15 research outputs found

    Dynamic spatio-temporal patterns of metapopulation occupancy in patchy habitats

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    Spatio-temporal dynamics in habitat suitability and connectivity among mosaics of heterogeneous wetlands are critical for biological diversity and species persistence in aquatic patchy landscapes. Despite the recognized importance of stochastic hydroclimatic forcing in driving wetlandscape hydrological dynamics, linking such effects to emergent dynamics of metapopulation poses significant challenges. To fill this gap, we propose here a dynamic stochastic patch occupancy model (SPOM), which links parsimonious hydrological and ecological models to simulate spatio-temporal patterns in species occupancy in wetlandscapes. Our work aims to place ecological studies of patchy habitats into a proper hydrologic and climatic framework to improve the knowledge about metapopulation shifts in response to climate-driven changes in wetlandscapes. We applied the dynamic version of the SPOM (D-SPOM) framework in two wetlandscapes in the US with contrasting landscape and climate properties. Our results illustrate that explicit consideration of the temporal dimension proposed in the D-SPOM is important to interpret local- A nd landscape-scale patterns of habitat suitability and metapopulation occupancy. Our analyses show that spatio-temporal dynamics of patch suitability and accessibility, driven by the stochasticity in hydroclimatic forcing, influence metapopulation occupancy and the topological metrics of the emergent wetlandscape dispersal network. D-SPOM simulations also reveal that the extinction risk in dynamic wetlandscapes is exacerbated by extended dry periods when suitable habitat decreases, hence limiting successful patch colonization and exacerbating metapopulation extinction risks. The proposed framework is not restricted only to wetland studies but could also be applied to examine metapopulation dynamics in other types of patchy habitats subjected to stochastic external disturbances

    Understanding Factors Associated With Psychomotor Subtypes of Delirium in Older Inpatients With Dementia

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    Stochastic dynamics of wetlandscapes: Ecohydrological implications of shifts in hydro-climatic forcing and landscape configuration

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    Wetlands play an important role in watershed eco\u2010hydrology. The occurrence and distribution of wetlands in a landscape are affected by the surface topography and the hydro\u2010climatic conditions. Here, we propose a minimalist probabilistic approach to describe the dynamic behaviour of wetlandscape attributes, including number of inundated wetlands and the statistical properties of wetland stage, surface area, perimeter, and storage volume. The method relies on two major assumptions: (a) wetland bottom hydrologic resistance is negligible; and (b) groundwater level is parallel to the mean terrain elevation. The approach links the number of inundated wetlands (depressions with water) to the distribution of wetland bottoms and divides, and the position of the shallow water table. We compared the wetlandscape attribute dynamics estimated from the probabilistic approach to those determined from a parsimonious hydrologic model for groundwater\u2010dominated wetlands. We test the reliability of the assumptions of both models using data from six cypress dome wetlands in the Green Swamp Wildlife Management Area, Florida. The results of the hydrologic model for groundwater\u2010dominated wetlands showed that the number of inundated wetlands has a unimodal dependence on the groundwater level, as predicted by the probabilistic approach. The proposed models provide a quantitative basis to understand the physical processes that drive the spatiotemporal hydrologic dynamics in wetlandscapes impacted by shallow groundwater fluctuations. Emergent patterns in wetlandscape hydrologic dynamics are of key importance not only for the conservation of water resources, but also for a wide range of eco\u2010hydrological services provided by connectivity between wetlands and their surrounding uplands

    Dynapenic abdominal obesity as predictor of mortality and disability worsening in older adults: A 10-year prospective study

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    There are relatively few prospective studies evaluating the combined effect of abdominal obesity and low muscle strength on worsening disability and on mortality. The study aimed at evaluating prospectively the prognostic value of dynapenic abdominal obesity definition on disability worsening in a 5.5-year follow-up and mortality in a 10-year follow-up. Methods: In 93 men and 169 women aged between 66 and 78 years, leg isometric strength, waist circumference (WC), BMI, glycemia, HOMA, lipid profile, vitamin D3, albumin, fibrinogen, physical activity level, income, smoking status and comorbidities were evaluated at the baseline.Reported disabilities were measured at baseline, 1-y, 2-y, 3-y and 5.5-y follow-up and mortality rate was evaluated during a 10-y follow-up. The study population was categorized in dynapenic abdominal obese (D/AO), nondynapenic abdominal obese (ND/AO), dynapenic nonabdominal obese (D/NAO), nondynapenic nonabdominal obese (ND/NAO) according to muscle strength/WC tertiles. Results: D/NAO subjects presented a disability worsening risk of 1.69 times (95%CI:1.11-2.57), ND/AO subjects showed a 2-fold increase in risk (95%CI:1.34-2.98), while being D/AO more than trebled the risk, even after considering confounding variables (HR:3.39,95%CI:1.91-6.02).Mortality risk after adjustment for other confounding variables was 1.57 (95%CI:1.16-2.13) for ND/AO and 2.46 (95%CI:1.34-4.52) for D/AO. Conclusions: Dynapenic abdominal obese subjects are at higher risk of worsening disability and mortality than subjects with dynapenia or central fat distribution only

    Dynamic spatio-temporal patterns of metapopulation occupancy in patchy habitats

    No full text
    Spatio-temporal dynamics in habitat suitability and connectivity among mosaics of heterogeneous wetlands are critical for biological diversity and species persistence in aquatic patchy landscapes. Despite the recognized importance of stochastic hydroclimatic forcing in driving wetlandscape hydrological dynamics, linking such effects to emergent dynamics of metapopulation poses significant challenges. To fill this gap, we propose here a dynamic stochastic patch occupancy model (SPOM), which links parsimonious hydrological and ecological models to simulate spatio-temporal patterns in species occupancy in wetlandscapes. Our work aims to place ecological studies of patchy habitats into a proper hydrologic and climatic framework to improve the knowledge about metapopulation shifts in response to climate-driven changes in wetlandscapes. We applied the dynamic version of the SPOM (D-SPOM) framework in two wetlandscapes in the US with contrasting landscape and climate properties. Our results illustrate that explicit consideration of the temporal dimension proposed in the D-SPOM is important to interpret local- and landscape-scale patterns of habitat suitability and metapopulation occupancy. Our analyses show that spatio-temporal dynamics of patch suitability and accessibility, driven by the stochasticity in hydroclimatic forcing, influence metapopulation occupancy and the topological metrics of the emergent wetlandscape dispersal network. D-SPOM simulations also reveal that the extinction risk in dynamic wetlandscapes is exacerbated by extended dry periods when suitable habitat decreases, hence limiting successful patch colonization and exacerbating metapopulation extinction risks. The proposed framework is not restricted only to wetland studies but could also be applied to examine metapopulation dynamics in other types of patchy habitats subjected to stochastic external disturbances

    Identifying sarcopenia in acute care setting patients

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    To evaluate the prevalence of sarcopenia by applying European Working Group on Sarcopenia in Older People (EWGSOP) flow chart in an acute care geriatric unit as well as to test a modified version of the EWGSOP diagnostic algorithm combining handgrip and gait speed test to identify subjects with low muscle mass
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