bluuebunny/crossref_metadata_2025 huggingface dataset:
Regional and global myocardial deformation of the fetal right ventricle in hypoplastic left heart syndrome
Authors: Miller Thomas A. , Puchalski Michael D. , Weng Cindy , Menon Shaji C.
Published: July 2012

Objective

Quantification of fetal right ventricular (RV) function by 2D‐echocardiography is challenging. Velocity vector imaging (VVI) is an angle independent speckle tracking technique that assesses regional myocardial mechanics. Alteration in the deformation of the fetal RV in hypoplastic left heart syndrome (HLHS) is unknown. This study aimed to evaluate the regional mechanics of the fetal RV in HLHS.

Methods

We retrospectively analyzed HLHS fetuses imaged at our center. Velocity, strain and strain rate were obtained using VVI. Global and regional parameters of RV deformation were compared between HLHS fetuses and gestational age matched controls.

Results

A total of 30 HLHS fetuses and 30 gestational age matched controls were analyzed. The mean gestational age was 30.5 ±3.5 weeks. Global myocardial strain was significantly decreased in HLHS RVs compared to controls (−1.9% vs. ‐4.1%, p = 0.003). The volume of the hypoplastic left ventricle did not affect RV deformation in HLHS.

Conclusions

Compared to controls, the RV in HLHS fetuses has decreased systolic strain. Prenatal abnormalities in RV myocardial deformation may be responsible for inefficient cardiac performance and output. RV myocardial performance in HLHS can be measured prenatally and may be predictive of post‐natal RV dysfunction. © 2012 John Wiley & Sons, Ltd.
Microwave dielectric properties and EMI shielding effectiveness of poly(styrene‐b‐styrene‐ butadiene‐styrene) copolymer filled with PAni.Dodecylbenzenesulfonic acid and carbon black
Authors: Schettini Anderson R.A. , Khastgir Dipak , Soares Bluma G.
Published: July 2012

Conducting composites of polyaniline doped with dodecylbenzenesulfonic acid (PAni.DBSA), carbon black (CB) and poly(styrene‐b‐styrene‐butadiene‐b‐styrene) (STF) as supporting matrix were prepared by in situ polymerization. The influence of components and composition (% w/w) on the electromagnetic properties (dielectric constant ε′ and the dielectric loss ε″) and electromagnetic interference shielding effectiveness (EMI‐SE) of the materials were evaluated with a waveguide, using a microwave network analyzer from 8.2 to 12.4 GHz (X‐band). It was found that CB presence generates adverse effects on PAni.DBSA yield during synthesis, as it can be seen by X‐ray diffraction and TGA analyses. The type of PAni.DBSA formed modifies the composites properties. Dielectric constant, loss factor, and EMI shielding increase with conductive filler loading. Both the fillers, individually and in combination, increase the properties; however, the effect is not additive in nature. POLYM. ENG. SCI., 52:2041–2048, 2012. © 2012 Society of Plastics Engineers
Acrylic microspheres as drug‐delivery systems: synthesis through in situ microemulsion photoinduced polymerization and characterization
Authors: Bruno Patrizia , Malucelli Giulio , Tylkowski Bartosz , Ferré Joan , Giamberini Marta
Published: July 2012

Acrylic microspheres bearing a dense shell were successfully prepared by an in situ microemulsion photoinduced polymerization. Experiments following a fractional factorial design were performed for assessing the effect of the main reaction parameters (surfactant concentration in the aqueous phase, stirring rate, organic to water volume ratio, irradiation time) on the morphology of the microspheres and on their encapsulation yield. Environmental scanning electron microscopy and porosity measurements were carried out. Finally, the drug‐delivery features of the obtained products were investigated, evaluating the release of vanillin, chosen as a reference compound. The diffusion coefficients were found to be almost unvaried despite the increase in BET area. Such products show promising potentialities for home and personal care applications. © 2012 Society of Chemical Industry
Biomarker discovery using a comparative omics approach in a mouse model developing heterogeneous mammary cancer subtypes
Authors: Pennings Jeroen L.A. , Van Dycke Kirsten C.G. , van Oostrom Conny T.M. , Kuiper Raoul V. , Rodenburg Wendy , de Vries Annemieke
Published: July 2012

Identification of biomarkers for early breast cancer detection in blood is a challenging task, since breast cancer is a heterogeneous disease with a wide range of tumor subtypes. This is envisioned to result in differences in serum protein levels. The p53R270H/+WAPCre mouse model is unique in that these mice spontaneously develop both ER− and ER+ tumors, in proportions comparable to humans. Therefore, these mice provide a well‐suited model system to identify human relevant biomarkers for early breast cancer detection that are additionally specific for different tumor subtypes. Mammary gland tumors were obtained from p53R270H/+WAPCre mice and cellular origin, ER, and HER2 status were characterized. We compared gene expression profiles for tumors with different characteristics versus control tissue, and determined genes differentially expressed across tumor subtypes. By using literature data (Gene Ontology, UniProt, and Human Plasma Proteome), we further identified protein candidate biomarkers for blood‐based detection of breast cancer. Functional overrepresentation analysis (using Gene Ontology, MSigDB, BioGPS, Cancer GeneSigDB, and proteomics literature data) showed enrichment for several processes relevant for human breast cancer. Finally, Human Protein Atlas data were used to obtain a prioritized list of 16 potential biomarkers that should facilitate further studies on blood‐based breast cancer detection in humans.
Interdomain orientation of cardiac Troponin C characterized by paramagnetic relaxation enhancement NMR reveals a compact state
Authors: Cordina Nicole M. , Liew Chu Kong , Gell David A. , Fajer Piotr G. , Mackay Joel P. , Brown Louise J.
Published: July 2012

Cardiac troponin C (cTnC) is the calcium binding subunit of the troponin complex that triggers the thin filament response to calcium influx into the sarcomere. cTnC consists of two globular EF‐hand domains (termed the N‐ and C‐domains) connected by a flexible linker. While the conformation of each domain of cTnC has been thoroughly characterized through NMR studies involving either the isolated N‐domain (N‐cTnC) or C‐domain (C‐cTnC), little attention has been paid to the range of interdomain orientations possible in full‐length cTnC that arises as a consequence of the flexibility of the domain linker. Flexibility in the domain linker of cTnC is essential for effective regulatory function of troponin. We have therefore utilized paramagnetic relaxation enhancement (PRE) NMR to assess the interdomain orientation of cTnC. Ensemble fitting of our interdomain PRE measurements reveals that isolated cTnC has considerable interdomain flexibility and preferentially adopts a bent conformation in solution, with a defined range of relative domain orientations.
The statistician's role in the prevention of missing data
Authors: Hughes Sara , Harris Julia , Flack Nancy , Cuffe Robert L.
Published: July 2012

Considerable statistical research has been performed in recent years to develop sophisticated statistical methods for handling missing data and dropouts in the analysis of clinical trial data. However, if statisticians and other study team members proactively set out at the trial initiation stage to assess the impact of missing data and investigate ways to reduce dropouts, there is considerable potential to improve the clarity and quality of trial results and also increase efficiency. This paper presents a Human Immunodeficiency Virus (HIV) case study where statisticians led a project to reduce dropouts. The first step was to perform a pooled analysis of past HIV trials investigating which patient subgroups are more likely to drop out. The second step was to educate internal and external trial staff at all levels about the patient types more likely to dropout, and the impact this has on data quality and sample sizes required. The final step was to work collaboratively with clinical trial teams to create proactive plans regarding focused retention efforts, identifying ways to increase retention particularly in patients most at risk. It is acknowledged that identifying the specific impact of new patient retention efforts/tools is difficult because patient retention can be influenced by overall study design, investigational product tolerability profile, current standard of care and treatment access for the disease under study, which may vary over time. However, the implementation of new retention strategies and efforts within clinical trial teams attests to the influence of the analyses described in this case study. Copyright © 2012 John Wiley & Sons, Ltd.
Antihyperglycemic Activity of Extracts from Boldoa purpurascens Leaves in Alloxan‐Induced Diabetic Rats
Authors: González Mosquera D. M. , Hernandez Ortega Y. , By B. , Vicet Muro L. , Saucedo Hernandez Y. , Grau Ábalos R. , Dehaen W. , Pieters L. , Apers S.
Published: July 2012

In order to investigate the potential use of Boldoa purpurascens against diabetes, the antihyperglycemic effect of an ethanol extract obtained from its leaves was evaluated at doses of 50, 100 and 200 mg/kg in rats after induction of hyperglycemia by alloxan. Insulin 5 IU/kg was used as positive control and NaCl 0.9% as negative control. A similar experiment was performed with the aqueous extract used at doses of 50 and 100 mg/kg using metformin at a dose of 50mg/kg as positive control. Statistical analysis was carried using the Kruskal–Wallis test with an interval of trust of 99%. The ethanolic and aqueous extract of B. purpurascens showed a significant decrease of blood glucose levels 72 h after administration. Phytochemical analysis of the ethanol extract showed the presence of D‐pinitol, a compound known for its hypoglycemic properties. In conclusion, ethanolic as well as aqueous extracts of B. purpurascens leaves show antihyperglycemic activity, possibly due to the presence of D‐pinitol and flavonoids. Copyright © 2012 John Wiley & Sons, Ltd.
Comparison of molecular graphs of Lin, Nanand Cun(n= 2–5) clusters obtained from the density and the molecular electrostatic potential
Authors: Calaminici Patrizia , Domínguez‐Soria Victor Daniel , Köster Andreas M.
Published: July 2012

The analysis of the molecular graphs of the density and the molecular electrostatic potential (MEP) of small lithium, sodium and copper ground state cluster structures up to the pentamer is presented. For the underlying topological analysis all‐electron calculations were performed within the framework of Kohn–Sham density functional theory. The calculations are performed with the local level of theory in combination with all‐electron double zeta valence polarization basis sets. For this analysis, the ground state cluster structures obtained at the same level of theory were used. Molecular graphs of the density as well as the MEP are reported. The differences in the topology of the electronic density, MEP, and corresponding molecular graphs of the studied small lithium, sodium, and copper clusters are discussed. © 2012 Wiley Periodicals, Inc.
Synchronization of coupled neural networks with random coupling strengths and mixed probabilistic time‐varying delays
Authors: Yang Xinsong , Cao Jinde , Lu Jianquan
Published: July 2012

This paper investigates the global asymptotic synchronization in an array of coupled neural networks with random coupling strengths, probabilistic interval time‐varying coupling delays as well as unbounded distributed delays (mixed delays). Two important integral inequalities that include the Jensen's inequality as a special case are developed. On the basis of the developed inequalities, the properties of random variables and Lyapunov functional method, several delay‐dependent sufficient synchronization criteria are derived for the considered model. The derived synchronization criteria are formulated by linear matrix inequalities (LMIs) and can be easily verified by using MATLAB LMI Toolbox. Some existing results are improved and extended by taking different values of parameters of the obtained results. Numerical simulations are finally given to demonstrate the effectiveness of the theoretical results. Copyright © 2012 John Wiley & Sons, Ltd.
Input‐to‐state stability of a class of descriptor systems
Authors: Zhou Juan , Zhang Qingling , Men Bo , Huang Shoudong
Published: July 2012

This paper studies the input‐to‐state stability (ISS) of descriptor systems with exogenous disturbances. on the basis of the ISS theory of standard state‐space nonlinear systems, a sufficient condition for a class of nonlinear descriptor system to be ISS is proved. Furthermore, a design method of the state feedback controllers is given to make the closed‐loop system ISS. A numerical example is given to illustrate the effectiveness of the controller design.Copyright © 2012 John Wiley & Sons, Ltd.
ToF‐SIMS studies of the TiO2‐ZrO2 supported palladium as trace level used in the total oxidation of TCE in humid air
Authors: Nuns N. , Lamonier J.‐F. , Giraudon J.‐M. , Siffert S. , Su B.‐L.
Published: July 2012

New pre‐reduced titanium‐zirconium (x/1‐x) oxide(s) supported palladium samples 0.5w% Pd/TixZr1‐x (x = 0; 0.2; 0.3; 0.5; 0.7; 0.8; 1) have been shown to be efficient catalysts for the total oxidation of trichloroethylene (solvent widely used in dry cleaning and degreasing processes) in humid air (1mol%). A challenging task which must be addressed regarding that type of reaction is the chlorine location on the used catalyst surface in order to better understand the catalyst functioning. In spite of a few studies, time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS) has been elsewhere proved to be a highly relevant tool to resolve such a problem. Hence, in this study, Tof‐SIMS measurements have been performed on as‐prepared and selected used Pd/TixZr1‐x catalysts (x = 0; 0.2; 0.5; 1). On fresh catalysts, the Pd‐based ions detected in both polarities are Pd+, PdO‐ and PdO2‐. In addition, detection of Ti2ZrO5+ and TiZr2O5+ cluster ions provides for the first time a direct proof of titanium–zirconium mixed oxides (x≠ 0; 1). The negative ion‐mass spectrum of the related used samples exhibit relevant signals attributed to PdCl2‐, ZrO2Cl‐ and TiO2Cl‐ cluster ions. The chlorinated PdCl2‐ ion provides direct spectroscopic clue that some Cl atoms are still bound to Pd. By opposition, the quasi non‐observance of MCl‐ (M = Zr; Ti) indicates that chlorine deposit on the support does not directly affect the titanium and zirconium atoms. Copyright © 2012 John Wiley & Sons, Ltd.
ToF‐SIMS analysis of biomolecules in the model organism Caenorhabditis elegans
Authors: Geier Florian M. , Fearn Sarah , Bundy Jacob G. , McPhail David S.
Published: July 2012

C.elegans is a biomedical key model organism as it is a simple, easy to maintain eukaryote, which shares many gene homologues with higher mammals. As each of its cells has been traced during development and characterized by light microscopy, mass spectrometry‐based time‐of‐flight secondary ion mass spectrometry (ToF‐SIMS) imaging seems to promise exciting new insights. In this study, we have investigated simple but basic factors for ToF‐SIMS‐based imaging of C.elegans. By comparing chemical standards and two authentic C. elegans mutant extracts (N2 and Daf‐2), we found that for our purposes, Bi3+ is better suited due to its higher mass and spatial resolution. We also investigated the use of light microscopy slides as imaging substrates and gold coating as standard for mass calibration in higher mass ranges. Our findings and preliminary imaging results show that ToF‐SIMS is a well‐suited platform for mass spectrometry imaging. Copyright © 2012 John Wiley & Sons, Ltd.
ToF‐SIMS of polyphosphate glasses
Authors: Crobu Maura , Rossi Antonella , Spencer Nicholas D.
Published: July 2012

The increasing interest in phosphate glasses is due to the fact that they are considered to be bioactive functional materials in applications such as hard and soft tissue engineering and also that they possess interesting optical properties. These include low dispersion, high refractive index and high transparency for ultraviolet light. They have also been found to be responsible for the good anti‐wear properties of phosphorus‐based engine‐oil additives. More recently, the low processing temperature of zinc and iron phosphates, as well as their chemical durability, has opened the possibility for new applications, such as the immobilization of nuclear wastes. Understanding the surface chemistry of such glasses turns out to be a key step for inferring their underlying mechanisms of action. In this work, zinc phosphate and iron phosphate glasses of different chain lengths were synthesized and characterized by means of time‐of‐flight secondary ion mass spectroscopy (ToF‐SIMS). ToF‐SIMS was able to successfully differentiate between the samples of different composition. A characteristic pattern of phosphate fragments was observed in the negative‐mode ToF‐SIMS spectra. The most intense peaks could be assigned to the phosphate fragments PO−, PO2−, PO3− and PO4−. Toward higher masses, fragments containing up to four phosphorus atoms with a periodicity of PO2 were observed: FePO3−, ZnPO3−, FePO4−, ZnPO4−, FeP2O6−, ZnP2O6−, FeP2O7−, ZnP2O7−; FeP3O8−, ZnP3O8−, FeP3O9− and ZnP3O9−. This pattern characterizes the spectra of all the glasses under investigation. For the first time, a method is proposed that allows the discrimination between polyphosphates of different chain lengths, by comparing the intensities of the relevant ToF‐SIMS peaks. Copyright © 2012 John Wiley & Sons, Ltd.
Dual beam depth profiling of polymer materials: comparison of C60 and Ar cluster ion beams for sputtering
Authors: Rading D. , Moellers R. , Cramer H.‐G. , Niehuis E.
Published: July 2012

Dual beam depth profiling was applied in order to investigate the possibilities and limitations of C60 and Ar cluster ion sputtering for depth profiling of polymer materials. Stability and intensity of characteristic high mass molecular ion signals as well as sputter yields will be compared. For this purpose, different beam energies resulting in 2–10 eV/atom for Arn and 167–667 eV/atom for C60 sputtering were applied to various polymer samples. From our experiments, we can conclude that most of the limitations C60 sputtering suffers from could be successfully overcome and that the Ar gas cluster ion beam seems to be a more universal tool for sputtering of organic materials. Copyright © 2012 John Wiley & Sons, Ltd.
Spatial cluster detection for ordinal outcome data
Authors: Jung Inkyung , Lee Hana
Published: July 2012

In geographical disease surveillance, spatial scan statistics are used to identify areas having unusually high or low rates of disease outcomes and to determine the statistical significance of detected clusters. The spatial scan statistic for ordinal data such as stage of cancer has been developed to detect clusters representing areas with high rates of more serious stages compared with the surrounding areas. Such areas were expressed using likelihood ratio ordering, which is a rather strict order restriction, and hence, the method might fail to detect spatial clusters with high rates of worse categories (e.g., later stage). In this paper, we relax the order restriction using stochastic ordering and examine differences between the two approaches in detecting spatial clusters. Through simulation studies, we show that the stochastic ordering‐based approach has higher power, sensitivity, and positive predictive value under several scenarios. We illustrate the two methods with the use of a real data example. Copyright © 2012 John Wiley & Sons, Ltd.
Molded electrode test system for evaluating wet electrical performance of flexible poly(vinyl chloride)
Authors: Neese Bret P. , Chaudhary Bharat I.
Published: July 2012

The molded electrode test system (METS) test has long been used with flexible poly(vinyl chloride) (PVC) electrical insulation. However, there are many questions regarding its precision and accuracy, as there is no industry‐accepted standard regarding this test. This paper aims to answer some of these questions in terms of the measurement precision as well as the ability of the test to predict wet electrical performance on wire. A repeatability study was conducted on flexible PVC compound where 10 samples were produced and tested under identical conditions. The mean insulation resistance was (550 MΩ)/(305 m) with a standard deviation of (120 MΩ)/(305 m). As the thickness of the insulation increased, the insulation resistance decreased. Furthermore, the study showed that there was no correlation between the METS test and wet volume resistivity, while there was some correlation with wet insulation resistance (IR) at high temperature, though the ability to predict wet IR from the METS test was limited. J. VINYL ADDIT. TECHNOL., 18:178–183, 2012. © 2012 Society of Plastics Engineers
Measurement and simple equation models of the specific heats of neat and glycerol‐plasticized poly(vinyl alcohol)
Authors: Sin Lee Tin , Rahman W.A.W.A. , Rahmat A.R. , Bee Soo Tueen , Tee Tiam Ting , Low Chong Yu
Published: July 2012

The specific heats (Csp) of neat and glycerol‐plasticized poly(vinyl alcohol) (PVOH) were studied by differential scanning calorimetry at 330–530 K. Glycerol‐plasticized poly(vinyl alcohol) was prepared by a melt‐blending method. The outcomes were modeled into mathematical functions. Incorporation of glycerol increased the specific heat of PVOH. Glycerol provided internal lubrication to the PVOH system, giving a smoother and lower‐amplitude melting curve. As a result, glycerol‐plasticized PVOH had a lower melting‐temperature range than neat PVOH. However, higher energy was required to increase the temperature of glycerol‐plasticized PVOH. The modeling functions showed a best fits regression range of 0.967–0.999. Neat PVOH and glycerol‐plasticized PVOH required 1166.05 J/g and 2113.09 J/g, respectively, to increase the temperature from 330 to 530 K. J. VINYL ADDIT. TECHNOL., 18:198–203, 2012. © 2012 Society of Plastics Engineers
Characterization of glycolytic metabolism and ion transport of Candida albicans
Authors: Calahorra Martha , Sánchez Norma Silvia , Peña Antonio
Published: July 2012

The main energetic pathways, fermentation and respiration, and the general ion transport properties of Candida albicans were studied. Compared to Saccharomyces cerevisiae, we found that in C. albicans: (a) the cell mass yield when grown in YPD was significantly larger; (b) it required longer times to be starved of endogenous substrates; (c) ethanol production was lower but significant; (d) respiration was also lower; (e) it showed a small activity of an alternative oxidase; (f) fermentation and oxidative phosphorylation seemed to compete for both ADP and NADH; and (g) NADH levels were lower. Regarding ion transport and compared to S. cerevisiae: (a) the general mechanism was similar, with a plasma membrane H+‐ATPase that generates both a plasma membrane ΔpH and a ΔΨ, the latter being responsible for driving K+ inside; (b) its acidification capacity is slightly smaller and less sensitive to activation by high pH; and (c) the presence of K+ results in a large activation of both respiration and fermentation, most probably due to the energy required in the process. ADP produced by H+‐ATPase stimulation by high pH or the addition of K+ at low pH results in the increase of both respiration and fermentation. Copyright © 2012 John Wiley & Sons, Ltd.
Stop the top background of the stop search
Authors: Bai Yang , Cheng Hsin-Chia , Gallicchio Jason , Gu Jiayin
Published: July 2012

Abstract

The main background for the supersymmetric stop direct production search comes from Standard Model
$ t\overline t $
events. For the single-lepton search channel, we introduce a few kinematic variables to further suppress this background by focusing on its dileptonic and semileptonic topologies. All are defined to have end points in the background, but not signal distributions. They can substantially improve the stop signal significance and mass reach when combined with traditional kinematic variables such as the total missing transverse energy. Among them, our variable
$ M_{{T2}}^W $
hasthebestoverallperformancebecause it uses all available kinematic information, including the on-shell mass of both W’s. We see 20 %-30 % improvement on the discovery significance and estimate that the 8 TeV LHC run with 20 fb−1 of data would be able to reach an exclusion limit of 650-700 GeV for direct stop production, as long as the stop decays dominantly to the top quark and a light stable neutralino. Most of the mass range required for the supersymmetric solution of the naturalness problem in the standard scenario can be covered.
An innovative approach to the treatment of Gaucher disease and possibly other metabolic disorders of the brain
Authors: Brady Roscoe O. , Yang Chunzhang , Zhuang Zhengping
Published: July 2012

The extraordinary benefit of enzyme replacement therapy (ERT) on the systemic manifestations of Gaucher disease was demonstrated in 1991. Since that time, investigators have devoted substantial effort to improve the delivery of enzymes to the brain because many hereditary metabolic disorders are characterized by extensive central nervous system involvement. Because the required supplemental enzyme is too large to cross the blood‐brain barrier (BBB), ERT for central nervous system involvement was out of the question at that time. Several innovative strategies that have been reported to overcome this impediment are discussed. Recent investigations have provided additional insight concerning the pathogenesis of enzyme deficiency disorders. For many years it was presumed that alterations of the amino acid sequence of enzymes such as glucocerebrosidase reduced the catalytic activity of the enzyme. It has recently been shown that the decrease of glucocerebrosidase activity was the result of a quantitative loss of the amount of this enzyme. Significant increases of its activity were obtained with small molecule inhibitors of histone deacetylase that cross the BBB. The effect of such materials on neuronopathic Gaucher disease and other CNS metabolic disorders is discussed.
Procurement Change in Canada: An Opportunity for Improving System Performance
Authors: Arshoff Larry , Henshall Chris , Juzwishin Don , Racette Ray
Published: July 2012

The Canadian healthcare system is undergoing restructuring of how goods and services are purchased. A conference “Navigating Hospital and Health System Procurement” was organized by MEDEC and the Canadian College of Health Leaders to examine the issues. This paper describes the implications and opportunities these changes present for healthcare policy, regulation, practice, and the supplier marketplace.
Leaders and Emotional Intelligence: A View from Those Who Follow
Authors: Zakariasen Ken , Victoroff Kristin Zakariasen
Published: July 2012

Boyatzis and Goleman state that Emotional Intelligence (EI) “is an important predictor of success.” In their book Primal Leadership, they refer to “the leadership competencies of emotional intelligence: how leaders handle themselves and their relationships.” The leadership exercises reported here examined the practices of effective and ineffective leaders as identified by individuals who have worked under such leaders (ie, followers/subordinates). We sought to ascertain to what extent these practices are related to EI. The 2-year data from these leadership exercises show the strong relationships between perceived leadership effectiveness and emotionally intelligent leadership practices as observed by leaders' followers. For example, whether considering the practices that made effective leaders effective or the practices that ineffective leaders needed to adopt or significantly improve upon (in the eyes of subordinates), these practices were almost exclusively related to EI. These findings are supported in the EI literature, as is the strength of subordinates' assessments in predicting leadership effectiveness.
On the role of vortex stretching in energy optimal growth of three-dimensional perturbations on plane parallel shear flows
Authors: Vitoshkin H. , Heifetz E. , Gelfgat A. Yu. , Harnik N.
Published: July 2012

The three-dimensional linearized optimal energy growth mechanism, in plane parallel shear flows, is re-examined in terms of the role of vortex stretching and the interplay between the spanwise vorticity and the planar divergent components. For high Reynolds numbers the structure of the optimal perturbations in Couette, Poiseuille and mixing-layer shear profiles is robust and resembles localized plane waves in regions where the background shear is large. The waves are tilted with the shear when the spanwise vorticity and the planar divergence fields are in (out of) phase when the background shear is positive (negative). A minimal model is derived to explain how this configuration enables simultaneous growth of the two fields, and how this mutual amplification affects the optimal energy growth. This perspective provides an understanding of the three-dimensional growth solely from the two-dimensional dynamics on the shear plane.
Guzhangian (mid Cambrian) trilobites from siliceous concretions of the Valtorres Formation, Iberian Chains, NE Spain
Authors: ÁLVARO J. JAVIER , ZAMORA SAMUEL , VIZCAÏNO DANIEL , AHLBERG PER
Published: July 2012

In the carbonate-siliciclastic strata of West Gondwana (e.g. in the Montagne Noire, France), the aftermath of the mid Languedocian (mid Cambrian) regression is characterized by a late Languedocian major turnover of trilobite families and a Furongian–early Tremadocian radiation related to the stepwise immigration of trilobite invaders from East Gondwana under persistent transgressive conditions. The scarcity of upper Languedocian fossil accumulations in clayey substrates has inspired the sampling of the palaeogeographically most distal parts of the Iberian Chains (Spain), where diagenetic dissolution of ubiquitous hexactinellid sponge spicules has favoured the formation of siliceous concretions. These have yielded the trilobitesPeronopsiscf.insignis,Oidalagnostus trispinifer,Proampyx difformis(=Proampyx aculeatus),Bailiaspis?glabrata(=Holocephalina agrauloides, by ontogeny),Holasaphuscf.centropygeand a paradoxidid gen. et sp. indet. Despite preservation and sampling biases, the identification of this taphonomic window in offshore clayey substrates of West Gondwana allows the recognition of a strong biogeographical link with Baltica, and the correlation of the global Guzhangian Stage and theSolenopleura?brachymetopaZone of Scandinavia with part of the Mediterranean upper Languedocian Substage.
Late Roman Precious-Metal Deposits: Worth their Weight in Gold?
Authors: Baratte François
Published: July 2012

Over recent years the question of ancient hoards, in particular of precious metal, coins, plate or jewellery, has been the subject of numerous considerations (notably S. Gelichi and C. La Rocca (eds), Tesori. Forme di accumulazione della richezza nell'alto medioevo (secoli V–XI) (Rome, 2004)) in order to try to grasp the characteristics of a complex phenomenon that relates to multiple aspects of society in whatever period is under consideration: the economy, social organisation, the possible role of the images … The difficulties encountered by researchers when addressing these problems are illustrated by the ambivalence, indeed the ambiguity in many languages of the term ‘trésor/hoard’. Richard Hobbs has thus chosen, very judiciously, to take as his subject here ‘deposits of precious metal’, which defines the topic perfectly. On the other hand, one could question the descriptor ‘late Roman’ when applied to the period covered here, five centuries, from a.d. 200 to 700. There could be discussion over whether the third century should be included in Late Antiquity; others will challenge whether the sixth century still belongs to that same world. But from the first page H. effectively corrects his title by stating that it also covers the early Byzantine period, something I would feel is a better definition. It may certainly be felt that these are just questions of nomenclature, but they do have their importance for the topic of this study. All the same, the important thing is that H. wanted to study an extended period, as stated by the book's sub-title. One cannot but approve of his choice.
Translation, Emphasis, Synthesis, Disturbance: On the function of music in visual music
Authors: Fuxjäger Anton
Published: July 2012

Starting from the premiss that the central aesthetic feature of non-representational moving images (visual music) is their structuring of reception time, the function of the accompanying music in contributing to the total (combined) temporal structure of the resulting artwork is discussed. A taxonomy of the different roles that music can play in the production and reception of visual music consisting of three basic categories is presented and examples are given:

•

‘Music translations’: certain parameters of the accompanying music are transcoded into certain visual parameters, the accompanying music thereby provides the temporal structure of the audiovisual artwork.

•

‘Synthetic structures’: the music and the images provide different temporal informations with enough coincidences to be synthesised into a combined audiovisual strucuture by the viewer/listener.

•

‘Mutual disturbance’: the aforementioned process fails to be realised due to a lack of sufficient points of synchronisation. As a result the accompanying music will disrupt the recognition of the temporal structure of the images and vice versa.
Establishment of a cassava (Manihot esculenta Crantz) core collection based on agro-morphological descriptors
Authors: Bhattacharjee Ranjana , Dumet Dominique , Ilona Paul , Folarin Soyode , Franco Jorge
Published: July 2012

International Institute of Tropical Agriculture maintains 2544 cassava accessions (Manihot esculenta Crantz) from 28 countries in its field bank. Being vegetatively propagated, this poses challenges in maintenance in terms of cost as well as in labour requirements. A core collection representing the range of phenotypic diversity present in the entire collection would enhance the conservation aspects and increase the potential for its exploitation in crop improvement programmes. The present study aimed to establish a core collection using 40 agro-morphological traits evaluated at two locations using a different number of accessions in each location. To meet the challenges generated by the types of variables and include maximum diversity in the core collection, a sequential strategy based on five major concepts was used: hierarchical multiple factor analysis allowing the mixture of variables of different kinds; three-way analysis that included the effect of genotype × environment interaction in the clustering process; linear discriminant function to assign all those individuals who were included in one location but not in the other to the groups that were generated from the common number of accessions evaluated in both locations; and D-allocation method to select samples from each cluster. The representativeness of the core subset to the entire collection was further estimated by comparing means and variances, range, and distances between accessions. The established cassava core collection consisted of 428 accessions that conserved 15% higher phenotypic diversity with no redundancies. The phenotypic diversity represented in this core collection will be a guide to users of cassava germplasm in their crop improvement programmes.
Explaining the dealings of Dutch SMEs with potential legal problems: a plea for a theory-driven approach
Authors: Croes M. T.
Published: July 2012

The previous decade has seen a wealth of studies into the potential legal problems of citizens, problems that could have or did result in legal procedures. Although this has greatly enhanced our understanding of the kinds of difficulties that citizens experience and the frequency with which this happens, some important topics have received little attention. This is especially true for the explanation of the chances that people have or the choices they make regarding the problems they face. In part, this is the result of the chosen approach, which was aimed at description and lacked the rigour needed for explanation. In this article, I will argue that in order to make progress regarding these topics, it is necessary to use a theory-driven approach. What a theory-driven approach is and what such an approach would look like when applied to the paths to justice field, is demonstrated with regard to the way in which small and medium-sized enterprises (SMEs, companies with less than 100 employees) in the Netherlands deal with potential legal problems (Croes & Maas, 2009).
CD36 inhibition prevents lipid accumulation and contractile dysfunction in rat cardiomyocytes
Authors: Angin Yeliz , Steinbusch Laura K. M. , Simons Peter J. , Greulich Sabrina , Hoebers Nicole T. H. , Douma Kim , van Zandvoort Marc A. M. J. , Coumans Will A. , Wijnen Wino , Diamant Michaela , Ouwens D. Margriet , Glatz Jan F. C. , Luiken Joost J. F. P.
Published: July 2012

An increased cardiac fatty acid supply and increased sarcolemmal presence of the long-chain fatty acid transporter CD36 are associated with and contribute to impaired cardiac insulin sensitivity and function. In the present study we aimed at preventing the development of insulin resistance and contractile dysfunction in cardiomyocytes by blocking CD36-mediated palmitate uptake. Insulin resistance and contractile dysfunction were induced in primary cardiomyocytes by 48 h incubation in media containing either 100 nM insulin (high insulin; HI) or 200 μM palmitate (high palmitate; HP). Under both culture conditions, insulin-stimulated glucose uptake and Akt phosphorylation were abrogated or markedly reduced. Furthermore, cardiomyocytes cultured in each medium displayed elevated sarcolemmal CD36 content, increased basal palmitate uptake, lipid accumulation and decreased sarcomere shortening. Immunochemical CD36 inhibition enhanced basal glucose uptake and prevented elevated basal palmitate uptake, triacylglycerol accumulation and contractile dysfunction in cardiomyocytes cultured in either medium. Additionally, CD36 inhibition prevented loss of insulin signalling in cells cultured in HP, but not in HI medium. In conclusion, CD36 inhibition prevents lipid accumulation and lipid-induced contractile dysfunction in cardiomyocytes, but probably independently of effects on insulin signalling. Nonetheless, pharmacological CD36 inhibition may be considered as a treatment strategy to counteract impaired functioning of the lipid-loaded heart.
Selective STAT3-α or -β expression reveals spliceform-specific phosphorylation kinetics, nuclear retention and distinct gene expression outcomes
Authors: Ng Ivan H. W. , Ng Dominic C. H. , Jans David A. , Bogoyevitch Marie A.
Published: July 2012

Phosphorylation of STAT3 (signal transducer and activator of transcription 3) is critical for its nuclear import and transcriptional activity. Although a shorter STAT3β spliceform was initially described as a negative regulator of STAT3α, gene knockout studies have revealed that both forms play critical roles. We have expressed STAT3α and STAT3β at comparable levels to facilitate a direct comparison of their functional effects, and have shown their different cytokine-stimulated kinetics of phosphorylation and nuclear translocation. Notably, the sustained nuclear translocation and phosphorylation of STAT3β following cytokine exposure contrasted with a transient nuclear translocation and phosphorylation of STAT3α. Importantly, co-expression of the spliceforms revealed that STAT3β enhanced and prolonged the phosphorylation and nuclear retention of STAT3α, but a STAT3β R609L mutant, with a disrupted SH2 (Src homology 2) domain, was not tyrosine phosphorylated following cytokine stimulation and could not cross-regulate STAT3α. The physiological importance of prolonged phosphorylation and nuclear retention was indicated by transcriptome profiling of STAT3−/− cells expressing either STAT3α or STAT3β, revealing the complexity of genes that are up- and down-regulated by the STAT3 spliceforms, including a distinct set of STAT3β-specific genes regulated under basal conditions and after cytokine stimulation. These results highlight STAT3β as a significant transcriptional regulator in its own right, with additional actions to cross-regulate STAT3α phosphorylation and nuclear retention after cytokine stimulation.
The prototypic class Ia ribonucleotide reductase from Escherichia coli: still surprising after all these years
Authors: Brignole Edward J. , Ando Nozomi , Zimanyi Christina M. , Drennan Catherine L.
Published: July 2012

RNRs (ribonucleotide reductases) are key players in nucleic acid metabolism, converting ribonucleotides into deoxyribonucleotides. As such, they maintain the intracellular balance of deoxyribonucleotides to ensure the fidelity of DNA replication and repair. The best-studied RNR is the class Ia enzyme from Escherichia coli, which employs two subunits to catalyse its radical-based reaction: β2 houses the diferric-tyrosyl radical cofactor, and α2 contains the active site. Recent applications of biophysical methods to the study of this RNR have revealed the importance of oligomeric state to overall enzyme activity and suggest that unprecedented subunit configurations are in play. Although it has been five decades since the isolation of nucleotide reductase activity in extracts of E. coli, this prototypical RNR continues to surprise us after all these years.
Thiamin biosynthesis: still yielding fascinating biological chemistry
Authors: Begley Tadhg P. , Ealick Steven E. , McLafferty Fred W.
Published: July 2012

The present paper describes the biosynthesis of the thiamin thiazole in Bacillus subtilis and Saccharomyces cerevisiae. The two pathways are quite different: in B. subtilis, the thiazole is formed by an oxidative condensation of glycine, deoxy-D-xylulose 5-phosphate and a protein thiocarboxylate, whereas, in S. cerevisiae, the thiazole is assembled from glycine, NAD and Cys205 of the thiazole synthase.
Self-assembled synthesis and characterization of microchannels in polymeric membranes
Authors: Kahsai Wintana T. , Pham Uyen H. T. , Sankaran Jeyantt S. , Iqbal Samir M.
Published: July 2012

This article describes a novel self-assembly approach to create microchannels in polydimethylsiloxane (PDMS) membranes using poly(ethylene oxide) (PEO) and polyurethane (PU). The interactions between hydrophilic PEO/PU and hydrophobic PDMS, as it cross-links, result into PEO/PU pushed out of the bulk PDMS. As this occurs, PEO/PU particles leave behind their tracks. PEO depicts ease of handling, better inherent alignment, and excellent repeatability. Fourier transform infrared spectroscopy, optical/confocal laser scanning microscopy, and fluid flow measurements are done to characterize the microfluidic channels. These channels have a circular cross-section and are parallel to each other. PEO generates smaller channels compared to PU. The diameter, arrangement, and height of these channels are seen to depend on temperature; for example, channel length increases linearly with temperature. An interdependent relationship between temperature, pore size, and number of pores is also exhibited. During phase separation of hydrophilic and hydrophobic materials, interface shows concentric circular arrangements of hydrophilic molten polymer. The circular pattern shows almost similar radial change in size. The flow behavior of colored ink solutions shows higher velocity at the entrance of microchannels which decreases to sustained lower velocity as fluid travels farther in the microchannels. The fabrication of membrane does not need lithography or etching, and channels are self-assembled from bottom-up interactions. These microchannel membranes can have applications in drug delivery, cell culture studies, mixing of solutions, separation of mixtures, lab-on-a-chip, etc.
Mechanism of flow separation control using plasma actuation
Authors: Greenblatt David , Schneider Torsten , Schüle Chan Yong
Published: July 2012

The mechanism of flow separation control was investigated experimentally and computationally using pulse-modulated dielectric barrier discharge (DBD) plasma actuation on a stalled flat plate airfoil at a Reynolds number of 3000. Load measurements were complimented with two-dimensional phase-averaged particle image velocimetry performed in the flowfield above the airfoil. A parametric study was carried out where the pulse-modulation frequency, duty cycle, and peak plasma body-force were varied. The two-dimensional Navier-Stokes equations, with no turbulence modeling, were solved directly using a commercial flow solver and a simple but satisfactory heuristic DBD plasma body-force model was incorporated. The overall experimental trends were well predicted by the computations, where the frequencies that produced the largest increases in lift coefficient excited bluff-body shedding at a frequency corresponding approximately to its unforced sub-harmonic. At non-dimensional frequencies most effective for increasing lift (∼0.2 to 0.5), the leading-edge shear layer was severed by the perturbations and then merged with a downstream vortex. In a time-mean sense this mechanism forced relatively high momentum fluid towards the surface with typically two re-circulating structures present on the airfoil. Although the essential flow control mechanism was captured by the computation, the idealized 2D approach was identified as a weakness due to the shedding instability not being present in the baseline experiments and the inability to account for three-dimensional structures in the shear layer.
Cross-sectional and plan-view cathodoluminescence of GaN partially coalesced above a nanocolumn array
Authors: Lethy K. J. , Edwards P. R. , Liu C. , Wang W. N. , Martin R. W.
Published: July 2012

The optical properties of GaN layers coalesced above an array of nanocolumns have important consequences for advanced optoelectronic devices. GaN nanocolumns coalesced using a nanoscale epitaxial overgrowth technique have been investigated by high resolution cathodoluminescence (CL) hyperspectral imaging. Plan-view microscopy reveals partially coalesced GaN layers with a sub-μm scale domain structure and distinct grain boundaries, which is mapped using CL spectroscopy showing high strain at the grain boundaries. Cross-sectional areas spanning the partially coalesced GaN and underlying nanocolumns are mapped using CL, revealing that the GaN bandedge peak shifts by about 25 meV across the partially coalesced layer of ∼2 μm thick. The GaN above the nanocolumns remains under tensile strain, probably due to Si out-diffusion from the mask or substrate. The cross-sectional data show how this strain is reduced towards the surface of the partially coalesced layer, possibly due to misalignment between adjacent partially coalesced regions.