EFFECT OF FATIGUE ON MUSCLE COORDINATION IN REPEATED ALL-OUT BOUTS

The aim of the present study was to analyse the fatigue occurring during repeated all-out short cycling bouts through mechanical and electromyographic (EMG) data and to focus on . inter-muscle coordination. The results showed a significant decrease in peak power output without significant modifications in the EMG activity through sprint repetitions. However, the coordination timing between agonist and antagonist muscles was reduced. In conclusion, power output decreased during high-intensity repeated sprints due to the inability of quadriceps to maintain maximal force and owing to inter-muscle coordination limitations

Probing the Cosmic Distance Duality Relation with the Sunyaev-Zeldovich Effect, X-rays Observations and Supernovae Ia

The angular diameter distances toward galaxy clusters can be determined with measurements of the Sunyaev-Zel'dovich effect and X-ray surface brightness combined with the validity of the distance-duality relation, $D_L(z) (1 + z)^{2}/D_{A}(z) = 1$, where $D_L(z)$ and $D_A(z)$ are, respectively, the luminosity and angular diameter distances. This combination enables us to probe galaxy cluster physics or even to test the validity of the distance-duality relation itself. We explore these possibilities based on two different, but complementary approaches. Firstly, in order to constrain the possible galaxy cluster morphologies, the validity of the distance-duality relation (DD relation) is assumed in the $\Lambda$CDM framework (WMAP7). Secondly, by adopting a cosmological-model-independent test, we directly confront the angular diameters from galaxy clusters with two supernovae Ia (SNe Ia) subsamples (carefully chosen to coincide with the cluster positions). The influence of the different SNe Ia light-curve fitters in the previous analysis are also discussed. We assumed that $\eta$ is a function of the redshift parametrized by two different relations: $\eta(z) = 1 + \eta_{0}z$, and $\eta(z)=1 + \eta_{0}z/(1+z)$, where $\eta_0$ is a constant parameter quantifying the possible departure from the strict validity of the DD relation. The statistical analysis presented here provides new evidence that the true geometry of clusters is elliptical. We find that the two-light curve fitters (SALT2 and MLCS2K2) present a statistically significant conflict, and a joint analysis involving the different approaches suggests that clusters are endowed with an elliptical geometry as previously assumed.Comment: 33 pages, 15 figures, some typos corrected, accepted for publication in the Astronomy \& Astrophysic

Antibacterial and dermal toxicological profiles of ethyl acetate extract from Crassocephalum bauchiense (Hutch.) Milne-Redh (Asteraceae)

<p>Abstract</p> <p>Background</p> <p>The emergence in recent years of numerous resistant strains of pathogenic bacteria to a range of formerly efficient antibiotics constitutes a serious threat to public health. <it>Crassocephalum bauchiense</it>, a medicinal herb found in the West Region of Cameroon is used to treat gastrointestinal infections as well as liver disorders. The ethyl acetate extract from the leaves of <it>C. bauchiense </it>was evaluated for its antibacterial activity as well as acute and sub-acute toxicities.</p> <p>Methods</p> <p>The plant extract was prepared by maceration in ethyl acetate. Its phytochemical screening was done by standard methods. The broth microdilution method was used to evaluate the <it>in vitro </it>antibacterial activity. The <it>in vivo </it>antibacterial activity of a gel formulation (0.05, 1 and 2% w/v) of this extract was evaluated using a <it>Staphylococcus aureus</it>-induced dermatitis in a murine model. Selected haematological and biochemical parameters were used to evaluate the dermal sub-acute toxicity of the extract in rats.</p> <p>Results</p> <p>Phytochemical screening of the <it>C. bauchiense </it>extract revealed the presence of alkaloids, phenols, tannins and sterols. <it>In vitro </it>antibacterial activities were observed against all the tested microorganisms (MIC = 0.04-6.25 mg/ml). Formulated extract-gel (2% w/v) and gentamycin (reference drug) eradicated the microbial infection after five days of treatment. A single dermal dose of this extract up to 32 g/kg body weight (bw) did not produce any visible sign of toxicity. Also, daily dermal application of the <it>C. bauchiense </it>extract gel formulation for 28 days did not show any negative effect, instead some biochemical parameters such as alanine aminotransferase (ALT and AST), low density lipoprotein (LDL), high density lipoprotein (HDL) and triglycerides were significantly (p < 0.05) affected positively.</p> <p>Conclusion</p> <p>These results indicate that the <it>C. bauchiense </it>ethyl acetate extract can be used safely for the treatment of some bacterial infections.</p

MEMS Technologies for Energy Harvesting

The objective of this chapter is to introduce the technology of Microelectromechanical Systems, MEMS, and their application to emerging energy harvesting devices. The chapter begins with a general introduction to the most common MEMS fabrication processes. This is followed with a survey of design mechanisms implemented in MEMS energy harvesters to provide nonlinear mechanical actuations. Mechanisms to produce bistable potential will be studied, such as introducing fixed magnets, buckling of beams or using slightly slanted clamped-clamped beams. Other nonlinear mechanisms are studied such as impact energy transfer, or the design of nonlinear springs. Finally, due to their importance in the field of MEMS and their application to energy harvesters, an introduction to actuation using piezoelectric materials is given. Examples of energy harvesters found in the literature using this actuation principle are also presented

Effects of long-term exposure to an electronic containment system on the behaviour and welfare of domestic cats

Free-roaming cats are exposed to a variety of risks, including involvement in road traffic accidents. One way of mitigating these risks is to contain cats, for example using an electronic boundary fence system that delivers an electric ‘correction’ via a collar if a cat ignores a warning cue and attempts to cross the boundary. However, concerns have been expressed over the welfare impact of such systems. Our aim was to determine if long-term exposure to an electronic containment system was associated with reduced cat welfare. We compared 46 owned domestic cats: 23 cats that had been contained by an electronic containment system for more than 12 months (AF group); and 23 cats with no containment system that were able to roam more widely (C group). We assessed the cats’ behavioural responses and welfare via four behavioural tests (unfamiliar person test; novel object test; sudden noise test; cognitive bias test) and an owner questionnaire. In the unfamiliar person test, C group lip-licked more than the AF group, whilst the AF group looked at, explored and interacted more with the unfamiliar person than C group. In the novel object test, the AF group looked at and explored the object more than C group. No significant differences were found between AF and C groups for the sudden noise or cognitive bias tests. Regarding the questionnaire, C group owners thought their cats showed more irritable behaviour and AF owners thought that their cats toileted inappropriately more often than C owners. Overall, AF cats were less neophobic than C cats and there was no evidence of significant differences between the populations in general affective state. These findings indicate that an electronic boundary fence with clear pre-warning cues does not impair the long term quality of life of cat

Touchard (Jean), Aux origines du catholicisme social, Louis Rousseau (1787-1856)

Basset Guy. Touchard (Jean), Aux origines du catholicisme social, Louis Rousseau (1787-1856). In: Annales de Bretagne et des pays de l'Ouest. Tome 106, numéro 2, 1999. pp. 114-117

Lire les Carnets : suivre la philosophie à la trace

Il y a sans doute quelque paradoxe à relever qu’en septembre 1937, pendant son voyage en Italie à Florence, ville artistique et politique s’il en est, Camus notait : « Si j’avais à écrire ici un livre de morale, il aurait cent pages et 99 seraient blanches. Sur la dernière, j’écrirais : “Je ne connais qu’un seul devoir, c’est celui d’aimer.” » (II, 830) Cette incursion subite de la philosophie prend place en plein milieu de deux des caractéristiques des Cahiers : des récits de voyage dans les..

Les complicités artistiques : retour sur la jeunesse algéroise de Camus

1930 marque une date importante pour l’itinéraire personnel de Camus : il est reçu à la première partie du baccalauréat et découvre à la rentrée Jean Grenier, son professeur de philosophie en terminale. Gardien de but au RUA, il est atteint en décembre des premières marques de la tuberculose et interrompt, alors, son année scolaire. Mais 1930 – l’année plus que l’anniversaire – est marquée aussi par les manifestations liées au Centenaire (de la conquête) de l’Algérie qui ont pris des formes a..

Touchard (Jean), Aux origines du catholicisme social, Louis Rousseau (1787-1856)

Basset Guy. Touchard (Jean), Aux origines du catholicisme social, Louis Rousseau (1787-1856). In: Annales de Bretagne et des pays de l'Ouest. Tome 106, numéro 2, 1999. pp. 114-117