2,651 research outputs found
Broader niches revealed by fossil data donât reduce estimates of range loss and fragmentation of African montane trees
This is the author accepted manuscript. The final version is available from Wiley via the DOI in this record.The data supporting the results already exists and is freely available in the Global Biodiversity Information Facility (GBIF) and the African Pollen Database (APD).Aim: Many speciesâ climate tolerances are broader than those estimated from current native ranges. Indeed, some Afromontane treesâ niches are up to 50% larger after incorporating fossil data. This expansion could reduce estimates of speciesâ future range loss due to climate change but also implies strong non-climatic limitations on speciesâ current ranges. One such limitation is land use, which fossil data suggest influences Afromontane tree distribution, preventing these trees from occupying warmer conditions than they currently do. We aim to assess the degree to which the broader climatic tolerances revealed by fossil data buffers projected range loss from climate and land use for Afromontane trees.
Location: Africa.
Time period: Last 21,000 years.
Major taxa studied: Afromontane trees.
Methods: We used species distribution models informed by both current and fossil distributions to project future ranges under climate and land-use projections. Results: We found that projected range reductions are only slightly ameliorated by incorporating fossil distributions and these improvements diminish further under severe land use or climate change scenarios. Taxa that are less impacted by climate are more impacted by intense land use. Depending on the severity of climate and land use, the geographic extent of Afromontane tree speciesâ ranges will contract by 40-85% and the trees will completely be lost from large portions of Africa. We projected that the surviving speciesâ ranges will become increasingly fragmented.
Main conclusions: Maintaining Afromontane ecosystems will require mitigation of both climate and land-use change and protecting areas to optimize connectivity. Our findings caution that species with climate tolerances broader than their current range might not necessarily fare better under strong changes in climate or land use
Properties of HxTaS2
The preparation of Hx TaS2 (0 \u3c x \u3c 0.87) is described. The compounds are only marginally stable at room temperature, slowly evolving H2S and H2 (and possibly Hp in air). Magnetic susceptibility data show that a low temperature transformation in 2H ... TaS2 (at soâąK) is suppressed with the addition of hydrogen, and· at the same time the superconducting transition temperature T c rises from 0.8 to ~4.2âąK at x = 0.11. Heat capacity measurements near this concentration show the superconductivity to be a bulk effect. Finally, by correlation of this data with susceptibility and T c measurements in other intercalation compounds, we suggest that the rise of T c (at low electron transfer) is due to suppression of the low temperature transformation and not due to an excitonic mechanism of superconductivity
Estimating the Economic Value of Australian Stock Herding Dogs
This study aimed to estimate the value of the typical Australian herding dog in terms of predicted return on investment. This required an assessment of the costs associated with owning herding dogs and estimation of the work they typically perform. Data on a total of 4,027 dogs were acquired through The Farm Dog Survey which gathered information from 812 herding dog owners around Australia. The median cost involved in owning a herding dog was estimated to be a total of AU40,000. So, herding dogs typically provided their owners with a 5.2-fold return on investment. When respondents were asked to nominate the maximal, one-off, veterinary expenditure they would consider to remedy an illness or injury for an especially valued dog, the median response was AU$1,001â2,000 which is not concordant with the dogsâ calculated median lifetime value. The current findings equip working dog owners with useful information to make financially appropriate expenditure decisions related to their working dogs. This is expected to increase farm profitability and improve welfare for farm dogs
Valuable Behavioural Phenotypes in Australian Farm Dogs
This report presents findings regarding the ways to optimise the performance of livestock working dogs in Australia. The methods available to optimise dog performance include both environmental and genetic factors. The objectives of this study were to identify objective measures of desirable behavioural phenotypes in Australian livestock working dogs and explore genetic parameters of these \u27quality of working life\u27 traits within the Kelpie breed. The document reports on genotyping that reveals gene-behaviour associations and describes heritability estimates that underpin a database for potential estimated breeding value (EBV) calculations
Valuable Behavioural Phenotypes in Australian Farm Dogs
This report presents findings regarding the ways to optimise the performance of livestock working dogs in Australia. The methods available to optimise dog performance include both environmental and genetic factors. The objectives of this study were to identify objective measures of desirable behavioural phenotypes in Australian livestock working dogs and explore genetic parameters of these \u27quality of working life\u27 traits within the Kelpie breed. The document reports on genotyping that reveals gene-behaviour associations and describes heritability estimates that underpin a database for potential estimated breeding value (EBV) calculations
Estimating the Economic Value of Australian Stock Herding Dogs
This study aimed to estimate the value of the typical Australian herding dog in terms of predicted return on investment. This required an assessment of the costs associated with owning herding dogs and estimation of the work they typically perform. Data on a total of 4,027 dogs were acquired through The Farm Dog Survey which gathered information from 812 herding dog owners around Australia. The median cost involved in owning a herding dog was estimated to be a total of AU40,000. So, herding dogs typically provided their owners with a 5.2-fold return on investment. When respondents were asked to nominate the maximal, one-off, veterinary expenditure they would consider to remedy an illness or injury for an especially valued dog, the median response was AU$1,001â2,000 which is not concordant with the dogsâ calculated median lifetime value. The current findings equip working dog owners with useful information to make financially appropriate expenditure decisions related to their working dogs. This is expected to increase farm profitability and improve welfare for farm dogs
Is early center-based child care associated with tantrums and unmanageable behavior over time up to school entry?
Background. Existing research suggests that there is a relationship between greater exposure to center-based child care and child behavioral problems though the mechanism for the impact is unclear. However the measure used to document child care has usually been average hours, which may be particularly unreliable in the early months when fewer children are in center care. In addition individual trajectories for behavior difficulties have not been studied.
Objective. The purpose of the current study was to examine whether the extent of exposure to center-based child care before two years predicted the trajectory of childrenâs difficult behavior (i.e., tantrums and unmanageable behavior) from 30 to 51 months controlling for child and maternal characteristics.
Method. Data were drawn from UK-based Families, Children and Child Care (FCCC) study (n=1201). Individual growth models were fitted to test the relation between early center-based child care experiences and subsequent difficult behavior.
Results. Children with more exposure to center-based care before two had less difficult behavior at 30 months, but more increase over time. Initial levels were predicted by higher difficult temperament and lower verbal ability. Higher difficult temperament and lower family socio-economic status predicted its change over time.
Conclusion. Findings suggest that early exposure to center-based care before two years old is a risk factor for subsequent behavior problems especially when children have a longer period of exposure. A possible explanatory process is that child coping strategies to manage frustration are less well developed in a group context, especially when they lag behind in expressive language
The quality of different types of child care at 10 and 18 months. A comparison between types and factors related to quality.
The quality of care offered in four different types of non-parental child care to 307 infants at 10 months old and 331 infants at 18 months old was compared and factors associated with higher quality were identified. Observed quality was lowest in nurseries at each age point, except that at 18 months they offered more learning activities. There were few differences in the observed quality of care by child-minders, grandparents and nannies, although grandparents had somewhat lower safety and health scores and offered children fewer activities. Cost was largely unrelated to quality of care except in child-minding, where higher cost was associated with higher quality. Observed ratios of children to adults had a significant impact on quality of nursery care; the more infants or toddlers each adult had to care for, the lower the quality of the care she gave them. Mothers' overall satisfaction with their child's care was positively associated with its quality for home-based care but not for nursery settings
Superconducting d-wave junctions: The disappearance of the odd ac components
We study voltage-biased superconducting planar d-wave junctions for arbitrary
transmission and arbitrary orientation of the order parameters of the
superconductors. For a certain orientation of the superconductors the odd ac
components disappear, resulting in a doubling of the Josephson frequency. We
study the sensitivity of this disappearance to orientation and compare with
experiments on grain boundary junctions. We also discuss the possibility of a
current flow parallel to the junction.Comment: 5 pages, 3 figure
Phase separation transition in liquids and polymers induced by electric field gradients
Spatially uniform electric fields have been used to induce instabilities in
liquids and polymers, and to orient and deform ordered phases of
block-copolymers. Here we discuss the demixing phase transition occurring in
liquid mixtures when they are subject to spatially nonuniform fields. Above the
critical value of potential, a phase-separation transition occurs, and two
coexisting phases appear separated by a sharp interface. Analytical and
numerical composition profiles are given, and the interface location as a
function of charge or voltage is found. The possible influence of demixing on
the stability of suspensions and on inter-colloid interaction is discussed.Comment: 7 pages, 3 figures. Special issue of the J. Phys. Soc. Ja
- âŠ