bluuebunny/crossref_metadata_2025 huggingface dataset:
On Direct Numerical Simulation of Turbulent Flows
Authors: Alfonsi Giancarlo
Published: December 2011

The direct numerical simulation of turbulence (DNS) has become a method of outmost importance for the investigation of turbulence physics, and its relevance is constantly growing due to the increasing popularity of high-performance-computing techniques. In the present work, the DNS approach is discussed mainly with regard to turbulent shear flows of incompressible fluids with constant properties. A body of literature is reviewed, dealing with the numerical integration of the Navier-Stokes equations, results obtained from the simulations, and appropriate use of the numerical databases for a better understanding of turbulence physics. Overall, it appears that high-performance computing is the only way to advance in turbulence research through the front of the direct numerical simulation.
Power effect of ZnO:Al film as back reflector on the performance of thin-film solar cells
Authors: Lin Yang-Shih , Lien Shui-Yang , Wang Chao-Chun , Liu Chueh-Yang , Nautiyal Asheesh , Wuu Dong-Sing , Tsai Pi-Chuen , Chen Chia-Fu , Lee Shuo-Jen
Published: December 2011

Aluminum-doped zinc oxide (AZO) is attracting interest as a potential transparent conducting oxide material for use in amorphous silicon (a-Si) thin-film solar cells. The absorption loss in the n-a-Si:H/Ag interface of the p-i-n thin film solar is high because the extinction coefficient of the Ag that is used as a back reflector is high. In this work, transparent conducting AZO films with a power in the range 500 W to 900 W prepared under Ar-ambient at a substrate temperature of 25 °C by RF-magnetron in-line sputtering. To minimize the absorption loss at longer wavelengths, an AZO layer we inserted at the n-a-Si:H/Ag interface of a solar cell with a glass/SnO2:F/p-a-SiC:H/buffer-layer/i-a-Si:H/n-a-Si:H/Ag structure and the performance of the cell with AZO/Ag deposited instead of Ag on the back contact, was investigated. The effects of the RF-magnetron sputtering deposition parameters on the optical, electrical and structural properties of the AZO films were analyzed. Optimized AZO films with high transmittance (> 80%) and low resistivity (1.47 × 10−3 Ω-cm) in the wavelength range 400–800 nm were obtained under the sputtering conditions. The p-i-n a-Si solar cell with the AZO/Ag back contact had a conversion efficiency of 9.42%, which was higher than that (7.36%) of the cell without the AZO/Ag back contact. Light-soaking of these cells for 1000 h at 60 °C led to stabilization at 8.32% for the best cell. The relative typical efficiency degradation of about 10% for single-junction cells demonstrates that this treatment does not negatively influence stability.
Low temperature and roll-to-roll spatial atomic layer deposition for flexible electronics
Authors: Poodt Paul , Knaapen Raymond , Illiberi Andrea , Roozeboom Fred , van Asten Almie
Published: December 2011

Spatial atomic layer deposition can be used as a high-throughput manufacturing technique in functional thin film deposition for applications such as flexible electronics. This; however, requires low-temperature processing and handling of flexible substrates. The authors investigate the process conditions under which low-temperature spatial atomic layer deposition of alumina from trimethyl aluminum and water is possible. The water partial pressure is the critical parameter in this case. Finally, our approach to roll-to-roll spatial atomic layer deposition is discussed.
Neuronal Growth Cone Retraction Relies on Proneurotrophin Receptor Signaling Through Rac
Authors: Deinhardt Katrin , Kim Taeho , Spellman Daniel S. , Mains Richard E. , Eipper Betty A. , Neubert Thomas A. , Chao Moses V. , Hempstead Barbara L.
Published: December 2011

Whereas NGF promotes neurite outgrowth, the precursor form proNGF triggers neurite retraction.
How to Design a Better Antipsychotic?
Authors: Wong Wei
Published: December 2011

The effectiveness of antipsychotics may be related to their effect on signaling through a GPCR heteromer.
Summer Workshop in Metagenomics: One Week Plus Eight Students Equals Gigabases of Cloned DNA
Authors: Rios-Velazquez Carlos , Williamson Lynn L. , Cloud-Hansen Karen A. , Allen Heather K. , McMahon Mathew D. , Sabree Zakee L. , Donato Justin J. , Handelsman Jo
Published: December 2011

We designed a week-long laboratory workshop in metagenomics for a cohort of undergraduate student researchers. During this course, students learned and utilized molecular biology and microbiology techniques to construct a metagenomic library from Puerto Rican soil. Pre-and postworkshop assessments indicated student learning gains in technical knowledge, skills, and confidence in a research environment. Postworkshop construction of additional libraries demonstrated retention of research techniques by the students.
Designing Cancer-Killing Artificial Viruses to Improve Student Understanding of Microbiology
Authors: Kuniyuki Andy , Sharp Gwen
Published: December 2011

Our objective was to assess the effectiveness of a “learning by designing” group project used in a lower-division Microbiology course. Students used knowledge gained from the course to design an artificial virus that would kill cancer cells. The assignment required groups to integrate the individual course topics into a unified, complex understanding of the field of microbiology. Throughout the course, students and the instructor collaborated in creating a rubric to evaluate the groups’ final presentations. This paper reports the results of an assessment of the project by comparing the instructor’s and the students’ scores for the presentations. Students’ and the instructor’s scores were correlated; the Pearson coefficient of 0.52 was statistically significant. The results indicate that students gained sufficient knowledge to accurately evaluate proposed designs. Additionally, the overall course grade distribution improved compared to the semester before the project was introduced. Finally, in order to engage students in thinking about their own learning process, they completed a reflection assignment that required them to discuss the changes in their understanding of microbiology over the course of the semester. Our assessment indicates that a design project can serve as an effective and useful learning technique in undergraduate Microbiology courses, though modifications are suggested.
Bugs and Movies: Using Film to Teach Microbiology
Authors: Sánchez Manuel
Published: December 2011

A YouTube channel has been created to watch commented video fragments from famous movies or TV series that can be used to teach microbiology. Although microbes are usually depicted in terms of their roles in causing infectious disease, numerous movies reflect other scientific aspects, such as biotechnological applications or bioethical issues.
Authentic Active Learning Activities Demonstrating the Use of Serial Dilutions and Plate Counts
Authors: March Jordon K. , Jensen Kyle C. , Porter Nathan T. , Breakwell Donald P.
Published: December 2011

Serial dilution and plate counting is often taught in courses for both microbiology and allied health students. Lecture examples and examination questions addressing how the method is used can sometimes be contrived: artificial data sets may have little or no meaning other than to have students perform a calculation. Here we provide a set of activities employing data sets acquired from the primary literature. Our objective was to have the students think critically about a real scenario in which serial dilution and plate count was used. Each activity requires students to read a paragraph describing the study, predict the results, perform the appropriate calculations, and then evaluate the results in light of their predictions. To test the efficacy of these activities, a pretest quiz was given to approximately 100 students in an allied health/general microbiology course. After a lecture on how microbes are enumerated, students were given a different quiz. The class was then divided randomly into groups of three or four students and assigned one of the activities. A postactivity quiz was also administered. Approximately two weeks later, a serial dilution/plate count question was used on an examination and served as a final posttest. Standardized learning gains were calculated for the quiz administered after each learning activity. Even though learning gains were significantly higher after the lecture, there was also a significant improvement between the lecture and the activity. Using an exercise based on an authentic set of data significantly improved student learning gains, and is a useful practice for teaching microbiology.
Investigating How Streptococcus Responds to Their Environment: Bringing Together Current Research, a Case Study and Laboratory Investigation
Authors: Quimby B. Boots , McIver Kevin S. , Marbach-Ad Gili , Smith Ann C.
Published: December 2011

Understanding the link between course work and unanswered authentic research questions being explored in the research lab is an important goal in undergraduate science teaching. The activity presented here focuses on current research regarding the virulence characteristics of
Streptococcus pyogenes
particularly targeting the control of sugar uptake regulated via catabolite repression. Students were challenged to formulate a research question and use higher-order thinking skills to analyze data, work collaboratively to solve problems, and pose and test a hypothesis in the laboratory setting. The activity employed an interrupted case study approach using both online and face-to-face settings. The case story and problems were distributed online and were followed by in-class discussions and lab work. Aspects of the activity required independent thinking, as well as collaborative work. Student learning gains were demonstrated via comparison of pre- and postscores on the Host Pathogen Interactions (HPI) concept inventory, results from an end of semester Student Perception Survey, and from analysis of students’ work.
Using a Molecular-Genetic Approach to Investigate Bacterial Physiology in a Continuous, Research-Based, Semester-Long Laboratory for Undergraduates
Authors: Ault Jeremiah Foster , Renfro Betsey Marie , White Andrea Kirsten
Published: December 2011

Designing investigative laboratory exercises that encourage critical thinking, problem solving, and independent thought for upper-division biology courses is a difficult but worthwhile task. In an effort to do so, we developed a semester-long, continuous, research-based investigative laboratory that integrates numerous genetic and molecular biology methods into the investigation of a bacterial physiological process. In this lab, students use random Tn5 transposon mutagenesis to create prodigiosin pigment mutants in the bacterium,
Serratia marcescens
. This is followed by phenotypic characterization, cloning, and sequencing the Tn insertion site to identify genes involved in pigment biosynthesis. During this lab, students gain ample experience performing basic lab techniques while learning about — and applying — methods for elucidating gene function. The approach to the laboratory and the outcomes are intimately integrated into the teaching of many fundamental physiological processes underlying prodigiosin production in bacteria. The result is a cohesive course that integrates the theory and application of molecular genetic techniques with the study of bacterial physiology. Assessments of student learning objectives demonstrated that students greatly improved their understanding of both physiological processes and the genetic techniques used to investigate them. In addition, students felt that this semester-long exercise provided the necessary laboratory experience they needed and desired in preparation for careers in molecular biology, microbiology, and biochemistry.
The Big Picture: A Comparative Review of Several Interactive Web-Based Tools for Problem Analysis in Public Health
Authors: Fass Marion Field
Published: December 2011

Review of:
four web-based tools that complement courses in biology, public health, and global health, including:
Gapminder, HealthMap, Worldmapper, and Food Environment Atlas.
A Review of
Marine Microbiology: Ecology and Applications
Review of:
Marine Microbiology: Ecology and Applications,
2nd ed.; Colin Munn; (2011). Garland Science, Taylor and Francis Group, New York, NY. Paperback, 364 pages. ISBN 9780815365174.
Authors: Mixter Phil
Published: December 2011

Review of:
Marine Microbiology: Ecology and Applications, 2nd ed.;
Colin Munn; (2011). Garland Science, Taylor and Francis Group, New York, NY. Paperback, 364 pages. ISBN 9780815365174.
A Review of Microbiology: An Evolving Science, Second EditionReview of:
Microbiology: An Evolving Science,
2nd ed.; Joan L Slonczweski and John W. Foster; (2011). W.W. Norton & Company, New York NY. 1096 pages. ISBN: 978-0-393-93447-2.
Authors: May Barbara
Published: December 2011

Review of:
Microbiology: An Evolving Science,
2nd ed.; Joan L Slonczweski and John W. Foster; (2011). W.W. Norton & Company, New York NY. 1096 pages. ISBN: 978-0-393-93447-2.
Publication trends in newspapers and scientific journals for SSRIs and suicidality: a systematic longitudinal study
Authors: Hernandez J F , Mantel-Teeuwisse A K , van Thiel G J M W , Belitser S V , Raaijmakers J A M , Pieters T
Published: December 2011

Background

In the period 2003–2008, the regulatory authorities issued several warnings restricting the use of selective serotonin re-uptake inhibitors (SSRIs) in paediatrics, in reaction to safety concerns regarding the risk of suicidality. In this study, the SSRIs and suicidality controversy serves as a template to analyse the long-term publication trends regarding the benefit/risk profile of medications. The aim is to ascertain differences (in terms of numbers, categories and timing) between negative and positive newspaper and journal articles on SSRIs and suicidality and to ascertain correlations between changes in the reports and regulatory warnings.

Methods

A systematic review of scientific articles (Embase) and the Netherlands (NL) and the UK newspapers (LexisNexis) was performed between 2000 and 2010. Categorisation was done by ‘effect’ (related treatment effect), ‘type of article’ and ‘age group’. The articles' positive-to-negative effect ratio was determined. Differences in distribution of effect categories were analysed across sources, type of article and age group using the Mann–Whitney (two subgroups) or Kruskal–Wallis test (three or more).

Findings

In total, 1141 articles were categorised: 352 scientific, 224 Dutch and 565 British newspaper articles. Scientific articles were predominantly on research and were positive, whereas newspaper articles were negative (ratios=3.50—scientific, 0.69—NL and 0.94—UK; p<0.001). Articles on paediatrics were less positive in scientific journals and more negative in newspapers (ratios=2.29—scientific, 0.26—NL and 0.20—UK; p<0.001), while articles on adults were positive overall (ratios=10.0—scientific, 1.06—NL and 1.70—UK; p<0.001). In addition, negative-effect reporting trends were exacerbated following regulatory warnings and were generally opinion articles, both in scientific journals and in newspapers (2003/2004 and after 2007).

Interpretation

The authors found a positive publication tendency inherent in journal research articles. This apparent positive publication bias present in scientific journals, however, does not seem to prevent the dissemination of ‘bad’ news about medications. The negative tendency present in Dutch and British newspapers was perceivable in the paediatrics group and during the warnings, indicating that national news media have informed the public about this international drug safety controversy on time.
Validating the acute heart failure index for patients presenting to the emergency department with decompensated heart failure
Authors: Hsiao James , Motta Michelle , Wyer Peter
Published: December 2011

Background

The acute heart failure index (AHFI) is a previously derived prediction rule to identify patients presenting to emergency departments (ED) with decompensated heart failure (DHF) at low risk of early life-threatening events.

Study objectives

To validate the AHFI prospectively.

Methods

Using a prospective cohort study, adult patients presenting to an urban university hospital ED with DHF were included. Data on 21 variables were gathered to calculate the AHFI. Primary endpoints included inpatient death and non-fatal serious outcomes (myocardial infarction, ventricular fibrillation, cardiogenic shock, cardiac arrest, intubation, or cardiac reperfusion). Secondary endpoints included death from any cause or readmission for heart failure within 30 days. Primary and secondary endpoint rates were calculated with 95% CI for the low and higher-risk subgroups.

Results

259 patients were enrolled. 245/259 (95%) were admitted. 60/259 (23%) met low-risk criteria, of whom 1/60 (1.7%, CI 0.04 to 8.9) was discharged after sustaining pulseless electrical activity arrest. The comparable primary outcome rate in the derivation study was 1.4% (CI 1.1 to 1.7). 17/199 (8.5%, CI 5.1 to 13.3) higher-risk patients experienced an endpoint, compared with 13.3% (CI 12.9 to 13.7) in the derivation cohort. One low-risk patient (1.7%, CI 0.04 to 8.9) died within 30 days, and five (8.3%, CI 2.8 to 18.4) were readmitted. Corresponding rates in the derivation study were 2% and 5%, respectively.

Conclusion

The results are consistent with those previously reported for the low-risk subgroup of the AHFI. Further research is needed to determine the impact, safety and full range of generalisability of the AHFI as an adjunct to decision making.
Migrating husbands and changing cardiovascular risk factors in the wife: a cross sectional study in Asian Indian women
Authors: Gupta Rajeev , Gupta Rajiv , Agrawal Aachu , Misra Anoop , Guptha Soneil , Pandey Ravindra M , Misra Puneet , Vikram Naval K , Dey Sanjit , Rao Shobha , Menon V Usha , Kamalamma N , Revathi K , Mathur Beena , Sharma Vinita
Published: December 2011

Objective

The authors studied the influence of migration of husband on cardiovascular risk factors in Asian Indian women.

Methods

Population-based studies in women aged 35–70 years were performed in four urban and five rural locations. 4608 (rural 2604 and urban 2004) of the targeted 8000 (57%) were enrolled. Demographic details, lifestyle factors, anthropometry, fasting glucose and cholesterol were measured. Multivariate logistic and quadratic regression was performed to compare influence of migration and its duration on prevalence of risk factors.

Results

Details of migration were available in 4573 women (rural 2267, rural–urban migrants 455, urban 1552 and urban–rural migrants 299). Majority were married, and illiteracy was high. Median (interquartile) duration of residence in urban locations among rural–urban migrants was 9 (4–18) years and in rural areas for urban–rural migrants 23 (18–30) years. In rural, rural–urban migrants, urban and urban–rural migrants, age-adjusted prevalence (%) of risk factors was tobacco use 41.9, 22.7, 18.8 and 38.1; sedentary lifestyle 69.7, 82.0, 79.9 and 74.6; high-fat diet 33.3, 54.2, 66.1 and 61.1; overweight 21.3, 42.7, 46.3 and 29.7; large waist 8.5, 38.5, 29.2 and 29.2; hypertension 30.4, 49.4, 47.7 and 38.4; hypercholesterolaemia 14.4, 31.3, 26.6 and 9.1 and diabetes 3.9, 15.8, 14.9 and 8.4, respectively (p<0.001). In rural–urban migrants, there was a significant correlation of duration of migration with waist size, waist-to-hip ratio and systolic blood pressure (quadratic regression, p<0.001). Association of risk factors with migration remained significant, though attenuated, after adjustment for socioeconomic, lifestyle and obesity variables (logistic regression, p<0.01).

Conclusions

Compared with rural women, rural–urban migrants and urban have significantly greater cardiometabolic risk factors. Prevalence is lower in urban–rural migrants. There is significant correlation of duration of migration with obesity and blood pressure. Differences are attenuated after adjusting for social and lifestyle variables.
A TWO-LEVEL MULTISCALE DECONVOLUTION METHOD FOR THE LARGE EDDY SIMULATION OF TURBULENT FLOWS
Authors: DUNCA ARGUS ADRIAN
Published: December 2011

This report presents a novel continuous deconvolution method which is used to solve the closure problem in Large Eddy Simulation (LES for short) leading to a new LES model. In the deconvolution method described herein the flow velocities u are approximated by their average ũ on a fine intermediate length scale γ and then, by means of an exact extrapolation formula, expressed in terms of the averaged flow ū on the length scale α, which we seek to resolve. We prove existence, uniqueness and regularity of the weak solution w(α, γ) of the resulting LES models as well as energy estimates of the weak solution that are uniform in the intermediate length scale γ of the deconvolution procedure. We show also that the modeling error ‖ū - w(α, γ)‖ is driven only by the deconvolution error ‖u - ũ‖ and is independent of the resolved scale α.
COUPLING HETEROGENEOUS MULTISCALE FEM WITH RUNGE–KUTTA METHODS FOR PARABOLIC HOMOGENIZATION PROBLEMS: A FULLY DISCRETE SPACETIME ANALYSIS
Authors: ABDULLE ASSYR , VILMART GILLES
Published: December 2011

Numerical methods for parabolic homogenization problems combining finite element methods (FEMs) in space with Runge–Kutta methods in time are proposed. The space discretization is based on the coupling of macro and micro finite element methods following the framework of the Heterogeneous Multiscale Method (HMM). We present a fully discrete analysis in both space and time. Our analysis relies on new (optimal) error bounds in the norms L2(H1), [Formula: see text], and [Formula: see text] for the fully discrete analysis in space. These bounds can then be used to derive fully discrete spacetime error estimates for a variety of Runge–Kutta methods, including implicit methods (e.g. Radau methods) and explicit stabilized method (e.g. Chebyshev methods). Numerical experiments confirm our theoretical convergence rates and illustrate the performance of the methods.
SYSTEM IDENTIFICATION IN TUMOR GROWTH MODELING USING SEMI-EMPIRICAL EIGENFUNCTIONS
Authors: COLIN THIERRY , IOLLO ANGELO , LOMBARDI DAMIANO , SAUT OLIVIER
Published: December 2011

A tumor growth model based on a parametric system of partial differential equations is considered. The system corresponds to a phenomenological description of a multi-species population evolution. A velocity field taking into account the volume increase due to cellular division is introduced and the mechanical closure is provided by a Darcy-type law. The complexity of the biological phenomenon is taken into account through a set of parameters included in the model that need to be calibrated. To this end, a system identification method based on a low-dimensional representation of the solution space is introduced. We solve several idealized identification cases corresponding to typical situations where the information is scarce in time and in terms of observable fields. Finally, applications to actual clinical data are presented.
NUMERICAL EXPLORATION OF A FORWARD–BACKWARD DIFFUSION EQUATION
Authors: LAFITTE P. , MASCIA C.
Published: December 2011

We analyze numerically a forward–backward diffusion equation with a cubic-like diffusion function — emerging in the framework of phase transitions modeling — and its "entropy" formulation determined by considering it as the singular limit of a third-order pseudo-parabolic equation. Precisely, we propose schemes for both the second- and the third-order equations, we discuss the analytical properties of their semi-discrete counterparts and we compare the numerical results in the case of initial data of Riemann type, showing strengths and flaws of the two approaches, the main emphasis being given to the propagation of transition interfaces.
EVALUATION OF THE MAGNITUDE OF PISTONING MOTION OF THE BELOW KNEE PROSTHESES
Authors: KARIMI MOHAMMAD TAGHI , ABTAHI FAHIMOSSADAT
Published: December 2011

The incidence of amputation varies between 2.8 and 43.9 per 100,000 of population. Nearly 43% of the lower limb amputations are below knee amputee. One of the prosthesis which has being used for transtibial is patellar-tendon-bearing prosthesis (PTB) developed in the Biomechanics laboratory of California University. It is made of socket, foot and suspension system. The main role of the suspension system is to minimize the motion occurring between residual limb and prosthesis. Any failures in the function of the suspension system increase the interface motion between stump and socket and lead to troubling issues for the prosthesis users. It is not clearly defined which types of suspension systems of this prosthesis have better performance to decrease the pistoning motions. Therefore, the aim of this research was to evaluate the effects of using different kinds of suspension systems on the magnitude of pistoning motion and also on the functional performance of the below knee prosthesis.

Method: A group of 51 below knee amputee participated in this study. The main criteria for selecting the patients were having no contraindications for standing and walking with prosthesis and using the current prosthesis for at least one year. In order to evaluate the efficiency of suspension system on pistoning movement, the distance between some fixed markers on the prosthesis was measured under various weight bearing conditions.

Results: The correlation between the amount of pistoning movement and the type of suspension system was not significant. However, the function of the supracondylar strap and PTB total contact was better than other systems. The amount of pistoning movement differed between left and right sides.

Conclusion: The magnitude of pistoning motion of the stump is not influenced by the type of selected suspension system and the stump length.
ESTIMATION OF ANKLE JOINT ANGLE FROM PERONEAL AND TIBIAL ELECTRONEUROGRAMS — A MUSCLE SPINDLE MODEL APPROACH
Authors: CHAN CHING-CHAO , LIN CHOU-CHING K. , JU MING-SHAUNG
Published: December 2011

This study develops a method for estimating the angle of a passively stretched ankle joint from electroneurograms (ENGs) based on structural muscle spindle models of the tibial and peroneal nerves. Passive ramp-and-hold and alternating stretches of the ankle joint are performed on an anesthetized rabbit. Two cuff electrodes are employed to measure the ENGs of peroneal and tibial nerves simultaneously. From the two ENG signals and the joint angle trajectory, two intrafusal muscle fiber models are constructed and their inverse models are derived. The results of the two models are combined to generate the final angle estimate. An optimization method, called sequential quadratic programming, is employed to find the model parameters that minimize the squared errors between the ankle angles predicted by the model and the measured ankle angles. The performance of the proposed approach is compared with those of an adaptive neuro-fuzzy inference system and an artificial neural network model. The results reveal that the proposed model has the best performance in estimating the ankle joint angle in large-range movements and the smallest tracing error. The proposed method effectively estimates the passive ankle joint angle using the inverse physiological model of an intrafusal muscle fiber.
THE INFLUENCE OF WALL COMPLIANCE ON FLOW PATTERN IN A CURVED ARTERY EXPOSED TO A DYNAMIC PHYSIOLOGICAL ENVIRONMENT: AN ELASTIC WALL MODEL VERSUS A RIGID WALL MODEL
Authors: WANG XIAOHONG , LI XIAOYANG
Published: December 2011

Plenty of well-established medical research works have shown that many vascular diseases such as stenosis and atherosclerosis are prone to appear in curved arteries. In this paper, we investigated the influence of wall compliance on flow pattern in curved arteries exposed to dynamic physiological environments in order to understand the hemodynamic mechanism and provide a basis for clinical research in related areas. Representative curved arteries with elastic and rigid walls are constructed by computers. The fluid-structure interaction (FSI) effect is considered in our calculations. Physiological velocity profile is assigned as the inlet boundary condition. No-slip boundary condition is applied at the blood-wall interface. Our results show that the maximum axial velocity in the rigid wall model is larger than that in the elastic wall model. Wall compliance also has a remarkable effect on backflow patterns. Significant differences in pressure distribution are found between the elastic and rigid wall models. Blood strain rate distribution patterns in the two models were also compared. It was interesting to discover that in the straight part of the artery, the flexible wall made the counter-rotating vortices induced by the curvature gradually disappear along a downstream direction. However, for the flow feature in the rigid wall model, strong vortices existed throughout the entire straight part of the artery. It revealed that the increment of wall rigidity results in a reduction in wall movement capacity, thus affecting the physiological function of the arterial wall, making it incapable of effectively regulating the flow pattern inside the artery. The current work indicates that the influence of wall compliance on flow pattern in curved artery is significant.
HETEROATOM EFFECTS ON THE TRIAFLUAVENE AND HEAVIER ANALOGUES, XC5H4AND XC5H3(X =C,Si,Ge,N,P, ANDAs): DFT CALCULATIONS
Authors: VESSALLY ESMAIL , BASHARZAD SAMANEH FATEH , MOTALLEBZADEH MARYAM , EDJLALI LADAN
Published: December 2011

DFT calculations were carried out on molecular structure of triafluavenes and their heavier analogues, X C5H4and X C5H3; 1Xand 2X(X = C , Si , Ge , N , P , and As ); by using B3LYP/6-311++G** and MP2/6-311++G** //B3LYP/6-311++G** levels of theory with the Gaussian 03 program. The thermal energies (E), enthalpies (H), and free Gibbs energies (G) of 1Xand 2Xwere calculated. The geometrical parameters, natural bonding orbital charge at atoms HOMO and LUMO, the chemical hardness (η), chemical potential (μ), electrophilicity (ω), and the maximum amount of electronic charge, ΔNmax, were obtained. The NICS calculations were preformed for both rings of 1Xas well as 2Xdue to determination of the aromatic character of each rings. Molecular electrostatic potential maps were plotted and the infrared and ultraviolet spectra were calculated for 1Xand 2X.
AB INITIOSTUDY OF SPECTROSCOPIC CONSTANTS AND ANHARMONIC FORCE FIELD OFAsH2RADICAL
Authors: GUO YURONG , WANG MEISHAN , YANG CHUANLU , SUN YUTING , ZHU ZILIANG
Published: December 2011

The equilibrium structure, spectroscopic constants and anharmonic force field of AsH2have been investigated at B3LYP, B3PW91 and MP2 methods employing the basis sets of cc-pVNZ and aug-cc-pVNZ (N ∈ { T , Q }), respectively. The computed geometries, rotational constants, part of vibrational frequencies, quartic and sextic centrifugal distortion constants are compared with the available experimental data or theoretical results. The other vibrational frequencies, equilibrium rotational constants, anharmonic constants, vibration–rotation interaction constants, cubic and quartic force constants of AsH2are also predicted for the first time. Furthermore, the calculated results show that the DFT method is superior to MP2 at the calculations of geometries, spectroscopic constants and force constants. The B3PW91/aug-cc-pVQZ results are more reliable. Our predictions can provide useful data for the experimental studies of the corresponding spectroscopic constants of AsH2.
EFFECTS OF STRUCTURAL MODIFICATION ON THE GROUND STATE OF METALLABENZENES: SINGLET VERSUS TRIPLET STATE
Authors: LIN MINGLIAN , LI PENGFEI , CAO ZEXING
Published: December 2011

Extensive density functional calculations were used to explore the geometries and relative stabilities of metallabenzenes with various spin multiplicities. The structural modification effects on the energy splittings between the singlet and triplet states, including the replacement of metal, the change of ligand environment, and the substitution of hydrogen and carbon atoms in the aromatic ring, were investigated. Calculations show that the stability of the singlet and triplet metallabenzenes strongly depends on the metal center, and the first-row transition metal metallabenzenes most probably have the triplet ground state. The stability of the triplet state can be enhanced by the strong π- and weak-field ligands as well as the electron-withdrawing substituent for hydrogen at the aromatic carbon such as - PPh3+ . Present results can help us understand the magnetic properties of metallabenzenes and construct the function-orientated metallacyclic compounds.
THREE-QUBIT QUANTUM ENTANGLEMENT FOR SI (S = 3/2, I = 1/2) SPIN SYSTEM
Authors: GÜN A. , GENÇTEN A.
Published: December 2011

In quantum information processing, spin-3/2 electron or nuclear spin states are known as two-qubit states. For SI (S = 3/2, I = 1/2) spin system, there are eight three-qubit states. In this study, first, three-qubit CNOT logic gates are obtained. Then three-qubit entangled states are obtained by using the matrix representation of Hadamard and three-qubit CNOT logic gates. By considering single 31P@C60 molecule as SI (S = 3/2, I = 1/2) spin system, three-qubit entangled states are also obtained using the magnetic resonance pulse sequences of Hadamard and CNOT logic gates.
NON-MARKOVIAN OPEN QUANTUM SYSTEMS: SYSTEM–ENVIRONMENT CORRELATIONS IN DYNAMICAL MAPS
Authors: RODRÍGUEZ-ROSARIO CÉSAR A. , SUDARSHAN E. C. G.
Published: December 2011

We construct a non-Markovian dynamical map that accounts for systems correlated to the environment. We refer to it as a canonical dynamical map, which forms an evolution family. The relationship between inverse maps and correlations with the environment is established. The mathematical properties of complete positivity is related to classical correlations, according to quantum discord, between the system and the environment. A generalized non-Markovian master equation is derived from the canonical dynamical map.
GLOBAL QUANTUM CORRELATIONS IN THE ISING MODEL
Authors: CAMPBELL STEVE , MAZZOLA LAURA , PATERNOSTRO MAURO
Published: December 2011

We study quantum correlations in an isotropic Ising ring under the effects of a transverse magnetic field. After characterizing the behavior of two-spin quantum correlations, we extend our analysis to global properties of the ring, using a figure of merit for quantum correlations that shows enough sensitivity to reveal the drastic changes in the properties of the system at criticality. This opens up the possibility to relate statistical properties of quantum many-body systems to suitably tailored measures of quantum correlations that capture features going far beyond standard quantum entanglement.
Indium as a central metal enhances the photosensitizing efficacy of benzoporphyrin derivatives
Authors: Saenz Courtney , Ethirajan Manivannan , Iacobucci Gary , Pandey Ankit , Missert Joseph R. , Dobhal Mahabeer P. , Pandey Ravindra K.
Published: December 2011

Compared to benzoporphyrin derivative-dimethyl ester (BPD-DME) and its 8-(1′-hexyloxy)ethyl analog the corresponding In(III) complexes showed enhanced in vitro photosensitizing efficacy in Colon26 tumor cells, which could be due to their higher singlet oxygen producing ability. In both organic (methanol) and aqueous Bovine Calf Serum (17% BCS) solutions the metalated analogs were significantly more stable than the parent photosensitizers. Presence of Indium as a central metal gave 13–25 nm hypsochromic shift to the long wavelength absorption band with reduced absorption and fluorescence intensity. The insertion of metal did not produce any difference in intracellular localization of the photosensitizers and were mainly localized in mitochondria.
Glucocorticoid acts on a putative G protein-coupled receptor to rapidly regulate the activity of NMDA receptors in hippocampal neurons
Authors: Zhang Yanmin , Sheng Hui , Qi Jinshun , Ma Bei , Sun Jihu , Li Shaofeng , Ni Xin
Published: December 2011

Glucocorticoids (GCs) have been demonstrated to act through both genomic and nongenomic mechanisms. The present study demonstrated that corticosterone rapidly suppressed the activity of N-methyl-d-aspartate (NMDA) receptors in cultured hippocampal neurons. The effect was maintained with corticosterone conjugated to bovine serum albumin and blocked by inhibition of G protein activity with intracellular GDP-β-S application. Corticosterone increased GTP-bound Gsprotein and cyclic AMP (cAMP) production, activated phospholipase Cβ3(PLC-β3), and induced inositol-1,4,5-triphosphate (IP3) production. Blocking PLC and the downstream cascades with PLC inhibitor, IP3receptor antagonist, Ca2+chelator, and protein kinase C (PKC) inhibitors prevented the actions of corticosterone. Blocking adenylate cyclase (AC) and protein kinase A (PKA) caused a decrease in NMDA-evoked currents. Application of corticosterone partly reversed the inhibition of NMDA currents caused by blockage of AC and PKA. Intracerebroventricular administration of corticosterone significantly suppressed long-term potentiation (LTP) in the CA1 region of the hippocampus within 30 min in vivo, implicating the possibly physiological significance of rapid effects of GC on NMDA receptors. Taken together, our results indicate that GCs act on a putative G protein-coupled receptor to activate multiple signaling pathways in hippocampal neurons, and the rapid suppression of NMDA activity by GCs is dependent on PLC and downstream signaling.
The anorexigenic cytokine ciliary neurotrophic factor stimulates POMC gene expression via receptors localized in the nucleus of arcuate neurons
Authors: Couvreur Odile , Aubourg Alain , Crépin Delphine , Degrouard Jéril , Gertler Arieh , Taouis Mohammed , Vacher Claire-Marie
Published: December 2011

Ciliary neurotrophic factor (CNTF) is a neural cytokine that reduces appetite and body weight when administrated to rodents or humans. We have demonstrated recently that the level of CNTF in the arcuate nucleus (ARC), a key hypothalamic region involved in food intake regulation, is positively correlated with protection against diet-induced obesity. However, the comprehension of the physiological significance of neural CNTF action was still incomplete because CNTF lacks a signal peptide and thus may not be secreted by the classical exocytosis pathways. Knowing that CNTF distribution shares similarities with that of its receptor subunits in the rat ARC, we hypothesized that CNTF could exert a direct intracrine effect in ARC cells. Here, we demonstrate that CNTF, together with its receptor subunits, translocates to the cell nucleus of anorexigenic POMC neurons in the rat ARC. Furthermore, the stimulation of hypothalamic nuclear fractions with CNTF induces the phosphorylation of several signaling proteins, including Akt, as well as the transcription of the POMC gene. These data strongly suggest that intracellular CNTF may directly modulate POMC gene expression via the activation of receptors localized in the cell nucleus, providing a novel plausible mechanism of CNTF action in regulating energy homeostasis.
Increased shelterin mRNA expression in peripheral blood mononuclear cells and skeletal muscle following an ultra-long-distance running event
Authors: Laye Matthew J. , Solomon Thomas P. J. , Karstoft Kristian , Pedersen Karin K. , Nielsen Susanne D. , Pedersen Bente K.
Published: December 2011

Located at the end of chromosomes, telomeres are progressively shortened with each replication of DNA during aging. Integral to the regulation of telomere length is a group of proteins making up the shelterin complex, whose tissue-specific function during physiological stress is not well understood. In this study, we examine the mRNA and protein levels of proteins within and associated with the shelterin complex in subjects ( n = 8, mean age = 44 yr) who completed a physiological stress of seven marathons in 7 days. Twenty-two to 24 h after the last marathon, subjects had increased mRNA levels of DNA repair enzymes Ku70 and Ku80 ( P < 0.05) in both skeletal muscle and peripheral blood mononuclear cells (PBMCs). Additionally, the PBMCs displayed an increment in three shelterin protein mRNA levels (TRF1, TRF2, and Pot-1, P < 0.05) following the event. Seven days of ultrarunning did not result in changes in mean telomere length, telomerase activity, hTert mRNA, or hterc mRNAs found in PBMCs. Higher protein concentrations of TRF2 were found in skeletal muscle vs. PBMCs at rest. Mean telomere length in skeletal muscle did not change and did not contain detectable levels of htert mRNA or telomerase activity. Furthermore, changes in the PBMCs could not be attributed to changes in the proportion of subtypes of CD4+ or CD8+ cells. We have provided the first evidence that, in humans, proteins within and associated with the shelterin complex increase at the mRNA level in response to a physiological stress differentially in PBMCs and skeletal muscle.
Effects of ambient pressure on pulmonary nitric oxide
Authors: Hemmingsson Tryggve E. , Linnarsson Dag , Frostell Claes , Van Muylem Alain , Kerckx Yannick , Gustafsson Lars E.
Published: December 2011

Airway nitric oxide (NO) has been proposed to play a role in the development of high-altitude pulmonary edema. We undertook a study of the effects of acute changes of ambient pressure on exhaled and alveolar NO in the range 0.5–4 atmospheres absolute (ATA, 379–3,040 mmHg) in eight healthy subjects breathing normoxic nitrogen-oxygen mixtures. On the basis of previous work with inhalation of low-density helium-oxygen gas, we expected facilitated backdiffusion and lowered exhaled NO at 0.5 ATA and the opposite at 4 ATA. Instead, the exhaled NO partial pressure (PeNO) did not differ between pressures and averaged 1.21 ± 0.16 (SE) mPa across pressures. As a consequence, exhaled NO fractions varied inversely with pressure. Alveolar estimates of the NO partial pressure differed between pressures and averaged 88 ( P = 0.04) and 176 ( P = 0.009) percent of control (1 ATA) at 0.5 and 4 ATA, respectively. The airway contribution to exhaled NO was reduced to 79% of control ( P = 0.009) at 4 ATA. Our finding of the same PeNO at 0.5 and 1 ATA is at variance with previous findings of a reduced PeNO with inhalation of low-density gas at normal pressure, and this discrepancy may be due to the much longer durations of low-density gas breathing in the present study compared with previous studies with helium-oxygen breathing. The present data are compatible with the notion of an enhanced convective backtransport of NO, compensating for attenuated backdiffusion of NO with increasing pressure. An alternative interpretation is a pressure-induced suppression of NO formation in the airways.
Analysis of early C2C12 myogenesis identifies stably and differentially expressed transcriptional regulators whose knock-down inhibits myoblast differentiation
Authors: Rajan Saravanan , Dang Huan Chu Pham , Djambazian Haig , Zuzan Harry , Fedyshyn Yaroslav , Ketela Troy , Moffat Jason , Hudson Thomas J. , Sladek Rob
Published: December 2011

Myogenesis is a tightly controlled process involving the transcriptional activation and repression of thousands of genes. Although many components of the transcriptional network regulating the later phases of myogenesis have been identified, relatively few studies have described the transcriptional landscape during the first 24 h, when myoblasts commit to differentiate. Through dense temporal profiling of differentiating C2C12 myoblasts, we identify 193 transcriptional regulators (TRs) whose expression is significantly altered within the first 24 h of myogenesis. A high-content shRNA screen of 77 TRs involving 427 stable lines identified 42 genes whose knockdown significantly inhibits differentiation of C2C12 myoblasts. Of the TRs that were differentially expressed within the first 24 h, over half inhibited differentiation when knocked down, including known regulators of myogenesis ( Myod1, Myog, and Myf5), as well as 19 TRs not previously associated with this process. Surprisingly, a similar proportion (55%) of shRNAs targeting TRs whose expression did not change also inhibited C2C12 myogenesis. We further show that a subset of these TRs inhibits myogenesis by downregulating expression of known regulatory and structural proteins. Our findings clearly illustrate that several TRs critical for C2C12 myogenesis are not differentially regulated, suggesting that approaches that focus functional studies on differentially-expressed transcripts will fail to provide a comprehensive view of this complex process.
Influence of atrial fibrillation on microRNA expression profiles in left and right atria from patients with valvular heart disease
Authors: Cooley Nicola , Cowley Mark J. , Lin Ruby C. Y. , Marasco Silvana , Wong Chiew , Kaye David M. , Dart Anthony M. , Woodcock Elizabeth A.
Published: December 2011

Chronic atrial fibrillation (AF) is a complication associated with the dilated atria of patients with valvular heart disease and contributes to worsened pathology. We examined microRNA (miRNA) expression profiles in right and left atrial appendage tissue from valvular heart disease (VHD) patients. Right atrial (RA) appendage from patients undergoing coronary artery bypass grafting and left atrial (LA) appendage from healthy hearts, not used for transplant, were used as controls. There was no detectable effect of chronic AF on miRNA expression in LA tissue, but miRNA expression in RA was strongly influenced by AF, with 47 miRNAs (15 higher, 32 lower) showing differential expression between the AF and control sinus rhythm groups. VHD induced different changes in miRNA expression in LA compared with RA. Fifty-three (12 higher, 41 lower) miRNAs were altered by VHD in LA, compared with 5 (4 higher, 1 lower) in RA tissue. miRNA profiles also differed between VHD-LA and VHD-RA (13 higher, 26 lower). We conclude that VHD and AF influence miRNA expression patterns in LA and RA, but these are affected differently by disease progression and by the development of AF. These findings provide new insights into the progression of VHD.
Numerical Modeling and Experimental Investigation of the Nonlinear Polarization Rotation Phenomenon in Semiconductor Optical Amplifiers
Authors: Said Youssef , Rezig Houria
Published: December 2011

The focus of this paper is to analyze in detail the nonlinear polarization rotation phenomenon in the Semiconductor Optical Amplifier (SOA) according to the injection conditions. To this end, we have developed a numerical model based on the coupled mode theory and the formalism of Stokes. The obtained results are in agreement with the experimental measurements that have been carried out in free space, which allows optimum control and preservation of the polarization state of the injected and collected signals.
Precipitation of Zinc Oxide Nanoparticles in Bicontinuous Microemulsions
Authors: Romo Liliana E. , Saade Hened , Puente Bertha , López Ma. Luisa , Betancourt Rebeca , López Raúl G.
Published: December 2011

Zinc oxide nanoparticles were obtained directly, avoiding the calcination step, by precipitation at 70°C in bicontinuous microemulsions stabilized with a mixture of surfactants sodium bis (2-ethylhexyl) sulfosuccinate/sodium dodecyl sulfate (2/1, wt./wt.) containing 0.7 M zinc nitrate aqueous solution. Two concentrations of aqueous solution of precipitating agent sodium hydroxide were used under different dosing times on microemulsion. Characterization by X-ray diffraction and electron microscopy allowed us to identify particles with an acicular rod-like morphology and a hexagonalwurtzitecrystal structure as small as 8.5 and 30 nm in average diameter and length, respectively. Productivities much higher than those typical in the preparation of zinc oxide nanoparticles via reverse microemulsions were obtained. Particle size was the same at the two studied sodium hydroxide concentrations, while it increases as dosing time of the precipitant agent increases. It is believed that the surfactant film on the microemulsion channels restricts the particle diameter growth.