Últimos itens adicionados do Acervo: Harvard University

A Universidade de Harvard (em inglês: Harvard University) é uma universidade privada membro da Ivy League, localizada em Cambridge, Massachusetts, Estados Unidos, e cuja história, influência e riqueza tornam-a uma das mais prestigiadas universidades do mundo.

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Beyond the numbers: institutional influences on experiences with diversity on elite college campuses

Warikoo, Natasha Kumar; Deckman, Sherry
Fonte: Wiley Publicador: Wiley
Tipo: Artigo de Revista Científica
Português
In this paper we bring together the burgeoning qualitative literature on the socializing influence of residential colleges; the predominantly survey-based literature on campus racial climate; and the literature on diversity work in organizations, to analyze how two elite universities’ approaches to diversity shape students’ experiences with and feelings about diversity. We employ 77 in-depth interviews with undergraduates at two elite universities, and find that while the universities appear comparable on measures of student demographics and overall diversity infrastructure, they take different approaches. These varying approaches lead to important differences in student perspectives. At the university that takes a power analysis and minority support approach, students who participate in minority-oriented activities develop a critical race theory perspective, while their white and non-participating minority peers frequently feel alienated from that programming. At the university that takes an integration and celebration approach, most students embrace a cosmopolitan perspective, celebrating diversity while paying less attention to power and resource differences between racial groups. The findings suggest that higher education institutions can influence the race frames of students as well as their approaches to multiculturalism...

Cultural explanations for racial and ethnic stratification in academic achievement: a call for a new and improved theory.

Warikoo, Natasha Kumar; Carter, Prudence
Fonte: Sage Publicador: Sage
Tipo: Artigo de Revista Científica
Português
In this article we assess the literature on cultural explanations for ethno-racial differences in K-12 schooling and academic performance. Some cultural arguments problematically define certain ethno-racial identities and cultures as subtractive from the goal of academic mobility, while simultaneously defining the ethnic cultures and identities of others as additive and oriented towards this goal. We review two prevailing schools of thought that compare immigrant and native minority students: cultural ecological theory (CET) and segmented assimilation theory. Second, we examine empirical research that highlights the complexity of culture, focusing on four domains: (1) the school’s cultural ethos; (2) variation in identities and cultural practices within ethnic and racial groups; (3) the multidimensional nature of culture and its variable impact on students; and (4) the intersections of race, ethnicity, class, and gender. This literature—when synthesized—suggests that a coherent theory of culture’s impact on ethnic and racial differences in schooling outcomes must unpack the multiple influences of identity and context more deliberately than previous literature has done. Finally, we call for studies that employ comparative research across groups and treat race and ethnicity as dependent rather than independent variables...

Designing a 21st Century Corporate Tax — An Advance U.S. Minimum Tax on Foreign Income and Other Measures to Protect the Base

Shay, Stephen E.; Fleming, J. Clifton, Jr.; Peroni, Robert J.
Fonte: Tax Analysts Publicador: Tax Analysts
Tipo: Artigo de Revista Científica
Português
The 21st Century has seen unprecedented levels of corporate tax aggressiveness and avoidance. This Article continues our exploration of second-best international tax reforms that would protect the U.S. corporate tax base and have some likelihood of adoption. In this case, we consider how a U.S. minimum tax on foreign income earned by a controlled foreign corporation should be designed to protect the United States against erosion of its corporate income tax base and to combat tax competition by low-tax intermediary countries. In the authors’ view, a minimum tax should be an interim levy that preserves the residual U.S. tax on foreign income, as distinguished from a final minimum tax that partially eliminates the U.S. residual tax. An interim minimum tax would be a significant improvement over current law and would more effectively limit incentives to seek low-taxed foreign income while ameliorating pressure to retain excess earnings abroad. To achieve the objectives of such a minimum tax, corresponding changes should be made to the U.S. corporate resident definition, the source taxation of foreign multinational corporations, and the residence taxation of U.S. portfolio investors in foreign corporations to reduce tax advantages under current law for investments in foreign corporations. These changes would reduce tax advantages for foreign parent corporate groups and thereby further protect the U.S. tax base...

Designing a U.S. Exemption System For Foreign Income When the Treasury is Empty

Fleming, J. Clfton, Jr.; Shay, Stephen E.; Peroni, Robert J.
Fonte: Tax Analysts Publicador: Tax Analysts
Tipo: Artigo de Revista Científica
Português
The U.S. government faces a well-documented long-term revenue shortage that is unlikely to be cured by government expenditure reductions. Thus, it is curious that there is currently considerable pressure for the United States to adopt some type of territorial or exemption system under which most foreign-source active business income earned by U.S. resident corporations would become substantially free of U.S. income tax. Although we are not fans of territoriality, we recognize that a significant reform of the U.S. international tax system is necessary. In other articles, we have expressed our clear preference for strengthening the U.S. worldwide taxation system by repealing the deferral privilege and instituting a per-country foreign tax credit limitation. However, if such a reform is not politically feasible, we believe that a properly designed exemption or territorial system could be an improvement over the current U.S. international tax regime, which is badly flawed for multiple reasons. In any event, there is a significant likelihood that Congress will sooner or later be considering legislation to create a U.S territorial or exemption system. Accordingly, it is important for academics and policymakers to thoughtfully discuss the structure of such a system. We hope that this article will contribute to that conversation. Our fundamental point is that because of the U.S. fiscal situation...

Commentary: Ownership Neutrality and Practical Complications

Shay, Stephen E.
Fonte: New York University Publicador: New York University
Tipo: Artigo de Revista Científica
Português
In "Reconsidering the Taxation of Foreign Income," Jim Hines analyzes the consequences of taxing, as opposed to exempting, active foreign business income by comparing the expected effects on capital ownership of a "pure" worldwide income taxation system with the effects on capital ownership of a "pure" territorial taxation regime. Consistent with his earlier work, Hines asserts that a capital ownership neutrality analysis supports exempting foreign active business income from home country residence taxation and points to global welfare losses from taxing income on a worldwide basis with a credit for foreign taxes. As he has previously, Hines sets up his discussion of capital ownership neutrality by criticizing the "older wisdom" of international tax policy that established a "tension between policies that maximize national welfare - NN - and policies that maximize global welfare - CEN." According to Hines, perhaps the most critical of the assumptions underlying the traditional investment location neutrality framework is that "home country taxation does not directly or indirectly affect foreign firms." Hines argues that if greater investment abroad triggers greater investment by foreign firms in the residence country, "[t]he NN implication that home countries maximize their own welfare by subjecting foreign income to taxation with only deductions for foreign income tax payments then no longer follows." If the productivity of an investment depends on its ownership (without regard to the location of the investment) and home and foreign firms compete for ownership of capital around the world...

The David R. Tillinghast Lecture - What's Source Got to Do with it - Source Rules and U.S. International Taxation

Shay, Stephen E.; Fleming, J. Clifton, Jr.; Peroni, Robet J.
Fonte: New York University Publicador: New York University
Tipo: Artigo de Revista Científica
Português
Arguably, the largest problem in international income taxation is the proper treatment of income that is subject to the legitimate taxing claims of two or more countries. A source country's jurisdiction to tax foreign persons is limited to income earned within the source country's borders. Under current international norms, however, the taxpayer's residence country is required to accommodate the source country's taxing right by employing a foreign tax credit or by exempting foreign source income. Thus, source taxation is at once geographically constrained, but also jurisdictionally superior to residence taxation. These principles require that international income be divided and accounted for between countries according to criteria that relate income and deductions to geographic locations. To be specific, the consequence of geographically limited source taxation and overlapping, but secondary, residence taxation is that the source of income must be determined so that the right to tax can be assigned. In this sense, the concept of "source" is at the heart of international taxation. We argue in Section II that the right of source countries to tax foreign persons on their source country income has a robust normative foundation. By contrast...

Fairness in International Taxation: The Ability-to-Pay Case for Taxing Worldwide Income

Shay, Stephen E.; Fleming, J. Clifton, Jr.; Peroni, Robert J.
Fonte: Tax Analysts Publicador: Tax Analysts
Tipo: Artigo de Revista Científica
Português
Although the ability-to-pay fairness principle is a foundational element of American income tax policy, it has played a surprisingly small role in evaluating the U.S. international income tax regime. Perhaps this is because the application of the ability-to-pay concept to international income taxation is complicated by the presence of foreign taxpayers, by income earned through C corporations and by the claims of other governments to tax cross-border income. Nevertheless, it is possible, and indeed essential, to analyze international tax policy in terms of fairness. In this article, we extensively explore the international dimension of the ability-to-pay norm. We argue that this fairness criterion supports the conclusion that taxing worldwide income and ending the deferral privilege provides a tax regime that is superior to either the current U.S. international income tax system or the adoption of an exemption system.

Jobs, Deficit Reduction, Revenues, and Fundamental Tax Reform

Shay, Stephen E.
Fonte: Tax Analysts and Advocates Publicador: Tax Analysts and Advocates
Tipo: Artigo de Revista Científica
Português
In this article, Shay argues that flat opposition to revenue increases has contributed to U.S. economic vulnerability and has had unintended effects, including contributing to increased deficits instead of smaller government. Shay also distinguishes fundamental income tax reform from raising revenues from tax expenditures. He urges President Obama to have Treasury spearhead fundamental income tax reform, within the context of an overall budget framework that includes revenue increases, and to develop detailed proposals to make the individual and corporate income taxes fairer, simpler, and more efficient.

Territoriality in Search of Principles and Revenue: Camp and Enzi

Shay, Stephen E.; Fleming, J. Clifton, Jr.; Peroni, Robert J.
Fonte: Tax Analysts and Advocates Publicador: Tax Analysts and Advocates
Tipo: Artigo de Revista Científica
Português
This article reviews proposals by House Ways and Means Committee Chairman Camp and Senator Mike Enzi to shift the United States from its current system of deferring taxation of active foreign income to a system that would exempt foreign business income from U.S. tax. (Neither proposal would materially affect the present U.S. system for taxing U.S.-source income.) The major contributions of the Camp Proposal lie in its recognition of the need to (i) make the treatment of foreign branches and foreign subsidiaries more neutral, and (ii) protect the U.S. tax base from excess interest deductions and the base-eroding incentives of very low foreign tax environments that stimulate U.S. income shifting. However, these improvements to current law would not justify changing to an exemption regime under the Camp Proposal in light of its many weaknesses, which include (but are not limited to) (i) material under-allocation of expenses to exempt foreign income, (ii) material loopholes in its anti-abuse rules for protecting the U.S. tax base, (iii) an apparent failure to tax gain upon transfers of appreciated assets into the exemption regime, (iv) foreign tax credit changes that would result in additional erosion of the U.S. tax base and (v) a misguided proposal for a reduced tax rate on royalties earned from foreign persons. The Enzi Proposal has similar weaknesses while lacking the strengths of the Camp Proposal. Our analysis of the Camp and Enzi Proposals highlights that U.S. international tax reform is integrally related to U.S. corporate...

Toward Democracy: The Struggle for Self-Rule in European and American Thought

Kloppenberg, James T.
Fonte: Oxford University Press Publicador: Oxford University Press
Tipo: Monograph or Book
Português
History

Screening for Obstructive Sleep Apnea: Bayes Weighs in

Bianchi, Matt Travis
Fonte: Bentham Science Publishers Ltd. Publicador: Bentham Science Publishers Ltd.
Tipo: Artigo de Revista Científica
Português
A fundamental challenge associated with screening tests is recognition of the impact of disease prevalence upon the predictive value of the result. For example, in the common circumstance of screening for low prevalence diseases, even good tests may have unacceptably high false positive rates. The converse situation, screening in high prevalence populations, is less common but occurs with obstructive sleep apnea (OSA): even ostensibly good screening tests may have unacceptably high false negative rates. The challenge of recognizing false negative OSA screening results has important implications as screens are increasingly implemented in high risk populations. This raises two clinically important questions: 1) How sensitive and specific should a screening test be to minimize false negative results across a spectrum of baseline prevalence; and 2) Given a screening test with known sensitivity and specificity, in what range of disease prevalence may the test be reasonably applied? Simple graphics are presented that incorporate acceptable risk thresholds and illustrate combinations of prevalence, sensitivity, and specificity in which disease probability remains high despite a negative test result. Adopting a Bayesian approach, together with acceptable risk thresholds...

Obstructive Sleep Apnea Alters Sleep Stage Transition Dynamics

Bianchi, Matt Travis; Cash, Sydney S.; Mietus, Joseph; Peng, Chung-Kang; Thomas, Robert Joseph
Fonte: Public Library of Science (PLoS) Publicador: Public Library of Science (PLoS)
Tipo: Artigo de Revista Científica
Português
Introduction: Enhanced characterization of sleep architecture, compared with routine polysomnographic metrics such as stage percentages and sleep efficiency, may improve the predictive phenotyping of fragmented sleep. One approach involves using stage transition analysis to characterize sleep continuity. Methods and Principal Findings: We analyzed hypnograms from Sleep Heart Health Study (SHHS) participants using the following stage designations: wake after sleep onset (WASO), non-rapid eye movement (NREM) sleep, and REM sleep. We show that individual patient hypnograms contain insufficient number of bouts to adequately describe the transition kinetics, necessitating pooling of data. We compared a control group of individuals free of medications, obstructive sleep apnea (OSA), medical co-morbidities, or sleepiness (n = 374) with mild (n = 496) or severe OSA (n = 338). WASO, REM sleep, and NREM sleep bout durations exhibited multi-exponential temporal dynamics. The presence of OSA accelerated the “decay” rate of NREM and REM sleep bouts, resulting in instability manifesting as shorter bouts and increased number of stage transitions. For WASO bouts, previously attributed to a power law process, a multi-exponential decay described the data well. Simulations demonstrated that a multi-exponential process can mimic a power law distribution. Conclusion and Significance: OSA alters sleep architecture dynamics by decreasing the temporal stability of NREM and REM sleep bouts. Multi-exponential fitting is superior to routine mono-exponential fitting...

Nature of the quantum metal in a two-dimensional crystalline superconductor

Tsen, Adam; Hunt, B.; Kim, Y. D.; Yuan, Z. J.; Jia, S.; Cava, R. J.; Hone, J.; Kim, Philip; Dean, C. R.; Pasupathy, A. N.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Português
Two-dimensional (2D) materials are not expected to be metals at low temperature owing to electron localization. Consistent with this, pioneering studies on thin films reported only superconducting and insulating ground states, with a direct transition between the two as a function of disorder or magnetic field. However, more recent works have revealed the presence of an intermediate quantum metallic state occupying a substantial region of the phase diagram, whose nature is intensely debated. Here, we observe such a state in the disorder-free limit of a crystalline 2D superconductor, produced by mechanical co-lamination of NbSe2 in an inert atmosphere. Under a small perpendicular magnetic field, we induce a transition from superconductor to the quantum metal. We find a unique power-law scaling with field in this phase, which is consistent with the Bose-metal model where metallic behaviour arises from strong phase fluctuations caused by the magnetic field.

Murine “Model” Monotheism: an Iconoclast at the Altar of Mouse

Libby, Peter
Fonte: Ovid Technologies (Wolters Kluwer Health) Publicador: Ovid Technologies (Wolters Kluwer Health)
Tipo: Artigo de Revista Científica
Português
Many use mice for contemporary cardiovascular research, as we should, given the power of the genetic and other tools developed to permit rigorous mechanistic experimentation in this species. We must remain mindful, nonetheless, of the reasons why the results of mouse experiments may not extrapolate readily to human disease. Large gaps separate our mouse experiments and clinical conditions. The differences arise from the genetic homogeneity of inbred mouse strains used in experimentation, the restricted exposure of mice to many microbes and a more monotonous microbiome in mice than in free-living rodents and humans, lack of comorbidities, focus on youthful mice and exaggerated experimental conditions contrived to speed up studies, and the lack of congruence between many experimental “models” and human cardiovascular conditions. We must and should continue to mine studies on mice for the incredibly valuable mechanistic insight they provide. Yet, we as a community could consider more carefully some of the barriers to glib extrapolation of the results of experiments in mice to human disease.

Self-renewing resident arterial macrophages arise from embryonic CX3CR1+ precursors and circulating monocytes immediately after birth

Ensan, Sherine; Li, Angela; Besla, Rickvinder; Degousee, Norbert; Cosme, Jake; Roufaiel, Mark; Shikatani, Eric A; El-Maklizi, Mahmoud; Williams, Jesse W; Robins, Lauren; Li, Cedric; Lewis, Bonnie; Yun, Tae Jin; Lee, Jun Seong; Wieghofer, Peter; Khattar, R
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
Português
Resident macrophages densely populate the normal arterial wall, yet their origins and the mechanisms that sustain them are poorly understood. Here we use gene-expression profiling to show that arterial macrophages constitute a distinct population among macrophages. Using multiple fate-mapping approaches, we show that arterial macrophages arise embryonically from CX3CR1+ precursors and postnatally from bone marrow–derived monocytes that colonize the tissue immediately after birth. In adulthood, proliferation (rather than monocyte recruitment) sustains arterial macrophages in the steady state and after severe depletion following sepsis. After infection, arterial macrophages return rapidly to functional homeostasis. Finally, survival of resident arterial macrophages depends on a CX3CR1-CX3CL1 axis within the vascular niche.

Einstein, history, and other passions : the rebellion against science at the end of the twentieth century

Holton, Gerald
Fonte: Harvard University Press Publicador: Harvard University Press
Tipo: Monograph or Book
Português
History of Science

The scientific imagination

Holton, Gerald
Fonte: Harvard University Press Publicador: Harvard University Press
Tipo: Monograph or Book
Português
History of Science

The advancement of science, and its burdens : with a new introduction

Holton, Gerald
Fonte: Harvard University Press Publicador: Harvard University Press
Tipo: Monograph or Book
Português
History of Science

Science and anti-science

Holton, Gerald
Fonte: Harvard University Press Publicador: Harvard University Press
Tipo: Monograph or Book
Português
History of Science

Thematic origins of scientific thought . Kepler to Einstein

Holton, Gerald
Fonte: Harvard University Press Publicador: Harvard University Press
Tipo: Monograph or Book
Português
History of Science