bluuebunny/crossref_metadata_2025_split huggingface dataset:
On linear instability of solitary waves for the nonlinear Dirac equation
Authors: Guan Meijiao , Comech Andrew , Gustafson Stephen 
Published: June 2013

We consider the nonlinear Dirac equation, also known as the Soler model:

i\partial _{t}\psi = −i\boldsymbol{\alpha } \cdot \mathbf{∇}\psi + m\beta \psi −\left(\psi ^{⁎}\beta \psi \right)^{k}\beta \psi ,\:m > 0,\:\psi (x,t) \in \mathbb{C}^{N},\:x \in \mathbb{R}^{n},\:k \in \mathbb{N}.

We study the point spectrum of linearizations at small amplitude solitary waves in the limit

\omega \rightarrow m

, proving that if

k > 2/ n

, then one positive and one negative eigenvalue are present in the spectrum of the linearizations at these solitary waves with

ω

sufficiently close to

m

, so that these solitary waves are linearly unstable. The approach is based on applying the Rayleigh–Schrödinger perturbation theory to the nonrelativistic limit of the equation. The results are in formal agreement with the Vakhitov–Kolokolov stability criterion.

Résumé

Nous considérons l'équation de Dirac non linéaire, aussi connue comme modèle de Soler. Nous étudions le spectre ponctuel des linéarisations autour d'ondes solitaires de petite amplitude dans la limite

\omega \rightarrow m

, et montrons que si

k > 2/ n

une valeur propre positive et une négative sont présentes dans le spectre des linéarisations autour de ces ondes solitaires lorsque

ω

est suffisamment proche de

m

, ce qui entraîne que ces ondes solitaires sont linéairement instables. L'approche est basée sur l'application de la théorie des perturbations de Rayleigh–Schrödinger à la limite non relativiste de l'équation. Les résultats sont en accord formel avec le critère de stabilité de Vakhitov–Kolokolov.
Flow of a viscous nematic fluid around a sphere
Authors: Gómez-González Manuel , del Álamo Juan C. 
Published: June 2013

AbstractWe analyse the creeping flow generated by a spherical particle moving through a viscous fluid with nematic directional order, in which momentum diffusivity is anisotropic and which opposes resistance to bending. Specifically, we provide closed-form analytical expressions for the response function, i.e. the equivalent to Stokes’s drag formula for nematic fluids. Particular attention is given to the rotationally pseudo-isotropic condition defined by zero resistance to bending, and to the strain pseudo-isotropic condition defined by isotropic momentum diffusivity. We find the former to be consistent with the rheology of biopolymer networks and the latter to be closer to the rheology of nematic liquid crystals. These ‘pure’ anisotropic conditions are used to benchmark existing particle tracking microrheology methods that provide effective directional viscosities by applying Stokes’s drag law separately in different directions. We find that the effective viscosity approach is phenomenologically justified in rotationally isotropic fluids, although it leads to significant errors in the estimated viscosity coefficients. On the other hand, the mere concept of directional effective viscosities is found to be misleading in fluids that oppose an appreciable resistance to bending. Finally, we observe that anisotropic momentum diffusivity leads to asymmetric streamline patterns displaying enhanced (reduced) streamline deflection in the directions of lower (higher) diffusivity. The bending resistance of the fluid is found to modulate the asymmetry of streamline deflection. In some cases, the combined effects of both anisotropy mechanisms leads to streamline patterns that converge towards the sphere.
Reflections on dissipation associated with thermal convection
Authors: Alboussière Thierry , Ricard Yanick 
Published: June 2013

AbstractBuoyancy-driven convection is modelled using the Navier–Stokes and entropy equations. It is first shown that the coefficient of heat capacity at constant pressure, ${c}_{p} $, must in general depend explicitly on pressure (i.e. is not a function of temperature alone) in order to resolve a dissipation inconsistency. It is shown that energy dissipation in a statistically steady state is the time-averaged volume integral of $- \mathrm{D} P/ \mathrm{D} t$ and not that of $- \alpha T(\mathrm{D} P/ \mathrm{D} t)$. Secondly, in the framework of the anelastic equations derived with respect to the adiabatic reference state, we obtain a condition when the anelastic liquid approximation can be made, $\gamma - 1\ll 1$, independent of the dissipation number.
Reduced-energy cranberry juice increases folic acid and adiponectin and reduces homocysteine and oxidative stress in patients with the metabolic syndrome
Authors: Simão Tathiana Name Colado , Lozovoy Marcell Alysson Batisti , Simão Andréa Name Colado , Oliveira Sayonara Rangel , Venturini Danielle , Morimoto Helena Kaminami , Miglioranza Lúcia Helena Silva , Dichi Isaias 
Published: June 2013

The metabolic syndrome (MetS) comprises pathological conditions that include insulin resistance, arterial hypertension, visceral adiposity and dyslipidaemia, which favour the development of CVD. Some reports have shown that cranberry ingestion reduces cardiovascular risk factors. However, few studies have evaluated the effect of this fruit in subjects with the MetS. The objective of the present study was to assess the effect of reduced-energy cranberry juice consumption on metabolic and inflammatory biomarkers in patients with the MetS, and to verify the effects of cranberry juice concomitantly on homocysteine and adiponectin levels in patients with the MetS. For this purpose, fifty-six individuals with the MetS were selected and divided into two groups: control group (n36) and cranberry-treated group (n20). After consuming reduced-energy cranberry juice (0·7 litres/d) containing 0·4 mg folic acid for 60 d, the cranberry-treated group showed an increase in adiponectin (P= 0·010) and folic acid (P= 0·033) and a decrease in homocysteine (P< 0·001) in relation to baseline values and also in comparison with the controls (P< 0·05). There was no significant change in the pro-inflammatory cytokines TNF-α, IL-1 and IL-6. In relation to oxidative stress measurements, decreased (P< 0·05) lipoperoxidation and protein oxidation levels assessed by advanced oxidation protein products were found in the cranberry-treated group when compared with the control group. In conclusion, the consumption of cranberry juice for 60 d was able to improve some cardiovascular risk factors. The present data reinforce the importance of the inverse association between homocysteine and adiponectin and the need for more specifically designed studies on MetS patients.
COULD PARENTAL RULES PLAY A ROLE IN THE ASSOCIATION BETWEEN SHORT SLEEP AND OBESITY IN YOUNG CHILDREN?
Authors: JONES CAROLINE H. D. , POLLARD TESSA M. , SUMMERBELL CAROLYN D. , BALL HELEN 
Published: June 2013

SummaryShort sleep duration is associated with obesity in young children. This study develops the hypothesis that parental rules play a role in this association. Participants were 3-year-old children and their parents, recruited at nursery schools in socioeconomically deprived and non-deprived areas of a North-East England town. Parents were interviewed to assess their use of sleep, television-viewing and dietary rules, and given diaries to document their child's sleep for 4 days/5 nights. Children were measured for height, weight, waist circumference and triceps and subscapular skinfold thicknesses. One-hundred and eight families participated (84 with complete sleep data and 96 with complete body composition data). Parental rules were significantly associated together, were associated with longer night-time sleep and were more prevalent in the non-deprived-area compared with the deprived-area group. Television-viewing and dietary rules were associated with leaner body composition. Parental rules may in part confound the association between night-time sleep duration and obesity in young children, as rules cluster together across behavioural domains and are associated with both sleep duration and body composition. This hypothesis should be tested rigorously in large representative samples.
Evaluating the relevance of dosimetric considerations to patient instructions regarding skin care during radiation therapy
Authors: Morley Lyndon , Cashell Angela , Sperduti Annette , McQuestion Maurene , Chow James C. L. 
Published: June 2013

AbstractIntroductionPatient teaching in radiation therapy may include restrictions on applying skin products owing to concerns that the presence of such materials may increase skin dose. These restrictions may create unnecessarily complicated and conflicting self-care instructions.PurposeTo determine what thickness of skin product is necessary to produce a clinically meaningful dose increase to the skin, and provide recommendations for evidence-based patient instructions.MethodsDosimetric measurements and Monte Carlo simulations were used to calculate skin dose under 0–1·5 mm thicknesses of two common classes of skin product for a variety of treatment geometries. The thickness of product required to produce a clinically significant dose increase to the skin was determined.ResultsThe thickness of product required to create a clinically meaningful dose increase was >0·7 mm for 10 × 10 cm2fields and >1·5 mm for 1 × 1 cm2fields. A typical application of product would be only 0·3 mm.ConclusionIt seems unrealistic to anticipate patients using sufficiently large quantities of skin product to be of clinical concern. We therefore recommend that there are no dosimetric reasons to restrict the use of these types of skin products during radiation therapy for common treatment scenarios.
Association of qLTG3-1 with germination stage cold tolerance in diverse rice germplasm from the Indian subcontinent
Authors: Challam Clarissa , Kharshing Gayle Alisha , Yumnam Julia S. , Rai Mayank , Tyagi Wricha 
Published: June 2013

Low temperature is a major constraint for crop productivity. To cope with this challenge, plants have developed several mechanisms to adapt to low temperature. Developing breeding strategies to enhance cold stress tolerance in crops requires an understanding of the mechanisms by which plants perceive and transmit cold stress-related signals to their cellular machinery, thereby activating adaptive responses. Only one quantitative trait locus for tolerance to low-temperature germination, qLTG3-1, has been narrowed down to the gene level in rice. A 71 bp indel that can be used to distinguish between tolerant and susceptible parents has been identified. We tested the 71 bp indel on 65 diverse rice genotypes including those adapted to colder climates of North and Northeastern India to find evidence of the tolerant allele (insertion) and to see whether it is associated with low-temperature germinability in these genotypes. Our results show that 48% of the rice genotypes tested carried the tolerant allele. The insertion was found to be significantly associated with cold tolerance during germination. Moreover, several landraces/improved varieties known for their superior performance in other abiotic stress conditions such as drought and high salinity conditions, and which were previously never exposed to low temperature, carry the beneficial allele for qLTG3-1, suggesting an additional role of this allele in adverse climatic conditions. This study enhances current understanding of the distribution of the tolerant allele qLTG3-1 in rice germplasm, which could help in the identification of suitable donors for potential marker-assisted breeding programmes.
The physical interaction of Mcm10 with Cdc45 modulates their DNA-binding properties
Authors: Di Perna Roberta , Aria Valentina , De Falco Mariarosaria , Sannino Vincenzo , Okorokov Andrei L. , Pisani Francesca M. , De Felice Mariarita 
Published: June 2013

The eukaryotic DNA replication protein Mcm10 (mini-chromosome maintenance 10) associates with chromatin in early S-phase and is required for assembly and function of the replication fork protein machinery. Another essential component of the eukaryotic replication fork is Cdc45 (cell division cycle 45), which is required for both initiation and elongation of DNA replication. In the present study we characterize, for the first time, the physical and functional interactions of human Mcm10 and Cdc45. First we demonstrated that Mcm10 and Cdc45 interact in cell-free extracts. We then analysed the role of each of the Mcm10 domains: N-terminal, internal and C-terminal (NTD, ID and CTD respectively). We have detected a direct physical interaction between CTD and Cdc45 by both in vitro co-immunoprecipitation and surface plasmon resonance experiments. On the other hand, we have found that the interaction of the Mcm10 ID with Cdc45 takes place only in the presence of DNA. Furthermore, we found that the isolated ID and CTD domains are fully functional, retaining DNA-binding capability with a clear preference for bubble and fork structures, and that they both enhance Cdc45 DNA-binding affinity. The results of the present study demonstrate that human Mcm10 and Cdc45 directly interact and establish a mutual co-operation in DNA binding.
Orientation-specific responses to sustained uniaxial stretching in focal adhesion growth and turnover
Authors: Chen Yun , Pasapera Ana M. , Koretsky Alan P. , Waterman Clare M. 
Published: June 2013

Significance
Cells are mechanosensitive: a cell’s adaptive responses to mechanical inputs will determine its morphology, gene expression, and posttranslational protein modification. Focal adhesions (FAs), the integrin-containing complexes positioned between the extracellular matrix and the cell, are key in transmitting the mechanosignal to initiate these downstream adaptive responses. In this study we made the unique observation that FA and cellular morphology changes in response to sustained uniaxial stretch are orientation specific. Our results also suggest orientation-specific responses at the molecular level in individual FAs propagate up to regulate cell morphology, which may in turn mediate adaptive responses that promote tissue growth.
Frictional catastrophe behaviors and mechanisms of brake shoe for mine hoisters during repetitious emergency brakings
Authors: Zhu Zhencai , Bao Jiusheng , Yin Yan , Chen Guoan 
Published: June 2013

PurposeIn order to improve the braking safety of mine hoisters, this paper aims to focus on the continuous repetitious emergency braking conditions to investigate an abnormal frictional phenomena called “Frictional catastrophe (FC)” and its mechanisms.Design/methodology/approachThe non‐asbestos brake shoe of a mine hoister was selected as frictional material and its paring material is 16Mn steel. The tribological properties of the brake shoe were tested on the pad‐on‐disc friction tester by the simulation of continuous emergency braking conditions. The thermal analysis experiments, the temperature field simulations and the SEM analysis of the brake shoe were accomplished to reveal the mechanisms of the FC.FindingsIt was found that the friction coefficient of the brake shoe sometimes falls suddenly during braking. This abnormal frictional phenomena is called “Frictional catastrophe (FC)”. It is considered that the friction heat, which is accumulated rapidly by the braking on the surface of the brake shoe, makes the surface layer material qualitatively change from the solid state to a mixed state composed of gases, liquids and solid. The frictional modality of the braking changes accordingly from dry friction to lubrication with gases and liquids. The sudden lubrication makes the friction coefficient fall suddenly and induces the FC phenomena.Originality/valueAn abnormal tribological phenomena called “Frictional catastrophe (FC)” was found in this paper. The investigations about the behaviors and mechanisms of the FC are considered helpful for improving the braking safety of mine hoisters and other machines.
Loan defaults and hazard models for bankruptcy prediction
Authors: Foster Benjamin P. , Zurada Jozef 
Published: June 2013

PurposeRecent bankruptcy research uses hazard models and extensive samples of companies. The large samples used have precluded the inclusion of a variable related to companies' loan default status in the models. With a sample limited to financially distressed companies, the authors aim to examine if results differ when loan default status and/or audit opinion variables are omitted from hazard bankruptcy prediction models.Design/methodology/approachThe sampling frame is publicly traded US companies, consisting of 111 bankrupt and 310 matching companies from 2003 to 2007. The study applies logistic regression to choose variables for parsimonious bankruptcy prediction models to validate hypotheses. Loan default status and/or audit opinion variables are included as potential predictive variables along with variables included in previous hazard bankruptcy prediction models.FindingsResults reveal that loan default and audit opinion variables: improve the predictive accuracy for financially distressed samples with hazard model characteristics; and change the significance on some variables included in previous hazard models.Research limitations/implicationsAuditors' propensity to issue going‐concern modifications varies over time. To allow manual collection of loan default status information, the authors' sample was limited. Consequently, their results may not be generalizable to other bankruptcy hazard models.Practical implicationsResults from hazard models that do not include loan default status or auditor opinion variables should be interpreted with caution. Auditors might improve their going‐concern modification decisions by attributing more importance to loan default status. Also, the auditor's opinion adds incremental bankruptcy risk information to lenders and investors.Originality/valueRecent bankruptcy research uses hazard models and extensive samples of companies. However, these studies omit a potentially important variable available to financial statement users, loan default status. The authors demonstrate that including variables for loan default status and auditor's opinion improves bankruptcy prediction models and can change conclusions drawn about other variables.
Socio‐demographic factors and network configuration among MENA entrepreneurs
Authors: Zengyu Huang Victor , Nandialath Anup , Kassim Alsayaghi Abdulkareem , Esra Karadeniz Emine 
Published: June 2013

PurposeThe field of entrepreneurship has seen a dramatic increase in studies focusing on networks and relations. Research in this area has thus far focused on how the structure and quality of entrepreneurs' existing interpersonal ties shape information access and thereby influence entrepreneurial outcomes. The purpose of this paper is to extend the focus further by examining how the entrepreneur's socio‐demographic profile affects advisory network configuration in the Middle East and North Africa (MENA) context.Design/methodology/approachIn this paper, the authors used Global Entrepreneurship Monitor (GEM) data, at the individual level (total early‐stage entrepreneurial activities) in 14 countries within the MENA region over the course of three years (2009, 2010 and 2011). The sample of networks is obtained from the entrepreneurs identified among the adults interviewed in the adult population survey of GEM participating countries from the MENA region.FindingsStrong evidence was found that socio‐demographic variables such as gender, age, income and education have an impact on the usage of advice‐seeking networks by entrepreneurs across MENA. For instance, the findings suggest that women entrepreneurs in the MENA region tend to rely more on personal networks compared to male entrepreneurs.Originality/valueThe paper's contribution is novel in providing empirical evidence exposing the interplay between socio‐demographic factors, new venture start‐up phases, to entrepreneurial networks. Prospective scholarly research need to improve our understanding about the effects of network evolution on the entrepreneurial trajectory, as well to develop a greater understanding on how, when and why MENA‐based entrepreneurial networks emerge, develop and change over time.
Evidence on the nature, extent and determinants of disclosures in Libyan banks’ annual reports
Authors: Kribat Musa , Burton Bruce , Crawford Louise 
Published: June 2013

PurposeThe paper aims to investigate disclosure practices in the annual reports of Libyan banks in the run‐up to the opening of the nation's first stock exchange. Banks dominate this embryonic market but very little research has examined the extent (or determinants) of transparency achieved by these firms, an issue argued by Stiglitz and others to be crucial in the post‐crisis era. Currently, no detailed evidence of disclosure practices prior to the launch of the exchange exists, making an accurate assessment of the market's impact in this area impossible; the present study therefore contributes in this regard as well.Design/methodology/approachThe study employs two main methods: a disclosure index‐based analysis of mandatory and overall disclosure levels; and panel regression analysis of the determinants of the overall disclosure levels.FindingsThe results suggest that while many items are disclosed on a regular basis, on average barely more than half of all possible items appear in the annual reports. As regards compliance with mandatory requirements, the figures are higher but, worryingly, begin to fall as the launch of the market neared. The results of panel‐data analysis suggest that the overall extent of disclosure is non‐random, instead reflecting the profits achieved by the banks concerned.Originality/valueThis paper is the first detailed analysis of disclosure practices in Libyan banks and the results suggest that market authorities should be looking for an improvement in the figures, in particular the reversal of a downward trend in compliance with mandatory requirements. The paper reports a link between profit level and disclosure propensity; this evidence might be of use to regulators charged with increasing disclosure levels in the future. More generally, the results provide a comparative basis on which to assess the effect of the market's launch on disclosure practices in Libya.
What's in the closet: dress and appearance codes and lessons from sexual orientation
Authors: Brower Todd 
Published: June 2013

PurposeDress and appearance codes are often seen as trivial, both because they seem to fit within our notions of how people ought to behave, and because they appear to reflect legitimate employer concerns in running a business. But they are not constructed in a vacuum. They reflect and enshrine societal stereotypes and expectations of women and men and how they look – including assumptions about gender and sexuality and majoritarian norms. As such, they punish anyone who is an outlier by reason of gender, sexuality, race, religion, or culture. This paper seeks to identify the assumptions and effects on gender, sexuality, professionalism and class in appearance and behavior codes.Design/methodology/approachThis is a conceptual paper exploring US case law on dress codes and employee appearance standards to examine issues of gender and sexual orientation identity on the job. By combining insights from sexual orientation identity theories and visibility, the paper seeks to uncover some of the interactions and effects of these appearance policies on women and LGBT persons in the workplace.FindingsThis paper shows that identity strategies and performances used by LGBT individuals and women in the workplace implicate sexuality and gender, but also professionalism and class. These dress and appearance codes carry with them consequences for both employers and employees.Practical implicationsThe paper highlights the gender, sexuality and identity performance burdens on women and sexual minorities workplace controls over dress and appearance.Originality/valueThe paper discusses topics that are of interest to persons studying sexuality and gender identity issues in employment. It is based on an unpublished talk at the EDI conference in Vienna 2010.