Tree root dynamics in montane and sub-alpine mixed forest patches.

Background And Aims: The structure of heterogeneous forests has consequences for their biophysical environment. Variations in the local climate significantly affect tree physiological processes. We hypothesize that forest structure also alters tree root elongation and longevity through temporal and spatial variations in soil temperature and water potential.

Genetic analysis of milking ability in Lacaune dairy ewes.

The milking ability of Lacaune ewes was characterised by derived traits of milk flow patterns, in an INRA experimental farm, from a divergent selection experiment in order to estimate the correlated effects of selection for protein and fat yields. The analysis of selected divergent line effects (involving 34 616 data and 1204 ewes) indicated an indirect improvement of milking traits (+17% for maximum milk flow and -10% for latency time) with a 25% increase in milk yield. Genetic parameters were estimated by multi-trait analysis with an animal model, on 751 primiparous ewes.

[Nitric oxide: a different kind of gas].

Nitric oxide (NO), the first gas to obtain temporary approval for use in medicine, is regulated in private and public health care facilities by the supply, prescription and dispensing rules applied for drugs with special modalities controlling its administration. This apparently simple gas which diffuses easily from one cell to another is actually very complex in its form and reactivity, making it an unconventional messenger. The life time of a molecule is very short.

Study protocol: stability of morphine injected without preservative, delivered with a disposable infusion device.

Background And Objective: Morphine hydrochloride, a major analgesic drug, is being increasingly administered using portable disposable infusion devices. The objective of this study was to investigate the stability of morphine in such a system at two concentrations (2.50 and 5.

[Ecstasy: psychostimulant, hallucinogen and toxic substance].

MDMA or 3,4-methylenedioxymethamphetamine, more commonly called "ecstasy", is a drug classified as a stupefiant and increasingly used by young people for its stimulant and hallucinogen effects. This popular designer drug is often used in techno or rave parties and perceived by users as relatively harmless. It has however been associated with disorders of thermoregulation and has been the cause of several deaths.

[Aluminum, hypothetic cause of Alzheimer disease].

A great deal of research has focused on aluminium as a putative causative factor in Alzheimer's disease. We measured by atomic absorption spectrophotometry aluminium levels in blood, urine and cerebrospinal fluid from 15 patients with Alzheimer's disease, compared with 20 control individuals. There were no statistically significant differences between the two groups.

New calibration method for gas chromatographic assay of carbon monoxide in blood.

The calibration method described is based on the in situ formation of carbon monoxide in a closed system by the reaction of hot concentrated sulfuric acid with formic acid. Carbon monoxide is released from hemoglobin by treatment with 85% phosphoric acid, diluted 1:2 (v/v). Carbon monoxide is analyzed by means of headspace gas chromatography on a Porapak Q 80-100 column, following catalytic reduction to methane, using a flame-ionization detector.

Urinary 5 alpha-androstane-3 alpha, 17 beta-diol (5-Ad) determination in healthy children and adults.

The authors suggest a method for the evaluation of the urinary 5 alpha-androstane-3 alpha, 17 beta-diol (5 Ad) carried out by gas-liquid chromatography. 5-Ad is separated from its isomers, first by means of an adsorption chromatography on alumina and then by means of a high performance liquid chromatography on porous silica. The reliability criteria of the method have been studied according to the advice of the French Society of Clinical Biology.