Comparative Effects of Ambient Ultraviolet-B Radiation on Two Sympatric Species of Australian Frogs

Abstract: Declines have been observed in a number of Australian frog species, many of these at high elevations. Alpine regions in Australia are likely to be particularly subject to increases in ultraviolet-B radiation ( UV-B, 280–320 nm) because UV-B levels increase with elevation and because anthropogenic depletion of ozone has been particularly severe in the southern hemisphere. We compared survivorship of embryos and tadpoles of a declining species of frog, Litoria verreauxii alpina , with those of a sympatric nondeclining species, Crinia signifera , under three ambient UV-B treatments, unshielded, control, and UV-B–excluding. Experiments were conducted in artificial water bodies established at three different elevations (1365, 1600, and 1930 m) in the Snowy Mountains of southeastern Australia. The exclusion of UV-B significantly enhanced survival of L. v. alpina (declining species) at all elevations. Overall, the probability of dying was highest in the unshielded treatments and lowest under the UV-B–excluding treatment for both species over all elevations. The probability of dying was significantly higher in L. v. alpina than in C. signifera for a given UV-B treatment at the two highest elevations. Our results support the hypothesis that ultraviolet radiation is likely to be a contributing factor in the disappearance of L. v. alpina at high elevations in southern Australia.     

Calibration and field application of a solvent-based cellulose membrane passive sampling device for the monitoring of polar herbicides

A passive sampler device selective for hydrophilic analytes was constructed from cellulose membrane (40microm thickness) pre-stained with ruthenium red for 96-168h to impede degradation of the cellulose. The sampling device consisted of pre-stained cellulose membrane tubing containing a binary mixture of the solvents 1-dodecanol and 2,2,4-trimethylpentane as the sequestering medium. A laboratory flow-through system was used to investigate the rates of uptake of herbicides into the solvent mixture of the device and their release. The target herbicides were diuron, atrazine, metolachlor and molinate. Uptake of the herbicides into the solvent mixture of the cellulose membrane device was linear for up to 22 days, and daily sampling rates were determined. Release half-lives from the solvent mixture of the sampling device varied from 14 days for diuron, 15 days for atrazine, 84 days for metolachlor and 28 days for molinate. A field study was undertaken to determine if herbicide concentrations in agricultural drainage water derived from the passive sampler devices deployed for periods from 7 to 22 days, using the laboratory-derived sampling rates, would compare closely with time-weighted average herbicide concentrations determined from extractions of daily composite water samples. The concentrations of diuron, atrazine, metolachlor and molinate determined using the cellulose membrane devices were within twofold of the cumulated mean of the daily drainage water extractions.     

Using individual-based movement information to identify spatial conservation priorities for mobile species

The optimal design of reserve networks and fisheries closures depends on species occurrence information and knowledge of how anthropogenic impacts interact with the species concerned. However, challenges in surveying mobile and cryptic species over adequate spatial and temporal scales can mask the importance of particular habitats, leading to uncertainty about which areas to protect to optimize conservation efforts. We investigated how telemetry-derived locations can help guide the scale and timing of fisheries closures with the aim of reducing threatened species bycatch. Forty juvenile speartooth sharks (Glyphis glyphis) were monitored over 22 months with implanted acoustic transmitters and an array of hydrophone receivers. Using the decision-support tool Marxan, we formulated a permanent fisheries closure that prioritized areas used more frequently by tagged sharks and considered areas perceived as having high value to fisheries. To explore how the size of the permanent closure compared with an alternative set of time-area closures (i.e., where different areas were closed to fishing at different times of year), we used a cluster analysis to group months that had similar arrangements of selected planning units (informed by shark movements during that month) into 2 time-area closures. Sharks were consistent in their timing and direction of migratory movements, but the number of tagged sharks made a big difference in the placement of the permanent closure; 30 individuals were needed to capture behavioral heterogeneity. The dry-season (May–January) and wet-season (February–April) time-area closures opened 20% and 25% more planning units to fishing, respectively, compared with the permanent closure with boundaries fixed in space and time. Our results show that telemetry has the potential to inform and improve spatial management of mobile species and that the temporal component of tracking data can be incorporated into prioritizations to reduce possible impacts of spatial closures on established fisheries.     

Converging disciplinary understandings of social aspects of resilience

Resilience thinking has developed separately in the bodies of literature on social-ecological systems, and that published principally within developmental psychology and mental health on the resilience of individuals. This paper explores what these bodies of literature might learn from the other towards a more integrated and enriched understanding of both social-ecological systems and social resilience. The psychology-based literature recognises a strong set of factors that enhance the strengths of individuals and communities, but lacks a sophisticated integration of the physical environmental context. The social-ecological systems literature offers an excellent foundation in complex adaptive systems, but tends to superimpose ecological concepts of system function onto the human domain, and needs to include an array of core social science concepts that are important to a full understanding of social-ecological systems. An example on north eastern Australia suggests how a converged understanding of social resilience could assist managers to acknowledge, enhance and foster social resilience in linked social-ecological systems.     

Affordable CO2 negative emission through hydrogen from biomass,ocean liming,and CO2 storage

Mitigation and Adaptation Strategies for Global Change - A new process to remove carbon dioxide (CO2) from the atmosphere, by combining commercial industrial technologies with ocean liming and CO2...     

Populations of the Sydney rock oyster, Saccostrea glomerata, vary in response to ocean acidification

Acidifying oceans are predicted to fundamentally alter marine ecosystems. Over the next century, acute studies suggest that the impacts of climate change on marine organisms and ecosystems may be catastrophic. To date, however, little is known about whether the response of marine organisms varies within a species and whether this provides a potential ??adaptive capacity??. Here, we show that selectively bred lines of the ecologically and economically important estuarine mollusc, the Sydney rock oyster Saccostrea glomerata, are more resilient to ocean acidification than the wild populations. When reared at elevated pCO₂, we found a 25% reduction in shell growth of the selectively bred population of the Sydney rock oyster, Saccostrea glomerata, compared to a 64% reduction in shell growth of wild populations. This study shows that there are significantly different sensitivities to ocean acidification even within the same species, providing preliminary evidence that selective breeding may be a solution for important aquaculture industries to overcome the future effects of ocean acidification.     

The Tucson Mineral Show and the market for collector minerals: The potential for artisanal and small scale miners

Minerals that are sold to collectors are often produced by artisanal and small scale miners in many developing countries. The market for collector minerals is not well understood by most government agencies or NGOs but has a large impact on the artisanal and small miners that have the opportunity to produce these minerals because of the high prices that can be realized. This paper describes the collector mineral market that is held annually in Tucson, Arizona, that analyzes the competitive forces that affect the profitability of the mineral dealers at the show and describes potential methods for artisanal and small scale miners to participate successfully in the show. Most collector minerals produced by artisanal and small-scale miners are valued for their aesthetic qualities instead of mineral content. The 43 shows that operate during the first two weeks in February make up the largest gem and mineral show in the world, the Tucson Show. The Tucson Mineral Show is a subgroup of six shows that specialize primarily in collector minerals.There are several competitive forces at the Tucson Mineral Show that can affect the profit potential of dealers that participate in the show. These forces include potential entrants, suppliers, buyers, substitutes, and rivalry among existing competitors. New entrants face several barriers to entering the market place including the supply side economies of scale, demand side benefits of scale, and capital requirements. Because of these barriers, the cost of doing business and the way that promoters organize and manage the shows, it is difficult for artisanal and small scale miners to enter the show and compete with established dealers. However, with support from entities such as local governments, non-profit organizations, and international organizations the artisanal and small scale miners have the potential to have their minerals sold at the Tucson Shows for prices that would be greater than what can be achieved in the local market. Methods to help the artisanal and small scale miners compete include direct sales or consignments to retail dealers, tailgating, development of sales co-operatives, and the creation of an artisanal/small scale mineral show.     

Performance of single-gene noninvasive prenatal testing for autosomal recessive conditions in a general population setting

Objective

Carrier screening with reflex to single-gene noninvasive prenatal testing (sgNIPT) is an alternative approach for identifying pregnancies at risk for inherited autosomal recessive conditions without the need for a sample from the reproductive partner. This study is the largest clinical validation of this approach in a general population setting.

Methods

The clinical performance of carrier screening with reflex to sgNIPT for cystic fibrosis, spinal muscular atrophy, alpha thalassemias, and beta hemoglobinopathies was assessed by collecting pregnancy outcome data on patients who underwent this testing and comparing the neonatal outcome to the assay-predicted fetal risk.

Results

Of 42,067 pregnant individuals who underwent screening, 7538 carriers (17.9%) had reflex sgNIPT, and neonatal or fetal outcomes were obtained for 528 cases, including 25 affected pregnancies. Outcomes demonstrated high concordance with sgNIPT, for example, all pregnancies with 9 in 10 personalized fetal risk results were affected (positive predictive value (PPV) of 100% for the sub-group) and the sgNIPT assay showed a sensitivity of 96.0% (95% CI: 79.65%–99.90%), specificity of 95.2% (95% CI: 92.98%–96.92%), average PPV of 50.0% (95% CI: 35.23%–64.77%), and negative predictive value (NPV) of 99.8% (95% CI: 98.84%–99.99%). The end-to-end performance of carrier screening with reflex to sgNIPT was calculated to have a sensitivity of 92.4% and specificity of 99.9%, which are unaffected by partner carrier screening or misattributed paternity unlike a traditional carrier screening workflow, which has a 35% sensitivity and a maximum of 25% PPV (1 in 4) in a real-life setting.

Conclusion

This study builds upon earlier findings to confirm that carrier testing with reflex to sgNIPT is highly accurate for general population screening. Given this high accuracy and an NPV of 99.8%, this workflow should be considered as an option for most of the general pregnant population. When the biological partner sample is unavailable, this workflow should be recommended as the first-line approach.