249 research outputs found

    Distribution and conservation status of two endemic Tasmanian crustaceans, Allanaspides hickmani and Allanaspides helonomus (Syncarida: anaspididae)

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    Extant representatives of the ancient crustacean family Anaspididae (Syncarida) are restricted to the island state of Tasmania, Australia. The most recently described species, Allanaspides helonomus Swain, Wilson, Hickman & Ong, 1970 and A. hickmani Swain, Wilson & Ong, 1971, were described from buttongrass moorland in southwestern Tasmania. Large areas of their habitat were subsequently inundated for hydroelectric power generation. We surveyed the extant distributions of A. hickmani and A. helonomus, assessed potential threats to the species, and reviewed their conservation status against state, national and international criteria. A. hickmani is restricted to a single catchment and occurs in a very small number (<10) of highly fragmented subpopulations on the margins of two hydroelectric impoundments. A. helonomus has a substantially larger range and Area of Occupancy spanning three separate catchments, and is now known to also occur in the Lake Pedder hydro-electric impoundment. Both species are listed as vulnerable on the IUCN Red List. This listing appears warranted for A. hickmani based on its restricted Area of Occupancy and the small number of extant subpopulations. However, A. helonomus no longer appears to fulfil the IUCN criterion for vulnerable. Neither species appears to be eligible for listing as vulnerable under the Australian Environment Protection and Biodiversity Conservation Act 1999 and the Tasmanian Threatened Species Protection Act 1995. The current listing of A. hickmani as rare under the Tasmanian Threatened Species Protection Act 1995 appears warranted as extant subpopulations may be at risk of extinction. The level of risk for A. helonomus is considerably lower than is the case for A. hickmani, and A. helonomus may not be eligible for listing as rare. The potential impacts of climate change on buttongrass moorland may present the most serious long-term threat to the two Allanaspides species

    Terrestrial mammals of a sheep-grazing property on Bruny Island, Tasmania

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    Land-based mammals were surveyed in a mosaic of dry sclerophyll forests and pasture on a sheep-grazing property on Bruny Island, Tasmania, using a range of methods in August 2010. 'This is the first mammal survey of a sheep-grazing property in Tasmania and the first large-scale survey of mammals on Bruny Island. Ten species were recorded comprising seven native and three introduced species. The Little Forest Bat, Vespadelus vulturnus, and the Black Rat, Rattus rattus, were recorded for the first time on Bruny Island, although both are probably long-term residents. No mammal species listed as rare or threatened under Tasmanian or Australian legislation were found on the property. Large numbers of Eastern Quolls, Dasyurus viverrinus, Brushtail Possums, Trichosurus vulpecula, Tasmanian Pademelons, Thylogale billardierii, and Bennetts Wallabies, Macropus rufogriseus, were recorded in a range of dry sclerophyll forests and in pasture. Longnosed Potoroos, Potorous tridactylus, were recorded widely on the property in native vegetation with relatively thick ground cover. Eastern Quoll capture rates were highest in pasture areas and in Eucalyptus ovata forest. Brushtail Possums, Long-nosed Potoroos, Tasmanian Pademelons and Bennetts Wallabies were virtually unrecorded from E. tenuiramis forest and woodlands. Given the level of survey effort and their potential to occur on the property it was remarkable that no Tasmanian Bettong, Bettongia gaimardi, Eastern Barred Bandicoot, Perameles gunnii, Southern Brown Bandicoot, lsoodon obesulus, or introduced House Mouse, Mus musculus, were recorded. We found that camera trapping was more cost-efficient than cage trapping for detecting the presence of mammals on "Murrayfield". Recommendations for ongoing management and monitoring of mammals are provided

    The impact of cave lighting on the bioluminescent display of the Tasmanian glow-worm Arachnocampa tasmaniensis

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    Bioluminescent larvae of the dipteran genus Arachnocampa are charismatic microfauna that can reach high densities in caves, where they attract many visitors. These focal populations are the subjects of conservation management because of their high natural and commercial value. Despite their tourism importance, little is known about their susceptibility and resilience to natural or human impacts. At Marakoopa Cave in northern Tasmania, guided tours take visitors through different chambers and terminate at a viewing platform where the cave lighting is extinguished and a glowing colony of Arachnocampa tasmaniensis (Diptera: Keroplatidae) larvae on the chamber ceiling is revealed. Research has shown that exposure to artificial light can cause larvae to douse or dim their bioluminescence; hence, the cave lighting associated with visitor access could reduce the intensity of the natural display. We used time-lapse digital photography to record light output over 10 days to determine whether cave lighting affects the intensity or rhythmicity of bioluminescence. Simultaneously, another colony in a different section of the cave, away from tourist activity, was photographed over 3 days. Both colonies showed high-amplitude 24 h cycling of bioluminescence intensity, with the peak occurring at 11.50 h at the unvisited site and 12.50 h at the main chamber, so the time of peak display did not appear to be substantially affected by light exposure. Intermittent light exposure experienced by larvae in the main chamber caused detectable reductions in bioluminescence intensity; however, recovery was rapid and the overall shape of the daily bioluminescence curve closely matched that of the unvisited colony. In conclusion, the artificial light exposure regime used in Marakoopa Cave does not have a substantial effect on the timing or quality of the bioluminescence display. The time-lapse photographic monitoring method could be permanently implemented at focal tourism sites to provide information about daily, seasonal and annual fluctuations in the displays, the response to events such as drought and flood, and the population's ability to recover from adverse conditions

    Does publication bias inflate the apparent efficacy of psychological treatment for major depressive disorder? A systematic review and meta-analysis of US national institutes of health-funded trials

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    Background The efficacy of antidepressant medication has been shown empirically to be overestimated due to publication bias, but this has only been inferred statistically with regard to psychological treatment for depression. We assessed directly the extent of study publication bias in trials examining the efficacy of psychological treatment for depression. Methods and Findings We identified US National Institutes of Health grants awarded to fund randomized clinical trials comparing psychological treatment to control conditions or other treatments in patients diagnosed with major depressive disorder for the period 1972–2008, and we determined whether those grants led to publications. For studies that were not published, data were requested from investigators and included in the meta-analyses. Thirteen (23.6%) of the 55 funded grants that began trials did not result in publications, and two others never started. Among comparisons to control conditions, adding unpublished studies (Hedges’ g = 0.20; CI95% -0.11~0.51; k = 6) to published studies (g = 0.52; 0.37~0.68; k = 20) reduced the psychotherapy effect size point estimate (g = 0.39; 0.08~0.70) by 25%. Moreover, these findings may overestimate the "true" effect of psychological treatment for depression as outcome reporting bias could not be examined quantitatively. Conclusion The efficacy of psychological interventions for depression has been overestimated in the published literature, just as it has been for pharmacotherapy. Both are efficacious but not to the extent that the published literature would suggest. Funding agencies and journals should archive both original protocols and raw data from treatment trials to allow the detection and correction of outcome reporting bias. Clinicians, guidelines developers, and decision makers should be aware that the published literature overestimates the effects of the predominant treatments for depression

    Improvement of infrared single-photon detectors absorptance by integrated plasmonic structures

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    Plasmonic structures open novel avenues in photodetector development. Optimized illumination configurations are reported to improve p-polarized light absorptance in superconducting-nanowire single-photon detectors (SNSPDs) comprising short- and long-periodic niobium-nitride (NbN) stripe-patterns. In OC-SNSPDs consisting of ~quarter-wavelength dielectric layer closed by a gold reflector the highest absorptance is attainable at perpendicular incidence onto NbN patterns in P-orientation due to E-field concentration at the bottom of nano-cavities. In NCAI-SNSPDs integrated with nano-cavity-arrays consisting of vertical and horizontal gold segments off-axis illumination in S-orientation results in polar-angle-independent perfect absorptance via collective resonances in short-periodic design, while in long-periodic NCAI-SNSPDs grating-coupled surface waves promote EM-field transportation to the NbN stripes and result in local absorptance maxima. In NCDAI-SNSPDs integrated with nano-cavity-deflector-array consisting of longer vertical gold segments large absorptance maxima appear in 3p-periodic designs due to E-field enhancement via grating-coupled surface waves synchronized with the NbN stripes in S-orientation, which enable to compensate fill-factor-related retrogression.United States. Dept. of Energy (Frontier Research Centers

    Environmental suitability of bare-nosed wombat burrows for Sarcoptes scabiei

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    Some of the most important pathogens affecting wildlife are transmitted indirectly via the environment. Yet the environmental stages of pathogens are often poorly understood, relative to infection in the host, making this an important research frontier. Sarcoptic mange is a globally widespread disease caused by the parasitic mite Sarcoptes scabiei. The bare-nosed wombat (Vombatus ursinus) is particularly susceptible, and their solitary nature and overlapping use of burrows strongly indicate the importance of environmental transmission. However, due to the challenge of accessing and monitoring within wombat burrows, there has been limited research into their suitability for off-host mite survival and environmental transmission (i.e., to serve as a fomite). We created a model using published laboratory data to predict mite survival times based on temperature and humidity. We then implemented innovative technologies (ground-penetrating radar and a tele-operated robotic vehicle) to map and access wombat burrows to record temperature and relative humidity. We found that the stable conditions within burrows were conducive for off-host survival of S. scabiei, particularly in winter (estimated mite survival of 16.41 ± 0.34 days) and less so in warmer and drier months (summer estimated survival of 5.96 ± 0.37 days). We also compared two areas with higher and lower average mange prevalence in wombats (13.35% and 4.65%, respectively), finding estimated mite survival was slightly higher in the low prevalence area (10.10 and 12.12 days, respectively), contrary to our expectations, suggesting other factors are also important for population prevalence. Our study is the first to demonstrate the suitability of the bare-nosed wombat burrow for off-host mite survival and environmental transmission. Our findings have implications for understanding observed patterns of mange, disease dynamics and disease management for not only bare-nosed wombats, but also other burrow or den-obligate species exposed to S. scabiei via environmental transmission

    Lipids modulate the conformational dynamics of a secondary multidrug transporter

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    Direct interactions with lipids have emerged as key determinants of the folding, structure and function of membrane proteins, but an understanding of how lipids modulate protein dynamics is still lacking. Here, we systematically explored the effects of lipids on the conformational dynamics of the proton-powered multidrug transporter LmrP from Lactococcus lactis, using the pattern of distances between spin-label pairs previously shown to report on alternating access of the protein. We uncovered, at the molecular level, how the lipid headgroups shape the conformational-energy landscape of the transporter. The model emerging from our data suggests a direct interaction between lipid headgroups and a conserved motif of charged residues that control the conformational equilibrium through an interplay of electrostatic interactions within the protein. Together, our data lay the foundation for a comprehensive model of secondary multidrug transport in lipid bilayers
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