868 research outputs found

    PEP Property Estimation Program and Chemical Property Database

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    PEP Overview A property Estimation Program (PEP), utilizing MCI-property, TSA-property and property correlations and UNIFAC-derived activity coefficients, has been developed for the Apple Macintosh microcomputer to provide the user with several approaches to estimate S, Kow, Pv, H, Koc, and BCF depending on the information available. Structural information required for the MCi and UNIFAC calculation routines can be entered using either Simplified Molecular Identification and Line Entry System (SMILES) notation or connection tables generated with commercially available two-dimensional drawing programs. The TSA module accepts 3-D atomic coordinates entered manually or directly reads coordinate files generated by molecular modeling software. The program’s built-in intelligence helps the user choose the most appropriate QSPR or QPPR based on the structure of the chemical of interest. In addiction, the statistical information associated with each QSPR or QPPR in PEP can be displayed to help the user determine the model’s validity. For the regression-based property estimation models, assessments of accuracy based on the 95% confidence interval and estimated precision of the experimental values are also provided along with the estimated property value. PEP also provides a batch mode that provides users with a method for the convenient, unattended calculation of MCIs, TSA and UNIFAC activity coefficients and the subsequent estimation of physical properties for large numbers of compounds. A chemical property database, containing experimental values of S, Kow, H, Pv, Koc, and BCF complied from a variety of literature sources and computerized databases was used for developing the MCI-property, TSA-Property and property-property relationships used in PEP. This database, which currently contains over 800 chemicals, is linked directly to PEP. The property estimation modules in PEP are also linked directly to the Level 1 and 2 Fugacity Models. The combination of the various property estimation methods, chemical property database, and simple environmental fate models provides users with a methodology for predicting the environmental distribution of an organic chemical in a multi-phase system requiring only the structure of the chemical of interest as input. PEP was designed to be intuitive and user friendly. The easiest way to become familiar with the PEP is to try clicking on the buttons and pull down menus found on each card. Any comments or suggestions regarding improving the operation of PEP would be greatly appreciated by the authors

    Measures of Obesity Associated with Asthma Diagnosis in Ethnic Minority Children

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    Objective. The study objective was to examine relationships between different body size measurements and asthma in ethnic minority children. Methods. We used data from a community-based study of 505 children aged 6-to-8 years old to study the association of percent body fat, fat distribution, and BMI percentile with asthma diagnosis. Poisson regression models were used to compute prevalence ratios (PRs) for sex-specific quintiles of the body fat measures on the main outcome of asthma. Results. When comparing the highest quintile of each body fat measure to the combined lowest two quintiles, higher body mass index percentile, percent body fat, and waist circumference all were associated with a higher likelihood of physician-diagnosed asthma (PR = 1.63 (95% CI 1.12–2.39), 1.50 (95% CI 1.02–2.21), and 1.56 (95% CI 1.04–2.34), resp.). Conclusions. This study found a significant association between increased body size and asthma diagnosis, regardless of the measurement examined

    Adaptation to Aquatic Risks due to Climate Change in Pangnirtung, Nunavut

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    We use a vulnerability framework to examine how residents of Pangnirtung, Nunavut, perceive the risks of aquatic activities in the context of adaptation to a changing climate. Our findings suggest that community members identify climate change as increasing the risk of many aquatic activities and have adapted some practices accordingly. However, further adaptation to these changing risks is impeded by three main barriers: (1) financial constraints, (2) Inuit resistance to adopting what some consider Euro-Canadian water safety practices, and (3) issues with the design of flotation devices. Participants suggested the following practical changes: (1) make personal flotation devices, lifejackets, and floater suits available to all residents at local stores at a subsidized rate, or provide them free of charge through the community; (2) create water safety promotional items that feature locally developed messages in both Inuktitut and English; (3) include traditional knowledge in water safety campaigns; and (4) use the local pool to train residents in water safety. These changes would not only help residents adapt to changing risks, but also help incorporate climate considerations into policies and programs.Nous utilisons un cadre de vulnérabilité pour examiner comment les habitants de Pangnirtung, au Nunavut, perçoivent les risques inhérents aux activités aquatiques dans le contexte de l’adaptation au changement climatique. Cette étude nous a permis de constater que les membres de la collectivité estiment que le changement climatique augmente le risque de nombreuses activités aquatiques et qu’ils ont modifié certaines de leurs manières de faire en conséquence. Cependant, trois grands obstacles entravent une adaptation plus poussée de ces risques : 1) les contraintes financières, 2) la résistance des Inuits à adopter ce que certains considèrent comme des méthodes eurocanadiennes plus sécuritaires, et 3) des problèmes de conception des appareils de flottaison. Les participants ont suggéré les changements pratiques suivants : 1) faire en sorte que des dispositifs de flottaison personnels, des gilets de sauvetage et des survêtements protecteurs soient à la disposition de tous les résidents à des prix subventionnés aux magasins de la région ou encore, qu’ils soient distribués aux gens gratuitement;2) créer du matériel promotionnel élaboré localement, en anglais et en inuktitut, pour promouvoir la sécurité sur l’eau; 3) faire en sorte que des connaissances traditionnelles soient intégrées aux campagnes relatives à la sécurité sur l’eau; et 4) montrer aux habitants de la région des techniques de sécurité sur l’eau à la piscine locale. Ces initiatives aideront non seulement les résidents à s’adapter aux risques changeants, mais également à tenir compte des considérations climatiques dans le cadre de leurs programmes et politiques

    Get it from the Source: Identifying Library Resources and Software Used in Faculty Research

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    Libraries and Information Technology departments aim to support the educational and research needs of students, researchers, and faculty members. Close matches between the resources those departments provide and the resources the institution’s community members actually use highlight the value of the departments, demonstrate fiscally responsibility, and show attentiveness to the community’s needs. Traditionally, libraries rely on usage statistics to guide collection development decisions, but usage statistics can only imply value. Identifying a resource by name in a publication demonstrates the value of that resource more clearly. This pilot project examined the full-text of articles published in 2016-2017 by faculty members at a mid-sized, special-focus institution to answer the questions “Do faculty members have university-provided access to the research tools they need to publish?” and “If not, where are they getting them?” Using a custom database, the presenters indexed every publication by author, publication, resources used, availability of the identified resources, and more. This pilot study can be adapted to projects at other institutions, allowing them to gain a better understanding of the strengths and weaknesses of their own institution’s offerings. In addition, they will be able to identify ways to use that data to negotiate for additional resources, inform strategic partnerships, and facilitate open discussions with the institution’s community

    The Sky is Falling: Chemical Characterization and Corrosion Evaluation of Deposition Produced During the Static Testing of Solid Rocket Motors

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    Static tests of horizontally restrained rocket motors at the ATK facility in Promontory UT, USA result in the deposition of entrained soil and fuel combustion products, referred to as Test Fire Soil (TFS), over areas as large as 30–50 mile2 (80–130 km2) and at distances up to 10–12 miles (16–20 km) from the test site. Chloride is the main combustion product generated from the ammonium perchlorate–aluminum based composite propellant. Deposition sampling/characterization and a 6-month field corrosivity study using mild steel coupons were conducted in conjunction with the February 25th 2010 FSM-17 static test. The TFS deposition rates at the three study sites ranged from 1 to 5 g/min/m2. TFS contained significantly more chloride than the surface soil collected from the test site. The TFS collected during two subsequent tests had similarly elevated chloride, suggesting that the results obtained in this study are applicable to other tests assuming that the rocket fuel composition remains similar. The field-deployed coupons exposed to the TFS had higher corrosion rates (3.6–5.0 mpy) than paired non-exposed coupons (1.6–1.8 mpy). Corrosion rates for all coupon

    Genomic constitution of an H-2:Tla variant leukemia.

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    Assessment of HCC response to Yttrium-90 radioembolization with gadoxetate disodium MRI: correlation with histopathology.

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    Transarterial <sup>90</sup> Y radioembolization (TARE) is increasingly being used for hepatocellular carcinoma (HCC) treatment. However, tumor response assessment after TARE may be challenging. We aimed to assess the diagnostic performance of gadoxetate disodium MRI for predicting complete pathologic necrosis (CPN) of HCC treated with TARE, using histopathology as the reference standard. This retrospective study included 48 patients (M/F: 36/12, mean age: 62 years) with HCC treated by TARE followed by surgery with gadoxetate disodium MRI within 90 days of surgery. Two radiologists evaluated tumor response using RECIST1.1, mRECIST, EASL, and LI-RADS-TR criteria and evaluated the percentage of necrosis on subtraction during late arterial, portal venous, and hepatobiliary phases (AP/PVP/HBP). Statistical analysis included inter-reader agreement, correlation between radiologic and pathologic percentage of necrosis, and prediction of CPN using logistic regression and ROC analyses. Histopathology demonstrated 71 HCCs (2.8 ± 1.7 cm, range: 0.5-7.5 cm) including 42 with CPN, 22 with partial necrosis, and 7 without necrosis. EASL and percentage of tumor necrosis on subtraction at the AP/PVP were independent predictors of CPN (p = 0.02-0.03). Percentage of necrosis, mRECIST, EASL, and LI-RADS-TR had fair to good performance for diagnosing CPN (AUCs: 0.78 - 0.83), with a significant difference between subtraction and LI-RADS-TR for reader 2, and in specificity between subtraction and other criteria for both readers (p-range: 0.01-0.04). Radiologic percentage of necrosis was significantly correlated to histopathologic degree of tumor necrosis (r = 0.66 - 0.8, p < 0.001). Percentage of tumor necrosis on subtraction and EASL criteria were significant independent predictors of CPN in HCC treated with TARE. Image subtraction should be considered for assessing HCC response to TARE when using MRI. • Percentage of tumor necrosis on image subtraction and EASL criteria are significant independent predictors of complete pathologic necrosis in hepatocellular carcinoma treated with <sup>90</sup> Y radioembolization. • Subtraction, mRECIST, EASL, and LI-RADS-TR have fair to good performance for diagnosing complete pathologic necrosis in hepatocellular carcinoma treated with <sup>90</sup> Y radioembolization

    Neurological Disease Rises from Ocean to Bring Model for Human Epilepsy to Life

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    Domoic acid of macroalgal origin was used for traditional and medicinal purposes in Japan and largely forgotten until its rediscovery in diatoms that poisoned 107 people after consumption of contaminated mussels. The more severely poisoned victims had seizures and/or amnesia and four died; however, one survivor unexpectedly developed temporal lobe epilepsy (TLE) a year after the event. Nearly a decade later, several thousand sea lions have stranded on California beaches with neurological symptoms. Analysis of the animals stranded over an eight year period indicated five clusters of acute neurological poisoning; however, nearly a quarter have stranded individually outside these events with clinical signs of a chronic neurological syndrome similar to TLE. These poisonings are not limited to sea lions, which serve as readily observed sentinels for other marine animals that strand during domoic acid poisoning events, including several species of dolphin and whales. Acute domoic acid poisoning is five-times more prominent in adult female sea lions as a result of the proximity of their year-round breeding grounds to major domoic acid bloom events. The chronic neurological syndrome, on the other hand, is more prevalent in young animals, with many potentially poisoned in utero. The sea lion rookeries of the Channel Islands are at the crossroads of domoic acid producing harmful algal blooms and a huge industrial discharge site for dichlorodiphenyltrichloroethane (DDTs). Studies in experimental animals suggest that chronic poisoning observed in immature sea lions may result from a spatial and temporal coincidence of DDTs and domoic acid during early life stages. Emergence of an epilepsy syndrome from the ocean brings a human epilepsy model to life and provides unexpected insights into interaction with legacy contaminants and expression of disease at different life stages
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