306 research outputs found

    Body composition and body fat distribution are related to cardiac autonomic control in non-alcoholic fatty liver disease patients

    Get PDF
    BACKGROUND/OBJECTIVES: Heart rate recovery (HRR), a cardiac autonomic control marker, was shown to be related to body composition (BC), yet this was not tested in non-alcoholic fatty liver disease (NAFLD) patients. The aim of this study was to determine if, and to what extent, markers of BC and body fat (BF) distribution are related to cardiac autonomic control in NAFLD patients. SUBJECTS/METHODS: BC was assessed with dual-energy X-ray absorptiometry in 28 NAFLD patients (19 men, 51±13 years, and 9 women, 47±13 years). BF depots ratios were calculated to assess BF distribution. Subjects’ HRR was recorded 1 (HRR1) and 2 min (HRR2) immediately after a maximum graded exercise test. RESULTS: BC and BF distribution were related to HRR; particularly weight, trunk BF and trunk BF-to-appendicular BF ratio showed a negative relation with HRR1 (r 1⁄4 0.613, r 1⁄4 0.597 and r 1⁄4 0.547, respectively, Po0.01) and HRR2 (r 1⁄4 0.484, r 1⁄4 0.446, Po0.05, and r 1⁄4 0.590, Po0.01, respectively). Age seems to be related to both HRR1 and HRR2 except when controlled for BF distribution. The preferred model in multiple regression should include trunk BF-to-appendicular BF ratio and BF to predict HRR1 (r2 1⁄4 0.549; Po0.05), and trunk BF-to-appendicular BF ratio alone to predict HRR2 (r2 1⁄4 0.430; Po0.001). CONCLUSIONS: BC and BF distribution were related to HRR in NAFLD patients. Trunk BF-to-appendicular BF ratio was the best independent predictor of HRR and therefore may be best related to cardiovascular increased risk, and possibly act as a mediator in age-related cardiac autonomic control variation.info:eu-repo/semantics/publishedVersio

    Short-Run Regional Forecasts: Spatial Models through Varying Cross-Sectional and Temporal Dimensions

    Get PDF
    In any economic analysis, regions or municipalities should not be regarded as isolated spatial units, but rather as highly interrelated small open economies. These spatial interrelations must be considered also when the aim is to forecast economic variables. For example, policy makers need accurate forecasts of the unemployment evolution in order to design short- or long-run local welfare policies. These predictions should then consider the spatial interrelations and dynamics of regional unemployment. In addition, a number of papers have demonstrated the improvement in the reliability of long-run forecasts when spatial dependence is accounted for. We estimate a heterogeneouscoefficients dynamic panel model employing a spatial filter in order to account for spatial heterogeneity and/or spatial autocorrelation in both the levels and the dynamics of unemployment, as well as a spatial vector-autoregressive (SVAR) model. We compare the short-run forecasting performance of these methods, and in particular, we carry out a sensitivity analysis in order to investigate if different number and size of the administrative regions influence their relative forecasting performance. We compute short-run unemployment forecasts in two countries with different administrative territorial divisions and data frequency: Switzerland (26 regions, monthly data for 34 years) and Spain (47 regions, quarterly data for 32 years)

    Hyperdominance in the Amazonian tree flora

    Get PDF
    The vast extent of the Amazon Basin has historically restricted the study of its tree communities to the local and regional scales. Here, we provide empirical data on the commonness, rarity, and richness of lowland tree species across the entire Amazon Basin and Guiana Shield (Amazonia), collected in 1170 tree plots in all major forest types. Extrapolations suggest that Amazonia harbors roughly 16,000 tree species, of which just 227 (1.4%) account for half of all trees. Most of these are habitat specialists and only dominant in one or two regions of the basin. We discuss some implications of the finding that a small group of species--less diverse than the North American tree flora--accounts for half of the world's most diverse tree community.This work was supported by Alberta Mennega Stichting; ALCOA Suriname; Banco de la República; Center for Agricultural Research in Suriname; Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (Plano Nacional de Pós-Graduação); Conselho Nacional de Desenvovimento Científico e Tecnológico of Brazil (CNPq) projects Programa de Pesquisas Ecológicas de Longa Duração (PELD) (558069/2009-6), Programa de Apoio a Núcleos de Excelência da Fundação de Amparo à Pesquisa do Estado do Amazonas (PRONEX-FAPEAM) (1600/2006), Áreas Úmidas, and MAUA; PELD (403792/2012-6), PPBio, CENBAM, Universal (479599/2008-4), and Universal 307807-2009-6; Fundação de Amparo À Pesquisa Do Estado Do Amazonas (APEAM) projects DCR/2006, Hidroveg with FAPESP, and PRONEX with CNPq; FAPESP; Colciencias; Duke University; Ecopetrol; FEPIM 044/2003; the Field Museum; Conservation International/DC (TEAM/INPA Manuas), Gordon and Betty Moore Foundation; Guyana Forestry Commission; Investissement d’Avenir grant of the French Agence Nationale de la Recherche (ANR) (Centre d’Étude de la Biodiversité Amazonienne ANR-10-LABX-0025); Margaret Mee Amazon Trust; Miquel fonds; National Geographic Society (7754-04, 8047-06 to P.M.J.); Netherlands Foundation for the Advancement of Tropical Research WOTRO grants WB85- 335 and W84-581; Primate Conservation Incorporated; Programme Ecosystèmes Tropicaux (French Ministry of Ecology and Sustainable Development; Shell Prospecting and Development Peru; Smithsonian Institution’s Biological Diversity of the Guiana Shield Program; Stichting het van Eeden-fonds; the Body Shop; the Ministry of the Environment of Ecuador; TROBIT; Tropenbos International; NSF (NSF-0743457 and NSF-0101775 to P.M.J.); USAID; Variety Woods Guyana; WWF-Brazil; WWF-Guianas; XIIéme Contrat de Plan Etat Région-Guyane (French Government and European Union); and grants to RAINFOR from the European Union, UK Natural Environment Research Council, the Gordon and Betty Moore Foundation, and U.S. National Geographic Society. O.L.P. is supported by a European Research Council Advanced Grant and a Royal Society Wolfson Research Merit Award

    The clinical and functional significance of c-Met in breast cancer: a review

    Get PDF
    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.CMH-Y is funded by a Cancer Research UK Clinical Research Fellowship. JLJ is funded by the Breast Cancer Campaign Tissue Bank

    Effectiveness of habitat management in the recovery of low-density populations of wild rabbit.

    Get PDF
    Understanding the relationship between spatial patterns of landscape attributes and population presence and abundance is essential for understanding population processes as well as supporting management and conservation strategies. This study evaluates the influence of three factors: environment, habitat management, and season on the presence and abundance of the wild rabbit (Oryctolagus cuniculus), an important prey species for Mediterranean endangered predator species. To address this issue, we estimated wild rabbit presence and abundance by latrine counting in transects located in 45 plots within a 250×250 m grid from June 2007 until June 2009 in a 1,200 ha hunting area in southern Portugal.We then analyzed how wild rabbit presence and abundance correlatewith the aforementioned factors. Our results showed that the main variable influencing wild rabbit presence and abundance was the distance to the artificial warrens. North and northeast slope directions were negatively related to wild rabbit presence. Conversely, rabbit presence was positively correlated with short distances to ecotone, artificial warrens, and spring. Regarding rabbit abundance, in addition to artificial warrens, soft soils, bushes, and season also had a positive effect. We found that environmental variables, management practices, and season each affect wild rabbit presence and abundance differently at a home range scale in low-density population. Thus, our major recommendations are reducing the distance to artificial warrens and ecotone, ideally to less than 100 m, and promoting habitat quality improvement on slopes with plenty of sun exposure

    Seasonal drought limits tree species across the Neotropics

    Get PDF
    AcceptedArticle in Press© 2016 Nordic Society Oikos.Within the tropics, the species richness of tree communities is strongly and positively associated with precipitation. Previous research has suggested that this macroecological pattern is driven by the negative effect of water-stress on the physiological processes of most tree species. This implies that the range limits of taxa are defined by their ability to occur under dry conditions, and thus in terms of species distributions predicts a nested pattern of taxa distribution from wet to dry areas. However, this 'dry-tolerance' hypothesis has yet to be adequately tested at large spatial and taxonomic scales. Here, using a dataset of 531 inventory plots of closed canopy forest distributed across the western Neotropics we investigated how precipitation, evaluated both as mean annual precipitation and as the maximum climatological water deficit, influences the distribution of tropical tree species, genera and families. We find that the distributions of tree taxa are indeed nested along precipitation gradients in the western Neotropics. Taxa tolerant to seasonal drought are disproportionally widespread across the precipitation gradient, with most reaching even the wettest climates sampled; however, most taxa analysed are restricted to wet areas. Our results suggest that the 'dry tolerance' hypothesis has broad applicability in the world's most species-rich forests. In addition, the large number of species restricted to wetter conditions strongly indicates that an increased frequency of drought could severely threaten biodiversity in this region. Overall, this study establishes a baseline for exploring how tropical forest tree composition may change in response to current and future environmental changes in this region.This paper is a product of the RAINFOR and ATDN networks and of ForestPlots.net researchers (http://www.forestplots.net). RAINFOR and ForestPlots have been supported by a Gordon and Betty Moore Foundation grant, the European Union’s Seventh Framework Programme (283080, ‘GEOCARBON’; 282664, ‘AMAZALERT’); European Research Council (ERC) grant ‘Tropical Forests in the Changing Earth System’ (T-FORCES), and Natural Environment Research Council (NERC) Urgency Grant and NERC Consortium Grants ‘AMAZONICA’ (NE/F005806/1) and ‘TROBIT’ (NE/D005590/1). Additional funding for fieldwork was provided by Tropical Ecology Assessment and Monitoring (TEAM) Network, a collaboration among Conservation International, the Missouri Botanical Garden, the Smithsonian Institution, and the Wildlife Conservation Society. A.E.M. receives a PhD scholarship from the T-FORCES ERC grant. O.L.P. is supported by an ERC Advanced Grant and a Royal Society Wolfson Research Merit Award. We thank Jon J. Lloyd, Chronis Tzedakis, David Galbraith, and two anonymous reviewers for helpful comments and Dylan Young for helping with the analyses. This study would not be possible without the extensive contributions of numerous field assistants and rural communities in the Neotropical forests. Alfredo Alarcón, Patricia Alvarez Loayza, Plínio Barbosa Camargo, Juan Carlos Licona, Alvaro Cogollo, Massiel Corrales Medina, Jose Daniel Soto, Gloria Gutierrez, Nestor Jaramillo Jarama, Laura Jessica Viscarra, Irina Mendoza Polo, Alexander Parada Gutierrez, Guido Pardo, Lourens Poorter, Adriana Prieto, Freddy Ramirez Arevalo, Agustín Rudas, Rebeca Sibler and Javier Silva Espejo additionally contributed data to this study though their RAINFOR participations. We further thank those colleagues no longer with us, Jean Pierre Veillon, Samuel Almeida, Sandra Patiño and Raimundo Saraiva. Many data come from Alwyn Gentry, whose example has inspired new generations to investigate the diversity of the Neotropics

    Spatiotemporal Infectious Disease Modeling: A BME-SIR Approach

    Get PDF
    This paper is concerned with the modeling of infectious disease spread in a composite space-time domain under conditions of uncertainty. We focus on stochastic modeling that accounts for basic mechanisms of disease distribution and multi-sourced in situ uncertainties. Starting from the general formulation of population migration dynamics and the specification of transmission and recovery rates, the model studies the functional formulation of the evolution of the fractions of susceptible-infected-recovered individuals. The suggested approach is capable of: a) modeling population dynamics within and across localities, b) integrating the disease representation (i.e. susceptible-infected-recovered individuals) with observation time series at different geographical locations and other sources of information (e.g. hard and soft data, empirical relationships, secondary information), and c) generating predictions of disease spread and associated parameters in real time, while considering model and observation uncertainties. Key aspects of the proposed approach are illustrated by means of simulations (i.e. synthetic studies), and a real-world application using hand-foot-mouth disease (HFMD) data from China.J.M. Angulo and A.E. Madrid have been partially supported by grants MTM2009-13250 and MTM2012-32666 of SGPI, and P08-FQM-3834 of the Andalusian CICE, Spain. H-L Yu has been partially supported by a grant from National Science Council of Taiwan (NSC101-2628-E-002-017-MY3 and NSC102-2221-E-002-140-MY3). A. Kolovos was supported by SpaceTimeWorks, LLC. G. Christakos was supported by a Yongqian Chair Professorship (Zhejiang University, China)

    Generalization of entropy based divergence measures for symbolic sequence analysis

    Get PDF
    Entropy based measures have been frequently used in symbolic sequence analysis. A symmetrized and smoothed form of Kullback-Leibler divergence or relative entropy, the Jensen-Shannon divergence (JSD), is of particular interest because of its sharing properties with families of other divergence measures and its interpretability in different domains including statistical physics, information theory and mathematical statistics. The uniqueness and versatility of this measure arise because of a number of attributes including generalization to any number of probability distributions and association of weights to the distributions. Furthermore, its entropic formulation allows its generalization in different statistical frameworks, such as, non-extensive Tsallis statistics and higher order Markovian statistics. We revisit these generalizations and propose a new generalization of JSD in the integrated Tsallis and Markovian statistical framework. We show that this generalization can be interpreted in terms of mutual information. We also investigate the performance of different JSD generalizations in deconstructing chimeric DNA sequences assembled from bacterial genomes including that of E. coli, S. enterica typhi, Y. pestis and H. influenzae. Our results show that the JSD generalizations bring in more pronounced improvements when the sequences being compared are from phylogenetically proximal organisms, which are often difficult to distinguish because of their compositional similarity. While small but noticeable improvements were observed with the Tsallis statistical JSD generalization, relatively large improvements were observed with the Markovian generalization. In contrast, the proposed Tsallis-Markovian generalization yielded more pronounced improvements relative to the Tsallis and Markovian generalizations, specifically when the sequences being compared arose from phylogenetically proximal organisms.publishedVersionFil: Ré, Miguel Ángel. Universidad Tecnológica Nacional. Facultad Regional Córdoba. Centro de Investigación en Informática para la Ingeniería. Departamento de Ciencias Básicas; Argentina.Fil: Ré, Miguel Ángel. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentina.Fil: Azad, Rajeev K. University of North Texas. College of Science. Department of Biological Sciences; Estados Unidos de América.Fil: Azad, Rajeev K. University of North Texas. College of Science. Department of Mathematics; Estados Unidos de América.Ciencias de la Información y Bioinformática (desarrollo de hardware va en 2.2 "Ingeniería Eléctrica, Electrónica y de Información" y los aspectos sociales van en 5.8 "Comunicación y Medios"

    Local circuits targeting parvalbumin-containing interneurons in layer IV of rat barrel cortex

    Get PDF
    Interactions between inhibitory interneurons and excitatory spiny neurons and also other inhibitory cells represent fundamental network properties which cause the so-called thalamo-cortical response transformation and account for the well-known receptive field differences of cortical layer IV versus thalamic neurons. We investigated the currently largely unknown morphological basis of these interactions utilizing acute slice preparations of barrel cortex in P19-21 rats. Layer IV spiny (spiny stellate, star pyramidal and pyramidal) neurons or inhibitory (basket and bitufted) interneurons were electrophysiologically characterized and intracellularly biocytin-labeled. In the same slice, we stained parvalbumin-immunoreactive (PV-ir) interneurons as putative target cells after which the tissue was subjected to confocal image acquisition. Parallel experiments confirmed the existence of synaptic contacts in these types of connection by correlated light and electron microscopy. The axons of the filled neurons differentially targeted barrel PV-ir interneurons: (1) The relative number of all contacted PV-ir cells within the axonal sphere was 5–17% for spiny (n = 10), 32 and 58% for basket (n = 2) and 12 and 13% for bitufted (n = 2) cells. (2) The preferential subcellular site which was contacted on PV-ir target cells was somatic for four and dendritic for five spiny cells; for basket cells, there was a somatic and for bitufted cells a dendritic preference in each examined case. (3) The highest number of contacts on a single PV-ir cell was 9 (4 somatic and 5 dendritic) for spiny neurons, 15 (10 somatic and 5 dendritic) for basket cells and 4 (1 somatic and 3 dendritic) for bitufted cells. These patterns suggest a cell type-dependent communication within layer IV microcircuits in which PV-ir interneurons provide not only feed-forward but also feedback inhibition thus triggering the thalamo-cortical response transformation
    corecore