bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of electronic and mechanical Schmidt hammers in the context of exposure‐age dating: are Q‐ and R‐values interconvertible?
Authors: Winkler Stefan , Matthews John A. 
Published: April 2014

ABSTRACTApplication of Schmidt‐hammer exposure‐age dating (SHD) to landforms has substantially increased in recent years. The original mechanical Schmidt hammer records R‐(rebound) values. Although the newly introduced electronic Schmidt hammer (SilverSchmidt) facilitates greatly improved data processing, it measures surface hardness differently, recording Q‐(velocity) values that are not a priori interconvertible with R‐values. This study is the first to compare the performance of both instruments in the context of field‐based exposure‐age dating with a particular focus on the interconvertibility of R‐values and Q‐values. The study was conducted on glacially polished pyroxene‐granulite gneiss, Jotunheimen, southern Norway. Results indicate that mean Q‐values are consistently 8–10 units higher than mean R‐values over the range of values normally encountered in the application of SHD to glacial and periglacial landforms. A convenient conversion factor of ±10 units may, therefore, be appropriate for all but the softest rock types close to the technical resolution of the instruments. The electronic Schmidt hammer should therefore be regarded as a useful complement and potential replacement for the mechanical Schmidt hammer. Conversion of published R‐values data to Q‐values requires, however, careful control and documentation of instrument calibration. Copyright © 2014 John Wiley & Sons, Ltd.
Ecological factors contributing to variability of persistent organic pollutant bioaccumulation within forage fish communities of the Detroit River, Ontario, Canada
Authors: McLeod Anne M. , Paterson Gord , Drouillard Ken G. , Haffner G. Douglas 
Published: April 2014

Abstract
Understanding variability of contaminant bioaccumulation within and among fish populations is critical for distinguishing between the chemical and biological mechanisms that contribute to food web biomagnification and quantifying contaminant exposure risks in aquatic ecosystems. The present study examined the relative contributions of chemical hydrophobicity (octanol–water partition coefficient [KOW]) and habitat use as factors regulating variability in polychlorinated biphenyl (PCB) congener bioaccumulation in 3 lower trophic level cyprinid species across spatial and temporal scales. Bluntnose minnows (Pimephales notatus), spottail shiners (Notropis hudsonius), and emerald shiners (Notropis atherinoides) were sampled at 3 locations in the Detroit River, Ontario, Canada. Variability in PCB concentration was evaluated with respect to several factors, including chemical hydrophobicity, site, season, species, and weight using sum of squares and Levene's test of homogeneity of variance. Individual variability in bioaccumulated congener-specific residues depended on chemical hydrophobicity with mid- and high-range KOW congeners (log KOW &gt; 6.0), demonstrating the highest amount of variance compared with low KOW congeners. Different feeding strategies also contributed to the variance observed for mid-range KOW congeners among species. In the present study, benthic feeding specialists exhibited lower variance in PCB concentrations compared with the 2 generalist species. The results indicate that chemical hydrophobicity and feeding ecology not only contribute to differences in the biomagnification potentials of fish, but also regulate between-individual variation in PCB concentrations both across and within fish species. Environ Toxicol Chem 2014;33:1825–1831. © 2014 SETAC
Self organising cloud cells: a resource efficient network densification strategy
Authors: Alsedairy Talal , Qi Yinan , Imran Ali , Imran Muhammad Ali , Evans Barry 
Published: April 2014

AbstractNetwork densification is envisioned as the key enabler for 2020 vision that requires cellular systems to grow in capacity by hundreds of times to cope with unprecedented traffic growth trends being witnessed since advent of broadband on the move. However, increased energy consumption and complex mobility management associated with network densifications remain as the two main challenges to be addressed before further network densification can be exploited on a wide scale. In the wake of these challenges, this paper proposes and evaluates a novel dense network deployment strategy for increasing the capacity of future cellular systems without sacrificing energy efficiency and compromising mobility performance. Our deployment architecture consists of smart small cells, called cloud nodes, which provide data coverage to individual users on a demand bases while taking into account the spatial and temporal dynamics of user mobility and traffic. The decision to activate the cloud nodes, such that certain performance objectives at system level are targeted, is carried out by the overlaying macrocell based on a fuzzy‐logic framework. We also compare the proposed architecture with conventional macrocell only deployment and pure microcell‐based dense deployment in terms of blocking probability, handover probability and energy efficiency and discuss and quantify the trade‐offs therein.© 2014 The Authors. Transactions on Emerging Telecommunications Technologies published by John Wiley & Sons, Ltd.
A decision theoretic approach for clustering and rate allocation in coordinated multi‐point (CoMP) networks with delayed channel state information
Authors: Cai Yegui , Yu F. Richard , Bu Shengrong 
Published: April 2014

AbstractCoordinated multi‐point (CoMP) is a promising technique in next generation cellular networks. Compared with traditional mobile networks, one of the important design problems in CoMP is clustering, which decides how the base stations cooperate with each other. Channel state information (CSI) is needed in clustering decisions in CoMP. Most previous works assume that perfect CSI is available. However, practical systems suffer from constraints imposed by backhaul networks, which are used for CSI exchange. In this paper, we study the clustering and rate allocation problem in CoMP with delayed CSI. We present a decision theoretic approach to this problem. Specifically, we model such a system in the framework of networked Markov decision process (networked‐MDP) with delays, which is equivalent to a partial observable Markov decision process (POMDP). We derive an optimal policy for such POMDP with low computation complexity. Simulation results are provided to show promising gain achieved in the proposed scheme over existing schemes especially when the delay is large and the channel coherence time is small. Copyright © 2014 John Wiley & Sons, Ltd.
REALIZED BETA GARCH: A MULTIVARIATE GARCH MODEL WITH REALIZED MEASURES OF VOLATILITY
Authors: Hansen Peter Reinhard , Lunde Asger , Voev Valeri 
Published: April 2014

SUMMARYWe introduce a multivariate generalized autoregressive conditional heteroskedasticity (GARCH) model that incorporates realized measures of variances and covariances. Realized measures extract information about the current levels of volatilities and correlations from high‐frequency data, which is particularly useful for modeling financial returns during periods of rapid changes in the underlying covariance structure. When applied to market returns in conjunction with returns on an individual asset, the model yields a dynamic model specification of the conditional regression coefficient that is known as the beta. We apply the model to a large set of assets and find the conditional betas to be far more variable than usually found with rolling‐window regressions based exclusively on daily returns. In the empirical part of the paper, we examine the cross‐sectional as well as the time variation of the conditional beta series during the financial crises. Copyright © 2014 John Wiley & Sons, Ltd.
Optofluidic rotation of living cells for single‐cell tomography
Authors: Kolb Thorsten , Albert Sahradha , Haug Michael , Whyte Graeme 
Published: April 2014

Flow cytometry provides a high throughput, multi‐dimensional analysis of cells flowing in suspension. In order to combine this feature with the ability to resolve detailed structures in 3D, we developed an optofluidic device that combines a microfluidic system with a dual beam trap. This allows for the rotation of single cells in a continuous flow, around an axis perpendicular to the imaging plane. The combination of both techniques enables the tomographic reconstruction of the 3D structure of the cell. In addition this method is capable to provide detailed 3D structural data for flow cytometry, as it improves the reconstructed z‐resolution of a standard microscopy system to produce images with isotropic resolution in all three axes.
magnified image
Preparation and Electrochemical Characterization of an Enzyme Electrode Based on Catalase Immobilized onto a Multiwall Carbon Nanotube‐Thionine Film
Authors: Hashemnia Sedigheh , Eskanari Mahbubeh 
Published: April 2014

AbstractThe present study was aimed at investigating the use of a mixture multiwall carbon nanotube (MWCNT) and thionine (Th) dye in designing of a thionine‐based electrochemical biosensor containing catalase (Ct) enzyme (MWCNT‐Nafion‐Th/Ct) onto a glassy carbon electrode (GCE). The effects of pH, MWCNT concentration and thionine concentration on electrochemical response were explored for optimum analytical performance. The modified electrode exhibited a pair of well‐defined, quasi‐reversible peaks at formal potential (Eo′) = ‐0.218 ± 0.017 V vs. Ag/AgCl corresponding to the Thox/Thred redox couples in the presence of MWCNT, Nafion, and Ct. The electrochemical parameters, including charge‐transfer coefficient (0.36), and apparent heterogeneous electron transfer rate constant (4.28 ± 0.26 s−1) were determined. Using differential pulse voltammetry, the prepared enzyme electrode exhibited a linear response to hydrogen peroxide (H2O2) in the range of 10.0‐100.0 μM with a detection limit 8.7 μM and a sensitivity of 6051.0 μA mM−1 cm−2.
Development of a Novel Hybrid Immobilization Material (HY‐IM) for Fermentative Biohydrogen Production from Beverage Wastewater
Authors: Sivagurunathan Periyasamy , Kumar Gopalakrishnan , Sen Biswarup , Lin Chiu‐Yue 
Published: April 2014

AbstractA novel material (hybrid immobilization material, HY‐IM) was developed by the combination of calcium‐alginate, activated carbon (prepared from de‐oiled jatropha waste), wako gel (silica gel) and chitosan for immobilization of hydrogen‐producing bacteria. The stability of the prepared immobilized cells was evaluated by ten repetitive batch experimental runs; the cumulative hydrogen production from beverage wastewater during ten runs was in the range of 2865 to 3300 mL H2/L. The Scanning electron microscopy (SEM) images of the HY‐IM showed bacterial cells entrapment. The hydrogen production performance of the reactor with HY‐IM (1.12 ± 0.04 mol H2/mol hexoseutilized) was comparable to suspended cells reactor (1.07 ± 0.01 mol H2/mol hexoseutilized), and demonstrated repeated usage of same HY‐IM in the reactor with high stability. Experimental evidence suggests that HY‐IM can be applied in continuous biohydrogen production from industrial wastewaters with high efficiency and stability.
Partial ‐Parallelisms in Finite Projective Spaces
Authors: Etzion Tuvi 
Published: April 2014

AbstractIn this paper, we consider the following question. What is the maximum number of pairwise disjoint k‐spreads that exist in PG()? We prove that if divides and then there exist at least two disjoint k‐spreads in PG() and there exist at least pairwise disjoint k‐spreads in PG(n, 2). We also extend the known results on parallelism in a projective geometry from which the points of a given subspace were removed.
Mg2+‐Dependent Modulation of BKCa Channels by Genistein in Rat Arteriolar Smooth Muscle Cells
Authors: Wang Xiaoran , Zhao Tingting , Zhou Shanshan , Sun Lina , Zhang Liming , Yu Guichun 
Published: April 2014

AbstractGenistein, a protein tyrosine kinase (PTK) inhibitor, regulates ion channel activities. However, the mechanism of action of genistein on large‐conductance calcium‐activated potassium (BKCa) channels is unclear. This study aimed to investigate whether the mechanism of Mg2+‐dependent modulation of BKCa channel activity in vascular smooth muscle cells involved inhibition of phosphorylation by genistein or direct interaction between genistein and BKCa channels. The whole‐cell and inside‐out patch‐clamp techniques were used to measure BKCa currents and the effects of genistein on BKCa channel activities in rat mesenteric arteriolar smooth muscle cells. We found that the effects of genistein on BKCa currents were Mg2+‐dependent. Genistein (50 μM) inhibited BKCa currents if the intracellular free magnesium concentration ([Mg2+]i) was 2 μM or 20 μM, but amplified BKCa currents if [Mg2+]i was 200 μM or 2000 μM. The inhibitory effect of genistein on BKCa currents was reversed by the protein tyrosine phosphatase inhibitor sodium orthovanadate (0.5 mM). Daidzein (50 μM), an inactive analogue of genistein, also amplified BKCa currents, and its amplification was insensitive to orthovanadate. Another PTK inhibitor, tyrphostin 23 (50 μM), reduced the open probability of BKCa channels. This inhibitory effect was weaker at 200 μM [Mg2+]i than at 2 μM [Mg2+]i, and was countered by orthovanadate. Our results suggest that genistein amplifies BKCa currents at a high [Mg2+]i, but inhibits BKCa currents at a low [Mg2+]i. The mechanism of this biphasic effects involves PTK‐independent amplification and [Mg2+]i‐PTK‐dependent inhibition. J. Cell. Physiol. 229: 1981–1989, 2014. © 2014 Wiley Periodicals, Inc.
Plasma and cerebrospinal fluid concentrations of ibuprofen in pediatric patients and antipyretic effect: Pharmacokinetic–pharmacodynamic modeling analysis
Authors: Har‐Even Ronly , Stepensky David , Britzi Malka , Soback Stefan , Chaim Adina Bar , Brandriss Norit , Goldman Michael , Berkovitch Matitiahu , Kozer Eran 
Published: April 2014

AbstractWe aimed to determine the relationship between plasma and cerebrospinal fluid (CSF) concentrations of ibuprofen and the antipyretic effect in pediatric patients. A prospective cohort of infants and children aged 3 months to 15 years and treated with ibuprofen was studied. The patients received ibuprofen (via oral route, median dose of 10.0 mg/kg; 3.4–11.4 mg/kg range), samples of blood and CSF were collected, and body temperature was measured. Sequential analysis of the pharmacokinetic and pharmacodynamic data from 28 patients was performed using a population modeling approach. The observed concentration versus time data indicated substantial pharmacokinetic variability in absorption and distribution of ibuprofen between the patients. The pharmacokinetic modeling outcomes indicate that following a ∼25‐minute lag time, ibuprofen is rapidly absorbed to the central compartment and rapidly equilibrates with the CSF, resulting in the total ibuprofen concentration in the CSF versus plasma (CCSF/Cplasma) of 0.011 ± 0.007. The antipyretic effect of ibuprofen was best described by an indirect response PK‐PD model incorporating patient baseline body temperature and ibuprofen concentration in the CSF. We conclude that the pharmacokinetic–pharmacodynamic modeling can be used to predict the time course of ibuprofen plasma and CSF concentrations and of the antipyretic effects in individual pediatric patients.
Person‐centric clinical trials: Ethical challenges in recruitment and data transparency for improved outcomes
Authors: Robbins Dennis A. , Curro Frederick A. , Mattison John 
Published: April 2014

AbstractPractitioners participating in clinical studies are faced with a number of ethical issues related to recruitment, informed consent, handling and transparency of data. Practitioners educated in Good Clinical Practice, applying the philosophy of person‐centricity within a network utilizing risk‐based monitoring and remote data entry can provide the requisite infrastructure and oversight to support person‐centric clinical studies. While “patient‐centered” clinical studies allow for a broader clinical outcome perspective beyond the investigator, the person‐centric approach, accounts for the comprehensiveness and complexity of how we make health and healthcare decisions. Augmenting person centricity with comparative effectiveness studies allow for the inclusion of individual data significantly contributing to the aggregation of multiple data sets about individuals and populations. This enables more powerful and personal analytics and care and everyone is afforded the opportunity and privilege to contribute to improve clinical outcomes and in controlling and containing costs. Policy and institutional investment in infrastructure are prerequisite to accommodate these opportunities, to minimize abuses, and provide pathways for analyzing alternative healthcare patterns. Data provided will be comprehensive and robust, representative of use, with safety data more easily discernible from persons with a known past medical and health history.
Three‐phase hollow fiber liquid‐phase microextraction based on a magnetofluid for the analysis of aristolochic acids in plasma by high‐performance liquid chromatography
Authors: Song Rui Juan , Pu Feng Ping , Zhou Jun , Sun Jiang Bing , Zeng Ping , Zhang Qiong 
Published: April 2014

A new and fast sample preparation technique based on three‐phase hollow fiber liquid‐phase microextraction with a magnetofluid was developed and successfully used to quantify the aristolochic acid I (AA‐I) and AA‐II in plasma after oral administration of Caulis akebiae extract. Analysis was accomplished by reversed‐phase high‐performance liquid chromatography with fluorescence detection. Parameters that affect the hollow fiber liquid‐phase microextraction processes, such as the solvent type, pH of donor and acceptor phases, content of magnetofluid, salt content, stirring speed, hollow fiber length, extraction temperature, and extraction time, were investigated and optimized. Under the optimized conditions, the preconcentration factors for AA‐I and AA‐II were >627. The calibration curve for two AAs was linear in the range of 0.1–10 ng/mL with the correlation coefficients >0.9997. The intraday and interday precision was <5.71% and the LODs were 11 pg/mL for AA‐I and 13 pg/mL for AA‐II (S/N = 3). The separation and determination of the two AAs in plasma after oral administration of C. akebiae extract were completed by the validated method.
Using DNA to describe and quantify interspecific killing of fishers in California
Authors: Wengert Greta M. , Gabriel Mourad W. , Matthews Sean M. , Higley J. Mark , Sweitzer Rick A. , Thompson Craig M. , Purcell Kathryn L. , Barrett Reginald H. , Woods Leslie W. , Green Rebecca E. , Keller Stefan M. , Gaffney Patricia M. , Jones Megan , Sacks Benjamin N. 
Published: April 2014

ABSTRACTInterspecific killing is common among carnivores and can have population‐level effects on imperiled species. The fisher (Pekania [Martes] pennanti) is a rare forest carnivore in western North America and a candidate for listing under the United States Endangered Species Act. Interspecific killing and intraguild predation are poorly understood in fishers and potential threats to existing western populations. We studied the prevalence and patterns of interspecific killing of fishers in the southern Sierra Nevada and Coastal Range of California. We collected forensic evidence and samples from the carcasses and predation sites, conducted full necropsies when possible, and used molecular methods to determine species of predators responsible for killing fishers. We recovered 101 (59 female, 42 male) fisher carcasses; for 62 (61%) carcasses, we attributed cause of death to interspecific killing. We found that bobcats (Lynx rufus, n = 25 fisher mortalities), mountain lions (Puma concolor, n = 20), and coyotes (Canis latrans, n = 4) were predators of fishers in our study areas. Bobcats killed only female fishers, whereas mountain lions more frequently killed male than female fishers, confirming our hypothesis that female fishers would suffer lethal attacks by smaller predators than would male fishers. Coyotes rarely killed fishers. We found differences in pathologic characteristics of the predation events among the 3 predator species, which may be helpful in identifying predator species. © 2014 The Wildlife Society.
Targeting mitigation efforts: The role of speed limit and road edge clearance for deer–vehicle collisions
Authors: Meisingset Erling L. , Loe Leif E. , Brekkum Øystein , Mysterud Atle 
Published: April 2014

ABSTRACTDeer–vehicle collisions (DVCs) have major social, economic, and animal welfare costs. Modeling of accident risk relative to environmental characteristics could enable managers to plan the layout of new roads or determine optimal location of mitigation measures to reduce the number of accidents on existing roads. We analyzed position data providing road crossings from 67 global positioning system (GPS)‐marked red deer (Cervus elaphus) and location data of 271 car killed deer within the home ranges of the GPS‐marked red deer. We modeled collision risk as a function of speed limit, season, road characteristics, and habitat features. For a subset of the data, we tested if vegetation clearance along a highway reduced the collision frequency of red deer. The relative risk for DVCs increased with speed limit. We found a higher risk for DVCs during winter compared to the other seasons. Forest cover, distance to pasture, and terrain ruggedness substantially affected risk of DVCs. Road edge clearance reduced the frequency of DVCs, but the effect appeared in the winter season only with a decrease of 53%. Our study highlights that speed limit reduction and road edge clearance are both powerful mitigation tools to reduce the number of DVCs. © 2014 The Wildlife Society.
Carbon Life Cycle Assessment for Prairie as a Crop in Reclaimed Mine Land
Authors: Guzman Jose G. , Lal Rattan , Byrd Shana , Apfelbaum Steven I. , Thompson Ry. L. 
Published: April 2014

ABSTRACTA life cycle assessment with carbon (C) as the reference unit was used to balance the benefits of land preparation practices of establishing tall‐grass prairies as a crop for reclaimed mine land with reduced environmental damage. Land preparation and management practices included disking with sub‐soiling (DK‐S), disking only (DK), no tillage (NT), and no tillage with grazing (NT‐G). To evaluate the C balance and energy use of each of the land preparations, an index of sustainability (Is = CO/CI, Where: CO is the sum of all outputs and CI is the sum of all inputs) was used to assess temporal changes in C.Of the four land preparation and management practices, DK had the highest Is at 8·53. This was due to it having the least degradation of soil organic carbon (SOC) during land‐use change (−730 kg ha−1 y−1) and second highest aboveground biomass production (9,881 kg ha−1). The highest aboveground biomass production occurred with NT (11,130 kg ha−1), although SOC losses were similar to DK‐S, which on average was 2,899 kg ha−1 y−1. The Is values for NT and DK‐S were 2·50 and 1·44, respectively. Grazing from bison reduced the aboveground biomass to 8,971 kg ha−1 compared with NT with no grazing, although stocking density was low enough that Is was still 1·94. This study has shown that converting from cool‐season forage grasses to tall‐grass prairie results in a significant net sink for atmospheric CO2 3 years after establishment in reclaimed mine land, because of high biomass yields compensating for SOC losses from land‐use change. Copyright © 2014 John Wiley & Sons, Ltd.