bluuebunny/crossref_metadata_2025 huggingface dataset:
Fostering Knowledge Transfer and Learning in Shift Work Environments
Authors: Bosua Rachelle , Venkitachalam Krishna
Published: January 2015

Shift work is a continuous ‘round‐the‐clock’ work practice that involves rotating work schedules with a vital process of ‘handover’ denoting a change of teams between shifts. Handover as an activity requires that outgoing shift teams pass on insights and responsibility to incoming shift teams. Knowledge transfer in shift work environments is therefore crucial to allow for a seamless continuation of work practices between shifts. Studies in shift work indicate that knowledge transfer between shifts often fails—that is, incoming workers tend to solve problems with inadequate information, have an incomplete understanding of significant events that occurred in prior shifts, while workers often attempt to solve the same problems across different shifts. This study investigates the challenges associated with shift handover and proposes knowledge transfer enablers that can make a difference to handover. In addition, these enablers can foster learning, a process often overlooked in shift environments. A qualitative research methodology was used to study three distinctive case organisations in the manufacturing and educational sectors, where the nature of day‐to‐day work is shift‐bound and transfer issues were present during handover processes. Our findings suggest that three enablers facilitate knowledge transfer problems associated with shift work: (1) a purposeful knowledge codification and classification culture, (2) open access to established boundary objects and boundary spanners and (3) a unified information infrastructure to facilitate knowledge transfer during shifts and handover. Copyright © 2015 John Wiley & Sons, Ltd.
Knowledge Integration in Government–Industry Project Network
Authors: Tiwari Shalini Rahul
Published: January 2015

Organizations in project networks often integrate specialized knowledge that resides within participants in the network to undertake collaborative ventures. Thus, knowledge integration forms an important aspect of any knowledge management process. Knowledge integration in past studies has been conceptualized as laddering up from knowledge identification to knowledge acquisition to knowledge utilization. However, this study reveals that on the basis of three knowledge typologies—object‐based knowledge, professional knowledge, and coordinating knowledge—the process of knowledge integration progresses from knowledge identification to knowledge coordination to knowledge utilization. This study was carried out as an embedded case study of a large project network (TAXNET) comprising nine actors (i.e. firms). It was designed as a longitudinal study to be conducted in two phases, data being collected through in‐depth interviews, non‐obtrusive observations, and a diary. Other sources of information were minutes of meetings, e‐mails, and company records. The contribution of this study lies in the fact that knowledge integration within project networks has not been fully explored in past studies. Hence, the revelation that actors in a project network do not need to acquire knowledge that is not available in‐house but rather collaborate and coordinate with each other to draw on specialized knowledge that resides within other actors of the project network is unique. An important implication would therefore be that while establishing project networks, managers should be more cognizant that there are different types of knowledge and that the success of collaborative ventures would be determined by how knowledge is identified, coordinated, or used. Copyright © 2015 John Wiley & Sons, Ltd.
Novel Linear Polymers Able to Inhibit Bacterial Quorum Sensing
Authors: Cavaleiro PhD Eliana , Duarte PhD Ana Sofia , Esteves PhD Ana Cristina , Correia PhD António , WhitcombePhD Michael J. , Piletska PhD Elena V. , Piletsky PhD Sergey A. , Chianella PhD Iva
Published: January 2015

Bacterial phenotypes, such as biofilm formation, antibiotic resistance and virulence expression, are associated with quorum sensing. Quorum sensing is a density‐dependent regulatory system of gene expression controlled by specific signal molecules, such as N‐acyl homoserine lactones (AHLs), produced and released by bacteria. This study reports the development of linear polymers capable to attenuate quorum sensing by adsorption of AHLs. Linear polymers were synthesized using MMA as backbone monomer and methacrylic acid and itaconic acid as functional monomers. Two different quorum sensing‐controlled phenotypes, Vibrio fischeri bioluminescence and Aeromonas hydrophila biofilm formation, were evaluated to test the polymers' efficiency. Results showed that both phenotypes were significantly affected by the polymers, with the itaconic acid‐containing material being more effective than the methacrylic acid one. The polymer inhibitory effects were reverted by the addition of lactones, confirming attenuation of quorum sensing through sequestration of signal molecules. The polymers also showed no cytotoxicity when tested using a mammalian cell line.
Phase Separated Methylated Polybenzimidazole (O‐PBI) Based Anion Exchange Membranes
Authors: Germer Wiebke , Leppin Janine , Nunes Kirchner Carolina , Cho Hyeongrae , Kim Hyoung‐Juhn , Henkensmeier Dirk , Lee Kwan‐Young , Brela Mateusz , Michalak Artur , Dyck Alexander
Published: January 2015

Methylated polybenzimidazole (O‐PBI) based anion exchange membranes with a degree of methylation of ca. 78% were prepared in the iodide, chloride, carbonate, bicarbonate, and hydroxide form. Swelling in water showed a high anisotropy for chloride and carbonate exchanged membranes and a strong plasticizing effect of water was confirmed by DMA. Carbonate and bicarbonate exchanged membranes revealed an ionomer peak around 0.25 Å−1 in SAXS measurements suggesting a phase separated morphology. Theoretical DFT calculations were used to characterize geometries and electronic structure of polymer models and interactions with different anions, and to rationalize the water uptake/swelling behavior.
Online Consumption Communities: An Introduction
Authors: Stokburger‐Sauer Nicola E. , Wiertz Caroline
Published: January 2015

Online consumption communities play a significant role in the life of many consumers. These communities remove temporal and spacial boundaries, allowing consumers to convene online to connect over a shared consumption interest anytime and from anywhere. The objective of this special issue is to advance our understanding of online consumption communities and stimulate future research in this exciting research domain. Eight papers are included that present cutting‐edge research exploring three issues: (1) governance and conflict management in online consumption communities, (2) implications of community membership for individual and societal well‐being, and (3) drivers of community success under different ownership structures. In this introductory editorial, each of the papers and its contribution is briefly overviewed.
Conflict Culture and Conflict Management in Consumption Communities
Authors: Husemann Katharina C. , Ladstaetter Florian , Luedicke Marius K.
Published: January 2015

This study explores conflict culture as a distinct and influential element of a consumption community's broader culture, and explores how communities initiate, perform, manage, and resolve intracommunity conflicts. A four‐year interpretive study of the Premium Cola consumption community reveals two sets of formal and informal elements of conflict culture; explains how community members perform routine, and manage transgressive conflicts; shows how members garner positive and negative practical, identity, and relationship value from these two types of conflict; and documents how a community's conflict culture develops through inventing new conflict behaviors to resolve transgressive conflicts. The study thus contributes new theoretical insights to the literature on social conflict in online consumption communities, discusses managerial implications, and initiates a discussion about conflict culture.
Exploring Consumptive Moments of Value‐Creating Practice in Online Community
Authors: Hartmann Benjamin J. , Wiertz Caroline , Arnould Eric J.
Published: January 2015

Conceptual blind spots persist when it comes to understanding the value of consumptive dimensions of participation, such as lurking, in online community. This article uses a practice‐theoretical lens to conceptualize the consumptive moments of online community practices and explores how they shape different value outcomes. Building on a mixed‐method investigation through two studies within an online gardening community, findings reveal two specific consumptive moments, direct and vicarious, and their differential role in the creation of community engagement and vitality. These findings suggest that lurking is not adequately described as a unidimensional construct, but is best understood as vicarious consumptive moments of specific online community practices with distinctive value outcomes. Implications for research on online consumption community are discussed.
The impact of rare variants in FUS in essential tremor
Authors: Hopfner Franziska , Stevanin Giovanni , Müller Stefanie H. , Mundwiller Emeline , Bungeroth May , Durr Alexandra , Pendziwiat Manuela , Anheim Mathieu , Schneider Susanne A. , Tittmann Lukas , Klebe Stephan , Lorenz Delia , Deuschl Günther , Brice Alexis , Kuhlenbäumer Gregor
Published: January 2015

Objective

We analyzed the coding region of the Fused in Sarcoma (FUS) gene in familial essential tremor (ET) and reviewed previous studies assessing FUS variants in ET.

Background

ET is often a familial disorder with an autosomal dominant inheritance pattern. A potentially causative variant in FUS has been identified in one ET family. Subsequent studies described further putatively causal variants.

Methods

We performed DNA sequencing of FUS in 85 unrelated, familial German and French definite ET patients.

Results

We did not find novel variants affecting the protein sequence. Seven previously published studies and data from the exome variant server (EVS) showed that rare exonic variants in FUS are not more frequent in ET than in the general population.

Conclusions

Our findings provide no evidence for a role of rare genetic variants in the pathogenesis of ET, apart from the initially published FUS mutation segregating in a large ET family. © 2015 International Parkinson and Movement Disorder Society
Green tea changes serum and liver metabolomic profiles in mice with high‐fat diet‐induced obesity
Authors: Lee Lan‐Sook , Choi Ji Hea , Sung Mi Jeong , Hur Jin‐Young , Hur Haeng Jeon , Park Jong‐Dae , Kim Young‐Chan , Gu Eun‐Ji , Min Byungjin , Kim Hyun‐Jin
Published: January 2015

Scope

Green tea (GT) consumption helps to prevent and control obesity by stimulating hepatic lipid metabolism. However, GT‐induced changes in serum and liver metabolomes associated with the anti‐obesity effects are not clearly understood. The aim of this study was to identify and validate metabolomic profiles in the livers and sera of GT‐fed obese mice to elucidate the relationship between GT consumption and obesity prevention.

Methods and results

Serum and liver metabolites were analyzed in mice fed normal diet, high‐fat diet (HFD), HFD with GT, and HFD with crude catechins, using LC‐quadrupole TOF MS. The addition of 1% GT to HFD reduced adipose tissue and the levels of blood triglycerides, glucose, insulin, and leptin elevated in HFD‐fed mice. We proposed an HFD‐induced obesity pathway and validated it by investigating the key regulatory enzymes of mitochondrial β‐oxidation: carnitine palmitoyltransferase‐1 and ‐2, acyl‐coenzyme A dehydrogenase, and acetyl‐coenzyme A acyltransferase. The results showed that HFD‐induced abnormal mitochondrial β‐oxidation was moderated by the consumption of caffeine‐ and theanine‐enriched GT.

Conclusion

Results of LC/MS‐based metabolomic analysis of obese mice showed changes associated with abnormal lipid and energy metabolism, which were alleviated by GT intake, indicating the mechanism underlying the anti‐obesity effects of GT.
Docosahexaenoic acid and eicosapentaenoic acid suppress adhesion molecule expression in human aortic endothelial cells via differential mechanisms
Authors: Huang Chun‐Ying , Sheu Wayne Huey‐Herng , Chiang An‐Na
Published: January 2015

Scope

Dietary PUFAs modulate the progression of cardiovascular disease, but the underlying mechanisms within vascular cells remain unclear. The aim of this study was to investigate the biological function and regulatory mechanisms of PUFAs in LPS‐activated human aortic endothelial cells (HAECs).

Methods and results

To simulate the in vivo conditions of atherosclerosis, we have established an in vitro model in which THP‐1 monocytes adhere to HAECs. Our results showed thatn‐3 PUFAs docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) remarkably attenuated the adhesion of THP‐1 cells to HAECs, probably through inhibiting the expression of VCAM‐1 and ICAM‐1. Using lipid raft isolation and confocal microscopy, we found that DHA and EPA suppressed the translocation of TLR4 into lipid rafts. Furthermore, DHA and EPA inhibited the ubiquitination and translocation of TRAF6, and the phosphorylation of TAK1, p38, and IκBα. We demonstrated that DHA reduced the phosphorylation of PKR, but EPA increased the expression of A20. Additionally, silencing of A20 reversed the inhibitory effect of EPA on the expression of adhesion molecules.

Conclusion

Our study revealed differential signaling pathways modulated byn‐3 PUFAs in LPS‐stimulated HAECs. These signaling pathways are potential targets for the prevention of atherosclerotic progression.
The importance of GLP‐1 and PYY in resistant starch's effect on body fat in mice
Authors: Zhou June , Martin Roy J. , Raggio Anne M. , Shen Li , McCutcheon Kathleen , Keenan Michael J.
Published: January 2015

Resistant starch (RS) is a dietary fermentable fiber that decreases body fat accumulation, and stimulates the secretion of glucagon‐like peptide‐1 (GLP‐1) and peptide YY (PYY) in rodents. GLP‐1 and PYY are gut‐secreted hormones with antiobesity effect. Thus, blocking the signals of increased GLP‐1 and PYY may also block the effect of dietary RS on body fat. In a 10‐week study, C57BL/6J and GLP‐1 receptor null (GLP‐1R KO) mice were fed control or 30% RS diet, and received daily intraperitoneal injection of either saline or PYY receptor antagonist (BIIE0246, 20 μg/kg body weight). Dietary RS significantly decreased body fat accumulation only in wild‐type mice that has saline injection, but not in GLP‐1R KO mice. PYY receptor antagonist diminished RS action on body fat in wild‐type mice, but did not interfere with GLP‐1R KO mice response to RS. Regardless of genotype and injection received, all RS‐fed mice had increased cumulative food intake, cecal fermentation, and mRNA expression of proglucagon and PYY. Thus, our results suggest that increased GLP‐1 and PYY is important in RS effects on body fat accumulation.
Strategies to Encourage a Sustainable Interorganizational Collaborative Culture
Authors: Glowacki–Dudka Michelle , Murray Jennifer
Published: January 2015

Interorganizational collaboration allows community organizations to work together to achieve common goals without duplicating services. Collaboration creates challenges when working with organizations from different sectors, but it can be achieved even if it is for a limited time. In this paper, we examine a case study conducted with collaborative partners from a private communications company, a small nonprofit organization, and a public/academic institution. In the findings, we offer ten themes for beginning the collaborative process, to better ensure its success to the end of the project and perhaps beyond. Through conclusions, we recommend strategies based on the case study and supported by the literature.
Creating Fugitive Knowledge through Disorienting Dilemmas: The Issue of Bottom Identity Development
Authors: McGill Craig M. , Collins Joshua C.
Published: January 2015

Despite sexuality being a powerful source of emotional and physical experiences and learning, it remains underexplored as an area of interest and investigation in adult education and human resource development (HRD). Most work on sexuality in adult education and HRD has focused on learning, work experiences, discrimination, acceptance, and health and wellness for lesbian, gay, bisexual, and transgender (LGBT) people. Notably, there is a need for conversations about sexuality that move beyond our most basic understandings of orientations (such as heterosexual, bisexual, and homosexual) or temperaments (such as conservative/traditional or progressive/nontraditional). One particularly interesting place to begin new conversations is by examining subidentity groups, such as gay men who identify as bottoms (generally prefer receptive roles during anal and/or oral intercourse) because these men are likely to experience stigma related to the constraints of both heteronormative, homonormative, and gendered ideals. The purpose of this article is to explore how the fields of adult education and HRD might come to understand bottom identity development and how some gay men cultivate, construct, perform, and embody bottom identities in a variety of contexts.
Multidimensional parallelepiped model—a new type of non‐probabilistic convex model for structural uncertainty analysis
Authors: Jiang C. , Zhang Q. F. , Han X. , Liu J. , Hu D. A.
Published: January 2015

Non‐probabilistic convex models need to be provided only the changing boundary of parameters rather than their exact probability distributions; thus, such models can be applied to uncertainty analysis of complex structures when experimental information is lacking. The interval and the ellipsoidal models are the two most commonly used modeling methods in the field of non‐probabilistic convex modeling. However, the former can only deal with independent variables, while the latter can only deal with dependent variables. This paper presents a more general non‐probabilistic convex model, the multidimensional parallelepiped model. This model can include the independent and dependent uncertain variables in a unified framework and can effectively deal with complex ‘multi‐source uncertainty’ problems in which dependent variables and independent variables coexist. For any two parameters, the concepts of the correlation angle and the correlation coefficient are defined. Through the marginal intervals of all the parameters and also their correlation coefficients, a multidimensional parallelepiped can easily be built as the uncertainty domain for parameters. Through the introduction of affine coordinates, the parallelepiped model in the original parameter space is converted to an interval model in the affine space, thus greatly facilitating subsequent structural uncertainty analysis. The parallelepiped model is applied to structural uncertainty propagation analysis, and the response interval of the structure is obtained in the case of uncertain initial parameters. Finally, the method described in this paper was applied to several numerical examples. Copyright © 2015 John Wiley & Sons, Ltd.
Mature and immature teratoma: A report from the second Italian pediatric study
Authors: Terenziani Monica , D'Angelo Paolo , Inserra Alessandro , Boldrini Renata , Bisogno Gianni , Babbo Gian Luca , Conte Massimo , Dall' Igna Patrizia , De Pasquale Maria Debora , Indolfi Paolo , Piva Luigi , Riccipetitoni Giovanna , Siracusa Fortunato , Spreafico Filippo , Tamaro Paolo , Cecchetto Giovanni
Published: January 2015

Background

Teratomas demonstrate a benign clinical behavior, however they may recur with malignant components or as teratoma, and in a small group of patients prognosis could be fatal. After the first Italian study, we collected cases of teratoma, alongside the protocol for malignant germ cell tumors.

Procedure

Patients with teratoma were collected from 2004 to 2014. Teratomas were classified according to the WHO classifications, as mature and immature. Patients with pathological aFP and/or bHCG, and those with a malignant germ cell component were not included.

Results

The study enrolled 219 patients (150 mature, 69 immature teratomas) with a median age at diagnosis of 42 months. The primary sites involved were: 118 gonadal and 101 extragonadal teratomas. Two females with ovarian teratoma had a positive family history. Complete and incomplete surgeries were performed in 85% and 9% of cases. Seventeen events occurred: six females had a second metachronous tumor (5 contralateral ovarian teratoma, 1 adrenal neuroblastoma) and 11 teratomas relapsed/progressed (3 mature, 8 immature teratomas). Two patients died, one of progressive immature teratoma and one of surgical complications. At a median follow up of 68 months, the event‐free, relapse‐free, and overall survival rates were 90.6%, 94.3%, 98.6%, respectively.

Conclusions

Teratomas show a good prognosis, especially the mature ones: surgery and follow‐up remain the standard approach. Incomplete surgery in immature teratoma is the group at greatest risk of relapse. Bilateral ovarian tumors are a possibility, and the rare family predisposition to ovarian mature teratoma warrants further analyses. Pediatr Blood Cancer 2015;62:1202–1208. © 2015 Wiley Periodicals, Inc.
Prediction of distal residue participation in enzyme catalysis
Authors: Brodkin Heather R. , DeLateur Nicholas A. , Somarowthu Srinivas , Mills Caitlyn L. , Novak Walter R. , Beuning Penny J. , Ringe Dagmar , Ondrechen Mary Jo
Published: January 2015

A scoring method for the prediction of catalytically important residues in enzyme structures is presented and used to examine the participation of distal residues in enzyme catalysis. Scores are based on the Partial Order Optimum Likelihood (POOL) machine learning method, using computed electrostatic properties, surface geometric features, and information obtained from the phylogenetic tree as input features. Predictions of distal residue participation in catalysis are compared with experimental kinetics data from the literature on variants of the featured enzymes; some additional kinetics measurements are reported for variants of Pseudomonas putida nitrile hydratase (ppNH) and for Escherichia coli alkaline phosphatase (AP). The multilayer active sites of P. putida nitrile hydratase and of human phosphoglucose isomerase are predicted by the POOL log ZP scores, as is the single‐layer active site of P. putida ketosteroid isomerase. The log ZP score cutoff utilized here results in over‐prediction of distal residue involvement in E. coli alkaline phosphatase. While fewer experimental data points are available for P. putida mandelate racemase and for human carbonic anhydrase II, the POOL log ZP scores properly predict the previously reported participation of distal residues.
The role of NFATc1 in prostate cancer progression: Cyclosporine A and tacrolimus inhibit cell proliferation, migration, and invasion
Authors: Kawahara Takashi , Kashiwagi Eiji , Ide Hiroki , Li Yi , Zheng Yichun , Ishiguro Hitoshi , Miyamoto Hiroshi
Published: January 2015

BACKGROUND

The functional role of nuclear factor of activated T‐cells (NFAT), a well‐characterized regulator of the immune response, in prostate cancer progression remains largely unknown. We aim to investigate biological significance of NFATc1, a NFAT isoform shown to function as an oncogene in a sarcoma model, in human prostate cancer.

METHODS

We first determined the expression levels of NFAT in prostate cell lines and tissue specimens. We then assessed the effects of NFAT inhibition via NFATc1‐small interfering RNA (siRNA) as well as immunosuppressants including cyclosporine A (CsA) and tacrolimus (FK506) on prostate cancer cell proliferation, apoptosis, migration, and invasion in vitro and in vivo.

RESULTS

Immunohistochemistry revealed that the expression levels of NFATc1 were significantly elevated in prostatic carcinomas, compared with non‐neoplastic prostate or high‐grade prostatic intraepithelial neoplasia tissues, and in high‐grade (Gleason scores ≥7) tumors. NFATc1 positivity in carcinomas, as an independent prognosticator, also correlated with the risk of biochemical recurrence after radical prostatectomy. In prostate cancer cell lines, CsA and FK506 inhibited NFATc1 expression and its nuclear translocation, NFAT transcriptional activity, and the expression of c‐myc, a downstream target of NFAT. NFAT silencing or treatment with these NFAT inhibitors resulted in decreases in cell viability/colony formation and cell migration/invasion, as well as increases in apoptosis, in androgen receptor (AR)‐negative, AR‐positive/androgen‐sensitive, and AR‐positive/castration‐resistant lines. No significant additional inhibition in the growth of NFAT‐siRNA cells by CsA and FK506 was seen, whereas these agents, especially FK506, further inhibited their invasion. In xenograft‐bearing mice, CsA and FK506 significantly retarded tumor growth.

CONCLUSIONS

Our results suggest that NFATc1 plays an important role in prostate cancer outgrowth. Thus, NFATc1 inactivation, especially using CsA and FK506, has the potential of being a therapeutic approach for not only hormone‐naïve but also castration‐resistant prostate cancers.Prostate 75: 573–584, 2015. © 2015 Wiley Periodicals, Inc.
AlN, ZnO thin films and AlN/ZnO or ZnO/AlN multilayer structures deposited by PLD for surface acoustic wave applications
Authors: Dutheil P. , Orlianges J.‐C. , Crunteanu A. , Catherinot A. , Champeaux C.
Published: January 2015

(0002)‐oriented AlN and ZnO thin films are deposited on C‐sapphire substrates by pulsed laser deposition at 700 °C. Multilayered structures AlN/ZnO and ZnO/AlN are also grown on C‐sapphire and investigated by X‐ray diffraction, scanning electron microscopy and transmission measurements. Ellipsometry analysis is employed to investigate the stack of layers and the optical properties of thin films. This non‐destructive analysis identified an intermediate layer between AlN and ZnO thin films for AlN/ZnO multilayer which didn't change the crystalline structure or piezoelectric properties of the multilayer. Surface acoustic wave velocities are respectively 5060 m s−1 for AlN and 5350 m s−1 for ZnO. In fact, investigations of surface acoustic wave (SAW) devices revealed a similar resonant frequency for both multilayers and in agreement with those measured for ZnO or AlN thin films.
Validation of methods for H, C, N and S stable isotopes and elemental analysis of cheese: results of an international collaborative study
Authors: Camin Federica , Bertoldi Daniela , Santato Alessandro , Bontempo Luana , Perini Matteo , Ziller Luca , Stroppa Angelo , Larcher Roberto
Published: January 2015

Rationale

PDO cheeses, such as Parmigiano Reggiano and Grana Padano, which cost more than double generic similar cheeses, must be protected against mislabelling. The aim of this study was to validate the methods for the isotopic and elemental analysis of cheese, in order to support official recognition of their use in authenticity assessment.

Methods

An international collaborative study based on blind duplicates of seven hard cheeses was performed according to the IUPAC protocol and ISO Standards 5725/2004 and 13528/2005. The H, C, N and S stable isotope ratios of defatted cheese determined using Isotope Ratio Mass Spectrometry (IRMS) and the content of Li, Na, Mn, Fe, Cu, Se, Rb, Sr, Mo, Ba, Re, Bi, U in cheese after acid microwave digestion using Inductively Coupled Plasma Mass Spectrometry or Optical Emission Spectrometry (ICP‐MS or ‐OES) were measured in 13 different laboratories.

Results

The average standard deviations of repeatability (sr) and reproducibility (sR) were 0.1 and 0.2 ‰ for δ13C values, 0.1 and 0.3 ‰ for δ15N values, 2 and 3 ‰ for δ2H values, and 0.4 and 0.6 ‰ for δ34S values, thus comparable with results of official methods and the literature for other food matrices. For elemental data, the average RSDr and RSDR values ranged between 2 and 11% and between 9 and 28%, respectively, consistent with methods reported by the FDA and in the literature for cheese.

Conclusions

The validation data obtained here can be submitted to the standardisation agencies to obtain official recognition for the methods, which is fundamental when they are used in commercial disputes and legal debates. Copyright © 2015 John Wiley & Sons, Ltd.
An online temperature‐controlled vacuum‐equilibration preparation system for the measurement of δ2H values of non‐exchangeable‐H and of δ18O values in organic materials by isotope‐ratio mass spectrometry
Authors: Wassenaar Leonard I. , Hobson Keith A. , Sisti Leonardo
Published: January 2015

Rationale

Measurement of δ2H values in non‐exchangeable‐H (δ2Hn) and δ18O values in organic environmental samples are inconsistent among laboratories worldwide due to varied and lengthy approaches in controlling for H isotope exchange (for δ2Hn values) and removal of trace moisture (δ2Hn and δ18O values), which undermines the comparability of organic δ2H and δ18O data produced among different laboratories.

Methods

An online preparation system was developed for the measurement of the δ2Hn and δ18O values of organic samples, coupled to isotope‐ratio mass spectrometers. The system features a 50‐position autosampler and isolation valve where (1) the samples are held isothermal between ambient to 40–120 ± 0.1 °C for H isotopic exchange experiments (δ2Hn) and drying of hygroscopic samples (δ2Hn and δ18O), (2) the samples are evacuated to <5 mbar and flushed with helium for moisture and N2 removal, and (3) injection of up to 500 μL of H2O is possible for controlled vapour exchangeable‐H experiments.

Results

The system provides highly reproducible and precise δ2Hn isotope estimates for a range of organic keratinous standard powders over a wide range of experimental temperatures. A reproducible sample processing regimen can now be applied to a wider range of organics and hygroscopic samples that are currently hampered by poorly controlled preparative methods amongst laboratories.

Conclusions

Rapid and reproducible online vacuum equilibration of samples and standards for the routine measurement of δ2Hn and δ18O values is now possible using the online equilibration system, with the added benefit that sample processing times for organic δ2H values are reduced from weeks to hours. Copyright © 2015 John Wiley & Sons, Ltd.
Laser desorption ionization time‐of‐flight mass spectrometry of Ge‐As‐Te chalcogenides
Authors: Šútorová Katarína , Hawlová Petra , Prokeš Lubomír , Němec Petr , Boidin Rémi , Havel Josef
Published: January 2015

Rationale

GexAsyTez glasses have a broad window of optical transparency and high refractive index which make them promising for applications in the infrared region. The aim of this work is to reveal structural motifs which could be present during the fabrication of Ge‐As‐Te thin films by plasma deposition techniques; such knowledge is important for the optimization of thin film growth.

Methods

Mass spectra were acquired using a laser desorption ionization time‐of‐flight (LDI‐TOF) mass spectrometer equipped with a nitrogen laser (337 nm) coupled with a quadrupole ion trap, and recorded in positive and negative ion reflectron modes. XRD, SEM (EDX) and Raman spectroscopy were also used for the characterization of Ge‐As‐Te bulk or powdered samples.

Results

Bulk GexAsyTez samples (x = 10–20%, y = 20–60%, z = 30–70%) were synthesized. LDI‐MS of Ge‐As‐Te powders provided evidence for the formation of both positively and negatively charged clusters, whose stoichiometry was determined as Ten+/– (n = 1–4), Te5+, binary AsTen+/– (n = 1–3), GeTen+/– (n = 1–3), As2Te+/–, As2Te3+, As3Te+, AsTe4+, Ge2H6+/–, ternary GeAsTe+, GeAsTe2+/–, GeAsH5+, GeAsH6+, GeAsH12+, and tertiary GeAsTeH5–, GeAsTeH8–, GeAsTe2H3+/–.

Conclusions

The local structure of GexAsyTez materials is at least partly different from that of species identified in plasma by mass spectrometry, as deduced from Raman scattering spectroscopy analysis. However, LDI‐TOFMS was found to be a suitable technique for the partial structure characterization of Ge‐As‐Te bulk samples and especially for the identification of the structural motifs present in the plasma during the preparation of the corresponding thin films. Copyright © 2015 John Wiley & Sons, Ltd.
Estimation of nitric oxide synthase activity via liquid chromatography/tandem mass spectrometric assay determination of 15N3‐citrulline in biological samples
Authors: Shin Beom Soo , Fung Ho‐Leung , Upadhyay Mahesh , Shin Soyoung
Published: January 2015

Rationale

We showed that the metabolite peaks of 15N3‐citrulline (15N3‐CIT) and 15N3‐arginine (15N3‐ARG) could be detected when 15N4‐ARG was metabolized by nitric oxide synthase (NOS) in endothelial cells. The usefulness of these metabolites as potential surrogate indices of nitric oxide (NO) generation is evaluated.

Methods

A hydrophilic‐interaction liquid chromatography/electrospray tandem mass spectrometric assay (LC/MS/MS) was utilized for the simultaneous analysis of 15N4‐ARG, ARG, CIT, 15N3‐CIT and 15N3‐ARG. 15N3‐CIT and 15N3‐ARG from impurities of 15N4‐ARG were determined and corrected for the calculation of their concentration. 15N4‐ARG‐derived NO, i.e., 15NO formation was determined by analyzing 15N‐nitrite accumulation by another LC/MS/MS assay.

Results

After EA.hy926 human endothelial cells were challenged with 15N4‐ARG for 2 hours, the peak intensities of 15N3‐CIT and 15N3‐ARG significantly increased with 15N4‐ARG concentration and positively correlated with 15N‐nitrite production. The estimated Km values were independent of the metabolite (i.e., 15N3‐CIT, 15N3‐CIT+15N3‐ARG or 15N‐nitrite) used for calculation. However, after correction for its presence as a chemical contaminant of 15N4‐ARG, 15N3‐ARG was only a marginal contributor for the estimation of NOS activity.

Conclusions

These data suggest that the formation of 15N3‐CIT can be used as an indicator of NOS activity when 15N4‐ARG is used as a substrate. This approach may be superior to the radioactive 14C‐CIT method which can be contaminated by 14C‐urea, and to the 14N‐nitrite method which lacks sensitivity. Copyright © 2015 John Wiley & Sons, Ltd.
Robust nonlinear sampled‐data system analysis based on Fridman's method and S‐procedure
Authors: Seifullaev Ruslan E. , Fradkov Alexander L.
Published: January 2015

This paper is devoted to the evaluation of sampling interval providing robust exponential stability of nonlinear system with sector‐bounded nonlinearities. It extends our previous results (R. E. Seifullaev, A. L. Fradkov. Sampled‐data control of nonlinear oscillations based on LMIs and Fridman's method. In 5th IFAC International Workshop on Periodic Control Systems, 95‐100. Caen, France. 2013). The proposed approach exploits E. Fridman's method for linear systems based on a general time‐dependent Lyapunov–Krasovskii functional. With classical results of V. A. Yakubovich about S‐procedure, the problem is reduced to feasibility analysis of linear matrix inequalities. The results are illustrated by example: the pendulum system with friction and sector‐bounded multiple nonlinearities. Copyright © 2015 John Wiley & Sons, Ltd.
Adaptive actuator failure compensation for multivariable feedback linearizable systems
Authors: Yao Xuelian , Tao Gang , Jiang Bin
Published: January 2015

A feedback linearization‐based adaptive control scheme is developed for multivariable nonlinear systems with redundant actuators subject to uncertain failures. Such an adaptive controller contains a direct adaptive actuator failure compensator to compensate the uncertain actuator failure, a nonlinear feedback to linearize the nonlinear dynamics, and a linear feedback to stabilize the linearized system. The key new design feature is the estimation of both the failure patterns and the failure values, for direct adaptive actuator failure compensation, newly developed for multivariable feedback linearizable nonlinear systems. With direct control signal adaptation, the adaptive failure compensation design ensures closed‐loop stability and asymptotic output tracking in the presence of actuator failure uncertainties. Simulation results from an application to attitude control of a near‐space vehicle dynamic model are presented to verify the desired system performance with adaptive actuator failure compensation. Copyright © 2015 John Wiley & Sons, Ltd.
Mathematical modeling of the propagation of malware: a review
Authors: del Rey Angel Martín
Published: January 2015

In the present work, we offer a critical review of the mathematical models that have been proposed to date to simulate malware propagation in a network of computers or mobile devices. We analyze the models proposed determining the deficits and possible alternatives for improving them. Copyright © 2015 John Wiley & Sons, Ltd.
CDMCR: multi‐level fault‐tolerant system for distributed applications in cloud
Authors: Qiang Weizhong , Jiang Changqing , Ran Longbo , Zou Deqing , Jin Hai
Published: January 2015

Cloud provides users with a new model of utilizing the computing infrastructure with the ability to perform parallel and distributed computations using elastic virtual cluster. However, the multi‐level and complex features make cloud computing system more prone to failure. In this paper, we present a multi‐level fault‐tolerant system for distributed applications in cloud named Distributed‐application oriented Multi‐level Checkpoint/Restart for Cloud (CDMCR). The CDMCR system backups the complete state of applications periodically with a snapshot‐based distributed checkpointing protocol, including file system state. Thus, we cannot only recover processes but also rollback data. A multi‐level recovery strategy is proposed, which includes process‐level recovery, virtual machine recreation, and host rescheduling, enabling comprehensive and efficient fault tolerance for different components in cloud. We deploy CDMCR as PaaS, so that users can be liberated from node management and system configuration and get access to fault‐tolerant service conveniently. We have implemented this system based on the Xen virtualization platform and the OpenNebula cloud platform. Experiments on the prototype demonstrate the correctness of the system. Analysis shows that CDMCR does not cause message loss or data loss, and the backup time remains nearly constant as the number of nodes increases on virtual cluster. Copyright © 2015 John Wiley & Sons, Ltd.
A survey on reversible watermarking techniques for relational databases
Authors: Iftikhar Saman , Kamran M. , Anwar Zahid
Published: January 2015

Over the past few years, reversible watermarking techniques for relational databases have been proposed to provide protection of ownership rights, data tempering, and data integrity. Mainly, these techniques ensure original data recovery from watermarked data, whereas irreversible watermarking schemes only protect ownership rights. This characteristic of reversible watermarking has emerged as a candidate solution for the protection of ownership rights of data, intolerable to modifications such as medical data, genetic data, credit card, and bank account data. The main objective of this paper is to make an extensive survey of the state‐of‐the‐art in reversible watermarking techniques for relational databases to reflect recent research progress and to point out the key issues for future research. In order to analyze these techniques, a classification has been performed on the basis of (i) the extent of modifications introduced by the watermarking scheme in the underlying data and (ii) the robustness of the embedded watermark against malicious attacks. Copyright © 2015 John Wiley & Sons, Ltd.
Summarising censored survival data using the mean residual life function
Authors: Alvarez‐Iglesias Alberto , Newell John , Scarrott Carl , Hinde John
Published: January 2015

The mean residual life function provides a clear and simple summary of the effect of a treatment or a risk factor in units of time, avoiding hazard ratios or probability scales, which require careful interpretation. Estimation of the mean residual life is complicated by the upper tail of the survival distribution not being observed as, for example, patients may still be alive at the end of the follow‐up period. Various approaches have been developed to estimate the mean residual life in the presence of such right censoring. In this work, a novel semi‐parametric method that combines existing non‐parametric methods and an extreme value tail model is presented, where the limited sample information in the tail (prior to study termination) is used to estimate the upper tail behaviour. This approach will be demonstrated with simulated and real‐life examples. Copyright © 2015 John Wiley & Sons, Ltd.
Penalized regression procedures for variable selection in the potential outcomes framework
Authors: Ghosh Debashis , Zhu Yeying , Coffman Donna L.
Published: January 2015

A recent topic of much interest in causal inference is model selection. In this article, we describe a framework in which to consider penalized regression approaches to variable selection for causal effects. The framework leads to a simple ‘impute, then select’ class of procedures that is agnostic to the type of imputation algorithm as well as penalized regression used. It also clarifies how model selection involves a multivariate regression model for causal inference problems and that these methods can be applied for identifying subgroups in which treatment effects are homogeneous. Analogies and links with the literature on machine learning methods, missing data, and imputation are drawn. A difference least absolute shrinkage and selection operator algorithm is defined, along with its multiple imputation analogs. The procedures are illustrated using a well‐known right‐heart catheterization dataset. Copyright © 2015 John Wiley & Sons, Ltd.
Bridging continual reassessment method for phase I clinical trials in different ethnic populations
Authors: Liu Suyu , Pan Haitao , Xia Jielai , Huang Qin , Yuan Ying
Published: January 2015

Accumulating evidence shows that the conventional one‐size‐fits‐all dose‐finding paradigm is problematic when applied to different ethnic populations. Because of inter‐ethnic heterogeneity, the dosage established in a landmark trial for a certain population may not be generalizable to a different ethnic population, and a follow‐up bridge trial is often needed to find the maximum tolerated dose for the new population. We propose the bridging continual reassessment method (B‐CRM) to facilitate dose finding for such follow‐up bridge trials. The B‐CRM borrows information from the landmark trial through a novel estimate of the dose‐toxicity curve and accommodates the inter‐ethnic heterogeneity using the Bayesian model averaging approach. Extensive simulation studies show that the B‐CRM has desirable operating characteristics with a high probability to select the target dose. This article focuses on ethnic heterogeneity, but the proposed method can be directly used to handle other types of patient heterogeneity, for example, patient subgroups defined by prognostic factors or biomarkers. The software to implement the B‐CRM design is available for free download at http://odin.mdacc.tmc.edu/~yyuan/. Copyright © 2015 John Wiley & Sons, Ltd.
Numerical Analysis of Temperature Distribution and Its Optimization for Thin Foils in Micro Deep Drawing Assisted by Resistance Heating
Authors: Zheng Qiu , Shimizu Tetsuhide , Yang Ming
Published: January 2015

Application of resistance heating to micro metal forming process can achieve not only the improvement of the material formability, but also the less consumption of energy. In this study, finite element (FE) models for the numerical analysis of micro deep drawing process assisted by resistance heating are developed. Coupled thermal‐electrical procedure and coupled thermal‐displacement dynamic explicit procedure are conducted for the analysis of temperature distribution and material deformation, respectively. The results show that the temperature distribution of the blank is influenced not only by the difference in electrical current density, but also by the heat transfer from the material to the tools. The results of temperature distribution obtained from the simulation show the same tendency with the experiments, which confirms the feasibility of the developed FE models. In addition, to obtain uniform temperature distribution of the blank, the process parameters are optimized. It is demonstrated that the material formability can be improved by obtaining more uniform temperature distribution of the blank.
The Human Right to Water: Critiques and Condition of Possibility
Authors: Sultana Farhana , Loftus Alex
Published: January 2015

This Advanced Review analyzes recent debates over the human right to water. While accepting critiques from scholars that the right to water risks entrenching unequal and unjust forms of water governance, the paper nevertheless takes a more sympathetic view of the potentials within struggles for the right to water. Recognizing that such struggles can take many different forms, we urge scholars to adopt more nuanced and geographically sensitive analyses of the conditions out of which movements for the right to water have emerged. We reject the claim that the right to water depoliticises struggles for water justice and we instead find conditions of possibility for deeper and more lasting changes to water governance within struggles for the right to water. WIREs Water 2015, 2:97–105. doi: 10.1002/wat2.1067

This article is categorized under:

Human Water > Rights to Water

Human Water > Water Governance
Linguistic capacity of non‐human animals
Authors: Zuberbühler Klaus
Published: January 2015

Linguists interested in language evolution tend to focus on combinatorial features and rightly point out the lack of comparable evidence in animal communication. However, human language is based on various unique capacities, such as a motor capacity of sophisticated vocal control and a cognitive capacity of acting on others' psychological states. These features are only present in very rudimentary forms in non‐human primates, suggesting they have evolved more recently in the human lineage. Here, the evidence from recent fieldwork for precursors of these abilities is reviewed, notably sequence‐based semantic communication, vocal tract control, and audience awareness. Overall, there is evidence for both continuity and discontinuity when comparing modern primate and human communication, suggesting that the origin of language is the result of multiple gradual transitions from earlier forms of primate‐like communication and social cognition, rather than a sudden and fundamental redesign in ancestral human communication and cognition. WIREs Cogn Sci 2015, 6:313–321. doi: 10.1002/wcs.1338

This article is categorized under:

Cognitive Biology > Evolutionary Roots of Cognition

Linguistics > Evolution of Language
Subgroup discovery
Authors: Atzmueller Martin
Published: January 2015

Subgroup discovery is a broadly applicable descriptive data mining technique for identifying interesting subgroups according to some property of interest. This article summarizes fundamentals of subgroup discovery, before that it also reviews algorithms and further advanced methodological issues. In addition, we briefly discuss tools and applications of subgroup discovery approaches. In that context, we also discuss experiences and lessons learned and outline some of the future directions in order to show the advantages and benefits of subgroup discovery. WIREs Data Mining Knowl Discov 2015, 5:35–49. doi: 10.1002/widm.1144

This article is categorized under:

Fundamental Concepts of Data and Knowledge > Motivation and Emergence of Data Mining