1,424 research outputs found
Extreme Galactic-Winds and Starburst in IR Mergers and IR QSOs
We report -as a part of a long-term study of mergers and IR QSOs- detailed
spectroscopic evidences for outflow (OF) and/or Wolf Rayet features in: (i) low
velocity OF in the ongoing mergers NGC 4038/39 and IRAS 23128-5919; (ii)
extreme velocity OF (EVOF) in the QSOs IRAS 01003-2238 and IRAS 13218+0552;
(iii) OF and EVOF in a complete sample of ultra-luminous IR galaxies/QSOs ("The
IRAS 1 Jy MKO-KPNO Survey", of 118 objects). We found EVOF in IRAS 11119+3257,
14394+5332, 15130+1958 and 15462-0450. The OF components detected in these
objects were mainly associated to starburst processes: i.e., to galactic-winds
generated in multiple type II SN explosions and massive stars. The EVOF were
detected in objects with strong starburst plus obscured IR QSOs; which suggest
that interaction of both processes could generate EVOF. In addition, we analyze
the presence of Wolf Rayet features in the large sample of Bright PG-QSOs
(Boroson and Green 1992), and nearby mergers and galactic-wind galaxies. We
found clear WR features in the Fe II QSOs (type I): PG 1244+026, 1444+407,
1448+273, 1535+547; and in the IR merger Arp 220. HST archive images of IR+BAL
QSOs show in practically all of these objects "arc or shell" features probably
associated to galactic-winds (i.e., to multiple type II SN explosions) and/or
merger processes. Finally, we discuss the presence of extreme starburst and
galactic wind as a possible evolutive link between IR merger and IR QSOs; where
the relation between mergers and extreme starburst (with powerful
galactic-winds) plays in important role, in the evolution of galaxies.Comment: 14 pages, 6 figure
Analysis of oscillations of atmospheric neutrinos
We briefly review the current status of standard oscillations of atmospheric
neutrinos in schemes with two, three, and four flavor mixing. It is shown that,
although the pure \nu_\mu-->\nu_\tau channel provides an excellent 2\nu fit to
the data, one cannot exclude, at present, the occurrence of additional
subleading \nu_\mu-->\nu_e oscillations (3\nu schemes) or of sizable
\nu_\mu-->\nu_s oscillations (4\nu schemes). It is also shown that the wide
dynamical range of energy and pathlength probed by the Super-Kamiokande
experiment puts severe constraints on nonstandard explanations of the
atmospheric neutrino data, with a few notable exceptions.Comment: Talk at the 19th International Conference on Neutrino Physics and
Astrophysics - Neutrino 2000 (Sudbury, Ontario, Canada, 16-21 June 2000
Trimethylsilyl Trifluoromethanesulfonate- Accelerated Addition of Catalytically Generated Zinc Acetylides to Aldehydes
In the presence of TMSOTf, a wide variety of terminal acetylenes add rapidly and efficiently to aldehydes via a catalytically generated zinc acetylide. In the absence of TMSOTf, no reaction is observed under otherwise identical conditions
Manifestations of Extra Dimensions in a Neutrino Telescope
Theories with large extra dimensions provide the possibility that a flavor
neutrino, localized in a 3+1 brane, can mix with a singlet neutrino living in
the bulk. This mixing leads to unconventional patterns of neutrino matter
oscillations and we examine in details how these oscillations depend upon two
parameters: the brane-bulk coupling and the effective mass of the
flavor neutrino inside matter. We find that high energy GeV)
neutrinos, to be detected by neutrino telescopes, can give signals of
extra dimensions. With a 1 k neutrino telescope extra dimensions with
radius down to can be tested directly, while for smaller radius an
indirect evidence can be established.Comment: 14 pages, 5 figures, added conclusion
A three-dimensional calculation of atmospheric neutrinos
A Monte-Carlo calculation of the atmospheric neutrino fluxes [1,2] has been
extended to take account of the three-dimensional (3D) nature of the problem,
including the bending of secondary particles in the geomagnetic field. Emphasis
has been placed on minimizing the approximations when introducing the 3D
considerations. In this paper, we describe the techniques used and quantify the
effects of the small approximations which remain. We compare 3D and 1D
calculations using the same physics input in order to evaluate the conditions
under which the 3D calculation is required and when the considerably simpler 1D
calculation is adequate. We find that the 1D and 3D results are essentially
identical for neutrino energy greater than 5 GeV except for small effects in
the azimuthal distributions due to bending of the secondary muon by the
geomagnetic field during their propagation in the atmosphere.Comment: 24 pages, 15 figures, LaTeX, to be submitted to Physical Review
Molecular analysis of sarcomeric and non-sarcomeric genes in patients with hypertrophic cardiomyopathy.
Background: Hypertrophic cardiomyopathy (HCM) is a common genetic heart disorder characterized by
unexplained left ventricle hypertrophy associated with non-dilated ventricular chambers. Several genes
encoding heart sarcomeric proteins have been associated to HCM, but a small proportion of HCM patients
harbor alterations in other non-sarcomeric loci. The variable expression of HCM seems influenced by genetic
modifier factors and new sequencing technologies are redefining the understanding of genotype–phenotype
relationships, even if the interpretations of the numerous identified variants pose several challenges.
Methods and results: We investigated 62 sarcomeric and non-sarcomeric genes in 41 HCM cases and in
3 HCM-related disorders patients. We employed an integrated approach that combines multiple tools for
the prediction, annotation and visualization of functional variants. Genotype–phenotype correlations
were carried out for inspecting the involvement of each gene in age onset and clinical variability of HCM. The
80% of the non-syndromic patients showed at least one rare non-synonymous variant (nsSNV) and among
them, 58% carried alterations in sarcomeric loci, 14% in desmosomal and 7% in other non-sarcomeric ones
without any sarcomere change. Statistical analyses revealed an inverse correlation between the number of
nsSNVs and age at onset, and a relationship between the clinical variability and number and type of variants.
Conclusions: Our results extend the mutational spectrum of HCM and contribute in defining the molecular
pathogenesis and inheritance pattern(s) of this condition. Besides, we delineate a specific procedure for the
identification of the most likely pathogenetic variants for a next generation sequencing approach embodied in
a clinical context
Comparison of 3-Dimensional and 1-Dimensional Schemes in the calculation of Atmospheric Neutrinos
A 3-dimensional calculation of atmospheric neutrinos flux is presented, and
the results are compared with those of a 1-dimensional one. In this study,
interaction and propagation of particles is treated in a 3-dimensional way
including the curvature of charged particles due to the geomagnetic field,
which is assumed to be a dipole field. The purpose of this paper is limited to
the comparison of calculation schemes. The updated flux value with new
interaction model and primary flux model will be reported in a separate paper.
Except for nearly horizontal directions, the flux is very similar to the
result of 1 dimensional calculations. However, for near-horizontal directions
an enhancement of the neutrino flux is seen even at energies as high as 1 GeV.
The production height of neutrinos is lower than the prediction by
1-dimensional calculation for near-horizontal directions, and is a little
higher for near-vertical directions. However, the difference is not evident
except for near-horizontal directions.Comment: 22 pages, 15figure
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