bluuebunny/crossref_metadata_2025 huggingface dataset:
Ferroelectric properties and switching endurance of Hf0.5Zr0.5O2 films on TiN bottom and TiN or RuO2 top electrodes
Authors: Park Min Hyuk , Kim Han Joon , Kim Yu Jin , Jeon Woojin , Moon Taehwan , Hwang Cheol Seong
Published: February 2014

magnified image

The effect of the top electrode (TE) on the ferroelectric properties and switching endurance of thin Hf0.5Zr0.5O2 films was examined. The TiN/Hf0.5Zr0.5O2/TiN capacitor can endure electric cycling up to 109 times, which is promising for the next‐generation memory. RuO2 TE was reduced during annealing due to the reactive TiN bottom electrode, resulting in the degradation of the ferroelectric properties and endurance. In addition, the endurance of the TiN/Hf0.5Zr0.5O2/TiN capacitors was optimized by changing the film thickness and the postannealing temperature. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A systematic investigation of the fragmentation pattern of two furanoheliangolide C‐8 stereoisomers using electrospray ionization mass spectrometry
Authors: Sartori Lucas Rossi , Vessecchi Ricardo , Humpf Hans‐Ulrich , Da Costa Fernando Batista , Lopes Norberto Peporine
Published: February 2014

RATIONALE

Budlein A is a sesquiterpene lactone (STL) with some reported biological activities. Pre‐clinical studies to identify in vivo metabolites often employ hyphenated techniques such as liquid chromatography/tandem mass spectrometry (LC/MS/MS). It is also possible to use the fragmentation pattern obtained by Collision‐Induced Dissociation (CID) and Higher Energy Collision‐Induced Dissociation (HCD) to distinguish between the stereoisomers budlein A and centratherin.

METHODS

The experiments were carried out in the positive mode using four different spectrometers with an electrospray ionization (ESI) source: (a) Waters ACQUITY® TQD triple quadrupole mass spectrometer (QqQ), (b) AB Sciex API 4000 QTrap® (QqQ), (c) Bruker Daltonics micrOTOF™‐Q II (time‐of‐flight, QTOF), and (d) Thermo Scientific LTQ Orbitrap XL hybrid FTMS (Fourier transform mass spectrometer). Computational chemistry studies helped to identify the protonation sites. The B3LYP/6‐31G(d) model furnished the equilibrium geometries and energies.

RESULTS

The stereochemistry (α‐ or β‐orientation) of the centratherin and budlein A side‐chain esters influences the fragmentation pattern recorded on QqQ, QTOF, and Orbitrap‐HCD. On QqQ, centratherin releases the side chain, to generate the m/z 275 fragment ion, whereas budlein A gives the m/z 83 fragment ion. On QTOF and Orbitrap‐HCD, only budlein A affords the m/z 293 and 83 fragment ions, respectively.

CONCLUSIONS

The data suggest that proton migration governs the fragmentation pathways under α‐ or β‐orientation. The difference in the QqQ, QTOF, and Orbitrap‐HCD spectral profiles of each isomer can help to distinguish between centratherin and budlein A using MS/MS, which becomes an alternative to nuclear magnetic resonance (NMR) analysis. Copyright © 2014 John Wiley & Sons, Ltd.
Moving to the next school at age 10–14 years: an international review of psychological development at school transition
Authors: Symonds Jennifer E. , Galton Maurice
Published: February 2014

Context and Implications
Context and Implications Document for: Moving to the next school at age 10–14 years: an international review of psychological development at school transition
Authors: Symonds Jennifer E. , Galton Maurice
Published: February 2014

This guide accompanies the following article: Jennifer Symonds and Maurice Galton. Moving to the next school at age 10‐14 years: an international review of psychological development at school transition. Review of Education, 10.1002/rev3.3021
Fault estimation observer design for discrete‐time systems in finite‐frequency domain
Authors: Zhang Ke , Jiang Bin , Shi Peng , Xu Jingfa
Published: February 2014

This paper proposes a framework of fault estimation observer design in finite‐frequency domain for discrete‐time systems. First, under the multiconstrained idea, a full‐order fault estimation observer in finite‐frequency domain is designed to achieve fault estimation by using the generalized Kalman–Yakubovich–Popov lemma to reduce conservatism generated by the entire frequency domain. Then, a reduced‐order fault estimation observer is constructed, which results in a new fault estimator to realize fault estimation using current output information. Furthermore, by introducing slack variables, improved results on full‐order fault estimation observer and reduced‐order fault estimation observer design with finite‐frequency specifications are obtained such that different Lyapunov matrices can be separately designed for each constraint. Simulation results are presented to illustrate the advantages of the theoretic results obtained. Copyright © 2014 John Wiley & Sons, Ltd.
Ga‐focused ion beam time‐of‐flight secondary ion mass spectrometer analysis of the grain boundary segregation/precipitation of boron in steel
Authors: Tanaka Tomohito , Fujishiro Taishi , Shigesato Genichi , Hayashi Shun‐ichi
Published: February 2014

Ga‐focused ion beam time‐of‐flight secondary ion mass spectrometry (FIB‐TOF‐SIMS) analysis was performed to investigate the grain boundary segregation/precipitation of boron in steel. To overcome the low secondary ion yield from the primary Ga+ source and the sensitivity using a high‐resolution Ga‐FIB source, a low energy oxygen ion beam was used prior to the Ga‐FIB‐TOF‐SIMS analysis. As a result, it was found that Ga‐FIB‐TOF‐SIMS is a very powerful tool for mapping boron segregation and/or precipitation in steel with a spatial resolution of ~200 nm. In addition, the results were strongly dependent on the surface composition. Copyright © 2014 John Wiley & Sons, Ltd.
Real options in divestment alternatives
Authors: Damaraju Naga Lakshmi , Barney Jay B. , Makhija Anil K.
Published: February 2014

This paper examines the implications of real options theory for both the decision to divest a business unit and the mode of divestment. It is shown that the decision to divest a business unit and the decision to engage in staged modes of divestment are both sensitive to uncertainty, consistent with a real options logic. However, in the face of uncertainty, the results suggest that staged forms of governance create real options that are of lesser value as compared to simply not divesting a business unit and also as compared to completely divesting a business unit. Thus, this study shows that firms have real options of varied value to choose from in the context of divestments. Copyright © 2014 John Wiley & Sons, Ltd.
Disentangling the performance effects of efficiency and bargaining power in horizontal growth strategies: An empirical investigation in the global retail industry
Authors: Moatti Valérie , Ren Charlotte R. , Anand Jaideep , Dussauge Pierre
Published: February 2014

Mergers and acquisitions (M&A) and organic growth are two common strategies to achieve horizontal growth. In this study, we disentangle two distinct sources of firm performance corresponding to different theoretical perspectives on firm size: firms' bargaining power with respect to suppliers and customers, and operating efficiency arising from scale economies. We conceptually argue and empirically show that relatively, M&A enhance bargaining power in the short term while organic growth enhances operating efficiency over the long term. In order to disaggregate these effects, we use accounting rather than financial or managerial data and test our predictions in the global retail industry over a 20‐year period. We examine implications of these results for sustainability of size‐based competitive advantages. Copyright © 2014 John Wiley & Sons, Ltd.
Modeling Study of Nitrogen Removal from the Vacuum Tank Degasser
Authors: Yu Shan , Miettinen Jyrki , Louhenkilpi Seppo
Published: February 2014

Low nitrogen content in liquid steel is required for most of the steelmaking companies, where vacuum degassing of liquid steel is usually carried out to remove nitrogen as well as other impurity elements during ladle treatment. This paper presents an integrated computational fluid dynamics (CFD) model for simulating the nitrogen removal in an industrial vacuum tank degasser (VTD). In the CFD model, oxygen and sulfur are considered as surface‐active elements decreasing the denitrogenation rate at the gas–steel interface. An activity coefficient and a desulfurization sub‐model are implemented to compute the effective activity coefficients of the related elements and the evolution of sulfur content in liquid steel during the process, respectively. The effect of various elements on denitrogenation rate in the VTD is studied with the developed model. For the used steel compositions the denitrogenation rate decreases with an increase in the content of [S], [O], [Cr], [Nb], [V], [Ti], or [Mn], whereas it increases with an increase in the content of [C], [Si], [P], [Ni], or [Al]. The model is validated by comparing final nitrogen contents measured from the industrial plant with the ones predicted by the model and good agreements were found. The model has proven to be a useful and accurate tool for predicting final nitrogen content of liquid steel in the plant.
Running Rescues Defective Adult Neurogenesis by Shortening the Length of the Cell Cycle of Neural Stem and Progenitor Cells
Authors: Farioli-Vecchioli Stefano , Mattera Andrea , Micheli Laura , Ceccarelli Manuela , Leonardi Luca , Saraulli Daniele , Costanzi Marco , Cestari Vincenzo , Rouault Jean-Pierre , Tirone Felice
Published: February 2014

Physical exercise increases the generation of new neurons in adult neurogenesis. However, only few studies have investigated the beneficial effects of physical exercise in paradigms of impaired neurogenesis. Here, we demonstrate that running fully reverses the deficient adult neurogenesis within the hippocampus and subventricular zone of the lateral ventricle, observed in mice lacking the antiproliferative gene Btg1. We also evaluated for the first time how running influences the cell cycle kinetics of stem and precursor subpopulations of wild-type and Btg1-null mice, using a new method to determine the cell cycle length. Our data show that in wild-type mice running leads to a cell cycle shortening only of NeuroD1-positive progenitor cells. In contrast, in Btg1-null mice, physical exercise fully reactivates the defective hippocampal neurogenesis, by shortening the S-phase length and the overall cell cycle duration of both neural stem (glial fibrillary acidic protein+ and Sox2+) and progenitor (NeuroD1+) cells. These events are sufficient and necessary to reactivate the hyperproliferation observed in Btg1-null early-postnatal mice and to expand the pool of adult neural stem and progenitor cells. Such a sustained increase of cell proliferation in Btg1-null mice after running provides a long-lasting increment of proliferation, differentiation, and production of newborn neurons, which rescues the impaired pattern separation previously identified in Btg1-null mice. This study shows that running positively affects the cell cycle kinetics of specific subpopulations of newly generated neurons and suggests that the plasticity of neural stem cells without cell cycle inhibitory control is reactivated by running, with implications for the long-term modulation of neurogenesis. Stem Cells  2014;32:1968–1982
Crown–rump length discordance and adverse perinatal outcome in twin pregnancies: systematic review and meta‐analysis
Authors: D'Antonio F. , Khalil A. , Pagani G. , Papageorghiou A. T. , Bhide A. , Thilaganathan B.
Published: February 2014

Objective

The aim of this systematic review was to explore the relationship between crown–rump length (CRL) discordance detected at 11–14 weeks of gestation and adverse outcome in twin pregnancy and to assess its predictive accuracy.

Methods

A protocol designed a priori following MOOSE guidelines and recommended for systematic review and meta‐analysis was used. The outcomes observed were: total fetal and perinatal loss, fetal loss at < 24 weeks, fetal loss at ≥ 24 weeks, birth‐weight (BW) discordance, preterm delivery (PTD) at < 34 weeks and fetal anomalies. The analysis was performed for all twins and for dichorionic (DC) and monochorionic (MC) twins separately.

Results

A total of 2008 articles were identified and 17 studies were included in the systematic review. Twin pregnancies with CRL discordance ≥ 10% were at significantly higher risk of perinatal loss (RR, 2.80; 95% CI, 1.25−6.27; P = 0.012), fetal loss at ≥ 24 weeks (RR, 4.07; 95% CI, 1.47−11.23; P = 0.006), BW discordance (RR, 2.24; 95% CI, 1.89–2.64; P < 0.001) and PTD at < 34 weeks (RR, 1.49; 95% CI, 1.23−1.80; P < 0.001) but not of fetal loss at < 24 weeks (P = 0.130). A meta‐analysis of fetal anomalies was not possible because fewer than two studies explored this outcome. However, when used alone to screen for adverse pregnancy outcome, the predictive accuracy of CRL discordance was low for each of the outcomes explored.

Conclusion

CRL discordance is associated with an increased risk of adverse pregnancy outcome. However, the accuracy of CRL discordance in predicting adverse outcome is poor and thus limits its routine use in clinical practice. Copyright © 2014 ISUOG. Published by John Wiley & Sons Ltd
Communicating adaptation to climate change: the art and science of public engagement when climate change comes home
Authors: Moser Susanne C.
Published: February 2014

This article synthesizes relevant literature and examples from practice to examine what is known to date about communicating climate change adaptation. It explores the language used to discuss adaptation, what is known about resonant frames, drawing on adaptation discourses in policy, practice, and the media. Identifying trends and widely applicable insights is made challenging not only by the variety of words used to speak of adaptation, but by the fact that ‘adaptation’ language is often not used at all. A broad literature on perceptions and experiences of climate change impacts and how these experiences affect people's valuations and emotional responses to climate change offers crucial insights to the challenges and opportunities in communicating adaptation. It reveals much about people's interest in and acceptability and knowledge of adaptation, about preferred timing and who is thought to be responsible for enacting adaptive actions. Insights from the literature on place attachment and place identity are of particular relevance to public engagement on adaptation as it goes a long way toward explaining the quality of the adaptation debate to date while offering promising opportunities for dialogue. Suggestions for improved adaptation communication practice and critical research gaps are offered.

This article is categorized under:

Perceptions, Behavior, and Communication of Climate Change > Communication

Vulnerability and Adaptation to Climate Change > Institutions for Adaptation
Models of language evolution and change
Authors: Smith Andrew D.M.
Published: February 2014

In the absence of direct evidence of the emergence of language, the explicitness of formal models which allow the exploration of interactions between multiple complex adaptive systems has proven to be an important tool. Computational simulations have been at the heart of the field of evolutionary linguistics for the past two decades, particularly through the language game and iterated learning paradigms, but these are now being extended and complemented in a number of directions, through formal mathematical models, language‐ready robotic agents, and experimental simulations in the laboratory.

This article is categorized under:

Linguistics > Computational Models of Language

Linguistics > Evolution of Language
Applied statistics for extreme wind estimate
Authors: Castellani Francesco , Garinei Alberto , Terzi Ludovico , Astolfi Davide
Published: February 2014

The assessment of extreme wind speeds is a crucial issue for securing structural safety of wind turbines and inquiring largest loads to which turbines must be prepared to undergo.

International standards suggest applying the Gumbel method of fitting the annual maxima to their theoretic probability distribution. Yet, often, wind databases are too short to apply such methods with statistical significance, and other procedures are commonly adopted [such as peaks over threshold (POT) and independent storms], which involve dependency on arbitrary thresholds for filtering data and issues of sub‐asymptocity, i.e. how well the selected dataset fits to density functions describing the distribution of peaks or extreme values.

The present paper aims at contributing to such currently ongoing debate, providing a statistical analysis of the application of POT and independent storms methods on wind time series of various lengths from different geographical areas.

The CERN data analysis framework ROOT has been employed for guaranteeing excellent standards of computational precision and wealth of statistical information. Analysis of uncertainties in the wind speeds estimates and tests of the goodness of fit of the datasets to the proper distributions have been carried on. An algorithm for choosing the optimum thresholds was developed, which encapsules and compromises the statistical complexity of the methods. A declustering procedure has been carried on for discriminating proper peaks in the POT method: it has been tested that such declustering provides a dramatic improvement of the statistical quality of the method. Copyright © 2014 John Wiley & Sons, Ltd.
A novel in vivo model of tau propagation with rapid and progressive neurofibrillary tangle pathology: the pattern of spread is determined by connectivity, not proximity
Authors: Ahmed Zeshan , Cooper Jane , Murray Tracey K. , Garn Katya , McNaughton Emily , Clarke Hannah , Parhizkar Samira , Ward Mark A. , Cavallini Annalisa , Jackson Samuel , Bose Suchira , Clavaguera Florence , Tolnay Markus , Lavenir Isabelle , Goedert Michel , Hutton Michael L. , O’Neill Michael J.
Published: February 2014

Intracellular inclusions composed of hyperphosphorylated filamentous tau are a hallmark of Alzheimer’s disease, progressive supranuclear palsy, Pick’s disease and other sporadic neurodegenerative tauopathies. Recent in vitro and in vivo studies have shown that tau aggregates do not only seed further tau aggregation within neurons, but can also spread to neighbouring cells and functionally connected brain regions. This process is referred to as ‘tau propagation’ and may explain the stereotypic progression of tau pathology in the brains of Alzheimer’s disease patients. Here, we describe a novel in vivo model of tau propagation using human P301S tau transgenic mice infused unilaterally with brain extract containing tau aggregates. Infusion-related neurofibrillary tangle pathology was first observed 2 weeks post-infusion and increased in a stereotypic, time-dependent manner. Contralateral and anterior/posterior spread of tau pathology was also evident in nuclei with strong synaptic connections (efferent and afferent) to the site of infusion, indicating that spread was dependent on synaptic connectivity rather than spatial proximity. This notion was further supported by infusion-related tau pathology in white matter tracts that interconnect these regions. The rapid and robust propagation of tau pathology in this model will be valuable for both basic research and the drug discovery process.
Efficacy and safety of ipilimumab in patients with advanced melanoma and brain metastases
Authors: Queirolo Paola , Spagnolo Francesco , Ascierto Paolo Antonio , Simeone Ester , Marchetti Paolo , Scoppola Alessandro , Del Vecchio Michele , Di Guardo Lorenza , Maio Michele , Di Giacomo Anna Maria , Antonuzzo Andrea , Cognetti Francesco , Ferraresi Virginia , Ridolfi Laura , Guidoboni Massimo , Guida Michele , Pigozzo Jacopo , Chiarion Sileni Vanna
Published: February 2014

Patients with melanoma brain metastases have a poor prognosis and historically have been excluded from clinical trials. The Expanded Access Program (EAP) provided an opportunity to evaluate the feasibility of ipilimumab (3 mg/kg every 3 weeks for four doses) in patients with stage 3 (unresectable) or 4 melanoma and asymptomatic brain metastases, who had failed or did not tolerate previous treatments and had no other therapeutic option available. Tumor assessments were conducted at baseline and week 12 using immune-related response criteria and patients were monitored for adverse events (AEs). Of 855 patients participating in the EAP in Italy, 146 had asymptomatic brain metastases. With a median follow-up of 4 months, the global disease control rate was 27 %, including 4 patients with a complete response and 13 with a partial response. Median progression-free survival and overall survival were 2.8 and 4.3 months, respectively and approximately one-fifth of patients were alive 1 year after starting ipilimumab. In total, 29 % of patients reported a treatment-related AE of any grade, which were grade 3/4 in 6 % of patients. AEs were generally reversible with treatment as per protocol-specific guidelines. Ipilimumab shows durable benefits in some patients with advanced melanoma metastatic to the brain, with safety results consistent with those previously reported in clinical trials.
Curvatures of the DIP Joints of the Hand
Authors: Graham Kraig S. , Goitz Robert J. , Kaufmann Robert A.
Published: February 2014

Background

The distal interphalangeal (DIP) joints of the hand are highly susceptible to osteoarthritis and trauma. Surgical treatment options mandate accurate characterization of their osseous anatomy; however, there are few studies that describe this. We describe the curvatures of the DIP joints by measuring the bone morphology using advanced imaging and modeling methods.

Methods

The fingers of 16 right hand fresh frozen human cadavers were analyzed. Fingers showing signs of DIP joint arthritis were excluded. The fingers were scanned using microtomography (microCT). Measurements of the bony morphology were made using models created from the scans.

Results

In each finger, there is no statistically significant difference between the radii of curvature of the ulnar and radial condyles of the middle phalanx head. Conversely, the radius of curvature of the distal phalanx ulnar groove is significantly greater than that of the radial groove. The radii of curvature of the groove of the distal phalanx and the condyles of the middle phalanx displayed nonconformity with disparity increasing from the index to small fingers. Remarkably, the radius of curvature of the distal phalanx central ridge and the mean radius of the middle phalanx condyles are essentially the same.

Conclusion

The purpose of this study is to gain better insight into the DIP joints of the hand. The asymmetry between the distal phalanx grooves and the middle phalanx condyles suggests that there may be a translational component to DIP joint motion. Our understanding of morphology may lend insight into the biomechanics and disease progression within the DIP joints.
Structure and Physical Properties of Plant Wax Crystal Networks and Their Relationship to Oil Binding Capacity
Authors: Blake Alexia I. , Co Edmund D. , Marangoni Alejandro G.
Published: February 2014

The microstructure, melting and crystallization behavior, rheological properties and oil binding capacity of crystalline networks of plant‐derived waxes in edible oil were studied and then compared amongst different wax types. The critical concentrations for oleogelation of canola oil by rice bran wax (RBX), sunflower wax, candelilla wax, and carnauba wax were 1, 1, 2, and 4 %, respectively, suggesting RBX and sunflower wax are more efficient structurants. A phenomenological two‐phase exponential decay model was implemented to quantify the oil‐binding capacity of these oleogels. Parameters obtained from this empirical model were then evaluated against microscale structural attributes such as crystal size, mass distribution and porosity to determine the structural dependence of oil‐binding capacity. Gels containing candelilla wax exhibited the greatest oil‐binding capacity, as they retained nearly 90 % of their oil. This is due to the small crystal size as well as the spatial distribution of these crystals. Using a microscopic to macroscopic approach, this study examines how the structural characteristics unique to each wax and resulting oleogel system affect functionality and macroscopic behavior.
Assessing skeletal muscle mass: historical overview and state of the art
Authors: Heymsfield Steven B. , Adamek Michael , Gonzalez M. Cristina , Jia Guang , Thomas Diana M.
Published: February 2014

Background

Even though skeletal muscle (SM) is the largest body compartment in most adults and a key phenotypic marker of sarcopenia and cachexia, SM mass was until recently difficult and often impractical to quantify in vivo. This review traces the historical development of SM mass measurement methods and their evolution to advances that now promise to provide in‐depth noninvasive measures of SM composition.

Methods

Key steps in the advancement of SM measurement methods and their application were obtained from historical records and widely cited publications over the past two centuries. Recent advances were established by collecting information on notable studies presented at scientific meetings and their related publications.

Results

The year 1835 marks the discovery of creatine in meat by Chevreul, a finding that still resonates today in the D3‐creatine method of measuring SM mass. Matiegka introduced an anthropometric approach for estimating SM mass in 1921 with the vision of creating a human “capacity” marker. The 1940s saw technological advances eventually leading up to the development of ultrasound and bioimpedance analysis methods of quantifying SM mass in vivo. Continuing to seek an elusive SM mass “reference” method, Burkinshaw and Cohn introduced the whole‐body counting‐neutron activation analysis method and provided some of the first detailed reports of cancer cachexia in the late 1970s. Three transformative breakthroughs leading to the current SM mass reference methods appeared in the 1970s and early 1980s as follows: the introduction of computed tomography (CT), photon absorptiometry, and magnetic resonance (MR) imaging. Each is advanced as an accurate and/or practical approach to quantifying whole‐body and regional SM mass across the lifespan. These advances have led to a new understanding of fundamental body size‐SM mass relationships that are now widely applied in the evaluation and monitoring of patients with sarcopenia and cachexia. An intermediate link between SM mass and function is SM composition. Advances in water‐fat MR imaging, diffusion tensor imaging, MR elastography, imaging of connective tissue structures by ultra‐short echo time MR, and other new MR approaches promise to close the gap that now exists between SM anatomy and function.

Conclusions

The global efforts of scientists over the past two centuries provides us with highly accurate means by which to measure SM mass across the lifespan with new advances promising to extend these efforts to noninvasive methods for quantifying SM composition.
Medical students with low self-efficacy bolstered by calling to medical speciality
Authors: Goodin Joel B. , D’Brot Vanessa M. , Duffy Ryan D. , Borges Nicole J. , Ulman Catherine A. , Manuel R. Stephen
Published: February 2014

This study was performed to understand the degree to which medical students’ self-efficacy (SE) moderates the influence of calling on students’ speciality commitment, emphasizing the need to understand variables that predict primary care specialization. The researchers hypothesized that students who perceived their career as a calling would be more committed to their speciality, especially when students had high SE. Medical students (Years 1–4; N = 152) completed an online survey to rate their calling, speciality commitment, and SE. Calling was measured by the Brief Calling scale (Dik et al., J Career Assess 20:242–263, 2012), while speciality choice was measured by Hollenbeck et al. (J Appl Psychol 74:18–23, 1989) measure of commitment. SE was measured by the Jerusalem and Schwarzer's general SE scale (see Scholz et al., Eur J Psychol Assess 18:242–51, 2002). Calling (r = 0.24, p < 0.01) and SE (r = 0.20, p < 0.05) were found to moderately correlate with speciality commitment, thus emphasizing the possibility that they may have an interaction. The interaction of calling and SE significantly predicted speciality commitment (β = −0.20, t(148) = −2.55, p < 0.05) and explained a significant proportion of variance in speciality commitment (R 2 = 0.12, F(3, 148) = 6.875, p < 0.001). Students with a high presence of calling may have high speciality commitment, despite low SE.
Eroding Trust – an Agent Based Model to Explore how Trust Flows
Authors: Doloswala Kalika Navin
Published: February 2014

The emergence and deterioration of trust between agents is a critical feature of many open distributed systems. This paper reports on a simulation of one aspect of relationships: the behaviour of peer groups when confronted with lying. It presents an abstract model of shared cognitive space, using NetLogo, where agents (1) determine a perception of trust towards other agents, (2) interrogate nearby agents, and (3) reassess their perceptions of trust based on judgements of others. (4) Some agents are discovered to be liars, (5) causing agents to move away from the liar in their cognitive space. Group cohesion is tested by varying (i) decay of agents’ memory, (ii) penalty for lying, (iii) proportion of liars, (iv) probability of discovery, and (v) distance an agents moves away from a liar in cognitive space. We find that penalty for lying has little effect on group cohesion, but the other factors can cause significant disruption.
PTPLAD2 is a tumor suppressor in esophageal squamous cell carcinogenesis
Authors: Zhu Shaojun , Wang Zhipeng , Zhang Zhipei , Wang Jian , Li Yanhong , Yao Li , Mei Qibing , Zhang Wei
Published: February 2014

Esophageal squamous cell carcinomas (ESCCs) are highly invasive and have poor prognoses. We investigated the role of PTPLAD2, a protein tyrosine phosphatase‐like A domain (PTPLAD) family member, in ESCC carcinogenesis. Survival analysis was performed using patient data. ESCC tissue samples lost PTPLAD2 heterozygosity and had decreased PTPLAD2 expression. Low PTPLAD2 expression and high p‐STAT3 correlated with poor prognosis. Overexpression of PTPLAD2 in ESCC cells reduced STAT3 phosphorylation, decreased FoxM1, inhibited proliferation and decreased in mouse xenograft tumor formation. Therefore, PTPLAD2 is a potential tumor suppressor and prognostic indicator that reduces STAT3 phosphorylation. PTPLAD2 is a possible clinical target for ESCC treatment.
Global gene expression changes induced by prolonged cold ischemic stress and preservation method of breast cancer tissue
Authors: Aktas Bilge , Sun Hongxia , Yao Hui , Shi Weiwei , Hubbard Rebekah , Zhang Ya , Jiang Tingting , Ononye Sophia N. , Wali Vikram B. , Pusztai Lajos , Symmans W. Fraser , Hatzis Christos
Published: February 2014

Background

Tissue handling can alter global gene expression potentially affecting the analytical performance of genomic signatures, but such effects have not been systematically evaluated.

Methods

Tissue samples from 11 previously untreated breast tumors were minced and aliquots were either snap frozen or placed in RNAlater immediately or after 20, 40, 60, 120 or 180 min at room temperature. RNA was profiled on Affymetrix HG‐U133A arrays. We used probe‐set‐wise hierarchical models to evaluate the effect of preservation method on transcript expression and linear mixed effects models to assess the effect of cold ischemic delay on the expression of individual probe sets. Gene set enrichment analysis identified pathways overrepresented in the affected transcripts. We combined the levels of 41 most sensitive transcripts to develop an index of ischemic stress.

Results

Concordance in global gene expression between the baseline and 40 min delay was higher for samples preserved in RNAlater (average concordance correlation coefficient CCC = 0.92 compared to 0.88 for snap frozen). Overall, 481 transcripts (3%) were significantly affected by the preservation method, most of them involved in processes important in cancer. Prolonged cold ischemic delay of up to 3 h induced marginal global gene expression changes (average CCC = 0.90 between baseline and 3 h delay). However 41 transcripts were significantly affected by cold ischemic delay. Among the induced transcripts were stress response genes, apoptotic response genes; among the downregulated were genes involved in metabolism, protein processing and cell cycle regulation. An index combining the expression levels of these genes was proportional to the cold ischemic delay.

Conclusions

Prolonged cold ischemia induces significant transcriptional changes in a small subset of transcripts in the tissue. Furthermore, the expression level of about 3% of the transcripts is affected by the preservation method. These sensitive transcripts should not be included in genomic signatures for more reliable analytical performance.
Role of chemokines in proteinuric kidney disorders
Authors: Moreno Juan Antonio , Moreno Sara , Rubio-Navarro Alfonso , Gómez-Guerrero Carmen , Ortiz Alberto , Egido Jesús
Published: February 2014

Experimental and human studies have shown that proteinuria contributes to the progression of renal disease. Overexposure to filtered proteins promotes the expression and release of chemokines by tubular epithelial cells, thus leading to inflammatory cell recruitment and renal impairment. This review focuses on recent progress in cellular and molecular understanding of the role of chemokines in the pathogenesis of proteinuria-induced renal injury, as well as their clinical implications and therapeutic potential.
Instability of an inhomogeneous bacterial suspension subjected to a chemo-attractant gradient
Authors: Kasyap T. V. , Koch Donald L.
Published: February 2014

The stability of a suspension of chemotactic bacteria confined in an infinitely long channel and subjected to a stationary, linear chemo-attractant gradient is investigated. While swimming, individual bacteria exert force dipoles on the fluid, which at the continuum level lead to a stress depending upon the bacterial orientation and number density fields. The presence of the attractant gradient causes bacteria to tumble less frequently when swimming along the gradient, leading to a mean orientation and a non-zero chemotactic drift velocity$U_0$in that direction. At long length and time scales compared to those associated with the persistence of bacterial swimming, fluxes due to chemotaxis and the random run–tumble motion of bacteria balance to yield an exponentially varying number density profile across the channel in the base state. The associated bacterial stress field is also exponentially varying and is normal. This spatially non-uniform base state is unstable to fluctuations in the bacterial concentration field when the scaled bacterial concentration$\beta = (3 C/8) \langle n_0\rangle L^2 H$exceeds a critical value determined by a Péclet number defined as${\mathit{Pe}} = U_0 H/\kappa $. Here,$C$is a non-dimensional dipole strength, which depends on the geometry of the bacterium,$\langle n_0\rangle $is the bacterial concentration averaged across the channel of depth$H$,$L$is the total length of the bacterium,$\kappa $is the bacterial diffusivity, and$\beta _{\mathit{crit}}$is a monotonically decreasing function of${\mathit{Pe}}$, with$\beta _{\mathit{crit}} \sim 720/{\mathit{Pe}}^3$for${\mathit{Pe}} \ll 1$and$\beta _{\mathit{crit}} \sim 2$for${\mathit{Pe}} \gg 1$. The instability is the result of the coupling between the active stress-driven fluid flow and the bacterial concentration, and manifests as rectangular convection patterns. When$\beta $first exceeds$\beta _{\mathit{crit}}$, the unstable wavelengths are large with$\lambda \gg H$and the mode of instability is stationary. Although oscillatory modes appear when$\lambda \leq O(H)$and$\beta > 247$, the most dangerous mode of instability is found to be always stationary with a wavelength$\lambda _m/H \sim {\mathit{Pe}}^{-1}$. To study the coupling between the previously analysed orientation shear instability mechanism of bacterial suspensions and the new chemotaxis-driven instability, a new set of continuum equations that consistently account for weak chemotaxis, rotation of bacteria by weak fluid shear and weak non-continuum effects along with their coupled effects has been derived. The stability analysis of those equations showed that the orientation shear mechanism has only a negligible influence on the critical concentration for the present chemotaxis-induced instability when the suspension depth is large, and it is the latter that has the lowest critical concentration.
Absolute instabilities in eccentric Taylor–Couette–Poiseuille flow
Authors: Leclercq Colin , Pier Benoît , Scott Julian F.
Published: February 2014

The effect of eccentricity on absolute instabilities (AI) in the Taylor–Couette system with pressure-driven axial flow and fixed outer cylinder is investigated. Five modes of instability are considered, characterized by a pseudo-angular order $m$, with here $\vert m\vert \leq 2$. These modes correspond to toroidal ($m=0$) and helical structures ($m\neq 0$) deformed by the eccentricity. Throughout the parameter range, the mode with the largest absolute growth rate is always the Taylor-like vortex flow corresponding to $m=0$. Axial advection, characterized by a Reynolds number ${\mathit{Re}_z}$, carries perturbations downstream, and has a strong stabilizing effect on AI. On the other hand, the effect of the eccentricity $e$ is complex: increasing $e$ generally delays AI, except for a range of moderate eccentricites ${0.3\lesssim e \lesssim 0.6}$, where it favours AI for large enough ${\mathit{Re}_z}$. This striking behaviour is in contrast with temporal instability, always inhibited by eccentricity, and where left-handed helical modes of increasing $\vert m\vert $ dominate for larger ${\mathit{Re}_z}$. The instability mechanism of AI is clearly centrifugal, even for the larger values of ${\mathit{Re}_z}$ considered, as indicated by an energy analysis. For large enough ${\mathit{Re}_z}$, critical modes localize in the wide gap for low $e$, but their energy distribution is shifted towards the diverging section of the annulus for moderate $e$. For highly eccentric geometries, AI are controlled by the minimal annular clearance, and the critical modes are confined to the vicinity of the inner cylinder. Untangling the AI properties of each $m$ requires consideration of multiple pinch points.
Sidewall effects in Rayleigh–Bénard convection
Authors: Stevens Richard J. A. M. , Lohse Detlef , Verzicco Roberto
Published: February 2014

We investigate the influence of the temperature boundary conditions at the sidewall on the heat transport in Rayleigh–Bénard (RB) convection using direct numerical simulations. For relatively low Rayleigh numbers $Ra$ the heat transport is higher when the sidewall is isothermal, kept at a temperature $T_c+\Delta /2$ (where $\Delta $ is the temperature difference between the horizontal plates and $T_c$ the temperature of the cold plate), than when the sidewall is adiabatic. The reason is that in the former case part of the heat current avoids the thermal resistance of the fluid layer by escaping through the sidewall that acts as a short-circuit. For higher $Ra$ the bulk becomes more isothermal and this reduces the heat current through the sidewall. Therefore the heat flux in a cell with an isothermal sidewall converges to the value obtained with an adiabatic sidewall for high enough $Ra$ (${\simeq }10^{10}$). However, when the sidewall temperature deviates from $T_c+\Delta /2$ the heat transport at the bottom and top plates is different from the value obtained using an adiabatic sidewall. In this case the difference does not decrease with increasing $Ra$ thus indicating that the ambient temperature of the experimental apparatus can influence the heat transfer. A similar behaviour is observed when only a very small sidewall region close to the horizontal plates is kept isothermal, while the rest of the sidewall is adiabatic. The reason is that in the region closest to the horizontal plates the temperature difference between the fluid and the sidewall is highest. This suggests that one should be careful with the placement of thermal shields outside the fluid sample to minimize spurious heat currents. When the physical sidewall properties (thickness, thermal conductivity and heat capacity) are considered the problem becomes one of conjugate heat transfer and different behaviours are possible depending on the sidewall properties and the temperature boundary condition on the ‘dry’ side. The problem becomes even more complicated when the sidewall is shielded with additional insulation or temperature-controlled surfaces; some particular examples are illustrated and discussed. It has been observed that the sidewall temperature dynamics not only affects the heat transfer but can also trigger a different mean flow state or change the temperature fluctuations in the flow and this could explain some of the observed differences between similar but not fully identical experiments.
What happens to food choices when a gluten-free diet is required? A prospective longitudinal population-based study among Swedish adolescent with coeliac disease and their peers
Authors: Kautto E. , Rydén P. J. , Ivarsson A. , Olsson C. , Norström F. , Högberg L. , Carlsson A. , Hagfors L. , Hörnell A.
Published: February 2014

A dietary survey was performed during a large screening study in Sweden among 13-year-old adolescents. The aim was to study how the intake of food groups was affected by a screening-detected diagnosis of coeliac disease (CD) and its gluten-free (GF) treatment. Food intake was reported using a FFQ, and intake reported by the adolescents who were diagnosed with CD was compared with the intake of two same-aged referent groups: (i) adolescents diagnosed with CD prior to screening; and (ii) adolescents without CD. The food intake groups were measured at baseline before the screening-detected cases were aware of their CD, and 12–18 months later. The results showed that food intakes were affected by screen-detected CD and its dietary treatment. Many flour-based foods were reduced such as pizza, fish fingers and pastries. The results also indicated that bread intake was lower before the screened diagnosis compared with the other studied groups, but increased afterwards. Specially manufactured GF products (for example, pasta and bread) were frequently used in the screened CD group after changing to a GF diet. The present results suggest that changing to a GF diet reduces the intake of some popular foods, and the ingredients on the plate are altered, but this do not necessarily include a change of food groups. The availability of manufactured GF replacement products makes it possible for adolescents to keep many of their old food habits when diagnosed with CD in Sweden.
Lower resting and total energy expenditure in postmenopausal compared with premenopausal women matched for abdominal obesity
Authors: Hodson Leanne , Harnden Karin , Banerjee Rajarshi , Real Belen , Marinou Kyriakoula , Karpe Fredrik , Fielding Barbara A.
Published: February 2014

The menopause is accompanied by increased risk of obesity, altered body fat distribution and decreased skeletal muscle mass. The resulting decrease in RMR should be accompanied by a compensatory change in energy balance to avoid weight gain. We aimed to investigate habitual energy intake and expenditure in pre- and postmenopausal women matched for abdominal obesity. We recruited fifty-one healthy Caucasian women, BMI > 18·5 and <35 kg/m2, aged 35–45 years (premenopausal, n 26) and 55–65 years (postmenopausal, n 25). Energy intake was measured using 3 d diet diaries and dietary fat quality assessed using adipose tissue fatty acid biomarkers. RMR was measured using indirect calorimetry, and total energy expenditure (TEE) and activity energy expenditure using a combined accelerometer and heart rate monitor. Postmenopausal women had lower RMR and TEE and spent significantly less time undertaking moderate exercise than premenopausal women. Postmenopausal women had a tendency for a lower energy intake, and a similar macronutrient intake but a significantly lower adipose tissue n-6:n-3 ratio (24·6 (se 1·6) v. 37·7 (se 3·1); P < 0·001). The main lifestyle determinant of bone mineral density (which was significantly lower in postmenopausal women) was TEE for premenopausal women, and dietary n-6:n-3 ratio for postmenopausal women. The present results suggest that weight maintenance is achieved in the post- compared with premenopausal status through a combination of reduced energy intake and reduced TEE in a regimen that compromises micronutrient intake and has a negative impact on lean tissue mass. However, lower n-6:n-3 fatty acid intake in postmenopausal women is associated with greater bone mineral density.
History 4°: Postcolonial Method and Anthropocene Time
Authors: Baucom Ian
Published: February 2014

The essay opens by situating Dipesh Chakrabarty’s recent work on climate change and the anthropocene (the new geological period of time in which humans have become a planet-reshaping “force of nature”) together with a broader contemporary discourse on the human/nonhuman in relation to Claude Lévi-Strauss and Jean Paul Sartre’s 1960s debate on the nature of history and the dialectic. Although not explicitly advanced under the sign of that debate, these recent discourses, I suggest, share and extend some of its crucial features, taking something from both sides. From Sartre: the call for a search for critical method adequate to addressing Marx’s observation that we make our own history, but not under circumstances of our own choosing. From Lévi-Strauss: the argument that “history” is inadequately addressed by the “historian’s code,” that the situation of our time encompasses multiple scales and orders of time: most significantly, an array of “extra-historical,” “infra-historical,” and “supra-historical” registers of human/nonhuman time. From there, I return to Chakrabarty, to discuss the ways in which his work takes up those twin challenges. I pursue this reading by considering the relation between his earlier conceptualization (inProvincializing Europe) of History 1 and History 2 and the new theory of history emerging from his work on climate change, which I call History 3. I conclude by suggesting that despite its enormously rich considerations of the multiscaled temporality of the anthropocene, Chakrabarty’s recent work also sometimes bends the time of climate linear in the progress toward catastrophe, thereby bypassing the full possibility of a multitemporal ontology of the present that would include the persistence into the anthropocene of History 1 and 2. I suggest, therefore, that while drawing on his recent work, we need to continue in a search for a method adequate to the situation of our time; a time that knots together (minimally) Histories 1, 2, and 3; a time that I am provisionally calling History 4°.