bluuebunny/crossref_metadata_2025 huggingface dataset:
Ribosome abundance regulates the recovery of skeletal muscle protein mass upon recuperation from postnatal undernutrition in mice
Authors: Fiorotto Marta L. , Davis Teresa A. , Sosa Horacio A. , Villegas‐Montoya Carolina , Estrada Irma , Fleischmann Ryan
Published: September 2014

Key points

Inadequate nutrient intake during early life can programme a low adult muscle mass. We have used a mouse model to identify the developmental window when the skeletal musculature is vulnerable to programming and to identify factors that limit the muscle's ability to respond when normal nutrition is restored.

We established that the developmental age when nutritional rehabilitation occurs following an episode of poor nutrition, rather than the duration or severity of the nutrient restriction, is the critical factor that determines if muscle mass can be recuperated.

The ability to recover depends on whether the muscles’ translational capacity, i.e. ribosomal abundance, can increase sufficiently to raise protein synthesis rates sufficiently to accelerate protein deposition.

We show that the ability to increase ribosomal abundance was associated with increased expression of the nucleolar transcription factor UBF (upstream binding factor), which regulates RNA polymerase 1 activity and rRNA transcription, the limiting factor for ribosomal production.

Nutritionally‐induced growth faltering in the perinatal period has been associated with reduced adult skeletal muscle mass; however, the mechanisms responsible for this are unclear. To identify the factors that determine the recuperative capacity of muscle mass, we studied offspring of FVB mouse dams fed a protein‐restricted diet during gestation (GLP) or pups suckled from postnatal day 1 (PN1) to PN11 (E‐UN), or PN11 to PN22 (L‐UN) on protein‐restricted or control dams. All pups were refed under control conditions following the episode of undernutrition. Before refeeding, and 2, 7 and 21 days later, muscle protein synthesis was measured in vivo. There were no long‐term deficits in protein mass in GLP and E‐UN offspring, but in L‐UN offspring muscle protein mass remained significantly smaller even after 18 months (P < 0.001). E‐UN differed from L‐UN offspring by their capacity to upregulate postprandial muscle protein synthesis when refed (P < 0.001), a difference that was attributable to a transient increase in ribosomal abundance, i.e. translational capacity, in E‐UN offspring (P < 0.05); translational efficiency was similar across dietary treatments. The postprandial phosphorylation of Akt and extracellular signal‐regulated protein kinases were similar among treatments. However, activation of the ribosomal S6 kinase 1 via mTOR (P < 0.02), and total upstream binding factor abundance were significantly greater in E‐UN than L‐UN offspring (P < 0.02). The results indicate that the capacity of muscles to recover following perinatal undernutrition depends on developmental age as this establishes whether ribosome abundance can be enhanced sufficiently to promote the protein synthesis rates required to accelerate protein deposition for catch‐up growth.
Numerical Study on the Adhesion Strength Between Ice and Aluminium Based on a Cohesive Zone Model
Authors: Chen Yong , Wenhao Wang , Dong Wei , Li Mo , Lei Lei
Published: September 2014

Accumulation of ice on aeroengine components could cause serious aircraft accidents. An understanding of the adhesion characteristics of ice-substrate interfaces is essential in order to design reliable anti-icing and de-icing systems. The main purpose of this paper is on the application of a bilinear cohesive zone model to simulate the interface between ice and aluminum by using ANSYS software. A finite element model which coupled with the cohesive zone model is built and some factors that affect the Al/ice tensile strength are discussed. These factors include interface roughness, initial damage of the interface, which is caused by the existence of bubbles. The adhesion strength between ice and aluminum are predicted and analyzed. This model could be used to further study on the mechanisms responsible for the non-linear relationship between the surface roughness and ice adhesion strength.
CFD Prediction and Calibration of Transient Aerodynamics Around an Auxiliary Power Unit Inlet Door
Authors: Bouldin Bruce , Reich Jennifer , Royalty Chuck
Published: September 2014

Auxiliary power units (APUs) are gas turbine engines that provide high-pressure air and electrical power to aircraft systems. They provide primary power while the aircraft is parked on the ramp, starting services for the main engines, and backup power while the aircraft is in flight. Many APUs employ inlet systems which include a “pop-up” door that allow for the capture of freestream ram pressure during flight. This results in increased inlet recovery and a corresponding improvement in the performance of the APU. This APU door, when open, is exposed to airflow instability inherent in the aircraft boundary layer in the aft section of the fuselage, where APUs are typically housed. Additionally, the pop-up nature of the inlet door produces a large region of separated airflow off of the back side of the door. Systematic vortex shedding is frequently a major component of this separated region.

As new APU doors are made with less rigid material to save weight, a need to better understand the unsteady aerodynamic excitations of the flow field around the door has arisen, as these new doors may be more susceptible to vibration during flight.

Recent advances in Computational Fluid Dynamics (CFD) meshing tools and transient modeling have enabled a CFD study to be performed which will investigate this time-dependent phenomenon. As transient CFD analysis is still a relatively new field for commercial CFD codes, a calibration was needed to verify the accuracy of the CFD predictions and to form any calibration correction terms.

Honeywell Aerospace owns a Boeing 757 flight test vehicle which is normally used to flight test propulsion engines. However, this aircraft also includes a pop-up APU inlet door that is similar to most other APU inlet door styles. This APU door was instrumented using high response pressure transducers placed on the forward and aft sides of the inlet door as well as upstream of the door to measure upstream instability. The aircraft was flown at a variety of flight conditions and APU operating points and the transient data was recorded.

After the completion of the flight test, a CFD model was constructed of the B757 flight test vehicle. Because aerodynamic instability can be generated anywhere on the aircraft, the entire airframe from nose to tail was modeled. The APU inlet door geometry was also created, meshed and added to the CFD model. This CFD model was run in a transient mode to simulate the exact same flight conditions and APU operating points as were tested during the flight test. Dynamic results in the time and frequency domains predicted by the CFD analyses were compared to flight test data and correlation and calibration factors were derived.
Space Infill Study of Kriging Meta-Model for Multi-Objective Optimization of an Engine Cooling Fan
Authors: Zhang Zebin , Demory Bruno , Henner Manuel , Ferrand Pascal , Gillot Frédéric , Beddadi Youssef , Franquelin François , Marion Vivien
Published: September 2014

The meta-model based optimization is widely used in the aerodynamical design process for rotating machines, and the main industrial cost of such techniques comes from physical evaluations of answers, either by experimental or numerical means. Design of experiment (DoE) with Latin Hypercube sampling has been studied for the design of an automotive fan system for engine cooling. Surrogate models constructed with Kriging and Co-Kriging methods are estimated with the help of a reference numerical model. The objective of the present work is to assess the necessary number of sampling points for the initial DoE for this kind of meta-model method and to study the influence brought by the sample dispersion. The objective being to execute future aerodynamic optimizations at a reduced cost in term of timeframe and CPU effort. Two parameters, camber and chord length were used to investigate geometrical changes and they are completed with a physical parameter which is the flow rate. The optimization should lead to a higher level of performances with given constraints of rotational speed, torque and packaging. A criterion was defined for the initial necessary number of evaluations and the variances for different DoE design were controlled for the sake of comparison. Starting from an initial meta-model, a variance based method was used for further training with additional points. Uncertainties due to lack of information outside the domain led the model to regularly propose new points on the borders, yielding to high sample variance. A genetic-algorithm was employed to explore the final meta-model and to conduct a multi-objective optimization. Results are presented in terms of Pareto Front and are analysed with SOM to understand the relations between factors and objectives. A final optimal design was selected, and proposed to demonstrate the relevancy of the method.
Effect of Near Melting Temperatures on Microparticle Sand Rebound Characteristics at Constant Impact Velocity
Authors: Delimont J. M. , Murdock M. K. , Ng W. F. , Ekkad S. V.
Published: September 2014

When gas turbine engines operate in environments where the intake air has some concentration of particles, the engine will experience degradation. Very few studies of microparticles at temperatures approaching the melting temperature of the particles are available in open literature. Coefficient of Restitution (COR), a measure of the particles’ impact characteristics, was measured for microparticles using a particle tracking technique. This study presents data taken using the Virginia Tech Aerothermal Rig and Arizona Road Dust (ARD) of 20–40μm size range. Data was taken at temperatures up to and including 1323 K, where significant deposition of the sand particles was observed. The velocity at which the particles impact the surface was held at a constant 70m/s for all of the temperature cases. The target on which the particles impacted was made of a nickel alloy, Hastelloy X. The particle angle of impact was also varied between 30° and 80°. The COR of the particles decreases slightly as some of the particles approach their glass transition point and start to become molten. Other particles, which do not become molten due to different particle composition, rebound and maintain a relatively high COR. Images were taken using a microscope to examine the particle deposition that occurs at various angles. A rebound ratio is formulated to give a measure of the number of particles which deposit on the surface. The results show an increase in deposition as the temperature approaches the melting temperature of sand.
Aerodynamic Characterization of a High Speed Propeller
Authors: Ghenaiet Adel , Halimi Akila
Published: September 2014

This paper presents a numerical study aimed at characterizing the aerodynamics of an advanced propeller distinguished by its high rotational speed, blade sweep and airfoil sections. Many of the difficulties encountered when applying CFD to an open rotor (a propeller) arise due to removal of the casing existing in a conventional aero-engine turbomachinery. For this purpose the propeller computational domain needed to be well parameterized to keep sufficient outer domains distances where the appropriate boundary conditions are imposed. The mesh of a certain resolution was extended radially, five times the tip radii, to fully capture the stream-tube and minimize the effect of free-stream boundary conditions. Comparisons of obtained flow field results with some available experimental data shows in general similar quantitative results and trends. The estimated propulsive efficiency is shown to be strongly dependent upon the cruise flight Mach number, advance ratio and pitch angle. The maximum propulsive efficiency reached a value of 76.2 % around flight Mach number of 0.8, twist angle of 66 deg and advance ratio of 4.1. The effect of blades number has revealed a higher propulsive efficiency for the six and eight-bladed propellers but at the expense of lower power and thrust coefficients.
Quantitative Evaluation of Flow-Induced Fan Casing Structural Vibration and Noise Radiation of Air-Conditioner Outdoor Unit
Authors: Zhao Xifeng , Sun Jinju , Gao Renheng , Zhang Zhi , Xue Weifei
Published: September 2014

Noise level of AC (Air-Conditioner) outdoor unit fan system has always been receiving much concern. It involves both aerodynamic noise and vibroacoustic noise. But most previous studies have been focused on aeroacoustics, and less attention is paid to the latter.

The objective of present study is to identify the influential factors of vibroacoustic noise and quantify its contribution to the overall noise level of the fan system. A numerical approach has been developed for predicting the flow-induced fan casing vibration and noise radiation. A fluid-solid-sound unidirectional coupling technique is used to transfer the unsteady loading to the structure, and the results arising from structural vibration analysis are used as sound radiation boundary conditions. Unsteady fan flow is solved by Large Eddy Simulation (LES) method. Then, the fluid force produced by the fluctuating pressure component acting on the inner casing surfaces is obtained, and it is used as external excitation in the Finite Element Analysis (FEA) model of the casing structure. Further, harmonic response analysis is conducted and the obtained results are used to calculate sound radiation through Indirect Boundary Element Method (IBEM), while the displacement amplitude obtained in structural analysis is used as boundary condition.

Experimental tests are conducted respectively on fan aerodynamic and aeroacoustic performance, and casing vibration. The numerical approach is partially validated by the experimental data. The validated models are used to predict the vibroacoustic noise, based on which, a quantitative evaluation of its contribution to overall sound level is conducted.
Tonal Noise Reduction in a Radial Fan With Forward-Curved Blades
Authors: Darvish Manoochehr , Tietjen Bastian , Beck Daniel , Frank Stefan
Published: September 2014

The main focus of this work is on the geometrical modifications that can be applied to the fan wheel and the volute tongue of a radial fan to reduce the tonal noise. The experimental measurements are performed by using the in-duct method in accordance with ISO 5136. In addition to the experimental measurements, CFD (Computational Fluid Dynamics) and CAA (Computational Aeroacoustics) simulations are carried out to investigate the effects of different modifications on the noise and performance of the fan. It is shown that by modifying the blade outlet angle, the tonal noise of the fan can be reduced without affecting the performance of the fan. Moreover, it is indicated that increasing the number of blades leads to a significant reduction in the tonal noise and also an improvement in the performance. However, this trend is only valid up to a certain number of blades, and a further increment might reduce the aerodynamic performance of the fan. Besides modifying the impeller geometry, new volute tongues are designed and manufactured. It is demonstrated that the shape of the volute tongue plays an important role in the tonal noise generation of the fan. It is possible to reduce the tonal noise by using stepped tongues which produce phase-shift effects that lead to an effective local cancellation of the noise.
Experimental Investigation of Ambient Wind Influence on the Performance of Axial Fans
Authors: Heinemann Till , Becker Stefan
Published: September 2014

The EU-funded MACCSol project is developing a new modular air-cooled condenser design for power plant applications in water scarce regions. In that scope, this work is to examine the influence ambient winds may have on an axial ventilator’s performance. An axial fan test rig was built inside a wind tunnel environment at the University of Erlangen to realize different wind velocities and angles. Total fan pressure was captured using an array of 81 Kiel probes. The validity of the test rig adaptations to the wind tunnel restrictions was shown in comparison to results from ISO 5801 standard fan test rigs. Two different fan geometries were examined in their characteristic fan curves’ reactions to wind influence at the free fan inlet. The two fans’ characteristic curves showed effects differing in magnitude, but similar in their tendency. While frontal winds tended to improve fan performance, cross winds reduced it. In reverse operating mode, the effect of wind at the fan outlet demonstrated little but positive influence on the fan curve. In order to reduce negative cross wind influence at the fan inlet, different conical and cylindrical inlet extensions were tested. Short conical shrouds performed best.
Investigation on the Influence of Mesh Topology and Freestream Turbulence Intensity in Broadband Noise Prediction of Axial Fans
Authors: Zanon A. , De Gennaro M. , Kuehnelt H. , Langmayr D. , Caridi D.
Published: September 2014

Aerodynamic noise prediction is a major challenge in computational aeroacoustics due to the complexity of phenomena involved such as turbulence and laminar to turbulent transition. Accurate numerical methodologies, capable to provide reliable predictions in a reasonable computational time, are of large interest for the industrial design of Heating, Ventilation and Air-Conditioning (HVAC) systems. The objective of the present research work is to benchmark different CFD/CAA simulation setup (i.e. mesh topologies, boundary conditions) for predicting the broadband noise generated by low speed axial fans to develop guidelines for reliable and computationally affordable simulation.

In previous works the authors investigated the capabilities of the Zonal LES technique coupled with the Ffowcs Williams-Hawkings acoustic analogy for the prediction of the noise generated by an unducted low speed axial fan. The results showed a good agreement with aerodynamic and aeroacoustic experimental data.

Despite the achievements obtained so far, the high physical and numerical complexity of the problem calls for further investigations. The latest developments, presented here, focus on the impact of the mesh topology and the inflow turbulence on the far field noise prediction.

Two computational meshes with different topology are investigated: an unstructured-hybrid mesh, which can be generated with fast and highly automated methods, and a structured-hybrid mesh, which allows better control of the volume mesh around the blade. Both meshes are designed to adequately resolve the boundary layer, providing LES driven values of y+, x+ and z+ on the blade surface for the operating condition considered.

Two different levels of inflow turbulence are studied, one representing an ideal turbulence-free unbounded environment, and one mimicking the experimental measurements environment.

All the aerodynamic and aeroacoustic simulation results presented are benchmarked with experimental data acquired by the authors.
Real-Time Simulation of Rotor Blade Aeroelasticity for the Multidisciplinary Design of Rotorcraft
Authors: Goulos Ioannis , Pachidis Vassilios
Published: September 2014

This paper elaborates on the theoretical development of a mathematical approach, targeting the real-time simulation of aeroelastic rotor blade dynamics for the multidisciplinary design of rotorcraft. A Lagrangian approach is formulated for the rapid estimation of natural vibration characteristics of rotor blades with nonuniform structural properties. Modal characteristics obtained from classical vibration analysis methods, are utilized as assumed deformation functions. Closed form integral expressions are incorporated, describing the generalized centrifugal forces and moments acting on the blade. The treatment of three-dimensional elastic blade kinematics in the time-domain is thoroughly discussed. In order to ensure robustness and establish applicability in real-time, a novel, second-order accurate, finite-difference scheme is utilized for the temporal discretization of elastic blade motion. The developed mathematical approach is coupled with a finite-state induced flow model, an unsteady blade element aerodynamics model, and a dynamic wake distortion model. The combined aeroelastic rotor formulation is implemented in a helicopter flight mechanics code.

The aeroelastic behavior of a full-scale hingeless helicopter rotor has been investigated. Results are presented in terms of rotor blade resonant frequencies, airframe–rotor trim performance, oscillatory structural blade loads, and transient rotor response to control inputs. Extensive comparisons are carried out with wind tunnel and flight test measurements found in the open literature, as well as with non-real-time comprehensive analysis methods. It is shown that, the proposed approach exhibits good agreement with flight test data regarding trim performance and transient rotor response characteristics. Accurate estimation of structural blade loads is demonstrated, in terms of both amplitude and phase, up to the third harmonic component of oscillatory loading. It is shown that, the developed model can be utilized for real-time simulation on a modern personal computer. The proposed methodology essentially constitutes an enabling technology for the multidisciplinary design of rotorcraft, when a compromise between simulation fidelity and computational efficiency has to be sought for in the model development process.
Mixed Flow Fans — Comparative Investigations of Blade Design Methods
Authors: Thamsen Paul Uwe , Treder Anne , Hammer Steffen , Tunsi Khaled
Published: September 2014

According to the direction of flow, fans can be classified in the following three types: axial, mixed flow and radial fans. If large volume flows are required with a proportionally high pressure increase, mixed flow fans can be used. Similar to axial fans, mixed flow fans provide a large flow rate and because of the radial portion in the flow deflection they increase the pressure ratio. Contrary to axial and radial fans, in technical literature there are only a few recommendations concerning the design method of mixed flow fans available.

The present study focuses on the comparative research of four different blade design methods adapted to mixed flow fans. The selected methods created a straight blade, a profiled blade, a foreward curved “Engelberg” blade and a backward curved “Pfleiderer” blade. The contour of the hub and shroud remained unchanged during the entire design process as a fixed parameter. The 4 different blade sets were manufactured and experimentally tested on a suction side chamber test stand according to DIN EN ISO 5801.

The measurement results show, for comparison, the characteristic curves relating flow rate and pressure increase and the achieved overall efficiencies. Here, the design method of “Pfleiderer” has proved its worth, both through its precise meeting of the design point as well as by achieving the highest efficiency.
Experimental and Numerical Analysis of Flow Instabilities in a Radial Fan
Authors: Lucius Andreas , Lehwald Andreas , Thévenin Dominique , Brenner Gunther
Published: September 2014

Dynamic loads in turbomachines may lead to severe fluid induced vibrations, in particular, if resonance conditions are matched. The major sources of such unsteadiness are rotor/stator interaction, flow separation on the blade suction side at part-load and separation due to the curvature of the shroud. In the present work, some of these phenomena are investigated using computational techniques (Computational Fluid Dynamics - CFD) as well as novel measurement methods (High-Speed Particle Image velocimetry - PIV). The measurements provide a unique database of the velocity fields in an industrial impeller at various operation conditions. They are the base for validation of the computational methods. In view of the complexity of the separated, transient and turbulent flow field, this is still an open issue. Besides that, the analysis of the transient flow fields allows the determination of the “modes” of unsteady forces und thus, to shed some light on the sources of unsteadiness in the flow.
Far Field Noise Prediction for Subsonic Hot and Cold Jets Using Large-Eddy Simulation
Authors: Wang Zhong-Nan , Naqavi Iftekhar Z. , Mahak Mahak , Tucker Paul , Yuan Xin , Strange Paul
Published: September 2014

Large eddy simulations are performed for hot and cold single stream jets with an acoustic Mach number of (Ma = Vj/a∞ = 0.875). The temperature ratio (Tj/T∞) for the hot jet is 2.7 and for the cold jet it is 1.0. Grids with 34 million points are used. The simulation results for the flow field are in encouraging agreement with the mean velocity and Reynolds stress measurements. The Ffowcs Williams-Hawkings (FW-H) equation is used to predict the far-field noise. In this study four cylindrical FW-H surfaces around the jet at various radial distances from the centreline are used. The FW-H surfaces are closed at the downstream end with multiple endplates. These endplates are at x = 25.0D – 30.0D with Δ = 0.5D apart. It is shown that surfaces close to jet get affected with pseudo sound. To avoid pseudo sound, surfaces must be placed in the irrotational region. To account for all the acoustic signals end plates are necessary. However, a simple averaging process to cancel pseudo sound at the end plates is not sufficient.
Plasmon resonance based analysis of a single protein conjugated Au nanoshell
Authors: Dan Berco , Hu Chin-Kun
Published: September 2014

The authors perform a numerical calculation of a gold nanoshell, having either a silica core or a hollow one, interacting with incident electromagnetic radiation and aggregated with a single protein on its surface, by using the discrete dipole approximation. The protein model accounts for a tertiary structure that may contain internal cavities, while the entire structure is placed either in vacuum or a uniform host medium. The authors further analyze the near field pattern by a spherical harmonic transform. Our results identify the interactions that account for the observed extinction peak and wavelength shift in related optical experiments. The theoretical basis provided in this work may be used not only to identify a single protein conjugated nanoparticle, but also to determine the cavity content of the protein by its refractive index properties, determined from optical measurements.
Integration of optical imaging with a small animal irradiator
Authors: Weersink Robert A. , Ansell Steve , Wang An , Wilson Graham , Shah Duoaud , Lindsay Patricia E. , Jaffray David A.
Published: September 2014

Purpose:

The authors describe the integration of optical imaging with a targeted small animal irradiator device, focusing on design, instrumentation, 2D to 3D image registration, 2D targeting, and the accuracy of recovering and mapping the optical signal to a 3D surface generated from the cone‐beam computed tomography (CBCT) imaging. The integration of optical imaging will improve targeting of the radiation treatment and offer longitudinal tracking of tumor response of small animal models treated using the system.

Methods:

The existing image‐guided small animal irradiator consists of a variable kilovolt (peak) x‐ray tube mounted opposite an aSi flat panel detector, both mounted on a c‐arm gantry. The tube is used for both CBCT imaging and targeted irradiation. The optical component employs a CCD camera perpendicular to the x‐ray treatment/imaging axis with a computer controlled filter for spectral decomposition. Multiple optical images can be acquired at any angle as the gantry rotates. The optical to CBCT registration, which uses a standard pinhole camera model, was modeled and tested using phantoms with markers visible in both optical and CBCT images. Optically guided 2D targeting in the anterior/posterior direction was tested on an anthropomorphic mouse phantom with embedded light sources. The accuracy of the mapping of optical signal to the CBCT surface was tested using the same mouse phantom. A surface mesh of the phantom was generated based on the CBCT image and optical intensities projected onto the surface. The measured surface intensity was compared to calculated surface for a point source at the actual source position. The point‐source position was also optimized to provide the closest match between measured and calculated intensities, and the distance between the optimized and actual source positions was then calculated. This process was repeated for multiple wavelengths and sources.

Results:

The optical to CBCT registration error was 0.8 mm. Two‐dimensional targeting of a light source in the mouse phantom based on optical imaging along the anterior/posterior direction was accurate to 0.55 mm. The mean square residual error in the normalized measured projected surface intensities versus the calculated normalized intensities ranged between 0.0016 and 0.006. Optimizing the position reduced this error from 0.00016 to 0.0004 with distances ranging between 0.7 and 1 mm between the actual and calculated position source positions.

Conclusions:

The integration of optical imaging on an existing small animal irradiation platform has been accomplished. A targeting accuracy of 1 mm can be achieved in rigid, homogeneous phantoms. The combination of optical imaging with a CBCT image‐guided small animal irradiator offers the potential to deliver functionally targeted dose distributions, as well as monitor spatial and temporal functional changes that occur with radiation therapy.
Investigating Motivational Regulations and Physical Activity Over 25 Weeks
Authors: Sweet Shane N. , Fortier Michelle S. , Blanchard Chris M.
Published: September 2014

Background:

Because motivation has been deemed a key barrier to physical activity, it is imperative that we know how motivational levels change over time and how that change relates to physical activity. Based in Self-Determination Theory, this study investigated fluctuations in physical activity and motivational regulations over 25 weeks and tested the relationship between these 2 variables.

Methods:

Data from the Physical Activity Counseling trial were examined. Inactive adults recruited from a primary care center (N = 120) answered motivation and physical activity questionnaires during the intervention and postintervention phases. Hierarchical linear modeling was used to test the hypotheses.

Results:

Quadratic changes were found for external regulation (γ20= 0.02, P < .05) and physical activity (γ20 = –2.64, P < .001), while identified (γ10= 0.04, P = .03) and intrinsic (γ10= 0.04, P = .01) regulations increased linearly over the course of the 25 weeks. Only identified regulation (γ30= 3.15, P = .01) and intrinsic motivation (γ30= 4.68, P < .001) were significantly and positively related with physical activity.

Conclusion:

Physical activity, external and identified regulations and intrinsic motivation changed over the 25 weeks. Intervention should aim at fostering identified regulation and intrinsic motivation as greater levels of these regulations were related with physical activity.
Automatic and Motivational Predictors of Children’s Physical Activity: Integrating Habit, the Environment, and the Theory of Planned Behavior
Authors: Thomas Erica , Upton Dominic
Published: September 2014

Background:

Physical activity determinant studies now often include both environmental and sociocognitive factors but few of them acknowledge and explore the mechanisms underlying relevant environmental influences. This study explored environmental correlates of children’s self-reported physical activity and potential mediation through the Theory of Planned Behavior (TPB) and habit strength.

Methods:

Six hundred and twenty-one pupils aged 9–11 years were recruited from 4 primary schools in the UK. TPB variables, habit strength and environmental variables were assessed at baseline. Self-reported physical activity was assessed 1 week later.

Results:

Mediation tests revealed that 43% of the association between convenient facilities and intention was mediated through subjective norms (17%) and habit (26%), while 15% of the association between convenient facilities and physical activity was mediated through habit strength alone. A significant direct effect of convenient facilities and resources in the home environment on physical activity was also found. The school environment was not significantly related to children’s physical activity intentions or behavior.

Conclusion:

The results suggest that the environment influences children’s physical activity both directly and indirectly and that habit strength seems to be the most important mediator for this association.
Adolescents’ Perception of Environmental Features and its Association With Physical Activity: Results From de Azorean Physical Activity and Health Study II
Authors: Oliveira André , Mota Jorge , Moreira Carla , Vale Susana , Abreu Sandra , Moreira Pedro , Santos Rute Marina
Published: September 2014

Background:

The aim of the current study was to verify if physical activity (PA) behavior (steps/day) was associated with environmental features that may be able to promote PA and walking in a sample of Portuguese adolescents living in the Azorean Archipelago.

Methods:

The sample comprised 948 adolescents aged 15–18 years (543 girls) from the Azorean Physical Activity Health Study II. PA was objectively measured with pedometers. Participants were classified as active if they belong to percentile 75th (by age and gender) or more. Environmental perceptions were assessed with a questionnaire. Binary logistic regression analyzed relationships between PA and environmental perceptions controlling for age, body mass index, gender and socioeconomic status.

Results:

Regression analysis showed that participants with a positive overall perception in the transportation dimension were 44.2% (OR = 1.442, P = .025) more likely to be classified as active than those with a negative overall perception. No significant results were found for safety, aesthetics and facilities dimensions.

Conclusions:

A positive overall perception of the transportation dimension was positively associated with PA in Azorean Adolescents. Future health promotion strategies aimed to increase PA in this population should consider the environmental features that are associated with PA levels.
Who Uses Exercise as a Coping Strategy for Stress? Results From a National Survey of Canadians
Authors: Cairney John , Kwan Matthew YW , Veldhuizen Scott , Faulkner Guy EJ
Published: September 2014

Purpose:

To examine the prevalence of exercise as a coping behavior for stress, compare this to other coping behaviors, and examine its demographic, behavioral, and health correlates in a nationally representative sample of Canadians.

Method:

We used data from the Canadian Community Health Survey 1.2, a cross-sectional survey of 36,984 Canadians aged 15 and over, and conducted univariate and logistic regression analyses to address our objectives.

Results:

40% of Canadians reported using exercise for coping with stress (ranked 8th overall). These individuals were more likely to endorse other ‘positive’ coping strategies and less likely to use alcohol or drugs for coping. Being younger, female, unmarried, of high SES, and a nonsmoker were associated with higher likelihoods of using exercise as a coping strategy. High levels of leisure-time physical activity were associated with increased, and heavy physical activity at work with decreased, odds of reporting using exercise for stress coping.

Conclusions:

While reported use of exercise for stress coping is common in the general population, it is less so than several other behaviors. Encouraging exercise, particularly in groups identified as being less likely to use exercise for stress coping, could potentially reduce overall stress levels and improve general health and well-being.
Identifying Similar and Different Factors Effecting Long-Term Cardiac Exercise Rehabilitation Behavior Modification Between New Zealand and the United Kingdom
Authors: Dunn Stephanie , Lark Sally , Fallows Stephen
Published: September 2014

Background:

Cardiac Rehabilitation (CR) programs are the most cost-effective measure for reducing morbidity associated with Coronary Vascular Disease (CVD). To be more effective there is a need to understand what influences the maintenance of healthy behaviors. This study identifies similar and different influences in CR of the United Kingdom (UK) and New Zealand (NZ).

Methods:

A retrospective study. Participants had previously been discharged from CR for 6 to 12+ months within the UK (n = 22) and NZ (n = 21). Participant’s attended a focus group. Discussions were digitally recorded, transcribed then thematically analyzed. The CR programs were observed over 2 months to enable comment on findings relating to ‘theory in practice.’

Results:

Similar positive patient experiences influencing behavior between groups and countries were; support, education, positive attitude, and motivation. Companionship and exercising alongside people with similar health problems was the major determinant for positive exercise behavior. Barriers to maintaining exercise included; physical disabilities, time constraints, and weather conditions. NZ participants were more affected by external factors (eg, opportunity, access, and time).

Conclusion:

Both CR programs were successful in facilitating the maintenance of healthy lifestyles. Exercising with other cardiac patients for support in a structured environment was the strongest influence in maintaining healthy lifestyles beyond CR programs.
Screen Time Increases Risk of Overweight and Obesity in Active and Inactive 9-Year-Old Irish Children: A Cross Sectional Analysis
Authors: Lane Aoife , Harrison Michael , Murphy Niamh
Published: September 2014

Background:

Independent associations between screen time (ST)/physical activity (PA) and overweight (OW)/obesity have been demonstrated but little research exists on the role of ST among sufficiently active children.

Purpose:

To examine the combined influence of ST and PA on risk of OW/obesity in a nationally representative sample of 9-year-old Irish children.

Methods:

The sample in this cross sectional analysis contained 8568 children. Self-report parent data were used to group children into ST and PA categories and related to OW/obesity using forced entry logistic regression.

Results:

High ST (> 3 hours/day), bedroom TV and mobile phone ownership increased risk of OW/obesity in high and low active children (P < .05). Low PA (<9 bouts fortnightly) was also associated with OW/obesity. In combined analyses, OW/obesity was lowest in the reference low ST/high PA group with ORs of 1.38, 1.63, and 2.07, respectively, in the low ST/low PA, high ST/high PA, and high ST/low PA groups. Access to electronic media, low socioeconomic status, parental obesity, and not engaging in sports were all related to high ST (P < .05).

Conclusion:

This study supports findings that ST is associated with OW/Obesity demonstrating this separately in high and low active children.
Day of the Week is Associated With Meeting Physical Activity Recommendations and Engaging in Excessive Sedentary Time in Youth
Authors: Moore Justin B. , Beets Michael W. , Morris Sara F. , Kolbe Mary Bea
Published: September 2014

Background:

Most youth fail to achieve 60 minutes of moderate-to-vigorous physical activity (MVPA) daily while engaging in excessive amounts of sedentary behaviors. The objective of this investigation was to identify modifiable factors associated with meeting MVPA recommendations or engaging in greater than 55% of observed time sedentary.

Methods:

Youth (N = 1005, 10.5 yrs, 52% girls) wore accelerometers with daily minutes of MVPA (≥ 2296 counts·min−1) classified as ≥ 60mins/d vs. < 60min/d of MVPA. Sedentary behavior (< 100 counts·min−1) was classified as < 55% or ≥ 55% of total wear-time. Two-level random effects logit survival models for repeated events (days of monitoring) examined the association of psychosocial self-report measures and demographic characteristics to meeting the MVPA recommendation and spending ≥ 55% of time sedentary.

Results:

Wednesdays, Thursdays, and Sundays were associated with a decreased likelihood of meeting MVPA recommendations relative to Mondays. Wednesday thru Sunday were associated with a decreased likelihood of spending ≥ 55% of time sedentary. Being a boy, receiving transportation, and fewer reported barriers to physical activity were associated with meeting MVPA recommendations.

Conclusions:

Relatively few youth are engaging in recommended levels of physical activity. Provision of transportation and reduction of barriers to physical activity are relevant targets for physical activity promotion.
Effects of Exergaming Based Exercise on Urban Children’s Physical Activity Participation and Body Composition
Authors: Gao Zan , Xiang Ping
Published: September 2014

Background:

Exergaming has been considered a fun solution to promoting a physically active lifestyle. This study examined the impact of an exergaming-based program on urban children’s physical activity participation, body composition and perceptions of the program.

Methods:

A sample of 185 children’s physical activity was measured in August 2009 (pretest), and percent body fat was used as index of body composition. Fourth graders were assigned to intervention group engaging in 30 minutes exergaming-based activities 3 times per week, while third and fifth graders were in comparison group. Measurements were repeated 9 months later (posttest). Interviews were conducted among 12 intervention children.

Results:

ANCOVA with repeated measures revealed a significant main effect for intervention, F(1, 179) = 10.69, P < .01. Specifically, intervention children had significantly greater increased physical activity levels than comparison children. Logistic regression for body composition indicated intervention children did not differ significantly in percent body fat change from comparison children, Chi square = 5.42, P = .14. Children interviewed reported positive attitudes toward the intervention.

Conclusions:

The implementation of exergaming-based program could have a significantly positive effect on children’s physical activity participation and attitudes. Meanwhile, long-term effect of the program on children’s body composition deserves further investigation.
Physical Activity, Sedentary Behavior, and Body Mass Index in the Czech Republic: A Nationally Representative Survey
Authors: Mitáš Josef , Ding Ding , Frömel Karel , Kerr Jacqueline
Published: September 2014

Background:

Post-communist countries have experienced rapid economic development and social changes, which have been accompanied by changes in health-related lifestyle behaviors, such as physical activity. The purpose of this study was to examine the associations of domain-specific physical activity and total sedentary time with BMI among adults in the Czech Republic.

Methods:

We surveyed a nationally representative sample (n = 4097) of the Czech Republic in fall 2007 using the International Physical Activity Questionnaire (long form). Multiple linear regression analyses were used to examine associations of physical activity, sedentary time and sociodemograhic characteristics with BMI.

Results:

Older age, lower educational attainment, and lower levels of leisure-time physical activity were associated with higher BMI. Compared with those living in large cities, men living in small towns and women living in small villages had higher BMI.

Conclusions:

This study has identified correlates of BMI in the Czech Republic. Although more evidence from longitudinal studies is needed, findings from the current study can inform interventions to prevent the rising obesity epidemic.
Exercise Throughout Pregnancy Does not Cause Preterm Delivery: A Randomized, Controlled Trial
Authors: Barakat Ruben , Pelaez Mireia , Montejo Rocio , Refoyo Ignacio , Coteron Javier
Published: September 2014

Background:

In spite of an extensive knowledge of the physiologic features of exercise during pregnancy, we still lack a comprehensive understanding of the effects of different types, intensities and duration of exercise throughout pregnancy on maternal and fetal well being. The aim of the current study was to examine the influence of an aerobic exercise program throughout pregnancy on gestational age at the moment of delivery.

Methods:

This study was a randomized controlled trial. Three hundred and twenty Caucasian (Spanish) healthy pregnant women with singleton gestation were randomly assigned to either an exercise (n = 160) or a control (n = 160) group. Gestational age (weeks) and other outcomes were measured. The exercise program included 85 sessions (general fitness class, 3 times/week, 55–60 min/session from weeks 8–10 to weeks 38–39 of pregnancy).

Results:

Two hundred and ninety women were analyzed (exercise group EG, n = 138, control group CG, n = 152). The mean gestational age did not differ between groups (EG= 39.7± 1.3 vs CG= 39.6 ± 1.1 weeks, P = .81). Relative to preterm deliveries in EG we found 6 (4.3%) and 11 (7.2%) in CG, (P = .73).

Conclusions:

A supervised program of moderate exercise performed throughout pregnancy is not a risk of preterm delivery for healthy pregnant women.
Quality control of inner nuclear membrane proteins by the Asi complex
Authors: Foresti Ombretta , Rodriguez-Vaello Victoria , Funaya Charlotta , Carvalho Pedro
Published: September 2014

Trashing misfolded membrane proteins

Proteins move to and from the inner nuclear membrane (INM) from the rest of the endoplasmic reticulum through the nuclear pores. This movement is tightly controlled. Consequently, the INM accumulates a specific set of proteins required for a variety of functions, including chromosome organization and transcriptional control. But when INM proteins misfold, how are they eliminated? Foresti
et al.
addressed this question in yeast and found that a previously elusive branch of the endo–plasmic reticulum–associated degradation system was key (see the Perspective by Shao and Hegde).

Science
, this issue p.
751
; see also p.
701
Neural correlates of strategic reasoning during competitive games
Authors: Seo Hyojung , Cai Xinying , Donahue Christopher H. , Lee Daeyeol
Published: September 2014

Although human and animal behaviors are largely shaped by reinforcement and punishment, choices in social settings are also influenced by information about the knowledge and experience of other decision-makers. During competitive games, monkeys increased their payoffs by systematically deviating from a simple heuristic learning algorithm and thereby countering the predictable exploitation by their computer opponent. Neurons in the dorsomedial prefrontal cortex (dmPFC) signaled the animal’s recent choice and reward history that reflected the computer’s exploitative strategy. The strength of switching signals in the dmPFC also correlated with the animal’s tendency to deviate from the heuristic learning algorithm. Therefore, the dmPFC might provide control signals for overriding simple heuristic learning algorithms based on the inferred strategies of the opponent.
Genome Sequence of Bacillus anthracis STI, a Sterne-Like Georgian/Soviet Vaccine Strain
Authors: Okinaka Richard T. , Challacombe Jean , Drees Kevin , Birdsell Dawn N. , Janke Nicolette , Naumann Amber , Seymour Meagan , Hornstra Heidie , Schupp James , Sahl Jason , Foster Jeffrey T. , Pearson Talima , Turnbull Peter , Keim Paul
Published: September 2014

The
Bacillus anthracis
strain STI is a Soviet vaccine strain that lacks the pXO2 plasmid. Previous data indicate that this isolate forms a new branch within the
B. anthracis
sub-group originally identified as A. Br.008/009.
Complete Coding Sequences of Three Members of the Kokobera Group of Flaviviruses
Authors: Warrilow David , Hall-Mendelin Sonja , Hobson-Peters Jody , Prow Natalie A. , Allcock Richard , Hall Roy A.
Published: September 2014

The Kokobera group of flaviviruses circulates in Australia and Papua, New Guinea, and has been associated with occasional human polyarticular disease. To facilitate future studies to identify virulence determinants, the complete coding regions of the Stratford virus, and isolates of the Bainyik virus and Torres virus were obtained.