1,161 research outputs found

    Flexible Bayesian Dynamic Modeling of Correlation and Covariance Matrices

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    Modeling correlation (and covariance) matrices can be challenging due to the positive-definiteness constraint and potential high-dimensionality. Our approach is to decompose the covariance matrix into the correlation and variance matrices and propose a novel Bayesian framework based on modeling the correlations as products of unit vectors. By specifying a wide range of distributions on a sphere (e.g. the squared-Dirichlet distribution), the proposed approach induces flexible prior distributions for covariance matrices (that go beyond the commonly used inverse-Wishart prior). For modeling real-life spatio-temporal processes with complex dependence structures, we extend our method to dynamic cases and introduce unit-vector Gaussian process priors in order to capture the evolution of correlation among components of a multivariate time series. To handle the intractability of the resulting posterior, we introduce the adaptive Δ\Delta-Spherical Hamiltonian Monte Carlo. We demonstrate the validity and flexibility of our proposed framework in a simulation study of periodic processes and an analysis of rat's local field potential activity in a complex sequence memory task.Comment: 49 pages, 15 figure

    Arthropods and other biota associated with the Azorean trees and shrubs : Laurus azorica (Seub) Franco (Magnoliophyta, Magnoliopsida, Laurales, Lauraceae)

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    This study explores the composition and structure of species communities associated with the native Azorean tree species Laurus azorica (Seub) Franco (Magnoliophyta, Magnoliopsida, Laurales, Lauraceae). Communities were sampled in six Islands covering the occidental (Flores), central (Faial, Pico, Terceira) and eastern (São Miguel, Santa Maria) groups of Azores Archipelago during the BALA project, using standardised sampling protocols for surveying canopy arthropod fauna. In addition, the study characterises the distribution of species regarding their colonisation status and feeding modes and, finally, compares communities of different Islands. Ninety-four arthropod species totalling 10,313 specimens were collected on L. azorica. The Arthropod community was dominated by Hemiptera species, most of them being herbivores. Endemic and native species showed a very high abundance representing about 94% of the total species abundance. However, despite introduced species being represented by few individuals (6% of the total abundance), their diversity was remarkable (28 species and no significant difference with diversity found in endemic and native species communities). Analysis of rarity patterns revealed a stable community of endemic species (alpha gambin SAD model approaching a log-normal shape), intermediate stable community of native species (alpha SAD gambin model approaching a poisson log-normal) and a less stable community of introduced species (alpha SAD gambin model approaching a log-series shape). A dissimilarity analysis revealed high similarity between communities of Terceira and Pico and high dissimilarity between Flores and Faial communities. We observed a clear individualisation of the different islands when considering endemic species, whereas we observed high overlap when considering native and introduced species groups. Canopy community distribution confirms the results obtained in a previous study which suggest the stability of native and endemic arthropods species communities over introduced species community in native forests fragments. Arthropod species were richer than bryophytes, lichens and vascular plants species. We found that L. azorica serve as the substrate for very few vascular plants species (four epiphytes species), which were present in all Islands, except Elaphoglossum semicylindricum, which does not occur in Santa Maria. L. azorica shelters a significant number of bryophytes and lichens species. Thirty-two lichens and 92 bryophyte species, including 57 liverworts and 35 mosses, are referred to this phorophyte. Five bryophyte species, all Azorean endemics, are considered Endangered by IUCN Criteria. L. azorica harbours a poor community of epiphyte vascular plant species and all of them were ferns, but the community of bryophytes and lichens are not negligible although very low compared to the community found on other previously studied Azorean trees, the Azorean cedar Juniperus brevifolia. The present study shows that most islands present particular species distribution patterns without geographical correlation and that conservation programmes should be adapted to each Island. The study, therefore, calls for a specialisation of conservation programmes for each of the Islands.NT and MTF are currently funded by the project LIFE BEETLES (LIFE 18 NAT/PT/000864) at "Secretaria Regional do Ambiente e Alterações Climáticas". PAVB, RE and RG are funded by the project AZORESBIOPORTAL-PORBIOTA (ACORES-01-0145FEDER-000072) (2019).info:eu-repo/semantics/publishedVersio

    Implications of climate change to the design of protected areas : The case study of small islands (Azores)

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    Climate change is causing shifts in species distributions worldwide. Understanding how species distributions will change with future climate change is thus critical for conservation planning. Impacts on oceanic islands are potentially major given the disproportionate number of endemic species and the consequent risk that local extinctions might become global ones. In this study, we use species climate envelope models to evaluate the current and future potential distributions of Azorean endemic species of bryophytes, vascular plants, and arthropods on the Islands of Terceira and Sao Miguel in the Azores archipelago (Macaronesia). We examined projections of climate change effects on the future distributions of species with particular focus on the current protected areas. We then used spatial planning optimization software (PRION) to evaluate the effectiveness of protected areas at preserving species both in the present and future. We found that contractions of species distributions in protected areas are more likely in the largest and most populated island of Sao Miguel, moving from the coastal areas towards inland where the current protected areas are insufficient and inadequate to tackle species distribution shifts. There will be the need for a revision of the current protected areas in Sao Miguel to allow the sustainable conservation of most species, while in Terceira Island the current protected areas appear to be sufficient. Our study demonstrates the importance of these tools for informing long-term climate change adaptation planning for small islands.Peer reviewe

    Long-term monitoring across elevational gradients to assess ecological hypothesis : a description of standardized sampling methods in oceanic islands and first results

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    We are launching a long-term study to characterize the biodiversity at different elevations in several Azorean Islands. Our aim is to use the Azores as a model archipelago to answer the fundamental question of what generates and maintains the global spatial heterogeneity of diversity in islands and to be able to understand the dynamics of change across time. An extensive, standardized sampling protocol was applied in most of the remnant forest fragments of five Azorean Islands. Fieldwork followed BRYOLAT methodology for the collection of bryophytes, ferns and other vascular plant species. A modified version of the BALA protocol was used for arthropods. A total of 70 plots (10 m x 10 m) are already established in five islands (Flores, Pico, São Jorge, Terceira and São Miguel), all respecting an elevation step of 200 m, resulting in 24 stations examined in Pico, 12 in Terceira, 10 in Flores, 12 in São Miguel and 12 in São Jorge. The first results regarding the vascular plants inventory include 138 vascular species including taxa from Lycopodiophyta (N=2), Pteridophyta (N=27), Pinophyta (N=2) and Magnoliophyta (N=107). In this contribution we also present the main research question for the next six years within the 2020 Horizon

    The Yellow-­crowned Night Heron Nyctanassa violacea (Aves: Pelecaniformes: Ardeidae) in the Azores and Madeira Archipelagos: a new species for the Western Palearctic

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    This paper presents and describes the first confirmed occurrence of the Yellow-crowned Night Heron Nyctanassa violacea in the Azores, which also represents the first record for Europe and the Western Palearctic. We also present and discuss subsequent reports of the species in Macaronesia. Several hypotheses may help to explain the occurrence of this species in this part of the Atlantic, including disorientation caused by strong winds and increasing observation pressure. However, further studies are necessary to assess the part played by the different factors in the occurrence of new vagrant individuals/species in Macaronesia

    Assessing the efficiency of protected areas to represent biodiversity : a small island case study

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    Protected areas (PAs) have been selected using either subjective or objective criteria applied to an extremely limited subset of biodiversity. Improved availability of species distribution data, better statistical tools to predict species distributions and algorithms to optimize spatial conservation planning allow many impediments to be overcome, particularly on small islands. This study analyses whether 219 species are adequately protected by PAs on Pico Island (theAzores, Portugal), and if they are as efficient as possible, maximizing species protection while minimizing costs. We performed distribution modelling of species’ potential distributions, proposed individual conservation targets (considering the context of each species in the archipelago and their current conservation status) to determine the efficiency of current PAs in meeting such targets and identify alternative or complementary areas relevant for conservation. Results showed that current PAs do not cover all taxa, leaving out important areas for conservation. We demonstrate that by using optimization algorithms it is possible to include most species groups in spatial conservation planning in the Azores with the current resources. With increasing availability of data and methods, this approach could be readily extended to other islands and regions with high endemism levels.info:eu-repo/semantics/publishedVersio

    Growing up beside you: a relational sociology of early childhood

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    This article will begin by outlining influential attempts by historians and sociologists to develop a more adequate theoretical understanding of past and contemporary childhoods, focusing on the major problems that stem from the pivotal role that ‘developmentalism’ plays in their arguments. I will argue that sociologists can overcome some of their deepest fears about the role of developmental psychology by developing a relational approach that integrates the biological and social aspects of children’s development. In the development of a relational sociology of early childhood we need to make important connections with closely related disciplines, but at the same time draw on and integrate research findings from relevant areas within the social and natural sciences. An alternative perspective drawn from the writings of Norbert Elias will be put forward and illustrated by discussing some of the key concepts that Elias and Vygotsky used to explain the language development of young children

    Studies of the Response of the Prototype CMS Hadron Calorimeter, Including Magnetic Field Effects, to Pion, Electron, and Muon Beams

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    We report on the response of a prototype CMS hadron calorimeter module to charged particle beams of pions, muons, and electrons with momenta up to 375 GeV/c. The data were taken at the H2 and H4 beamlines at CERN in 1995 and 1996. The prototype sampling calorimeter used copper absorber plates and scintillator tiles with wavelength shifting fibers for readout. The effects of a magnetic field of up to 3 Tesla on the response of the calorimeter to muons, electrons, and pions are presented, and the effects of an upstream lead tungstate crystal electromagnetic calorimeter on the linearity and energy resolution of the combined calorimetric system to hadrons are evaluated. The results are compared with Monte Carlo simulations and are used to optimize the choice of total absorber depth, sampling frequency, and longitudinal readout segmentation.Comment: 89 pages, 41 figures, to be published in NIM, corresponding author: P de Barbaro, [email protected]

    Estudo epidemiológico da Infecções do Trato Urinário no Tocantins de 2017 a 2021

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    Introdução: Transtorno do trato urinário é caracterizada pela presença de agente infeccioso na urina. Já a cistite é uma infecção e/ou inflamação da bexiga. Tanto Transtorno do Trato Urinário quanto a cistite caracterizam Infecção do Trato Urinário. O diagnóstico clínico é feito com base no raciocínio clínico e diagnóstico laboratorial. Objetivos: realizar uma arguição epidemiológica das internações por Infecções do Trato Urinário no Tocantins de 2017 a 2021 Metodologia: estudo epidemiológico descritivo, realizado por meio da coleta de dados anuais referentes ao período de 2017 a 2021, no estado do Tocantins (TO), disponibilizado pelo Sistema de Informações Hospitalares (SIH). Resultados: Nos 5 anos de análise foram registrados 1.495 casos. Adultos com 63,87% dos registros foi o grupo etário mais acometido, sendo que mulheres com 87,49% foi o sexo mais atingido. Capim dourado foi a região de saúde com mais notificações (34,51%). Conclusão: as Infecções do Trato Urinário têm suas peculiaridades o que dificulta seu tratamento, nesse viés políticas públicas e estratégias governamentais são precípuos Palavras-chave: Cistite. Trato urinário. Epidemiologia. Transtorn
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