765 research outputs found
Keeping Up-to-Date with Bayes (Abstract)
Bayes’ theorem, a rule for updating probabilities as new information is obtained, may be over two centuries old but it has been the driving force behind many of the most significant recent advances in statistics and other sciences
COVID and Coraje: Negotiating Latinx Immigrant Experiences of the Pandemic
11 pagesIn this paper, we compare observations from engaged ethnography and participant observation with Latinx immigrants in Colorado and Oregon during the COVID-19 pandemic. In particular, we focus on lived experiences of structural vulnerability, as well as the ways in which COVID-related disparities have become internalized as stigma and have amplified immigrants’ experiences of stress, anxiety, and “aislamiento,” or isolation. Indeed, Latinx immigrants in the US—especially those without legal status and those in mixed-status families—face a range of exclusions, discourses of blame and (un)deservingness, and forms of precarity that have contributed to disproportionate risk, suffering, and fear as the pandemic has unfolded. At the same time, by laying bare blatant injustices and racist exclusions, the pandemic has prompted some Latinx immigrants in our research and advocacy sites to enact new forms of resistance and contestation. We detail the range of ways which, in efforts to stay healthy and to challenge discriminatory portrayals of themselves as either disease carriers unlikely to heed public health warnings or as “public charges,” they insist upon their own rights, worth, belonging, and dignity. Finally, we conclude by discussing some of the ways in which these two U.S. states—and the health and social service organizations working with Latinx communities within them—have attempted to address coronavirus disparities among Latinx communities, showing how particular approaches can assuage short-term suffering and improve access to healthcare and other social supports, while others may create a new set of barriers to access for already marginalized communitiesNational Science Foundatio
The Kinematics and Dynamics of the Globular Clusters and the Planetary Nebulae of NGC 5128
A new kinematic and dynamic study of the halo of the giant elliptical galaxy,
NGC 5128, is presented. From a spectroscopically confirmed sample of 340
globular clusters and 780 planetary nebulae, the rotation amplitude, rotation
axis, velocity dispersion, and the total dynamical mass are determined for the
halo of NGC 5128. The globular cluster kinematics were searched for both radial
dependence and metallicity dependence by subdividing the globular cluster
sample into 158 metal-rich ([Fe/H] > -1.0) and 178 metal-poor ([Fe/H] < -1.0)
globular clusters. Our results show the kinematics of the metal-rich and
metal-poor subpopulations are quite similar. The kinematics are compared to the
planetary nebula population where differences are apparent in the outer regions
of the halo. The total mass of NGC 5128 is found using the Tracer Mass
estimator (Evans et al. 2003), to determine the mass supported by internal
random motions, and the spherical component of the Jeans equation to determine
the mass supported by rotation. We find a total mass of (1.0+/-0.2) x 10^(12)
Msun from the planetary nebulae data out to a projected radius of 90 kpc and
(1.3+/-0.5) x 10^(12) Msun from the globular clusters out to a projected radius
of 50 kpc. Lastly, we present a new and homogeneous catalog of known globular
clusters in NGC 5128. This catalog combines all previous definitive cluster
identifications from radial velocity studies and HST imaging studies, as well
as 80 new globular clusters from a study of M.A. Beasley et al. (2007, in
preparation).Comment: Accepted in the Astronomical Journal,52 pages, 13 figures, 6 tables -
Changes made to Table 1 from originally submitted 0704.118
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Examining Design and Inter-Rater Reliability of a Rubric Measuring Research Quality across Multiple Disciplines
The paper presents a rubric to help evaluate the quality of research projects. The rubric was applied in a competition across a variety of disciplines during a two-day research symposium at one institution in the southwest region of the United States of America. It was collaboratively designed by a faculty committee at the institution and was administered to 204 undergraduate, master, and doctoral oral presentations by approximately 167 different evaluators. No training or norming of the rubric was given to 147 of the evaluators prior to the competition. The findings of the inter-rater reliability analysis reveal substantial agreement among the judges, which contradicts literature describing the fact that formal norming must occur prior to seeing substantial levels of inter-rater reliability. By presenting the rubric along with the methodology used in its design and evaluation, it is hoped that others will find this to be a useful tool for evaluating documents and for teaching research methods. Accessed 15,405 times on https://pareonline.net from May 29, 2009 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right
Protecting Undocumented Students Post-Election
5 pages; news article from a websit
Basal channels drive active surface hydrology and transverse ice shelf fracture
Ice shelves control sea-level rise through frictional resistance, which slows the seaward flow of grounded glacial ice. Evidence from around Antarctica indicates that ice shelves are thinning and weakening, primarily driven by warm ocean water entering into the shelf cavities. We have identified a mechanism for ice shelf destabilization where basal channels underneath the shelves cause ice thinning that drives fracture perpendicular to flow. These channels also result in ice surface deformation, which diverts supraglacial rivers into the transverse fractures. We report direct evidence that a major 2016 calving event at Nansen Ice Shelf in the Ross Sea was the result of fracture driven by such channelized thinning and demonstrate that similar basal channel–driven transverse fractures occur elsewhere in Greenland and Antarctica. In the event of increased basal and surface melt resulting from rising ocean and air temperatures, ice shelves will become increasingly vulnerable to these tandem effects of basal channel destabilization
Exposure and potential effects of pesticides and pharmaceuticals in protected streams of the US National park Service southeast region
Globally, protected areas offer refugia for a broad range of taxa including threatened and endangered species. In the United States (US), the National Park Service (NPS) manages public lands to preserve biodiversity, but increasing park visitation and development of surrounding landscapes increase exposure to and effects from bioactive contaminants. The risk (exposure and hazard) to NPS protected-stream ecosystems within the highly urbanized southeast region (SER) from bioactive contaminants was assessed in five systems based on 334 pesticide and pharmaceutical analytes in water and 119 pesticides in sediment. Contaminant mixtures were common across all sampled systems, with approximately 24% of the unique analytes (80/334) detected at least once and 15% (49/334) detected in half of the surface-water samples. Pharmaceuticals were observed more frequently than pesticides, consistent with riparian buffers and concomitant spatial separation from non-point pesticide sources in four of the systems. To extrapolate exposure data to biological effects space, site-specific cumulative exposure-activity ratios (REAR) were calculated for detected surface-water contaminants with available ToxCast data; common exceedances of a 0.001 REAR effects-screening threshold raise concerns for molecular toxicity and possible, sub-lethal effects to non-target, aquatic vertebrates. The results illustrate the need for continued management of protected resources to reduce contaminant exposure and preserve habitat quality, including prioritization of conservation practices (riparian buffers) near stream corridors and increased engagement with upstream/up-gradient property owners and municipal wastewater facilities
The role of herbivory in structuring tropical seagrass ecosystem service delivery
Seagrass meadows support key ecosystem services, via provision of food directly for herbivores, and indirectly to their predators. The importance of herbivores in seagrass meadows has been well-documented, but the links between food webs and ecosystem services in seagrass meadows have not previously been made explicit. Herbivores interact with ecosystem services – including carbon sequestration, cultural values, and coastal protection. Interactions can be positive or negative and depend on a range of factors including the herbivore identity and the grazing type and intensity. There can be unintended consequences from management actions based on a poor understanding of trade-offs that occur with complex seagrass-herbivore interactions. Tropical seagrass meadows support a diversity of grazers spanning the meso-, macro- and megaherbivore scales. We present a conceptual model to describe how multiple ecosystem services are influenced by herbivore pressure in tropical seagrass meadows. Our model suggests that a balanced ecosystem, incorporating both seagrass and herbivore diversity, is likely to sustain the broadest range of ecosystem services. Our framework suggests the pathway to achieve desired ecosystem services outcomes requires knowledge on four key areas: (1) how size classes of herbivores interact to structure seagrass; (2) desired community and management values; (3) seagrass responses to top-down and bottom-up controls; (4) the pathway from intermediate to final ecosystem services and human benefits. We suggest research should be directed to these areas. Herbivory is a major structuring influence in tropical seagrass systems and needs to be considered for effective management of these critical habitats and their services
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