3,570 research outputs found
Deaf STEM Community Alliance: Establishing a model virtual academic community
Abstract - This presentation describes the incremental and iterative development of the Deaf STEM Community Alliance’s virtual academic community, the Deaf and Hard of Hearing Virtual Academic Community (DHHVAC). The DHHVAC components address three critical barriers to the success of students who are deaf or hard-of-hearing: student preparation, socialization, and access to media
Strategies Employed by Community-Based Service Providers to Address HIV-Associated Neurocognitive Challenges: A Qualitative Study
Background: HIV-associated neurocognitive disorders and other causes of neurocognitive challenges experienced by people living with HIV (PLWH) persist as public health concerns in developed countries. Consequently, PLWH who experience neurocognitive challenges increasingly require social support and mental health services from community-based providers in the HIV sector. Methods: Thirty-three providers from 22 AIDS service organizations across Ontario, Canada, were interviewed to determine the strategies they used to support PLWH experiencing neurocognitive difficulties. Thematic analysis was conducted to determine key themes from the interview data. Results: Three types of strategies were identified: (a) intrapersonal, (b) interpersonal, and (c) organizational. Intrapersonal strategies involved learning and staying informed about causes of neurocognitive challenges. Interpersonal strategies included providing practical assistance, information, counseling, and/or referrals to PLWH. Organizational strategies included creating dedicated support groups for PLWH experiencing neurocognitive challenges, partnering with other organizations with services not available within their own organization, and advocating for greater access to services with expertise and experience working with PLWH. Conclusion: Through concerted efforts in the future, it is likely that empirically investigating, developing, and customizing these strategies specifically to address HIV-associated neurocognitive challenges will yield improved social support and mental health outcomes for PLWH
Heteroclinic intersections between Invariant Circles of Volume-Preserving Maps
We develop a Melnikov method for volume-preserving maps with codimension one
invariant manifolds. The Melnikov function is shown to be related to the flux
of the perturbation through the unperturbed invariant surface. As an example,
we compute the Melnikov function for a perturbation of a three-dimensional map
that has a heteroclinic connection between a pair of invariant circles. The
intersection curves of the manifolds are shown to undergo bifurcations in
homologyComment: LaTex with 10 eps figure
Environmental Drivers of Mesophotic Echinoderm Assemblages of the Southeastern Pacific Ocean
Mesophotic ecosystems (50–400 m depth) of the southeastern Pacific have rarely been studied because of the logistical challenges in sampling across this remote zone. This study assessed how oxygen concentrations and other environmental predictors explain variation in echinoderm assemblages at these mesophotic systems, where this group is among the predominant fauna. We compiled data on echinoderm taxa at 91 sampling stations, from historical and recent surveys (between 1950 and 2019), covering a longitudinal gradient of approximately 3,700 km along with the Nazca, Salas y Gómez, and Juan Fernández ridges. Uni- and multivariate model-based tools were applied to analyze the patterns of benthic fauna in relation to environmental factors. Our results indicate a significant positive relationship between echinoderm species richness and depth, oxygen, and salinity. Changes in echinoderm community composition were significantly explained by oxygen, longitude, and chlorophyll-a. We observed notable species turnovers at ∼101 and ∼86°W, where assemblages tend to be more variable across stations. This turnover possibly reflects the effects of physical barriers to dispersion (e.g., currents) and habitat changes. Echinoderm assemblages observed around Easter and Desventuradas Islands presented a high occurrence of potentially endemic taxa and distinct species assemblages. This study is the first to assess the structure of mesophotic echinoderm assemblages of the southeastern Pacific Ocean along a large spatial scale. The information reported here could help design appropriate management tools for the vast, recently created, marine protected areas in the southeastern Pacific
Terminal valuations, growth rates and the implied cost of capital
This article is published with open access at Springerlink.comWe develop a model based on the notion that prices lead earnings,
allowing for a simultaneous estimation of the implied growth rate and the cost of
equity capital for US industrial sectors. The major difference between our approach
and that in prior literature is that ours avoids the necessity to make assumptions
about terminal values and consequently about future growth rates. In fact, growth
rates are an endogenous variable, which is estimated simultaneously with the
implied cost of equity capital. Since we require only 1-year-ahead forecasts of
earnings and no assumptions about dividend payouts, our methodology allows us to
estimate ex ante aggregate growth and risk premia over a larger sample of firms than
has previously been possible. Our estimate of the risk premium being between 3.1
and 3.9 % is at the lower end of recent estimates, reflecting the inclusion of these
short-lived companies. Our estimate of the long run growth is from 4.2 to 4.7 %
Conceptual design of a nonscaling fixed field alternating gradient accelerator for protons and carbon ions for charged particle therapy
Published by the American Physical Society under the terms of the Creative Commons Attribution 3.0 License. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.The conceptual design for a nonscaling fixed field alternating gradient accelerator suitable for charged particle therapy (the use of protons and other light ions to treat some forms of cancer) is described.EPSR
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Development of guidance on applications of regulatory requirements for regulating large, contaminated equipment and large decommissioning and decontamination (D and D) components
In 1985, the International Atomic Energy Agency issued revised regulations for the safe transport of radioactive material. Significant were major changes to requirements for Low Specific Activity material and Surface Contaminated Objects. As these requirements were adopted into regulations in the US, it was recognized that guidance on how to apply these requirements to large, contaminated/activated pieces of equipment and decommissioning and decontamination objects would be needed both by the regulators and those regulated to clarify technical uncertainties and ensure implementation. Thus, the US Department of Transportation and the US Nuclear Regulatory Commission, with assistance of staff from Oak Ridge National Laboratory, are preparing regulatory guidance which will present examples of acceptable methods for demonstrating compliance with the revised rules for large items. Concepts being investigated for inclusion in the pending guidance are discussed in this paper. Under current plans, the guidance will be issued for public comment before final issuance in 1997
'Word from the street' : when non-electoral representative claims meet electoral representation in the United Kingdom
Taking the specific case of street protests in the UK – the ‘word from the street’– this article examines recent (re)conceptualizations of political representation, most particularly Saward’s notion of ‘representative claim’. The specific example of nonelectoral claims articulated by protestors and demonstrators in the UK is used to illustrate: the processes of making, constituting, evaluating and accepting claims for and by constituencies and audiences; and the continuing distinctiveness of claims based upon electoral representation. Two basic questions structure the analysis: first, why would the political representative claims of elected representatives trump the nonelectoral claims of mass demonstrators and, second, in what ways does the ‘perceived legitimacy’ of the former differ from the latter
BRCA1 and BRCA2 mutations in a population-based study of male breast cancer
Background: The contribution of BRCA1 and BRCA2 to the incidence of male breast cancer (MBC)
in the United Kingdom is not known, and the importance of these genes in the increased risk of female
breast cancer associated with a family history of breast cancer in a male first-degree relative is unclear.
Methods: We have carried out a population-based study of 94 MBC cases collected in the UK. We
screened genomic DNA for mutations in BRCA1 and BRCA2 and used family history data from these
cases to calculate the risk of breast cancer to female relatives of MBC cases. We also estimated the
contribution of BRCA1 and BRCA2 to this risk.
Results: Nineteen cases (20%) reported a first-degree relative with breast cancer, of whom seven also
had an affected second-degree relative. The breast cancer risk in female first-degree relatives was 2.4
times (95% confidence interval [CI] = 1.4–4.0) the risk in the general population. No BRCA1 mutation
carriers were identified and five cases were found to carry a mutation in BRCA2. Allowing for a
mutation detection sensitivity frequency of 70%, the carrier frequency for BRCA2 mutations was 8%
(95% CI = 3–19). All the mutation carriers had a family history of breast, ovarian, prostate or
pancreatic cancer. However, BRCA2 accounted for only 15% of the excess familial risk of breast
cancer in female first-degree relatives.
Conclusion: These data suggest that other genes that confer an increased risk for both female and
male breast cancer have yet to be found
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