69 research outputs found
Theoretical analysis of thin-wire elliptic antennas
In this communication we extend the state-of-the art by providing closed-form equations for
thin-wire elliptical antennas with arbitrary current distributions, valid from low frequencies to
the infrared regime. To this end, we derive an electric-field integral equation (EFIE) for
imperfectly conducting wires and elliptical geometries. Using this formulation, we obtain
unknown arbitrary current distributions through a modal expansion, enabling thus the
calculation of far-fields and other radiation parameters. Results shown not only achieve
remarkable but also to show the superior design possibilities of elliptical geometries in
comparison to the classical circular loops, which may be considered just a particular case of the
methodology here presented. Special attention is paid to mathematical details of electric farfield
equations, thus providing guidelines to produce efficient codes
Time-domain numerical modeling of THz receivers based on photoconductive antennas
We present here a simulator that solves the main semiconductor charge and transport equations coupled to Maxwell equations to study receivers based on photoconductive antennas (R-PCAs). Making use of this tool we were able to correctly characterize the operation of these antennas. In doing so, we compared simulations with the results of the semi-empirical expression ITHz(t) ∝ σc(t) ∗ ETHz(t) employed to evaluate the detected photo-current by means of the convolution between the photoconductivity in the receiver and the electric field linked to the emitter antenna. We were able to accurately reproduce experimental data with our simulation tool. These kind of tools are essential to model photoconductive antennas, a fundamental step needed for the development of terahertz time domain spectroscopy (THz-TDS) applications based on PCAs.The work described in this paper is partially funded by the Spanish
National Projects TEC2013-48414-C3-01, CSD2008-00068, P09-TIC-5327, P12-TIC-1442, and by the GENIL excellence network
iSTAR first light: Characterizing astronomy education research dissertations in the iSTAR database
There is widespread interest among discipline-based science education researchers to situate their research in the existing scholarly literature base. Unfortunately, traditional approaches to conducting a thorough literature review are unduly hindered in astronomy education research as the venues in which scholarship is reported are fragmented and widely dispersed across journals of varying disciplines. The international STudies of Astronomy education Research (iSTAR) online repository is the result of a concerted international community effort to collect and categorize existing research from peer-reviewed journal articles, dissertations/theses, and grey literature. In a “first light” survey of over 300 U.S. dissertations, we find: (i) work in AER dates back to 1923; (ii) the number of extant dissertations is far greater than anticipated; (iii) research methods definitions have evolved; and (iv) most work has studied participants’ broad knowledge rather than specific learning targets. The surprisingly wide breadth of rarely cited research motivates us to collect more AER from across international and cross-disciplinary sources
SME’s perspective on psychosocial risks: From identifying to intervening in four countries
Introduction: Certain aspects of the work design or the organization as well as the social context of work may lead to negative physical, psychological and social outcomes. These aspects are considered psychosocial risks. Portugal, Spain, Italy, and Greece are facing the biggest consequences of the economic crisis with psychosocial risks being exacerbated. In these countries, small and medium enterprises play an important role in the economy. This paper presents the quantitative data from the project, collected in those four countries. The main goal of the survey was to determine the SMEs’ perspective about emergent psychosocial risks, difficulties and concerns related to its prevention as well as to assess their knowledge and existing practices regarding psychosocial risks prevention.info:eu-repo/semantics/publishedVersio
Analysis of ATG4C function in vivo
Despite the great advances in macroautophagy/autophagy research in the last years, the in vivo role of the different members of the four mammalian orthologs of yeast Atg4 protease (ATG4A-D) remain unclear. To gain further insights into the functional relevance of Atg4 orthologs, we have generated mutant mice deficient in Atg4c. These mice are viable and fertile, and do not display any obvious abnormalities, indicating that they are able to develop the autophagic response required during the early neonatal period. However, they show tissue-specific autophagy alterations, including reduced autophagic flux in diaphragm and show decreased breathing and locomotor activity after fasting. In addition, atg4c-/- mice show reduced number of circulating T and B lymphocytes, which is associated with accumulation of apoptotic cells in the spleen and an increased susceptibility to develop chemically-induced fibrosarcomas. Moreover, through the analysis of cells and mice simultaneously deficient for ATG4C and ATG4D proteases we also reveal a role for ATG4C in mATG8 proteins delipidation.This work was supported by grants from Ministerio Ciencia eInnovación (Spain) (PID2021-127534OB-I00), the South-Eastern 1315 Norway Regional Health Authority (2021088 to N.E.) and Instituto de Salud Carlos III (RTICC Spain). Jesús Prieto-Lloret is funded by Programa Estrategico IBGM, Escalera de Excelencia, ref. CCVC8485, Consejería de
Educación, Junta de Castilla y León (Spain). Funding for open Access Charge: Roche Farma”, as the aricle will be published via Open access and the OA costs will be funded by Roche Farma.Peer reviewe
Participative prevention of psychosocial emergent risks in small and medium enterprises Overview of a collaborative project
info:eu-repo/semantics/publishedVersio
Evidence for a contribution of the APOE (but not the ACE) gene to the sleep profile of non-demented elderly adults
This study aims to investigate alleles of the human apolipoprotein E (APOE) and of the angiotensin-converting enzyme (ACE) genes as risk factors for poor quality of sleep in elderly individuals with no major cognitive decline. This cross-sectional, analytical study was conducted with 163 participants aged 75 years in average and 85% female. Sociodemographic, anthropometric and clinical data were gathered, and sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI) and the Epworth scale, with patient followed for years prior to these evaluations to rule out onset of major mental disorders. Genotyping of classic polymorphic sites for the ApoE (rs429358 and rs7412) and the ACE (rs4646994) genes used peripheral DNA. A total of 63% of the subjects reported poor quality of sleep assessed by the PSQI whereas 54 (33%) reported daytime sleepiness through the Epworth scale. A
significant correlation was observed between APOE and PSQI, with a greater frequency of the poor nighttime sleep quality phenotype among ε2 carriers, whereas no correlation was found among any of the sleep scores and the ACE genotypes. Thus, we suggest a correlation between APOE alleles and scale-assessed sleep quality scores in older adults, with no implications for ACE alleles, in a context devoid of cognitive impairment
SIVA UAV: A Case Study for the EMC Analysis of Composite Air Vehicles
[EN] The increased use of carbon-fiber composites in unmanned aerial vehicles is a challenge for their EMC assessment by numerical solvers. For accurate and reliable simulations, numerical procedures should be tested not only for individual components, but also within the framework of complete systems. With this aim, this paper presents a benchmark test case based on experimental measurements coming from direct-current injection tests in the SIVA unmanned air vehicle, reproduced by a numerical finite-difference-time-domain solver that employs a new subgridding scheme to treat lossy composite thin panels. Validation was undertaken by applying the feature selective validation method, which quantifies the agreement between experimental and numerical data.This work was supported by the Projects TEC2013-48414C3-{ 1,2,3}-R, TEC2016-79214-C3-{1,2,3}-R, and TEC2015-68766-REDC (Spanish MINECO, EU FEDER), P12-TIC-1442 (J. de Andalucia, Spain), Alhambra-UGRFDTD (AIRBUS DS), and by the CSIRC alhambra.ugr.es supercomputing center.Cabello, MR.; Fernández, S.; Pous, M.; Pascual-Gil, E.; Angulo, LD.; López, P.; Riu, PJ.... (2017). SIVA UAV: A Case Study for the EMC Analysis of Composite Air Vehicles. IEEE Transactions on Electromagnetic Compatibility. 59(4):1103-1113. https://doi.org/10.1109/TEMC.2017.2648507S1103111359
A genome-wide screening uncovers the role of CCAR2 as an antagonist of DNA end resection
There are two major and alternative pathways to repair DNA double-strand breaks: non-homologous end-joining and homologous recombination. Here we identify and characterize novel factors involved in choosing between these pathways; in this study we took advantage of the SeeSaw Reporter, in which the repair of double-strand breaks by homology-independent or -dependent mechanisms is distinguished by the accumulation of green or red fluorescence, respectively. Using a genome-wide human esiRNA (endoribonuclease- prepared siRNA) library, we isolate genes that control the recombination/endjoining ratio. Here we report that two distinct sets of genes are involved in the control of the balance between NHEJ and HR: those that are required to facilitate recombination and those that favour NHEJ. This last category includes CCAR2/DBC1, which we show inhibits recombination by limiting the initiation and the extent of DNA end resection, thereby acting as an antagonist of CtIP
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