35 research outputs found

    Synthetic Mudscapes: Human Interventions in Deltaic Land Building

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    In order to defend infrastructure, economy, and settlement in Southeast Louisiana, we must construct new land to mitigate increasing risk. Links between urban environments and economic drivers have constrained the dynamic delta landscape for generations, now threatening to undermine the ecological fitness of the entire region. Static methods of measuring, controlling, and valuing land fail in an environment that is constantly in flux; change and indeterminacy are denied by traditional inhabitation. Multiple land building practices reintroduce deltaic fluctuation and strategic deposition of fertile material to form the foundations of a multi-layered defence strategy. Manufactured marshlands reduce exposure to storm surge further inland. Virtual monitoring and communication networks inform design decisions and land use becomes determined by its ecological health. Mudscapes at the threshold of land and water place new value on former wastelands. The social, economic, and ecological evolution of the region are defended by an expanded web of growing land

    Procedure Volume and the Association with Short-term Mortality Following Abdominal Aortic Aneurysm Repair in European Populations: A Systematic Review

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    Objective: To evaluate the relationship between the volume of abdominal aortic aneurysm (AAA) procedures undertaken and the primary outcome of mortality in Europe. Previous systematic reviews of this relationship are outdated and are overwhelmingly based on US data. Data sources: Comprehensive searching within MEDLINE and other bibliographic databases supplemented by citation searching and hand-searching of journals was undertaken to identify studies that reported the effect of hospital or clinician volume on any reported outcomes in adult, European populations, undergoing AAA repair and published in the last 10 years. Methods: Two reviewers conducted study selection with independent, duplicate data extraction and quality assessment. A planned meta-analysis was not conducted because of the high risk of bias, the likelihood of individual study subjects being included in more than one study and diversity in the clinical populations studied and methods used. Results: Sixteen studies (n = 237,074 participants) from the UK (n = 11 studies), Germany (n = 3 studies), Norway (n = 1 study), and one from the UK and Sweden were included. Data in the included studies came from administrative databases and clinical registries incorporating a variety of clinical and procedural groups; the study quality was limited by the use of observational study designs. Overall, the evidence favoured the existence of an inverse volume outcome relationship between hospital volume and mortality. Insufficient evidence was available to reach conclusions on the relationship between clinician volume and outcome and between hospital or clinician volume and secondary outcomes including complications and length of hospital stay. Conclusions: The evidence from this review suggests a relationship between the hospital volume of AAA procedures conducted and short-term mortality; however, as volume typically represents a complex amalgamation of factors further research will be useful to identify the core characteristics of volume that influence improved outcomes

    The relationship between hospital or surgeon volume and outcomes in lower limb vascular surgery in the United Kingdom and Europe

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    Introduction Peripheral vascular disease is a major cause of death and disability. The extent to which volume influences outcome of lower limb (LL) vascular surgery remains unclear. This review evaluated the relationship between hospital/surgeon volume and outcome in LL surgery. Methodology Electronic databases; Medline, Embase, the Cochrane Library Databases, Science Citation Index, and CINAHL, proceedings from conferences, citations, and references of included studies were searched. Studies from Europe, of adults undergoing LL vascular surgery reporting outcomes by hospital or surgeon volume were included. Quality of studies was assessed using a modified ACROBAT-NRSI(Robins1) tool. Association between hospital/surgeon volume and outcome were summarised using tables. Results Nine studies from different European countries, comprising 67,445 patients who had undergone diverse LL surgeries were included. Increase in hospital/surgeon volume was associated with a decrease in amputations. The evidence on an association between hospital/surgeon volume and mortality was contradictory, but mortality and amputations may co-vary by hospital volume. There were an insufficient number of studies reporting on the other variables to draw firm conclusions; but their results suggest high volume hospitals may undertake more repeated surgeries/revascularisations and limb salvage. The impact of hospital/surgical volume on adverse events and length of hospitalisation could not be determined. Conclusion High volume hospitals/surgeons may undertake fewer amputations and mortality and amputations may co-vary. The finding that hospital and surgeon volume affected the number of secondary amputations has implications on re-organisation of vascular surgery services. However due to the small number and poor quality of some of the included studies, decisions on reorganisation of LL vascular surgery services should be supplemented by results from clinical audits. There is need for standardisation of definition of volume stratification of outcomes by patient’s clinical conditions

    Charge Asymmetries for D, D_s and Lambda_c Production in Sigma- - Nucleus Interactions at 340 GeV/c

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    CERN experiment WA89 has studied charmed particles produced by a Sigma^- beam at 340 GeV/c on nuclear targets. Production of particles which have light quarks in common with the beam is compared to production of those which do not. Considerable production asymmetries between D^- and D^p, D_s^ and D_s^+ and Lambda_c and Antilambda_c are observed. The results are compared with pion beam data and with theoretical calculations.Comment: LaTeX ; 16 pages including 4 ps figure

    Dust Devil Sediment Transport: From Lab to Field to Global Impact

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    The impact of dust aerosols on the climate and environment of Earth and Mars is complex and forms a major area of research. A difficulty arises in estimating the contribution of small-scale dust devils to the total dust aerosol. This difficulty is due to uncertainties in the amount of dust lifted by individual dust devils, the frequency of dust devil occurrence, and the lack of statistical generality of individual experiments and observations. In this paper, we review results of observational, laboratory, and modeling studies and provide an overview of dust devil dust transport on various spatio-temporal scales as obtained with the different research approaches. Methods used for the investigation of dust devils on Earth and Mars vary. For example, while the use of imagery for the investigation of dust devil occurrence frequency is common practice for Mars, this is less so the case for Earth. Modeling approaches for Earth and Mars are similar in that they are based on the same underlying theory, but they are applied in different ways. Insights into the benefits and limitations of each approach suggest potential future research focuses, which can further reduce the uncertainty associated with dust devil dust entrainment. The potential impacts of dust devils on the climates of Earth and Mars are discussed on the basis of the presented research results

    Juvenis de carpa capim alimentados com capim teosinto e suplementados com diferentes taxas de arraçoamento Grass carp juveniles fed with teosinte grass and supplied with different feeding rates

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    Avaliou-se o desenvolvimento de juvenis de carpa capim (Ctenopharyngodon idella) alimentados com capim teosinto (Euchlaena mexicana) e suplementados com ração. Realizaram-se dois experimentos, de 45 dias, utilizando 240 juvenis em cada um (peso médio: 10,9&plusmn;0,3g e 20,2&plusmn;0,2g). No experimento 1, os peixes foram alimentados com capim teosinto mais ração, em 4 níveis de suplementação: 1, 2, 3 e 4% do PV, denominados S1, S2, S3 e S4. No experimento 2, testou-se: C=Somente Capim Teosinto; SD=Capim Teosinto+ Suplementação diária (3%PV); SA=Capim Teosinto + Suplementação a cada dois dias (3%PV); R=Somente ração (3% PV). No experimento 1, observou-se aumento linear positivo do peso em relação à suplementação com ração. A melhor taxa de crescimento específico foi obtida com o tratamento S4. O rendimento de filé foi maior nos tratamentos S3 e S4. No experimento 2, para a variável peso, o tratamento SD diferiu significativamente dos demais. Os tratamentos SD, SA e R não diferiram estatisticamente em relação ao rendimento de filé, porém, houve diferença entre o tratamento SD e o C. Conclui-se que a associação do capim teosinto com a ração (3%PV) proporciona bom crescimento para juvenis de carpa capim.<br>This study was aimed at evaluating the growth of grass carp juveniles (Ctenopharyngodon idella) fed with teosinte grass (Euchlaena mexicana) and supplied with different feeding rates. Two experiments were done (45 days each), using 240 juveniles (weight=10.33 &plusmn; 0.33 and 20.15 &plusmn; 0.23g). In the first, four feeding rates (1, 2, 3 and 4% of body weight (BW), called S1, S2, S3 and S4 respectively) were tested. In the second, the treatments were: C = Only teosinte grass; SD = Teosinte grass + ration daily (3%BW); SA = Teosinte grass + ration each 2 days (3%BW); R = Only ration (3%BW). In the experiment 1, it was observed a weight increasing following the ration supply. The higher specific growth rate was obtained in S4. No differences among treatments was verify for carcass yield, however, the fillet yield was higher in S3 and S4. In the experiment 2, weight was higher in SD. The carcass yield (RC) did not present significant difference among the treatments in the experiment 2. Fillet yield was lower in fish fed only with teosinte grass (C). We concluded that the grass carp juveniles growing is positively affected by association of teosinte grass and ration supply, being necessary a minimum feeding rate (3%BW) daily for achieving good growth
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