1,431 research outputs found

    Volunteers and volunteering in leisure : social science perspectives

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    Leisure has been widely examined within the context of social science theory; however, little work has considered the range of social science disciplines and applied them to specific phenomena located within the leisure field. This paper adopts such an approach to conceptualise and examine volunteers and volunteering in leisure settings. In a disciplinary sense, therefore, the sociological view focuses upon the conceptualisation of volunteering as leisure, the psychological view seeks to understand motivations driving volunteering while the perspective of economists tends to complement these standpoints in terms of why people volunteer and further examines the value of volunteer contributions. Comparative analysis of the perspectives enunciated within these key disciplines provides a picture of the status of research relating to leisure volunteers and volunteering. The purposes of this paper are to identify gaps in current knowledge, drawing out conclusions and their implications for an improved understanding of this area as well as to enhance comprehension of disciplinary contributions to the study of leisure phenomena

    Trends in Organochlorine Residue Concentrations in Ringed Seal (Phoca hispida) from Holman, Northwest Territories, 1972-91

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    Samples of blubber for organochlorine (OC) analysis were collected from ringed seals (Phoca hispida) taken during subsistence hunts at Holman, Northwest Territories, in 1972, 1981, 1989, and 1991. DDT-group residue burdens did not change appreciably between 1972 and 1981, but after 1981 concentrations of p,p'-DDE and p,p'-DDT began to fall. By 1991, p,p'-DDE concentrations were less than half, and p,p'-DDT concentrations about 20%, of their 1972 values. Concentrations of polychlorinated biphenyls (PCB) fell to about one-third of their 1972 values by 1981, and then stayed constant until 1991; small but significant changes in the relative proportions of individual congeners, probably resulting from metabolism, occurred between 1981 and 1991. Concentrations of hexachlorobenzene (HCB) fell by 40 to 50% between 1981 and 1991, but those of alpha and beta hexachlorocyclohexanes (HCH) did not change. Only minor changes were seen in the distribution of other OC pesticides (oxychlordane, cis- and trans-chlordane, cis- and trans-nonachlor, mirex, heptachlor epoxide and dieldrin). Female ringed seals consistently had lower blubber DDT-group and PCB concentrations than males. These temporal trends are consistent with changes in the production and use pattern of some OCs, and with their expected environmental behaviour as inferred from their physico-chemical properties.En 1972, 1981, 1989 et 1991, on a prélevé des échantillons de lard de phoques annelés (Phoca hispida) pris durant des chasses de subsistance à Holman (Territoires du Nord-Ouest), en vue d'en analyser les organochlorés. Les charges des résidus du groupe DDT n'ont pas changé de façon appréciable entre 1972 et 1981, mais après 1981 les concentrations de p,p'-DDE et de p,p'-DDT ont commencé à chuter. En 1991, les concentrations de p,p'-DDE étaient de plus de 50 p. cent inférieures à leurs valeurs de 1972, et celles de p,p'-DDT, d'environ 20 p. cent. En 1981, les concentrations de diphényles polychlorés (PCB) avaient baissé pour atteindre environ un tiers de leurs valeurs de 1972, puis elles se sont stabilisées jusqu'en 1991; des changements faibles mais significatifs dans les proportions relatives des congénères analysés individuellement, résultant probablement du métabolisme, se sont produits entre 1981 et 1991. Les concentrations d'hexachlorobenzène (HCB) ont diminué de 40 à 50 p. cent entre 1981 et 1991, mais celles des I- et K-hexachlorocyclohexanes (HCH) n'ont pas varié. Seuls des changements mineurs ont été observés dans la distribution d'autres pesticides organochlorés (oxychlordane, cis- et trans-chlordane, cis- et trans-nonachlore, mirex, époxyde d'heptachlore et dieldrine). Les concentrations de substances du groupe DDT et celles de PCB dans le lard des phoques annelés femelles étaient systématiquement moindres que dans celui des mâles. Ces tendances temporelles sont en harmonie avec les changements survenus dans la production et le schéma d'utilisation de certains organochlorés, ainsi qu'avec le comportement environnemental que leurs propriétés physico-chimiques laissent prévoir

    Measurement of species flux from a bubble using an acousto-electrochemical technique

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    An acousto-electrochemical technique is presented which, for the first time, offers the potential for measuring the flux of dissolved species in a liquid resulting from bubbles of a specific chosen size in the population. Laboratory trials are presented, but the device itself was damaged in the surf zone and no data was obtained from the ocean deployment. Nevertheless, the preceding laboratory tests demonstrate the viability of the technique. The device responds to perturbations of the fluid around a small electrode. Three such sources of motion must be characterised if it is to achieve the objective stated above. First, the perturbations resulting form the translatory motions of bubbles in the liquid. To obtain bubble radius resolution in the measurement of mass flux, however, it is necessary to apply to driving (‘pump’) sound field. Bubbles close to resonance will, in addition to a translatory motion, impart to the liquid a component of mass flux at the pump frequency. This is detected. However to show that this is the result of bubble wall pulsation, and not someother coupling, the amplitude of the pump field is increased until the electrochemical sensor detects Faraday waves on the bubble wall. Not only does this prove the relation between mass flux to bubble wall motion, it provides a second route by which the radius-resolved component of mass flux might be identified. In these preliminary laboratory tests, electrochemical detection of these motions was achieved through the observation of current produced by the reduction of a suitable redox agent present within the liquid phase of the solution employed. Preparations were made to obtain preliminary data from the Hurst Spit 2000 surf zone trial, but the device was damaged by the environment

    Hematology and Plasma Chemistry as Indicators of Health and Ecological Status In Beluga Whales, Delphinapterus Leucas

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    The capture of beluga whales, Delphinapterus leucas, for instrumentation or tagging afforded the opportunity to collect blood, which was analyzed to evaluate the animals' health and gain information on basic physiological systems. Here, we report on hematological and plasma chemical constituents in samples obtained from 183 belugas, 55 of which were handled during attempts to apply tracking instruments. The other 128 samples were either drawn from live belugas captured for exhibit in zoological parks or research or obtained from the fresh carcasses of whales taken by Inuit hunters. The data span a 15-year period beginning in 1983 and represent various beluga stocks in the Canadian Arctic. The majority of the specimens were collected during the summer or estuarine phase of the belugas' annual cycle. Comparisons by age group, sex, stock, season, and year revealed significant differences in most of the cellular and chemical constituents examined. These results demonstrate some of the variability that might be encountered when examining a "random" selection of belugas at a particular location and time. Immature-sized whales had higher leucocyte counts, electrolyte concentrations, enzyme activity, total protein, albumin, hemoglobin, and some metabolites than older animals. Sex alone was associated with few hematological and plasma chemical differences. Seasonal variation in thyroid hormone activity was linked to marked environmental changes associated with the transition from cold oceanic waters to relatively warm estuaries. Two belugas recaptured 19 and 24 days after instrumentation showed changes in leucocyte counts, hematocrit, and a variety of plasma chemical constituents, some of which indicate inflammation and a likely physiological response to handling and tagging stresses.On a profité du fait qu'on capturait des bélougas, Delphinapterus leucas, en vue de les équiper d'instruments ou de les marquer, pour prélever des échantillons de sang qu'on a ensuite analysés afin d'évaluer l'état de santé des individus et de collecter de l'information sur leurs grands systèmes physiologiques. Nous présentons ici un rapport sur les constituants hématologiques et chimiques du plasma dans des échantillons provenant de 183 bélougas, dont 55 ont été manipulés au cours de tentatives visant à les équiper d'instruments de poursuite. Les 128 autres échantillons ont été obtenus soit de bélougas vivants capturés en vue d'être placés dans des zoos ou pour la recherche, soit de carcasses fraîches de baleines prises par les chasseurs inuits. Les données couvrent une période de 15 ans, commençant en 1983, et représentent divers stocks de bélougas de l'océan Arctique canadien. La plupart des spécimens ont été recueillis durant l'été ou durant la phase estuarienne du cycle annuel du bélouga. Des comparaisons par groupe d'âge, sexe, stock, saison et année ont révélé des différences marquées dans la plupart des constituants cellulaires et chimiques examinés. Ces résultats font ressortir une certaine variabilité à laquelle on peut s'attendre quand on étudie un échantillon "aléatoire" de bélougas pris à un endroit et à un moment donnés. Par rapport à des individus plus âgés, les baleines qui n'avaient pas atteint leur taille adulte avaient un compte de globules blancs plus élevé, de même qu'une plus forte concentration d'électrolytes, une plus grande activité enzymatique, et un taux plus fort d'albumine, d'hémoglobine et de certains métabolites. Le sexe seul n'était associé qu'à quelques différences hématologiques et chimiques du plasma. Une variation saisonnière de l'activité des hormones thyroïdiennes était liée à des changements nets du milieu correspondant à la transition des eaux froides océaniques aux estuaires relativement chauds. Deux bélougas recapturés 19 et 24 jours après avoir été équipés d'instruments montraient des changements dans le compte de globules blancs, dans l'hématocrite et dans divers constituants chimiques du plasma, dont certains révèlent une inflammation et probablement une réaction physiologique au stress dû à la manipulation et au marquage

    Summer and Autumn Movements and Habitat Use by Belugas in the Canadian High Arctic and Adjacent Areas

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    Twenty-one adult belugas (8M, 13F) were live-captured and instrumented with satellite-linked transmitters in the summer and fall of 1996. Twelve were captured in estuaries along the coast of Somerset Island in July and nine were captured in September in Croker Bay, SE Devon Island. This paper reports on the summer and autumn movements and dive depths of these animals from late July 1996 until the last tags ceased transmitting in November 1996. Of the 12 captured in July, 11 provided data for 30-126 days (mean = 84 days). Most of the animals moved rapidly to southern Peel Sound, where they all spent the month of August, making frequent deep dives, some of which were to depths near or at the seabed of the Franklin Trench. The belugas also used several bays along the coast of Prince of Wales Island and another one on Melville Peninsula. They left southern Peel Sound between late August and early September and moved rapidly to the south coast of Devon Island, many using Maxwell Bay and Croker Bay for several days. All belugas instrumented in Croker Bay in September, as well as the summer-tagged individuals that were still transmitting, moved east and north along the south and east coasts of Devon Island, eventually reaching Jones Sound and north Baffin Bay. They used many bays along the east coast of Devon Island and dove to depths often exceeding 200 m in the surrounding waters. Fifteen of the tags continued to transmit during the period when belugas are normally observed migrating along the West Greenland coast (late September-early October). Only one of the tagged animals moved to Greenland waters in late September. The others remained in the area known in winter as the North Water. The autumn tracking results suggest that the North Water may harbour a larger winter population of belugas than was previously suspected.Durant l'été et l'automne de 1996, on a capturé 21 bélugas adultes (8 mâles, 13 femelles), qu'on a équipés d'émetteurs-satellite. Douze d'entre eux ont été capturés en juillet dans des estuaires de l'île Somerset et neuf autres l'ont été en septembre dans la baie Croker du sud-est de l'île Devon. Cet article fait état des déplacements et profondeurs de plongée de ces animaux en été et en automne, de la fin juillet 1996 jusqu'à ce que les émetteurs cessent de transmettre, en novembre 1996. Sur 12 individus capturés en juillet, 11 ont transmis des données pendant 30 à 126 jours (moy. = 84 jours). La plupart des animaux se sont déplacés rapidement vers le sud du détroit de Peel où ils ont tous passé le mois d'août, plongeant fréquemment à de grandes profondeurs dont certaines atteignaient ou presque le fond marin de la fosse Franklin. Les bélugas ont aussi utilisé plusieurs baies le long de la côte de l'île Prince of Wales et une autre dans la péninsule Melville. Ils ont quitté le sud du détroit de Peel entre fin août et début septembre et se sont déplacés rapidement vers la côte sud de l'île Devon. Plusieurs d'entre eux ont passé quelques jours dans les baies Maxwell et Croker. Tous les bélugas équipés d'instruments dans la baie Croker en septembre, ainsi que ceux relâchés en été et qui continuaient à transmettre, se sont déplacés vers l'est et le nord en suivant les côtes sud et est de l'île Devon, finissant par atteindre le détroit de Jones et le nord de la baie de Baffin. Ils ont occupé de nombreuses baies sur la côte est de l'île Devon et effectué des plongées atteignant souvent plus de 200 m dans les eaux avoisinantes. Quinze des émetteurs ont continué à transmettre durant la période où on observe normalement des bélugas en migration au large de la côte du Groenland occidental (fin septembre - début octobre). Un seul des animaux portant un émetteur a pénétré dans les eaux groenlandaises à la fin septembre. Les autres sont restés dans une zone connue en hiver sous le nom de "North Water" (Eau du Nord). Ces résultats suggèrent qu'en hiver le "North Water" abrite une population de bélugas plus abondante qu'on ne le pensait antérieurement

    Inside an Environmental Data Archive WWW Site

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    The Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC), which is associated with NASA`s Earth Observing System Data and Information System (EOSDIS), provides access to tabular and imagery datasets used in ecological and environmental research. Because of its large and diverse data holdings, twin challenges for the ORNL DAAC are to help users find data of interest from the hundreds of thousands of files available at the DAAC without overwhelming them and to manage such a large collection of data. Therefore, the ORNL DAAC has developed a number of World Wide Web (WWW) tools such as the Biogeochemical Information Ordering Management Environment (BIOME), a WWW search and order system, as well as WWW-based data management and configuration control tools. This paper describes the specialized attributes incorporated into these systems that allow for easy access to and management of the data

    Flow around a cube in a turbulent boundary layer: LES and experiment

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    We present a numerical simulation of flow around a surface mounted cube placed in a turbulent boundary layer which, although representing a typical wind environment, has been specifically tailored to match a series of wind tunnel observations. The simulations were carried out at a Reynolds number, based on the velocity U at the cube height h, of 20,000—large enough that many aspects of the flow are effectively Reynolds number independent. The turbulence intensity was about 18% at the cube height, and the integral length scale was about 0.8 times the cube height h. The Jenson number Je=h/z0, based on the approach flow roughness length z0, was 600, to match the wind tunnel situation. The computational mesh was uniform with a spacing of h/32, aiding rapid convergence of the multigrid solver, and the governing equations were discretised using second-order finite differences within a parallel multiblock environment. The results presented include detailed comparison between measurements and LES computations of both the inflow boundary layer and the flow field around the cube including mean and fluctuating surface pressures. It is concluded that provided properly formulated inflow and surface boundary conditions are used, LES is now a viable tool for use in wind engineering problems concerning flow over isolated bodies. In particular, both mean and fluctuating surface pressures can be obtained with a similar degree of uncertainty as usually associated with wind tunnel modelling
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