Non-conventional gas phase remediation of volatile halogenated compounds by dehydrated bacteria

Traditional biological removal processes are limited by the low solubility of halogenated compounds in aqueous media. A new technology appears very suitable for the remediation of these volatile organic compounds (VOCs). Solid/gas bio-catalysis applied in VOC remediation can transform halogenated compounds directly in the gas phase using dehydrated cells as a bio-catalyst.     

Estimation of selected physicochemical properties for methylated naphthalene compounds

Liquid aqueous solubility (S(w,L)), octanol/water partition coefficients (K(ow)), liquid vapor pressure (P(v,L)), and Henry's law constants (H(c)) were estimated for 20 methylated naphthalenes ranging from monomethyl to tetramethylnaphthalenes. Chromatographic methods were used for the estimation. Chromatographic retention measurements were conducted for 11 reference compounds and regressions were fit between the retention indices and the physicochemical properties. HPLC octadecylsilyl column with acetonitrile/water eluent was used for the estimation of S(w,L) and K(ow). Two GC columns, HP5-MS and a more hydrophobic HP-1, were tested for the estimation of P(v,L). Measured retention indices for the methylated naphthalenes were entered to the regression equations to calculate the physicochemical properties for these compounds. Literature values, where available, were used to validate the calculated values. The method accurately estimated the physicochemical properties. Estimated S(w,L) and P(v,L) decreased with the number of methyl groups. K(ow) increased with the number of methyl groups. There was no obvious relation between H(c) and the number of methyl groups. Log S(w,L) ranged from 0.885 for 1,2,5,6-tetramethylnaphthalene to 2.269 for 1-methylnaphthalene (mmol/m(3)). Log K(ow) varied from 3.89 for 1-methylnaphthalene to 4.95 for 1,2,5,6-tetramethylnaphthalene. Log P(v,L) ranged from -0.983 for 1,2,5,6-tetramethylnaphthalene to 0.789 for 2-methylnaphthalene (Pa). Log H(c) varied from 1.03 for 1,4,5-trimethylnaphthalene to 1.73 for 2,6-dimethylnaphthalene (Pa m(3)/mol). There were no apparent effects of GC column hydrophobicity on the accuracy of the results. Estimation of S(w,L) and K(ow) based on GC retention indices was not as accurate as with HPLC. Comparison of the estimated values with values predicted by EPIWIN indicated that EPIWIN is useful in giving order-of-magnitude prediction of physicochemical properties.     

The effects of light and thallus scour from<Emphasis Type="Italic"> Ecklonia radiata</Emphasis> canopy on an associated foliose algal assemblage: the importance of photoacclimation

Kelp canopies have long been recognised for their influence on the structure of algal assemblages on sublittoral reefs. In Marmion Lagoon, Western Australia, we investigated how a canopy of the small kelp Ecklonia radiata affected the associated foliose algal assemblage and what potential mechanisms were responsible for the effects we observed. Light levels and physical abrasion (thallus scour) by an E. radiata canopy were manipulated in an orthogonal fixed-factor experiment that revealed that changes in light, but not thallus scour, had a significant effect on the composition of the algal assemblage. Reduced light levels were associated with a decrease in the Shannon-Wiener diversity index and an increased dominance of the foliose algae Pterocladia lucida and Rhodymenia sonderi. Photobiological investigations of three foliose species, P. lucida, R. sonderi and Chauviniella coriifolia indicated that they were able to photoacclimate to low light levels by increasing thallus absorption by up to 11%. Photoacclimation was also evident by an increase in the maximum rate of electron transport under low-light conditions. We conclude that the E. radiata canopy in Marmion Lagoon structures the foliose algal assemblage through the modification of the light environment and that this effect may be mediated by differences in the ability of different species of foliose algae to photoacclimate.Communicated by M.S. Johnson, Crawley     

Effect of queen quality on interactions between workers and dueling queens in honeybee (Apis mellifera L.) colonies

The fitness of a social insect colony depends greatly on the quality (i.e., mating ability, fecundity, and offspring viability) of its queen(s). In honeybees, there is marked variation in the quality of young queens that compete in a series of lethal duels to replace a colonys previous queen. Workers interact with queens during these duels and could increase their inclusive fitness by biasing the outcomes of the duels in favor of high-quality queens. We predicted that workers will have more antagonistic interactions (chasing, grabbing, clamping) and fewer beneficent interactions (feeding, grooming) with low-quality than high-quality queens. To test this prediction, we reared queens from 0-day-old, 2-day-old, and 3-day-old worker larvae in observation colonies undergoing queen replacement, thus producing high-quality, low-quality, and very low-quality queens, respectively. Immediately after each queen emerged, we observed her for 1 h to record her interactions with the workers. Subsequent morphological measurement of the queens confirmed that initial larval age had a significant effect on queen quality. However, there was no consistent effect of queen quality on the rates of worker–queen interactions, thus falsifying our hypothesis. The mean power of our tests was high (0.599), therefore the probability of a type II error (a false negative) is low. We conclude that if workers actively select high-quality queens, then they do so prior to queen duels, during queen development. We suggest that each worker–queen interaction has a distinct adaptive significance rather than forming a suite of behavior that favors particular queens (e.g., chasing repels any queen that approaches a queen cell, thus protecting all queen cells from destruction).Communicated by M. Giurfa     

Motivating ergonomic computer workstation setup: sometimes training is not enough

Musculoskeletal disorders lead to pain and suffering and result in high costs to industry. There is evidence to suggest that whereas conventional ergonomics training programs result in knowledge gains, they may not necessarily translate to changes in behavior. There were 11 participants in an ergonomics training program, and a subsample of participants received a motivational intervention in the form of incentives for correct workstation setup. Training did not yield any changes in ergonomics measures for any participant. Incentives resulted in marked and durable changes in targeted workstation measures. The data suggest that improving worker knowledge about ergonomically correct workstation setup does not necessarily lead to correct workstation setup, and that motivational interventions may be needed to achieve lasting behavior change.     

Effects of macroalgal structural complexity on nearshore larval and post-larval crab composition

Larval and post-larval crab distribution was surveyed in three different habitats in Kachemak Bay, Alaska to determine temporal and spatial variability. Distribution varied temporally and spatially from June 2005 to September 2006. Nine sites of varying habitat complexity were surveyed monthly using scuba surveys and light traps to measure habitat variables and quantify crab zoeae and megalopae. A total of 10,016 crabs belonging to seven families were identified. Four species comprised the majority (97%) of the total crab assemblages and included Cancer oregonensis, Fabia subquadrata, Telmessus cheiragonus, and Pugettia gracilis. Peak abundances occurred in summer but varied on small temporal scales with species. No single bay-wide variable determined the appearance of all species. Depending on species, appearance may be influenced by seasonality of environmental variables. Spatially, highest abundances occurred in habitats with less structural complexity. Spatial differences in crab abundance may have resulted from variability on large scale physical transport mechanisms and not kelp-mediated flow alterations.     

Understanding and predicting ecological dynamics: are major surprises inevitable?

Ecological surprises, substantial and unanticipated changes in the abundance of one or more species that result from previously unsuspected processes, are a common outcome of both experiments and observations in community and population ecology. Here, we give examples of such surprises along with the results of a survey of well-established field ecologists, most of whom have encountered one or more surprises over the course of their careers. Truly surprising results are common enough to require their consideration in any reasonable effort to characterize nature and manage natural resources. We classify surprises as dynamic-, pattern-, or intervention-based, and we speculate on the common processes that cause ecological systems to so often surprise us. A long-standing and still growing concern in the ecological literature is how best to make predictions of future population and community dynamics. Although most work on this subject involves statistical aspects of data analysis and modeling, the frequency and nature of ecological surprises imply that uncertainty cannot be easily tamed through improved analytical procedures, and that prudent management of both exploited and conserved communities will require precautionary and adaptive management approaches.     

Use of carrion fly iDNA metabarcoding to monitor invasive and native mammals

Severely fragmented habitats increase the risk of extirpation of native mammal populations through isolation, increased edge effects, and predation. Therefore, monitoring the movement of mammal populations through anthropogenically altered landscapes can inform conservation. We used metabarcoding of invertebrate-derived DNA (iDNA) from carrion flies (Calliphoridae and Sarcophagidae) to track mammal populations in the wheat belt of southwestern Australia, where widespread clearing for agriculture has removed most of the native perennial vegetation and replaced it with an agricultural system. We investigated whether the localization of the iDNA signal reflected the predicted distribution of 4 native species—echidna (Tachyglossus aculeatus), numbat (Myrmecobius fasciatus), woylie (Bettongia penicillata), and chuditch (Dasyurus geoffroii)—and 2 non-native, invasive mammal species—fox (Vulpes vulpes) and feral cat (Felis catus). We collected bulk iDNA samples (n = 150 samples from 3428 carrion flies) at 3 time points from 3 conservation reserves and 35 road edges between them. We detected 14 of the 40 mammal species known from the region, including our target species. Most detections of target taxa were in conservation reserves. There were a few detections from road edges. We detected foxes and feral cats throughout the study area, including all conservation reserves. There was a significant difference between the diversity (F_3, 98 = 5.91, p < 0.001) and composition (F_3, 43 = 1.72, p < 0.01) of taxa detections on road edges and conservation reserves. Conservation reserves hosted more native biodiversity than road edges. Our results suggest that the signals from iDNA reflect the known distribution of target mammals in this region. The development of iDNA methods shows promise for future noninvasive monitoring of mammals. With further development, iDNA metabarcoding could inform decision-making related to conservation of endangered taxa, invasive species management, and impacts of habitat fragmentation.     

The jurisdictional framework for municipal action to reduce greenhouse gas emissions: Case studies from Canada, the USA and Germany

This paper addresses two questions: (1) Given a commitment at the national level to reduce greenhouse gas (GHG) emissions, what tools are available to national-level governments to induce complimentary actions required at subnational levels? (2) In the absence of a serious commitment at national and regional levels to reduce GHG emissions, what is the scope for, and jurisdictional rights of, cities to undertake actions? In this context, federal, regional and municipal legislation relevant for GHG emissions is examined in Canada, the USA and Germany. Regarding the first question, different national governments find themselves in considerably different positions to implement climate initiatives at subnational levels, with the German government in the strongest position and the Canadian government in the weakest. The implications of this for a nation's willingness to adopt emission reduction targets could be serious. Regarding the second question, there are few significant differences among Canadian, US and German municipalities' jurisdictional capabilities (and limitations) to reduce GHG emissions. Though limited in their legal capacity, these municipalities demonstrate that through their own, often informal, initiatives they can reinforce and compliment the more formal, regulatory actions by senior-level governments, thereby paving the way for senior-level governments to deliver meaningful domestic emission reductions.