bluuebunny/crossref_metadata_2025 huggingface dataset:
Synergetic Effect on PP/mEPDM Blends Under Vibration Force Field in Tri-Screw Dynamic Mixing Extruder
Authors: Baohua Wei  , Jinping Qu  , Xu Gang
Published: October 2008

Vibration force field was introduced into plastics processing in tri-screw dynamic mixing extruders, so as to intensify mixability and dispersion. The effects of vibration force field on toughened PP by mEPDM during plastics processing in tri-screw dynamic mixing extruders were investigated experimentally and synergism on polymer blends under vibration force field was discussed by using PP/mEPDM blends as a sample. The results showed a synergism effect on mechanical properties of PP/mEPDM blends under dynamic conditions and it was found that the vibration force field enhanced impact strength of PP/mEPDM blends, the amplitude of enhancement varied as mEPDM content varied, and the impact strength of PP/mEPDM blends basically presented a rising tendency followed by a fall with the increase of frequency and amplitude. The impact strength had a maximum value of 54.4 kJ/m2 which was much larger than that under steady conditions as amplitude and frequency were 0.6 mm and 20 Hz, respectively, and the mEPDM content was 25%. Therefore, good synergism would be caused and the mechanical properties of PP/mEPDM blends would be modified due to the vibration force field.
The Role of Correction of Anemia in Patients With Congestive Heart Failure Associated with Chronic Kidney Failure
Authors: Silverberg Donald S. , Wexler Dov , Iaina Adrian , Schwartz Doron
Published: October 2008

Patients with congestive heart failure (CHF) who are also anemic have more severe CHF and a higher mortality, morbidity, and hospitalization rate than those who are not anemic. However, it is not known if the anemia is actually contributing to the CHF or if it is merely comorbidity (ie a marker of increased inflammation or chronic kidney disease [CKD]). The only way to demonstrate that anemia is a causative factor is to correct it, independent of other CHF factors. In this paper we review the results of the published papers about correction of anemia in patients with CHF. Taken in sum, these reports show a quite consistent positive effect of erythropoietic stimulating agents (ESAs) along with oral or intravenous (IV) iron or even of IV alone on clinical indicators and clinical outcomes of patients with CHF. More work is needed to clarify the important relationship between anemia, CHF, and CKD.
Caffeic acid phenethyl ester modulates methotrexate-induced oxidative stress in testes of rat
Authors: Armagan A , Uzar E , Uz E , Yilmaz HR , Kutluhan S , Koyuncuoglu HR , Soyupek S , Cam H , Serel TA
Published: October 2008

The aim of this study was to investigate the possible protective role of caffeic acid phenethyl ester on testicular toxicity of methotrexate in rats. Nineteen male rats were divided into three groups as follows: group I, control; group II, methotrexate-treated; group III, methotrexate + caffeic acid phenethyl ester-treated. In the second day of experiment, a single dose of methotrexate was intraperitoneally administered to groups II and III, although a daily single dose of caffeic acid phenethyl ester was intraperitoneally administered to group III for 7 days. At the end of the experiment, the testes of the animals were removed and weighed. In the tissue, the level of lipid peroxidation as malondialdehyde and activities of superoxide dismutase were higher in the methotrexate group than in the control group. Lipid peroxidation levels and superoxide dismutase activities were decreased in caffeic acid phenethyl ester + methotrexate group compared with methotrexate group. The activities of catalase in the methotrexate group decreased insignificantly although its activities were significantly increased by caffeic acid phenethyl ester administration. The activity of glutathione peroxidase did not change in the groups. There was significant difference in body weight between control and methotrexate-induced groups. In conclusion, the administration of methotrexate causes elevation of oxidative stress although treatment with caffeic acid phenethyl ester has protective effects on the oxidative stress in testes.
Arginine Metabolites in Wound Fluids From Pressure Ulcers: A Pilot Study
Authors: Childress Beverly , Stechmiller Joyce K. , Schultz Gregory S.
Published: October 2008

Compelling evidence suggests that nitric oxide (NO•), a metabolite of arginine, plays an important role in wound healing. Arginine is a semi-essential amino acid that is metabolized by nitric oxide synthase and arginase. One model for wound-healing regulation suggests the importance of strict reciprocal control of these enzymes in wounds. The purpose of this pilot study was to investigate arginine metabolism in wound fluids from patients with Stage III or IV pressure ulcers receiving negative pressure wound therapy (NPWT). Wound fluids were collected from 8 patients, aged 31—79 years, before and after initiation of NPWT on Days 1, 3, and 7. Wound fluids were analyzed for nitrates/nitrites (NOx), arginine, citrulline, proline, and ornithine. There were no significant differences between NOx, arginine, citrulline, proline, and ornithine concentrations before and after initiation of NPWT among the various timepoints. However, we observed a downward trend of NO • levels from baseline to Day 7 of NPWT treatment. Furthermore, we detected a decrease in arginine levels over the study period, suggesting that the iNOS/citrulline pathway predominated during the first 72 hr of treatment, and the arginase/ ornithine pathway dominated thereafter. Arginine and its metabolites are detectable in wound fluids from patients with Stage III or IV pressure ulcers on NPWT. Further studies on chronic wounds are warranted to correlate wound-healing outcomes with arginine metabolites at the cellular and molecular level over a longer period of time.
The Relationship Between Job Stress and Urinary Cytokines in Healthy Nurses: A Cross-Sectional Study
Authors: Fukuda Hiromi , Ichinose Takamichi , Kusama Tomoko , Yoshidome Atsuko , Anndow Kazuyo , Akiyoshi Nobuko , Shibamoto Takayuki
Published: October 2008

Cytokines such as angiogenin (ANG) and interleukin (IL-8) have been shown to be related to depressive symptoms and inflammatory diseases like coronary heart disease. They may thus be used as stress biomarkers to identify and prevent health problems. To investigate the relationship between cytokines and nurses' job-related stress, levels of urinary ANG and IL-8 were measured in healthy female hospital nurses in Japan. The level of job-related stress of the subjects was evaluated using the Nursing Stress Scale (NSS), with the participants being classified into high- or low-stress groups for each subscale according to their scores. The participants' subjective psychological states were assessed using the Profile of Mood States—Short Form Japanese version (POMS-SFJ). Urinary ANG, IL-8, and cortisol levels and subjective psychological states for two groups were compared for each NSS subscale. The fatigue and depression scores of POMS-SFJ subscales in the present study were higher than those of the general healthy Japanese population. Based on the mean score of the combined participants, nurses were experiencing the highest stress related to the pressure of having responsibility for patients' life support care (PPLC). Nurses reporting high levels of stress related to PPLC and conflict with physicians had high levels of urinary ANG. Urinary ANG levels may thus be associated with high levels of job stress.
Research on Ni–Mn alloy electroforming process for revolving parts
Authors: Yang J. M. , Zhu D.
Published: September 2008

The quality control of the electrodeposit is one of the keys to extending the application of electroforming technology. In this paper, experimental equipment was developed to electroform revolving parts. The conformal anode, high frequency pulse current and well chosen electrolyte were employed to carry out Ni–Mn alloy electroforming for a model of the rocket nozzle. The reasons why the electrodeposits broke and pores existed in the deposits were found. By adding additives to the electrolyte and improving agitation of the electrolyte, the break and pore of the deposits were eliminated. Finally, the acceptable electroforms were obtained.
TiAlCN/VCN nanolayer coatings suitable for machining of Al and Ti alloys deposited by combined high power impulse magnetron sputtering/unbalanced magnetron sputtering
Authors: Hovsepian P. E. , Ehiasarian A. P. , Petrov I.
Published: September 2008

Nanoscale multilayer TiAlCN/VCN coatings with bilayer thickness Δ=2·2 nm were deposited by the combined high power impulse magnetron sputtering (HIPIMS)/unbalanced magnetron sputtering technology. The V+ HIPIMS etching produced atomically clean interface and V implantation resulting in enhanced coating adhesion LC=58 N. High resolution transmission electron microscopy and electron energy loss spectroscopy revealed that in TiAlCN/VCN, carbon forms a lateral phase between the nanolayers, producing low shear strength interfaces. This results in a well defined nanometre scale layer by layer wear mechanism, which is the key for prevention of tribofilm and consequently thick built up layer formation. In dry milling of Al 7010-T 7651 alloy, TiAlCN/VCN outperformed state of the art diamond like carbon, Cr/WC/a-CH coated and uncoated end mills by factors of 4 and 8 respectively. In turning of Ti alloys (Ti0·90Al0·06V0·04) the TiAlCN/VCN coated cemented carbide inserts produced two to three times more components (orthopaedic implants), as compared to uncoated tools.
Investigation of tribological and electrochemical properties of dual layer after low temperature plasma carbo-nitriding
Authors: Yetim A. F. , Alsaran A. , Çelik A.
Published: September 2008

In the present study, the wear and corrosion properties of the modified layer that was obtained as a result of plasma nitriding were investigated. The plasma nitriding was achieved by adding carbon containing gas into the gas mixture. Plasma nitriding treatments were performed with different gas mixtures at 500°C for 4 h. While a single modified layer was produced through the application of plasma nitriding into a gas mixture of N2–H2, a dual layer structure was attained on the surface after adding carbon containing gas into N2–H2. The inner layer was in a carbon solid solution phase ( γC) and the outer layer was in a nitrogen solid solution phase ( γN). It was observed that the dual layer structure improved the wear properties of the 316L stainless steel without having any adverse effect on the corrosion resistance.
Influence of plasma electrolytic oxidation on mechanical characteristics of NiTi alloy
Authors: Sinebryukhov S. L. , Gnedenkov A. S. , Khrisanfova O. A. , Gnedenkov S. V.
Published: September 2008

The aim of the present work was to examine the effect of the plasma electrolytic oxidation (PEO) process on the mechanical properties of nitinol. The comparative evaluation of the microhardness and elastic modulus of the nitinol alloy and the PEO coating was carried out.

The analysis of the obtained data confirmed closeness of the microhardness and elastic modulus with the respective values for nitinol layers adjacent to the coating. The reason for such a transformation on the boundary with the coating layers of nitinol could consist in the alloy amorphism as a result of the microsecond high temperature plasma influence occurring under PEO conditions and followed by sharp material cooling after attenuation of the plasma microdischarge. Unlike the thermal air oxidation (as a result, the hardness and fragility of the titanium alloy surface layers increase sharply), the changes described above facilitate increase of the mechanical and corrosion mechanical strength of the processed sample.
Effect of grain size and indium addition on tensile characteristics of Al–1Si alloy
Authors: Abd El-Khalek A. M.
Published: September 2008

The effect of grain size and indium addition on the workhardening characteristics of Al–1Si (wt-%) alloy has been investigated at room temperature (RT). The samples were preaged at different temperatures in the range 523–623 K. The yield stress, the fracture stress, the fracture time and the linear workhardening coefficient generally decreased with increasing temperature and/or grain size, while the fracture strain and dislocation slip distance increased. The yield and fracture stresses for different grain sizes at different temperatures were found to be linearly related to grain diameters. Indium addition caused general increase for all the measured strength parameters. As concluded from transmission electron microscope (TEM) investigations, In addition to Al–Si alloy may retard the coarsening of Si particles. The energies activating the operating fracture mechanisms were found to be 79·6±0·4 and 32·4±0·4 kJ mol−1 for alloys Al–1Si and Al–1Si–0·2In respectively. This suggests a value of 47·2 kJ mol−1 as a binding energy between Si and In atoms in Al matrix.
Superhydrophobic treatment for textiles via engineering nanotextured silica/polysiloxane hybrid material onto fibres
Authors: Zhang H. , Lamb R. N.
Published: September 2008

A rapid, cost effective and easy to implement method for treating wool and wool blend textiles to superhydrophobic with controllable interference on other properties such as handle is demonstrated. The process is based on in situ chemical binding of inexpensive silica and polysiloxane hybrid material onto fibres. Superhydrophobicity is achieved upon architecting nanoroughness on textile surfaces using silica nanoparticles. Modified textiles exhibit extremely high water repellency with contact angle reaching 166° and sliding angle ≤6°. Superhydrophobicity was maintained after three times of accelerated washing (equally 15 times of standard laundry wash). Topographical studies using AFM indicate that nanoscale roughness has been engineered on fibres with original size ∼22 μm. The rough structure at two length scales plays a key role in enhancing surface hydrophobicity. Simplicity of processing such coatings onto textiles makes it possible for potentially large scale production.
Electroless Ni–P–(nano-MoS2) composite coatings and their corrosion properties
Authors: Hu X. G. , Cai W. J. , Xu Y. F. , Wan J. C. , Sun X. J.
Published: September 2008

Ni–P coatings were co-deposited with MoS2 nanoparticles on medium carbon steel substrate by electroless plating. The effects of incorporation of MoS2 nanoparticles into the Ni–P coating on the morphology of the coating surface and corrosion properties were investigated. X-ray diffraction pattern and X-ray photoelectron spectroscopy spectra showed that the MoS2 nanoparticles were covered in the nickel phosphor matrix. Corrosion tests were conducted in aqueous 10 wt-%HCl, 10 wt-%NaOH and 3·5 wt-%NaCl using a weight loss method, and in aqueous 3·5 wt-%NaCl by electrochemical measurement for bare substrate, Ni–P coating and Ni–P–(nano-MoS2) composite coating, respectively. The experimental results showed that corrosion resistance of the coating containing MoS2 was slightly lower than that of the coating without MoS2. The corrosion rate of Ni–P–(nano-MoS2) composite coating in HCl aqueous solution was found to be increased owing to the corrosion microcells and high porosity and rougher surface. Ni–P– (nano-MoS2) composite coating, however, exhibited significantly enhanced corrosion resistance in both aqueous NaOH and NaCl solutions compared with substrate. The corrosion mechanism of the composite coatings was also discussed.
Multi-objective optimisation of gas carburising process in batch furnaces with endothermic carburising atmosphere
Authors: Karabelchtchikova O. , Hsiang S. M. , Sisson R. D.
Published: September 2008

A methodology for multi-objective optimisation of gas carburising heat treatment has been developed in terms of cost, cycle time and quality of carburised parts. The optimisation strategy is based on: modelling the effect of process parameters (carbon potential, temperature and time) on the mass transfer coefficient and carbon diffusivity in austenite, correlating the observed variations in the process parameters on the carburising kinetics, and developing a robust multiobjective optimisation technique to achieve the desired case depth with minimum cost and minimum case depth variation. The tradeoff between these two objective functions corresponded to carburising at 938·5°C and carbon potential of 1·14 wt-%C. This combination produced the target case depth of 0·6 mm with corresponding ±0·05 mm case depth variation and minimum total cycle cost. Overall, application of this multi-objective optimisation will result in significant energy reduction by shortening cycle time and thereby enhancing furnace capacity.
Electroless Ni–P coating on W–Cu composite via three different activation processes
Authors: Hao L. , Wei J. , Gan F. X.
Published: September 2008

To obtain qualified electroless Ni–P coating on W–Cu composite, the influences of three different activation processes, chemical activation, chemical activation and strike nickel plating, and anodic activation and strike nickel plating, on the adhesion of electroless Ni–P coating to W–Cu composite have been studied in this paper. The adhesion between the Ni–P coating and the W–Cu composite has been estimated by scratch, file and bend tests. The results indicate that the samples, pretreated by anodic activation and strike nickel plating, have the qualified adhesion. The samples that pretreated by chemical activation and chemical activation and strike nickel plating do not have the qualified adhesion. SEM shows that the surface morphology of Ni–P coating is smooth, no hemispherical clusters appeared and XRD indicates that it has an amorphous structure.
Time from diagnosis to treatment initiation predicts survival in younger, but not older, acute myeloid leukemia patients
Authors: Sekeres Mikkael A. , Elson Paul , Kalaycio Matt E. , Advani Anjali S. , Copelan Edward A. , Faderl Stefan , Kantarjian Hagop M. , Estey Elihu
Published: October 2008

Acute myeloid leukemia (AML) is considered an oncologic emergency. Delaying induction chemotherapy until molecular testing results return, may benefit some patients but harm others. We examined the effect of time from AML diagnosis to treatment (TDT) on complete remission (CR) and overall survival (OS), using patient characteristics available at diagnosis. Regression models were applied to older (≥ 60 years) and younger (< 60 years) adults, controlling for age, baseline white blood cell count, secondary AML (sAML), and performance status. Median patient age was 60 years (range, 17-87 years), TDT 4 days (range, 1-78 days), and 45% had sAML. Cytogenetic risk distribution was: favorable, 8%; intermediate, 66%; unfavorable, 26%. CR rate was 67% and median OS was 68 weeks in patients younger than 60 years; 55% and 33 weeks in older patients, respectively. In univariate and multivariate analyses, longer TDT was associated with worse CR and OS in younger (univariate: P < .001 in both; multivariate: P < .001 and P = .001, respectively), but not older patients (univariate: P = .45, P = .19; multivariate: P = .63, P = .30, respectively). Results did not change with inclusion of cytogenetic data or in risk group subsets. AML therapy should be initiated immediately in younger patients. Delaying treatment does not seem harmful in older patients, allowing individualized approaches.
Direct Activation of Transient Receptor Potential Vanilloid 1(TRPV1) by Diacylglycerol (DAG)
Authors: Woo Dong Ho , Jung Sung Jun , Zhu Mei Hong , Park Chul-Kyu , Kim Yong Ho , Oh Seog Bae , Lee C Justin
Published: October 2008

The capsaicin receptor, known as transient receptor potential channel vanilloid subtype 1 (TRPV1), is activated by a wide range of noxious stimulants and putative ligands such as capsaicin, heat, pH, anandamide, and phosphorylation by protein kinase C (PKC). However, the identity of endogenous activators for TRPV1 under physiological condition is still debated. Here, we report that diacylglycerol (DAG) directly activates TRPV1 channel in a membrane-delimited manner in rat dorsal root ganglion (DRG) neurons. 1-oleoyl-2-acetyl- sn-glycerol (OAG), a membrane-permeable DAG analog, elicited intracellular Ca2+transients, cationic currents and cobalt uptake that were blocked by TRPV1-selective antagonists, but not by inhibitors of PKC and DAG lipase in rat DRG neurons or HEK 293 cells heterologously expressing TRPV1. OAG induced responses were about one fifth of capsaicin induced signals, suggesting that OAG displays partial agonism. We also found that endogenously produced DAG can activate rat TRPV1 channels. Mutagenesis of rat TRPV1 revealed that DAG-binding site is at Y511, the same site for capsaicin binding, and PtdIns(4,5)P2binding site may not be critical for the activation of rat TRPV1 by DAG in heterologous system. We propose that DAG serves as an endogenous ligand for rat TRPV1, acting as an integrator of Gq/11-coupled receptors and receptor tyrosine kinases that are linked to phospholipase C.
Cortical and subcortical anatomy of chronic spatial neglect following vascular damage
Authors: Golay Laetitia , Schnider Armin , Ptak Radek
Published: October 2008

Background

The role of the inferior parietal lobule (IPL) and superior temporal gyrus (STG) or subcortical pathways as possible anatomical correlates of spatial neglect is currently intensely discussed. Some of the conflicting results might have arisen because patients were examined in the acute stage of disease.

Methods

We examined the anatomical basis of spatial neglect in a sample of patients examined in the post-acute stage following right-hemispheric vascular brain damage. Lesions of 28 patients with chronic spatial neglect were contrasted to lesions of 22 control patients without neglect using lesion subtraction techniques and voxel-wise comparisons.

Results

The comparisons identified the temporo-parietal junction (TPJ) with underlying white matter, the supramarginal gyrus, the posterior STG, and the insula as brain regions damaged significantly more often in neglect compared to non-neglect patients. In a subgroup of neglect patients showing particularly large cancellation bias together with small errors on line bisection damage was prevalent deep in the frontal lobe while damage of patients with the reverse pattern was located in the white matter of the TPJ.

Conclusion

Considering our results and the findings of previous studies, spatial neglect appears to be associated with a network of regions involving the TPJ, inferior IPL, posterior STG, the insular cortex, and posterior-frontal projections. Frontal structures or projections may be of particular relevance for spatial exploration, while the IPL may be important for object-based attention as required for line bisection.
ST6Gal-I expression in ovarian cancer cells promotes an invasive phenotype by altering integrin glycosylation and function
Authors: Christie Daniel R , Shaikh Faheem M , Lucas John A , Lucas John A , Bellis Susan L
Published: October 2008

Background

Ovarian adenocarcinoma is not generally discovered in patients until there has been widespread intraperitoneal dissemination, which is why ovarian cancer is the deadliest gynecologic malignancy. Though incompletely understood, the mechanism of peritoneal metastasis relies on primary tumor cells being able to detach themselves from the tumor, escape normal apoptotic pathways while free floating, and adhere to, and eventually invade through, the peritoneal surface. Our laboratory has previously shown that the Golgi glycosyltransferase, ST6Gal-I, mediates the hypersialylation of β1 integrins in colon adenocarcinoma, which leads to a more metastatic tumor cell phenotype. Interestingly, ST6Gal-I mRNA is known to be upregulated in metastatic ovarian cancer, therefore the goal of the present study was to determine whether ST6Gal-I confers a similarly aggressive phenotype to ovarian tumor cells.

Methods

Three ovarian carcinoma cell lines were screened for ST6Gal-I expression, and two of these, PA-1 and SKOV3, were found to produce ST6Gal-I protein. The third cell line, OV4, lacked endogenous ST6Gal-I. In order to understand the effects of ST6Gal-I on cell behavior, OV4 cells were stably-transduced with ST6Gal-I using a lentiviral vector, and integrin-mediated responses were compared in parental and ST6Gal-I-expressing cells.

Results

Forced expression of ST6Gal-I in OV4 cells, resulting in sialylation of β1 integrins, induced greater cell adhesion to, and migration toward, collagen I. Similarly, ST6Gal-I expressing cells were more invasive through Matrigel.

Conclusion

ST6Gal-I mediated sialylation of β1 integrins in ovarian cancer cells may contribute to peritoneal metastasis by altering tumor cell adhesion and migration through extracellular matrix.
A Novel Point Mutation in the Amino Terminal Domain of the Human Glucocorticoid Receptor (hGR) Gene Enhancing hGR-Mediated Gene Expression
Authors: Charmandari Evangelia , Ichijo Takamasa , Jubiz William , Baid Smita , Zachman Keith , Chrousos George P. , Kino Tomoshige
Published: October 2008

Context: Interindividual variations in glucocorticoid sensitivity have been associated with manifestations of cortisol excess or deficiency and may be partly explained by polymorphisms in the human glucocorticoid receptor (hGR) gene. We studied a 43-yr-old female, who presented with manifestations consistent with tissue-selective glucocorticoid hypersensitivity. We detected a novel, single, heterozygous nucleotide (G → C) substitution at position 1201 (exon 2) of the hGR gene, which resulted in aspartic acid to histidine substitution at amino acid position 401 in the amino-terminal domain of the hGRα. We investigated the molecular mechanisms of action of the natural mutant receptor hGRαD401H.

Methods-Results: Compared with the wild-type hGRα, the mutant receptor hGRαD401H demonstrated a 2.4-fold increase in its ability to transactivate the glucocorticoid-inducible mouse mammary tumor virus promoter in response to dexamethasone but had similar affinity for the ligand (dissociation constant = 6.2 ± 0.6 vs. 6.1 ± 0.6 nm) and time to nuclear translocation (14.75 ± 0.25 vs. 14.25 ± 1.13 min). The mutant receptor hGRαD401H did not exert a dominant positive or negative effect upon the wild-type receptor, it preserved its ability to bind to glucocorticoid response elements, and displayed a normal interaction with the glucocorticoid receptor-interacting protein 1 coactivator.

Conclusions: The mutant receptor hGRαD401H enhances the transcriptional activity of glucocorticoid-responsive genes. The presence of the D401H mutation may predispose subjects to obesity, hypertension, and other manifestations of the metabolic syndrome.
EVT-based estimation of risk capital and convergence of high quantiles
Authors: Degen Matthias , Embrechts Paul
Published: October 2008

We discuss some issues regarding the accuracy of a quantile-based estimation of risk capital. In this context, extreme value theory (EVT) emerges naturally. The paper sheds some further light on the ongoing discussion concerning the use of a semi-parametric approach like EVT and the use of specific parametric models such as theg-and-h. In particular, we discusses problems and pitfalls evolving from such parametric models when using EVT and highlight the importance of the underlying second-order tail behavior.
Survival of inhomogeneous Galton-Watson processes
Authors: Broman Erik , Meester Ronald
Published: October 2008

We study the survival properties of inhomogeneous Galton-Watson processes. We determine the so-called branching number (which is the reciprocal of the critical value for percolation) for these random trees (conditioned on being infinite), which turns out to be an almost sure constant. We also shed some light on the way in which the survival probability varies between the generations. When we perform independent percolation on the family tree of an inhomogeneous Galton-Watson process, the result is essentially a family of inhomogeneous Galton-Watson processes, parameterized by the retention probability p. We provide growth rates, uniformly in p, of the percolation clusters, and also show uniform convergence of the survival probability from the nth level along subsequences. These results also establish, as a corollary, the supercritical continuity of the percolation function. Some of our results are generalizations of results in Lyons (1992).
A limit theorem with application to Båth's law in seismology
Authors: Vere-Jones David
Published: October 2008

In this paper a limit theorem is proved that establishes conditions under which the distribution of the difference between the size of the initial event in a random sequence, modeled as a finite point process, and the largest subsequent event approaches a limiting form independent of the size of the initial event. The underlying assumptions are that the sizes of the individual events follow an exponential distribution, that the expected total number of events increases exponentially with the size of the initial event, and that the structure of the sequence approximates that of a Poisson process. Particular cases to which the results apply include sequences of independent and identically distributed exponential variables, and the epidemic-type aftershock (ETAS) branching process model in the subcritical case. In all these cases the form of the limit distribution is shown to be that of a double exponential (type-I extreme value distribution). In sampling from a family of aftershock sequences, with possibly different underlying parameters, the limit distribution is a mixture of such double exponential distributions. The conditions for the simple limit to exist relate to the approximation of the distribution of the number of events by a Poisson distribution. One such condition requires the coefficient of variation (ratio of standard deviation to mean) of the number of events to converge to 0 as the mean increases. The results provide a statistical background to Båth's law in seismology, which asserts that in an aftershock sequence the magnitude of the main shock is commonly around 1.2 units higher than the magnitude of the largest aftershock.
Loss of protein kinase Cϵ results in impaired cutaneous wound closure and myofibroblast function
Authors: Leask Andrew , Shi-wen Xu , Khan Korsa , Chen Yunliang , Holmes Alan , Eastwood Mark , Denton Christopher P. , Black Carol M. , Abraham David J.
Published: October 2008

Cutaneous wound repair requires the de novo induction of a specialized form of fibroblast, the α-smooth muscle actin (α-SMA)-expressing myofibroblast, which migrates into the wound where it adheres to and contracts extracellular matrix (ECM), resulting in wound closure. Persistence of the myofibroblast results in scarring and fibrotic disease. In this report, we show that, compared with wild-type littermates, PKCϵ-/- mice display delayed impaired cutaneous wound closure and a reduction in myofibroblasts. Moreover, both in the presence and absence of TGFβ, dermal fibroblasts from PKCϵ-/- mice cultured on fibronectin show impaired abilities to form `supermature' focal adhesions and α-SMA stress fibers, and reduced pro-fibrotic gene expression. Smad3 phosphorylation in response to TGFβ1 was impaired in PKCϵ-/- fibroblasts. PKCϵ-/- fibroblasts show reduced FAK and Rac activation, and adhesive, contractile and migratory abilities. Overexpressing constitutively active Rac1 rescues the defective FAK phosphorylation, cell migration, adhesion and stress fiber formation of these PKCϵ-/- fibroblasts, indicating that Rac1 operates downstream of PKCϵ, yet upstream of FAK. These results suggest that loss of PKCϵ severely impairs myofibroblast formation and function, and that targeting PKCϵ may be beneficial in selectively modulating wound healing and fibrotic responses in vivo.
TorsinA binds the KASH domain of nesprins and participates in linkage between nuclear envelope and cytoskeleton
Authors: Nery Flávia C. , Zeng Juan , Niland Brian P. , Hewett Jeffrey , Farley Jonathan , Irimia Daniel , Li Yuqing , Wiche Gerhard , Sonnenberg Arnoud , Breakefield Xandra O.
Published: October 2008

A specific mutation (ΔE) in torsinA underlies most cases of the dominantly inherited movement disorder, early-onset torsion dystonia (DYT1). TorsinA, a member of the AAA+ ATPase superfamily, is located within the lumen of the nuclear envelope (NE) and endoplasmic reticulum (ER). We investigated an association between torsinA and nesprin-3, which spans the outer nuclear membrane (ONM) of the NE and links it to vimentin via plectin in fibroblasts. Mouse nesprin-3α co-immunoprecipitated with torsinA and this involved the C-terminal region of torsinA and the KASH domain of nesprin-3α. This association with human nesprin-3 appeared to be stronger for torsinAΔE than for torsinA. TorsinA also associated with the KASH domains of nesprin-1 and -2 (SYNE1 and 2), which link to actin. In the absence of torsinA, in knockout mouse embryonic fibroblasts (MEFs), nesprin-3α was localized predominantly in the ER. Enrichment of yellow fluorescent protein (YFP)-nesprin-3 in the ER was also seen in the fibroblasts of DYT1 patients, with formation of YFP-positive globular structures enriched in torsinA, vimentin and actin. TorsinA-null MEFs had normal NE structure, but nuclear polarization and cell migration were delayed in a wound-healing assay, as compared with wild-type MEFs. These studies support a role for torsinA in dynamic interactions between the KASH domains of nesprins and their protein partners in the lumen of the NE, with torsinA influencing the localization of nesprins and associated cytoskeletal elements and affecting their role in nuclear and cell movement.
Covering the Uninsured in the United States
Authors: Gruber Jonathan
Published: October 2008

One of the major social policy issues facing the United States in the first decade of the twenty-first century is the large number of Americans lacking health insurance. This article surveys the major economic issues around covering the uninsured. I review the facts on insurance coverage and the nature of the uninsured; explore explanations for why the United States has such a large, and growing, uninsured population; and discuss why we should care if individuals are uninsured. I then examine policy options to address the problem of the uninsured, beginning with a discussion of the key issues and available evidence and then turning to estimates from a micro-simulation model of the impact of alternative interventions to increase insurance coverage.
Performance Analysis of a Queue with Congestion-Based Staffing Policy
Authors: Zhang Zhe George
Published: October 2008

This paper analyzes a waiting line system that is motivated by the operations of border-crossing stations between the United States and Canada. There are two main conflicting goals in such a system: high security level, which often leads to a longer line; and good customer service, which requires a shorter line. Thus, unlike other queueing systems, maintaining the average queue length within a certain range is the primary objective. This is achieved using a staffing policy, called “congestion-based staffing,” or CBS, where the number of servers (inspection booths) is adjusted according to the queue length during a planning period. We first present an exact benchmark model of Markovian type based on the matrix-geometric solution. For practical CBS policies, we develop a set of closed-form formulas for the major performance measures based on regenerative cycle analysis and fluid limit approximation. Numerical examples show that these approximation formulas are simple, accurate, and robust for practitioners to use in designing CBS policies.
Consistencies in sex differences on the Cognitive Abilities Test across countries, grades, test forms, and cohorts
Authors: Lohman David F. , Lakin Joni M.
Published: September 2008

Background Strand, Deary, and Smith (2006) reported an analysis of sex differences on the Cognitive Abilities Test (CAT) for over 320,000 UK students 11–12 years old. Although mean differences were small, males were overrepresented at the upper and lower extremes of the score distributions on the quantitative and non‐verbal batteries and at the lower extreme of the verbal battery.

Aims We investigate whether these results were unique to the UK or whether they would be seen in other countries, at other grades, cohorts, or forms of the test.

Sample The sample consisted of three nationally representative cohorts of US students in grades 3 through 11 (total N = 318,599) for the 1984, 1992, and 2000 standardizations of the US version of the CAT.

Methods We replicated and extended the Strand et al. (2006) results by comparing the proportions of males and females at each score level across countries (UK vs. US), grades (3–11), and cohorts/test forms (Forms 4, 5, and 6 standardized in 1984, 1992, and 2000, respectively).

Results The results showed an astonishing consistency in sex differences across countries, grades, cohorts, and test forms.

Conclusions Implications for the current debate about sex differences in quantitative reasoning abilities are discussed.
Domain knowledge moderates the influence of visual saliency in scene recognition
Authors: Humphrey Katherine , Underwood Geoffrey
Published: September 2008

Is the sequence of eye‐movements made when viewing a picture related to encoding the image into memory? The suggestion of a relationship is supported by studies that have found that scanpaths are more similar over multiple viewings of a stimulus than would be expected by chance. It has also been found that low‐level visual saliency contributes to the initial formation of these scanpaths, and has lead to formation of theories such as the saliency map hypothesis. However, bottom‐up processes such as these can be overridden by top‐down cognitive knowledge in the form of domain proficiency. Domain specialists were asked to look at a set of photographs of real‐world scenes in preparation for a memory test. Then they were given a second set of stimuli and were asked to identify the picture as old (from the previous set) or new (never seen before). Eye tracking analyses (including scanpath comparison using a string editing algorithm) revealed that saliency did influence where participants looked and in what sequence. However, this was reliably reduced when participants viewed pictures from their specialist domain. This effect is shown to be robust in a repeated viewing of the stimuli.
Relationships between magical thinking, obsessive‐compulsiveness and other forms of anxiety in a sample of non‐clinical children
Authors: Simonds Laura M. , Demetre James D. , Read Cristina
Published: September 2008

Despite the obvious phenomenological similarities between magical thinking and obsessive‐compulsiveness, the relationship between them has been the subject of few empirical investigations in samples of children. The present study aimed to examine the relationship between a general epistemic stance towards magical causation and tendencies towards obsessive‐compulsiveness in a non‐clinical sample of schoolchildren. One‐hundred and two children, aged between 5 and 10 years (48 boys and 54 girls), completed questionnaire measures designed to assess magical thinking, obsessive‐compulsiveness, and other forms of anxiety. School teachers completed a measure of strengths and difficulties for each child. General belief in magical causation was correlated with all types of anxiety, not just obsessive‐compulsiveness, with significant correlations shown for boys in the sample, but not girls. General belief in magical causation contributed little to the prediction of obsessive‐compulsiveness beyond general anxiety. In this study, a general epistemic stance towards magical causation did not differentiate obsessive‐compulsiveness from other anxiety dimensions. The findings are considered in the context of developmental theories of magical and scientific causal reasoning.
Hyperactivity, shyness, and sex: Development and socio‐emotional functioning
Authors: Rydell Ann‐Margret , Diamantopoulou Sofia , Thorell Lisa B. , Bohlin Gunilla
Published: September 2008

Based on formulations about the possible consequences for adaptation of gender non‐normative behaviour, we investigated predictive and concurrent relations of hyperactivity and shyness to various aspects of adaptation focusing on possible effects of sex. At ages 5–6, parents and preschool teachers rated hyperactivity and shyness for 151 children (50% boys). At age 9, we obtained teacher ratings of hyperactivity, internalizing and externalizing problems, self‐ratings of trait anxiety, and peer nominations of shyness, social preference, and aggression. Several effects of sex were found. Hyperactivity ratings were more strongly related across time and raters for boys than for girls. In the predictive analyses, boys' hyperactivity was more strongly related to aggression than was girls' hyperactivity, and in concurrent analyses, girls' hyperactivity was more strongly associated with low social preference than was boys' hyperactivity. There was a protective effect of shyness with regard to aggression that applied only to boys, that is, at high hyperactivity levels, boys with high shyness levels were less aggressive than boys with low shyness levels. There were also main effects of hyperactivity and shyness. In predictive and concurrent analyses, hyperactivity was associated with low social preference, high levels of externalizing problems and with aggression, whereas shyness was associated with high levels of internalizing problems. Finally, there was an interactive effect of hyperactivity and shyness. In the concurrent analyses, an exacerbating effect was demonstrated insofar as high shyness was associated with low social preference at high, but not at low levels of hyperactivity. The different developmental risks of hyperactivity and shyness were discussed.
Television alcohol advertising: Do children really mean what they say?
Authors: Nash Avril S. , Pine Karen J. , Messer David J.
Published: September 2008

Few studies have investigated children's responses to television alcohol advertising. Two separate studies evaluated the appeal of alcohol advertisements on children aged 7–10. An exploratory interview study (N=17) was carried out to assess children's verbal responses to both alcohol and non‐alcohol advertisements and to elicit vocabulary to be used in the second study. Whilst the 7–8 years old children were very positive about the alcohol advertisements, older children did not like them, nor did they perceive them to be effective. The second study was designed to assess children's implicit knowledge, in view of developmental theory that knowledge is not always available for verbal report. This study (N=179) used a simple categorization programme on computer. Using this methodology, children of all ages liked the alcohol advertisements and perceived them as effective. Advertising styles affected popularity with humour, cartoon format or the inclusion of an animal, or character increasing the appeal of an advertisement. The discussion draws attention to the importance of multiple methodologies in eliciting valid and accurate information from children, and to policy matters with regard to alcohol advertising regulation.
Linking actions and emotions: Evidence from 15‐ and 18‐month‐old infants
Authors: Repacholi Betty M.
Published: September 2008

This study investigated 15‐ and 18‐month‐olds' understanding of the link between actions and emotions. Infants watched a videotape in which three adult models performed an action on an object. Each adult expressed the same emotion (positive, negative, or neutral affect) on completion of the action. Infants were subsequently given 20 seconds to interact with the object. Infants were less likely to perform the target action after the models' expressed negative as opposed to positive or neutral affect. Although infants' imitative behaviour was influenced by the models' emotional displays, this social referencing effect was not apparent in their more general object‐directed behaviour. For instance, infants in the negative emotion condition were just as quick to touch the object and spent the same amount of time touching the object as did infants in the neutral and positive emotion conditions. These findings suggest that infants understood that the models' negative affect was in response to the action, rather than the object itself. Infants apparently used this negative emotional information to appraise the action as one that was ‘undesirable’ or ‘bad’. Consequently, infants were now loath to reproduce the action themselves.
A measure of inspection time in 4‐year‐old children: The Benny Bee IT task
Authors: Williams Sarah E. , Turley Christopher , Nettelbeck Ted , Burns Nicholas R.
Published: September 2008

Inspection time (IT) measures speed of information processing without the confounding influence of motor speed. While IT has been found to relate to cognitive abilities in adults and older children, no measure of IT has been validated for use with children younger than 6 years. This study examined the validity of a new measure of IT for preschool children. N=71 4‐year‐old children completed the new IT task and standardized measures of fluid ability, visuospatial ability, and speed of processing. N=50 adults completed the same tasks and, additionally, a standard IT task. Results showed that the new IT task is a stable, reliable measure of IT in 4‐year‐old children. The new task had reasonable concurrent validity with the standard IT task in adults and the relationships between cognitive abilities, particularly general cognitive ability, and IT are sufficiently similar in young children and adults to suggest that the new IT task may be a useful tool for research in populations where IT was previously not measurable.
What's the difference? Insider perspectives on the importance, content, and meaning of interpersonal differences
Authors: Oosterhof Aad , Van der Vegt Gerben S. , Van de Vliert Evert , Sanders Karin , Kiers Henk A. L.
Published: September 2008

This study presents a new approach to examine how team members experience interpersonal differences. This approach offers a way to examine how team members experience their differences with specific other individuals, and how these differences are related to the amount of perceived conflict with these individuals in an organizational context. Data from a non‐profit governmental institution in The Netherlands were analysed, including 80 participants from 15 diverse teams. Five types of differences were salient to the individuals in this sample: differences related to extraversion; work pose; approach to work; task‐related expertise; and seniority. Furthermore, individuals tend to contrast positive and negative evaluations of differences related to extraversion and approaches to work, but to conceptualize positive and negative evaluations of task‐related expertise, seniority, and work pose as more mutually independent phenomena. Moreover, we found that differences related to task‐related expertise were negatively related to both task and relationship conflict. In contrast, differences related to extraversion were positively related to both task and relationship conflict. Finally, the approach‐to‐work cluster was positively related to only task conflict.