Chemical investigations of defensive steroid sequestration by the Asian snake Rhabdophis tigrinus

Rhabdophis tigrinus is an Asian natricine snake that possesses unusual defensive glands on the dorsal surface of its neck. These nuchal glands typically contain cardiotonic steroidal toxins known as bufadienolides, which are also abundant in the skin of toads. Feeding experiments demonstrated that toads consumed as prey are the ultimate sources of the bufadienolides in nuchal glands of R. tigrinus. Indeed, snakes on a toad-free Japanese island (Kinkasan, Miyagi Prefecture) lack these compounds in their nuchal glands, confirming that these snakes are unable to synthesize defensive bufadienolides. However, when snakes from Kinkasan are fed toads in the laboratory, they accumulate bufadienolides in their nuchal glands, indicating that they have not lost the ability to sequester defensive compounds from prey. In contrast, R. tigrinus from a toad-rich island (Ishima, Tokushima Prefecture) possess large quantities of bufadienolides, reflecting the abundance of toads from which these compounds can be sequestered. Feeding experiments involving gravid R. tigrinus demonstrated that bufadienolides can be provisioned to offspring so that hatchlings are chemically defended before their first toad meal. Maternal provisioning of bufadienolides can take place through two routes: by deposition in yolk and by diffusion in utero, even late in gestation. We applied bufadienolides to the surface of eggs from Kinkasan and found that the embryos are able to take up these compounds into their nuchal glands, demonstrating the feasibility of uptake across the eggshell. Female R. tigrinus provision bufadienolides to their offspring in direct proportion to their own level of chemical defense. By feeding toad-derived bufotoxins to R. tigrinus hatchlings, we determined that the sequestration of these compounds involves at least three types of modification: hydrolytic cleavage of suberylarginine side chains, hydroxylation, and epimerization.     

Tertiary recycling of plastics waste: an analysis of feedstock,chemical and biological degradation methods

Journal of Material Cycles and Waste Management - Globally, there is rising awareness of the severity of the plastic waste problem, and the implications of plastics accumulation in the environment....     

Acquisition of fission–fusion social organization in a chimpanzee (Pan troglodytes troglodytes) community released into the wild

The social aspects of primate reintroduction are of primary importance to the success of release programs and need to be assessed through the study of changes in social behavior over time. This study reports on the development of social structure and organization in a community of 37 chimpanzees (Pan troglodytes troglodytes) released into the wild in the Conkouati Douli National Park, Republic of Congo. Analyses of post-release monitoring data collected over 10 years on association patterns between individuals show that during the years following individual releases, chimpanzees exhibited changing social structure and organization until they stabilized in one community living in a fission–fusion system. Social organization development was directly affected by several factors including community size and experience in the wild, while social structure was affected by individual characteristics: gender, pre-release history, and release history. Similarities between social structure and organization observed in the released community and wild chimpanzee communities demonstrate that the release program is a success from a social point of view.     

Synthesis and applications of carbon quantum dots derived from biomass waste: a review

Environmental Chemistry Letters - In the context of the circular economy and decreasing earth resources, waste should be converted into value-added materials such as carbon quantum dots, which are...     

Science and Management of the Introduced Seagrass Zostera japonica in North America

Healthy seagrass is considered a prime indicator of estuarine ecosystem function. On the Pacific coast of North America, at least two congeners of Zostera occur: native Zostera marina, and introduced, Zostera japonica. Z. japonica is considered “invasive” and therefore, ecologically and economically harmful by some, while others consider it benign or perhaps beneficial. Z. japonica does not appear on the Federal or the Oregon invasive species or noxious weed lists. However, the State of California lists it as both an invasive and noxious weed; Washington State recently listed it as a noxious weed. We describe the management dynamics in North America with respect to these congener species and highlight the science and policies behind these decisions. In recent years, management strategies at the state level have ranged from historical protection of Z. japonica as a priority habitat in Washington to eradication in California. Oregon and British Columbia, Canada appear to have no specific policies with regard to Z. japonica. This fractured management approach contradicts efforts to conserve and protect seagrass in other regions of the US and around the world. Science must play a critical role in the assessment of Z. japonica ecology and the immediate and long-term effects of management actions. The information and recommendations provided here can serve as a basis for providing scientific data in order to develop better informed management decisions and aid in defining a uniform management strategy for Z. japonica.     

EVALUATION OF GREAT LAKES NET BASIN SUPPLY FORECASTS1

ABSTRACT: Evaluation of the Great Lakes Environmental Research Laboratory's (GLERL's) physically-based monthly net basin supply forecast method reveals component errors and the effects of model improvements for use on the Laurentian Great Lakes. While designed for probabilistic outlooks, it is assessed for giving deterministic outlooks along with other net basin supply forecast methods of the U.S. Army Corps of Engineers and Environment Canada, and with a stochastic approach commissioned by the Corps. The methods are compared to a simple clima-tological forecast and to actual time series of net basin supplies. Aetual net basin supplies are currently determined by estimating all components directly, instead of as water-balance residuals. This is judged more accurate and appropriate for both forecasting and simulation. GLERL's physically-based method forecasts component supplies while the other methods are based on residual supplies. These other methods should be rederived to be based on component supplies. For each of these other methods, differences between their outlooks and residual supplies are used as error estimates for the rederived methods and component supplies. The evaluations are made over a recent period of record high levels followed by a record drought. Net basin supply outlooks are better than climatology, and GLERL's physically-based method performs best with regard to either component or residual net basin supplies. Until advances are made in long-range climate outlooks, deterministic supply outlooks cannot be improved significantly.     

Improved direct molecular diagnosis and rapid fetal sexing

Adaptations of the techniques of modern molecular biology to prenatal diagnosis has opened new avenues for the detection of genetic diseases. We have taken advantage of the rapid adhesion of colony forming cells in cultured amniotic fluid samples to develop an improved method for molecular diagnosis. By employing the cell adherence regime sickle cell diagnosis using Mst II can be undertaken directly. In addition, hybridization with a cloned repetitive sequence that is of Y origin and has limited autosomal homology permits rapid fetal sexing in 3 to 4 days without compromising conventional cytogenetic or biochemical analysis. This combination of techniques provides a useful adjunct to convential prenatal genetic diagnosis in the second trimester.     

Availability and Extraction of Forest Products in Managed and Primary Forest around a Dayak Village in West Kalimantan, Indonesia

We examined the density and abundance of marketable products in managed forest (rubber gardens, fruit gardens, and dry rice fallows) and in primary forest surrounding the Dayak village of Kembera, near Gunung Palung National Park, West Kalimantan, Indonesia. We calculated the proportion of trees that were marketable and useful for local consumption by counting and identifying trees in each managed forest type, and we documented extraction of products through interviews. Villagers harvested four marketable tree products: tengkawang seeds ( Shorea stenoptera ), durian fruits (various Durio spp.), rubber ( Hevea brasiliensis ), and timber, especially Bornean ironwood ( Eusideroxylon zwageri ). We inventoried trees at least 20 cm diameter at breast height (dbh) of marketed species from 0.4-ha plots in primary forest ( n = 8) and from 0.1-ha plots in each managed forest type ( n = 10–11). With the exception of timber, the density of trees producing a marketable product was significantly higher in the forest type managed for that product than the density of the marketed species, or of similar wild species, in primary forest. Total abundance (product of density and available area) of durian and tengkawang was greater in primary forest; however, villagers gathered these products only from managed forest. We infer from this choice a greater efficiency of harvesting from trees in dense stands near the village. Historically, this choice resulted in deliberate development of fruit gardens in preference or in addition to gathering from the more distant, primary forest. Because of low product density in primary forest, extractive forest reserves or buffer zones designed to encourage the production of fruits such as tengkawang or durian may not provide a sufficient incentive for the protection of primary forest around Kembera and other Dayak villages near Gunung Palung National Park.     

Advanced multivariate analysis to assess remediation of hydrocarbons in soils

Accurate monitoring of degradation levels in soils is essential in order to understand and achieve complete degradation of petroleum hydrocarbons in contaminated soils. We aimed to develop the use of multivariate methods for the monitoring of biodegradation of diesel in soils and to determine if diesel contaminated soils could be remediated to a chemical composition similar to that of an uncontaminated soil. An incubation experiment was set up with three contrasting soil types. Each soil was exposed to diesel at varying stages of degradation and then analysed for key hydrocarbons throughout 161 days of incubation. Hydrocarbon distributions were analysed by Principal Coordinate Analysis and similar samples grouped by cluster analysis. Variation and differences between samples were determined using permutational multivariate analysis of variance. It was found that all soils followed trajectories approaching the chemical composition of the unpolluted soil. Some contaminated soils were no longer significantly different to that of uncontaminated soil after 161 days of incubation. The use of cluster analysis allows the assignment of a percentage chemical similarity of a diesel contaminated soil to an uncontaminated soil sample. This will aid in the monitoring of hydrocarbon contaminated sites and the establishment of potential endpoints for successful remediation.