92 research outputs found

    Monitoring of northern climate exposure

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    Currently, facility managers are faced with many advanced decisions regarding when and how to inspect, maintain, repair or renew existing facilities in a costeffective manner. The evolution of the deteriorations of road structures in reinforced concrete depends on the exposure of the elements to water in liquid form or vapour and to other aggressive agents such as chloride. Current models of ionic transport neglect the effect of real ionic concentration in contact with concrete structures, it means boundary conditions are considered with simple tendency as uniform concentration during the winter period and model parameters are derived from the fitting method. Therefore, it implies in ineffective prediction models of deterioration, i.e. steel rebar corrosion by chloride presence or carbonation, alkali-granular reaction, acid attacks, etc. Structure are sensitive to their environment and their interaction with it is directly related to the processes of deterioration. The degradation of structures exposed to salt-laden mist is faster in the wetter areas. On the contrary, the deterioration of the structures caused by salt spray in the drier zone is slower. The structures, exposed to splashing (precipitation, wind, splash, etc.), have a slower rate of degradation in the wetter regions. The amount of rain has an indirect effect in the process of deterioration of the structure exposed to salt-laden mist because it changes the contact time of chloride on the surface of the structures. For this purpose, a unique exposure monitoring was developed. This mobile station, named MExStUL, contains an atmospheric sensor and new possibilities of chloride detection contained in splashes, mist and static water near the road improving the real exposure of structure and the boundary conditions. First results highlight the real influence of environmental parameters on structures durability on highways. Salt concentration is not uniform during winter period and water thickness demonstrate important periods of drying

    Antarctic pack ice algal distribution: Floe-scale spatial variability and predictability from physical parameters

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    ©2017. Commonwealth of Australia. Antarctic pack ice serves as habitat for microalgae which contribute to Southern Ocean primary production and serve as important food source for pelagic herbivores. Ice algal biomass is highly patchy and remains severely undersampled by classical methods such as spatially restricted ice coring surveys. Here we provide an unprecedented view of ice algal biomass distribution, mapped (as chlorophyll a) in a 100 m by 100 m area of a Weddell Sea pack ice floe, using under-ice irradiance measurements taken with an instrumented remotely operated vehicle. We identified significant correlations (p < 0.001) between algal biomass and concomitant in situ surface measurements of snow depth, ice thickness, and estimated sea ice freeboard levels using a statistical model. The model's explanatory power (r2 = 0.30) indicates that these parameters alone may provide a first basis for spatial prediction of ice algal biomass, but parameterization of additional determinants is needed to inform more robust upscaling efforts

    Promotoras as Mental Health Practitioners in Primary Care: A Multi-Method Study of an Intervention to Address Contextual Sources of Depression

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    We assessed the role of promotoras—briefly trained community health workers—in depression care at community health centers. The intervention focused on four contextual sources of depression in underserved, low-income communities: underemployment, inadequate housing, food insecurity, and violence. A multi-method design included quantitative and ethnographic techniques to study predictors of depression and the intervention’s impact. After a structured training program, primary care practitioners (PCPs) and promotoras collaboratively followed a clinical algorithm in which PCPs prescribed medications and/or arranged consultations by mental health professionals and promotoras addressed the contextual sources of depression. Based on an intake interview with 464 randomly recruited patients, 120 patients with depression were randomized to enhanced care plus the promotora contextual intervention, or to enhanced care alone. All four contextual problems emerged as strong predictors of depression (chi square, p < .05); logistic regression revealed housing and food insecurity as the most important predictors (odds ratios both 2.40, p < .05). Unexpected challenges arose in the intervention’s implementation, involving infrastructure at the health centers, boundaries of the promotoras’ roles, and “turf” issues with medical assistants. In the quantitative assessment, the intervention did not lead to statistically significant improvements in depression (odds ratio 4.33, confidence interval overlapping 1). Ethnographic research demonstrated a predominantly positive response to the intervention among stakeholders, including patients, promotoras, PCPs, non-professional staff workers, administrators, and community advisory board members. Due to continuing unmet mental health needs, we favor further assessment of innovative roles for community health workers

    The James Webb Space Telescope Mission

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    Twenty-six years ago a small committee report, building on earlier studies, expounded a compelling and poetic vision for the future of astronomy, calling for an infrared-optimized space telescope with an aperture of at least 4m4m. With the support of their governments in the US, Europe, and Canada, 20,000 people realized that vision as the 6.5m6.5m James Webb Space Telescope. A generation of astronomers will celebrate their accomplishments for the life of the mission, potentially as long as 20 years, and beyond. This report and the scientific discoveries that follow are extended thank-you notes to the 20,000 team members. The telescope is working perfectly, with much better image quality than expected. In this and accompanying papers, we give a brief history, describe the observatory, outline its objectives and current observing program, and discuss the inventions and people who made it possible. We cite detailed reports on the design and the measured performance on orbit.Comment: Accepted by PASP for the special issue on The James Webb Space Telescope Overview, 29 pages, 4 figure

    Flumazenil kinetics in the elderly

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    Objectively assessing bioartificial organs

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    The metrics used, thus far, to assess bioartificial organ function are shown to be subjective and requiring validation. Therefore, four categories of correlations are proposed based on, respectively, device, in vitro and in vivo evaluations, and clinical function. Examples are presented whereby the correlations among individual indicators are used as a means to expedite the development of immunoisolated cells. Specifically, a case study illustrating the validation of in vitro indicators of in vivo graft function for the bioartificial pancreas (microencapsulated islets) is summarized. This has revealed thresholds with respect to given metrics relating to in vivo device function, the necessity to couple bioartificial organ design with transplant site selection, as well as the lack of objectivity involved in the evaluation and establishment of hypotheses. Specific quantitative indicators illustrate the need for quality-controlled measures, for example, relating to the tolerance of microcapsule diameter and membrane thickness distributions. Qualitative indices representing fibrosis and device properties (e.g., sphericity) are also used to describe the need for in vitro experiments in the development of bioartificial organs. [on SciFinder (R)

    Identification, categorization and life cycle validation

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    Indicators which reflect environmental, economic, health and safety issues, have been categorized as microecometrics and macroecometrics. The former, generally flow based measures, have been developed for local, firm- wide or product based assessments. Microecometrics include materials intensity, energy consumption and emissions data, often from life cycle perspectives. They are, generally, intensive and are scaled with respect to unit of production, GDP or per capita, though other normalization factors have been proposed. In contrast macroecometrics tend to be extensive and represent global conditions such as temperatures and environmental concentrations. Ecometrics are subjective and reflect the dominant value of the individual, family unit, stakeholder group or firm. As such overaggregating or reducing the number of ecometrics for given applications, such as the rating of investments or access to credit, presents potential conflicts. Furthermore, while eco-indicators used for internal corporate reporting should not, necessarily, be validated, those microecometrics which involve external reporting, or multiple stakeholders, are arbitrary if not derived from, or based on, comprehensive life cycle approaches. This paper summarizes ECOMETRICS'98, a workshop held in Lausanne, Switzerland in January 19-20, 1998. It discusses ecometric needs of various users including consumers, designers, private sector decision makers as well as politicians and policy makers. A discussion regarding appropriate microecometrics for industrial sectors including chemical, pharmaceutical, insurance, finance, electronics, manufacturing and consumer products is also summarized

    Identification, categorization and life cycle validation

    No full text
    Indicators which reflect environmental, economic, health and safety issues, have been categorized as microecometrics and macroecometrics. The former, generally flow based measures, have been developed for local, firm- wide or product based assessments. Microecometrics include materials intensity, energy consumption and emissions data, often from life cycle perspectives. They are, generally, intensive and are scaled with respect to unit of production, GDP or per capita, though other normalization factors have been proposed. In contrast macroecometrics tend to be extensive and represent global conditions such as temperatures and environmental concentrations. Ecometrics are subjective and reflect the dominant value of the individual, family unit, stakeholder group or firm. As such overaggregating or reducing the number of ecometrics for given applications, such as the rating of investments or access to credit, presents potential conflicts. Furthermore, while eco-indicators used for internal corporate reporting should not, necessarily, be validated, those microecometrics which involve external reporting, or multiple stakeholders, are arbitrary if not derived from, or based on, comprehensive life cycle approaches. This paper summarizes ECOMETRICS'98, a workshop held in Lausanne, Switzerland in January 19-20, 1998. It discusses ecometric needs of various users including consumers, designers, private sector decision makers as well as politicians and policy makers. A discussion regarding appropriate microecometrics for industrial sectors including chemical, pharmaceutical, insurance, finance, electronics, manufacturing and consumer products is also summarized
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