bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kinetic responses of Dunaliella in moving fluids
Authors: Chengala Ahammed Anwar , Hondzo Miki , Troolin Dan , Lefebvre Paul A 
Published: April 2010

AbstractThe objective of this work was to quantify the kinetic behavior of Dunaliella primolecta (D. primolecta) subjected to controlled fluid flow under laboratory conditions. In situ velocities of D. primolecta were quantified by micron‐resolution particle image velocimetry and particle tracking velocimetry. Experiments were performed under a range of velocity gradients and corresponding energy dissipation levels at microscopic scales similar to the energy dissipation levels of natural aquatic ecosystems. An average swimming velocity of D. primolecta in a stagnant fluid was 41 µm/s without a preferential flow direction. In a moving fluid, the sample population velocities of D. primolecta follow a log‐normal distribution. The variability of sample population velocities was maximal at the highest fluid flow velocity in the channel. Local fluid velocity gradients inhibited the accrual of D. primolecta by twofold 5 days after the initiation of the experiment in comparison to the non‐moving fluid control experiment. Biotechnol. Bioeng. 2010;107: 65–75. © 2010 Wiley Periodicals, Inc.
Comparative analysis of breast cancer risk factors among hispanic and non‐hispanic white women
Authors: Hines Lisa M. , Risendal Betsy , Slattery Martha L. , Baumgartner Kathy B. , Giuliano Anna R. , Sweeney Carol , Rollison Dana E. , Byers Tim 
Published: April 2010

AbstractBACKGROUND:Hispanic and non‐Hispanic white (NHW) populations within the United States have different breast cancer incidence rates, yet there is limited research on how ethnic differences in the prevalence of established risk factors and their associations with breast cancer contribute to the observed differences.METHODS:Odds ratios and population‐attributable risk estimates for breast cancer were determined for Hispanic and NHW women in the population‐based, case‐control 4‐Corners Breast Cancer Study.RESULTS:When comparing NHW and Hispanic women, the authors observed differences in the prevalence of certain risk factors and in the magnitude and direction of their associations with breast cancer. Hispanic women were more likely to have characteristics associated with lower breast cancer risk, such as younger age at first birth, having more children, shorter height, less hormone use, and less alcohol consumption. Among premenopausal women, ethnic differences in risk were observed with taller height and positive family history, which were not associated with breast cancer among Hispanic women. Among postmenopausal women, associations for certain risk factors were either weaker or were not observed in Hispanics, such as recent estrogen plus progestin hormone therapy use and younger age at menarche. Among NHW women, an estimated 62% to 75% of breast cancers were attributed to the evaluated risk factors compared with 7% to 36% in Hispanic women.CONCLUSIONS:Breast cancer risk factors established in NHW populations had less influence on breast cancer risk in Hispanic women. These findings reflect the need to further evaluate breast cancer risk factors among different ethnic and racial populations. Cancer 2010. © 2010 American Cancer Society.
Capacity of the two‐way relay channel within a constant gap
Authors: Avestimehr Amir Salman , Sezgin Aydin , Tse David N. C. 
Published: April 2010

AbstractWe study the capacity of the full‐duplex bidirectional (or two‐way) relay channel with two nodes and one relay. The channels in the forward direction are assumed to be different (in general) than the channels in the backward direction, i.e. channel reciprocity is not assumed. We use the recently proposed deterministic approach to capture the essence of the problem and to determine a good transmission and relay strategy for the Gaussian channel. Depending on the ratio of the individual channel gains, we propose to use either a simple amplify‐and‐forward or a particular superposition coding strategy at the relay. We analyse the achievable rate region and show that the scheme achieves to within 3 bits the cut‐set bound for all values of channel gains. Copyright © 2010 John Wiley & Sons, Ltd.
A simplified MAP channel estimator for OFDM systems under Rayleigh fading
Authors: Çürük Selva Muratoğlu , Tanık Yalçın 
Published: April 2010

AbstractThis paper presents a simplified Maximum A Posteriori (SMAP) channel estimator to be used in orthogonal frequency division multiplexing (OFDM) systems under the Rayleigh fading assumption for the subchannels, using a parametric correlation model and assuming that the channel is frequency selective and slowly time varying. Expressions for the mean‐square error (MSE) of estimations are derived to evaluate the performance of the estimator. The relation between the correlation of subchannels taps and error variance is investigated. Dependencies of the proposed estimator's performance on the correlation parameter estimation error and signal‐to‐noise ratios (SNR) estimation error are analysed. We provide approximations on the estimator algorithms in order to make the estimator practical. The simulations done using measured channel data show that the proposed estimator with approximations operates satisfactorily with negligible loss in performance. Finally, we investigate the symbol error rate (SER) performance of an OFDM system using quadrature phase‐shift keying (QPSK) modulation, based on channel estimation modes (a) training sequence (b) decision feedback and (c) pilot subcarriers. The results have indicated that the proposed estimator performance is always better than maximum likelihood (ML) estimator, and as the subchannel correlation increases (large number of subcarriers) the performance comes very close to that of exactly known channel case. Copyright © 2010 John Wiley & Sons, Ltd.
A stable and accurate projection method on a locally refined staggered mesh
Authors: Liu Qianlong 
Published: April 2010

AbstractIn this paper, a robust projection method on a locally refined mesh is proposed for two‐ and three‐dimensional viscous incompressible flows. The proposed method is robust not only when the interface between two meshes is located in a smooth flow region but also when the interface is located in a flow region with large gradients and/or strong unsteadiness. In numerical simulations, a locally refined mesh saves many grid points in regions of relatively small gradients compared with a uniform mesh. For efficiency and ease of implementation, we consider a two‐level blocked structure, for which both of the coarse and fine meshes are uniform Cartesian ones individually. Unfortunately, the introduction of the two‐level blocked mesh results in an important but difficult issue: coupling of the coarse and fine meshes. In this paper, by properly addressing the issue of the coupling, we propose a stable and accurate projection method on a locally refined staggered mesh for both two‐ and three‐dimensional viscous incompressible flows. The proposed projection method is based on two principles: the linear interpolation technique and the consistent discretization of both sides of the pressure Poisson equation. The proposed algorithm is straightforward owing to the linear interpolation technique, is stable and accurate, is easy to extend from two‐ to three‐dimensional flows, and is valid even when flows with large gradients cross the interface between the two meshes. The resulting pressure Poisson equation is non‐symmetric on a locally refined mesh. The numerical results for a series of exact solutions for 2D and 3D viscous incompressible flows verify the stability and accuracy of the proposed projection method. The method is also applied to some challenging problems, including turbulent flows around particles, flows induced by impulsively started/stopped particles, and flows induced by particles near solid walls, to test the stability and accuracy. Copyright © 2010 John Wiley & Sons, Ltd.
High resolution analysis of follicular lymphoma genomes reveals somatic recurrent sites of copy‐neutral loss of heterozygosity and copy number alterations that target single genes
Authors: Cheung K‐John J. , Delaney Allen , Ben‐Neriah Susana , Schein Jacquie , Lee Tang , Shah Sohrab P. , Cheung Dorothy , Johnson Nathalie A. , Mungall Andrew J. , Telenius Adele , Lai Betty , Boyle Merrill , Connors Joseph M. , Gascoyne Randy D. , Marra Marco A. , Horsman Douglas E. 
Published: April 2010

AbstractA multiplatform approach, including conventional cytogenetic techniques, BAC array comparative genomic hybridization, and Affymetrix 500K SNP arrays, was applied to the study of the tumor genomes of 25 follicular lymphoma biopsy samples with paired normal DNA samples to characterize balanced translocations, copy number imbalances, and copy‐neutral loss of heterozygosity (cnLOH). In addition to the t(14;18), eight unique balanced translocations were found. Commonly reported FL‐associated copy number regions were revealed including losses of 1p32‐36, 6q, and 10q, and gains of 1q, 6p, 7, 12, 18, and X. The most frequent regions affected by copy‐neutral loss of heterozygosity were 1p36.33 (28%), 6p21.3 (20%), 12q21.2‐q24.33 (16%), and 16p13.3 (24%). We also identified by SNP analysis, 45 aberrant regions that each affected one gene, including CDKN2A, CDKN2B, FHIT, KIT, PEX14, and PTPRD, which were associated with canonical pathways involved in tumor development. This study illustrates the power of using complementary high‐resolution platforms on paired tumor/normal specimens and computational analysis to provide potential insights into the significance of single‐gene somatic aberrations in FL tumorigenesis. © 2010 Wiley‐Liss,Inc.
Citalopram versus other antidepressants for late‐life depression: a systematic review and meta‐analysis
Authors: Seitz Dallas P. , Gill Sudeep S. , Conn David K. 
Published: April 2010

AbstractObjectiveTo determine the efficacy and tolerability of citalopram when compared to other antidepressants for late‐life depression (LLD).MethodsWe searched electronic databases and trial registries to identify randomized controlled trials comparing citalopram to other antidepressants for LLD. Study quality was assessed using the Cochrane collaboration risk of bias tool. We summarized the efficacy of citalopram compared to other antidepressants by examining rates of depression remission, depression response and change in depression symptom scores. Medication tolerability was assessed through trial withdrawals due adverse events and withdrawals due to any cause. We used meta‐analysis to determine the odds ratios (OR) of efficacy and tolerability outcomes for citalopram compared to other antidepressants.ResultsSeven studies comparing citalopram (N = 647) to other antidepressants (N = 641) for LLD were identified including four studies with tricyclic comparators and three studies with non‐tricyclic comparators. Most of the studies had methodological limitations that placed them at risk for potential bias. The majority of studies reported no significant differences between citalopram and comparator medications for depression efficacy or tolerability outcomes. Meta‐analysis did not find any significant differences between citalopram and other antidepressants for depression remission [OR = 0.84; 95%CI: 0.56–1.28] or for trial withdrawals due to adverse effects [OR = 0.70; 95%CI: 0.48–1.02].ConclusionsCurrently there are few studies directly comparing citalopram to other antidepressants for LLD. The small number of studies and methodological issues in many studies limit any conclusions about the relative efficacy and tolerability of citalopram compared to other antidepressants. Well‐designed studies comparing citalopram to other antidepressants for LLD are required. Copyright © 2010 John Wiley & Sons, Ltd.
Generality of fractal 1/f scaling in catchment tracer time series, and its implications for catchment travel time distributions
Authors: Godsey Sarah E. , Aas Wenche , Clair Thomas A. , de Wit Heleen A. , Fernandez Ivan J. , Kahl J. Steve , Malcolm Iain A. , Neal Colin , Neal Margaret , Nelson Sarah J. , Norton Stephen A. , Palucis Marisa C. , Skjelkvåle Brit Lisa , Soulsby Chris , Tetzlaff Doerthe , Kirchner James W. 
Published: April 2010

AbstractCatchment travel time distributions reflect how precipitation from different storms is stored and mixed as it is transported to the stream. Catchment travel time distributions can be described by the mean travel time and the shape of the distribution around the mean. Whereas mean travel times have been quantified in a range of catchment studies, only rarely has the shape of the distribution been estimated. The shape of the distribution affects both the short‐term and long‐term catchment response to a pulse input of a soluble contaminant. Travel time distributions are usually estimated from conservative tracer concentrations in precipitation and streamflow, which are analyzed using time‐domain convolution or spectral methods. Of these two approaches, spectral methods are better suited to determining the shape of the distribution. Previous spectral analyses of both rainfall and streamflow tracer time series from several catchments in Wales showed that rainfall chemistry spectra resemble white noise, whereas the stream tracer spectra in these same catchments exhibit fractal 1/f scaling over three orders of magnitude. Here we test the generality of the observed fractal scaling of streamflow chemistry, using spectral analysis of long‐term tracer time series from 22 catchments in North America and Europe. We demonstrate that 1/f fractal scaling of stream chemistry is a common feature of these catchments. These observations imply that catchments typically exhibit an approximate power‐law distribution of travel times, and thus retain a long memory of past inputs. The observed fractal scaling places strong constraints on possible models of catchment behavior, because it is inconsistent with the exponential travel time distributions that are predicted by simple mixing models. Copyright © 2010 John Wiley & Sons, Ltd.
Modelling rapid flow response of a tile‐drained field site using a 2D physically based model: assessment of ‘equifinal’ model setups
Authors: Klaus Julian , Zehe Erwin 
Published: April 2010

AbstractRapid flow in connected preferential flow paths is crucial for fast transport of water and solutes through soils, especially at tile‐drained field sites. In the present study, we propose a spatially explicit approach to represent worm burrows as connected structures of realistic geometry, high conductivity and low retention capacity in a two‐dimensional physically based model. We show that this approach allows successful prediction of a tile‐drain discharge and preferential flow patterns in soil observed during the irrigation of a tile‐drained hillslope in the Weiherbach catchment. However, we found a considerable equifinality in the spatial setup of the model when key parameters such as the area density of worm burrows, the maximum volumetric water flows inside these macropores and the conductivity of the tile drain were varied within the ranges of either our measurements or measurements reported in the literature. In total, we found that 67 out of 432 model runs were acceptable [Nash–Sutcliffe (NS) ≥ 0·75]. Among these, the 13 best yielded a NS coefficient of more than 0·9, which means that more than 90% of the flow variability is explained by the model. Also, the flow volumes were in good accordance and timing errors were less than or equal to 20 min. It is suggested that this uncertainty/equifinality could be reduced when more precise data on initial states of the subsurface and on the width of the control volume draining into a single drainage tube could be made available. However, such data are currently most difficult to assess even at very well investigated sites such as those studied here. We thus suggest that non‐uniqueness of the spatial setup of process‐based model seems to be an important factor causing predictive uncertainty at many sites where preferential flow dominates system response. Copyright © 2010 John Wiley & Sons, Ltd.
Inhibition of creatine kinase activity by 3‐butyl‐1‐phenyl‐2‐(phenyltelluro)oct‐en‐1‐one in the cerebral cortex and cerebellum of young rats
Authors: de Andrade Rodrigo Binkowski , Gemelli Tanise , Guerra Robson Brum , Funchal Cláudia , Duval Wannmacher Clovis Milton 
Published: April 2010

AbstractIn the present study, we investigated the potential in vitro toxicity of the tellurium compound 3‐butyl‐1‐phenyl‐2‐(phenyltelluro)oct‐en‐1‐one on creatine kinase activity in cerebral cortex and cerebellum of 30‐day‐old Wistar rats. First, enriched mitochondrial and cytosolic fractions from the two tissues were pre‐incubated for 30 min in the presence or absence of 1, 5 or 20 µm of organotellurium and the creatine kinase activity was measured. The organochalcogen reduced creatine kinase activity in a concentration‐dependent pattern in the two tissues studied. Furthermore, the enzyme activity was performed after pre‐incubation for 30, 60 or 90 min in the presence of 5 µm of the organotellurium. The compound inhibited creatine kinase activity in a time‐dependent way in the enriched mitochondrial fraction of both tissues, but not in the cytosolic fraction, indicating different mechanisms for the organochalcogen in the mitochondrial and in the cytosolic creatine kinase. Pre‐incubation of tellurium compound with reduced glutathione suggests that creatine kinase activity inhibition might be caused by direct interaction with thiol groups or by oxidative stress. Our findings suggest that creatine kinase inhibition may be one of the mechanisms by which this organotellurium could cause toxicity to the rat brain. Copyright © 2010 John Wiley & Sons, Ltd.
Anaerobic digestion of Aegean olive mill effluents with and without pretreatment
Authors: Pekin Gülseren , Haskök Senem , Sargın Sayit , Gezgin Yüksel , Eltem Rengin , İkizoǧlu Erdinç , Azbar Nuri , Sukan Fazilet Vardar 
Published: April 2010

AbstractBACKGROUND: Olive oil production is an important economical activity in the Aegean region of Turkey. However, the effluents of the olive oil producing mills with their high organic loads and toxic compounds are causing serious environmental problems. The anaerobic biological treatment of olive mill wastewater (OMWW) using the treatment plants of the regional industries could be a method of choice and within the scope of this study floccular and granular sludges were investigated in batch mode for their success in the treatment of OMWW while producing biogas.The major limitation of this treatment is the inhibition of methanogenic bacteria by the phenolic compounds in OMWW. Thus an integrated solution was suggested in which a pre‐treatment step (dephenolization) was also introduced before biological step.RESULTS: The effluents of 27 olive mills out of 47 were found to have total phenolics (TP) less than 3 g L−1 and could be treated anaerobically after simple dilution. The biogas production for the untreated OMWW was higher for floccular sludge than for the granular sludge (68.5 mL and 45.7 mL respectively). Combined pre‐treatment experiments, first coagulation with polyaluminum chloride, followed by flocculation with cationic polyelectrolyte and finally Fenton's oxidation, could remove 80% of TP and 95% of the total suspended solids.CONCLUSION: OMWW having TP values less than 3 g L−1 can be treated anaerobically using floccular sludge after simple dilution and biogas can be produced. For OMWW samples having higher TP values pre‐treatment is necessary and the pre‐treatment given in this study may be used effectively. Copyright © 2010 Society of Chemical Industry
Construction of self‐organized free‐standing TiO2 nanotube arrays for effective disinfection of drinking water
Authors: Ng Jiawei , Zhang Xiwang , Zhang Tong , Pan Jia‐Hong , Du Jian‐Hong Alan , Sun Darren D. 
Published: April 2010

AbstractBACKGROUND: In this study, the efficacy of disinfection surface water using anodic TiO2 films was investigated. The as‐prepared photocatalyst demonstrated excellent photocatalytic disinfection of E. coli cells. Free‐standing and self‐organized TiO2 nanotube arrays were synthesized via a facile electrochemical anodization method, prior to calcination.RESULTS: Over 95% of the initial 106 cpu mL−1 E. coli cells were inactivated within 50 min of UV‐A photocatalytic disinfection, despite the influence of various ionic species and organic compounds commonly present in groundwater. This was justified by the unique double‐walled nanotubular structure of the TiO2 photocatalyst, which provided efficient delocalization of electron carriers and promoted anti‐recombination of photogenerated pairs of electrons and holes. Based on the experimental results obtained, cations enhanced the overall disinfection process while anions had an inhibitory effect on disinfection rates.CONCLUSION: The photocatalyst exhibited high efficiency in terms of photocatalytic disinfection of E. coli cells present in groundwater. It is deemed promising for applications in drinking water treatment owing to its superior disinfection performance, as well as high settleability, which promotes recovery and reuse of the catalyst. Copyright © 2010 Society of Chemical Industry
Sorption of polycyclic aromatic hydrocarbons from aqueous solution by hexadecyltrimethylammonium bromide modified fibric peat
Authors: Tang Xuanyi , Zhou Yanbo , Xu Yanxiao , Zhao Qing , Zhou Xiao , Lu Jun 
Published: April 2010

AbstractBACKGROUND: Fibric peat was modified by hexadecyltrimethylammonium bromide (HTAB) to improve its performance in sorption of polycyclic aromatic hydrocarbons (PAHs). The raw fibric peat (P‐R) and surfactant modified peat (P‐HTAB) were characterized by capillary rise test to determine the effect of HTAB on surface hydrophobicity. Effect of contact time was also investigated. Batch sorption data were fitted to the Freundlich model and pseudo‐second‐order model for isotherm and kinetics study.RESULTS: P‐HTAB had a more hydrophobic surface than P‐R. After modification, the sorption coefficients (KOC) of naphthalene, phenanthrene and pyrene on fibric peat increased from 1590, 29661 and 204171 mL g−1 to 2006, 52410 and 358569 mL g−1, respectively; the sorption rate constants of naphthalene, phenanthrene and pyrene increased from 0.00057, 0.00036 and 0.00051 g µg−1 min−1 to 0.00062, 0.00140 and 0.00155 g µg−1 min−1, respectively. The sorption coefficients of PAHs were positively correlated with the octane‐water partition coefficients of PAHs.CONCLUSIONS: The hydrophobicity of fibric peat was enhanced through modification by HTAB, which resulted in the improved sorption rate and sorption capacity for PAHs. The sorption performance of P‐HTAB reveals that it is an effective biosorbent for PAHs and has potential for treatment of wastewater containing hydrophobic organic contaminants. Copyright © 2010 Society of Chemical Industry