381 research outputs found

    The db mouse as a model for steatohepatitis

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    Includes bibliographical references.Fatty liver disease is a collective phrase for a spectrum of diseases characterised by increased liver fat content. It ranges from fatty infiltration of the liver to an inflammatory condition, steatohepatitis, which may lead onto cirrhosis. Although not associated with alcohol consumption, non-alcoholic steatohepatitis (NASH) has strong associations with obesity, diabetes and dyslipidaemia. Overlapping pathological mechanisms may be involved. The course of the disease will remain unpredictable, and specific treatment will only be able to be instituted once the pathogenesis is fully understood. This thesis reviews current understanding of the pathogenesis and explores the suitability of a recently defined obese diabetic mouse model for its value as a model in the heterozygous and homozygous states. Observations revealed that the db/wt phenotype has a larger mass than the wt/wt and responds with hyperglycaemia. Lipid accumulation occurs in this model when alcohol is administered and lipid peroxidation occurs but histological changes of steatosis and steatohepatitis do not occur. The db/db model is phenotypically distinguished by a large amount of fat storage, diabetes and macrovesicular steatosis that has more lipid peroxidation but no steatohepatitis even when alcohol further increases lipid peroxidation. The model, as explored, did not reveal steatohepatitis either alone, or with alcohol as a single additional stressor, but both the db/wt and db/db mouse model could be further investigated to explore whether additional stressors could induce steaotohepatitis in this model

    Bundled payments for care improvement initiative – insights from the test pilots of payment reform

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    Background: The Medicare Bundled Payments for Care Improvement (BPCI) pilot program aims to reward high-value providers by setting a global payment target for particular episodes of care. The representativeness of BPCI participants will influence the ability of this pilot to inform policy decisions. Methods: We linked the Medicare lists of participants in the risk-bearing portion of BPCI Model 2, encompassing acute and post-acute care, to the American Hospital Association resource file and the 2013 Hospital Value-Based Purchasing quality performance data. We classified episode-initiating hospitals by the number of bundles in which they were participating into “narrow”, “medium” and “comprehensive”. The analysis described the characteristics of hospitals in each of these categories. Results: The 105 hospitals with linkable data were predominantly large, urban, non-profit, teaching hospitals. These hospitals were quite similar to the general population in terms of disproportionate share, Medicare, and Medicaid percentages. Most participants selected a narrow number of bundles, with the majority selecting a single bundle around joint replacement. There were only minor differences in quality between Model 2 participants and non-participants. Conclusions: Informing the decision about whether to scale the BPCI program nationally will require evaluation of the pilot’s performance by participants’ characteristics to understand in what conditions and for which providers the program is most effective

    (η5-Cyclo­penta­dien­yl)[(1,2,3,4,4a,12a-η)-naphtho­[2,3-b][1,4]benzodioxine]iron(II) hexa­fluoridophosphate

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    At 296 (2) K, both complexed rings in the iron(II) complex cation of the title salt, [Fe(C5H5)(C16H10O2)]PF6, are almost parallel [dihedral angle between planes = 2.4 (3)°]. The quaternary C atoms of the complexed arene ring are located at the longest distance from the Fe atom, with Fe—C distances of 2.112 (4) and 2.105 (3) Å, which are slightly longer than the average Fe—C distance for this ring (2.083 Å). The Fe ion is located 1.660 (1) and 1.543 (1) Å, respectively, from the cyclo­penta­dienyl and the complexed arene ring

    Meltwater Intrusions Reveal Mechanisms for Rapid Submarine Melt at a Tidewater Glacier

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    Submarine melting has been implicated as a driver of glacier retreat and sea level rise, but to date melting has been difficult to observe and quantify. As a result, melt rates have been estimated from parameterizations that are largely unconstrained by observations, particularly at the near-vertical termini of tidewater glaciers. With standard coefficients, these melt parameterizations predict that ambient melting (the melt away from subglacial discharge outlets) is negligible compared to discharge-driven melting for typical tidewater glaciers. Here, we present new data from LeConte Glacier, Alaska, that challenges this paradigm. Using autonomous kayaks, we observe ambient meltwater intrusions that are ubiquitous within 400 m of the terminus, and we provide the first characterization of their properties, structure, and distribution. Our results suggest that ambient melt rates are substantially higher (×100) than standard theory predicts and that ambient melting is a significant part of the total submarine melt flux. We explore modifications to the prevalent melt parameterization to provide a path forward for improved modeling of ocean-glacier interactions.This work was funded by NSF OPP Grants 1503910, 1504191, 1504288, and 1504521 and National Geographic Grant CP4-171R-17. Additionally, this research was supported by the NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by UCAR’s Cooperative Programs for the Advancement of Earth System Science (CPAESS) under award #NA18NWS4620043B. These observations would not be possible without the skilled engineering team who developed the autonomous kayaks—including Jasmine Nahorniak, June Marion, Nick McComb, Anthony Grana, and Corwin Perren—and also the Captain and crew of the M/V Amber Anne. We thank Donald Slater and an anonymous reviewer for valuable feedback that improved this manuscript. Data availability: All of the oceanographic data collected by ship and kayak have been archived with the National Centers for Environmental Information (Accession 0189574, https://accession.nodc.noaa.gov/ 0189574). The glacier data have been archived at the Arctic Data Center (https://doi.org/10.18739/A22G44).Ye

    Tracking icebergs with time-lapse photography and sparse optical flow, LeConte Bay, Alaska, 2016–2017

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    We present a workflow to track icebergs in proglacial fjords using oblique time-lapse photos and the Lucas-Kanade optical flow algorithm. We employ the workflow at LeConte Bay, Alaska, where we ran five time-lapse cameras between April 2016 and September 2017, capturing more than 400 000 photos at frame rates of 0.5–4.0 min−1. Hourly to daily average velocity fields in map coordinates illustrate dynamic currents in the bay, with dominant downfjord velocities (exceeding 0.5 m s−1 intermittently) and several eddies. Comparisons with simultaneous Acoustic Doppler Current Profiler (ADCP) measurements yield best agreement for the uppermost ADCP levels (∼ 12 m and above), in line with prevalent small icebergs that trace near-surface currents. Tracking results from multiple cameras compare favorably, although cameras with lower frame rates (0.5 min−1) tend to underestimate high flow speeds. Tests to determine requisite temporal and spatial image resolution confirm the importance of high image frame rates, while spatial resolution is of secondary importance. Application of our procedure to other fjords will be successful if iceberg concentrations are high enough and if the camera frame rates are sufficiently rapid (at least 1 min−1 for conditions similar to LeConte Bay).This work was funded by the U.S. National Science Foundation (OPP-1503910, OPP-1504288, OPP-1504521 and OPP-1504191).Ye

    Economics of Voluntary Information Sharing

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    We show that lenders join a U.S. commercial credit bureau when information asymmetries between incumbents and entrants create an adverse selection problem that hinders market entry. Lenders also delay joining when information asymmetries protect them from competition in existing markets, consistent with lenders trading off new market entry against heightened competition. We exploit shocks to information coverage to show that lenders enter new markets after joining the bureau in a pattern consistent with this trade-off. Our results illuminate why intermediaries voluntarily share information and show how financial technology that mitigates information asymmetries can shape the boundaries of lending

    Economics of Voluntary Information Sharing

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    We show that lenders join a U.S. commercial credit bureau when information asymmetries between incumbents and entrants create an adverse selection problem that hinders market entry. Lenders also delay joining when information asymmetries protect them from competition in existing markets, consistent with lenders trading off new market entry against heightened competition. We exploit shocks to information coverage to show that lenders enter new markets after joining the bureau in a pattern consistent with this trade-off. Our results illuminate why intermediaries voluntarily share information and show how financial technology that mitigates information asymmetries can shape the boundaries of lending

    School-Based Relationships Among Children with or at Risk for Emotional and Behavioral Disorders

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    We investigated the influence of a teacher’s perceived emotional state (e.g., feeling emotionally exhausted; feeling accomplished) on the association between parent-teacher relationships and teacher-child conflict among young children. We used pretest data from a pilot study examining the efficacy of a socio-emotional learning intervention for children with or at risk for emotional or behavioral disorders (EBD). Twenty-six teachers and 45 children (Mean age= 7.46 years; SD = 1.21) participated in the intervention. Teachers rated their relationships with children and their parents using the Parent-Teacher Relationship Scale and Student-Teacher Relationship Scale. Multilevel models showed that teachers with a higher sense of personal accomplishment evidenced a negative association between parent-teacher relationships and teacher-child conflict. However, for teachers who felt emotionally exhausted or those who had a lower sense of personal achievement, the association between parent-teacher relationships and teacher-child conflict either remained unchanged or was positive. We conclude by discussing findings in relation to the importance of increasing teacher efficacy, reducing teacher burnout, and strengthening parent-teacher relationships in schools to improve teacher-child relationships and children’s psychosocial outcomes

    Medicare Payments for Common Inpatient Procedures: Implications for Episode-Based Payment Bundling

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    Aiming to align provider incentives toward improving quality and efficiency, the Center for Medicare and Medicaid Services is considering broader bundling of hospital and physician payments around episodes of inpatient surgery. Decisions about bundled payments would benefit from better information about how payments are currently distributed among providers of different perioperative services and how payments vary across hospitals.Using the national Medicare database, we identified patients undergoing one of four inpatient procedures in 2005 (coronary artery bypass [CABG], hip fracture repair, back surgery, and colectomy). For each procedure, price-standardized Medicare payments from the date of admission for the index procedure to 30 days postdischarge were assessed and categorized by payment type (hospital, physician, and postacute care) and subtype.Average total payments for inpatient surgery episodes varied from U.S.26,515forbacksurgerytoU.S.26,515 for back surgery to U.S.45,358 for CABG. Hospital payments accounted for the largest share of total payments (60–80 percent, depending on procedure), followed by physician payments (13–19 percent) and postacute care (7–27 percent). Overall episode payments for hospitals in the lowest and highest payment quartiles differed by U.S.16,668forCABG,U.S.16,668 for CABG, U.S.18,762 for back surgery, U.S.10,615forhipfracturerepair,andU.S.10,615 for hip fracture repair, and U.S.12,988 for colectomy. Payments to hospitals accounted for the largest share of variation in payments. Among specific types of payments, those associated with 30-day readmissions and postacute care varied most substantially across hospitals.Fully bundled payments for inpatient surgical episodes would need to be dispersed among many different types of providers. Hospital payments—both overall and for specific services—vary considerably and might be reduced by incentives for hospitals and physicians to improve quality and efficiency.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/79298/1/j.1475-6773.2010.01150.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/79298/2/HESR_1150_sm_authormatrix.pd
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