Search results for "existence"
showing 10 items of 191 documents
Le regard de l’Autre et son impact sur notre existence : notre honte face au regard de l’Autre
2014
National audience
Reliable numerical solution of a class of nonlinear elliptic problems generated by the Poisson-Boltzmann equation
2020
We consider a class of nonlinear elliptic problems associated with models in biophysics, which are described by the Poisson-Boltzmann equation (PBE). We prove mathematical correctness of the problem, study a suitable class of approximations, and deduce guaranteed and fully computable bounds of approximation errors. The latter goal is achieved by means of the approach suggested in [S. Repin, A posteriori error estimation for variational problems with uniformly convex functionals. Math. Comp., 69:481-500, 2000] for convex variational problems. Moreover, we establish the error identity, which defines the error measure natural for the considered class of problems and show that it yields computa…
Effects of density, species interactions, and environmental stochasticity on the dynamics of British bird communities
2022
Our knowledge of the factors affecting species abundances is mainly based on time-series analyses of a few well-studied species at single or few localities, but we know little about whether results from such analyses can be extrapolated to the community level. We apply a joint species distribution model to long-term time-series data on British bird communities to examine the relative contribution of intra- and interspecific density dependence at different spatial scales, as well as the influence of environmental stochasticity, to spatiotemporal interspecific variation in abundance. Intraspecific density dependence has the major structuring effect on these bird communities. In addition, envi…
Vecchi e nuovi problemi in tema di intervento dei creditori nell’esecuzione (note a margine di Cass. S.U. n. 61 del 7 gennaio 2014)
2015
Nel contributo in oggetto l'autore, muovendo dalla decisione delle Sezioni Unite della Cassazione n. 61 del 7 gennaio 2014, coglie l'occasione per riesaminare le vecchie e nuove problematiche sottese all’intervento dei creditori nel processo esecutivo. Il primo tema affrontato è quello della par condicio creditorum, che viene esaminata nella sua storia evolutiva dal Code Napoleon, al suo periodo di massima estensione, dato dal codice del 1940, fino al suo ridimensionamento a seguito delle riforme del 2005. Esamina quindi la possibilità del possibile superamento quoad effectum della distinzione tra intervento di creditori con titolo e senza titolo, alla luce delle evoluzioni della giurisprud…
Exploitation competition between hole‐nesters ( Muscardinus avellanarius , Mammalia and Parus caeruleus , Aves) in Mediterranean woodlands
2005
Data from a long-term study (1993-2003) using artificial nest-boxes, were analysed to examine competition for nesting between blue tit Parus caeruleus and common dormouse Muscardinus avellanarius in Sicily. Occupation rates and the reproductive biology of the blue tit in sample woodlots outside the distribution area of the common dormouse were used as a control in sample areas where the two species were syntopic. A selection test showed that the two species, when living in syntopy, actively chose the small nest-boxes, thus overlapping in the use of the same spatial resource. The experimental exclusion of the common dormouse from nest-boxes caused an increase of blue tit occupation rate. Onc…
Learning from Errors: Detecting ZigBee Interference in WiFi Networks
2014
In this work we show how to detect ZigBee interference on commodity WiFi cards by monitoring the reception errors, such as synchronization errors, invalid header formats, too long frames, etc., caused by ZigBee transmissions. Indeed, in presence of non-WiFi modulated signals, the occurrence of these types of errors follows statistics that can be easily recognized. Moreover, the duration of the error bursts depends on the transmission interval of the interference source, while the error spacing depends on the receiver implementation. On the basis of these considerations, we propose the adoption of hidden Markov chains for characterizing the behavior of WiFi receivers in presence of controlle…
Ecological and evolutionary consequences of selective interspecific information use
2023
Recent work has shown that animals frequently use social information from individuals of their own species as well as from other species; however, the ecological and evolutionary consequences of this social information use remain poorly understood. Additionally, information users may be selective in their social information use, deciding from whom and how to use information, but this has been overlooked in an interspecific context. In particular, the intentional decision to reject a behaviour observed via social information has received less attention, although recent work has indicated its presence in various taxa. Based on existing literature, we explore in which circumstances selective i…
The joint evolution of learning and dispersal maintains intraspecific diversity in metapopulations
2021
The evolution of dispersal tendencies and of cognitive abilities have both been intensely studied. Yet little attention has been given to the question of how these two aspects may relate to each other, as a result of their joint evolution. On the one hand, learning abilities may help dispersers to cope with their new habitat. On the other hand, dispersal may sometimes reduce the need for learning, because local environments may differ in how much there is to learn. To get a better understanding of this relationship, we built an individual‐based simulation in which both learning speed and dispersal tendency were free to evolve. We found that both positive and negative correlations could evol…
The Participation of Families in the Analysis and Transformation of their Reality through a Family Debate about Values and Living Together
2015
Este estudio aborda la socialización en valores y convivencia a partir de una investigación acción que parte de un enfoque participativo y dialéctico y que utiliza el Debate familiar, una herramienta innovadora cuyas finalidades son favorecer la reflexión y el diálogo intrafamiliar e implicar a las familias en el análisis y transformación de su realidad. Esta estrategia estimula el debate e invita a pensar sobre los valores presentes en la familia, recoge información de los diferentes miembros de la unidad familiar y a su vez, sensibiliza sobre los temas tratados. Un total de 492 familias, con al menos un hijo o hija entre 7 y 16 años, participaron en este estudio. Los resultados ponen de r…
Model wielowymiarowej profilaktyki pozytywnej w teorii i praktyce pedagogicznej
2019
Artykuł opisuje teoretyczne oraz empiryczne założenia autorskiego modelu wielowymiarowej profilaktyki pozytywnej. Ponadto prezentuje sposób jego urzeczywistnienia w praktyce pedagogicznej, przedstawiając strukturę autorskiego programu profilaktycznego Wsparcie wielowymiarowego rozwoju młodzieży, zrealizowanego wśród wychowanków Domu Dziecka w Chmielowicach. Teoretyczne podstawy modelu odnoszą się do teorii głównych i teorii szczegółowych. Natomiast założenia empiryczne sprowadzają się do metodyki konstruowania programów profilaktycznych, a więc kryteriów doboru i metod oddziaływań profilaktycznych, uczestników oraz strategii ewaluacyjnej. Model wielowymiarowej profilaktyki pozytywnej w prak…