bluuebunny/crossref_metadata_2025_split huggingface dataset:
Neural Control of Muscle Length and Tension
Authors: Houk James C. , Rymer W. Zev 
Published: October 2010

AbstractThe sections in this article are:Control Theory ConceptsSystems and ModelsControl SystemsFeedback, Feedforward, and Adaptive SystemsPrinciple of Negative FeedbackRegulated Variables and PropertiesControl ConfigurationsSummaryHypotheses of Motor Servo FunctionSalient Features of the Available SensorsFollow‐up Servo HypothesisSpindle Receptors as Model‐Reference Error DetectorsConditional Feedback and Servo Assistanceβ‐System and the Possibility for Zero SensitivityStiffness RegulationSummary ModelAdaptive ModelsSummaryMuscle Mechanical StiffnessStiffness DefinitionsLength DependenceRecruitment of Motor UnitsRate Modulation of Motor UnitsInstantaneous Stiffness and Short‐Range ElasticityInstantaneous Stiffness Beyond the Short‐Range RegionRamp Responses: Transient Properties and NonlinearityNatural Combinations of Recruitment and Rate ModulationSummaryCentral PathwaysPrimary Ending ProjectionsTendon Organ ProjectionsProjections From Secondary Endings and GroupIIFree Nerve EndingsProjections From GroupsIIIandIVFree Nerve EndingsClasp‐Knife ReflexLong‐Loop ReflexesSummarySimplified Animal ModelsDecerebrate PreparationSpinal PreparationSummaryTonic Stretch Reflex in Functionally Isolated MusclesBasic Features of the Stretch ReflexStatic Force‐Length RelationsNormalized StiffnessMechanically and Neurally Mediated ComponentsActions of Control Signals on the Motor ServoDependence of Incremental Stiffness on Initial ForceLoop Gain of Force FeedbackSummaryStatic Regulatory Characteristics in Intact SubjectsSkeletal Mechanics and Coordinate SystemsSteady‐State Responses to Changes in Load ForceTorque‐Angle RelationsEquivalent Stiffness and the Concept of Composite Motor ServosEffect of Instructional SetGain Variation vs. Gain ControlSummaryDynamic Responses to Mechanical DisturbancesDynamic Features of Force DevelopmentDependence of Transient Responses on Initial ForceAmplitude Dependence and LinearityAsymmetry of Motor Servo ResponseCompensation for YieldingPredictive Compensation: Feedforward vs. Nonlinear Feedback ViewpointsVibration and the Stretch ReflexVelocity Dependence and DampingSummaryImplementation of Movement Commandsα‐γ‐RelationsPositional Stiffness Deduced From Spindle Relationsβ‐Innervation of Muscle SpindlesAnalytical Approaches to Actions of α‐, β‐, and γ‐MotoneuronsEquilibrium Point ControlStiffness Regulation vs. Stiffness ControlPerturbations During MovementCompliance, Load Compensation, and Biological DesignSummary
Peripheral Mechanisms of Hearing
Authors: Dallos Peter 
Published: October 2010

AbstractThe sections in this article are:Overview and Gross AnatomyEvolution of Ears and Their VarietyEvolution of the Inner EarEvolution of the middle earSensory ReceptorsCochlear Hair Cells in the MammalHair Cells as TransducersFunction of Cochlear Hair CellsEvents at Receptive Region of CellsAnatomy of Mammalian Cochlear DuctGeneration of Receptor CurrentMicromechanics of Organ of CortiInput to Organ of Corti: Basilar Membrane MechanicsStructure and Properties of Cochlear Canal and Basilar MembraneThe Traveling WaveNonlinearitiesThe Second FilterThe Middle and Outer EarEvolutionary NecessityThe Middle EarThe Outer EarElectrical Signs of Transduction: Cochlear PotentialsRecording MethodsIntracellular RecordingGross RecordingOutput of Receptor CellsTransmitter SubstancesSite of Impulse InitiationAction of Efferent Nerve FibersSummaryNote Added in Proof
Growth and magnetic‐optical properties of Sr3Gd(BO3)3 and Sr3TbxGd1‐x(BO3)3 single crystals
Authors: Junye Lu , Jianzhong Chen 
Published: October 2010

AbstractSingle crystals of Sr3Gd(BO3)3 (SGB) and Sr3TbxGd1‐x(BO3)3 (TSGB) with dimension Ø 20 mm×20 mm have been grown by Czochralski method. The grown crystals were characterized by X‐ray powder diffraction analysis which showed the crystals belong to hexagonal structure with lattice parameters of a=b=1.254 nm, c=0.926 nm (SGB) and a=b=1.253 nm, c=0.925 nm (TSGB). In TSGB, x=17.7% was obtained by X‐ray fluorometry which showed the segregation coefficient of Tb is closed to 1. The transmission spectrum was measured, which indicated the crystals have high transmittance in 400‐1100 nm region. The Faraday rotation of single crystals at 532 nm wavelength was measured at room temperature. Finally, the Verdet constants were investigated, (SGB) V=17.9 degcm‐1T‐1 and (TSGB) V=21.3 degcm‐1T‐1. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Role of annealing environment and partial pressure on structure and optical performance of TiO2 thin films fabricated by rf sputter method
Authors: Yildirim G. , Akdogan M. , Varilci A. , Terzioglu C. 
Published: October 2010

AbstractInfluences of the different annealing ambient (in air, 1 bar, 2 bar, 3 bar and 4 bar oxygen partial pressure) on the titanium dioxide (TiO2) thin films deposited on soda lime glass by standard radio frequency (rf) magnetron reactive sputtering method at 100 watt were investigated by means of X–ray diffractometer (XRD), ultra violet spectrometer (UV–vis), and Scanning Electron Microscopy (SEM). It was found that either optical properties or energy band gaps of the films enhanced with increase in the oxygen partial pressure up to 3 bar. The energy band gaps of the films (except for the film annealed in 4 bar oxygen partial pressure) became larger than the film annealed in atmospheric pressure. The best transmission was observed for the thin film annealed in 3 bar oxygen partial pressure. Moreover, not only was grain–like structure found to be more dominant than dot–like structure but also growth of anatase phase was observed instead of that of the rutile phase with increasing oxygen partial pressure up to 3 bar. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Novel nontoxic nanopigments based on zirconia and rare earth mixed oxides
Authors: Chandini Sam S. P. , Prasad V. S. , Sudarsana Kumar K. 
Published: October 2010

AbstractThis paper embodies the result of the investigations carried out on the synthesis of zirconia‐ rare earth mixed oxide pigments: ZrCe1‐xYxO4‐δ and ZrCe1‐xPrxO4‐δ by the solution combustion method and their characterization by X‐ray powder diffraction, transmission electron microscopy, energy dispersive spectrometric analysis, thermal analysis, reflectance spectral data and surface area measurements. The synthesized nano pigments possess low a and high b and exhibit yellow color when doped with Y and changes from yellow to orange‐red color when doped with Pr, with increase in x values. These pigments show maximum reflectance of 90% when the wavelength is above 550 nm. Due to the homogeneity of the phase formed and resistance to water, acids and alkali, the rare earth mixed oxides developed are found to be promising candidates as nontoxic pigments. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis of Benzotriazine and Aryltriazene Derivatives Starting from 2‐Azidobenzonitrile Derivatives
Authors: Nakhai Azadeh , Stensland Birgitta , Svensson Per H. , Bergman Jan 
Published: October 2010

Abstract3‐Substituted 3,4‐dihydro‐4‐imino‐1,2,3‐benzotriazine derivatives 7 were formed from 2‐azidobenzonitriles 4 as starting materials on treatment with Grignard or lithium organic reagents. In some cases these procedures gave aryltriazenes 10 and 11 as products. All compounds were identified by NMR spectroscopy and the structures of three products, namely 7a, 10a and 11i, were corroborated by X‐ray crystallography.
Uncatalyzed One‐Pot Diastereoselective Synthesis of α‐Amino Phosphonates Under Solvent‐Free Conditions
Authors: Tibhe Gaurao D. , Lagunas‐Rivera Selene , Vargas‐Díaz Elena , García‐Barradas Oscar , Ordoñez Mario 
Published: October 2010

AbstractUncatalyzed one‐pot, three‐component reactions of aldehydes, chiral α‐methylamines, and dimethyl phosphite under solvent‐free conditions were used for the diastereoselective synthesis of α‐amino phosphonates. The reactions proceeded with extremely high efficiency under mild conditions and gave good yields and diastereoselectivities (70:30 to 93:7 dr). This approach could be useful for the large‐scale synthesis of several α‐amino phosphonates.
Mutation spectrum in FE1‐MUTATMMouse lung epithelial cells exposed to nanoparticulate carbon black
Authors: Jacobsen Nicklas Raun , White Paul A. , Gingerich John , Møller Peter , Saber Anne Thoustrup , Douglas George R. , Vogel Ulla , Wallin Håkan 
Published: October 2010

AbstractIt has been shown previously that carbon black (CB), Printex 90 exposure induces cII and lacZ mutants in the FE1‐MutaTMMouse lung epithelial cell line and causes oxidatively damaged DNA and the production of reactive oxygen species (ROS). The purpose of this study was to determine the mutation spectrum in the cII gene of Printex 90 exposed cells. Cells exposed to CB have a substantially different mutation spectrum in the cII gene compared with vehicle exposed controls. The mutation spectra differ both in the positions (P < 0.0001) and types of the mutations (P < 0.0001). Exposure to Printex 90 increased the number of single base deletions by 2.3‐fold and larger deletions by 1.9‐fold. Most single base deletions were within two repetitive sequences in cII, but the large deletions were not. The mechanism behind the large deletions is not yet known. The largest increases in base substitutions were observed in G:C→T:A, G:C→C:G, and A:T→T:A transversion mutations; this is in keeping with a genetic finger print of ROS and is further substantiated by the observations that Printex 90 generates ROS and oxidatively damaged DNA. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.
Comparison of in vitro micronucleus and gene mutation assay results for p53‐competent versus p53‐deficient human lymphoblastoid cells
Authors: Honma Masamitsu , Hayashi Makoto 
Published: October 2010

AbstractThe high frequency of false or irrelevant positive results in in vitro mammalian cell genotoxicity tests is a critical concern for regulators. Here, we tested whether such results may be due to the mammalian cells used in the tests being deficient in p53, which is involved in the maintenance of genomic stability. We compared the in vitro responses of two human lymphoblastoid cell lines derived from the same progenitor cell‐p53‐competent (TK6) and p53‐deficient (WTK‐1) cells‐in a micronucleus (MN) test and a thymidine kinase gene (TK) mutation assay. We tested 14 chemicals including three mutagens and 11 clastogens and spindle poisons. The three mutagens evoked clear positive responses in both assays in both cell lines. The responses to the clastogens and spindle poisons, on the other hand, depended on the assay endpoint and/or the cell line. Most of clastogens and spindle poisons were positive in the MN test in both cell lines. In the TK mutation assay, on the other hand, WTK‐1 cells but not TK6 cells detected spindle poisons, which may have been due to the disturbance of the spindle checkpoint and lack of apoptosis in the p53‐deficient cells. Some chemicals that induced chromosome aberrations in rodent cells were negative in both TK6 and WTK‐1 cells, indicating that a species‐specific factor rather than p53 status was associated with the response. In conclusion, the p53 status did not seriously influence the MN test results but it did influence the TK mutation assay results. Environ. Mol. Mutagen., 2011. © 2010 Wiley‐Liss, Inc.
Production of activated carbon by K2CO3 activation treatment of furfural production waste and its application in gas storage
Authors: Sun Yong , Yang Gang , Wang Yun‐Shan , Zhang Jin‐Ping 
Published: October 2010

AbstractActivated carbon was produced by K2CO3 chemical activation of furfural production waste. The results showed that the product is essentially microporous carbon whose BET surface area and pore volume when the carbon was activated at 800°C were 2218 m2/g and 1.04 cm3/g, respectively. The potential usefulness of resultant carbons for gas storage is closely investigated. The hydrogen adsorption study showed that all the carbons exhibited a fast adsorption rate and the carbon activated at 800°C had the largest amount of adsorbed hydrogen due to its greater specific surface area and micropore volume. The hydrogen adsorption capacity of the carbon activated at 800°C can reach 1.7 wt % at 77K 1 atm and 0.48 wt % at 298K 6 MPa, respectively. The isosteric heat of adsorption with zero loading of hydrogen on carbon with the largest specific surface area can be 5 kJ/mol. The adsorption model based on Tóth equation together with Benedict‐Webb‐Rubin (BWR) equation of state is proposed for this carbon in adsorbing hydrogen under high pressure. © 2010 American Institute of Chemical Engineers Environ Prog, 2010.
Subaerial weathering versus wave processes in shore platform development: reappraising the Old Hat Island evidence
Authors: Kennedy David M. , Paulik Ryan , Dickson Mark E. 
Published: October 2010

AbstractOne of the longest standing debates in rocky coast geomorphology is whether subaerial weathering or wave processes dominate shore platform evolution. The origins of this debate date to the mid‐nineteenth century when the first descriptions of Old Hat Islands were provided from northern New Zealand. Old Hat Islands are surrounded by a broad near‐horizontal shore platform. Their formation was inferred to relate to subaerial weathering of bedrock to a level of permanent saturation with wave processes acting only to remove the weathered debris. To date, no detailed topographic surveys have been conducted on the Old Hat Islands in New Zealand that initiated this debate; in this study we provide the first quantitative data on the original field sites. Topographical surveying and Schmidt Hammer hardness testing were conducted on >25 profiles of varying wave exposure. In contrast to the classic descriptions, platform elevation varies from just above mean high water spring (MHWS) at the most exposed sites, to mean high water neap (MHWN) at the most protected sites or mean sea level (MSL) where beaches occur on the platform surface. There is no significant difference between the hardness of the cliffs and the platforms fronting them and no clear relationship between wave exposure and platform width. Rather than being exclusively dominated by subaerial process, the formation of microtidal, sheltered, Old Hat Island platforms is considered to be a function of (i) the rate of weathering, (ii) exposure to wave energy, (iii) nearshore water depth and (iv) rock resistance. Shore platform elevation in the study area is thought to be a function of the level at which waves erode cliff rock, and the action of weathering which lowers platform surfaces. The width of platforms is strongly influenced by the ability of waves to dissect the platform edge along vertical joint lines. Copyright © 2010 John Wiley & Sons, Ltd.
Defining and modeling known adverse outcome pathways: Domoic acid and neuronal signaling as a case study
Authors: Watanabe Karen H , Andersen Melvin E , Basu Niladri , Carvan Michael J , Crofton Kevin M , King Kerensa A , Suñol Cristina , Tiffany-Castiglioni Evelyn , Schultz Irvin R 
Published: October 2010

Abstract
An adverse outcome pathway (AOP) is a sequence of key events from a molecular-level initiating event and an ensuing cascade of steps to an adverse outcome with population-level significance. To implement a predictive strategy for ecotoxicology, the multiscale nature of an AOP requires computational models to link salient processes (e.g., in chemical uptake, toxicokinetics, toxicodynamics, and population dynamics). A case study with domoic acid was used to demonstrate strategies and enable generic recommendations for developing computational models in an effort to move toward a toxicity testing paradigm focused on toxicity pathway perturbations applicable to ecological risk assessment. Domoic acid, an algal toxin with adverse effects on both wildlife and humans, is a potent agonist for kainate receptors (ionotropic glutamate receptors whose activation leads to the influx of Na+ and Ca2+). Increased Ca2+ concentrations result in neuronal excitotoxicity and cell death, primarily in the hippocampus, which produces seizures, impairs learning and memory, and alters behavior in some species. Altered neuronal Ca2+ is a key process in domoic acid toxicity, which can be evaluated in vitro. Furthermore, results of these assays would be amenable to mechanistic modeling for identifying domoic acid concentrations and Ca2+ perturbations that are normal, adaptive, or clearly toxic. In vitro assays with outputs amenable to measurement in exposed populations can link in vitro to in vivo conditions, and toxicokinetic information will aid in linking in vitro results to the individual organism. Development of an AOP required an iterative process with three important outcomes: a critically reviewed, stressor-specific AOP; identification of key processes suitable for evaluation with in vitro assays; and strategies for model development. Environ. Toxicol. Chem. 2011;30:9–21. © 2010 SETAC
Reverse engineering adverse outcome pathways
Authors: Perkins Edward J , Chipman J. Kevin , Edwards Stephen , Habib Tanwir , Falciani Francesco , Taylor Ronald , Van Aggelen Graham , Vulpe Chris , Antczak Philipp , Loguinov Alexandre 
Published: October 2010

Abstract
The toxicological effects of many stressors are mediated through unknown, or incompletely characterized, mechanisms of action. The application of reverse engineering complex interaction networks from high dimensional omics data (gene, protein, metabolic, signaling) can be used to overcome these limitations. This approach was used to characterize adverse outcome pathways (AOPs) for chemicals that disrupt the hypothalamus-pituitary-gonadal endocrine axis in fathead minnows (FHM, Pimephales promelas). Gene expression changes in FHM ovaries in response to seven different chemicals, over different times, doses, and in vivo versus in vitro conditions, were captured in a large data set of 868 arrays. Potential AOPs of the antiandrogen flutamide were examined using two mutual information-based methods to infer gene regulatory networks and potential AOPs. Representative networks from these studies were used to predict network paths from stressor to adverse outcome as candidate AOPs. The relationship of individual chemicals to an adverse outcome can be determined by following perturbations through the network in response to chemical treatment, thus leading to the nodes associated with the adverse outcome. Identification of candidate pathways allows for formation of testable hypotheses about key biological processes, biomarkers, or alternative endpoints that can be used to monitor an AOP. Finally, the unique challenges facing the application of this approach in ecotoxicology were identified and a road map for the utilization of these tools presented. Environ. Toxicol. Chem. 2011;30:22–38. © 2010 SETAC
Predicting chemical impacts on vertebrate endocrine systems
Authors: Nichols John W , Breen Miyuki , Denver Robert J , DiStefano Joseph J , Edwards Jeremy S , Hoke Robert A , Volz David C , Zhang Xiaowei 
Published: October 2010

AbstractAnimals have evolved diverse protective mechanisms for responding to toxic chemicals of both natural and anthropogenic origin. From a governmental regulatory perspective, these protective responses complicate efforts to establish acceptable levels of chemical exposure. To explore this issue, we considered vertebrate endocrine systems as potential targets for environmental contaminants. Using the hypothalamic-pituitary-thyroid (HPT), hypothalamic-pituitary-gonad (HPG), and hypothalamic-pituitary-adrenal (HPA) axes as case examples, we identified features of these systems that allow them to accommodate and recover from chemical insults. In doing so, a distinction was made between effects on adults and those on developing organisms. This distinction was required because endocrine system disruption in early life stages may alter development of organs and organ systems, resulting in permanent changes in phenotypic expression later in life. Risk assessments of chemicals that impact highly regulated systems must consider the dynamics of these systems in relation to complex environmental exposures. A largely unanswered question is whether successful accommodation to a toxic insult exerts a fitness cost on individual animals, resulting in adverse consequences for populations. Mechanistically based mathematical models of endocrine systems provide a means for better understanding accommodation and recovery. In the short term, these models can be used to design experiments and interpret study findings. Over the long term, a set of validated models could be used to extrapolate limited in vitro and in vivo testing data to a broader range of untested chemicals, species, and exposure scenarios. With appropriate modification, Tier 2 assays developed in support of the U.S. Environmental Protection Agency's Endocrine Disruptor Screening Program could be used to assess the potential for accommodation and recovery and inform the development of mechanistically based models. Environ. Toxicol. Chem. 2011;30:39–51. © 2010 SETAC
In vitro screening of organotin compounds and sediment extracts for cytotoxicity to fish cells
Authors: Giltrap Michelle , Macken Ailbhe , McHugh Brendan , McGovern Evin , Foley Barry , Davoren Maria 
Published: October 2010

AbstractThe present study reports an in vitro screening method for contaminants in sediment samples utilizing an RTG-2 cell line. This technique integrates cytotoxicity testing with analytical chemistry with the aim of achieving a toxicity evaluation of the sediment sample. The toxic effect of individual organotin (OT) compounds and their presence in the sediment sample is the focus of the present study; however, other contaminants are also discussed. The following OT compounds: tributyltin (TBT), dibutyltin (DBT), monobutyltin (MBT), triphenyltin (TPT), diphenyltin (DPT), and a sediment solvent extract are exposed to the RTG-2 fish cell line. Both the alamar blue (AB) and neutral red (NR) assays are used to assess cytotoxicity after 24-h and 96-h exposure. Methodology for preparation of a sediment solvent extract suitable for biological testing and analytical determination is also described. With the RTG-2 cells, the AB and NR assays had comparable sensitivity for each individual OT compound exposure after 24 h, with TPT being the most toxic compound tested. The individual OT compound concentrations required to induce a 50% toxic effect on the cells (369 ng ml−1 TBT, 1,905 ng ml−1 DBT) did not equate to the concentrations of these contaminants present in the sediment extract that induced a 50% effect on the cells (294 ng ml−1 TBT, 109 ng ml−1 DBT). The solvent extract therefore exhibited a greater toxicity, and this suggests that the toxic effects observed were not due to OT compounds alone. The presence of other contaminants in the solvent extract is confirmed with chemical analysis, warranting further toxicity testing of contaminant mixtures and exposure to the cell line to further elucidate a complete toxicity evaluation. Environ. Toxicol. Chem. 2011;30:154–161. © 2010 SETAC