3,260 research outputs found
Geographic variations in cervical cancer risk in San Luis Potosí state, Mexico: A spatial statistical approach
El trabajo es una investigación orientada al uso de herramientas de análisis espacial para analizar la distribución del cáncer cervicouterino en el Estado de San Luis Potosí. Se consideran aspectos como el lugar de residencia de la población usuaria de los servicios de detección-tratamiento y los lugares donde se ogrecen los servicos. se aplica un modelo de accesibilidad potencial a los servicios a fin de diferenciar las ventajas y desventajas que tiene la población
Cumulative dietary risk characterisation of pesticides that have chronic effects on the thyroid
A retrospective chronic cumulative risk assessment of dietary exposure to pesticide residues, supported by an uncertainty analysis based on expert knowledge elicitation, was conducted for two effects on the thyroid, hypothyroidism and parafollicular cell (C‐cell) hypertrophy, hyperplasia and neoplasia. The pesticides considered in this assessment were identified and characterised in the scientific report on the establishment of cumulative assessment groups of pesticides for their effects on the thyroid. Cumulative exposure assessments were conducted through probabilistic modelling by EFSA and the Dutch National Institute for Public Health and the Environment (RIVM) using two different software tools and reported separately. These exposure assessments used monitoring data collected by Member States under their official pesticide monitoring programmes in 2014, 2015 and 2016 and individual consumption data from 10 populations of consumers from different countries and different age groups. This report completes the characterisation of cumulative risk, taking account of the available data and the uncertainties involved. For each of the 10 populations, it is concluded with varying degrees of certainty that cumulative exposure to pesticides that have the chronic effects on the thyroid mentioned above does not exceed the threshold for regulatory consideration established by risk managers
Symphony on strong field approximation
This paper has been prepared by the Symphony collaboration (University of Warsaw, Uniwersytet Jagiellonski, DESY/CNR and ICFO) on the occasion of the 25th anniversary of the 'simple man's models' which underlie most of the phenomena that occur when intense ultrashort laser pulses interact with matter. The phenomena in question include high-harmonic generation (HHG), above-threshold ionization (ATI), and non-sequential multielectron ionization (NSMI). 'Simple man's models' provide both an intuitive basis for understanding the numerical solutions of the time-dependent Schrodinger equation and the motivation for the powerful analytic approximations generally known as the strong field approximation (SFA). In this paper we first review the SFA in the form developed by us in the last 25 years. In this approach the SFA is a method to solve the TDSE, in which the non-perturbative interactions are described by including continuum-continuum interactions in a systematic perturbation-like theory. In this review we focus on recent applications of the SFA to HHG, ATI and NSMI from multi-electron atoms and from multi-atom molecules. The main novel part of the presented theory concerns generalizations of the SFA to: (i) time-dependent treatment of two-electron atoms, allowing for studies of an interplay between electron impact ionization and resonant excitation with subsequent ionization; (ii) time-dependent treatment in the single active electron approximation of 'large' molecules and targets which are themselves undergoing dynamics during the HHG or ATI processes. In particular, we formulate the general expressions for the case of arbitrary molecules, combining input from quantum chemistry and quantum dynamics. We formulate also theory of time-dependent separable molecular potentials to model analytically the dynamics of realistic electronic wave packets for molecules in strong laser fields. We dedicate this work to the memory of Bertrand Carre, who passed away in March 2018 at the age of 60
The Star Formation History of the Local Group dwarf galaxy Leo I
We present a quantitative analysis of the star formation history (SFH) of the
Local Group dSph galaxy Leo I, from the information in its HST [(V-I),I]
color-magnitude diagram (CMD). The method we use is based in comparing, via
synthetic CMDs, the expected distribution of stars in the CMD for different
evolutionary scenarios, with the observed distribution. We consider the SFH to
be composed by the SFR(t), the Z(t), the IMF, and a function ,
controlling the fraction and mass ratio distribution of binary stars.
The comparison between the observed CMD and the model CMDs is done through
chi-square minimization of the differences in the number of stars in a set of
regions of the CMD.
Our solution for the SFH of Leo I defines a minimum of chi-square in a well
defined position of the parameter space, and the derived SFR(t) is robust, in
the sense that its main characteristics are unchanged for different
combinations of the remaining parameters. However, only a narrow range of
assumptions for Z(t), IMF and result in a good agreement between
the data and the models, namely: Z=0.0004, a Kroupa et al. (1993) IMF or
slightly steeper, and a relatively large fraction of binary stars. Most star
formation activity (70% to 80%) occurred between 7 and 1 Gyr ago. At 1 Gyr ago,
it abruptly dropped to a negligible value, but seems to have been active until
at least ~ 300 Myr ago. Our results don't unambiguously answer the question of
whether Leo I began forming stars around 15 Gyr ago, but it appears that the
amount of this star formation, if existing at all, would be small.Comment: 25 pages + 14 figures. Accepted by The Astronomical Journa
The questionnaire design process in the European Human Biomonitoring Initiative (HBM4EU)
This document was created for the HBM4EU project. HBM4EU has received funding from the European Union's Horizon 2020 research and innovation programme under grant agreement No 733032. The Swiss participation in this European Program is funded by the Swiss State Secretary for Education Research and Innovation (SERI).Background: Designing questionnaires is a key point of epidemiological studies assessing human exposure to
chemicals. The lack of validated questionnaires can lead to the use of previously developed and sub-optimally
adapted questionnaires, which may result in information biases that affect the study’s validity. On this
ground, a multidisciplinary group of researchers developed a series of tools to support data collection within the
HBM4EU initiative. The objective of this paper is to share the process of developing HBM4EU questionnaires, as
well as to provide researchers with harmonized procedures that could help them to design future questionnaires
to assess environmental exposures.
Methods: In the frame of the work package on survey design and fieldwork of the HBM4EU, researchers carried
out procedures necessary for the development of quality questionnaires and related data collection tools. These
procedures consisted of a systematic search to identify questionnaires used in previous human biomonitoring
(HBM) studies, as well as the development of a checklist and evaluation sheet to assess the questionnaires
identified. The results of these evaluations were taken into consideration for the development of the final
questionnaires.
Results: The main points covered by each of the sections included in HBM4EU questionnaires are described and
discussed in detail. Additional tools developed for data collection in the HBM4EU (e.g. non-responder questionnaire,
satisfaction questionnaire, matrix-specific questionnaire) are also addressed. Special attention is paid
to the limitations faced and hurdles overcome during the process of questionnaire development.
Conclusions: Designing questionnaires for use in HBM studies requires substantial effort by a multidisciplinary
team to guarantee that the quality of the information collected meets the study’s objectives. The process of
questionnaire development described herein will contribute to improve the harmonization of HBM studies within
the social and environmental context of the EU countries.European Union's Horizon 2020 research and innovation programme 733032Swiss State Secretary for Education Research and Innovation (SERI
Direct exfoliation and dispersion of two-dimensional materials in pure water via temperature control
The high-volume synthesis of two-dimensional (2D) materials in the form of platelets is desirable for various applications. While water is considered an ideal dispersion medium, due to its abundance and low cost, the hydrophobicity of platelet surfaces has prohibited its widespread use. Here we exfoliate 2D materials directly in pure water without using any chemicals or surfactants. In order to exfoliate and disperse the materials in water, we elevate the temperature of the sonication bath, and introduce energy via the dissipation of sonic waves. Storage stability greater than one month is achieved through the maintenance of high temperatures, and through atomic and molecular level simulations, we further discover that good solubility in water is maintained due to the presence of platelet surface charges as a result of edge functionalization or intrinsic polarity. Finally, we demonstrate inkjet printing on hard and flexible substrates as a potential application of water-dispersed 2D materials.close1
Ventricular arrhythmias in patients with functional mitral regurgitation and implantable cardiac devices: implications of mitral valve repair with Mitraclip
Background: Limited information has been reported regarding the impact of percutaneous mitral valve repair (PMVR) on ventricular arrhythmic (VA) burden. The aim of this study was to address the incidence of VA and appropriate antitachycardia implantable cardiac defibrillator (ICD) therapies before and after PMVR. Methods: We retrospectively analyzed all consecutive patients with heart failure with reduce left ventricular ejection fraction (LVEF), functional mitral regurgitation (FMR) grade 3+ or 4+ and an active ICD or cardiac resynchronizer who underwent PMVR in any of the eleven recruiting centers. Only patients with complete available device VA monitoring from one-year before to one year after PMVR were included. Baseline clinical and echocardiographic characteristics were collected before PMVR and at 12-months follow-up. Results: Ninety-three patients (68.2+/-10.9 years old, male 88.2%) were enrolled. PMVR was successfully performed in all patients and device success at discharge was 91.4%. At 12-month follow-up, we observed a significant reduction in mitral regurgitation severity, NT-proBNP and prevalence of severe pulmonary hypertension and severe kidney disease. Patients also referred a significant improvement in NYHA functional class and showed a non-significant trend to reserve left ventricular remodeling. After PMVR a significant decrease in the incidence of non-sustained ventricular tachycardia (VT) (5.0+/-17.8 vs. 2.7+/-13.5, P=0.002), sustained VT or ventricular fibrillation (0.9+/-2.5 vs. 0.5+/-2.9, P=0.012) and ICD antitachycardia therapies (2.5+/-12.0 vs. 0.9+/-5.0, P=0.033) were observed. Conclusions: PMVR was related to a reduction in arrhythmic burden and ICD therapies in our cohort
Ameliorating Systematic Uncertainties in the Angular Clustering of Galaxies: A Study using SDSS-III
We investigate the effects of potential sources of systematic error on the
angular and photometric redshift, z_phot, distributions of a sample of redshift
0.4 < z < 0.7 massive galaxies whose selection matches that of the Baryon
Oscillation Spectroscopic Survey (BOSS) constant mass sample. Utilizing over
112,778 BOSS spectra as a training sample, we produce a photometric redshift
catalog for the galaxies in the SDSS DR8 imaging area that, after masking,
covers nearly one quarter of the sky (9,913 square degrees). We investigate
fluctuations in the number density of objects in this sample as a function of
Galactic extinction, seeing, stellar density, sky background, airmass,
photometric offset, and North/South Galactic hemisphere. We find that the
presence of stars of comparable magnitudes to our galaxies (which are not
traditionally masked) effectively remove area. Failing to correct for such
stars can produce systematic errors on the measured angular auto-correlation
function, w, that are larger than its statistical uncertainty. We describe how
one can effectively mask for the presence of the stars, without removing any
galaxies from the sample, and minimize the systematic error. Additionally, we
apply two separate methods that can be used to correct the systematic errors
imparted by any parameter that can be turned into a map on the sky. We find
that failing to properly account for varying sky background introduces a
systematic error on w. We measure w, in four z_phot slices of width 0.05
between 0.45 < z_phot < 0.65 and find that the measurements, after correcting
for the systematic effects of stars and sky background, are generally
consistent with a generic LambdaCDM model, at scales up to 60 degrees. At
scales greater than 3 degrees and z_phot > 0.5, the magnitude of the
corrections we apply are greater than the statistical uncertainty in w.Comment: Accepted by MNRA
In memoriam of Ricardo Flores: The career, achievements, and legacy of an inspirational plant virologist
[EN] Ricardo Flores (1947-2020) focused his research on the identification, replication, pathogenesis, and evolution of viroids, the minimal non-protein-coding circular RNAs (250-400 nt) able to replicate and incite diseases in plants that are remarkable for being at the lowest step of the biological scale. He and his collaborators initially identified and characterized additional group members, adding six new ones to the family Pospiviroidae, and expanding the Avsunviroidae from one to four members. They showed that members of the second family "encode" ribozymes, a property that, together with others, makes them candidates for being the most primitive replicons that emerged on our planet 3500 million years ago. He also made important contributions regarding how viroids replicate, providing relevant data on the templates, enzymes, and ribozymes that mediate this process and on the mutation rate, which turned out to be the highest reported for any biological entity. More recently, he concentrated on the role that RNA silencing could play on viroid-host interactions, describing details of this process. Ricardo also worked on citrus tristeza virus, a widely different type of subcellular pathogen, and made important contributions on the structure, localization and functions of its unique p23 protein. His research has produced 170 original articles and reviews, according to Web of Science. He encouraged the scientific careers of a large number of researchers, and collaborated with many others, some of whom have recapitulated his scientific legacy in this review and contributed with other chapters in this special issue.This work was supported by the Spanish Agencia Estatal de Investigaci ' on (AEI) and Fondo Europeo de Desarrollo Regional (FEDER), grant number PID2020-115571RB-100. We apologize to colleagues whose work was not cited in this review due to the page limit.Pallás Benet, V.; Hernandez Fort, C.; Marcos, JF.; Daròs, J.; Ambrós, S.; Navarro, B.; Navarro Bohigues, JA.... (2022). In memoriam of Ricardo Flores: The career, achievements, and legacy of an inspirational plant virologist. Virus Research. 312(198718):1-9. https://doi.org/10.1016/j.virusres.2022.1987181931219871
- …