20 research outputs found

    Evaluating expert-based habitat suitability information of terrestrial mammals with GPS-tracking data

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    Aim Macroecological studies that require habitat suitability data for many species often derive this information from expert opinion. However, expert-based information is inherently subjective and thus prone to errors. The increasing availability of GPS tracking data offers opportunities to evaluate and supplement expert-based information with detailed empirical evidence. Here, we compared expert-based habitat suitability information from the International Union for Conservation of Nature (IUCN) with habitat suitability information derived from GPS-tracking data of 1,498 individuals from 49 mammal species. Location Worldwide. Time period 1998-2021. Major taxa studied Forty-nine terrestrial mammal species. Methods Using GPS data, we estimated two measures of habitat suitability for each individual animal: proportional habitat use (proportion of GPS locations within a habitat type), and selection ratio (habitat use relative to its availability). For each individual we then evaluated whether the GPS-based habitat suitability measures were in agreement with the IUCN data. To that end, we calculated the probability that the ranking of empirical habitat suitability measures was in agreement with IUCN's classification into suitable, marginal and unsuitable habitat types. Results IUCN habitat suitability data were in accordance with the GPS data (> 95% probability of agreement) for 33 out of 49 species based on proportional habitat use estimates and for 25 out of 49 species based on selection ratios. In addition, 37 and 34 species had a > 50% probability of agreement based on proportional habitat use and selection ratios, respectively. Main conclusions We show how GPS-tracking data can be used to evaluate IUCN habitat suitability data. Our findings indicate that for the majority of species included in this study, it is appropriate to use IUCN habitat suitability data in macroecological studies. Furthermore, we show that GPS-tracking data can be used to identify and prioritize species and habitat types for re-evaluation of IUCN habitat suitability data

    Global maps of soil temperature

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    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-kmÂČ resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e., offset) between in-situ soil temperature measurements, based on time series from over 1200 1-kmÂČ pixels (summarized from 8500 unique temperature sensors) across all the world’s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in-situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

    Global maps of soil temperature

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    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0–5 and 5–15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world\u27s major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (−0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

    Global maps of soil temperature.

    Get PDF
    Research in global change ecology relies heavily on global climatic grids derived from estimates of air temperature in open areas at around 2 m above the ground. These climatic grids do not reflect conditions below vegetation canopies and near the ground surface, where critical ecosystem functions occur and most terrestrial species reside. Here, we provide global maps of soil temperature and bioclimatic variables at a 1-km2 resolution for 0-5 and 5-15 cm soil depth. These maps were created by calculating the difference (i.e. offset) between in situ soil temperature measurements, based on time series from over 1200 1-km2 pixels (summarized from 8519 unique temperature sensors) across all the world's major terrestrial biomes, and coarse-grained air temperature estimates from ERA5-Land (an atmospheric reanalysis by the European Centre for Medium-Range Weather Forecasts). We show that mean annual soil temperature differs markedly from the corresponding gridded air temperature, by up to 10°C (mean = 3.0 ± 2.1°C), with substantial variation across biomes and seasons. Over the year, soils in cold and/or dry biomes are substantially warmer (+3.6 ± 2.3°C) than gridded air temperature, whereas soils in warm and humid environments are on average slightly cooler (-0.7 ± 2.3°C). The observed substantial and biome-specific offsets emphasize that the projected impacts of climate and climate change on near-surface biodiversity and ecosystem functioning are inaccurately assessed when air rather than soil temperature is used, especially in cold environments. The global soil-related bioclimatic variables provided here are an important step forward for any application in ecology and related disciplines. Nevertheless, we highlight the need to fill remaining geographic gaps by collecting more in situ measurements of microclimate conditions to further enhance the spatiotemporal resolution of global soil temperature products for ecological applications

    Assessment of Chemical-Induced Impairment of Human Neurite Outgrowth by Multiparametric Live Cell Imaging in High-Density Cultures

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    Chemicals that specifically alter human neurite outgrowth pose a hazard for the development of the nervous system. The identification of such compounds remains a major challenge, especially in a human test system. To address this issue, we developed an imaging-based procedure in LUHMES human neuronal precursor cells to quantify neurite growth of unfixed cultures. Live imaging allowed the simultaneous evaluation of cell viability and neurite outgrowth within one culture dish. The procedure was used to test the hypothesis that inhibitors of specific pathways can impair neurite outgrowth without affecting cell viability. Although the cells were grown at high density to allow extensive networking, overall neurite growth in this complex culture was quantified with a signal-to-noise ratio of > 50. Compounds such as U0126 slowed the extension of neuronal processes at concentrations > 4 times lower than those causing cell death. High numbers of individual viable cells without neurites were identified under such conditions, and neurite outgrowth recovered after washout of the chemical. Also an extensionpromoting compound, Y-27632, was identified by this unique multiparametric imaging approach. Finally, the actions of unspecific cytotoxicants such as menadione, cadmium chloride, and sodium dodecyl sulfate were tested to evaluate the specificity of the new assay. We always found a ratio of EC50 (cell death)/EC50 (neurites) < 4 for such chemicals. The described novel test system may thus be useful both for high-throughput screens to identify neuritotoxic agents and for their closer characterization concerning mode of action, compound interactions, or the reversibility of their effects

    What is aphasia? Results of an international survey

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    Background: Although the literature implies that there is limited public awareness of aphasia, direct data have been lacking. Aims: Therefore, a survey was undertaken to sample public awareness of aphasia. Methods & Procedures: A face-to-face survey of individuals in public places in England, the USA, and Australia was undertaken. A total of 978 individuals were surveyed. Data were analysed to determine the number of informants who had ''heard of aphasia'' and the number with ''basic knowledge of aphasia''. In addition, characteristics of informants were analysed. Outcomes & Results: Of the individuals surveyed, 133 said they had heard of aphasia (13.6%), but only 53 (5.4%) met the criterion of having ''basic knowledge of aphasia''. Conclusions: These findings lend support to the notion that the public lacks awareness or understanding of aphasia. As public awareness can affect funding, quality of services, and public acceptance of individuals with a disorder, public awareness and advocacy campaigns are needed.12 page(s

    Evaluation of developmental toxicants and signaling pathways in a functional test based on the migration of human neural crest cells

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    BACKGROUND: Information on the potential developmental toxicity (DT) of the majority of chemicals is scarce, and test capacities for further animal-based testing are limited. Therefore, new approaches with higher throughput are required. A screening strategy based on the use of relevant human cell types has been proposed by the EPA and others. As impaired neural crest (NC) function is one of the known causes for teratologic effects, testing of toxicant effects on NC is desirable for a DT test battery.OBJECTIVE: To develop a robust and widely applicable human-relevant NC function assay, allowing sensitive screening of environmental toxicants, and a definition of toxicity pathways.METHODS: We generated NC cells from human embryonic stem cells, and after establishing a migration assay of NC (MINC), we tested environmental toxicants as well as inhibitors of physiological signal transduction pathways.RESULTS: Methylmercury (50 nM), valproic acid (> 10 ”M) and Lead-acetate (1 ”M) affected migration of NC more potently than migration of other cell types. The MINC assay correctly identified the neural crest toxicants triadimefon and triadimenol, additionally it showed different sensitivities to various organic and inorganic mercury compounds. Applying classic pharmacologic inhibitors and large-scale microarray gene expression profiling, we found several signaling pathways that are relevant for the migration of NC in the MINC.CONCLUSIONS: The MINC assay faithfully models human NC migration, and reveals impairment of this function by developmental toxicants with good sensitivity and specificity

    Automated image processing to quantify neurite growth in Luhmes human neuronal precursor cells

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    Chemicals that specifically inhibit human neurite outgrowth pose a hazard to the developing nervous system. Identifying such chemicals remains a major challenge in biological research. In response to the need for more efficient methods to identify potential developmental neurotoxicants, an image processing framework is presented that allows to automatically quantify neurite growth in LUHMES human neuronal precursor cells. For this purpose, a H-33342 staining is used in order to identify the outline of the nucleus of each neuronal cell. Based on this outline, a region growing approach is performed that expands the soma until an intensity threshold is reached, which allows to quantify the number of cells with neurites. The results demonstrate that our image processing framework can rapidly quantify chemical effects on neurite outgrowth. Concentration-response data for neurite outgrowth allows for the determination of the specificity of chemical effects on developing neuronal cells. Further studies will examine the utility of the approach for other cell-based assays of neurite outgrowth
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