1,018 research outputs found

    Key aspects of stratospheric tracer modeling using assimilated winds

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    International audienceThis study describes key aspects of global chemistry-transport models and their impact on stratospheric tracer transport. We concentrate on global models that use assimilated winds from numerical weather predictions, but the results also apply to tracer transport in general circulation models. We examined grid resolution, numerical diffusion, air parcel dispersion, the wind or mass flux update frequency, and time interpolation. The evaluation is performed with assimilated meteorology from the "operational analyses or operational data" (OD) from the European Centre for Medium-Range Weather Forecasts (ECMWF). We also show the effect of the mass flux update frequency using the ECMWF 40-year re-analyses (ERA40). We applied the three-dimensional chemistry-transport Tracer Model version 5 (TM5) and a trajectory model and performed several diagnoses focusing on different transport regimes. Covering different time and spatial scales, we examined (1) polar vortex dynamics during the Arctic winter, (2) the large-scale stratospheric meridional circulation, and (3) air parcel dispersion in the tropical lower stratosphere. Tracer distributions inside the Arctic polar vortex show considerably worse agreement with observations when the model grid resolution in the polar region is reduced to avoid numerical instability. The results are sensitive to the diffusivity of the advection. Nevertheless, the use of a computational cheaper but diffusive advection scheme is feasible for tracer transport when the horizontal grid resolution is equal or smaller than 1 degree. The use of time interpolated winds improves the tracer distributions, particularly in the middle and upper stratosphere. Considerable improvement is found both in the large-scale tracer distribution and in the polar regions when the update frequency of the assimilated winds is increased from 6 to 3 h. It considerably reduces the vertical dispersion of air parcels in the tropical lower stratosphere. Strong horizontal dispersion is not necessarily an indication of poor wind quality, as observations indicate. Moreover, the generally applied air parcel dispersion calculations should be interpreted with care, given the strong sensitivity of dispersion with altitude. The results in this study provide a guideline for stratospheric tracer modeling using assimilated winds. They further demonstrate significant progress in the use of assimilated meteorology in chemistry-transport models, relevant for both short- and long-term integrations

    Comparative use of active searches and artificial refuges to detect amphibians in terrestrial environments

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    Artificial refuges (cover boards) are commonly used to survey and monitor herpetofauna in many parts of the world. Despite the extensive use of artificial refuges in mesic environments, their effectiveness for detecting amphibians in temperate zones has rarely been examined. We compared amphibian detection probabilities between two survey methods; active searches of natural habitat and artificial refuges of three different types (corrugated steel, roofing tiles and timber railway sleepers). Our study area included five bioregions encompassing a 1,180 km latitudinal gradient across a modified, temperate eucalypt woodland vegetation community in south-eastern Australia. We deployed 14,778 artificial refuges in terrestrial environments, within patches of remnant vegetation, and collected presence and abundance data on herpetofauna between 1999 and 2017. We used Bayesian logistic regression to identify the most effective survey method for detecting frog species across all bioregions. We modelled frog detections by fitting survey method, time since refuge deployment, and rainfall prior to each survey. We detected 3970 individuals from 18 frog species. Overall, we found active searches and timber substrates most effective for detecting a broad range of species, although detection rates were driven by the numerically abundant spotted marsh frog Limnodynastes tasmaniensis. Timber refuges were effective for detecting several burrowing species, whereas active searches were effective at detecting habitat generalists. Quadratic effects of rainfall prior to survey as opposed to linear effects of time since artificial refuge placement was important in explaining frog detection rates in some bioregions. Active searches, timber railway sleepers and sheets of corrugated steel provide complimentary survey methods for detecting amphibians, although detection rates are influenced by rainfall patterns. Artificial refuges provide a time-effective and standardised method for studying amphibians in their non-breeding terrestrial environment and should be incorporated into future surveys and biodiversity monitoring programs.The work was funded by the Australian Govern-ment's Caring for Our Country Initiative, the National Environmental Science Program's Threatened Species Recovery Hub and the Australian Research Council, and is supported by the Murray Local Land Services, Riverina Local land Services, Central Tablelands Local land Services, North East Catchment Management Authority, Goulburn Broken Catchment Management Authority, NSW Environment Trust, Ian Potter Foundation and the Vincent Fairfax Family Foundation

    Do Patients with Craniosynostosis Have an Increased Incidence of Auditory Neuropathy as Newborns?

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    Neuroscience - Vision & Functional Brain Imaging Poster SessionOBJECTIVE: To investigate the incidence of auditory neuropathy, abnormal auditory brainstem response (ABR) with normal otoacoustic emissions, in newborn patients with craniosynostosis as compared to published standards. DESIGN: A retrospective review of consecutive patients with single or multiple-suture craniosynostosis who were seen between 2002 and 2009. Patients identified by the diagnostic code of craniosynostosis were divided into groups based on suture involvement. The newborn ABR screening and, if patients were referred, diagnosis from audiologic diagnostic testing were obtained from the Missouri Department of Health. Institutional review board approval was obtained. PATIENTS: One hundred and thirty-five patients were identified. Seventy-two were excluded; 3 were listed as “missed” and 69 were not born in-state. The 63 patients included in the study were grouped by involved sutures: 2 left coronal, 7 right coronal, 2 nonsyndromic bicoronal, 3 syndromic bicoronal, 13 sagittal, 17 operative metopic, 15 nonoperative metopic, 1 pansynostosis, and 3 multiple-suture. MAIN OUTCOME MEASURES: The newborn screening results for each patient were recorded as well as the diagnosis from audiologic diagnostics if the patient was referred. RESULTS: Of the 63 patients, 94% (59/63) passed their ABR screening. Four were referred for diagnostic exam in both ears. Of those, one had a normal exam (right coronal) and three did not have diagnostic exams on file (right coronal, bicoronal syndromic and bicoronal non-syndromic). CONCLUSIONS: According to the Centers for Disease Control, 1.8 percent of newborns failed their ABR screening in 2007. Of those, 37% were found to have normal hearing on diagnostic exam. Although our study was inconclusive due to inadequate state records, it does demonstrate an increased incidence in abnormal ABR's in patients with coronal craniosynostosis. This is consistent with a recent publication that demonstrated higher incidence of abnormal ABR's in syndromic coronal craniosynostosis. If auditory abnormalities are present at birth, as our study suggests, the etiology would be unrelated to increased intracranial pressures

    Amphibians in agricultural landscapes: the habitat value of crop areas, linear plantings and remnant woodland patches

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    Mitigating the negative impacts of agriculture on amphibians requires knowledge of how different land uses affect species distribution and community composition. In the case of frogs, there is currently insufficient information on their use of terrestrial habitats in cropping landscapes to inform conservation planning. We examined how four different farmland types (linear plantings, cereal crops, grazing paddocks and woody mulch) and crop harvesting influenced amphibian abundance, richness, body condition and movement. We found the abundance of frogs was significantly higher in linear plantings compared to grazing paddocks and adjacent patches of remnant woodland vegetation. However, species richness and abundance of three individual species did not vary significantly between farmland types. For the most common frog Uperoleia laevigata, body condition was higher at the edges of the woody debris treatment (coupled with higher abundance) and lower in farmland with debris and linear plantings. The body condition of Limnodynastes tasmaniensis and L. interioris was not influenced by farmland type. Frog abundance and condition was largely unaffected by crop harvesting. However, frogs were less common after harvesting at the edges of farmland and within remnant patches. Movement patterns did not suggest mass movement out of crops after harvest, where almost half of all individuals recaptured remained within the farmland. These results suggest that some generalist frog species may have an affinity for habitats within agricultural paddocks, particularly when key habitat features like plantings are present. However, we found overall frog richness was low and did not differ between remnant patches, edges and farmland which may be an indication of habitat degradation within terrestrial habitats across the landscape. Although protection of remnant native vegetation is important, conservation strategies for the protection of amphibians will be ineffective if they do not consider the variety of land uses and the relationships of different species and their microhabitats within and outside of patches.Funding was provided by the Australian Government Research Training Program, Central Tablelands Local Land Services, NSW Environmental Trust and the Lake Cowal Foundation

    PAR5 THE TOTAL COSTS OF TREATMENT WITH VALDECOXIB COMPARED TO GENERIC DICLOFENAC ARE SIMILAR IN PATIENTS WITH RHEUMATOID ARTHRITIS IN GERMANY

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    Spatiotemporal effects of logging and fire on tall, wet temperate eucalypt forest birds

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    Forests globally are subject to disturbances such as logging and fire that create complex temporal variation in spatial patterns of forest cover and stand age. However, investigations that quantify temporal changes in biodiversity in response to multiple forms of disturbance in space and time are relatively uncommon. Over a 10-yr period, we investigated the response of bird species to spatiotemporal changes in forest cover associated with logging and wildfire in the mountain ash (Eucalyptus regnans) forests of southeastern Australia. Specifically, we examined how bird occurrence changed with shifts in the proportion of area burned or logged in a 4.5 km radius surrounding our 88 long-term field survey sites, each measuring 1 ha in size. Overall species richness was greatest in older forest patches, but declined as the amount of fire around each site increased. At the individual species level, 31 of the 37 bird species we modeled exhibited a negative response to the amount of fire in the surrounding landscape, while one species responded positively to fire. Only nine species exhibited signs of recovery in the 6 yr of surveys following the fire. Five species were more likely to be detected as the proportion of logged forest surrounding a site increased, suggesting a possible "concentration effect" with displaced birds moving into unlogged areas following harvesting of adjacent areas. We also identified relationships between the coefficients of life history attributes and spatiotemporal changes in forest cover and stand age. Large-bodied birds and migratory species were associated with landscapes subject to large amounts of fire in 2009. There were associations between old growth stands and small-bodied bird species and species that were not insectivores. Our study shows that birds in mountain ash forests are strongly associated with old growth stands and exhibit complex, time-dependent, and species-specific responses to landscape disturbance. Despite logging and fire both being high-severity perturbations, no bird species exhibited similar responses to fire and logging in the landscape surrounding our sites. Thus, species responses to one kind of landscape-scale disturbance are not readily predictable based on an understanding of the responses to another kind of (albeit superficially similar) disturbance.Threatened Species Recovery Hub of the National Environmental Science Program, Parks Victoria, and Victorian Government Department of Environment, Land, Water and Plannin

    Cell-Free Synthesis of the Mitochondrial ADP/ATP Carrier Protein of Neurospora crassa

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    ADP/ATP carrier protein was synthesized in heterologous cell-free systems programmed with Neurospora poly(A)-containing RNA and homologous cell-free systems from Neurospora. The apparent molecular weight of the product obtained in vitro was the same as that of the authentic mitochondrial protein. The primary translation product obtained in reticulocyte lysates starts with formylmethionine when formylated initiator methionyl-tRNA (fMet-tRNAfMet) was present. The product synthesized in vitro was released from the ribosomes into the postribosomal supernatant. The evidence presented indicates that the ADP/ATP carrier is synthesized as a polypeptide with the same molecular weight as the mature monomeric protein and does not carry an additional sequence
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