124 research outputs found

    Skewed temperature dependence affects range and abundance in a warming world

    Get PDF
    Population growth metrics such as R0 are usually asymmetric functions of temperature, with cold-skewed curves arising when the positive effects of a temperature increase outweigh the negative effects, and warm-skewed curves arising in the opposite case. Classically, cold-skewed curves are interpreted as more beneficial to a species under climate warming, because cold-skewness implies increased population growth over a larger proportion of the species's fundamental thermal niche than warm-skewness. However, inference based on the shape of the fitness curve alone, and without considering the synergistic effects of net reproduction, density and dispersal, may yield an incomplete understanding of climate change impacts. We formulate a moving-habitat integrodifference equation model to evaluate how fitness curve skewness affects species’ range size and abundance during climate warming. In contrast to classic interpretations, we find that climate warming adversely affects populations with cold-skewed fitness curves, positively affects populations with warm-skewed curves and has relatively little or mixed effects on populations with symmetric curves. Our results highlight the synergistic effects of fitness curve skewness, spatially heterogeneous densities and dispersal in climate change impact analyses, and that the common approach of mapping changes only in R0 may be misleading

    Polar Bears Are Threatened by the Effects of Climate Change

    Get PDF
    The rapid warming of the Arctic caused by climate change is negatively affecting polar bears. This research proposes an accurate method of predicting polar bear population abundance under climate change. This will aid with proactive conservation measures.York's Knowledge Mobilization Unit provides services and funding for faculty, graduate students, and community organizations seeking to maximize the impact of academic research and expertise on public policy, social programming, and professional practice. It is supported by SSHRC and CIHR grants, and by the Office of the Vice-President Research & Innovation. [email protected] www.researchimpact.c

    Az Istállós-kői-barlang ásatásának folytatása és a Bükki Aurignaci kérdése = Continuation of Excavating Istállós-kő Cave and Problem of Bükk Aurignacian

    Get PDF
    A T046892 OTKA pályázat kutatási programja keretében 2004-2005-ben sikerült tovább folytatni az Istállós-kői-barlang, 2005-2006-ban pedig a Herman Otto-barlang revíziós ásatását elvégezni. A program keretében lehetőség nyílt a teljes Bükki-Aurignacien kultúra techno-tipológiai és komplex rétegtani-őskörnyezettani, kronológiai és paleoetnológiai feldolgozására. Szerencsés módon William Davies (University of Southampton) és Marcel Otte (Universite de Liege) C14 programjával együttműködve, több új radiometrikus kormeghatározást elvégezni a Bükki-Aurignacien kultúrával kapcsolatban. Így sor került a különleges jelentőségű Miskolc-Tapolcai-kőfülke Aurignacien koponyaleletének C14 kormeghatározására is. Az eredményeket több konferencián és publikációban mutattuk be. | The number T46892 research program funded by the OTKA, included further excavations and revisions of two main sites: the Istallós-kő (2004-2005) and the Otto Herman Cave (2005-2006). The detailed research program on the Aurignacien Culture in the Bükk Mountains, involved processing all the available data; such as the techno-tipological and the complex stratigraphical-paleoenvironmental, the chronological and the paleoethnological. Working closely with other research programs led by William Davies (University of Southampton) and Marcel Otte (Universite de Liege) we were able to perform many new C14 radiometric dating. Among others, the extremely significant one was done on the occipital bone found in Miskolc-Tapolca's Rockshelter. We have presented the results and conclusions in many conferences and in publications

    Secondary forest is utilized by Great Curassows (Crax rubra) and Great Tinamous (Tinamus major) in the absence of hunting

    Get PDF
    Deforestation and hunting are the leading human-driven disturbances causing population declines of the vulnerable Great Curassow (Crax rubra) and the near threatened Great Tinamou (Tinamus major). These threats typically co-occur, with synergistic effects. We investigated habitat use of Great Curassows and Great Tinamous in the Matapalo corridor of the Osa Peninsula, southwest Costa Rica, where they are not hunted, to understand whether disturbed habitats can be suitable for these species. We analyzed camera trap data from 56 locations and 5579 trapping days using occupancy modeling. We obtained 195 independent captures of Great Curassows at 33 of 56 locations (59%) and 429 independent captures of Great Tinamous at 37 of 56 locations (66%). Great Curassow occupancy did not vary with habitat type but was negatively influenced by distance from roads and by elevation; detection probability varied with habitat type. Great Tinamou occupancy probability was principally related to habitat type; primary, secondary and plantation forest areas all displayed high occupancy probabilities, but occupancy of agricultural land was low. Our work suggests that secondary-growth forests can offer valuable complementary habitat to assist in the recovery of these declining species, at least when hunting is controlled and intact forests are nearby

    Efficacy of drug-eluting balloon in patients with bare-metal or drug-eluting stent restenosis.

    Get PDF
    INTRODUCTION: In spite of improving results, the treatment of in-stent restenosis (ISR) of bare-metal stents (BMS), and particularly drug-eluting stents (DES), is a challenging clinical problem. There are promising but limited follow-up data concerning drug-eluting balloons in the treatment of BMS and DES restenosis. The goal of this real-world registry was to assess the long-term safety and efficacy of drug-eluting balloons in the treatment of BMS and DES restenosis. METHODS: In this prospective registry, 82 patients with BMS or DES restenosis treated with paclitaxel-eluting balloons were enrolled. The primary endpoint was ischemia-driven target lesion revascularization (TLR); a secondary endpoint was the rate of major adverse cardiac events (MACE) at 28 months. RESULTS: Thirty-five patients (42.7%) had DES ISR and 16 patients (19.5%) presented with an acute coronary syndrome. The success rate of drug-eluting balloon inflation was 97.6%. The median (interquartile range) duration of follow up was 28.0 (25.0-30.3) months. The rate of TLR was 24.5%, and was not significantly higher in the DES-ISR group than in the BMS-ISR group: 29.0% vs. 21.1%, respectively (p=0.687). There were two cases of definite stent thrombosis in the BMS-ISR group and one probable subacute stent thrombosis in the DES-ISR group. The overall MACE rate was 37.0% and did not differ between the DES-ISR and BMS-ISR group (40.8% vs. 34.7%, respectively; p=0.994). CONCLUSIONS: This real-world registry provided less favorable long-term results for drug-eluting balloons in the treatment of BMS restenosis and in DES restenosis, compared to the promising mid-term results of previous studies. The TLR rate was slightly but not significantly higher after DES restenosis compared to BMS restenosis treatment

    More than one way to count a cat: estimation of ocelot population density using frameworks for marked and unmarked species

    Get PDF
    Camera-traps have become one of the most common tools for studying wildlife abundance and population density. Traditionally, absolute density could be estimated only for species with individual markings, using capture–recapture frameworks. Newer methods allow to estimate density of unmarked species, but these have yet to be thoroughly tested and compared against capture–recapture methods. To make this comparison requires an identifiable species, for which both types of frameworks can be used. Here, we estimate the population density of ocelots (Leopardus pardalis) in the Osa peninsula, Costa Rica, comparing methods for marked and unmarked species. We deployed camera-trap grids between 2017 and 2019, identified individuals and determined spatially resolved individual detection histories, station-specific detection frequencies and times to first detection. Estimates obtained with methods for unmarked species (Time-to-Event and Random Encounter Model) varied widely among surveys, from 11 to 169 individuals/100 km2, and were significantly different from spatial capture–recapture estimates (28.1 individuals/100 km2). Differences were largely driven by the non-random placement of cameras on human-made trails, which inflated the detection frequency. Maximizing the number of encounters benefits methods based on capture–recapture but is detrimental for methods based on random detections. Our results highlight the incompatibility between surveys designed for capture–recapture analyses, and those that assume random movement of animals. For recently developed unmarked species methods to be used for a larger and more diverse set of species, it is necessary to further test and define the requirements and factors that affect their calculations. This information will ultimately allow for a greater diversity of population and community studies

    MSTO1 is a cytoplasmic pro-mitochondrial fusion protein, whose mutation induces myopathy and ataxia in humans.

    Get PDF
    The protein MSTO1 has been localized to mitochondria and linked to mitochondrial morphology, but its specific role has remained unclear. We identified a c.22G > A (p.Val8Met) mutation of MSTO1 in patients with minor physical abnormalities, myopathy, ataxia, and neurodevelopmental impairments. Lactate stress test and myopathological results suggest mitochondrial dysfunction. In patient fibroblasts, MSTO1 mRNA and protein abundance are decreased, mitochondria display fragmentation, aggregation, and decreased network continuity and fusion activity. These characteristics can be reversed by genetic rescue. Short-term silencing of MSTO1 in HeLa cells reproduced the impairment of mitochondrial morphology and dynamics observed in the fibroblasts without damaging bioenergetics. At variance with a previous report, we find MSTO1 to be localized in the cytoplasmic area with limited colocalization with mitochondria. MSTO1 interacts with the fusion machinery as a soluble factor at the cytoplasm-mitochondrial outer membrane interface. After plasma membrane permeabilization, MSTO1 is released from the cells. Thus, an MSTO1 loss-of-function mutation is associated with a human disorder showing mitochondrial involvement. MSTO1 likely has a physiologically relevant role in mitochondrial morphogenesis by supporting mitochondrial fusion

    Orexinergic Input to Dopaminergic Neurons of the Human Ventral Tegmental Area

    Get PDF
    The mesolimbic reward pathway arising from dopaminergic (DA) neurons of the ventral tegmental area (VTA) has been strongly implicated in reward processing and drug abuse. In rodents, behaviors associated with this projection are profoundly influenced by an orexinergic input from the lateral hypothalamus to the VTA. Because the existence and significance of an analogous orexigenic regulatory mechanism acting in the human VTA have been elusive, here we addressed the possibility that orexinergic neurons provide direct input to DA neurons of the human VTA. Dual-label immunohistochemistry was used and orexinergic projections to the VTA and to DA neurons of the neighboring substantia nigra (SN) were analyzed comparatively in adult male humans and rats. Orexin B-immunoreactive (IR) axons apposed to tyrosine hydroxylase (TH)-IR DA and to non-DA neurons were scarce in the VTA and SN of both species. In the VTA, 15.062.8% of TH-IR perikarya in humans and 3.260.3% in rats received orexin B-IR afferent contacts. On average, 0.2460.05 and 0.0560.005 orexinergic appositions per TH-IR perikaryon were detected in humans and rats, respectively. The majority(86–88%) of randomly encountered orexinergic contacts targeted the dendritic compartment of DA neurons. Finally, DA neurons of the SN also received orexinergic innervation in both species. Based on the observation of five times heavierorexinergic input to TH-IR neurons of the human, compared with the rat, VTA, we propose that orexinergic mechanism acting in the VTA may play just as important roles in reward processing and drug abuse in humans, as already established well in rodents

    Validation of diagnostic accuracy using digital slides in routine histopathology

    Get PDF
    Background: Robust hardware and software tools have been developed in digital microscopy during the past years for pathologists. Reports have been advocated the reliability of digital slides in routine diagnostics. We have designed a retrospective, comparative study to evaluate the scanning properties and digital slide based diagnostic accuracy. Methods: 8 pathologists reevaluated 306 randomly selected cases from our archives. The slides were scanned with a 20 × Plan-Apochromat objective, using a 3-chip Hitachi camera, resulting 0.465 μm/pixel resolution. Slide management was supported with dedicated Data Base and Viewer software tools. Pathologists used their office PCs for evaluation and reached the digital slides via intranet connection. The diagnostic coherency and uncertainty related to digital slides and scanning quality were analyzed. Results: Good to excellent image quality of slides was recorded in 96%. In half of the critical 61 digital slides, poor image quality was related to section folds or floatings. In 88.2 % of the studied cases the digital diagnoses were in full agreement with the consensus. Out of the overall 36 incoherent cases, 7 (2.3%) were graded relevant without any recorded uncertainty by the pathologist. Excluding the non-field specific cases from each pathologist’s record this ratio was 1.76 % of all cases. Conclusions: Our results revealed that: 1) digital slide based histopathological diagnoses can be highly coherent with those using optical microscopy; 2) the competency of pathologists is a factor more important than the quality of digital slide; 3) poor digital slide quality do not endanger patient safety as these errors are recognizable by the pathologist and further actions for correction could be taken. Virtual slides: The virtual slide(s) for this article can be found here

    The mineralogical composition of calcium and calcium-magnesium carbonate pedofeatures of calcareous soils in the European prairie ecodivision in Hungary

    Get PDF
    Abstract There is little data on the mineralogy of carbonate pedofeatures in the calcareous soils in Hungary which belong to the European prairie ecodivision. The aim of the present study is to enrich these data. The mineralogical composition of the carbonate pedofeatures from characteristic profiles of the calcareous soils in Hungary was studied by X-ray diffractometry, thermal analysis, SEM combined with microanalysis, and stable isotope determination. Regarding carbonate minerals only aragonite, calcite (+ magnesian calcite) and dolomite (+proto-dolomite) were identified in carbonate grains, skeletons and pedofeatures. The values relating, respectively, to stable isotope compositions (C13, O18) of carbonates in chernozems and in salt-affected soils were in the same range as those for recent soils (latter data reported earlier). There were no considerable differences between the values for the carbonate nodules and tubules from the same horizons, nor were there significant variations between the values of the same pedofeatures from different horizons (BC-C) of the same profile. Thus it can be assumed that there were no considerable changes in conditions of formation. Tendencies were recognized in the changes of (i) carbonate mineral associations, (ii) the MgCO3 content of calcites, (iii) the corrected decomposition temperatures, and (iv) the activation energies of carbonate thermal decompositions among the various substance-regimes of soils. Differences were found in substance-regimes types of soils rather than in soil types
    corecore