Ballistic Localization in Quasi-1D Waveguides with Rough Surfaces

Structure of eigenstates in a periodic quasi-1D waveguide with a rough surface is studied both analytically and numerically. We have found a large number of "regular" eigenstates for any high energy. They result in a very slow convergence to the classical limit in which the eigenstates are expected to be completely ergodic. As a consequence, localization properties of eigenstates originated from unperturbed transverse channels with low indexes, are strongly localized (delocalized) in the momentum (coordinate) representation. These eigenstates were found to have a quite unexpeted form that manifests a kind of "repulsion" from the rough surface. Our results indicate that standard statistical approaches for ballistic localization in such waveguides seem to be unappropriate.Comment: 5 pages, 4 figure

Classical versus Quantum Structure of the Scattering Probability Matrix. Chaotic wave-guides

The purely classical counterpart of the Scattering Probability Matrix (SPM) $\mid S_{n,m}\mid^2$ of the quantum scattering matrix $S$ is defined for 2D quantum waveguides for an arbitrary number of propagating modes $M$. We compare the quantum and classical structures of $\mid S_{n,m}\mid^2$ for a waveguide with generic Hamiltonian chaos. It is shown that even for a moderate number of channels, knowledge of the classical structure of the SPM allows us to predict the global structure of the quantum one and, hence, understand important quantum transport properties of waveguides in terms of purely classical dynamics. It is also shown that the SPM, being an intensity measure, can give additional dynamical information to that obtained by the Poincar\`{e} maps.Comment: 9 pages, 9 figure

Analysis of the absorption coefficient by annealing in carbon implanted Nd:YVO4

Low loss in optical waveguides is very important in order to achieve high laser efficiency. Waveguide fabrication by ion implantation generates color centers, leading to absorption losses which can be reduced by annealing; however, this process may eliminate the waveguide and hence it is necessary to consider both the optimum annealing time and temperature. This work reports the behavior of the absorption coefficient by successive annealing steps in Nd:YVO4 implanted with a dose of 5×1014 ions/cm2

Predicting the onset and persistence of episodes of depression in primary health care. The predictD-Spain study: Methodology

Background: The effects of putative risk factors on the onset and/or persistence of depression remain unclear. We aim to develop comprehensive models to predict the onset and persistence of episodes of depression in primary care. Here we explain the general methodology of the predictD-Spain study and evaluate the reliability of the questionnaires used. Methods: This is a prospective cohort study. A systematic random sample of general practice attendees aged 18 to 75 has been recruited in seven Spanish provinces. Depression is being measured with the CIDI at baseline, and at 6, 12, 24 and 36 months. A set of individual, environmental, genetic, professional and organizational risk factors are to be assessed at each follow-up point. In a separate reliability study, a proportional random sample of 401 participants completed the test-retest (251 researcher-administered and 150 self-administered) between October 2005 and February 2006. We have also checked 118,398 items for data entry from a random sample of 480 patients stratified by province. Results: All items and questionnaires had good test-retest reliability for both methods of administration, except for the use of recreational drugs over the previous six months. Cronbach's alphas were good and their factorial analyses coherent for the three scales evaluated (social support from family and friends, dissatisfaction with paid work, and dissatisfaction with unpaid work). There were 191 (0.16%) data entry errors. Conclusion: The items and questionnaires were reliable and data quality control was excellent. When we eventually obtain our risk index for the onset and persistence of depression, we will be able to determine the individual risk of each patient evaluated in primary health car

Population vulnerability to extreme cold days in rural and urban municipalities in ten provinces in Spain

Background: The objective was to analyze whether there are differences in vulnerability to Extreme Cold Days (ECD) between rural and urban populations in Spain. Methodology: Time series analysis carried out from January 1, 2000, through December 31, 2013. Municipalities with over 10,000 inhabitants were included from 10 Spanish provinces, classified into 42 groups by isoclimate and urban/rural character as defined by Eurostat criteria. The statistical strategy was carried out in two phases. First: It was analyzed the relationship between minimum daily temperature (Tmin) (source: AEMET) and the rate of daily winter mortality due to natural causes —CIE-10: A00 – R99— (source: National Statistics Institute). Then, It was determinated the threshold of Tmin that defines the ECD and its percentile in the series of winter Tmin (Pthreshold), which is a measure of vulnerability to ECD so that the higher the percentile, the higher the vulnerability. Second: possible explanatory variables of vulnerability were explored using Mixed Generalized Models, using 13 independent variables related to meteorology, environment, socioeconomics, demographics and housing quality. Results: The average Pthreshold was 18 %. The final model indicated that for each percentage point increase in unemployment, the vulnerability to ECD increased by 0.4 (0.2, 0.6) points. Also, with each point increase in rurality index, this vulnerability decreased by −6.1 (−2.1, −10.0) points. Although less determinant, other factors that could contribute to explaining vulnerability at the province level included minimum winter daily temperatures and the percentage of housing with poor insulation. Conclusions: The vulnerability to ECD was greater in urban zones than in rural zones. Socioeconomic status is a key to understanding how this vulnerability is distributed. These results suggest the need to implement public health prevention plans to address ECD at the state level. These plans should be based on threshold temperatures determined at the smallest scale possibleThe authors wish to thank the funding provided by the ENPY107/18, ENPY 376/18, ENPY 304/20 projects of the Carlos III Health Institute III (ISCIII

Photoelectric Properties of MOS-like Structures with Twofold SRO Films

AbstractThe optical properties of silicon rich oxide (SRO) have been deeply studied because, between other reasons, they emit an intense photoluminescence (PL) from visible to the near infrared range when excited with UV light. MOS-like structures with SRO film as the active layer have shown an enhanced conductivity under different illumination conditions. In this paper, MOS-like structures with double SRO layer were fabricated in order to have a barrier to isolate the silicon substrate from the active SRO layer. Results show that all structures have a higher current when light shines on them than that obtained under dark conditions. A possible application of this photo-effect can be used to increase the response of photodetectors and silicon solar cells

Distinctive Traits for Drought and Salt Stress Tolerance in Melon (Cucumis melo L.)

Melon (Cucumis melo L.) is a crop with important agronomic interest worldwide. Because of the increase of drought and salinity in many cultivation areas as a result of anthropogenic global warming, the obtention of varieties tolerant to these conditions is a major objective for agronomical improvement. The identification of the limiting factors for stress tolerance could help to define the objectives and the traits which could be improved by classical breeding or other techniques. With this objective, we have characterized, at the physiological and biochemical levels, two different cultivars (sensitive or tolerant) of two different melon varieties (Galia and Piel de Sapo) under controlled drought or salt stress. We have performed physiological measurements, a complete amino acid profile and we have determined the sodium, potassium and hormone concentrations. This has allowed us to determine that the distinctive general trait for salt tolerance in melon are the levels of phenylalanine, histidine, proline and the Na+/K+ ratio, while the distinctive traits for drought tolerance are the hydric potential, isoleucine, glycine, phenylalanine, tryptophan, serine, and asparagine. These could be useful markers for breeding strategies or to predict which varieties are likely perform better under drought or salt stress. Our study has also allowed us to identify which metabolites and physiological traits are differentially regulated upon salt and drought stress between different varieties.SC was a recipient of grant FPU19/01977 from the Spanish Ministerio de Universidades. LM and AV activities were funded by the Prometeu program (IMAGINA project, PROMETEU/2019/110). LM was also supported by the Spanish MICINN (PTA2019-018094). The CEAM foundation was funded by the Generalitat Valenciana

The Role of Pediatricians in Providing Greater-Quality Care for Children: An Ongoing Debate

Child healthcare frequently is regarded as a secondary objective in the development of public health policies and not as a central issue. Cost-containment policies instead of quality of healthcare frequently have inspired strategic decisions in public health investments for pediatric structures and workforce. The negative implications of this decisional approach have been shown by the substantial unpreparedness of virtually all European health systems during the coronavirus disease 2019 (COVID-19) pandemic,5 particularly in the area of primary care. The debate on the negative effects of cost-containment policies in the area of primary care in not new. In recent years, the role of pediatricians within the several European healthcare systems was variously reformed by governments, with an eye more to the budget than to the quality of care and its structural components, including staffing adequacy, training, and consistency as well as facility environment and size.1 As a result, the number of general pediatricians in Europe has decreased during the past 20 years.Data from the World Health Organization show that the average number of general pediatricians per 100 000 population in Europe declined 30.1% from 26.5% in 1998 to 18.5% in 2013.A further reduction in the pediatric workforce was reported in 2018 by the European Paediatric Association, the Union of National European Paediatric Societies and Associations (EPA-UNEPSA). During the past 20 years, due to different factors, including socioeconomic and political reasons, several European countries decided to reform their public health systems and the responsibility of pediatric healthcare delivery was moved from pediatricians to general and family practitioners. The aim of this commentary by the Spanish Primary Care Pediatrics Association (AEPap), in collaboration with the European Confederation of Primary Care Pediatricians and EPA-UNEPSA, is to discuss data supporting the essential role played in Europe by well-trained pediatricians vs other providers in delivering quality healthcare for children