94 research outputs found

    Chloro-s-triazine Dyes as Vital Markers in Monkeys

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66977/2/10.1177_00220345730520034601.pd

    The Structure of the Prodromal Questionnaire-16 (PQ-16) in a Non-Help-Seeking Youth Population: Exploratory and Confirmatory Factor Analyses Study

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    Aims: The present study aimed to examine the structure of the Prodromal Questionnaire-16 (PQ-16) in a non-help-seeking youth population through exploratory and confirmatory factor analysis. Previous studies have not examined the structure of this self-report measure in this age group outside a clinical setting. Methods: Participants (n = 1165) aged 11–19 years were recruited to an epidemiological study of young people in Northern Ireland, and completed the PQ-16 alongside other measures. The dataset was split randomly in two for separate factor analyses. A polychoric correlation matrix was created and exploratory factor analysis was used to identify the optimal number of factors. In addition, based on previous studies, six models were tested through confirmatory factor analysis to determine best fit. A one-factor, 3 two-factor, a three-factor and a four-factor model were all tested. Results: The exploratory factor analysis indicated a two-factor structure of the PQ-16 in this population, which we have labelled ‘general unusual experiences’ and ‘hallucinations’. Confirmatory analysis indicated that the two-factor model identified through the exploratory analysis was the best fit for the data. Discussion: The present study suggests that the structure of the PQ-16 may vary across age groups in non-clinical settings, and adds further support to the validity of the PQ-16 is a cost-effective, easy to administer self-report measure that is suitable for use in non-help-seeking populations as a screening tool for prodromal symptoms.</p

    How useful are volunteers for visual biodiversity surveys? An evaluation of skill level and group size during a conservation expedition

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    The ability of volunteers to undertake different tasks and accurately collect data is critical for the success of many conservation projects. In this study, a simulated herpetofauna visual encounter survey was used to compare the detection and distance estimation accuracy of volunteers and more experienced observers. Experience had a positive effect on individual detection accuracy. However, lower detection performance of less experienced volunteers was not found in the group data, with larger groups being more successful overall, suggesting that working in groups facilitates detection accuracy of those with less experience. This study supports the idea that by optimizing survey protocols according to the available resources (time and volunteer numbers), the sampling efficiency of monitoring programs can be improved and that non-expert volunteers can provide valuable contributions to visual encounter-based biodiversity surveys. Recommendations are made for the improvement of survey methodology involving non-expert volunteers

    Exposure to Sublethal Doses of Fipronil and Thiacloprid Highly Increases Mortality of Honeybees Previously Infected by Nosema ceranae

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    International audienceBACKGROUND: The honeybee, Apis mellifera, is undergoing a worldwide decline whose origin is still in debate. Studies performed for twenty years suggest that this decline may involve both infectious diseases and exposure to pesticides. Joint action of pathogens and chemicals are known to threaten several organisms but the combined effects of these stressors were poorly investigated in honeybees. Our study was designed to explore the effect of Nosema ceranae infection on honeybee sensitivity to sublethal doses of the insecticides fipronil and thiacloprid. METHODOLOGY/FINDING: Five days after their emergence, honeybees were divided in 6 experimental groups: (i) uninfected controls, (ii) infected with N. ceranae, (iii) uninfected and exposed to fipronil, (iv) uninfected and exposed to thiacloprid, (v) infected with N. ceranae and exposed 10 days post-infection (p.i.) to fipronil, and (vi) infected with N. ceranae and exposed 10 days p.i. to thiacloprid. Honeybee mortality and insecticide consumption were analyzed daily and the intestinal spore content was evaluated 20 days after infection. A significant increase in honeybee mortality was observed when N. ceranae-infected honeybees were exposed to sublethal doses of insecticides. Surprisingly, exposures to fipronil and thiacloprid had opposite effects on microsporidian spore production. Analysis of the honeybee detoxification system 10 days p.i. showed that N. ceranae infection induced an increase in glutathione-S-transferase activity in midgut and fat body but not in 7-ethoxycoumarin-O-deethylase activity. CONCLUSIONS/SIGNIFICANCE: After exposure to sublethal doses of fipronil or thiacloprid a higher mortality was observed in N. ceranae-infected honeybees than in uninfected ones. The synergistic effect of N. ceranae and insecticide on honeybee mortality, however, did not appear strongly linked to a decrease of the insect detoxification system. These data support the hypothesis that the combination of the increasing prevalence of N. ceranae with high pesticide content in beehives may contribute to colony depopulation

    Risk, responsibilities and rights: reassessing the ‘economic causes of crime’ thesis in a recession

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    This paper explores competing accounts of an apparent inversion of the previously-prevailing relationship between young people's unemployment and the incidence of youth offending at a time of economic recession. It begins by highlighting the faltering association between unemployment and offending, and considers the paradoxical implications for risk-based methodologies in youth justice practice. The paper then assesses explanations for the changing relationship that suggest that youth justice policies have successfully broken the unemployment-offending link; and alternatively that delayed effects of recession have yet to materialise, by reference to the work of four Inter-governmental organisations and to youth protests beyond the UK. In place of ever more intensive risk analyses, the paper then focusses on the adverse effects of unemployment on social cohesion, and proposes a rights-based approach to youth justice that recognises the growing disjuncture between the rights afforded to young people and the responsibilities expected of them

    Pilot testing of a sampling methodology for assessing seed attachment propensity and transport rate in a soil matrix carried on boot soles and bike tires

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    Land managers of natural areas are under pressure to balance demands for increased recreation access with protection of the natural resource. Unintended dispersal of seeds by visitors to natural areas has high potential for weedy plant invasions, with initial seed attachment an important step in the dispersal process. Although walking and mountain biking are popular nature-based recreation activities there are few studies quantifying propensity for seed attachment and transport rate on boot soles and none for bike tires. Attachment and transport rate can potentially be affected by a wide range of factors for which field testing can be time-consuming and expensive. We pilot tested a sampling methodology for measuring seed attachment and transport rate in a soil matrix carried on boot soles and bike tires traversing a known quantity and density of a seed analog (beads) over different distances and soil conditions. We found % attachment rate on boot soles was much lower overall than previously reported but that boot soles had a higher propensity for seed attachment than bike tires in almost all conditions. We believe our methodology offers a cost-effective option for researchers seeking to manipulate and test effects of different influencing factors on these two dispersal vectors

    The Role of Visible Wealth for Deprivation

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    Motivated by the lack of literature linking actual to perceived relative deprivation, this paper assesses the role of visibility in the deprivation of goods and assets vis-à-vis income behind perceptions of relative deprivation. We rely on household survey data that includes unique information on reported perceived deprivation with a pre-specified reference group, namely others in the town or village. Based on a large number of asset and consumption items, we create an index of visible wealth by aggregating visible goods and assets using principal component weights. We find that relative deprivation in visible wealth has a ten percentage point higher explanatory power for reporting a high level of perceived deprivation than that of deprivation in income. The effect is robust under various sensitivity checks and for a number of controls. The finding sheds light on the importance of the visibility of the objects of comparison for an individual's assessment of his relative economic situation and proposes that future research should not solely rely on income-based deprivation measures
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