bluuebunny/crossref_metadata_2025 huggingface dataset:
High excitation density recombination dynamics in InGaN/GaN quantum well structures in the droop regime
Authors: Davies Matthew J. , Badcock Tom J. , Dawson Philip , Oliver Rachel A. , Kappers Menno J. , Humphreys Colin J.
Published: February 2014

We report on the low temperature time‐integrated and time‐resolved photoluminescence properties of an (0001) InGaN/GaN multiple quantum well structure. From excitation power dependent studies, we observe a clear correlation between the onset of efficiency droop and the broadening of the time‐integrated luminescence spectra. Time‐resolved spectroscopy reveals that this spectral broadening is associated with a large and rapid red‐shift of the spectrum with increasing time after the excitation pulse. This dynamic shift of the spectrum also modifies the form of the luminescence transients, yet the spectrally integrated luminescence dynamics have the same non‐exponential shape as those obtained under much lower excitation levels. This observation is consistent with the emission originating from the recombination of independently localised carriers, even under very high excitation levels. Nevertheless, at these high excitation levels we propose that there also is a population of weakly localised carriers, probably electrons. We suggest that these more mobile carriers are effective in screening the built‐in electric field across the quantum well as well as being more susceptible to non‐radiative loss. The collapse in this population, due to radiative and non‐radiative recombination, restores the built‐in polarisation induced field and results in the observed time dependent redshift of the luminescence spectrum. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Native seeding and silicon doping in bulk growth of AlN single crystals by PVT method
Authors: Radhakrishnan Sumathi R.
Published: February 2014

Homo‐epitaxial growth of AlN crystals using native seeds prepared from our hetero‐epitaxial AlN/SiC template crystals has been successfully carried out. Single crystals of acceptable structural properties with XRD‐RC FWHM of 150 arcsec, Raman E2(high) phonon mode FWHM of 9 cm‐1 and with low concentrations of background impurities (below the detection limit of EPMA) were obtained. An effort has been made to obtain n‐type conductivity in the PVT grown AlN single crystals through intentional Si‐doping during bulk growth. The investigations using EPMA and micro‐Raman measurements confirm that it is possible to incorporate intentionally the Si atoms in the bulk AlN host lattice without any kind of Si inclusions or precipitates. Structural quality of the Si‐doped crystals was almost same as that of the native seed crystal. Si‐doping induces a compressive strain in the doped AlN crystals as seen from the 5 cm–1 shift (blue shift) in the Raman E2(high) peak position. EPR measurement gives first evidence of the presence of shallow level Si donor in the grown crystal, though the free‐carrier concentrations are quite low for a semiconductor doping. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Europium‐doped GaN(Mg): beyond the limits of the light‐emitting diode
Authors: O'Donnell K. P. , Edwards P. R. , Kappers M. J. , Lorenz K. , Alves E. , Boćkowski M.
Published: February 2014

Rare‐earth doped III‐N semiconductors have been studied for decades on account of their possible application in visible light‐emitting diodes (LED) with built‐in utility as red (e.g. Eu), green (Er) and blue (Tm) monochromatic sources (O'Donnell and Dierolf (eds.), Topics in Applied Physics, Vol. 124 (Springer, Dordrecht, 2010) [1]). However, to date, no commercial devices have been introduced on the basis of these materials. Recently, we discovered thermally activated hysteresis in the emission spectrum of p‐type GaN thin films that were co‐doped with Mg and Eu (O'Donnell et al., Proc. ICPS31, Zurich, July 2012 [2]). We have also reported an unexpected Zeeman splitting and induced magnetic moment of Eu3+ ions in GaN (Kachkanov et al., Scientific Rep. 2, 969 (2012) and MRS Proc. 1290–i03–06 (2011) [3, 4]). These findings encourage speculation on taking the study of RE‐doped III‐N beyond the limited goal of improving LED efficiency into the realm of novel magneto‐optic and quantum‐optical devices. In particular we will describe in this presentation the spectroscopy of ion‐implanted and annealed GaN(Mg): Eu samples and the possible exploitation of the Mg acceptor in GaN as a qubit. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Assessing the Efficiency of an Elver Ladder Using a Multi‐State Mark–Recapture Model
Authors: Drouineau H. , Rigaud C. , Laharanne A. , Fabre R. , Alric A. , Baran P.
Published: February 2014

The decline of the European eel (Anguilla anguilla) stock has led the European Commission to enforce a regulation (Council Regulation N° 1100/2007), in which each member state was required to establish an eel management plan. Various measures in the French plan aim at restoring river connectivity by mitigating the impact of obstacles on the colonization of continental water by eels. Consequently, many obstacles are going to be equipped with elver ladder in the near future. In this context, a method to assess the passability of an obstacle seems essential. In this study, we developed a tag–recapture method, appropriate to glass eels and elvers, and an associated multi‐state mark–recapture model (i) to assess the passability of a ladder and (ii) to quantify the effect of various environmental factors on this passability. An application to a specific obstacle is applied as an illustrative example that demonstrates the relevance of the assessment method, and how the results can be used to propose technical solution to improve the efficiency of the ladder. Nine tag–recapture campaigns were carried on this obstacle, and about 4400 young eels were tagged. The model demonstrates that the efficiency of the ladder was rather low, especially during low river flow periods, mainly because of accessibility problems. The model also demonstrates the major influence of the river flow on the probability for an eel to pass the ladder; consequently, managing river flow during the migration period can be a relevant measure to improve river connectivity and facilitate colonization of the watershed. Copyright © 2014 John Wiley & Sons, Ltd.
Copy Number Variation in CCND1 Gene Is Implicated in the Pathogenesis of Sporadic Parathyroid Carcinoma
Authors: Zhao Lin , Sun Li‐hao , Liu Dong‐mei , He Xiao‐yan , Tao Bei , Ning Guang , Liu Jian‐min , Zhao Hong‐yan
Published: February 2014

Background

The molecular bases for parathyroid carcinomas present in conjunction with sporadic primary hyperparathyroidism are not fully elucidated. Gene copy number variations (CNVs) play an important role in tumorigenesis. The aim of the current study was to explore whether the CNVs of specific tumor‐associated genes are involved in parathyroid carcinogenesis.

Methods

A multiplex ligation‐dependent probe amplification method was used to compare differences in copy number in 39 common tumor‐associated genes among 7 patients with parathyroid carcinoma and 14 age‐ and sex‐matched subjects with parathyroid adenoma.

Results

It was shown that amplification of CCND1, a gene encoding cyclin D1, was more prevalent in parathyroid carcinomas than in adenomas (71 vs. 21 %, p = 0.056). This result was confirmed quantitatively by real‐time polymerase chain reaction. Expression of CCND1 mRNA level was significantly higher in carcinomas than in adenomas (p = 0.003). Western blot and immunohistochemical analysis also demonstrated higher expression of CCND1 in carcinoma specimens than in adenoma samples.

Conclusions

It is thus inferred that gain in copy number of CCND1 is implicated in the molecular pathogenesis of parathyroid carcinoma.
Personalized Genomic Results: Analysis of Informational Needs
Authors: Schmidlen Tara J. , Wawak Lisa , Kasper Rachel , García‐España J. Felipe , Christman Michael F. , Gordon Erynn S.
Published: February 2014

Use of genomic information in healthcare is increasing; however data on the needs of consumers of genomic information is limited. The Coriell Personalized Medicine Collaborative (CPMC) is a longitudinal study investigating the utility of personalized medicine. Participants receive results reflecting risk of common complex conditions and drug—gene pairs deemed actionable by an external review board. To explore the needs of individuals receiving genomic information we reviewed all genetic counseling sessions with CPMC participants. A retrospective qualitative review of notes from 157 genetic counseling inquiries was conducted. Notes were coded for salient themes. Five primary themes; “understanding risk”, “basic genetics”, “complex disease genetics”, “what do I do now?” and “other” were identified. Further review revealed that participants had difficulty with basic genetic concepts, confused relative and absolute risks, and attributed too high a risk burden to individual single nucleotide polymorphisms (SNPs). Despite these hurdles, counseled participants recognized that behavior changes could potentially mitigate risk and there were few comments alluding to an overly deterministic or fatalistic interpretation of results. Participants appeared to recognize the multifactorial nature of the diseases for which results were provided; however education to understand the complexities of genomic risk information was often needed.
Adalimumab versus infliximab for the treatment of moderate to severe ulcerative colitis in adult patients naïve to anti-TNF therapy: An indirect treatment comparison meta-analysis
Authors: Thorlund Kristian , Druyts Eric , Mills Edward J. , Fedorak Richard N. , Marshall John K.
Published: February 2014

Objective

To compare the efficacy of adalimumab and infliximab for the treatment of moderate to severe ulcerative colitis using indirect treatment comparison meta-analysis.

Methods

A systematic review and Bayesian indirect treatment comparison meta-analyses were performed for seven patient-important clinical outcomes at 8 weeks and 52 weeks. Odds ratio (OR) estimates and associated 95% credible intervals (CrIs) were produced.

Results

Five eligible RCTs informed clinical remission, response, mucosal healing, quality of life, colectomy, serious adverse events, and discontinuation due to adverse events at 8 weeks and 52 weeks. At 8 weeks of induction therapy, clinical remission (OR = 0.42, 95% CrI 0.17–0.97), clinical response (OR = 0.45, 95% CrI 0.23–0.89) and mucosal healing (OR = 0.46, 95% CrI 0.25–0.86) statistically favored infliximab. However, after 52 weeks of maintenance therapy OR estimates showed no significant difference between infliximab and adalimumab. For serious adverse events and discontinuations due to adverse events, adalimumab and infliximab were similar to placebo. Further, the indirect treatment comparison of adalimumab and infliximab yielded odds ratios close to 1.00 with wide credible intervals.
The dark sides of amyloid in Alzheimer's disease pathogenesis
Authors: Sorrentino Pierpaolo , Iuliano Antonietta , Polverino Arianna , Jacini Francesca , Sorrentino Giuseppe
Published: February 2014

Although widely explored, the pathogenesis of Alzheimer's disease (AD) has yet to be cleared. Over the past twenty years the so call amyloid cascade hypothesis represented the main research paradigm in AD pathogenesis. In spite of its large consensus, the proposed role of β‐amyloid (Aβ) remain to be elucidated. Many evidences are starting to cast doubt on Aβ as the primary causative factor in AD. For instance, Aβ is deposited in the brain following many different kinds of injury. Also, concentration of Aβ needed to induce toxicity in vitro are never reached in vivo. In this review we propose an amyloid‐independent interpretation of several AD pathogenic features, such as synaptic plasticity, endo‐lysosomal trafficking, cell cycle regulation and neuronal survival.
The role of connexin40 in developing atrial conduction
Authors: Benes Jiri , Ammirabile Grazia , Sankova Barbora , Campione Marina , Krejci Eliska , Kvasilova Alena , Sedmera David
Published: February 2014

Connexin40 (Cx40) is the main connexin expressed in the murine atria and ventricular conduction system. We assess here the developmental role of Cx40 in atrial conduction of the mouse. Cx40 deficiency significantly prolonged activation times in embryonic day 10.5, 12.5 and 14.5 atria during spontaneous activation; the severity decreased with increasing age. In a majority of Cx40 deficient mice the impulse originated from an ectopic focus in the right atrial appendage; in such a case the activation time was even longer due to prolonged activation. Cx40 has thus an important physiological role in the developing atria.
Induction of microRNA‐138 by pro‐inflammatory cytokines causes endothelial cell dysfunction
Authors: Sen Anagha , Most Patrick , Peppel Karsten
Published: February 2014

Exposure to pro‐inflammatory cytokines, such as Angiotensin II, endothelin‐1 or TNF leads to endothelial dysfunction, characterized by the reduced production of nitric oxide via endothelial nitric oxide synthase (eNOS). We recently identified the Ca2+ binding protein S100A1 as an essential factor required for eNOS activity. Here we report that pro‐inflammatory cytokines down‐regulate expression of S100A1 in primary human microvascular endothelial cells (HMVECs) via induction of microRNA‐138 (miR‐138), in a manner that depends on the stabilization of HIF1‐α. We show that loss of S100A1 in ECs reduces stimulus‐induced NO production, which can be prevented by inhibition of miR‐138. Our study suggests that targeting miR‐138 might be beneficial for the treatment of cardiovascular disease.
Functional analysis of the C‐terminal region of the vacuolar cadmium‐transporting rice OsHMA3
Authors: Kumagai Saori , Suzuki Tatsuya , Tezuka Kouichi , Satoh-Nagasawa Namiko , Takahashi Hidekazu , Sakurai Kenji , Watanabe Akio , Fujimura Tatsuhito , Akagi Hiromori
Published: February 2014

Rice OsHMA3 is a vacuolar cadmium (Cd) transporter belonging to the P1B‐ATPase family and has a long (273aa) C‐terminal region. We analyzed the function of the region related to Cd using the transgenic Arabidopsis Col‐0 ecotype, which is sensitive to Cd. The OsHMA3 variant containing a truncated (58aa) C‐terminal region did not confer Cd tolerance, whereas an OsHMA3 variant containing a longer truncated (105aa) C‐terminal region conferred Cd tolerance to transgenic Arabidopsis. We conclude that the C‐terminal region, particularly the region containing the first 105aa, has an important role in OsHMA3 activity.
Peripherally administrated prions reach the brain at sub‐infectious quantities in experimental hamsters
Authors: Chen Baian , Soto Claudio , Morales Rodrigo
Published: February 2014

The mechanisms implicated in prion infection and tissue distribution are not completely understood. In this study we investigated the levels of 263K prions in brain and spleen of Syrian hamsters few days after intra‐peritoneal challenge. For this purpose we utilized the PMCA technology which permits to detect as little as few PrPSc molecules. Our results show that peripherally administered prions directly reach the brain, although at levels below the minimum necessary to produce disease. PrPSc remains in the brain several days after administration suggesting inefficient clearance or early replication. Understanding the fate of the infectious agent after administration and its uptake in different organs and fluids may provide useful information to develop strategies to minimize further spreading of prion diseases.
H3K9 histone methyltransferase G9a‐mediated transcriptional activation of p21
Authors: Oh Si-Taek , Kim Kee-Beom , Chae Yun-Cheol , Kang Joo-Young , Hahn Yoonsoo , Seo Sang-Beom
Published: February 2014

We report that H3K9 HMTase G9a activates transcription of the cell cycle regulatory gene, p21, in p53‐null H1299 cells. Positive regulation of p21 by G9a is independent of its HMTase activity. We demonstrate that G9a upregulates p21 via interaction with PCAF, and provide evidence that the activating complex is recruited to the p21 promoter upon DNA damage‐inducing agent etoposide treatment. Our study suggests that G9a decreases proliferation and cell viability by increasing the level of p21‐mediated apoptosis. Our results suggest that G9a functions as a coactivator for p21 transcription, and directs cells to undergo apoptosis.
Trps1 is associated with the multidrug resistance of osteosarcoma by regulating MDR1 gene expression
Authors: Jia Ming , Hu Jing , Li Weiwei , Su Peng , Zhang Hui , Zhang Xiaofang , Zhou Gengyin
Published: February 2014

Multidrug resistance (MDR) is a significant clinical problem in the chemotherapy of osteosarcoma and has been linked to the cellular expression of several multidrug‐efflux transporters such as MDR1/P‐gp. Our inhibition of the transcription factor Trps1 led to repression of MDR1/P‐gp while its overexpression resulted in upregulation of MDR1/P‐gp. Flow cytometric analysis suggested Trps1 increased the release of several anti‐cancer drugs, thus decreasing their accumulation. Immunohistochemical analysis of clinical samples indicated that the expression of Trps1 directly correlated with MDR1/P‐gp. Trps1 inhibited TGFbeta‐1 and directly bound to the MDR1 promoter. Our data demonstrate a role for Trps1 in the regulation of MDR1 expression in osteosarcoma.
Structure and closure of connexin gap junction channels
Authors: Oshima Atsunori
Published: February 2014

Connexin gap junctions comprise assembled channels penetrating two plasma membranes for which gating regulation is associated with a variety of factors, including voltage, pH, Ca2+, and phosphorylation. Functional studies have established that various parts of the connexin peptides are related to channel closure and electrophysiology studies have provided several working models for channel gating. The corresponding structural models supporting these findings, however, are not sufficient because only small numbers of closed connexin structures have been reported. To fully understand the gating mechanisms, the channels should be visualized in both the open and closed states. Electron crystallography and X‐ray crystallography studies recently revealed three‐dimensional structures of connexin channels in a couple of states in which the main difference is the conformation of the N‐terminal domain, which have helped to clarify the structure in regard to channel closure. Here the closure models for connexin gap junction channels inferred from structural and functional studies are described in the context of each domain of the connexin protein associated with gating modulation.
Synthetic crowding agent dextran causes excluded volume interactions exclusively to tracer protein apoazurin
Authors: Christiansen Alexander , Wittung-Stafshede Pernilla
Published: February 2014

To understand protein biophysics in crowded cellular environments, researchers often use synthetic polymers as ‘crowding agents’ in vitro. The idea is that these agents will occupy space and reproduce the in vivo scenario in terms of excluded volume. However, recent work has challenged this concept and pointed out that attractive interactions between protein and crowding agent will provide an enthalpic contribution to the overall effect on protein thermodynamics. Here we use a typical synthetic crowding agent and a well‐studied model protein to demonstrate in a window of 50 K that the presence of dextran 20 affects apoazurin by steric repulsion.
A plausible model for bimodal p53 switch in DNA damage response
Authors: Sun Tingzhe , Cui Jun
Published: February 2014

p53 is a tumor suppressor and the p53 dynamics displays stimulus dependent patterns. Recent evidence suggests a bimodal p53 switch in cell fate decision. However, no theoretical studies have been proposed to investigate bimodal p53 induction. Here we constructed a model and showed that MDM2–p53 mRNA binding might contribute to bimodal p53 switch through an intrinsic positive feedback loop. Lower damage favored pulsing while monotonic increasing was generated with higher damage. Bimodal p53 dynamics was largely influenced by cellular MDM2 and elevated p53/MDM2 ratios with increasing etoposide favor mono‐ubiquitination. Our model replicated recent experiments and provided potential insights into dynamic mechanisms of bimodal switch.
Dissection of the role of p62/Sqstm1 in activation of Nrf2 during xenophagy
Authors: Ishimura Ryosuke , Tanaka Keiji , Komatsu Masaaki
Published: February 2014

Upon infection of a cell by Salmonella, p62/Sqstm1 assembles on the microbes; simultaneously, p62/Sqstm1 is phosphorylated at Ser351, leading to inactivation of Keap1, which is responsible for degrading Nrf2. Thus, cytoprotective Nrf2 targets are induced at the same time that autophagosomes entrap the microbes (xenophagy). However, the detailed role of p62/Sqstm1 during xenophagy has remained unclear. Here we show that translocation of p62/Sqstm1 to invasive Salmonella precedes Ser351 phosphorylation. Furthermore, in addition to Ser351 phosphorylation, oligomerization of p62/Sqstm1 is also required for localization of Keap1 onto microbes, which is followed by Nrf2 activation. Our data reveal the sequential dynamics of p62/Sqstm1 in response to bacterial infection.
End‐binding protein 1 (EB1) up‐regulation is an early event in colorectal carcinogenesis
Authors: Stypula-Cyrus Yolanda , Mutyal Nikhil N. , Dela Cruz Mart , Kunte Dhananjay P. , Radosevich Andrew J. , Wali Ramesh , Roy Hemant K. , Backman Vadim
Published: February 2014

End‐binding protein (EB1) is a microtubule protein that binds to the tumor suppressor adenomatous polyposis coli (APC). While EB1 is implicated as a potential oncogene, its role in cancer progression is unknown. Therefore, we analyzed EB1/APC expression at the earliest stages of colorectal carcinogenesis and in the uninvolved mucosa (“field effect”) of human and animal tissue. We also performed siRNA‐knockdown in colon cancer cell lines. EB1 is up‐regulated in early and field carcinogenesis in the colon, and the cellular/nano‐architectural effect of EB1 knockdown depended on the genetic context. Thus, dysregulation of EB1 is an important early event in colon carcinogenesis.
EGF induces efficient Cx43 gap junction endocytosis in mouse embryonic stem cell colonies via phosphorylation of Ser262, Ser279/282, and Ser368
Authors: Fong John T. , Nimlamool Wutigri , Falk Matthias M.
Published: February 2014

Gap junctions (GJs) traverse apposing membranes of neighboring cells to mediate intercellular communication by passive diffusion of signaling molecules. We have shown previously that cells endocytose GJs utilizing the clathrin machinery. Endocytosis generates cytoplasmic double‐membrane vesicles termed annular gap junctions or connexosomes. However, the signaling pathways and protein modifications that trigger GJ endocytosis are largely unknown. Treating mouse embryonic stem cell colonies – endogenously expressing the GJ protein connexin43 (Cx43) – with epidermal growth factor (EGF) inhibited intercellular communication by 64% and activated both, MAPK and PKC signaling cascades to phosphorylate Cx43 on serines 262, 279/282, and 368. Upon EGF treatment Cx43 phosphorylation transiently increased up to 4‐fold and induced efficient (66.4%) GJ endocytosis as evidenced by a 5.9‐fold increase in Cx43/clathrin co‐precipitation.
Relative Specificity: All Substrates Are Not Created Equal
Authors: Zeng Yan
Published: February 2014

A biological molecule, e.g., an enzyme, tends to interact with its many cognate substrates, targets, or partners differentially. Such a property is termed relative specificity and has been proposed to regulate important physiological functions, even though it has not been examined explicitly in most complex biochemical systems. This essay reviews several recent large-scale studies that investigate protein folding, signal transduction, RNA binding, translation and transcription in the context of relative specificity. These results and others support a pervasive role of relative specificity in diverse biological processes. It is becoming clear that relative specificity contributes fundamentally to the diversity and complexity of biological systems, which has significant implications in disease processes as well.
A point‐based tool to predict conversion from mild cognitive impairment to probable Alzheimer's disease
Authors: Barnes Deborah E. , Cenzer Irena S. , Yaffe Kristine , Ritchie Christine S. , Lee Sei J. ,   Alzheimer's Disease Neuroimaging Initiative
Published: February 2014

Background

Our objective in this study was to develop a point‐based tool to predict conversion from amnestic mild cognitive impairment (MCI) to probable Alzheimer's disease (AD).

Methods

Subjects were participants in the first part of the Alzheimer's Disease Neuroimaging Initiative. Cox proportional hazards models were used to identify factors associated with development of AD, and a point score was created from predictors in the final model.

Results

The final point score could range from 0 to 9 (mean 4.8) and included: the Functional Assessment Questionnaire (2‒3 points); magnetic resonance imaging (MRI) middle temporal cortical thinning (1 point); MRI hippocampal subcortical volume (1 point); Alzheimer's Disease Cognitive Scale—cognitive subscale (2‒3 points); and the Clock Test (1 point). Prognostic accuracy was good (Harrell's c = 0.78; 95% CI 0.75, 0.81); 3‐year conversion rates were 6% (0‒3 points), 53% (4‒6 points), and 91% (7‒9 points).

Conclusions

A point‐based risk score combining functional dependence, cerebral MRI measures, and neuropsychological test scores provided good accuracy for prediction of conversion from amnestic MCI to AD.
The impact of cultural differences on buyer–supplier negotiations: An experimental study
Authors: Ribbink Dina , Grimm Curtis M.
Published: February 2014

In today's global economy, an ever‐increasing number of companies are dealing with international partners, instigating a need to understand the impact of cultural differences on business interactions. Using Hall's distinction of high‐ and low‐context culture, this study investigates the direct and moderating effects of cultural differences in dyadic buyer–supplier negotiations. Theory is developed regarding the impact of culture on joint profits, juxtaposing Transaction Cost Economics and the Relational View. The theory is tested with a negotiation experiment. Participants, classified by their country of origin, negotiate prices and quality levels for three products. This study finds that cultural differences within the negotiation dyad reduce joint profits when compared to dyads of participants with similar cultural backgrounds. Cultural differences also moderate the impact of trust and bargaining strategy on joint profits. Overall, this study concludes that cultural differences, as encountered in day‐to‐day business interactions in global supply chains, significantly impact negotiation outcomes.
Chain liability in multitier supply chains? Responsibility attributions for unsustainable supplier behavior
Authors: Hartmann Julia , Moeller Sabine
Published: February 2014

When it becomes publicly known that products are associated with suppliers that engage in unsustainable behaviors, consumers protest, as Nestlé, Zara, and Kimberly Clark, among others, have learned. The phenomenon by which consumers hold firms responsible for the unsustainable behavior of their upstream partners suggests the notion of “chain liability.” This study aims to generate insights into the antecedents and consequences of such consumer responsibility attributions. Using data from four vignette‐based survey experiments, the authors find that the chain liability effect increases if an environmental degradation incident (1) results from supplier behavior rather thanforce majeure, (2) results from a company decision rather than the decision of an individual employee, and (3) is more severe. Responsibility attributions do not differ with varying organizational distance from the supplier, firm size, strategic importance of the supplied product, or the existence of environmental management systems. The chain liability effect also creates strong risks for the focal firm; higher responsibility attributions increase consumers’ anger and propensity to boycott. Therefore, firms should work to ensure sustainable behavior throughout the supply chain, to protect them from chain liability.
Validation of a prognostic multi‐gene signature in high‐risk neuroblastoma using the high throughput digital NanoString nCounter™ system
Authors: Stricker Thomas P. , Morales La Madrid Andres , Chlenski Alexandre , Guerrero Lisa , Salwen Helen R. , Gosiengfiao Yasmin , Perlman Elizabeth J. , Furman Wayne , Bahrami Armita , Shohet Jason M. , Zage Peter E. , Hicks M. John , Shimada Hiroyuki , Suganuma Rie , Park Julie R. , So Sara , London Wendy B. , Pytel Peter , Maclean Kirsteen H. , Cohn Susan L.
Published: February 2014

Microarray‐based molecular signatures have not been widely integrated into neuroblastoma diagnostic classification systems due to the complexities of the assay and requirement for high‐quality RNA. New digital technologies that accurately quantify gene expression using RNA isolated from formalin‐fixed paraffin embedded (FFPE) tissues are now available. In this study, we describe the first use of a high‐throughput digital system to assay the expression of genes in an “ultra‐high risk” microarray classifier in FFPE high‐risk neuroblastoma tumors. Customized probes corresponding to the 42 genes in a published multi‐gene neuroblastoma signature were hybridized to RNA isolated from 107 FFPE high‐risk neuroblastoma samples using the NanoString nCounter™ Analysis System. For classification of each patient, the Pearson's correlation coefficient was calculated between the standardized nCounter™ data and the molecular signature from the microarray data. We demonstrate that the nCounter™ 42‐gene panel sub‐stratified the high‐risk cohort into two subsets with statistically significantly different overall survival (p = 0.0027) and event‐free survival (p = 0.028). In contrast, none of the established prognostic risk markers (age, stage, tumor histology, MYCN status, and ploidy) were significantly associated with survival. We conclude that the nCounter™ System can reproducibly quantify expression levels of signature genes in FFPE tumor samples. Validation of this microarray signature in our high‐risk patient cohort using a completely different technology emphasizes the prognostic relevance of this classifier. Prospective studies testing the prognostic value of molecular signatures in high‐risk neuroblastoma patients using FFPE tumor samples and the nCounter™ System are warranted.
Droplet–turbulence interaction in a confined polydispersed spray: effect of droplet size and flow length scales on spatial droplet–gas velocity correlations
Authors: Sahu S. , Hardalupas Y. , Taylor A. M. K. P.
Published: February 2014

This paper discusses the interaction between droplets and entrained turbulent air flow in the far-downstream locations of a confined polydispersed isothermal spray. Simultaneous and planar measurements of droplet and gas velocities in the spray along with droplet size are obtained with the application of a novel experimental technique, developed by Hardalupaset al. (Exp. Fluids, vol. 49, 2010, pp. 417–434), which combines interferometric laser imaging for droplet sizing (ILIDS) with particle image velocimetry (PIV). These measurements quantified the spatial correlation coefficients of droplet–gas velocity fluctuations ($R_{dg}$) and droplet–droplet velocity fluctuations ($R_{dd}$) conditional on droplet size classes, for various separation distances, and for axial and cross-stream velocity components. At the measurement location close to the spray edge, with increasing droplet size,$R_{dg}$was found to increase in axial direction and decrease in cross-stream direction. This suggests that as the gas-phase turbulence becomes more anisotropic away from the spray axis, the gravitational influence on droplet–gas correlated motion tends to increase. The effective length scales of the correlated droplet–gas motion were evaluated and compared with that for gas and droplet motion. The role of different turbulent eddies of the gas flow on the droplet–gas interaction was examined. The flow structures were extracted using proper orthogonal decomposition (POD) of the instantaneous gas velocity data, and their contribution on the spatial droplet–gas velocity correlation was evaluated, which quantified the momentum transfer between the two phases at different length scales of the gas flow. The droplets were observed to augment turbulence for the first three POD modes (larger scales) and attenuate it for the rest of the modes (smaller scales). It has been realized that apart from droplet Stokes number and mass loading, the dynamic range of length scales of the gas flow and the relative turbulent kinetic energy content of the flow structures (POD modes) must be considered in order to conclude if the droplets enhance or reduce the carrier-phase turbulence especially at the lower wavenumbers.
BUSINESS CYCLE ACCOUNTING FOR CHILE
Authors: Simonovska Ina , Söderling Ludvig
Published: February 2014

We investigate sources of economic fluctuations in Chile during 1998–2007 within the framework of a standard neoclassical growth model with time-varying frictions (wedges). We analyze the relative importance of efficiency, labor, investment, and government/trade wedges for business cycles in Chile. The purpose of this exercise is twofold: (i) focusing the policy discussion on the most important wedges in the economy and (ii) identifying which broad class of models would present fruitful avenues for further research. We find that different wedges have played different roles during our studied period, but that the efficiency, labor, and investment wedges have had the greatest impact. We also compare our results with existing studies on emerging and developed economies.
Genetic diversity inVicia fabaL. populations cultivated in Tunisia revealed by simple sequence repeat analysis
Authors: Yahia Yassine , Hannachi Hédia , Monforte Antonio Jose , Cockram James , Loumerem Mohamed , Zarouri Belkacem , Ferchichi Ali
Published: February 2014

Faba bean (Vicia fabaL.) is one of the most important legumes in the world. Little is known about the genetic resources of faba bean in Southern Tunisia. In the present study, genetic diversity within Tunisian faba bean germplasms was investigated using 16 simple sequence repeat markers. In total, 50 alleles were detected. The number of alleles per marker ranged from 2 to 6, with an average of 3. Genetic diversity and polymorphism information content values averaged, respectively, 0.43 (range 0.34–0.51) and 0.36 (range 0.28–0.43). The mean heterozygosity value was 0.27. A model-based structure analysis based on neighbour-joining tree and factorial correspondence analysis revealed the presence of two subpopulations, consistent with the clustering based on genetic distance (GD). The overallFisvalue was 0.36, indicating the importance of selfing in these populations. Analysis of molecular variance revealed that the within-population genetic variance component was much higher than the between-population or between-subpopulation variance component. The genetic relationships based on Nei's GD revealed that AGD (Aguadulce) and SAG (Super Aguadulce) and TF1 and TF2 (Tafartassa-Gafsa) were the most closely related populations. Assessment of genetic variation within faba bean populations will be informative for the conservation of germplasms and the implementation of effective breeding programmes in Tunisia.
Right-Hemisphere Specialization for Contour Grouping
Authors: Volberg Gregor
Published: February 2014

Previous studies often revealed a right-hemisphere specialization for processing the global level of compound visual stimuli. Here we explore whether a similar specialization exists for the detection of intersected contours defined by a chain of local elements. Subjects were presented with arrays of randomly oriented Gabor patches that could contain a global path of collinearly arranged elements in the left or in the right visual hemifield. As expected, the detection accuracy was higher for contours presented to the left visual field/right hemisphere. This difference was absent in two control conditions where the smoothness of the contour was decreased. The results demonstrate that the contour detection, often considered to be driven by lateral coactivation in primary visual cortex, relies on higher-level visual representations that differ between the hemispheres. Furthermore, because contour and non-contour stimuli had the same spatial frequency spectra, the results challenge the view that the right-hemisphere advantage in global processing depends on a specialization for processing low spatial frequencies.
Individual and Combined Effects of Enactment and Testing on Memory for Action Phrases
Authors: Kubik Veit , Söderlund Hedvig , Nilsson Lars-Göran , Jönsson Fredrik U.
Published: February 2014

We investigated the individual and combined effects of enactment and testing on memory for action phrases to address whether both study techniques commonly promote item-specific processing. Participants (N = 112) were divided into four groups (n = 28). They either exclusively studied 36 action phrases (e.g., “lift the glass”) or both studied and cued-recalled them in four trials. During study trials participants encoded the action phrases either by motorically performing them, or by reading them aloud, and they took final verb-cued recall tests over 18-min and 1-week retention intervals. A testing effect was demonstrated for action phrases, however, only when they were verbally encoded, and not when they were enacted. Similarly, enactive (relative to verbal) encoding reduced the rate of forgetting, but only when the action phrases were exclusively studied, and not when they were also tested. These less-than-additive effects of enactment and testing on the rate of forgetting, as well as on long-term retention, support the notion that both study techniques effectively promote item-specific processing that can only be marginally increased further by combining them.
Simultaneous determination of 14 major components in Longhu Rendan pills by ultra-high-performance liquid chromatography coupled with electrospray ionisation tandem mass spectrometry
Authors: Wang Tian-Ming , Ding Li-Qin , Jin Jia-Hua , Shi Rong , Zhong Jie , Gao Cui , Wang Qian , Zhu Li , Ma Yue-Ming
Published: February 2014

A novel method based on UHPLC-MS was developed for the simultaneous determination of the 14 major active constituents of Longhu Rendan pills.
Stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4: an efficient synthesis of multi-substituted perhydrofuro[2,3-b]furans and perhydrofuro[2,3-b]pyrans
Authors: Ma Xiaofeng , Zhang Jichao , Tang Qin , Ke Jun , Zou Wei , Shao Huawu
Published: February 2014

An efficient stereospecific [3+2] cycloaddition of 1,2-cyclopropanated sugars and ketones catalyzed by SnCl4 is described.
Modelling excited states of weakly bound complexes with density functional theory
Authors: Briggs Edward A. , Besley Nicholas A.
Published: February 2014

Different dispersion correction parameters are required to describe the interaction when the molecule is in an excited Rydberg state.
A ternary memory module using low-voltage control over optical properties of metal-polypyridyl monolayers
Authors: Kumar Anup , Chhatwal Megha , Mondal Prakash Chandra , Singh Vikram , Singh Alok Kumar , Cristaldi Domenico A. , Gupta Rinkoo D. , Gulino Antonino
Published: February 2014

A resettable ternary memory module is proposed via commutable redox states.
Design considerations for enhancing absorption in semiconductors on metals through surface plasmon polaritons
Authors: Bohn Christopher D. , Agrawal Amit , Lee Youngmin , Choi Charles J. , Davis Matthew S. , Haney Paul M. , Lezec Henri J. , Szalai Veronika A.
Published: February 2014

Efficiency limits based on absorption through surface plasmon polaritons are incorporated into the detailed balance approach of Shockley and Queisser.
N-terminus oligomerization is conserved in intracellular calcium release channels
Authors: Zissimopoulos Spyros , Marsh Jason , Stannard Laurence , Seidel Monika , Lai F. Anthony
Published: February 2014

Oligomerization of all three mammalian ryanodine receptor isoforms, a structural requirement for normal intracellular Ca2+ release channel function, is displayed by the discrete N-terminal domain which assembles into homo- and hetero-tetramers. This is demonstrated in yeast, mammalian cells and native tissue by complementary yeast two-hybrid, chemical cross-linking and co-immunoprecipitation assays. The IP3 (inositol 1,4,5-trisphosphate) receptor N-terminus (residues 1–667) similarly exhibits tetrameric association as indicated by chemical cross-linking and co-immunoprecipitation assays. The presence of either a 15-residue splice insertion or of the cognate ligand IP3 did not affect tetramerization of the IP3 receptor N-terminus. Thus N-terminus tetramerization appears to be an essential intrinsic property that is conserved in both the ryanodine receptor and IP3 receptor families of mammalian intracellular Ca2+ release channels.
Implementation of modified artificial bee colony (ABC) optimization technique for minimum cost design of welded structures
Authors: Savsani Vimal
Published: February 2014

Welded structures are widely used in many engineering load carrying structures such as columns, towers for wind turbine or water tanks, offshore and submarine structures, girders, stiffened doors, etc. welding is a costly fabrication process and proper sequence and welding process effect the cost of a huge structure. Keeping this in view two different problems from the literature for the cost optimization of welded structures are considered in this paper. The optimization procedure is carried out using artificial bee colony (ABC) optimization technique. Classical ABC is modified to increase the convergence rate of the original algorithm. Comparison of both the variants is experimented on many bench mark examples from the literature and also on two cost optimization problems of welded structures. The results of the considered techniques are compared with the previously published results. The considered techniques have given much better results in comparison to the previously tried approaches and also modified ABC has shown superiority over classical ABC.
Adaptive resolution simulation of an atomistic protein in MARTINI water
Authors: Zavadlav Julija , Melo Manuel Nuno , Marrink Siewert J. , Praprotnik Matej
Published: February 2014

We present an adaptive resolution simulation of protein G in multiscale water. We couple atomistic water around the protein with mesoscopic water, where four water molecules are represented with one coarse-grained bead, farther away. We circumvent the difficulties that arise from coupling to the coarse-grained model via a 4-to-1 molecule coarse-grain mapping by using bundled water models, i.e., we restrict the relative movement of water molecules that are mapped to the same coarse-grained bead employing harmonic springs. The water molecules change their resolution from four molecules to one coarse-grained particle and vice versa adaptively on-the-fly. Having performed 15 ns long molecular dynamics simulations, we observe within our error bars no differences between structural (e.g., root-mean-squared deviation and fluctuations of backbone atoms, radius of gyration, the stability of native contacts and secondary structure, and the solvent accessible surface area) and dynamical properties of the protein in the adaptive resolution approach compared to the fully atomistically solvated model. Our multiscale model is compatible with the widely used MARTINI force field and will therefore significantly enhance the scope of biomolecular simulations.
Sparsity-promoting dynamic mode decomposition
Authors: Jovanović Mihailo R. , Schmid Peter J. , Nichols Joseph W.
Published: February 2014

Dynamic mode decomposition (DMD) represents an effective means for capturing the essential features of numerically or experimentally generated flow fields. In order to achieve a desirable tradeoff between the quality of approximation and the number of modes that are used to approximate the given fields, we develop a sparsity-promoting variant of the standard DMD algorithm. Sparsity is induced by regularizing the least-squares deviation between the matrix of snapshots and the linear combination of DMD modes with an additional term that penalizes the ℓ1-norm of the vector of DMD amplitudes. The globally optimal solution of the resulting regularized convex optimization problem is computed using the alternating direction method of multipliers, an algorithm well-suited for large problems. Several examples of flow fields resulting from numerical simulations and physical experiments are used to illustrate the effectiveness of the developed method.
In-situ neutron diffraction study of deformation behavior of a multi-component high-entropy alloy
Authors: Wu Y. , Liu W. H. , Wang X. L. , Ma D. , Stoica A. D. , Nieh T. G. , He Z. B. , Lu Z. P.
Published: February 2014

Deformation behavior of a high-entropy alloy (HEA) was investigated by in situ tensile deformation with neutron diffraction. It was found that the face-centered cubic (FCC) HEA alloy showed strong crystal elastic and plastic anisotropy, and the evolution of its lattice strains and textures were similar to those observed in conventional FCC metals and alloys. Our results demonstrated that, in spite of chemical complexity, the multi-component HEA behaved like a simple FCC metal and the deformation was caused by the motion of mixed dislocations.
Organic solar cells: a rigorous model of the donor-acceptor interface for various bulk heterojunction morphologies
Authors: Raba Adam , Leroy Yann , Cordan Anne-Sophie
Published: February 2014

Theoretical studies of organic solar cells are mostly based on one dimensional models. Despite their accuracy to reproduce most of the experimental trends, they intrinsically cannot correctly integrate the effects of morphology in cells based on a bulk heterojunction structure. Therefore, accounting for these effects requires the development of two dimensional models, in which donor and acceptor domains are explicitly distinct. In this context, we propose an analytical approach, which focuses on the description of the interface between the two domains. Assuming pinned charge transfer states, we rigorously derive the corresponding boundary conditions and explore the differences between this model and other existing models in the literature for various morphologies of the active layer. On one hand, all tested models are equivalent for an ideal interdigitated bulk heterojunction solar cell with a planar donor-acceptor interface, but divergences between the models rise for small sizes of the donor domain. On the other hand, we carried out a comparison on a less ideal case of cell, with a rough interface between the two domains. Simulations with such cells exhibit distinct behaviors for each model. We conclude that the boundary condition for the interface between the materials is of great importance for the study of solar cells with a non-planar interface. The model must account initially for the roughness of the interface.
Enhanced photoelectrochemical activity of vertically aligned ZnO-coated TiO2 nanotubes
Authors: Cai Hua , Yang Qin , Hu Zhigao , Duan Zhihua , You Qinghu , Sun Jian , Xu Ning , Wu Jiada
Published: February 2014

Vertically aligned ZnO-TiO2 hetero-nanostructures constructed of anatase TiO2 nanotubes (NTs) and wurtzite ZnO coatings are fabricated by atomic layer deposition of ZnO coatings on electrochemical anodization formed TiO2 NTs, and their photoelectrochemical activities are studied through photoelectrochemical and electrochemical characterization. Compared with bare TiO2 NTs, the transient photocurrent increases to over 1.5-fold for the annealed ZnO-coated TiO2 NTs under visible illumination. The ZnO-coated TiO2 NTs also show a longer electron lifetime, a lower charge-transfer resistance and a more negative flat-band potential than the bare TiO2 NTs, confirming the improved photoelectrochemical activity due to the enhanced charge separation.