3,469 research outputs found
Differences in telomere length between sporadic and familial cutaneous melanoma
BACKGROUND:
Several pieces of evidence indicate that a complex relationship exists between constitutional telomere length (TL) and the risk of cutaneous melanoma. Although the general perception is that longer telomeres increase melanoma risk, some studies do not support this association. We hypothesise that discordant data are due to the characteristics of the studied populations.
OBJECTIVES:
To evaluate the association of telomere length with familial and sporadic melanoma.
METHODS:
TL was measured by multiplex quantitative PCR in leukocytes from 310 melanoma patients according to familial/sporadic and single/multiple cancers and 216 age-matched controls.
RESULTS:
Patients with sporadic melanoma were found to have shorter telomeres as compared to those with familial melanoma. In addition, shorter telomeres, while tending to reduce the risk of familial melanoma regardless of single or multiple tumors, nearly trebled the risk of single sporadic melanoma.
CONCLUSIONS:
This is the first time that TL has been correlated to opposite effects on melanoma risk according to the presence or absence of familial predisposition. Individual susceptibility to melanoma should be taken into account when assessing the role of TL as a risk factor. This article is protected by copyright. All rights reserved
A Subset of the CERN Virtual Machine File System: Fast Delivering of Complex Software Stacks for Supercomputing Resources
Delivering a reproducible environment along with complex and up-to-date
software stacks on thousands of distributed and heterogeneous worker nodes is a
critical task. The CernVM-File System (CVMFS) has been designed to help various
communities to deploy software on worldwide distributed computing
infrastructures by decoupling the software from the Operating System. However,
the installation of this file system depends on a collaboration with system
administrators of the remote resources and an HTTP connectivity to fetch
dependencies from external sources. Supercomputers, which offer tremendous
computing power, generally have more restrictive policies than grid sites and
do not easily provide the mandatory conditions to exploit CVMFS. Different
solutions have been developed to tackle the issue, but they are often specific
to a scientific community and do not deal with the problem in its globality. In
this paper, we provide a generic utility to assist any community in the
installation of complex software dependencies on supercomputers with no
external connectivity. The approach consists in capturing dependencies of
applications of interests, building a subset of dependencies, testing it in a
given environment, and deploying it to a remote computing resource. We
experiment this proposal with a real use case by exporting Gauss-a Monte-Carlo
simulation program from the LHCb experiment-on Mare Nostrum, one of the top
supercomputers of the world. We provide steps to encapsulate the minimum
required files and deliver a light and easy-to-update subset of CVMFS: 12.4
Gigabytes instead of 5.2 Terabytes for the whole LHCb repository
The ESPERIA satellite project for detecting seismo-associated effects in the topside ionosphere. First instrumental tests in space
In recent times, ionospheric and magnetospheric perturbations constituted by radiation belt particle precipitations, variations of temperature and density of ionic and electronic components of ionospheric plasma as well as electric and magnetic field fluctuations have been detected on board of the LEO satellites and associated with earthquake preparation and occurrence. Several mechanisms have been suggested as justifying the seismoelectromagnetic phenomena observed in the upper lithosphere and in the topside ionosphere before, during and after an earthquake. Their propagation in these media has also been investigated, but physical knowledge of such processes is below standard. Consequently, coordinated space and ground-based observations based on data gathered simultaneously in space and at the Earth's surface are needed to investigate seismo-associated phenomena. To this end, the ESPERIA space mission project has been designed for the Italian Space Agency (ASI). To date, a few instruments of its payload have been built and tested in space. This paper reports on the justification, science background, and characteristics of the ESPERIA mission project as well as the description and testing of ESPERIA Instruments (ARINA and LAZIO-EGLE) in space
Theory-based scaling laws of near and far scrape-off layer widths in single-null L-mode discharges
Theory-based scaling laws of the near and far scrape-off layer (SOL) widths
are analytically derived for L-mode diverted tokamak discharges by using a
two-fluid model. The near SOL pressure and density decay lengths are obtained
by leveraging a balance among the power source, perpendicular turbulent
transport across the separatrix, and parallel losses at the vessel wall, while
the far SOL pressure and density decay lengths are derived by using a model of
intermittent transport mediated by filaments. The analytical estimates of the
pressure decay length in the near SOL is then compared to the results of
three-dimensional, flux-driven, global, two-fluid turbulence simulations of
L-mode diverted tokamak plasmas, and validated against experimental
measurements taken from an experimental multi-machine database of divertor heat
flux profiles, showing in both cases a very good agreement. Analogously, the
theoretical scaling law for the pressure decay length in the far SOL is
compared to simulation results and to experimental measurements in TCV L-mode
discharges, pointing out the need of a large multi-machine database for the far
SOL decay lengths
Imaging nuclear, endoplasmic reticulum, and plasma membrane events in real time
Live cell imaging can provide important information on cellular dynamics; however, the full utilisation of this technology has been hampered by the limitations of imaging reagents. Metal-based complexes have the potential to overcome many of the issues common to many current imaging agents. The rhenium (I)-based complex fac-[Re(CO)3(1,10-phenanthroline)(4-pyridyltetrazolate)], herein referred to as ReZolve-ER™, shows promise as a live cell imaging agent with rapid cell uptake, low cytotoxicity, resistance to photobleaching and compatibility with multicolour imaging. ReZolve-ER™ localised to the nuclear membrane/endoplasmic reticulum (ER) and allowed the detection of exocytotic events at the plasma membrane. Thus, we present a new imaging agent for monitoring live cell events in real time, which is ideal for imaging either short- or long-time courses
Low- and intermediate-temperature ammonia/hydrogen oxidation in a flow reactor: Experiments and a wide-range kinetic modeling
Understanding the chemistry behind the oxidation of ammonia/hydrogen mixtures is crucial for ensuring the flexible use of such mixtures in several applications, related to propulsion systems and power generation. In this work, the oxidation of ammonia/hydrogen blends was investigated through an experimental and kinetic-modeling study, where the low- and intermediate-temperature conditions were considered. An experimental campaign was performed in a flow reactor, at stoichiometric conditions and near-atmospheric pressure (126.7 kPa). The mole fraction of fuels, oxidizer and final products was measured. At the same time, a comprehensive kinetic model was set up, following a modular and hierarchical approach, and implementing the recently-available elementary rates. Such a model was used to interpret the experimental results, and to extend the analysis to literature data, covering several oxidation features. The reactivity boost provided by H2 addition was found to be approximately linear with its mole fraction in both flow- and jet-stirred-reactor conditions (except for the smallest H2 amounts in the flow reactor), in contrast with the more-than-linear increase in the laminar flame speed. The key role of HO2 in regulating fuel conversion and autoignition at low temperature was confirmed for binary mixtures, with H2NO being the bottleneck to the low-temperature oxidation of NH3-rich blends. On the other hand, the nitrogen fate was found to be mostly regulated by NHx + NO propagation and termination channels
Enhanced deep-blue emission from Pt(II) complexes bound to 2-pyridyltetrazolate and an ortho-xylene-linked bis(NHC)cyclophane
The coordination of 2-pyridyltetrazolate and ortho-xylene-linked bis(NHC)cyclophane to Pt(II) yielded a novel complex characterised by enhanced pure deep-blue emission, whose intensity can be modulated via methylation of the tetrazole ring
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