Species-specific bioluminescence facilitates speciation in the deep sea

The vast darkness of the deep sea is an environment with few obvious genetic isolating barriers, and little is known regarding the macroevolutionary processes that have shaped present-day biodiversity in this habitat. Bioluminescence, the production and emission of light from a living organism through a chemical reaction, is thought to occur in approximately 80 % of the eukaryotic life that inhabits the deep sea (water depth greater than 200 m). In this study, we show, for the first time, that deep-sea fishes that possess species-specific bioluminescent structures (e.g., lanternfishes, dragonfishes) are diversifying into new species at a more rapid rate than deep-sea fishes that utilize bioluminescence in ways that would not promote isolation of populations (e.g., camouflage, predation). This work adds to our understanding of how life thrives and evolution shaped present-day biodiversity in the deep sea, the largest and arguably least explored habitat on earth.     

Sorption of MS2 bacteriophage to layered double hydroxides: effects of reaction time, pH, and competing anions

Batch sorption and column breakthrough studies were conducted to investigate the potential of layered double hydroxides (LDHs) to remove bacteriophage MS2 from contaminated waters. All four of the LDHs evaluated in this study had very high retention capacities for MS2. Sorption results showed that MS2 could be completely removed from 5.2 x 10(2) plaque-forming units (pfu)/mL solution by Mg-Al LDH 2 (i.e., 2:1 Mg to Al ratio LDH), with the highest sorption capacity observed in this study of 1.51 x 10(10) pfu/g. Attachment of MS2 to LDHs was a rapid process and reached quasi-equilibrium after a 1-h reaction time. Within the pH range studied (pH 4-9), Mg-Al LDH 2 showed high sorption potential for MS2 at all pH values but sorption decreased slightly with increasing solution pH. Background solution anions influenced virus sorption, with SO4(2-) and HPO4(2-) decreasing sorption significantly whereas the presence of NO3- had little effect on the attachment of MS2 to Mg-Al LDH 2. The addition of another virus (phiX174) only caused a slight decrease in the retention of MS2 by Mg-Al LDH 2, suggesting that there was insignificant competitive sorption between MS2 and phiX174 on LDH surfaces. Results from column experiments indicate that there was no MS2 breakthrough from columns packed with Mg-Al LDH 2-coated sand, suggesting complete MS2 retention at the virus concentration tested. The high mass recovery by beef extract solution revealed that the removal of viruses by the LDH was due to sorption of MS2 to LDH surfaces, rather than inactivation.     

How accurate is the assessment of phosphorus pools in poultry litter by sequential extraction?

Amending poultry litter with Al sulfate (alum) has proven effective in reducing water-soluble P in the litter and in runoff from fields that have received litter applications. Although its effectiveness has been demonstrated on a macroscopic scale in the field or in the poultry houses, little is known about P speciation in either alum-amended or unamended litter. This knowledge is important for the evaluation of long-term stability and bioavailability of P, which is a necessary prerequisite for the assessment of the sustainability of intensive poultry operations. Here we report results from an investigation of alum-amended poultry litter (PL) that combined a chemical extraction sequence with solid-state 31P nuclear magnetic resonance (NMR) spectroscopic analysis of the residues. Aluminum is predominantly found in the fine size separate (<125 microm), indicating that the alum added to the poultry houses hydrolyzed without being completely dispersed in the litter. The NMR spectra confirmed the hypothesis that calcium phosphate phases are only dissolved during extraction with dilute acid and phosphate associated with Al is mainly dissolved during extraction with NaOH. Extraction of phosphate associated with Al was incomplete, however, as evidenced by 31P NMR spectroscopy. It could also be demonstrated that the extraction sequence overestimates the calcium phosphate fraction by an order of magnitude in this particular sample. Results from sequential chemical extraction should therefore be used with caution when assessing the magnitude of different phosphate pools in poultry litter.     

Evaluating sources of indoor air pollution

Evaluation of indoor air pollution problems requires an understanding of the relationship between sources, air movement, and outdoor air exchange. Research is underway to investigate these relationships. A three-phase program is being implemented: 1) Environmental chambers are used to provide source emission factors for specific indoor pollutants; 2) An IAQ (Indoor Air Quality) model has been developed to calculate indoor pollutant concentrations based on chamber emissions data and the air exchange and air movement within the indoor environment; and 3) An IAQ test house is used to conduct experiments to evaluate the model results. Examples are provided to show how this coordinated approach can be used to evaluate specific sources of indoor air pollution. Two sources are examined: 1) para-dichlorobenzene emissions from solid moth repellant; and 2) particle emissions from unvented kerosene heaters. The evaluation process for both sources followed the three-phase approach discussed above. Para-dichlorobenzene emission factors were determined by small chamber testing at EPA's Air and Energy Engineering Research Laboratory. Particle emission factors for the kerosene heaters were developed in large chambers at the J. B. Pierce Foundation Laboratory. Both sources were subsequently evaluated in EPA's IAQ test house. The IAQ model predictions showed good agreement with the test house measurements when appropriate values were provided for source emissions, outside air exchange, in-house air movement, and deposition on "sink" surfaces.     

Characterization of dissolved organic matter in the rhizosphere of hyperaccumulator Sedum alfredii and its effect on the mobility of zinc

Pot experiments were performed to investigate the characteristics of dissolved organic matter (DOM) in the rhizosphere soil of hyperaccumulating ecotype (HE) and a non-hyperaccumulating ecotype (NHE) of Sedum alfredii and its effects on the mobility of zinc (Zn). DOM was fractionated using XAD resins into six fractions. The acid fraction was the predominant component of DOM in the rhizosphere of S. alfredii, with hydrophilic acid (HiA), hydrophilic base (HiB), and hydrophilic neutral (HiN) in HE-DOM being 1.6, 1.9, and 1.2 times higher respectively, as compared to NHE-DOM. ATR-FTIR results showed that DOM in the rhizosphere of S. alfredii consisted of a mixture of hydroxylated and carboxylic acids, and HE-DOM exhibited more CO, OH, CC and CO functional groups than NHE-DOM. Resin equilibration experiment results indicated that DOM from the rhizosphere of both ecotypes of S. alfredii had the ability to form complexes with Zn, whereas the degree of complexation was significantly higher for HE-DOM (60%) than NHE-DOM (42%). The addition of HE-DOM significantly (P < 0.05) increased the solubility of four Zn minerals while NHE-DOM was not as effective at the same concentration. It was concluded that DOM derived from the rhizosphere of hyperaccumulating ecotype of S. alfredii could significantly increase Zn mobility through the formation of soluble DOM-metal complexes, this might be one of the important mechanism by which S. alfredii is involved in activating metal in rhizosphere.     

Improvement of Hot–side Precipitator Performance with Sodium Conditioning—An Interim Report

The development of an unexpected, time-dependent degradation of performance of hot-side precipitators collecting ash from certain coals (usually low-sodium, low-sulfur coals) has caused serious problems at a number of major utility installations. A jointly funded research project was developed under the sponsorship of the U.S. Environmental Protection Agency, the Electric Power Research Institute, and Southern Company Services, Inc., to evaluate sodium conditioning as a possible solution to these performance deficiency problems.     

Medium-Sulfur Coal and Fly Ash Resistivity

Electric generating plants burning medium-sulfur coal need a way to predict when ESP performance will be limited by high electrical resistivity of the collected fly ash. The main uncertainty in mathematical predictions of fly ash resistivity lies in the marginal effect of naturally occurring SO₃ vapor in the flue gas. This paper results from a project to expand the data base of SO₃/SO₂ concentrations and fly ash resistivities measured in utility fly ash precipitators. Complete data sets are presented from three plants in the Southern Company electric system. In situ resistivity data are compared with laboratory measurements and with two different mathematical predictions of resistivity based on coal and ash analyses. The revised version of the resistivity predictor gives results in good agreement with resistivity values measured both in situ and in the laboratory.     

XANES spectroscopic analysis of phosphorus speciation in alum-amended poultry litter

Aluminum sulfate (alum; Al(2)(SO(4))(3).14H(2)O) is used as a chemical treatment of poultry litter to reduce the solubility and release of phosphate, thereby minimizing the impacts on adjacent aquatic ecosystems when poultry litter is land applied as a crop fertilizer. The objective of this study was to determine, through the use of X-ray absorption near edge structure (XANES) spectroscopy and sequential extraction, how alum amendments alter P distribution and solid-state speciation within the poultry litter system. Our results indicate that traditional sequential fractionation procedures may not account for variability in P speciation in heterogeneous animal manures. Analysis shows that NaOH-extracted P in alum amended litters is predominantly organic ( approximately 80%), whereas in the control samples, >60% of NaOH-extracted P was inorganic P. Linear least squares fitting (LLSF) analysis of spectra collected of sequentially extracted litters showed that the P is present in inorganic (P sorbed on Al oxides, calcium phosphates) and organic forms (phytic acid, polyphosphates, and monoesters) in alum- and non-alum-amended poultry litter. When determining land application rates of poultry litter, all of these compounds must be considered, especially organic P. Results of the sequential extractions in conjunction with LLSF suggest that no P species is completely removed by a single extractant. Rather, there is a continuum of removal as extractant strength increases. Overall, alum-amended litters exhibited higher proportions of Al-bound P species and phytic acid, whereas untreated samples contained Ca-P minerals and organic P compounds. This study provides in situ information about P speciation in the poultry litter solid and about P availability in alum- and non-alum-treated poultry litter that will dictate P losses to ground and surface water systems.     

Engaging with the natural environment: The role of affective connection and identity

Research has shown pro-environmental behaviour to be positively associated with the strength of emotional connection towards the natural environment. The present study (N=199) investigated the predictive utility of an extended model of the theory of planned behaviour (TPB) [ Ajzen, I. (1991). The theory of planned behaviour. Organizational Behaviour and Human Decision Processes, 50, 179–211] for people's intentions to engage with the natural environment. It was hypothesised that both affective connection and identification with the natural environment would contribute significantly to the prediction of people's intentions. A secondary hypothesis was that participants who had grown up in rural areas would report more positive orientations towards engaging with the natural environment than would urban participants. The research found that affective connection was a significant independent predictor of intentions to engage with the natural environment. Environmental identity was only a significant predictor in the absence of affective connection in the regression model. As predicted, rural and urban participants differed significantly along the measured variables.