1,468 research outputs found

    Identification of Ambient Molecular Clouds Associated with Galactic Supernova Remnant IC443

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    The Galactic supernova remnant (SNR) IC443 is one of the most studied core-collapse SNRs for its interaction with molecular clouds. However, the ambient molecular clouds with which IC443 is interacting have not been thoroughly studied and remain poorly understood. Using Five College Radio Astronomy Observatory 14m telescope, we obtained fully sampled maps of ~ 1{\deg} \times 1{\deg} region toward IC443 in the 12CO J=1-0 and HCO+ J=1-0 lines. In addition to the previously known molecular clouds in the velocity range v_lsr = -6 to -1 km/s (-3 km/s clouds), our observations reveal two new ambient molecular cloud components: small (~ 1') bright clouds in v_lsr = -8 to -3 km/s (SCs), and diffuse clouds in v_lsr = +3 to +10 km/s (+5 km/s clouds). Our data also reveal the detailed kinematics of the shocked molecular gas in IC443, however the focus of this paper is the physical relationship between the shocked clumps and the ambient cloud components. We find strong evidence that the SCs are associated with the shocked clumps. This is supported by the positional coincidence of the SCs with shocked clumps and other tracers of shocks. Furthermore, the kinematic features of some shocked clumps suggest that these are the ablated material from the SCs upon the impact of the SNR shock. The SCs are interpreted as dense cores of parental molecular clouds that survived the destruction by the pre-supernova evolution of the progenitor star or its nearby stars. We propose that the expanding SNR shock is now impacting some of the remaining cores and the gas is being ablated and accelerated producing the shocked molecular gas. The morphology of the +5 km/s clouds suggests an association with IC443. On the other hand, the -3 km/s clouds show no evidence for interaction.Comment: Accepted for publication in ApJ. 15 pages (with emulateapj.cls), 17 figures, and 2 table

    Reducing the Stigma of Mental Illness Among Medical Students

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    Abstract: The American Osteopathic Association House of Delegates Resolution 205 recommends “increased awareness of depression amongst U.S. Medical students” due to the increasing body of research describing the rise of depression, burn-out and suicide ideation among medical students. There is consequently a need to understand mental health issues as a component of professional development. Hypothesis: A student-led symposium addressing mental and emotional health topics relevant to medical students would reduce the stigma associated with mental illness. Materials and Methods: A 2-hour student-run “Patient Perspective” was held during the second neuroscience block at an osteopathic medical school in the northeastern United States. One week before the program, a student-developed online Wellness Survey measured prevalence of mental illness, common feelings during medical school, coping mechanisms used for stress, and use of mental health resources. Immediately before and after the program, students were asked to report their familiarity with mental illness and their feelings regarding a vignette about a mentally ill woman using “Mental Illness Among Us” pre and post surveys provided by the University of California San Francisco School of Medicine and adapted for the event. During the program, data from the online survey were shared, student organizers discussed emotional wellness and positive coping mechanisms in the context of the profession, and student panelists shared their experiences with mental health issues. A faculty psychiatrist spoke about mental health resources, and attendees received pamphlets listing these resources. The event concluded with student-led breakout sessions at which stress during medical school and strategies for promoting positive coping mechanisms were discussed, followed by the post survey. Results: 113 students completed the pre survey, 89 of whom completed the post survey. For these 89, differences between post and pre responses were universally in the direction of increasing acceptance and decreasing stigma of those with mental illness; all differences were statistically significant. The largest shift regarded students’ reluctance to disclose their own theoretical mental illness to colleagues. Conclusion: Incorporating an emotional health symposium into medical students’ training may increase understanding and acceptance of those who may have mental illness and reduce stigma associated with mental illness.https://digitalcommons.pcom.edu/posters/1002/thumbnail.jp

    Reducing the stigma of mental illness among medical students

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    Background: The American Osteopathic Association House of Delegates Resolution 205 recommends “increased awareness of depression amongst U.S. medical students” due to the increasing body of research describing the rise of depression, burn-out and suicide ideation among medical students. There is consequently a need to understand mental health issues as a component of professional development. Hypothesis: A student-led symposium addressing mental and emotional health topics relevant to medical students will reduce the stigma associated with mental illness. Materials and Methods: A 2-hour student-run “Patient Perspective” session was held during the second year neuroscience block in the PCOM DO program. One week before the program, a student-developed, online Wellness Survey measured prevalence of mental illness, common feelings during medical school, coping mechanisms used for stress, and use of mental health resources. Immediately before and after the program, students were asked to report their familiarity with mental illness and their feelings regarding a vignette about a mentally ill woman. Pre- and post-activity surveys were provided by the University of California San Francisco School of Medicine and adapted for the event. During the program, data from the online survey were shared, student organizers discussed emotional wellness and positive coping mechanisms in the context of the profession, and student panelists shared their experiences with mental health issues. A faculty psychiatrist spoke about mental health resources, and attendees received pamphlets listing these resources. The event concluded with student-led breakout sessions in which stress during medical school and strategies for promoting positive coping mechanisms were discussed, followed by administration of the post-activity survey. Results: 113 students completed the pre-activity survey; 89 completed the post-activity survey. For these 89, differences between responses were universally in the direction of increasing acceptance and decreasing stigma of those with mental illness; all differences were statistically significant. The largest shift regarded students’ reluctance to disclose their own theoretical mental illness to colleagues. Conclusion: Incorporating an emotional health symposium into medical students’ training may increase understanding and acceptance of those who may have mental illness and reduce stigma associated with mental illness

    The Grand Tour of the Ruby-East Humboldt Metamorphic Core Complex, Northeastern Nevada: Part 1-Introduction & Road Log

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    The purpose of this geological excursion is to provide an overview of the multiphase developmental history of the Ruby Mountains and East Humboldt Range, northeastern Nevada. Although these mountain ranges are commonly cited as a classic example of a Cordilleran metamorphic core complex developed through large-magnitude, mid-Tertiary crustal extension, a preceding polyphase Mesozoic contractional history is also well preserved in the ranges. An early phase of this history involved Late Jurassic two-mica granitic magmatism, high-temperature but relatively low-pressure metamorphism, and polyphase deformation in the central Ruby Mountains. In the northern Ruby Mountains and East Humboldt Range, a Late Cretaceous history of crustal shortening, metamorphism, and magmatism is manifested by fold-nappes (involving Archean basement rocks in the northern East Humboldt Range), widespread migmatization, injection of monzogranitic and leucogranitic magmas, all coupled with sillimanite-grade metamorphism. Following Late Cretaceous contraction, a protracted extensional deformation partially overprinted these areas during the Cenozoic. This extensional history may have begun as early as the Late Cretaceous or as late as the mid-Eocene. Late Eocene and Oligocene magmatism occurred at various levels in the crust yielding mafic to felsic orthogneisses in the deep crust, a composite granitic pluton in the upper crust, and volcanic rocks at the surface. Movement along a west-rooted, extensional shear zone in the Oligocene and early Miocene led to core-complex exhumation. The shear zone produced mylonitic rocks about 1 km thick at deep crustal levels, and an overprint of brittle detachment faulting at shallower levels as unroofing proceeded. Megabreccias and other synextensional sedimentary deposits are locally preserved in a tilted, upper Eocene through Miocene stratigraphic sequence. Neogene magmatism included the emplacement of basalt dikes and eruption of rhyolitic rocks. Subsequent Basin and Range normal faulting, as young as Holocene, records continued tectonic extension

    A phase II study of paclitaxel for the treatment of ovarian stromal tumors: An NRG Oncology/ Gynecologic Oncology Group Study

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    To estimate the probability of complete clinical response and toxicity of paclitaxel as second-line chemotherapy in measurable disease patients with malignant tumors of the ovarian stroma, and to evaluate the value of inhibin for predicting response

    Holomorphic Hartree-Fock Theory: The Nature of Two-Electron Problems.

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    We explore the existence and behavior of holomorphic restricted Hartree-Fock (h-RHF) solutions for two-electron problems. Through algebraic geometry, the exact number of solutions with n basis functions is rigorously identified as 1/2(3n - 1), proving that states must exist for all molecular geometries. A detailed study on the h-RHF states of HZ (STO-3G) then demonstrates both the conservation of holomorphic solutions as geometry or atomic charges are varied and the emergence of complex h-RHF solutions at coalescence points. Using catastrophe theory, the nature of these coalescence points is described, highlighting the influence of molecular symmetry. The h-RHF states of HHeH2+ and HHeH (STO-3G) are then compared, illustrating the isomorphism between systems with two electrons and two electron holes. Finally, we explore the h-RHF states of ethene (STO-3G) by considering the π electrons as a two-electron problem and employ NOCI to identify a crossing of the lowest energy singlet and triplet states at the perpendicular geometry

    Probing ISM Structure in Trumpler 14 & Carina I Using The Stratospheric Terahertz Observatory 2

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    We present observations of the Trumpler 14/Carina I region carried out using the Stratospheric Terahertz Observatory 2 (STO2). The Trumpler 14/Carina I region is in the west part of the Carina Nebula Complex, which is one of the most extreme star-forming regions in the Milky Way. We observed Trumpler 14/Carina I in the 158 ÎŒ\mum transition of [C\,{\sc ii}] with a spatial resolution of 48â€Čâ€Č'' and a velocity resolution of 0.17 km s−1^{-1}. The observations cover a 0.25∘^\circ by 0.28∘^\circ area with central position {\it l} = 297.34∘^\circ, {\it b} = -0.60∘^\circ. The kinematics show that bright [C\,{\sc ii}] structures are spatially and spectrally correlated with the surfaces of CO clouds, tracing the photodissociation region and ionization front of each molecular cloud. Along 7 lines of sight that traverse Tr 14 into the dark ridge to the southwest, we find that the [C\,{\sc ii}] luminosity from the HII region is 3.7 times that from the PDR. In same los we find in the PDRs an average ratio of 1:4.1:5.6 for the mass in atomic gas:dark-CO gas: molecular gas traced by CO. Comparing multiple gas tracers including HI 21cm, [C\,{\sc ii}], CO, and radio recombination lines, we find that the HII regions of the Carina Nebula Complex are well-described as HII regions with one-side freely expanding towards us, consistent with the champagne model of ionized gas evolution. The dispersal of the GMC in this region is dominated by EUV photoevaporation; the dispersal timescale is 20-30 Myr.Comment: ApJ accepte

    An Analysis of Private School Closings

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    We add to the small literature on private school supply by exploring exits of K-12 private schools. We find that the closure of private schools is not an infrequent event, and use national survey data from the National Center for Education Statistics to study closures of private schools. We assume that the probability of an exit is a function of excess supply of private schools over the demand, as well as the school's characteristics such as age, size, and religious affiliation. Our empirical results generally support the implications of the model. Working Paper 07-0

    Elevated carbon dioxide and ozone alter productivity and ecosystem carbon content in northern temperate forests

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    Three young northern temperate forest communities in the north‐central United States were exposed to factorial combinations of elevated carbon dioxide ( CO 2 ) and tropospheric ozone (O 3 ) for 11 years. Here, we report results from an extensive sampling of plant biomass and soil conducted at the conclusion of the experiment that enabled us to estimate ecosystem carbon (C) content and cumulative net primary productivity ( NPP ). Elevated CO 2 enhanced ecosystem C content by 11%, whereas elevated O 3 decreased ecosystem C content by 9%. There was little variation in treatment effects on C content across communities and no meaningful interactions between CO 2 and O 3 . Treatment effects on ecosystem C content resulted primarily from changes in the near‐surface mineral soil and tree C, particularly differences in woody tissues. Excluding the mineral soil, cumulative NPP was a strong predictor of ecosystem C content ( r 2  = 0.96). Elevated CO 2 enhanced cumulative NPP by 39%, a consequence of a 28% increase in canopy nitrogen (N) content (g N m −2 ) and a 28% increase in N productivity ( NPP /canopy N). In contrast, elevated O 3 lowered NPP by 10% because of a 21% decrease in canopy N, but did not impact N productivity. Consequently, as the marginal impact of canopy N on NPP (∆ NPP /∆N) decreased through time with further canopy development, the O 3 effect on NPP dissipated. Within the mineral soil, there was less C in the top 0.1 m of soil under elevated O 3 and less soil C from 0.1 to 0.2 m in depth under elevated CO 2 . Overall, these results suggest that elevated CO 2 may create a sustained increase in NPP , whereas the long‐term effect of elevated O 3 on NPP will be smaller than expected. However, changes in soil C are not well‐understood and limit our ability to predict changes in ecosystem C content.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108065/1/gcb12564.pd
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