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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Non-monotonic effect of growth temperature on carrier collection in SnS solar cells

Chakraborty, Ritayan; Steinmann, Vera; Mangan, N; Brandt, R. E.; Poindexter, J. R.; Jaramillo, R; Mailoa, J. P.; Hartman, K.; Polizzotti, A.; Yang, Chuanxi; Gordon, Roy Gerald; Buonassisi, T.
Fonte: AIP Publishing Publicador: AIP Publishing
Tipo: Artigo de Revista Científica
EN_US
e quantify the effects of growth temperature on material and deviceproperties of thermally evaporated SnSthin-films and test structures. Grain size, Hall mobility, and majority-carrier concentration monotonically increase with growth temperature. However, the charge collection as measured by the long-wavelength contribution to short-circuit current exhibits a non-monotonic behavior: the collection decreases with increased growth temperature from 150 °C to 240 °C and then recovers at 285 °C. Fits to the experimental internal quantum efficiency using an opto-electronic model indicate that the non-monotonic behavior of charge-carrier collection can be explained by a transition from drift- to diffusion-assisted components of carrier collection. The results show a promising increase in the extracted minority-carrier diffusion length at the highest growth temperature of 285 °C. These findings illustrate how coupled mechanisms can affect early stage device development, highlighting the critical role of direct materials property measurements and simulation.; Chemistry and Chemical Biology

A Neuroidal Architecture for Cognitive Computation

Valiant, Leslie G.
Fonte: Harvard University Publicador: Harvard University
Tipo: Research Paper or Report
EN_US
An architecture is described for designing systems that acquire and manipulate large amounts of unsystematized, or so-called commonsense, knowledge. Its aim is to exploit to the full those aspects of computational learning that are known to offer powerful solutions in the acquisition and maintenance of robust knowledge bases. The architecture makes explicit the requirements on the basic computational tasks that are to be performed and is designed to make these computationally tractable even for very large databases. The main claims are that (i) the basic learning tasks are tractable and (ii) tractable learning offers viable approaches to a range of issues that have been previously identified as problematic for artificial intelligence systems that are entirely programmed. In particular, attribute efficiency holds a central place in the definition of the learning tasks, as does also the capability to handle relational information efficiently. Among the issues that learning offers to resolve are robustness to inconsistencies, robustness to incomplete information and resolving among alternatives.; Engineering and Applied Sciences

A Collaborative Approach to Newspaper Layout

Lubin, Benjamin
Fonte: Harvard University Publicador: Harvard University
Tipo: Research Paper or Report
EN_US
Engineering and Applied Sciences

Multi-Domain Sandboxing: An Overview

Fischer, Robert; Kao, Ming-Yang
Fonte: Harvard University Publicador: Harvard University
Tipo: Research Paper or Report
EN_US
In today’s computing world, computer code is most often developed on one computer and run on another. Code is increasingly downloaded and run on a casual basis, as the line between code and data is blurred and executable code is found in web pages, spreadsheets, word processor documents, etc. Not having the knowledge or resources to verify the lack of malicious intent of that code, the user must rely on here say and technological solutions to ensure that casually downloaded code does not damage his computer or steal his data. Building on the past concepts of sandboxing and multi-level security, we propose multi-domain sandboxing. This security system allows programs more flexibility than traditional sandboxing, while preventing them from malicious actions. We propose applications of this new technology to the web, increasing the functionality and security possible in web applications.; Engineering and Applied Sciences

Comments on Michael Strevens's Depth

Hall, Edward J
Fonte: Wiley-Blackwell Publicador: Wiley-Blackwell
Tipo: Artigo de Revista Científica
EN_US
Philosophy

Out of Africa: Tocqueville's Imperial Voyages

Welch, Cheryl B.
Fonte: Middle East Studies Association of North America (MESA) Publicador: Middle East Studies Association of North America (MESA)
Tipo: Artigo de Revista Científica
EN_US
Government

Evolution of Highly Polymorphic T Cell Populations in Siblings with the Wiskott-Aldrich Syndrome

Remold, Susanna K.; Lutskiy, Maksim; Park, Jun Y.; Remold-O'Donnell, Eileen
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
EN_US
Population level evolutionary processes can occur within a single organism when the germ line contains a mutation that confers a cost at the level of the cell. Here we describe how multiple compensatory mutations arose through a within-individual evolutionary process in two brothers with the immune deficiency Wiskott-Aldrich Syndrome (WAS). As a result, both brothers have T lymphocyte populations that are highly polymorphic at the locus of the germ line defect, and no single allele achieves fixation. WASP, the gene product affected in this disease, is specific to white blood cells where it is responsible for regulating actin cytoskeleton dynamics in a wide range of cellular responses. The brothers inherited a rare allele predicted to result in truncated WASP lacking the carboxy-terminal VCA domains, the region that directly catalyzes actin filament generation. Although the brothers' T cell populations are highly polymorphic, all share a corrective effect relative to the inherited allele in that they restore the VCA domain. This indicates massive selection against the truncated germ line allele. No single somatic allele becomes fixed in the circulating T cell population of either brother, indicating that a regulated step in maturation of the affected cell lineage is severely compromised by the germ line allele. Based on the finding of multiple somatic mutations...

An AICD-based functional screen to identify APP metabolism regulators

Khandelwal, Preeti J; Chakraborty, Ranjita; Cuellar, Trinna L; Sarangi, Srikant; Patel, Shyam A; Cosentino, Christopher P; Lee, Jeremy C; Saunders, Aleister J; Zhang, Can; O'Connor, Michael; Tanzi, Rudolph Emile
Fonte: BioMed Central Publicador: BioMed Central
Tipo: Artigo de Revista Científica
EN_US
Background: A central event in Alzheimer's disease (AD) is the regulated intramembraneous proteolysis of the β-amyloid precursor protein (APP), to generate the β-amyloid (Aβ) peptide and the APP intracellular domain (AICD). Aβ is the major component of amyloid plaques and AICD displays transcriptional activation properties. We have taken advantage of AICD transactivation properties to develop a genetic screen to identify regulators of APP metabolism. This screen relies on an APP-Gal4 fusion protein, which upon normal proteolysis, produces AICD-Gal4. Production of AICD-Gal4 induces Gal4-UAS driven luciferase expression. Therefore, when regulators of APP metabolism are modulated, luciferase expression is altered. Results: To validate this experimental approach we modulated α-, β-, and γ-secretase levels and activities. Changes in AICD-Gal4 levels as measured by Western blot analysis were strongly and significantly correlated to the observed changes in AICD-Gal4 mediated luciferase activity. To determine if a known regulator of APP trafficking/maturation and Presenilin1 endoproteolysis could be detected using the AICD-Gal4 mediated luciferase assay, we knocked-down Ubiquilin 1 and observed decreased luciferase activity. We confirmed that Ubiquilin 1 modulated AICD-Gal4 levels by Western blot analysis and also observed that Ubiquilin 1 modulated total APP levels...

A PHARMACIST'S DUTY TO WARN: SOUND ECONOMICS, EFFECTIVE MEDICINE, AND CONSISTENT WITH DRUG REGULATION THEORY

Trivedi, Harit U.
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
This paper argues in favor of a duty to warn on the part of the pharmacist. In the next section, I begin with a discussion of two common regulatory approaches to warning patients of prescription drug hazards and flesh out their inadequacies. In section three, I will discuss the legal status of the pharmacist's duty to warn and the negative reaction to the current trends in that doctrine. Then, in section four, I will go on to propose an alternative model for the duty to warn, explore arguments in support of this model, and finally attempt to reconcile the proposed duty to warn scheme with the primary theoretical underpinnings of drug regulation in the United States.

First Amendment Scrutiny of FDA'S Fight Against Misbranding: Placing Labeling on the Spectrum of Speech

Weissman, Kenneth I.
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
In order to further the Food and Drug Administration's (FDA) mission of "assur[ing] that the products it regulates are safe and truthfully labeled," the Federal Food, Drug, and Cosmetic Act (FD&C Act) gives FDA the power to enforce prohibitions on labeling that causes a food, drug, cosmetic, or medical device to be misbranded. The FD&C Act defines labeling as "all labels and other written, printed, or graphic matter (1) upon any article or any of its containers or wrappers, or (2) accompanying such article." Because of the expansive nature of this definition, independently written pamphlets, newspapers, and books that accompany products covered by the FD&C Act constitute labeling in certain circumstances. This exacerbates the tension between the First Amendment's free speech guarantee and FDA's mandate, and raises the question of how courts should scrutinize FDA's ability to seize or enjoin the sale of misleading labeling. The importance of both the Free Speech Clause and the protection of consumers makes this a difficult issue to resolve, and as of yet, "no case has squarely confronted the issue."

The H2 Blockers' Rx-to OTC Switch: For Whom Will It Spell Relief?

Kisloff, Michelle A.
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
Tylenol. Advil. Monistat 7. Imodium AD. These are some of the most commonly used, widely available, and successful drugs in the United States. All of them began as drugs only available by a prescription. All of them made a successful prescription-only to over-the-counter (Rx-to-OTC) switch through the switch" mechanisms of the Food and Drug Administration (FDA). Due to the amount of money that pharmaceutical companies can make with an Rx-to-OTC switch, the FDA has received dozens of switch requests in the last few years, and it expects to receive many more in the near future.

THE EFFECT OF FDA'S POLICIES ON THE DECREASING EFFECTIVENESS OF ANTIBIOTICS

Derzko, Natalie
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
This paper will evaluate the effect that the Food and Drug Administration (FDA) has had on the drug resistance problem and will consider how the FDA could tailor its regulatory policies to better safeguard the effectiveness of the American antibiotic supply. The discussion will be divided in two parts. First, we will look at the consequences of FDA's approach to controlling the dissemination of antibiotics. Secondly, we will examine the effect that FDA policies have had on the development of new antibiotics. In both parts, we will consider how the FDA's present approach may be improved upon.

MISPLACED MANDATE: AN EXAMINATION OF FDA'S SILICONE BREAST IMPLANT POLICY

Granoff, Susan N.
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
Why did the Food and Drug Administration (FDA) suddenly call for a forty-five day moratorium on silicone gel breast implants in 1 992 and then ban virtually all cosmetic breast implants' only months after an FDA advisory panel had recommended that silicone breast implants remain on the market for both reconstructive and cosmetic uses?2 Is FDA's policy, which remains in force today, justified? What is FDA's mandate, and has FDA overstepped it in banning cosmetic breast implants?

What the FDA Doesn't Want You to Hear: Regulation of Tobacco Advertising and Disease-Specific Health Claims (A Hypothetical and a Fictional Discussion)

Friedman, Andy
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
A hypothetical and fictional discussion of a law that would ban political advertising on food products.

The Department of Agriculture's Regulation of Poultry Under the Poultry Products Inspection Act of 1957

Coble, Charles
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
The purpose of this paper is to investigate the reasons how conflicts between the USDA and FDA create obstacles to effective public health policy exist in the United States. I will begin my investigation by briefly outlining the earlier chronology of meat regulation in the United States. When I reach the period of time in which poultry inspection became mandatory, I will engage in a more in depth historical analysis of the reasons why the system which prevails today developed as it did. This portion of the paper is based largely upon Congressional hearings, reports, and floor debate. I will then conclude by noting proposals for reform and offer my own assessment of division of food regulation between USDA and FDA.

FDA's Role in the Silicone Breast Implant Story

Friedland, Shelly
Fonte: Harvard University Publicador: Harvard University
Tipo: Paper (for course/seminar/workshop)
EN_US
This paper will present the history of FDA's policy regarding silicone breast implants, as well as an analysis of the strengths and weaknesses of these actions. Although FDA Commissioner David Kessler's essential judgment that the implants had not been proven safe was sound, both in evaluating the nature and quality of the scientific evidence available, and in adhering to the Congressional guidelines for the type of proof necessary before a device can be approved for marketing, there were many flaws along the way.

Sparrows, Hares and Doves: 'Source Criticism' and the Limits of Plurality

Thomas, Richard F.
Fonte: Texas Tech University Press Publicador: Texas Tech University Press
Tipo: Artigo de Revista Científica
EN_US
The Classics

The Old Man Revisited: Memory, Reference and Genre in Virg., Geo. 4.116–48

Thomas, Richard F.
Fonte: Istituti editoriali e poligrafici internazionali Publicador: Istituti editoriali e poligrafici internazionali
Tipo: Artigo de Revista Científica
EN_US
The Classics

Tito Vespasiano Strozzi's "Ad psyttacum": A Renaissance Latin Poet Parrots the Past

Ziolkowski, Jan Michael
Fonte: Harvard University Library Publicador: Harvard University Library
Tipo: Artigo de Revista Científica
EN_US
The Classics

Generosity: A Winner's Advice

Nowak, Martin A.
Fonte: Nature Publishing Group Publicador: Nature Publishing Group
Tipo: Artigo de Revista Científica
EN_US
Mathematical models can reveal how prosocial human behaviour — and even social intelligence and language — have evolved, argues Martin A. Nowak.; Mathematics; Organismic and Evolutionary Biology