“At the water's edge”: community voices on climate change

The photovoice research project, “At the water's edge”, which gives voice to communities exploring the threats and impact of climate change and rising sea levels on coastal communities, was conducted during an environmental art symposium in the Noosa Biosphere Reserve, Australia in June 2009. Photos by participants illustrated both local and global threats and reflected psychological tension between global and local action. This research partnership with the local people demonstrated an innovative visualisation technique which can be used to collaboratively build capacity and consensus about adaptation to climate change. It also contributed to the Biosphere Reserve's educational and cultural aims in relation to climate change.     

Controlling urban air pollution caused by households: uncertainty, prices, and income

We examine the control of air pollution caused by households burning wood for heating and cooking in the developing world. Since the problem is one of controlling emissions from nonpoint sources, regulations are likely to be directed at household choices of wood consumption and combustion technologies. Moreover, these choices are subtractions from, or contributions to, the pure public good of air quality. Consequently, the efficient policy design is not independent of the distribution of household income. Since it is unrealistic to assume that environmental authorities can make lump sum income transfers part of control policies, efficient control of air pollution caused by wood consumption entails a higher tax on wood consumption and a higher subsidy for more efficient combustion technologies for higher income households. Among other difficulties, implementing a policy to promote the adoption of cleaner combustion technologies must overcome the seemingly paradoxical result that efficient control calls for higher technology subsidies for higher income households.     

Microsatellite data reveal fine genetic structure in male Guiana dolphins (<Emphasis Type="Italic">Sotalia guianesis)</Emphasis> in two geographically close embayments at south-eastern coast of Brazil

A large macrogeographic differentiation has been observed among Sotalia guianensis populations along the South American coast. However, no genetic structure has been detected so far in closely distributed populations of this species, even though it has been observed in other cetaceans. Here, we examined the fine scale population structure for the largest populations of S. guianensis inhabiting Sepetiba and Paraty embayments at the south-eastern coast of Rio de Janeiro, Brazil. Analysis of mitochondrial DNA (mtDNA) control region sequences failed to detect variability among sequences. Conversely, evidence of significant male population structure was found on the basis of ten nuclear microsatellite loci. Surprisingly, the microsatellite markers were able to distinguish between individuals from the two embayments located 60 km apart. The results suggest that differences in habitat type and behavioral specializations are likely to explain the patterns of genetic structure. These findings should provide baselines for the management of communities exposed to increasing human-driven habitat loss.     

Lock-release gravity currents propagating over roughness elements

Environmental Fluid Mechanics - The influence of bottom roughness on the development of lock-release gravity currents is investigated through laboratory experiments using Particle Image...     

Bioassay-guided isolation of allelochemicals from Avena sativa L.: allelopathic potential of flavone C-glycosides

The allelopathic potential of oat (Avena sativa L., var. Argentina, Poaceae, Cyperales) was investigated under field and laboratory conditions. In field trials, oat plants provided an effective control of weeds, showing a species-specific impact: the most abundant weed species, Picris echioides was reduced by 94% in number of individuals. Aerial parts of oat plants, harvested immediately before soil incorporation, were utilized in a bioassay-guided isolation, which was aimed at identifying the phytotoxic compounds in a methanol/water extract of the aerial parts of the plants. Further partitions of extract gave an active n-butanol portion composed of flavonoids and saponins. Phytotoxic activity was detected for the flavonoid fraction, whereas no activity was found for the saponin mixture. Germination of an indicator species, lettuce (Lactuca sativa L.), was completely inhibited at flavonoid concentrations of 6.7, 10.0, and 20.0 mg/mL, and conversely the number of abnormal seedlings was greatly increased from 2% of control to over 96% at concentrations equal to 6.7 and 10.0 mg/mL. Analysis of the flavonoid fraction by ESI-MS techniques identified two components of the mixture as isoorientin 2-O-glucoside and isovitexin 2″-O-arabinoside. Saponins were characterized as avenacoside A, avenacoside B, 26-desglucoavenacoside A, and 26-desglucoavenacoside B. Both flavone C-glycosides and saponins were isolated previously from oat.     

Biotransformation and antioxidant enzymes of Lumbriculus variegates as biomarkers of contaminated sediment exposure

In this study the black worm Lumbriculus variegatus was tested for suitability as biomonitor for moderately contaminated sediments. The response capacity of the biotransformation system phase II enzyme glutathione-S-transferase (GST) and the oxidative defense enzyme catalase (CAT) to contaminated sediment and atrazine was investigated to establish them as sensitive biomarkers. To get an integrated view on the enzyme activity kinetics, increasing concentrations of the herbicide atrazine were applied to stimulate GST response, and relationship between enzyme activity and herbicide concentration was observed at various exposure durations. Furthermore, animals were exposed for up to 1 week to sediments of four typical urban river sections with high anthropogenic impact. L. variegatus was capable to accomplish the environmental stress and the selected enzymes showed elevation. Significant changes of GST (membrane-bound and soluble) were detected after at least 4 days of exposure to atrazine and contaminated sediments. Although CAT increase could be observed already after 1 day of exposure to sediments, an exposure time of one week is considerable for accurate interpretation of the enzymatic response. The clear enzymatic response of especially the membrane-bound GST indicated charges with organic lipophilic substances at all sampling sites.     

Histological changes in the reproductive system of male rats exposed to cigarette smoke or electronic cigarette vapor

Abstract

The use of electronic cigarettes increases as a supposedly healthier form of nicotine consumption, but safety of vaping remains uncertain. In this study, we assessed whether the use of electronic cigarettes increases the risk of infertility in male rats. Malformations of sperm morphology were more frequent in nicotine-exposed groups than in the control group. Vacuolization of seminiferous epithelium, reduction of spermatogenesis, increased apoptosis of spermatogonia and spermatocytes, and acceleration of degeneration of testes were observed. The male reproductive organs are slightly less affected by vaping than by smoking. Nevertheless, in consequence both may lead to the reduction of fertility.     

Environmental pollution of China to foreign investors: detrimental or beneficial?

Environmental Science and Pollution Research - This study investigates the dynamic linkage among foreign direct investment, energy consumption, and environmental pollution of China spanning from...     

A simplified clean-up procedure for the rapid determination of PCDDs and PCDFs based on retention on activated carbon AX-21

Different 2,3,7,8-substituted polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs) were investigated for their retention behaviour on a disposable minicolumn containing activated carbon AX-21. Elution behaviour and recovery were examined, using native and radiolabelled PCDD and PCDF isomers.

A comparison of the total mass chromatograms of PCDDs and PCDFs in an extract from animal adipose tissue, before and after activated carbon treatment, demonstrates the efficiency of this cleanup step with respect to the elimination of interfering compounds.