1,207 research outputs found
1.65 micrometers (H-band) surface photometry of galaxies. III: observations of 558 galaxies with the TIRGO 1.5m telescope
We present near-infrared H-band (1.65 micron) surface photometry of 558
galaxies in the Coma Supercluster and in the Virgo cluster. This data set,
obtained with the Arcetri NICMOS3 camera ARNICA mounted on the Gornergrat
Infrared Telescope, is aimed at complementing, with observations of mostly
early-type objects, our NIR survey of spiral galaxies in these regions,
presented in previous papers of this series. Magnitudes at the optical radius,
total magnitudes, isophotal radii and light concentration indices are derived.
We confirm the existence of a positive correlation between the near-infrared
concentration index and the galaxy H-band luminosity. (Tables 1 and 2 are only
available in electronic form upon request to [email protected])Comment: 12 pages, 6 figures. Accepted for publication in A&A
Combined analysis of KamLAND and Borexino neutrino signals from Th and U decays in the Earth's interior
The KamLAND and Borexino experiments have detected electron antineutrinos
produced in the decay chains of natural thorium and uranium (Th and U
geoneutrinos). We analyze the energy spectra of current geoneutrino data in
combination with solar and long-baseline reactor neutrino data, with
marginalized three-neutrino oscillation parameters. We consider the case with
unconstrained Th and U event rates in KamLAND and Borexino, as well as cases
with fewer degrees of freedom, as obtained by successively assuming for both
experiments a common Th/U ratio, a common scaling of Th+U event rates, and a
chondritic Th/U value. In combination, KamLAND and Borexino can reject the null
hypothesis (no geoneutrino signal) at 5 sigma. Interesting bounds or
indications emerge on the Th+U geoneutrino rates and on the Th/U ratio, in
broad agreement with typical Earth model expectations. Conversely, the results
disfavor the hypothesis of a georeactor in the Earth's core, if its power
exceeds a few TW. The interplay of KamLAND and Borexino geoneutrino data is
highlighted.Comment: 12 pages, including 6 figure
A solitary fibrous tumor of the parotid gland: Case report
Introduction: Solitary fibrous tumor is a rare neoplasm that can affect any part of the body, also head and neck region. Etiology is unknown. The incidence is slightly higher in males, the age ranges from 11 to 79 years. Presentation of case: It's the first case in our country of left parotid solitary fibrous tumor, removed by partial parotidectomy with facial nerve preservation. Histology examination showed diffuse spindle-shaped cells proliferation, moderate polymorphism, low mitotic index (<4 mitoses per 10 HPF), partially bordered by fibrous capsule. Immunohistochemistry showed STAT6, CD34, CD99 positivity. Six-months follow-up didn't show sign of recurrence. Discussion: Solitary fibrous tumor is a mesenchymal spindle cell neoplasm with fibroblastic differentiation ubiquitous in soft tissues, that involved the head and neck region in 6 % of cases. Etiology is unknown. The possible pathogenesis is NAB2-STAT6 gene fusion. It's asymptomatic or symptoms are related to space-occupying mass. Diagnostic work up involves imaging, immunohistochemistry, histology. Radiographic finding may lead to incorrect assessment of the mass: the same imaging features are present in pleomorphic adenoma, the most frequent tumor of salivary glands. Conclusion: This case report aims to stress that, although rare, solitary fibrous tumor should be considered in differential diagnosis in case of indolent salivary gland mass, since it may require more invasive approach (e.g., total parotidectomy, adjuvant radiotherapy). It would like to highlight the role of multidisciplinary team to define the best therapy, tailored for the patient, as well as to give awareness to a rare but sometimes aggressive tumor
The TNG Near Infrared Camera Spectrometer
NICS (acronym for Near Infrared Camera Spectrometer) is the near-infrared
cooled camera-spectrometer that has been developed by the Arcetri Infrared
Group at the Arcetri Astrophysical Observatory, in collaboration with the
CAISMI-CNR for the TNG (the Italian National Telescope Galileo at La Palma,
Canary Islands, Spain).
As NICS is in its scientific commissioning phase, we report its observing
capabilities in the near-infrared bands at the TNG, along with the measured
performance and the limiting magnitudes. We also describe some technical
details of the project, such as cryogenics, mechanics, and the system which
executes data acquisition and control, along with the related software.Comment: 7 pages, 5 figures, compiled with A&A macros. A&A in pres
Super-Kamiokande data and atmospheric neutrino decay
Neutrino decay has been proposed as a possible solution to the atmospheric
neutrino anomaly, in the light of the recent data from the Super-Kamiokande
experiment. We investigate this hypothesis by means of a quantitative analysis
of the zenith angle distributions of neutrino events in Super-Kamiokande,
including the latest (45 kTy) data. We find that the neutrino decay hypothesis
fails to reproduce the observed distributions of muons.Comment: 6 pages (RevTeX) + 2 figures (Postscript
Super-Kamiokande atmospheric neutrinos: Status of subdominant oscillations
In the context of the recent (79.5 kTy) Super-Kamiokande atmospheric neutrino
data, we concisely review the status of muonic-tauonic flavor oscillations and
of the subdominant electron or sterile neutrino mixing, in schemes with three
or four families and one dominant mass scale. In the three-family case, where
we include the full CHOOZ spectral data, we also show, through a specific
example, that ``maximal'' violations of the one-dominant mass scale
approximation are not ruled out yet.Comment: 8 pages + 10 figure
Signatures of supernova neutrino oscillations in the Earth mantle and core
The Earth matter effects on supernova (SN) neutrinos can be identified at a
single detector through peaks in the Fourier transform of their ``inverse
energy'' spectrum. The positions of these peaks are independent of the SN
models and therefore the peaks can be used as a robust signature of the Earth
matter effects, which in turn can distinguish between different neutrino mixing
scenarios. Whereas only one genuine peak is observable when the neutrinos
traverse only the Earth mantle, traversing also the core gives rise to multiple
peaks. We calculate the strengths and positions of these peaks analytically and
explore their features at a large scintillation detector as well as at a
megaton water Cherenkov detector through Monte Carlo simulations. We propose a
simple algorithm to identify the peaks in the actual data and quantify the
chances of a peak identification as a function of the location of the SN in the
sky.Comment: 17 pages, 9 figure
Faculty Productivity, Seniority, and Salary Compression
For decades, many senior professors have noticed that the earnings of entry-level faculty are often very close to, or greater than their own. This trend in faculty life-cycle earnings can be illustrated by the 1998 salary and seniority data obtained from a public, liberal arts college (PLAC) that are reported in Table 1. Salary compression is evidenced by the narrow earnings difference (200 more than the average associate professor. Also, the highest paid assistant in this department earns $2,000 more than the highest-paid associate. These data indicate a U-shaped wage-tenure profile. Such a profile suggests that faculty with low levels of seniority can expect their earnings to fall, or invert, relative to the salaries of new hires as their careers unfold at this institution. Similarly, the earnings gap between new hires and faculty with high levels of seniority will compress over time.Productivity; Salary; Seniority
Hints of theta_13>0 from global neutrino data analysis
Nailing down the unknown neutrino mixing angle theta_13 is one of the most
important goals in current lepton physics. In this context, we perform a global
analysis of neutrino oscillation data, focusing on theta_13, and including
recent results [Neutrino 2008, Proceedings of the XXIII International
Conference on Neutrino Physics and Astrophysics, Christchurch, New Zealand,
2008 (unpublished)]. We discuss two converging hints of theta_13>0, each at the
level of ~1sigma: an older one coming from atmospheric neutrino data, and a
newer one coming from the combination of solar and long-baseline reactor
neutrino data. Their combination provides the global estimate sin^2(theta_13) =
0.016 +- 0.010 (1sigma), implying a preference for \theta_13>0 with
non-negligible statistical significance (~90% C.L.). We discuss possible
refinements of the experimental data analyses, which might sharpen such
intriguing indication.Comment: Minor changes in the text. Matches published version in PR
Ribosomal stress activates eEF2K-eEF2 pathway causing translation elongation inhibition and recruitment of Terminal Oligopyrimidine (TOP) mRNAs on polysomes
The synthesis of adequate amounts of ribosomes is an essential task for the cell. It is therefore not surprising that regulatory circuits exist to organize the synthesis of ribosomal components. It has been shown that defect in ribosome biogenesis (ribosomal stress) induces apoptosis or cell cycle arrest through activation of the tumor suppressor p53. This mechanism is thought to be implicated in the pathophysiology of a group of genetic diseases such as Diamond Blackfan Anemia which are called ribosomopathies. We have identified an additional response to ribosomal stress that includes the activation of eukaryotic translation elongation factor 2 kinase with a consequent inhibition of translation elongation. This leads to a translational reprogramming in the cell that involves the structurally defined group of messengers called terminal oligopyrimidine (TOP) mRNAs which encode ribosomal proteins and translation factors. In fact, while general protein synthesis is decreased by the impairment of elongation, TOP mRNAs are recruited on polysomes causing a relative increase in the synthesis of TOP mRNA-encoded proteins compared to other proteins. Therefore, in response to ribosomal stress, there is a change in the translation pattern of the cell which may help restore a sufficient level of ribosomes
- …