1,225 research outputs found
Weyl approach to representation theory of reflection equation algebra
The present paper deals with the representation theory of the reflection
equation algebra, connected with a Hecke type R-matrix. Up to some reasonable
additional conditions the R-matrix is arbitrary (not necessary originated from
quantum groups). We suggest a universal method of constructing finite
dimensional irreducible non-commutative representations in the framework of the
Weyl approach well known in the representation theory of classical Lie groups
and algebras. With this method a series of irreducible modules is constructed
which are parametrized by Young diagrams. The spectrum of central elements
s(k)=Tr_q(L^k) is calculated in the single-row and single-column
representations. A rule for the decomposition of the tensor product of modules
into the direct sum of irreducible components is also suggested.Comment: LaTeX2e file, 27 pages, no figure
Transvenous Lead Extraction in Patients with Cardiac Implantable Device: The Impact of Systemic and Local Infection on Clinical Outcomes. An ESCâEHRA ELECTRa (European Lead Extraction Controlled) Registry Substudy
Background: Infections of cardiac implantable devices (CIEDI) have poor outcomes despite improvement in lead extraction (TLE) procedures. Methods: To explore the influence of CIEDI on the outcomes of TLE and the differences between patients with systemic (Sy) vs. local (Lo) CIEDI, we performed a subâanalysis of the EORP ELECTRa (European Lead Extraction ConTRolled) Registry. Results: Among 3555 patients enrolled by 73 centers in 19 Countries, the indication for TLE was CIEDI in 1850: 1170 with LoâCIEDI and 680 with SyâCIEDI. Patients with CIEDI had a worse inâhospital prognosis in terms of major complications (3.57% vs. 1.71%; p = 0.0007) and mortality (2.27% vs. 0.49%; p < 0.0001). SyâCIEDI was an independent predictor of inâhospital death (H.R. 2.14; 95%CI 1.06â4.33. p = 0.0345). Patients with SyâCIEDI more frequently had an initial CIED implant and a higher prevalence of comorbidities, while subjects with LoâCIEDI had a higher prevalence of previous CIED procedures. Time from signs of CIEDI and TLE was longer for LoâCIEDI despite a shorter preâTLE antibiotic treatment. Conclusions: Patients with CIEDI have a worse inâhospital prognosis after TLE, especially for patients with SyâCIEDI. These results raise the suspicion that in a relevant group of patients CIEDI can be systemic from the beginning without progression from LoâCIEDI. Future research is needed to characterize this subgroup of patients
High-resolution tSZ cartography of clusters of galaxies with NIKA at the IRAM 30-m telescope
The thermal Sunyaev-Zeldovich effect (tSZ) is a powerful probe to study
clusters of galaxies and is complementary with respect to X-ray, lensing or
optical observations. Previous arcmin resolution tSZ observations ({\it e.g.}
SPT, ACT and Planck) only enabled detailed studies of the intra-cluster medium
morphology for low redshift clusters (). Thus, the development of
precision cosmology with clusters requires high angular resolution observations
to extend the understanding of galaxy cluster towards high redshift. NIKA2 is a
wide-field (6.5 arcmin field of view) dual-band camera, operated at and containing KID (Kinetic Inductance Detectors), designed to
observe the millimeter sky at 150 and 260 GHz, with an angular resolution of 18
and 12 arcsec respectively. The NIKA2 camera has been installed on the IRAM
30-m telescope (Pico Veleta, Spain) in September 2015. The NIKA2 tSZ
observation program will allow us to observe a large sample of clusters (50) at
redshift ranging between 0.5 and 1. As a pathfinder for NIKA2, several clusters
of galaxies have been observed at the IRAM 30-m telescope with the NIKA
prototype to cover the various configurations and observation conditions
expected for NIKA2.Comment: Proceedings of the 28th Texas Symposium on Relativistic Astrophysics,
Geneva, Switzerland, December 13-18, 201
High angular resolution Sunyaev-Zel'dovich observations of MACS J1423.8+2404 with NIKA: Multiwavelength analysis
The prototype of the NIKA2 camera, NIKA, is an instrument operating at the
IRAM 30-m telescope, which can observe simultaneously at 150 and 260GHz. One of
the main goals of NIKA2 is to measure the pressure distribution in galaxy
clusters at high resolution using the thermal SZ (tSZ) effect. Such
observations have already proved to be an excellent probe of cluster pressure
distributions even at high redshifts. However, an important fraction of
clusters host submm and/or radio point sources, which can significantly affect
the reconstructed signal. Here we report on <20" resolution observations at 150
and 260GHz of the cluster MACSJ1424, which hosts both radio and submm point
sources. We examine the morphology of the tSZ signal and compare it to other
datasets. The NIKA data are combined with Herschel satellite data to study the
SED of the submm point source contaminants. We then perform a joint
reconstruction of the intracluster medium (ICM) electronic pressure and density
by combining NIKA, Planck, XMM-Newton, and Chandra data, focusing on the impact
of the radio and submm sources on the reconstructed pressure profile. We find
that large-scale pressure distribution is unaffected by the point sources
because of the resolved nature of the NIKA observations. The reconstructed
pressure in the inner region is slightly higher when the contribution of point
sources are removed. We show that it is not possible to set strong constraints
on the central pressure distribution without accurately removing these
contaminants. The comparison with X-ray only data shows good agreement for the
pressure, temperature, and entropy profiles, which all indicate that MACSJ1424
is a dynamically relaxed cool core system. The present observations illustrate
the possibility of measuring these quantities with a relatively small
integration time, even at high redshift and without X-ray spectroscopy.Comment: 15 pages, 17 figures, submitted to A&
Microfabrication technology for large LEKID arrays : from NIKA2 to future applications
The Lumped Element Kinetic Inductance Detectors (LEKID)demonstrated full
maturity in the NIKA (New IRAM KID Arrays)instrument. These results allow
directly comparing LEKID performance with other competing technologies (TES,
doped silicon) in the mm and sub-mm range. A continuing effort is ongoing to
improve the microfabrication technologies and concepts in order to satisfy the
requirements of new instruments. More precisely, future satellites dedicated to
CMB (Cosmic Microwave Background) studies will require the same focal plane
technology to cover, at least, the frequency range of 60 to 600 GHz. Aluminium
LEKID developed for NIKA have so far demonstrated, under real telescope
conditions, performance approaching photon-noise limitation in the band 120-300
GHz. By implementing superconducting bi-layers we recently demonstrated LEKID
arrays working in the range 80-120 GHz and with sensitivities approaching the
goals for CMB missions. NIKA itself (350 pixels) is followed by a more
ambitious project requiring several thousands (3000-5000) pixels. NIKA2 has
been installed in October 2015 at the IRAM 30-m telescope. We will describe in
detail the technological improvements that allowed a relatively harmless
10-fold up-scaling in pixels count without degrading the initial sensitivity.
In particular we will briefly describe a solution to simplify the difficult
fabrication step linked to the slot-line propagation mode in coplanar
waveguide
NIKA2: a mm camera for cluster cosmology
Galaxy clusters constitute a major cosmological probe. However, Planck 2015
results have shown a weak tension between CMB-derived and cluster-derived
cosmological parameters. This tension might be due to poor knowledge of the
cluster mass and observable relationship.
As for now, arcmin resolution Sunyaev-Zeldovich (SZ) observations ({\it e.g.}
SPT, ACT and Planck) only allowed detailed studies of the intra cluster medium
for low redshift clusters () high
resolution and high sensitivity SZ observations are needed. With both a wide
field of view (6.5 arcmin) and a high angular resolution (17.7 and 11.2 arcsec
at 150 and 260 GHz), the NIKA2 camera installed at the IRAM 30-m telescope
(Pico Veleta, Spain) is particularly well adapted for these observations. The
NIKA2 SZ observation program will map a large sample of clusters (50) at
redshifts between 0.5 and 0.9. As a pilot study for NIKA2, several clusters of
galaxies have been observed with the pathfinder, NIKA, at the IRAM 30-m
telescope to cover the various configurations and observation conditions
expected for NIKA2.
Nika2: A mm camera for cluster cosmology
Galaxy clusters constitute a major cosmological probe. However, Planck 2015 results have shown a weak tension between CMB-derived and cluster-derived cosmological parameters. This tension might be due to poor knowledge of the cluster mass and observable relationship. As for now, arcmin resolution Sunyaev-Zeldovich (SZ) observations (e.g. SPT, ACT and Planck) only allowed detailed studies of the intra cluster medium for low redshift clusters (z 0:5) high resolution and high sensitivity SZ observations are needed. With both a wide field of view (6.5 arcmin) and a high angular resolution (17.7 and 11.2 arcsec at 150 and 260 GHz), the NIKA2 camera installed at the IRAM 30-m telescope (Pico Veleta, Spain) is particularly well adapted for these observations. The NIKA2 SZ observation program will map a large sample of clusters (50) at redshifts between 0.5 and 0.9. As a pilot study for NIKA2, several clusters of galaxies have been observed with the pathfinder, NIKA, at the IRAM 30-m telescope to cover the various configurations and observation conditions expected for NIKA2
Fast-TIPL Occurs for Salient Images without a Memorization Requirement in Men but Not in Women
Recent research of task-irrelevant perceptual learning (TIPL) demonstrates that stimuli that are consistently presented at relevant point in times (e.g. with task-targets or rewards) are learned, even in the absence of attention to these stimuli. However, different research paradigms have observed different results for how salient stimuli are learned; with some studies showing no learning, some studies showing positive learning and others showing negative learning effects. In this paper we focused on how the level of processing of stimuli impacts fast-TIPL. We conducted three different experiments in which the level of processing of the information paired with a target was manipulated. Our results indicated that fast-TIPL occurs when participants have to memorize the information presented with the target, but also when they just have to process this information for a secondary task without an explicit memorization of those stimuli. However, fast-TIPL does not occur when participants have to ignore the target-paired information. This observation is consistent with recent models of TIPL that suggest that attentional signals can either enhance or suppress learning depending on whether those stimuli are distracting or not to the subjects' objectives. Our results also revealed a robust gender effect in fast-TIPL, where male subjects consistently show fast-TIPL, whereas the observation of fast-TIPL is inconsistent in female subjects
Mapping the kinetic Sunyaev-Zel'dovich effect toward MACS J0717.5+3745 with NIKA
Measurement of the gas velocity distribution in galaxy clusters provides
insight into the physics of mergers, through which large scale structures form
in the Universe. Velocity estimates within the intracluster medium (ICM) can be
obtained via the Sunyaev-Zel'dovich (SZ) effect, but its observation is
challenging both in term of sensitivity requirement and control of systematic
effects, including the removal of contaminants. In this paper we report
resolved observations, at 150 and 260 GHz, of the SZ effect toward the triple
merger MACS J0717.5+3745 (z=0.55), using data obtained with the NIKA camera at
the IRAM 30m telescope. Assuming that the SZ signal is the sum of a thermal
(tSZ) and a kinetic (kSZ) component and by combining the two NIKA bands, we
extract for the first time a resolved map of the kSZ signal in a cluster. The
kSZ signal is dominated by a dipolar structure that peaks at -5.1 and +3.4
sigma, corresponding to two subclusters moving respectively away and toward us
and coincident with the cold dense X-ray core and a hot region undergoing a
major merging event. We model the gas electron density and line-of-sight
velocity of MACS J0717.5+3745 as four subclusters. Combining NIKA data with
X-ray observations from XMM-Newton and Chandra, we fit this model to constrain
the gas line-of-sight velocity of each component, and we also derive, for the
first time, a velocity map from kSZ data (i.e. that is model-dependent). Our
results are consistent with previous constraints on the merger velocities, and
thanks to the high angular resolution of our data, we are able to resolve the
structure of the gas velocity. Finally, we investigate possible contamination
and systematic effects with a special care given to radio and submillimeter
galaxies. Among the sources that we detect with NIKA, we find one which is
likely to be a high redshift lensed submillimeter galaxy.Comment: 19 pages, 9 figures, accepted in A&
Promising role of preoperative neutrophil-to-lymphocyte ratio in patients treated with radical nephroureterectomy.
Several retrospective studies with small cohorts reported neutrophil-to-lymphocyte ratio (NLR) as a prognostic marker in upper tract urothelial carcinoma (UTUC) following radical nephroureterectomy (RNU). We aimed at validating the predictive and prognostic role of NLR in a large multi-institutional cohort.
Preoperative NLR was assessed in a multi-institutional cohort of 2477 patients with UTUC treated with RNU. Altered NLR was defined by a ratio >2.7. Logistic regression analyses were performed to assess the association between NLR and lymph node metastasis, muscle-invasive and non-organ-confined disease. The association of altered NLR with recurrence-free survival (RFS) and cancer-specific survival (CSS) was evaluated using Cox proportional hazards regression models.
Altered NLR was observed in 1428 (62.8 %) patients and associated with more advanced pathological tumor stage, lymph node metastasis, lymphovascular invasion, tumor necrosis and sessile tumor architecture. In a preoperative model that included age, gender, tumor location and architecture, NLR was an independent predictive factor for the presence of lymph node metastasis, muscle-invasive and non-organ-confined disease (p < 0.001). Within a median follow-up of 40 months (IQR 20-76 months), 548 (24.1 %) patients experienced disease recurrence and 453 patients (19.9 %) died from their cancer. Compared to patients with normal NLR, those with altered NLR had worse RFS (0.003) and CSS (p = 0.002). In multivariable analyses that adjusted for the effects of standard clinicopathologic features, altered NLR did not retain an independent value. In the subgroup of patients treated with lymphadenectomy in addition to RNU, NLR was independently associated with CSS (p = 0.03).
In UTUC, preoperative NLR is associated with adverse clinicopathologic features and independently predicts features of biologically and clinically aggressive UTUC such as lymph node metastasis, muscle-invasive or non-organ-confined status. NLR may help better risk stratify patients with regard to lymphadenectomy and conservative therapy
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