88 research outputs found

    Novel multipactor studies in RF satellite payloads: Single-carrier digital modulated signals and ferrite materials

    Get PDF
    In this work it is reviewed the most novel advances in the multipactor RF breakdown risk assessment devoted to RF satellite microwave passive devices employed in space telecommunication systems. On one side, it is studied the effect of transmitting a single-carrier digital modulated signal in the multipactor RF voltage threshold in a coaxial line. On the other hand, an analysis of the multipactor phenomenon in a parallel-plate waveguide containing a magnetized ferrite slab it is presented

    Analysis of multipactor RF breakdown in a waveguide containing a transversely magnetized ferrite

    Get PDF
    In this paper, the multipactor RF breakdown in a parallel-plate waveguide partially filled with a ferrite slab magnetized normal to the metallic plates is studied. An external magnetic field is applied along the vertical direction between the plates in order to magnetize the ferrite. Numerical simulations using an in-house 3D code are carried out to obtain the multipactor RF voltage threshold in this kind of structures. The presented results show that the multipactor RF voltage threshold at certain frequencies becomes considerably lower than for the corresponding classical metallic parallel-plate waveguide with the same vacuum gap.This work was supported by the European Space Agency (ESA) under Novel Investigation in Multipactor Effect in Ferrite and other Dielectrics used in high power RF Space Hardware Contract AO 1-7551/13/NL/GLC, and partially by the Spanish Government (under coordinated R&D projects TEC2013-47037-C5-R and TEC2014-55463-C3-3-P)

    Presenteeism and mental health of workers during the COVID-19 pandemic: a systematic review

    Get PDF
    BackgroundA large number of workers attend work despite being ill. Attending work during sickness can have a number of consequences for the worker (e.g., worsening of physical and mental condition), for co-workers, and for the company, and for service users.ObjectivesThe aim of this study was to assess the factors influencing presenteeism and mental health of workers during the COVID-19 pandemic.MethodsA systematic review following the PRISMA format was conducted in the PubMed, Scopus, Web of Science (WoS), Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo, and ScienceDirect electronic databases in January 2023, using the following key words: Presenteeism, Mental Health, and COVID-19. The eligibility criteria applied were original articles published in English, Spanish, French, German, and Portuguese, workers during the COVID-19 pandemic (data collection date: January 01, 2020 – January 01, 2023), and articles assessing at least one measure of presenteeism and mental health status. Methodological quality was assessed using the critical appraisal tools of the Joanna Briggs Institute. The followed protocol is listed in the International Prospective Register of Systematic Reviews (PROSPERO) with code CRD42023391409.ResultsA total of 25 studies were included in this review recruiting a total of 164,274 participants. A number of factors influencing mental health and sickness presenteeism were identified: (1) mental health-related factors (burnout [in 4 studies], stress [in 9 studies], depression [in 1 study], fear of COVID-19 [in 1 study], no well-being [in 2 studies], etc.); (2) individual factors (health status [in 1 study], being young [in 1 study], workers who experienced interrupted medical care [in 2 studies], having a chronic disease [in 1 study], etc.); (3) factors related to the situation caused by COVID-19 (confinement, symptoms, loss of contract, risk of bankruptcy, etc. [in 1 study each one]); and (4) factors derived from working conditions (organisational support [in 1 study], patient care [in 1 study], work functioning or task performance impairment [in 4 studies], work fatigue [in 2 studies], safety climate [in 1 study], workload [in 1 study], etc.).ConclusionIdentifying the key determinants of presenteeism and understanding the phenomena and origins of sickness presenteeism will help to create a safe working environment and optimal organisational systems to protect vulnerable workers in a pandemic context.Systematic review registrationThe unique identifier is CRD42023391409

    CLARC: A cognitive robot for helping geriatric doctors in real scenarios

    Get PDF
    Third Iberian Robotics Conference (ROBOT 2017). 22 to 24 November 2017, Seville, SpainAbstract: Comprehensive Geriatric Assessment (CGA) is an integrated clinical process to evaluate the frailty of elderly persons in order to create therapy plans that improve their quality of life. For robotizing these tests, we are designing and developing CLARC, a mobile robot able to help the physician to capture and manage data during the CGA procedures, mainly by autonomously conducting a set of predefined evaluation tests. Built around a shared internal representation of the outer world, the architecture is composed of software modules able to plan and generate a stream of actions, to execute actions emanated from the representation or to update this by including/removing items at different abstraction levels. Percepts, actions and intentions coming from all software modules are grounded within this unique representation. This allows the robot to react to unexpected events and to modify the course of action according to the dynamics of a scenario built around the interaction with the patient. The paper describes the architecture of the system as well as the preliminary user studies and evaluation to gather new user requirements.This work has been partially funded by the EU ECHORD++ project (FP7-ICT-601116) and the TIN2015-65686-C5-1-R (MINECO and FEDER funds). Javier García is partially supported by the Comunidad de Madrid (Spain) funds under the project 2016-T2/TIC-171

    Engineering Multi-Agent Systems: State of Affairs and the Road Ahead

    Get PDF
    The continuous integration of software-intensive systems together with the ever-increasing computing power offer a breeding ground for intelligent agents and multi-agent systems (MAS) more than ever before. Over the past two decades, a wide variety of languages, models, techniques and methodologies have been proposed to engineer agents and MAS. Despite this substantial body of knowledge and expertise, the systematic engineering of large-scale and open MAS still poses many challenges. Researchers and engineers still face fundamental questions regarding theories, architectures, languages, processes, and platforms for designing, implementing, running, maintaining, and evolving MAS. This paper reports on the results of the 6th International Workshop on Engineering Multi-Agent Systems (EMAS 2018, 14th-15th of July, 2018, Stockholm, Sweden), where participants discussed the issues above focusing on the state of affairs and the road ahead for researchers and engineers in this area

    Cellular and humoral functional responses after BNT162b2 mRNA vaccination differ longitudinally between naive and subjects recovered from COVID-19

    Get PDF
    We have analyzed BNT162b2 vaccine-induced immune responses in naive subjects and individuals recovered from coronavirus disease 2019 (COVID-19), both soon after (14 days) and later after (almost 8 months) vaccination. Plasma spike (S)-specific immunoglobulins peak after one vaccine shot in individuals recovered from COVID-19, while a second dose is needed in naive subjects, although the latter group shows reduced levels all along the analyzed period. Despite how the neutralization capacity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) mirrors this behavior early after vaccination, both groups show comparable neutralizing antibodies and S-specific B cell levels late post-vaccination. When studying cellular responses, naive individuals exhibit higher SARS-CoV-2-specific cytokine production, CD4+ T cell activation, and proliferation than do individuals recovered from COVID-19, with patent inverse correlations between humoral and cellular variables early post-vaccination. However, almost 8 months post-vaccination, SARS-CoV-2-specific responses are comparable between both groups. Our data indicate that a previous history of COVID-19 differentially determines the functional T and B cell-mediated responses to BNT162b2 vaccination over time.C.d.F., J.G.-P., and J.A. are supported by Instituto de Salud Carlos III (ISCII). We thank JM Ligos and Cytek Biosciences for their technical support. Research in E.L.-C.’s lab was supported by Fundación Familia Alonso, Santander Bank, Real Seguros, Fundación Mutua Madrileña, Fundación Uria, Fundación La Caixa, and Ayuntamiento de Madrid.S

    The Courtyard of TT 209 (Areas C1 and C2) Seasons 2012 to 2014

    Get PDF
    In 2012, the Archaeological Mission of the University of La Laguna began its work in TT 209 (Luxor, Egypt) under the name Proyecto dos cero nueve [Project two zero nine]. The objective of this article is to present a synthesis of the processes of excavation and documentation in the area of the tomb where activities began, the courtyard (areas C1 and C2), during the first three seasons (2012, 2013/14 and 2014). The working method is explained, the two main formation processes of the sedimentary deposits that the archaeological investigation recognised—geogonic and anthropic—are described, and the different kinds of materials found there are examined, which correspond to a broad chronological and cultural framework. The analysis of this dataset has made it possible to obtain a historical interpretation of the activities that were carried out in this external part of the funerary complex, from the moment of its construction to the present.En 2012 la Misión Arqueológica de la Universidad de La Laguna comenzó sus trabajos en la TT 209 (Luxor, Egipto) en el marco del denominado Proyecto dos cero nueve. El objetivo del presente artículo es presentar una síntesis del proceso de excavación y documentación de la zona de la tumba donde se iniciaron las actividades, el patio (áreas C1 y C2), durante las tres primeras campañas (2012, 2013-2014 y 2014). Se expone el método de trabajo, se explican los dos principales procesos de formación del depósito sedimentario, tanto geogénicos como antrópicos, reconocidos a través de la intervención arqueológica y se exponen las diferentes clases de materiales hallados, que corresponden a un amplio marco cronológico y cultural. El análisis de este conjunto de informaciones ha permitido obtener una interpretación desde la perspectiva histórica de las actividades desarrolladas en esta parte exterior del complejo funerario desde el momento de su construcción hasta la actualidad

    Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

    Get PDF
    Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score ? 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score

    Monitorización y seguimiento del esfuerzo realizado por los estudiantes y de su asistencia a actividades presenciales

    Get PDF
    Este artículo documenta el planteamiento, la metodología y los primeros resultados de un plan de monitorización detallada del esfuerzo y de asistencia a actividades presenciales por parte de los estudiantes de las titulaciones ofertadas por la Escuela Técnica Superior de Ingenieros Navales de la Universidad Politécnica de Madrid durante el segundo cuatrimestre del curso 2011-2012. Se ha establecido un sistema mecánico de recogida de datos de esfuerzo por parte de los estudiantes utilizando una hoja tipo test especialmente configurada al efecto. Se pasa una hoja en todas y cada una de las actividades presenciales realizadas y en la hoja se solicita información sobre el trabajo "fuera de clase". Se documenta en este artículo cómo se ha estructurado esa hoja, qué tipo de datos se recogen, cómo se tratan mediante una base de datos creada al efecto, qué tipo de análisis se puede realizar y qué resultados preliminares obtenemos de dichos análisis

    Risk Factors and Predictive Score for Bacteremic Biliary Tract Infections Due to Enterococcus faecalis and Enterococcus faecium: a Multicenter Cohort Study from the PROBAC Project

    Get PDF
    Biliary-tract bloodstream infections (BT-BSI) caused by Enterococcus faecalis and E. faecium are associated with inappropriate empirical treatment and worse outcomes compared to other etiologies. The objective of this study was to investigate the risk factors for enterococcal BT-BSI. Patients with BT-BSI from the PROBAC cohort, including consecutive patients with BSI in 26 Spanish hospitals between October 2016 and March 2017, were selected; episodes caused by E. faecalis or E. faecium and other causes were compared. Independent predictors for enterococci were identified by logistic regression, and a predictive score was developed. Eight hundred fifty episodes of BT-BSI were included; 73 (8.5%) were due to target Enterococcus spp. (48 [66%] were E. faecium and 25 [34%] E. faecalis). By multivariate analysis, the variables independently associated with Enterococcus spp. were (OR; 95% confidence interval): cholangiocarcinoma (4.48;1.32 to 15.25), hospital acquisition (3.58;2.11 to 6.07), use of carbapenems in the previous month (3.35;1.45 to 7.78), biliary prosthesis (2.19;1.24 to 3.90), and moderate or severe chronic kidney disease (1.55;1.07 to 2.26). The AUC of the model was 0.74 [95% CI0.67 to 0.80]. A score was developed, with 7, 6, 5, 4, and 2 points for these variables, respectively, with a negative predictive value of 95% for a score # 6. A model, including cholangiocarcinoma, biliary prosthesis, hospital acquisition, previous carbapenems, and chronic kidney disease showed moderate prediction ability for enterococcal BT-BSI. Although the score will need to be validated, this information may be useful for deciding empirical therapy in biliary tract infections when bacteremia is suspected. IMPORTANCE Biliary tract infections are frequent, and a significant cause of morbidity and mortality. Bacteremia is common in these infections, particularly in the elderly and patients with cancer. Inappropriate empirical treatment has been associated with increased risk of mortality in bacteremic cholangitis, and the probability of receiving inactive empirical treatment is higher in episodes caused by enterococci. This is because many of the antimicrobial agents recommended in guidelines for biliary tract infections lack activity against these organisms. To the best of our knowledge, this is the first study analyzing the predictive factors for enterococcal BT-BSI and deriving a predictive score.8 página
    corecore