quinta-feira, 20 de outubro de 2011


NATURE | LETTER

Verbal and non-verbal intelligence changes in the teenage brain

Nature
 
(2011)
 
doi:10.1038/nature10514
Received
 
 
Accepted
 
 
Published online
 
Intelligence quotient (IQ) is a standardized measure of human intellectual capacity that takes into account a wide range of cognitive skills1. IQ is generally considered to be stable across the lifespan, with scores at one time point used to predict educational achievement and employment prospects in later years1. Neuroimaging allows us to test whether unexpected longitudinal fluctuations in measured IQ are related to brain development. Here we show that verbal and non-verbal IQ can rise or fall in the teenage years, with these changes in performance validated by their close correlation with changes in local brain structure. A combination of structural and functional imaging showed that verbal IQ changed with grey matter in a region that was activated by speech, whereas non-verbal IQ changed with grey matter in a region that was activated by finger movements. By using longitudinal assessments of the same individuals, we obviated the many sources of variation in brain structure that confound cross-sectional studies. This allowed us to dissociate neural markers for the two types of IQ and to show that general verbal and non-verbal abilities are closely linked to the sensorimotor skills involved in learning. More generally, our results emphasize the possibility that an individual’s intellectual capacity relative to their peers can decrease or increase in the teenage years. This would be encouraging to those whose intellectual potential may improve, and would be a warning that early achievers may not maintain their potential.

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doi:10.1016/j.aos.2011.05.002 | How to Cite or Link Using DOI
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Capital rationing, competition, and misrepresentation in budget forecasts
Alexander Brüggena, Corresponding Author Contact Information, E-mail The Corresponding Author, Joan Luftb, E-mail The Corresponding Author
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aDepartment of Accounting and Information Management, School of Business and Economics, Maastricht University, PO Box 616, 6200 MD Maastricht, The Netherlands
bDepartment of Accounting and Information Systems, Broad Graduate School of Management, Michigan State University, East Lansing, MI 48824-1121, USA
Available online 14 July 2011.

Abstract

In this study, we ask: how does the intensity of internal competition for resources affect the communication of private information in an organization? Although competition between different divisions or units for resources is pervasive in many organizations, much of the accounting literature examines non-competitive resource allocation and thus does not provide guidance on this point. To address this question, we conduct an experiment in which a principal allocates capital among three agents, who can each propose a single project. In the high (medium, low) competition condition, principals have sufficient funds to accept only one (only two, all three) projects. We test three competing predictions based on prior literature: (1) Agents will make maximum credible misrepresentations under both medium and high competition, in order to maximize their chance of receiving capital. (2) Agents will weigh the disutility of misrepresentation against the expected utility of receiving project funding, resulting in more misrepresentation at medium than at high levels of competition, because the probability of receiving funding is lower in high competition. (3) Misrepresentation will be highest in high competition, because agents will interpret the high-competition setting as one in which misrepresentation is most necessary to win funding and most socially appropriate. Consistent with the second prediction, misrepresentation is highest in medium competition. These results suggest that a medium level of competition is a less favorable setting for voluntary information-sharing than either uncompetitive or high competition settings, and therefore costly formal enforcement mechanisms such as post-audits are likely to be more valuable in medium-competition settings.

Corresponding Author Contact InformationCorresponding author.
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Veja oito dicas para fazer o Enem 2011

 
 
As provas do Enem são do tipo objetivas, ou seja, com questões de múltipla escolha. Teste aqui seu inglês e veja se você está preparadoDivulgação
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As provas do Enem são do tipo objetivas, ou seja, com questões de múltipla escolha. Teste aqui seu inglês e veja se você está preparado
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Enem 2011

Enem 2011
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Chronic phase of Chagas disease: why should it be treated? 
A comprehensive review


José Rodrigues Coura/+, José Borges-Pereira

Laboratório de Doenças Parasitárias, Instituto Oswaldo Cruz-Fiocruz, Av. Brasil 4365, 21040-360 Rio de Janeiro, RJ, Brasil

The pathogenesis and evolutive pattern of Chagas disease suggests that the chronic phase should be more 
widely treated in order to (i) eliminate  Trypanosoma cruzi and prevent new inflammatory foci and the extension of tissue lesions, (ii) promote tissue regeneration to prevent fibrosis, (iii) reverse existing fibrosis, (iv) prevent cardiomyopathy, megaoesophagus and megacolon and (v) reduce or eliminate cardiac block and arrhythmia. 
All cases of the indeterminate chronic form of Chagas disease without contraindications due to other concomitant diseases or pregnancy should be treated and not only cases involving children or recently infected cases. Patients with chronic Chagas cardiomyopathy grade II of the New York Heart Association classification should be treated with specific chemotherapy and grade III can be treated according to medical-patient decisions. We are proposing the following new strategies for chemotherapeutic treatment of the chronic phase of Chagas disease: 
(i) repeated short-term treatments for 30 consecutive days and interval of 30-60 days for six months to one yearand (ii) combinations of drugs with different mechanisms of action, such as benznidazole + nifurtimox, benznidazole or nifurtimox + allopurinol or triazole antifungal agents, inhibition of sterol synthesis.

Key words: Chagas disease - chronic phase - chemotherapy - new strategies - repeated treatment combination of drug
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