879 research outputs found

    Diffusion of Common Application Membership and Admissions Outcomes at American Colleges and Universities

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    We study the adoption of Common Application membership by private four-year postsecondary institutions and its role in explaining the growth in undergraduate applications. Using data from the College Board’s Annual Survey of Colleges, proportional hazards models suggest that institutions respond to the net benefit of adoption. We then estimate that membership increases applications by 5.7–7.0 percent and decreases yield rates by 2.8–3.9 percent. Acceptance rates decrease for members when their local networks are large. Falsification tests indicate that membership effects occur as a one-time adoption shock. Membership also decreases SAT scores and increases the percent students of color

    Satellite Structure In Laser-assisted Charge-transfer Cross Sections

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    A six-state coupled-channel calculation has been performed on the laser-assisted charge-transfer collision H++Na+Latin small letter h with stroke. A greatly enhanced charge-transfer cross section is observed for low-energy collisions if the photon energy is matched to the classical satellite frequency. This frequency is determined by the location of an extremum in the difference of potential energies between the laser-pumped initial and final molecular states. The stationary-phase method has been used to reproduce the general features and the magnitude of the cross-section structure. © 1985 The American Physical Society

    Laser-assisted Charge-transfer Collisions: K++Na

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    A theory has been formulated to characterize charge-transfer collisions in the presence of an external laser field. The molecular-state-expansion method is used to describe the scattering process within the impact-parameter formalism. Electron translation factors are included in the molecular-state expansion so that the scattering wave function satisfies the correct boundary conditions. The theory is applied to the process K++NaK+Na+. In addition, we have made a detailed analysis of laser-assisted charge transfer for low-energy collisions. In this case, a Landau-Zener formula can be derived which shows that the cross section increases with decreasing incident energy. In general the laser coupling is dominant in the low-energy region, while the dynamical coupling becomes important as the collision energy increases. © 1985 The American Physical Society

    Hydrodynamical Simulations of the Barred Spiral Galaxy NGC 1097

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    NGC 1097 is a nearby barred spiral galaxy believed to be interacting with the elliptical galaxy NGC 1097A located to its northwest. It hosts a Seyfert 1 nucleus surrounded by a circumnuclear starburst ring. Two straight dust lanes connected to the ring extend almost continuously out to the bar. The other ends of the dust lanes attach to two main spiral arms. To provide a physical understanding of its structural and kinematical properties, two-dimensional hydrodynamical simulations have been carried out. Numerical calculations reveal that many features of the gas morphology and kinematics can be reproduced provided that the gas flow is governed by a gravitational potential associated with a slowly rotating strong bar. By including the self-gravity of the gas disk in our calculation, we have found the starburst ring to be gravitationally unstable which is consistent with the observation in \citet{hsieh11}. Our simulations show that the gas inflow rate is 0.17 M_\sun yr−1^{-1} into the region within the starburst ring even after its formation, leading to the coexistence of both a nuclear ring and a circumnuclear disk.Comment: 32 pages, 14 figures, 1 table, accepted for publication in the Ap

    Heme Oxygenase-1 Expression Affects Murine Abdominal Aortic Aneurysm Progression.

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    Heme oxygenase-1 (HO-1), the rate-limiting enzyme in heme degradation, is a cytoprotective enzyme upregulated in the vasculature by increased flow and inflammatory stimuli. Human genetic data suggest that a diminished HO-1 expression may predispose one to abdominal aortic aneurysm (AAA) development. In addition, heme is known to strongly induce HO-1 expression. Utilizing the porcine pancreatic elastase (PPE) model of AAA induction in HO-1 heterozygous (HO-1+/-, HO-1 Het) mice, we found that a deficiency in HO-1 leads to augmented AAA development. Peritoneal macrophages from HO-1+/- mice showed increased gene expression of pro-inflammatory cytokines, including MCP-1, TNF-alpha, IL-1-beta, and IL-6, but decreased expression of anti-inflammatory cytokines IL-10 and TGF-beta. Furthermore, treatment with heme returned AAA progression in HO-1 Het mice to a wild-type profile. Using a second murine AAA model (Ang II-ApoE-/-), we showed that low doses of the HMG-CoA reductase inhibitor rosuvastatin can induce HO-1 expression in aortic tissue and suppress AAA progression in the absence of lipid lowering. Our results support those studies that suggest that pleiotropic statin effects might be beneficial in AAA, possibly through the upregulation of HO-1. Specific targeted therapies designed to induce HO-1 could become an adjunctive therapeutic strategy for the prevention of AAA disease

    Recruitment of dentists by military services: implications for academia

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    This study seeks to explore the perceptions of senior dental students and junior military dental officers regarding their choice of a military career to identify the recruitment methodologies that influenced their decisions, and to determine if these strategies might suggest ways of increasing recruitment for dental academia. Official documentation of activities related to recruitment was requested from the military services. In-depth telephone interviews were conducted to gather qualitative data from senior dental students and junior military dental officers. The interviews suggest that, although obtaining a dental education paid for by military scholarship was a dominant factor, other inducements to sign with the military included: guaranteed employment upon graduation; the prestige associated with the military; access to post graduate training; minimal practice management concerns; and opportunities for continue education. A career in dental education can offer similar incentives, and students may choose academia as a career if the incentives are emphasized

    A Study of Military Recruitment Strategies for Dentists: Possible Implications for Academia

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    Results of the annual American Dental Education Association surveys of dental school seniors show approximately 10 percent of graduates enter federal government services while less than 1 percent enter dental academia. To examine this difference, this study sought the perceptions of senior dental students and junior military dental officers regarding their choice of a military career in order to determine how military recruitment strategies influenced their career decisions. Official documents explaining military recruitment efforts were requested from the military services and summarized. In-depth telephone interviews were conducted to gather perception data from the students and dental officers on successful strategies. By employing several strategies, the military was able to inform potential recruits about the benefits of being a dentist in the military. The opportunity to have the military finance a student's dental education was a successful military recruitment tool. Other enticing factors included guaranteed employment upon graduation, prestige associated with serving in the military, access to postgraduate training, minimal practice management responsibilities, and opportunities to continue learning and improve clinical skills without significant financial implications. It was concluded that dental education can use the same strategies to highlight the benefits of an academic career and offer many similar incentives that may encourage students to consider a career path in dental education
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