bluuebunny/crossref_metadata_2025 huggingface dataset:
nbce1andH+–atpasemRNA expression are stimulated in the mitochondria-rich cells of freshwater-acclimating Japanese eels (Anguilla japonica)
Authors: Tse William Ka Fai , Wong Chris Kong Chu
Published: April 2011

Mitochondria-rich cells (MRCs) of fish gills are well known for their roles in Na+and Cl–excretion in seawater environment. However, the level of understanding of their roles in fresh water is limited. In this study, we used the Percoll gradient technique to isolate gill MRCs from Japanese eels ( Anguilla japonica Temminck and Schlegel, 1846) and measured the mRNA expression of two selected ion transporters, which were partially cloned in our laboratory: sodium bicarbonate co-transporter 1 (nbce1) and vacuolar proton pumps (H+–atpase). In addition, protein expressions of H+–ATPase and NBCe1 in whole gill were studied using Western blotting. The data indicated that both NBCe1 and H+–ATPase mRNA and protein expressions increased after seawater to freshwater transfer. This is the first report of changes in mRNA expression for these two ion transporters in MRCs of Japanese eels during seawater to freshwater transfer, confirming the roles of MRCs in osmoregulation in fresh water.
BOUND FERMION STATES IN A VECTOR 1/r AND AHARONOV–BOHM POTENTIAL IN (2+1) DIMENSIONS
Authors: KHALILOV V. R. , LEE K. E.
Published: April 2011

We construct systematically all the self-adjoint Dirac Hamiltonians with a vector 1/r and Aharonov–Bohm potential in (2+1) dimensions with taking into account the fermion spin. Then we find spectra of these self-adjoint Dirac Hamiltonians. There are one-parameter families of the self-adjoint Dirac Hamiltonians selected by physically acceptable boundary conditions. Equations determining spectra of the self-adjoint radial Dirac Hamiltonians are derived for various values of parameters. We show that the lowest fermion state in the considered potential becomes unstable when the effective charge is greater than the so-called critical charge, and that the effective charge is influenced by the magnetic flux and spin particle.
PRICING ASIAN OPTIONS IN AFFINE GARCH MODELS
Authors: LORENZO MERCURI
Published: April 2011

We derive recursive relationships for the m.g.f. of the geometric average of the underlying within some affine Garch models [Heston and Nandi (2000), Christoffersen et al. (2006), Bellini and Mercuri (2007), Mercuri (2008)] and use them for the semi-analytical valuation of geometric Asian options. Similar relationships are obtained for low order moments of the arithmetic average, that are used for an approximated valuation of arithmetic Asian options based on truncated Edgeworth expansions, following the approach of Turnbull and Wakeman (1991). In both cases the accuracy of the semi-analytical procedure is assessed by means of a comparison with Monte Carlo prices. The results are quite good in the geometric case, while in the arithmetic case the proposed methodology seems to work well only in the Heston and Nandi case.
MICROWAVE-ASSISTED SYNTHESIS AND CHARACTERIZATION OF CaO NANOPARTICLES
Authors: ROY ARUP , BHATTACHARYA JAYANTA
Published: April 2011

Calcium oxide ( CaO ) is an important inorganic compound, which is used across various industries as catalyst, toxic-waste remediation agent, adsorbent, etc. CaO nanoparticles were obtained by the microwave irradiation technique, using Ca(NO3)2 ⋅ 4H2O and NaOH as starting materials. The formation of monocrystalline CaO nanoparticles was confirmed by the XRD (X-ray diffraction) and TEM (transmission electron microscopy) as well as by SAED (selected area electron diffraction) analysis. The structure of the CaO nanocrystal was found to be cubic with particle size, 24 nm and surface area, 74 m2/g.
PHOTON-ASSISTED TRANSPORT IN CARBON NANOTUBE MESOSCOPIC DEVICE
Authors: AWADALLAH ATTIA A. , PHILLIPS ADEL H. , MINA AZIZ N. , AHMED RIHAM R.
Published: April 2011

The aim of the present paper is to investigate the quantum transport properties of a mesoscopic device under the influence of gate voltage and photon energy. A model for such mesoscopic devices is proposed as two metal contacts are deposited on the carbon nanotube quantum dot to serve as source and drain electrodes. The conducting substrate is the gate electrode in this three-terminal mesoscopic device. Another metallic gate is used to govern the electrostatics and the switching of carbon nanotube channel. The substrate at the carbon nanotube quantum dot contacts are controlled by the back gate. Both effects of the photons energy and gate voltage are investigated. The photon-assisted tunneling probability is deduced by solving Dirac equation. Then the current is deduced according to Landauer–Buttiker formula. The quantum capacitance for the device is deduced in terms of density of states. Oscillatory behavior of the current is observed which is due to the Coulomb blockade oscillations. It was found, also, that the peak heights of the dependence of the current on the parameters under study are strongly affected by the interplay between the tunneled electrons and the photon energy. This interplay affects the sidebands resonance. The results obtained in this study are found to be in concordant with those in the literature, which confirm the correctness of the proposed model. This study is valuable for nanotechnology applications, e.g., photodetector devices and solid state quantum computing systems and quantum information processes.
EFFECTIVE MASS OF STRONG-COUPLED BOUND POLARON IN AN ASYMMETRIC QUANTUM DOT INDUCED WITH RASHBA EFFECT
Authors: LI ZHIXIN , XIAO JUAN , LIU AIYONG , XIAO JINGLIN
Published: April 2011

In this paper, on the basis of Huybrechs' strong-coupled polaron model, the Tokuda-modified linear-combination operator method and the unitary transformation method are used to study the properties of the strong-coupled bound polaron considering the influence of Rashba effect, which is brought by the spin-orbit (SO) interaction, in an asymmetric quantum dot (QD). The expression for the effective mass of the polaron as functions of the transverse and longitudinal bound strengths, velocity, vibration frequency, and the bound potential has been derived. After a simple numerical calculation on the RbCl crystal, we found that the total effective mass of the bound polaron is composed of three parts. The interaction between the orbit and the spin with different directions has different effects on the effective mass of the bound polaron.
INFLUENCE OF AMMONIATING TIME ON Nb-CATALYZED GaN NANOSTRUCTURED MATERIALS
Authors: ZHUANG HUIZHAO , WANG JIE , ZHANG XIAOKAI , LI JUNLIN
Published: April 2011

Gallium nitride ( GaN ): nanostructured materials are synthesized by ammoniating Ga2O3/Nb films which are deposited in turn on Si(111) substrates at 900°C. The morphology and structure of the nanostructured materials are characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Optical property of GaN nanostructured materials are analyzed by photoluminescence (PL). The results demonstrated that as-synthesized nanostructured materials are hexagonal wurtzite-structured. Ammoniating time of the samples has an evident influence on the morphology of GaN nanostructured materials synthesized by this method. The PL spectra indicate good emission property for the nanostructured materials. Finally, the growth mechanism is also briefly discussed.
THE STABILITY AND ALMOST PERIODIC SOLUTION FOR GENERALIZED LOGISTIC ALMOST PERIODIC SYSTEM WITH DELAYS
Authors: ZHUO XIANGLAI
Published: April 2011

The stability and almost periodic solution for generalized logistic almost periodic system with infinite and discrete delays is considered. Some sufficient conditions for the boundedness of the system are obtained to guarantee that the system is globally asymptotically stable. We also show that the almost periodic system has a unique globally asymptotically stable strictly positive almost periodic solution by using the almost periodic functional Hull theory and new computational techniques. Furthermore, some recent results are improved, and an open question is answered.
INTRINSIC TRANSMISSION GLOBAL DYNAMICS OF TUBERCULOSIS WITH AGE STRUCTURE
Authors: YANG JUN-YUAN , WANG XIAO-YAN , LI XUE-ZHI , ZHANG FENG-QIN
Published: April 2011

An age-structured epidemiological model for the disease transmission dynamics of TB is studied. We show that the infection-free steady state is locally and globally asymptotically stable if the basic reproductive number is below one, and in this case, the disease always dies out. We prove that the endemic steady state exists when the basic reproductive number is above one. In addition, the endemic steady state is globally asymptotically stable if the basic reproductive number is above one and death rate due to TB is zero.
TRAVELING WAVE SOLUTIONS IN A THREE-SPECIES FOOD-CHAIN MODEL WITH DIFFUSION AND DELAYS
Authors: DU YANKE , XU RUI
Published: April 2011

This paper deals with the existence of traveling wave solutions in a three-species food-chain model with spatial diffusion and time delays due to gestation and negative feedback. By using a cross iteration scheme and Schauder's fixed point theorem, we reduce the existence of traveling wave solutions to the existence of a pair of upper-lower solutions. By constructing a pair of upper-lower solutions, we derive the existence of a traveling wave solution connecting the trivial steady state and the positive steady state. Numerical simulations are carried out to illustrate the main results. In particular, our results extend and improve some known results.
IMF POLICY ADVICE TO EMERGING MARKET ECONOMIES DURING THE 2008–2009 CRISIS: NEW FUND OR NEW FUNDAMENTALS?
Authors: GHOSH ATISH R. , CROWE CHRISTOPHER , KIM JUN IL , OSTRY JONATHAN D. , CHAMON MARCOS
Published: April 2011

This paper reviews the International Monetary Fund (IMF) policy advice to emerging market economies (EMEs) during the 2008-09 crisis, contrasting it to previous crisis episodes. EMEs that had strong fundamentals, and were mainly affected through international trade and financial spillovers, were advised to loosen monetary and fiscal policies, much like the counter-cyclical policies pursued by advanced economies. But in EMEs with "home-grown" vulnerabilities, the advice was more traditional fiscal consolidation, monetary restraint and structural reform, albeit with more financing and greater emphasis on cushioning the impact of the shock. Thus, the "new" IMF advice was the result of "new fundamentals" in EMEs.
THE GLOBAL ENTREPRENEURSHIP AND DEVELOPMENT INDEX: A US PERSPECTIVE
Authors: ACS ZOLTAN J.
Published: April 2011

This paper looks at the performance of the United States (US) on the Global Entrepreneurship and Development Index (GEDI), capturing the contextual features of entrepreneurship. The US ranks third on the GEDI. It performs well on the aspirations sub-index but lags on the attitudes and activity sub-indices. Its performance is strong in areas of startu skills, competition, and new technology but weak in cultural support, tech sector, and high-growth business. Performance is stronger on institutional variables than on individual variables. Apparent weakness in the tech sector, lack of cultural support for entrepreneurship and lack of high-growth business can be due to the changing political environment and international volatility, 1990s tech sector bubble burst, the recent recession, and the improving performance of other counties.
CLIMATE POLICY IN CRISIS AND RECOVERY
Authors: JONES BENJAMIN , KEEN MICHAEL
Published: April 2011

This paper focuses on the implications of the economic crisis and recession of 2008–2009 for climate change and related policy responses. Stressing that even prolonged output losses make very little difference to appropriate emissions reduction objectives, the paper argues that a cautious shift towards a more aggressive path of carbon pricing need not impede recovery and could make a valuable contribution to addressing looming fiscal challenges. Well-designed and monitored "green" stimulus measures can help sustain aggregate demand during the downturn, while increased climate-related public spending will likely be needed into the longer-term. However, it is critical to avoid undue reliance on spending rather than tax measures, particularly as the recovery strengthens.
Mutations in the DDR2 Kinase Gene Identify a Novel Therapeutic Target in Squamous Cell Lung Cancer
Authors: Hammerman Peter S. , Sos Martin L. , Ramos Alex H. , Xu Chunxiao , Dutt Amit , Zhou Wenjun , Brace Lear E. , Woods Brittany A. , Lin Wenchu , Zhang Jianming , Deng Xianming , Lim Sang Min , Heynck Stefanie , Peifer Martin , Simard Jeffrey R. , Lawrence Michael S. , Onofrio Robert C. , Salvesen Helga B. , Seidel Danila , Zander Thomas , Heuckmann Johannes M. , Soltermann Alex , Moch Holger , Koker Mirjam , Leenders Frauke , Gabler Franziska , Querings Silvia , Ansén Sascha , Brambilla Elisabeth , Brambilla Christian , Lorimier Philippe , Brustugun Odd Terje , Helland Åslaug , Petersen Iver , Clement Joachim H. , Groen Harry , Timens Wim , Sietsma Hannie , Stoelben Erich , Wolf Jürgen , Beer David G. , Tsao Ming Sound , Hanna Megan , Hatton Charles , Eck Michael J. , Janne Pasi A. , Johnson Bruce E. , Winckler Wendy , Greulich Heidi , Bass Adam J. , Cho Jeonghee , Rauh Daniel , Gray Nathanael S. , Wong Kwok-Kin , Haura Eric B. , Thomas Roman K. , Meyerson Matthew
Published: April 2011

Although genomically targeted therapies have improved outcomes for patients with lung adenocarcinoma, little is known about the genomic alterations that drive squamous cell cancer (SCC) of the lung. Sanger sequencing of the tyrosine kinome identified mutations in the DDR2 kinase gene in 3.8% of lung SCCs and cell lines. Lung SCC cell lines harboring DDR2 mutations were selectively killed by knockdown of DDR2 by RNA interference or by treatment with the multitargeted kinase inhibitor dasatinib. Tumors established from a DDR2 mutant cell line were sensitive to dasatinib in xenograft models. Expression of mutated DDR2 led to cellular transformation that was blocked by dasatinib. A patient with lung SCC that responded to dasatinib and erlotinib treatment harbored a DDR2 kinase domain mutation. These data suggest that gain-of-function mutations in DDR2 are important oncogenic events and are amenable to therapy with dasatinib. Because dasatinib is already approved for use, these findings could be used to rapidly generate clinical trials.

Significance: DDR2 mutations are present in 4% of lung SCCs, and DDR2 mutations are associated with sensitivity to dasatinib. These findings provide a rationale for designing clinical trials with the FDA-approved drug dasatinib in patients with lung SCCs. Cancer Discovery; 1(1); 78–89. ©2011 AACR.

Read the Commentary on this article by Ohashi and Pao, p. 23

This article is highlighted in the In This Issue feature, p. 4
A Rapid Generalized Least Squares Model for a Genome-Wide Quantitative Trait Association Analysis in Families
Authors: Li Xiang , Basu Saonli , Miller Michael B. , Iacono William G. , McGue Matt
Published: April 2011

Genome-wide association studies (GWAS) using family data involve association analyses between hundreds of thousands of markers and a trait for a large number of related individuals. The correlations among relatives bring statistical and computational challenges when performing these large-scale association analyses. Recently, several rapid methods accounting for both within- and between-family variation have been proposed. However, these techniques mostly model the phenotypic similarities in terms of genetic relatedness. The familial resemblances in many family-based studies such as twin studies are not only due to the genetic relatedness, but also derive from shared environmental effects and assortative mating. In this paper, we propose 2 generalized least squares (GLS) models for rapid association analysis of family-based GWAS, which accommodate both genetic and environmental contributions to familial resemblance. In our first model, we estimated the joint genetic and environmental variations. In our second model, we estimated the genetic and environmental components separately. Through simulation studies, we demonstrated that our proposed approaches are more powerful and computationally efficient than a number of existing methods are. We show that estimating the residual variance-covariance matrix in the GLS models without SNP effects does not lead to an appreciable bias in the p values as long as the SNP effect is small (i.e. accounting for no more than 1% of trait variance).
100 Years of Thoracoscopy: Historical Notes
Authors: Marchetti Gian Pietro , Pinelli Valentina , Tassi Gian Franco
Published: April 2011

In the historical evolution of thoracoscopy, which was initiated exactly one century ago by Hans Christian Jacobaeus, two distinct periods can be identified: one between 1910 and 1955, characterised by its use for the lysis of pleural adhesions to obtain therapeutic pneumothorax in lung tuberculosis, and the subsequent period which has seen the development of diagnostic applications, principally due to pulmonologists and, after 1990, the start of an exclusively surgical thoracoscopy called video-assisted thoracoscopic surgery or VATS to perform video-assisted interventions.
BDNF/TrkB Content and Interaction with Gastrin-Releasing Peptide Receptor Blockade in Colorectal Cancer
Authors: Brunetto de Farias Caroline , Rosemberg Denis Broock , Heinen Tiago Elias , Koehler-Santos Patricia , Abujamra Ana Lucia , Kapczinski Flávio , Brunetto Algemir Lunardi , Ashton-Prolla Patricia , Meurer Luise , Reis Bogo Maurício , Damin Daniel C. , Schwartsmann Gilberto , Roesler Rafael
Published: April 2011

Objective: Neurotrophin and neuropeptide pathways are emerging targets in cancer. Here we show that brain-derived neurotrophic factor (BDNF) and its receptor, TrkB, are present in colorectal cancer and that BDNF levels are increased in tumors compared to nontumor tissue. In addition, we investigate the role of BDNF in influencing the response of colorectal cancer cells to inhibition of gastrin-releasing peptide receptors (GRPR). Methods: Fresh-frozen sporadic colorectal adenocarcinoma specimens and adjacent nonneoplastic tissue from 30 patients, as well as paraffin-embedded colorectal cancer samples from 21 patients, were used in this study. Cell proliferation and mRNA and protein levels were examined in HT-29 or SW620 cells treated with a GRPR antagonist, human recombinant BDNF (hrBDNF), a Trk antagonist K252a, or cetuximab. Results: Expression of BDNF and TrkB was detected in tumor samples and cell lines. BDNF levels were higher in tumor samples compared to nonneoplastic tissue. BDNF expression and secretion were increased by GRPR blockade in HT-29 cells through a mechanism dependent on epidermal growth factor receptors. Treatment with hrBDNF prevented the effect of GRPR blockade on cell proliferation, whereas a Trk inhibitor reduced proliferation. Conclusions: BDNF and TrkB are present in colorectal cancer and might contribute to resistance to GRPR antagonists.
Use of Complementary and Alternative Medicine Supplements in Patients with Diabetes Mellitus
Authors: Fabian Elisabeth , Töscher Sabine , Elmadfa Ibrahim , Pieber Thomas R.
Published: April 2011

Background/Aims: This study was conducted to evaluate the current use of biologically-based complementary and alternative medicine (CAM) therapies in diabetics, considering health awareness, motivation, and expectations for CAM use. Moreover, patients’ attitudes toward cinnamon preparations and the need for appropriate information from health care professionals were determined. Methods: A total of 200 patients (59% men and 41% women) with type 1 (16%) or type 2 diabetes (84%) were interviewed using a standardized, validated questionnaire; the results from 198 respondents were analyzed. Results: A third of type 1 and type 2 diabetics (women > men; p < 0.01) reported current use of biologically-based CAM supplements, and intake was significantly (r = 0.203; p < 0.05) correlated to the degree of health awareness/interest in self-care in type 2 diabetics. The use of nutritional supplements (vitamins/multivitamins and minerals), herbal medicine, and cinnamon was reported most frequently. Prevention (36%) and improved well-being/quality of life (13%) but not the positive modulation of diabetes management (4%) were given as main motivations. Eighty-three percent of type 1 diabetics (women > men; p < 0.05) and 70% of type 2 diabetics already knew about the postulated positive effect of cinnamon on blood glucose. Up to 85% reported a willingness or a probable willingness to test the effect of cinnamon on blood glucose. Among patients with type 2 diabetes the subjectively felt disease burden was found to have a significant (r = 0.235; p < 0.01) impact on the willingness to use cinnamon preparations for better diabetes management. Conclusion: This study indicates a remarkable interest in CAM remedies in the investigated group of diabetics as a strategy for active engagement in health and disease self-management. Healthcare professionals should be aware of the increasing number of patients using CAM supplements and hence incorporate these aspects into patient care in order to ensure patient satisfaction and optimize health care.
Peroxisome Proliferator–Activated Receptor-α Gene Level Differently Affects Lipid Metabolism and Inflammation in Apolipoprotein E2 Knock-In Mice
Authors: Lalloyer Fanny , Wouters Kristiaan , Baron Morgane , Caron Sandrine , Vallez Emmanuelle , Vanhoutte Jonathan , Baugé Eric , Shiri-Sverdlov Ronit , Hofker Marten , Staels Bart , Tailleux Anne
Published: April 2011

Objective—

Peroxisome proliferator–activated receptor-α (PPARα) is a ligand-activated transcription factor that controls lipid metabolism and inflammation. PPARα is activated by fibrates, hypolipidemic drugs used in the treatment of dyslipidemia. Previous studies assessing the influence of PPARα agonists on atherosclerosis in mice yielded conflicting results, and the implication of PPARα therein has not been assessed. The human apolipoprotein E2 knock-in (apoE2-KI) mouse is a model of mixed dyslipidemia, atherosclerosis, and nonalcoholic steatohepatitis (NASH). The aim of this study was to analyze, using homo- and heterozygous PPARα-deficient mice, the consequences of quantitative variations of PPARα gene levels and their response to the synthetic PPARα agonist fenofibrate on NASH and atherosclerosis in apoE2-KI mice.

Methods and Results—

Wild-type (+/+), heterozygous (+/−), and homozygous (−/−) PPARα-deficient mice in the apoE2-KI background were generated and subjected to a Western diet supplemented with fenofibrate or not supplemented. Western diet–fed PPARα−/− apoE2-KI mice displayed an aggravation of liver steatosis and inflammation compared with PPARα+/+ and PPARα+/− apoE2-KI mice, indicating a role of PPARα in liver protection. Moreover, PPARα expression was required for the fenofibrate-induced protection against NASH. Interestingly, fenofibrate treatment induced a similar response on hepatic lipid metabolism in PPARα+/+ and PPARα+/− apoE2-KI mice, whereas, for a maximal antiinflammatory response, both alleles of the PPARα gene were required. Surprisingly, atherosclerosis development was not significantly different among PPARα+/+, PPARα+/−, and PPARα−/− apoE2-KI mice. However, PPARα gene level determined both the antiatherosclerotic and vascular antiinflammatory responses to fenofibrate in a dose-dependent manner.

Conclusion—

These results demonstrate a necessary but quantitatively different role of PPARα in the modulation of liver metabolism, inflammation, and atherogenesis.
Src Phosphorylation of Endothelial Cell Surface Intercellular Adhesion Molecule-1 Mediates Neutrophil Adhesion and Contributes to the Mechanism of Lung Inflammation
Authors: Liu Guoquan , Vogel Stephen M. , Gao Xiaopei , Javaid Kamran , Hu Guochang , Danilov Sergei M. , Malik Asrar B. , Minshall Richard D.
Published: April 2011

Objective—

The goal of this study was to determine whether tumor necrosis factor α (TNFα)–induced Src activation and intercellular adhesion molecule-1 (ICAM-1) phosphorylation rapidly increase endothelial cell adhesivity and polymorphonuclear leukocyte (PMN) sequestration independently of de novo ICAM-1 synthesis.

Methods and Results—

TNFα exposure of mouse lungs for 5 minutes produced a 3-fold increase in
125
I-anti-ICAM-1 monoclonal antibody (mAb) binding and
111
In oxine-labeled PMN sequestration, as well as Src activation, ICAM-1 Tyr518 phosphorylation, and phospho- Tyr518-ICAM-1 coimmunoprecipitation with actin. The response was absent in
Nox2
−/−
lungs or following Src inhibition. In COS-7 cells transfected with wild-type (WT), phospho-defective (Tyr518Phe), or phospho-mimicking (Tyr518Asp) mouse ICAM-1 cDNA constructs, TNFα increased the B
max
of YN1/1.7.4 anti-ICAM-1 mAb binding to WT-ICAM-1 but not to Tyr518Phe-ICAM-1, indicating increased binding avidity secondary to ICAM-1 phosphorylation. This effect was mimicked by expression of the Tyr518Asp-ICAM-1 mutant. TNFα also increased the staining intensity and cell surface clustering of YN1/1.7.4 mAb-labeled WT-ICAM-1 that colocalized with F-actin, which was not observed with Tyr518Phe-ICAM-1 but was recapitulated with Tyr518Asp-ICAM-1. Finally, overexpression of ICAM-1 in mouse lungs significantly increased lipopolysaccharide-induced transvascular albumin leakage and bronchoalveolar lavage PMN counts at 2 and 24 hours after lipopolysaccharide inhalation compared with lungs expressing the Tyr518Phe ICAM-1 mutant.

Conclusion—

Src-dependent phosphorylation of endothelial cell ICAM-1 Tyr518 induces PMN adhesion by promoting ICAM-1 clustering, which we propose mediates rapid-phase lung vascular accumulation of PMNs during inflammation.
The Ras Activator RasGRP3 Mediates Diabetes-Induced Embryonic Defects and Affects Endothelial Cell Migration
Authors: Randhawa Paramjeet K. , Rylova Svetlana , Heinz Jessica Y. , Kiser Stephanie , Fried Joanna H. , Dunworth William P. , Anderson Amanda L. , Barber Andrew T. , Chappell John C. , Roberts David M. , Bautch Victoria L.
Published: April 2011

Rationale:

Fetuses that develop in diabetic mothers have a higher incidence of birth defects that include cardiovascular defects, but the signaling pathways that mediate these developmental effects are poorly understood. It is reasonable to hypothesize that diabetic maternal effects are mediated by 1 or more pathways activated downstream of aberrant glucose metabolism, because poorly controlled maternal glucose levels correlate with the frequency and severity of the defects.

Objective:

We investigated whether RasGRP3 (Ras guanyl-releasing protein 3), a Ras activator expressed in developing blood vessels, mediates diabetes-induced vascular developmental defects. RasGRP3 is activated by diacylglycerol, and diacylglycerol is overproduced by aberrant glucose metabolism in diabetic individuals. We also investigated the effects of overactivation and loss of function for RasGRP3 in primary endothelial cells and developing vessels.

Methods and Results:

Analysis of mouse embryos from diabetic mothers showed that diabetes-induced developmental defects were dramatically attenuated in embryos that lacked
Rasgrp3
function. Endothelial cells that expressed activated RasGRP3 had elevated Ras-ERK signaling and perturbed migration, whereas endothelial cells that lacked
Rasgrp3
function had attenuated Ras-ERK signaling and did not migrate in response to endothelin-1. Developing blood vessels exhibited endothelin-stimulated vessel dysmorphogenesis that required
Rasgrp3
function.

Conclusions:

These findings provide the first evidence that RasGRP3 contributes to developmental defects found in embryos that develop in a diabetic environment. The results also elucidate RasGRP3-mediated signaling in endothelial cells and identify endothelin-1 as an upstream input and Ras/MEK/ERK as a downstream effector pathway. RasGRP3 may be a novel therapeutic target for the fetal complications of diabetes.
Developing a Tool to Assess Quality of Stroke Care Across European Populations
Authors: Wellwood Ian , Wu Olivia , Langhorne Peter , McKevitt Christopher , Di Carlo Antonio , Rudd Anthony G. , Wolfe Charles D.A. ,   on behalf of the European Registers of Stroke (EROS) Collaborative Group
Published: April 2011

Background and Purpose—

There are significant differences in the provision of care and outcome after stroke across countries. The European Registers of Stroke study aimed to develop, test, and refine a tool to assess quality of care.

Methods—

We used a systematic review and grading of evidence for stroke care across the clinical pathway and developed and field-tested a quality tool that was delivered by post and later by site visit at 7 centers. Items were refined by using an algorithm that took into account the level of evidence, measurement properties, and consensus of opinion obtained using, the Delphi techniques.

Results—

The tool included 251 items across 11 domains, of which 214 items could be categorized by any level of evidence. Overall agreement between postal and site visit modes of delivery was acceptable (κ=0.77), with most items having a κ >0.5. The refinement process resulted in 2 practical versions of the tool (93 items and 22 items). Positive responses to items in the tool indicated implementation of evidence-based stroke care. In field testing, the proportion of positive responses to evidence-based items ranged from 43% to 79% across populations. Proportions of different types of evidence being implemented were similar: high quality 62%, limited quality 72%, and expert opinion 54% across the populations. More than half (4 of 7) of the centers provided stroke unit care and thrombolysis, but availability and access to inpatient rehabilitation varied significantly, with poor access to community follow-up for rehabilitation and medical management.

Conclusions—

The European Registers of Stroke Quality Assessment Tool has potential to be used as a framework to compare services and promote increased implementation of evidence-based care.
Adiponectin Level as a Consequence of Genetic Variation, but Not Leptin Level or Leptin
Authors: Bevan Steve , Meidtner Karina , Lorenz Matthias , Sitzer Matthias , Grant Peter J. , Markus Hugh S.
Published: April 2011

Background and Purpose—

The adipocytokines adiponectin and leptin have been suggested as risk factors for cardiovascular disease, including stroke, acting through atherosclerosis. However, studies have provided conflicting results in underpowered cohorts with some suggesting that the leptin:adiponectin ratio is a better predictor of risk. We examined these associations with carotid intima-media thickness (IMT), a marker of early atherosclerosis and arterial remodeling and an independent predictor of stroke. We also examined association between genetic variants in the leptin and adiponectin genes and IMT.

Methods—

Adiponectin and leptin levels were determined in 990 individuals from the community Carotid Atherosclerosis Progression Study. Five variants in the gene encoding adiponectin and 7 in the gene encoding leptin were genotyped and their effects on circulating levels assessed. Both were then correlated with IMT.

Results—

Adiponectin levels negatively correlated with IMT (−0.079,
P
=0.013). There was no correlation between leptin levels or leptin:adiponectin ratio and IMT. Two variants in the
ADIPOQ
gene encoding adiponectin were associated with altered adiponectin levels, 1 of which (rs266729) was associated with IMT. There was also an interaction with body mass index (
P
=0.019) with the association being present in obese subjects (
P
=0.02).

Conclusions—

Our results support a causal role for adiponectin in early carotid IMT and suggest it may act through interaction with obesity. In contrast, we found no evidence of a role for leptin and no evidence that leptin:adiponectin ratio is a better predictor of risk that adiponectin levels alone.
Isoflurane Enhanced Hemorrhagic Transformation by Impairing Antioxidant Enzymes in Hyperglycemic Rats With Middle Cerebral Artery Occlusion
Authors: Hu Qin , Ma Qingyi , Zhan Yan , He Zhaohui , Tang Jiping , Zhou Changman , Zhang John
Published: April 2011

Background and Purpose—

Because the potential neuroprotective effect of isoflurane is controversial, we attempted to study whether isoflurane after treatment provides neuroprotection in a rat model of hyperglycemia-induced ischemic hemorrhagic transformation.

Methods—

Rats received an injection of 50% dextrose (6 mL/kg intraperitoneally) and had a middle cerebral artery occlusion 30 minutes later. Four groups were included: sham-operated, ischemia/reperfusion, isoflurane treatment, and vehicle groups. In the treatment group, after 2 hours of ischemia, 2% isoflurane was administered at the onset of reperfusion. We measured the level of blood glucose at 0, 2.5, 4.5, and 6.5 hours after dextrose injection. Infarct and hemorrhagic volumes, neurological scores, oxidative stress (malondialdehyde, 4-hydroxy-2-nonenal, and nitrotyrosine) and the activities of superoxide dismutase and catalase were measured at 24 hours after ischemia.

Results—

Isoflurane had no effects on blood glucose, it failed to reduce infarct, hemorrhage volume, and brain edema, and it enhanced neurobehavioral deficits when compared with the ischemia/reperfusion group at 24 hours after middle cerebral artery occlusion. On the contrary, isoflurane exacerbated these parameters compared with the vehicle group. In addition, it increased the expressions of malondialdehyde, 4-hydroxy-2-nonenal, and nitrotyrosine, and it decreased the activities of superoxide dismutase and catalase compared to the vehicle group.

Conclusions—

Isoflurane after treatment worsened physiological and neurological outcomes in this ischemia hyperglycemia-induced hemorrhagic transformation possibly by impairing the antioxidant defense system.
Is the Montreal Cognitive Assessment Superior to the Mini-Mental State Examination to Detect Poststroke Cognitive Impairment?
Authors: Godefroy Olivier , Fickl Andreas , Roussel Martine , Auribault Caroline , Bugnicourt Jean Marc , Lamy Chantal , Canaple Sandrine , Petitnicolas Gil
Published: April 2011

Background and Purpose—

A screening test is required to improve the diagnosis of poststroke cognitive impairment. The Montreal Cognitive Assessment (MoCA), a newly designed screening test, has been found to be more sensitive than Mini-Mental State Examination (MMSE), but its clinical value has not been established by means of a comprehensive neuropsychological battery. This study was designed to assess the value of MoCA and MMSE to detect poststroke cognitive impairment determined by a neuropsychological battery.

Methods—

Both screening tests and a neuropsychological battery were administered during the acute phase in 95 patients referred for recent infarct or hemorrhage. Raw MMSE and MoCA scores were used with published cutoffs and new cutoff scores for MMSE and MoCA were also computed after adjustment for age and education.

Results—

Using raw scores, MoCA was more frequently impaired (
P
=0.0001) than MMSE. MoCA showed good sensitivity (sensitivity, 0.94) but moderate specificity (specificity, 0.42; positive predictive value, 0.77; negative predictive value, 0.76), whereas an inverse profile was observed for MMSE (sensitivity, 0.66; specificity, 0.97; positive predictive value, 0.98; negative predictive value, 0.58). Adjusted scores with new cutoffs (MMSE
adj
≤24, MoCA
adj
≤20) provided good sensitivity and very good specificity for both tests (MMSE
adj
: sensitivity, 0.7, specificity, 0.97, positive predictive value, 0.98, negative predictive value, 0.61; MoCA
adj
: sensitivity, 0.67, specificity, 0.9, positive predictive value, 0.93, negative predictive value, 0.57). On receiver operating characteristic curve analysis, areas under the curve of all scores were >0.88.

Conclusions—

The previously reported high sensitivity of MoCA is associated with low specificity. Both screening tests are moderately sensitive to acute poststroke cognitive impairment. This study provides indications for the diagnosis of poststroke cognitive impairment.
The Importance of Size
Authors: Riedel Christian H. , Zimmermann Philip , Jensen-Kondering Ulf , Stingele Robert , Deuschl Günther , Jansen Olav
Published: April 2011

Background and Purpose—

We hypothesize that in acute middle cerebral artery stroke, thrombus lengths measured in thin-slice nonenhanced CT images define a limit beyond which systemic thrombolysis will fail to recanalize occluded arteries.

Methods—

In 138 patients who presented with acute middle cerebral artery stroke and who were treated with intravenous thrombolysis (IVT), we measured lengths of thrombotic clots depicted as arterial hyperdensities in admission nonenhanced CT images with 2.5-mm slice width. Vascular recanalization was investigated after thrombolysis and recanalization results were related to thrombus lengths by logistic regression.

Results—

In 62 patients, IVT resulted in recanalization; among these patients, no thrombus length exceeded 8 mm. The median modified Rankin scale score at hospital discharge was 2. In the remaining 76 patients, thrombus lengths mostly exceeded 8 mm and IVT failed in recanalization. These patients were discharged with a median modified Rankin scale score of 5.

Conclusions—

This study shows that in acute middle cerebral artery stroke, IVT has nearly no potential to recanalize occluded vessels if thrombus length exceeds 8 mm.
The Military and Its Role in Albania’s Democratization
Authors: Danopoulos Constantine P. , Skandalis Konstantinos S.
Published: April 2011

Communist and hermetically sealed Albania entered a process of democratization in the early 1990s. One of the most salient characteristics of democratic governance is to bring and keep the military under the control of the elected authorities. Following a theoretical discussion on the differences between civilian and democratic control, the article dwells on the specifics of the Albanian case. The work identifies, analyzes, and assesses the strategies employed by the first postcommunist government to bring about democratic control over the nation’s military. The four strategies included: departization, depoliticization, democratization, and professionalization. The article argues that the government’s efforts ended up damaging the military organization to the point that the Albanian army disintegrated and did not and could not heed the President’s call to quell the popular uprising in March 1997. The concluding section of the article discusses post-1997 developments and assesses the lessons learned.
Foreign takeovers of Australian listed entities
Authors: Bugeja Martin
Published: April 2011

This study examines if Australian target firm abnormal returns and characteristics differ between Australian and foreign bidders. The results indicate that takeovers from foreign bidders are associated with higher target firm abnormal returns than bids from Australian firms. Overseas bidders also pay an additional premium for research-intensive target firms. Target firms that receive an offer from outside Australia are significantly larger, have lower leverage, and are more likely to operate in the resources sector. Foreign acquisitions are also more likely to be a friendly takeover. The relative exchange rate is not associated with the likelihood of a foreign takeover. There is no difference in takeover success or competition between domestic and foreign bids.
The economic significance of trading based on the size effect in Australia
Authors: Bettman Jenni L , Ng Wen Sern Kelvin , Sault Stephen J
Published: April 2011

It is generally accepted within the extant literature that a size effect exists, whereby smaller firms tend to experience higher rates of return than those of large firms. This small size effect is identified in a number of studies over a variety of equity markets. Despite this, however, no study to date considers the dollar profits attainable by executing a trading strategy that constructs a portfolio based on stocks within the lowest market capitalization decile. Specifically, this paper seeks to identify the existence of a size effect in Australia, but, moreover, attempts to ascertain if a dollar profit can be obtained from executing a trading strategy based on small market capitalization stocks. In doing this, we consider all stocks listed on the Australian stock exchange, and use volume and bid-ask prices to account for liquidity and transactions costs, respectively. Overall, our regression analysis confirms the existence of a size effect within the Australian equity market. However, in executing a trading strategy based on stocks with low market capitalization, we find that after accounting for liquidity and transaction costs the profits obtainable are extremely small and statistically insignificant. This suggests that while the firm size effect exists, the illiquidity and relatively large transaction costs of small stocks eliminate the potential for economic profits.
Information and the cost of capital: The Easley-O’Hara (2004) model with endogenous information acquisition
Authors: Clinch Greg , Lombardi Brett
Published: April 2011

We investigate the impact of endogenous information acquisition on Easley and O’Hara’s (2004) result that moving information from being publicly to privately available results in an increase in a firm’s cost of capital. As in Christensen et al. (2010), when the cost of information acquisition is fixed, Easley and O’Hara’s result reverses. We study two scenarios, however, where Easley and O’Hara’s result can continue to hold (i): where the cost of information acquisition is increasing in its precision, and (ii) where the benefits of acquiring private information span multiple firms.
An efficient method for determining the critical modification coefficient for cylindrical worm gearing in which the worm is generated by a curve
Authors: Lee C-K , Chen C-K
Published: April 2011

This paper proposes an efficient method for the determination of the critical modification coefficient (CMC) for the cylindrical worm gearing in which the worm is generated by a curve. The term CMC is defined as the modification coefficient that causes the first boundary points to be just on the boundary of the area of meshing. Solved from a system of five non-linear equations, the CMC not only avoids gear undercutting, but also produces the maximum contact ratio. In developing the system equations, the equation of non-undercutting is derived directly from the curvature information of the generating curve and the parameters of relative motion, without the need to derive any partial derivatives to the equation of the generating surface. By using an equivalent generation mechanism rather than the real one, an explicit form of equation of meshing is created. The equation of meshing created can simplify the form of the equation of non-undercutting, reduce the number of non-linear equations and unknowns in the system equations, increase the speed of convergence and decrease numerical instability. Based on the proposed method, a computer program is created and applied to analyse the CMCs of four commonly used worm gearings: ZA, ZN, ZE and ZC3.
The effects of tool geometry change on shearing edge finish in fine-blanking of different materials
Authors: Leung Y C , Chan L C , Cheng C H , Lee T C
Published: April 2011

An excellent quality of shearing edge implies that a smooth cutting edge without tearing will be observed on the whole edge surface. This is one of the most significant features of the fine-blanking process. To achieve this good blanking edge quality in fine-blanking, quite a large number of factors need to be considered simultaneously during the operation, such as blanking speed, processing material, product shape, lubrication and tool geometry. Thus, the objective of this paper is mainly to study the influence of tool geometry change in fine-blanking for different materials. This is because the nose radius usually seriously deteriorates with increasing service period in mass production, which eventually causes the entire loss of the specific features of the fine-blanking process. Therefore, a tailor-made experimental study was carried out to investigate the relationship between the punch nose radius and the shearing edge quality, such as the shearing edge surface finish, burr height and die-roll height, during fine-blanking for different types of materials. Consequently, findings show that an increase in the punch nose radius produces a higher percentage of fracture of the blanked edge and increases the amount of burr height.
Correction of milling tool paths by tool positioning defect compensation
Authors: Landon Y , Segonds S , Mousseigne M , Lagarrigue P
Published: April 2011

In considering errors due to elastic deformations in milling, the workpiece-work-holding fixture assembly is generally considered to be infinitely rigid, at least when the geometrical features so permit. The tool-tool-holder-spindle assembly and the machine axes are then deformed under the action of the cutting forces. This deformation leads to a positioning defect of the tool in relation to the theoretical position. With the aim of taking this positioning defect into account in manufacturing, a ‘Virtual Worker’ was implemented that was capable of predicting this defect, in relation to the type of machining, and of compensating for it. It was built on a set of data blocks drawn up for each tool. In order to fill in these tool data blocks quickly, a master workpiece was elaborated that brought together the milling operation characteristics for the tool's behaviour at work. By milling and then measuring this master workpiece, the behaviour of the tool-tool-holder-spindle assembly was able to be fully characterized at work.
The evaluation of technology change projects: Literature overview and suggestions for further inquiry
Authors: Nasierowski W
Published: April 2011

The objective of this paper is to advance the assessment of efficiency and effectiveness of technology development, transfer and implementation, and to explore industrial patterns of technological change. Based on a literature overview, methods used to measure technological change are identified and their usefulness assessed. Criteria for evaluation and selection of individuals, institutions and projects are examined. The summary section provides some advice for the development and use of methods to evaluate/select technology change agents and projects.
Predictions of roll force under heavy-reduction hot rolling using a large-deformation constitutive model
Authors: Byon S M , Kim S I , Lee Y
Published: April 2011

A large-deformation constitutive model applicable to the calculation of roll force and torque in heavy-reduction rolling has been presented. The concept of the volume fraction of dynamically recrystallized grains, which depicts the flow stress softening correctly with the level of strain, strain rate and temperature has been newly introduced in the proposed model. The material constants required in the proposed model have been obtained by a series of hot-torsion tests.

A laboratory-scale hot-plate rolling experiment, together with three-dimensional finite element analysis coupled with the proposed model, has been performed to investigate the accuracy of the proposed constitutive model. The soundness of the proposed model has been demonstrated through a series of finite element simulations with temperature and reduction changed.

The finite element predictions of roll force based on the proposed model and the experimental results was shown to be in fair agreement whereas those based on the Misaka-Yoshimoto model, in which dynamic recrystallization was not considered, failed to predict the roll force precisely at heavy reduction. The results also revealed that, for a typical reduction, the flow stress softening effect was not observed during deformation, whereas the effect was considerable when the material underwent heavy reduction.