Power-law statistics and stellar rotational velocities in the Pleiades

In this paper we will show that, the non-gaussian statistics framework based on the Kaniadakis statistics is more appropriate to fit the observed distributions of projected rotational velocity measurements of stars in the Pleiades open cluster. To this end, we compare the results from the $\kappa$ and $q$-distributions with the Maxwellian.Comment: 13 pages, 3 figure

Observational constraints for Lithium depletion before the RGB

Precise Li abundances are determined for 54 giant stars mostly evolving across the Hertzsprung gap. We combine these data with rotational velocity and with information related to the deepening of the convective zone of the stars to analyse their link to Li dilution in the referred spectral region. A sudden decline in Li abundance paralleling the one already established in rotation is quite clear. Following similar results for other stellar luminosity classes and spectral regions, there is no linear relation between Li abundance and rotation, in spite of the fact that most of the fast rotators present high Li content. The effects of convection in driving the Li dilution is also quite clear. Stars with high Li content are mostly those with an undeveloped convective zone, whereas stars with a developed convective zone present clear sign of Li dilution.Comment: 5 pages, 4 figures. accepted for publicatio

Resistance exercise load reduction and exercise-induced micro-damage

High volumes of resistance exercise increase muscle hypertrophy, independent of the extent of muscle damage. We compared volume load and markers of muscle damage after resistance exercise using two load reduction strategies versus a constant intensity. Methods: Twenty-seven trained men (age = 23.4±3.5 years, body mass = 74.5±10.7 Kg, height = 174±8 cm, 10 RM = 211±40 Kg) completed one weekly bout of 4 sets of leg press exercise under three loading schemes in a randomized, counterbalanced order over a three-week period. The loading schemes were (a) constant load for all sets (CON), (b) 5% load reduction after each set (LR5), and (c) 10% load reduction after each set (LR10). Volume load, muscle soreness (SOR), and range of motion (ROM) at the knee were assessed after each bout. Results: Volume load was significantly different amongst all conditions (CON = 6799±1583 Kg; LR5 = 8753±1789 Kg; 10896±2262 Kg; F=31,731; p<0.001). ROM and SOR were significantly different among conditions, with LR5 and LR10 producing greater preservations of ROM (p =<0.001) and less SOR (p < 0.001). These data may support the use of load reductions when training for hypertrophy

Análise florística e estrutural do estrato arbóreo-arbustivo de um sistema agroflorestal na caatinga, em Sobral, CE.

A Caatinga, que ocupa mais de 10% do território nacional, é o bioma semi-árido mais rico do mundo em biodiversidade. Entretanto, desmatamentos e queimadas praticados pela agropecuária tradicional vem provocando alterações neste ecossistema. Como alternativa, a Embrapa Caprinos desenvolveu um sistema agroflorestal (SAF) voltado para o semi-árido. O objetivo deste trabalho foi avaliar a preservação da flora nativa em um SAF implantado em Sobral/CE. O estudo foi conduzido em 2008, em 1,6 ha de área destinada ao plantio agrícola no SAF. Foram calculadas a densidade, a frequência e a dominância relativas, índice de valor de importância, Índice de diversidade de Shannon (H?) e a Equabilidade (J.). Foram encontrados 24 indivíduos, distribuídos em quatro famílias e seis espécies. Boraginaceae foi a família que apresentou o maior número de indivíduos. Fabaceae foi a família com o maior número de espécies. A espécie que apresentou o maior valor de importância foi Auxemma oncocalyx, apresentando também a maior dominância (72,4%) e densidade (62,5%). Para freqüência relativa, as espécies A. oncocalyx e Caesalpinia gardeniariana apresentaram os mesmos valores (30,8%). O índice de diversidade de Shannon foi de 1,20 e a Equabilidade igual 0,44. Os resultados apontam que a diversidade encontrada no sistema agroflorestal permite preservar árvores nativas da Caatinga ao mesmo tempo em que produz a cultura agrícola para o sertanejo, sem a necessidade de desmatamento

Non-gaussian statistics and stellar rotational velocities of main sequence field stars

In this letter we study the observed distributions of rotational velocity in a sample of more than 16,000 nearby F and G dwarf stars, magnitude complete and presenting high precision $Vsin i$ measurements. We show that the velocity distributions cannot be fitted by a maxwellian. On the other hand, an analysis based on both Tsallis and Kaniadakis power-law statistics is by far the most appropriate statistics and give a very good fit. It is also shown that single and binary stars have similar rotational distributions. This is the first time, to our knowledge, that these two new statistics are tested for the rotation of such a large sample of stars, pointing solidly to a solution of the puzzling problem on the function governing the distribution of stellar rotational velocityComment: 10 pages, 2 figures, accepted for publication in ApJ Letter