bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust Stabilization for a Class of Nonlinear Singularly Perturbed Systems
Authors: Amjadifard R. , Beheshti M. T. H. , Yazdanpanah M. J.
Published: July 2011

In this paper, the problem of disturbance attenuation with internal stability for a class of nonlinear singularly perturbed systems via nonlinear H∞ approach is studied. It is shown through a useful theorem that under appropriate assumptions, the problem of disturbance attenuation for the main system may be related to the problem of disturbance attenuation for the reduced-order system. This is carried out by a new approach in which we use the quasi-steady state of fast variables. Therefore, the problem of existence of a positive definite solution for the Hamilton–Jacobi–Isaacs (HJI) inequality related to the main system leads to the problem of existence of a solution of a simpler HJI inequality related to the reduced-order system.
Utilization of Actuators to Improve Vehicle Stability at the Limit: From Hydraulic Brakes Toward Electric Propulsion
Authors: Jonasson Mats , Andreasson Johan , Solyom Stefan , Jacobson Bengt , Stensson Trigell Annika
Published: July 2011

The capability of over-actuated vehicles to maintain stability during limit handling is studied in this paper. A number of important differently actuated vehicles, equipped with hydraulic brakes toward more advanced chassis solutions, are presented. A virtual evaluation environment has specifically been developed to cover the complex interaction between the driver and the vehicle under control. In order to fully exploit the different actuators setup, and the hard nonconvex constraints they possess, the principle of control allocation by nonlinear optimization is successfully employed. The final evaluation is made by exposing the driver and the over-actuated vehicles to a safety-critical double lane change. Thereby, the differently actuated vehicles are ranked by a quantitative indicator of stability.
An Analytical Solution to Heat and Mass Transfer in Hollow Fiber Membrane Contactors for Liquid Desiccant Air Dehumidification
Authors: Zhang Li-Zhi
Published: July 2011

Hollow fiber membrane contactors are used in air dehumidification. The benefit of this technology is that the liquid desiccant is not in a direct contact with the process air; therefore, the problem of liquid droplets crossover is prevented. The equations governing the heat and moisture transfer from the air to the liquid, through the membranes, are described. An analytical solution is obtained for the dimensionless differential equations, with which the dehumidification effectiveness could be estimated by simple algebraic calculations. It provides a convenient yet accurate tool for the component design and system optimization. The model is validated by experiments. The effects of varying operating conditions on system performance are investigated. It is found that the total number of transfer units for sensible heat and the overall Lewis number are the most dominant parameters influencing heat and mass transfer.
A Compact 3 Degree of Freedom Spherical Joint
Authors: Guckert Mark L. , Naish Michael D.
Published: July 2011

Spherical joints have evolved into a critical component of many robotic systems, often used to provide dexterity at the wrist of a manipulator. In this work, a novel 3 degree of freedom spherical joint is proposed, actuated by tendons that run along the surface of the sphere. The joint is mechanically simple and avoids mechanical singularities. The kinematics and mechanics of the joint are modeled and used to develop both open- and closed-loop control systems. Simulated and experimental assessment of the joint performance demonstrates that it can be successfully controlled in 3 degrees of freedom. It is expected that the joint will be a useful option in the development of emerging robotic applications, particularly those requiring miniaturization.
Assessment of Pedicle Bone Strength in the Lumbar Spine Using a “Smart” Ball Tip Probe
Authors: Liddle Kate D. , Tufaga Michael A. , Diekmann Glenn , Buckley Jenni M. , Tai Viva , Mulligan Kathleen , Ames Christopher , McClellan R. Trigg
Published: July 2011

Preoperative assessment of bone mineral density (BMD) via dual X-ray absorptiometry (DEXA) has been shown to help determine the need for screw augmentation, particularly in the pedicle. However, patients frequently present without preoperative DEXA scans, especially in trauma situations. We developed a “smart” probe for intra-operative assessment of local bone strength in the pedicle. A standard ball tip probe was instrumented with an in-line load cell and was used to test the bone strength of fresh-frozen human cadaveric lumbar spine. Local bone crush strength was assessed using the probe at five locations within the centrum and the pedicle. The contralateral pedicle was outfitted with a standard pedicle screw and insertion torque and pull-out force of the screw were measured. Correlation was found between PS-centrum (probe strength-centrum) and screw pull-out strength (adj. R2 = 0.42). A stepwise linear regression revealed that when considering BMD, insertion torque, and PS-centrum, pull-out strength could be predicted based on PS-centrum and insertion torque (adj. R2 = 0.51, p < 0.01, Fisher test). The results suggest that use of the new probe may be a more quantitative measurement of screw purchase when DEXA is unavailable, such as in spinal trauma cases. Furthermore, when used in conjunction with DEXA, the “smart” ball tip probe may improve assessment of the strength of pedicle screw purchase.
Thermal Modeling of Forced Convection in a Parallel-Plate Channel Partially Filled With Metallic Foams
Authors: Xu H. J. , Qu Z. G. , Lu T. J. , He Y. L. , Tao W. Q.
Published: July 2011

Fully developed forced convective heat transfer in a parallel-plate channel partially filled with highly porous, open-celled metallic foam is analytically investigated. The Navier–Stokes equation for the hollow region is connected with the Brinkman–Darcy equation in the foam region by the flow coupling conditions at the porous–fluid interface. The energy equation for the hollow region and the two energy equations of solid and fluid for the foam region are linked by the heat transfer coupling conditions. The normalized closed-form analytical solutions for velocity and temperature are also obtained to predict the flow and temperature fields. The explicit expression for Nusselt number is also obtained through integration. A parametric study is conducted to investigate the influence of different factors on the flow resistance and heat transfer performance. The analytical solution can provide useful information for related heat transfer enhancement with metallic foams and establish a benchmark for similar work.
Improved One-Dimensional Unsteady Modeling of Thermally Choked Ram Accelerator in Subdetonative Velocity Regime
Authors: Bengherbia Tarek , Yao Yufeng , Bauer Pascal , Giraud Marc , Knowlen Carl
Published: July 2011

The subdetonative propulsion mode using thermal choking has been studied with a one-dimensional (1D) real gas model that included projectile acceleration. Numerical results from a control volume analysis that accounted for unsteady flow effects established that the thrust coefficient versus Mach number profile was lower than that obtained with a quasi-steady model. This deviation correlates with experimental results obtained in a 38-mm-bore ram accelerator at 5.15 MPa fill pressure. Theoretical calculations were initially carried out with the assumption that the combustion process thermally choked the flow about one projectile length behind the projectile base. Thus the control volume length used in this 1D modeling was twice the projectile length, which is consistent with experimental observations at velocities corresponding to Mach number less than 3.5. Yet the choice of the length of the combustion zone and thus the control volume length remains a key issue in the unsteady modeling of the ram accelerator. The present paper provides a refinement of the unsteady one-dimensional model in which the effect of control volume length on the thrust coefficient and the projectile acceleration were investigated. For this purpose the control volume length determined from computational fluid dynamics (CFD) as a function of projectile Mach number was applied. The CFD modeling utilized the Reynolds-averaged Navier-Stokes (RANS) equations to numerically simulate the reacting flow in the ram accelerator. The shear-stress transport turbulence and the eddy dissipation combustion models were used along with a detailed chemical kinetic mechanism with six species and five-step reactions to account for the influence of turbulence and rate of heat release on the length of the combustion zone. These CFD computational results provided Mach number dependent estimates for the control volume length that were implemented in the 1D modeling. Results from the proposed improved 1D unsteady modeling were compared and validated with ram accelerator experimental data with significant improvements in terms of the predicted thrust dependence on Mach number.
Design and Evaluation of a Computer-Controlled Pressure Algometer
Authors: Zimkowski Michael M. , Lindley Emily M. , Patel Vikas V. , Rentschler Mark E.
Published: July 2011

A challenge is always presented when attempting to measure the pain an individual patient experiences. Unfortunately, present technologies rely nearly exclusively on subjective techniques. Using these current techniques, a physician may use a manually operated algometer and a series of questionnaires to gauge an individual patient’s pain scale. Unfortunately these devices and test methods have been suggested to introduce error due to variability and inconsistent testing methods. Some studies have shown large variability, while others have shown minimal variability, both between patients and within the same patient during multiple testing sessions. Recent studies have also shown a lack of correlation between pain threshold and pain tolerance in pain sensitivity tests. Hand-held algometer devices can be difficult to maintain consistent application rates over multiple test periods, possibly adding to widespread variability. Furthermore, there are limited test results that correlate pain ratings with biological measures in real time. The computer-controlled pressure algometer described is not hand-held or dependent on significant examiner input. This new device is capable of recording electrocardiograph (ECG), blood pressure (BP), pressure pain threshold (PPT), and pressure pain tolerance (PPTol) in real time. One major goal is the capability of correlating pain stimuli with algometer pressure, heart rate, and blood pressure. If a predictable correlation between vital signs and pain could be established, significant gains in the understanding of pain could result. Better understanding of pain will ultimately lead to improvements in treatment and diagnosis of pain conditions, helping patients and physicians alike.
Elliptical-Arc-Fillet Flexure Hinges: Toward a Generalized Model for Commonly Used Flexure Hinges
Authors: Chen Guimin , Liu Xiaoyuan , Du Yunlei
Published: July 2011

Flexure hinges have been used to produce frictionless and backlashless transmissions in a variety of precision mechanisms. Although there are many types of flexure hinges available, designers often chose a single type of flexure hinge (e.g., circular flexure hinges) without considering others in the design of flexure-based mechanisms. This is because the analytical equations are unique to each kind of flexure hinge. This work offers a solution to this problem in the form of a generalized flexure hinge model. We propose a new class of flexure hinges, namely, elliptical-arc-fillet flexure hinges, which brings elliptical arc, circular-arc-fillet, elliptical-fillet, elliptical, circular, circular-fillet, and right-circular flexure hinges together under one set of equations. The closed-form equations for all the elements in the compliance and precision matrices of elliptical-arc-fillet flexure hinges have been derived. The analytical results are within 10 percent error compared to the finite element results and within 8 percent error compared to the experimental results. The equations for evaluating the strain energy and stress level for elliptical-arc-fillet flexure hinges are also provided. This model can be used as a complementary model for the generalized model for conic flexure hinges.
β-Pareto Set Prediction for Bi-Objective Reliability-Based Design Optimization
Authors: Lin Dong-Shin , Ho Chun-Min , Chan Kuei-Yuan
Published: July 2011

In this research, we investigate design optimization under uncertainties for problems with two objectives. Reliability-based design optimization (RBDO) that considers uncertainties as random variables and/or parameters and formulates constraints probabilistically has received extensive attention. However, research to date has focused primarily on single-objective problems only. We extend RBDO to problems for which multiple objectives are optimized simultaneously. Each constraint reliability value results in a Pareto set. The set of all Pareto frontiers at the various reliability values is denoted as the β-Pareto set. We study the relations between the deterministic Pareto set and the β-Pareto set and then develop a method to systematically determine the exact β-Pareto set of bi-objective linear programming problems. The method is also extended to predict the β-Pareto set of nonlinear problems using the sandwich technique. As a result, we are able to accurately predict the β-Pareto set in the objective space without solving multiple multi-objective optimization problems at various reliability levels. In the early stage of the product design process, the proposed approach can help decision-makers efficiently to determine how product performance varies with reliability level.
Concept and Design of a Multistable Plate Structure
Authors: Santer Matthew , Pellegrino Sergio
Published: July 2011

A concept is presented for a compliant plate structure that deforms elastically into a variety of cylindrical shapes and is able to maintain such shapes due to the presence of bistable components within the structure. The whole structure may be fabricated as a monolithic entity using low-cost manufacturing techniques such as injection molding. The key steps in the analysis of this novel concept are presented, and a functional model is designed and constructed to demonstrate the concept and validate the analysis.
Pulsed chemical vapor deposition of Cu2S into a porous TiO2 matrix
Authors: Carbone I. , Zhou Q. , Vollbrecht B. , Yang L. , Medling S. , Bezryadina A. , Bridges F. , Alers G. B. , Norman J. T. , Kinmen T.
Published: July 2011

Chalcocite (Cu2S) has been deposited via pulsed chemical vapor deposition (PCVD) into a porous TiO2 matrix using hydrogen sulfide and a metal-organic precursor. The precursor used is similar to the more common Cu(hfac)(tmvs) precursor, but it is fluorine free and exhibits increased thermal stability. The simultaneous exposure of the substrate to the copper precursor and hydrogen sulfide resulted in nonuniform Cu2S films with a temperature independent deposition rate implying gas phase reaction kinetics. The exposure of mesoporous TiO2 and planar ZnO to alternating cycles of the copper precursor and hydrogen sulfide resulted in a PCVD film that penetrated fully into the porous TiO2 layer with a constant deposition rate of 0.08 nm/cycle over a temperature range of 150–400 °C. The chalcocite (Cu2S) stoichiometry was confirmed with extended x-ray absorption fine structure measurements (EXAFS) and x-ray photoelectron spectroscopy. Calculations of the EXAFS spectrum for different CuxS phases show that EXAFS is sensitive to the different phase stoichiometries. Optical absorption measurements of CVD thin films using photothermal deflection spectroscopy show the presence of a metallic copper-poor phase for gas phase nucleated films less than 100 nm thick and a copper-rich semiconducting phase for thicknesses greater than 100 nm with a direct band gap of 1.8 eV and an indirect bandgap of 1.2 eV.
Size control of nanopores formed on SiO2 glass by swift-heavy-ion irradiation and its application to highly sensitive biomolecular detection
Authors: Nomura Ken-ichi , Fujimaki Makoto , Awazu Koichi , Komatsubara Tetsuro
Published: July 2011

Swift-heavy-ion irradiation creates latent tracks in SiO2 glass and nanopores with a high aspect ratio can be formed along these ion paths by selective etching of the latent tracks using hydrogen fluoride (HF) vapor. Here we report that the size of nanopores can easily be controlled by simply changing the temperature of the HF solution generating the vapor and/or that of the SiO2 glass exposed to the vapor. Furthermore, this method of size control was used to produce SiO2 glass sheets with nanopores of different sizes and number densities for use as the waveguide layer in the sensing plates for a waveguide-mode sensor. In comparison with nonperforated plates, the increased surface area due to the formation of nanopores was found to create up to a tenfold increase in sensitivity.
Dependence of film texture on substrate and growth conditions for CdTe films deposited by close-spaced sublimation
Authors: Gao Junning , Jie Wanqi , Yuan Yanyan , Wang Tao , Zha Gangqiang , Tong Junli
Published: July 2011

The texture of CdTe films deposited via close-spaced sublimation (CSS) was studied. Different substrates were used, including Si(100), fluorine-doped SnO2 (FTO), and CdS, and different growth conditions were applied. The texture behaviors of each sample were evaluated based on its XRD spectrum and are found to be dependent on both the substrate and the growth conditions. The texture strength is found to be, in order, Si(100) > FTO > CdS at a substrate temperature of 763 K under 100 Pa Ar, which is the opposite of the order of the surface roughness of the substrates. The textures of the films on FTO and chemical bath deposition (CBD)-CdS substrates, especially on CBD-CdS, are very sensitive to the growth conditions, whereas those on Si(100) are not. It is found that the texture is strengthened at elevated temperatures and suppressed under decreased ambient pressure. It is also found that the textured films are composed of both (111) and (511) texture components, which is believed to be the result of the twinning in (111) oriented grains.
Energy and angular momentum storage in a rotating magnet
Authors: Mani H. S. , Pathak Praveen , Singh Vijay A.
Published: July 2011

We consider a cylindrical metallic magnet that is set into rotation about a horizontal axis by a falling mass. In such a system the magnetic field causes a radial current which is non-solenoidal. The current leads to charge accumulation and a partial attenuation of the radial current. The magnetic field acting on the radially flowing current slows down the acceleration. We evaluate the angular velocity and displacement using Newtonian dynamics. We show that the electromagnetic angular momentum must be taken into account to calculate the change in the angular momentum due to the external torque on the system. The loss in the potential energy of the falling mass can be explained only by taking into consideration the electrostatic energy and the Joule loss.
Public exhibit for demonstrating the quantum of electrical conductance
Authors: Huisman E. H. , Bakker F. L. , der Pal J. P. van , Jonge R. M. de , der Wal C. H. van
Published: July 2011

We present a robust setup that demonstrates the quantum of electrical conductance for a general audience. The setup is continuously available in a public space and allows users to manually thin a gold wire of several atoms in diameter while monitoring its conductance in real time. During the experiment, a characteristic step-like decrease in the conductance due to rearrangements of atoms in the cross-section of the wire is observed. Just before the wire breaks, a contact consisting of a single atom with a characteristic conductance close to the quantum of conductance can be maintained for up to several seconds. The setup is permanently available, needs little maintenance and can be used on different educational levels.
Capillary rise and condensation in a cone as an illustration of a spinodal
Authors: Pettersen M. S. , Rolley E. , Treiner J.
Published: July 2011

Spinodal decomposition can be observed only in systems whose dynamics are slow enough to quench through the metastable region where the phase transition occurs by nucleation. We discuss the capillary rise of a fluid in a cone inserted into a bulk fluid, with the wide end down. The rise displays a first-order phase transition with a spinodal and is easily accessible both theoretically and experimentally.
Investigation of skin effect in mercury using a simple solenoid setup
Authors: Wagner Jerome , Syed Maarij
Published: July 2011

An experimental setup to study the skin effect involving two identical solenoids, one empty and the other filled with mercury, is described. The solenoids are excited by an external frequency generator. We investigate the effects of shielding inside a metal for induced high frequency azimuthal currents by varying the frequency from 1000 to 10,000 Hz. We model the distribution of the induced emf and the magnetic field and show that a simple model based on Maxwell’s equations is satisfactory. We discuss how the setup can be implemented as an experiment for students taking their first course in electromagnetism beyond the usual introductory physics sequence.
Assessing the Safety of Adjuvanted Vaccines
Authors: Ahmed S. Sohail , Plotkin Stanley A. , Black Steven , Coffman Robert L.
Published: July 2011

Preclinical and clinical studies assess the risk of adverse events from vaccine adjuvants.
Photoactivated Composite Biomaterial for Soft Tissue Restoration in Rodents and in Humans
Authors: Hillel Alexander T. , Unterman Shimon , Nahas Zayna , Reid Branden , Coburn Jeannine M. , Axelman Joyce , Chae Jemin J. , Guo Qiongyu , Trow Robert , Thomas Andrew , Hou Zhipeng , Lichtsteiner Serge , Sutton Damon , Matheson Christine , Walker Patricia , David Nathaniel , Mori Susumu , Taube Janis M. , Elisseeff Jennifer H.
Published: July 2011

Photoactivated composite poly(ethylene glycol)–hyaluronic acid biomaterials demonstrate enhanced physicochemical properties for facial soft tissue reconstruction.
IL-7 Promotes T
H
1 Development and Serum IL-7 Predicts Clinical Response to Interferon-β in Multiple Sclerosis
Authors: Lee Li-Fen , Axtell Robert , Tu Guang Huan , Logronio Kathryn , Dilley Jeanette , Yu Jessica , Rickert Mathias , Han Bora , Evering Winston , Walker Michael G. , Shi Jing , de Jong Brigit A. , Killestein Joep , Polman Chris H. , Steinman Lawrence , Lin John C.
Published: July 2011

High serum IL-7 predicts responsiveness of multiple sclerosis patients to IFN-β therapy and indicates a T
H
1 cell–driven disease.
Losing the War Against Obesity: The Need for a Developmental Perspective
Authors: Gluckman Peter D. , Hanson Mark , Zimmet Paul , Forrester Terrence
Published: July 2011

Recent scientific insights into early-life contributions to the adult obesity epidemic must now be translated into interventions.
Phylogenetic Molecular Ecological Network of Soil Microbial Communities in Response to Elevated CO
2
Authors: Zhou Jizhong , Deng Ye , Luo Feng , He Zhili , Yang Yunfeng
Published: July 2011

Understanding the interactions among different species and their responses to environmental changes, such as elevated atmospheric concentrations of CO
2
, is a central goal in ecology but is poorly understood in microbial ecology. Here we describe a novel random matrix theory (RMT)-based conceptual framework to discern phylogenetic molecular ecological networks using metagenomic sequencing data of 16S rRNA genes from grassland soil microbial communities, which were sampled from a long-term free-air CO
2
enrichment experimental facility at the Cedar Creek Ecosystem Science Reserve in Minnesota. Our experimental results demonstrated that an RMT-based network approach is very useful in delineating phylogenetic molecular ecological networks of microbial communities based on high-throughput metagenomic sequencing data. The structure of the identified networks under ambient and elevated CO
2
levels was substantially different in terms of overall network topology, network composition, node overlap, module preservation, module-based higher-order organization, topological roles of individual nodes, and network hubs, suggesting that the network interactions among different phylogenetic groups/populations were markedly changed. Also, the changes in network structure were significantly correlated with soil carbon and nitrogen contents, indicating the potential importance of network interactions in ecosystem functioning. In addition, based on network topology, microbial populations potentially most important to community structure and ecosystem functioning can be discerned. The novel approach described in this study is important not only for research on biodiversity, microbial ecology, and systems microbiology but also for microbial community studies in human health, global change, and environmental management.

IMPORTANCE
The interactions among different microbial populations in a community play critical roles in determining ecosystem functioning, but very little is known about the network interactions in a microbial community, owing to the lack of appropriate experimental data and computational analytic tools. High-throughput metagenomic technologies can rapidly produce a massive amount of data, but one of the greatest difficulties is deciding how to extract, analyze, synthesize, and transform such a vast amount of information into biological knowledge. This study provides a novel conceptual framework to identify microbial interactions and key populations based on high-throughput metagenomic sequencing data. This study is among the first to document that the network interactions among different phylogenetic populations in soil microbial communities were substantially changed by a global change such as an elevated CO
2
level. The framework developed will allow microbiologists to address research questions which could not be approached previously, and hence, it could represent a new direction in microbial ecology research.
Physiological Differentiation within a Single-Species Biofilm Fueled by Serpentinization
Authors: Brazelton William J. , Mehta Mausmi P. , Kelley Deborah S. , Baross John A.
Published: July 2011

Carbonate chimneys at the Lost City hydrothermal field are coated in biofilms dominated by a single phylotype of archaea known as Lost City
Methanosarcinales
. In this study, we have detected surprising physiological complexity in single-species biofilms, which is typically indicative of multispecies biofilm communities. Multiple cell morphologies were visible within the biofilms by transmission electron microscopy, and some cells contained intracellular membranes that may facilitate methane oxidation. Both methane production and oxidation were detected at 70 to 80°C and pH 9 to 10 in samples containing the single-species biofilms. Both processes were stimulated by the presence of hydrogen (H
2
), indicating that methane production and oxidation are part of a syntrophic interaction. Metagenomic data included a sequence encoding AMP-forming acetyl coenzyme A synthetase, indicating that acetate may play a role in the methane-cycling syntrophy. A wide range of nitrogen fixation genes were also identified, many of which were likely acquired via lateral gene transfer (LGT). Our results indicate that cells within these single-species biofilms may have differentiated into multiple physiological roles to form multicellular communities linked by metabolic interactions and LGT. Communities similar to these Lost City biofilms are likely to have existed early in the evolution of life, and we discuss how the multicellular characteristics of ancient hydrogen-fueled biofilm communities could have stimulated ecological diversification, as well as unity of biochemistry, during the earliest stages of cellular evolution.

IMPORTANCE
Our previous work at the Lost City hydrothermal field has shown that its carbonate chimneys host microbial biofilms dominated by a single uncultivated “species” of archaea. In this paper, we integrate evidence from these previous studies with new data on the metabolic activity and cellular morphology of these archaeal biofilms. We conclude that the archaeal biofilm must contain cells that are physiologically and possibly genetically differentiated with respect to each other. These results are especially interesting considering the possibility that the first cells originated and evolved in hydrothermal systems similar to Lost City.
Is activation of transversus abdominis and obliquus internus abdominis associated with long-term changes in chronic low back pain? A prospective study with 1-year follow-up
Authors: Unsgaard-Tøndel Monica , Lund Nilsen Tom Ivar , Magnussen Jon , Vasseljen Ottar
Published: July 2011

Objective

To investigate associations between deep abdominal muscle activation and long-term pain outcome in chronic non-specific low back pain (LBP).

Methods

Recruitment of transversus abdominis and obliquus internus abdominis during the abdominal drawing-in manoeuvre was recorded by B-mode ultrasound and anticipatory onset of deep abdominal muscle activity with M-mode ultrasound. Recordings were done before and after 8 weeks with guided exercises for 109 patients with chronic non-specific LBP. Pain was assessed with a numeric rating scale (0–10) before and 1 year after intervention. Associations between muscle activation and long-term pain were examined by multiple linear and logistic regression methods.

Results

Participants with a combination of low baseline lateral slide in transversus abdominis and increased slide after intervention had better odds for long-term clinically important pain reduction (≥2 points on the numeric rating scale) compared with participants with small baseline slide and no improvement in slide (OR 14.70, 95% CI 2.41 to 89.56). There were no associations between contraction thickness ratios in transversus abdominis or obliquus internus abdominis and pain at 1-year follow-up. Transversus abdominis lateral slide before intervention was marginally associated with a lower OR for clinically important improvement in pain at 1-year follow-up (OR 0.76, 95% CI 0.62 to 0.93). Delayed onset of the abdominal muscles after the intervention period was weakly associated with higher long-term pain.

Conclusion

Improved transversus abdominis lateral slide among participants with low baseline slide was associated with clinically important long-term pain reduction. High baseline slide and delayed onset of abdominal muscles after the intervention period were weakly associated with higher pain at 1-year follow-up.

Clinical Trial Registration number

The study was preregistered in ClinicalTrials.gov with identifierNCT00201513.
Structural cardiac disease diagnosed by echocardiography in asymptomatic young male soccer players: implications for pre-participation screening
Authors: Rizzo Marta , Spataro Antonio , Cecchetelli Cristiano , Quaranta Federico , Livrieri Simona , Sperandii Fabio , Cifra Barbara , Borrione Paolo , Pigozzi Fabio
Published: July 2011

Purpose

To evaluate the prevalence of structural cardiac lesions using echocardiography in apparently healthy boys referred for pre-participation screening (PPS).

Subjects and methods

3100 male soccer players were evaluated by echocardiography in addition to the standard PPS.

Results

In 56 subjects (1.8%), a structural cardiac lesion with potential future complication was detected. Specifically, hypertrophic cardiomyopathy (HCM) was found in two boys; bicuspid aortic valve (BAV) in 24; mitral valve prolapse in 10 and atrial septal defects (ASDs) in 20. Resting physical examination (PE) failed to identify any abnormalities in the majority of the subjects. All the boys presented an uncomplicated echocardiography, except two boys with HCM, one with BAV associated with aortic dilatation and one with a large ASD.

Conclusion

Asymptomatic young athletes may have a structural cardiac alteration with the potential of present or future haemodynamic and arrhythmic consequences. A majority of mild cardiac lesions are difficult to diagnose or suspect by the current screening based on medical history, PE and ECG. Transthoracic echocardiography significantly improves the diagnostic power of screening in the detection of both mild and serious cardiac conditions in the athletic population.
Physical activity and cardiovascular risk factors in children
Authors: Andersen Lars Bo , Riddoch Chris , Kriemler Susi , Hills Andrew
Published: July 2011

Background

A number of recent systematic reviews have resulted in changes in international recommendations for children's participation in physical activity (PA) for health. The World Health Authority (WHO) has recently released new recommendations. The WHO still recommends 60 min of moderate to vigorous physical activity (MVPA), but also emphasises that these minutes should be on top of everyday physical activities. Everyday physical activities total around 30 min of MVPA in the quintile of the least active children, which means that the new recommendations constitute more activity in total compared with earlier recommendations.

Objective To summarise evidence justifying new PA recommendation for cardiovascular health in children.

Methods

The results of recent systematic reviews are discussed and supplemented with relevant literature not included in these reviews. PubMed was searched for the years 2006–2011 for additional topics not sufficiently covered by the reviews.

Results

PA was associated with lower blood pressure and a healthier lipid blood profile in children. The association was stronger when a composite risk factor score was analysed, and the associations between physical fitness and cardiovascular disease (CVD) risk factors were even stronger. Muscle strength and endurance exercise each had an effect on blood lipids and insulin sensitivity even if the effect was smaller for muscle strength than for aerobic exercise. New evidence suggests possible effects of PA on C-reactive protein.

Conclusion

There is accumulating evidence that PA can have beneficial effects on the risk factors of CVD in children. Public health policy to promote PA in children, especially the most sedentary children, may be a key element to prevent the onset of CVD later in the children's lives.
Exploring the role of fish in a lake ecosystem (Lake Kinneret, Israel) by coupling an individual-based fish population model to a dynamic ecosystem model
Authors: Makler-Pick Vardit , Gal Gideon , Shapiro James , Hipsey Matthew R.
Published: July 2011

To explore the role that fish play in aquatic ecosystems, a hydrodynamic–ecological model (DYRESM–CAEDYM) was coupled to a novel fish population model. The coupled model (DYCD–FISH) combined two modelling approaches: a complex dynamic model and an individual-based model. The coupled model simulates fish growth population dynamics and predicts fish impacts on various ecosystem components, including nutrients and lower trophic levels. The model was employed to explore the role of the dominant fish in Lake Kinneret (Israel), Acanthobrama terraesanctae (Kinneret bleak, or in Hebrew, lavnun ha’kinneret; hereafter lavnun). Model results suggested that the lavnun has a significant impact (p < 0.05) on the magnitude of output variables including its prey food (the predatory and microzooplankton), major nutrients such as ammonium (NH4) and phosphate (PO4), and on several phytoplankton species, but not on the seasonality of any of the output variables. Since the model incorporates trophic levels from nutrients to fish, it revealed the nonlinear dynamic impacts of fish on different ecosystem components and in particular has led to quantitative insights into the relative influence of top-down control on water quality attributes. Besides being an ecosystem research tool, DYCD–FISH can also be employed as a fishery management tool, and in particular facilitate ecosystem-based fishery management.
Home range of European lobster (Homarus gammarus) in a marine reserve: implications for future reserve design
Authors: Moland Even , Olsen Esben Moland , Andvord Kristian , Knutsen Jan Atle , Stenseth Nils Chr.
Published: July 2011

Marine reserves are perceived as a critical component in successful rebuilding of overharvested marine populations. Such efforts can be particularly successful in species with limited movement rates. However, long-term data on movement is sparse for most marine species. Here, we investigated space use in European lobster ( Homarus gammarus ) by ultrasonic tracking in a reserve on the Norwegian Skagerrak coast from September 2006 to August 2007. Over the period, 95% of tagged lobsters remained either within the reserve or near reserve boundaries. Home range estimates based on a kernel density estimator of the 95% utilization distribution ranged from 5728 to 41 548 m2 (mean 19 879 ± 2152 m2 standard error), representing 0.57%–4.15% of the reserve area (1 km2), with no significant difference among males, non-ovigerous females, and ovigerous females for an overlapping observation period of 242 days. Logistic regression predicted average time to reach 50% and 95% of minimum convex polygon home range area at 98 and 259 days, respectively. These results show that European lobsters can be resident with limited home ranges. Small coastal reserves can be designed to afford complete or partial protection by letting boundaries engulf or intersect patches of habitat preferred by this species.
A deathly odor suggests a new sustainable tool for controlling a costly invasive species
Authors: Wagner C. Michael , Stroud Eric M. , Meckley Trevor D.
Published: July 2011

Here we confirm a long-standing anecdotal observation; the sea lamprey ( Petromyzon marinus ) actively avoids the odor emitted by decaying conspecifics. We extracted the semiochemical mixture produced by the putrefying carcasses of sea lampreys via Soxhlet extraction in ethanol and exposed groups of 10 migratory-phase lampreys to either the putrefaction extract (N = 8) or an ethanol control (N = 8) in a laboratory raceway. Sea lampreys rapidly avoided the putrefaction odor while exhibiting no response to the ethanol control. This response was elicited with a diluted mixture (1:373 000) and was maintained for 40 min (the duration of exposure), after which the lampreys quickly returned to their nominal distribution. The ease with which this odor is obtained, and the rapid and consistent behavioral response, suggests the substance will prove useful as a repellent in the sea lamprey control program carried out in the Laurentian Great Lakes.
Biodiversity studies inPhaseolusspecies by DNA barcoding
Authors: Nicolè Silvia , Erickson David L. , Ambrosi Daria , Bellucci Elisa , Lucchin Margherita , Papa Roberto , Kress W. John , Barcaccia Gianni
Published: July 2011

The potential of DNA barcoding was tested as a system for studying genetic diversity and genetic traceability in bean germplasm. This technique was applied to several pure lines of Phaseolus vulgaris L. belonging to wild, domesticated, and cultivated common beans, along with some accessions of Phaseolus coccineus L., Phaseolus lunatus L., and Vigna unguiculata (L.) Walp. A multilocus approach was exploited using three chloroplast genic regions (rbcL, trnL, and matK), four intergenic spacers (rpoB-trnC, atpBrbcL, trnT-trnL, and psbA-trnH), and nuclear ITS1 and ITS2 rDNA sequences. Our main goals were to identify the markers and SNPs that show the best discriminant power at the variety level in common bean germplasm, to examine two methods (tree based versus character based) for biodiversity analysis and traceability assays, and to evaluate the overall utility of chloroplast DNA barcodes for reconstructing the origins of modern Italian varieties. Our results indicate that the neighbor-joining method is a powerful approach for comparing genetic diversity within plant species, but it is relatively uninformative for the genetic traceability of plant varieties. In contrast, the character-based method was able to identify several distinct haplotypes over all target regions corresponding to Mesoamerican or Andean accessions; Italian accessions originated from both gene pools. On the whole, our findings raise some concerns about the use of DNA barcoding for intraspecific genetic diversity studies in common beans and highlights its limitations for resolving genetic relationships between landraces and varieties.
Genome size variation inCorchorus olitorius(Malvaceae s.l.) and its correlation with elevation and phenotypic traits
Authors: Benor Solomon , Fuchs Jörg , Blattner Frank R.
Published: July 2011

In this study, we report genome size variations in Corchorus olitorius L. (Malvaceae s.l.), a crop species known for its morphological plasticity and broad geographical distribution, and Corchorus capsularis L., the second widely cultivated species in the genus. Flow cytometric analyses were conducted with several tissues and nuclei isolation buffers using 69 accessions of C. olitorius and 4 accessions of C. capsularis, representing different habitats and geographical origins. The mean 2C nuclear DNA content (± SD) of C. olitorius was estimated to be 0.918 ± 0.011 pg, with a minimum of 0.882 ± 0.004 pg, and a maximum of 0.942 ± 0.004 pg. All studied plant materials were found to be diploid with 2n = 14. The genome size is negatively correlated with days to flowering (r = –0.29, p < 0.05) and positively with seed surface area (r = 0.38, p < 0.05). Moreover, a statistically significant positive correlation was detected between genome size and growing elevation (r = 0.59, p < 0.001) in wild populations. The mean 2C nuclear DNA content of C. capsularis was estimated to be 0.802 ± 0.008 pg. In comparison to other economically important crop species, the genome sizes of C. olitorius and C. capsularis are much smaller, and therewith closer to that of rice. The relatively small genome sizes will be of general advantage for any efforts into genomics or sequencing approaches of these species.
THE ESSENTIAL RANK OF FUSION SYSTEMS OF BLOCKS OF SYMMETRIC GROUPS
Authors: AN JIANBEI , DIETRICH HEIKO
Published: July 2011

Let p be a prime and let B be a p-block of the symmetric group S(n) on n points. Let (D, bD) be a Sylow B-subgroup of S(n). We consider the fusion system [Formula: see text] and determine a precise formula for its essential rank. In addition, the p-blocks B which admit a p-local subgroup of S(n) controlling B-fusion are characterized.
LINEAR ESTIMATES FOR SOLUTIONS OF QUADRATIC EQUATIONS IN FREE GROUPS
Authors: KHARLAMPOVICH OLGA , VDOVINA ALINA
Published: July 2011

We prove that in a free group the length of the value of each variable in a minimal solution of a standard quadratic equation is bounded by 2s for an orientable equation and by 12s4 for a non-orientable equation, where s is the sum of the lengths of the coefficients.
PHOTOTHERAPY OF GINGIVITIS: PILOT CLINICAL STUDY
Authors: GENINA ELINA A. , TITORENKO VLADIMIR A. , TUCHIN VALERY V. , SIMONENKO GEORGY V. , BASHKATOV ALEXEY N. , SHUB GENNADY M. , LEPILIN ALEXANDER V. , YAROSLAVSKY ILYA V. , ALTSHULER GREGORY B.
Published: July 2011

The goal of this work was to evaluate the safety and efficacy of the Red Light Emitted Toothbrush (R-LETB) emitting at wavelength of 663 nm with power density of 3.3 mW/cm2 in combination with 0.1%-methylene blue (MB) solution for the reduction of plaque and treatment of gingivitis. A microbiological in vitro study and a pilot clinical study were conducted. The microbiological study has shown total suppression of pathogenic flora after a 3-min exposure to the dye solution followed by a 20-sec treatment with the R-LETB. For the clinical study, 37 subjects of both sexes with gingivitis were enrolled and randomly assigned to one of two groups. Subjects in the first (treatment) group were instructed to rinse their mouth with MB solution provided for 1 min and then brush the teeth with the R-LETB and standardized toothpaste. The second (control) group used only the toothpaste and a regular toothbrush. Subjects in both groups followed their respective procedures 2 times a day (morning and evening) for 30 days. Indices of plaque, gingival bleeding, and inflammation were evaluated at 14-day and 30-day timepoints. In the both groups, all indices improved in comparison with baseline. However, the treatment group demonstrated more pronounced improvement of the studied indices that was attributed to additional anti-microbial action of red light and MB on gum tissue. Thus, the use of R-LETB with MB appears to have a multifactor therapeutic action on oral pathological microflora: mechanical removal of the bacteria and suppressing action on microorganisms due to photodynamic reaction.
Activation of G protein-coupled estrogen receptor induces endothelium-independent relaxation of coronary artery smooth muscle
Authors: Yu Xuan , Ma Handong , Barman Scott A. , Liu Alexander T. , Sellers Minga , Stallone John N. , Prossnitz Eric R. , White Richard E. , Han Guichun
Published: July 2011

Estrogens can either relax or contract arteries via rapid, nongenomic mechanisms involving classic estrogen receptors (ER). In addition to ERα and ERβ, estrogen may also stimulate G protein-coupled estrogen receptor 1 (GPER) in nonvascular tissue; however, a potential role for GPER in coronary arteries is unclear. The purpose of this study was to determine how GPER activity influenced coronary artery reactivity. In vitro isometric force recordings were performed on endothelium-denuded porcine arteries. These studies were augmented by RT-PCR and single-cell patch-clamp experiments. RT-PCR and immunoblot studies confirmed expression of GPER mRNA and protein, respectively, in smooth muscle from either porcine or human coronary arteries. G-1, a selective GPER agonist, produced a concentration-dependent relaxation of endothelium-denuded porcine coronary arteries in vitro. This response was attenuated by G15, a GPER-selective antagonist, or by inhibiting large-conductance calcium-activated potassium (BKCa) channels with iberiotoxin, but not by inhibiting NO signaling. Last, single-channel patch-clamp studies demonstrated that G-1 stimulates BKCachannel activity in intact smooth muscle cells from either porcine or human coronary arteries but had no effect on channels isolated in excised membrane patches. In summary, GPER activation relaxes coronary artery smooth muscle by increasing potassium efflux via BKCachannels and requires an intact cellular signaling mechanism. This novel action of estrogen-like compounds may help clarify some of the controversy surrounding the vascular effects of estrogens.