1,928 research outputs found

    Consideraciones ante una eventual regularización del cannabis recreativo en Colombia

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    Seminario InternacionalEl marco jurídico en relación al uso recreativo y médico del cannabis varía mucho según el país y la región, pero sigue estando prohibido en gran medida a nivel internacional. Los defensores a favor de medidas regulativas, han enfatizado el potencial para erradicar el mercado negro del cannabis, mejorar el control de su calidad, aumentar los ingresos fiscales, mejorar la disponibilidad de cannabis medicinal y reducir la violencia relacionada con las pandillas y carteles que trafican con drogas.1. INTRODUCCIÓN 2. DESARROLLO 3. CONCLUSIONES 4. BIBLIOGRAFÍAPregradoEconomist

    The Role of Scientific Source Credibility and Goodwill in Public Skepticism Toward GM Foods

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    The complex web of political-economic relations that constitutes biotechnology coupled with a contentious history of public resistance, illustrates the power of perceptions of credibility in mediating individuals’ judgements about GMOs. To more accurately measure what contributes to public skepticism of GM foods, the present research applies a multidimensional model of source credibility comprised of scientific understanding, integrity, agreement, concern, trust, and goodwill (bias). Testing the Anti-Reflexivity Thesis in a new context, we also explore the role of attitudes about science and economic innovation by analyzing associations between political ideology and beliefs about the potential impacts of GM foods. Using data from the Pew Research Center’s American Trends Panel, we find evidence of politically polarized perceptions of GM scientists’ credibility and public beliefs about the environmental risks and benefits of GM foods. Results suggest that political ideology is indirectly associated with beliefs about GM impacts on the food supply, largely through perceptions of goodwill, the so-called “lost” dimension of source credibility. Because demand for biotechnology products like gene edited foods is expected to increase, consumer beliefs about GMOs will likely have significant implications for the future of the bioeconomy

    Retrievals of Riming and Snow Density From Vertically Pointing Doppler Radars

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    Retrievals of ice and snow are made from Ka- and W-band zenith-pointing Doppler radars at Hyytiala, Finland, during the snow experiment component of the Biogenic Aerosols: Effects on Clouds and Climate (2014) field campaign. In a novel optimal estimation retrieval, mean Doppler velocity is exploited to retrieve a density factor parameter, which modulates the mass, shape, terminal velocity, and backscatter cross sections of ice particles. In a case study including aggregate snow and graupel we find that snow rate and ensemble mean ice density can be retrieved to within 50% of in situ measurements at the surface using dual-frequency Doppler radar retrievals. While Doppler measurements are essential to the retrieval of particle density, the dual-frequency ratio provides a strong constraint on particle size. The retrieved density factor is strongly correlated with liquid water path, indicating that riming is the primary process by which the density factor is modulated. Using liquid water path as a proxy for riming, profiles classified as unrimed snow, rimed snow, and graupel exhibit distinct features characteristic of aggregation and riming processes, suggesting the potential to make estimates of process rates from these retrievals. We discuss the potential application of the technique to future satellite missions. Plain Language Summary Ground-based radar measurements of ice clouds and snow are used to estimate the size, number, and density of snowflakes. Doppler velocity measurements of particle fall speeds are used to estimate the mass and shape of the snow particles. The properties of snow estimated using radar compare well against measurements of particles at the surface and estimates of the amount of liquid water in the atmosphere; the presence of liquid water relates to the potential for riming, in which snowflakes increase in density and fall speed by collecting and freezing liquid droplets. More accurate estimates of snow density from ground-based and satellite radars help to improve global estimates of precipitation and snow accumulation and the representation of clouds and snow in weather and climate models.Peer reviewe

    Dietary Iron bioavailability: A simple model that can be used to derive country-specific dietary reference values for adult men and women

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    Background: Reference intakes for iron are derived from physiological requirements, with an assumed value for dietary iron absorption. A new approach to estimate iron bioavailability, calculated from iron intake, status, and requirements was used to set European dietary reference values, but the values obtained cannot be used for low- and middle-income countries where diets are very different. Objective: We aimed to test the feasibility of using the model developed from United Kingdom and Irish data to derive a value for dietary iron bioavailability in an African country, using data collected from women of child-bearing age in Benin. We also compared the effect of using estimates of iron losses made in the 1960s with more recent data for whole body iron losses. Methods: Dietary iron intake and serum ferritin (SF), together with physiological requirements of iron, were entered into the predictive model to estimate percentage iron absorption from the diet at different levels of iron status. Results: The results obtained from the 2 different methods for calculating physiological iron requirements were similar, except at low SF concentrations. At a SF value of 30 µg/L predicted iron absorption from the African maize-based diet was 6%, compared with 18% from a Western diet, and it remained low until the SF fell below 25 µg/L. Conclusions: We used the model to estimate percentage dietary iron absorption in 30 Beninese women. The predicted values agreed with results from earlier single meal isotope studies; therefore, we conclude that the model has potential for estimating dietary iron bioavailability in men and nonpregnant women consuming different diets in other countries

    The proteomes of the human eye, a highly compartmentalized organ

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/136012/1/pmic12540_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/136012/2/pmic12540.pd

    Differences in use of electronic nicotine delivery systems by smoking status and demographic characteristics among Australian young adults

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    Issue addressed: Electronic nicotine delivery systems (ENDS) continue to grow in popularity, particularly among young adults. Understanding by whom various ENDS are being used and why within this population segment can assist the development of appropriate interventions targeting those most vulnerable to use and inform policy decisions in this area. Accordingly, this study assessed the demographic characteristics associated with ENDS use among Australian young adults, and reasons for current e-cigarette use. Methods: An online survey was administered to 1116 Australians aged 18-25 years (59% female). Results: Smokers were more likely than non-smokers to report (a) ever use of ENDS (67% vs 28%), (b) ever use of an e-cigarette (64% vs 24%), e-cigar (17% vs 8%) or e-hookah (15% vs 8%) and (c) current use of e-cigarettes (19% vs 6%). Male smokers were more likely than female smokers to be current e-cigarette users. The most common reason for current e-cigarette use was enjoyment. Conclusions: Young male adults appear to be particularly vulnerable to becoming regular e-cigarette users. This demographic group may need to be a primary focus of prevention and intervention efforts. Contrary to popular belief, smoking cessation was not a primary reason for e-cigarette use. So what?: Greater efforts are needed to educate young adults on the harms associated with ENDS use, especially if use is being driven by the perception that they are a harmless means of amusement. Maintaining existing regulations limiting the accessibility of these products is crucial to ensuring widespread use is minimised

    Negative emissions technologies and carbon capture and storage to achieve the Paris Agreement commitments

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    How will the global atmosphere and climate be protected? Achieving net-zero CO2 emissions will require carbon capture and storage (CCS) to reduce current GHG emission rates, and negative emissions technology (NET) to recapture previously emitted greenhouse gases. Delivering NET requires radical cost and regulatory innovation to impact on climate mitigation. Present NET exemplars are few, are at small-scale and not deployable within a decade, with the exception of rock weathering, or direct injection of CO2 into selected ocean water masses. To keep warming less than 2°C, bioenergy with CCS (BECCS) has been modelled but does not yet exist at industrial scale. CCS already exists in many forms and at low cost. However, CCS has no political drivers to enforce its deployment. We make a new analysis of all global CCS projects and model the build rate out to 2050, deducing this is 100 times too slow. Our projection to 2050 captures just 700 Mt CO2 yr−1, not the minimum 6000 Mt CO2 yr−1 required to meet the 2°C target. Hence new policies are needed to incentivize commercial CCS. A first urgent action for all countries is to commercially assess their CO2 storage. A second simple action is to assign a Certificate of CO2 Storage onto producers of fossil carbon, mandating a progressively increasing proportion of CO2 to be stored. No CCS means no 2°C.This article is part of the theme issue ‘The Paris Agreement: understanding the physical and social challenges for a warming world of 1.5°C above pre-industrial levels'
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