901 research outputs found
Low loss optical waveguides fabricated in LiTaO3 by swift heavy ion irradiation
© 2019 Optical Society of America. Users may use, reuse, and build upon the article, or use the article for text or data mining, so long as such uses are for non-commercial purposes and appropriate attribution is maintained. All other rights are reservedOptical waveguides are fabricated by irradiation of LiTaO 3 with a variety of swift heavy ions that provide increasing levels of both nuclear and electronic damage rates, including C, F and Si ions, in the energy range of 15-40 MeV. A systematic study of the role of the ion fluence has been carried out in the broad range of 1e13-2e15 at/cm 2 . The kinetics of damage is initially of nuclear origin for the lowest fluences and stopping powers and, then, is enhanced by the electronic excitation (for F and Si ions) in synergy with the nuclear damage. Applying suitable annealing treatments, optical propagation losses values as low as 0.1 dB have been achieved. The damage rates found in LiTaO 3 have been compared with those known for the reference LiNbO 3 and discussed in the context of the thermal spike modelV. Tormo-Márquez thanks the CMAM-UAM for their financial support. We thank the Technical staff of the CMAM-UAM center for support with the ion irradiation
High-temperature recrystallization effects in swift heavy ion irradiated KY(WO<sub>4</sub>)<sub>2</sub>
High precision fundamental constants at the TeV scale
This report summarizes the proceedings of the 2014 Mainz Institute for
Theoretical Physics (MITP) scientific program on "High precision fundamental
constants at the TeV scale". The two outstanding parameters in the Standard
Model dealt with during the MITP scientific program are the strong coupling
constant and the top-quark mass . Lacking knowledge on the
value of those fundamental constants is often the limiting factor in the
accuracy of theoretical predictions. The current status on and
has been reviewed and directions for future research have been identified.Comment: 57 pages, 24 figures, pdflate
Muon decay in orbit: spectrum of high-energy electrons
Experimental searches for lepton-flavor-violating coherent muon-to-electron
conversion in the field of a nucleus, have been proposed to reach the
unprecedented sensitivity of 10^(-16) - 10^(-18) per stopped muon. At that
level, they probe new interactions at effective-mass scales well beyond 1000
TeV. However, they must contend with background from ordinary bound muon decay.
To better understand the background-spectrum shape and rate, we have carried
out a detailed analysis of Coulombic-bound-state muon decay, including nuclear
recoil. Implications for future experiments are briefly discussed.Comment: 11 pages, 6 figures. Accepted for publication in Phys.Rev.D. v2: One
sentence modified to avoid possible misunderstandings. Journal versio
Phage inducible islands in the gram-positive cocci
The SaPIs are a cohesive subfamily of extremely common phage-inducible chromosomal islands (PICIs) that reside quiescently at specific att sites in the staphylococcal chromosome and are induced by helper phages to excise and replicate. They are usually packaged in small capsids composed of phage virion proteins, giving rise to very high transfer frequencies, which they enhance by interfering with helper phage reproduction. As the SaPIs represent a highly successful biological strategy, with many natural Staphylococcus aureus strains containing two or more, we assumed that similar elements would be widespread in the Gram-positive cocci. On the basis of resemblance to the paradigmatic SaPI genome, we have readily identified large cohesive families of similar elements in the lactococci and pneumococci/streptococci plus a few such elements in Enterococcus faecalis. Based on extensive ortholog analyses, we found that the PICI elements in the four different genera all represent distinct but parallel lineages, suggesting that they represent convergent evolution towards a highly successful lifestyle. We have characterized in depth the enterococcal element, EfCIV583, and have shown that it very closely resembles the SaPIs in functionality as well as in genome organization, setting the stage for expansion of the study of elements of this type. In summary, our findings greatly broaden the PICI family to include elements from at least three genera of cocci
Environmental impact assessment of Pinaceae airborne pollen and green infrastructure using BIM
Urban air quality is a parameter that plays a major role in human health at the local scale. Consequently, in urban planning, the behavior and potential risk of allergenicity for some pollen grains coming from ornamental trees and green spaces surrounding newly built buildings, should be considered. This paper aims to study how pollen exposure, influenced by weather parameters, can be assessed and integrated in the designing and building of constructions as other component of air quality assessment beforehand, by using BIM. Based on a comparative aerobiological study at the height over a building (sampled by two traps at ground and at 16 m), a 3D local dynamic parametric scenario was modelled using BIM, and hourly average Pinaceae pollen concentrations (due to the closeness of pine trees to the samplers). From continuous recording (2009–2011) influenced by height and the influence of wind direction and speed was analysed. Additionally, a map of pine trees geolocated around the studied building was produced and the hourly average Pinaceae pollen concentrations were represented by Revit. BIM together with aerobiology can be a novel and useful tool for the construction of buildings considering airborne biological particles. This represents a first step towards the integration of some unusual environmental parameters in urban planning. Pollen grains modelling as an environmental health criterion for the construction of new buildings will allow technicians to avoid possible future isolation points in the design of building envelopes, and high pollen exposure rates could be avoided, creating ‘allergy-free’ buildings
Relationship between anthropometric parameters, physiological responses, routes and competition results in formula windsurfing
Formula windsurfing is faster than the Olympic version, due to anumber of unique differences. This study was designed to identify the importance of anthropometric and cardiac factors on the final result of the European Formula Windsurf Championships (2007). We selected 45 competitors (30 amateurs and 15 professionals) of 30±9.77 years of age, a height of 182.6±0.06 cm, a weight of 81.67±7.35 kg and a BMIof 24.7±2.1 kg. They were divided into three groups (PG: 15; TG: 45and GPSG: 12). We followed the recommendations of Carter and Marfell-Jones for the anthropometric measurements. The route, speed, distance and heart rate were recorded using an FRWD W600 GPS (Global Positioning System) unit. The anthropometric measurements indicate a professional profile with 2.3±0.4 endomorphy 5±0.8 mesomorphy and 2.4±0.6 ectomorphy. Arm span and fat mass show a significant (p≤0.02) and very significant (p≤0.005) correlation with the final classification. The average speed was 11.84±2.38 km·h–1, the heart rate varied from 128 to 180 b·min–1 and the average was 127.62±13.73 b·min–1. The distances covered (12784.77±5522.19 m) and the times used for the races (2049.3±989.68 s) were very variable. This will assist not only in initial selection for the sport, but also in the design of training programmes which further develop that morphology, where possible, in the pursuit of improved performance
Cardiovascular risk estimated after 13 years of follow-up in a low-incidence Mediterranean region with high-prevalence of cardiovascular risk factors
<p>Abstract</p> <p>Background</p> <p>Murcia (south-east Spain) shows increased cardiovascular (CV) morbimortality as compared to other Spanish regions. Our objective was to assess the CV risk associated with major risk factors (RF) among adult population of Murcia.</p> <p>Methods</p> <p>A cohort of 2314 subjects (18-70 years) with full biochemical and questionnaire data was followed-up for 13 years. Incident cases of ischemic heart disease and stroke were identified by record linkage, individual questionnaires and revision of medical records. Relative risks were obtained by multivariate Cox regression stratified by age and sex, and ischemic risk attributable to CVRF was calculated.</p> <p>Results</p> <p>After more than 26276 person-years of follow-up, 57 incident ischemic events (77% men) and 37 stroke cases (62% men) were identified. Independent risk factors of ischemic heart disease (IHD) and all CV events combined, with RR ranging from 1.6 to 2.6, were total serum cholesterol ≥ 240 mg/dl (HR = 2.6, 95%CI:1.3-5.1), blood pressure levels ≥ 140/90 mmHg (HR = 2.6, 95%CI:1.4-4.8), ever tobacco smoking (HR = 2.2; 95%CI:1.1-4.5), and diabetes (HR = 2.0; 95%CI: 1.0-3.8). No increased CV risk was detected for known participants under treatment who showed cholesterol and blood pressure values below the clinical risk threshold. Smoking was significantly associated with stroke. For all events combined, the major risk factors were hypercholesterolemia, hypertension and ever use of tobacco. Despite its high prevalence, obesity was not associated to CV risk. Most of the IHD cases were attributable to smoking (44%), hypertension (38%) and hypercholesterolemia (26%).</p> <p>Conclusions</p> <p>In the Region of Murcia, smoking accounted for the largest proportion of cardiovascular risk, whereas hypertension displaced hypercholesterolemia as the second leading cause of CV disease. Our study deepens in our understanding of the cardiovascular epidemiology in Spanish areas of Mediterranean Europe with relatively high cardiovascular morbimortality, that are poorly represented by the available risk equations.</p
High-precision measurements from LHC to FCC-ee
This document provides a writeup of all contributions to the workshop on
"High precision measurements of : From LHC to FCC-ee" held at CERN,
Oct. 12--13, 2015. The workshop explored in depth the latest developments on
the determination of the QCD coupling from 15 methods where high
precision measurements are (or will be) available. Those include low-energy
observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv)
decays, (v) soft parton-to-hadron fragmentation functions, as well as
high-energy observables: (vi) global fits of parton distribution functions,
(vii) hard parton-to-hadron fragmentation functions, (viii) jets in p
DIS and -p photoproduction, (ix) photon structure function in
-, (x) event shapes and (xi) jet cross sections in
collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv)
top-quark cross sections in proton-(anti)proton collisions. The current status
of the theoretical and experimental uncertainties associated to each extraction
method, the improvements expected from LHC data in the coming years, and future
perspectives achievable in collisions at the Future Circular Collider
(FCC-ee) with (1--100 ab) integrated luminosities yielding
10 Z bosons and jets, and 10 W bosons and leptons, are
thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong
coupling world-average value, = 0.1177 0.0013, is about
1\%. Some participants believed this may be reduced by a factor of three in the
near future by including novel high-precision observables, although this
opinion was not universally shared. At the FCC-ee facility, a factor of ten
reduction in the uncertainty should be possible, mostly thanks to
the huge Z and W data samples available.Comment: 135 pages, 56 figures. CERN-PH-TH-2015-299, CoEPP-MN-15-13. This
document is dedicated to the memory of Guido Altarell
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