bluuebunny/crossref_metadata_2025 huggingface dataset:
Biochemical and Cellular Characterization of Helicobacter pylori RecA, a Protein with High-Level Constitutive Expression
Authors: Orillard Emilie , Radicella J. Pablo , Marsin Stéphanie
Published: September 2011

Helicobacter pylori
is a bacterial pathogen colonizing half of the world's human population. It has been implicated in a number of gastric diseases, from asymptomatic gastritis to cancer. It is characterized by an amazing genetic variability that results from high mutation rates and efficient DNA homologous recombination and transformation systems. Here, we report the characterization of
H. pylori
RecA (HpRecA), a protein shown to be involved in DNA repair, transformation, and mouse colonization. The biochemical characterization of the purified recombinase reveals activities similar to those of
Escherichia coli
RecA (EcRecA). We show that in
H. pylori
, HpRecA is present in about 80,000 copies per cell during exponential growth and decreases to about 50,000 copies in stationary phase. The amount of HpRecA remains unchanged after induction of DNA lesions, suggesting that HpRecA is always expressed at a high level in order to repair DNA damage or facilitate recombination. We performed HpRecA localization analysis by adding a Flag tag to the protein, revealing two different patterns of localization. During exponential growth, RecA-Flag presents a diffuse pattern, overlapping with the DAPI (4′,6-diamidino-2-phenylindole) staining of DNA, whereas during stationary phase, the protein is present in more defined areas devoid of DAPI staining. These localizations are not affected by inactivation of competence or DNA recombination genes. Neither UV irradiation nor gamma irradiation modified HpRecA localization, suggesting the existence of a constitutive DNA damage adaptation system.
Peroxide Stimulon and Role of PerR in Group A Streptococcus
Authors: Grifantini Renata , Toukoki Chadia , Colaprico Annalisa , Gryllos Ioannis
Published: September 2011

We have characterized group A
Streptococcus
(GAS) genome-wide responses to hydrogen peroxide and assessed the role of the peroxide response regulator (PerR) in GAS under oxidative stress. Comparison of transcriptome changes elicited by peroxide in wild-type bacteria with those in a
perR
deletion mutant showed that 76 out of 237 peroxide-regulated genes are PerR dependent. Unlike the PerR-mediated upregulation of peroxidases and other peroxide stress defense mechanisms previously reported in Gram-positive species, PerR-dependent genes in GAS were almost exclusively downregulated and encoded proteins involved in purine and deoxyribonucleotide biosynthesis, heme uptake, and amino acid/peptide transport, but they also included a strongly activated putative transcriptional regulator (
SPy1198
). Of the 161 PerR-independent loci, repressed genes (86 of 161) encoded proteins with functions similar to those coordinated by PerR, in contrast to upregulated loci that encoded proteins that function in DNA damage repair, cofactor metabolism, reactive oxygen species detoxification, pilus biosynthesis, and hypothetical proteins. Complementation of the
perR
deletion mutant with wild-type PerR restored PerR-dependent regulation, whereas complementation with either one of two PerR variants carrying single mutations in two predicted metal-binding sites did not rescue the mutant phenotype. Metal content analyses of the recombinant wild type and respective PerR mutants, in addition to regulation studies in metal-supplemented and iron-depleted media, showed binding of zinc and iron by PerR and an iron requirement for optimal responses to peroxide. Our findings reveal a novel physiological contribution of PerR in coordinating DNA and protein metabolic functions in peroxide and identify GAS adaptive responses that may serve to enhance oxidative stress resistance and virulence in the host.
FraH Is Required for Reorganization of Intracellular Membranes during Heterocyst Differentiation in Anabaena sp. Strain PCC 7120
Authors: Merino-Puerto Victoria , Mariscal Vicente , Schwarz Heinz , Maldener Iris , Mullineaux Conrad W. , Herrero Antonia , Flores Enrique
Published: September 2011

In the filamentous, heterocyst-forming cyanobacteria, two different cell types, the CO
2
-fixing vegetative cells and the N
2
-fixing heterocysts, exchange nutrients and regulators for diazotrophic growth. In the model organism
Anabaena
sp. strain PCC 7120, inactivation of
fraH
produces filament fragmentation under conditions of combined nitrogen deprivation, releasing numerous isolated heterocysts. Transmission electron microscopy of samples prepared by either high-pressure cryo-fixation or chemical fixation showed that the heterocysts of a Δ
fraH
mutant lack the intracellular membrane system structured close to the heterocyst poles, known as the honeycomb, that is characteristic of wild-type heterocysts. Using a green fluorescent protein translational fusion to the carboxyl terminus of FraH (FraH-C-GFP), confocal microscopy showed spots of fluorescence located at the periphery of the vegetative cells in filaments grown in the presence of nitrate. After incubation in the absence of combined nitrogen, localization of FraH-C-GFP changed substantially, and the GFP fluorescence was conspicuously located at the cell poles in the heterocysts. Fluorescence microscopy and deconvolution of images showed that GFP fluorescence originated mainly from the region next to the cyanophycin plug present at the heterocyst poles. Intercellular transfer of the fluorescent tracers calcein (622 Da) and 5-carboxyfluorescein (374 Da) was either not impaired or only partially impaired in the Δ
fraH
mutant, suggesting that FraH is not important for intercellular molecular exchange. Location of FraH close to the honeycomb membrane structure and lack of such structure in the Δ
fraH
mutant suggest a role of FraH in reorganization of intracellular membranes, which may involve generation of new membranes, during heterocyst differentiation.
INTRINSIC CURVATURE: A MARKER OF MILLIMETER-SCALE TANGENTIAL CORTICO-CORTICAL CONNECTIVITY?
Authors: RONAN LISA , PIENAAR RUDOLPH , WILLIAMS GUY , BULLMORE ED , CROW TIM J. , ROBERTS NEIL , JONES PETER B. , SUCKLING JOHN , FLETCHER PAUL C.
Published: September 2011

In this paper, we draw a link between cortical intrinsic curvature and the distributions of tangential connection lengths. We suggest that differential rates of surface expansion not only lead to intrinsic curvature of the cortical sheet, but also to differential inter-neuronal spacing. We propose that there follows a consequential change in the profile of neuronal connections: specifically an enhancement of the tendency towards proportionately more short connections. Thus, the degree of cortical intrinsic curvature may have implications for short-range connectivity.
Contributions of A2Aand A2Badenosine receptors in coronary flow responses in relation to the KATPchannel using A2Band A2A/2Bdouble-knockout mice
Authors: Sanjani Maryam Sharifi , Teng Bunyen , Krahn Thomas , Tilley Stephen , Ledent Catherine , Mustafa S. Jamal
Published: September 2011

Adenosine plays a role in physiological and pathological conditions, and A2adenosine receptor (AR) expression is modified in many cardiovascular disorders. In this study, we elucidated the role of the A2BAR and its relationship to the A2AAR in coronary flow (CF) changes using A2Bsingle-knockout (KO) and A2A/2Bdouble-KO (DKO) mice in a Langendorff setup. We used two approaches: 1) selective and nonselective AR agonists and antagonists and 2) A2AKO and A2BKO and A2A/2BDKO mice. BAY 60-6583 (a selective A2Bagonist) had no effect on CF in A2BKO mice, whereas it significantly increased CF in wild-type (WT) mice (maximum of 23.3 ± 9 ml·min−1·g−1). 5′- N-ethylcarboxamido adenosine (NECA; a nonselective AR agonist) increased CF in A2BKO mice (maximum of 34.6 ± 4.7 ml·min−1·g−1) to a significantly higher degree compared with WT mice (maximum of 23.1 ± 2.1 ml·min−1·g−1). Also, CGS-21680 (a selective A2Aagonist) increased CF in A2BKO mice (maximum of 29 ± 1.9 ml·min−1·g−1) to a significantly higher degree compared with WT mice (maximum of 25.1 ± 2.3 ml·min−1·g−1). SCH-58261 (an A2A-selective antagonist) inhibited the NECA-induced increase in CF to a significantly higher degree in A2BKO mice (19.3 ± 1.6 vs. 0.5 ± 0.4 ml·min−1·g−1) compared with WT mice (19 ± 3.5 vs. 3.6 ± 0.5 ml·min−1·g−1). NECA did not induce any increase in CF in A2A/2BDKO mice, whereas a significant increase was observed in WT mice (maximum of 23.1 ± 2.1 ml·min−1·g−1). Furthermore, the mitochondrial ATP-sensitive K+(KATP) channel blocker 5-hydroxydecanoate had no effect on the NECA-induced increase in CF in WT mice, whereas the NECA-induced increase in CF in WT (17.6 ± 2 ml·min−1·g−1), A2AKO (12.5 ± 2.3 ml·min−1·g−1), and A2BKO (16.2 ± 0.8 ml·min−1·g−1) mice was significantly blunted by the KATPchannel blocker glibenclamide (to 0.7 ± 0.7, 2.3 ± 1.1, and 0.9 ± 0.4 ml·min−1·g−1, respectively). Also, the CGS-21680-induced (22 ± 2.3 ml·min−1·g−1) and BAY 60-6583-induced (16.4 ± 1.60 ml·min−1·g−1) increase in CF in WT mice was significantly blunted by glibenclamide (to 1.2 ± 0.4 and 1.8 ± 1.2 ml·min−1·g−1, respectively). In conclusion, this is the first evidence supporting the compensatory upregulation of A2AARs in A2BKO mice and demonstrates that both A2AARs and A2BARs induce CF changes through KATPchannels. These results identify AR-mediated CF responses that may lead to better therapeutic approaches for the treatment of cardiovascular disorders.
Physiological effect of protein kinase C on ENaC-mediated lung liquid regulation in the adult rat lung
Authors: Soukup Benjamin , Benjamin Audra , Orogo-Wenn Maria , Walters Dafydd
Published: September 2011

Tight control of lung liquid (LL) regulation is vital for pulmonary function. The aim of this work was to determine whether PKC activation is involved in the physiological regulation of LL volume in a whole lung preparation. Rat lungs were perfused with a modified Ringer solution, and the lumen was filled with the same solution without glucose. LL volume was measured during a control period and after modulating drugs were administered, and net LL transepithelial movement ( Jv) was calculated. When the PKC activator PMA (10−5 M) and the Ca2+ ionophore ionomycin (10−6 M) were instilled into the lung together, Jv was significantly reduced ( P = 0.03). This reduction was blocked by the PKC inhibitor chelerythrine chloride (10−6 M; P = 0.56) and by a second PKC inhibitor GF109203X (10−5 M; P = 0.98). When PMA and ionomycin were added with the β-adrenergic agonist terbutaline, the terbutaline-induced increase in Jv was abolished. Addition of PMA and ionomycin with the epithelial Na+ channel (ENaC) blocker amiloride had no additional inhibitory effect. Together, these results suggest that PKC is likely to be involved in LL absorption, and the ability of PMA/ionomycin to block the terbutaline-induced increase in Jv suggests that the downstream target of PKC is ENaC.
Contributions of TRPV1, endovanilloids, and endoplasmic reticulum stress in lung cell death in vitro and lung injury
Authors: Thomas Karen C. , Roberts Jessica K. , Deering-Rice Cassandra E. , Romero Erin G. , Dull Randal O. , Lee Jeewoo , Yost Garold S. , Reilly Christopher A.
Published: September 2011

Endogenous agonists of transient receptor potential vanilloid-1 (TRPV1) (endovanilloids) are implicated as mediators of lung injury during inflammation. This study tested the hypothesis that endovanilloids produced following lipopolysaccharide (LPS) treatment activate TRPV1 and cause endoplasmic reticulum stress/GADD153 expression in lung cells, representing a mechanistic component of lung injury. The TRPV1 agonist nonivamide induced GADD153 expression and caused cytotoxicity in immortalized and primary human bronchial, bronchiolar/alveolar, and microvascular endothelial cells, proportional to TRPV1 mRNA expression. In CF-1 mice, Trpv1 mRNA was most abundant in the alveoli, and intratracheal nonivamide treatment promoted Gadd153 expression in the alveolar region. Treatment of CF-1 mice with LPS increased Gadd153 in the lung, lactate dehydrogenase (LDH) in bronchoalveolar lavage (BAL) fluid, and lung wet-to-dry weight ratio. Cotreating mice with LPS and the TRPV1 antagonist LJO-328 reduced Gadd153 induction and LDH in BAL but did not inhibit increases in lung wet-to-dry ratio. In Trpv1−/−mice treated with LPS, Gadd153 induction and LDH in BAL were reduced relative to wild-type mice, and the wet-to-dry weight ratios of lungs from both wild-type and Trpv1−/−mice decreased. Organic extracts of blood collected from LPS-treated mice were more cytotoxic to TRPV1-overexpressing cells compared with BEAS-2B cells and extracts from control mice, however, most pure endovanilloids did not produce cytotoxicity in a characteristic TRPV1-dependent manner. Collectively, these data indicate a role for TRPV1, and endogenous TRPV1 agonists, in ER stress and cytotoxicity in lung cells but demonstrate that ER stress and cytotoxicity are not essential for pulmonary edema.
An Extension of Young′s Inequality
Authors: Mitroi Flavia-Corina , Niculescu Constantin P.
Published: September 2011

Young′s inequality is extended to the context of absolutely continuous measures. Several applications are included.
Further Stability Criterion on Delayed Recurrent Neural Networks Based on Reciprocal Convex Technique
Authors: Zhang Guobao , Li Tao , Fei Shumin
Published: September 2011

Together with Lyapunov‐Krasovskii functional theory and reciprocal
convex technique, a new sufficient condition is derived to guarantee the global stability for recurrent neural networks with both time‐varying and continuously distributed delays, in which one improved delay‐partitioning technique is employed. The LMI‐based criterion heavily depends on both the upper and lower bounds on state delay and its derivative, which is different from the existent ones and has more application areas as the lower bound of delay derivative is available. Finally, some numerical examples can illustrate the reduced conservatism of the derived results by thinning the delay interval.
Complex Patterns of Altered MicroRNA Expression during the Adenoma-Adenocarcinoma Sequence for Microsatellite-Stable Colorectal Cancer
Authors: Bartley Angela N. , Yao Hui , Barkoh Bedia A. , Ivan Cristina , Mishra Bal M. , Rashid Asif , Calin George A. , Luthra Rajyalakshmi , Hamilton Stanley R.
Published: September 2011

Purpose: MicroRNAs are short noncoding RNAs that regulate gene expression and are over- or underexpressed in most tumors, including colorectal adenocarcinoma. MicroRNAs are potential biomarkers and therapeutic targets and agents, but limited information on microRNAome alterations during progression in the well-known adenoma-adenocarcinoma sequence is available to guide their usage.

Experimental Design: We profiled 866 human microRNAs by microarray analysis in 69 matched specimens of microsatellite-stable adenocarcinomas, adjoining precursor adenomas including areas of high- and low-grade dysplasia, and nonneoplastic mucosa.

Results: We found 230 microRNAs that were significantly differentially expressed during progression, including 19 not reported previously. Altered microRNAs clustered into two major patterns of early (type I) and late (type II) differential expression. The largest number (n = 108) was altered at the earliest step from mucosa to low-grade dysplasia (subtype IA) prior to major nuclear localization of β-catenin, including 36 microRNAs that had persistent differential expression throughout the entire sequence to adenocarcinoma. Twenty microRNAs were intermittently altered (subtype IB), and six were transiently altered (subtype IC). In contrast, 33 microRNAs were altered late in high-grade dysplasia and adenocarcinoma (subtype IIA), and 63 in adenocarcinoma only (subtype IIB). Predicted targets in 12 molecular pathways were identified for highly altered microRNAs, including the Wnt signaling pathway leading to low-grade dysplasia. β-catenin expression correlated with downregulated microRNAs.

Conclusions: Our findings suggest that numerous microRNAs play roles in the sequence of molecular events, especially early events, resulting in colorectal adenocarcinoma. The temporal patterns and complexity of microRNAome alterations during progression will influence the efficacy of microRNAs for clinical purposes. Clin Cancer Res; 17(23); 7283–93. ©2011 AACR.
Efficacy of Low Interatrial Septum and Right Atrial Appendage Pacing for Prevention of Permanent Atrial Fibrillation in Patients With Sinus Node Disease
Authors: Verlato Roberto , Botto Giovanni Luca , Massa Riccardo , Amellone Claudia , Perucca Antonello , Bongiorni Maria Grazia , Bertaglia Emanuele , Ziacchi Vigilio , Piacenti Marcello , Del Rosso Attilio , Russo Giovanni , Baccillieri Maria Stella , Turrini Pietro , Corbucci Giorgio
Published: September 2011

Background—

The role of pacing sites and atrial electrophysiology on the progression of atrial fibrillation (AF) to the permanent form in patients with sinus node dysfunction (SND) has never been investigated. The aim of the study was to investigate the relationship between atrial electrophysiology and the efficacy of atrial pacing at the low interatrial septum (IAS) or at the right atrial appendage (RAA) to prevent persistent/permanent AF in patients with SND.

Methods and Results—

The Electrophysiology-Guided Pacing Site Selection (EPASS) Study was a prospective, controlled, randomized study. Atrial refractoriness, basal and incremental conduction times from the RAA to the coronary sinus ostium were measured before implantation, and the difference (ΔCTos) was calculated. Patients with ΔCTos ≥50 ms (study group) and those with ΔCTos <50 ms (control group) were randomly assigned to RAA or IAS with algorithms for continuous atrial stimulation “on.” The primary end point was time to development of permanent or persistent AF within a 2-year follow-up in the study group, IAS versus RAA. Data were analyzed by intention to treat. One hundred two patients (77±7 years, 44 mol/L) were enrolled, 69 (68%) in the study group and 33 (32%) in the control group. Of these, 97 ended the study, respectively, randomly assigned: 29 IAS versus 36 RAA and 18 IAS versus 14 RAA. After a mean follow-up of 15±7 (median, 17) months, 11 (16.6%) patients in the study group met the primary end point: 2 IAS versus 9 RAA (log rank=3.93,
P
=0.047).

Conclusions—

In patients with SND and intra-atrial conduction delay, low IAS pacing was superior to RAA pacing in preventing progression to persistent or permanent AF.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00239226.
Radiofrequency Catheter Ablation and Antiarrhythmic Drug Therapy
Authors: Pappone Carlo , Vicedomini Gabriele , Augello Giuseppe , Manguso Francesco , Saviano Massimo , Baldi Mario , Petretta Andrea , Giannelli Luigi , Calovic Zarko , Guluta Vladimir , Tavazzi Luigi , Santinelli Vincenzo
Published: September 2011

Background—

Information on comparative outcome between radiofrequency catheter ablation (RFA) and antiarrhythmic drugs (AADs) >1 year after randomization is important for clinical decision-making.

Methods and Results—

A total of 198 patients (age, 56±10 years) with paroxysmal atrial fibrillation were randomly assigned to RFA (99 patients) or to AADs (99 patients). We evaluated efficacy of RFA or AADs in a comparable 48-month follow-up period according to intention-to-treat analysis. Cardiac rhythm was assessed with daily transtelephonic transmissions. Quality of life was also analyzed. At 4 years, among the 99 patients first assigned to RFA, the procedure was repeated because of recurrent atrial fibrillation/atrial tachycardia in 27 patients (27.3%). Among the 99 patients randomly assigned to AADs, 87 (87.9%) crossed over to undergo RFA and 4 years after random assignment only 12 (12.1%) were in sinus rhythm with AAD alone without ablation. Despite the high level of crossovers, at 4 years the intention-to-treat analysis showed that 72.7% of patients in the ablation arm and 56.5% of those initially randomly assigned to AADs were free of recurrent atrial fibrillation/atrial tachycardia (
P
=0.017). During the follow-up, 19.2% of AAD patients progressed to persistent atrial fibrillation before switching to RFA. RFA significantly improved quality of life (
P
<0.001), whereas before crossing over to RFA, patients receiving AADs showed poorer quality of life. Except for new left atrial tachycardia, there were no serious complications caused by RFA.

Conclusions—

With follow-up extended to 4 years after randomly assigned, ablation remains superior to antiarrhythmic drug in these patients with paroxysmal atrial fibrillation.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00340314.
Changes in Secondary Sexual Characters of Males of Thor Floridanus (Decapoda, Hippolytidae), Infested by Bopyrinella Thorii (Isopoda, Bopyridae)
Authors: Romero-Rodríguez J. , Román-Contreras R.
Published: September 2011

This study describes changes in the secondary sexual characters of Thor floridanus Kingsley, 1878 males, caused by the isopod Bopyrinella thorii (Richardson, 1904). Of 380 specimens of T. floridanus examined, the females were more often infested (n = 313) than the males (n = 41), and had a wider size range (0.7-2.85 mm POCL) compared to the males (0.9-2.32 mm POCL); no ovigerous females of T. floridanus were found. In 25 males the appendix masculina was reduced in size, the endopod of the second pleopod was barely ornamented, and the flexor margin of the propod of the third pereiopod was similar to that of the female of the species; all those males were classified as “feminized”. Those individuals were infested mainly by pairs of mature parasites, and 75% of the “primary” males carried cryptoniscus larvae, suggesting that the “feminization” of the males is caused by the parasite, as a result of the sexual development of hosts and parasites.
Land Tax alā l-misāa and muqāsama: Legal Theory and the Balance of Social Forces in Early Medieval Iraq (6th-8th Centuries C.E.)
Authors: Campopiano Michele
Published: September 2011

The article argues that any analysis of tax policies must be grounded in the given society’s ‘mode of production’. This is demonstrated through analysis of the political relationship between the Abbasid state and the landlords, and the reasons why certain prominent Muslim jurists between 750 and ca. 900. promoted muqāsama in the Sawād of Iraq. These jurists’ tax policy is explained with reference to Haldon’s concept of the tributary mode of production. It is concluded that according to the jurists, muqāsama favoured a redistribution of surpluses between the state and the landowners which could strengthen relations between the Abbasid state and the powerful landlords in Iraq.
Numerical Experiments of an Advanced Radiative Transfer Model in the U.S. Navy Operational Global Atmospheric Prediction System
Authors: Liu Ming , Kim Young-Joon , Zhao Qingyun
Published: September 2011

A high-order accurate radiative transfer (RT) model developed by Fu and Liou has been implemented into the Navy Operational Global Atmospheric Prediction System (NOGAPS) to improve the energy budget and forecast skill. The Fu–Liou RT model is a four-stream algorithm (with a two-stream option) integrating over 6 shortwave bands and 12 longwave bands. The experimental 10-day forecasts and analyses from data assimilation cycles are compared with the operational output, which uses a two-stream RT model of three shortwave and five longwave bands, for both winter and summer periods. The verifications against observations of radiosonde and surface data show that the new RT model increases temperature accuracy in both forecasts and analyses by reducing mean bias and root-mean-square errors globally. In addition, the forecast errors also grow more slowly in time than those of the operational NOGAPS because of accumulated effects of more accurate cloud–radiation interactions. The impact of parameterized cloud effective radius in estimating liquid and ice water optical properties is also investigated through a sensitivity test by comparing with the cases using constant cloud effective radius to examine the temperature changes in response to cloud scattering and absorption. The parameterization approach is demonstrated to outperform that of constant radius by showing smaller errors and better matches to observations. This suggests the superiority of the new RT model relative to its operational counterpart, which does not use cloud effective radius. An effort has also been made to improve the computational efficiency of the new RT model for operational applications.
The Hybrid Hospitalist Teaching Service
Authors: Lee Benjamin C. , Flores Glenn
Published: September 2011

Background. Alternative inpatient teams are increasing, but little is known about their impact on patient care and trainee education. Purpose. To evaluate whether a hybrid hospitalist teaching service meets trainee and attending educational, clinical, support, patient-mix, autonomy, and efficiency needs. Methods. Post pediatric rotations, team members anonymously completed surveys with Likert-scale and open-ended questions. Results. In total, 78 of 80 surveys were completed. Trainees rated educational, clinical, support, and case-mix domains highly. Senior residents responded positively for autonomy, education, and opinions of hospitalists, but neutrally on leadership. Attending scores varied for efficiency, teaching, and clinical duties; the service resulted in direct observation and teaching outside of rounds, but poor delineation of roles and expectations impeded clinical task completion, teaching on rounds, and attending meetings. Conclusions. This model is a satisfying, well-accepted means of enhancing trainee education and patient care, but roles and expectations must be clearly defined to maximize efficiency and satisfaction.
The Role of Reputable Auditors and Underwriters in the Design of Bond Contracts
Authors: Lou Yun , Vasvari Florin P.
Published: September 2011

The authors empirically test the certification hypothesis by studying the roles of reputable auditors and bank underwriters in the design of bond contracts. The certification hypothesis suggests that reputable capital market intermediaries can credibly communicate inside information to outside investors, thereby helping improve financing terms for firms that raise external funding. Consistent with this hypothesis, the authors provide evidence that reputable auditors and underwriters help corporate bond issuers obtain lower bond yields. The effect of reputable auditors on the yields is greater than that of reputable underwriters in terms of economic magnitude and significance, consistent with auditors’ multiple roles as information intermediaries, monitors, and insurance providers. The authors also find that the presence of reputable auditors and underwriters affects bonds’ nonpricing terms. Firms that hire reputable auditors obtain longer term bonds, whereas those that engage reputable underwriters can issue larger bonds. Taken together, the results suggest that reputable auditors and underwriters have integral, but different, roles in the bond-issuing process.
The Impact of Status Orientations on Purchase Preference for Foreign Products in Vietnam, and Implications for Policy and Society
Authors: Mai Nguyen Thi Tuyet , Smith Kirk
Published: September 2011

In this article, the authors examine the impact of status orientations on consumer purchase preferences for foreign products, an emerging disposition in Vietnam. Both qualitative (in-depth interviews and focus groups) and quantitative methods (survey with urban Vietnamese consumers) were employed in this investigation. The results of structural equation modeling (SEM) provided empirical evidence for the positive influence of modern status orientation (MSO) on willingness to buy imported products. Traditional status orientation (TSO) was found not to be a predictor of willingness to buy. Consistent with the findings from literature, consumer ethnocentrism was negatively related to willingness to buy imported products. Implications for public policy and marketers pertaining to the emerging proclivity of status-seeking foreign purchase and the social motives underlying this phenomenon are provided.
The impact of heavy metals on the activity of carbonic anhydrase from rainbow trout (Oncorhynchus mykiss) kidney
Authors: Söyüt Hakan , Beydemir Şükrü
Published: September 2011

Many environmental and health problems have become a consequence of contamination of soil and water by toxic heavy metals and organic pollutants in the present age of technology. Heavy metals play vital roles in enzyme activities and other metabolic events with their bioaccumulative and nonbiodegradable properties among aquatic pollutants. Metal toxicity causes irregular metallothioneins protein synthesis, renal damage, and disruption of bone structure in humans and wildlife. In this study, we investigated in vitro effects of some metals on chemical-targeted carbonic anhydrase (CA) enzyme from rainbow trout kidney. The enzyme was purified with a specific activity of 17,285 EU × mg−1 and 31.7% yield and approximately 1800-fold using simple affinity purification method. Molecular weights of the subunit and native enzyme were estimated as 28.7 kDa and 26.9 kDa via sodium dodecyl sulfate polyacrylamide gel electrophoresis and Sephadex-G 200 column, respectively. Other kinetic properties of the enzyme were determined. Apparent Km, Vmax and kcat values were 0.40 mM, 0.097 µmol min−1 and 15.2 s−1 for p-nitrophenylacetate substrate, respectively. Inhibitory effects of cobalt, zinc, copper, cadmium and silver on CA activity were determined using the esterase method under in vitro conditions. IC50 and Ki values were calculated for metals. Ki values for Co2+, Zn2+, Cu2+, Cd2+ and Ag+ were 0.035, 1.2, 34.8, 103 and 257 from Lineweaver–Burk graphs, respectively. Consequently, in vitro inhibition rank order was determined as Co2+ > Zn2+ > Cu2+ > Cd2+ > Ag+. The potential inhibitor for CA was found as Co2+ from these results.
The (Twice) Failure of the Wisconsin Risk Need Assessment in a Sample of Probationers
Authors: Henderson Howard , Miller Holly A.
Published: September 2011

Despite being created and validated in the 1970s and 1980s, and widely adopted by many agencies in the United States, including Texas, the Wisconsin Risk Need Assessment Instrument has yet to be examined with a contemporaneous Texas probationer sample. Due to the majority of previous research reporting poor utility, the instrument’s authors proposed a new scoring system for the risk portion of the instrument in 2009 in an attempt to increase the predictive utility. This study examines the original instrument and is the first to examine the proposed reweighted risk scale’s relationship to recidivism with an independent sample of 194 male probationers. Findings revealed that the original risk/need sections and proposed reweighted risk items failed to explain significant variance in recidivism with very few items relating to reoffense. The current results provide further evidence that the Wisconsin Risk Need Assessment should be replaced by other empirically validated risk/need instruments.
Cultural Tourism as an Economic Development Strategy for Ethnic Neighborhoods
Authors: Loukaitou-Sideris Anastasia , Soureli Konstantina
Published: September 2011

Many ethnic inner city neighborhoods in US cities are rich in traditions, history, art, and cuisine but are also suffering from disinvestment, high poverty rates, and deterioration. In the face of a growing popularity of cultural tourism, an opportunity exists to explore how neighborhood cultural assets can be used to promote economic development in such neighborhoods. In this study we draw information from a literature review, surveys of merchants and cultural institutions in four ethnic neighborhoods of Los Angeles, and analysis of the characteristics and impact of existing cultural tourism programs in seven US cities to discuss the opportunities and challenges of using cultural tourism as an economic development strategy in ethnic inner city neighborhoods.
A model of political information-processing and learning cooperation in the repeated Prisoner’s Dilemma
Authors: Kim Sung-youn
Published: September 2011

A model of political information processing drawn from the studies of political behavior and psychology is applied to the emergence of cooperation observed in classic repeated Prisoner’s Dilemma (PD) game experiments. The results show that the model can robustly account for the learning of cooperation observed in the experiments when players are aware of the strategic nature of the game and make choices over immediate actions. In effect, basic psychological learning mechanisms, well-established in political behavior and psychology research, together tend to lead players to learn to cooperate over time under quite general conditions. In particular, the evaluative affect players develop towards choice objects and a belief learning that weighs an actually obtained outcome more than a forgone outcome play a central role in these processes.
Is there any similarity between tumour growth and thermal expansion?
Authors: Golneshan A A , Nemati H
Published: September 2011

To model growth in a soft tissue, the tissue is considered as an open system wherein mass is not conserved. This leads to modifying the basic balance equations to accommodate this mass change. On the other hand, a number of researchers have assumed that there exists an analogy between tumour growth and thermal expansion phenomena. However, no mathematical proof yet has supported this analogy. In this paper, based on a new explanation of growth, the set of modified basic balance equations is closed using a new constitutive equation in conjunction with the Clausius–Duhem inequality to model the residual stresses in a growing solid tumour. Applying the model to two popular tumour types (carcinoma and tumour spheroid), which can be examined experimentally, revealed a perfect similarity between the resulting stresses in the growing tumour and those predicted by thermal expansion analogy, although the predicted displacements are different in these two models. Moreover, it is shown that the coefficient of growth expansion, analogous to the coefficient of thermal expansion, is not an independent variable and is related to the tissue measurable known quantities: Poisson’s ratio and density.
Numerical and experimental analysis for the skew phenomena on the flexible belt and roller contact systems
Authors: Yoon J S , Choi J H , Suzuki T , Choi J H
Published: September 2011

The thin, flexible, flat belt system is frequently employed for power transmission, conveyor systems, and various manufacturing process equipments, such as printers, elevators, and automated teller machines. In general, some critical problems can happen during operation, since a thin flexible belt on rollers can easily skew. This is especially serious for high-speed belt operations. In this skewed situation, due to possible relative roller misalignment, roller deflection, and/or belt non-uniformity itself, a thin flexible belt can move along the perpendicular direction to the travelling direction. In this investigation, an efficient analysis method for simulating skewing phenomena of thin flexible belt systems is presented using the complete integration of large deformable finite element methods and multibody dynamics. A 4-node shell element is used to describe a thin flexible belt and two rigid cylindrical bodies describe the roller. Each cylindrical body is fixed with a pin joint and the positions of the rollers are adjusted to impose a tension to thebelt. For the interactions between the belt and the rollers, an efficient contact search algorithm based on a compliant contact force model is presented in this study. The contact search algorithm is composed of a pre-search and a detailed search to identify points of contact between the belt and the rollers. In the pre-search, a simple algorithm is used to identify lines on the belt that are close enough to the rollers that there might potentially be contact between them. The detailed search is performed by making efficient two-dimensional (2D) comparisons of the cross-section of the roller with a 2D projection of the belt lines identified in the pre-search. Afterwards, the contact force is generated by a compliant force model that uses a stick–slip frictional algorithm. The simulation model is validated against experimental measurement systems for thin flexible belt and rollers. It shows a good agreement with the numerical results. Furthermore CPU time with commercial software ANSYS Workbench is compared to check the performance of the algorithm. The proposed method is more than 10 times faster compared with ANSYS Workbench.
On the detection of nearly optimal solutions in the context of single-objective space mission design problems
Authors: Schütze O , Lara A , Coello C A Coello , Vasile M
Published: September 2011

When making decisions, having multiple options available for a possible realization of the same project can be advantageous. One way to increase the number of interesting choices is to consider, in addition to the optimal solution x*, also nearly optimal or approximate solutions; these alternative solutions differ from x* and can be in different regions – in the design space – but fulfil certain proximity to its function value f( x*). The scope of this article is the efficient computation and discretization of the set E of ϵ–approximate solutions for scalar optimization problems. To accomplish this task, two strategies to archive and update the data of the search procedure will be suggested and investigated. To make emphasis on data storage efficiency, a way to manage significant and insignificant parameters is also presented. Further on, differential evolution will be used together with the new archivers for the computation of E. Finally, the behaviour of the archiver, as well as the efficiency of the resulting search procedure, will be demonstrated on some academic functions as well as on three models related to space mission design.
Economic Inequality Is Linked to Biased Self-Perception
Authors: Loughnan Steve , Kuppens Peter , Allik Jüri , Balazs Katalin , de Lemus Soledad , Dumont Kitty , Gargurevich Rafael , Hidegkuti Istvan , Leidner Bernhard , Matos Lennia , Park Joonha , Realo Anu , Shi Junqi , Sojo Victor Eduardo , Tong Yuk-yue , Vaes Jeroen , Verduyn Philippe , Yeung Victoria , Haslam Nick
Published: September 2011

People’s self-perception biases often lead them to see themselves as better than the average person (a phenomenon known as self-enhancement). This bias varies across cultures, and variations are typically explained using cultural variables, such as individualism versus collectivism. We propose that socioeconomic differences among societies—specifically, relative levels of economic inequality—play an important but unrecognized role in how people evaluate themselves. Evidence for self-enhancement was found in 15 diverse nations, but the magnitude of the bias varied. Greater self-enhancement was found in societies with more income inequality, and income inequality predicted cross-cultural differences in self-enhancement better than did individualism/collectivism. These results indicate that macrosocial differences in the distribution of economic goods are linked to microsocial processes of perceiving the self.
Venous Thromboembolism Pharmacy Intervention Management Program With an Active, Multifaceted Approach Reduces Preventable Venous Thromboembolism and Increases Appropriate Prophylaxis
Authors: Mahan Charles E. , Hussein Mohamed A. , Amin Alpesh N. , Spyropoulos Alex C.
Published: September 2011

Two concepts relating to venous thromboembolism (VTE) prevention have recently emerged—“appropriate” prophylaxis and “preventable” VTE. We evaluated whether a human alert, as part of a pharmacy intervention program, can increase appropriate prophylaxis and decrease preventable symptomatic VTE in hospitalized patients. This prospective study with retrospective data collection was conducted utilizing data from 1879 patients in 2006 as a control cohort. The intervention cohort data were from 1646 patients during 2007, after program implementation. The rate of appropriate prophylaxis increased from 23.8% in 2006 to 37.9% in 2007 (odds ratio 1.8; 95% confidence interval [CI] = 1.6-2.1; P < .0001). Preventable VTE incidence was reduced by 74% (95% CI = 44%-88%) from 18.6 to 4.9 per 1000 patient discharges in 2006 and 2007, respectively ( P = .0006). In conclusion, a pharmacy-led multifaceted intervention can significantly increase the rates of appropriate prophylaxis and significantly reduce the incidence of preventable VTE in hospitalized patients.
Passivity based control of under-actuated mechanical systems with nonlinear dynamic friction
Authors: Cornejo Cecilia , Alvarez-Icaza Luis
Published: September 2011

Passivity-based control of under-actuated mechanical systems with nonlinear friction effects in the generalized coordinates of motion is analyzed in this paper. Nonlinear friction is modeled with a modified LuGre dynamic friction model. The internal states of the dynamic friction model are incorporated as generalized coordinates in a port-controlled Hamiltonian formulation for the complete mechanical system in such a way that all passivity properties of this formulation are preserved for the extended generalized coordinates system. Interconnection and damping assignment passivity-based control laws are developed for the models of two case studies: a building with a magneto-rheological damper and a double pendulum. Simulation results are also presented.
Fuzzy adaptive observer-based projective synchronization for nonlinear systems with input nonlinearity
Authors: Boulkroune Abdesselem , M’saad Mohammed
Published: September 2011

In this paper, a projective synchronization problem of master-slave chaotic systems is investigated. More specifically, a fuzzy adaptive slave chaotic system subject to both sector nonlinearities and dead-zone in the input channel is proposed using only the measurable output of the master system thanks to a suitable observer. The asymptotical projective synchronization between the master and slave systems is achieved by an adequate fuzzy adaptive variable-structure control system. The underlying parameter adaptation design as well as the asymptotical synchronization and stability analysis are carried out using a Lyapunov based approach. The distinctive feature of the control design is that the uncertainties function and the gain reduction tolerances of the dead-zone are no longer required to be known thanks to the parameter adaptation capability of the control system. The proposed synchronization scheme is extended to two classes of the master-slave chaotic systems with time-delays. By using the Lyapunov-Krasovskii approach, some stability conditions relating to these classes are derived. Simulation results are given to show the effectiveness of the proposed projective synchronization scheme.
Finding and Measuring Horizontal Curves in a Large Highway Network
Authors: Findley Daniel J. , Zegeer Charles V. , Sundstrom Carl A. , Hummer Joseph E. , Rasdorf William , Fowler Tyler J.
Published: September 2011

Roadways are continuous elements that consist of straight and curved segments that are of particular interest to transportation agencies because of safety concerns for motorists. An analysis was undertaken on curves to determine the accuracy of using GIS to identify curves. The safety of horizontal curves from a system perspective was also benchmarked to understand curves as a system instead of as isolated roadway features. The automated application, Curve Finder, was able to locate 532 of 799 curves along three routes studied. Roadway agencies can use Curve Finder to identify and measure a set of curves automatically. This GIS application for horizontal curves enables transportation agencies to leverage existing resources to manage their infrastructure more efficiently. The policy implications are that the additional curve data will enable a more cost-effective distribution of funding for improvements, a more efficient delivery of maintenance operations, and a safer roadway network.
Efficient and accurate simulation of the rope–sheave interaction in weight-lifting machines
Authors: Lugrís U , Escalona J L , Dopico D , Cuadrado J
Published: September 2011

This article presents different approaches that can be used for modelling wire ropes in weight-lifting machines. It is shown that modelling the rope as a linear spring, although very simple and efficient, is energetically inconsistent and produces spurious terms in the equations of motion if the rope deformation along the segment in contact with the sheave is not considered. In order to overcome this problem and obtain an efficient yet accurate method for the simulation of such systems, a semi-analytical method is derived by introducing an analytical model of the rope–sheave interaction in the system, and the obtained results are compared with a finite-element numerical model. The semi-analytical model is based on a continuum mechanics approach of the rope; it assumes Coulomb friction between the sheave and the rope and neglects the centrifugal force of the segment of rope in contact with the sheave while accounting for tangential inertia forces in the rope. The numerical model is based on the Absolute Nodal Coordinate Formulation, and accounts for both the inertia forces and the bending and axial deformation of the rope.
Stand up for dementia: Performance, improvisation and stand up comedy as therapy for people with dementia; a qualitative study
Authors: Stevens John
Published: September 2011

The aim of this qualitative study was to describe and investigate the effects of a programme of stand up comedy and improvisation workshops on people with early stage dementia. Interviews from participants ( n = 6), their carers ( n = 6), and the comedian facilitator were analysed using constant comparative analysis. The findings indicated that dementia did not prevent participants from laughing appropriately or successfully creating and performing comedy. The data suggest that the programme may have therapeutic benefits as improvements in memory, learning, sociability, communication and self esteem were demonstrated. The study also develops a set of hypotheses for further research which includes: that active participation by people with dementia (PWD) in performing to create laughter is more beneficial therapeutically than passively induced laughter.
Terror in and out of power
Authors: Howes Dustin Ells
Published: September 2011

This article explores the relationship between terror, power and the rule of law. First, tracing Burke's use of the term terror back to ancient Greek usage, I argue that being terrified is incommensurable with the experience of acting together with others. In this way, terror and power are distinct. However, most acts of terror aim to terrify some people while inoculating others from terror. Witnesses to the terror of others may feel empowered by the destruction of the power of others. Second, the rule of law and terror seem incommensurable because causing terror often involves violating the law. However, modern political thought is founded on the idea that the law itself ought to be terrifying. That the terror of non-state actors appears random and the terror of the law has hardly been noticed in recent commentary on terrorism indicate that the rule of law produces an interesting audience effect. In order to sustain power and legitimacy while practising terror, governments use the rule of law to divide audiences up into terrified criminals and innocent witnesses. The practice of terror as an ‘open secret’ also produces similar audience effects. Finally, despite these connections between power, terror and the rule of law, I argue that terror is always technically out of power, even when practised by states. Terror is the true weapon of the weak because it always admits a failure to foster human connections with certain people and groups. Nonviolence is a weapon of the weak in the sense that it instantiates new, unencumbered power.