1,601 research outputs found

    Mercury concentrations in south Texas game fishes

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    Mercury (Hg) is one of the most ubiquitous and controversial metals in the world primarily due to the toxicity of the organic form of the metal, methylmercury (MeHg). MeHg is a neurotoxin at high levels, known to manifest its effects on humans primarily through consumption of certain fish and marine mammals, which tend to bioaccumulate MeHg in their tissues over time. Increased fish consumption and, thus, mercury intake in residents of coastal areas necessitates a better awareness of MeHg content in game fish species, thus the subject of this study. Three hundred thirty-nine tissue samples were taken from 19 south Texas marine species collected primarily at three fishing tournaments in 2004, tested for total Hg concentrations and analyzed with regression analyses and ANOVA. Results of individual species regression analyses all indicate exponential correlations for the comparisons of fish length (curved fork length for pelagic species and total length for the remainder) vs. total Hg. Sampled species were divided into four groups for further analysis: demersal vs. pelagic and inshore vs. offshore. Inshore and demersal fish species were found to exhibit mean concentrations of total Hg of 0.22 and 0.19 ppm. Both offshore and pelagic fish species had higher mean total Hg concentrations of 0.80 ppm. Two species were found to equal or exceed the U.S. Food and Drug Administration\u27s action level of 1.0 ppm for fish. Those were blackfin tuna (Thunnus atlanticus) and king mackerel (Scomberomorus cavalla). Tissue samples were analyzed from blue crab (Callinectes sapidus) taken from the Arroyo Colorado, yielding a low unadjusted mean total Hg concentration of 0.15±0.08 ppm for a mean carapace length 14. 5 cm. Consumption limit comparisons are presented for 11 south Texas game fish species using EPA recommendations based on a reference dose (RID) of 0.0001 mg/kg of body weight/day (U.S. EPA, 1999). Similar comparisons are offered for different size ranges of nine of those species with significant length to total Hg relationships

    Research Notes: A technique for evaluating nodulation response of soybean genotypes with specific Rhizobium strains

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    Previous research on the interactions of Rhizobium strains with host cultivars has involved the testing of small numbers of plants with a specific strain of Rhizobium in Leonard jar assemblies (Leonard, 1943). The Leonard jar technique in our greenhouse requires frequent watering (up to twice daily) and periodic adjustment of the wick element. We have found the traditional Leonard jar assembly technique inadequate to efficiently accommodate the large plant populations required in plant selection and genetic studies of allelism and linkage

    An ellipsoidal mirror for focusing neutral atomic and molecular beams

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    Manipulation of atomic and molecular beams is essential to atom optics applications including atom lasers, atom lithography, atom interferometry and neutral atom microscopy. The manipulation of charge-neutral beams of limited polarizability, spin or excitation states remains problematic, but may be overcome by the development of novel diffractive or reflective optical elements. In this paper, we present the first experimental demonstration of atom focusing using an ellipsoidal mirror. The ellipsoidal mirror enables stigmatic off-axis focusing for the first time and we demonstrate focusing of a beam of neutral, ground-state helium atoms down to an approximately circular spot, (26.8±0.5) μm×(31.4±0.8) μm in size. The spot area is two orders of magnitude smaller than previous reflective focusing of atomic beams and is a critical milestone towards the construction of a high-intensity scanning helium microscope

    An ellipsoidal mirror for focusing neutral atomic and molecular beams

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    Manipulation of atomic and molecular beams is essential to atom optics applications including atom lasers, atom lithography, atom interferometry and neutral atom microscopy. The manipulation of charge-neutral beams of limited polarizability, spin or excitation states remains problematic, but may be overcome by the development of novel diffractive or reflective optical elements. In this paper, we present the first experimental demonstration of atom focusing using an ellipsoidal mirror. The ellipsoidal mirror enables stigmatic off-axis focusing for the first time and we demonstrate focusing of a beam of neutral, ground-state helium atoms down to an approximately circular spot, (26.8±0.5) μm×(31.4±0.8) μm in size. The spot area is two orders of magnitude smaller than previous reflective focusing of atomic beams and is a critical milestone towards the construction of a high-intensity scanning helium microscope

    Evaluation of Intestinal Barrier Dysfunction with Serum Iohexol Concentration in Dogs with Acute Hemorrhagic Diarrhea Syndrome

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    Histopathologic examination of intestinal biopsies from dogs with acute hemorrhagic diarrhea syndrome (AHDS) reveals necrotizing enteritis and epithelial integrity loss. Serum iohexol measurement has been utilized to assess intestinal permeability. Our hypothesis is that dogs with AHDS have increased intestinal permeability, which is associated with the severity of clinical signs. In this prospective case–control study, 53 client-owned dogs (28 AHDS, 25 healthy controls) were evaluated. Clinical severity was assessed using the AHDS index and systemic inflammatory response syndrome (SIRS) criteria. Simultaneously, dogs received oral iohexol, and serum iohexol concentrations (SICs) were measured two hours later. Results indicated significantly higher (p = 0.002) SIC in AHDS dogs (median: 51 µg/mL; min–max: 9–246) than in healthy controls (30 µg/mL; 11–57). There was a significant positive correlation between AHDS index and SIC (rS = 0.4; p = 0.03) and a significant negative between SIC and serum albumin concentrations (Pearson r = −0.55; p = 0.01). Dogs with severe AHDS (mean 106 µg/mL; range: 17–246) demonstrated significantly higher (p = 0.002) SIC than those with mild to moderate disease (29 µg/mL; 9–54). These findings underscore the association between intestinal permeability and clinical severity in dogs with AHDS assessed by iohexol

    Obesity Management: Clinical Review and Update of the Pharmacologic Treatment Options

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    The toolbox of medications available for medical weight management is more robust than ever and includes a wide variety of mechanisms of actions and options for patients

    SGLT2 Inhibitors for Type 2 Diabetes Mellitus Treatment

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    SGLT2 inhibitors are plausible second-line drugs that provide powerful additional A1c-lowering effects while inducing weight loss without hypoglycemia

    Zero-order filter for diffractive focusing of de Broglie matter waves

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    The manipulation of neutral atoms and molecules via their de Broglie wave properties, also referred to as de Broglie matter wave optics, is relevant for several fields ranging from fundamental quantum mechanics tests and quantum metrology to measurements of interaction potentials and new imaging techniques. However, there are several challenges. For example, for diffractive focusing elements, the zero-order beam provides a challenge because it decreases the signal contrast. Here we present the experimental realization of a zero-order filter, also referred to as an order-sorting aperture for de Broglie matter wave diffractive focusing elements. The zero-order filter makes it possible to measure even at low beam intensities. We present measurements of zero-order filtered, focused, neutral helium beams generated at source stagnation pressures between 11 and 81 bars. We show that for certain conditions the atom focusing at lower source stagnation pressures (broader velocity distributions) is better than what has previously been predicted. We present simulations with the software ray-tracing simulation package mcstas using a realistic helium source configuration, which gives very good agreement with our measurements

    RE-AIM for rural health innovations: perceptions of (mis) alignment between the RE-AIM framework and evaluation reporting in the Department of Veterans Affairs Enterprise-Wide Initiatives program

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    BackgroundThe Department of Veterans Affairs (VA) Office of Rural Health (ORH) supports national VA program offices' efforts to expand health care to rural Veterans through its Enterprise-Wide Initiatives (EWIs) program. In 2017, ORH selected Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM), an implementation science framework, to structure the EWI evaluation and reporting process. As part of its mandate to improve EWI program evaluation, the Center for the Evaluation of Enterprise-Wide Initiatives conducted a qualitative evaluation to better understand EWI team' perceptions of, and barriers and facilitators to, the EWI evaluation process.MethodsWe conducted 43 semi-structured interviews with 48 team members (e.g., evaluators, program office leads, and field-based leads) representing 21 EWIs from April-December 2020. Questions focused on participants' experiences using strategies targeting each RE-AIM dimension. Interviews were inductively analyzed in MAXQDA. We also systematically reviewed 51 FY19-FY20 EWI annual reports to identify trends in misapplications of RE-AIM.ResultsParticipants had differing levels of experience with RE-AIM. While participants understood ORH's rationale for selecting a common framework to structure evaluations, the perceived misalignment between RE-AIM and EWIs' work emerged as an important theme. Concerns centered around 3 sub-themes: (1) (Mis)Alignment with RE-AIM Dimensions, (2) (Mis)Alignment between RE-AIM and the EWI, and (3) (Mis)Alignment with RE-AIM vs. other Theories, Models, or Frameworks. Participants described challenges differentiating between and operationalizing dimensions in unique contexts. Participants also had misconceptions about RE-AIM and its relevance to their work, e.g., that it was meant for established programs and did not capture aspects of initiative planning, adaptations, or sustainability. Less commonly, participants shared alternative models or frameworks to RE-AIM. Despite criticisms, many participants found RE-AIM useful, cited training as important to understanding its application, and identified additional training as a future need.DiscussionThe selection of a shared implementation science framework can be beneficial, but also challenging when applied to diverse initiatives or contexts. Our findings suggest that establishing a common understanding, operationalizing framework dimensions for specific programs, and assessing training needs may better equip partners to integrate a shared framework into their evaluations
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