Lien entre la qualité des relations familiales et sociales à l'adolescence et à l'age adulte.

Fifty-seven families with adolescent children participated in a study of a) the quality of family and friendship relationships in adolescence, and b) the quality of family, friendship, and romantic relationships of adolescents 7 years later. Observation measures and self-report questionnaires were used to examine the variables. Regression analyses showed that mothers' marital satisfaction, conjugal conflict, and quality of mother-daughter relationship in adolescence predicted daughters' satisfaction with romantic relationships in adulthood. However, only the parental variables during adolescence predicted the quality of friendship relationships in adulthood. This study highlighted the contribution that quality of family relationships in adolescence makes to the quality of interpersonal relationships in adulthood. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental and numerical simulations of turbulent ventilation in aircraft cabins

Airflow in a generic airplane cabin has been investigated numerically by means of Reynolds averaged Navier–Stokes computations and experimentally by particle image velocimetry (PIV). High and low Reynolds number as well as two layer turbulence models were tested for their ability to describe turbulent velocity fields. Special attention was given to the flow of the incoming air jet along the luggage compartment. Comparison with PIV measurements reveals that for reliable prediction of isothermal cabin flow, low Reynolds number turbulence models have to be used.     

Oxidative stress, mutant SOD1, and neurofilament pathology in transgenic mouse models of human motor neuron disease

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease that primarily affects motor neurons in the spinal cord and brain stem. About 10% of all ALS cases are familial (FALS), inherited in an autosomal dominant manner. One fifth of FALS patients carry mutations in the Cu/Zn superoxide dismutase (SOD1) gene, and several lines of transgenic mice have been engineered to express mutant forms of the SOD1 gene that are linked to FALS. Significantly, many of these transgenic lines of mice develop a motor neuron disease (MND) that resembles human FALS. Oxidative stress induced by human SOD1 mutations is believed to play an important role in the pathogenesis of FALS and the FALS-like MND seen in the mutant SOD1 transgenic mice. For example, two lines of these mice showed prominent degeneration of mitochondria and endoplasmic reticulum in spinal cord neurons. Furthermore, recent studies have shown that neurofilament (NF)-rich spheroids. Lewy body-like NF inclusions, altered ubiquitin immunoreactivity, and Golgi fragmentation occur in the spinal cord motoneurons of these mutant SOD1 transgenic mice. Because these lesions recapitulate hallmark abnormalities of human ALS, mutant SOD1 transgenic mice provide a useful model for studies designed to elucidate the pathogenesis of ALS. Furthermore, transgenic mice that overexpress NF proteins also develop a clinical and pathologic phenotype similar to human MND, and polymorphisms in an NF gene have been linked to patients with ALS. Collectively, these observations implicate NF protein abnormalities in the pathogenesis of this disorder. Accordingly, this review summarizes recent insights into mechanisms of motor neuron degeneration in ALS that have emerged from studies of these new animal models of this neurodegenerative disease.     

Synthesis and biological evaluation of potent, selective, hexapeptide CCK-A agonist anorectic agents

Cholecystokinin (CCK) is a 33-amino acid peptide with multiple functions in both the central nervous system (via CCK-B receptors) and the periphery (via CCK-A receptors). CCK mediation of satiety via the A-receptor subtype suggest a role for CCK in the management of obesity. The carboxy terminal octapeptide (CCK-8) is fully active in this regard, but is lacking in receptor selectivity, metabolic stability, and oral bioavailability. Inversion of the chirality of Asp7 in conjunction with N-methylation of Phe8 produces compound 5 which exhibits high affinity and 2100-fold selectivity for CCK-A receptors. Compound 6 (Hpa(SO3H)-Nle-Gly-Trp-Nle-MeAsp-Phe-NH2), derived from moving the N-methyl group from Phe to Asp, decreased CCK-B affinity substantially without affecting CCK-A affinity, giving a compound with 6600-fold selectivity for CCK-A receptors. These compounds inhibit food intake with nanomolar potency following intraperitoneal administration in fasted rats. In addition to greater potency, compound 6 produces weight loss in rats when administered over nine consecutive days. Intranasal administration of 6 potently inhibits feeding in beagle dogs. Compound 6 produces potent anorectic activity via the CCK-A receptor system.     

Protective effect of neurofilament heavy gene overexpression in motor neuron disease induced by mutant superoxide dismutase

To investigate the role of neurofilaments in motor neuron disease caused by superoxide dismutase (SOD1) mutations, transgenic mice expressing a amyotrophic lateral sclerosis-linked SOD1 mutant (SOD1(G37R)) were mated with transgenic mice expressing human neurofilament heavy (NF-H) subunits. Unexpectedly, expression of human NF-H transgenes increased by up to 65%, the mean lifespan of SOD1(G37R) mice. Microscopic examination corroborated the protective effect of NF-H protein against SOD1 toxicity. Although massive neurodegeneration occurred in 1-yr-old mice expressing SOD1(G37R) alone, spinal root axons and motor neurons were remarkably spared in doubly SOD1(G37R);NF-H-transgenic littermates.     

A role for neurofilaments in the pathogenesis of amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a late-onset degenerative disease of motor neurons, characterized by abnormal accumulation of neurofilaments (NFs) in perikarya and proximal axons. Two lines of evidence suggest that neurofilament accumulation can play a crucial role in ALS pathogenesis. First, transgenic mouse models overexpressing NF proteins were found to develop motor neuron degeneration and, second, variant alleles of the NF heavy-subunit (NF-H) gene have been found in some human ALS patients. Our axonal transport studies with transgenic mice overexpressing the human NF-H gene, a model of ALS, revealed defects of intracellular transport not only for neurofilament proteins but also for other cytoskeletal proteins and organelles such as mitochondria. Therefore, we propose that neurofilament accumulation in mice causes neurodegeneration by disrupting axonal transport, a mechanism that may account for the pathogenesis of ALS.     

Influence of δ phase precipitation on the stress corrosion cracking resistance of alloy 718 in PWR primary water

The negative influence of δ phase on the intergranular stress corrosion cracking (IGSCC) resistance of alloy 718 is commonly taken for granted. In addition, δ phase formed at low temperature (about 1023 K) do not present the same characteristics than the one formed at higher temperatures (from 1173 to 1273 K). The aim of the present study is then to understand how δ phase precipitation could enhance crack initiation in alloy 718, whatever the form of δ phase is. For that purpose, several heat treatments leading to δ phase precipitation were realized on two alloy 718 heats, one sensitive to IGSCC and the second not. Specific slow strain rate tensile tests carried out on thin tensile specimens in simulated PWR primary medium at 633 K conclusively prove that δ phase has no effect on the intrinsic sensitivity to intergranular crack initiation of tested heats.     

Identification of volatile quality markers of ready-to-use lettuce and cabbage

Volatile emission changes of ready-to-use vegetables directly result from minimal processing and can reflect the sensory changes occurring in the product. Based on the detection of key volatile compounds, novel on-line and consumer quality-monitoring methods can be developed. The aim of this study was to identify volatile biomarkers for a range of leafy green ready-to-use vegetables (Butterhead and Iceberg lettuce and Irish York cabbage). Headspace volatile compounds were monitored using gas chromatography/mass spectrometry (GC/MS). The sensory quality of the products was evaluated at days 1, 7 and 14 using sensory and analytical measurements. Changes of volatile concentrations and sensory attributes were statistically correlated. The main quality markers identified for active modified atmosphere packaged (MAP) Butterhead lettuce were: 2-ethyl-1-hexanol, cis-3-dodecene, 4-ethylbenzaldehyde, acetocinnamone, β-elemene, 1-chlorododecane, dimethylethylphenol, ester pentanoic acid and thio-amino-butanamide. The main indicators of freshness were dimethylethylphenol and ester pentanoic acid, while the main quality loss markers were cis-3-dodecene and β-elemene.     

Dynamics of spatial structure in French urban agglomerations

P. Allen's intra-urban model applies the bifurcation theory to simulate the evolution of urban spatial structure. Until now, this model has only been tested to simulate plausible fictitious urban structures but its ability to reproduce observed evolutions has still to be tested. We carried out such an application to post-war evolution of spatial structure in a few French urban agglomerations. Many problems were encountered in choosing the data, estimating parameters and calibrating the model. The high degree of complexity of the model raises much theoretical interest but makes calibration rather difficult.