Energy availability and macronutrient intake over a 7-day training period in adolescent rugby players.

Background: Understanding the dietary intake of elite adolescent athletes and its adequacy with sport nutrition recommendation is a key issue for health and player development, as well as performance and recovery. Energy availability needs to be considered to ensure optimal health and performance in young athletes. The present study aimed to quantify energy availability, energy expenditure and macronutrient intake in young male rugby union players competing at national level.

Effect of muscle length on the modulation of H-reflex and inhibitory mechanisms of Ia afferent discharges during passive muscle lengthening.

The effectiveness of activated Ia afferents to discharge α-motoneurons is decreased during passive muscle lengthening compared with static and shortening muscle conditions. Evidence suggests that these regulations are explained by ) greater postactivation depression induced by homosynaptic postactivation depression (HPAD) and ) primary afferent depolarization (PAD). It remains uncertain whether muscle length impacts the muscle lengthening-related aspect of regulation of the effectiveness of activated Ia afferents to discharge α-motoneurons, HPAD, PAD, and heteronymous Ia facilitation (HF).

Regulation of primary afferent depolarization and homosynaptic post-activation depression during passive and active lengthening, shortening and isometric conditions.

Purpose: This study aimed to determine whether the modulation of primary afferent depolarization (PAD) and homosynaptic post-activation depression (HPAD) are involved in the lower efficacy of Ia-afferent-α-motoneuron transmission commonly observed during lengthening compared to isometric and shortening conditions.

Methods: 15 healthy young individuals participated in two experimental sessions dedicated to measurement in passive and active muscle states, respectively. In each session, PAD, HPAD and the efficacy of Ia-afferent-α-motoneuron transmission were evaluated during lengthening, shortening and isometric conditions.

Technetium absorption and turnover in monogastric and polygastric animals.

Technetium (Tc) released into the environment can reach animals in various chemical forms: as pertechnetate (TcO-4) in drinking water or deposited on the surface of vegetables and forage plants, or as Tc bioincorporated into plants and associated with various plant constituents. In addition to being influenced by chemical speciation in the diet, absorption, metabolism, and retention of Tc in animals are modified by the treatment that the alimentary bolus undergoes during its passage through the gastrointestinal tract. This behavior differs markedly between polygastric and monogastric animals.

Metabolism of 51Cr, 54Mn, 59Fe and 60Co in lactating dairy cows.

Different radionuclides which can be released by nuclear installations (Na2(51) CrO4 , 54MnCl2 , 59FeCl3 and 60CoCl2 ) were given to lactating dairy cows either orally or by intravenous (i.v.) injection.