bluuebunny/crossref_metadata_2025 huggingface dataset:
EMOCIONES AUTOPERCIBIDAS EN LAS CLASES DE EDUCACIÓN FÍSICA EN PRIMARIA
Authors: Gil Madrona Pedro
Published: December 2015

El presente trabajo ofrece los resultados y las principales conclusiones sobre el estudio de las emociones autopercibidas que predominan en los alumnos y maestros en las clases de Educación Física en 6º curso de Educación Primaria, para poder planificar con éxitos programas efectivos de educación emocional en ambos colectivos. La muestra han sido 376 alumnos de 6º curso de Educación Primaria y 14 maestros que imparten las clases de Educación Física a esos alumnos. Los instrumentos de medida han sido conjuntamente el cuestionario y el diferencial semántico. Los resultados revelan que alumnos y profesores experimentan emociones placenteras en la asignatura de Educación Física. Pero son los alumnos los que experimentan este tipo de emociones de manera más intensa y mayoritaria. En los profesores existe una mayor heterogeneidad de emociones, las emociones experimentadas por este grupo resultan ser menos placenteras que las de los alumnos. Respecto a las emociones displacenteras los alumnos manifiestan una identificación bastante limitada con las emociones displacenteras. Los maestros experimentan emociones displacenteras en una intensidad mayor que los alumnos.
Ideación suicida y grupo de iguales: análisis en una muestra de adolescentes venezolanos
Authors: Rodríguez Ramírez Juan Antonio , Oduber Jesús Angel
Published: December 2015

El objetivo de este estudio fue determinar un modelo de relaciones para predecir la ideación suicida de adolescentes escolarizados. Se propuso un modelo basado en la conducta suicida de los iguales, el apoyo del padre y de la madre, la violencia familiar y la depresión. La muestra estuvo conformada por 912 sujetos. Los resultados obtenidos mediante un path analysis indican que los adolescentes con síntomas de depresión optan por amigos con conductas suicidas y éstos, además, aumentan directamente la probabilidad de ideación suicida.
Percepción de la experiencia de violencia doméstica en mujeres víctimas de maltrato de pareja
Authors: Molina Rico Janneth Elizabeth , Moreno Méndez Jaime Humberto
Published: December 2015

El presente estudio tuvo como objetivo comprender las percepciones que sobre la violencia doméstica tienen un grupo de mujeres víctimas de la misma. Para tal fin se llevó a cabo una investigación de tipo cualitativo bajo la técnica de grupos focales. Los participantes de la investigación fueron 9 mujeres víctimas de la Violencia Doméstica con edades comprendidas entre los 25 y 60 años atendidas en una ONG de la ciudad de Bogotá. Se encontró en las mujeres una percepción negativa de sí mismas minimizando muchas de las capacidades que poseen y evaluando sus habilidades como inferiores a las de los hombres, las cuales han aprendido desde sus familias de origen.
Propiedades psicométrica de la escala de presencia social de las mentes en red y su aplicación en el Entorno Virtual de Enseñanza Aprendizaje UTAmed
Authors: Baez-Estradas Mario Leonardo , Ossandón Núñez Yanko
Published: December 2015

Se estudian las propiedades psicométricas de la versión en español de la medida de la presencia social de las mentes en red (Networked Minds Social Presence Measure) de Harms & Biocca (2004) en una muestra de 94 estudiantes universitarios de Arica, Chile, que hacen uso del entorno virtual de enseñanza aprendizaje (EVEA UTAmed). Se realizaron estudios de fiabilidad y un análisis factorial exploratorio con el método de componentes principales y rotación varimax y posteriormente un análisis factorial confirmatorio. Los resultados muestran la existencia de cinco subescalas con un total de 23 ítems que explican el 81,25 % de la varianza, un alpha de Cronbach de .94 y un ajuste adecuado del modelo. Se confirma además una relación positiva de la presencia social con el aprendizaje percibido. El estudio permite disponer de un instrumento más breve y adaptado a la medición de la presencia social en entornos virtuales de enseñanza aprendizaje con resultados notoriamente superior a la de los instrumentos existentes.
Precisión en la recuperación de parámetros, con datos ordinales, en el Análisis de Estructura de Covarianza y el Modelo de Rutas mediante Mínimos Cuadrados Parciales
Authors: Miranda Zapata Edgardo Daniel , Ruiz Díaz Miguel Ángel
Published: December 2015

Se compara la precisión en la recuperación de parámetros del Análisis de Estructura de Covarianza (ACOV) y el Modelo de Rutas mediante Mínimos Cuadrados Parciales (PLS-PM), en un modelo simple con variables manifiestas simuladas con escala ordinal de 5 puntos. Se utiliza un diseño experimental, manipulando el método de estimación, tamaño muestral, nivel de asimetría y tipo de especificación del modelo. Se valora la media de las diferencias absolutas para el modelo estructural. ACOV presenta estimaciones más precisas que PLS-PM en distintas condiciones experimentales. Cuando se utiliza un tamaño muestral pequeño ambas técnicas son igualmente precisas. Se sugiere utilizar ACOV frente a PLS-PM. Se desaconseja fundamentar la elección de PLS-PM frente a ACOV en la utilización de una muestra pequeña.
Social competence and career development: validation of a scale with secondary students
Authors: Carneiro Pinto Joana , Taveira Maria do Céu , Faria Liliana , Candeias Adelinda
Published: December 2015

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The Feasibility of Using Augmented Auditory Feedback From a Pressure Detecting Insole to Reduce the Knee Adduction Moment: A Proof of Concept Study
Authors: Ferrigno Christopher , Stoller Ina S. , Shakoor Najia , Thorp Laura E. , Wimmer Markus A.
Published: December 2015

The objective of this work was to conduct a proof of concept study utilizing auditory feedback from a pressure-detecting shoe insole to shift plantar pressure medially in order to reduce the knee adduction moment (KAM). When compared with normal walking, 32 healthy subjects significantly reduced their peak KAM using feedback (p < 0.001). When compared with medial thrust gait, an established gait modification, walking with pressure-based feedback was equally effective at reducing the peak KAM, yet it successfully mitigated other potentially detrimental gait measures such as the peak knee flexion moment (KFM), knee internal rotation moment (KIrM), and a reduction in speed.
Adaptive-Robust Stabilization of the Furuta's Pendulum Via Attractive Ellipsoid Method
Authors: Ordaz Patricio , Poznyak Alex
Published: December 2015

This paper focuses on the issue of adaptive-robust stabilization of the Furuta's pendulum around unstable equilibrium where the dynamical model is unknown. The control scheme lies at the lack of the dynamical model as well as external disturbances. The stabilization analysis is based on the attractive ellipsoid method (AEM) for a class of uncertain nonlinear systems having “quasi-Lipschitz” nonlinearities. Even more, a modification of the AEM concept that permits to use online information obtained during the process is suggested here. This adjustment (or adaptation) is made only in some fixed sample times, so that the corresponding gain matrix of the robust controller is given on time interval too. Furthermore, under a specific “regularized persistent excitation condition,” the proposed method guarantees that the controlled system trajectories remain inside an ellipsoid of a minimal size (the minimal size is refereed to as the minimal trace of the corresponding inverse ellipsoidal matrix). Finally, the adaptive process describes a region of attraction (ROA) of the considered system under adaptive-robust nonlinear control law.
Pilot-Dynamics Coupled Finite-Volume Analysis of Main Flow Transients Through a Pneumatic Pressure-Regulating Valve
Authors: Saha Binod Kumar , Gangopadhyay Tapas , Sanyal Dipankar
Published: December 2015

The environment management system of an aircraft requires regulated air at nearly constant temperature and pressure, despite their wide variations at the system inlet. A pressure regulation valve is an important part of that system. In response to the variation of inlet pressure, a change in the motive flow force on a spool causes a change in the steady-state opening of an orifice in the main flow path, thereby providing the pressure regulation. The change in the flow force is contributed both by the main flow and a pilot flow through a fixed orifice and a relief valve. Simple models for the pilot flow and the pressure dynamics of a pilot chamber at the head side of the spool have been developed here for capturing the spool dynamics. The transient flow through the fixed valve body and the moving spool chamber has been solved by finite-volume method with dynamic meshing. The numerical results of the pressure drop in the main flow path for the fully open spool valve have shown good agreement with the corresponding experimental results with the pilot-line flow put off by the closed relief valve. Detailed analysis of the transient main flow leading to useful design conclusions has been provided in terms of different contour plots. For a given specification of the spool valve, a parametric study has provided the appropriate length of the pilot chamber, the stiffness of the spring in the relief valve, and the size of the fixed orifice in the pilot line.
Simulation of Plasto-Elastohydrodynamic Lubrication in a Rolling Contact
Authors: He Tao , Zhu Dong , Wang Jiaxu
Published: December 2015

Surface plastic deformation due to contact (lubricated or dry) widely exists in many mechanical components, as subsurface stress caused by high-pressure concentrated in the contact zone often exceeds the material yielding limit, and the plastic strain accumulates when the load is increased and/or repeatedly applied to the surface in a rolling contact. However, previous plasto-elastohydrodynamic lubrication (PEHL) studies were mainly for the preliminary case of having a rigid ball (or roller) rotating on a stationary elastic–plastic flat with a fixed contact center, for which the numerical simulation is relatively simple. This paper presents an efficient method for simulating PEHL in a rolling contact. The von Mises yield criteria are used for determining the plastic zone, and the total computation domain is discretized into a number of cuboidal elements underneath the contacting surface, each one is considered as a cuboid with uniform plastic strain inside. The residual stress and surface plastic deformation resulted from the plastic strain can be solved as a half-space eigenstrain–eigenstress problem. A combination of three-dimensional (3D) and two-dimensional (2D) discrete convolution and fast Fourier transform (DC-FFT) techniques is used for accelerating the computation. It is observed that if a rigid ball rolls on an elastic–plastic surface, the characteristics of PEHL lubricant film thickness and pressure distribution are different from those of PEHL in the preliminary cases previously investigated. It is also found that with the increase of rolling cycles, the increment of plastic strain accumulation gradually approaches a stable value or drops down to zero, determined by the applied load and the material hardening properties, eventually causing a groove along the rolling direction. Simulation results for different material hardening properties are also compared to reveal the effect of body materials on the PEHL behaviors.
Analytical Acoustic Power Spectrum Formulations for Rotating Monopole and Dipole Point Sources
Authors: Mao Yijun , Xu Chen
Published: December 2015

Analytical acoustic power spectrum formulations for the rotating monopole and dipole point sources are proposed by employing the spherical harmonic series expansion method. Both the analytical acoustic power spectra and the overall acoustic power show a good agreement with the results obtained from other methods. A nondimensional acoustic power ratio (APR) is employed to investigate the effects of the rotational Mach number, the direction of the dipole source, and the number of sources on the acoustic power output.
Proton minibeam radiation therapy: Experimental dosimetry evaluation
Authors: Peucelle C. , Nauraye C. , Patriarca A. , Hierso E. , Fournier‐Bidoz N. , Martínez‐Rovira I. , Prezado Y.
Published: December 2015

Purpose:

Proton minibeam radiation therapy (pMBRT) is a new radiotherapy (RT) approach that allies the inherent physical advantages of protons with the normal tissue preservation observed when irradiated with submillimetric spatially fractionated beams. This dosimetry work aims at demonstrating the feasibility of the technical implementation of pMBRT. This has been performed at the Institut Curie ‐ Proton Therapy Center in Orsay.

Methods:

Proton minibeams (400 and 700 μm‐width) were generated by means of a brass multislit collimator. Center‐to‐center distances between consecutive beams of 3200 and 3500 μm, respectively, were employed. The (passive scattered) beam energy was 100 MeV corresponding to a range of 7.7 cm water equivalent. Absolute dosimetry was performed with a thimble ionization chamber (IBA CC13) in a water tank. Relative dosimetry was carried out irradiating radiochromic films interspersed in a IBA RW3 slab phantom. Depth dose curves and lateral profiles at different depths were evaluated. Peak‐to‐valley dose ratios (PVDR), beam widths, and output factors were also assessed as a function of depth.

Results:

A pattern of peaks and valleys was maintained in the transverse direction with PVDR values decreasing as a function of depth until 6.7 cm. From that depth, the transverse dose profiles became homogeneous due to multiple Coulomb scattering. Peak‐to‐valley dose ratio values extended from 8.2 ± 0.5 at the phantom surface to 1.08 ± 0.06 at the Bragg peak. This was the first time that dosimetry in such small proton field sizes was performed. Despite the challenge, a complete set of dosimetric data needed to guide the first biological experiments was achieved.

Conclusions:

pMBRT is a novel strategy in order to reduce the side effects of RT. This works provides the experimental proof of concept of this new RT method: clinical proton beams might allow depositing a (high) uniform dose in a brain tumor located in the center of the brain (7.5 cm depth, the worst scenario), while a spatial fractionation of the dose is retained in the normal tissues in the beam path, potentially leading to a gain in tissue sparing. This is the first complete experimental implementation of this promising technique. Biological experiments are needed in order to confirm the clinical potential of pMBRT.
Mud tsunami wreaks ecological havoc in Brazil
Authors: Escobar Herton
Published: December 2015

Researchers analyze sludge for heavy metals and assess potential for recovery.
DNA helps build molecular libraries for drug testing
Authors: Gura Trisha
Published: December 2015

Pharmaceutical firms and biotech companies embrace DNA-encoded chemical libraries.
U.K. research wins hollow victory
Authors: Stokstad Erik
Published: December 2015

Budget is protected for 5 years, but lags because of past inflation.
NSF's novel solution to a workload crunch
Authors: Mervis Jeffrey
Published: December 2015

Hiring more rotators and clamping down on submissions helped avert a labor crisis.
Cell-sorting technologies: Organelle recitals
Authors: Dove Alan
Published: December 2015

To isolate and study organelles from cells, scientists use methods that range from primitive to modern.

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Stem cells and healthy aging
Authors: Goodell Margaret A. , Rando Thomas A.
Published: December 2015

Research into stem cells and aging aims to understand how stem cells maintain tissue health, what mechanisms ultimately lead to decline in stem cell function with age, and how the regenerative capacity of somatic stem cells can be enhanced to promote healthy aging. Here, we explore the effects of aging on stem cells in different tissues. Recent research has focused on the ways that genetic mutations, epigenetic changes, and the extrinsic environmental milieu influence stem cell functionality over time. We describe each of these three factors, the ways in which they interact, and how these interactions decrease stem cell health over time. We are optimistic that a better understanding of these changes will uncover potential strategies to enhance stem cell function and increase tissue resiliency into old age.
Democratizing education? Examining access and usage patterns in massive open online courses
Authors: Hansen John D. , Reich Justin
Published: December 2015

Toward a level playing field?

Do free learning resources benefit the disadvantaged and decrease gaps between rich and poor? Hansen and Reich studied the relationships between socioeconomic status (SES) and enrollment in and completion of free Massive Open Online Courses (MOOCs) offered by Harvard and MIT. Students from low-SES backgrounds were less likely to enroll in MOOCs and earn a certificate than their high-SES peers. Thus, although there are many free online learning opportunities, it is not safe to assume that they will “level the playing field.”

Science
, this issue p. 1245
Evidence for a fractional fractal quantum Hall effect in graphene superlattices
Authors: Wang Lei , Gao Yuanda , Wen Bo , Han Zheng , Taniguchi Takashi , Watanabe Kenji , Koshino Mikito , Hone James , Dean Cory R.
Published: December 2015

Mixing interactions and superlattices

Under the influence of an external magnetic field, the energies of electrons in two-dimensional systems group into the so-called Landau levels. In the cleanest samples, interactions among electrons lead to fractional quantum Hall (FQH) states. If such a system is then subjected to a superlattice potential, it is unclear whether the fragile FQH states will survive. To address this question, Wang
et al.
sandwiched graphene between two layers of hexagonal boron nitride. Transport measurements on the superlattice showed that some FQH states did survive. Furthermore, the interplay between interactions and the superlattice potential produced additional, anomalous states.

Science
, this issue p. 1231
Comment on “Worldwide evidence of a unimodal relationship between productivity and plant species richness”
Authors: Laanisto Lauri , Hutchings Michael J.
Published: December 2015

Fraser
et al
. (Reports, 17 July 2015, p. 302) report that a hump-backed model describes the worldwide relationship between productivity and plant species richness in grassland communities. We reanalyze their data from a larger-scale perspective, using local species pool. This influences richness far more strongly than productivity, and, when this is taken into account, the hump-backed richness-productivity relationship disappears.
Teamwork: The tumor cell edition
Authors: Cleary Allison S.
Published: December 2015

Subclone cooperation maintains tumor growth
HIV-specific B cell response in patients with broadly neutralizing serum activity
Authors: Scheid Johannes F.
Published: December 2015

Antibody characterization from single B cells led to identification of monoclonal antibodies with broad and potent activity against HIV
A simple prioritisation system to improve the electronic handover
Authors: Ah-kye Laura , Moore Madeline
Published: December 2015

The General Medical Council (GMC) states, “A well managed, thorough and organized handover is crucial for ensuring the quality and safety for patient care,” and in their guidance on safe handover the British Medical Association (BMA) advised that “clinically unstable patients are known to the senior and covering clinicians; tasks should be prioritised; plans for further care are put in place; unstable patients are reviewed.”

The orthopaedic department at King’s College Hospital, a busy major trauma centre in London, UK, has a significantly reduced workforce during the weekend. The general consensus was that the ward round was taking too long, giving the foundation year one (FY1) doctor very little time to commit to other ward jobs and reviewing unstable patients, making it a stressful and challenging environment.

The electronic patient record (EPR), an electronic programme available on all Trust computers, is already a very reliable way to allow safe handover of information via a central electronic database. However it has limitations in clearly prioritising more unstable patients from those needing routine review.

We created an easily identifiable traffic light coding system that could be simply incorporated into the electronic handover that was re-reviewed and finalised in order to improve the ability to prioritise patients for senior review. This in turn would directly impact the efficiency of the ward round and improve patient safety.

Our immediate results demonstrated the efficiency of the ward round improved in all parameters: time to complete the ward round improved from 7.1% to 50%; prioritisation and ability to highlight the clinical urgency for patient review improved from 15.4% to 100%; and more notably, the clinician’s impression of patient safety improved from 38.5% to 100%.

Overall the introduction of an uncomplicated traffic light system provided an effective addition to the electronic handover structure aimed to allow patient prioritisation and improved efficiency during weekend hours.
Improving emergency department flow through Rapid Medical Evaluation unit
Authors: Chartier Lucas , Josephson Timothy , Bates Kathy , Kuipers Meredith
Published: December 2015

The Toronto Western Hospital is an academic hospital in Toronto, Canada, with an annual Emergency Department (ED) volume of 64,000 patients. Despite increases in patient volumes of almost six percent per annum over the last decade, there have been no commensurate increases in resources, infrastructure, and staffing. This has led to substantial increase in patient wait times, most specifically for those patients with lower acuity presentations. Despite requiring only minimal care, these patients contribute disproportionately to ED congestion, which can adversely impact resource utilization and quality of care for all patients.

We undertook a retrospective evaluation of a quality improvement initiative aimed at improving wait times experienced by patients with lower acuity presentations. A rapid improvement event was organized by frontline workers to rapidly overhaul processes of care, leading to the creation of the Rapid Medical Evaluation (RME) unit – a new pathway of care for patients with lower acuity presentations. The RME unit was designed by re-purposing existing resources and re-assigning one physician and one nurse towards the specific care of these patients. We evaluated the performance of the RME unit through measurement of physician initial assessment (PIA) times and total length of stay (LOS) times for multiple groups of patients assigned to various ED care pathways, during three periods lasting three months each.

Weekly measurements of mean and 90th percentile of PIA and LOS times showed special cause variation in all targeted patient groups. Of note, the patients seen in the RME unit saw their median PIA and LOS times decrease from 98min to 70min and from 165min to 130min, respectively, from baseline. Despite ever-growing numbers of patient visits, wait times for all patients with lower acuity presentations remained low, and wait times of patients with higher acuity presentations assigned to other ED care pathways were not adversely affected.

By specifically re-purposing a fraction of existing staff, resources, and infrastructure for patients with lower acuity presentations, we were able to streamline their care and decrease wait times in the ED. These results were achieved through the incremental improvements afforded by rapidly cycling through PDSA cycles, with strong frontline staff involvement and continuously eliciting feedback for improvement. We believe the model to be replicable in other academic medical centres.
Cause of death in patients with atrial fibrillation admitted to French hospitals in 2012: a nationwide database study
Authors: Fauchier Laurent , Samson Adeline , Chaize Gwendoline , Gaudin Anne-Françoise , Vainchtock Alexandre , Bailly Cécile , Cotté Francois-Emery
Published: December 2015

Objective

Most patients with atrial fibrillation (AF) have risk factors and coexisting conditions that increase their mortality risk. We performed a cause-of-death analysis to identify predictors of mortality in hospitalised patients with AF in France.

Methods and results

In this retrospective, population-based cross-sectional study, theProgramme de médicalisation des systèmes d'informationwas used to identify 533 044 adults with a diagnosis of AF or atrial flutter hospitalised for any reason in France from January through December 2012. Stepwise multivariable analyses were performed to identify determinants of mortality. The mean age was 78.0±11.4 years, 47.1% were women, and the mean CHA2DS2-VASc score was 4.0±1.8. During hospitalisation, 9.4% (n=50 165) of the patients died, 34% due to a cardiovascular event, most often heart failure (16.6%), stroke/transient ischaemic attack/systemic embolism (9.8%) or vascular or ischaemic disease (4.0%). The strongest predictors of overall death were age ≥75 years (OR 2.57, 95% CI 2.47 to 2.68), renal failure (OR 1.85, 95% CI 1.81 to 1.89), cancer (OR 1.81, 95% CI 1.78 to 1.85) and lung disease (OR 1.58, 95% CI 1.55 to 1.62).

Conclusions

Cardiovascular events were the most common cause of death, occurring in one-third of patients, in this comprehensive study of hospitalised patients with AF. Despite the high risk of stroke in this population, only 10% died from stroke/transient ischaemic attack/systemic embolism. The strongest predictors of overall death were non-cardiovascular. Physicians should be encouraged to focus on preventable serious and disabling cardiovascular events (such as stroke) as well as on potentially fatal non-cardiovascular comorbidities.
Thermal corrections to the Casimir energy in a general weak gravitational field
Authors: Nazari Borzoo
Published: December 2015

We calculate finite temperature corrections to the energy of the Casimir effect of a two conducting parallel plates in a general weak gravitational field. After solving the Klein–Gordon equation inside the apparatus, mode frequencies inside the apparatus are obtained in terms of the parameters of the weak background. Using Matsubara’s approach to quantum statistical mechanics gravity-induced thermal corrections of the energy density are obtained. Well-known weak static and stationary gravitational fields are analyzed and it is found that in the low temperature limit the energy of the system increases compared to that in the zero temperature case.
New full velocity difference model considering the driver’s heterogeneity of the disturbance risk preference for car-following theory
Authors: Zeng You-Zhi , Zhang Ning
Published: December 2015

This paper proposes a new full velocity difference model considering the driver’s heterogeneity of the disturbance risk preference for car-following theory to investigate the effects of the driver’s heterogeneity of the disturbance risk preference on traffic flow instability when the driver reacts to the relative velocity. We obtain traffic flow instability condition and the calculation method of the unstable region headway range and the probability of traffic congestion caused by a small disturbance. The analysis shows that has important effects the driver’s heterogeneity of the disturbance risk preference on traffic flow instability: (1) traffic flow instability is independent of the absolute size of the driver’s disturbance risk preference coefficient and depends on the ratio of the preceding vehicle driver’s disturbance risk preference coefficient to the following vehicle driver’s disturbance risk preference coefficient; (2) the smaller the ratio of the preceding vehicle driver’s disturbance risk preference coefficient to the following vehicle driver’s disturbance risk preference coefficient, the smaller traffic flow instability and vice versa. It provides some viable ideas to suppress traffic congestion.
Influence of community structure on the synchronization of power network
Authors: Yang Li-Xin , Jiang Jun , Liu Xiao-Jun
Published: December 2015

This paper studies the synchronizability of power network with community structure. Second-order Kuramoto-like oscillators with dissimilar natural frequencies are used as a coarse-scale model for an electrical power network that contains generators and consumers. The impact of community structure on frequency synchronization of power network is investigated, focusing on the parameters such as community strength, community number and connection strategy between communities. Numerical simulations show that increasing the community strength above a certain critical threshold or adding new communities to the network will be beneficial for the synchronization. Of course, connecting high-degree nodes among communities will be a best strategy to enhance synchronization. Furthermore, it is observed that the synchronizability of the network is significantly influenced by adding new links with different characteristics.
Noise Induced Jumping Dynamics Between Synchronized Modes
Authors: Algar Shannon D. , Stemler Thomas , De Saedeleer Bernard
Published: December 2015

Synchronization is a common phenomenon whereby a dynamical system follows the pacemaker provided by an external forcing. Often, such systems have multiple synchronization modes, which are equivalent solutions. We investigate the specific case of two to one synchronization produced by the periodic forcing of a van der Pol oscillator where two possible modes, shifted by one period of the modulation, exist. By studying the flow and the local Lyapunov exponents along the orbit we give an explanation of the noise induced jumps observed in a stochastic forced oscillator. While this investigation gives results that are specific to this system, the framework presented is more general and can be applied to any system showing similar jumping dynamics.
Period-Adding Structures in the Parameter-Space of a Driven Josephson Junction
Authors: Rech Paulo C.
Published: December 2015

Two-dimensional parameter-space diagrams related to a driven Josephson junction are reported. Three cases are considered, namely those involving the external direct current as one of the parameters. Typical periodic structures embedded in a chaotic region are observed in all diagrams, organized in different ways: (i) As structures with a similar shape to the Arnold tongues of the circle map, in period-adding sequences, and (ii) as structures with other shapes, in arrangements including two mixed sets of period-adding sequences.
A Simple Chaotic Flow with a Continuously Adjustable Attractor Dimension
Authors: Munmuangsaen Buncha , Sprott Julien Clinton , Thio Wesley Joo-Chen , Buscarino Arturo , Fortuna Luigi
Published: December 2015

This paper describes two simple three-dimensional autonomous chaotic flows whose attractor dimensions can be adjusted continuously from [Formula: see text] to [Formula: see text] by a single control parameter. Such a parameter provides a means to explore the route through limit cycles, period-doubling, dissipative chaos, and eventually conservative chaos. With an absolute-value nonlinearity and certain choices of parameters, the systems have a vast and smooth continual transition path from dissipative chaos to conservative chaos. One system is analyzed in detail by means of the largest Lyapunov exponent, Kaplan–Yorke dimension, bifurcations, coexisting attractors and eigenvalues of the Jacobian matrix. An electronic version of the system has been constructed and shown to perform in accordance with expectations.
Parameters Identification by a Piecewise Adaptive Rule with a Fractional Power
Authors: Xu Bing , Lin Wei
Published: December 2015

Unraveling parameters in real systems, such as physical systems and biological systems, is one of the central topics in model-driven research including computational systems biology. The existing adaptive synchronization technique, though theoretically proved to be valid for parameters identification in some representative models, is always showing unsatisfactory convergence rate when the number of parameters increases and real data are taken into account. In this paper, a piecewise adaptive rule with a fractional power based on finite time control is proposed to accelerate the rate for parameter identification. The global feasibility of the proposed rule is proved theoretically and illustrated by several examples of physical and biological significance.
Nuts and Bolts of a Knowledge Management System
Authors: Williams David
Published: December 2015

This paper draws on work previously published on the difference between knowledge and information by the author (2014) as well as research into management and systems design, to propose a model for what a knowledge management system (KMS) might be comprised of. It proposes an architecture comprising specific elements that must be in place for a system to be considered a “KMS”. These elements are further broken down into a range of components within those elements that may exist to contribute to the functioning of a KMS.
Finite Element Model to Study One Dimensional Calcium Dyanmics in Cardiac Myocytes
Authors: Pathak Kunal B , Adlakha Neeru
Published: December 2015

The multi physical process involving calcium ions regulate expansion and contraction of cardiac myocytes. This mechanism of expansion and contraction of cardiac myocytes is responsible for contraction and expansion of heart for pumping of blood into arteries and receiving blood into heart from vein. Thus calcium dynamics in cardiac myocytes is responsible for the activities of the myocytes cells and functioning of the heart. The specific spatiotemporal calcium ion dynamics is required to trigger, sustain and terminate activity of the cell. In this paper an attempt has been done to propose a model to study calcium dynamics in cardiac myocytes for a one-dimensional unsteady state case. The model incorporates the process like diffusion, reaction involving source and excess buffers. Appropriate boundary conditions and initial conditions have been framed. The finite element method has been employed to obtain the solution. The numerical results have been used to study the effect of buffers and source influx on calcium dynamics in cardiac myocytes.
Meiotic Silencing in Mammals
Authors: Turner James M.A.
Published: December 2015

Meiosis is essential for reproduction in sexually reproducing organisms. A key stage in meiosis is the synapsis of maternal and paternal homologous chromosomes, accompanied by exchange of genetic material to generate crossovers. A decade ago, studies found that when chromosomes fail to synapse, the many hundreds of genes housed within them are transcriptionally inactivated. This process, meiotic silencing, is conserved in all mammals studied to date, but its purpose is not yet defined. Here, I review the molecular genetics of meiotic silencing and consider the many potential functions that it could serve in the mammalian germ line. In addition, I discuss how meiotic silencing influences sex differences in meiotic infertility and the profound impact that meiotic silencing has had on the evolution of mammalian sex chromosomes.
Reduction in single muscle fiber rate of force development with aging is not attenuated in world class older masters athletes
Authors: Power Geoffrey A. , Minozzo Fábio C. , Spendiff Sally , Filion Marie-Eve , Konokhova Yana , Purves-Smith Maddy F. , Pion Charlotte , Aubertin-Leheudre Mylène , Morais José A. , Herzog Walter , Hepple Russell T. , Taivassalo Tanja , Rassier Dilson E.
Published: December 2015

Normal adult aging is associated with impaired muscle contractile function; however, to what extent cross-bridge kinetics are altered in aging muscle is not clear. We used a slacken restretch maneuver on single muscle fiber segments biopsied from the vastus lateralis of young adults (∼23 yr), older nonathlete (NA) adults (∼80 yr), and age-matched world class masters athletes (MA; ∼80 yr) to assess the rate of force redevelopment ( ktr) and cross-bridge kinetics. A post hoc analysis was performed, and only the mechanical properties of “slow type” fibers based on unloaded shortening velocity ( Vo) measurements are reported. The MA and NA were ∼54 and 43% weaker, respectively, for specific force compared with young. Similarly, when force was normalized to cross-sectional area determined via the fiber shape angularity data, both old groups did not differ, and the MA and NA were ∼43 and 48% weaker, respectively, compared with young ( P < 0.05). Vo for both MA and NA old groups was 62 and 46% slower, respectively, compared with young. Both MA and NA adults had approximately two times slower values for ktr compared with young. The slower Vo in both old groups relative to young, coupled with a similarly reduced ktr, suggests impaired cross-bridge kinetics are responsible for impaired single fiber contractile properties with aging. These results challenge the widely accepted resilience of slow type fibers to cellular aging.
Maternal conjugated linoleic acid supplementation reverses high-fat diet-induced skeletal muscle atrophy and inflammation in adult male rat offspring
Authors: Pileggi C. A. , Segovia S. A. , Markworth J. F. , Gray C. , Zhang X. D. , Milan A. M. , Mitchell C. J. , Barnett M. P. G. , Roy N. C. , Vickers M. H. , Reynolds C. M. , Cameron-Smith D.
Published: December 2015

A high-saturated-fat diet (HFD) during pregnancy and lactation leads to metabolic disorders in offspring concomitant with increased adiposity and a proinflammatory phenotype in later life. During the fetal period, the impact of maternal diet on skeletal muscle development is poorly described, despite this tissue exerting a major influence on life-long metabolic health. This study investigated the effect of a maternal HFD on skeletal muscle anabolic, catabolic, and inflammatory signaling in adult rat offspring. Furthermore, the actions of maternal-supplemented conjugated linoleic acid (CLA) on these measures of muscle phenotype were investigated. A purified control diet (CD; 10% kcal fat), a CD supplemented with CLA (CLA; 10% kcal fat, 1% total fat as CLA), a high-fat (HFD; 45% kcal fat from lard), or a HFD supplemented with CLA (HFCLA; 45% kcal fat from lard, 1% total fat as CLA) was fed ad libitum to female Sprague-Dawley rats for 10 days before mating and throughout gestation and lactation. Male offspring received a standard chow diet from weaning, and the gastrocnemius was collected for analysis at day 150. Offspring from HF and HFCLA mothers displayed lower muscular protein content accompanied by elevated monocyte chemotactic protein-1, IL-6, and IL-1β concentrations. Phosphorylation of NF-κBp65 (Ser536) and expression of the catabolic E3 ligase muscle ring finger 1 (MuRF1) were increased in HF offspring, an effect reversed by maternal CLA supplementation. The present study demonstrates the importance of early life interventions to ameliorate the negative effects of poor maternal diet on offspring skeletal muscle development.
Sampling frequency affects the processing of Actigraph raw acceleration data to activity counts
Authors: Brønd Jan Christian , Arvidsson Daniel
Published: December 2015

ActiGraph acceleration data are processed through several steps (including band-pass filtering to attenuate unwanted signal frequencies) to generate the activity counts commonly used in physical activity research. We performed three experiments to investigate the effect of sampling frequency on the generation of activity counts. Ideal acceleration signals were produced in the MATLAB software. Thereafter, ActiGraph GT3X+ monitors were spun in a mechanical setup. Finally, 20 subjects performed walking and running wearing GT3X+ monitors. Acceleration data from all experiments were collected with different sampling frequencies, and activity counts were generated with the ActiLife software. With the default 30-Hz (or 60-Hz, 90-Hz) sampling frequency, the generation of activity counts was performed as intended with 50% attenuation of acceleration signals with a frequency of 2.5 Hz by the signal frequency band-pass filter. Frequencies above 5 Hz were eliminated totally. However, with other sampling frequencies, acceleration signals above 5 Hz escaped the band-pass filter to a varied degree and contributed to additional activity counts. Similar results were found for the spinning of the GT3X+ monitors, although the amount of activity counts generated was less, indicating that raw data stored in the GT3X+ monitor is processed. Between 600 and 1,600 more counts per minute were generated with the sampling frequencies 40 and 100 Hz compared with 30 Hz during running. Sampling frequency affects the processing of ActiGraph acceleration data to activity counts. Researchers need to be aware of this error when selecting sampling frequencies other than the default 30 Hz.
No effect of acute beetroot juice ingestion on oxygen consumption, glucose kinetics, or skeletal muscle metabolism during submaximal exercise in males
Authors: Betteridge Scott , Bescós Raúl , Martorell Miquel , Pons Antoni , Garnham Andrew P. , Stathis Christos C. , McConell Glenn K.
Published: December 2015

Beetroot juice, which is rich in nitrate (NO3−), has been shown in some studies to decrease oxygen consumption (V̇o2) for a given exercise workload, i.e., increasing efficiency and exercise tolerance. Few studies have examined the effect of beetroot juice or nitrate supplementation on exercise metabolism. Eight healthy recreationally active males participated in three trials involving ingestion of either beetroot juice (Beet; ∼8 mmol NO3−), Placebo (nitrate-depleted Beet), or Beet + mouthwash (Beet+MW), all of which were performed in a randomized single-blind crossover design. Two-and-a-half hours later, participants cycled for 60 min on an ergometer at 65% of V̇o2 peak. [6,6-2H]glucose was infused to determine glucose kinetics, blood samples obtained throughout exercise, and skeletal muscle biopsies that were obtained pre- and postexercise. Plasma nitrite [NO2−] increased significantly (∼130%) with Beet, and this was attenuated in MW+Beet. Beet and Beet+MW had no significant effect on oxygen consumption, blood glucose, blood lactate, plasma nonesterified fatty acids, or plasma insulin during exercise. Beet and Beet+MW also had no significant effect on the increase in glucose disposal during exercise. In addition, Beet and Beet+MW had no significant effect on the decrease in muscle glycogen and phosphocreatine and the increase in muscle creatine, lactate, and phosphorylated acetyl CoA carboxylase during exercise. In conclusion, at the dose used, acute ingestion of beetroot juice had little effect on skeletal muscle metabolism during exercise.
Flexible adaptation to an artificial recurrent connection from muscle to peripheral nerve in man
Authors: Kato Kenji , Sasada Syusaku , Nishimura Yukio
Published: December 2015

Controlling a neuroprosthesis requires learning a novel input-output transformation; however, how subjects incorporate this into limb control remains obscure. To elucidate the underling mechanisms, we investigated the motor adaptation process to a novel artificial recurrent connection (ARC) from a muscle to a peripheral nerve in healthy humans. In this paradigm, the ulnar nerve was electrically stimulated in proportion to the activation of the flexor carpi ulnaris (FCU), which is ulnar-innervated and monosynaptically innervated from Ia afferents of the FCU, defined as the “homonymous muscle,” or the palmaris longus (PL), which is not innervated by the ulnar nerve and produces similar movement to the FCU, defined as the “synergist muscle.” The ARC boosted the activity of the homonymous muscle and wrist joint movement during a visually guided reaching task. Participants could control muscle activity to utilize the ARC for the volitional control of wrist joint movement and then readapt to the absence of the ARC to either input muscle. Participants reduced homonymous muscle recruitment with practice, regardless of the input muscle. However, the adaptation process in the synergist muscle was dependent on the input muscle. The activity of the synergist muscle decreased when the input was the homonymous muscle, whereas it increased when it was the synergist muscle. This reorganization of the neuromotor map, which was maintained as an aftereffect of the ARC, was observed only when the input was the synergist muscle. These findings demonstrate that the ARC induced reorganization of neuromotor map in a targeted and sustainable manner.
Vestibulo-spinal and vestibulo-ocular reflexes are modulated when standing with increased postural threat
Authors: Naranjo E. N. , Cleworth T. W. , Allum J. H. J. , Inglis J. T. , Lea J. , Westerberg B. D. , Carpenter M. G.
Published: December 2015

We investigated how vestibulo-spinal reflexes (VSRs) and vestibulo-ocular reflexes (VORs) measured through vestibular evoked myogenic potentials (VEMPs) and video head impulse test (vHIT) outcomes, respectively, are modulated during standing under conditions of increased postural threat. Twenty-five healthy young adults stood quietly at low (0.8 m from the ground) and high (3.2 m) surface height conditions in two experiments. For the first experiment ( n = 25) VEMPs were recorded with surface EMG from inferior oblique (IO), sternocleidomastoid (SCM), trapezius (TRP), and soleus (SOL) muscles in response to 256 air-conducted short tone bursts (125 dB SPL, 500 Hz, 4 ms) delivered via headphones. A subset of subjects ( n = 19) also received horizontal and vertical head thrusts (∼150°/s) at each height in a separate session, comparing eye and head velocities by using a vHIT system for calculating the functional VOR gains. VEMP amplitudes (IO, TRP, SOL) and horizontal and vertical vHIT gains all increased with high surface height conditions ( P < 0.05). Changes in IO and SCM VEMP amplitudes as well as horizontal vHIT gains were correlated with changes in electrodermal activity (ρ = 0.44–0.59, P < 0.05). VEMP amplitude for the IO also positively correlated with fear (ρ = 0.43, P = 0.03). Threat-induced anxiety, fear, and arousal have significant effects on VSR and VOR gains that can be observed in both physiological and functional outcome measures. These findings provide support for a potential central modulation of the vestibular nucleus complex through excitatory inputs from neural centers involved in processing fear, anxiety, arousal, and vigilance.
MIrExpress: A Database for Gene Coexpression Correlation in Immune Cells Based on Mutual Information and Pearson Correlation
Authors: Wang Luman , Mo Qiaochu , Wang Jianxin
Published: December 2015

Most current gene coexpression databases support the analysis for linear correlation of gene pairs, but not nonlinear correlation of them, which hinders precisely evaluating the gene-gene coexpression strengths. Here, we report a new database, MIrExpress, which takes advantage of the information theory, as well as the Pearson linear correlation method, to measure the linear correlation, nonlinear correlation, and their hybrid of cell-specific gene coexpressions in immune cells. For a given gene pair or probe set pair input by web users, both mutual information (MI) and Pearson correlation coefficient (r) are calculated, and several corresponding values are reported to reflect their coexpression correlation nature, including MI andrvalues, their respective rank orderings, their rank comparison, and their hybrid correlation value. Furthermore, for a given gene, the top 10 most relevant genes to it are displayed with the MI,r, or their hybrid perspective, respectively. Currently, the database totally includes 16 human cell groups, involving 20,283 human genes. The expression data and the calculated correlation results from the database are interactively accessible on the web page and can be implemented for other related applications and researches.