排序方式： 共有80条查询结果，搜索用时 31 毫秒
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Diego Giulliano Destro Christofaro Selma Maffei De Andrade Arthur Eumann Mesas Rômulo Araújo Fernandes José Cazuza Farias Júnior 《European Journal of Sport Science》2016,16(4):498-506
Objectives: To analyse the associations between high screen time and overweight, poor dietary habits and physical activity in adolescents according to sex. Methods: The study comprised 515 boys and 716 girls aged 14–17 years from Londrina, Brazil. Nutritional status (normal weight or overweight/obese) was assessed by calculating the body mass index. Eating habits and time spent in physical activity were reported using a questionnaire. The measurement of screen time considered the time spent watching television, using a computer and playing video games during a normal week. Associations between high screen time and dependent variables (nutritional status, eating habits and physical activity levels) were assessed by binary logistic regression, adjusted for sociodemographic and lifestyle variables. Results: Most adolescents (93.8% of boys and 87.2% of girls) spent more than 2 hours per day in screen-time activities. After adjustments, an increasing trend in the prevalence of overweight and physical inactivity with increasing time spent on screen activities was observed for both sexes. Screen times of >4 hours/day compared with <2 hours/day were associated with physical inactivity, low consumption of vegetables and high consumption of sweets only in girls and the consumption of soft drinks in both sexes. Conclusions: The frequency of overweight and physical inactivity increased with increasing screen time in a trending manner and independently of the main confounders. The relationship between high screen time and poor eating habits was particularly relevant for adolescent girls. 相似文献
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Caio Moura Daoud Edleno Silva de Moura David Fernandes Altigran Soares da Silva Cristian Rossi Andre Carvalho 《Information Retrieval》2017,20(3):292-316
In this paper, we present Waves, a novel document-at-a-time algorithm for fast computing of top-k query results in search systems. The Waves algorithm uses multi-tier indexes for processing queries. It performs successive tentative evaluations of results which we call waves. Each wave traverses the index, starting from a specific tier level i. Each wave i may insert only those documents that occur in that tier level into the answer. After processing a wave, the algorithm checks whether the answer achieved might be changed by successive waves or not. A new wave is started only if it has a chance of changing the top-k scores. We show through experiments that such lazy query processing strategy results in smaller query processing times when compared to previous approaches proposed in the literature. We present experiments to compare Waves’ performance to the state-of-the-art document-at-a-time query processing methods that preserve top-k results and show scenarios where the method can be a good alternative algorithm for computing top-k results. 相似文献
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Sandra Fernandes Luís Querido Arlette Verhaeghe Catarina Marques Luísa Araújo 《Reading and writing》2017,30(9):1987-2007
This study investigated direct and indirect effects between oral reading fluency, vocabulary and reading comprehension across reading development in European Portuguese. Participants were 329 children attending basic education, from grade 1 to grade 6. The results of path analyses showed that text reading fluency is much more dependent on the foundational skills of word recognition than reading comprehension, and the later, in turn, depends crucially on the specific constituent skill of text reading fluency. Text reading fluency has a significant influence on vocabulary from the beginning, but vocabulary contributed to reading comprehension only in more advanced grades. These results, obtained with an orthography of intermediate depth, are in line with the Simple View of Reading (SVR). However, they also highlight the importance of textual cues—besides the pivotal role of decoding—from the beginning of learning to read, which must be taken into account in the SVR. 相似文献
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Luiz Marcelo de Carvalho Jorge Megid Neto Clarice Sumi Kawasaki Dalva Maria Bianchini Bonotto Ivan Amorosino do Amaral José Artur Barroso Fernandes 《Environmental Education Research》2018,24(10):1447-1463
AbstractThis article discusses an analysis of abstracts of Brazilian theses and dissertations on environmental education from a database organised and maintained by a group of researchers in the EArt Project (www.earte.net). In presenting extracts of key trends in this dataset, our aim is to provide a snapshot of the many possible approaches to, and histories of, Brazilian environmental education research. The data also allow us to raise some questions that explore possible ‘blank spots’, ‘blind spots’ and ‘bald spots’ in Brazilian research on environmental education. Given the temporal development of the research field since the 1980s, we illustrate these ‘spots’ by exploring data related to epistemological and methodological diversity, from the viewpoint of knowledge areas as well as the graduate programmes that have been developing research on environmental education. Finally, we draw a picture of the methodological trends that have been privileged by Brazilian researchers, and pose questions as to what is needed in shaping an agenda for research on environmental education in Brazil into the future. 相似文献
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Geraldo W. Rocha Fernandes António M. Rodrigues Carlos Alberto Ferreira 《Research in Science Education》2018,48(5):1071-1106
This study investigated some of the aspects that characterise the understanding of the Nature of Science (NOS) and Nature of Technology (NOT) of 20 children and youths from different countries who perform scientific and technological activities in a non-formal teaching and learning setting. Data were collected using a questionnaire and semistructured interviews. A categorical instrument was developed to analyse the participants’ conceptions of the following subjects: (1) the role of the scientist, (2) NOS and (3) NOT. The results suggest that the participants had naïve conceptions of NOS that are marked by empirical and technical-instrumental views. They characterised NOT primarily as an instrumental apparatus, an application of knowledge and something important that is part of their lives. They exhibited a stereotypical understanding of the role of the scientist (development of methods, demonstration of facts, relationship with technological devices, etc.). 相似文献
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Fernandes E Pacheco A Penha-Gonçalves C 《Journal of Zhejiang University. Science. B》2007,8(11):792-801
In standard interval mapping (IM) of quantitative trait loci (QTL), the QTL effect is described by a normal mixture model. When this assumption of normality is violated, the most commonly adopted strategy is to use the previous model after data transformation. However, an appropriate transformation may not exist or may be difficult to find. Also this approach can raise interpretation issues. An interesting alternative is to consider a skew-normal mixture model in standard IM, and the resulting method is here denoted as skew-normal IM. This flexible model that includes the usual symmetric normal distribution as a special case is important, allowing continuous variation from normality to non-normality. In this paper we briefly introduce the main peculiarities of the skew-normal distribution. The maximum likelihood estimates of parameters of the skew-normal distribution are obtained by the expectation-maximization (EM) algorithm. The proposed model is illustrated with real data from an intercross experiment that shows a significant departure from the normality assumption. The performance of the skew-normal IM is assessed via stochastic simulation. The results indicate that the skew-normal IM has higher power for QTL detection and better precision of QTL location as compared to standard IM and nonparametric IM. 相似文献
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V. L. C. Fernandes D. K. Bhasin S. V. Rana 《Indian journal of clinical biochemistry : IJCB》2006,21(1):169-172
The aim of this study was to measure the levels of lactase, sucrase, maltase, leucine amino peptidase and gamma-glutamyl transpeptidase
in duodenum of Indian patients with duodenal ulcer. The effect of duodenum inflammation on these brush border enzymes has
also been analysed in this study. Levels of lactase, sucrase, maltase, leucine amino peptidase and gamma-glutamyl transpeptidase
were assessed in duodenal biopsies of 20 patients of duodenal ulcer and 20 non-ulcer dyspepsia. The duodenal biopsy specimens
were also examined histopathologically for presence or absence of inflammation. There was no significant difference (p>0.05)
in the activity of above mentioned enzyme levels in both the groups. Only levels of gamma-glutamyl transpeptidase were significantly
decreased in patients of duodenal ulcer with duodenal inflammation. This study shows that only the levels of gamma-glutamyl
transpeptidase were significantly decreased in patients of duodenal ulcer with inflammation but no change in duodenal enzymes
due to duodenal ulcer as compared to non-ulcer dyspepsia. 相似文献
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Vicente Javier Clemente-Suárez Athanasios Dalamitros João Ribeiro Ana Sousa Ricardo J. Fernandes J. Paulo Vilas-Boas 《European Journal of Sport Science》2017,17(4):425-432
This study analysed the effects of two different periodization strategies on physiological parameters at various exercise intensities in competitive swimmers. Seventeen athletes of both sexes were divided to two groups, the traditional periodization (TPG, n?=?7) and the reverse periodization group (RPG, n?=?10). Each group followed a 10-week training period based on the two different periodization strategies. Before and after training, swimming velocity (SV), energy expenditure (EE), energy cost (EC) and percentage of aerobic (%Aer) and anaerobic (%An) energy contribution to the swimming intensities corresponding to the aerobic threshold (AerT), the anaerobic threshold (AnT) and the velocity at maximal oxygen uptake (vVO2max) were measured. Both groups increased the %An at the AerT and AnT intensity (P?≤?.05). In contrast, at the AnT intensity, EE and EC were only increased in TPG. Complementary, %Aer, %An, EE and EC at vVO2max did not alter in both groups (P?>?.05); no changes were observed in SV in TPG and RPG at all three intensities. These results indicate that both periodization schemes confer almost analogous adaptations in specific physiological parameters in competitive swimmers. However, given the large difference in the total training volume between the two groups, it is suggested that the implementation of the reverse periodization model is an effective and time-efficient strategy to improve performance mainly for swimming events where the AnT is an important performance indicator. 相似文献