bluuebunny/crossref_metadata_2025 huggingface dataset:
Gamma-Butyrolactone Regulatory System of Streptomyces chattanoogensis Links Nutrient Utilization, Metabolism, and Development
Authors: Du Yi-Ling , Shen Xue-Ling , Yu Pin , Bai Lin-Quan , Li Yong-Quan
Published: September 2011

Gamma-butyrolactones (GBLs) produced by several
Streptomyces
species have been shown to serve as quorum-sensing signaling molecules for activating antibiotic production. The GBL system of
Streptomyces chattanoogensis
L10, a producer of antifungal agent natamycin, consists of three genes:
scgA
,
scgX
, and
scgR
. Both
scgA
and
scgX
contribute to GBL production, while
scgR
encodes a GBL receptor.
ΔscgA
and
ΔscgX
mutants of
S. chattanoogensis
behaved identically: they had a growth defect in submerged cultures and delayed or abolished the morphological differentiation and secondary metabolites production on solid medium. ScgR could bind to the promoter region of
scgA
and repress its transcription. Moreover,
scgA
seems also to be controlled by a GBL-mediated negative-feedback system. Hence, it is apparent that GBL biosynthesis is tightly controlled to ensure the correct timing for metabolic switch. An additional direct ScgR-target gene
gbdA
was identified by genomic SELEX and transcriptional analysis. Comparative proteomic analysis between L10 and its
ΔscgA
mutant revealed that the GBL system affects the expression of more than 50 proteins, including enzymes involved in carbon uptake system, primary metabolism, and stress response, we thus conclude that
scgR-scgA-scgX
constitute a novel GBL regulatory system involved in nutrient utilization, triggering adaptive responses, and finally dictating the switch from primary to secondary metabolism.
Activity-Based Metagenomic Screening and Biochemical Characterization of Bovine Ruminal Protozoan Glycoside Hydrolases
Authors: Findley Seth D. , Mormile Melanie R. , Sommer-Hurley Andrea , Zhang Xue-Cheng , Tipton Peter , Arnett Krista , Porter James H. , Kerley Monty , Stacey Gary
Published: September 2011

The rumen, the foregut of herbivorous ruminant animals such as cattle, functions as a bioreactor to process complex plant material. Among the numerous and diverse microbes involved in ruminal digestion are the ruminal protozoans, which are single-celled, ciliated eukaryotic organisms. An activity-based screen was executed to identify genes encoding fibrolytic enzymes present in the metatranscriptome of a bovine ruminal protozoan-enriched cDNA expression library. Of the four novel genes identified, two were characterized in biochemical assays. Our results provide evidence for the effective use of functional metagenomics to retrieve novel enzymes from microbial populations that cannot be maintained in axenic cultures.
Diversity and Abundance of Single-Stranded DNA Viruses in Human Feces
Authors: Kim Min-Soo , Park Eun-Jin , Roh Seong Woon , Bae Jin-Woo
Published: September 2011

In this study, we investigated the abundance and diversity of single-stranded DNA (ssDNA) viruses in fecal samples from five healthy individuals through a combination of serial filtration and CsCl gradient ultracentrifugation. Virus abundance ranged from 10
8
to 10
9
per gram of feces, and virus-to-bacterium ratios were much lower (less than 0.1) than those observed in aquatic environments (5 to 10). Viral DNA was extracted and randomly amplified using phi29 polymerase and analyzed through high-throughput 454 pyrosequencing. Among 400,133 sequences, an average of 86.2% viromes were previously uncharacterized in public databases. Among previously known viruses, double-stranded DNA podophages (52 to 74%), siphophages (11 to 30%), myophages (1 to 4%), and ssDNA microphages (3 to 9%) were major constituents of human fecal viromes. A phylogenetic analysis of 24 large contigs of microphages based on conserved capsid protein sequences revealed five distinct newly discovered evolutionary microphage groups that were distantly related to previously known microphages. Moreover, putative capsid protein sequences of five contigs were closely related to prophage-like sequences in the genomes of three
Bacteroides
and three
Prevotella
strains, suggesting that
Bacteroides
and
Prevotella
are the sources of infecting microphages in their hosts.
Hemocytes Are Sites of Enteric Virus Persistence within Oysters
Authors: Provost Keleigh , Dancho Brooke A. , Ozbay Gulnihal , Anderson Robert S. , Richards Gary P. , Kingsley David H.
Published: September 2011

The goal of this study was to determine how enteric viruses persist within shellfish tissues. Several lines of novel evidence show that phagocytic blood cells (hemocytes) of Eastern oysters (
Crassostrea virginica
) play an important role in the retention of virus particles. Our results demonstrated an association of virus contamination with hemocytes but not with hemolymph. Live oysters contaminated overnight with hepatitis A virus (HAV) and murine norovirus (MNV) had 56% and 80% of extractable virus associated with hemocytes, respectively. Transfer of HAV-contaminated hemocytes to naï¿½ve (virus-free) oysters resulted in naï¿½ve oyster meat testing HAV positive for up to 3 weeks. Acid tolerance of HAV, MNV, poliovirus (PV), and feline calicivirus (FCV) correlated with the ability of each virus to persist within oysters. Using reverse transcription-PCR (RT-PCR) to evaluate persistence of these viruses in oysters, we showed that HAV persisted the longest (>21 days) and was most acid resistant, MNV and PV were less tolerant of acidic pH, persisting for up to 12 days and 1 day, respectively, and FCV did not persist (<1 day) within oysters and was not acid tolerant. This suggests that the ability of a virus to tolerate the acidic conditions typical of phagolysosomal vesicles within hemocytes plays a role in determining virus persistence in shellfish. Evaluating oyster and hemocyte homogenates and live contaminated oysters as a prelude to developing improved viral RNA extraction methods, we found that viruses were extracted more expediently from hemocytes than from whole shellfish tissues and gave similar RT-PCR detection sensitivities.
Whole-Genome Association Study on Tissue Tropism Phenotypes in Group A Streptococcus
Authors: Bessen Debra E. , Kumar Nikhil , Hall Gerod S. , Riley David R. , Luo Feng , Lizano Sergio , Ford Candace N. , McShan W. Michael , Nguyen Scott V. , Hotopp Julie C. Dunning , Tettelin Hervé
Published: September 2011

Group A
Streptococcus
(GAS) has a rich evolutionary history of horizontal transfer among its core genes. Yet, despite extensive genetic mixing, GAS strains have discrete ecological phenotypes. To further our understanding of the molecular basis for ecological phenotypes, comparative genomic hybridization of a set of 97 diverse strains to a GAS pangenome microarray was undertaken, and the association of accessory genes with
emm
genotypes that define tissue tropisms for infection was determined. Of the 22 nonprophage accessory gene regions (AGRs) identified, only 3 account for all statistically significant linkage disequilibrium among strains having the genotypic biomarkers for throat versus skin infection specialists. Networked evolution and population structure analyses of loci representing each of the AGRs reveal that most strains with the skin specialist and generalist biomarkers form discrete clusters, whereas strains with the throat specialist biomarker are highly diverse. To identify coinherited and coselected accessory genes, the strength of genetic associations was determined for all possible pairwise combinations of accessory genes among the 97 GAS strains. Accessory genes showing very strong associations provide the basis for an evolutionary model, which reveals that a major transition between many throat and skin specialist haplotypes correlates with the gain or loss of genes encoding fibronectin-binding proteins. This study employs a novel synthesis of tools to help delineate the major genetic changes associated with key adaptive shifts in an extensively recombined bacterial species.
In Rhodobacter sphaeroides, Chemotactic Operon 1 Regulates Rotation of the Flagellar System 2
Authors: Martínez-del Campo Ana , Ballado Teresa , Camarena Laura , Dreyfus Georges
Published: September 2011

Rhodobacter sphaeroides
is able to assemble two different flagella, the subpolar flagellum (Fla1) and the polar flagella (Fla2). In this work, we report the swimming behavior of
R. sphaeroides
Fla2
+
cells lacking each of the proteins encoded by chemotactic operon 1. A model proposing how these proteins control Fla2 rotation is presented.
Role of Sphingomonas sp. Strain Fr1 PhyR-NepR-σ
EcfG
Cascade in General Stress Response and Identification of a Negative Regulator of PhyR
Authors: Kaczmarczyk Andreas , Campagne Sébastien , Danza Francesco , Metzger Lisa C. , Vorholt Julia A. , Francez-Charlot Anne
Published: September 2011

The general stress response in
Alphaproteobacteria
was recently described to depend on the alternative sigma factor σ
EcfG
, whose activity is regulated by its anti-sigma factor NepR. The response regulator PhyR, in turn, regulates NepR activity in a partner-switching mechanism according to which phosphorylation of PhyR triggers sequestration of NepR by the sigma factor-like effector domain of PhyR. Although genes encoding predicted histidine kinases can often be found associated with
phyR
, little is known about their role in modulation of PhyR phosphorylation status. We demonstrate here that the PhyR-NepR-σ
EcfG
cascade is important for multiple stress resistance and competitiveness in the phyllosphere in a naturally abundant plant epiphyte,
Sphingomonas
sp. strain Fr1, and provide evidence that the partner switching mechanism is conserved. We furthermore identify a gene, designated
phyP
, encoding a predicted histidine kinase at the
phyR
locus as essential. Genetic epistasis experiments suggest that PhyP acts upstream of PhyR, keeping PhyR in an unphosphorylated, inactive state in nonstress conditions, strictly depending on the predicted phosphorylatable site of PhyP, His-341.
In vitro
experiments show that
Escherichia coli
inner membrane fractions containing PhyP disrupt the PhyR-P/NepR complex. Together with the fact that PhyP lacks an obvious ATPase domain, these results are in agreement with PhyP functioning as a phosphatase of PhyR, rather than a kinase.
Attitudes regarding ski helmet use among helmet wearers and non-wearers
Authors: Ruedl Gerhard , Kopp Martin , Rumpold Gerhard , Holzner Bernhard , Ledochowski Larissa , Burtscher Martin
Published: September 2011

Objective

The aim of this study was to compare attitudes regarding ski helmet use in helmet wearers and non-wearers.

Methods

In total, 924 persons ≥18 years (52% men and 48% women) participating in sport programmes at the University Sports Institute Innsbruck/Austria were interviewed about their attitudes regarding ski helmets and scored 14 statements on a five-level Likert Scale. A factor analysis was employed to determine clusters of underlying attitudes that have subsequently been used as predictors of helmet non-use in a conditional logistic regression analysis.

Results

In total, 65% of participants declared to use a helmet during their preferred winter sport activity while more than 80% of helmet wearers and non-wearers totally agreed that helmets protect from head injuries. According to the factor analysis, attitudes about ski helmets clustered around four major dimensions—subjective disadvantages, safety awareness, comfort/style and risk compensation. Adjusted ORs of regression analysis showed that helmet non-use increased with age and decreased with increasing skill level (beginner: OR 5.4, 95% CI 2.6 to 11.1; intermediate: OR 4.3, 95% CI 2.4 to 7.9; advanced: OR 3.1, 95% CI 1.7 to 5.4). In addition, helmet non-use was associated with subjective disadvantages (OR 2.3, 95% CI 1.8 to 2.9). However, a negative association between helmet non-use and safety awareness (OR 0.3, 95% CI 0.2 to 0.4) was found.

Conclusion

Helmet use was associated with higher safety awareness, while most arguments against helmet use seem to belong to subjective perception and to represent anticipatory negative cognitions, poorly supported by evidence. Therefore, evidence-based information about wearing a ski helmet should be implemented in preventive helmet campaigns focusing on non-wearers. In addition, health communication programmes should be instituted to get non-helmeted skiers and snowboarders to try out helmets to eliminate their potential prejudices.
ETA and ETB receptors are expressed in vascular adventitial fibroblasts
Authors: Boyd Ryan , Rätsep Matthew T. , Ding Li Li , Wang Hui Di
Published: September 2011

The adventitia has been recognized to play important roles in vascular oxidative stress, remodeling, and contraction. We recently demonstrated that adventitial fibroblasts are able to express endothelin (ET)-1 in response to ANG II. However, it is unclear whether ET-1 receptors are expressed in the adventitia. We therefore investigated the expression and roles of both ETA and ETB receptors in collagen synthesis and ET-1 clearance in adventitial fibroblasts. Adventitial fibroblasts were isolated and cultured from the mouse thoracic aorta by the explant method. Cultured cells were treated with ANG II (100 nmol/l) or ET-1 (10 pM) in the presence or absence of the ANG II type 1 receptor antagonist losartan (100 μM), the ET-1 receptor antagonists BQ-123 (ETA receptor, 1 μM) and BQ-788 (ETB receptor, 1 μM), and the ETB receptor agonist sarafotoxin 6C (100 nM). ET-1 peptide levels were determined by ELISA, whereas ETA, ETB, and collagen levels were determined by Western blot analysis. ANG II increased ET-1 peptide levels in a time-dependent manner. ANG II increased ETA and ETB receptor protein levels as well as collagen in a similar fashion. ANG II-induced collagen was reduced while in the presence of BQ-123, suggesting a role for the ETA receptor in the regulation of the extracellular matrix. ANG II treatment in the presence of BQ-788 significantly increased ET-1 peptide levels. Conversely, the ETB receptor agonist sarafotoxin 6C significantly decreased ET-1 peptide levels. These data implicate a role for the ETB receptor in the clearance of the ET-1 peptide. In conclusion, both ETA and ETB receptors are expressed in adventitial fibroblasts, which paves the ground for the biological significance of adventitial ET-1. The ETA receptor subtype mediates collagen I expression, whereas the ETB receptor subtype may play a protective role through increasing the clearance of the ET-1 peptide.
Regulation and function of the two-pore-domain (K2P) potassium channel Trek-1 in alveolar epithelial cells
Authors: Schwingshackl Andreas , Teng Bin , Ghosh Manik , West Alina Nico , Makena Patrudu , Gorantla Vijay , Sinclair Scott E. , Waters Christopher M.
Published: September 2011

Hyperoxia can lead to a myriad of deleterious effects in the lung including epithelial damage and diffuse inflammation. The specific mechanisms by which hyperoxia promotes these pathological changes are not completely understood. Activation of ion channels has been proposed as one of the mechanisms required for cell activation and mediator secretion. The two-pore-domain K+ channel (K2P) Trek-1 has recently been described in lung epithelial cells, but its function remains elusive. In this study we hypothesized that hyperoxia affects expression of Trek-1 in alveolar epithelial cells and that Trek-1 is involved in regulation of cell proliferation and cytokine secretion. We found gene expression of several K2P channels in mouse alveolar epithelial cells (MLE-12), and expression of Trek-1 was significantly downregulated in cultured cells and lungs of mice exposed to hyperoxia. Similarly, proliferation cell nuclear antigen (PCNA) and Cyclin D1 expression were downregulated by exposure to hyperoxia. We developed an MLE-12 cell line deficient in Trek-1 expression using shRNA and found that Trek-1 deficiency resulted in increased cell proliferation and upregulation of PCNA but not Cyclin D1. Furthermore, IL-6 and regulated on activation normal T-expressed and presumably secreted (RANTES) secretion was decreased in Trek-1-deficient cells, whereas release of monocyte chemoattractant protein-1 was increased. Release of KC/IL-8 was not affected by Trek-1 deficiency. Overall, deficiency of Trek-1 had a more pronounced effect on mediator secretion than exposure to hyperoxia. This is the first report suggesting that the K+ channel Trek-1 could be involved in regulation of alveolar epithelial cell proliferation and cytokine secretion, but a direct association with hyperoxia-induced changes in Trek-1 levels remains elusive.
Inhibition of the Notch-Hey1 Axis Blocks Embryonal Rhabdomyosarcoma Tumorigenesis
Authors: Belyea Brian C. , Naini Sarasija , Bentley Rex C. , Linardic Corinne M.
Published: September 2011

Purpose: Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood and remains refractory to combined-modality therapy in patients with high risk disease. In skeletal myogenesis, Notch signaling prevents muscle differentiation and promotes proliferation of satellite cell progeny. Given its physiologic role in myogenesis and oncogenic role in other human cancers, we hypothesized that aberrant Notch signaling may contribute to RMS tumorigenesis and present novel therapeutic opportunities.

Experimental Design: Human RMS cell lines and tumors were evaluated by immunoblot, IHC, and RT-PCR to measure Notch ligand, receptor, and target gene expression. Manipulation of Notch signaling was accomplished using genetic and pharmacologic approaches. In vitro cell growth, proliferation, and differentiation were assessed using colorimetric MTT and BrdU assays, and biochemical/morphologic changes after incubation in differentiation-promoting media, respectively. In vivo tumorigenesis was assessed using xenograft formation in SCID/beige mice.

Results: Notch signaling is upregulated in human RMS cell lines and tumors compared with primary skeletal muscle, especially in the embryonal (eRMS) subtype. Inhibition of Notch signaling using Notch1 RNAi or γ-secretase inhibitors reduced eRMS cell proliferation in vitro. Hey1 RNAi phenocopied Notch1 loss and permitted modest myogenic differentiation, while overexpression of an activated Notch moiety, ICN1, promoted eRMS cell proliferation and rescued pharmacologic inhibition. Finally, Notch inhibition using RNAi or γ-secretase inhibitors blocked tumorigenesis in vivo.

Conclusions: Aberrant Notch-Hey1 signaling contributes to eRMS by impeding differentiation and promoting proliferation. The efficacy of Notch pathway inhibition in vivo supports the development of Notch-Hey1 axis inhibitors in the treatment of eRMS. Clin Cancer Res; 17(23); 7324–36. ©2011 AACR.
Quantitative Assessment of Artifacts on Cardiac Magnetic Resonance Imaging of Patients With Pacemakers and Implantable Cardioverter-Defibrillators
Authors: Sasaki Takeshi , Hansford Rozann , Zviman Menekhem M. , Kolandaivelu Aravindan , Bluemke David A. , Berger Ronald D. , Calkins Hugh , Halperin Henry R. , Nazarian Saman
Published: September 2011

Background—

The safety and clinical utility of MRI at 1.5 T in patients with cardiac implantable devices such as pacemakers (PM) and implantable cardioverter-defibrillators (ICD) have been reported. This study aims to evaluate the extent of artifacts on cardiac magnetic resonance (CMR) in patients with PM and ICD (PM/ICD).

Methods and Results—

A total of 71 CMR studies were performed with an established safety protocol in patients with prepectoral PM/ICD. The artifact area around the PM/ICD generator was measured in all short-axis (SA), horizontal (HLA), and vertical long-axis (VLA) SSFP cine planes. The location and extent of artifacts were also assessed in all SA (20 sectors per plane), HLA, and VLA (6 sectors per plane) late gadolinium-enhanced CMR (LGE-CMR) planes. The artifact area on cine CMR was significantly larger with ICD versus PM generators in each plane (
P
<0.001, respectively). In patients with left-sided ICD or biventricular ICD systems, the percentages of sectors with any artifacts on LGE-CMR were 53.7%, 48.0%, and 49.2% in SA, HLA, and VLA planes, respectively. Patients with left-sided PM or right-sided PM/ICD had fewer artifacts. Anterior and apical regions were severely affected by artifact caused by left-sided PM/ICD generators.

Conclusions—

In contrast to patients with right-sided PM/ICD and left-sided PM, the anterior and apical left ventricle can be affected by susceptibility artifacts in patients with left-sided ICD. Artifact reduction methodologies will be necessary to improve the performance of CMR in patients with left sided ICD systems.
Prevalence and Predictors of Coexistent Silent Atherosclerotic Cardiovascular Disease in Patients With Abdominal Aortic Aneurysm Without Previous Symptomatic Cardiovascular Diseases
Authors: Takigawa Masateru , Yoshimuta Tsuyoshi , Akutsu Koichi , Takeshita Satoshi , Yokoyama Naoyuki
Published: September 2011

Although patients with abdominal aortic aneurysm (AAA) often have other cardiovascular diseases (CVDs), the exact prevalence remains unclear. We aimed to determine the prevalence and predictors of coexistent silent atherosclerotic cardiovascular diseases (SACVDs) in patients with AAA without a history of CVD. Consecutive 157 patients with AAA (mean age, 73 years), without any previous history of CVD, were included. Silent myocardial ischemia (SMI), cerebrovascular disease (CeVD), peripheral artery disease (PAD), and thoracic aortic aneurysm (TAA) without symptoms coexisted in 29.3%, 25.5%, 15.9%, and 8.3%, respectively. The significant predictors of SMI were diabetes mellitus ( P = .025) and male sex ( P = .048). The significant predictor of silent CeVD was older age ( P = .039). The borderline predictors of asymptomatic PAD and TAA were diabetes mellitus ( P = .056) and AAA size ( P = .053), respectively. Even with no previous symptomatic CVD, patients with AAA have high prevalence of coexistent SACVD.
Platelet-Activating Factor and Its Basic Metabolic Enzymes in Blood of Naive HIV-Infected Patients
Authors: Tsoupras Alexandros B. , Chini Maria , Mangafas Nikos , Tsogas Nikos , Stamatakis George , Tsantila Nektaria , Fragopoulou Elizabeth , Antonopoulou Smaragdi , Gargalianos Panagiotis , Demopoulos Constantinos A. , Lazanas Marios C.
Published: September 2011

Platelet-activating factor (PAF), a mediator of proatherosclerotic inflammatory processes, is also implicated in endothelial dysfunction during human immunodeficiency virus (HIV) infection. We examined PAF metabolism in blood of naive male patients, 8 with early HIV infection (group A) and 17 just before treatment initiation (group B), versus 18 healthy age-matched males (group C). Statistical analysis was performed with 1-way analysis of variance (ANOVA) criterion and Pearson r test. Higher PAF biosynthesis in patients’ leukocytes versus group C was accompanied by an increase in lipoprotein-associated phospholipase A2 (Lp-PLA2) activity that degrades PAF. Moreover, PAF synthesis was higher and Lp-PLA2 activity was lower in group B compared to group A. Lipoprotein-associated phospholipase A2 was positively correlated with viral load and negatively correlated with CD4 cell counts in group B. The activities of PAF-basic biosynthetic enzymes in patients’ leukocytes were also negatively correlated with CD4 cell counts. The observed continuous increase in PAF biosynthesis during HIV infection progress seems to amplify the risk of AIDS manifestations and/or cardiovascular complications in HIV-infected patients, while a subsequent increase in Lp-PLA2 activity seems to be a host response.
Deriving an empirical formula to determine the optimum level of false-twist in mechanically-crimped textured polyester yarn
Authors: Shaikh Tasnim N , Bhattacharya Someswar S
Published: September 2011

Flat polyester yarn is bulked by the mechanical crimp texturizing process. The magnitude of the false-twist, introduced together with the torsional rigidity of the supply yarn, has a significant effect on the transformation process. The torsional rigidity of the supply yarn is in turn influenced by its fineness and bending characteristics. It is therefore deemed necessary to establish a mathematical relationship between the optimum false-twist level and the yarn fineness for materials with known bending characteristics. Such a relationship may help in producing a yarn with optimum bulk properties, while minimizing resource utilization and waste generation. This paper reports research work done in this direction.

Polyester yarn is chosen for this investigation as it has a wide range of applications. Fully drawn multifilament polyester yarns, with different linear densities, are textured on a single-head mechanical crimp texturing machine. The results are analysed with the help of polynomial curve fitting (Polyfit) using MATLAB. This mathematical tool facilitated the derivation of the desired formula (polynomial equation) for the calculation of optimum false-twist level for fully drawn multifilament polyester yarns undergoing mechanical crimp texturizing.
Population Pharmacokinetics of Pegaptanib in Patients With Neovascular, Age‐Related Macular Degeneration
Authors: Basile Anthony S. , Hutmacher Matt , Nickens Dana , Nielsen Jace , Kowalski Ken , Whitfield Lloyd , Masayo Oishi , Nakane Masami
Published: September 2011

The anti—vascular endothelial growth factor (VEGF) aptamer pegaptanib is eliminated primarily by renal clearance. Because renal function declines with age, pegaptanib exposure in patients with age‐related macular degeneration (AMD) may increase. Therefore, a population pharmacokinetic (PK) analysis of pegaptanib was undertaken in Western and Asian AMD patients to determine the influence of renal function on apparent pegaptanib clearance (CL). Pegaptanib (0.3–3 mg per eye) was administered every 4 to 6 weeks to 262 AMD patients in 4 studies. Pegaptanib exposures (area under the concentration—time curve [AUC] and maximum plasma concentration) after 8 doses were similar to exposures following the first dose, consistent with the absence of plasma accumulation. A 1‐compartment model parameterized in terms of the absorption rate constant, apparent volume of distribution, and CL was used to describe the pegaptanib plasma concentration data. Creatinine clearance (CLCR), body weight (WT), and age influenced pegaptanib PK. Decreasing CLCR from 70 to 30 mL/min doubled AUC. After adjustment for CLCR, WT, and age, the model predicted no race differences in CL or AUC. Given that the therapeutic 0.3 mg per eye dose of pegaptanib results in exposures one‐tenth of those observed following the well‐tolerated 3‐mg dose, these results suggest that no dose adjustment is warranted for AMD patients with moderate renal insufficiency (CLCR >30 mL/min).
Effects of reboxetine and citalopram on appraisal of infant facial expressions and attentional biases
Authors: Stein Alan , Murphy Susannah , Arteche Adriane , Lehtonen Annukka , Harvey Allison , Craske Michelle G , Harmer Catherine
Published: September 2011

Difficulties in mother–child interaction are commonly observed in the context of postnatal depression. These difficulties may result in part from the negative cognitive bias present in depression, which may in turn lead to biased negative perceptions of the infant: in particular, these biases encompass the negative appraisal of facial expressions. Given the important role of early mother–child interactions in child development it is vital to investigate potential interventions that might be beneficial in ameliorating the negative cognitive bias. This study aimed to examine the effects of two different antidepressants (reboxetine and citalopram) on the appraisal of infant facial expressions of emotion using a faces rating task, and on attention to infant emotion using an attentional probe. Thirty-nine volunteers were randomly assigned to a double-blind 7-day intervention with either placebo, citalopram or reboxetine. There were significant positive effects on the appraisal of facial expressions; participants assigned to the placebo group rated positive faces less positively than those either in the citalopram or in the reboxetine groups. However, there was no evidence that these drugs had an effect on attentional vigilance. If antidepressants are able to help a mother to perceive her infant’s facial expressions as more positive, this may lead to more positive interactions, thereby potentially mitigating the negative effects of depression on infant development. These findings should be treated with caution until replicated in larger and clinical samples.
Psychological Capital, Quality of Work Life, and Quality of Life of Marketers
Authors: Nguyen Tho D. , Nguyen Trang T. M.
Published: September 2011

This study examines the roles of psychological capital (PsyCap) in job performance and quality of work life (QWL) of marketers in a transitioning market, Vietnam. It also investigates the impacts of marketers’ QWL on their job performance and quality of life (QoL). A test based upon a sample of 364 marketers in Ho Chi Minh (HCM) City reveals that PsyCap has positive impacts on both job performance and QWL of marketers. In addition, QWL underlies both job performance and QoL of marketers. These findings confirm the importance of PsyCap in marketers’ work and lives in a transitioning market.
The Writing’s on the Board
Authors: Artemeva Natasha , Fox Janna
Published: September 2011

This article reports on an international study of the teaching of undergraduate mathematics in seven countries. Informed by rhetorical genre theory, activity theory, and the notion of Communities of Practice, this study explores a pedagogical genre at play in university mathematics lecture classrooms. The genre is mediational in that it is a tool employed in the activity of teaching. The data consist of audio/video-recorded lectures, observational notes, semistructured interviews, and written artifacts collected from 50 participants who differed in linguistic, cultural, and educational backgrounds; teaching experience; and languages of instruction. The study suggests that chalk talk, namely, writing out a mathematical narrative on the board while talking aloud, is the central pedagogical genre of the undergraduate mathematics lecture classroom. Pervasive pedagogical genres, like chalk talk, which develop within global disciplinary communities of practice, appear to override local differences across contexts of instruction. Better understanding these genres may lead to new insights regarding academic literacies and teaching.
Perspectives on the Effectiveness of the Late Night Liquor Trading Lockout Legislative Provision
Authors: Palk Gavan , Davey Jeremy , Freeman James , Morgan Hannah
Published: September 2011

The effectiveness of “the lockout policy” integrated within a broader police enforcement strategy to reduce alcohol-related harm, in and around late night licensed premises, in major drinking precincts is examined. First response operational police ( n = 280) records all alcohol and non–alcohol-related incidents they attended in and around late night liquor trading premises. A before and after study design is used, with police completing modified activity logs prior to and following the introduction of the lockout policy in two policing regions: Gold Coast ( n = 12,801 incidents) and Brisbane City/Fortitude Valley ( n = 9,117 incidents). Qualitative information from key stakeholders (e.g., police, security staff, and politicians; n = 20) is also obtained. The number of alcohol-related offences requiring police attention is significantly reduced in some policing areas and for some types of offences (e.g., sex offences, street disturbances, traffic incidents). However, there is no variation for a number of other offence categories (e.g., assault). Interviews with licensees reveal that although all were initially opposed to the lockout policy, most perceived benefits from its introduction. This study is the first of its kind to comprehensively examine the impact of a lockout policy and provides supportive evidence for the effectiveness of the lockout policy as integrating positively with police enforcement to enhance public safety in some areas in and around late night liquor trading premises.
Incarcerated Fathers
Authors: Visher Christy A.
Published: September 2011

Prior research indicates that strong family support can play an important role in helping men and women transition from prison to home and can actually reduce the likelihood of recidivism. Assuming traditional roles within a family, such as parent or spouse, can also aid in the reentry transition process and has been linked to positive outcomes after release. Using data from a longitudinal study of fathers returning to the community after a period of incarceration, this article examines how the relationship between fathers and their children may influence aspects of recently released fathers’ lives that are important to a successful reentry transition, such as employment, abstinence from substance abuse, and mental health. Analyses show that fathers who have regular contact with their children before release and report good family support overall are more likely to be attached to their children after release. Moreover, in the first few months after release, fathers who are more strongly attached to their children work more hours per week, have better mental health, and are less likely to commit crime, get arrested, or violate conditions of their supervision.
Self-Protection in Rural America
Authors: Giblin Matthew J. , Burruss George W. , Corsaro Nicholas , Schafer Joseph A.
Published: September 2011

Scholarly interest in self-protective behaviors is demonstrated in studies examining victimization; these behaviors are presumed to reduce the likelihood of experiencing crime. Protective behaviors are not taken by all citizens equally, however, so it is critical to explain these behaviors within the population. The current study extends existing works, most of which were based on urban samples, by examining the determinants of protective behaviors in a sample of rural residents in the United States. Predictors are derived from a modified risk interpretation model (Ferraro, 1995) and include risk, fear, victimization experiences, and perceived collective efficacy. Results show that household protective behaviors are influenced by perceptions of risk and, indirectly through risk, by perceived collective efficacy and victimization experiences.
The Location of Foreign Human Capital in the United States
Authors: Waldorf Brigitte
Published: September 2011

Among the millions of newcomers entering the United States every decade, those with extensive human capital are of particular importance for local economies. This study uses data from the American Community Surveys, 2004 to 2007 and compares the locational patterns of highly educated individuals coming from abroad with that of highly educated individuals migrating internally. The study finds that the locational choices of highly educated newcomers from abroad are similar to those of highly educated domestic migrants but that there are some important differences. Gateway states are substantially more successful in attracting human capital from abroad than domestic human capital; foreign human capital is more strongly attracted to existing human capital agglomerations than domestic human capital; and a manufacturing-based industry is a deterrent for the attraction of both foreign and domestic highly educated in-migrants, but the deterrent effect is stronger for domestic human capital than for human capital from abroad.
Sustainability of additive manufacturing: measuring the energy consumption of the laser sintering process
Authors: Baumers M , Tuck C , Bourell D L , Sreenivasan R , Hague R
Published: September 2011

The term additive manufacturing (AM) describes a collection of production techniques enabling the layer-by-layer manufacture of components using digital data and raw material as inputs. The AM technology variant most frequently used in the production of end use parts is laser sintering (LS).

It has been suggested that efficient usage of the energy inputs is one of the advantages of the technology. This paper presents a comparative assessment of the electricity consumptions of two major polymeric LS platforms: the Sinterstation HiQ + HS from 3D Systems and the EOSINT P 390 from EOS GmbH. The energy inputs to a build consisting of two prosthetic parts were recorded during power-monitoring experiments conducted on both platforms. This paper injects clarity into the ongoing research on the AM energy consumption by applying a novel classification system; it is argued that the AM energy usage can be divided into the job-dependent, time-dependent, geometry-dependent, and Z-height-dependent energy consumption values. The recorded mean real power consumption conforms to the values that have been reported for similar platforms. The measured energy consumption rates are higher than reported elsewhere. It is also shown that the purely time-dependent energy consumption is the main energy drain. Furthermore, the presentation of results in the context of previous literature highlights the caveats attached to summary metrics of the AM input usage.
Modelling of parametric excitation of a flexible coupling–rotor system due to misalignment
Authors: Ganesan S , Padmanabhan C
Published: September 2011

A flexible diaphragm coupling, connecting two rotating shafts, is investigated for its dynamic characteristics, when subjected to parallel offset misalignment. The diaphragm coupling is a constant velocity coupling which becomes asymmetric once misaligned. Asymmetry creates directional difference or spatial variation of stiffness, as shown by a quasi-static finite element (FE) analysis using ABAQUS software. As the shafts rotate, this spatial variation in stiffness makes the diaphragm coupling–rotor system model to become time-varying. The time-varying direct and cross–coupled stiffness terms of the coupling are synthesized from the FE model and used in the governing equations of motion of the coupling–rotor system. This leads to a parametrically excited system due to the time-periodic stiffness coefficients of the coupling. Using Simulink, numerical integration has been performed to find the response of the system for both mass unbalance and inclination unbalance excitations that arise due to the tilt of the principal axes of the diaphragm due to parallel misalignment. The responses obtained clearly indicate the effect of parametric excitation at one-fourth, one-third, and one-half of the principal parametric resonance. To verify this model, an experimental setup has been developed for the coupling–rotor system model with misalignment. The experimental results clearly show the asymmetry between the two lateral direction responses, as predicted by the model.
Experiments on and thermodynamic analysis of a turbocharged engine with producer gas as fuel
Authors: Dasappa S , Sridhar H V , Muzumdar I
Published: September 2011

This article presents the studies conducted on turbocharged producer gas engines designed originally for natural gas (NG) as the fuel. Producer gas, whose properties like stoichiometric ratio, calorific value, laminar flame speed, adiabatic flame temperature, and related parameters that differ from those of NG, is used as the fuel. Two engines having similar turbochargers are evaluated for performance.

Detailed measurements on the mass flowrates of fuel and air, pressures and temperatures at various locations on the turbocharger were carried out. On both the engines, the pressure ratio across the compressor was measured to be 1.40 ± 0.05 and the density ratio to be 1.35 ± 0.05 across the turbocharger with after-cooler. Thermodynamic analysis of the data on both the engines suggests a compressor efficiency of 70 per cent. The specific energy consumption at the peak load is found to be 13.1 MJ/kWh with producer gas as the fuel. Compared with the naturally aspirated mode, the mass flow and the peak load in the turbocharged after-cooled condition increased by 35 per cent and 30 per cent, respectively. The pressure ratios obtained with the use of NG and producer gas are compared with corrected mass flow on the compressor map.
A thermography-based approach for structural analysis and fatigue evaluation
Authors: Wang X G , Crupi V , Guo X L , Guglielmino E
Published: September 2011

The infrared thermography has been developed for Non-Destructive Testing (NDT), stress analysis, and in the last 10 years for metal fatigue assessment. The present research enables to realize these different research objectives all together thanks to an innovative experimental procedure, which includes NDT by lock-in thermography, thermoelastic stress analysis, and fatigue parameters assessment by Rapid Thermographic Method ( RTM). The developed procedure has been performed on a set of hole-notched specimens, achieving good results and predictions in a relatively short time. Moreover, the fatigue strength reduction coefficients of the specimens were determined by RTM. This thermography-based approach is dedicated for structural analysis and fatigue evaluation; it is an interesting attempt to apply different thermographic methods to a common research topic.
Influence of rub-plate length on forces and displacements of longitudinally coupled slab track for a bridge turnout
Authors: Wang P , Ren J J , Xiang R , Liu X Y
Published: September 2011

Because of the successful construction and operation of the Beijing–Tianjin intercity railway line, the longitudinally coupled prefabricated slab track (LCPBT) system has shown its outstanding advantages in both mechanical and structural aspects. With a design speed of 350 km/h, the LCPBT system was also used on the 595.62-m-long, double-track LeiDa Bridge on the Wuhan–Guangzhou passenger dedicated line (PDL) in China.

To equably transfer longitudinal force from the coupled concrete base to the subbase by friction, a reinforced concrete rub-plate was placed in transition zones from bridges to the subgrade. A 100-m-long, 0.4-m-thick rub-plate was built at the Beijing–Tianjin intercity railway line, whereas a 50-m-long rub-plate was used at the Wuhan–Guangzhou PDL. This article established an integral finite element model of jointless turnout (crossover)-track slab-bridge-pier taking the LCPBT system on LeiDa Bridge as an example, and researched the proper setting length of the rub-plate in this structure. Calculation conclusions and suggestions were given: the 100-m-long rub-plate used on the Beijing–Tianjin intercity railway line can be shortened; a length of 50–75 m will be appropriate as the case may be; in specific circumstances, it can be designed within the range 25–50 m.
Low order model for the dynamics of bi-stable composite plates
Authors: Arrieta A.F. , Spelsberg-Korspeter G. , Hagedorn P. , Neild S.A. , Wagg D.J.
Published: September 2011

This article presents the derivation and validation of a low order model for the non-linear dynamics of cross-ply bi-stable composite plates focusing on the response of one stable state. The Rayleigh–Ritz method is used to solve the associated linear problem to obtain valuable theoretical insight into how to formulate an approximate non-linear dynamic model. This allows us to follow a Galerkin approach projecting the solution of the non-linear problem onto the mode shapes of the linear problem. The order of the non-linear model is reduced using theoretical results from the linear solution yielding a low order model. The dynamic response of a bi-stable plate specimen is studied to simplify the model further by only keeping the non-linear terms leading to observed oscillations. Simulations for the dynamic response using the derived model are presented showing excellent agreement with the experimentally observed behaviour. Additionally, deflection shapes are measured and compared with the calculated mode shapes, showing good agreement.
Players as Coresearchers
Authors: Jørgensen Kristine
Published: September 2011

This article argues for the use of expert players as coresearchers when studying game systems and game design choices. As emergent systems that may react differently to different playstyles, games need to be studied from a variety of gameplay perspectives. Combining approaches from game studies with usability testing, interpretative phenomenological analysis, and reader-response theory, this article suggests a method for game research that is relevant for the study of games as both artifacts and playgrounds.
Significant Associations Among Hemostatic Parameters, Adipokines, and Components of the Metabolic Syndrome in Japanese Preschool Children
Authors: Horigome Hitoshi , Katayama Yasutomi , Yoshinaga Masao , Kato Yoshiaki , Takahashi Hideto , Sumazaki Ryo
Published: September 2011

Development of cardiovascular diseases could originate in early childhood. However, reference values of hemostatic parameters and adipokines in preschool children remain to be explored. We measured blood levels of adipokines and parameters of the hemostatic/fibrinolytic systems in 167 healthy children aged 4 to 6 years at 9:00 to 10:30 am after a strictly enforced overnight fast. Participants with body mass index (BMI) values ≥90th percentile had significantly higher values of systolic blood pressure and heart rate, as well as blood levels of insulin, coagulation factor (F) VII, FX, protein S, leptin, and homeostasis model assessment of insulin resistance (HOMA-IR), and lower values of desacyl-ghrelin than children with BMI < 90th percentile. Circulating levels of fibrinogen and leptin increased with increased number of cardiovascular risk factors. Stepwise regression analysis identified many hematological variables to be associated with features of the metabolic syndrome. The results implicated the hemostatic/fibrinolytic system or adipokines in the insidious progression of cardiovascular diseases from an early age.
Platelet Activity Indices in Patients With Deep Vein Thrombosis
Authors: Cay Nurdan , Ipek Ali , Gumus Mehmet , Birkan Zulfu , Ozmen Evrim
Published: September 2011

Background: Extensive research has been performed regarding the association between platelet activity indices and various cardiovascular disorders. Less clear data, however, are present between these indices and deep vein thrombosis (DVT). Aim: The aim of this study was to investigate the association between platelet activity indices and DVT in a relatively large population. Methods: Mean platelet volume (MPV), mean platelet mass (MPM), and mean platelet component (MPC) were measured by an autoanalyzer in a total of 203 patients with DVT and the results were compared with 210 age- and sex-matched controls without DVT. Results: There were significant differences between the study and control groups in MPV (8.6 ± 1.3 fL vs 7.9 ± 0.5 fL [95% CI −0.82 to −0.44], P < .001, respectively), MPM (2.2 ± 0.3 pg vs 2.0 ± 0.1 pg [95% CI −0.20 to −0.11], P < .001, respectively), and MPC (24.9 ± 3.2 g/dL vs 26.3 ± 1.6 g/dL [95% CI 0.91 to 1.89], P < .001, respectively). These 3 platelet activity indices were also found to be significant predictors of the presence of DVT (all Ps < .001). Conclusion: In patients with DVT, the presence of DVT was closely associated with increased platelet activation. The MPV, MPM, and MPC may identify patients requiring aggressive antiplatelet treatment.
Predictive controller design for electromagnetic suspension based on mixed logical dynamical model
Authors: Huang Kun , Zhang Yongchao , Yu Fan
Published: September 2011

In this paper, a mathematical model for the developed electromagnetic suspension actuator is established using measured parameters and test data. A main/inner-loop control structure is proposed for its active control where the inner loop undertakes the control of a three-phase motor and applies hysteresis current control method to track the calculated signal by the main loop. With the simplification of the inner-loop control system, an achievable range of control current is acquired. Then, due to the nonlinear damping characteristic of the actuator, a mixed logical dynamical model is built up for the vehicle system and the optimal control to improve vehicle ride comfort is carried out based on the model predictive control method. Simulations are carried out using random uneven road inputs and the results demonstrate that the electromagnetic suspension with the proposed controller can provide better vehicle ride comfort compared with a corresponding passive suspension.