Comparison of proton-specific ATPase activities in plume and root tissues of two co-occurring hydrocarbon seep tubeworm species Lamellibrachia luymesi and Seepiophila jonesi

Lamellibrachia luymesi and Seepiophila jonesi are co-occurring species of vestimentiferan tubeworms found at hydrocarbon seepage sites on the upper Louisiana slope of the Gulf of Mexico. Like all vestimentiferans, they rely on internal sulfide-oxidizing symbiotic bacteria for nutrition. These symbionts produce hydrogen ions as a byproduct of sulfide oxidation, which the host tubeworm needs to eliminate to prevent acidosis. The hydrothermal vent tubeworm Riftia pachyptila uses a high activity of P- and V-type H⁺-ATPases located in its plume epithelium to excrete protons. Unlike R. pachyptila, the seep species grow a posterior root, which they can use in addition to their plumes as a nutrient exchange surface. In this study we measured the ATPase activities of plume and root tissues collected from L. luymesi and S. jonesi, and used a combination of inhibitors to determine the relative activities of P- and V-type H⁺-ATPases. We found that the total H⁺-ATPase activity of their plumes was approximately 14 μmol h⁻¹ g⁻¹ wet weight, and that of their roots was between 5 and 7 μmol h⁻¹ g⁻¹ wet weight. These activities were more than ten times lower than those measured in R. pachyptila. We suggest that seep tubeworms might use passive channels to eliminate protons across their roots, in addition to ATP-dependant proton pumps located in their plumes and roots. In addition, we found strong differences between the types of ATPase activities in the plumes of L. luymesi and S. jonesi. While the H⁺-ATPase activity of L. luymesi plumes is dominated by P-type ATPases, S. jonesi has an unusually high activity of V-type H⁺-ATPases. We suggest that S. jonesi relies on its high V-type H⁺-ATPase activity to drive carbon dioxide uptake across its plume surface. L. luymesi, on the other hand, might rely partially on bicarbonate uptake across its root.     

Using a combined approach to explain the morphological and ecological diversity in <Emphasis Type="Italic">Phanogenia gracilis</Emphasis> Hartlaub, 1893 (Echinodermata: Crinoidea) <Emphasis Type="Italic">sensu lato</Emphasis>: two species or intraspecific variation?

Phanogenia gracilis sensu lato is a shallow-water crinoid distributed throughout the Indo-western Pacific. The taxonomy of P. gracilis s.l. is clouded by the presence of two distinct morphotypes, each differing in morphology and ecology. The goal was to determine the taxonomic status of P. gracilis s.l. using partial gene sequences of two mitochondrial DNA genes, cytochrome oxidase c subunit I and NADH dehydrogenase subunit II, in conjunction with morphological and ecological data. The molecular phylogenies revealed three lineages separated by 5.0–6.6% corrected genetic distance, which is consistent with the genetic distances among other echinoderm species. Neither morphotype was monophyletic, nor was any examined morphological character exclusive to any one lineage. Discriminant function analysis (DFA) of the morphological and ecological data yielded significant results when grouping P. gracilis by morphotype and by clades recovered in the phylogenetic analyses, but grouping by sample locality was rejected. Although DFA results of grouping by clade were significant, jackknife support was weak, while only correctly grouping specimens by their respective clades 65% of the time. The results suggest the possibility of cryptic species, but additional molecular and morphological data are needed to confirm this. This study demonstrates the need to reevaluate the taxonomy of crinoid species and their respective diagnostic characters.     

利用EQuan~(TM)环境分析系统直接进样技术(20ml)LC-MS/MS分析饮用水样品中飞克级含量除草剂化合物

随着人们对环境中除草剂以及其它化学药物残留的毒性作用关注程度的增加,实现对饮用水以及食物中这些物质的准确检测的需要显得更加迫切.     

When information becomes action: drivers of individuals' trust in broadcast versus peer‐to‐peer information in disaster response

Information and communications technology (ICT), primarily mobile telephones and social media, is increasingly important in crisis and disaster response in developing countries. This fact raises an important question: in an information environment that includes traditional media such as radio and television, who are the people that trust information from ICT enough to act on it during a disaster? Drawing on a case study of and original survey data from the island nation of the Independent State of Samoa, this paper yields insights into who uses new technologies, particularly mobile telephones, to make decisions at the local level during crises such as natural disasters, as well as the socio‐political factors that motivate their behaviour. The results add to the growing pool of knowledge on utilisation of ICT and new technologies in developing countries for disaster response, and provide practical information on the social and political factors that lead people to trust different information sources and media.     

Microbial responses to combined oxidation and catalysis treatment of 1,4-dioxane and co-contaminants in groundwater and soil

Post-treatment impacts of a novel combined hydrogen peroxide (H₂O₂) oxidation and WO_x/ZrO₂ catalysis used for the removal of 1,4-dioxane and chlorinated volatile organic compound (CVOC) contaminants were investigated in soil and groundwater microbial community. This treatment train removed ~90% 1,4-dioxane regardless of initial concentrations of 1,4-dioxane and CVOCs. The Illumina Miseq platform and bioinformatics were used to study the changes to microbial community structure. This approach determined that dynamic shifts of microbiomes were associated with conditions specific to treatments as well as 1,4-dioxane and CVOCs mixtures. The biodiversity was observed to decrease only after oxidation under conditions that included high levels of 1,4-dioxane and CVOCs, but increased when 1,4-dioxane was present without CVOCs. WO_x/ZrO₂ catalysis reduced biodiversity across all conditions. Taxonomic classification demonstrated oxidative tolerance for members of the genera Massilia and Rhodococcus, while catalyst tolerance was observed for members of the genera Sphingomonas and Devosia. Linear discriminant analysis effect size was a useful statistical tool to highlight representative microbes, while the multidimensional analysis elucidated the separation of microbiomes under the low 1,4-dioxane-only condition from all other conditions containing CVOCs, as well as the differences of microbial population among original, post-oxidation, and post-catalysis states. The results of this study enhance our understanding of microbial community responses to a promising chemical treatment train, and the metagenomic analysis will help practitioners predict the microbial community status during the post-treatment period, which may have consequences for long-term management strategies that include additional biodegradation treatment or natural attenuation.

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Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket reactors

Calcium carbonate often precipitates in anaerobic reactors treating wastewater with high calcium content. The aim of this paper is to study the effect of wastewater composition on calcium carbonate precipitation in upflow anaerobic sludge blanket (UASB) reactors. Two laboratory-scale UASB reactors were operated with calcium-containing influents using acetate and carbohydrate as substrate, respectively. There was an obvious accumulation of inorganic precipitate observed in the biogranules. Observations via scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS) showed that the acclimated biogranules in the two reactors differed in microstructure. Calcium carbonate was found to have precipitated on the surface of acetate-degrading biogranules, but precipitated at the core of the carbohydrate-degrading biogranules. The results indicated that substrates had significant influence on the location of calcium carbonate precipitation in anaerobic granular sludge, which was expected due to the different methanogens distribution and pH gradient within the granular sludge degrading various substrates. Moreover, the location of calcium carbonate precipitation substantially affected the specific methanogenic activity (SMA) of the granular sludge. The SMA of the acetate-degrading biogranules dropped from \(1.96 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} \) to \(0.61 gCOD_{CH_4 } \cdot gVSS^{ - 1} \cdot d^{ - 1} \) after 180-d of operation in the reactor. However, the SMA of the carbohydrate-degrading biogranules was not adversely affected by calcium carbonate precipitation.     

Reproductive allocation in female house wrens is not influenced by experimentally altered male attractiveness

The differential allocation hypothesis proposes that females mated to attractive males should invest more resources in their offspring than those mated to less-attractive males, whereas the compensation hypothesis posits that females mated to less-attractive males should invest more resources in their offspring to compensate for lower-quality young. We tested these hypotheses by manipulating attractiveness of male house wrens (Troglodytes aedon) prior to female arrival by adding extra nest sites to territories of some males while leaving control males with only a single nest site. Females laid their eggs sooner in the nests of attractive males, and attractive males were more likely to retain their territory over successive broods and were marginally more likely to obtain a mate for a second brood later in the season than were control males, thereby confirming the effect of our manipulation on male attractiveness. Experimentally enhanced attractiveness also led to increased hematocrit in males. However, there were no consistent differences in the number, size, or quality of eggs laid by females mated to attractive and control males, nor were there any differences in the size, health state, or immune function of nestlings produced from these eggs. There was also no effect of treatment on the number of nestlings surviving to fledging. Collectively, these results are inconsistent with both the differential allocation hypothesis and the compensation hypothesis. Future studies should consider the possibility that the criteria used by females in selecting a mate may vary temporally and be more flexible than generally thought.     

The influence of seasonal vertical temperature gradients on no‐purge sampling of wells

Seasonal changes in ambient temperature create vertical temperature gradients in shallow groundwater (less than 15 m). These temperature gradients can affect in‐well flow dynamics that impact samples collected using no‐purge sampling methods. In late winter, the shallower water is colder, resulting in thermally mixed conditions and uniform contaminant concentrations. In late summer, the shallower water is warmer, resulting in thermally stratified conditions and contaminant distributions in the monitoring well more consistent with the distribution in the surrounding aquifer. The importance of seasonal temperature gradients on in‐well mixing was evaluated in two shallow monitoring wells in Houston, Texas. In each of the two wells, four vertically spaced passive diffusion samples collected in late winter showed a less than 1.3x difference in trichloroethene (TCE) concentration between depths, while the same sampling conducted in late summer showed greater than a 100x difference in TCE concentration between depths. A simple analytical model originally developed to predict vertical soil temperature profiles can also be used to predict the occurrence of thermally stratified and thermally mixed conditions in monitoring wells as a function of time and well depth. The results of this analysis and modeling suggest that shallow monitoring wells in most of the United States and Canada can have significantly different vertical concentration profiles within the well over the course of a year due to seasonal vertical temperature gradients. This can induce additional intra‐annual temporal variability on passive no‐purge sampling results from these shallow wells, potentially making it more difficult to discern true trends in the data. © 2012 Wiley Periodicals, Inc.     

Chemical signals of epiphytic lichens in southwestern North America; natural versus man-made sources for airborne particulates

Ambient airborne particulate matter (PM) in southwestern North America consists of naturally derived desert dust, plus anthropogenic inputs from several sources. Epiphytic lichens (Usnea sp.) in this region are a useful biomonitor for the airborne PM because they derive nutrients and moisture largely from incorporated atmospheric aerosols, and not by absorption from the host tree limb from which they are suspended. Using a broad-based sampling strategy from southern Chihuahua, Mexico, to northern New Mexico, USA, we show that select elemental abundance ratios and lead isotopes from epiphytic lichens are useful for distinguishing between sources of airborne PM, and for gauging anthropogenic inputs into desert ecosystems. Abundance patterns of the trace elements La, Nd, and Sm in the lichens suggest origination from continental crust, but rare earth elements display a pronounced enrichment relative to the major element Fe by a factor of about 5. This enrichment appears related to geologic weathering, aeolian transport, and grain-size biases toward trace-element-rich mineral grains in the arid setting. Using the metal Pb as an indicator of human inputs, epiphytic lichens typically show Pb enrichments by a factor of about 25–60 over typical upper crustal values. Regional-scale differences in Pb isotope ratios of these lichens relate to different pollutant sources in southwestern North America.