Search results for "FN"

Effects of Transcranial Direct Current Stimulation on Baseline and Slope of Prefrontal Cortex Hemodynamics During a Spatial Working Memory Task

2020

Background: Transcranial direct current stimulation (tDCS) has been shown to be an inexpensive, safe, and effective way of augmenting a variety of cognitive abilities. Relatively recent advances in neuroimaging technology have provided the ability to measure brain activity concurrently during active brain stimulation rather than after stimulation. The effects on brain activity elicited by tDCS during active tDCS reported by initial studies have been somewhat conflicted and seemingly dependent on whether a behavioral improvement was observed. Objective: The current study set out to address questions regarding behavioral change, within and between-participant designs as well as differentiatin…

Enhancing the performance of HSDPA communication with multipoint transmission techniques

2015

The evolution of mobile phones, tablets and other mobile communication devices has led to a significant increase in the amount of data delivered over mobile networks. In order to satisfy the climbing data rate demands of customers, existing mobile broadband networks are being expanded with new features that allow ubiquitous and consistent networking experience. This research presents three multipoint transmission techniques for Wideband Code Division Multiple Access (WCDMA) based High-Speed Downlink Packet Access (HSDPA) communication protocol. Multiflow, High-Speed Single-Frequency Network (HS-SFN) and Multipoint-to-Point Single-Frequency Network (M2P-SFN) enable transmission of user-dedicat…

Multipoint transmission scheme for HSDPA

2013

<p>Effects of losartan and atorvastatin on the development of early posttraumatic joint stiffness in a rat model</p>

2019

Background After a trauma, exuberant tissue healing with fibrosis of the joint capsule can lead to posttraumatic joint stiffness (PTJS). Losartan and atorvastatin have both shown their antifibrotic effects in different organ systems. Objective The purpose of this study was the evaluation of the influence of losartan and atorvastatin on the early development of joint contracture. In addition to joint angles, the change in myofibroblast numbers and the distribution of bone sialoprotein (BSP) were assessed. Study design and methods In this randomized and blinded experimental study with 24 rats, losartan and atorvastatin were compared to a placebo. After an initial joint injury, rat knees were …

Acute (0-2h) and delayed (2-8D) effects of exercise-induced muscle damage and soreness on elbow target movements.

2011

The aim was to examine the acute and delayed effects of exercise-induced muscle damage and soreness on elbow target movements (TM) performance and control. Ten males performed an exercise of 50 maximal eccentric elbow actions. TMs were performed at three movement ranges. Maximal forces, active stretch reflex and TM were tested, and muscle soreness, creatine kinase and elbow joint stiffness were determined acute (after and 2 h) and delayed (2, 4, 6, 8d) postexercise. Both the long lasting muscle soreness and force drop were observed after the exercise. Joint stiffness was increased at 2 h postexercise. The highest deterioration in flexion-TM performance was found at the time (2 h) and at the…

Leg and joint stiffness in human hopping

2010

The present study investigated the regulation of leg and joint stiffness in hopping at different intensity levels. Eight male subjects performed bilateral hopping at various intensity levels that were determined by peak vertical ground reaction force (GRF). In addition to the GRF, the measurements included hopping kinematics and electromyography (EMG) of selected leg muscles. While the leg and ankle joint stiffness remained invariant, the knee joint stiffness increased significantly (P<0.01) with the hopping intensity. EMG analysis revealed a significant increase in averaged EMG for all the measured muscles before and during the early phase of ground contact (P<0.05-0.001) with increasing h…

Viewpoint: On the hysteresis in the human Achilles tendon.

2012

This viewpoint was stimulated by two observations: 1) the statistical skewness whereby numerous articles have reported tendon stiffness and Young9s modulus, but far fewer have reported tendon hysteresis; 2) in vivo human studies seem very often to report hysteresis values greater than 10%, suggesting either that there are methodological differences between human and animal studies, or that human tendons have a much poorer capacity to store and reutilize elastic energy. In this article we focus on the healthy human Achilles/gastrocnemius tendon (AT) since it has an important locomotor function and clearly a low AT hysteresis would allow elastic recoil for efficient locomotion. We discuss tha…

Numerical experimental analysis of hybrid double lap aluminum-CFRP joints

2015

Abstract Due to their reliability and ease of assembly, both the adhesively bonded and the mechanical joints are commonly used in different fields of modern industrial design and manufacturing, to joint composite materials or composites with metals. As it is well known, adhesively bonded joints are characterized by high stiffness and good fatigue life, although delamination phenomena localized near the free edges may limit their use, especially for applications where corrosive environments and/or moisture can lead to premature failure of the bonding. In these cases, a possible alternative is given by the well-known mechanical joints. On the contrary, these last joints (bolted, riveted) requ…

Ritz Solution for Transient Analysis of Variable-Stiffness Shell Structures

2020

The dynamic response of thin-walled structures is driven by mass and stiffness distribution. As such, variable-stiffness (VS) composites offer opportunities to tune structural dynamic responses. To this extent, efficient analysis tools become increasingly important for structural analysis and design purposes. In this work, an efficient and versatile Ritz method for free vibrations and linear transient analysis of VS doubly curved shell structures is presented. VS shell structures are modeled as an assembly of shell-like domains. The shell kinematics is based on the first-order shear deformation theory, and no further assumption is made on the shallowness or on the thinness of the structure.…

Stiffness and Reinforcement Effect of electrical Resistance Strain Gauges

2007

:  The increasing use of low-modulus materials, on which the reinforcement effect of the electrical resistance strain gauge is not negligible, has re-opened the research interest into this issue. This study deals with the evaluation of stiffness, and of the strain gauge Young's modulus involved in the estimation of both the global and the local reinforcement effect; the relationship between the strain gauge stiffness and the local reinforcement effect is also analysed. In particular, the experimental technique used to determine the stiffness of some commercial strain gauges is described. The results show that the strain gauge stiffness alone does not permit an accurate evaluation of the loc…