Search results for "31"
showing 10 items of 4401 documents
Fall of Potential Measurement of the Earth Resistance in Urban Environments: Accuracy Evaluation
2019
Both Standards EN 50522 and IEEE 81 propose the fall of potential method (FPM) to carry out the measurement of the resistance to earth ( $R_{\text{ES}}$ ) of an earthing system (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Furthermore, unknown buried metallic parts and interconnections among ESs could modify the earth potential profile of the area, affecting the measurement results. In this paper, the key-issues that influence the measured $R_{\text{ES}}$ when the FPM is used in an urban environment are presented. A parametric analysis, carried out with Comsol Multiphysic…
Cold-Atom-Induced Control of an Optomechanical Device
2010
We consider a cavity with a vibrating end mirror and coupled to a Bose-Einstein condensate. The cavity field mediates the interplay between mirror and collective oscillations of the atomic density. We study the implications of this dynamics and the possibility of an indirect diagnostic. Our predictions can be observed in a realistic setup that is central to the current quest for mesoscopic quantumness.
Non-syndromic Mitral Valve Dysplasia Mutation Changes the Force Resilience and Interaction of Human Filamin A
2018
International audience; Filamin A (FLNa), expressed in endocardial endothelia during fetal valve morphogenesis, is key in cardiac development. Missense mutations in FLNa cause non-syndromic mitral valve dysplasia (FLNA-MVD). Here, we aimed to reveal the currently unknown underlying molecular mechanism behind FLNA-MVD caused by the FLNa P637Q mutation. The solved crystal structure of the FLNa3-5 P637Q revealed that this mutation causes only minor structural changes close to mutation site. These changes were observed to significantly affect FLNa's ability to transmit cellular force and to interact with its binding partner. The performed steered molecular dynamics simulations showed that signi…
Dynamic force sensing of filamin revealed in single-molecule experiments
2012
Mechanical forces are important signals for cell response and development, but detailed molecular mechanisms of force sensing are largely unexplored. The cytoskeletal protein filamin is a key connecting element between the cytoskeleton and transmembrane complexes such as integrins or the von Willebrand receptor glycoprotein Ib. Here, we show using single-molecule mechanical measurements that the recently reported Ig domain pair 20–21 of human filamin A acts as an autoinhibited force-activatable mechanosensor. We developed a mechanical single-molecule competition assay that allows online observation of binding events of target peptides in solution to the strained domain pair. We find that fi…
FILTRI EMI COMPATTI NEI CONVERTITORI ELETTRONICI DI POTENZA
2015
The goal of the research recently started is to create efficient EMI filters compact that allow to obtain converters with low dimensions and economically competitive.
Corporate Investment, Debt and Liquidity Choices in the Light of Financial Constraints and Hedging Needs
2015
We examine firms' simultaneous choice of investment, debt financing and liquidity in a large sample of US corporates between 1980 and 2014. We partition the sample according to the firms' financial constraints and their needs to hedge against future shortfalls in operating income. In contrast to earlier work, our joint estimation approach shows that cash flows affect the corporate decisions of unconstrained firms more strongly than those of constrained firms. Investment-cash flow sensitivities are particularly intense for unconstrained firms with high hedging needs. Investment opportunities (as proxied by Q), however, play a larger role for constrained firms with the effects being strongest…
The associations among fundamental movement skills, self-reported physical activity and academic performance during junior high school in Finland.
2015
The purpose of this study was to analyse the longitudinal associations between (1) fundamental movement skills (FMSs) and academic performance, and (2) self-reported physical activity and academic performance through junior high school in Finland. The participants of the study were 325 Finnish students (162 girls and 163 boys), who were 13 years old at the beginning of the study at Grade 7. Students performed three FMS tests and responded to a self-reported physical activity questionnaire at Grades 7 and 8. Marks in Finnish language, mathematics and history from Grades 7, 8 and 9 were collected. Structural equation modelling with multigroup method demonstrated that in the boys' group, a cor…
A Spatial Multilevel Analysis of Italian SMEs Productivity
2009
Abstract In this paper, we adapt multilevel analysis methods to investigate the spatial variability of SMEs' productivity across the Italian territory, and account for differences in the socio-economic context. Our results suggest that to properly capture the variability of the data, it is important to allow for both spatial mean and slope effects. Social decay has the expected negative impact. However, while this effect is larger on firms with smaller capital intensity, firms with higher capital intensity seem to be less affected by geography. Greater territorial heterogeneity emerges among those firms with lower capital to labour ratios. Une analyse spatiale a plusieurs niveaux de la prod…
Seguimiento digitalizado combinado en población con alto riesgo de desarrollar un melanoma maligno: análisis retrospectivo de 152 pacientes
2021
Resumen: Antecedentes: La dermatoscopia digitalizada (DD) ha demostrado mejorar la precisión en el diagnóstico del melanoma (MM) en pacientes de alto riesgo. La combinación de DD y fotografía corporal total (FCT) puede facilitar la detección de nuevas lesiones o la aparición de cambios macroscópicos precoces en lesiones previamente registradas. Objetivos: El objetivo del presente estudio fue determinar el número de biopsias necesarias para diagnosticar un MM y, las características clínicas y dermatoscópicas asociadas al diagnóstico de melanoma en pacientes en seguimiento, mediante DD y FCT, de lesiones pigmentadas. Pacientes y métodos: Se realizó un estudio retrospectivo de 152 pacientes co…
Seasonal changes in predator community switch the direction of selection for prey defences
2014
Insect communities consist of aposematic species with efficient warning colours against predation, as well as abundant examples of crypsis. To understand such coexistence, we here report results from a field experiment where relative survival of artificial larvae, varying in conspicuousness, was estimated in natural bird communities over an entire season. This takes advantage of natural variation in the proportion of naive predators: naivety peaks when young birds have just fledged. We show that the relative benefit of warning signals and crypsis changes accordingly. When naive birds are rare (early and late in the season), conspicuous warning signals improve survival, but conspicuousness b…