106 research outputs found

    Research on Access and Success of Under-Represented Groups in the Geosciences

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    The geosciences as an allied group of fields touch virtually all aspects of the human enterprise: locating and providing water, energy and mineral resources; assuring a safe and resilient environment for civilization; and providing an understanding of how the Earth system functions today, in the past and into the future. Given how the geosciences touch the lives of all people, it should also be a field that is representative of all people, but this is not yet the case. Especially with the global importance of the geosciences growing and the geoscience workforce projected to encounter shortfalls of qualified practitioners in the coming decades, it is imperative that the geoscience education research community frame and investigate central questions that can help increase the diversity of the geosciences at all levels. We must find ways to attract all kinds of students, especially those from under-represented groups to our sciences and build programs, experiences and careers in which they thrive. The research challenges proposed in this chapter focus on two essential and interdependent perspectives (1) the point of view of the individual students, faculty and professionals as they manage their own internal balance of identities as they traverse curricula, programs and career pathways, and (2) a view that captures system-wide interactions around the individuals at all stages, including family, culture, department, university and society

    Simulating the WFIRST coronagraph Integral Field Spectrograph

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    A primary goal of direct imaging techniques is to spectrally characterize the atmospheres of planets around other stars at extremely high contrast levels. To achieve this goal, coronagraphic instruments have favored integral field spectrographs (IFS) as the science cameras to disperse the entire search area at once and obtain spectra at each location, since the planet position is not known a priori. These spectrographs are useful against confusion from speckles and background objects, and can also help in the speckle subtraction and wavefront control stages of the coronagraphic observation. We present a software package, the Coronagraph and Rapid Imaging Spectrograph in Python (crispy) to simulate the IFS of the WFIRST Coronagraph Instrument (CGI). The software propagates input science cubes using spatially and spectrally resolved coronagraphic focal plane cubes, transforms them into IFS detector maps and ultimately reconstructs the spatio-spectral input scene as a 3D datacube. Simulated IFS cubes can be used to test data extraction techniques, refine sensitivity analyses and carry out design trade studies of the flight CGI-IFS instrument. crispy is a publicly available Python package and can be adapted to other IFS designs.Comment: 15 page

    Synthesis: Discussion and Implications

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    This project was a formidable undertaking, necessary to position our community to achieve an important goal: to improve undergraduate teaching and learning about the Earth by focusing the power of Geoscience Education Research (GER) on a set of ambitious, high-priority, community-endorsed grand challenges. Working groups, through examination of the literature and with the aid of reviewers\u27 insights, identified two to five grand challenges for each of the ten research themes. The thematic grand challenges illuminate interconnected paths for future GER. Collective this creates a guiding framework to harness the power of GER to improve undergraduate teaching and learning about the Earth. While the individual theme chapters lay out the rationales for those large-scale grand challenge research questions and offer strategies for addressing them, here the purpose is to summarize and synthesize - to highlight thematic research priorities and synergies that may be avenues for research efficiencies and powerful outcomes

    Sensitivity of global soil carbon stocks to combined nutrient enrichment

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    Soil stores approximately twice as much carbon as the atmosphere and fluctuations in the size of the soil carbon pool directly influence climate conditions. We used the Nutrient Network global change experiment to examine how anthropogenic nutrient enrichment might influence grassland soil carbon storage at a global scale. In isolation, enrichment of nitrogen and phosphorous had minimal impacts on soil carbon storage. However, when these nutrients were added in combination with potassium and micronutrients, soil carbon stocks changed considerably, with an average increase of 0.04 KgCm−2 year−1 (standard deviation 0.18 KgCm−2 year−1). These effects did not correlate with changes in primary productivity, suggesting that soil carbon decomposition may have been restricted. Although nutrient enrichment caused soil carbon gains most dry, sandy regions, considerable absolute losses of soil carbon may occur in high‐latitude regions that store the majority of the world's soil carbon. These mechanistic insights into the sensitivity of grassland carbon stocks to nutrient enrichment can facilitate biochemical modelling efforts to project carbon cycling under future climate scenarios

    White and Gray Matter Abnormalities After Cranial Radiation in Children and Mice

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    PurposePediatric patients treated with cranial radiation are at high risk of developing lasting cognitive impairments. We sought to identify anatomical changes in both gray matter (GM) and white matter (WM) in radiation-treated patients and in mice, in which the effect of radiation can be isolated from other factors, the time course of anatomical change can be established, and the effect of treatment age can be more fully characterized. Anatomical results were compared between species.Methods and MaterialsPatients were imaged with T1-weighted magnetic resonance imaging (MRI) after radiation treatment. Nineteen radiation-treated patients were divided into groups of 7 years of age and younger (7−) and 8 years and older (8+) and were compared to 41 controls. C57BL6 mice were treated with radiation (n=52) or sham treated (n=52) between postnatal days 16 and 36 and then assessed with in vivo and/or ex vivo MRI. In both cases, measurements of WM and GM volume, cortical thickness, area and volume, and hippocampal volume were compared between groups.ResultsWM volume was significantly decreased following treatment in 7− and 8+ treatment groups. GM volume was unchanged overall, but cortical thickness was slightly increased in the 7− group. Results in mice mostly mirrored these changes and provided a time course of change, showing early volume loss and normal growth. Hippocampal volume showed a decreasing trend with age in patients, an effect not observed in the mouse hippocampus but present in the olfactory bulb.ConclusionsChanges in mice treated with cranial radiation are similar to those in humans, including significant WM and GM alterations. Because mice did not receive any other treatment, the similarity across species supports the expectation that radiation is causative and suggests mice provide a representative model for studying impaired brain development after cranial radiation and testing novel treatments

    Learning from the COVID-19 Pandemic: How Faculty Experiences Can Prepare Us for Future System-Wide Disruption

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    The COVID-19 pandemic provided education researchers with a natural experiment: an opportunity to investigate the impacts of a system-wide, involuntary move to online teaching and to assess the characteristics of individuals who adapted more readily. To capture the impacts in real time, our team recruited college-level geoscience instructors through the National Association of Geoscience Teachers (NAGT) and American Geophysical Union (AGU) communities to participate in our study in the spring of 2020. Each weekday for three successive weeks, participants (n = 262) were asked to rate their experienced disruption in four domains: teaching, research, ability to communicate with their professional community, and work-life balance. The rating system (a scale of 1–5, with 5 as severely disrupted) was designed to assess (a) where support needs were greatest, (b) how those needs evolved over time, and (c) respondents’ capacity to adapt. In addition, participants were asked two open-response questions, designed to provide preliminary insights into how individuals were adapting—what was their most important task that day and what was their greatest insight from the previous day. Participants also provided information on their institution type, position, discipline, gender, race, dependents, and online teaching experience (see supplemental material)

    Nutritional predictors of complications following radical cystectomy

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    To determine the impact of preoperative nutritional status on the development of surgical complications following cystectomy using the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP)

    End-to-end numerical modeling of the Roman Space Telescope coronagraph

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    The Roman Space Telescope will have the first advanced coronagraph in space, with deformable mirrors for wavefront control, low-order wavefront sensing and maintenance, and a photon-counting detector. It is expected to be able to detect and characterize mature, giant exoplanets in reflected visible light. Over the past decade the performance of the coronagraph in its flight environment has been simulated with increasingly detailed diffraction and structural/thermal finite element modeling. With the instrument now being integrated in preparation for launch within the next few years, the present state of the end-to-end modeling is described, including the measured flight components such as deformable mirrors. The coronagraphic modes are thoroughly described, including characteristics most readily derived from modeling. The methods for diffraction propagation, wavefront control, and structural and thermal finite-element modeling are detailed. The techniques and procedures developed for the instrument will serve as a foundation for future coronagraphic missions such as the Habitable Worlds Observatory.Comment: 113 pages, 85 figures, to be published in SPIE Journal of Astronomical Telescopes, Instruments, and System

    Characteristics of patients initiating raloxifene compared to those initiating bisphosphonates

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    <p>Abstract</p> <p>Background</p> <p>Both raloxifene and bisphosphonates are indicated for the prevention and treatment of postmenopausal osteoporosis, however these medications have different efficacy and safety profiles. It is plausible that physicians would prescribe these agents to optimize the benefit/risk profile for individual patients. The objective of this study was to compare demographic and clinical characteristics of patients initiating raloxifene with those of patients initiating bisphosphonates for the prevention and treatment of osteoporosis.</p> <p>Methods</p> <p>This study was conducted using a retrospective cohort design. Female beneficiaries (45 years and older) with at least one claim for raloxifene or a bisphosphonate in 2003 through 2005 and continuous enrollment in the previous 12 months and subsequent 6 months were identified using a collection of large national commercial, Medicare supplemental, and Medicaid administrative claims databases (MarketScan<sup>®</sup>). Patients were divided into two cohorts, a combined commercial/Medicare cohort and a Medicaid cohort. Within each cohort, characteristics (demographic, clinical, and resource utilization) of patients initiating raloxifene were compared to those of patients initiating bisphosphonate therapy. Group comparisons were made using chi-square tests for proportions of categorical measures and Wilcoxon rank-sum tests for continuous variables. Logistic regression was used to simultaneously examine factors independently associated with initiation of raloxifene versus a bisphosphonate.</p> <p>Results</p> <p>Within both the commercial/Medicare and Medicaid cohorts, raloxifene patients were younger, had fewer comorbid conditions, and fewer pre-existing fractures than bisphosphonate patients. Raloxifene patients in both cohorts were less likely to have had a bone mineral density (BMD) screening in the previous year than were bisphosphonate patients, and were also more likely to have used estrogen or estrogen/progestin therapy in the previous 12 months. These differences remained statistically significant in the multivariate model.</p> <p>Conclusion</p> <p>In this sample of patients enrolled in commercial, Medicare, and Medicaid plans, patients who initiated raloxifene treatment differed from those initiating bisphosphonates. Raloxifene patients were younger, had better overall health status and appeared to be less likely to have risk factors for new osteoporotic fractures than bisphosphonate patients. Differences in the clinical profiles of these agents may impact prescribing decisions. Investigators using observational data to make comparisons of treatment outcomes associated with these medications should take these important differences in patient characteristics into consideration.</p

    Belowground biomass response to nutrient enrichment depends on light limitation across globally distributed grasslands

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    Anthropogenic activities are increasing nutrient inputs to ecosystems worldwide, with consequences for global carbon and nutrient cycles. Recent meta-analyses show that aboveground primary production is often co-limited by multiple nutrients; however, little is known about how root production responds to changes in nutrient availability. At twenty-nine grassland sites on four continents, we quantified shallow root biomass responses to nitrogen (N), phosphorus (P) and potassium plus micronutrient enrichment and compared below- and aboveground responses. We hypothesized that optimal allocation theory would predict context dependence in root biomass responses to nutrient enrichment, given variation among sites in the resources limiting to plant growth (specifically light versus nutrients). Consistent with the predictions of optimal allocation theory, the proportion of total biomass belowground declined with N or P addition, due to increased biomass aboveground (for N and P) and decreased biomass belowground (N, particularly in sites with low canopy light penetration). Absolute root biomass increased with N addition where light was abundant at the soil surface, but declined in sites where the grassland canopy intercepted a large proportion of incoming light. These results demonstrate that belowground responses to changes in resource supply can differ strongly from aboveground responses, which could significantly modify predictions of future rates of nutrient cycling and carbon sequestration. Our results also highlight how optimal allocation theory developed for individual plants may help predict belowground biomass responses to nutrient enrichment at the ecosystem scale across wide climatic and environmental gradients