Subharmonic stochastic synchronization and resonance in neuronal systems.

4 pages, 4 figures.-- PACS: 87.19.La, 05.40.Ca, 87.10.+eWe study the response of a model neuron, driven simultaneously by noise and at least two weak periodic signals. We focus on signals with frequencies components kf0,(k+1)f0,…(k+n)f0 with k>1. The neuron’s output is a sequence of pulses spaced at random interpulse intervals. We find an optimum input noise intensity for which the output pulses are spaced ∼1/f0, i.e., there is a stochastic resonance (SR) at a frequency missing in the input. Even higher noise intensities uncover additional, but weaker, resonances at frequencies present in the input. This is a different form of SR whereby the most robust resonance is the one enhancing a frequency, which is absent in the input, and which is not possible to recover via any linear processing. This can be important in understanding sensory systems including the neuronal mechanism for perception of complex tones.This work was supported by Spanish Ministerio de Ciencia y Technologia, Proyecto CONOCE contract BFM2000-1106, and by NIH-HL62543.Peer reviewe

Brote de toxiinfeccion alimentaria de probable etiologia virica por virus Norwalk

ResumenEn mayo de 1989 se produjo un brote de toxiinfección alimentaria (TIA) en el colegio público de Adzaneta, Castellón. Se realizó un estudio para describirlo, averiguar sus causas y adoptar las medidas de control adecuadas. Afectó a 16 niños y 2 profesores (tasa de ataque: 28,57 %). Se cumplieron los criterios clínicos y epidemiológicos para considerar al virus Norwalk como agente responsable. Probablemente su origen estuvo en un manipulador enfermo. En heces de éste y de un caso se visualizaron (ME) estructuras redondas de tamaño similar al virus Norwalk. En España el número de brotes de TIA sin agente causal conocido ha aumentado en los últimos años. Quizá este microorganismo sea responsable de una parte de estos brotes en los que, por diversos motivos, no se llega a identificar su agente causal.SummaryIn May 1989, a foodborne outbreak of acute gastroenteritis was Identified in a state school in Adzaneta, Castellón. A dtudy was undertaken to describe it, investigate its causes, and recommend adequate control measures. Sixteen children and 2 teachers were affected (attack rate: 28.57 %). Kaplan and cols clinical and epidemiological criteria for Norwalk-like virus as the responsable agent were present. The probable origin of the outbreak was a foodhandler who was already ill beforehand. The examination of stools of the foodhandler and a patient showed small round structures similar to the Norwalk virus. In Spain, the number of foodborne outbreaks without known causal agent has steadily increased in recent years. It may be that this microorganism is responsible for some of these outbreaks in which, for several reasons, the causal agent cannot be Identified

Novel InN/InGaN multiple quantum well structures for slow‐light generation at telecommunication wavelengths

The third order susceptibility is responsible for a variety of optical non-linear phenomena -like self focusing, phase conjugation and four-wave mixing- with applications in coherent control of optical communication. InN is particularly attractive due to its near-IR bandgap and predicted high nonlinear effects. Moreover, the synthesis of InN nanostructures makes possible to taylor the absorption edge in the telecomunication spectral range and enhance nonlinear parameters thanks to carrier confinement. In this work, we assess the nonlinear optical behavior of InN/InxGa(1-x)N (0.9 > x > 0.7) multiplequantum-well (MQW) structures grown by plasma-assisted MBE on GaN-on-sapphire templates. Low-temperature (5 K) photoluminescence measurements show near-IR emission whose intensity increases with the In content in the barriers, which is explained in terms of the existence of piezoelectric fields in the structures. The nonlinear optical absorption coefficient, α2, were measured at 1.55 μm using the Z-scan method. We observe a strong dependence of the nonlinear absorption coefficient on the In content in the barriers. Saturable absorption is observed for the sample with x = 0.9, with α2 ̃ -9x103 cm/GW. For this sample, an optically controlled reduction of the speed of light by a factor S ∼ 80 is obtained at 1.55 μm. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA

Development and Validation of the Overall Foot Health Questionnaire for Patients with Rheumatoid Arthritis: A Cross-Sectional Descriptive Analysis

[Abstract] Background and Objectives: In general, patients with rheumatoid arthritis (RA) are ignorant of the physician’s role and of RA-related feet problems. The aim of our study was to validate a questionnaire on the knowledge of different aspects of overall foot health in patients with RA. Materials and Methods: A cross-sectional descriptive analysis was carried out between March 2017 and April 2017. A questionnaire was designed and validated through the Delphi method to evaluate the knowledge about the illness, the repercussions on feet, medical podiatry care, and the role of the medical podiatrist. Results: After being checked by a panel of experts, all the items obtained a Cronbach’s alpha over 0.70. Conclusions: The content of this questionnaire about the knowledge of different aspects of medical podiatry health in patients with RA has internal consistenc

BAFF, APRIL and BAFFR on the pathogenesis of Immunoglobulin-A vasculitis

BAFF, APRIL and BAFF-R are key proteins involved in the development of B-lymphocytes and autoimmunity. Additionally, BAFF, APRIL and BAFFR polymorphisms were associated with immune-mediated conditions, being BAFF GCTGT>A a shared insertion-deletion genetic variant for several autoimmune diseases. Accordingly, we assessed whether BAFF, APRIL and BAFFR represent novel genetic risk factors for Immunoglobulin-A vasculitis (IgAV), a predominantly B-lymphocyte inflammatory condition. BAFF rs374039502, which colocalizes with BAFF GCTGT>A, and two tag variants within APRIL (rs11552708 and rs6608) and BAFFR (rs7290134 and rs77874543) were genotyped in 386 Caucasian IgAV patients and 806 matched healthy controls. No genotypes or alleles differences were observed between IgAV patients and controls when BAFF, APRIL and BAFFR variants were analysed independently. Likewise, no statistically significant differences were found in the genotype and allele frequencies of BAFF, APRIL or BAFFR when IgAV patients were stratified according to the age at disease onset or to the presence/absence of gastrointestinal (GI) or renal manifestations. Similar results were disclosed when APRIL and BAFFR haplotypes were compared between IgAV patients and controls and between IgAV patients stratified according to the clinical characteristics mentioned above. Our results suggest that BAFF, APRIL and BAFFR do not contribute to the genetic network underlying IgAV.Acknowledgements: We are indebted to the patients and healthy controls for their essential collaboration to this study. We also thank the National DNA Bank Repository (Salamanca) for supplying part of the control samples. This study was supported by European Union FEDER funds and `Fondo de Investigaciones Sanitarias´ (grant PI18/00042) from ‘Instituto de Salud Carlos III’ (ISCIII, Health Ministry, Spain). DP-P is a recipient of a Río Hortega programme fellowship from the ISCIII, co-funded by the European Social Fund (ESF, `Investing in your future´) (grant number CM20/00006). SR-M is supported by funds of the RETICS Program (RD16/0012/0009) (ISCIII, co-funded by the European Regional Development Fund (ERDF)). VP-C is supported by a pre-doctoral grant from IDIVAL (PREVAL 18/01). BA-M is a recipient of a `López Albo´ Post-Residency Programme funded by Servicio Cántabro de Salud. LL-G is supported by funds from IDIVAL (INNVAL20/06). OG is staff personnel of Xunta de Galicia (Servizo Galego de Saude (SERGAS)) through a research-staff stabilization contract (ISCIII/SERGAS) and his work is funded by ISCIII and the European Union FEDER fund (grant numbers RD16/0012/0014 (RIER) and PI17/00409). He is beneficiary of project funds from the Research Executive Agency (REA) of the European Union in the framework of MSCA-RISE Action of the H2020 Programme, Project 734899—Olive-Net. RL-M is a recipient of a Miguel Servet type I programme fellowship from the ISCIII, cofunded by ESF (`Investing in your future´) (grant number CP16/00033)

Straining Flow Spinning of Artificial Silk Fibers: A Review

This work summarizes the main principles and some of the most significant results of straining flow spinning (SFS), a technology developed originally by the authors of this work. The principles on which the technology is based, inspired by the natural spinning system of silkworms and spiders, are presented, as well as some of the main achievements of the technique. Among these achievements, spinning under environmentally friendly conditions, obtaining high-performance fibers, and imparting the fibers with emerging properties such as supercontraction are discussed. Consequently, SFS appears as an efficient process that may represent one of the first realizations of a biomimetic technology with a significant impact at the production level.Ministerio de Economía y Competitividad MAT2016-75544-C2-1-RMinisterio de Economía y Competitividad MAT2016-79832-RMinisterio de Economía y Competitividad CPI2016-78887-C3-1-RComunidad de Madrid NEUROCENTRO-B2017Comunidad de Madrid BMD-376

Mental health problems and resilience in adolescents during the COVID-19 pandemic in a post-armed conflict area in Colombia.

The impact of COVID-19 pandemic on mental health of adolescents are emerging and require particular attention in settings where challenges like armed conflict, poverty and internal displacement have previously affected their mental wellbeing. This study aimed to determine the prevalence of anxiety symptoms, depressive symptomatology, probable post-traumatic stress disorder and resilience in school-attending adolescents in a post-conflict area of Tolima, Colombia during the COVID-19. A cross-sectional study was carried out with 657 adolescents from 12 to 18 years old, recruited by convenience sampling in 8 public schools in the south of Tolima, Colombia, who completed a self-administered questionnaire. Mental health information was obtained through screening scales for anxiety symptoms (GAD-7), depressive symptomatology (PHQ-8), probable post-traumatic stress disorder (PCL-5) and resilience (CD-RISC-25). The prevalence observed for moderate to severe anxiety symptoms was 18.9% (95% CI 16.0-22.1) and for moderate to severe depressive symptomatology was 30.0% (95% CI 26.5-33.7). A prevalence of probable post-traumatic stress disorder (PTSD) of 22.3% (95% CI 18.1-27.2) was found. The CD-RISC-25 results for resilience had a median score of 54 [IQR 30]. These results suggest that approximately two-thirds of school-attending adolescents in this post-conflict area experienced at least one mental health problem such as anxiety symptoms, depressive symptomatology or probable PTSD during the COVID-19 pandemic. Future studies are of interest to establish the causal relationship between these findings and the impact of the pandemic. These findings highlight the challenge that schools have after pandemic to address the mental health of their students in order to promoting adequate coping strategies and implement prompt multidisciplinary interventions to reduce the burden of mental health problems in adolescents

The knee prosthesis constraint dilemma: Biomechanical comparison between varus-valgus constrained implants and rotating hinge prosthesis. A cadaver study

The real degree of constriction of rotating hinge knee (RHK) and condylar constrained prostheses (CCK) is a matter of discussion in revision knee arthroplasty. The objectives of this study are to compare the tibial rotation of both implants and validate the use of inertial sensors with optical tracking system as movement measurement tools. A total of 16 cadaver knees were used. Eight knees were replaced using a RHK (Endomodel LINK), and the remaining eight received a CCK prosthesis (LCCK, Zimmer). Tibial rotation range of motion was measured in full extension and at 30°, 60°, and 90° of flexion, with four continuous waveforms for each measurement. Measurements were made using two inertial sensors with specific software and compared with measurements obtained using the gold standard technique - the motion capture camera. The comparison of the accuracy of both measurement methods showed no statistically significant differences between inertial sensors and motion capture cameras, with p > .1; the mean error for tibial rotation was 0.21°. Tibial rotation in the RHK was significantly greater than in the CCK (5.25° vs. 2.28°, respectively), p < .05. We have shown that RHK permit greater tibial rotation, being closer to physiological values than CCKs. Inertial sensors have been validated as an effective and accurate method of measuring knee movement. The clinical significance: RHK appears to represent a lower constriction degree than CCK systems.This study wassupported by Ministerio de Ciencia, Innovación y Universidades, Instituto de Salud Carlos III and European Regional Development Fund "Una manera de hacer Europa" (grant number PI18/01625

Nonlinear absorption of InN/InGaN multiple-quantum-well structures at optical telecommunication wavelengths

We report on the nonlinear optical absorption of InN/ InxGa 1-x N (x=0.8,0.9) multiple-quantum-well structures characterized at 1.55 μm by the Z-scan method in order to obtain the effective nonlinear absorption coefficient (α2) of the samples at high repetition rate. Saturable absorption is observed for the sample with x=0.9, with an effective α2 ∼-9× 103 cm/GW for the studied optical regime. For lower In content in the barrier, reverse saturable absorption is observed, which is attributed to two-photon absorption. © 2011 American Institute of Physics.Peer Reviewe

Non-linear absorption of InN/InGaN multiple-quantum-well structures at optical telecommunication wavelengths

We report on the nonlinear optical absorption of InN/ InxGa1−xN x=0.8, 0.9 multiple-quantum-well structures characterized at 1.55 m by the Z-scan method in order to obtain the effective nonlinear absorption coefficient 2 of the samples at high repetition rate. Saturable absorption is observed for the sample with x=0.9, with an effective 2 −9 103 cm/GW for the studied optical regime. For lower In content in the barrier, reverse saturable absorption is observed, which is attributed to two-photon absorption.Ministerio de Ciencia e InnovaciónComunidad de Madri