deposit, were dependent on the type of the used modifier, and the artificial fluid used in in vitro studies

    Co-localization and regulation of basic fibroblast growth factor and arginine vasopressin in neuroendocrine cells of the rat and human brain

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    <p>Abstract</p> <p>Background</p> <p>Adult rat hypothalamo-pituitary axis and choroid plexus are rich in basic fibroblast growth factor (FGF2) which likely has a role in fluid homeostasis. Towards this end, we characterized the distribution and modulation of FGF2 in the human and rat central nervous system. To ascertain a functional link between arginine vasopressin (AVP) and FGF2, a rat model of chronic dehydration was used to test the hypothesis that FGF2 expression, like that of AVP, is altered by perturbed fluid balance.</p> <p>Methods</p> <p>Immunohistochemistry and confocal microscopy were used to examine the distribution of FGF2 and AVP neuropeptides in the normal human brain. In order to assess effects of chronic dehydration, Sprague-Dawley rats were water deprived for 3 days. AVP neuropeptide expression and changes in FGF2 distribution in the brain, neural lobe of the pituitary and kidney were assessed by immunohistochemistry, and western blotting (FGF2 isoforms).</p> <p>Results</p> <p>In human hypothalamus, FGF2 and AVP were co-localized in the cytoplasm of supraoptic and paraventricular magnocellular neurons and axonal processes. Immunoreactive FGF2 was associated with small granular structures distributed throughout neuronal cytoplasm. Neurohypophysial FGF2 immunostaining was found in axonal processes, pituicytes and Herring bodies. Following chronic dehydration in rats, there was substantially-enhanced FGF2 staining in basement membranes underlying blood vessels, pituicytes and other glia. This accompanied remodeling of extracellular matrix. Western blot data revealed that dehydration increased expression of the hypothalamic FGF2 isoforms of ca. 18, 23 and 24 kDa. In lateral ventricle choroid plexus of dehydrated rats, FGF2 expression was augmented in the epithelium (Ab773 as immunomarker) but reduced interstitially (Ab106 immunostaining).</p> <p>Conclusions</p> <p>Dehydration altered FGF2 expression patterns in AVP-containing magnocellular neurons and neurohypophysis, as well as in choroid plexus epithelium. This supports the involvement of centrally-synthesized FGF2, putatively coupled to that of AVP, in homeostatic mechanisms that regulate fluid balance.</p
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