5,700 research outputs found
Preliminary Measurements of Be-10/Be-7 Ratio in Rainwater for Atmospheric Transport Analysis
The meteoric cosmogenic beryllium has been used as an essential geophysical tracer in the analysis of atmospheric flows and erosion soils since 1960. The first measurements Be-7 and Be-10 concentrations in rainwater from Mexico, have been carried out by using gamma decay spectroscopy and AMS techniques, respectively for each isotope. With this it was possible to report a preliminar value for the Be-10/Be-7 isotopic ratio in such environmental samples. The present work described preliminary results related to rainwater collected at mountain and metropolitan areas. Results are compared with predictions and previous measurements for both radioisotopes, observing a very sensible behavior particularly for the case of Be-7 activities
Predictors of diabetes risk in urban and rural areas in Colombia
Background: Nutritional habits low in fruits and vegetables and sedentary lifestyle are associated with a higher risk of developing Type 2 Diabetes (T2D). However, it is important to assess differences between urban and rural areas. This study aimed to analyze the associations between the risk of developing T2D and setting in the Colombian north coast in 2017. Methods: This cross-sectional study included 1,005 subjects. Data was collected by interviewing self-identified members of an urban community and a rural-indigenous population. The interaction terms were evaluated as well as the confounders. Then, adjusted binary logistic regressions were used to estimate the odds ratio (OR) and 95% Confidence Intervals (CI). Results: subjects with a high risk of T2D are more likely to belong to the urban setting (OR = 1.908; 95%CI = 1.201-2.01) compared with those with lower T2D after adjusting for age, Body Mass Index (BMI), physical activity, history of high levels of glycemia, and diabetes in relatives. Conclusions: Urban communities are more likely to have T2D compared with rural-indigenous populations. These populations have differences from the cultural context, including personal, and lifestyle factors.Peer reviewe
Determination of the Axial-Vector Weak Coupling Constant with Ultracold Neutrons
A precise measurement of the neutron decay -asymmetry has been
carried out using polarized ultracold neutrons (UCN) from the pulsed spallation
UCN source at the Los Alamos Neutron Science Center (LANSCE). Combining data
obtained in 2008 and 2009, we report , from which we determine the ratio of the
axial-vector to vector weak coupling of the nucleon .Comment: 5 pages, 2 figure
Diagnostic procedures for non-small-cell lung cancer (NSCLC): recommendations of the European Expert Group
Background There is currently no Europe-wide consensus on the appropriate preanalytical measures and workflow to optimise procedures for tissue-based molecular testing of non-small-cell lung cancer (NSCLC). To address this, a group of lung cancer experts (see list of authors) convened to discuss and propose standard operating procedures (SOPs) for NSCLC. Methods Based on earlier meetings and scientific expertise on lung cancer, a multidisciplinary group meeting was aligned. The aim was to include all relevant aspects concerning NSCLC diagnosis. After careful consideration, the following topics were selected and each was reviewed by the experts: surgical resection and sampling; biopsy procedures for analysis; preanalytical and other variables affecting quality of tissue; tissue conservation; testing procedures for epidermal growth factor receptor, anaplastic lymphoma kinase and ROS proto-oncogene 1, receptor tyrosine kinase (ROS1) in lung tissue and cytological specimens; as well as standardised reporting and quality control (QC). Finally, an optimal workflow was described. Results Suggested optimal procedures and workflows are discussed in detail. The broad consensus was that the complex workflow presented can only be executed effectively by an interdisciplinary approach using a well-trained team. Conclusions To optimise diagnosis and treatment of patients with NSCLC, it is essential to establish SOPs that are adaptable to the local situation. In addition, a continuous QC system and a local multidisciplinary tumour-type-oriented board are essential
New result for the neutron -asymmetry parameter from UCNA
The neutron -decay asymmetry parameter defines the correlation
between the spin of the neutron and the momentum of the emitted electron, which
determines , the ratio of the axial-vector to
vector weak coupling constants. The UCNA Experiment, located at the Ultracold
Neutron facility at the Los Alamos Neutron Science Center, is the first to
measure such a correlation coefficient using ultracold neutrons (UCN).
Following improvements to the systematic uncertainties and increased
statistics, we report the new result which yields . Combination with the previous UCNA result and
accounting for correlated systematic uncertainties produces
and .Comment: 9 pages, 7 figures, updated to as-published versio
Selenium and impaired physical function in US and Spanish older adults
Background: Selenium (Se) is a trace element with a narrow safety margin.
Objectives: To evaluate the cross-sectional and longitudinal dose-response association between Se exposure and
measures of impaired physical function and disability in older adults.
Design: NHANES 2011–2014 cross-sectional (US, n = 1733, age ≥60 years) and Seniors-ENRICA-2 2017–2019
cross-sectional and longitudinal (Spain, n = 2548 and 1741, respectively, age ≥65 years) data were analyzed.
Whole blood and serum Se levels were measured using inductively coupled plasma-mass spectrometry. Lowerextremity
performance was assessed with the Short Physical Performance Battery, and muscle weakness with
a dynamometer. Incident mobility and agility limitations, and disability in instrumental activities of daily living
(IADL) were ascertained with standardized questionnaires. Analyses were adjusted for relevant confounders,
including physical activity. Results across studies were pooled using random-effects meta-analysis.
Results: Meta-analyzed odds ratios (95% confidence interval) per log2 increase in whole blood Se were 0.54
(0.32; 0.76) for weakness, 0.59 (0.34; 0.83) for impaired lower-extremity performance, 0.48 (0.31; 0.68) for
mobility limitations, 0.71 (0.45; 0.97) for agility limitations, and 0.34 (0.12; 0.56) for disability in at least one
IADL. Analyses for serum Se in NHANES showed similar results. Findings suggest the inverse association with
grip strength is progressive below 140 μg/L (p-value for non-linear trend in the Seniors-ENRICA-2 study = 0.13),
and above 140 μg/L (p-value for non-linear trend in NHANES = 0.11). In the Seniors-ENRICA-2 cohort, with a
2.2 year follow-up period, a doubling in baseline Se levels were associated with a lower incidence of weakness
[odds ratio (95% confidence interval): 0.45 (0.22; 0.91)], impaired lower-extremity performance [0.63 (0.32;
1.23)], mobility [0.43 (0.21; 0.91)] and agility [0.38 (0.18; 0.78)] limitations.
Discussion: In US and Spanish older adults, Se concentrations were inversely associated with physical function
limitations. Further studies are needed to elucidate underlying mechanisms.Instituto de Salud Carlos III
European Commission
PI18/287
16/609State Secretary of R + D + I
PID2019-108973RB-C21/C22European Social Fund (ESF)
European Commissio
Light scattering from disordered overlayers of metallic nanoparticles
We develop a theory for light scattering from a disordered layer of metal
nanoparticles resting on a sample. Averaging over different disorder
realizations is done by a coherent potential approximation. The calculational
scheme takes into account effects of retardation, multipole excitations, and
interactions with the sample. We apply the theory to a system similar to the
one studied experimentally by Stuart and Hall [Phys. Rev. Lett. {\bf 80}, 5663
(1998)] who used a layered Si/SiO/Si sample. The calculated results agree
rather well with the experimental ones. In particular we find conspicuous
maxima in the scattering intensity at long wavelengths (much longer than those
corresponding to plasmon resonances in the particles). We show that these
maxima have their origin in interference phenomena in the layered sample.Comment: 19 pages, 12 figure
Surface plasmon-related resonances on deep and asymmetric gold gratings
M. Kreiter, S. Mittler, W. Knoll, and J. Roy Sambles, Physical Review B, Vol. 65, article 125415 (2002). "Copyright © 2002 by the American Physical Society."Based on theoretical calculations, the surface plasmonlike resonances on deep and asymmetric gold gratings are reinvestigated and assigned to two classes possessing different characteristic symmetry properties. Reflectivity measurements on deep grating structures with varying depth and asymmetry allow for a detailed study of the influence of these parameters on the lowest-order resonances as well as the experimental observation of a higher-order resonance
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Search for supersymmetry in hadronic final states with missing transverse energy using the variables αT and b-quark multiplicity in pp collisions at [Formula: see text].
An inclusive search for supersymmetric processes that produce final states with jets and missing transverse energy is performed in pp collisions at a centre-of-mass energy of 8 TeV. The data sample corresponds to an integrated luminosity of 11.7 fb-1 collected by the CMS experiment at the LHC. In this search, a dimensionless kinematic variable, αT, is used to discriminate between events with genuine and misreconstructed missing transverse energy. The search is based on an examination of the number of reconstructed jets per event, the scalar sum of transverse energies of these jets, and the number of these jets identified as originating from bottom quarks. No significant excess of events over the standard model expectation is found. Exclusion limits are set in the parameter space of simplified models, with a special emphasis on both compressed-spectrum scenarios and direct or gluino-induced production of third-generation squarks. For the case of gluino-mediated squark production, gluino masses up to 950-1125 GeV are excluded depending on the assumed model. For the direct pair-production of squarks, masses up to 450 GeV are excluded for a single light first- or second-generation squark, increasing to 600 GeV for bottom squarks
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