bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Sludge Retention Time on Nitrifiers' Biomass and Kinetics in an Anaerobic/Oxic Process
Authors: Pai Tzu‐Yi , Wan Terng‐Jou , Tsai Yung‐Pin , Tzeng Chwen‐Jeng , Chu Hsiao‐Hsing , Tsai Yao‐Sheng , Lin Ching‐Yuan 
Published: February 2010

AbstractIn this study, the effect of sludge retention time on ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) in an anaerobic/oxic (AO) process, was explored. The results indicated that the growth rate constants of AOB were 0.97, 0.88, and 0.79 d–1, respectively, meanwhile, those of NOB were 1.22, 1.03, and 0.93 d–1, respectively, when the sludge retention time (SRT) was 15 days, 10 days and 5 days. The relation between the growth rate constant and the SRT could be best described using a simple exponential curve and a second type hyperbolic curve. The lysis rate constants for AOB and NOB were 0.13 and 0.18 d–1, respectively. The yield coefficients values of AOB and NOB were 0.22 and 0.21, respectively. The percentage of AOB to mixed liquid suspended solids (MLSS) was 0.64%, 0.53%, and 0.35%, respectively. Meanwhile, the percentage of NOB was 2.24%, 1.87%, and 1.11%, respectively, at SRT values of 15 days, 10 days and 5 days. When the SRT value decreased, the AOB and NOB biomass levels decreased by 12.75 and 47.01 mg L–1, respectively. Meanwhile the removal efficiency of NH4+‐N decreased from 90 to 26%, while the removal efficiency of total nitrogen (TN) decreased from 14 to 8%.
Use, misuse, and abuse of apparent diffusion coefficients
Authors: Grebenkov Denis S. 
Published: February 2010

AbstractThe notion of effective, time‐dependent or, equivalently, apparent diffusion coefficient (ADC) and its use for characterization of porous media are revisited. It is argued that the dynamic ADC, quantifying the mean‐square displacement of spin‐bearing particles, should not be confused with its counterpart measured by a pulsed gradient spin echo technique. The former is an intrinsic characteristic of the medium, independent of the applied magnetic field. In contrast, the spin‐echo ADC depends on the experimental setup (e.g., gradient intensity and temporal profile), raising potential ambiguities in the interpretation of diffusion‐weighted measurements, which may be strongly misleading when the Gaussian phase approximation (GPA) does not hold. The oversimplified use of a single b‐value is criticized. Several fitting models beyond the GPA are discussed. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part A 36A: 24–35, 2010.
A simple wide‐band gradiometer for operation in very low background field
Authors: Bidinosti C.P. , Xian Z. , Hayden M.E. 
Published: February 2010

AbstractA simple gradiometer, capable of sensing submicrotesla changes in magnetic field with 10‐μs resolution, is constructed from a pair of low‐cost, wide‐band Hall‐effect sensors output to a voltage preamplifier and digital storage oscilloscope. The linear operational range of the sensors (±7.5 mT) limits typical applications, such as gradient coil development and testing, to environments where background fields are very low. The gradiometer is ideal for characterizing gradient field rise times and waveforms in this limit and applications pertinent to very‐low‐field nuclear magnetic resonance and magnetic resonance imaging are presented. © 2010 Wiley Periodicals, Inc. Concepts Magn Reson Part B (Magn Reson Engineering) 37B: 1–6, 2010
Comparison of fatty acid profiles and mid‐infrared spectral data for classification of olive oils
Authors: Gurdeniz Gozde , Ozen Banu , Tokatli Figen 
Published: February 2010

AbstractThe composition of olive oils may vary depending on environmental and technological factors. Fatty acid profiles and Fourier‐transform infrared (FT‐IR) spectroscopy data in combination with chemometric methods were used to classify extra‐virgin olive oils according to geographical origin and harvest year. Oils were obtained from 30 different areas of northern and southern parts of the Aegean Region of Turkey for two consecutive harvest years. Fatty acid composition data analyzed with principal component analysis was more successful in distinguishing northern olive oil samples from southern samples compared to spectral data. Both methods have the ability to differentiate olive oil samples with respect to harvest year. Partial least squares (PLS) analysis was also applied to detect a correlation between fatty acid profile and spectral data. Correlation coefficients (R2) of a calibration set for stearic, oleic, linoleic, arachidic and linolenic acids were determined as 0.83, 0.97, 0.97, 0.83 and 0.69, respectively. Fatty acid profiles were very effective in classification of oils with respect to geographic origin and harvest year. On the other hand, FT‐IR spectra in combination with PLS could be a useful and rapid tool for the determination of some of the fatty acids of olive oils.
Probing Phosphane‐Mediated [2+1] Annulation Reactions
Authors: Liu Xu‐Guang , Wei Yin , Shi Min 
Published: February 2010

AbstractPhosphane‐mediated cyclizations between α‐keto nitriles and methylidenemalononitriles, producing highly functionalized cyclopropanes in good to excellent yields, are reported. The presence of strongly electron‐withdrawing cyano groups directly bound to the ketone carbonyl groups is believed to play a critical role in these transformations.
CE detection of N‐(3‐dimethylaminopropyl)‐N‐carbodiimide/N‐hydroxysuccinimide‐coupled proteins after homo‐ and hetero‐crosslinking reactions
Authors: Muskotál Adél , Kokol Vanja 
Published: February 2010

AbstractProtein–protein conjugates formed by carbodiimide crosslinking reactions have been analyzed for the first time using CE. Lysozyme and BSA were chosen as model proteins to study the efficacy of N‐(3‐dimethylaminopropyl)‐N‐ethylcarbodiimide and N‐hydroxysuccinimide as crosslinkers. Detection of the molecular mass increase was checked by SDS‐PAGE. Commercially available, PVA‐coated capillaries showed appropriate selection, while phospho‐deactivated and dynamic PVA‐coated capillaries did not give suitable resolution. CE was found to be an efficient tool to characterize homo‐ (lysozyme–lysozyme) and hetero‐ (lysozyme–BSA) protein coupling by suitable variations of electrophoretic mobilities.
Optimization of culture conditions for glucose oxidase production by a Penicillium chrysogenum SRT 19 strain
Authors: Bodade Ragini G. , Khobragade Chandarahas N. , Arfeen Saiful 
Published: February 2010

AbstractThe enzyme glucose oxidase (GOD) has been used for a variety of biotechnological applications in food and pharmaceutical industries. In this study, the optimization of extracellular GOD production was carried out in a Penicillium chrysogenum SRT 19 strain isolated from contaminated and decaying cheese samples. Maximum GOD production was attained at pH 6 and 20°C in fermentation broth after 72 h of incubation. The effects of metal ions and sugars were screened for the induction of higher GOD production. The results revealed that glucose and lactose give the highest production of enzyme (0.670 and 0.552 U/mL, respectively) as compared with other sugars (sucrose, cellulose, mannitol and fructose). Out of the seven metal ions studied, CaCO3 (1.123 U/mL) and FeSO4 (0.822 U/mL) act as modulators, while MgSO4 (0.535 U/mL), CuSO4 (0.498 U/mL), HgCl2 (0.476 U/mL), ZnSO4 (0.457 U/mL) and BaSO4 (0.422 U/mL) yield lower production. The study therefore suggests that a strain of P. chrysogenum SRT 19 can be used as a new strain for GOD production.
Effect of aluminum on cellular division and photosynthetic electron transport in Euglena gracilis and Chlamydomonas acidophila
Authors: Perreault François , Dewez David , Fortin Claude , Juneau Philippe , Diallo Amirou , Popovic Radovan 
Published: February 2010

Abstract
The present study investigated aluminum's effect on cellular division and the photosynthetic processes in Euglena gracilis and Chlamydomonas acidophila at pH 3.0, at which Al is present mostly as Al3+, AlSO 4+, and Al(SO4) 2−. These algal species were exposed to 100, 188, and 740 µM Al, and after 24 h cell-bound Al was significantly different from control only for the highest concentration tested. However, very different effects of Al on algal cellular division, biomass per cell, and photosynthetic activity were found. Aluminum stimulated cell division but decreased at some level biomass per cell in C. acidophila. Primary photochemistry of photosynthesis, as Photosystem II quantum yield, and energy dissipation via nonphotochemical activity were slightly affected. However, for E. gracilis, under the same conditions, Al did not show a stimulating effect on cellular division or photosynthetic activity. Primary photochemical activity was diminished, and energy dissipation via nonphotochemical pathways was strongly increased. Therefore, when Al is highly available in aquatic ecosystems, these effects may indicate very different response mechanisms that are dependent on algal species. Environ. Toxicol. Chem. 2010;29:887–892. © 2009 SETAC
Investigating the link between pulp mill effluent and endocrine disruption: Attempts to explain the presence of intersex fish in the Wabigoon River, Ontario, Canada
Authors: Pollock Michael S. , Dubé Monique G. , Schryer Richard 
Published: February 2010

Abstract
The ability of some pulp mill effluents (PME) to act as reproductive and endocrine disrupters in fish is well documented in the literature. However, changes are not always consistent with regard to species, gender, hormones, or reproductive effects. In the present study, the presence of the first intersexed fish that, to our knowledge, has been found in a Canadian river exposed to PME, is reported. A field survey of the Wabigoon River near Dryden, Ontario, in the fall of 2000 found intersexed walleye (Sander vitreus vitreus) with significantly altered hormone levels and reduced gonad size. The Wabigoon River receives discharge from a bleached kraft pulp and paper mill and a municipal wastewater (MWW) plant. It also has historical sediment contamination (wood fiber mats) contributing to extended periods of low dissolved oxygen under low flow, drought conditions. A mesocosm-based partial life cycle test exposing fathead minnows (Pimephales promelas) to reference water, 20% effluent volume to river volume (v/v), 40% (v/v), or 60% (v/v) PME as well as a field survey of the walleye in the Wabigoon River were conducted. The only change in our mesocosm exposure was a decrease in testosterone in males with increasing effluent concentration and vitellogenin induction in males exposed to 60% (v/v) effluent. These results did not reflect the magnitude of endocrine disruption seen in the wild fish survey. Several hypotheses that may explain these discrepancies are proposed. Specifically, evidence is offered from published studies indicating that either hypoxia or MWW, alone or in combination with PME, may explain the discrepancy between our field experiment and the wild fish survey. The present study illustrates the complexities of multistressor receiving environments and the need for the development of cumulative effects assessment approaches. Environ. Toxicol. Chem. 2010;29:952–965. © 2010 SETAC
Application of a congener-specific debromination model to study photodebromination, anaerobic microbial debromination, and FE0 reduction of polybrominated diphenyl ethers
Authors: Zeng Xia , Massey Simonich Staci L. , Robrock Kristin R. , Korytár Peter , Alvarez-Cohen Lisa , Barofsky Douglas F. 
Published: February 2010

Abstract
A model was used to predict the photodebromination of the BDE-203, 197, 196, and 153, the major components of the octa-polybrominated diphenyl ether (PBDE) technical mixture, as well as BDE-47, and the predicted results were compared to the experimental results. The predicted reaction time profiles of the photodebromination products correlate well with the experimental results. In addition, the slope of the linear regression between the measured product concentrations of the first step of the photodebromination products and their enthalpies of formation was found to be close to their theoretical value. The photodebromination results of the octa-BDE technical mixture were compared with anaerobic microbial debromination results and were found to be the same in both experiments. The debromination pathways of technical octa-BDE mixture were identified and BDE-154, 99, 47, and 31 were found to be the most abundant hexa-, penta-, tetra-, and tri-BDE debromination products, respectively. In addition to photodebromination and anaerobic biodebromination, the model prediction was also compared to the zero-valent iron reduction of BDE-209, 100, and 47 and the same debromination products were observed. Good correlation was observed between the photodebromination rate constants of fifteen PBDE congeners and their calculated lowest unoccupied molecular orbital (LUMO) energies, indicating that PBDE photodebromination is caused by electron transfer. Furthermore, the rate constants for the three different PBDE debromination processes are controlled by C–Br bond dissociation energy. With the model from the present study, the major debromination products for any PBDE congener released into the environment can be predicted. Environ. Toxicol. Chem. 2010;29:770–778. © 2010 SETAC
Ecological models and pesticide risk assessment: Current modeling practice
Authors: Schmolke Amelie , Thorbek Pernille , Chapman Peter , Grimm Volker 
Published: February 2010

Abstract
Ecological risk assessments of pesticides usually focus on risk at the level of individuals, and are carried out by comparing exposure and toxicological endpoints. However, in most cases the protection goal is populations rather than individuals. On the population level, effects of pesticides depend not only on exposure and toxicity, but also on factors such as life history characteristics, population structure, timing of application, presence of refuges in time and space, and landscape structure. Ecological models can integrate such factors and have the potential to become important tools for the prediction of population-level effects of exposure to pesticides, thus allowing extrapolations, for example, from laboratory to field. Indeed, a broad range of ecological models have been applied to chemical risk assessment in the scientific literature, but so far such models have only rarely been used to support regulatory risk assessments of pesticides. To better understand the reasons for this situation, the current modeling practice in this field was assessed in the present study. The scientific literature was searched for relevant models and assessed according to nine characteristics: model type, model complexity, toxicity measure, exposure pattern, other factors, taxonomic group, risk assessment endpoint, parameterization, and model evaluation. The present study found that, although most models were of a high scientific standard, many of them would need modification before they are suitable for regulatory risk assessments. The main shortcomings of currently available models in the context of regulatory pesticide risk assessments were identified. When ecological models are applied to regulatory risk assessments, we recommend reviewing these models according to the nine characteristics evaluated here. Environ. Toxicol. Chem. 2010;29:1006–1012. © 2010 SETAC
UO 22+ speciation determines uranium toxicity and bioaccumulation in an environmental Pseudomonas sp. isolate
Authors: VanEngelen Michael R. , Field Erin K. , Gerlach Robin , Lee Brady D. , Apel William A. , Peyton Brent M. 
Published: February 2010

Abstract
In the present study, experiments were performed to investigate how representative cellulosic breakdown products, when serving as growth substrates under aerobic conditions, affect hexavalent uranyl cation (UO 22+) toxicity and bioaccumulation within a Pseudomonas sp. isolate (designated isolate A). Isolate A taken from the Cold Test Pit South (CTPS) region of the Idaho National Laboratory (INL), Idaho Falls, ID, USA. The INL houses low-level uranium-contaminated cellulosic material and understanding how this material, and specifically its breakdown products, affect U-bacterial interactions is important for understanding UO 22+ fate and mobility. Toxicity was modeled using a generalized Monod expression. Butyrate, dextrose, ethanol, and lactate served as growth substrates. The potential contribution of bicarbonate species present in high concentrations was also investigated and compared with toxicity and bioaccumulation patterns seen in low-bicarbonate conditions. Isolate A was significantly more sensitive to UO 22+ and accumulated significantly more UO 22+ in low-bicarbonate concentrations. In addition, UO 22+ growth inhibition and bioaccumulation varied depending on the growth substrate. In the presence of high bicarbonate concentrations, sensitivity to UO 22+ inhibition was greatly mitigated, and did not vary between the four substrates tested. The extent of UO 22+ accumulation was also diminished. The observed patterns were related to UO 22+ aqueous complexation, as predicted by MINTEQ (ver. 2.52) (Easton, PA, USA). In the low- bicarbonate medium, the presence of positively charged and unstable UO 22+-hydroxide complexes explained both the greater sensitivity of isolate A to UO 22+, and the ability of isolate A to accumulate significant amounts of UO 22+. The exclusive presence of negatively charged and stable UO 22+-carbonate complexes in the high bi-carbonate medium explained the diminished sensitivity of isolate A to UO 22+ toxicity, and limited ability of isolate A to accumulate UO 22+. Environ. Toxicol. Chem. 2010;29:763–769. © 2010 SETAC
Larvicidal properties of decomposed leaf litter in the subalpine mosquito breeding sites
Authors: David Jean-Philippe , Rey Delphine , Cuany Andre , Bride Jean-Marc , Meyran Jean-Claude 
Published: February 2010

Abstract
The larvicidal properties of the dietary leaf litter originating from the vegetation surrounding the subalpine mosquito breeding sites were investigated by using 10-month decomposed alder leaf litter against different field collections of culicine taxa of various ecological origin (Aedes cantans, Aedes caspius, Aedes cataphylla, Aedes detritus, Aedes punctor, Aedes pullatus, Aedes rusticus, Anopheles claviger, Culex hortensis, Culex pipiens, Culiseta morsitans). Larvae originating from sites with polyphenol-poor vegetation appeared more sensitive to ingested leaf litter than those originating from sites with polyphenol-rich vegetation. Within a given taxon (e.g., A. rusticus, A. cataphylla, C. hortensis), the overall levels of cytochrome P450 monooxygenase and esterase activities appeared higher in larvae able to feed on leaf litter than in pupae and adults unable to feed on leaf litter. This suggests the involvement of these enzymes in the detoxification mechanisms responsible for larval tolerance to polyphenols of the dietary leaf litter. Such a tolerance of the larval stage thus appears as fundamental in the ecotoxicological adaptation of mosquito taxa to the polyphenolic profiles of the riparian vegetation.
Relative sensitivity of bull trout (Salvelinus confluentus) and rainbow trout (Oncorhynchus mykiss) to acute exposures of cadmium and zinc
Authors: Hansen James A. , Welsh Paul G. , Lipton Josh , Cacela Dave , Dailey Anne D. 
Published: February 2010

AbstractBull trout (Salvelinus confluentus) were recently listed as threatened in the United States under the federal Endangered Species Act. Present and historical habitat of this species includes waterways that have been impacted by metals released from mining and mineral processing activities. We conducted paired bioassays with bull trout and rainbow trout (Oncorhynchus mykiss) to examine the relative sensitivity of each species to Cd and Zn independently and as a mixture. A total of 15 pairs of acute toxicity bioassays were completed to evaluate the effects of different water hardness (30 or 90 mg/L as CaCO3), pH (6.5 or 7.5), and temperature (8 or 12°C) on Cd and Zn toxicity. For both species, the acute toxicity of both Cd and Zn was greater than previously observed in laboratory studies. Bull trout were about twice as tolerant of Cd and about 50% more tolerant of Zn than were rainbow trout. Higher hardness and lower pH water produced lower toxicity and slower rates of toxicity in both species. Elevated temperature significantly increased the sensitivity of bull trout to Zn but decreased the sensitivity (not significantly) of rainbow trout to Zn. At a hardness of 30 mg/L, the toxicity values (i.e., median lethal concentration; 120-h LC50) for both species were lower than the current U.S. national water quality criteria for protection of aquatic life, indicating that current national criteria may not be protective of sensitive salmonids—including the threatened bull trout—in low calcium waters.
Aminolevulinic acid dehydratase activity in American dippers (Cinclus mexicanus) from a metal-impacted stream
Authors: Strom Sean M. , Ramsdell Howard S. , Archuleta Andrew S. 
Published: February 2010

Abstract
Blood samples collected from adult and nestling American dippers (Cinclus mexicanus) along the Arkansas River (CO, USA), a stream impacted by discharges from historical mining operations, and a reference stream were analyzed for lead concentration and δ-aminolevulinic acid dehydratase (ALAD) activity. Median ALAD activities of adult and nestling dippers from the Arkansas River were found to be significantly different from median ALAD activities of reference adults and nestlings (p = 0.002 and p = 0.028). Median ALAD activity for adult dippers from the Arkansas River was more than 50% lower relative to reference adults and activity approached a level close to 50% lower in nestlings from the same site. Median blood lead concentrations from adult (range 15.4–386.0 ppb) and nestling (range 12.1–323.0 ppb) dippers from the Arkansas River were found to be significantly different from median blood lead concentrations of reference adult (range 4.2–29.6 ppb) and nestling (range 4.2–8.2 ppb) dippers (p &lt; 0.001 and p = 0.011). The median hematocrit level in adult dippers did not vary between sites (p = 0.73), whereas the median hematocrit level of nestling dippers from the reference site was significantly lower compared to Arkansas River nestlings (p = 0.042). Blood lead concentration in both adult and nestling dippers was found to be significantly correlated with invertebrate lead concentration (r = 0.81, p &lt; 0.001 and r = 0.62, p = 0.01, respectively). Highly significant negative correlations were observed between blood lead concentration and ALAD activity in both adult and nestling dippers (r = −0.86, p &lt; 0.001 and r = −0.84, p &lt; 0.001, respectively). This study suggests that dippers (both adults and nestlings) from the Arkansas River have significantly lower ALAD activity and significantly higher blood lead concentrations compared to reference values. The measurement of ALAD activity may be a sensitive and accurate biomarker for environmental lead exposure in dippers.
Lethal and sublethal effects of polychlorinated biphenyls onRana sylvaticatadpoles
Authors: Savage Wesley K. , Quimby Fred W. , DeCaprio Anthony P. 
Published: February 2010

AbstractIn static experiments, we exposed tadpoles of the wood frog (Rana sylvatica) to sediment collected from a riverine wetland in the St. Lawrence River basin that is highly contaminated with polychlorinated biphenyls (PCBs). Significant mortality occurred early in the experiment and was not explained by a simple dose-dependent relationship. Direct sediment contact resulted in higher tadpole mortality compared with tadpoles suspended in mesh containers above the sediment. Sublethal effects of exposure were also apparent, characterized by behavioral abnormalities, including reduced activity levels and swimming speed, that differed depending on whether tadpoles were in contact with or suspended above the sediment. We demonstrate in this experiment that PCB-contaminated sediment induced significant mortality and behavioral dysfunction in early development, but the effects on natural populations existing in the contaminated region is not known.