1,130 research outputs found

    Evaluation of the swirl characteristics of a tidal stream turbine wake

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    © 2015 The Authors. Published by Elsevier Ltd. Tidal stream turbines (TSTs) produce a rotating downstream wake. This paper describes the characteristics of the swirl flow in the wake of a TST with a view of comparing these against classical swirl theory and investigating whether swirl is an important factor in wake recovery prediction. Using computational fluid dynamics the paper describes the characteristics of velocities, pressure drop, viscosity and swirl number of 2, 3 and 4 bladed TSTs. To provide confidence in the results the characteristics are compared to the findings in the literature for a set of generic swirl generators. The swirl numbers for the TSTs in a 3.08 m/s tidal (plug) flow were found to be between 0.14 and 0.28, which describes a weak or very weak swirl flow. Whilst the characteristics are in agreement with theory it also means that the swirl component of the wake is not coupled with the axial component and cannot be used to estimate the wake length. However, peak swirl number for the 4 bladed turbine is close to the threshold of 0.3 at which axial velocity starts to become coupled with tangential velocity and therefore wake recovery may be related to S for some turbine designs

    Targeting Conservation Investments in Heterogeneous Landscapes: A distance function approach and application to watershed management

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    To achieve a given level of an environmental amenity at least cost, decision-makers must integrate information about spatially variable biophysical and economic conditions. Although the biophysical attributes that contribute to supplying an environmental amenity are often known, the way in which these attributes interact to produce the amenity is often unknown. Given the difficulty in converting multiple attributes into a unidimensional physical measure of an environmental amenity (e.g., habitat quality), analyses in the academic literature tend to use a single biophysical attribute as a proxy for the environmental amenity (e.g., species richness). A narrow focus on a single attribute, however, fails to consider the full range of biophysical attributes that are critical to the supply of an environmental amenity. Drawing on the production efficiency literature, we introduce an alternative conservation targeting approach that relies on distance functions to cost-efficiently allocate conservation funds across a spatially heterogeneous landscape. An approach based on distance functions has the advantage of not requiring a parametric specification of the amenity function (or cost function), but rather only requiring that the decision-maker identify important biophysical and economic attributes. We apply the distance-function approach empirically to an increasingly common, but little studied, conservation initiative: conservation contracting for water quality objectives. The contract portfolios derived from the distance-function application have many desirable properties, including intuitive appeal, robust performance across plausible parametric amenity measures, and the generation of ranking measures that can be easily used by field practitioners in complex decision-making environments that cannot be completely modeled. Working Paper # 2002-01

    Detection of Maternal Alcohol Use Problems in the Pediatric Emergency Department

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    Maternal alcohol use problems may impact the health and well-being of children, but often remain unrecognized. Mothers of young children seldom seek outpatient care for themselves; thus, pediatric settings may present an opportunity for the detection of maternal alcohol use problems. This study examines the feasibility of screening for and prevalence of alcohol use problems in mothers of young children in the context of seeking pediatric emergency care. We also examined the relationship of maternal alcohol use problems with use of pediatric emergency care. Methods : A total of 361 English-speaking mothers of children aged 7 and younger completed screening measures during their child's emergency care visit. TWEAK was used to screen for alcohol use problems. The screening survey also included information on children's health status and health care use, demographics, and the Center for Epidemiological Studies Depression Scale. Results : Of the women approached, 90% agreed to complete the screening measure. On the basis of cutoff score of 2 or more, 7% of women had elevated TWEAK scores. Those women with a TWEAK score >2 reported greater use of the pediatric emergency department (PED) than women scoring below the cutoff. On the basis of multivariate analyses, significant predictors of recent PED use included the presence of child chronic illness, younger maternal age, and TWEAK score. Conclusions : Screening for alcohol use problems among mothers of young children using the TWEAK appears to be feasible in a busy PED setting. The PED setting is promising for identifying risk drinking among women who may be less likely to be otherwise detected and for whom alcohol use may be impacting child outcomes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66222/1/j.1530-0277.2006.00132.x.pd

    Discordant antibiotic therapy and length of stay in children hospitalized for urinary tract infection

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    BACKGROUND: Urinary tract infections (UTIs) are a common reason for pediatric hospitalizations. OBJECTIVE: To determine the effect of discordant antibiotic therapy (in vitro nonsusceptibility of the uropathogen to initial antibiotic) on clinical outcomes for children hospitalized for UTI. DESIGN/SETTING: Multicenter retrospective cohort study in children aged 3 days to 18 years, hospitalized at 5 children's hospitals with a laboratory‐confirmed UTI. Data were obtained from medical records and the Pediatric Hospital Information System (PHIS) database. PARTICIPANTS: Patients with laboratory‐confirmed UTI. MAIN EXPOSURE: Discordant antibiotic therapy. MEASUREMENTS: Length of stay and fever duration. Covariates included age, sex, insurance, race, vesicoureteral reflux, antibiotic prophylaxis, genitourinary abnormality, and chronic care conditions. RESULTS: The median age of the 216 patients was 2.46 years (interquartile range [IQR]: 0.27, 8.89) and 25% were male. The most common causative organisms were E. coli and Klebsiella species. Discordant therapy occurred in 10% of cases and most commonly in cultures positive for Klebsiella species, Enterobacter species, and mixed organisms. In adjusted analyses, discordant therapy was associated with a 1.8 day (95% confidence interval [CI]: 1.5, 2.1) longer length of stay [LOS], but not with fever duration. CONCLUSIONS: Discordant antibiotic therapy for UTI is common and associated with longer hospitalizations. Further research is needed to understand the clinical factors contributing to the increased LOS and to inform decisions for empiric antibiotic selection in children with UTIs. Journal of Hospital Medicine 2012; © 2012 Society of Hospital MedicinePeer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94298/1/1960_ftp.pd

    “It was touching”: Experiences and views of students in the June 3 flood and fire disaster relief response volunteerism in Accra, Ghana

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    Evidence from Africa on the motivations and experiences of student volunteers in community disaster relief response programs are rare. This study explores the experiences and views of the students who volunteered at the emergency mental health relief response site after the June 3, 2015, flood and fire disaster in Accra, and the implications for future professional response work in Ghana. Thematic analysis of 15 qualitative in-depth interviews showed that, overall, the student volunteers were both self-oriented and other-oriented. The students viewed work at the emergency response site as a touching experience and a call of duty. The response work provided the students with practical pathways to linking their clinical and community learning experiences. This study recommends that, rather than an ad hoc response team, the Ghana Psychological Association should consider setting up a standing disaster relief response network to provide mental health relief and recovery response in community emergency situations in Ghana

    Impacts of traditional food consumption advisories: Compliance, changes in diet and loss of confidence in traditional foods

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    <p>Abstract</p> <p>Background</p> <p>Food consumption advisories are often posted when industrial activities are expected to affect the quality and availability of traditional foods used by First Nations. We were recently involved in a project and asked to summarize details regarding the impacts of traditional food consumption advisories with respect to compliance, broader changes in diet and loss of confidence in traditional foods by people.</p> <p>Methods</p> <p>Our review was not conducted as a formal systematic comprehensive review; rather, we focused on primary and grey literature presenting academic, health practitioner and First Nations viewpoints on the topic available from literature databases (i.e., PubMed, Web of Knowledge<sup>SM</sup>) as well as the internet search engine Google. Some information came from personal communications.</p> <p>Results</p> <p>Our overview suggests that when communicated effectively and clearly, and when community members are involved in the process, consumption advisories can result in a decrease in contaminant load in people. On the other hand, consumption advisories can lead to cultural loss and have been linked to a certain amount of social, psychological, nutritional, economic and lifestyle disruption. In some cases, communities have decided to ignore consumption advisories opting to continue with traditional lifestyles believing that the benefits of doing so outweigh the risk of following advisories.</p> <p>Conclusions</p> <p>We identified that there are both positive and negative aspects to the issuance of traditional food consumption advisories. A number of variables need to be recognized during the development and implementation of advisories in order to ensure a balance between human health, maintenance of cultures and industrial activity.</p

    Written information about individual medicines for consumers.

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    Medicines are the most common intervention in most health services. As with all treatments, those taking medicines need sufficient information: to enable them to take and use the medicines effectively, to understand the potential harms and benefits, and to allow them to make an informed decision about taking them. Written medicines information, such as a leaflet or provided via the Internet, is an intervention that may meet these purposes
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