On a Gromoll-Meyer type theorem in globally hyperbolic stationary spacetimes

Following the lines of the celebrated Riemannian result of Gromoll and Meyer, we use infinite dimensional equivariant Morse theory to establish the existence of infinitely many geometrically distinct closed geodesics in a class of globally hyperbolic stationary Lorentzian manifolds.Comment: 39 pages, LaTeX2e, amsar

The Kempf–Ness Theorem and invariant theory for real reductive representations

This paper does not contain any new result. We give new proofs of the Kempf–Ness Theorem and Hilbert–Mumford criterion for real reductive representations avoiding any algebraic results

A group theoretic proof of a compactness lemma and existence of nonradial solutions for semilinear elliptic equations

Symmetry plays a basic role in variational problems (settled, e.g., in Rn or in a more general manifold), for example, to deal with the lack of compactness which naturally appears when the problem is invariant under the action of a noncompact group. In Rn, a compactness result for invariant functions with respect to a subgroup G of O (n) has been proved under the condition that the G action on Rn is compatible, see Willem (Minimax theorem. Progress in nonlinear differential equations and their applications, vol 24, Birkhäuser Boston Inc., Boston, 1996). As a first result, we generalize this and show here that the compactness is recovered for particular subgroups of the isometry group of a Riemannian manifold. We investigate also isometric action on Hadamard manifold (M, g) proving that a large class of subgroups of Iso (M, g) is compatible. As an application, we get a compactness result for “invariant” functions which allows us to prove the existence of nonradial solutions for a classical scalar equation and for a nonlocal fractional equation on Rn for n= 3 and n= 5 , improving some results known in the literature. Finally, we prove the existence of nonradial invariant functions such that a compactness result holds for some symmetric spaces of noncompact type

Large quartic groups on translation planes, III-groups with common centers

The 'desirable' planes odd order of Biliotti, Jha, Johnson, Menichetti are shown to be exactly the class of planes that admit two trivially intersecting quartic groups of order q with common centers

Investigation of the mechanisms mediating genetic susceptibility to cardiovascular disease on chromosomes 9p21 and 2q24

Recent genome-wide studies have identified novel loci associated with cardiovascular diseases, but the mechanisms mediating these associations are unknown. Investigation of intermediate phenotypes can identify the pathways involved and potential targets for therapeutic intervention. This study investigated the relationship with intermediate phenotypes at risk loci on chromosome 9p21 and 2q24. Chromosome 9p21 polymorphisms are associated with coronary artery disease and congenital intracranial aneurysms. In the present study risk variants were not associated with traditional risk factors, inflammatory mediators, carotid artery intimamedia thickness, echocardiographic measures of cardiac structure and function, or congenital heart defects. There was no evidence of copy number variation using MLPA. To identify genes involved in mediating disease susceptibility this study examined the association of chromosome 9p21 variants with peripheral blood expression in healthy subjects of three neighbouring genes: two cyclin-dependent kinase inhibitors, CDKN2A and CDKN2B, and a non-coding RNA of unknown function, ANRIL. Novel methodology combining allelic expression data from multiple transcribed markers was more powerful than total expression analysis for mapping cis-acting effects. Multiple loci were independently associated with expression of each gene, suggesting that several sites may modulate disease susceptibility. Disease-associated variants were all associated with allelic expression of ANRIL, while association with the other two genes was only detectable for some risk variants. Variants had an inverse effect on ANRIL and CDKN2B expression, supporting a role of antisense transcription in CDKN2B regulation. This study suggests that modulation of ANRIL expression mediates susceptibility to several important human diseases. Chromosome 2q24 polymorphisms were associated with hypertension in a study involving an Amish population; in vitro experiments suggested that influences on STK39 expression might mediate these effects. In the present study allelic expression analysis confirmed that reported SNPs were associated with STK39 expression in vivo, but were not associated with blood pressure in a large British cohort.EThOS - Electronic Theses Online ServiceBritish Cardiovascular Society : Swire Newcastle Healthcare Charity : British Heart FoundationGBUnited Kingdo

GIANO-TNG spectroscopy of red supergiants in the young star cluster RSGC3

The Scutum complex in the inner disk of the Galaxy has a number of young star clusters dominated by red supergiants that are heavily obscured by dust extinction and observable only at infrared wavelengths. These clusters are important tracers of the recent star formation and chemical enrichment history in the inner Galaxy. During the technical commissioning and as a first science verification of the GIANO spectrograph at the Telescopio Nazionale Galileo, we secured high-resolution (R=50,000) near-infrared spectra of five red supergiants in the young Scutum cluster RSGC3. Taking advantage of the full YJHK spectral coverage of GIANO in a single exposure, we were able to measure several tens of atomic and molecular lines that were suitable for determining chemical abundances. By means of spectral synthesis and line equivalent width measurements, we obtained abundances of Fe and iron-peak elements such as Ni, Cr, and Cu, alpha (O, Mg, Si, Ca, Ti), other light elements (C, N, F, Na, Al, and Sc), and some s-process elements (Y, Sr). We found average half-solar iron abundances and solar-scaled [X/Fe] abundance patterns for most of the elements, consistent with a thin-disk chemistry. We found depletion of [C/Fe] and enhancement of [N/Fe], consistent with standard CN burning, and low 12C/13C abundance ratios (between 9 and 11), which require extra-mixing processes in the stellar interiors during the post-main sequence evolution. We also found local standard of rest V(LSR)=106 km/s and heliocentric V(HEL)=90 km/s radial velocities with a dispersion of 2.3 km/s. The inferred radial velocities, abundances, and abundance patterns of RSGC3 are very similar to those previously measured in the other two young clusters of the Scutum complex, RSGC1 and RSGC2, suggesting a common kinematics and chemistry within the Scutum complex