65 research outputs found
Ground-based Raman-lidar for day and night measurements of water-vapor in the boundary layer
The solar-blind Raman-lidar based on a KrF laser (248 nm) developed at Lecceâs University (407 208 N, 187 68 E) is described. The lidar is currently used for day and night measurements of water vapor. The dependence of the measurement range of the lidar on the laser beam divergence is investigated and it is shown that the KrF laser beam divergence can be reduced by a factor A10 by using a quite
simple unstable cavity configuration. The maximum range which was limited to approximately 500 m for a A3 mrad divergence laser beam has increased up to 1200 m with a A0.3 mrad divergence laser beam since the field of view of the telescope was of 1 mrad. Water vapor profiles retrieved from lidar measurements under different operating conditions are presented. The effect of boundary-layer ozone absorption has also been investigated
Post-translational deregulation of YAP1 is genetically controlled in rat liver cancer and determines the fate and stem-like behavior of the human disease
Previous studies showed that YAP1 is over-expressed in hepatocellular carcinoma
(HCC). Here we observed higher expression of Yap1/Ctgf axis in dysplastic nodules and
HCC chemically-induced in F344 rats, genetically susceptible to hepatocarcinogenesis,
than in lesions induced in resistant BN rats. In BN rats, highest increase in Yap1-
tyr357, p73 phosphorylation and Caspase 3 cleavage occurred. In human HCCs with
poorer prognosis (< 3 years survival after partial liver resection, HCCP), levels of
YAP1, CTGF, 14â3â3, and TEAD proteins, and YAP1-14-3-3 and YAP1-TEAD complexes
were higher than in HCCs with better outcome (> 3 years survival; HCCB). In the
latter, higher levels of phosphorylated YAP1-ser127, YAP1-tyr357 and p73, YAP1
ubiquitination, and Caspase 3 cleavage occurred. Expression of stemness markers
NANOG, OCT-3/4, and CD133 were highest in HCCP and correlated with YAP1 and
YAP1-TEAD levels. In HepG2, Huh7, and Hep3B cells, forced YAP1 over-expression
led to stem cell markers expression and increased cell viability, whereas inhibition
of YAP1 expression by specific siRNA, or transfection of mutant YAP1 which does
not bind to TEAD, induced opposite alterations. These changes were associated, in
Huh7 cells transfected with YAP1 or YAP1 siRNA, with stimulation or inhibition of cell
migration and invasivity, respectively. Furthermore, transcriptome analysis showed
that YAP1 transfection in Huh7 cells induces over-expression of genes involved
in tumor stemness. In conclusion, Yap1 post-translational modifications favoring
its ubiquitination and apoptosis characterize HCC with better prognosis, whereas
conditions favoring the formation of YAP1-TEAD complexes are associated with
aggressiveness and acquisition of stemness features by HCC cells
Planck early results IX : XMM-Newton follow-up for validation of Planck cluster candidates
Peer reviewe
Planck early results. X. Statistical analysis of Sunyaev-Zeldovich scaling relations for X-ray galaxy clusters
All-sky data from the Planck survey and the Meta-Catalogue of X-ray detected Clusters of galaxies (MCXC) are combined to investigate the relationship between the thermal Sunyaev-Zeldovich (SZ) signal and X-ray luminosity. The sample comprises similar to 1600 X-ray clusters with redshifts up to similar to 1 and spans a wide range in X-ray luminosity. The SZ signal is extracted for each object individually, and the statistical significance of the measurement is maximised by averaging the SZ signal in bins of X-ray luminosity, total mass, or redshift. The SZ signal is detected at very high significance over more than two decades in X-ray luminosity (10(43) erg s(-1) less than or similar to L500E(z)(-7/3) less than or similar to 2 x 10(45) erg s(-1)). The relation between intrinsic SZ signal and X-ray luminosity is investigated and the measured SZ signal is compared to values predicted from X-ray data. Planck measurements and X-ray based predictions are found to be in excellent agreement over the whole explored luminosity range. No significant deviation from standard evolution of the scaling relations is detected. For the first time the intrinsic scatter in the scaling relation between SZ signal and X-ray luminosity is measured and found to be consistent with the one in the luminosity - mass relation from X-ray studies. There is no evidence of any deficit in SZ signal strength in Planck data relative to expectations from the X-ray properties of clusters, underlining the robustness and consistency of our overall view of intra-cluster medium properties
Planck Early Results XXVI: Detection with Planck and confirmation by XMM-Newton of PLCK G266.6-27.3, an exceptionally X-ray luminous and massive galaxy cluster at z~1
We present first results on PLCK G266.6-27.3, a galaxy cluster candidate
detected at a signal-to-noise ratio of 5 in the Planck All Sky survey. An
XMM-Newton validation observation has allowed us to confirm that the candidate
is a bona fide galaxy cluster. With these X-ray data we measure an accurate
redshift, z = 0.94 +/- 0.02, and estimate the cluster mass to be M_500 = (7.8
+/- 0.8)e+14 solar masses. PLCK G266.6-27.3 is an exceptional system: its
luminosity of L_X(0.5-2.0 keV)=(1.4 +/- 0.05)e+45 erg/s, equals that of the two
most luminous known clusters in the z > 0.5 universe, and it is one of the most
massive clusters at z~1. Moreover, unlike the majority of high-redshift
clusters, PLCK G266.6-27.3 appears to be highly relaxed. This observation
confirms Planck's capability of detecting high-redshift, high-mass clusters,
and opens the way to the systematic study of population evolution in the
exponential tail of the mass function.Comment: 6 pages, 3 figures; final version accepted for publication in A&A ;
minor changes in Sec.2.,3.2 and 4.1; Table 1: misprint on R500 error
corrected; abundance value adde
Planck intermediate results: III. the relation between galaxy cluster mass and Sunyaev-Zeldovich signal
We examine the relation between the galaxy cluster mass M and Sunyaev-Zeldovich (SZ) effect signal DA2 Y500 for a sample of 19 objects for which weak lensing (WL) mass measurements obtained from Subaru Telescope data are available in the literature. Hydrostatic X-ray masses are derived from XMM-Newton archive data, and the SZ effect signal is measured from Planck all-sky survey data. We find an MWL-D A2 Y500 relation that is consistent in slope and normalisation with previous determinations using weak lensing masses; however, there is a normalisation offset with respect to previous measures based on hydrostatic X-ray mass-proxy relations. We verify that our SZ effect measurements are in excellent agreement with previous determinations from Planck data. For the present sample, the hydrostatic X-ray masses at R500 are on average ~ 20 percent larger than the corresponding weak lensing masses, which is contrary to expectations. We show that the mass discrepancy is driven by a difference in mass concentration as measured by the two methods and, for the present sample, that the mass discrepancy and difference in mass concentration are especially large for disturbed systems. The mass discrepancy is also linked to the offset in centres used by the X-ray and weak lensing analyses, which again is most important in disturbed systems. We outline several approaches that are needed to help achieve convergence in cluster mass measurement with X-ray and weak lensing observations. © ESO, 2013
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