179 research outputs found

    Revealing microhabitat requirements of an endangered specialist lizard with LiDAR

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    A central principle of threatened species management is the requirement for detailed understanding of species habitat requirements. Difficult terrain or cryptic behaviour can, however, make the study of habitat or microhabitat requirements difficult, calling for innovative data collection techniques. We used high-resolution terrestrial LiDAR imaging to develop three-dimensional models of log piles, quantifying the structural characteristics linked with occupancy of an endangered cryptic reptile, the western spiny-tailed skink (Egernia stokesii badia). Inhabited log piles were generally taller with smaller entrance hollows and a wider main log, had more high-hanging branches, fewer low-hanging branches, more mid- and understorey cover, and lower maximum canopy height. Significant characteristics linked with occupancy were longer log piles, an average of three logs, less canopy cover, and the presence of overhanging vegetation, likely relating to colony segregation, thermoregulatory requirements, and foraging opportunities. In addition to optimising translocation site selection, understanding microhabitat specificity of E. s. badia will help inform a range of management objectives, such as targeted monitoring and invasive predator control. There are also diverse opportunities for the application of this technology to a wide variety of future ecological studies and wildlife management initiatives pertaining to a range of cryptic, understudied taxa

    Fracture Toughness of Composite and Unfilled Restorative Resins

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    Fracture toughness, critical strain energy release rate, and critical stress intensity factor were determined for experimental and commercial restorative resins. A composite resin had lower resistance to arack initiation than an unfilled acrylic resin. The data were consistent with surface failure observed in single-pass wear studies of these resins.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66920/2/10.1177_00220345770560070801.pd

    Computing the output distribution and selection probabilities of a stack filter from the DNF of its positive Boolean function

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    Many nonlinear filters used in practise are stack filters. An algorithm is presented which calculates the output distribution of an arbitrary stack filter S from the disjunctive normal form (DNF) of its underlying positive Boolean function. The so called selection probabilities can be computed along the way.Comment: This is the version published in Journal of Mathematical Imaging and Vision, online first, 1 august 201

    Revealing microhabitat requirements of an endangered specialist lizard with LiDAR

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    A central principle of threatened species management is the requirement for detailed understanding of species habitat requirements. Difcult terrain or cryptic behaviour can, however, make the study of habitat or microhabitat requirements difcult, calling for innovative data collection techniques. We used high-resolution terrestrial LiDAR imaging to develop three-dimensional models of log piles, quantifying the structural characteristics linked with occupancy of an endangered cryptic reptile, the western spiny-tailed skink (Egernia stokesii badia). Inhabited log piles were generally taller with smaller entrance hollows and a wider main log, had more high-hanging branches, fewer low-hanging branches, more mid- and understorey cover, and lower maximum canopy height. Signifcant characteristics linked with occupancy were longer log piles, an average of three logs, less canopy cover, and the presence of overhanging vegetation, likely relating to colony segregation, thermoregulatory requirements, and foraging opportunities. In addition to optimising translocation site selection, understanding microhabitat specifcity of E. s. badia will help inform a range of management objectives, such as targeted monitoring and invasive predator control. There are also diverse opportunities for the application of this technology to a wide variety of future ecological studies and wildlife management initiatives pertaining to a range of cryptic, understudied taxa.Holly S. Bradley, Michael D. Craig, Adam T. Cross, SeanTomlinson, Michael J. Bamford, Philip W. Batema

    Predators in a mining landscape: Threats to a behaviourally unique, endangered lizard

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    First published: 09 June 2022Patchy resource distribution can cluster predator activity around areas of the highest productivity in ecosystems. For the endangered Western Spiny-tailed Skink (Egernia stokesii badia) in Western Australia, the log piles that they permanently inhabit in an otherwise patchy, arid landscape, represent a potentially reliable, high abundance food source for predators. Not only are encounter rates by potential predators of E. s. badia likely to be influenced by vegetation structure at the micro habitat scale but also E. s. badia occurs in a region where minesites and associated infrastructure, such as landfill sites, likely concentrate generalist predators (e.g. Feral Cats and corvids). We assessed the influence of the presence of coarse woody debris (CWD) and distance to the land-fill on predator behaviour towards E. s. badia through plasticine model experiments, unbounded point count bird surveys and camera trapping. We found that CWD inhabited byE. s. badia attracted a greater relative activity of corvids compared with uninhabited CWD, or control sites without CWD. The relative activity of corvids and predatory birds combined increased with decreasing distance from the landfill. Preferential hunting by corvids at CWD inhabited byE. s. badia compared to both uninhabited CWD and open sites suggests that inhabited CWD may be targeted by generalist predators in the region, and that adaptive management may be required for species conservation around active mining areas.Holly S. Bradley, Michael D. Craig, Sean Tomlinson, Adam T. Cross, Michael J. Bamford, Philip W. Batema

    A life-of-mine approach to fauna monitoring is critical for recovering functional ecosystems to restored landscapes

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    First published: 06 September 2021Mineral extraction activities are intensely disruptive to ecosystems and their associated fauna. Few countries globally have comprehensive legislation surrounding mine site restoration, but within Australia, restoration of discontinued mine sites is a legislative requirement. However, substantial ambiguity regarding the optimal techniques for restoring biodiverse and functional fauna assemblages remains, and monitoring activities typically focus on vegetation communities despite functioning ecosystems being reliant on key trophic interactions involving fauna. When fauna are considered, monitoring efforts typically yield baseline surveys of species richness and the presence or absence of conservation-significant taxa. Even where complete ecosystem recovery is not the goal of post-mining ecological recovery, we argue that there is a critical need for a life-of-mine approach to fauna monitoring underpinned by greater dialog between researchers, environmental regulators, and the mining industry. Environmental Impact Assessments should include requirements for the consideration of all potential impacts of mining on the structure, behavior, and ecological roles of fauna communities, restoration practices must facilitate the return of functional, resilient, and biodiverse fauna communities to restored post-mining landscapes, and the scope of monitoring practices should be broadened to a holistic examination of fauna communities. Recognizing, quantifying, and monitoring the impacts of mining activities and subsequent rehabilitation or restoration on fauna is vital to understanding how anthropogenic disturbances affect natural ecosystems, and in assisting in the successful recovery of ecosystem functionality to areas that have been damaged, degraded, or destroyed.Sophie L. Cross, Holly S. Bradley, Emily P. Tudor, Michael D. Craig, Sean Tomlinson, Michael J. Bamford, Philip W. Bateman, Adam T. Cros

    Effect of the Aerosol-Phase State on Secondary Organic Aerosol Formation from the Reactive Uptake of Isoprene-Derived Epoxydiols (IEPOX)

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    Acid-catalyzed reactions between gas- and particle-phase constituents are critical to atmospheric secondary organic aerosol (SOA) formation. The aerosol-phase state is thought to influence the reactive uptake of gas-phase precursors to aerosol particles by altering diffusion rates within particles. However, few experimental studies have explored the precise role of the aerosol-phase state on reactive uptake processes. This laboratory study systematically examines the reactive uptake coefficient (γ) of trans-β-isoprene epoxydiol (trans-β-IEPOX), the predominant IEPOX isomer, on acidic sulfate particles coated with SOA derived from α-pinene ozonolysis. γIEPOX is obtained for core-shell particles, the morphology of which was confirmed by microscopy, as a function of SOA coating thickness and relative humidity. γIEPOX is reduced, in some cases by half of the original value, when SOA coatings are present prior to uptake, especially when coating thicknesses are > 15 nm. The diurnal trend of IEPOX lost to acid-catalyzed reactive uptake yielding SOA compared with other known atmospheric sinks (gas-phase oxidation or deposition) is derived by modeling the experimental coating effect with field data from the southeastern United States. IEPOX-derived SOA is estimated to be reduced by 16-27% due to preexisting organic coatings during the afternoon (12:00 to 7:00 p.m., local time), corresponding to the period with the highest level of production

    Improving Genetic Prediction by Leveraging Genetic Correlations Among Human Diseases and Traits

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    Genomic prediction has the potential to contribute to precision medicine. However, to date, the utility of such predictors is limited due to low accuracy for most traits. Here theory and simulation study are used to demonstrate that widespread pleiotropy among phenotypes can be utilised to improve genomic risk prediction. We show how a genetic predictor can be created as a weighted index that combines published genome-wide association study (GWAS) summary statistics across many different traits. We apply this framework to predict risk of schizophrenia and bipolar disorder in the Psychiatric Genomics consortium data, finding substantial heterogeneity in prediction accuracy increases across cohorts. For six additional phenotypes in the UK Biobank data, we find increases in prediction accuracy ranging from 0.7 for height to 47 for type 2 diabetes, when using a multi-trait predictor that combines published summary statistics from multiple traits, as compared to a predictor based only on one trait. © 2018 The Author(s)

    Genome-wide association study identifies 30 Loci Associated with Bipolar Disorder

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    This paper is dedicated to the memory of Psychiatric Genomics Consortium (PGC) founding member and Bipolar disorder working group co-chair Pamela Sklar. We thank the participants who donated their time, experiences and DNA to this research, and to the clinical and scientific teams that worked with them. We are deeply indebted to the investigators who comprise the PGC. The views expressed are those of the authors and not necessarily those of any funding or regulatory body. Analyses were carried out on the NL Genetic Cluster Computer (http://www.geneticcluster.org ) hosted by SURFsara, and the Mount Sinai high performance computing cluster (http://hpc.mssm.edu).Bipolar disorder is a highly heritable psychiatric disorder. We performed a genome-wide association study including 20,352 cases and 31,358 controls of European descent, with follow-up analysis of 822 variants with P<1x10-4 in an additional 9,412 cases and 137,760 controls. Eight of the 19 variants that were genome-wide significant (GWS, p < 5x10-8) in the discovery GWAS were not GWS in the combined analysis, consistent with small effect sizes and limited power but also with genetic heterogeneity. In the combined analysis 30 loci were GWS including 20 novel loci. The significant loci contain genes encoding ion channels, neurotransmitter transporters and synaptic components. Pathway analysis revealed nine significantly enriched gene-sets including regulation of insulin secretion and endocannabinoid signaling. BDI is strongly genetically correlated with schizophrenia, driven by psychosis, whereas BDII is more strongly correlated with major depressive disorder. These findings address key clinical questions and provide potential new biological mechanisms for BD.This work was funded in part by the Brain and Behavior Research Foundation, Stanley Medical Research Institute, University of Michigan, Pritzker Neuropsychiatric Disorders Research Fund L.L.C., Marriot Foundation and the Mayo Clinic Center for Individualized Medicine, the NIMH Intramural Research Program; Canadian Institutes of Health Research; the UK Maudsley NHS Foundation Trust, NIHR, NRS, MRC, Wellcome Trust; European Research Council; German Ministry for Education and Research, German Research Foundation IZKF of Münster, Deutsche Forschungsgemeinschaft, ImmunoSensation, the Dr. Lisa-Oehler Foundation, University of Bonn; the Swiss National Science Foundation; French Foundation FondaMental and ANR; Spanish Ministerio de Economía, CIBERSAM, Industria y Competitividad, European Regional Development Fund (ERDF), Generalitat de Catalunya, EU Horizon 2020 Research and Innovation Programme; BBMRI-NL; South-East Norway Regional Health Authority and Mrs. Throne-Holst; Swedish Research Council, Stockholm County Council, Söderström Foundation; Lundbeck Foundation, Aarhus University; Australia NHMRC, NSW Ministry of Health, Janette M O'Neil and Betty C Lynch

    A importância da associação obesidade e gravidez

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    Characteristics of the evolution of pregnancy in obese women were studied for their effect on newborn infants. Two control groups were observed - one of normal weight pregnant women, one of obese. The variables selected were: the socio-economic status of the family and the mother's age, height, arm circunference, prepregancy weight, total number of pregnancies, parity, weight gain during pregnancy, obstetric complications, birth weight, and fetal vitality. Results showed that pregnancy in obese women differs from that in normal weight women and that they show a larger incidence of obstetric complications. Children of obese mothers had a higher mortality rate principally in the perinatal period; moreover, there was also a higher rate of prematurity and a higher proportion of overweight babies among obese mothers. As a result, the distribution of the curve of the birth weight of infants of obese morthers was higher than that of infants of normal weight mothers. The conclusion reached was that whenever a pregnant obese woman reduced foot intake, with resultant insufficient weight gain, intrauterine growth was affected. Thus, it follows that pregnancy is not the best time for the obese mother to lose weight; for this reason, it is important that she receive adequate guidance in regard to diet. Obesity, therefore, is a factor contributing to high-risk pregnancy which can affect both mother and child.Foram estudados dois grupos de gestantes, sendo um de grávidas normais e outro de obesas, com a finalidade de reconhecer algumas características da evolução da gravidez, em mulheres obesas, e suas repercussões sobre o concepto. Foram relacionadas as seguintes variáveis: status sócio-econômico familiar, idade, altura, perímetro braquial, peso habitual, número de gestações anteriores, paridade materna, ganho de peso durante a gestação, idade gestacional, intercorrências durante a gestação, peso ao nascer e vitalidade do recém-nascido. Pelos resultados concluiu-se que as gestantes obesas são diferentes das normais e apresentam maior incidência de complicações obstétricas. Os recém-nascidos, filhos de obesas, registraram índice maior de mortalidade, principalmente no período perinatal. Houve maior incidência de prematuridade e de fetos macrossômicos, sendo a curva de distribuição de peso ao nascer diferente da dos recém-nascidos das gestantes normais. A média de peso ao nascer das crianças das gestantes obesas é maior que o das normais. Concluiu-se ainda que toda vez que a gestante obesa sofre restrição alimentar, com ganho de peso inadequado, o crescimento intra-uterino é afetado; não sendo, portanto, a época da gravidez a melhor para a obesa perder peso, mas, ao contrário, ela deveria receber uma orientação alimentar adequada. A obesidade é pois um fator de aumento do risco gravídico, que pode afetar tanto a mãe como o concepto
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