bluuebunny/crossref_metadata_2025 huggingface dataset:
In vivo imaging of the time‐dependent apparent diffusional kurtosis in the human calf muscle
Authors: Marschar Anja Maria , Kuder Tristan Anselm , Stieltjes Bram , Nagel Armin Michael , Bachert Peter , Laun Frederik Bernd
Published: September 2014

Purpose

To evaluate the time dependency of apparent diffusion coefficient Dapp and apparent diffusional kurtosis Kapp in vivo in the human calf.

Materials and Methods

Diffusion‐weighted images of five healthy male volunteers were acquired using a 1.5T MR scanner. A stimulated echo sequence with echo planar imaging readout was used with diffusion gradients oriented along the three main axes. Mixing times (TM) of 100, 300, 500, and 700 ms and b‐values ranging from 0 to 5600 s/mm2 were used. Dapp and Kapp were determined.

Results

Dapp and Kapp decreased with increasing TM. As an example for absolute values, Dapp of the tibialis anterior drops from 1.18 ± 0.04 μm2/ms (TM = 100 ms) to 0.86 ± 0.02 μm2/ms (TM = 700 ms) (P = 0.001) and Kapp from 0.38 ± 0.06 to 0.32 ± 0.03 (P = 0.046) for a diffusion weighting along the left–right direction. Kapp was smaller than 0.43 in all muscles and at all TMs.

Conclusion

The clearly observed time‐dependence of Dapp and Kapp is an indicator of restricted diffusion in muscle tissue and may thus be a promising marker to investigate alterations of the microstructure. Compared to typical kurtosis values in white matter tissue of the brain, the kurtosis in muscle tissue is much smaller, which we attribute to the absence of the almost impermeable myelin sheath. J. Magn. Reson. Imaging 2015;41:1581–1590. © 2014 Wiley Periodicals, Inc.
Neuroscience and organizational behavior: Avoiding both neuro‐euphoria and neuro‐phobia
Authors: Ashkanasy Neal M. , Becker William J. , Waldman David A.
Published: September 2014

Organizational neuroscience has great promise for advancing organizational research and practice. The field, however, is developing rapidly and has also become the subject of technological and methodological challenges that must be considered when conducting or interpreting neuroscience research as applied to organizational behavior. We explore four issues we deem to be important in understanding the role of neuroscience in organizational behavior research: (i) neuroscientific research and reductionism; (ii) the need to address methodological and technological challenges in conducting this type of research; (iii) how neuroscientific research is meaningful in organizations (the “So what?” issue); and (iv) neuroscience as just another management fad. In addressing these issues, we hope to set out a roadmap that will enable organizational scholars to avoid past mistakes and thus serve to advance multidisciplinary research in organizational behavior using neuroscientific approaches. Copyright © 2014 John Wiley & Sons, Ltd.
Peak inspiratory flow is a simple means of predicting decannulation success following head and neck cancer surgery: A prospective study of fifty‐six patients
Authors: Guerlain Joanne , Guerrero Jose A. S. , Baujat Bertrand , St Guily Jean L. , Périé Sophie
Published: September 2014

Objectives/Hypothesis

Temporary tracheotomies are commonly performed in head and neck cancer surgery. The aim of this study was to propose a minimum peak inspiratory flow (PIF) as a standardized simple tool for successful decannulation after surgery.

Study Design

Prospective review between January 2011 and June 2013 in a university teaching hospital.

Methods

Fifty‐six patients after head and neck cancer surgery requiring tracheotomies were included. Decannulation failure was defined as the need to recannulate patients within 24 hours. PIF values did not influence the decisions to decannulate or recannulate. Pre‐ and postdecannulation PIF values, measured with a handheld PIF meter (In‐Check Dial), were registered until definitive decannulation.

Results

A total of 67 decannulation attempts were performed, with 47 positive and nine negative decannulations at the first attempt. Of the latter, seven were positive at the second attempt and two at the third. All patients were decannulated (mean, 6.3 days). PIF values of 40 L/min appear to be the threshold with the best sensitivity (90%) and specificity (95%) for predicting decannulation success. There was a significant difference (P < .001) between mean PIF in the positive (86 L/min) and negative (20 L/min) decannulation groups and between mean PIF values with (77 L/min) and without cannula (100 L/min).

Conclusions

PIF ≥40 L/min with cannula (>60 L/min without) using the In‐Check Dial oral method is a threshold associated with decannulation success. PIF is a simple quantitative parameter for evaluating the upper airway, aiding the decision to decannulate safely.

Level of Evidence

4. Laryngoscope, 125:365–370, 2015
Subnormothermic ex vivo liver perfusion reduces endothelial cell and bile duct injury after donation after cardiac death pig liver transplantation
Authors: Knaak Jan M. , Spetzler Vinzent N. , Goldaracena Nicolas , Boehnert Markus U. , Bazerbachi Fateh , Louis Kristine S. , Adeyi Oyedele A. , Minkovich Leonid , Yip Paul M. , Keshavjee Shaf , Levy Gary A. , Grant David R. , Selzner Nazia , Selzner Markus
Published: September 2014

An ischemic-type biliary stricture (ITBS) is a common feature after liver transplantation using donation after cardiac death (DCD) grafts. We compared sequential subnormothermic ex vivo liver perfusion (SNEVLP; 33°C) with cold storage (CS) for the prevention of ITBS in DCD liver grafts in pig liver transplantation (n = 5 for each group). Liver grafts were stored for 10 hours at 4°C (CS) or preserved with combined 7-hour CS and 3-hour SNEVLP. Parameters of hepatocyte [aspartate aminotransferase (AST), international normalized ratio (INR), factor V, and caspase 3 immunohistochemistry], endothelial cell (EC; CD31 immunohistochemistry and hyaluronic acid), and biliary injury and function [alkaline phosphatase (ALP), total bilirubin, and bile lactate dehydrogenase (LDH)] were determined. Long-term survival (7 days) after transplantation was similar between the SNEVLP and CS groups (60% versus 40%, P = 0.13). No difference was observed between SNEVLP- and CS-treated animals with respect to the peak of serum INR, factor V, or AST levels within 24 hours. CD31 staining 8 hours after transplantation demonstrated intact EC lining in SNEVLP-treated livers (7.3 × 10−4 ± 2.6 × 10−4 cells/μm2) but not in CS-treated livers (3.7 × 10−4 ± 1.3 × 10−4 cells/μm2, P = 0.03). Posttransplant SNEVLP animals had decreased serum ALP and serum bilirubin levels in comparison with CS animals. In addition, LDH in bile fluid was lower in SNEVLP pigs versus CS pigs (14 ± 10 versus 60 ± 18 μmol/L, P = 0.02). Bile duct histology revealed severe bile duct necrosis in 3 of 5 animals in the CS group but none in the SNEVLP group (P = 0.03). Sequential SNEVLP preservation of DCD grafts reduces bile duct and EC injury after liver transplantation. Liver Transpl 20:1296-1305, 2014. © 2014 AASLD.
Quantitative Structure‐Activity Relationship Analysis and a Combined Ligand‐Based/Structure‐Based Virtual Screening Study for Glycogen Synthase Kinase‐3
Authors: Fu Gang , Liu Sheng , Nan Xiaofei , Dale Olivia R. , Zhao Zhendong , Chen Yixin , Wilkins Dawn E. , Manly Susan P. , Cutler Stephen J. , Doerksen Robert J.
Published: September 2014

Glycogen synthase kinase‐3 (GSK‐3) is a multifunctional serine/threonine protein kinase which regulates a wide range of cellular processes, involving various signalling pathways. GSK‐3β has emerged as an important therapeutic target for diabetes and Alzheimer’s disease. To identify structurally novel GSK‐3β inhibitors, we performed virtual screening by implementing a combined ligand‐based/structure‐based approach, which included quantitative structure‐activity relationship (QSAR) analysis and docking prediction. To integrate and analyze complex data sets from multiple experimental sources, we drafted and validated a hierarchical QSAR method, which adopts a two‐level structure to take data heterogeneity into account. A collection of 728 GSK‐3 inhibitors with diverse structural scaffolds was obtained from published papers that used different experimental assay protocols. Support vector machines and random forests were implemented with wrapper‐based feature selection algorithms to construct predictive learning models. The best models for each single group of compounds were then used to build the final hierarchical QSAR model, with an overall R2 of 0.752 for the 141 compounds in the test set. The compounds obtained from the virtual screening experiment were tested for GSK‐3β inhibition. The bioassay results confirmed that 2 hit compounds are indeed GSK‐3β inhibitors exhibiting sub‐micromolar inhibitory activity, and therefore validated our combined ligand‐based/structure‐based approach as effective for virtual screening experiments.
Fractal Dimensions of Macromolecular Structures
Authors: Todoroff Nickolay , Kunze Jens , Schreuder Herman , Hessler Gerhard , Baringhaus Karl‐Heinz , Schneider Gisbert
Published: September 2014

Quantifying the properties of macromolecules is a prerequisite for understanding their roles in biochemical processes. One of the less‐explored geometric features of macromolecules is molecular surface irregularity, or ‘roughness’, which can be measured in terms of fractal dimension (D). In this study, we demonstrate that surface roughness correlates with ligand binding potential. We quantified the surface roughnesses of biological macromolecules in a large‐scale survey that revealed D values between 2.0 and 2.4. The results of our study imply that surface patches involved in molecular interactions, such as ligand‐binding pockets and protein‐protein interfaces, exhibit greater local fluctuations in their fractal dimensions than ‘inert’ surface areas. We expect approximately 22 % of a protein’s surface outside of the crystallographically known ligand binding sites to be ligandable. These findings provide a fresh perspective on macromolecular structure and have considerable implications for drug design as well as chemical and systems biology.
Cardiac lipid levels show diurnal changes and long‐term variations in healthy human subjects
Authors: Ith Michael , Stettler Christoph , Xu Jian , Boesch Chris , Kreis Roland
Published: September 2014

1H‐MRS is regularly applied to determine lipid content in ectopic tissue – mostly skeletal muscle and liver – to investigate physiological and/or pathologic conditions, e.g. insulin resistance. Technical developments also allow non‐invasive in vivo assessment of cardiac lipids; however, basic data about methodological reliability (repeatability) and physiological variations are scarce. The aim of the presented work was to determine potential diurnal changes of cardiac lipid stores in humans, and to put the results in relation to methodological repeatability and normal physiological day‐to‐day variations.

Optimized cardiac‐ and respiratory‐gated 1H‐MRS was used for non‐invasive quantification of intracardiomyocellular lipids (ICCL), creatine, trimethyl‐ammonium compounds (TMA), and taurine in nine healthy young men at three time points per day on two days separated by one week. This design allowed determination of (a) diurnal changes, (b) physiological variation over one week and (c) methodological repeatability of the ICCL levels.

Comparison of fasted morning to post‐absorptive evening measurements revealed a significant 37 ± 19% decrease of ICCL during the day (p = 0.0001). There was a significant linear correlation between ICCL levels in the morning and their decrease during the day (p = 0.015). Methodological repeatability for the ICCL/creatine ratio was excellent, with a coefficient of variance of ~5%, whereas physiological variation was found to be considerably higher (22%) in spite of a standardized physiological preparation protocol. In contrast, TMA levels remained stable over this time period.

The proposed 1H‐MRS technique provides a robust way to investigate relevant physiological changes in cardiac metabolites, in particular ICCL. The present results suggest that ICCL reveal a diurnal course, with higher levels in the morning as compared to evening. In addition, a considerable long‐term variation of ICCL levels, in both the morning and evening, was documented. Given the high methodological repeatability, these effects should be taken into account in studies investigating the metabolic role of ICCL. Copyright © 2014 John Wiley & Sons, Ltd.
Im Nebel perfekt getarnt
Authors: Schittny Robert , Bückmann Tiemo , Wegener Martin
Published: September 2014

Perfekte makroskopische Tarnkappen in Luft sind unmöglich, sie verletzen Einsteins Relativitätstheorie. In lichtstreuenden Medien können sie jedoch realisiert werden, wie unsere Gruppe am Karlsruher Institut für Technologie (KIT) kürzlich experimentell demonstriert hat.
Schnelles Verblassen leuchtender Spuren
Authors: Vollmer Michael , Möllmann Klaus‐Peter
Published: September 2014

Wohl jeder, der schon einmal mit Physik zu tun hatte, kennt die meist grünlichen Leuchtspuren von Oszillographen. Sie ermöglichen es, zeitabhängige Signale zu visualisieren und quantitativ auszumessen, insbesondere auch dann, wenn die Phänomene sehr schnell ablaufen. Die Reaktionsdynamik der leuchtenden Phosphore auf den Bildschirmen wird mit Hochgeschwindigkeits‐Videos deutlich sichtbar.
Low‐Pressure Plasma Methods for Generating Non‐Reactive Hydrophilic and Hydrogel‐Like Bio‐Interface Coatings – A Review
Authors: Siow Kim S. , Kumar Sunil , Griesser Hans J.
Published: September 2014

This review surveys low‐pressure plasma‐based methods for producing hydrophilic and hydrogel‐like bio‐interface coatings without reactive functional groups in aqueous media. The main focus of the review is one‐step plasma polymerization; other plasma‐based methods such as plasma with grafting are also discussed within the context of monomers used, process development, ageing properties, and interaction of these coatings with proteins and cells. Coatings containing polyethylene glycol (PEG) or polyethylene oxide (PEO), acrylamides such as N‐isopropylacrylamide (NIPAM), and sulfonate (SO3) or sulfate (SO4) moieties are reviewed here.
Mefloquine, an anti‐malaria agent, causes reactive oxygen species‐dependent cell death in mast cells via a secretory granule‐mediated pathway
Authors: Paivandy Aida , Calounova Gabriela , Zarnegar Behdad , Öhrvik Helena , Melo Fabio R. , Pejler Gunnar
Published: September 2014

Mast cells are known to have a detrimental impact on a variety of pathological conditions. There is therefore an urgent need of developing strategies that limit their harmful effects. The aim of this study was to accomplish this by developing a means of inducing mast cell apoptosis. The strategy was to identify novel compounds that induce mast cell apoptosis by permeabilization of their secretory lysosomes (granules). As a candidate, we assessed mefloquine, an anti‐malarial drug that has been proposed to have lysosome‐permeabilizing activity. Mefloquine was added to mast cells and administered in vivo, followed by assessment of the extent and mechanisms of mast cell death. Mefloquine was cytotoxic to murine and human mast cells. Mefloquine induced apoptotic cell death of wild‐type mast cells whereas cells lacking the granule compounds serglycin proteoglycan or tryptase were shown to undergo necrotic cell death, the latter finding indicating a role of the mast cell granules in mefloquine‐induced cell death. In support of this, mefloquine was shown to cause compromised granule integrity and to induce leakage of granule components into the cytosol. Mefloquine‐induced cell death was refractory to caspase inhibitors but was completely abrogated by reactive oxygen species inhibition. These findings identify mefloquine as a novel anti‐mast cell agent, which induces mast cell death through a granule‐mediated pathway. Mefloquine may thus become useful in therapy aiming at limiting harmful effects of mast cells.
Metabolomic evaluation of Mitomycin C and rapamycin in a personalized treatment of pancreatic cancer
Authors: Navarrete Alicia , Armitage Emily G. , Musteanu Monica , García Antonia , Mastrangelo Annalaura , Bujak Renata , López‐Casas Pedro P. , Hidalgo Manuel , Barbas Coral
Published: September 2014

In a personalized treatment designed for a patient with pancreatic cancer resistant to other treatments, the success of Mitomycin C (MMC) has been highlighted. This was revealed in a murine xenograft tumor model encompassing pancreatic adenocarcinoma cells extracted from the patient. The patient was found to exhibit a biallelic inactivation of the PALB2 gene, involved in DNA repair in addition to another mutation in the TSC2 gene that induces susceptibility of the tumor to therapeutic targets of the PI3K‐mTOR pathway. The aim of the study was to apply metabolomics to elucidate the modes of action of each therapy, suggesting why MMC was so successful in this patient and why it could be a more popular choice in future pancreatic cancer treatment. The effectiveness of MMC compared to rapamycin (RM), another relevant therapeutic agent has been evaluated through liquid‐ and gas‐chromatography mass spectrometry‐based metabolomic analyses of the xenograft tumors. The relative concentrations of many metabolites in the xenograft tumors were found to be increased by MMC relative to other treatments (RM and a combination of both), including a number that are involved in central carbon metabolism (CCM). Metabolic fingerprinting revealed statistically significantly altered pathways including, but not restricted to, the pentose phosphate pathway, glycolysis, TCA cycle, purine metabolism, fatty acid biosynthesis, in addition to many significant lipid and amino acid alterations. Given the genetic background of the patient, it was expected that the combined therapy would be most effective; however, the most effective was MMC alone. It is proposed that the effectiveness of MMC is owed to its direct effect on CCM, a vital region of tumor metabolism.
Empirical Bayes estimates for correlated hierarchical data with overdispersion
Authors: Iddi Samuel , Molenberghs Geert , Aregay Mehreteab , Kalema George
Published: September 2014

An extension of the generalized linear mixed model was constructed to simultaneously accommodate overdispersion and hierarchies present in longitudinal or clustered data. This so‐called combined model includes conjugate random effects at observation level for overdispersion and normal random effects at subject level to handle correlation, respectively. A variety of data types can be handled in this way, using different members of the exponential family. Both maximum likelihood and Bayesian estimation for covariate effects and variance components were proposed. The focus of this paper is the development of an estimation procedure for the two sets of random effects. These are necessary when making predictions for future responses or their associated probabilities. Such (empirical) Bayes estimates will also be helpful in model diagnosis, both when checking the fit of the model as well as when investigating outlying observations. The proposed procedure is applied to three datasets of different outcome types. Copyright © 2014 John Wiley & Sons, Ltd.
Oxidation of catechols during positive ion electrospray mass spectrometric analysis: Evidence for in‐source oxidative dimerization
Authors: Sojo Luis E. , Chahal Navjot , Keller Bernd O.
Published: September 2014

RATIONALE

Catechols are an important class of analytes occurring in many natural and synthetic products. Electrospray ionization in negative mode is the preferred way of ion generation for these compounds; however, studies in positive ion mode can reveal their potential for in‐source oxidation and further structural changes, some of which may also occur in the solution phase. Therefore in‐source oxidation can provide a forward look into the potential for solution oxidation.

METHODS

1:1 Acetonitrile/water solutions of catechol (Cat), 4,5‐dichlorocatechol (4,5‐DCC), 3,4‐dichlorocatechol (3,4‐DCC) and tetrachlorocatechol (TCC) were analyzed by positive ion ultrahigh‐performance liquid chromatography (UHPLC/ESI‐MS) and UHPLC/ESI‐MS/MS under various emitter voltages to assess their liability towards in‐source oxidation. Structural information for in‐source generated compounds was obtained through the use of product ion scans.

RESULTS

Using catechols as probe compounds, we have demonstrated that under the conditions used in many analytical laboratories in‐source oxidation can severely affect the sensitivity and response functions of an analyte. Under standard UHPLC conditions (300 μL/min flow rate), Cat, 3,4‐DCC, 4,5‐DCC and TCC can undergo in‐source oxidation. The extent of oxidation is dependent either on the instrument or on the characteristics of the emitter. This is evident by a change in the isotopic pattern of these compounds and the generation of ions at lower m/z values due to a loss of 1 and/or 2 hydrogens and electrons. In the case of catechol, the formation of a dimer resulting from in‐source oxidation reactions was observed. This dimer has the same fragmentation pattern as the dimer generated by oxidation in the solution phase.

CONCLUSIONS

The present work demonstrates the potential of positive ion ESI for oxidizing electroactive compounds during regular analytical operation using commercially available mass spectrometers. Using Cat and some of its chlorinated analogues as probe compounds, we have demonstrated that under the conditions used in many analytical laboratories in‐source oxidation and dimerization can and does take place. Copyright © 2014 John Wiley & Sons, Ltd.
Rapid and mild silylation of β‐amino alcohols at room temperature mediated by N‐methylimidazole for enhanced detectability by gas chromatography/electron ionization mass spectrometry
Authors: Valdez Carlos A. , Leif Roald N. , Hart Bradley R.
Published: September 2014

RATIONALE

In this work, we expand the use of in situ activation of chloro(dimethyl)phenylsilane using N‐methylimidazole (NMI) for the effective derivatization of β‐aminoethyl alcohols. Due to its enhanced nucleophilic character, NMI is expected to act as an efficient activator in these reactions.

METHODS

The derivatization of a panel of β‐aminoethyl alcohols was accomplished by reacting the analyte with chloro(dimethyl)phenylsilane in the presence of either NMI or pyridine. After the addition of chloro(dimethyl)phenylsilane, the vials were gently tumbled for 1 h at ambient temperature. The phenyldimethylsilyl derivatives were identified using gas chromatography/electron ionization mass spectrometry (GC/EI‐MS).

RESULTS

A total of ten β‐aminoethyl alcohols were successfully derivatized via in situ activation of chloro(dimethyl)‐phenylsilane with NMI. Derivatization with NMI was significantly more efficient than with pyridine by a factor of 3–6 for the studied alcohols. The derivatizations in the presence of NMI were found to occur in just 1 h and were conveniently executed at ambient temperature.

CONCLUSIONS

The use of the nitrogenous base NMI in order to activate chloro(dimethyl)phenylsilane for the efficient silylation of a panel of β‐aminoethyl alcohols has been demonstrated. The present work shows that NMI is an efficient base for the smooth derivatization of these types of alcohols. Furthermore, the installation of the bulky PDMS group onto these alcohols adds to the certainty that this is a viable approach for the installation of the more commonly employed, trimethylsilyl group. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA.
An ultra‐rigid close‐stacked piezo motor for harsh condition scanning probe microscopy
Authors: Guo Ying , Hou Yubin , Lu Qingyou
Published: September 2014

We designed and produced a nearly closest packed stack motor with only one tiny gap of 0.15 mm in the middle of the stack. A low‐voltage method of controlling the motor is introduced for the first time. Besides, the test results of the motor and the corresponding scanning tunneling microscope are also presented. To our surprise, it turns out to be so rigid that even running two oil pumps and one ultrasonic cleaner within 1 m range from a STM directly driven by this new motor cannot cause the STM to produce any visible difference in its the atomic resolution quality. This is a leap in building a true harsh condition atomic resolution SPM. SCANNING 36:554–559, 2014. © 2014 Wiley Periodicals, Inc.
Adaptations to Knowledge Templates in Base‐of‐the‐Pyramid Markets: The Role of Social Interaction
Authors: Sutter Christopher J. , Kistruck Geoffrey M. , Morris Shad
Published: September 2014

While templates may facilitate knowledge sharing within the base‐of‐the‐pyramid, it is often necessary for entrepreneurs to adapt the template for reasons of resource scarcity. We explore the role of social interaction in determining whether these adaptations are beneficial or detrimental. Our results suggest that interactions between the entrepreneur and technical experts who understand the ‘why’ behind each practice can result in improved performance while interactions with entrepreneurial peers can produce more varied results. Thus, the type of knowledge generated through social interaction plays a significant role in the degree to which adaptations to templates are principled versus presumptive in nature. Copyright © 2014 Strategic Management Society.
Selective Breakdown of Metallic Pathways in Double‐Walled Carbon Nanotube Networks
Authors: Ng Allen L. , Sun Yong , Powell Lyndsey , Sun Chuan‐Fu , Chen Chien‐Fu , Lee Cheng S. , Wang YuHuang
Published: September 2014

Covalently functionalized, semiconducting double‐walled carbon nanotubes exhibit remarkable properties and can outperform their single‐walled carbon nanotube counterparts. In order to harness their potential for electronic applications, metallic double‐walled carbon nanotubes must be separated from the semiconductors. However, the inner wall is inaccessible to current separation techniques which rely on the surface properties. Here, the first approach to address this challenge through electrical breakdown of metallic double‐walled carbon nanotubes, both inner and outer walls, within networks of mixed electronic types is described. The intact semiconductors demonstrate a ∼62% retention of the ON‐state conductance in thin film transistors in response to covalent functionalization. The selective elimination of the metallic pathways improves the ON/OFF ratio, by more than 360 times, to as high as 40 700, while simultaneously retaining high ON‐state conductance.
Behaviour of laminated glass beams reinforced with pre‐stressed cables
Authors: Jordão Sandra , Pinho Marco , Martin João Pedro , Santiago Aldina , Neves Luís Costa
Published: September 2014

Structural glass corresponds to an innovative material with extraordinary aesthetical and architectonic potential that has undergone significant technological advances in recent years, yielding it stronger and safer. For this reason, the use of structural glass has increased considerably in the last decade and is now an unavoidable presence in most of recent reference buildings.

The structural capacity of glass elements is brought in from reinforcing techniques of different types. One of the possibilities corresponds to pre stressed cables reinforcement. This technique is very effective in terms of resistance and deformability and corresponds to a light reinforcing element rendering the so called spider web effect. In the framework of the research project “S‐Glass: Structural performance and design rules of glass beams externally reinforced” [1] study the behavior of laminated glass beams reinforced by too twin external steel rods.

The work presented in the current paper is within the framework of S‐Glass project aiming at characterizing the behavior of reinforced laminated glass beams in the non‐crack regimen. For this purpose experimental and numerical analysis were prepared. The numerical model was used for a cable layout optimization analysis. Furthermore an analytical solution is put forward, which tackles the beam‐cable load transfer indetermination. Final conclusions are established on the bases of a comparison established between experimental, numerical and analytical results.
Fire resistance of slender section beams
Authors: Prachar Martin , Jandera Michal , Wald František , Zhaob Bin
Published: September 2014

The paper shows experimental and numerical research into slender cross‐section beams in case of fire. The topic is very important because little investigation has been made and little experimental data has been collected so far. In the framework of the RFCS project FIDESC4 – Fire Design of Steel Members with Welded or Hot‐rolled Class 4 Cross‐sections, several simple supported beams were tested at elevated temperature at the Czech Technical University in Prague.

Currently, Eurocode 3 contains a number of simple rules for design of slender Class 4 cross‐sections which, based on recent numerical simulations, proved themselves to be over‐conservative. Through refining these rules, material savings could be achieved, which would lead to greater competitiveness of the steel structures. This is being covered in existing research, but is not published in this paper, which is limited to lateral torsional buckling behaviour only.

Determination of the bending resistance for members subjected to lateral torsional buckling of Class 1–3 cross‐sections at elevated temperature is based on the same principles as the design at room temperature, according to EC 3 part 1‐1 [1]. However, it differs in using only one imperfection factor for all types of cross‐sections. The informative Annex E of the standard (EC 3 part 1‐2 [2]) recommends using the design formulas for slender (Class 4) sections as well. But there is a restriction of the critical temperature value and a different reduction of yield strength is used (0.2 % proof strength for Class 4 instead of 2.0 % proof strength for stockier Class 1–3 sections). For the non‐uniform members (variable section height), a limited design procedure is given in EC 3 part 1‐1 [1]. This is applicable for room temperature only. The possibility of using these rules for fire design is not yet confirmed.
Influence of fire scenarios on progressive collapse mechanisms of steel framed structures
Authors: Jiang Jian , Li Guo‐Qiang , Usmani Asif
Published: September 2014

OpenSees is an open‐source object‐oriented software framework developed at UC Berkeley. The OpenSees framework has been recently extended to deal with structural behaviour under fire conditions. This paper presents the results of a numerical study, using OpenSees, of the progressive collapse of steel frames exposed to fire. After validating the capability of OpenSees against available analytical and experimental results of fire tests on steel members, a parametric study is carried out to find the progressive collapse mechanism of steel frames exposed to fire and corresponding influencing factors. The factors include load levels, lateral restraint, beam strength and fire scenarios. The catenary action of beams is considered by using a temperature‐dependent corotational beam/column element. The results show that different progressive collapse mechanisms can happen due to the sequence of the buckling of columns. High load levels lead to the downward collapse of the whole structure compared with the lateral collapse for low load levels. The existing of lateral restraint causes the premature buckling of bottom columns which triggers the whole frame collapse. As the beam section increases, the collapse mechanism of steel frames changes from beam failure mode to column failure mode. The fire scenarios have significant effect on the collapse mode of steel frames. The work presented in this paper is a preliminary study of the progressive collapse of steel frames. Further work is underway to combine the influence of the effect of concrete floors. A simple design method is then expected to be proposed to investigate the robustness of steel structures against progressive collapse due to fire.
Optogenetics Reveal Delayed Afferent Synaptogenesis on Grafted Human-Induced Pluripotent Stem Cell-Derived Neural Progenitors
Authors: Avaliani Natalia , Sørensen Andreas Toft , Ledri Marco , Bengzon Johan , Koch Philipp , Brüstle Oliver , Deisseroth Karl , Andersson My , Kokaia Merab
Published: September 2014

Reprogramming of somatic cells into pluripotency stem cell state has opened new opportunities in cell replacement therapy and disease modeling in a number of neurological disorders. It still remains unknown, however, to what degree the grafted human-induced pluripotent stem cells (hiPSCs) differentiate into a functional neuronal phenotype and if they integrate into the host circuitry. Here, we present a detailed characterization of the functional properties and synaptic integration of hiPSC-derived neurons grafted in an in vitro model of hyperexcitable epileptic tissue, namely organotypic hippocampal slice cultures (OHSCs), and in adult rats in vivo. The hiPSCs were first differentiated into long-term self-renewing neuroepithelial stem (lt-NES) cells, which are known to form primarily GABAergic neurons. When differentiated in OHSCs for 6 weeks, lt-NES cell-derived neurons displayed neuronal properties such as tetrodotoxin-sensitive sodium currents and action potentials (APs), as well as both spontaneous and evoked postsynaptic currents, indicating functional afferent synaptic inputs. The grafted cells had a distinct electrophysiological profile compared to host cells in the OHSCs with higher input resistance, lower resting membrane potential, and APs with lower amplitude and longer duration. To investigate the origin of synaptic afferents to the grafted lt-NES cell-derived neurons, the host neurons were transduced with Channelrhodopsin-2 (ChR2) and optogenetically activated by blue light. Simultaneous recordings of synaptic currents in grafted lt-NES cell-derived neurons using whole-cell patch-clamp technique at 6 weeks after grafting revealed limited synaptic connections from host neurons. Longer differentiation times, up to 24 weeks after grafting in vivo, revealed more mature intrinsic properties and extensive synaptic afferents from host neurons to the lt-NES cell-derived neurons, suggesting that these cells require extended time for differentiation/maturation and synaptogenesis. However, even at this later time point, the grafted cells maintained a higher input resistance. These data indicate that grafted lt-NES cell-derived neurons receive ample afferent input from the host brain. Since the lt-NES cells used in this study show a strong propensity for GABAergic differentiation, the host-to-graft synaptic afferents may facilitate inhibitory neurotransmitter release, and normalize hyperexcitable neuronal networks in brain diseases, for example, such as epilepsy. Stem Cells  2014;32:3088–3098
Adenosine Triphosphate Prevents Serum Deprivation-Induced Apoptosis in Human Mesenchymal Stem Cells via Activation of the MAPK Signaling Pathways
Authors: Berlier Jessica L. , Rigutto Sabrina , Dalla Valle Antoine , Lechanteur Jessica , Soyfoo Muhammad S. , Gangji Valerie , Rasschaert Joanne
Published: September 2014

Human mesenchymal stem cells (hMSC) are multipotent cells derived from various sources including adipose and placental tissues as well as bone marrow. Owing to their regenerative and immunomodulatory properties, their use as a potential therapeutic tool is being extensively tested. However, one of the major hurdles in using cell-based therapy is the use of fetal bovine serum that can trigger immune responses, viral and prion diseases. The development of a culture medium devoid of serum while preserving cell viability is therefore a major challenge. In this study, we demonstrated that adenosine triphosphate (ATP) restrained serum deprivation-induced cell death in hMSC by preventing caspases 3/7 activation and modulating ERK1/2 and p38 MAPK signaling pathways. We also showed that serum deprivation conditions triggered dephosphorylation of the proapoptotic protein Bad leading to cell death. Adjunction of ATP restored the phosphorylation state of Bad. Furthermore, ATP significantly modulated the expression of proapoptopic and antiapoptotic genes, in favor of an antiapoptotic profile expression. Finally, we established that hMSC released a high amount of ATP in the extracellular medium when cultured in a serum-free medium. Collectively, our results demonstrate that ATP favors hMSC viability in serum deprivation conditions. Moreover, they shed light on the cardinal role of the MAPK pathways, ERK1/2 and p38 MAPK, in promoting hMSC survival. Stem Cells  2015;33:211–218
The influence of mistuned motor parameters on vector control performance and on line slip frequency correction strategy for induction machine operated under one‐pulse PWM mode
Authors: Zhou Minglei , You Xiaojie , Wang Chenchen
Published: September 2014

In high‐power, high‐speed traction drive systems, the traction motor usually operates under one‐pulse PWM (pulse width modulation) mode (square wave) during high‐speed operation. The constant output voltage in this condition makes the traditional vector control inoperative anymore. In this paper, a modified vector control strategy using open‐loop current control instead of closed‐loop current control is proposed. The modified control strategy is specially designed for an induction motor operating under one‐pulse PWM mode. As the field orientation is greatly affected by the deviation in the parameters, the influence of mistuned rotor time constant and mutual inductance (which are regarded as the most important parameters for field orientation) on the performance of modified vector control is studied comprehensively, including the influence on estimated angle and amplitude of rotor flux, d/q‐axis voltage, and output torque. Subsequently, based on the comparison between the different methods, a new slip frequency correction strategy is proposed to maintain proper field orientation for the modified vector control. The new correction strategy is based on the q‐axis current component error. It is independent of the motor parameters and can be easily realized through minor calculations. The simulation and experimental results show that the proposed slip frequency correction strategy can not only eliminate rotor flux angle error in steady state but also effect rapid torque response during the transient process under one‐pulse PWM mode. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
The effect of supplementation with vitamin A on serum and liver concentrations in Puerto Rican crested toads (Peltophryne lemur) and its lack of impact on brown skin disease
Authors: Dutton Christopher , Lentini Andrew , Berkvens Charlene , Crawshaw Graham
Published: September 2014

“Brown skin disease” (BSD) is a clinical syndrome of dysecdysis, chronic weight loss and death, previously reported in Puerto Rican crested toads (Peltophryne lemur). Although vitamin A deficiency has been suggested, its cause remains unknown and multiple treatments have failed to prevent or reverse the condition. This study compared the efficacy of vitamin A supplementation, administered in different forms and by different routes, in 48 captive born Puerto Rican crested toads fed from metamorphosis on gut‐loaded, dusted, commercially raised crickets. Forty‐five toads started to show clinical signs of BSD at 9 months of age; all toads were treated orally with an oil‐based vitamin A formulation twice weekly for 2 months but continued to deteriorate. Two treatment groups were then compared: Animals in one group (n = 19) received 2 IU injectable vitamin A (Aquasol‐A) per gram bodyweight subcutaneously twice weekly for 3 months with no change in diet. Toads in the other group (n = 22) received a single oral dose of vitamins A, D3, and E, and were fed on earthworms and crickets gut‐loaded with produce and a finely‐ground alfalfa‐based pellet, dusted with the same vitamin/mineral supplement. All affected animals developed severe BSD equally and died during, or were euthanized at the end of, the treatment regimen, with no clinical improvement. Animals supplemented with Aquasol‐A had significantly higher liver vitamin A concentrations compared with the other treatment group, whereas serum retinol concentrations showed no significant difference. Vitamin A supplementation does not appear a successful treatment once BSD symptoms have developed. Zoo Biol. 33:553–557, 2014. © 2014 Wiley Periodicals Inc.
Use of Micellar Solutions as Draw Agents in Forward Osmosis
Authors: Roach Jim D. , Al‐Abdulmalek Abdulrahman , Al‐Naama Alaa , Haji Mohammed
Published: September 2014

Recent advances in membrane technologies have enhanced the viability of water treatment strategies that employ semipermeable barriers. Forward osmosis (FO), which exploits the natural osmotic pressure gradient between a “draw” solution and a “feed” solution to produce potable water, offers a low‐energy, low‐cost alternative to more conventional treatment methods. Surfactants, because of their tendencies to aggregate into micelles and to adsorb at interfaces, provide intriguing osmotic pressures and offer exploitable properties by which draw solutions can be regenerated. The effectiveness of surfactant‐based FO using cellulose triacetate membranes has been assessed in terms of water flux and reverse surfactant diffusion using cetylpyridinium chloride, sodium dodecylsulfate, and Triton X‐100. The ratios of water flux to surfactant flux exceeded 600 L mol−1 for all surfactants studied. Surfactant recoveries of over 99 % were achieved by ultrafiltration using regenerated cellulose membranes.
Are My Symptoms Serious Dr Google? A Resource-Based Typology of Value Co-Destruction in Online Self-Diagnosis
Authors: Robertson Nichola , Polonsky Michael , McQuilken Lisa
Published: September 2014

Online self-diagnosis, where consumers engage with technology by applying their knowledge and skills to generate a medical diagnosis without the participation of a health care professional, is commonplace. Although co-creation of value for consumers and e-health service providers (i.e., suppliers of technological interfaces for consumers to self-diagnose) can occur via “do-it-yourself” diagnosis, we argue that it also has strong potential for value co-destruction. This is because of deficiencies in or misuse of resources (consumer or e-health provider). Based on a review of the service science, information systems and health care literatures, we develop a typology of value co-destruction in online self-diagnosis. It shows that online self-diagnosis can result in value co-destruction of consumers’ service process and outcome when consumer resources are deficient or misused (e.g., knowledge) or when e-health provider resources are lacking (e.g., poor quality offerings). The value co-destruction perspective has not been examined previously in this context and is important because it can negatively affect consumers’ well-being. A consumer and service focus is missing from research on online self-diagnosis, which our typology addresses. Implications of our typology for providing online health information and more specialised self-diagnosis services are discussed, drawing on a multi-pronged, multi-stakeholder approach, along with future research opportunities.
The dynamics of European regulatory regimes in higher education — Challenged prerogatives and evolutionary change
Authors: Gornitzka Åse , Stensaker Bjørn
Published: September 2014

European higher education has witnessed a substantial growth in regulatory arrangements in external quality assurance (EQA) during the last couple of decades. This current article describes the central characteristics and trajectories of this expansion, and discusses drivers of this development drawing on an institutional perspective. Empirically, three distinct, although overlapping, stages in the building up of a regulatory regime are identified — from formalization and agencification of EQA at national level, establishment of common standards at a European level, to the current stage of an emerging global market-based system. This combination of institutional layering, path-dependency, and conversion can be explained by the nature of political context and the ambiguities of regulation of quality in higher education. In the conclusion it is argued that the development of external quality assurance as a regulatory field is an example of how the dynamics of an evolving regulatory regime may in an unexpected way limit the public control of highly institutionalized fields.
Flow phenomena in the very near wake of a flat plate with a circular trailing edge
Authors: Rai Man Mohan
Published: September 2014

The very near wake of a flat plate with a circular trailing edge, exhibiting pronounced shedding of wake vortices, is investigated with data from direct numerical simulations (DNSs). Computations were performed for two cases. In the first case the Reynolds numbers based on plate length and thickness were $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}1.255 \times 10^{6}$ and $1.0 \times 10^{4}$, respectively. In the second case the two Reynolds numbers were $3.025 \times 10^{5}$ and $5.0 \times 10^{3}$, respectively. The separating boundary layers are turbulent and statistically identical thus resulting in a wake that is symmetric in the mean. The focus here is on the instability of the detached shear layers and the evolution of rib-vortex-induced localized regions of reverse flow. These regions detach from the main body of reverse flow in the trailing edge region and are convected downstream. The detached shear layers intermittently exhibit unstable behaviour, sometimes resulting in the development of shear-layer vortices as seen in earlier cylinder flow investigations with laminar separating boundary layers. Only a small fraction of the separated turbulent boundary layer experiences this instability, and also rolls up into the initial shed vortices. The instability causes a broadband peak in pressure spectra computed within the shear layers. Phase-averaged intensity and shear stress distributions of the randomly fluctuating component of velocity in the very near wake are also provided here and compared with those obtained in the near wake. The distributions of the production terms in the transport equations for the turbulent stresses are also provided.
Editor's invitational series: Human behavior as the warming of earth accelerates
Authors: Foo Koong Hean
Published: September 2014

I have welcomed comment from our Editorial Board and other experts on this topic, consistent with a major focus of our journal. First comment received is from Koong Hean Foo, PhD (Psych, NZ); PGD (CBT, NZ), Psychology Lecturer, James Cook University, Australia at JCU Singapore, which follows below. -Robert F. Morgan, Editor