bluuebunny/crossref_metadata_2025 huggingface dataset:
Aryl hydrocarbon receptor regulates the cholesterol biosynthetic pathway in a dioxin response element-independent manner
Authors: Tanos Rachel , Patel Rushang D. , Murray Iain A. , Smith Philip B. , Patterson Andrew D. , Perdew Gary H.
Published: January 2012

The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor. Activation of AhR mediates the expression of target genes (e.g.,

CYP1A1
) by binding to dioxin response element (DRE) sequences in their promoter region. To understand the multiple mechanisms of AhR-mediated gene regulation, a microarray analysis on liver isolated from ligand-treated transgenic mice expressing a wild-type (WT)

Ahr

or a DRE-binding mutant

Ahr

(A78D) on an

ahr
-null background was performed. Results revealed that AhR DRE binding is not required for the suppression of genes involved in cholesterol synthesis. Quantitative reverse-transcription polymerase chain reaction performed on both mouse liver and primary human hepatocyte RNA demonstrated a coordinated repression of genes involved in cholesterol biosynthesis, namely,

HMGCR,

FDFT1,

SQLE
, and

LSS

after receptor activation. An additional transgenic mouse line was established expressing a liver-specific

Ahr-A78D

on a

Cre

Alb/
Ahrflox/flox

background. These mice displayed a similar repression of cholesterol biosynthetic genes, compared to

Ahrflox/flox

mice, further indicating that the observed modulation is AhR specific and occurs in a DRE-independent manner. Elevated hepatic transcriptional levels of the genes of interest were noted in congenic C57BL/6J-
Ahd

allele mice, when compared to the WT C57BL/6J mice, which carry the

Ahb

allele. Down-regulation of AhR nuclear translocator levels using short interfering RNA in a human cell line revealed no effect on the expression of cholesterol biosynthetic genes. Finally, cholesterol secretion was shown to be significantly decreased in human cells after AhR activation.

Conclusion:

These data firmly establish an endogenous role for AhR as a regulator of the cholesterol biosynthesis pathway independent of its DRE-binding ability, and suggest that AhR may be a previously unrecognized therapeutic target.
Mechanical properties of tyramine substituted‐hyaluronan enriched fascia extracellular matrix
Authors: Chin LiKang , Calabro Anthony , Walker Esteban , Derwin Kathleen A.
Published: January 2012

Naturally occurring biomaterial scaffolds derived from extracellular matrix (ECM) have been the topic of recent investigation in the context of rotator cuff tendon repair. We previously reported a method to treat fascia ECM with high molecular weight tyramine substituted‐hyaluronan (TS‐HA) for use as a tendon augmentation scaffold. The presence of crosslinked TS‐HA in fascia was associated with an increased macrophage and giant cell response compared to water‐treated controls after implantation in a rat abdominal wall model. The objective of this study was to determine the extent to which TS‐HA treatment was associated with mechanical property changes of fascia after implantation in the rat model. Fascia samples in all groups demonstrated time‐dependent decreases in mechanical properties. TS‐HA‐treated fascia with crosslinking exhibited a lower toe modulus, a trend toward lower toe stiffness, and a higher transition strain than water‐treated controls not only after implantation, but also at time zero. TS‐HA treatment, with or without crosslinking, had no significant effect on time‐zero or post‐implantation load relaxation ratio, load relaxation rate, linear‐region stiffness, or linear‐region modulus. Our findings demonstrated that the particular TS‐HA treatment employed in this study decreased the low‐load elastic mechanical properties of fascia ECM, in keeping with the heightened macrophage and giant cell host response seen previously. This work provides a starting point and guidance for investigating alternative HA treatment strategies. © 2012 Wiley Periodicals, Inc. J Biomed Mater Res Part A, 2012.
Transthoracic echocardiography visualization of bicaval dual lumen catheters for veno‐venous extracorporeal membrane oxygenation
Authors: Tabak Benjamin , Elliott Christopher L. , Mahnke C. Becket , Tanaka Len Y. , Ogino Mark T.
Published: January 2012

Bicaval dual lumen catheters improve the efficiency of veno‐venous extracorporeal membrane oxygenation by minimizing recirculation with an innovative design, which requires precise placement of three catheter ports in the superior vena cava, right atrium, and inferior vena cava, respectively. However, the exact position of these catheter ports is usually not known during placement because they cannot be visualized with conventional radiography. We performed a retrospective review of our experience over the past year using transthoracic echocardiography to evaluate the position of the catheter ports. From a subcostal, sagittal imaging approach, we were able to identify all three catheter ports in 11 of 11 studies. At least one of the catheter ports was incorrectly positioned in 5 of 11 studies. Further prospective evaluation is necessary to determine if catheter repositioning based on transthoracic echocardiography findings can further improve the clinical efficiency of veno‐venous extracorporeal membrane oxygenation. © 2012 Wiley Periodicals, Inc. J Clin Ultrasound, 2012.
Electrochemical studies on the corrosion inhibition of AA2024 aluminium alloy by rare earth ammonium nitrates in 3.5% NaCl solutions
Authors: Matter E. A. , Kozhukharov S. , Machkova M. , Kozhukharov V.
Published: January 2012

The inhibitive effect of Ce(III) and Ce(IV) ammonium nitrate inhibitors on the corrosion behavior of aluminium alloy AA2024 in 3.5% NaCl solution has been investigated. Four different concentrations (10−2, 10−3, 10−4, and 10−5 M) of the inhibitors were studied. Ce3+ and Ce4+ ions are introduced into the corrosive medium with similar anionic compositions – (NH4)2Ce(NO3)5 and (NH4)2Ce(NO3)6. The inhibition efficiency (IE%) of the ions has been evaluated by using electrochemical methods – linear voltammetry (LVA) and electrochemical impedance spectroscopy (EIS). Moreover, the inhibitive ability has been investigated at different duration after addition of these salts into the corrosive media. It is established that the pH of the solutions plays an important role on the inhibition process for both cations. The results revealed that at relatively similar conditions, the cerium (III) ions showed higher inhibition efficiency than cerium (IV) ions, when they were compared to the case without inhibitor.
Influence of microstructure on mechanical properties and corrosion behavior of 3%Cr steel in CO2 environment
Authors: Xu L. N. , Guo S. Q. , Gao C. L. , Chang W. , Chen T. H. , Lu M. X.
Published: January 2012

Corrosion behavior and mechanical properties of two 3%Cr pipeline steels were studied which have same chemical compositions but different microstructures, bainite‐ferrite and ferrite‐pearlite microstructures. Analysis of chemical compositions and surface morphology of the corrosion scale were performed using X‐ray diffraction and scanning electron microscopy in conjunction with energy dispersive X‐ray spectroscopy. The semi‐passive character of corrosion scale was investigated using polarization curves measurements. The influence of microstructure on the chromium enrichment in the corrosion scale for different test periods was investigated. The microstructure was observed to affect the corrosion behavior even when the steel surface has been covered with corrosion scales and continue to have an effect until the corrosion scale possessing semi‐passive character. Possessing both good strength and corrosion resistance, 3%Cr steel with bainite‐ferrite microstructure was very promising for pipeline steel applications.
Preventing Post‐Thoracotomy Pain Syndrome
Authors: Khelemsky Yury , Noto Christopher J.
Published: January 2012

This article provides a concise overview of post‐thoracotomy pain syndrome, describes anesthetic and surgical factors that have been investigated to reduce the incidence of the syndrome, and explores the effectiveness of various treatments for this condition. Although some interventions (both procedural and pharmacologic) have been investigated in both preventing and treating post‐thoracotomy pain syndrome, definitive studies are lacking and firm conclusions regarding the benefit of any intervention cannot be drawn. The problem is compounded further by our lack of understanding of the pathophysiologic mechanisms underlying the development of chronic pain after surgery. Going forward, it will be important to elucidate these mechanisms and conduct well‐designed trials involving novel therapeutic agents for both prevention and treatment of post‐thoracotomy pain syndrome. Mt Sinai J Med 79:133–139, 2012. © 2012 Mount Sinai School of Medicine
Perioperative Dental Evaluation
Authors: Yasny Jeffrey S. , Herlich Andrew
Published: January 2012

Typically, a patient's intraoral condition is not a chief perioperative concern. The need for proper dental care is often unmet prior to a surgical procedure. Consequently, patients presenting for surgery may possess untreated decayed teeth and/or periodontal disease. These individuals may be harboring a quiescent and potent odontogenic infection. In the perioperative period, the deleterious effects of such an infection can not only compromise surgical outcome, but also magnify treatment and expenses. This article will elaborate on the connection between oral health and systemic disease, and discuss the barriers that exist with improving oral health. It will review pertinent dental nomenclature and anatomy, as well as emphasize the practice and value of a preoperative dental evaluation. Various compromised intraoral conditions are presented among a range of patient populations. The importance of treating an acute odontogenic infection before surgery is also discussed. Healthcare providers who recognize significant perioperative dental conditions can implement effective and preventive actions that can contain costs and achieve optimal patient care. Mt Sinai J Med 79:34–45, 2012. © 2012 Mount Sinai School of Medicine
Expression of a soluble form of iodotyrosine deiodinase for active site characterization by engineering the native membrane protein from Mus musculus
Authors: Buss Jennifer M. , McTamney Patrick M. , Rokita Steven E.
Published: January 2012

Reductive deiodination is critical for thyroid function and represents an unusual exception to the more common oxidative and hydrolytic mechanisms of dehalogenation in mammals. Studies on the reductive processes have been limited by a lack of convenient methods for heterologous expression of the appropriate proteins in large scale. The enzyme responsible for iodide salvage in the thyroid, iodotyrosine deodinase, is now readily generated after engineering its gene from Mus musculus. High expression of a truncated derivative lacking the membrane domain at its N‐terminal was observed in Sf9 cells, whereas expression in Pichia pastoris remained low despite codon optimization. Ultimately, the desired expression in Escherichia coli was achieved after replacing the two conserved Cys residues of the deiodinase with Ala and fusing the resulting protein to thioredoxin. This final construct provided abundant enzyme for crystallography and mutagenesis. Utility of the E. coli system was demonstrated by examining a set of active site residues critical for binding to the zwitterionic portion of substrate.
Simulations of the p97 complex suggest novel conformational states of hydrolysis intermediates
Authors: Wereszczynski Jeff , McCammon J. Andrew
Published: January 2012

The vitally important AAA (ATPases associated with various cellular activities) protein p97 is involved in cellular functions ranging from replication to degradation of misfolded proteins and has recently been proposed as a novel chemotherapeutic target. p97 is a large molecular machine that has been shown to hexamerize in vitro, with each monomer consisting of an N domain responsible for binding to effector proteins and two AAA repeats (D1 and D2). However, structural studies are inconclusive or in disagreement with one another on several important features such as the locations of the N domains, the relative orientations of the D1 and D2 rings, and the dimensions of the central pore. Here, we present atomic‐scale simulations of the p97 hexamer in the prehydrolysis, transition, and post‐hydrolysis states. To improve the agreement between low‐ and high‐resolution experimental studies, we first use a biased simulation technique, molecular dynamics flexible fitting (MDFF), to improve the correlation between the structures described in these experiments. We follow this with extended, classical molecular dynamics simulations, which not only show that structures generated in the MDFF phase are stable, but reveal insights into the dynamics important to each state. Simulation results suggest a hybrid model for hydrolysis, in which the N and D2 domains are dynamic while the D1 domains are relatively static, salt bridges stabilize the position of the N domains in the pre‐hydrolysis state, and the rings formed by D1 and D2 rotate relative to one another.
Prediction of protein–protein binding free energies
Authors: Vreven Thom , Hwang Howook , Pierce Brian G. , Weng Zhiping
Published: January 2012

We present an energy function for predicting binding free energies of protein–protein complexes, using the three‐dimensional structures of the complex and unbound proteins as input. Our function is a linear combination of nine terms and achieves a correlation coefficient of 0.63 with experimental measurements when tested on a benchmark of 144 complexes using leave‐one‐out cross validation. Although we systematically tested both atomic and residue‐based scoring functions, the selected function is dominated by residue‐based terms. Our function is stable for subsets of the benchmark stratified by experimental pH and extent of conformational change upon complex formation, with correlation coefficients ranging from 0.61 to 0.66.
A Monte Carlo study of the spin polarization of secondary electrons
Authors: Mao S. F. , Sun X. , Fang X. W. , Da B. , Ding Z. J.
Published: January 2012

A spin‐involved Monte Carlo simulation model is developed to study the mechanism of the spin polarization of secondary electrons. The spin‐dependent mean free path asymmetry and the Stoner excitation are considered in modeling electron inelastic scattering, and the spin‐dependent excitation mechanism of cascade electrons is introduced according to the spin density of the state of a magnetism sample. The simulation has been performed for Ni and Fe. The simulated results, including secondary electron yields, secondary electron energy spectrum, and spin polarization of secondary electrons, are in good agreement with experimental results. According to the present simulation results, it is concluded that the high spin polarization of secondary electrons less than approximately 5 eV is inherently related to the cascade production process of secondary electrons; a more obvious effect of Stoner excitation is found for Ni but not for Fe because of the lack of unoccupied 3d states for spin‐majority electrons above the Fermi level for Ni. We have further studied the case that an unpolarized thin layer exists on Fe surface; the results show that the spin polarization of secondary electrons can be greatly affected at low primary energies. Copyright © 2012 John Wiley & Sons, Ltd.
A two‐stage Bayesian design for co‐development of new drugs and companion diagnostics
Authors: Karuri Stella Wanjugu , Simon Richard
Published: January 2012

Most new drug development in oncology is based on targeting specific molecules. Genomic profiles and deregulated drug targets vary from patient to patient making new treatments likely to benefit only a subset of patients traditionally grouped in the same clinical trials. Predictive biomarkers are being developed to identify patients who are most likely to benefit from a particular treatment; however, their biological basis is not always conclusive. The inclusion of marker‐negative patients in a trial is therefore sometimes necessary for a more informative evaluation of the therapy. In this paper, we present a two‐stage Bayesian design that includes both marker‐positive and marker‐negative patients in a clinical trial. We formulate a family of prior distributions that represent the degree of a priori confidence in the predictive biomarker. To avoid exposing patients to a treatment to which they may not be expected to benefit, we perform an interim analysis that may stop accrual of marker‐negative patients or accrual of all patients. We demonstrate with simulations that the design and priors used control type I errors, give adequate power, and enable the early futility analysis of test‐negative patients to be based on prior specification on the strength of evidence in the biomarker. Copyright © 2012 John Wiley & Sons, Ltd.
On the use of a linear microphone array to measure wind turbine aerodynamic noise
Authors: Genescà M. , Romeu J. , Pàmies T. , Solé J.
Published: January 2012

A linear microphone array is shown to be a simple tool to locate aerodynamic sound sources on a horizontal axis wind turbine. This paper discusses the capabilities and limitations of a linear microphone array to locate sound sources and measure aerodynamic noise on the blades of a horizontal axis wind turbine rotor. Compared with a planar microphone array, a linear array requires fewer microphones to achieve the same resolution, a simpler structure to support it and a simpler signal processing algorithm. For a linear array, areas exist in the rotor plane where the sources cannot be located unambiguously. For certain applications, it is not necessary to map the whole rotor plane. This paper also shows the result of an experimental test aimed at locating and measuring aerodynamic sound sources on the three blades of a wind turbine. Each blade received a different surface treatment, with the goal of comparing their relative sound emission levels. The test was carried out with a 10.32 m linear microphone array, placed horizontally near the ground, extending parallel to the rotor plane. The results show that for all three blades, most of the noise is generated in the outer 25% of the blade span, with a maximum occurring just after the blade has passed the horizontal position going downwards. Results also show that tripped blade is the noisiest of the three, whereas the smoothest, polished blade is clearly the quietest. Copyright © 2012 John Wiley & Sons, Ltd.
Omnipresent purinergic signaling: an editorial essay
Authors: Burnstock Geoffrey , Verkhratsky Alexei
Published: January 2012

WIREs Membr Transp Signal 2012, 1:113–115. doi: 10.1002/wmts.37

For further resources related to this article, please visit the WIREs website.
Distributed control of linearized Navier‐Stokes equations via discretized input/output maps
Authors: Heiland J. , Mehrmann V.
Published: January 2012

The construction of reduced order models for flow control via a direct discretization of the input/output behavior of the system is discussed. The spatially discretized equations are linearized such that an explicit formula for the corresponding input/output map can be used to generate a matrix representation of the input/output map. Estimates for the approximation error are derived and the applicability is illustrated via a numerical example for the control of a driven cavity flow.
Time Fractionation of Minor Lipids from Cold‐Pressed Rapeseed Cake Using Supercritical CO2
Authors: Uquiche Edgar , Fica Ximena , Salazar Katherine , del Valle José M.
Published: January 2012

This work explored the possibility of using supercritical carbon dioxide (SC‐CO2) to achieve fractionation of pre‐pressed rapeseed (Brassica napus) cake oil at 30–50 MPa, at 40 or 80 °C, and increase the concentration of minor lipids (sterols, tocopherols, carotenoids) in the oil. Minor lipids are partially responsible for desirable antioxidant effects that protect against degradation and impart functional value to the oil. The weight and concentration of minor lipids in oil fractions collected during the first 60 min were analyzed. Cumulative oil yield increased with pressure, and with temperature at ≥40 MPa, but was lower at 80 °C than at 40 °C when working at pressure ≤35 MPa. Differences in solubility between the oil and minor lipids explained fractionation effects that were small for tocopherols. Unlike tocopherols, which are more soluble in SC‐CO2 than the oil, sterols and carotenoids are less soluble than the oil, and their concentration increased in the later stages of extraction, particularly at ≥40 MPa, when there was not enough oil to saturate the CO2 phase. Because of the fractionating effects on rapeseed oil composition, there was an increase in the antioxidant activity of the oil in the second half as compared to the first half of the extraction. Consequently, this study suggests that SC‐CO2 extraction could be used to isolate vegetable oil fractions with increased functional value.
Varicocèle et infertilité masculine
Authors: Diao B. , Sy M. R. , Fall B. , Sow Y. , Sarr A. , Mohamed S. , Sine B. , Fall P. A. , Ndoye A. K. , Ba M. , Diagne B. A.
Published: January 2012

Introduction

La responsabilité de l’homme dans l’infertilité du couple est établie par plusieurs travaux. Le but de ce travail est de rapporter les aspects cliniques, spermiologiques de la varicocèle et d’évaluer les résultats de la varicocélectomie rétropéritonéale à ciel ouvert.

Patients et méthodes

Il s’agit d’une étude rétrospective évaluant les résultats de la varicocélectomie rétropéritonéale à ciel ouvert, dans le service d’urologie-andrologie du centre hospitalier et universitaire Aristide-Le-Dantec de Dakar, Sénégal. Nous nous sommes intéressés aux patients suivis pour infertilité du couple, porteurs de varicocèle et chez la (les) partenaire(s) de qui aucune autre cause d’infertilité n’a été décelée. Pour l’évaluation des résultats, nous avons comparé les moyennes des paramètres spermatiques pré-et postopératoires en utilisant le test Z (test de comparaison de deux moyennes sur deux séries appariées). Une différence était considérée comme significative si p inférieur ou égal à 0,05.

Résultats

Cinq cent quatorze dossiers ont été retenus au cours de l’exploitation sur une période de six ans (janvier 2005–décembre 2010). L’âge moyen de nos patients était de 36,5 ± 7,3 ans. L’infertilité était primaire dans 62,4 %. L’exploitation des spermogrammes préopératoires a permis de noter que l’oligozoospermie sévère (33,7 %) était associée à des degrés divers à une asthénozoospermie et à une thératozoospermie. Ces patients étaient suivis avec un recul moyen de 22 mois (6–48 mois). L’amélioration des paramètres spermatiques était significative, concernant la concentration et la mobilité des spermatozoïdes. Le taux de grossesses naturelles obtenu dans la série était de 20,8 %. Aucun cas de grossesse naturelle n’a été noté dans le groupe des patients présentant une azoospermie, mais une induction de la spermatogenèse a été notée dans 20,5 % des cas. Près de deux grossesses sur trois (64 %) ont été notées durant les 12 premiers mois postopératoires.

Conclusion

Le traitement chirurgical de la varicocèle permet d’améliorer les paramètres spermatiques, ce qui non seulement permet l’obtention de grossesses naturelles mais également de simplifier les techniques d’Assistance Médicale à la Procréation (AMP) prévues grâce aux nouveaux paramètres.
Drinking motives and alcoholic beverage preferences among Italian adolescents
Authors: Graziano Federica , Bina Manuela , Giannotta Fabrizia , Ciairano Silvia
Published: January 2012

Although drinking motives have been largely studied, research taking into account the Mediterranean drinking culture and focusing on motives specifically associated to adolescents' developmental tasks is lacking. For these reasons the study investigates drinking motives in a group of Italian adolescents and their relationships with drunkenness and high levels of alcohol consumption (wine, beer, spirits and alcopops). A self‐report questionnaire on drinking motives and amount of alcohol use was administered to 784 adolescents, boys (46%) and girls, ages 15–19. Using confirmatory factor analysis and stepwise logistic regressions, we found that: 1) motives for drinking were coping, conformity, self‐affirmation and experimentation‐transgression; 2) coping motives were positively related to the high consumption of all alcoholic beverages and to drunkenness; 3) conformity motives were negatively related to high beer consumption and drunkenness, while experimentation‐transgression motives were positively related to high alcopops consumption. Implications for prevention are discussed.
SNPs of hemocyanin C‐terminal fragment in shrimp Litopenaeus vannamei
Authors: Zhao Xianliang , Guo Lingling , Zhang Yueling , Liu Yao , Zhang Xiaoyu , Lun Jingsheng , Chen Jiehui , Li Yuanyou
Published: January 2012

In this study, we identified a variable region in the C‐terminus of hemocyanin from the shrimp Litopenaeus vannamei (2288–2503 bp, HcSC) by sequence alignments. A total of 13 SNPs were identified by PCR‐SSCP and HcSC clone sequencing. The SSCP patterns of HcSC could be modulated in Vibro parahaemolyticus‐treated shrimps. A novel SSCP band with four SNP sites was identified in V. parahaemolyticus‐resistant shrimps. More importantly, three of these four SNPs introduced variations in amino acid sequence and possibly secondary structure of the HcSC polypeptide and resulted in a higher agglutinative activity against seven pathogenic bacteria. These results suggest that the C‐terminus of shrimp L. vannamei hemocyanin possesses SNPs, which may be related to shrimp resistance to different pathogens.
QTL analysis of resistance to Mal de Río Cuarto disease in maize using recombinant inbred lines
Authors: BONAMICO N. C. , DI RENZO M. A. , IBAÑEZ M. A. , BORGHI M. L. , DÍAZ D. G. , SALERNO J. C. , BALZARINI M. G.
Published: January 2012

Mal de Río Cuarto (MRC) is a devastating disease that reduces yield, quality and economic value of maize in Argentina. The objective of the present study was to map quantitative trait loci (QTL) for reactions to MRC from recombinant inbred lines (RILs). Reactions to the endemic MRC disease were evaluated in 145 advanced F2:6lines, derived from a cross between a resistant (BLS14) and a susceptible (Mo17) line, at four environments in the temperate semi-arid crop region of Argentina. The evaluations of disease score (SCO), disease incidence (INC) and disease severity (SEV) were carried out on each individual RIL. Low heritability estimates were found across environments for SCO (0·23), INC (0·27) and SEV (0·22). A genetic map of simple sequence repeat (SSR) markers covering a total genetic distance of 1019 cM was built. QTL for resistance to MRC disease were found on different maize chromosomes. Four significant QTL, each explaining between 0·08 and 0·14 of the total phenotypic variation, were located on chromosomes 1, 4 and 10. Two QTL specific to the INC, and one specific to SEV, may be involved in different mechanisms of resistance to MRC. Although MRC reaction is highly affected by environmental effects, the QTL×environment interaction for INC and SEV was low. Most of the QTL for reaction to MRC detected in the present study were mapped to regions of the maize genome containing genes conferring resistance to various pathogens. The significant QTL across environments are good candidates to select for MRC resistance.
Cortisol levels and history of depression in acute coronary syndrome patients
Authors: Messerli-Bürgy N. , Molloy G. J. , Wikman A. , Perkins-Porras L. , Randall G. , Steptoe A.
Published: January 2012

Background

Depressed mood following an acute coronary syndrome (ACS) is a risk factor for future cardiac morbidity. Hypothalamic–pituitary–adrenal (HPA) axis dysregulation is associated with depression, and may be a process through which depressive symptoms influence later cardiac health. Additionally, a history of depression predicts depressive symptoms in the weeks following ACS. The purpose of this study was to determine whether a history of depression and/or current depression are associated with the HPA axis dysregulation following ACS.

Method

A total of 152 cardiac patients completed a structured diagnostic interview, a standardized depression questionnaire and a cortisol profile over the day, 3 weeks after an ACS. Cortisol was analysed using: the cortisol awakening response (CAR), total cortisol output estimated using the area under the curve method, and the slope of cortisol decline over the day.

Results

Total cortisol output was positively associated with history of depression, after adjustment for age, gender, marital status, ethnicity, smoking status, body mass index (BMI), Global Registry of Acute Cardiac Events (GRACE) risk score, days in hospital, medication with statins and antiplatelet compounds, and current depression score. Men with clinically diagnosed depression after ACS showed a blunted CAR, but the CAR was not related to a history of depression.

Conclusions

Patients with a history of depression showed increased total cortisol output, but this is unlikely to be responsible for associations between depression after ACS and later cardiac morbidity. However, the blunted CAR in patients with severe depression following ACS indicates that HPA dysregulation is present.
Nair–Tenenbaum bounds uniform with respect to the discriminant
Authors: HENRIOT KEVIN
Published: January 2012

For functionsFsatisfying a certain submultiplicativity condition and polynomialsQ1, . . .,Qkin[X], Nair and Tenenbaum obtained an upper bound on the short sum$\sum_{x < n \leq x+y} F(|Q_{1}(n)|,\dotsc,|Q_{k}(n)|)$with an implicit dependency on the discriminant ofQ1. . .Qk. We obtain a similar upper bound uniform in the discriminant.
Direct healthcare costs of selected diseases primarily or partially transmitted by water
Authors: COLLIER S. A. , STOCKMAN L. J. , HICKS L. A. , GARRISON L. E. , ZHOU F. J. , BEACH M. J.
Published: January 2012

Despite US sanitation advancements, millions of waterborne disease cases occur annually, although the precise burden of disease is not well quantified. Estimating the direct healthcare cost of specific infections would be useful in prioritizing waterborne disease prevention activities. Hospitalization and outpatient visit costs per case and total US hospitalization costs for ten waterborne diseases were calculated using large healthcare claims and hospital discharge databases. The five primarily waterborne diseases in this analysis (giardiasis, cryptosporidiosis, Legionnaires' disease, otitis externa, and non-tuberculous mycobacterial infection) were responsible for over 40 000 hospitalizations at a cost of $970 million per year, including at least $430 million in hospitalization costs for Medicaid and Medicare patients. An additional 50 000 hospitalizations for campylobacteriosis, salmonellosis, shigellosis, haemolytic uraemic syndrome, and toxoplasmosis cost $860 million annually ($390 million in payments for Medicaid and Medicare patients), a portion of which can be assumed to be due to waterborne transmission.
Sonic Menageries: Composing the sound of place
Authors: Chattopadhyay Budhaditya
Published: January 2012

This article investigates the essential association between location and sound, mediated and represented by the process of recording and the subsequent creation of an artwork. The basic argument this article would like to develop is that location-specific sound recording, as practised by artists and phonographers, is basically an exercise in disembodiment of sound from environment, whether it is observational or immersive in approach; if the purpose of this mediation by recording is artistically reconstructive, the location-specificity of the recorded sound is displaced by the further mediation of the creative process. By developing the argument from an experimental angle, in relation to an audio art projectLandscape in Metamorphoses, this article will try to examine how the discourse of acoustic ecology becomes reconfigured in the shift from environmental sound content recorded at location to production of soundscape composition as audio artwork. Today, the application of digital media to artistic practice has become integral – in the case of audio art via creation of auditory art works (for both spatial diffusion and live interaction); this can bring about a reconfiguration of environmental aesthetics. The article will find relevance in redesigning the ecological discourse in the digital realm of ‘soundscaping’ through the practice of mediation, as composing of the sound of location, or ‘place’.
Pedogenic carbonate formation: Recrystallization versus migration—Process rates and periods assessed by 14C labeling
Authors: Gocke Martina , Pustovoytov Konstantin , Kuzyakov Yakov
Published: January 2012

Under arid to semihumid climatic conditions, dissolution of primary carbonate and recrystallization with carbon (C) from soil CO2 leads to accumulation of significant amounts of pedogenic (secondary) carbonate. Most soils of arid and semiarid regions contain a carbonate accumulation horizon, the depth of which is related to climatic conditions and properties of parent material. It remains unclear whether this carbonate migrates from the upper horizons before or after recrystallization with soil CO2. The aim of this study was to determine recrystallization rates during initial pedogenesis and to estimate the accumulation depth of secondary carbonate based on C isotopic exchange during secondary carbonate formation in an experiment with alternating moisture conditions. Maize grown on 1 m high loess‐filled columns was pulse labeled in14CO2 atmosphere every 3 weeks. After 6 months, portions of secondary (recrystallized) CaCO3 were determined in 5 cm segments, based on 14C respired in the rhizosphere and subsequently incorporated into newly formed secondary carbonate. More than 80% of recrystallized carbonate (Ca14CO3) was leached from the uppermost 15 cm of the loess column, and more than 70% of total secondary carbonate were accumulated in a depth between 15 and 50 cm. Based on the recrystallization rate calculated for the uppermost 15 cm of the loess column (1.77 ± 0.26 ⋅ 10−5 day−1), between 300 and more than 1,700 years are necessary for complete decalcification of the upper 15 cm. Our modeled data are consistent with formation of calcic horizons under relatively humid conditions.
Influence of lithosphere‐asthenosphere interaction on the overriding lithosphere in a subduction zone: Numerical modeling
Authors: He Lijuan
Published: January 2012

Several factors influence the topography of the overriding plate in a subduction zone: mantle wedge flow caused by motion of the descending slab, lithosphere elasticity, and interaction between the solid lithosphere and the viscous asthenosphere. This paper presents the results of new subduction modeling that incorporates both elastic/elastoplastic deformation in the overriding plate and viscous deformation in the asthenosphere. The effects of fluid‐solid coupling and interaction were considered using an arbitrary Lagrangian‐Eulerian technique that solves for the continuous deformation of fluid flow in contact with the rigid plate. Modeling results show that thicker lithosphere, which is harder to deform, contributes to the development of broadly shallower back‐arc basins. As lithospheric strength decreases, its ability to withstand outside force (fluid load) resulting from flow in the mantle wedge also declines, leading to the development of deep and narrow basins. Large‐scale deformation of the lithosphere modifies both the mantle wedge geometry and the wedge flow pattern, which in turn increases the fluid load and thereby enhances topographic variation. Generally, the effect of interaction is enhanced with lithospheric deformation. The elastoplastic model also leads to a weaker lithosphere and a correspondingly larger deflection in the lithosphere. Similarly to previous studies, back‐arc basins are deeper when mantle viscosity is higher. For a 50 km thick elastic lithosphere, the lithosphere‐asthenosphere interaction is negligible when the asthenospheric viscosity is less than 4 × 1019 Pa s. Increasing the rate of subduction or decreasing the dip angle will also lead to the development of deeper basins.
Three‐dimensional dynamic rupture simulation with a high‐order discontinuous Galerkin method on unstructured tetrahedral meshes
Authors: Pelties Christian , de la Puente Josep , Ampuero Jean‐Paul , Brietzke Gilbert B. , Käser Martin
Published: January 2012

Accurate and efficient numerical methods to simulate dynamic earthquake rupture and wave propagation in complex media and complex fault geometries are needed to address fundamental questions in earthquake dynamics, to integrate seismic and geodetic data into emerging approaches for dynamic source inversion, and to generate realistic physics‐based earthquake scenarios for hazard assessment. Modeling of spontaneous earthquake rupture and seismic wave propagation by a high‐order discontinuous Galerkin (DG) method combined with an arbitrarily high‐order derivatives (ADER) time integration method was introduced in two dimensions by de la Puente et al. (2009). The ADER‐DG method enables high accuracy in space and time and discretization by unstructured meshes. Here we extend this method to three‐dimensional dynamic rupture problems. The high geometrical flexibility provided by the usage of tetrahedral elements and the lack of spurious mesh reflections in the ADER‐DG method allows the refinement of the mesh close to the fault to model the rupture dynamics adequately while concentrating computational resources only where needed. Moreover, ADER‐DG does not generate spurious high‐frequency perturbations on the fault and hence does not require artificial Kelvin‐Voigt damping. We verify our three‐dimensional implementation by comparing results of the SCEC TPV3 test problem with two well‐established numerical methods, finite differences, and spectral boundary integral. Furthermore, a convergence study is presented to demonstrate the systematic consistency of the method. To illustrate the capabilities of the high‐order accurate ADER‐DG scheme on unstructured meshes, we simulate an earthquake scenario, inspired by the 1992 Landers earthquake, that includes curved faults, fault branches, and surface topography.
In vivo Mesolimbic D2/3 Receptor Binding Predicts Posttherapeutic Clinical Responses in Restless Legs Syndrome: A Positron Emission Tomography Study
Authors: Oboshi Yumi , Ouchi Yasuomi , Yagi Shunsuke , Kono Satoshi , Nakai Noriyoshi , Yoshikawa Etsuji , Futatsubashi Masami , Terada Tatsuhiro , Kim Kang , Harada Kiyoshi
Published: January 2012

Although D2/3 agonists have been used as a first-line medication for idiopathic restless legs syndrome (iRLS), findings on D2/3 receptors have been inconsistent. Here, we aimed to clarify the contribution of D2/3 receptor function to the clinical symptoms of iRLS by comparing the binding potential (BPND) of [11C]raclopride with clinical improvements after D2/3 stimulation by pramipexole. Eight drug-naïve, iRLS patients and eight age-matched healthy subjects were scanned with positron emission tomography (PET). After PET scans, all patients received pramipexole (0.125 mg) orally for 2 weeks. Patients were evaluated every day with several standardized clinical tests. The BPND values were compared using regions of interest and voxel-based methods. Results showed that the mean magnitude of [11C]raclopride BPND in the mesolimbic dopamine region (nucleus accumbens (NA) and caudate) was significantly lower in the iRLS group. No significant differences between groups were observed in the putamen. The NA [11C]raclopride BPND levels correlated negatively with clinical severity scores and positively with the degree of posttreatment improvement in iRLS. The present results suggest that alterations in mesolimbic D2/3 receptor function reflect the pathophysiology of iRLS, and the baseline availability of D2/3 receptors may predict the clinical outcome after D2/3 agonist treatment.
Microwave-induced spin-flip scattering of electrons in point contacts
Authors: Kadigrobov A. M. , Shekhter R. I. , Aronov I. , Kulinich S. I. , Pulkin A. , Jonson M.
Published: January 2012

We investigate resonant interaction of conduction electrons with an electromagnetic field that irradiates a point contact between a ferromagnetic and a normal metal in the presence of a strong magnetic field of order 1 T. We show that electron spin-flips caused by resonant absorption and stimulated emission of photons result in a sharp peak in the magnetic-field dependence of the point-contact resistance. The height of the peak is shown to be directly proportional to the net rate of energy transfer to the electromagnetic field in the point contact due to absorption and stimulated emission of photons. Estimations indicate that our theory can serve as a basis for the explanation of recent experiments [A.M. Kadigrobov et al., New J. Phys. 13, 023007 (2011)].
Flux-cutting and flux-transport effects in type-II superconductor slabs in a parallel rotating magnetic field
Authors: Cortés-Maldonado R. , Espinosa-Rosales J. E. , Carballo-Sánchez A. F. , Pérez-Rodríguez F.
Published: January 2012

The magnetic response of irreversible type-II superconductor slabs subjected to in-plane rotating magnetic field is investigated by applying the circular, elliptic, extended-elliptic, and rectangular flux-line-cutting critical-state models. Specifically, the models have been applied to explain experiments on a PbBi rotating disk in a fixed magnetic field Ha, parallel to the flat surfaces. Here, we have exploited the equivalency of the experimental situation with that of a fixed disk under the action of a parallel magnetic field, rotating in the opposite sense. The effect of both the magnitude Ha of the applied magnetic field and its angle of rotation αs upon the magnetization of the superconductor sample is analyzed. When Ha is smaller than the penetration field HP, the magnetization components, parallel and perpendicular to Ha, oscillate with increasing the rotation angle. On the other hand, if the magnitude of the applied field, Ha, is larger than HP, both magnetization components become constant functions of αs at large rotation angles. The evolution of the magnetic induction profiles inside the superconductor is also studied.
Metafluid with anisotropic dynamic mass
Authors: Gumen L. N. , Arriaga J. , Krokhin A. A.
Published: January 2012

We show that a fluid filling the space between metallic cylinders arranged in a two-dimensional lattice exhibits anisotropic dynamic mass for sound waves propagating through the lattice, if its unit cell is anisotropic. Using the plane-waves expansion method we derive (in the long wavelength limit) a formula for the effective mass tensor of the metafluid. The proposed formula is very general—it is valid for arbitrary Bravais lattices and arbitrary filling fractions of the cylinders. We apply our method to a periodic structure with very high anisotropy, when other known methods fail. In particular, we calculate the effective mass tensor for sound waves in air with embedded lattice of aluminum cylinders having rectangular cross sections, and obtain excellent agreement with experiment. The proposed method of calculation may find numerous applications for tailoring of metafluids with prescribed anisotropy.
The influence of anisotropic gate potentials on the phonon induced spin-flip rate in GaAs quantum dots
Authors: Prabhakar Sanjay , Melnik Roderick V. N. , Bonilla Luis L.
Published: January 2012

We study the anisotropic orbital effect in the electric field tunability of the phonon induced spin-flip rate in quantum dots (QDs). Our study shows that anisotropic gate potential enhances the spin-flip rate and reduces the level crossing point to a lower QDs radius due to the suppression of the Landé g-factor towards bulk crystal. In the range of 104−106 V/cm, the electric field tunability of the phonon induced spin-flip rate can be manipulated through strong Dresselhaus spin-orbit coupling. These results might assist the development of a spin based solid state quantum computer by manipulating spin-flip rate through spin-orbit coupling in a regime where the g-factor changes its sign.
Identification of a silicon vacancy as an important defect in 4H SiC metal oxide semiconducting field effect transistor using spin dependent recombination
Authors: Cochrane C. J. , Lenahan P. M. , Lelis A. J.
Published: January 2012

A spin dependent recombination (SDR) spectrum observed in a wide range of SiC metal oxide semiconducting field effect transistors (MOSFETs) has previously been only tentatively linked to a silicon vacancy or vacancy related defect. By resolving hyperfine interactions in SDR detected spectra with 13C nuclei, we provide an extremely strong argument identifying the SDR spectrum with a silicon vacancy. Since the silicon vacancy spectrum dominates the SDR response in a wide variety of SiC MOSFETs, silicon vacancies are quite important traps in this technology.
Huge enhancement of optical nonlinearities in coupled Au and Ag nanoparticles induced by conjugated polymers
Authors: Polavarapu Lakshminarayana , Mamidala Venkatesh , Guan Zhenping , Ji Wei , Xu Qing-Hua
Published: January 2012

Exceptional optical limiting properties were observed in coupled Au and Ag nanoparticles that are induced by conjugated polymers. Fluence-dependent transmission measurements using 7-ns laser pulses of 532-nm wavelength showed that the optical limiting properties of Au and Ag nanoparticles were significantly enhanced upon assembly induced by addition of cationic conjugated polymers. The optical limiting performances of coupled Au and Ag nanoparticles (with optical limiting threshold as low as 2.8 J/cm2 and 2.6 J/cm2, respectively) are even better than that of the benchmark optical limiter-carbon nanotube suspensions (with threshold of 3.6 J/cm2). In addition, these coupled Au and Ag nanoparticle solutions are very stable and suitable for practical applications. Input fluence and angle-dependent scattering experiments suggested that nonlinear scattering should play an important role in the observed optical limiting effects.
Direct observation of magnetic phase coexistence and magnetization reversal in a Gd0.67Ca0.33MnO3 thin film
Authors: Kim Jeehoon , Haberkorn N. , Civale Leonardo , Nazaretski Evgeny , Dowden Paul , Saxena Avadh , Thompson J. D. , Movshovich Roman
Published: January 2012

We have investigated the ferrimagnetic domain structure in a Gd0.67Ca0.33MnO3 thin film using magnetic force microscopy. We observe clear signs of phase separation, with magnetic islands embedded in a non-magnetic matrix. We also directly visualize the reversal of magnetization of ferrimagnetic domains as a function of temperature and attribute it to a change in the balance of magnetization of anti-aligned Mn and Gd sublattices.
Controllable tunnel coupling and molecular states in a graphene double quantum dot
Authors: Wang Lin-Jun , Li Hai-Ou , Tu Tao , Cao Gang , Zhou Cheng , Hao Xiao-Jie , Su Zhan , Xiao Ming , Guo Guang-Can , Chang Albert M. , Guo Guo-Ping
Published: January 2012

We have measured a graphene double quantum dot device with multiple electrostatic gates that are used to enhance control to investigate it. At low temperatures, the transport measurements reveal honeycomb charge stability diagrams which can be tuned from weak to strong interdot tunnel coupling regimes. We precisely extract a large interdot tunnel coupling strength for this system allowing for the observation of tunnel-coupled molecular states extending over the whole double dot. This clean, highly controllable system serves as an essential building block for quantum devices in a nuclear-spin-free world.