113 resultados para Delineamento longitudinal


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Cross-sectional research has shown that frequency of self-disclosure to outgroup members mediates the positive relationship between intergroup friendship and outgroup attitudes. The current research investigated the relationship between self-disclosure and attitudes in more depth. New undergraduate students were asked to nominate an ingroup or outgroup friend and then report the intimacy of their disclosures to them, their anxiety and attitudes towards a series of social groups, in the first week of the semester and 6 weeks later. Intimacy of disclosure predicted more positive attitudes towards outgroups over time, but this association was only found among participants who nominated an outgroup friend. In the ingroup friend condition, a negative association was found. These associations were mediated by general intergroup anxiety. These relationships highlight the importance of integrating theories of interpersonal and intergroup relations when investigating intergroup contact. Copyright (C) 2011 John Wiley & Sons, Ltd.

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Cognitive deficits are a key feature of recent-onset psychosis, but there is no consensus on whether such deficits are generalized or confined to specific domains. Besides, it is unclear whether cognitive deficits: a) are found in psychotic patients in samples from outside high-income countries; and b) whether they progress uniformly over time in schizophrenia and affective psychoses. We applied 12 tests organized into eight cognitive domains, comparing psychosis patients (n = 56, time from initial contact = 677.95+/-183.27 days) versus healthy controls (n = 70) recruited from the same area of Sao Paulo, Brazil. Longitudinal comparisons (digit span and verbal fluency) were conducted between a previous assessment of the subjects carried out at their psychosis onset, and the current follow-up evaluation. Psychosis patients differed significantly from controls on five domains, most prominently on verbal memory. Cognitive deficits remained detectable in separate comparisons of the schizophrenia subgroup and, to a lesser extent, the affective psychosis subjects against controls. Longitudinal comparisons indicated significant improvement in schizophrenia, affective psychoses, and control subjects, with no significant group-by-time interactions. Our results reinforce the view that there are generalized cognitive deficits in association with recent-onset psychoses, particularly of non-affective nature, which persist over time. (C) 2009 Elsevier Ireland Ltd. All rights reserved.

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This article provides the introduction to a special edition that presents for the first time a series of detailed country case studies concerned with the matter of organizational life cycles. Building on some recent scholarship, it begins by surveying the development of the field, before setting out some of the key methodological and theoretical issues and challenges involved in adopting a longitudinal perspective to the study of organizational change. It proposes that by capturing the variety of ways in which public sector organizations emerge, survive, and terminate, new perspectives on how administrative systems evolve can be presented and compared. © Taylor & Francis Group, LLC.

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In response to claims that the quality (and in particular linearity) of children's mental representation of number acts as a constraint on number development, we carried out a longitudinal assessment of the relationships between number line estimation, counting, and mathematical abilities. Ninety-nine 5-year-olds were tested on 4 occasions at 3 monthly intervals. Correlations between the 3 types of ability were evident, but while the quality of children's estimations changed over time and performance on the mathematical tasks improved over the same period, changes in one were not associated with changes in the other. In contrast to the earlier claims that the linearity of number representation is potentially a unique contributor to children's mathematical development, the data suggest that this variable is not significantly privileged in its impact over and above simple procedural number skills. We propose that both early arithmetic success and estimating skill are bound closely to developments in counting ability.

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Aflatoxins are dietary contaminants that are hepatocarcinogenic and immunotoxic and cause growth retardation in animals, but there is little evidence concerning the latter two parameters in exposed human populations. Aflatoxin exposure of West African children is known to be high, so we conducted a longitudinal study over an 8-month period in Benin to assess the effects of exposure on growth. Two hundred children 16-37 months of age were recruited from four villages, two with high and two with low aflatoxin exposure (50 children per village). Serum aflatoxin-albumin (AF-alb) adducts, anthropometric parameters, information on food consumption, and various demographic data were measured at recruitment (February) and at two subsequent time points (June and October). Plasma levels of vitamin A and zinc were also measured. AF-alb adducts increased markedly between February and October in three of the four villages, with the largest increases in the villages with higher exposures. Children who were fully weaned at recruitment had higher AF-alb than did those still partially breast-fed (p < 0.0001); the major weaning food was a maize-based porridge. There was no association between AF-alb and micronutrient levels, suggesting that aflatoxin exposure was not accompanied by a general nutritional deficiency. There was, however, a strong negative correlation (p < 0.0001) between AF-alb and height increase over the 8-month follow-up after adjustment for age, sex, height at recruitment, socioeconomic status, village, and weaning status; the highest quartile of AF-alb was associated with a mean 1.7 cm reduction in growth over 8 months compared with the lowest quartile. This study emphasizes the association between aflatoxin and stunting, although the underlying mechanisms remain unclear. Aflatoxin exposure during the weaning period may be critical in terms of adverse health effects in West African children, and intervention measures to reduce exposure merit investigation.

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Postpartum depression has been associated with parenting stress, impacting attachment and child development. However, the relation between antenatal depression or anxiety and postpartum parenting stress has not been investigated. We studied the effect of antenatal depression and anxiety and treatment with selective serotonin reuptake inhibitors and selective norepinephrine reuptake inhibitors (antidepressants [ADs]) on postpartum parenting stress.

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Canadians are living longer, and older persons are making up a larger share of the population (14% in 2006, projected to rise to 20% by 2021). The Canadian Longitudinal Study on Aging (CLSA) is a national longitudinal study of adult development and aging that will recruit 50,000 Canadians aged 45 to 85 years of age and follow them for at least 20 years. All participants will provide a common set of information concerning many aspects of health and aging, and 30,000 will undergo an additional in-depth examination coupled with the donation of biological specimens (blood and urine). The CLSA will become a rich data source for the study of the complex interrelationship among the biological, physical, psychosocial, and societal factors that affect healthy aging. © 2009 Canadian Association on Gerontology.

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Introduction: An association between depression and folate has been found in clinical studies. Depression and dementia can contribute to nutritional deficiency. This study clinical depression in in octo/nonagenarians from the BELFAST study.
Method: In the BELFAST study, 38 free-living octo/nonagenarians (mean age 82 years), who apparently well and cognitively intact were followed up at 5 years and assessed using the Geriatric Depression Scale (GDS), Folstein (30 point), Mini Nutritional Assessment Tool (MNA) together with serum folate and vitamin B12 levels.
Results: Mean GDS was 3.4 (SD 2.5), serum folate 7.1 umol/l (SD 5.3) and B12 553 umol/l (458). With mean MNA and Folstein -25.8 (SD 2.7) and 27.6 (SD 2.7) respectively with no sex difference (p = 0.78; p = 0.36). 25% of subjects showed a GDS >5 indicating risk of mild depression and 21% had compromised nutritional status. MNA associated with GDS in male (r2 = 0.56 p = 0.01), but not in female elderly subjects (r2 = 0.01; p = 0.44). GDS score and lower serum folate were associated (r2 = -0.23; p = 0.01).
Conclusion: Overall there was the suggestion that nutritional status and depression might be linked in male subjects at 5 year follow-up in octo/nonagenarians from the BEFLAST study. The lower folate in subjects categorised at risk of mild depression might suggest vitamin supplementation could be useful.

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Purpose: To investigate the clinical and electrophysiologic natural history of Stargardt disease and correlate with the genotype. Design: Cohort study of 59 patients. Methods: Clinical history, examination, and electrophysiologic assessment were undertaken in a longitudinal survey. Patients were classified into 3 groups based on electrophysiologic findings, as previously published: Group 1 had dysfunction confined to the macula; Group 2 had macular and generalized cone system dysfunction; and Group 3 had macular and both generalized cone and rod system dysfunction. At baseline, there were 27 patients in Group 1, 17 in Group 2, and 15 in Group 3. Amplitude reduction of >50% in the relevant electroretinogram (ERG) component or a peak time shift of >3 ms for the 30 Hz flicker ERG or bright flash a-wave was considered clinically significant ERG deterioration. Molecular screening of ABCA4 was undertaken. Results: The mean age at baseline was 31.7 years, with the mean follow-up interval being 10.5 years. A total of 22% of patients from Group 1 showed ERG group transition during follow-up, with 11% progressing to Group 2 and 11% to Group 3. Forty-seven percent of patients in Group 2 progressed to Group 3. There was clinically significant ERG deterioration in 54% of all subjects: 22% of Group 1, 65% of Group 2, and 100% of Group 3. At least 1 disease-causing ABCA4 variant was identified in 47 patients. Conclusions: All patients with initial rod ERG involvement demonstrated clinically significant electrophysiologic deterioration; only 20% of patients with normal full-field ERGs at baseline showed clinically significant progression. Such data assist counseling by providing more accurate prognostic information and are also highly relevant in the design, patient selection, and monitoring of potential therapeutic interventions. © 2013 Elsevier Inc. All rights reserved.