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Recreational Users (recreational + user)
Selected AbstractsCLINICAL STUDY: FULL ARTICLE: Immunomodulating properties of gamma-hydroxybutyrate (GHB), flunitrazepam and ethanol in ,club drugs' usersADDICTION BIOLOGY, Issue 3 2010Simona Pichini ABSTRACT Despite the increasing concern about gamma-hydroxybutyrate (GHB) toxicity in users, no studies have addressed GHB and other club drugs effects on the immune system under controlled administration. Lymphocyte subsets and functional responsiveness of lymphocytes to mitogenic stimulation were measured in 10 healthy male recreational users of GHB who participated in five experimental sessions within the framework of a clinical trial. The study was randomized, double blind, double dummy and cross-over. Drug conditions were: a single oral dose of GHB (40 mg/kg or 60 mg/kg), ethanol (0.7 g/kg), flunitrazepam (1.25 mg) and placebo. Acute GHB produced a time-dependent immune impairment in the first 4 hours after drug administration associated with an increase in cortisol secretion. Although total leukocyte count remained unchanged, there was a significant decrease in the CD4 T/CD8 T-cell ratio, as well as in the percentage of mature T lymphocytes, probably because of a decrease in both the percentage and absolute number of T helper cells. A significant decrease was also observed in natural killer cells and in functional responsiveness of lymphocytes to mitogenic stimulation. Flunitrazepam administration did not produce any change in the immune system, while ethanol intake produced a decrease in B lymphocytes and in lymphocyte proliferative response to mitogens. These results provide the first evidence that GHB intake under a controlled environmental setting impairs the immunological status and confirms the alterations in the immune function caused by ethanol. [source] Managing Environmental Impacts of Recreation and Tourism in Rainforests of the Wet Tropics of Queensland World Heritage AreaGEOGRAPHICAL RESEARCH, Issue 2 2005Stephen M. Turton Abstract This paper describes environmental impacts of tourism and recreation activities in the world heritage listed rainforests of northeast Australia and presents management strategies for sustainable visitor use of the protected area. Tropical rainforests are characterised by their low resistance and moderate to high resilience to impacts associated with human visitation. Visitor use in the World Heritage Area is mostly associated with walking tracks, camping areas, day use areas and off-road vehicle use of old forestry roads and tracks. Adverse environmental impacts range from vegetation trampling, soil compaction, water contamination and soil erosion at the local scale through to spread of weeds, feral animals and soil pathogens along extensive networks of old forestry roads and tracks at the regional scale. Concentration of visitor use is the most desirable management strategy for controlling adverse impacts at most World Heritage Area visitor nodes and sites, and includes methods such as site hardening and shielding to contain impacts. For dispersed visitor activities, such as off-road vehicle driving and long-distance walking, application of best practice methods by the tourist industry and recreational users such as removal of mud and soils from vehicle tyres and hiking boots before entering pathogen-free catchments, together with seasonal closure of roads and tracks, are the preferred management strategies. Retention of canopy cover at camping areas and day use areas, as well as along walking tracks and forestry roads is a simple, yet effective, management strategy for reduction of a range of adverse impacts, including dispersal of weeds and feral animals, edge effects, soil erosion and nutrient loss, road kill and linear barrier effects on rainforest fauna. [source] Visual search and urban driving under the influence of marijuana and alcoholHUMAN PSYCHOPHARMACOLOGY: CLINICAL AND EXPERIMENTAL, Issue 5 2001C. T. J. Lamers Abstract The purpose of the present study was to assess the effects of low doses of marijuana and alcohol, and their combination, on visual search at intersections and on general driving proficiency in the City Driving Test. Sixteen recreational users of alcohol and marijuana (eight males and eight females) were treated with these substances or placebo according to a balanced, 4-way, cross-over, observer- and subject-blind design. On separate evenings, subjects received weight-calibrated doses of THC, alcohol or placebo in each of the following treatment conditions: alcohol placebo + THC placebo, alcohol + THC placebo, THC 100,,g/kg + alcohol placebo, THC 100,,g/kg + alcohol. Alcohol doses administered were sufficient for achieving a blood alcohol concentration (BAC) of about 0.05,g/dl. Initial drinking preceded smoking by one hour. The City Driving Test commenced 15 minutes after smoking and lasted 45 minutes. The test was conducted over a fixed route within the city limits of Maastricht. An eye movement recording system was mounted on each subject's head for providing relative frequency measures of appropriate visual search at intersections. General driving quality was rated by a licensed driving instructor on a shortened version of the Royal Dutch Tourist Association's Driving Proficiency Test. After placebo treatment subjects searched for traffic approaching from side streets on the right in 84% of all cases. Visual search frequency in these subjects did not change when they were treated with alcohol or marijuana alone. However, when treated with the combination of alcohol and marijuana, the frequency of visual search dropped by 3%. Performance as rated on the Driving Proficiency Scale did not differ between treatments. It was concluded that the effects of low doses of THC (100,,g/kg) and alcohol (BAC,<,0.05,g/dl) on higher-level driving skills as measured in the present study are minimal. Copyright © 2001 John Wiley & Sons, Ltd. [source] The use of willingness-to-pay approaches in mammal conservationMAMMAL REVIEW, Issue 2 2001Piran C. L. White ABSTRACT With limited monetary resources available for nature conservation, policy-makers need to be able to prioritize conservation objectives. This has traditionally been done using qualitative ecological criteria. However, since declines in species and habitats are largely the result of socio-economic and political forces, human preferences and values should also be taken into account. An environmental economics technique, contingent valuation, provides one way of doing this by quantifying public willingness-to-pay towards specific conservation objectives. In this paper, the use of this approach for quantifying public preferences towards the UK Biodiversity Action Plans for four different British mammal species is considered. The species included are the Red Squirrel Sciurus vulgaris, the Brown Hare Lepus europaeus, the Otter Lutra lutra and the Water Vole Arvicola terrestris. Willingness-to-pay for conservation was increased by the inclusion of the Otter among the species, membership of an environmental organization and awareness of the general and species-specific threats facing British mammals. It was reduced by the presence of the Brown Hare among the species being considered. These findings for British mammals are compared with other willingness-to-pay studies for mammal conservation worldwide. Willingness-to-pay tends to be greater for marine mammals than terrestrial ones, and recreational users of species (tourists or hunters) are generally more willing than residents to pay towards species conservation. The choice of technique for eliciting willingness-to-pay from respondents is also shown to be highly significant. Willingness-to-pay values for British mammals derived from contingent valuation are sensitive to the species included rather than merely symbolic. This indicates that, with care, such measures can be used as a reliable means of quantifying public preferences for conservation, and therefore contributing to the decision-making process. However, irrespective of the internal consistency of contingent valuation, the validity of the approach, especially for use in nature conservation, is disputed. Willingness-to-pay is likely to reflect many interrelated factors such as ethical and moral values, knowledge and tradition, and monetary values may not be an adequate representation of these broader considerations. Willingness-to-pay approaches should therefore be used in addition to, rather than in place of, expert judgements and more deliberative approaches towards policy decision-making for conservation. [source] | ||||||||||