5,383 research outputs found

    Developing flamingo husbandry practices through workshop communication

    Get PDF
    ArticleZoos are duty-bound to provide excellent welfare standards for the species that they keep. Curators and keepers have a role to play in ensuring that husbandry regimes are relevant and mimic a species’ natural environment. This paper explains the key outcomes from ABWAK’s (Association of British and Irish Wild Animal Keepers) first national flamingo keepers’ workshop. Research on flamingo breeding is well documented in the literature, but research into other aspects of husbandry may develop flamingo welfare further. By engaging keepers and academics with a direct influence over flamingo management, questions relating to best practice can be answered to establish areas of common good practice as well as novel approaches. Topics presented for discussion at the workshop focused on 1) informed enclosure design, 2) relevant enrichment ideas and 3) "promotion" of flamingos to the zoo visitor, with the aim of having a positive impact on the birds’ quality of life and their value as a zoo exhibit. Outcomes generated included the development of enrichment and husbandry modifications that may enhance flamingo activity patterns and their display to zoo visitors. Many aspects of regular flamingo husbandry can have an enriching influence on the birds’ lives, therefore encouraging zoo professionals to share ideas may benefit many flamingos in many zoos. Through the medium of a workshop, husbandry techniques for specialist species such as the flamingo can be shared and developed

    Light attenuation characteristics of glacially-fed lakes

    Get PDF
    Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400–700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems

    The UK Women's Cohort Study: comparison of vegetarians, fish-eaters and meat-eaters

    Get PDF
    Background: This paper describes the development of the UK Women's Cohort Study and presents cohort baseline characteristics. Methods: In total, 35 372 women, aged 35–69 years at recruitment, were selected to ensure a wide range of dietary intakes. Diet was assessed by a 217-item food-frequency questionnaire (FFQ). Detailed lifestyle information was collected by postal questionnaire. Vegetarians, fish-eaters and meat-eaters were compared. Results: The cohort women are mainly white, well-educated, middle-class and married with children. They are health-conscious with only 11% current smokers and 58% taking dietary supplements. Twenty-eight per cent of subjects self-report as being vegetarian and 1% as vegan. However, only 18% are defined as 'vegetarian' from the FFQ. Fat provides 32% of energy; vitamin and mineral intakes are high, with a broad range of intakes. Meat-eaters are older, with a higher body mass index (BMI) and the lowest intakes of carbohydrate, fibre, vitamin C, folate, iron and calcium. Other fish-eaters are similar to vegetarians. Vegetarians have the lowest intakes of protein, fat and saturated fat. Oily fish-eaters have the lowest BMI; are the least likely to smoke or use full-fat milk; and are the most likely to use dietary supplements and consume the most fruit and vegetables. Oily fish-eaters have the highest total energy intake and vegetarians the lowest. Semi-skimmed milk, bread, potatoes, wine, bananas and muesli are important contributors to energy for all groups

    Ready-made oTree apps for time preference elicitation methods

    Get PDF
    In the realm of time preference elicitation, several different methods to elicit preferences from individual choices and subsequently estimate discounting and utility function parameters have evolved. We provide ready-made oTree (Chen et al., 2016) applications for three of the mostly used elicitation tools in experiments. The first method (CTB — Convex Time Budgets) elicits discounting and utility function curvature jointly from choices over time (Andreoni and Sprenger, 2012; Andreoni et al., 2015). The second method elicits time preferences and utility function curvature using two different tasks and jointly estimating parameters (DMPL — Double Multiple Price List). It is fully nested in our first method and can be complemented via a risk elicitation task by Holzmeister (2017). The third method elicits discounting without eliciting utility (Attema et al., 2016) by measuring discounting without using explicit functional forms for utility. We provide the general theoretical background of the elicitation approaches, experimental designs, as well as a detailed description of our programs. Both programs can be easily and flexibly adapted to the user’s needs, even without any prior programming knowledge in oTree

    Endogenous cholinergic inputs and local circuit mechanisms govern the phasic mesolimbic dopamine response to nicotine

    Get PDF
    Nicotine exerts its reinforcing action by stimulating nicotinic acetylcholine receptors (nAChRs) and boosting dopamine (DA) output from the ventral tegmental area (VTA). Recent data have led to a debate about the principal pathway of nicotine action: direct stimulation of the DAergic cells through nAChR activation, or disinhibition mediated through desensitization of nAChRs on GABAergic interneurons. We use a computational model of the VTA circuitry and nAChR function to shed light on this issue. Our model illustrates that the α4β2-containing nAChRs either on DA or GABA cells can mediate the acute effects of nicotine. We account for in vitro as well as in vivo data, and predict the conditions necessary for either direct stimulation or disinhibition to be at the origin of DA activity increases. We propose key experiments to disentangle the contribution of both mechanisms. We show that the rate of endogenous acetylcholine input crucially determines the evoked DA response for both mechanisms. Together our results delineate the mechanisms by which the VTA mediates the acute rewarding properties of nicotine and suggest an acetylcholine dependence hypothesis for nicotine reinforcement.Peer reviewe

    No need for more time::Intertemporal allocation decisions under time pressure

    Get PDF
    Time preferences drive decisions in many economic contexts. For understanding theunderlying decision process, it is key to identify what affects these preferences in differentsituations. To shed light on how people make intertemporal allocation choices, we analyzethe stability of time preferences under time pressure. Conducting a laboratory study with144 subjects using convex time budgets, we elicit time preferences with and without timepressure in a within-subject design. We find preferences to be stable across conditions foraggregate estimates of present-bias and utility function curvature. For standard discounting, we find subjects to be significantly less impatient under time pressure. All results holdacross specifications and different sub-samples. Individual-level analyses confirm aggregate findings

    The International-Trade Network: Gravity Equations and Topological Properties

    Get PDF
    This paper begins to explore the determinants of the topological properties of the international - trade network (ITN). We fit bilateral-trade flows using a standard gravity equation to build a "residual" ITN where trade-link weights are depurated from geographical distance, size, border effects, trade agreements, and so on. We then compare the topological properties of the original and residual ITNs. We find that the residual ITN displays, unlike the original one, marked signatures of a complex system, and is characterized by a very different topological architecture. Whereas the original ITN is geographically clustered and organized around a few large-sized hubs, the residual ITN displays many small-sized but trade-oriented countries that, independently of their geographical position, either play the role of local hubs or attract large and rich countries in relatively complex trade-interaction patterns

    Systematic review and meta-analysis of the diagnostic accuracy of ultrasonography for deep vein thrombosis

    Get PDF
    Background Ultrasound (US) has largely replaced contrast venography as the definitive diagnostic test for deep vein thrombosis (DVT). We aimed to derive a definitive estimate of the diagnostic accuracy of US for clinically suspected DVT and identify study-level factors that might predict accuracy. Methods We undertook a systematic review, meta-analysis and meta-regression of diagnostic cohort studies that compared US to contrast venography in patients with suspected DVT. We searched Medline, EMBASE, CINAHL, Web of Science, Cochrane Database of Systematic Reviews, Cochrane Controlled Trials Register, Database of Reviews of Effectiveness, the ACP Journal Club, and citation lists (1966 to April 2004). Random effects meta-analysis was used to derive pooled estimates of sensitivity and specificity. Random effects meta-regression was used to identify study-level covariates that predicted diagnostic performance. Results We identified 100 cohorts comparing US to venography in patients with suspected DVT. Overall sensitivity for proximal DVT (95% confidence interval) was 94.2% (93.2 to 95.0), for distal DVT was 63.5% (59.8 to 67.0), and specificity was 93.8% (93.1 to 94.4). Duplex US had pooled sensitivity of 96.5% (95.1 to 97.6) for proximal DVT, 71.2% (64.6 to 77.2) for distal DVT and specificity of 94.0% (92.8 to 95.1). Triplex US had pooled sensitivity of 96.4% (94.4 to 97.1%) for proximal DVT, 75.2% (67.7 to 81.6) for distal DVT and specificity of 94.3% (92.5 to 95.8). Compression US alone had pooled sensitivity of 93.8 % (92.0 to 95.3%) for proximal DVT, 56.8% (49.0 to 66.4) for distal DVT and specificity of 97.8% (97.0 to 98.4). Sensitivity was higher in more recently published studies and in cohorts with higher prevalence of DVT and more proximal DVT, and was lower in cohorts that reported interpretation by a radiologist. Specificity was higher in cohorts that excluded patients with previous DVT. No studies were identified that compared repeat US to venography in all patients. Repeat US appears to have a positive yield of 1.3%, with 89% of these being confirmed by venography. Conclusion Combined colour-doppler US techniques have optimal sensitivity, while compression US has optimal specificity for DVT. However, all estimates are subject to substantial unexplained heterogeneity. The role of repeat scanning is very uncertain and based upon limited data
    corecore