3,954 research outputs found

    Changing distributions of body size and adiposity with age

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    Background: Adiposity and health risks are better indicated by waist circumference than body mass index (BMI). Patterns of change with age are incompletely documented.<p></p> Methods: Adults aged 18–92 years in the Scottish and English Health Surveys of 1994–96 and 2008–10 were divided into fifteen 5-year age bands. Sex-specific prevalences of overweight/obesity and of increased/high waist circumference against age were compared using analysis of covariance. <p></p> Results: Data available for 7932 Scottish and 55 925 English subjects in 1994–96, and for 27 391 Scottish and 30 929 English in 2008–10, showed generally similar patterns of change in the two countries. Prevalences of both elevated BMI and waist circumference rose with age for longer in 2008–10 than in 1994–96, reaching higher peaks at greater ages, particularly among men. Between 1994–96 and 2008–10, maximum prevalences of BMI >30 increased from 25 to 38% (larger increases in men than women), reaching a peak at age 60–70 years in both sexes. This peak prevalence was 5–10 years later than in 1994–96 for men and remained unchanged for women. Between 1994–96 and 2008–10, maximum prevalences of high waist circumference (men>>102 cm, women>88 cm) increased from 30 to –70% in both sexes, peaking in 2008–10 at ages 80–85 years (men) and 65–70 years (women). In 2008–10, proportions of adults with ‘normal’ BMI (18.5–25) fell with age to 15–20% at age 60–70 years (men) and 75 years (women). Among all those with BMI=18.5–25, aged>65 years, the proportions with unhealthily elevated waist circumference were 30 (men>94 cm) and 55% (women>80 cm). <p></p> Conclusions: Almost 40% of men and women are now becoming obese. People are growing fatter later in life, with waist circumference rising more persistently than BMI, which may indicate increased loss of muscle mass and sarcopenia in old age. Among older people, few now have ‘normal’ BMI, and of these up to half have elevated waist circumference, raising questions for the suitability of BMI as a measure of adiposity in this age group. <p></p&gt

    Characteristics of the low-energy reporters in a longitudinal national dietary survey

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    The aim of the present study was to establish whether the characteristics of members of a large national birth cohort study who submitted diet diaries with implausibly low-energy intake differed from those whose recorded energy intake was more plausible. Survey members (n 1898) recorded their diets in a 7 d diary in household measures. Those whose reported energy intake (EI) as a fraction of their estimated BMR was less than 1.10, here termed low-energy reporters (LER) but often called under-reporters, constituted 20.6 % of the study population. None of the variables describing dietary, smoking or exercise behaviour bore a significant relationship with low EI/BMR (<1.10), neither did those describing region of residence, subjective adequacy of income, current social class, social relations or the social environment of the subjects. Results of logistic regression analysis showed that the only independently significant characteristic for men was higher BMI. In women, in addition to higher BMI, having been overweight or obese as an adult independently, but less significantly, predicted low EI/BMR, while membership as a child of social class III (nonmanual), having more children in the household and having a paid job marginally but independently decreased the probability of reporting low EI/BMR. Submission of a diary with EI/BMR <1.10 7 years earlier in the same survey was an even more powerful predictor of current low EI/BMR than higher BMI in both sexes. The average reported diet-composition of LER was more micronutrient- and protein-rich than that of the others, indicating different dietary, or diet-recording, behaviour in this group of subjects. LER are not a random sample of the survey population, and their characteristics, definable to some extent, put them at risk for lower health status. Although EI/BMR cut-off points can be used to identify LER, the problem of how to use their data is still unresolved

    Weight management: a comparison of existing dietary approaches in a work-site setting

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    &lt;b&gt;OBJECTIVES:&lt;/b&gt; (1) To compare the effectiveness a 2512 kJ (600 kcal) daily energy deficit diet (ED) with a 6279 kJ (1500 kcal) generalized low-calorie diet (GLC) over a 24 week period (12 weeks weight loss plus 12 weeks weight maintenance). (2) To determine if the inclusion of lean red meat at least five times per week as part of a slimming diet is compatible with weight loss in comparison with a diet that excludes lean red meat. DESIGN: Randomized controlled trial. &lt;b&gt;SETTING:&lt;/b&gt; Large petrochemical work-site. &lt;b&gt;PARTICIPANTS:&lt;/b&gt; One-hundred and twenty-two men aged between 18 and 55 y. &lt;b&gt;MAIN OUTCOME MEASURES:&lt;/b&gt; Weight loss and maintenance of weight loss. &lt;b&gt;INTERVENTION:&lt;/b&gt; Eligible volunteers were randomized to one of the four diet=meat combinations (ED meat, ED no meat, GLC meat, GLC no meat). One-third of subjects in each diet/meat combination were randomized to an initial control period prior to receiving dietary advice. All subjects attended for review every 2 weeks during the weight loss period. For the 12 week structured weight maintenance phase, individualized energy prescriptions were re-calculated for the ED group as 1.4 (activity factor)x basal metabolic rate. Healthy eating advice was reviewed with subjects in the GLC group. All subjects were contacted by electronic mail at 2 week intervals and anthropometric and dietary information requested. &lt;b&gt;RESULTS:&lt;/b&gt; No difference was evident between diet groups in mean weight loss at 12 weeks (4.3 (s.d. 3.4) kg ED group vs 5.0 (s.d. 3.5) kg GLC group, P=0.34). Mean weight loss was closer to the intended weight loss in the 2512 kJ (600 kcal) ED group. The dropout rate was also lower than the GLC group. The inclusion of lean red meat in the diet on at least five occasions per week did not impair weight loss. Mean weight gain following 12 weeks weight maintenance was þ1.1 (s.d. 1.8) kg, P&lt;0.0001. No differences were found between groups. &lt;b&gt;CONCLUSIONS:&lt;/b&gt; This study has shown that the individualized 2512 kJ (600 kcal) ED approach was no more effective in terms of weight loss than the 6279 kJ (1500 kcal) GLC approach. However the ED approach might be considered preferable as compliance was better with this less demanding prescription. In terms of weight loss the elimination of red meat from the diet is unnecessary. The weight maintenance intervention was designed as a low-input approach, however weight regain was significant and weight maintenance strategies require further development

    Community Structure Characterization

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    This entry discusses the problem of describing some communities identified in a complex network of interest, in a way allowing to interpret them. We suppose the community structure has already been detected through one of the many methods proposed in the literature. The question is then to know how to extract valuable information from this first result, in order to allow human interpretation. This requires subsequent processing, which we describe in the rest of this entry

    Detecting rich-club ordering in complex networks

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    Uncovering the hidden regularities and organizational principles of networks arising in physical systems ranging from the molecular level to the scale of large communication infrastructures is the key issue for the understanding of their fabric and dynamical properties [1-5]. The ``rich-club'' phenomenon refers to the tendency of nodes with high centrality, the dominant elements of the system, to form tightly interconnected communities and it is one of the crucial properties accounting for the formation of dominant communities in both computer and social sciences [4-8]. Here we provide the analytical expression and the correct null models which allow for a quantitative discussion of the rich-club phenomenon. The presented analysis enables the measurement of the rich-club ordering and its relation with the function and dynamics of networks in examples drawn from the biological, social and technological domains.Comment: 1 table, 3 figure

    Generating Robust and Efficient Networks Under Targeted Attacks

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    Much of our commerce and traveling depend on the efficient operation of large scale networks. Some of those, such as electric power grids, transportation systems, communication networks, and others, must maintain their efficiency even after several failures, or malicious attacks. We outline a procedure that modifies any given network to enhance its robustness, defined as the size of its largest connected component after a succession of attacks, whilst keeping a high efficiency, described in terms of the shortest paths among nodes. We also show that this generated set of networks is very similar to networks optimized for robustness in several aspects such as high assortativity and the presence of an onion-like structure

    Globalization versus the State? Macro and micro-perspectives on Roman economies

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    This is the author accepted manuscript. The final version is available from Cambridge University Press via the DOI in this record.Book reviews of: ANDREW WILSON AND ALAN BOWMAN (eds.). 2018. Trade, Commerce and the State in the Roman World. Oxford Studies on the Roman Economy. Oxford: Oxford University Press; 978-0-19-879066-2; TYMON C. A. DE HAAS AND GIJS TOL (eds.). 2017. The Economic Integration of Roman Italy. Rural Communities in a Globalising World. Mnemosyne Supplements, History and Archaeology of Classical Antiquity. Leiden: Brill; 978-90-04-32590-

    Youth Justice and Education: A Typology of Educational Approaches to the Resocialisation of Young Offenders in Spain

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    The Young Offenders Act that entered Spanish law in 2000 represents a significant attempt to place personalised educational programmes for young people with social/criminal problems at the centre of policy and practice. This paper examines the teams and educational programmes designed to manage and implement the goal of ?re-socialisation? enshrined in the Act. This paper focuses on an analytical typology of the educational styles used at young offenders institutions in Spain. The analysis highlights the differences between styles in relation to the key underlying objectives of social reorientation and citizen empowerment. The wide range of models experimented with in different Spanish regions has great relevance to youth justice systems in other countries. For example, the typology we put forward has concrete implications for recent developments in England, in the light of moves towards establishing a national network of ?Secure Colleges? for convicted young people

    Evolving Clustered Random Networks

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    We propose a Markov chain simulation method to generate simple connected random graphs with a specified degree sequence and level of clustering. The networks generated by our algorithm are random in all other respects and can thus serve as generic models for studying the impacts of degree distributions and clustering on dynamical processes as well as null models for detecting other structural properties in empirical networks
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