Alternating or Bilateral Exercise Training does not Influence Force Control during Single-Leg Submaximal Contractions with the Dorsiflexors

The aim of the study was to assess the influence of habitual training history on force steadiness and the discharge characteristics of motor units in tibialis anterior during submaximal isometric contractions. Fifteen athletes whose training emphasized alternating actions (11 runners and 4 cyclists) and fifteen athletes who relied on bilateral actions with leg muscles (7 volleyball players, 8 weight-lifters) performed 2 maximal voluntary contractions (MVC) with the dorsiflexors, and 3 steady contractions at 8 target forces (2.5%, 5%, 10%, 20%, 30%, 40%, 50% and 60% MVC). The discharge characteristics of motor units in tibialis anterior were recorded using high-density electromyography grids. The MVC force and the absolute (standard deviation) and normalized (coefficient of variation) amplitudes of the force fluctuations at all target forces were similar between groups. The coefficient of variation for force decreased progressively from 2.5% to 20% MVC force, then it plateaued until 60% MVC force. Mean discharge rate of the motor units in tibialis anterior was similar at all target forces between groups. The variability in discharge times (coefficient of variation for interspike interval) and the variability in neural drive (coefficient of variation of filtered cumulative spike train) was also similar for the two groups. These results indicate that athletes who have trained with either alternating or bilateral actions with leg muscles has similar effects on maximal force, force control, and variability in the independent and common synaptic input during a single-limb isometric task with the dorsiflexors

Force variability during isometric wrist flexion in highly skilled and sedentary individuals

The association of expertness in specific motor activities with a higher ability to sustain a constant application of force, regardless of muscle length, has been hypothesized. Ten highly skilled (HS group) young tennis and handball athletes and 10 sedentary (S group) individuals performed maximal and submaximal (5, 10, 20, 50, and 75% of the MVC) isometric wrist flexions on an isokinetic dynamometer (Kin-Com, Chattanooga). The wrist joint was fixed at five different angles (230, 210, 180, 150, and 1300). For each position the percentages of the maximal isometric force were calculated and participants were asked to maintain the respective force level for 5 s. Electromyographic (EMG) activation of the Flexor Carpi Ulnaris and Extensor Digitorum muscles was recorded using bipolar surface electrodes. No significant differences were observed in maximal isometric strength between HS and S groups. Participants of HS group showed significantly (P < 0.05) smaller force coefficient of variability (CV) and SD values at all submaximal levels of MVC at all wrist angles. The CV and SD values remained unaltered regardless of wrist angle. No difference in normalized agonist and antagonist EMG activity was observed between the two groups. It is concluded that long-term practice could be associated with decreased isometric force variability independently from muscular length and coactivation of the antagonist muscles

Strategic positioning of the ‘ERATOSTHENES Research Centre’ and exploration of new R&D opportunities in the fields of Earth Surveillance and Space-Based of the Environment

The aim of this paper is to present our strategy and vision to upgrade the existing ERATOSTHENES Research Centre (ERC), established within Cyprus University of Technology (CUT), into a sustainable, viable and autonomous Centre of Excellence (CoE) for Earth Surveillance and Space-Based Monitoring of the Environment (EXCELSIOR), which will provide the highest quality of related services both on the National, European and International levels. The ‘EXCELSIOR’ project is a Horizon 2020 Teaming project, addressing the reduction of substantial disparities in the European Union by supporting research and innovation activities and systems in low performing countries. It also aims at establishing long-term and strategic partnerships between the Teaming partners, thus reducing internal research and innovation disparities within European Research and Innovation landscape. The ERCis already an established player in the local community and has excellent active collaboration with actors from various sectors in (a) the government, (b) industry, (c) local organisations, and (d) society. In order to further engage users and citizens and to become more attractive to international research and education community, the Centre aims to be fully involved in strategic positioning on the national level, but also in Europe, the Middle East region and internationally. Some examples of how space technologies are integrated with other tools or techniques such as UAV, field spectroscopy, micro-sensors, EO space/in-situ sensors etc. for the systematic monitoring of the environment is shown. Indeed such examples fulfills the objectives of the COPERNICUS academy network (in which ERC is a member) for empowering the next generation of researchers, scientists, and entrepreneurs with suitable skill sets to use Copernicus data and information services to their full potential. Finally, opportunities for future collaboration and investments with the ERC in the Eastern Mediterranean Region are stated. Five partners have united to upgrade the existing ERC into a CoE, with the common vision to become a world-class innovation, research and education centre, actively contributing to the European Research Area (ERA). More specifically, the Teaming project is a team effort between the Cyprus University of Technology (CUT, acting as the coordinator), the German Aerospace Centre (DLR), the Institute for Astronomy and Astrophysics Space Applications and Remote Sensing of the National Observatory of Athens (NOA), the German Leibniz Institute for Tropospheric Research (TROPOS) and the Cyprus’ Department of Electronic Communications of the Ministry of Transport, Communications and Works (DEC-MTCW)

MODIFIKACIJE MAKSIMALNE SILE I NEURALNE AKTIVACIJE MIŠIĆA GLEŽNJA U ZAVISNOSTI OD DOMINANTNOG EKSTREMITETA

The purpose of the present empirical study was to assess the differences in dominance between lower limb maximal voluntary contraction (MVC) and neural activation. Twenty active and right-leg dominant (age: 31.3 ± 9.5 years, height: 178.2 ± 7.6 cm, weight: 76.5 ± 11.0 kg) participants performed 3 maximal dorsal flexions (DF) and plantar flexions (PF) at 3 ankle angles (75°, 90°: anatomical position, and 105°) which corresponded to short, intermediate and long lengths for DF muscles and the opposite for PF muscles. Electromyography (EMG) was used to assess ankle muscle activity (tibialis anterior, gastrocnemius medialis and soleus). The results showed non-significant differences between lower limb MVC force and EMG-muscle activation. However, a significant main effect of the angle was observed. During DF, the MVC force was greater (p < 0.05) at 90° and 105° than at 75° for both legs and during PF, the MVC force was greater (p < 0.05) at 75° and 105° than at 90° for both legs. Moreover, during DF and PF, the EMG-muscle activation was greater (p < 0.05) at 105° than at 75° an 90° for both legs. The results indicate that dominance was not associated with different levels of force and neural activation during maximal voluntary contraction with the ankle muscles. It is concluded that dominance does not have an impact on maximal strength and neural activation of the ankle muscles and any mechanisms that contribute to the  dominance effect were not evident within this experimental protocol.Cilj istraživanja bio je da se procene razlike između maksimalne voljne kontrakcije donjih ekstremiteta (MVC) i neuronske aktivacije na osnovu dominantne noge. Dvadeset aktivnih ispitanika sa dominantnom desnom nogom (starost: 31,3 ± 9,5 godina, visina: 178,2 ± 7,6 cm, težina: 76,5 ± 11,0 kg) izvelo je 3 maksimalne dorzalne fleksije (DF) i plantarne fleksije (PF) pod 3 ugla skočnog zgloba (75 °, 90 °: anatomski položaj i 105 °), što odgovara kratkim, srednjim i većim dužinama za DF mišiće, a suprotno za PF mišiće. Elektromiografija (EMG) je korišćena za procenu aktivnosti mišića skočnog zgloba (tibialis anterior, gastrocnemius medialis i soleus). Rezultati su pokazali neznatne razlike između MVC sile donjih ekstremiteta i aktivacije EMG mišića. Međutim, primećen je značajan glavni efekat ugla. Tokom DF, MVC sila je bila veća (p < 0,05) na 90° i 105° nego na 75° za obe noge i tokom PF, MVC sila je bila veća (p < 0,05) na 75° i 105° nego na 90° za obe noge. Štaviše, tokom DF i PF, aktivacija EMG mišića bila je veća (p < 0,05) na 105° nego na 75° i 90° za obe noge. Rezultati pokazuju da dominantna noga nije bila povezana sa različitim nivoom sile i neuronske aktivacije tokom maksimalne dobrovoljne kontrakcije mišića skočnog zgloba. Zaključeno je da dominantna noga nema uticaja na maksimalnu silu i neuralnu aktivaciju mišića skočnog zgloba i da bilo kakvi mehanizmi koji doprinose efektu dominacije ekstremiteta nisu evidentni na primeru ovog eksperimentalnog protokola

Ultrasonographic findings in the ovine udder during involution

The objective of the study was to record, by means of ultrasonographic examination, changes occurring in the udder of ewes during involution and to compare differences between progressive or abrupt udder drying-off. In group A ewes, udder drying-off took place progressively during a period of 22 d; ewes were milked twice daily for the last time on day(D) 0; then, they were hand-milked once daily for a week (D1-D7), which was followed by another week during which ewes were hand-milked once every 2 d (D9, D11, D13), followed by a third week during which ewes were hand-milked once every 3 d (D16, D19, D22). In group B ewes, the procedure took place abruptly; ewes were milked twice daily for the last time on D0 and no milking was carried out after that. B-mode and Doppler ultrasonographic examination of the udder of all ewes was performed throughout the drying-off procedure. Appropriate data management and analysis were performed. Progressive changes of the various parameters evaluated throughout the study period were significant in both groups (P 0.3). Diameter of the external pudendal artery progressively decreased during the study and differed significantly between the two groups (P=0.037). Both resistance index and pulsatility index progressively increased throughout the study period in both groups; for both parameters, differences between the two groups were significant (P<0.0005). B-mode ultrasonographic examination indicated differences in remodelling of the extracellular matrix in relation to the procedure for udder drying-off. Volume of the gland cistern did not appear to be affected by the procedure for udder drying-off. Doppler ultrasonographic examination confirmed that blood flow during initiated involution was lower than during a progressive procedure for drying-off