671 research outputs found

    A comparison between direct and pan-derived measurements of the isotopic composition of atmospheric waters

    Get PDF
    The stable isotopes of water can be used to examine and quantify the contribution to atmospheric moisture from evaporation, transpiration and surface-waters. However, obtaining extensive and ongoing time series data of the isotopic composition of atmospheric moisture has been difficult. Presented here is an alternate method using an isotope mass balance approach to estimate the isotopic composition of atmospheric moisture using water samples collected from class A evaporation pans. While this evaporation pan method does not provide the high-resolution time series data that can be obtained from an isotope analyser taking in-situ measurements of atmospheric moisture, the method is relatively simple and inexpensive to set-up and maintain. In this preliminary investigation, a comparison between the isotopic composition of atmospheric moisture estimated from the evaporation pan method and in-situ measurements of the isotopic composition of water vapour using a Fourier Transform Infrared (FTIR) spectrometer deployed at the Lucas Heights weather station in New South Wales is undertaken. Through comparison of the two series of hydrogen isotope data, an assessment of the evaporation pan method can be made. Although there was some agreement between the isotopic composition of vapour measured by the FTIR spectrometer and the estimation for the atmospheric moisture (R2 = 0.49), the comparison is sensitive to climatic parameters that vary significantly within a 24-hour period such as the relative humidity of air and the air and pan temperatures. Inverting the model to use the FTIR spectrometer measurements at an hourly resolution improved the performance of the model (R2 =0.57). However, this also revealed that the model produced more depleted values of the evaporation pan water isotopes than those observed. In contrast, there was a variable relationship between the modelled and observed isotope values of atmospheric moisture. These conflicting results will need to be resolved before the evaporation pan method is broadly applied in isotope hydrology. © 2011 The Modelling and Simulation Society of Australia and New Zealand Inc

    Parents’ experiences of health visiting for children with Down syndrome

    Get PDF
    © MA Healthcare Limited.Children with Down syndrome have an increased likelihoodof experiencing serious health conditions. Health visitors canhave an important role in monitoring and promoting healthand development for young children with Down syndrome.This study aimed to explore parents’ experiences of healthvisiting services for children with Down syndrome. Twentyfour parents of children with Down syndrome aged 0–5 yearscompleted a brief questionnaire about the number and natureof visits from health visitors in the previous 12 months andtheir support needs. Some parents commented that otherprofessionals met the needs of their child, whereas others saidthat they would like more advice and support from healthvisitors. A further exploration of broader health serviceprovision, including health visiting, for young children withDown syndrome is needed.Peer reviewedFinal Accepted Versio

    Misuse of "study drugs:" prevalence, consequences, and implications for policy

    Get PDF
    BACKGROUND: Non-medical/illegal use of prescription stimulants popularly have been referred to as "study drugs". This paper discusses the current prevalence and consequences of misuse of these drugs and implications of this information for drug policy. RESULTS: Study drugs are being misused annually by approximately 4% of older teens and emerging adults. Yet, there are numerous consequences of misuse of prescription stimulants including addiction, negative reactions to high dosages, and medical complications. Policy implications include continuing to limit access to study drugs, finding more safe prescription drug alternatives, interdiction, and public education. CONCLUSION: Much more work is needed on prescription stimulant misuse assessment, identifying the extent of the social and economic costs of misuse, monitoring and reducing access, and developing prevention and cessation education efforts

    Variable-focus microlenses as a potential technology for endoscopy

    Get PDF
    Using a new device which contains an array of microlenses whose focal lengths can be electrically varied, we have been able to control the input from one microlens to a single mode fibre using an applied voltage. For such a microlens array many closely-spaced focal spots can be generated in parallel, and electrically switched to address, potentially, an array of receiver fibres. We show how the particular switching characteristics of the device, whereby the lenses switch from diverging to converging, serves in turn to disperse light and to focus it into the fibre

    A typology of alcohol consumption among young people – A narrative synthesis

    Get PDF
    Background: Currently, alcohol consumption levels are significantly higher among younger age groups. However, previous research has noted the diversity of motivations and patterns. These patterns of drinking have yet to be synthesised into a typology. The aim of the current study was to synthesise information from studies that produced types of alcohol consumption among young people. Method: Quantitative and qualitative literature investigating the different types of drinkers among young people [aged 12–24 years], published in peer reviewed journals, were eligible for inclusion in this systematic review. MEDLINE, PsychInfo and CINAHL were systematically searched for relevant articles published between January 1st 2000 and December 31st 2014. Included papers were critically appraised. A narrative synthesis approach was employed based on guidance from the UK Economic and Social Research Council. Results: In total, 13 studies were eligible for inclusion: 11 quantitative, one qualitative and one mixed methods. Six classes of drinkers were formed within this typology. Abstainers reported no alcohol consumption. Light drinkers reported drinking small amounts of alcohol infrequently. In comparison, social and hedonistic drinkers drank most in social situations and to have fun. Heavy and harmful consumers reported increased volume and frequency of consumption including harmful consequences. Conclusion: Currently, policy makers are attempting to combat the high levels of harmful alcohol consumption among young people. The current typology provides guidance for targeted interventions in addition to a practical analytic tool in future research

    Climate Dynamics: A Network-Based Approach for the Analysis of Global Precipitation

    Get PDF
    Precipitation is one of the most important meteorological variables for defining the climate dynamics, but the spatial patterns of precipitation have not been fully investigated yet. The complex network theory, which provides a robust tool to investigate the statistical interdependence of many interacting elements, is used here to analyze the spatial dynamics of annual precipitation over seventy years (1941-2010). The precipitation network is built associating a node to a geographical region, which has a temporal distribution of precipitation, and identifying possible links among nodes through the correlation function. The precipitation network reveals significant spatial variability with barely connected regions, as Eastern China and Japan, and highly connected regions, such as the African Sahel, Eastern Australia and, to a lesser extent, Northern Europe. Sahel and Eastern Australia are remarkably dry regions, where low amounts of rainfall are uniformly distributed on continental scales and small-scale extreme events are rare. As a consequence, the precipitation gradient is low, making these regions well connected on a large spatial scale. On the contrary, the Asiatic South-East is often reached by extreme events such as monsoons, tropical cyclones and heat waves, which can all contribute to reduce the correlation to the short-range scale only. Some patterns emerging between mid-latitude and tropical regions suggest a possible impact of the propagation of planetary waves on precipitation at a global scale. Other links can be qualitatively associated to the atmospheric and oceanic circulation. To analyze the sensitivity of the network to the physical closeness of the nodes, short-term connections are broken. The African Sahel, Eastern Australia and Northern Europe regions again appear as the supernodes of the network, confirming furthermore their long-range connection structure. Almost all North-American and Asian nodes vanish, revealing that extreme events can enhance high precipitation gradients, leading to a systematic absence of long-range patterns

    Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics

    Get PDF
    Sattler S, Mehlkop G, Graeff P, Sauer C. Evaluating the drivers of and obstacles to the willingness to use cognitive enhancement drugs: the influence of drug characteristics, social environment, and personal characteristics. Substance Abuse Treatment, Prevention, and Policy. 2014;9(1): 8.Background The use of cognitive enhancement (CE) by means of pharmaceutical agents has been the subject of intense debate both among scientists and in the media. This study investigates several drivers of and obstacles to the willingness to use prescription drugs non-medically for augmenting brain capacity. Methods We conducted a web-based study among 2,877 students from randomly selected disciplines at German universities. Using a factorial survey, respondents expressed their willingness to take various hypothetical CE-drugs; the drugs were described by five experimentally varied characteristics and the social environment by three varied characteristics. Personal characteristics and demographic controls were also measured. Results We found that 65.3% of the respondents staunchly refused to use CE-drugs. The results of a multivariate negative binomial regression indicated that respondents’ willingness to use CE-drugs increased if the potential drugs promised a significant augmentation of mental capacity and a high probability of achieving this augmentation. Willingness decreased when there was a high probability of side effects and a high price. Prevalent CE-drug use among peers increased willingness, whereas a social environment that strongly disapproved of these drugs decreased it. Regarding the respondents’ characteristics, pronounced academic procrastination, high cognitive test anxiety, low intrinsic motivation, low internalization of social norms against CE-drug use, and past experiences with CE-drugs increased willingness. The potential severity of side effects, social recommendations about using CE-drugs, risk preferences, and competencies had no measured effects upon willingness. Conclusions These findings contribute to understanding factors that influence the willingness to use CE-drugs. They support the assumption of instrumental drug use and may contribute to the development of prevention, policy, and educational strategies
    corecore