bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of an environmentally relevant polychlorinated biphenyl (PCB) mixture on embryonic survival and cardiac development in the domestic chicken
Authors: Carro Tiffany , Dean Karen , Ottinger Mary Ann 
Published: February 2013

Abstract

A 58-congener polychlorinated biphenyl (PCB) mixture based on contaminant analysis of spotted sandpiper eggs collected along the upper Hudson River, New York, USA, in 2004 was used to study in ovo PCB effects on cardiac development in the domestic chicken. Fertile eggs were injected prior to incubation with the following doses of the PCB mixture: untreated, sham, 0, 0.03, 0.08, 0.3, 0.5, 0.7, and 2.06 µg PCBs/g egg weight (toxic equivalent quotient [TEQ] range of 0.004–0.266 ng/g). In addition, there were untreated and sham-control groups. Embryonic development was monitored throughout incubation and chicks were necropsied at hatch. Hatchability followed a dose-dependent curve with significant (p &lt; 0.05) mortality above the 0.5 µg PCBs/g egg weight treatment compared with controls. The median lethal dose (LD50) of this PCB mixture in hatchling chicks was estimated as 0.4 µg/g egg weight (0.052 ng TEQ/g egg wt) based on the lethality curve. Cardiac arrhythmia was observed at embryonic day 14 of development in embryos treated at concentrations of 0.5 µg/g egg weight and above. Histological analysis was utilized to characterize any cardiac abnormalities. Cardiomyopathies increased across treatments in a dose-dependent manner compared with control groups. Identified abnormalities included the absence of the trabeculated layer of the ventricular wall, ventricular dilation, thinning of the ventricular walls, malformation of the septal wall, and most commonly, absence of the compact layer of the ventricular wall. Chick heart width, depth, total area, compact layer depth, septal width, chamber area, and ventricular wall dimensions did not differ across treatments. The present study supports prior reports of adverse developmental effects of PCBs on cardiovascular systems in birds. Although the eggs hatched, measured cardiomyopathies suggest potential deleterious long-term impacts on individual health and fitness. Environ Toxicol Chem 2013;32:1325–1331. © 2013 SETAC
Estimating population-level HC5 for copper using a species sensitivity distribution approach
Authors: Iwasaki Yuichi , Hayashi Takehiko I. , Kamo Masashi 
Published: February 2013

Abstract

Estimation of population-level benchmark concentrations for protecting aquatic organisms from chemicals is important for value-relevant ecological risk assessments. By employing a species sensitivity distribution (SSD) approach, the authors aimed to derive the population-level hazardous concentration for 5% of species (PHC5) for copper. Based on available information on copper toxicity and population models, the authors estimated population threshold concentrations at which the population size is stable (that is, 0 net population growth) for 13 freshwater species (3 algal, 6 invertebrate, and 4 fish species). The PHC5 for copper was then estimated (6.8 µg/L; 95% confidence interval [CI], 1.8–13.6 µg/L), by fitting a log-normal distribution to the population threshold concentrations obtained. The close overlap between the present study's estimate of the PHC5 and a field-derived threshold concentration suggests that the population-level SSD approach provides a reasonable level of protection for species richness in the natural environment. By contrast, and counterintuitively, the authors' estimate was comparable with the individual-level HC5 reported in the European Union risk assessment. Although the present study cannot determine the underlying reasons for the similar figures, the result provides an indication that the margin between individual-level and population-level benchmarks derived from SSD approaches can be very small. The results therefore suggest that attention is needed to achieve population-level protection using an individual-level SSD approach. Environ Toxicol Chem 2013;32:1396–1402. © 2013 SETAC
Determination of mercury speciation in fish tissue with a direct mercury analyzer
Authors: Barst Benjamin D. , Hammerschmidt Chad R. , Chumchal Matthew M. , Muir Derek C.G. , Smith James D. , Roberts Aaron P. , Rainwater Thomas R. , Drevnick Paul E. 
Published: February 2013

Abstract

Knowledge of Hg speciation in tissue is valuable for assessing potential toxicological effects in fish. Direct Hg analyzers, which use thermal decomposition and atomic absorption spectrometry, have recently gained popularity for determining organic Hg after procedural solvent extraction from some environmental media, although quantitative recovery from lipid-rich materials, such as fish liver, has been problematic. The authors developed a new method by which organic Hg in fish liver and muscle is estimated by the difference between direct measurements of inorganic Hg in an acid extract and total Hg in whole tissue. The method was validated by analysis of a certified reference material (DOLT-4 dogfish liver) and naturally contaminated fish tissues with comparison to an established Hg speciation method (gas chromatography cold vapor atomic fluorescence spectrometry). Recovery of organic Hg from DOLT-4, estimated by difference, averaged 99 ± 5% of the mean certified value for methylmercury. In most liver samples and all muscle samples, estimates of organic Hg from the proposed method were indiscernible from direct speciation measurements of methylmercury (99% ± 6%). Estimation of organic Hg by the difference between total Hg and inorganic Hg was less accurate in liver samples with a high percentage of inorganic Hg (90%). This was because of the increased uncertainty that results from estimating a third value (i.e., organic Hg) by using the difference between two large concentrations (inorganic and total Hg). The proposed method is a useful tool for examining the speciation of Hg in fish muscle and liver, and by extension, potentially other tissues and environmental media. Environ Toxicol Chem 2013;32:1237–1241. © 2013 SETAC
A Jump Diffusion Model for Agricultural Commodities with Bayesian Analysis
Authors: Schmitz Adam , Wang Zhiguang , Kimn Jung‐Han 
Published: February 2013

AbstractStochastic volatility, price jumps, seasonality, and stochastic cost of carry have been included separately, but not collectively, in pricing models of agricultural commodity futures and options. We propose a comprehensive model that incorporates all four features. We employ a special Markov chain Monte Carlo algorithm, new in the agricultural commodity derivatives pricing literature, to estimate the proposed stochastic volatility (SV) and stochastic volatility with jumps (SVJ) models. Overall model fitness tests favor the SVJ model. The in‐sample and out‐of‐sample pricing results for corn, soybeans and wheat generally, with few exceptions, lend support for the SVJ model. © 2013 Wiley Periodicals, Inc. Jrl Fut Mark 34:235–260, 2014
Upper‐mantle fabrics beneath the Northern Apennines revealed by seismic anisotropy
Authors: Munzarová Helena , Plomerová Jaroslava , Babuška Vladislav , Vecsey Luděk 
Published: February 2013

AbstractWe image anisotropic structure of the upper mantle beneath the Northern Apennines based on body‐wave data collected during the RETREAT experiment (2003–2006). Joint analysis of anisotropic parameters evaluated from independent data sets—teleseismic P‐wave travel times and shear‐wave splitting—allows us to identify regions of different fabrics both in the mantle lithosphere and in the sublithospheric mantle. We recognize three regions—the Tyrrhenian, Adriatic, and Transition—with their own anisotropic characteristics. The slab‐parallel flow prevails in the sublithospheric mantle beneath the thin Tyrrhenian plate, while nearly slab‐perpendicular orientation of the high velocities dominates on the Adriatic side of the region. The asthenospheric‐flow pattern excludes a simple corner‐flow model to fit the fabric of the upper mantle in the syn‐convergent extensional tectonics and suggests the end of the subduction roll‐back. We map fossil anisotropy with inclined symmetry axes within two domains of the thick continental Adriatic lithosphere. We estimate the lithosphere thickness of the Tyrrhenian and Adriatic plates at ~50 km and ~80 km, respectively, the latter being subducted down to no more than ~200 km with indications of inherited frozen‐in anisotropic fabric. If a potential detachment at the northern end of the Apennine slab exists, then it would have to be narrow and in its initial stage. Synthetic tests of the well‐known trade‐off between isotropic heterogeneity and evaluated anisotropic parameters, along with combining independent data sets, document a sufficient separation of both effects.
Triggering of El Niño onset through trade wind–induced charging of the equatorial Pacific
Authors: Anderson Bruce T. , Perez Renellys C. , Karspeck Alicia 
Published: February 2013

AbstractSea surface temperature variations over the equatorial Pacific associated with the El Niño/Southern Oscillation (ENSO) produce changes in climates across the globe. Here we report evidence from observationally constrained ocean data for the initiation of warm ENSO events (El Niños) resulting from subsurface equatorial Pacific heat content increases related to tropical/extratropical sea level pressure (SLP) changes over the North Pacific. We hypothesize that the increase in heat content is a response to SLP‐generated variations in the North Pacific trade winds, which we term trade wind charging of the equatorial Pacific. Experiments using a high‐resolution numerical ocean model verify that the charging of subsurface heat content along the equatorial Pacific can be induced by SLP‐generated trade wind variations. Furthermore, analysis of the numerical model results and historical observations indicates that the trade wind–induced ocean heat content increases are sufficiently large to initiate the onset of El Niño events, which mature approximately 12 months after the trade wind forcing itself.
Cracking the MJO nut
Authors: Zhang Chidong , Gottschalck Jon , Maloney Eric D. , Moncrieff Mitchell W. , Vitart Frederic , Waliser Duane E. , Wang Bin , Wheeler Matthew C. 
Published: February 2013

AbstractThe Madden‐Julian oscillation poses great challenges to our understanding and prediction of tropical convection and the large‐scale circulation. Several internationally coordinated activities were recently formed to meet the challenges from the perspectives of numerical simulations, prediction, diagnostics, and virtual and actual field campaigns. This article provides a brief description of these activities and their connections, with the motivation in part to encourage the next generation of physical scientists to help solve the grand challenging problem of the Madden‐Julian oscillation.
Hydrodynamic processes and sediment erosion mechanisms in an open channel bend of strong curvature with deformed bathymetry
Authors: Constantinescu G. , Kashyap S. , Tokyay T. , Rennie C. D. , Townsend R. D. 
Published: February 2013

AbstractMost rivers exhibit regions of strong channel curvature that are characterized by more complex and variable flow and erosion patterns, compared to regions of lower curvature. Studies investigating high‐curvature bends using eddy‐resolving techniques have been limited, and the effect of bend angle on flow and erosion has rarely been investigated. This study investigates flow in a 135° nonerodible bank open channel bend of high curvature: ratio of radius of curvature, R, to channel width, B, is 1.5. The bathymetry is obtained during the final stages of a clear water scour experiment. Large Eddy Simulation is used to investigate the effect of secondary flow on the redistribution of streamwise momentum, the details of coherent structures, and mechanisms leading to erosion within the bend. Results are compared with those from a similar numerical study of a 193° sharply curved open channel bend with R/B = 1.35. The angle of the 135° bend is representative of typical regular meander geometry, while the larger angle of the 193° bend is representative of a tortuous meander geometry. The different bathymetries induced important quantitative and qualitative differences in the vortical and turbulence structure within the open channel for the two cases. Inner bank streamwise‐oriented vortical (SOV) cells formed in both cases, but the position and extent of shear layers forming between regions of fast and slow moving fluid differed, and flow did not separate at the inner bank in the 135° bend. An outer‐bank cell was observed in the 135° bend, but not in the 193° bend. Distributions of predicted boundary shear stresses indicated the capacity of the flow to erode the outer bank of a sharply curved bend under two representative regimes found in the field.
Impact of influenza virus escape‐mutations on influenza detection by the rapid influenza diagnostic test
Authors: Yi Hwajung , Kim Young‐Hoon , Kim Jun‐Sub , Lee Nam‐Joo , Shin Kyeongcheol , Choi Jang‐Hoon , Kwon Donghyok , Lee Joo‐Yeon , Kang Chun 
Published: February 2013

AbstractDuring the influenza pandemic of 2009–2010, rapid influenza diagnostic tests (RIDTs) were used to detect influenza viral infections because they are quick and simple to use. However, retrospective studies showed that RIDTs performed poorly when used to diagnose pandemic viral infections. Determining how amino acid sequence changes in pandemic or epidemic influenza viral antigens impact clinical value of RIDTs has not been possible, because the viral epitopes recognized by RIDTs have been not mapped. In this study, the effect of escape‐variations or mutations in influenza viral antigens upon the sensitivity and specificity of an RIDT was investigated by characterizing the immunological properties of the antibodies used in the RIDT. Escape‐mutants were generated by cultivating A/Korea/01/2009 in the presence of an excess of the same antibodies used in the RIDT. Escape‐mutants not recognized by the RIDT were selected. Epitopes recognized by the RIDT were mapped by comparing the sequence and immunological analysis of the escape‐variants and wild‐type isolates. The RIDT antibodies recognized epitopes on the Sa antigenic site and in the F subdomain in hemagglutinin. Variants bearing mutations in these epitopes were not detected by the RIDT. The frequency of escape‐variants emerging since the 2009–2010 pandemic was calculated as 1.27% using in silico surveillance of influenza sequence databases. These results suggest that mapping the relevant epitopes of RIDTs and making such information available to clinics would be helpful for determining whether RIDTs match newly emergent strains and subtypes prior to retrospective re‐evaluation of the RIDTs using clinical specimens. J. Med. Virol. 85:709–715, 2013. © 2013 Wiley Periodicals, Inc.
Effect of pressure and temperature on the molecular interaction of polar lubricant containing oleic acid in polypropylene glycol observed by infrared spectroscopy
Authors: Takiwatari Koji , Nanao Hidetaka , Mori Shigeyuki 
Published: February 2013

ABSTRACTIn this work, we have investigated the infrared spectra of polar lubricant in order to explore the molecular interaction under high pressure and temperature conditions using diamond anvil cell. Polypropylene glycol and oleic acid were used as base oil and additive, respectively. Stretching vibration mode of polar functional groups, such as νO–H and νC═O, was found to be sensitive to pressure and temperature. The peak positions of the vibration mode were shifted clearly to lower wavenumber as pressure increases, and temperature increase induced a slight shift to higher wavenumber. These results indicate that hydrogen bonding between lubricant molecules of base oil and additive was influenced by pressure and temperature. And furthermore, the dependency of the peak shift was discontinuous and affected mainly by pressure. These results imply a structural change on the basis of the molecular interaction of the lubricating molecules at elastohydrodynamic lubrication contacts. Copyright © 2013 John Wiley & Sons, Ltd.
Analytic approximation of the blow‐up time for nonlinear differential equations by the ADM–Padé technique
Authors: Duan Jun‐Sheng , Rach Randolph , Lin Shi‐Ming 
Published: February 2013

AbstractWe present a new approach to calculate analytic approximations of blow‐up solutions and their critical blow‐up times. Our approach applies the Adomian decomposition–Padé method to quickly and easily compute the critical blow‐up times, which comprises the Adomian decomposition method combined with the Padé approximants technique. We validate our new approach with a variety of numerical examples, including nonlinear ODEs, systems of nonlinear ODEs, and nonlinear PDEs. Furthermore, our new method is shown to be more convenient than prior art that relies on compound discretized algorithms. Copyright © 2013 John Wiley & Sons, Ltd.
Parallel indirect solution of optimal control problems
Authors: Fabien Brian C. 
Published: February 2013

SUMMARYThis paper presents an algorithm for the indirect solution of optimal control problems that contain mixed state and control variable inequality constraints. The necessary conditions for optimality lead to an inequality constrained two‐point BVP with index‐1 differential‐algebraic equations (BVP‐DAEs). These BVP‐DAEs are solved using a multiple shooting method where the DAEs are approximated using a single‐step linearly implicit Runge–Kutta (Rosenbrock–Wanner) method. An interior‐point Newton method is used to solve the residual equations associated with the multiple shooting discretization. The elements of the residual equations, and the Jacobian of the residual equations, are constructed in parallel. The search direction for the interior‐point method is computed by solving a sparse bordered almost block diagonal (BABD) linear system. Here, a parallel‐structured orthogonal factorization algorithm is used to solve the BABD system. Examples are presented to illustrate the efficiency of the parallel algorithm. It is shown that an American National Standards Institute C implementation of the parallel algorithm achieves significant speedup with the increase in the number of processors used. Copyright © 2013 John Wiley & Sons, Ltd.
Absolute immature platelet count may predict imminent platelet recovery in thrombocytopenic children following chemotherapy
Authors: Have Laerke Walther Junggreen , Hasle Henrik , Vestergaard Else Marie , Kjaersgaard Mimi 
Published: February 2013

AbstractBackgroundImmature platelets are the youngest circulating platelets and they reflect the rate of thrombopoiesis. The immature platelet fraction (IPF) or the absolute immature platelet count (AIPC) may predict platelet count recovery following chemotherapy‐induced thrombocytopenia in pediatric patients and help guiding prophylactic platelet transfusion therapy.ProcedureTo test IPF and AIPC as predictors of platelet recovery, 19 children with platelet nadirs of less than 20 × 109/L after chemotherapy were prospectively enrolled. IPF, platelet count, and C‐reactive protein (CRP) were analyzed in 416 paired samples from 37 patients with malignancies to test if IPF‐levels were CRP dependent.ResultsA significant increase of 0.6 × 109/L in AIPC was seen between 1 and 2 days prior to platelet count recovery. No predictive day‐to‐day differences were found for IPF. Platelet count recovery did not occur significantly earlier for patients with a peak IPF > 10% than for those patients with a peak IPF < 10%. IPF and AIPC showed no correlation to CRP. AIPC was in contrast to IPF not influenced by platelet transfusions.ConclusionAIPC increased significantly between 24 and 48 hours before platelet recovery whereas IPF showed no significant increase during the same time period. AIPC may be a better indicator than IPF for predicting platelet recovery after chemotherapy in pediatric patients. Pediatr Blood Cancer 2013; 60: 1198–1203. © 2013 Wiley Periodicals, Inc.
Screening tool for late‐effect pediatric neuro‐oncological clinics: A treatment‐oriented questionnaire
Authors: Greenberg‐Kushnir Noa , Freedman Sigal , Eshel Rina , Zwerdling Nirit , Elhasid Ronit , Dvir Rina , Yalon Michal , Kulkarni Abhaya V. , Constantini Shlomi 
Published: February 2013

AbstractBackgroundMany survivors of pediatric brain tumors (SPBTs) suffer from long‐term late effects (LEs). Our aim was to create a practical screening tool for detecting LEs in this population. Such a screening tool will improve our ability to identify those patients who may benefit from treatment in LE clinics while focusing on individual relevant issues.ProcedureWe developed the Treatment‐Oriented Screening Questionnaire (TOSQ); a self‐reported, risk‐based questionnaire that addresses all LEs SPBTs can potentially suffer. As a basis for the TOSQ design we used the Long‐Term Follow‐Up Guidelines published by the Children's Oncology Group. Output includes individual recommendations for further treatment. We prospectively assessed whether the TOSQ can accurately detect treatment targets in SPBTs by comparing patient and caregiver questionnaire scores with physician evaluations. Data are presented from 41 SPBTs.ResultsThe TOSQ is a precise screening tool for identifying LEs in SPBTs based on the significant correlation (P < 0.05) that was found between parental scores and physician evaluations. Statistical testing proved that parents are a good source of information about child's health status, and that TOSQ accurately reflects the correlation between patient difficulties and quality of life.ConclusionsThe TOSQ is the first described screening tool for identification of LEs designed specifically for SPBTs. It is simple to use and provides a valid, comprehensive and economic assessment followed by targeted treatment plan for each patient. By repeatedly using the TOSQ over the years, we can improve our ability to detect and give focused treatment to those who require assistance. Pediatr Blood Cancer 2013;60:1369–1374. © 2013 Wiley Periodicals, Inc.
Solvent replacement to thermo‐responsive nanoparticles from long‐subchain hyperbranched PSt grafted with PNIPAM for encapsulation
Authors: He Chen , Jin Ban‐Kun , He Wei‐Dong , Ge Xue‐Song , Tao Jing , Yang Jing , Chen Sheng‐Qi 
Published: February 2013

AbstractLong‐subchain hyperbranched polystyrene (lsc‐hp PSt) with uniform subchain length was obtained through copper‐catalyzed azide‐alkyne cycloaddition click chemistry from seesaw macromonomer of PSt having one alkynyl group anchored at the chain centre and two azido group attached to both chain ends [alkynyl‐(PSt‐N3)2]. After precipitation fraction, different portions of lsc‐hp PSt having narrow overall molecular weight distribution were obtained for further grafting with alkynyl‐capped poly(N‐isopropylacrylamide) (alkynyl‐PNIPAM), which was obtained via single‐electron transfer living radical polymerization of NIPAM with propargyl 2‐bromoisobutyrate as the initiator and grafted onto the peripheral azido groups of lsc‐hp PSt via click chemistry. Thus, amphiphilic lsc‐hp PSt grafted with PNIPAM chains (lsc‐hp PSt‐g‐PNIPAM) was obtained and would have star‐like conformation in tetrahydrofuran (THF). By replacing THF with water, lsc‐hp PSt‐g‐PNIPAM was dissolved at molecular level in aqueous solution due to the hydrophilicity of PNIPAM and exhibited thermal induced shrinkage of PNIPAM arms. The water‐insoluble lsc‐hp PSt would collapse densely and could be served as a reservoir to absorb hydrophobic chemicals in aqueous solution. The influence of overall molecular weight of lsc‐hp PSt on the absorption of pyrene was studied. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013