Ação afirmativa nos Estados Unidos: breve síntese da jurisprudência e da pesquisa social científica

Este artigo pretende apresentar sucintamente aos leitores não familiarizados com a ação afirmativa nos Estados Unidos seus antecedentes históricos e atual status legislativo e, de maneira mais abrangente, abordar questões empíricas das ciências sociais relacionadas com a ação afirmativa. Abordam-se especificamente as falhas e/ou limitações da pesquisa que sustenta a hipótese da disparidade educacional, da evidência empírica da "disparidade científica", e a afirmação de que a ação afirmativa baseada em classe social seria tão ou quase tão eficaz na promoção da diversidade racial quanto a ação afirmativa baseada em raça. Examinam-se especificamente os trabalhos de Richard Sander, Richard Kahlenberg, Doug Williams e Peter Arcidiacono. O artigo também afirma que o casoBakke, que apresentou, pela primeira vez, uma decisão da Suprema Corte sobre a ação afirmativa, desvirtuou a jurisprudência a respeito da ação afirmativa na educação e as discussões sobre o tema, de modo a provocar efeitos lamentáveis e duradouros

Lack of effect of intravenous administration on time to respond to azathioprine for steroid-treated Crohn's disease

AbstractBackground & Aims: Azathioprine is effective for Crohn's disease but acts slowly. A loading dose may decrease the time to response. Methods: A placebo-controlled study was conducted in patients with active Crohn's disease despite prednisone treatment. Patients were randomized to a 36-hour infusion of azathioprine, 40 mg/kg (51 patients), or placebo (45 patients) followed by oral azathioprine, 2 mg/kg, for 16 weeks. Prednisone was tapered over 5 weeks. The primary outcome measure was complete remission at week 8, defined by discontinuation of prednisone and a Crohn's Disease Activity Index of ≤150 points. Erythrocyte concentrations of the azathioprine active metabolite, 6-thioguanine nucleotide, were measured. Results: At week 8, 13 patients (25%) were in complete remission in the azathioprine-loaded group compared with 11 patients (24%) in the placebo group. The frequency of complete remission did not increase after 8 weeks in either group. Both groups achieved steady state of 6-thioguanine nucleotide by week 2, and no differences were found in mean concentrations between the groups. There were no significant differences in the frequency of adverse events between the groups. Conclusions: A loading dose does not decrease the time to response in patients with steroid-treated Crohn's disease beginning azathioprine therapy. Steady state of erythrocyte 6-thioguanine nucleotide and complete response occurred earlier than previously reported.GASTROENTEROLOGY 1999;117:527-53

A Pre-Landing Assessment of Regolith Properties at the InSight Landing Site

This article discusses relevant physical properties of the regolith at the Mars InSight landing site as understood prior to landing of the spacecraft. InSight will land in the northern lowland plains of Mars, close to the equator, where the regolith is estimated to be ≥3--5 m thick. These investigations of physical properties have relied on data collected from Mars orbital measurements, previously collected lander and rover data, results of studies of data and samples from Apollo lunar missions, laboratory measurements on regolith simulants, and theoretical studies. The investigations include changes in properties with depth and temperature. Mechanical properties investigated include density, grain-size distribution, cohesion, and angle of internal friction. Thermophysical properties include thermal inertia, surface emissivity and albedo, thermal conductivity and diffusivity, and specific heat. Regolith elastic properties not only include parameters that control seismic wave velocities in the immediate vicinity of the Insight lander but also coupling of the lander and other potential noise sources to the InSight broadband seismometer. The related properties include Poisson’s ratio, P- and S-wave velocities, Young’s modulus, and seismic attenuation. Finally, mass diffusivity was investigated to estimate gas movements in the regolith driven by atmospheric pressure changes. Physical properties presented here are all to some degree speculative. However, they form a basis for interpretation of the early data to be returned from the InSight mission.Additional co-authors: Nick Teanby and Sharon Keda

Novel genetic loci associated with hippocampal volume

The hippocampal formation is a brain structure integrally involved in episodic memory, spatial navigation, cognition and stress responsiveness. Structural abnormalities in hippocampal volume and shape are found in several common neuropsychiatric disorders. To identify the genetic underpinnings of hippocampal structure here we perform a genome-wide association study (GWAS) of 33,536 individuals and discover six independent loci significantly associated with hippocampal volume, four of them novel. Of the novel loci, three lie within genes (ASTN2, DPP4 and MAST4) and one is found 200 kb upstream of SHH. A hippocampal subfield analysis shows that a locus within the MSRB3 gene shows evidence of a localized effect along the dentate gyrus, subiculum, CA1 and fissure. Further, we show that genetic variants associated with decreased hippocampal volume are also associated with increased risk for Alzheimer's disease (rg =-0.155). Our findings suggest novel biological pathways through which human genetic variation influences hippocampal volume and risk for neuropsychiatric illness

Uroleucon formosanum (Takahashi) (Homoptera: Aphididae) Found on Youngia japonica (L.) DC on Guam and Rota in the Mariana Islands

Scientific note.Uroleucon formosanum (Homoptera: Aphididae) was collected from Asiatic (Oriental) hawksbeard, Youngia japonica, on Guam and Rota in 2003. These collections constitute a significant range expansion for U. formosanum into the western Pacific region. The aphid and its host plant were likely accidentally introduced to the islands in cargo or by travelers returning from known host regions in eastern Asia and Japan

Uroleucon formosanum (Takahashi) and Uroleucon sonchellum (Monell) (Hemiptera, Aphididae): Morphological Comparison and Diagnosis

Uroleucon formosanum (Takahashi) and U. sonchellum (Monell) (Hemiptera: Aphididae: Aphidinae: Macrosiphini) are species of very similar morphology. Descriptions, illustrations, morphological measurements and a diagnosis are provided

Capital investment appraisal: a new risk premium model

Net Present Value (NPV) is the principal valuation model of the financial literature. Firms are accordingly directed, as a matter of good practice, to adopt the model for selecting investment projects, yet questionnaire surveys show that the adoption rate has been very slow and the quality of usage questionable. In particular, alternative risk measures are popular amongst practitioners. In this paper we remodel the treatment of risk in the NPV model based on assumptions that seem realistic in an organizational or operational, as opposed to a personal, investment context. We derive formulas for calculating: the appropriate discount rate, a 'risk horizon' (where the risk premium exceeds the expected value), and a maximum default hazard point for projects. These measures provide a rationale for non-NPV approaches to risk measurement in questionnaire responses and offer a practical benefit to investors