Cross-section and polarization of neutrino-produced τ\tau's made simple

Practical formulae are derived for the cross-section and polarization of the $\tau$ lepton produced in deep-inelastic neutrino-nucleon scattering in the frame of the simple quark-parton model.Comment: 10 pages, no figure

The second Born approximation in theory of bremsstrahlung of relativistic electrons and positrons in crystal

The formulae for the cross section of bremsstrahlung by relativistic electrons and positrons taking into account the contribution of the second Born approximation are obtained. The dependence of the radiation cross section in the field of atomic plane on the sign of charge of the particle is considered

Odyssey 2 : A mission toward Neptune and Triton to test General Relativity

Odyssey 2 will be proposed in December 2010 for the next call of M3 missions for Cosmic Vision 2015-2025. This mission, under a Phase 0 study performed by CNES, will aim at Neptune and Triton. Two sets of objectives will be pursued. The first one is to perform a set of gravitation experiments at the Solar System scale. Experimental tests of gravitation have always shown good agreement with General Relativity. There are however drivers to continue testing General Relativity, and to do so at the largest possible scales. From a theoretical point of view, Einstein's theory of gravitation shows inconsistencies with a quantum description of Nature and unified theories predict deviations from General Relativity. From an observational point of view, as long as dark matter and dark energy are not observed through other means than their gravitational effects, they can be considered as a manifestation of a modification of General Relativity at cosmic scales. The scientific objectives are to: (i) test the gravitation law at the Solar System scale; (ii) measure the Eddington parameter; and (iii) investigate the navigation anomalies during fly-bys. To fulfil these objectives, the following components are to be on board the spacecraft: (i) the Gravity Advanced Package (GAP), which is an electrostatic accelerometer to which a rotating stage is added; (ii) radio-science; (iii) laser ranging, to improve significantly the measure of the Eddington parameter. The second set of objectives is to enhance our knowledge of Neptune and Triton. Several instruments dedicated to planetology are foreseen: camera, spectrometer, dust and particle detectors, and magnetometer. Depending on the ones kept, the mission could provide information on the gravity field, the atmosphere and the magnetosphere of the two bodies as well as on the surface geology of Triton and on the nature of the planetary rings around Neptune.Comment: 61st International Astronautical Congress (Prague, Czech Republic - September 2010), 7 page

Quartz Enhanced Photoacoustic Spectroscopy Based on a Custom Quartz Tuning Fork.

We have designed and fabricated a custom quartz tuning fork (QTF) with a reduced fundamental frequency; a larger gap between the prongs; and the best quality factor in air at atmospheric conditions ever reported, to our knowledge. Acoustic microresonators have been added to the QTF in order to enhance the sensor sensitivity. We demonstrate a normalized noise equivalent absorption (NNEA) of 3.7 × 10-9 W.cm-1.Hz-1/2 for CO₂ detection at atmospheric pressure. The influence of the inner diameter and length of the microresonators has been studied, as well as the penetration depth between the QTF's prongs. We investigated the acoustic isolation of our system and measured the Allan deviation of the sensor

Genetic Variant in HK1 Is Associated With a Proanemic State and A1C but Not Other Glycemic Control–Related Traits

OBJECTIVE A1C is widely considered the gold standard for monitoring effective blood glucose levels. Recently, a genome-wide association study reported an association between A1C and rs7072268 within HK1 (encoding hexokinase 1), which catalyzes the first step of glycolysis. HK1 deficiency in erythrocytes (red blood cells [RBCs]) causes severe nonspherocytic hemolytic anemia in both humans and mice. RESEARCH DESIGN AND METHODS The contribution of rs7072268 to A1C and the RBC-related traits was assessed in 6,953 nondiabetic European participants. We additionally analyzed the association with hematologic traits in 5,229 nondiabetic European individuals (in whom A1C was not measured) and 1,924 diabetic patients. Glucose control–related markers other than A1C were analyzed in 18,694 nondiabetic European individuals. A type 2 diabetes case-control study included 7,447 French diabetic patients. RESULTS Our study confirms a strong association between the rs7072268–T allele and increased A1C (β = 0.029%; P = 2.22 × 10−7). Surprisingly, despite adequate study power, rs7072268 showed no association with any other markers of glucose control (fasting- and 2-h post-OGTT–related parameters, n = 18,694). In contrast, rs7072268–T allele decreases hemoglobin levels (n = 13,416; β = −0.054 g/dl; P = 3.74 × 10−6) and hematocrit (n = 11,492; β = −0.13%; P = 2.26 × 10−4), suggesting a proanemic effect. The T allele also increases risk for anemia (836 cases; odds ratio 1.13; P = 0.018). CONCLUSIONS HK1 variation, although strongly associated with A1C, does not seem to be involved in blood glucose control. Since HK1 rs7072268 is associated with reduced hemoglobin levels and favors anemia, we propose that HK1 may influence A1C levels through its anemic effect or its effect on glucose metabolism in RBCs. These findings may have implications for type 2 diabetes diagnosis and clinical management because anemia is a frequent complication of the diabetes state

G-allele of Intronic rs10830963 in MTNR1B Confers Increased Risk of Impaired Fasting Glycemia and Type 2 Diabetes Through an Impaired Glucose-Stimulated Insulin Release: Studies Involving 19,605 Europeans

OBJECTIVE Genome-wide association studies have identified several variants within the MTNR1B locus that are associated with fasting plasma glucose (FPG) and type 2 diabetes. We refined the association signal by direct genotyping and examined for associations of the variant displaying the most independent effect on FPG with isolated impaired fasting glycemia (i-IFG), isolated impaired glucose tolerance (i-IGT), type 2 diabetes, and measures of insulin release and peripheral and hepatic insulin sensitivity. RESEARCH DESIGN AND METHODS We examined European-descent participants in the Inter99 study (n = 5,553), in a sample of young healthy Danes (n = 372), in Danish twins (n = 77 elderly and n = 97 young), in additional Danish type 2 diabetic patients (n = 1,626) and control subjects (n = 505), in the Data from the Epidemiological Study on the Insulin Resistance Syndrome (DESIR) study (n = 4,656), in the North Finland Birth Cohort 86 (n = 5,258), and in the Haguenau study (n = 1,461). RESULTS The MTNR1B intronic variant, rs10830963, carried most of the effect on FPG and showed the strongest association with FPG (combined P = 5.3 × 10−31) and type 2 diabetes. The rs10830963 G-allele increased the risk of i-IFG (odds ratio [OR] 1.64, P = 5.5 × 10−11) but not i-IGT. The G-allele was associated with a decreased insulin release after oral and intravenous glucose challenges (P < 0.01) but not after injection of tolbutamide. In elderly twins, the G-allele associated with hepatic insulin resistance (P = 0.017). CONCLUSIONS The G-allele of MTNR1B rs10830963 increases risk of type 2 diabetes through a state of i-IFG and not through i-IGT. The same allele associates with estimates of β-cell dysfunction and hepatic insulin resistance

Visibilité et présence de l’image dans l’espace ecclésial

Cet ouvrage met au cœur de son propos une interrogation simple : dans l’organisation complexe de l’espace de l’église médiévale, les emplacements choisis pour les images qui ornent les murs et les objets n’offrent pas toujours la possibilité de voir celles-ci, d’en déchiffrer le contenu. Certaines semblent réservées à des groupes de l’assemblée stationnant dans des espaces spécifiques, d’autres ne sont pas visibles depuis les principales zones affectées aux fidèles ou aux clercs, d’autres encore sont situées trop haut. Le rapport, a priori évident, entre représentation et visibilité se trouve donc souvent démenti, appelant alors une nouvelle notion, celle de présence. Analyser la tension existant entre ces trois catégories – figuration, visibilité et présence – implique une étude croisée des œuvres figurées, des monuments et des sources écrites. Les notions de mobilité et de fixité permettent également de prendre en compte les multiples jeux d’échelles à l’œuvre dans ce lieu rituel qu’est l’église, impliquant des objets, des manuscrits, des dispositifs liturgiques, des gestes, des déplacements physiques, dialoguant avec un décor appliqué au corps même du monument, épousant l’immobilité de l’architecture. Les cinq chapitres thématiques qui organisent ce volume mettent en regard différents cas issus de l’Occident médiéval et de l’Orient byzantin, selon une chronologie longue (de l’Antiquité tardive à la fin du Moyen Âge), dans une volonté de décloisonner les disciplines et les aires géographiques afin de tirer tous les enseignements d’une approche transversale de l’image médiévale

Presence of three mycorrhizal genes in the common ancestor of land plants suggests a key role of mycorrhizas in the colonization of land by plants

• The colonization of land by plants fundamentally altered environmental conditions on earth. Plant–mycorrhizal fungus symbiosis likely played a key role in this process by assisting plants to absorb water and nutrients from soil. • Here, in a diverse set of land plants, we investigated the evolutionary histories and functional conservation of three genes required for mycorrhiza formation in legumes and rice ( Oryza sativa ), DMI1 , DMI3 and IPD3 . • The genes were isolated from nearly all major plant lineages. Phylogenetic analyses showed that they had been vertically inherited since the origin of land plants. Further, cross-species mutant rescue experiments demonstrated that DMI3 genes from liverworts and hornworts could rescue Medicago truncatula dmi3 mutants for mycorrhiza formation. Yeast two-hybrid assays also showed that bryophyte DMI3 proteins could bind to downstream-acting M. trunculata IPD3 protein. Finally, molecular evolutionary analyses revealed that these genes were under purifying selection for maintenance of their ancestral functions in all mycorrhizal plant lineages. • These results indicate that the mycorrhizal genes were present in the common ancestor of land plants, and that their functions were largely conserved during land plant evolution. The evidence presented here strongly suggests that plant–mycorrhizal fungus symbiosis was one of the key processes that contributed to the origin of land flora.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78704/1/j.1469-8137.2009.03137.x.pd