1,689 research outputs found

    Reflecting on non-reflective action: An exploratory think-aloud study of self-report habit measures

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    Objectives. Within health psychology, habit – the tendency to enact action automatically as a learned response to contextual cues – is most commonly quantified using the ‘Self-Report Habit Index’, which assesses behavioural automaticity, or measures combining self-reported behaviour frequency and context stability. Yet, the use of self-report to capture habit has proven controversial. This study used ‘think aloud’ methods to investigate problems experienced when completing these two measures. Design. Cross-sectional survey with think-aloud study. Methods. Twenty student participants narrated their thoughts while completing habit measures applied to four health-related behaviours (active commuting, unhealthy snacking, and one context-free and one context-specific variant of alcohol consumption). Data were coded using thematic analysis procedures. Results. Problems were found in 10% of responses. Notable findings included participants lacking confidence in reporting automaticity, struggling to recall behaviour or cues, differing in interpretations of ‘commuting’, and misinterpreting items. Conclusions. While most responses were unproblematic, and further work is needed to investigate habit self-reports among larger and more diverse samples, findings nonetheless question the sensitivity of the measures, and the conceptualisation of habit underpinning common applications of them. We offer suggestions to minimise these problems

    Korean adolescents' perceptions of nutrition and health towards fast foods in Busan area

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    Adolescents in Busan area were asked in a survey about their perception and attitudes towards fast food. Most respondents answered that they consume fast food once a month because it is fast, easily accessible and tasty. Although they perceived fast food as unhealthy and less nutritious, they were less aware of its effect on their health and nutritional status. The more knowledgeable respondents were about nutrition and health the less likely they were to choose fast food over other meals. However, respondents who had little or no knowledge about the nutritional factors of fast food accounted for 43.1%. As to their source of dietary information, students relied on themselves (31.0%), parents (20.5%) and friends (19.9%). The medium through which students got the most nutrition and health information was television (66.8%), followed by the Internet (36.7%) and magazines (29.7%). This study will enable educators to plan more effective strategies for improving the dietary knowledge of the adolescent population

    DEG 5.0, a database of essential genes in both prokaryotes and eukaryotes

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    Essential genes are those indispensable for the survival of an organism, and their functions are therefore considered a foundation of life. Determination of a minimal gene set needed to sustain a life form, a fundamental question in biology, plays a key role in the emerging field, synthetic biology. Five years after we constructed DEG, a database of essential genes, DEG 5.0 has significant advances over the 2004 version in both the number of essential genes and the number of organisms in which these genes are determined. The number of prokaryotic essential genes in DEG has increased about 10-fold, mainly owing to genome-wide gene essentiality screens performed in a wide range of bacteria. The number of eukaryotic essential genes has increased more than 5-fold, because DEG 1.0 only had yeast ones, but DEG 5.0 also has those in humans, mice, worms, fruit flies, zebrafish and the plant Arabidopsis thaliana. These updates not only represent significant advances of DEG, but also represent the rapid progress of the essential-gene field. DEG is freely available at the website http://tubic.tju.edu.cn/deg or http://www.essentialgene.org

    Growing fat on reform: obesity and nutritional disparities among China's children, 1979–2005

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    Economic growth over the past three decades has greatly improved the nutrition and living standards of people in China. However, increasingly, the Chinese are becoming heavier. As many as a quarter of Chinese school-age urban boys are overweight or obese, yet a third of Chinese children remain underweight. Drawing on six national surveys of children's health conducted since 1979, the article reports on trends in nutritional status and regional disparities. It shows that the drivers behind the increase in mean body mass and in nutritional inequality are associated with rising household incomes and associated inequalities between provinces

    Online Continual Learning on Sequences

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    Online continual learning (OCL) refers to the ability of a system to learn over time from a continuous stream of data without having to revisit previously encountered training samples. Learning continually in a single data pass is crucial for agents and robots operating in changing environments and required to acquire, fine-tune, and transfer increasingly complex representations from non-i.i.d. input distributions. Machine learning models that address OCL must alleviate \textit{catastrophic forgetting} in which hidden representations are disrupted or completely overwritten when learning from streams of novel input. In this chapter, we summarize and discuss recent deep learning models that address OCL on sequential input through the use (and combination) of synaptic regularization, structural plasticity, and experience replay. Different implementations of replay have been proposed that alleviate catastrophic forgetting in connectionists architectures via the re-occurrence of (latent representations of) input sequences and that functionally resemble mechanisms of hippocampal replay in the mammalian brain. Empirical evidence shows that architectures endowed with experience replay typically outperform architectures without in (online) incremental learning tasks.Comment: L. Oneto et al. (eds.), Recent Trends in Learning From Data, Studies in Computational Intelligence 89

    Combined dynamics of mercury and terrigenous organic matter following impoundment of Churchill Falls Hydroelectric Reservoir, Labrador

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    Sediments from two recently (40 years) flooded lakes (Gabbro lake and Sandgirt lake) and an unflooded lake (Atikonak lake) were sampled to investigate the effects of reservoir impoundment on mercury (Hg) and terrigenous organic matter (TOM) loading in the Churchill Falls Hydroelectric complex in Labrador, Canada. Lignin biomarkers in TOM, which exclusively derive from terrestrial vegetation, were used as biomarkers for the presence and source origin of TOM—and for Hg due to their close associations—in sediments. In the two flooded Gabbro and Sandgirt lakes, we observed drastic increases in total mercury concentrations, T-[Hg], in sediments, which temporally coincided with the time of reservoir impoundment as assessed by 210Pb age dating. In the natural Atikonak lake sediments, on the other hand, T-[Hg] showed no such step-increase but gradually and slowly increased until present. T-[Hg] increases in lake sediments after flooding were also associated with a change in the nature of TOM: biomarker signatures changed to typical signatures of TOM from vegetated terrestrial landscape surrounding the lakes, and indicate a change to TOM that was much less degraded and typical of forest soil organic horizons. We conclude that T-[Hg] increase in the sediments of the two flooded reservoirs was the result of flooding of surrounding forests, whereby mainly surface organic horizons and upper soil horizons were prone to erosion and subsequent re-sedimentation in the reservoirs. The fact that T-[Hg] was still enriched 40 years after reservoir impoundment indicates prolonged response time of lake Hg and sediment loadings after reservoir impoundments

    Origin and Evolution of Saturn's Ring System

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    The origin and long-term evolution of Saturn's rings is still an unsolved problem in modern planetary science. In this chapter we review the current state of our knowledge on this long-standing question for the main rings (A, Cassini Division, B, C), the F Ring, and the diffuse rings (E and G). During the Voyager era, models of evolutionary processes affecting the rings on long time scales (erosion, viscous spreading, accretion, ballistic transport, etc.) had suggested that Saturn's rings are not older than 100 My. In addition, Saturn's large system of diffuse rings has been thought to be the result of material loss from one or more of Saturn's satellites. In the Cassini era, high spatial and spectral resolution data have allowed progress to be made on some of these questions. Discoveries such as the ''propellers'' in the A ring, the shape of ring-embedded moonlets, the clumps in the F Ring, and Enceladus' plume provide new constraints on evolutionary processes in Saturn's rings. At the same time, advances in numerical simulations over the last 20 years have opened the way to realistic models of the rings's fine scale structure, and progress in our understanding of the formation of the Solar System provides a better-defined historical context in which to understand ring formation. All these elements have important implications for the origin and long-term evolution of Saturn's rings. They strengthen the idea that Saturn's rings are very dynamical and rapidly evolving, while new arguments suggest that the rings could be older than previously believed, provided that they are regularly renewed. Key evolutionary processes, timescales and possible scenarios for the rings's origin are reviewed in the light of tComment: Chapter 17 of the book ''Saturn After Cassini-Huygens'' Saturn from Cassini-Huygens, Dougherty, M.K.; Esposito, L.W.; Krimigis, S.M. (Ed.) (2009) 537-57

    Enzymes Are Enriched in Bacterial Essential Genes

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    Essential genes, those indispensable for the survival of an organism, play a key role in the emerging field, synthetic biology. Characterization of functions encoded by essential genes not only has important practical implications, such as in identifying antibiotic drug targets, but can also enhance our understanding of basic biology, such as functions needed to support cellular life. Enzymes are critical for almost all cellular activities. However, essential genes have not been systematically examined from the aspect of enzymes and the chemical reactions that they catalyze. Here, by comprehensively analyzing essential genes in 14 bacterial genomes in which large-scale gene essentiality screens have been performed, we found that enzymes are enriched in essential genes. Essential enzymes have overrepresented ligases (especially those forming carbon-oxygen bonds and carbon-nitrogen bonds), nucleotidyltransferases and phosphotransferases, while have underrepresented oxidoreductases. Furthermore, essential enzymes tend to associate with more gene ontology domains. These results, from the aspect of chemical reactions, provide further insights into the understanding of functions needed to support natural cellular life, as well as synthetic cells, and provide additional parameters that can be integrated into gene essentiality prediction algorithms
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