170 research outputs found

    Location of Decimetric Pulsations in Solar Flares

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    This work investigates the spatial relation between coronal X-ray sources and coherent radio emissions, both generally thought to be signatures of particle acceleration. Two limb events were selected during which the radio emission was well correlated in time with hard X-rays. The radio emissions were of the type of decimetric pulsations as determined from the spectrogram observed by Phoenix-2 of ETH Zurich. The radio positions were measured from observations with the Nançay Radioheliograph between 236 and 432 MHz and compared to the position of the coronal X-ray source imaged with RHESSI. The radio pulsations originated at least 30 - 240Mm above the coronal hard X-ray source. The altitude of the radio emission increases generally with lower frequency. The average positions at different frequencies are on a line pointing approximately to the coronal hard X-ray source. Thus, the pulsations cannot be caused by electrons trapped in the flare loops, but are consistent with emission from a current sheet above the coronal sourc

    Understanding Which College Academic and Social Integration Factors Are Important in Predicting First-Generation College Students’ Retention in the First Year

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    Retention concerns remain high for postsecondary institutions and even more so when focusing on populations such as those who are the first in the family to attend college, first-generation college students. First-generation students account for 34% of the collegiate population, yet 40% of first-generation students do not return for their sophomore year. While prior theoretical frameworks and research points to academic and social integration as key indicators of retention, first-generation students are less likely to integrate into their institution. First-generation students are about 30% less likely compared to their continuing generation peers to be integrated at all on campus. Utilizing data from the National Survey of Student Engagement (NSSE), the purpose of this quantitative study was to understand which academic and social integration factors are important in predicting first-generation students’ intentions to return after their first year in college. Employing Astin’s theory of student involvement, Tinto’s theory of student departure, social and cultural capital frameworks, the study examined which academic and social integration factors are significantly related to retention among first-generation students. Additionally, control variables included demographic and institutional characteristics to understand what other factors are important in predicting first-generation student retention. The findings of this study indicate that academic and social integration variables related to institutional support, peers, and participation in extracurricular activities are influential in first-generation student retention. Race/ethnicity, academic major, grades, institutional size, and type were also factors related to retention. Recommendations for practice, policy, and implications for future research included increased funding for support services and co-curricular activities, increased financial aid, and updated frameworks to reflect the cultural differences of first-generation students

    A Study of e+e- -> H0A0 Production and the Constraint on Dark Matter Density

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    This paper reports the results of a study of the e+e- -> H0A0 process at 1 TeV performed on fully simulated and reconstructed events. The estimated accuracies on the heavy Higgs boson masses, widths and decay branching fractions are discussed in relation to the study of Supersymmetric Dark Matter.Comment: 5 pages, 4 figures, submitted to Phys. Rev.

    Sequencing of SARS-CoV-2 RNA Fragments in Wastewater Detects the Spread of New Variants during Major Events

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    The sequencing of SARS-CoV-2 RNA in wastewater is an unbiased method to detect the spread of emerging variants and to track regional infection dynamics, which is especially useful in case of limited testing and clinical sequencing. To test how major international events influence the spread of new variants we have sequenced SARS-CoV-2 RNA in the wastewater samples of Davos, Landquart, Lostallo, and St. Moritz in the Swiss canton of Grisons in the time around the international sports competitions in Davos and St. Moritz in December 2021, and additionally in May 2022 and January 2023 in Davos and St. Moritz during the World Economic Forum (WEF) in Davos. The prevalence of the variants identified from the wastewater sequencing data showed that the Omicron variant BA.1 had spread in Davos and St. Moritz during the international sporting events hosted there in December 2021. This spread was associated with an increase in case numbers, while it was not observed in Landquart and Lostallo. Another instance of new variant spread occurred during the WEF in January 2023, when the Omicron variant BA.2.75 arrived in Davos but not in St. Moritz. We can therefore conclude that major international events promote the spread of new variants in the respective host region, which has important implications for the protective measures that should be taken

    Translating research into practice: Protocol for a community-engaged, stepped wedge randomized trial to reduce disparities in breast cancer treatment through a regional patient navigation collaborative

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    BACKGROUND: Racial and socioeconomic disparities in breast cancer mortality persist. In Boston, MA, Black, Non-Hispanic women and Medicaid-insured individuals are 2-3 times more likely to have delays in treatment compared to White or privately insured women. While evidence-based care coordination strategies for reducing delays exist, they are not systematically implemented across healthcare settings. METHODS: Translating Research Into Practice (TRIP) utilizes community engaged research methods to address breast cancer care delivery disparities. Four Massachusetts Clinical and Translational Science Institute (CTSI) hubs collaborated with the Boston Breast Cancer Equity Coalition (The Coalition) to implement an evidence-based care coordination intervention for Boston residents at risk for delays in breast cancer care. The Coalition used a community-driven process to define the problem of care delivery disparities, identify the target population, and develop a rigorous pragmatic approach. We chose a cluster-randomized, stepped-wedge hybrid type I effectiveness-implementation study design. The intervention implements three evidence-based strategies: patient navigation services, a shared patient registry for use across academic medical centers, and a web-based social determinants of health platform to identify and address barriers to care. Primary clinical outcomes include time to first treatment and receipt of guideline-concordant treatment, which are captured through electronic health records abstraction. We will use mixed methods to collect the secondary implementation outcomes of acceptability, adoption/penetration, fidelity, sustainability and cost. CONCLUSION: TRIP utilizes an innovative community-driven research strategy, focused on interdisciplinary collaborations, to design and implement a translational science study that aims to more efficiently integrate proven health services interventions into clinical practice

    RE: How the Coronavirus Disease-2019 May Improve Care: Rethinking Cervical Cancer Prevention

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    Feldman and Haas have written a timely piece on the potential to enhance cancer prevention and cancer care delivery in the COVID-19 era. Using cervical cancer prevention as a use case, the commentary describes clinical care provided via virtual platforms and in nontraditional settings, such as the patient’s home, as areas needing creative approaches to ensure care is provided safely and efficiently. As we consider factors that are relevant to delivering effective cancer prevention and cancer care post-COVID, we suggest that addressing social determinants of health, an often forgotten dimension of lived experience, should be prioritized as a strategy to enhance the equity of care provision. Social determinants of health, including food and housing insecurity have been shown to impact outcomes of patients with cancer, through a number of mechanisms including delays and incomplete care

    Forced labor risk is pervasive in the US land-based food supply

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    Social risk assessments and case studies of labor conditions in food production primarily focus on specific subpopulations, regions, and commodities. To date, research has not systematically assessed labor conditions against international standards across diverse, complex food products. Here, we combine data on production, trade, labor intensity, and qualitative risk coding to quantitatively assess the risk of forced labor embedded in the U.S. land-based food supply, building upon our previous assessment of fruits and vegetables. We demonstrate that animal-based proteins, processed fruits and vegetables, and discretionary foods are major contributors to forced labor risk and that 62% of total forced labor risk stems from domestic production or processing. Our findings reveal the widespread risk of forced labor present in the US food supply and the necessity of collaborative action across all countries – high, middle, and low income - to eliminate reliance on labor exploitation

    Evidence that 5-HT2A Receptors in the Hypothalamic Paraventricular Nucleus Mediate Neuroendocrine Responses to (-)DOI

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    This is the publisher's version, also available electronically from "http://www.jneurosci.org".The present study determined whether the serotonin2A (5-HT2A) receptors in the hypothalamic paraventricular nucleus mediate the neuroendocrine responses to a peripheral injection of the 5-HT2A/2Creceptor agonist (−)DOI [(−)1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane]. The 5-HT2A receptor antagonist MDL100,907 ((±)-α-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenylethyl)]-4-piperidinemethanol), the 5-HT2C receptor antagonist SB-242084 (6-chloro-5-methyl-1-[[2-[(2-methyl-3-pyridyl)oxy]-5-pyridyl]carbamoyl]-indoline), or vehicle were microinjected bilaterally through a chronically implanted double-barreled cannula into the hypothalamic paraventricular nucleus 15 min before a peripheral injection of (−)DOI in conscious rats. (−)DOI significantly elevated plasma levels of oxytocin, prolactin, ACTH, corticosterone, and renin. Neither the 5-HT2A receptor antagonist nor the 5-HT2Creceptor antagonist, injected alone, altered the basal levels of these hormones. MDL100,907 (0.748, 7.48, and 18.7 nmol) dose dependently inhibited the (−)DOI-induced increase in all of the hormones except corticosterone. In contrast, SB-242084 (10 nmol) did not inhibit (−)DOI-increased hormone levels. To confirm the presence of 5-HT2A receptors in the hypothalamic paraventricular nucleus, 5-HT2A receptors were mapped using immunohistochemistry. Densely labeled magnocellular neurons were observed throughout the anterior and posterior magnocellular subdivisions of the hypothalamic paraventricular nucleus. Moderately to densely labeled cells were also observed in parvicellular regions. Thus, it is likely that 5-HT2A receptors are present on neuroendocrine cells in the hypothalamic paraventricular nucleus. These data provide the first direct evidence that neuroendocrine responses to a peripheral injection of (−)DOI are predominantly mediated by activation of 5-HT2A receptors in the hypothalamic paraventricular nucleus

    LoCuSS: The Sunyaev-Zel'dovich Effect and Weak Lensing Mass Scaling Relation

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    We present the first weak-lensing-based scaling relation between galaxy cluster mass, M_wl, and integrated Compton parameter Y_sph. Observations of 18 galaxy clusters at z~0.2 were obtained with the Subaru 8.2-m telescope and the Sunyaev-Zel'dovich Array. The M_wl-Y_sph scaling relations, measured at Delta=500, 1000, and 2500 rho_c, are consistent in slope and normalization with previous results derived under the assumption of hydrostatic equilibrium (HSE). We find an intrinsic scatter in M_wl at fixed Y_sph of 20%, larger than both previous measurements of M_HSE-Y_sph scatter as well as the scatter in true mass at fixed Y_sph found in simulations. Moreover, the scatter in our lensing-based scaling relations is morphology dependent, with 30-40% larger M_wl for undisturbed compared to disturbed clusters at the same Y_sph at r_500. Further examination suggests that the segregation may be explained by the inability of our spherical lens models to faithfully describe the three-dimensional structure of the clusters, in particular, the structure along the line-of-sight. We find that the ellipticity of the brightest cluster galaxy, a proxy for halo orientation, correlates well with the offset in mass from the mean scaling relation, which supports this picture. This provides empirical evidence that line-of-sight projection effects are an important systematic uncertainty in lensing-based scaling relations.Comment: Accepted versio
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