296 research outputs found

    Comparación de los anchos de los arcos dentarios en sujetos con y sin sobrepeso

    Get PDF
    Objective: To compare the width of the dental arches between overweight and non-overweight subjects . Materials and Methods: A cross-sectional comparative study was carried out with 54 subjects from 8 to 13 years of age, 27 normal-weight and 27 overweight. The presence of overweight was assessed according to the Quetelet index. To determine the width of the dental arches, measurements of the upper and lower intercanine and intermolar width were obtained with a digital calibrated Vernier caliper. The comparison between the dental arch width of normal-weight and overweight subjects was performed using the Mann-Whitney U test. Results: Statistically significant differences were found in the intercanine and intermolar widths between overweight and non-overweight subjects (p<0.05). Conclusion: The dental arches were wider in overweight subjects compared to those of normal-weight.Comparar los anchos de los arcos dentarios en sujetos con sobrepeso y sin sobrepeso. Materiales y Método: Se realizó un estudio transversal comparativo. Se evaluaron 54 sujetos de 8 a 13 años de edad, 27 sin sobrepeso y 27 con sobrepeso. La presencia de sobrepeso se evaluó según el índice de Quetelet. Para determinar los anchos de los arcos dentarios, se analizaron, en los modelos de estudio de cada grupo, las medidas de los anchos intercanino e intermolar superior e inferior con un vernier calibrado digital. La comparación de los anchos de los arcos dentarios de los sujetos con sobrepeso y sin sobrepeso se realizó mediante la prueba U de Mann-Whitney. Resultados: Se encontraron diferencias estadísticamente significativas en los anchos intercanino e intermolar entre los sujetos con sobrepeso y sin sobrepeso (p<0.05). Conclusión: Los anchos de los arcos dentarios fueron mayores en sujetos con sobrepeso que en sujetos sin sobrepeso

    A regulation-based classification system for marine protected areas: A response to Dudley et al. [9]

    Get PDF
    Dudley et al. [9] commented on our paper [11], arguing that the current IUCN objective-based categorization of protected areas, which is also used in marine protected areas (MPAs), should not be abandoned and replaced by the new regulation-based classification system [11]. Here we clarify that we do not advocate replacing the current IUCN categories, but highlight the benefits of using both the objective-based IUCN categories and the new regulation-based classification when applied to MPAs. With an increasing number of MPA types being implemented, most of them multiple-use areas zoned for various purposes, assessing ecological and socio-economic benefits is key for advancing conservation targets and policy objectives. Although the IUCN categories can be used both in terrestrial and marine systems, they were not designed to follow a gradient of impacts and there is often a mismatch between stated objectives and implemented regulations. The new regulation-based classification system addresses these problems by linking impacts of activities in marine systems with MPA and zone classes in a simple and globally applicable way. Applying both the IUCN categories and the regulation based classes will increase transparency when assessing marine conservation goals.ERA-Net BiodivERsA project "BUFFER Partially protected areas as buffers to increase the linked social ecological resilience"; national funders ANR (France); FCT (Portugal); FOR-MAS (Sweden); SEPA (Sweden); RCN (Norway); project BUFFER; Fernand Braudel IFER fellowship (Fondation Maison des Sciences de l'Homme); Fundacao para a Ciencia e a Tecnologia (FCT) [UID/MAR/04292/2013

    Multi-Armed Bandits for Correlated Markovian Environments with Smoothed Reward Feedback

    Full text link
    We study a multi-armed bandit problem in a dynamic environment where arm rewards evolve in a correlated fashion according to a Markov chain. Different than much of the work on related problems, in our formulation a learning algorithm does not have access to either a priori information or observations of the state of the Markov chain and only observes smoothed reward feedback following time intervals we refer to as epochs. We demonstrate that existing methods such as UCB and ε\varepsilon-greedy can suffer linear regret in such an environment. Employing mixing-time bounds on Markov chains, we develop algorithms called EpochUCB and EpochGreedy that draw inspiration from the aforementioned methods, yet which admit sublinear regret guarantees for the problem formulation. Our proposed algorithms proceed in epochs in which an arm is played repeatedly for a number of iterations that grows linearly as a function of the number of times an arm has been played in the past. We analyze these algorithms under two types of smoothed reward feedback at the end of each epoch: a reward that is the discount-average of the discounted rewards within an epoch, and a reward that is the time-average of the rewards within an epoch.Comment: Significant revision of prior version including deeper discussion of related work, gap-independent regret bounds, and regret bounds for discounted reward

    Assessing fish–fishery dynamics from a spatially explicit metapopulation perspective reveals winners and losers in fisheries management

    Get PDF
    Sustainable management of living resources must reconcile biodiversity conservation and socioeconomic viability of human activities. In the case of fisheries, sustainable management design is made challenging by the complex spatiotemporal interactions between fish and fisheries. We develop a comprehensive metapopulation framework integrating data on species life-history traits, connectivity and habitat distribution to identify priority areas for fishing regulation and assess how management impacts are spatially distributed. We trial this approach on European hake fisheries in the north-western Mediterranean, where we assess area-based management scenarios in terms of stock status and fishery productivity to prioritize areas for protection. Model simulations show that local fishery closures have the potential to enhance both spawning stock biomass and landings on a regional scale compared to a status quo scenario, but that improving protection is easier than increasing productivity. Moreover, the interaction between metapopulation dynamics and the redistribution of fishing effort following local closures implies that benefits and drawbacks are heterogeneously distributed in space, the former being concentrated in the proximity of the protected site. A network analysis shows that priority areas for protection are those with the highest connectivity (as expressed by network metrics) if the objective is to improve the spawning stock, while no significant relationship emerges between connectivity and potential for increased landings. Synthesis and applications. Our framework provides a tool for (1) assessing area-based management measures aimed at improving fisheries outcomes in terms of both conservation and socioeconomic viability and (2) describing the spatial distribution of costs and benefits, which can help guide effective management and gain stakeholder support. Adult dispersal remains the main source of uncertainty that needs to be investigated to effectively apply our model to fisheries regulation

    Escaping the perfect storm of simultaneous climate change impacts on agriculture and marine fisheries

    Get PDF
    The availability and production of food is threatened by climate change, with subsequent implications for food security and the global economy. In this study we assessed how the impacts of climate change on agriculture and marine fisheries interact under a range of scenarios. The 'business-as-usual' scenario would lead to ~90% of the global population, particularly in least developed countries, being exposed to declines in the productivity of both sectors, and < 3% of the world would experience productivity gains in both sectors. With strong mitigation equivalent to meeting Paris Agreement commitments, most countries including both the most vulnerable and the largest carbon emitters would show net gains in both agricultural and fisheries sectors

    Marine reserves: Fish life history and ecological traits matter

    Get PDF
    Copyright by the Ecological Society of AmericaMarine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data sets from 12 European marine reserves, we show that there is significant variation in the response of different species of fish to protection and that this heterogeneity can be explained, in part, by differences in their traits. Densities of targeted size-classes of commercial species were greater in protected than unprotected areas. This effect of protection increased as the maximum body size of the targeted species increased, and it was greater for species that were not obligate schoolers. However, contrary to previous theoretical findings, even mobile species with wide home ranges benefited from protection: the effect of protection was at least as strong for mobile species as it was for sedentary ones. Noncommercial bycatch and unexploited species rarely responded to protection, and when they did (in the case of unexploited bentho-pelagic species), they exhibited the opposite response: their densities were lower inside reserves. The use of marine reserves for marine conservation and fisheries management implies that they should ensure protection for a wide range of species with different life-history and ecological traits. Our results suggest this is not the case, and instead that effects vary with economic value, body size, habitat, depth range, and schooling behavior.Publicado

    Commissioning of the cryogenics of the LHC long straight sections

    Get PDF
    The LHC is made of eight circular arcs interspaced with eight Long Straight Sections (LSS). Most powering interfaces to the LHC are located in these sections where the particle beams are focused and shaped for collision, cleaning and acceleration. The LSSs are constituted of several unique cryogenic devices and systems like electrical feed-boxes, standalone superconducting magnets, superconducting links, RF cavities and final focusing superconducting magnets. This paper presents the cryogenic commissioning and the main results obtained during the first operation of the LHC Long Straight Sections.Comment: 8 pp. Cryogenic Engineering Conference and International Cryogenic Materials Conference, 28 Jun - 2 Jul 2009. Tucson, Arizon
    corecore