bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimation of molecular diffusivity in aqueous solution of acetonitrile by the Wilke–Chang equation
Authors: Miyabe Kanji
Published: August 2011

It was tried to estimate the molecular diffusivity (Dm) of solutes in the mixtures of acetonitrile (ACN) and water by the Wilke–Chang equation. Although the information about association coefficient (α) is necessary for the calculation, it has never been proposed for ACN. The value of α was estimated as 1.37 from Dm of benzene in ACN at 303 K experimentally measured by the peak parking method. The values of α, i.e. 2.6, 1.9, 1.5, and 1.0, which have respectively been proposed for four solvents, i.e. water, methanol, ethanol, and benzene, were correlated with two physico‐chemical parameters of the solvents, i.e. solubility parameter and ET value. The α value for ACN was plotted around the two correlations, indicating its appropriateness. The values of Dm calculated by the Wilke–Chang equation using the α value for ACN were compared with those measured by the peak parking method and the Aris–Taylor method in aqueous solutions of ACN. The mean square deviation of the estimation of Dm was calculated as 8.8 and 14%. It was demonstrated that the Wilke–Chang equation can be used for estimating Dm with a reasonable accuracy in the mixtures consisting of ACN and water.
Suburbs: dangers or drought refugia for freshwater turtle populations?
Authors: Roe John H. , Rees Martha , Georges Arthur
Published: August 2011

Urbanization is one of the most rapidly expanding forms of habitat alteration worldwide. Wildlife differs in their responses to urbanization depending upon species and site‐specific factors. We used capture‐mark‐recapture to examine the abundance, population demographics, growth, and movements of the eastern long‐necked turtle (Chelodina longicollis) in Australia over 1 year in a suburban environment and an adjacent nature reserve during drought. Contrary to expectations, sex ratios, injury incidence, and frequency of juvenile size classes did not differ between turtles in the suburbs and the nature reserve. Moreover, turtles in the suburbs were nearly 3 times more abundant, grew 5 times faster, and had populations comprised of more adults in the larger size classes than nature reserve populations. These findings, together with net movements from the nature reserves into the suburbs, suggest that suburban water bodies were the higher quality habitat, effectively buffering turtles from temporal fluctuations in environmental conditions during drought. However, reserve managers and urban planners need to recognize that suburban water bodies have the potential to attract turtles from nearby reserves during drought, and that even low levels of persistent mortality during these travels across reserve boundaries may have consequences for populations of long‐lived vertebrates. © 2011 The Wildlife Society.
Dark roast coffee is more effective than light roast coffee in reducing body weight, and in restoring red blood cell vitamin E and glutathione concentrations in healthy volunteers
Authors: Kotyczka Christine , Boettler Ute , Lang Roman , Stiebitz Herbert , Bytof Gerhard , Lantz Ingo , Hofmann Thomas , Marko Doris , Somoza Veronika
Published: August 2011

Recent results from prospective cohort studies have shown that moderate coffee consumption is associated with a reduced risk for diabetes mellitus type II or Alzheimer's disease. Since reactive oxygen species (ROS) are believed to be involved in the pathogenesis of these diseases, antioxidants in coffee might contribute to this risk reduction. We aimed at elucidating whether a dark roast coffee beverage (CB) rich in N‐methylpyridinium ions (NMP: 785 μmol/L) and low in chlorogenic acids (CGA: 523 μmol/L) has stronger antioxidant effects on human erythrocytes than a CB prepared from a light roast with opposite proportions (CGA: 4538 μmol/L; NMP: 56 μmol/L). Following a 2‐wk wash out period, 500 mL of the respective CB was administered to 30 subjects daily for 4‐wk. Blood and spot urine samples were collected at the beginning and at the end of each intervention. Intake of the dark roast CB most effectively improved the antioxidant status of erythrocytes: superoxide dismutase and glutathione peroxidase activity decreased by 5.8 and 15%, respectively, whereas tocopherol and total glutathione concentrations increased by 41 and 14%, respectively. Furthermore, administration of the NMP‐rich CB led to a significant body weight reduction in pre‐obese subjects, whereas the CGA‐rich CB did not.
A NEO‐PI‐R short form for older adults
Authors: Mooi Bianca , Comijs Hannie C. , De Fruyt Filip , De Ritter Dineke , Hoekstra Hans A. , Beekman Aartjan T. F.
Published: August 2011

This article reports on the construction and examination of a 120 item version (NEO‐PI‐R‐SF) of the Dutch/Belgian NEO‐Personality Inventory‐Revised (NEO‐PI‐R). The item selection was based on criteria of appropriateness for older adults and psychometric contribution. The factor structure of the NEO‐PI‐R‐SF proved highly equivalent to the parent instrument, indicating concordant validity. Coefficients alpha were generally lower due to the reduction of items. When assessed in a new sample of older adults (N = 794), the factor structure of the NEO‐PI‐R‐SF proved replicable, except for the facet scales A1: Trust and A3: Altruism. Coefficients alpha for the domain scales were satisfactory, while the coefficients alpha for the facet scales were marginal to satisfactory and below those found in two adult samples (N = 1305 and N = 682). It was concluded that the NEO‐PI‐R‐SF may be a time‐saving alternative for research when a fine‐grained description of personality among older adults is required. Copyright © 2011 John Wiley & Sons, Ltd.
Validation of a new strength measurement device for amyotrophic lateral sclerosis clinical trials
Authors: Andres Patricia L. , Skerry Linda M. , Munsat Theodore L. , Thornell Brenda J. , Szymonifka Jackie , Schoenfeld David A. , Cudkowicz Merit E.
Published: August 2011

Introduction:

Strength measures with reduced variability and higher sensitivity could improve efficiency in clinical trials of amyotrophic lateral sclerosis (ALS). The Accurate Test of Limb Isometric Strength (ATLIS) was developed to precisely and conveniently measure force in 12 muscle groups. In this study we evaluate the reliability and validity of the ATLIS testing protocol.

Methods:

Twenty healthy adults and 10 patients with ALS were tested twice by the same or by different evaluators to determine test–retest and interrater reliability. Twenty healthy adults were examined using ATLIS and a well‐validated strength testing protocol (TQNE) to assess criterion‐based validity.

Results:

Mean absolute variation between tests was 8.6%, and intraclass correlation coefficients for each muscle group were high (range 0.82–0.99). The Pearson correlation coefficient of mean ATLIS and TQNE scores was 0.90. A subject survey demonstrated high user acceptance of ATLIS.

Conclusions:

ATLIS is convenient for patients and evaluators, produces precise strength measurements, and is easily moved between examining rooms. Muscle Nerve 45: 81–85, 2012
Generalized network design polyhedra
Authors: Feremans Corinne , Labbé Martine , Letchford Adam N. , Salazar‐González Juan‐José
Published: August 2011

In recent years, there has been an increased literature on so‐called generalized network design problems (GNDPs), such as the generalized minimum spanning tree problem and the generalized traveling salesman problem. In a GNDP, the node set of a graph is partitioned into “clusters,” and the feasible solutions must contain one node from each cluster. Up to now, the polyhedra associated with different GNDPs have been studied independently. The purpose of this article is to show that it is possible, to a certain extent, to derive polyhedral results for all GNDPs simultaneously. Along the way, we point out some interesting connections to other polyhedra, such as the quadratic semiassignment polytope and the boolean quadric polytope. © 2011 Wiley Periodicals, Inc. NETWORKS, 2011
Progressive hedging‐based metaheuristics for stochastic network design
Authors: Crainic Teodor Gabriel , Fu Xiaorui , Gendreau Michel , Rei Walter , Wallace Stein W.
Published: August 2011

We consider the stochastic fixed‐charge capacitated multicommodity network design (S‐CMND) problem with uncertain demand. We propose a two‐stage stochastic programming formulation, where design decisions make up the first stage, while recourse decisions are made in the second stage to distribute the commodities according to observed demands. The overall objective is to optimize the cost of the first‐stage design decisions plus the total expected distribution cost incurred in the second stage. To solve this formulation, we propose a metaheuristic framework inspired by the progressive hedging algorithm of Rockafellar and Wets. Following this strategy, scenario decomposition is used to separate the stochastic problem following the possible outcomes, scenarios, of the random event. Each scenario subproblem then becomes a deterministic CMND problem to be solved, which may be addressed by efficient specialized methods. We also propose and compare different strategies to gradually guide scenario subproblems to agree on the status of design arcs and aim for a good global design. These strategies are embedded into a parallel solution method, which is numerically shown to be computationally efficient and to yield high‐quality solutions under various problem characteristics and demand correlations. © 2011 Wiley Periodicals, Inc. NETWORKS, 2011.
Depressive symptoms and occupational stress among Chinese female nurses: The mediating effects of social support and rational coping
Authors: Wu Hui , Ge Cui Xia , Sun Wei , Wang Jia Na , Wang Lie
Published: August 2011

The study reported here was designed to investigate the relationship between depressive symptoms and occupational stress in female nurses in China during the period June–July 2008. The hypothesis tested was that social support and rational coping would mediate the effects of occupational stress on depressive symptoms. Our structural equation modeling revealed that social support and rational coping were negatively correlated with depressive symptoms. Social support and rational coping mediated the effects of occupational stress on depressive symptoms. Role overload, role insufficiency, and role boundary were predictive of depressive symptoms. These results indicated that lessening occupational stress and strengthening social support and rational coping could decrease depressive symptoms among Chinese female nurses. © 2011 Wiley Periodicals, Inc. Res Nurs Health 34:401–407, 2011
Medicine safety: experiences and perceptions of the general public in Liverpool
Authors: Krska Janet , Jones Laura , McKinney Jonathan , Wilson Craig
Published: August 2011

Purpose

To determine whether views of medicine safety, awareness of medicines' side effects and reporting behaviours were related to experiences of suspected side effects among the general public.

Method

Street interviews with the general public in central Liverpool, using closed and open questions. University ethics approval was obtained.

Results

A total of 436 people were interviewed, most (313; 71.8%) of whom obtained a medicine at least once every 3 months, 153 (37.4%) only prescribed medicines, 73 (16.7%) only over‐the‐counter (OTC) medicines and 87 (19.9%) both. A total of 198 (45.4%) respondents claimed to have experienced a side effect from a prescription medicine, an OTC medicine or both, and 110 (25.2%) knew someone who had experienced a side effect. Experiences of suspected adverse drug reactions (ADRs) did not appear to influence perceptions of medicine safety, with most feeling that both prescribed and OTC medicines were safe.

Only 94 (21.6%) respondents identified the Medicines and Healthcare Products Regulatory Agency as being responsible for monitoring medicine safety, and only 27 (6.2%) were aware of direct patient reporting. Once informed about direct reporting, over half said that they were strongly likely to report in the future, with the main reasons (272) for reporting being an ADR which was serious, caused hospital admission or affected daily life.

Conclusion

Public understanding of medicine safety, how safety is monitored and how to report suspected ADRs is generally limited despite ADRs being commonly experienced. If awareness of direct patient reporting can be increased, the public appear to be willing to report and to be appropriately selective in reporting. Copyright © 2011 John Wiley & Sons, Ltd.
Towards mechanisms of bimolecular nucleophilic reactions in solution—probing the variation of the activation parameters in the reactions of aromatic compounds
Authors: Vlasov Vladislav M.
Published: August 2011

Variation of the activation parameters in the SN2, acyl‐transfer, SNAr, SNV, and AdN reactions offers a uniquely useful probe for the mechanistic features of these reactions in solution. New approach uses the substituent effects on the aromatic ring to the variation of the activation parameters, ΔH≠ and ΔS≠, in the above reactions in the frameworks of the Hammett‐like equations in order to evaluate the resultant δΔH≠ and δΔS≠ reaction constants. Compensation relationships of δΔH≠ versus δΔS≠ allow one to estimate the contribution of changes of the internal enthalpy, δΔH≠int, to the enthalpy reaction constant, δΔH≠, that is inherent to bimolecular nucleophilic reactions and gives a single linear dependence on the Hammett ρ reaction constants for these reactions. The deviations from dependence of δΔH≠int versus ρ serve as useful points of interpretation of changes of the transition state structure or reaction mechanism. The results obtained show that the substituent effects in the substrates, nucleophiles, and leaving groups on the mechanistic features in bimolecular nucleophilic reactions are governed by the magnitude of δΔH≠int. Copyright © 2011 John Wiley & Sons, Ltd.
Structural and biochemical analysis of mammalian methionine sulfoxide reductase B2
Authors: Aachmann Finn L. , Kwak Geun‐Hee , Del Conte Rebecca , Kim Hwa‐Young , Gladyshev Vadim N. , Dikiy Alexander
Published: August 2011

Methionine sulfoxide reductases are antioxidant enzymes that repair oxidatively damaged methionine residues in proteins. Mammals have three members of the methionine‐R‐sulfoxide reductase family, including cytosolic MsrB1, mitochondrial MsrB2, and endoplasmic reticulum MsrB3. Here, we report the solution structure of reduced Mus musculus MsrB2 using high resolution nuclear magnetic resonance (NMR) spectroscopy. MsrB2 is a β‐strand rich globular protein consisting of eight antiparallel β‐strands and three N‐terminal α‐helical segments. The latter secondary structure elements represent the main structural difference between mammalian MsrB2 and MsrB1. Structural comparison of mammalian and bacterial MsrB structures indicates that the general topology of this MsrB family is maintained and that MsrB2 more resembles bacterial MsrBs than MsrB1. Structural and biochemical analysis supports the catalytic mechanism of MsrB2 that, in contrast to MsrB1, does not involve a resolving cysteine (Cys). pH dependence of catalytically relevant residues in MsrB2 was accessed by NMR spectroscopy and the pKa of the catalytic Cys162 was determined to be 8.3. In addition, the pH‐dependence of MsrB2 activity showed a maximum at pH 9.0, suggesting that deprotonation of the catalytic Cys is a critical step for the reaction. Further mobility analysis showed a well‐structured N‐terminal region, which contrasted with the high flexibility of this region in MsrB1. Our study highlights important structural and functional aspects of mammalian MsrB2 and provides a unifying picture for structure‐function relationships within the MsrB protein family. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Exploring conformational changes coupled to ionization states using a hybrid Rosetta‐MCCE protocol
Authors: Song Yifan
Published: August 2011

A hybrid protocol combining Rosetta fullatom refinement and Multi‐Conformation Continuum Electrostatics (MCCE) to estimate pKa is applied to the blind prediction of 94 mutated residues in Staphylococcal nuclease (SNase), as part of the pKa‐cooperative benchmark test. The standard MCCE method is limited to sidechain conformational changes. The Rosetta refinement protocol is used to add the backbone conformational changes in pKa calculations. The non‐electrostatic energy component from Rosetta and the electrostatic energy from MCCE are combined to weight the calculated ionization states. Of 63 measured pKas, the root mean squared deviation (RMSD) between the calculated pKas and the measured values is 4.3, showing an improvement compared to the RMSD of 6.6 in the standard MCCE calculations, using a low protein dielectric constant of 4. The breakdown of pKa shift from the solution values (ΔpKa) shows that the desolvation energy contributes the most in the standard MCCE calculations. Lowering desolvation penalties and optimizing electrostatic interactions with the Rosetta/MCCE protocol reduces the ΔpKa to favor the charged states. Analysis also showed that the Rosetta/MCCE protocol samples conformations with pKas close to the solution values. The question remains whether the correct conformational changes coupled to the ionization changes are found here. Nevertheless, a challenge emerges to accurately estimate the reorganization energy, which is not directly measured from the electrostatic environment of the site of interest. Possible improvements to the protocol are also discussed. Proteins 2011; © 2011 Wiley‐Liss, Inc.
Design of a modified mouse protein with ligand binding properties of its human analog by molecular dynamics simulations: The case of C3 inhibition by compstatin
Authors: Tamamis Phanourios , Pierou Panayiota , Mytidou Chrystalla , Floudas Christodoulos A. , Morikis Dimitrios , Archontis Georgios
Published: August 2011

The peptide compstatin and its derivatives inhibit the complement‐component protein C3 in primate mammals and are potential therapeutic agents against the unregulated activation of complement in humans, but are inactive against C3 from lower mammals. Recent molecular dynamics (MD) simulations showed that the most potent compstatin analog comprised entirely of natural amino acids (W4A9) had a smaller affinity for rat C3, due to reproducible changes in the rat protein structure with respect to the human protein, which eliminated or weakened specific protein–ligand interactions seen in the human C3:W4A9 complex. Here, we study by MD simulations three W4A9 complexes with the mouse C3 protein, and two “transgenic” mouse derivatives, containing a small number (6–9) of human C3 substitutions. The mouse complex experiences the conformational changes and affinity reduction of the rat complex. In the “transgenic” complexes, the conformation remains closer to that of the human complex, the protein–ligand interactions are improved, and the affinity for compstatin becomes “human‐like.” The present work creates new avenues for a compstatin‐sensitive animal model. A similar strategy, involving the comparison of a series of complexes by MD simulations, could be used to design “transgenic” sequences in other systems. Proteins 2011;. © 2011 Wiley‐Liss, Inc.
Analysis and design of waveguide structures for InGaAs/InAlAs quantum cascade lasers at λ ∼ 4.6–9.5 µm
Authors: Ko Yeong Hwan , Yu Jae Su
Published: August 2011

Optical waveguide structures of InP‐based quantum cascade lasers (QCLs) are theoretically analyzed and designed using the finite element method. The optical confinement factor (Γ) and absorption coefficient (α) of the waveguide structures for λ ∼ 4.6, 6, 8.8, and 9.5 µm QCLs with different numbers of active/injector stages (Ns) are calculated. As Ns is decreased at longer wavelength, Γ is gradually decreased and α is increased. For double‐channel (DC) ridge waveguide structures of QCLs operating at λ ∼ 9.5 µm, a relatively high optical loss is caused by the lossy insulation layer. To improve the performance, the buried heterostructure (BH) by InP regrowth is used for waveguide design in terms of Ns and waveguide width. For a narrow BH width of ∼10 µm, a low α value of 3.92 cm−1 is obtained compared to 12.32 cm−1 in the DC ridge waveguide structure. With the calculated optical properties of waveguide structures, the device characteristics of QCLs operating at λ ∼ 4.6 and 9.5 µm are theoretically investigated in comparison with the experimental results.
Antarctic local wind dynamics and polynya effects on the Adélie Land coast
Authors: Savijärvi Hannu
Published: August 2011

Mesoscale winds on the sloping coast of Adélie Land in East Antarctica were studied via idealized clear‐sky integrations with a two‐dimensional model. The calm‐case (Vg = 0) wintertime surface winds were steady katabatic southeasterlies. They were enhanced to a strong downslope low‐level jet (LLJ) during a southerly geostrophic flow but damped during a moderate westerly ‘counter‐katabatic’ flow. A strong westerly flow could overwhelm the katabatic component while a northerly Vg induced strong coastal easterlies with an easterly LLJ. On‐slope flow without the katabatic forcing generated a barrier effect. An ice‐free wintertime zone (a coastal polynya) increased the coastal 2 m winds by about 50% (and drag on the ice floes, by 125%) through the induced extra land breeze circulation and unstable stratification. The midsummer morning coastal winds were also katabatic in the morning as the slopes cooled rapidly after midnight. In a prevailing flow these behaved much as in wintertime but were strong only at 0400–0700 hours local time. By 0800–0900 hours local time the snowy slopes were melting in sunshine. With Vg = 0 this induced weak anabatic winds up the slope. At the coast a midday ‘sea breeze’‐like circulation was present, insensitive however to the sea state (frozen vs. open) or the coast state (snowy vs. black rock) of the model. These anabatic winds were quite weak and hence easily overwhelmed by any larger‐scale flow, surviving only during a weak westerly flow. The typically easterly Vg along the East Antarctica coast induced katabatic‐like surface winds throughout the day, as is commonly observed, despite the midday solar heating. Copyright © 2011 Royal Meteorological Society
Multidecadal and interannual changes of stationary Rossby waves
Authors: Freitas Ana Carolina Vasques , Brahmananda Rao V.
Published: August 2011

Changes in stationary Rossby waves (SRW) are connected to regional climate change and the propagation of these waves has a large influence on the evolution and development of the general circulation. Since the late 1970s and early 1980s many studies have noted a major shift in the structure of large‐scale circulation occurring in both hemispheres. This paper explores the changes in the SRW pattern and their propagation associated with these climate shifts. First, multidecadal changes in SRW activity are examined, using NCEP‐NCAR reanalysis data, for two periods: 1948–1978 and 1979–2000. For comparison of these two periods, the zonal wind, SRW kinetic energy pattern along the waveguide and stationary wavenumber (Ks) are analysed. The results showed that in the Northern Hemisphere (NH) the SRW propagation is favoured in the Asian jet stream (AJS) waveguide (Ks = 7) in the period 1979–2000, mainly in the east Asia region. There are indications that this could be associated with the Pacific Decadal Oscillation warm phase. A favoured SRW propagation also occurs in the North Atlantic subtropical jet (NASJ) waveguide (Ks = 5) region in the latter period and could be linked with positive North Atlantic Oscillation. In the Southern Hemisphere (SH), a favoured SRW propagation in the polar jet waveguide (Ks = 4) region is observed in the latter period and this could be associated, indirectly, with tropical sea surface temperature fluctuations. The interannual changes in the SRW propagation during stronger El Niño and La Niña events, which occurred from 1948 to 2000 are then examined. The results showed that, during stronger El Niño events, in NH the SRW propagation in the AJS, mainly in the east Asia region, and in the NASJ waveguides (Ks = 7, 5, respectively) is reduced. On the other hand, in SH the SRW propagation in Australian and polar waveguides (Ks = 7, 4, respectively) is favoured. Copyright © 2011 Royal Meteorological Society
Leakage‐probability‐constrained secrecy capacity of a fading channel
Authors: Chen Zhi , Wu Dapeng , Fan Pingyi , Letaief Khaled Ben
Published: August 2011

Secure transmission of information over wireless channels in the presence of an eavesdropper has attracted much attention recently. Previous work assumes that a transmitter has perfect knowledge of the channel side information (CSI) of the legitimate channel and the eavesdropper's channel. To loosen this strong requirement, this paper considers the case where a transmitter has perfect knowledge of the CSI of the legitimate channel and only the average channel gain of the eavesdropper's channel. In this case, some information may be leaked to the eavesdropper because the eavesdropper's channel may have a higher gain than the legitimate channel. Hence, we propose, for the first time, to study leakage‐probability‐constrained secrecy capacity of a fading channel, that is, secrecy capacity under the constraint on leakage probability. We also propose an optimal power allocation strategy that maximizes leakage‐probability‐constrained secrecy capacity under average power constraint. Moreover, we study the impact of the bias of the average gain estimate of the eavesdropper's channel on leakage‐probability‐constrained secrecy capacity. Copyright © 2011 John Wiley & Sons, Ltd.
Insulin‐Coated Gold Nanoparticles: A Plasmonic Device for Studying Metal–Protein Interactions
Authors: Chanana Munish , Correa‐Duarte Miguel A. , Liz‐Marzán Luis M.
Published: August 2011

Insulin‐capped gold nanoparticles (Au@insulin NPs) are highly sensitive towards pH and heavy metals, due to the protein coating. Au@insulin NPs aggregate and disaggregate reversibly with pH and in the presence of various heavy metal ions, which can be monitored through reversible changes in their optical properties. The sensitivity of the NPs towards different metal ions is dissimilar and depends on the coordinative properties of each specific metal ion, its valence number, concentration, and reaction time (kinetics), representing a simple tool for studying fundamental metal–protein interactions. Moreover, Au@insulin NPs are biocompatible and highly stable at high ionic strengths, due to their robust protein coating.
Controlled Collapse of High‐Aspect‐Ratio Nanostructures
Authors: Duan Huigao , Yang Joel K. W. , Berggren Karl K.
Published: August 2011

Capillary‐force‐induced collapse of high‐aspect‐ratio (HAR) micro‐ and nanostructures is common in the evaporation–drying process and a number of applications based on the collapse have been proposed. However, the collapse of small HAR structures is usually uncontrollable, which has prevented it from being used in engineering applications. Here, the collapse of 10‐nm‐scale structures is separately controlled through engineering an asymmetric cross section, curvature, and tilt in the structures prior to collapse. It is shown that this deterministic‐collapse approach can be used to create linear structures from collapsed pillars and planar rectangular structures from collapsed fencelike linear structures, and can further be used to create small gaps by controlling the collapse of nearby structures. These techniques could be used to improve the performance of beam‐based lithography methods for certain types of patterns by increasing throughput and resolution, reducing the proximity effect, and reducing irradiation damage. In addition, this controlled‐collapse concept provides a possible platform with which to study mechanical behavior at the 10‐nm scale.
Flow Experience and Internet Shopping Behavior: Investigating the Moderating Effect of Consumer Characteristics
Authors: Hsu Chia‐Lin , Chang Kuo‐Chien , Chen Mu‐Chen
Published: August 2011

Researchers have recognized that flow is a constructive construct for elucidating consumer behavior in the context of computer‐mediated environments. Accordingly, this paper endeavours to investigate the relationship between flow experience and Internet shopping behavior to which the moderating role of consumer characteristics (trust propensity, willingness to buy and self‐confidence) is concerned. Data collected from 395 customers of an online shopping store provide support for the proposed research model. The results show that flow experience is significantly and positively related to Internet shopping behavior (continuance intention, purchase intention and impulsive buying). In addition, it also suggests that the relationship between flow experience and Internet shopping behavior is moderated by consumer characteristics. Specifically, when the extent of a customer's trust propensity, willingness to buy or self‐confidence is relatively high, the influence of flow experience on Internet shopping behaviors is maximized. According to the findings, the implications and future research suggestions are provided. Copyright © 2011 John Wiley & Sons, Ltd.
Cyclic Deformation Behaviour of Three Austenitic Cast CrMnNi TRIP/TWIP Steels with Various Ni Content
Authors: Glage A. , Weidner A. , Biermann H.
Published: August 2011

This study presents the cyclic deformation behaviour of three high‐alloyed austenitic cast steels which are characterized by different chemical compositions leading to different austenite stabilities and stacking fault energies. Thus, depending on the chemical composition different deformation mechanisms arise which have a significant influence on the cyclic deformation behaviour and life time relations.

The materials were characterized under total‐strain control. The fatigue life relations of Basquin and Manson‐Coffin are applied successfully for all steel variants. The cyclic stress‐strain response is described using the Ramberg‐Osgood relationship. It is shown that the parameters n' and K' depend strongly on the accumulated plastic strain λp. The mechanical properties are discussed together with microstructural investigations of deformation structures and martensitic transformations as well as twinning, respectively.
Sodium arsenite induced reactive oxygen species generation, nuclear factor (erythroid‐2 related) factor 2 activation, heme oxygenase‐1 expression, and glutathione elevation in Chang human hepatocytes
Authors: Li Bing , Li Xin , Zhu Bo , Zhang Xinyu , Wang Yi , Xu Yuanyuan , Wang Huihui , Hou Yongyong , Zheng Quanmei , Sun Guifan
Published: August 2011

Liver is one of the major target organs of arsenic toxicity and carcinogenesis. Nuclear factor (erythroid‐2 related) factor 2 (Nrf2) is a redox‐sensitive transcription factor, regulating critically cellular defense responses against the toxic metallic arsenic in many cell types and tissues. This study was conducted to evaluate the hepato‐cellular Nrf2 and Nrf2‐regulated antioxidant reactions of sodium arsenite exposure in Chang human hepatocytes. Nrf2 and heme oxygenase‐1 (HO‐1) protein levels were detected by Western blot, and Nrf2‐regulated HO‐1 mRNA expressions were determined using semiquantitative RT‐PCR by 0∼50 μmol/L of sodium arsenite exposure for 2, 6, 12, and 24 h. We also observed the changes of intracellular reactive oxygen species (ROS) and total cellular glutathione (GSH) by flow cytometry and spectrophotometry, respectively. Our results showed that intracellular ROS were both dose‐ and time‐dependent induced by inorganic arsenic; Cellular Nrf2 protein levels increased rapidly after 2 h of exposure, elevated significantly at 6 h, and reached the maximum at 12 h. The endogenous Nrf2‐regulated downstream HO‐1 mRNA and protein were also induced dramatically and lasted for as long as 24 h. In addition, intracellular GSH levels elevated in consistent with Nrf2 activation. Our findings here suggest that inorganic arsenic alters cellular redox balance in hepatocytes to trigger Nrf2‐regulated antioxidant responses promptly, which may represent an adaptive cell defense mechanism against inorganic arsenic induced liver injuries and hepatoxicity. © 2011 Wiley Periodicals, Inc. Environ Toxicol, 2013.
Laser Safety: The Game Is On
Authors: Castelluccio Donna L.
Published: August 2011

Any recurring mandatory education offering presents the risk of losing the audience's interest because of its repetitious nature. For example, laser safety in the OR is an important issue that should be reviewed annually, but most perioperative personnel have heard the laser safety talk and performed hands‐on training numerous times. Educational offerings that must be presented repeatedly should be provided in new and creative ways to maintain staff members' attention. Presenting valuable and necessary educational material in a game show format can engage personnel, heighten their interest, and improve the chances that learning will occur. As a means of accomplishing this, a perioperative educator created an inservice game that was a successful and fun way to provide laser safety education.
Managing Tissue Bank Access to the OR for Tissue Recovery
Authors: Trim Robert S.
Published: August 2011

Hospitals often have tissue recovery service agreements with regional tissue banks to facilitate the donation process. The agreements that outline the tissue bank–hospital relationship frequently allow tissue bank personnel to perform tissue recovery procedures in the referring hospital's OR and may or may not specify any preparatory orientation or any written protocols for tissue bank staff members to follow. This creates the potential for unintentional breaches of protocol that can affect operation of equipment or result in contamination that may put surgical patients and staff members at risk. The OR manager is responsible for establishing appropriate orientation plans for tissue bank employees to ensure they understand and adhere to the hospital's protocols.
Clinical Issues—August 2011
Authors: Van Wicklin Sharon A.
Published: August 2011

This Month

Discarding used syringes

Key words: needles, syringes, recapping, disposal.

Requirements for storing autologous tissue

Key words: autologous grafts, tissue storage.

Developing policies and procedures for autologous tissue banking

Key words: autologous grafts, tissue banking.

Labeling autograft storage packages

Key words: autologous grafts, tissue storage.

Documentation requirements for autologous tissue

Key words: documentation for autologous grafts, tissue banking.
The moderating effects of supplier portfolio characteristics on the competitive performance impacts of supplier‐facing process capabilities
Authors: Tang Xinlin , Rai Arun
Published: August 2011

We draw on the interorganizational relationship management literature to examine how contextual characteristics of the supplier portfolio (portfolio concentration, relationship length, and supplier substitutability) moderate the impacts of process alignment and partnering flexibility – two of a firm's key supplier‐facing process capabilities to manage supplier relationships – on a product line's competitive performance. Our analysis of survey data on a firm's supplier portfolio for a major product line indicates that the impacts of process alignment and partnering flexibility on competitive performance are moderated by the three supplier portfolio characteristics. Specifically, while concentrated relationship portfolios, long‐term relationships, and supplier substitutability amplify the positive effect of process alignment on competitive performance, concentrated relationship portfolios and long‐term relationships attenuate the competitive benefits that firms derive from partnering flexibility. While long‐term relationships and concentrated supplier portfolios enhance the competitive benefits of process alignment, operations managers also need to recognize the detrimental effects of these supplier portfolio characteristics on the competitive benefits of partnering flexibility.
SCALAR CURVATURE OF HYPERSURFACES WITH CONSTANT MEAN CURVATURE IN SPHERES
Authors: ZHANG QIN
Published: August 2011

Let Mn be an n-dimensional closed hypersurface with constant mean curvature H satisfying |H| ≤ ϵ(n) in a unit sphere Sn+1(1), n ≤ 8 and S the square of the length of the second fundamental form of M. There exists a constant δ(n, H) > 0, which depends only on n and H such that if S0 ≤ S ≤ S0 + δ(n, H), then S ≡ S0 and M is isometric to a Clifford hypersurface, where ϵ(n) is a sufficiently small constant depending on n and $S_0=n+\frac{n^3}{2(n-1)}H^2+\frac{n(n-2)}{2(n-1)}\sqrt{n^2H^4+4(n-1)H^2}$.
An unusual case of conjunctival irritation and epiphora following external dacryocystorhinostomy
Authors: Mezzana P , Marabottini N , Scarinci F , Pasquini P
Published: August 2011

Objective:

The authors discuss a case of conjunctival irritation and epiphora in a patient who had undergone dacryocystorhinostomy three years earlier.

Method:

Case report, and a review of the world literature concerning lacrimal canalicular air regurgitation after dacryocystorhinostomy.

Results:

A 70-year-old woman, who used continuous positive airway pressure therapy during sleep, complained of epiphora and conjunctival irritation. She had undergone dacryocystorhinostomy three years earlier. Her right eye had an augmented tear meniscus, with a predominantly medial conjunctival irritation. Conjunctival irritation from lacrimal canalicular air regurgitation was diagnosed. White petrolatum and mineral oil ophthalmic ointment was prescribed, applied topically before sleeping. After one month of treatment, complete relief of symptoms was obtained.

Conclusion:

There is little current information on managing such patients. It is imperative to discuss this potential complication when considering nasolacrimal surgery in patients using continuous positive airway pressure therapy.
Intratympanic methylprednisolone as first-line therapy in sudden sensorineural hearing loss: preliminary results from a case–control series
Authors: Dallan I , Fortunato S , Casani A P , Panicucci E , Berrettini S , Lenzi R , Nacci A
Published: August 2011

Background:

Sudden sensorineural hearing loss is a true audiological emergency, and its management is much discussed. Currently, no single therapy has been proven effective according to evidence criteria. Recently, intratympanic application of steroids has been increasingly used in refractory cases; however, it has only rarely been reported as first-line therapy.

Materials and methods:

Twenty consecutive patients with sudden sensorineural hearing loss treated between July 2008 and January 2010 were enrolled in this prospective, case–control study. Ten patients were treated with intratympanic steroids and 10 with systemic ‘shotgun’ therapy (including steroids, pentoxifylline, low molecular weight heparin and vitamin E). The two groups were homogeneous in all respects. Pure tone averages were assessed before and after treatment for both groups.

Results:

There were no statistically significant differences between the two groups.

Conclusion:

Intratympanic steroids seem to offer a valid alternative to systemic therapy, with few risks, in sudden sensorineural hearing loss patients, and we recommend their use as first-line therapy.
Human attitudes towards the conservation of protected areas: a case study from four protected areas in Bangladesh
Authors: Sarker A. H. M. R. , Røskaft E.
Published: August 2011

This study was based on interviews with 388 randomly selected households living near four protected areas in northern and south-eastern Bangladesh: Chunati Wildlife Sanctuary, Teknaf Game Reserve and two forest reserves. The respondents were generally poor and their perception of conservation varied across the study areas. Respondents were generally reluctant to embrace conservation and their attitude towards the conservation of protected areas depended on a set of demographic and socio-economic factors. People in northern Bangladesh had somewhat more positive attitudes towards conservation than those in the south-east. The two most important variables explaining respondents’ attitudes towards conservation were the distance they lived from protected areas and their monthly income. People who are poor and who live closer to the protected areas disliked the conservation measures most.
When conservation precedes development: a case study of the opening up of the Socotra archipelago, Yemen
Authors: Scholte Paul , Al-Okaishi Abdulraqueb , Suleyman Ahmed Saed
Published: August 2011

The Socotra archipelago, Yemen, in the north-west Indian Ocean, has outstanding endemic biodiversity, and was listed as a World Heritage Site in 2008. Although inhabited for 6 millennia Socotra only began to open up to the outside world in 1990. With conservation interventions starting prior to major developments, and building on centuries-old low-intensity resource management, Socotra has been in a unique position to practice pre-emptive conservation. In 1997 modern conservation started with biodiversity and socio-economic surveys, with inputs from communities and decision makers, which fed into the Conservation Zoning Plan. Approved in 2000, this has been the archipelago’s principal conservation planning and management tool. Regulations and bans on fishing practices, the collection of coral stones and export of biological materials have all been relatively well complied with by local communities and authorities. Inappropriate road construction, however, driven by non-islanders, has demonstrated the limits of the Conservation Zoning Plan, highlighting significant institutional challenges in planning and coordination. The capacity of the Socotra-based conservation institution has increased dramatically over the last decade. Its personnel are generally respected, largely because their roles include assisting local communities with development initiatives, underlining the importance of integrating conservation and development at the onset of conservation. Although the integrity of the landscape will inevitably decline, especially along the northern coastline, Socotri conservationists, backed by international support, are in a unique position to shape the archipelago’s future.
Assessing the ongoing threat from veterinary non-steroidal anti-inflammatory drugs to Critically Endangered Gyps vultures in India
Authors: Cuthbert Richard J. , Dave Ruchi , Chakraborty Soumya Sunder , Kumar Sashi , Prakash Satya , Ranade Sachin P. , Prakash Vibhu
Published: August 2011

Use of the veterinary drug diclofenac is responsible for bringing three species of Gyps vultures endemic to South Asia to the brink of extinction, and the Government of India banned veterinary use of the drug in May 2006. To evaluate the effectiveness of the ban we undertook surveys of > 250 veterinary and general pharmacies in 11 Indian states from November 2007 to June 2010. Twelve different classes of non-steroidal anti-inflammatory drugs (NSAIDs) were purchased from 176 pharmacies. Other than meloxicam (of negligible toxicity to vultures at likely concentrations in their food), diclofenac and ketoprofen (both toxic to vultures), little is known of the safety or toxicity of the remaining nine NSAIDs on sale. Meloxicam was the most commonly encountered drug, sold in 70% of pharmacies, but 50% of the meloxicam brands sold had paracetamol (acetaminophen) as a second ingredient. Diclofenac and ketoprofen were recorded in 36 and 29% of pharmacies, respectively, with states in western and central India having the highest prevalence of diclofenac (44–45%). Although the large number of manufacturers and availability of meloxicam is encouraging, the wide range of untested NSAIDs and continued availability of diclofenac is a major source of concern. Circumvention of the 2006 diclofenac ban is being achieved by illegally selling forms of diclofenac manufactured for human use for veterinary purposes. To provide a safer environment for vultures in South Asia we recommend reducing the size of vials of diclofenac meant for human use, to increase the costs of illegal veterinary use, and taking action against pharmaceutical manufacturers and pharmacies flouting the diclofenac ban.
DISCRETE TIME REPRESENTATION OF CONTINUOUS TIME ARMA PROCESSES
Authors: Chambers Marcus J. , Thornton Michael A.
Published: August 2011

This paper derives exact discrete time representations for data generated by a continuous time autoregressive moving average (ARMA) system with mixed stock and flow data. The representations for systems comprised entirely of stocks or of flows are also given. In each case the discrete time representations are shown to be of ARMA form, the orders depending on those of the continuous time system. Three examples and applications are also provided, two of which concern the stationary ARMA(2, 1) model with stock variables (with applications to sunspot data and a short-term interest rate) and one concerning the nonstationary ARMA(2, 1) model with a flow variable (with an application to U.S. nondurable consumers’ expenditure). In all three examples the presence of an MA(1) component in the continuous time system has a dramatic impact on eradicating unaccounted-for serial correlation that is present in the discrete time version of the ARMA(2, 0) specification, even though the form of the discrete time model is ARMA(2, 1) for both models.
EFFICIENT ESTIMATION OF FACTOR MODELS
Authors: Choi In
Published: August 2011

This paper considers the factor model Xt = ΛFt + et. Assuming a normal distribution for the idiosyncratic error et conditional on the factors {Ft}, conditional maximum likelihood estimators of the factor and factor-loading spaces are derived. These estimators are called generalized principal component estimators (GPCEs) without the normality assumption. This paper derives asymptotic distributions of the GPCEs of the factor and factor-loading spaces. It is shown that variance of the GPCE of the common component is smaller than that of the principal component estimator studied in Bai (2003, Econometrica 71, 135–172). The approximate variance of the forecasting error using the GPCE-based factor estimates is derived and shown to be smaller than that based on the principal component estimator. The feasible GPCE (FGPCE) of the factor space is shown to be asymptotically equivalent to the GPCE. The GPCE and FGPCE are shown to be more efficient than the principal component estimator in finite samples.
Food-web structure of coastal streams in Costa Rica revealed by dietary and stable isotope analyses
Authors: Winemiller Kirk O. , Zeug Steven C. , Robertson Clinton R. , Winemiller Brent K. , Honeycutt Rodney L.
Published: August 2011

Food webs of streams draining tropical rain forests on Costa Rica's Pacific and Caribbean coasts were examined in the 1980s via dietary analyses, and the same streams were surveyed again in 2004 to compare trophic structure based on analysis of stable isotope ratios of fish, macro-invertebrate and plant tissues. Estimates of species’ trophic positions (TP) were calculated from stomach-contents data (51 species; 5420 specimens) and compared with TP estimates derived from analysis of nitrogen isotope ratios (82 taxa; 240 samples). Coefficients of determination for TP based on dietary versus isotopic analysis ranged from 0.18 (Quebrada Camaronal, Corcovado) to 0.73 (Quebrada Estacion, Tortuguero). Consumer taxa within all four streams spanned a broad range of carbon isotope values, indicating assimilation of variable proportions of carbon from periphyton and terrestrial vegetation that in all but one of the streams had similar δ13C values. Approximately half the consumers in all four streams had carbon ratios heavier than any of the in situ production sources examined. This pattern could be explained by consumption of other production sources that were not sampled, including periphyton taxa with variable carbon isotope signatures, or migration of prey and/or consumers between these freshwater and coastal marine habitats.