bluuebunny/crossref_metadata_2025 huggingface dataset:
Stochastic representation of solutions to degenerate elliptic and parabolic boundary value and obstacle problems with Dirichlet boundary conditions
Authors: Feehan Paul , Pop Camelia
Published: October 2014

We prove existence and uniqueness of stochastic representations for solutions to elliptic and parabolic boundary value and obstacle problems associated with a degenerate Markov diffusion process. In particular, our article focuses on the Heston stochastic volatility process, which is widely used as an asset price model in mathematical finance and a paradigm for a degenerate diffusion process where the degeneracy in the diffusion coefficient is proportional to the square root of the distance to the boundary of the half-plane. The generator of this process with killing, called the elliptic Heston operator, is a second-order, degenerate, elliptic partial differential operator whose coefficients have linear growth in the spatial variables and where the degeneracy in the operator symbol is proportional to the distance to the boundary of the half-plane. In mathematical finance, solutions to terminal/boundary value or obstacle problems for the parabolic Heston operator correspond to value functions for American-style options on the underlying asset.
Reflection group presentations arising from cluster algebras
Authors: Barot Michael , Marsh Bethany
Published: October 2014

We give a presentation of a finite crystallographic reflection group in terms of an arbitrary seed in the corresponding cluster algebra of finite type and interpret the presentation in terms of companion bases in the associated root system.
Increase in cellular triacylglycerol content and emergence of large ER-associated lipid droplets in the absence of CDP-DG synthase function
Authors: He Yue , Yam Candice , Pomraning Kyle , Chin Jacqueline S. R. , Yew Joanne Y. , Freitag Michael , Oliferenko Snezhana
Published: October 2014

Excess fatty acids and sterols are stored as triacylglycerols and sterol esters in specialized cellular organelles, called lipid droplets. Understanding what determines the cellular amount of neutral lipids and their packaging into lipid droplets is of fundamental and applied interest. Using two species of fission yeast, we show that cycling cells deficient in the function of the ER-resident CDP-DG synthase Cds1 exhibit markedly increased triacylglycerol content and assemble large lipid droplets closely associated with the ER membranes. We demonstrate that these unusual structures recruit the triacylglycerol synthesis machinery and grow by expansion rather than by fusion. Our results suggest that interfering with the CDP-DG route of phosphatidic acid utilization rewires cellular metabolism to adopt a triacylglycerol-rich lifestyle reliant on the Kennedy pathway.
Pooled assembly of marine metagenomic datasets: enriching annotation through chimerism
Authors: Magasin Jonathan D. , Gerloff Dietlind L.
Published: October 2014

Motivation: Despite advances in high-throughput sequencing, marine metagenomic samples remain largely opaque. A typical sample contains billions of microbial organisms from thousands of genomes and quadrillions of DNA base pairs. Its derived metagenomic dataset underrepresents this complexity by orders of magnitude because of the sparseness and shortness of sequencing reads. Read shortness and sequencing errors pose a major challenge to accurate species and functional annotation. This includes distinguishing known from novel species. Often the majority of reads cannot be annotated and thus cannot help our interpretation of the sample.

Results: Here, we demonstrate quantitatively how careful assembly of marine metagenomic reads within, but also across, datasets can alleviate this problem. For 10 simulated datasets, each with species complexity modeled on a real counterpart, chimerism remained within the same species for most contigs (97%). For 42 real pyrosequencing (‘454’) datasets, assembly increased the proportion of annotated reads, and even more so when datasets were pooled, by on average 1.6% (max 6.6%) for species, 9.0% (max 28.7%) for Pfam protein domains and 9.4% (max 22.9%) for PANTHER gene families. Our results outline exciting prospects for data sharing in the metagenomics community. While chimeric sequences should be avoided in other areas of metagenomics (e.g. biodiversity analyses), conservative pooled assembly is advantageous for annotation specificity and sensitivity. Intriguingly, our experiment also found potential prospects for (low-cost) discovery of new species in ‘old’ data.

Contact:  dgerloff@ffame.org

Supplementary information:  Supplementary data are available at Bioinformatics online.
GeneNet Toolbox for MATLAB: a flexible platform for the analysis of gene connectivity in biological networks
Authors: Taylor Avigail , Steinberg Julia , Andrews Tallulah S. , Webber Caleb
Published: October 2014

Summary : We present GeneNet Toolbox for MATLAB (also available as a set of standalone applications for Linux). The toolbox, available as command-line or with a graphical user interface, enables biologists to assess connectivity among a set of genes of interest (‘seed-genes’) within a biological network of their choosing. Two methods are implemented for calculating the significance of connectivity among seed-genes: ‘seed randomization’ and ‘network permutation’. Options include restricting analyses to a specified subnetwork of the primary biological network, and calculating connectivity from the seed-genes to a second set of interesting genes. Pre-analysis tools help the user choose the best connectivity-analysis algorithm for their network. The toolbox also enables visualization of the connections among seed-genes. GeneNet Toolbox functions execute in reasonable time for very large networks (∼10 million edges) on a desktop computer.

Availability and implementation : GeneNet Toolbox is open source and freely available from http://avigailtaylor.github.io/gntat14 .

Supplementary information : Supplementary data are available at Bioinformatics online.

Contact:  avigail.taylor@dpag.ox.ac.uk
Marine conservation of multispecies and multi-use areas with various conservation objectives and targets
Authors: Schmiing Mara , Diogo Hugo , Serrão Santos Ricardo , Afonso Pedro
Published: October 2014

Marine spatial management is an important step in regulating the sustainable use of marine resources and preserving habitats and species. The systematic conservation planning software “Marxan” was used to analyse the effect of different conservation objectives and targets on the design of a network of marine protected areas around two islands of the Azores archipelago, Northeast Atlantic. The analyses integrated spatial patterns of the abundance and reproductive potential of multispecies, the vulnerability of fish to fishing, habitat type, algae biotopes, and socio-economic costs and benefits (including fishing effort and recreational activities). Three scenarios focused on fisheries-related objectives (“fisheries scenarios”, FSs) and three on multiple-use and biodiversity conservation objectives (“biodiversity scenarios”, BSs), respectively. Three different protection targets were compared for each set, the existing, minimum, and maximum levels of protection, whereas conservation features were weighted according to their biologically/ecologically functioning. Results provided contrasting solutions for site selection and identified potential gaps in the existing design. The influence of the conservation objective on site selection was most evident when minimum target levels were applied. Otherwise, solutions for FSs and BSs were very similar and mostly shaped by the protection level. More important, BSs that considered opportunity cost and benefits achieved conservation targets more cost-efficiently. The presented systematic approach ensures that targets for habitats with high fish abundance, fecundity, and vulnerability are achieved efficiently. It should be of high applicability for adaptive management processes to improve the effectiveness of existing spatial management practices, in particular when fishing and leisure activities coexist, and suggest that decision-makers should account for multiple users’ costs and benefits when designing and implementing marine reserve networks.
Two-staged Correction of Severe Congenital Scoliosis Associated With Intraspinal Abnormalities
Authors: Zhang Zhenxing , Hui Hua , Liu Tuanjiang , Zhang Zhenping , Hao Dingjun
Published: October 2014

Study Design:

A retrospective study.

Objective:

To analyze the efficacy and safety of perioperative halo-gravity traction as an adjunct to posterior vertebral column resection (PVCR) in the treatment of patients with severe congenital scoliosis and coexisting asymptomatic intraspinal pathologies (diastematomyelia and/or tethered cord).

Summary of Background Data:

Few reports to our knowledge review the use of perioperative halo-gravity traction and PVCR in this patient population.

Materials and Methods:

A total of 17 patients with a minimum 2-year follow-up who underwent PVCR using perioperative halo-gravity traction were analyzed. Patients were analyzed by age at date of examination (range, 11–23 y; mean, 14.4 y), sex (7 male, 10 female), major coronal curve magnitude (range, 108–149 degrees; average, 125 degrees), major sagittal curve magnitude (range, 72–118 degrees; average, 91 degrees). Complications related to halo traction and PVCR were reviewed.

Results:

Radiographic outcomes demonstrated Cobb angle of major curve had an average correction of 28% after halo traction and it measured 53 degrees (range, 42–84 degrees) at the last follow-up, for a 58% correction. Maximal kyphosis improved to 58 degrees (range, 43–76 degrees) at ultimate follow-up. There were no permanent neurological deficits in this series.

Conclusions:

The study results suggested that surgical treatment for intraspinal abnormality may be unnecessary in asymptomatic patients with severe congenital scoliosis who are undergoing scoliosis corrective surgery. PVCR combined with perioperative traction is a safe and effective alternative for such patients.
Reasons of Dysphagia After Operation of Anterior Cervical Decompression and Fusion
Authors: Wu Bing , Song Fei , Zhu Shourong
Published: October 2014

Study Design:

Retrospective study.

Objective:

To analyze the reasons, clinical manifestation, risk factors, prevention, and treatment of dysphagia after operation of anterior cervical decompression and fusion (ACDF).

Summary of Background Data:

Dysphagia is one of severe complications after ACDF. There were a few studies about reasons and prevention of dysphagia.

Methods:

We retrospectively reviewed medical charts of patients who underwent ACDF in our hospital from January 2012 to December 2012. Clinical symptom of dysphagia was recorded at the perioperative period and at the third and sixth month of the follow-up after surgery and assigned according to the Bazaz dysphagia score. We analyzed the reasons and risk factors leading to dysphagia and tried to find effective programs of prevention and treatment.

Results:

There were 358 patients who underwent ACDF. Of 358 patients, 39 patients including 14 men and 25 women complained of dysphagia. The mean age was 46.8 years, with an age range of 38–67 years. Clinical manifestation of dysphagia included difficulty to swallow, pain during swallowing, sticky throat feeling, and choking. All the patients were followed up over 6 months. The incidences of dysphagia were 10.9%, 6.4%, and 2.7%, respectively, at 1–5 days, 3 months, and 6 months after surgery. There was no severe dysphagia at 3 months after surgery. Mild or moderate dysphagia slightly affected the quality of life. Logistic regression showed multilevel cervical spine, and high-level cervical spine surgeries are high-risk factors for postoperative dysphagia.

Conclusions:

Dysphagia is a common complication of ACDF. Causes of dysphagia include multilevel cervical spine and upper cervical spine surgeries. Use of methylprednisolone and careful operation can reduce the incidence and result in good prognosis.
Perioperative Outcomes After Cervical Laminoplasty Versus Posterior Decompression and Fusion
Authors: Varthi Arya G. , Basques Bryce A. , Bohl Daniel D. , Golinvaux Nicholas S. , Grauer Jonathan N.
Published: October 2014

Study Design:

Retrospective cohort study.

Objective:

To compare the short-term outcomes for patients undergoing cervical laminoplasty versus posterior decompression and fusion for multilevel cervical pathology.

Summary of Background Data:

There are conflicting data regarding the merits of cervical laminoplasty and posterior decompression and fusion for the treatment of multilevel cervical pathology.

Methods:

Patients who underwent cervical laminoplasty or posterior decompression and fusion were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database from 2010 to 2012. Baseline patient characteristics were compared using bivariate logistic regression. Propensity-adjusted multivariate regressions were performed to assess differences in postoperative length of stay, adverse events, and 30-day readmission.

Results:

A total of 779 patients were included in this study: 437 (56.1%) underwent cervical decompression and fusion and 342 (43.9%) underwent cervical laminoplasty. Decompression and fusion patients were found to be more comorbid at baseline than laminoplasty patients based on increased American Society of Anesthesiologists scores and Charlson Comorbidity Index.

Propensity-adjusted multivariate analysis was used to control for differences in baseline patient characteristics, and found that compared with laminoplasty patients, decompression and fusion patients had increased length of stay (+1.2 d, P<0.001), greater rates of any adverse event (OR=1.7, P=0.018), and were more likely to be readmitted (OR=2.3, P=0.028).

Conclusions:

Posterior cervical decompression and fusion patients were found to have moderately worse short-term outcomes than laminoplasty patients. The information provided here can be used to inform patients and surgeons about the likely perioperative experience after they have made the decision to pursue 1 of these 2 procedures.
The Long-term Outcome of Early Spine Fusion for Scoliosis in Children With Cerebral Palsy
Authors: Sitoula Prakash , Holmes Laurens , Sees Julieanne , Rogers Kenneth , Dabney Kirk , Miller Freeman
Published: October 2014

Study Design:

Retrospective review of radiographs and charts (case-only).

Objective:

The aim of this study was to describe the long-term outcomes of spine fusion for neuromuscular scoliosis in children below 10 years of age with cerebral palsy (CP).

Summary of Background Data:

Severely involved children with CP may develop early-onset scoliosis. The outcome of spine fusion is not clear and there are no studies focused on spine fusion in this young patient population.

Methods:

This is a retrospective review of 33 children who underwent spine fusion with unit-rod instrumentation between 1989 and 2006 for CP neuromuscular scoliosis, aged below 10 years at spine fusion, and with follow-up >5 years. Demographic, medical, and radiographic data were retrospectively assessed. Repeated measure analysis of variance and Kaplan-Meier survival estimates were used for data assessment.

Results:

Thirty-three of 42 patients who underwent spine fusion in this period, 19 boys and 14 girls, met the inclusion criteria. Of 9 patients who were excluded, 3 were lost to follow-up and remaining 6 died within 5 years of surgery. Mean age at surgery was 8.3 years (range, 4.4–9.9 y). Mean follow-up was 9.8 years (range, 5.5–15.8 y). Gross motor function classification system level was V in 31 patients and IV in 2 patients. Thirty-one patients (94%) had seizure disorder, 29 patients (88%) had gastric feeding tubes, and 9 patients (27%) had tracheostomy tubes. Eighty-five percent of the patients had posterior-only surgery. Mean Cobb angles preoperative, immediately postoperative, and at final follow-up were 85, 21, and 24 degrees, respectively. Mean postoperative pelvic obliquity correction was 15±9 degrees (P<0.001). At final follow-up, there was no significant change from the postoperative measurements. Complications included 1 deep wound infection and 10 other problems. Eleven patients (28.2%) died after a mean follow-up of 5.6±3.8 years.

Conclusions:

In our cohort with early-onset neuromuscular scoliosis, spine fusion was associated with minimal short-term and long-term morbidity, but there was 28% mortality at 10 years of follow-up and 50% predicted mortality at 15 years.
Profile of Acute Asthma Exacerbation in Drug Users
Authors: Doshi Viral , Shenoy Sundeep , Ganesh Aarthi , Rishi Muhammad Adeel , Molnar Janos , Henkle Joseph
Published: October 2014

The characteristics of patients who use heroin, cocaine, or both and present with acute asthma exacerbations have not been well studied. In this retrospective study, we aimed to study the demographic characteristics of this patient population, the characteristics of their asthma attack, and the risk factors for the need for invasive mechanical ventilation in this patient population. We reviewed the charts of patients discharged from an inner-city hospital with a diagnosis of acute asthma exacerbation. Individuals who used either heroin or cocaine or both within 24 hours of presenting to the emergency department were identified as a cohort of drug users. The rest were classified as non–drug users. Both groups were compared, and a univariate analysis was performed. To assess the predictive value of drug use for the need for intubation in the presence of confounding factors, logistic regression analysis was performed to identify whether using cocaine or heroin or both was an individual predictor for the need for invasive ventilation. Data from 218 patients were analyzed. Drug users (n = 85) were younger (mean age in years 43.9 vs. 50.5, P < 0.01), predominantly male (63.5% vs. 33.8%, P < 0.01), and more likely to be cigarette smokers (90.6% vs. 57.6%, P < 0.01). A medical history of intubation and admissions to the intensive care unit (ICU) was more common among drug users (56.5% vs. 29.3%, P < 0.01 and 54.1% vs. 38.3%, P < 0.03, respectively). Drug use was associated with increased need for invasive mechanical ventilation (35% vs. 23.3%, P = 0.05). Non–drug users were more likely to be using inhaled corticosteroids (48.9% vs. 32.9%, P = 0.03) and had longitudinal care established with a primary care provider (50.6% vs. 68.9%, P < 0.01). After adjusting for a history of mechanical ventilation, history of ICU admission, use of systemic corticosteroids, smoking, and acute physiological assessment and chronic health evaluation 2 score, drug use remained predictive for the need for mechanical ventilation (P = 0.026). Acute asthma exacerbations triggered by cocaine and heroin should be treated aggressively because they represent a cohort with poor follow-up and undertreated asthma as outpatients and are associated with increased need for invasive mechanical ventilation and ICU admission during acute exacerbation.
To the non-local theory of cold nuclear fusion
Authors: Alexeev Boris V.
Published: October 2014

In this paper, we revisit the cold fusion (CF) phenomenon using the generalized Bolzmann kinetics theory which can represent the non-local physics of this CF phenomenon. This approach can identify the conditions when the CF can take place as the soliton creation under the influence of the intensive sound waves. The vast mathematical modelling leads to affirmation that all parts of soliton move with the same velocity and with the small internal change of the pressure. The zone of the high density is shaped on the soliton's front. It means that the regime of the ‘acoustic CF’ could be realized from the position of the non-local hydrodynamics.
Forward flight of birds revisited. Part 1: aerodynamics and performance
Authors: Iosilevskii G.
Published: October 2014

This paper is the first part of the two-part exposition, addressing performance and dynamic stability of birds. The aerodynamic model underlying the entire study is presented in this part. It exploits the simplicity of the lifting line approximation to furnish the forces and moments acting on a single wing in closed analytical forms. The accuracy of the model is corroborated by comparison with numerical simulations based on the vortex lattice method. Performance is studied both in tethered (as on a sting in a wind tunnel) and in free flights. Wing twist is identified as the main parameter affecting the flight performance—at high speeds, it improves efficiency, the rate of climb and the maximal level speed; at low speeds, it allows flying slower. It is demonstrated that, under most circumstances, the difference in performance between tethered and free flights is small.
Increased phosphorylation of the RcsB regulator of the RcsCDB phosphorelay in strains of Dickeya dadantii devoid of osmoregulated periplasmic glucans revealed by Phos-tag gel analysis
Authors: Madec Edwige , Bontemps-Gallo Sébastien , Lacroix Jean-Marie
Published: October 2014

Osmoregulated periplasmic glucans (OPGs) are general constituents of many proteobacteria. OPGs are important factors required for full virulence in many pathogens includingDickeya dadantii.D. dadantiicauses the soft-rot disease in a wide range of plant species. The pleiotropic phenotype ofopg-negative strains includes total loss of virulence and motility, and is linked to the constitutive activation of the RcsCDB phosphorelay, deduced from expression analysis of genes of the RcsCDB regulon. The constitutive activation of the RcsCDB phosphorelay in anopg-negative strain was demonstrated by direct analysis of the phosphorylation level of the RcsB regulator proteinin vivoby using a Phos-tag retardation gel approach, and was correlated with the phenotype and the expression of motility genes. Data revealed a low level of RcsB phosphorylated form in the wild-type strain and a slight increase of phosphorylation inopgGmutant strains sufficient to induce the pleiotropic phenotype observed.
All1371 is a polyphosphate-dependent glucokinase in Anabaena sp. PCC 7120
Authors: Klemke Friederike , Beyer Gabriele , Sawade Linda , Saitov Ali , Korte Thomas , Maldener Iris , Lockau Wolfgang , Nürnberg Dennis J. , Volkmer Thomas
Published: October 2014

The polyphosphate glucokinases can phosphorylate glucose to glucose 6-phosphate using polyphosphate as the substrate. ORFall1371encodes a putative polyphosphate glucokinase in the filamentous heterocyst-forming cyanobacteriumAnabaenasp. PCC 7120. Here, ORFall1371was heterologously expressed inEscherichia coli, and its purified product was characterized. Enzyme activity assays revealed that All1371 is an active polyphosphate glucokinase that can phosphorylate both glucose and mannose in the presence of divalent cationsin vitro. Unlike many other polyphosphate glucokinases, for which nucleoside triphosphates (e.g. ATP or GTP) act as phosphoryl group donors, All1371 required polyphosphate to confer its enzymic activity. The enzymic reaction catalysed by All1371 followed classical Michaelis–Menten kinetics, withkcat = 48.2 s−1at pH 7.5 and 28 °C andKM = 1.76 µM and 0.118 mM for polyphosphate and glucose, respectively. Its reaction mechanism was identified as a particular multi-substrate mechanism called the ‘bi-bi ping-pong mechanism’. Bioinformatic analyses revealed numerous polyphosphate-dependent glucokinases in heterocyst-forming cyanobacteria. Viability of anAnabaenasp. PCC 7120 mutant strain lackingall1371was impaired under nitrogen-fixing conditions. GFP promoter studies indicate expression ofall1371under combined nitrogen deprivation. All1371 might play a substantial role inAnabaenasp. PCC 7120 under these conditions.
Social evolution and genetic interactions in the short and long term
Authors: Van Cleve Jeremy
Published: October 2014

The evolution of social traits remains one of the most fascinating and feisty topics in evolutionary bi-ology even after half a century of theoretical research. W. D. Hamilton shaped much of the field initially with his 1964 papers that laid out the foundation for understanding the effect of genetic relatedness on the evolution of social behavior. Early theoretical investigations revealed two critical assumptions required for Hamilton’s rule to hold in dynamical models: weak selection and additive genetic interactions. However, only recently have analytical approaches from population genetics and evolutionary game theory developed sufficiently so that social evolution can be studied under the joint action of selection, mutation, and genetic drift. We review how these approaches suggest two timescales for evolution under weak mutation: (i) a short-term timescale where evolution occurs between a finite set of alleles, and (ii) a long-term timescale where a continuum of alleles are possible and populations evolve continuously from one monomorphic trait to another. We show how Hamilton’s rule emerges from the short-term analysis under additivity and how non-additive genetic interactions can be accounted for more generally. This short-term approach re-produces, synthesizes, and generalizes many previous results including the one-third law from evolutionary game theory and risk dominance from economic game theory. Using the long-term approach, we illustrate how trait evolution can be described with a diffusion equation that is a stochastic analogue of the canonical equation of adaptive dynamics. Peaks in the stationary distribution of the diffusion capture classic notions of convergence stability from evolutionary game theory and generally depend on the additive genetic in-teractions inherent in Hamilton’s rule. Surprisingly, the peaks of the long-term stationary distribution can predict the effects of simple kinds of non-additive interactions. Additionally, the peaks capture both weak and strong effects of social payoffs in a manner difficult to replicate with the short-term approach. Together, the results from the short and long-term approaches suggest both how Hamilton’s insight may be robust in unexpected ways and how current analytical approaches can expand our understanding of social evolution far beyond Hamilton’s original work.
Divergent functions of hematopoietic transcription factors in lineage priming and differentiation during erythro-megakaryopoiesis
Authors: Pimkin Maxim , Kossenkov Andrew V. , Mishra Tejaswini , Morrissey Christapher S. , Wu Weisheng , Keller Cheryl A. , Blobel Gerd A. , Lee Dongwon , Beer Michael A. , Hardison Ross C. , Weiss Mitchell J.
Published: October 2014

Combinatorial actions of relatively few transcription factors control hematopoietic differentiation. To investigate this process in erythro-megakaryopoiesis, we correlated the genome-wide chromatin occupancy signatures of four master hematopoietic transcription factors (GATA1, GATA2, TAL1, and FLI1) and three diagnostic histone modification marks with the gene expression changes that occur during development of primary cultured megakaryocytes (MEG) and primary erythroblasts (ERY) from murine fetal liver hematopoietic stem/progenitor cells. We identified a robust, genome-wide mechanism of MEG-specific lineage priming by a previously described stem/progenitor cell-expressed transcription factor heptad (GATA2, LYL1, TAL1, FLI1, ERG, RUNX1, LMO2) binding to MEG-associated cis-regulatory modules (CRMs) in multipotential progenitors. This is followed by genome-wide GATA factor switching that mediates further induction of MEG-specific genes following lineage commitment. Interaction between GATA and ETS factors appears to be a key determinant of these processes. In contrast, ERY-specific lineage priming is biased toward GATA2-independent mechanisms. In addition to its role in MEG lineage priming, GATA2 plays an extensive role in late megakaryopoiesis as a transcriptional repressor at loci defined by a specific DNA signature. Our findings reveal important new insights into how ERY and MEG lineages arise from a common bipotential progenitor via overlapping and divergent functions of shared hematopoietic transcription factors.
Widespread contribution of transposable elements to the innovation of gene regulatory networks
Authors: Sundaram Vasavi , Cheng Yong , Ma Zhihai , Li Daofeng , Xing Xiaoyun , Edge Peter , Snyder Michael P. , Wang Ting
Published: October 2014

Transposable elements (TEs) have been shown to contain functional binding sites for certain transcription factors (TFs). However, the extent to which TEs contribute to the evolution of TF binding sites is not well known. We comprehensively mapped binding sites for 26 pairs of orthologous TFs in two pairs of human and mouse cell lines (representing two cell lineages), along with epigenomic profiles, including DNA methylation and six histone modifications. Overall, we found that 20% of binding sites were embedded within TEs. This number varied across different TFs, ranging from 2% to 40%. We further identified 710 TF–TE relationships in which genomic copies of a TE subfamily contributed a significant number of binding peaks for a TF, and we found that LTR elements dominated these relationships in human. Importantly, TE-derived binding peaks were strongly associated with open and active chromatin signatures, including reduced DNA methylation and increased enhancer-associated histone marks. On average, 66% of TE-derived binding events were cell type-specific with a cell type-specific epigenetic landscape. Most of the binding sites contributed by TEs were species-specific, but we also identified binding sites conserved between human and mouse, the functional relevance of which was supported by a signature of purifying selection on DNA sequences of these TEs. Interestingly, several TFs had significantly expanded binding site landscapes only in one species, which were linked to species-specific gene functions, suggesting that TEs are an important driving force for regulatory innovation. Taken together, our data suggest that TEs have significantly and continuously shaped gene regulatory networks during mammalian evolution.
Time course of the rabbit's conditioned nictitating membrane movements during acquisition, extinction, and reacquisition
Authors: Kehoe E. James , Ludvig Elliot A. , Sutton Richard S.
Published: October 2014

The present experiment tested whether or not the time course of a conditioned eyeblink response, particularly its duration, would expand and contract, as the magnitude of the conditioned response (CR) changed massively during acquisition, extinction, and reacquisition. The CR duration remained largely constant throughout the experiment, while CR onset and peak time occurred slightly later during extinction. The results suggest that computational models can account for these results by using two layers of plasticity conforming to the sequence of synapses in the cerebellar pathways that mediate eyeblink conditioning.
Appetitive context conditioning proactively, but transiently, interferes with expression of counterconditioned context fear
Authors: Holmes Nathan M. , Westbrook R. Frederick
Published: October 2014

Four experiments used rats to study appetitive–aversive transfer. Rats trained to eat a palatable food in a distinctive context and shocked in that context ate and did not freeze when tested 1 d later but froze and did not eat when tested 14 d later. These results were associatively mediated (Experiments 1 and 2), observed when rats were or were not food deprived (Experiments 1 and 2), and were not due to latent inhibition (Experiment 3). In contrast, rats trained to eat in the context and shocked there 13 d later froze and did not eat when tested 1 d after the shocked exposure. However, rats that received an additional eating session in the context 1 d before the shocked exposure ate and did not freeze when tested 1 d after the shocked exposure (Experiment 4). The results show that appetitive conditioning transiently interferes with aversive conditioning. They are discussed in terms of a weak context–shock association becoming stronger with the lapse of time (so-called fear incubation) or of the interference by the context–food association becoming weaker with the lapse of time.
Prediction error demarcates the transition from retrieval, to reconsolidation, to new learning
Authors: Sevenster Dieuwke , Beckers Tom , Kindt Merel
Published: October 2014

Although disrupting reconsolidation is promising in targeting emotional memories, the conditions under which memory becomes labile are still unclear. The current study showed that post-retrieval changes in expectancy as an index for prediction error may serve as a read-out for the underlying processes engaged by memory reactivation. Minor environmental changes define whether retrieval induces memory reconsolidation or the initiation of a new memory trace even before fear extinction can be observed.
Synthesis, growth mechanism and physical properties of vapour-deposited GaTe platelets
Authors: Kunjomana A. G. , Teena M. , Chandrasekharan K. A.
Published: October 2014

The physical vapour deposition (PVD) method has been employed to yield gallium telluride (GaTe) platelets. The morphology and growth mechanism of these platelets were investigated with the aid of scanning electron micrographs. The stoichiometry and homogeneity of the grown samples were confirmed by chemical analysis. The X-ray diffraction (XRD) technique has been used to explore the structure and phase of the compound. On the basis of the Archimedes principle, the density of crystals was estimated to be 5.442 kg mm−3. The resistivity and conductivity type were determined by the van der Pauw method. UV–vis–NIR studies revealed a direct transition with an energy gap of 1.69 eV. Mechanical properties such as microhardness, toughness, Young's modulus and elastic stiffness constant of GaTe crystals in response to the stress field due to an external load were studied to realize their suitability for radiation detector applications. The present observations provide an insight into the physical properties of the vapour-grown GaTe platelets, which are found to be superior over their melt counterparts.
An accurate parameterization for scattering factors, electron densities and electrostatic potentials for neutral atoms that obey all physical constraints
Authors: Lobato I. , Van Dyck D.
Published: October 2014

An efficient procedure and computer program are outlined for fitting numerical X-ray and electron scattering factors with the correct inclusion of all physical constraints. The numerical electron scattering factors have been parameterized using five analytic non-relativistic hydrogen electron scattering factors as basis functions for 103 neutral atoms of the periodic table. The inclusion of the correct physical constraints in the electron scattering factor and its derived quantities allows the use of the new parameterization in different fields. In terms of quality of the fit, the proposed parameterization of the electron scattering factor is one order of magnitude better than the previous analytic fittings.
Psychopathology in severely obese women from a Canadian bariatric setting
Authors: Strimas Rachel , M. Dionne Michelle , E. Cassin Stephanie , Wnuk Susan , Taube-Schiff Marlene , Sockalingam Sanjeev
Published: October 2014

Purpose

– Evidence suggests high rates of psychiatric disorders in bariatric surgery candidates (e.g. Mitchell et al., 2012), although no rigorous studies have examined the prevalence in a Canadian sample. Improved understanding of the prevalence of psychopathology among female patients is an important area of study, as females comprise approximately 80 percent of surgical candidates (Martin et al., 2010; Padwal, 2005). The purpose of this paper is to assess the prevalence of Axis I disorders and associations with quality of life in a Canadian sample of female bariatric surgery candidates.

Design/methodology/approach

– Female patients (n=257) were assessed using a structured psychodiagnostic interview and completed a health-related quality of life questionnaire.

Findings

– Results indicated that 57.2 percent of patients met DSM-IV-TR criteria for a lifetime psychiatric disorder and 18.3 percent met criteria for a current psychiatric disorder. Major depressive disorder was the most common lifetime psychiatric disorder (35.0 percent) and binge eating disorder was the most prevalent current psychiatric disorder (6.6 percent). Patients scored significantly lower than Canadian population norms on all domains of the SF-36 (all p's<0.001). Patients with a current Axis I disorder also reported significantly worse functioning on four mental health domains and one physical health domain (p's<0.01) compared to patients without a current Axis I disorder.

Originality/value

– Results confirm high rates of psychiatric disorders in Canadian female bariatric surgery candidates and provide evidence for associated functional health impairment. Further study is needed to elucidate how pre-operative psychopathology may impact female patients’ post-operative outcomes.
The impact of education on weight control beliefs
Authors: M. Laliberte Michele , Balk Daniel , Tweed Stacey , Smith Jessica , Ghai Amrita
Published: October 2014

Purpose

– The purpose of this paper is to investigate whether reading a self-help chapter on the body's regulation of weight can change weight control beliefs, and whether such changes in turn predict improvements in body dissatisfaction and self-esteem.

Design/methodology/approach

– Participants of a mixed racial sample of undergraduate college women (n=154) completed measures of personal weight control beliefs, body dissatisfaction, self-esteem and knowledge before and after they read a self-help education chapter.

Findings

– Exposure to the education was associated with improvement in knowledge, body dissatisfaction and self-esteem and change in weight control beliefs. Increase in the belief in “striving for a healthy lifestyle with acceptance of one's natural weight” predicted improvement in body dissatisfaction and self-esteem.

Research limitations/implications

– This paper provides preliminary evidence that realistic information about weight control can impact weight control beliefs, and that this in turn is associated with improvement in body satisfaction and self-esteem. The major limitation of the study is the lack of control group to ensure changes are not due to factors like social desirability. Future directions would be to replicate this research using a control group, and to look at the role of education and weight control beliefs in eating disordered and bariatric populations.

Originality/value

– This is the first study to look at the impact of providing young women with realistic information about the body's regulation of weight and weight loss outcomes on their beliefs about weight control, body dissatisfaction and self-esteem. This information is valuable for health care providers and educators working with young women.
Body image concerns in obese women seeking bariatric surgery
Authors: Ghai Amrita , Milosevic Irena , Laliberte Michele , H. Taylor Valerie , E. McCabe Randi
Published: October 2014

Purpose

– The purpose of this paper is to assess multidimensional body image concerns in a sample of obese women seeking bariatric surgery at an outpatient hospital clinic in Hamilton, Ontario, Canada.

Design/methodology/approach

– A sample of obese adult women seeking bariatric surgery at an outpatient medical clinic in Hamilton, Ontario, Canada (n=148) completed various self-report measures of body image concerns, including body image dysphoria, body image quality of life, body image investment, and appearance satisfaction. Participant scores were compared to normative data. Correlations between body image concern measures and body mass index (BMI) were examined.

Findings

– Participants endorsed more body image dysphoria, more negative body image quality of life, and less appearance satisfaction than normative samples. BMI was not correlated with body image concern scores.

Practical implications

– Interventions aimed at reducing body image disturbance in obese women should target multiple components of body image concern. Decisions about who should receive interventions should not be based on BMI status.

Originality/value

– The majority of research on body image concerns focuses exclusively on evaluative constructs such as body image dissatisfaction. The current study examined affective, cognitive, and behavioural body image constructs. A better understanding of the multidimensional nature of body image concerns in obese women seeking bariatric surgery informs the development of effective, targeted interventions.
Knowledge sharing: insights from Campaign for Real Ale (CAMRA) Festival volunteers
Authors: Ragsdell Gillian , Jepson Allan
Published: October 2014

Purpose

– The purpose of this paper is to report the findings of a British Academy funded project that investigated the knowledge sharing activities of volunteers within three Campaign for Real Ale (CAMRA) festivals.

Design/methodology/approach

– Three case study festivals were selected based on factors such as longevity and size. Rich qualitative data were collected using semi-structured interviews with volunteers in key festival roles and focus groups with a range of other volunteers.

Findings

– A range of inhibitors and enablers to sharing festival knowledge were identified, some of which have not yet featured in the knowledge management (KM) literature. Riege's categorisation of individual, organisational and technological barriers to knowledge sharing was used to frame discussion of the findings.

Research limitations/implications

– Volunteer-led festivals are a novel context for knowledge sharing research yet the principles of volunteer working and the project-based approach to most festivals means they are a fertile arena for lessons in KM.

Practical implications

– Insights into knowledge sharing activities were generated from this study which could improve KM practices in festivals. They included the use of the master-apprentice model, raising the value of post-project reviews and designing festival layout with knowledge sharing in mind.

Originality/value

– The study of knowledge sharing is an original contribution to the field of event management.
Emporda music festivals as tourism diversification tools
Authors: Diaz Soria Inmaculada , Blanco-Romero Asunción , Canoves I. Valiente Gemma
Published: October 2014

Purpose

– The purpose of this paper is to focus on territorial dynamics generated by five music festivals in the Emporda region (Spain) and its tourism sector.

Design/methodology/approach

– Using qualitative methodology, 10 qualified informants were interviewed. Their answers were coded and analysed.

Findings

– Territorial features favour the organisation of festivals. Promoters wish to offer some added value using local products. Festivals broadcast local identity to the world. Festivals’ features as tourist products explain how they are perceived as innovative.

Practical implications

– These existing products are being further developed to meet cultural tourism requirements. This strategy is justified by the search for innovation in a fiercely global competitive context.

Originality/value

– Current paper focuses on a present product and analyses its transformation: how a territory uses an old strategy in a new way generating future opportunities for tourism sector and local economies.
Factors explaining the use-value of sport event experiences
Authors: D. Andersson Tommy , Armbrecht John
Published: October 2014

Purpose

– The purpose of this paper is to propose and test a model explaining the value of event experiences.

Design/methodology/approach

– Three versions of the explanatory model are tested by regression analysis of data from a survey of 650 visitors to a sports event.

Findings

– The three model versions are significant and explain the value of event experiences with satisfactoryR2 values (0.29, 0.46 and 0.68) using the concepts “Extent of visit”, “Experience intensity” and “Expenditure”. The measures of event experiences (Use-Value, Direct Use-Value as well as Indirect Use-Value) meet requirements for reliability and validity.

Originality/value

– The paper reveals that explanatory models are basic but novel in a sports event context and provide a basis for further research. Furthermore, the definition of Indirect Use-Value has been clarified and adapted for higher relevance to destination managers focusing on event tourism.
Cross training efficiency and flexibility with process change
Authors: A. Nembhard David
Published: October 2014

Purpose

– The purpose of this paper is to investigate the tradeoffs between efficiency and flexibility in production processes involve a cross-trained workforce. The study quantifies production losses that stem from worker learning and forgetting in a cross-training environment.

Design/methodology/approach

– The paper examines multiple levels of cross-training in the context of several workplace factors including absenteeism, turnover, process change frequency, and process change magnitude using discrete event simulation. The parameters of the simulation model are informed by data from a operating manufacturing system.

Findings

– Results suggest that productivity gains obtained from a moderate level of cross-training (e.g. two tasks) can outweigh the production losses from additional training, and that adding further cross-training beyond this may negatively affect system performance.

Originality/value

– Production systems exist in an environment of process change and competitive pressure. Cross-training is an often-used operational technology for managing process knowledge in an environment of change as well as providing employees with a richer work environment. While the potential benefits of enriching the workplace experience include greater motivation, less boredom and fatigue, greater task vigilance, and other effects generally regarded as beneficial, productivity losses brought about by training and retraining disruptions associated with cross-training have not been examined as widely.
Delegation revisited: how delegation can benefit globally-minded managers
Authors: G. Banford Christopher , Ronald Buckley M. , Roberts Foster
Published: October 2014

Purpose

– The purpose of this paper is to examine how the effectiveness of delegation as a management practice is impacted by various factors such as manager cognition, perceived subordinate competence, and cultural differences. This research may help global business leaders to better understand how cultural differences may impact managerial functions and how to manage culturally diverse employees.

Design/methodology/approach

– This paper is based upon a conceptual discussion of delegation as it has been studied in the past and a reflection on the ways in which past research can usefully inform current trends in the use of delegation as a management practice.

Findings

– A model is proposed that suggests that the effectiveness of delegation in a local context is a function of the global leader’s cognitions and perceptions of their subordinates. Further, it suggests that this relationship is moderated by the local cultural context in that some cultures may be opposed to being delegated authority.

Research limitations/implications

– This paper presents a conceptual framework and therefore empirical applicability of this model must be proven.

Originality/value

– Delegation is an under-researched management practice. This paper contributes to the delegation literature by exploring its value to management in a global context.