4,063 research outputs found
ALDH2*2 and peer drinking in East Asian college students
Background: The ALDH2*2 allele (A-allele) at rs671 is more commonly carried by Asians and is associated with alcohol-related flushing, a strong adverse reaction to alcohol that is protective against drinking. Social factors, such as having friends who binge drink, also contribute to drinking in Asian youth. Objectives: This study examined the interplay between ALDH2*2, peer drinking, and alcohol consumption in college students. We hypothesized that the relationship between ALDH2*2 and standard grams of ethanol per month would vary based on the level of peer drinking. Methods: Subjects (N = 318, 63.25% female) were East Asian college students in the United States who reported drinking alcohol. Data were from the freshman year of a university survey that included a saliva DNA sample. ALDH2*2 status was coded ALDH2*2(+) (A/G and A/A genotypes) and ALDH2*2(â) (G/G genotype). Peer drinking was studentsâ perception of how many of their friends âgot drunkâ. Results: Main effects of ALDH2*2(â) and having more friends who got drunk were associated with greater alcohol consumption. The ALDH2*2 Ă peer drunkenness interaction showed a stronger positive association with alcohol consumption for ALDH2*2(â) versus ALDH2*2(+) at increasing levels of peer drunkenness. Follow-up comparisons within each peer drunkenness level identified significantly higher alcohol consumption for ALDH2*2(â) compared to ALDH2*2(+) at the all friends got drunk level.
Conclusion: There was evidence of a stronger effect for ALDH2*2(â) compared to ALDH2*2(+) with greater alcohol use when students were more exposed to peer drinking. Findings contribute to a growing literature on the interrelationships between genetic influences and more permissive environments for alcohol consumption
Backward error analysis and the substitution law for Lie group integrators
Butcher series are combinatorial devices used in the study of numerical
methods for differential equations evolving on vector spaces. More precisely,
they are formal series developments of differential operators indexed over
rooted trees, and can be used to represent a large class of numerical methods.
The theory of backward error analysis for differential equations has a
particularly nice description when applied to methods represented by Butcher
series. For the study of differential equations evolving on more general
manifolds, a generalization of Butcher series has been introduced, called
Lie--Butcher series. This paper presents the theory of backward error analysis
for methods based on Lie--Butcher series.Comment: Minor corrections and additions. Final versio
Advanced Design and Fabrication of Microwave Components Based on Shape Optimization and 3D Ceramic Stereolithography Process
International audienceThe design of advanced components for space and terrestrial telecommunication systems requires both sophisticated design methodologies and manufacturing technologies for improving current component characteristics. In particular, optimizing the shape and the size of a component is a problem of primary importance for microwave engineers. Moreover, for designing RF and microwave components or antennas, the use of ceramic materials is preferable in order to satisfy both electrical and dimensional constraints. The main objective of this chapter is to demonstrate that it is possible to jointly improve the design and fabrication procedures of ceramic based advanced RF components. In this context, a ceramic 3D stereolithography based rapid prototyping technique is applied for fabricating 3D ceramic structures. As presented next, theoretical and experimental approaches are complementary and innovative components with excellent electrical performances have been designed, manufactured and characterized. Then the contribution demonstrates how an original CAD design approach based on shape optimization methods can be applied for improving electrical performance and integration of microwave and millimeter-wave devices
Asymptotic solvers for ordinary differential equations with multiple frequencies
We construct asymptotic expansions for ordinary differential equations with highly oscillatory forcing terms, focusing on the case of multiple, non-commensurate frequencies. We derive an asymptotic expansion in inverse powers of the oscillatory parameter and use its truncation as an exceedingly effective means to discretize the differential equation in question. Numerical examples illustrate the effectiveness of the method
Elaboration, by tape casting, of an SOFC half cell for low temperature applications
International audienceThese last past years, a major interest has been devoted to decrease the working temperature of solid oxide fuel cells (SOFCs) down to about 700°C. In this respect, materials with a high ionic conductivity at low temperature have to be found and the rpocess to elaborate fuel cells, using these new materials, has to be developed .....
First observation of 55,56Zn
In an experiment at the SISSI/LISE3 facility of GANIL, the most proton-rich
zinc isotopes 55,56Zn have been observed for the first time. The experiment was
performed using a high-intensity 58Ni beam at 74.5 MeV/nucleon impinging on a
nickel target. The identification of 55,56Zn opens the way to 54Zn, a good
candidate for two-proton radioactivity according to theoretical predictions.Comment: 2 pages, 1 figure, accepted for publication in Eur. Phys. J.
Decay of proton-rich nuclei between 39Ti and 49Ni
Decay studies of very neutron-deficient nuclei ranging from 39Ti to 49Ni have
been performed during a projectile fragmentation experiment at the GANIL/LISE3
separator. For all nuclei studied in this work, 39,40Ti, 42,43Cr, 46Mn,
45,46,47Fe and 49Ni, half-lives and decay spectra have been measured. In a few
cases, gamma coincidence measurements helped to successfully identify the
initial and final states of transitions. In these cases, partial decay scheme
are proposed. For the most exotic isotopes, 39Ti, 42Cr, 45Fe and 49Ni, which
are candidates for two-proton radioactivity from the ground state, no clear
evidence of this process is seen in our spectra and we conclude rather on a
delayed particle decay.Comment: 12 pages, 15 figures, submitted for publication in Eur. Phys. J.
Inventaire des mollusques d'eau douce en Ituri (Haut-Zaïre) : conséquences sanitaires pour l'homme et le bétail
Cent soixante-dix points d'abreuvement pour le bétail ont été prospectés de juin 1986 à août 1988 en Ituri (nord-est du Zaïre) afin de déterminer les principaux mollusques d'eau douce pouvant intervenir dans la transmission des trématodoses animales et humaines. Dix-neuf espÚces de gastéropodes ont été rencensées. Quatre gßtes sur dix n'hébergent pas ou trÚs peu de mollusques. Les trois espÚces les plus fréquemment rencontrées sont #Lymnaea natalensis, #Biomphalaria pfeifferi (15,3 %). La distribution des deux premiÚres espÚces semble trÚs homogÚne au niveau régional et ne permet pas l'établissement d'une relation avec le risque parasitaire (#Fasciola gigantica et #Schistosoma mansoni). Inversement, la répartition de #Bulinus africanus (et secondairement celle de #B. forskalii) correspond globalement à la distribution de #Schistosoma bovis chez les bovins. L'association de #Lymnaea natalensis et de #Bulinus africanus au sein des gßtes rend compte de l'association des infestations à #Fasciola gigantica et #Schistosoma bovis$ chez les bovins. (Résumé d'auteur
Hernie Inguinoscrotale de lâUretĂšre: Fait Clinique et Revue de la LittĂ©rature
la hernie intrascrotale de l’uretère est une situation rare, nous rapportons un cas clinique, compliqué d’hydronéphrose gauche chez un patient de 83ans, l’anomalie avait été reconnue en peropératoire.Mots clés: Hernie, de l’uretère, le scrotum, hydronéphros
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