900 research outputs found

    Conformal Invariance in the Long-Range Ising Model

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    We consider the question of conformal invariance of the long-range Ising model at the critical point. The continuum description is given in terms of a nonlocal field theory, and the absence of a stress tensor invalidates all of the standard arguments for the enhancement of scale invariance to conformal invariance. We however show that several correlation functions, computed to second order in the epsilon expansion, are nontrivially consistent with conformal invariance. We proceed to give a proof of conformal invariance to all orders in the epsilon expansion, based on the description of the long-range Ising model as a defect theory in an auxiliary higher-dimensional space. A detailed review of conformal invariance in the d-dimensional short-range Ising model is also included and may be of independent interest.Comment: 52pp; V2: refs added; V3: ref added, published versio

    Video Game–Based Exercise, Latino Children's Physical Health, and Academic Achievement

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    BackgroundThere is a paucity of research investigating the effects of innovative physical activity programs on physical health and academic performance in the Latino population.PurposeTo examine the impact of Dance Dance Revolution [DDR]–based exercise on Latino children's physical fitness and academic achievement.DesignA repeated-measures crossover design was used. In Year 1, Grade-4 students were assigned to the intervention group and offered 30 minutes of exercise (DDR, aerobic dance) three times per week. Grade-3 and Grade-5 students made up the comparison group and were offered no structured exercise at school. In Year 2, the Grade-4 students were again assigned to the intervention, whereas Grade-5 and Grade-6 students were in the comparison group.Setting/participantsAssessments were conducted with 208 Latino school children.Main outcome measuresThe baseline measures included time to complete a 1-mile run, BMI, and reading and math scores. Data were collected again 9 months later. Overall, data were collected in 2009–2011 and analyzed in 2012.ResultsData yielded significant differences between the intervention and comparison groups in differences in 1-mile run and math scores in Year 1 and Year 2. The results also revealed net differences in the intervention versus comparison group scores on the 1-mile run for Grade 3 (p<0.01). Additionally, children's yearly pre-test and post-test BMI group changes differed (χ2(2)=6.6, p<0.05) only for the first year of intervention.ConclusionsThe DDR-based exercise intervention improved children's cardiorespiratory endurance and math scores over time. Professionals should consider integrating exergaming at schools to achieve the goals of promoting a physically active lifestyle and enhancing academic success among Latino children

    A first assessment of genetic variability in the longhorn beetle Rosalia alpina (Coleoptera: Cerambycidae) from the Italian Apennines

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    The Rosalia longicorn (Rosalia alpina) is a strictly protected saproxylic beetle, widely distributed in Central and Southern Europe and mainly associated with ancient beech forests. To improve knowledge about the conservation status of R. alpina in Italy, available molecular markers (microsatellites and mitochondrial cytochrome c oxidase I(COI)) were tested for the first time on Italian populations. The study was performed in four sampling sites distributed in two areas placed in Northern (“Foreste Casentinesi” National Park) and Central Apennines (“Abruzzo, Lazio and Molise” National Park) where populational data about Rosalia longicorn were collected in the framework of the European LIFE MIPP Project. The genetic relationship among Apennine and Central/South-eastern European populations was explored by a comparison with mitochondrial DNA (mtDNA) data from literature. Microsatellite markers were only partially informative when applied to R. alpina Italian individuals, although providing some preliminary indication on an extensive gene flow among populations from the Apennines and local ongoing processes of genetic erosion. Genetic data are consistent with previous ecological data suggesting that the maintenance of variability in this species could be related to both habitat continuity and preservation of large senescent or standing dead trees in forests. Finally, a peculiar origin of the Apennine populations of R. alpina from a putative “Glacial Refugium” in Italy was inferred through COI data. The high genetic distance scored among the analysed populations and those from Central and South-eastern Europe indicates that the R. alpina deme from Apennine Mountains might represent a relevant conservation unit in Europe. Further genetic analyses will allow assessing other possible conservation units of R. alpina and, thus, defining large-scale conservation strategies to protect this endangered longhorn beetle in Europe

    Recognition and genotyping of minor germplasm of Friuli Venezia Giulia revealed high diversity

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    The wealth of vine varieties that used to exist in Friuli Venezia Giulia has been progressively lost. In order to ascertain the current situation regarding vine germplasm in the region, between 2001 and 2008, a wide-ranging study was conducted of recovery, conservation and molecular characterization with microsatellite markers (SSR) of accessions of minor germplasm at risk of erosion or extinction. A total of 178 accessions were analyzed and 93 varieties identified. Of these, 44 are already registered in the Italian Catalogue, 8 have been imported and are well-known foreign varieties even if not registered in the Italian Catalogue, 38 are potentially autochthonous and of these only 15 are described or at least cited in the literature; there are no hypotheses on the remaining three. In order to obtain information on possible genetic similarities, three types of software were used to process the molecular data, but only Structure allowed the existence of two principal groupings to be hypothesized for some of the presumed Friuli autochthons: one that gravitates around ‘Prosecco’ and the other around ‘Refoscone’.

    Optimization Matrix Factorization Recommendation Algorithm Based on Rating Centrality

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    Matrix factorization (MF) is extensively used to mine the user preference from explicit ratings in recommender systems. However, the reliability of explicit ratings is not always consistent, because many factors may affect the user's final evaluation on an item, including commercial advertising and a friend's recommendation. Therefore, mining the reliable ratings of user is critical to further improve the performance of the recommender system. In this work, we analyze the deviation degree of each rating in overall rating distribution of user and item, and propose the notion of user-based rating centrality and item-based rating centrality, respectively. Moreover, based on the rating centrality, we measure the reliability of each user rating and provide an optimized matrix factorization recommendation algorithm. Experimental results on two popular recommendation datasets reveal that our method gets better performance compared with other matrix factorization recommendation algorithms, especially on sparse datasets

    Guidelines for the monitoring of Rosalia alpina

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    Copyright Alessandro Campanaro et al. Rosalia alpina (Linnaeus, 1758) is a large longhorn beetle (Coleoptera: Cerambycidae) which is protected by the Habitats Directive and which typically inhabits beech forests characterised by the presence of mature, dead (or moribund) and sun-exposed trees. A revision of the current knowledge on systematics, ecology and conservation of R. alpina is reported. The research was carried out as part of the LIFE MIPP project which aims to find a standard monitoring method for saproxylic beetles protected in Europe. For monitoring this species, different methods were tested and compared in two areas of the Apennines, utilising wild trees, logs and tripods (artificially built with beech woods), all potentially suitable for the reproduction of the species. Even if all methods succeeded in the survey of the target species, these results showed that the use of wild trees outperformed other methods. Indeed, the use of wild trees allowed more adults to be observed and required less intensive labour. However, monitoring the rosalia longicorn on wild trees has the main disadvantage that they can hardly be considered “standard sampling units”, as each tree may be differently attractive to adults. Our results demonstrated that the most important factors influencing the attraction of single trunks were wood volume, sun-exposure and decay stage. Based on the results obtained during the project LIFE MIPP, as well as on a literature review, a standard monitoring method for R. alpina was developed

    Graphene re-knits its holes

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    Nano-holes, etched under an electron beam at room temperature in singlelayer graphene sheets as a result of their interaction with metalimpurities, are shown to heal spontaneously by filling up with either non-hexagon, graphene-like, or perfect hexagon 2D structures. Scanning transmission electron microscopy was employed to capture the healing process and study atom-by-atom the re-grown structure. A combination of these nano-scale etching and re-knitting processes could lead to new graphene tailoring approaches.Comment: 11 pages, 4 figure

    a cross-cultural comparison between Portugal and the United States

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    Background: Motor competence and health-related fitness are important components for the development and maintenance of a healthy lifestyle in children. This study examined cross-cultural performances on motor competence and health-related fitness between Portuguese and U.S. children. Methods: Portuguese (n = 508; 10.14 +/- 2.13 years , mean +/- SD) and U.S. (n = 710; 9.48 +/- 1.62 years) children performed tests of cardiorespiratory fitness (Progressive Aerobic Cardiovascular Endurance Run), upper body strength (handgrip), locomotor skill performance (standing long jump), and object projection skill performance (throwing and kicking). Portuguese and U.S. children were divided into 2 age groups (6=9 and 10=13 years) for data analysis purposes. A two=factor one=way analysis of covariance (ANOVA) was conducted with the Progressive Aerobic Cardiovascular Endur ance Run, handgrip, standing long jump scores, kicking, and throwing speed (km/h) as dependent variables. Results: Results indicated that Portuguese children, irrespective of sex, presented better performances in locomotor and cardiorespiratory performance (standing long jump and Progressive Aerobic Cardiovascular Endurance Run) than U.S. children in both age bands. U.S. children outper formed Portuguese children during throwing and handgrip tests. Kicking tests presented gender differences: Portuguese boys and U.S. girls outperformed their internationally matched counterparts. Conclusion: Cultural differences in physical education curricula and sports participation may impact differences in motor competence and fitness development in these countries.4811-99FE-2ECD | Luis Paulo RodriguesN/
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