Search results for "contraction"

Altération des performances neuromusculaires après un exercice physique prolongé. Analyse comparée d'une épreuve de marathon et de triathlon

1998

The aim of this study was to compare the effects of a marathon and a triathlon on isometric and dynamic neuromuscular performances. Seven triathletes took part in 3 experimental situations : a 2 h 15 mn triathlon (TRI) (30 min swimming, 60 min cycling and 45 min running), a 2 h 15 mn marathon (MA) and a 45 min isolated run done at triathlon speed. The results showed a reduction of the isometric endurance time for knee extensor muscles (35 % of maximal voluntary contraction) after TRI (41 ± 24 %) and after MA (59 ± 19 %). The height of rise of the center of gravity of the counter-movement jumps (CMJ) was also significantly lower after MA (-12 ± 1 cm) than after TRI (-2,5 0,5 cm). Kinetic ana…

BETWEEN SUCCESS AND UNSUCCESS IN ABSORBING EU FUNDS - POLAND VS. ROMANIA

2015

Component of the cohesion policy promoted by the European Commission, European grant financing represents an inexpensive and important resource for the social and economic recovery of the member states, offering the prospect for the budgetary sustainability, encouraging public and private investments and thereby reducing the development gaps both at national and international level. In the present study, through the comparative analysis between Romania and Poland in the field of EU funds absorption, we intend to identify the weaknesses and the strengths of each of the two member states, helping to formulate a set of recommendations that our country should follow in order to attract funds re…

Fixed point theorems for α-set-valued quasi-contractions in b-metric spaces

2015

Recently, Samet et al. [B. Samet, C. Vetro and P. Vetro, Fixed point theorems for alpha-psi-contractive type mappings, Nonlinear Anal., 75 (2012), 2154-2165] introduced the notion of alpha-psi-contractive mappings and established some fixed point results in the setting of complete metric spaces. In this paper, we introduce the notions of alpha-set-valued contraction and alpha-set-valued quasi-contraction and we give some fixed point theorems for such classes of mappings in the setting of b-metric spaces and ordered b-metric spaces. The presented theorems extend, unify and generalize several well-known comparable results in the existing literature.

Fluorine-Containing Functionalized Cyclopentene Scaffolds Through Ring Contraction and Deoxofluorination of Various Substituted Cyclohexenes

2018

Quantitative ring contraction of 5-hydroxy-1,3-oxazin-2-ones into 5-hydroxymethyl-1,3-oxazolidin-2-ones: A DFT study

2007

Abstract The ring contraction of trans -5-hydroxy-1,3-oxazin-2-ones 1 into cis -5-hydroxymethyl-oxazolidinones 3 was studied with different bases and nucleophiles and it was found that it is the basicity and not the nucleophilicity the factor responsible for the ring contractions. A DFT study was made for the proposed mechanism.

Effects of electrical stimulation pattern on quadriceps isometric force and fatigue in individuals with spinal cord injury

2015

Introduction Variable frequency trains (VFT) or train combinations have been suggested as useful strategies to offset the rapid fatigue induced by constant frequency trains (CFT) during electrical stimulation. However, most studies have been of short duration with limited functional application in those with spinal cord injury (SCI). We therefore tested force and fatigue in response to VFT, CFT, and combined patterns in strength training-like conditions (6-s contractions). Methods Ten SCI individuals underwent either CFT or VFT patterns until target torque was no longer produced and then switched immediately to the other pattern. Results Target torque was reached more times when VFT was use…

Coupled fixed-point results for T-contractions on cone metric spaces with applications

2015

The notion of coupled fixed point was introduced in 2006 by Bhaskar and Lakshmikantham. On the other hand, Filipovićet al. [M. Filipovićet al., “Remarks on “Cone metric spaces and fixed-point theorems of T-Kannan and T-Chatterjea contractive mappings”,” Math. Comput. Modelling 54, 1467–1472 (2011)] proved several fixed and periodic point theorems for solid cones on cone metric spaces. In this paper we prove some coupled fixed-point theorems for certain T-contractions and study the existence of solutions of a system of nonlinear integral equations using the results of our work. The results of this paper extend and generalize well-known comparable results in the literature.

Coupled fixed point theorems for symmetric (phi,psi)-weakly contractive mappings in ordered partial metric spaces

2013

We establish some coupled fixed point theorems for symmetric (phi,chi)-weakly contractive mappings in ordered partial metric spaces. Some recent results of Berinde (Nonlinear Anal. 74 (2011), 7347-7355; Nonlinear Anal. 75 (2012), 3218-3228) and many others are extended and generalized to the class of ordered partial metric spaces.

The Effect of the Cranial Electrotherapy on the Muscle Motor Function in Different Operating Modes

2015

The aim of the present study was to analyze the effect of cranial electrotherapy stimulation on muscle function analysis indicators. Instrumental assessment of muscle function (on a REV9000, Technogym, Italy) was performed before and after cranial electrotherapy stimulation, assessments of the muscle function was performed during knee extension maximum voluntary, isometric contraction (MVIC), angle velocity with load 45Nm isotonic contraction and maximum pick torque in isokinetic contraction on 30°/s, 200°/s and 300°/s and neuromuscular efficiency measurements. To analyze data was used Excel program Statistics 3.1. Subjects of our study were twenty healthy athletes of sport fitness. 1 minu…

Mechanical Coupling Between Muscle-Tendon Units Reduces Peak Stresses

2017

The presence of mechanical linkages between synergistic muscles and their common tendons may distribute forces among the involved structures. We review studies, using humans and other animals, examining muscle and tendon interactions and discuss the hypothesis that connections between muscle bellies and within tendons may serve as a mechanism to distribute forces and mitigate peak stresses. peerReviewed