1,888 research outputs found

    The Economics of Affirmative Action Admissions Policies for Asian American Students

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    In the realm of higher education, Asian American students have thrived in terms of academic excellence. During the last fifty years, many Asian Americans have done so well academically that they are no longer underrepresented on college campuses in the United States. For instance, in 2000, Asian Americans made up 5.9% of college students, but only 4% of the United States population (Harvey & Anderson, 2004). Although this may seem like a success story for Asian Americans, who were often discriminated against in the past, their triumphs in the academic world have actually caused them to again become victim to discriminatory affirmative action policies.Affirmative action is defined by the United States Commission of Civil Rights as “any measure, beyond simple termination of discriminatory practice, adopted to correct and compensate for past or present discrimination or to prevent discrimination from recurring in the future” (U.S. Commission of Civil Rights, 1977). Instead of being treated as a minority group that is given preferential treatment in college admissions, the opposite is occurring for Asian American students of East Asian or Indian descent. In college admissions, affirmative action policies often result in an Asian American student being passed over in favor of a non- Asian American minority student with lower grades, test scores, or achievements (Espenshade & Chung, 2005). This paper aims to illustrate that regarding college admissions, even though affirmative action policies were aimed at helping minorities, they have hurt Asian American students of East Asian or Indian descent more than they have benefited these students. The paper also includes a discussion on alternatives to affirmative action policies that are fair to all racial/ethnic groups, the future of college admissions policies, and whether America is ready to eliminate affirmative action policies.undergraduat

    Multi-Device Task-Oriented Communication via Maximal Coding Rate Reduction

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    Task-oriented communication offers ample opportunities to alleviate the communication burden in next-generation wireless networks. Most existing work designed the physical-layer communication modules and learning-based codecs with distinct objectives: learning is targeted at accurate execution of specific tasks, while communication aims at optimizing conventional communication metrics, such as throughput maximization, delay minimization, or bit error rate minimization. The inconsistency between the design objectives may hinder the exploitation of the full benefits of task-oriented communications. In this paper, we consider a specific task-oriented communication system for multi-device edge inference over a multiple-input multiple-output (MIMO) multiple-access channel, where the learning (i.e., feature encoding and classification) and communication (i.e., precoding) modules are designed with the same goal of inference accuracy maximization. Instead of end-to-end learning which involves both the task dataset and wireless channel during training, we advocate a separate design of learning and communication to achieve the consistent goal. Specifically, we leverage the maximal coding rate reduction (MCR2) objective as a surrogate to represent the inference accuracy, which allows us to explicitly formulate the precoding optimization problem. We cast valuable insights into this formulation and develop a block coordinate descent (BCD) solution algorithm. Moreover, the MCR2 objective also serves the loss function of the feature encoding network, based on which we characterize the received features as a Gaussian mixture (GM) model, facilitating a maximum a posteriori (MAP) classifier to infer the result. Simulation results on both the synthetic and real-world datasets demonstrate the superior performance of the proposed method compared to various baselines.Comment: submitted to IEEE for possible publicatio

    Human amniotic fluid stem cells do not differentiate into dopamine neurons in vitro or after transplantation in vivo.

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    Although embryonic stem (ES) cells can generate dopamine (DA) neurons that are potentially useful as a cell replacement therapy in Parkinson\u27s disease (PD), associated ethical and practical concerns remain major stumbling blocks to their eventual use in humans. In this study, we examined human amniotic fluid stem (hAFS) cells derived from routine amniocenteses for their potential to give rise to DA neurons in vitro and following transplantation into the 6-hydroxydopamine-lesioned rat brain. We show that undifferentiated hAFS cells constitutively expressed mRNAs and proteins typical of stem cells but also cell derivatives of all three germ layers, including neural progenitors/neurons (nestin, beta-tubulin III, neurofilament). Additionally, these cells expressed mRNAs of an immature DA phenotype (Lmx1a, Pitx-3, Nurr1, Aldh1a1) but not the corresponding proteins. Importantly, treatment with DA differentiation factors using a variety of protocols did not further promote the development of fully differentiated DA neurons from hAFS cells. Thus, Lmx1a, Aldh1a1, AADC, TH, and DAT proteins were not detected in hAFS cells in culture or after transplantation into the PD rat brain. Moreover, by 3 weeks after implantation, there were no surviving AFS cells in the graft, likely as a result of an acute immunorejection response, as evidenced by the abundant presence of CD11+ macrophage/microglia and reactive GFAP+ astrocytes in the host brain. Taken together, these results suggest that further studies will be needed to improve differentiation procedures in culture and to prolong cell survival in vivo if hAFS cells are to be useful as replacement cells in PD

    Impact of Invasive Fungal Infections on Mortality, Length of Hospital Stay, and Costs in Allogeneic Hematopoietic Stem Cell Transplant Patients

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    Over the last decade, unrelated donors have become a vital resource for hematopoietic stem cell transplantation (HSCT) and the number of allogeneic HSCT (allo-HSCT) has increased significantly. While invasive fungal infections (IFIs) remain major concerns in these patients, data regarding impact of these infections on mortality, length of hospital stay, and hospital charge are limited in the United States at a national level. Additionally, with many updates in transplant practice, risk factors for IFIs in these patients may have changed

    Trajectories of Body Mass Index Among Active-Duty U.S. Army Soldiers

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    Establishing the shape and determinants of trajectories of body mass index (BMI) among Soldiers is critical given the importance of weight management to military service requirements. To establish the shape and determinants of BMI trajectories among Soldiers, we aimed to (1) model the overall BMI trajectory of Soldiers, (2) find the most common trajectory groups among Soldiers, (3) investigate the relationship between BMI trajectories and sociodemographic and military-specific characteristics, and (4) determine if there were Soldiers with large fluctuations in BMI. The study population included all US Army Soldiers on active-duty between 2011 and 2014 who were age 17–62 (n = 827,126). With longitudinal data from the Stanford Military Data Repository, we used group-based trajectory modeling to identify the BMI trajectories of Soldiers and multinomial logistic regression to estimate associations between Soldier characteristics and trajectory membership. Four distinct BMI trajectory groups were found: increasing, decreasing, constant, and inconstant. The constant, increasing, and decreasing trajectories were similar in shape and percentage between men and women. The constant trajectory had the fewest Soldiers who exceeded weight standards or had duty limitations. The increasing trajectory was associated with marriage and fewer service years. The decreasing trajectory was associated with more service years and higher educational attainment. The inconstant trajectory differed in shape between men and women. Over 6% of men and 12% of women had fluctuations in BMI indicative of weight cycling. Understanding the characteristics associated with BMI trends may assist the Army in targeting resources aimed to improve Soldier health and combat readiness

    QCD ghost f(T)-gravity model

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    Within the framework of modified teleparallel gravity, we reconstruct a f(T) model corresponding to the QCD ghost dark energy scenario. For a spatially flat FRW universe containing only the pressureless matter, we obtain the time evolution of the torsion scalar T (or the Hubble parameter). Then, we calculate the effective torsion equation of state parameter of the QCD ghost f(T)-gravity model as well as the deceleration parameter of the universe. Furthermore, we fit the model parameters by using the latest observational data including SNeIa, CMB and BAO data. We also check the viability of our model using a cosmographic analysis approach. Moreover, we investigate the validity of the generalized second law (GSL) of gravitational thermodynamics for our model. Finally, we point out the growth rate of matter density perturbation. We conclude that in QCD ghost f(T)-gravity model, the universe begins a matter dominated phase and approaches a de Sitter regime at late times, as expected. Also this model is consistent with current data, passes the cosmographic test, satisfies the GSL and fits the data of the growth factor well as the LCDM model.Comment: 19 pages, 9 figures, 2 tables. arXiv admin note: substantial text overlap with arXiv:1111.726
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