3,354 research outputs found
The GAPS Programme with HARPS-N@TNG IX. The multi-planet system KELT-6: detection of the planet KELT-6 c and measurement of the Rossiter-McLaughlin effect for KELT-6 b
Aims. For more than 1.5 years we monitored spectroscopically the star KELT-6
(BD+312447), known to host the transiting hot Saturn KELT-6b, because a
previously observed long-term trend in radial velocity time series suggested
the existence of an outer companion. Methods. We collected a total of 93 new
spectra with the HARPS-N and TRES spectrographs. A spectroscopic transit of
KELT-6b was observed with HARPS-N, and simultaneous photometry was obtained
with the IAC-80 telescope. Results. We proved the existence of an outer planet
with a mininum mass Msini=3.710.21 M and a
moderately eccentric orbit () of period P3.5
years. We improved the orbital solution of KELT-6b and obtained the first
measurement of the Rossiter-McLaughlin effect, showing that the planet has a
likely circular, prograde, and slightly misaligned orbit, with a projected
spin-orbit angle =3611 degrees. We improved the KELT-6b
transit ephemeris from photometry, and we provided new measurements of the
stellar parameters. KELT-6 appears as an interesting case to study the
formation and evolution of multi-planet systems.Comment: Letter, 4 figures, accepted for publication in A&A. Some language
editing and numbering of the paper series changed (from X to IX
Coupled dark matter-dark energy in light of near Universe observations
Cosmological analysis based on currently available observations are unable to
rule out a sizeable coupling among the dark energy and dark matter fluids. We
explore a variety of coupled dark matter-dark energy models, which satisfy
cosmic microwave background constraints, in light of low redshift and near
universe observations. We illustrate the phenomenology of different classes of
dark coupling models, paying particular attention in distinguishing between
effects that appear only on the expansion history and those that appear in the
growth of structure. We find that while a broad class of dark coupling models
are effectively models where general relativity (GR) is modified --and thus can
be probed by a combination of tests for the expansion history and the growth of
structure--, there is a class of dark coupling models where gravity is still
GR, but the growth of perturbations is, in principle modified. While this
effect is small in the specific models we have considered, one should bear in
mind that an inconsistency between reconstructed expansion history and growth
may not uniquely indicate deviations from GR. Our low redshift constraints
arise from cosmic velocities, redshift space distortions and dark matter
abundance in galaxy voids. We find that current data constrain the
dimensionless coupling to be |xi|<0.2, but prospects from forthcoming data are
for a significant improvement. Future, precise measurements of the Hubble
constant, combined with high-precision constraints on the growth of structure,
could provide the key to rule out dark coupling models which survive other
tests. We shall exploit as well weak equivalence principle violation arguments,
which have the potential to highly disfavour a broad family of coupled models.Comment: 34 pages, 6 figures; changes to match published versio
Promoter hypomethylation of the LINE-1 retrotransposable elements activates sense/antisense transcription and marks the progression of chronic myeloid leukemia
Aberrant genome-wide hypomethylation is thought to be
related to tumorigenesis by promoting genomic instability.
Since DNA methylation is considered an important mechanism
for the silencingof retroelements, hypomethylation
in human tumors may lead to their reactivation. However,
the role of DNA hypomethylation in chronic myeloid
leukemia (CML) remains to be elucidated. In this study,
the methylation status of the LINE-1 (L1) retrotransposon
promoter was analysed in CML samples from the chronicphase
(CP, n¼140) and the blast crisis (BC, n¼47). L1
hypomethylation was significantly more frequent in BC
(74.5%) than in CP (38%) (Po0.0001). Furthermore,
L1 hypomethylation led to activation of both ORF1 sense
transcription (Po0.0001) and c-MET gene antisense
transcription (Po0.0001), and was significantly associated
with high levels of BCR–ABL (P¼0.02) and
DNMT3b4 (P¼0.001) transcripts. Interestingly, in
CP-CML, extensive L1 hypomethylation was associated
with poorer prognosis in terms of cytogenetic response
to interferon (P¼0.004) or imatinib (P¼0.034) and
progression-free survival (P¼0.005). The above results
strongly suggest that activation of both sense and
antisense transcriptions by aberrant promoter hypomethylation
of the L1 elements plays a role in the progression
and clinical behavior of the CML
Searching for a Cosmological Preferred Axis: Union2 Data Analysis and Comparison with Other Probes
We review, compare and extend recent studies searching for evidence for a
preferred cosmological axis. We start from the Union2 SnIa dataset and use the
hemisphere comparison method to search for a preferred axis in the data. We
find that the hemisphere of maximum accelerating expansion rate is in the
direction (\omm=0.19) while the hemisphere of
minimum acceleration is in the opposite direction
(\omm=0.30). The level of anisotropy is described by the normalized
difference of the best fit values of \omm between the two hemispheres in the
context of \lcdm fits. We find a maximum anisotropy level in the Union2 data of
\frac{\Delta \ommax}{\bomm}=0.43\pm 0.06. Such a level does not necessarily
correspond to statistically significant anisotropy because it is reproduced by
about of simulated isotropic data mimicking the best fit Union2 dataset.
However, when combined with the axes directions of other cosmological
observations (bulk velocity flow axis, three axes of CMB low multipole moments
and quasar optical polarization alignment axis), the statistical evidence for a
cosmological anisotropy increases dramatically. We estimate the probability
that the above independent six axes directions would be so close in the sky to
be less than . Thus either the relative coincidence of these six axes is a
very large statistical fluctuation or there is an underlying physical or
systematic reason that leads to their correlation.Comment: 10 pages, 7 figures. Accepted in JCAP (to appear). Extended analysis
with redshift tomography of SnIa, included errorbars and increased number of
axes. The Mathematica 7 files with the data used for the production of the
figures along with a Powerpoint file with additional figures may be
downloaded from http://leandros.physics.uoi.gr/anisotrop
Shoc2/Sur8 protein regulates neurite outgrowth
This is an openaccess
article distributed under the terms of the
Creative Commons Attribution License.-- et al.The Shoc2 protein has been implicated in the positive regulation of the Ras-ERK pathway by increasing the functional binding interaction between Ras and Raf, leading to increased ERK activity. Here we found that Shoc2 overexpression induced sustained ERK phosphorylation, notably in the case of EGF stimulation, and Shoc2 knockdown inhibited ERK activation. We demonstrate that ectopic overexpression of human Shoc2 in PC12 cells significantly promotes neurite extension in the presence of EGF, a stimulus that induces proliferation rather than differentiation in these cells. Finally, Shoc2 depletion reduces both NGF-induced neurite outgrowth and ERK activation in PC12 cells. Our data indicate that Shoc2 is essential to modulate the Ras-ERK signaling outcome in cell differentiation processes involved in neurite outgrowth.GL, TG and LMD were recipients of fellowships from the Ministerio de Educación y Ciencia (MEC) (to GL, TG), and Fondo de Investigaciones Sanitarias (FIS) (to LMD). LSR
held a postdoctoral research contract from CIBERNED. This work was supported by FIS grant
(PI10/00815) to JLO; CIBERNED to MC; SAF2008-01951, Comunidad Autónoma de Madrid (CAM) SSAL-0202-2006-01 and Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) to TI; FIS grant PI12/00775 and ISCIII-RETIC (Red Temática de Investigación Cooperativa en Cáncer) RD12/0036/0027 from the Instituto de Salud Carlos III to PSG; and FIS grants (PI09/0562 and PI13/00703), ISCIIIRETIC
(RD06/0020/0003 and RD12/0036/0021), and the Spanish Association Against Cancer
(AECC) to JMR.Peer Reviewe
BioJS: An open source standard for biological visualisation - its status in 2014
BioJS is a community-based standard and repository of functional components to represent biological information on the web. The development of BioJS has been prompted by the growing need for bioinformatics visualisation tools to be easily shared, reused and discovered. Its modular architecture makes it easy for users to find a specific functionality without needing to know how it has been built, while components can be extended or created for implementing new functionality. The BioJS community of developers currently provides a range of functionality that is open access and freely available. A registry has been set up that categorises and provides installation instructions and testing facilities at http://www.ebi.ac.uk/tools/biojs/. The source code for all components is available for ready use at https://github.com/biojs/biojs
Discovery of Water Maser Emission in Eight AGN with 70-m Antennas of NASA's Deep Space Network
We report the discovery of water maser emission in eight active galactic
nuclei (AGN) with the 70-m NASA Deep Space Network (DSN) antennas at
Tidbinbilla, Australia and Robledo, Spain. The positions of the newly
discovered masers, measured with the VLA, are consistent with the optical
positions of the host nuclei to within 1 sigma (0.3 arcsec radio and 1.3 arcsec
optical) and most likely mark the locations of the embedded central engines.
The spectra of two sources, NGC 3393 and NGC 5495, display the characteristic
spectral signature of emission from an edge-on accretion disk, with orbital
velocities of ~600 and ~400 km s^-1, respectively. In a survey with DSN
facilities of 630 AGN selected from the NASA Extragalactic Database, we have
discovered a total of 15 water maser sources. The resulting incidence rate of
maser emission among nearby (v_sys < 7000 km s^-1) Seyfert 1.8-2.0 and LINER
systems is ~10 percent for a typical rms noise level of ~14 mJy over 1.3 km
s^-1 spectral channels. As a result of this work, the number of nearby AGN
(v_sys < 7000 km s^-1) observed with <20 mJy rms noise has increased from 130
to 449.Comment: 7 pages, 1 figure, 2 tables, to appear in the 2006 February 10 issue
of the Astrophysical Journal, uses twocolumns.cl
A snapshot of cancer-associated thromboembolic disease in 2018-2019: First data from the TESEO prospective registry
BACKGROUND: The ever-growing complexity of cancer-associated thrombosis (CAT), with new antineoplastic drugs and anticoagulants, distinctive characteristics, and decisions with low levels of evidence, justifies this registry. METHOD: TESEO is a prospective registry promoted by the Spanish Society of Medical Oncology to which 34 centers contribute cases. It seeks to provide an epidemiological description of CAT in Spain. RESULTS: Participants (N=939) with CAT diagnosed between July 2018 and December 2019 were recruited. Most subjects had advanced colon (21.4%), non-small cell lung (19.2%), and breast (11.1%) cancers, treated with dual-agent chemotherapy (28.4%), monochemotherapy (14.4%), or immune checkpoint inhibitors (3.6%). Half (51%) were unsuspected events, albeit only 57.1% were truly asymptomatic. Pulmonary embolism (PE) was recorded in 571 (58.3%); in 120/571 (21.0%), there was a concurrent deep venous thromboembolism (VTE). Most initially received low molecular weight heparin (89.7%). Suspected and unsuspected VTE had an OS rate of 9.9 (95% CI, 7.3-non-computable) and 14.4 months (95% CI, 12.6-non-computable) (p=0.00038). Six-month survival was 80.9%, 55.9%, and 55.5% for unsuspected PE, unsuspected PE admitted for another reason, and suspected PE, respectively (p<0.0001). The 12-month cumulative incidence of venous rethrombosis was 7.1% (95% CI, 4.7-10.2) in stage IV vs 3.0% (95% CI, 0.9-7.1) in stages I-III. The 12-month cumulative incidence of major/clinically relevant bleeding was 9.6% (95% CI, 6.1-14.0) in the presence of risk factors. CONCLUSION: CAT continues to be a relevant problem in the era of immunotherapy and targeted therapies. The initial TESEO data highlight the evolution of CAT, with new agents and thrombotic risk factors
Herschel-ATLAS: Multi-wavelength SEDs and physical properties of 250 micron-selected galaxies at z < 0.5
We present a pan-chromatic analysis of an unprecedented sample of 1402 250
micron-selected galaxies at z < 0.5 (mean z = 0.24) from the Herschel-ATLAS
survey. We complement our Herschel 100-500 micron data with UV-K-band
photometry from the Galaxy And Mass Assembly (GAMA) survey and apply the
MAGPHYS energy-balance technique to produce pan-chromatic SEDs for a
representative sample of 250 micron selected galaxies spanning the most recent
5 Gyr of cosmic history. We derive estimates of physical parameters, including
star formation rates, stellar masses, dust masses and infrared luminosities.
The typical H-ATLAS galaxy at z < 0.5 has a far-infrared luminosity in the
range 10^10 - 10^12 Lsolar (SFR: 1-50 Msolar/yr) thus is broadly representative
of normal star forming galaxies over this redshift range. We show that 250
micron-selected galaxies contain a larger mass of dust at a given infra-red
luminosity or star formation rate than previous samples selected at 60 micron
from IRAS. We derive typical SEDs for H-ATLAS galaxies, and show that the
emergent SED shape is most sensitive to specific star formation rate. The
optical-UV SEDs also become more reddened due to dust at higher redshifts. Our
template SEDs are significantly cooler than existing infra-red templates. They
may therefore be most appropriate for inferring total IR luminosities from
moderate redshift submillimetre selected samples and for inclusion in models of
the lower redshift submillimetre galaxy populations.Comment: 26 pages, 24 figures, Accepted by MNRA
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