6,272 research outputs found
ID5.17: New LearnWeb tool v.0.3 evaluation outcomes
Mazzetti, A., & Perez, M. (2009). ID5.17: New LearnWeb tool v.0.3 evaluation outcomes: TENCompetence.This document describes the evaluation of the new version of LearnWeb2.0, called: LearnWeb v.0.3 and KRService v.0.3. After a brief introduction, the evaluation methodology is described, both in terms of functionality tests and of quality tests. Then the loadability tests are described along with the usability aspects. A summary of the functionality follows, with the final recommendations for future versions.
This document is an internal deliverable of WP5. It deals with the evaluation of the software LearnWeb2.0 v.0.3The work on this publication has been sponsored by the TENCompetence Integrated Project that is funded by the European Commission's 6th Framework Programme, priority IST/Technology Enhanced Learning. Contract 027087 [http://www.tencompetence.org
Molecular gas and nuclear activity in early-type galaxies: any link with radio-loudness?
Aims. We want to study the amount of molecular gas in a sample of nearby
early-type galaxies (ETGs) which host low-luminosity Active Galactic Nuclei
(AGN). We look for possible differences between the radio-loud (RL) and
radio-quiet (RQ) AGN. Methods. We observed the CO(1-0) and CO(2-1) spectral
lines with the IRAM 30m and NRO 45m telescopes for eight galaxies. They belong
to a large sample of 37 local ETGs which host both RQ and RL AGN. We gather
data from the literature for the entire sample. Results. We report the new
detection of CO(1-0) emission in four galaxies (UGC0968, UGC5617, UGC6946, and
UGC8355) and CO(2-1) emission in two of them (UGC0968 and UGC5617). The
CO(2-1)/CO(1-0) ratio in these sources is . Considering both the
new observations and the literature, the detection rate of CO in our sample is
55 9%, with no statistically significant difference between the hosts of
RL and RQ AGNs. For all the detected galaxies we converted the CO luminosities
into the molecular masses, , that range from 10 to 10
M, without any statistically significant differences between RL and
RQ galaxies. This suggests that the amount of molecular gas does not likely set
the radio-loudness of the AGN. Furthermore, despite the low statistical
significance, the presence of a weak trend between the H mass with
various tracers of nuclear activity (mainly [O III] emission line nuclear
power) cannot be excluded.Comment: Accepted for publication on A&A, 9 pages, 5 figure
Performance and reliability comparison of 1T-1R RRAM arrays with amorphous and polycrystalline HfO2
In this work, a comparison between 1T-1R RRAM 4kbits arrays manufactured either with amorphous or polycrystalline HfO2 in terms of performance, reliability, Set/Reset operations energy requirements, intra-cell and inter-cell variability during 10k Set/Reset cycles is reported. Polycrystalline array shows higher current ratio, lower switching voltages, lower power consumption, minor endurance degradation and higher overall yield than amorphous array. The drawbacks are represented by the higher Forming voltage, the larger read current distribution after Forming and the higher Reset voltage dispersion
Nuclear spirals as feeding channels to the Supermassive Black Hole: the case of the galaxy NGC 6951
We report the discovery of gas streaming motions along nuclear spiral arms
towards the LINER nucleus of the galaxy NGC 6951. The observations, obtained
using the GMOS integral field spectrograph on the Gemini North telescope,
yielded maps of the flux distributions and gas kinematics in the Halpha,
[NII]6584 and [SII]6717,31 emission lines of the inner 7x5 arcsec^2 of the
galaxy. This region includes a circumnuclear star-forming ring with radius
500pc, a nuclear spiral inside the ring and the LINER nucleus. The kinematics
of the ionized gas is dominated by rotation, but subtraction of a kinematic
model of a rotating exponential disk reveals deviations from circular rotation
within the nuclear ring which can be attributed to (1) streaming motions along
the nuclear spiral arms and (2) a bipolar outflow which seems to be associated
to a nuclear jet. On the basis of the observed streaming velocities and
geometry of the spiral arms we estimate a mass inflow rate of ionized gas of
3x10^(-4) Msun/yr, which is of the order of the accretion rate necessary to
power the LINER nucleus of NGC 6951. Similar streaming motions towards the
nucleus of another galaxy with LINER nucleus -- NGC 1097 -- have been reported
by our group in a previous paper. Taken together, these results support a
scenario in which nuclear spirals are channels through which matter is
transferred from galactic scales to the nuclear region to feed the supermassive
black hole.Comment: 25 pages, 6 eps figures, accepted for publication in Ap
ULYSSES: Universal LeptogeneSiS Equation Solver
ULYSSES is a python package that calculates the baryon asymmetry produced
from leptogenesis in the context of a type-I seesaw mechanism. The code solves
the semi-classical Boltzmann equations for points in the model parameter space
as specified by the user. We provide a selection of predefined Boltzmann
equations as well as a plugin mechanism for externally provided models of
leptogenesis. Furthermore, the ULYSSES code provides tools for
multi-dimensional parameter space exploration. The emphasis of the code is on
user flexibility and rapid evaluation. It is publicly available at
https://github.com/earlyuniverse/ulyssesComment: 20 pages, 2 figures, 4 table
Role and importance of polymorphisms with respect to DNA methylation for the expression of CYP2E1 enzyme
Different individuals possess slightly different genetic information and show genetically-determined differences
in several enzyme activities due to genetic variability. Following an integrated approach,we studied the polymorphisms
andmethylation of sites contained in the 5′ flanking region of themetabolizing enzyme CYP2E1 in correlation
to its expression in both tumor and non-neoplastic liver cell lines, since to date little is known about the
influence of these (epi)genetic elements in basal conditions and under induction by the specific inductor and a
demethylating agent. In treated cells, reduced DNA methylation, assessed both at genomic and gene level, was
not consistently associatedwith the increase of enzyme expression. Interestingly, the Rsa/Pst haplotype differentially
influenced CYP2E1 enzyme expression. In addition, regarding the Variable Number of Tandem Repeats
polymorphism, cells with A4/A4 genotype showed a greater expression inhibition (ranging from 20% to 30%)
compared with others carrying the A2/A2 one, while those cells bringing A2/A3 genotype showed an increase
of expression (of 25%, about). Finally, we demonstrated for the first time that the A2 and A3 CYP2E1 alleles
play a more important role in the expression of the enzyme, compared with other (epi)genetic factors, since
they are binding sites for trans-acting proteins
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