151 research outputs found
Testing the b-value variability in Italy and its influence on Italian PSHA
The supposed b-value spatial variability is the central topic of many scientific works dealing with forecasting modeling applications or geological correlations. If used for seismicity rates determination, the b-value plays an important role in probabilistic seismic hazard assessment, but how much does it influence PSHA? In the logic tree approach used for the new probabilistic seismic hazard map of Italy, named MPS04 (MPS Working Group, 2004), one of the sources of epistemic uncertainty considered was the procedure for computing seismicity rates. Two
alternatives were adopted: 1) compute the activity rates for each binned magnitude
class and 2) compute a Gutenberg-Richter (1944) distribution. In the logic tree
branches where Gutenberg-Richter distribution was adopted, the corresponding bvalue was evaluated for each seismogenic zone: it spans between 0.63 and 2.01. After analysing the b-value variability in the Italian region, this work evaluates the impact of setting the b-value equal to 1 on the results of seismic hazard assessment in terms of PGA and energy release compared to the choices adopted for MPS04 (MPS Working Group, 2004)
Y RNA: an overview of their role as potential biomarkers and molecular targets in human cancers
Y RNA are a class of small non-coding RNA that are largely conserved. Although their discovery was almost 40 years ago, their function is still under investigation. This is evident in cancer biology, where their role was first studied just a dozen years ago. Since then, only a few contributions were published, mostly scattered across different tumor types and, in some cases, also suffering from methodological limitations. Nonetheless, these sparse data may be used to make some estimations and suggest routes to better understand the role of Y RNA in cancer formation and characterization. Here we summarize the current knowledge about Y RNA in multiple types of cancer, also including a paragraph about tumors that might be included in this list in the future, if more evidence becomes available. The picture arising indicates that Y RNA might be useful in tumor characterization, also relying on non-invasive methods, such as the analysis of the content of extracellular vesicles (EV) that are retrieved from blood plasma and other bodily fluids. Due to the established role of Y RNA in DNA replication, it is possible to hypothesize their therapeutic targeting to inhibit cell proliferation in oncological patients
Bose-Einstein statistics in thermalization and photoluminescence of quantum well excitons
Quasi-equilibrium relaxational thermodynamics is developed to understand
LA-phonon-assisted thermalization of Bose-Einstein distributed excitons in
quantum wells. We study the quantum-statistical effects in the relaxational
dynamics of the effective temperature of excitons . When is less
than the degeneracy temperature , well-developed Bose-Einstein statistics
of quantum well excitons leads to nonexponential and density-dependent
thermalization. At low bath temperatures the thermalization of
quantum-statistically degenerate excitons effectively slows down and . We also analyze the optical decay of Bose-Einstein
distributed excitons in perfect quantum wells and show how nonclassical
statistics influences the effective lifetime . In particular,
of a strongly degenerate gas of excitons is given by ,
where is the intrinsic radiative lifetime of quasi-two-dimensional
excitons. Kinetics of resonant photoluminescence of quantum well excitons
during their thermalization is studied within the thermodynamic approach and
taking into account Bose-Einstein statistics. We find density-dependent
photoluminescence dynamics of statistically degenerate excitons. Numerical
modeling of the thermalization and photoluminescence kinetics of
quasi-two-dimensional excitons are given for GaAs/AlGaAs quantum wells.Comment: 19 pages, 9 figures. Phys. Rev. B (accepted for publication
Non-coding RNAs and endometrial cancer
Non-coding RNAs (ncRNAs) are involved in the regulation of cell metabolism and neoplastic transformation. Recent studies have tried to clarify the significance of these information carriers in the genesis and progression of various cancers and their use as biomarkers for the disease; possible targets for the inhibition of growth and invasion by the neoplastic cells have been suggested. The significance of ncRNAs in lung cancer, bladder cancer, kidney cancer, and melanoma has been amply investigated with important results. Recently, the role of long non-coding RNAs (lncRNAs) has also been included in cancer studies. Studies on the relation between endometrial cancer (EC) and ncRNAs, such as small ncRNAs or micro RNAs (miRNAs), transfer RNAs (tRNAs), ribosomal RNAs (rRNAs), antisense RNAs (asRNAs), small nuclear RNAs (snRNAs), Piwi-interacting RNAs (piRNAs), small nucleolar RNAs (snoRNAs), competing endogenous RNAs (ceRNAs), lncRNAs, and long intergenic ncRNAs (lincRNAs) have been published. The recent literature produced in the last three years was extracted from PubMed by two independent readers, which was then selected for the possible relation between ncRNAs, oncogenesis in general, and EC in particular
Spatio-temporal dynamics of quantum-well excitons
We investigate the lateral transport of excitons in ZnSe quantum wells by
using time-resolved micro-photoluminescence enhanced by the introduction of a
solid immersion lens. The spatial and temporal resolutions are 200 nm and 5 ps,
respectively. Strong deviation from classical diffusion is observed up to 400
ps. This feature is attributed to the hot-exciton effects, consistent with
previous experiments under cw excitation. The coupled transport-relaxation
process of hot excitons is modelled by Monte Carlo simulation. We prove that
two basic assumptions typically accepted in photoluminescence investigations on
excitonic transport, namely (i) the classical diffusion model as well as (ii)
the equivalence between the temporal and spatial evolution of the exciton
population and of the measured photoluminescence, are not valid for
low-temperature experiments.Comment: 8 pages, 6 figure
Epigrammi
Ġabra ta’ poeżiji u proża li tinkludi: Bandiera Maltija ta’ Karmenu Ellul Galea – Il-ħares tad-dar tagħna ta’ Tarcisio L. Xerri – Iżjed mill-għoli ta’ Dun Frans Camilleri – Il-kaċċatur ta’ P. P. Theuma – Siġra tal-ħawħ ta’ P. P. Theuma – Riflessjoni ta’ Ġużi Abela – Nawfraġju ta’ Ġużi Abela – Lill-Prof. Ġużè Galea fostna ta’ Ġużè Cardona – Poeta ta’ Wallace Ph. Gulia – Inti mifdija wkoll...! ta’ Pawlu Aquilina – Epigrammi ta’ Anton Buttigieg.peer-reviewe
Mhux li kieku jaħasra!
Ġabra ta’ poeżiji u proża li tinkludi: Ħsieb ta’ Trevor Zahra – Rebħu t-tnejn ta’ Alfred Massa – Nikol Biancardi ta’ Manwel Nicholas Borg – Alcide de Gasperi ta’ Karmenu Ellul Galea – L-għanja tax-xogħol ta’ Wallace Ph. Gulia – “Jien Alla Sidek......” ta’ J. Camilleri – Meta morna z-zoo ta’ Pawlu Mifsud – Sbuħija ta’ Tarcisio L. Xerri – Twajjeb Ġesù, aħfirli ta’ P. Alb. Sammut – Il-poeżija tal-ħajja ta’ Pawlu Cachia – Karba ta’ suldat ta’ Louis Buttigieg – Mhux li kieku jaħasra! ta’ Spiro Buhagiar.peer-reviewe
Front Matter
The carbohydrate Galα1-3Galβ1-(3)4GlcNAc-R (α-Gal) is produced in all mammals except for humans, apes and old world monkeys that lost the ability to synthetize this carbohydrate. Therefore, humans can produce high antibody titers against α-Gal. Anti-α-Gal IgE antibodies have been associated with tick-induced allergy (i.e. α-Gal syndrome) and anti-α-Gal IgG/IgM antibodies may be involved in protection against malaria, leishmaniasis and Chagas disease. The α-Gal on tick salivary proteins plays an important role in the etiology of the α-Gal syndrome. However, whether ticks are able to produce endogenous α-Gal remains currently unknown. In this study, the Ixodes scapularis genome was searched for galactosyltransferases and three genes were identified as potentially involved in the synthesis of α-Gal. Heterologous gene expression in α-Gal-negative cells and gene knockdown in ticks confirmed that these genes were involved in α-Gal synthesis and are essential for tick feeding. Furthermore, these genes were shown to play an important role in tick-pathogen interactions. Results suggested that tick cells increased α-Gal levels in response to Anaplasma phagocytophilum infection to control bacterial infection. These results provided the molecular basis of endogenous α-Gal production in ticks and suggested that tick galactosyltransferases are involved in vector development, tick-pathogen interactions and possibly the etiology of α-Gal syndrome in humans.This research was supported by the Consejería de Educación, Cultura y Deportes, JCCM, Spain, project CCM17-PIC-036 (SBPLY/17/180501/000185). JJV was supported by Project FIT (Pharmacology, Immunotherapy, nanoToxicology), funded by the European Regional Development Fund.Peer Reviewe
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