358 research outputs found
Millimeter observations of Planetary Nebulae: a contribution to the Planck pre-launch catalogue
We present new millimetre 43 GHz observations of a sample of radio-bright
Planetary Nebulae. Such observations were carried out to have a good
determination of the high-frequency radio spectra of the sample in order to
evaluate, together with far-IR measurements (IRAS), the fluxes emitted by the
selected source in the millimetre and sub-millimetre band. This spectral range,
even very important to constraint the physics of circumstellar environment, is
still far to be completely exploited. To estimate the millimetre and
sub-millimetre fluxes, we extrapolated and summed together the ionized gas
(free-free radio emission) and dust (thermal emission) contributions at this
frequency range. By comparison of the derived flux densities to the foreseen
sensitivity we investigate the possible detection of such source for all the
channels of the forthcoming ESA's PLANCK mission. We conclude that almost 80%
of our sample will be detected by PLANCK, with the higher detection rate in the
higher frequency channels, where there is a good combination of brighter
intrinsic flux from the sources and reduced extended Galactic foregrounds
contamination despite a worst instrumental sensitivity. From the new 43 GHz,
combined with single-dish 5 GHz observations from the literature, we derive
radio spectral indexes, which are consistent with optically thin free-free
nebula. This result indicates that the high frequency radio spectrum of our
sample sources is dominated by thermal free-free and other emission, if
present, are negligible.Comment: Submitted to A&A, 6 pages, 3 figure
Investigating Gender Bias in Machine Translation. A Case Study between English and Italian
Neural machine translation systems have substantially improved the quality of translation output, yet many issues still need to be addressed: one major problem to be addressed concerns the presence of gender bias, the prejudice against one gender based on the perception that women and men are not equal. In this work, we will manually evaluate the translation of a sentence pattern previously employed for similar purposes by Escud\ue9 Font and Costa-juss\ue0 (2019) in the English-Italian language combination using two of the most popular MT systems, DeepL and Google Translate. The sets of sentences include 40 male- and female-dominated occupations and three adjectives, beautiful, wise and strong. The aim of this study is to evaluate gender bias, that becomes apparent when translating from a gender-neutral language to a gender-marked language, and to verify whether adjectives usually associated with female or male entities can affect the final MT output. Furthermore, we provide some relevant insights about gender bias in MT for post-editors and MT users, with a particular focus on the under-representation of women in the Italian language
Adaptive Neural Translation for Enterprises (ANTE). La traduzione automatica neurale a sostegno delle imprese emiliano-romagnole
Il progetto ANTE riguarda i nuovi sistemi di traduzione automatica (TA) e la loro applicazione nel mondo delle imprese. Lo studio prende spunto dai recenti sviluppi legati all’intelligenza artificiale e ai Big Data che negli ultimi anni hanno permesso alla TA di raggiungere livelli qualitativi molto elevati, al punto tale da essere impiegata da grandi multinazionali per raggiungere nuove quote di mercato.
La TA può rispondere positivamente anche ai bisogni delle imprese di piccole dimensioni e a basso tenore tecnologico, migliorando la qualità delle comunicazioni multilingue attraverso delle traduzioni in tempi brevi e a costi contenuti. Lo studio si propone quindi di contribuire al rafforzamento della competitività internazionale delle piccole e medie imprese (PMI) emiliano- romagnole, migliorando la loro capacità di comunicazione in una o più lingue straniere attraverso l’introduzione e l’utilizzo efficace e consapevole di soluzioni ICT di ultima generazione e fornire, così, nuove opportunità di internazionalizzazione.The ANTE project focuses on new machine translation (MT) systems and their application in the business world. The study starts from the recent developments related to artificial intelligence and Big Data, which have enabled MT systems to reach very high levels of quality. For this reason, MT is nowadays employed by large multinational companies to achieve new market shares.
MT systems can also positively address the needs of small, low-tech firms by improving the quality of multilingual communications through cost-effective and time-efficient translations. The study aims to contribute to the strengthening of the international competitiveness of small and medium-sized enterprises (SMEs) in the Emilia-Romagna region, by improving their ability to communicate in one or more foreign languages through the introduction of the latest ICT solutions and thus provide new opportunities for internationalization
SF2/ASF binding region within JC virus NCCR limits early gene transcription in glial cells
Comparing extrapolations of the coronal magnetic field structure at 2.5 solar radii with multi-viewpoint coronagraphic observations
The magnetic field shapes the structure of the solar corona but we still know
little about the interrelationships between the coronal magnetic field
configurations and the resulting quasi-stationary structures observed in
coronagraphic images (as streamers, plumes, coronal holes). One way to obtain
information on the large-scale structure of the coronal magnetic field is to
extrapolate it from photospheric data and compare the results with
coronagraphic images. Our aim is to verify if this comparison can be a fast
method to check systematically the reliability of the many methods available to
reconstruct the coronal magnetic field. Coronal fields are usually extrapolated
from photospheric measurements typically in a region close to the central
meridian on the solar disk and then compared with coronagraphic images at the
limbs, acquired at least 7 days before or after to account for solar rotation,
implicitly assuming that no significant changes occurred in the corona during
that period. In this work, we combine images from three coronagraphs
(SOHO/LASCO-C2 and the two STEREO/SECCHI-COR1) observing the Sun from different
viewing angles to build Carrington maps covering the entire corona to reduce
the effect of temporal evolution to ~ 5 days. We then compare the position of
the observed streamers in these Carrington maps with that of the neutral lines
obtained from four different magnetic field extrapolations, to evaluate the
performances of the latter in the solar corona. Our results show that the
location of coronal streamers can provide important indications to discriminate
between different magnetic field extrapolations.Comment: Accepted by A&A the 20th of May, 201
Multiple sclerosis between genetics and infections: human endogenous retroviruses in monocytes and macrophages
The etiology of multiple sclerosis (MS) is still unknown, but there is strong evidence that genetic predisposition associated with environmental factors can trigger the disease. An estimated 30 million years ago, exogenous retroviruses are thought to have integrated themselves into human germ line cells, becoming part of human DNA and being transmitted over generations. Usually such human endogenous retroviruses (HERVs) are silenced or expressed at low levels, but in some pathological conditions, such as MS, their expression is higher than that in the healthy population. Three HERV families have been associated with MS: HERV-H, HERV-K, and HERV-W. The envelope protein of MS-associated retrovirus (MSRV) from the HERV-W family currently has the strongest evidence as a potential trigger for MS. In addition to expression in peripheral immune cells, MSRV is expressed in monocytes and microglia in central nervous system lesions of people with MS and, through the activation of toll-like receptor 4, it has been shown to drive the production of proinflammatory cytokines, reduction of myelin protein expression, and death of oligodendrocyte precursors. In conclusion, the association between HERVs and MS is well documented and a pathological role for MSRV in MS is plausible. Further studies are required to determine whether the presence of these HERVs is a cause or an effect of immune dysregulation in MS
Expression and activation of human endogenous retroviruses of the W family in blood cells and astrocytes: implications for the pathogenesis of multiple sclerosis
Background
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system, with demyelination
and gliosis. Proposed pathogenic co-factors triggering
MS pathogenesis are the Epstein Barr virus (EBV), and
two elements of the W family of human endogenous
retroviruses (HERV-W): MSRV, that forms free virions,
and syncytin-1, the ERVWE1env protein; both retroelements
have neuropathogenic properties. In the past we
studied MSRV in MS patients in various temporal and
clinical stages; in all cases, striking parallelisms
between MS behaviour and MSRV/HERV-W presence/
load were found. By simultaneous detection of MSRV
and HHV-6, we found a direct correlation between MS
and MSRV presence/load, but not for HHV-6. MS
brains over-express MSRVenv and syncytin-1 transcripts,
with respect to controls, while EBV presence
was not detected.
Materials and methods
Since late EBV seroconversion is a strong risk factor for MS development, we performed in vitro experiments on PBMC from MS patients and MSRV+ volunteers, as well as on U87-MG astroglioma cells, that were studied as such or were exposed to EBV or to recombinant EBV glycoprotein350 (EBVgp350), or to proinflammatory cytokines. The levels of MSRVenv and syncytin-1 mRNAs were evaluated by discriminatory real time RTPCR assays. Flow cytometry was used to evaluate the
HERV-Wenv protein on the plasmamembrane, as well
the PBMC subsets.
Results
Basal expression of MSRVenv and syncytin-1 occurs in
astrocytes and in NK, B and monocyte cells, but not in
T cells. This uneven expression is amplified in naive MS
patients. Astrocyte infection by EBV and exposure to
EBVgp350 stimulate the expression of HERV-W/MSRV/
syncytin-1, with requirement of the NF-kB pathway. In
EBVgp350-treated PBMC, MSRVenv and syncytin-1 are
activated in B cells and monocytes, but not in T cells,
nor in the highly expressing NK cells. The latter cells,
but not the T cells, are activated by proinflammatory
cytokines.
Conclusions
The study demonstrates that there are interactions
among the above proposed MS-cofactors. In vivo, a
pathogenic outcome would depend on activation in
abnormal situations/tissues, as it may occur in delayed
EBV infection, or in the presence of particular host
genetic backgrounds, or both.</br
Multiple signatures of the JC polyomavirus in paired normal and altered colorectal mucosa indicate a link with human colorectal cancer, but not with cancer progression.
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