73 research outputs found
Prospecting movements link phenotypic traits to female annual potential fitness in a nocturnal predator.
Recent biologging technology reveals hidden life and breeding strategies of nocturnal animals. Combining animal movement patterns with individual characteristics and landscape features can uncover meaningful behaviours that directly influence fitness. Consequently, defining the proximate mechanisms and adaptive value of the identified behaviours is of paramount importance. Breeding female barn owls (Tyto alba), a colour-polymorphic species, recurrently visit other nest boxes at night. We described and quantified this behaviour for the first time, linking it with possible drivers, and individual fitness. We GPS-equipped 178 female barn owls and 122 male partners from 2016 to 2020 in western Switzerland during the chick rearing phase. We observed that 111 (65%) of the tracked breeding females were (re)visiting nest boxes while still carrying out their first brood. We modelled their prospecting parameters as a function of brood-, individual- and partner-related variables and found that female feather eumelanism predicted the emergence of prospecting behaviour (less melanic females are usually prospecting). More importantly we found that increasing male parental investment (e.g., feeding rate) increased female prospecting efforts. Ultimately, females would (re)visit a nest more often if they had used it in the past and were more likely to lay a second clutch afterwards, consequently having higher annual fecundity than non-prospecting females. Despite these apparent immediate benefits, they did not fledge more chicks. Through biologging and long-term field monitoring, we highlight how phenotypic traits (melanism and parental investment) can be related to movement patterns and the annual potential reproductive output (fecundity) of female barn owls
Adolescent drug use escalation and de-escalation: a 3-year follow-up study [Abstract]
This study aims to assess adolescents drug use with a longitudinal perspective in order to identify factors interacting with drug use onset and course. Supported by the Swiss Federal Office of Public Health, the study was initiated in 1999 with a follow-up in 2001 and 2002. The first objective was to measure risk factors for substance use initiation. The second objective was to analyse the co-variation of substance use with environmental, social, relational, medical and psychological factors. A total of 102 adolescents, aged 14-19 years, were recruited for the study in the French-speaking part of Switzerland. Results clearly show that substance use is not a disorder per se in adolescence, but that it is part of a multidimensional complex of problems that some adolescents may encounter: increase and decrease in substance use is paralleled with an increase or decrease in the other areas. This implies that prevention of substance use should not be focused mainly on substances but should consider the adolescent's environment and significant life area
Estimates in Beurling--Helson type theorems. Multidimensional case
We consider the spaces of functions on the
-dimensional torus such that the sequence of the Fourier
coefficients belongs to
. The norm on is defined by
. We study the rate of
growth of the norms as
for -smooth real
functions on (the one-dimensional case was investigated
by the author earlier). The lower estimates that we obtain have direct
analogues for the spaces
Évolution des comportements et des représentations sociales liés à la consommation de cannabis chez les adolescents. Résumé
La recherche, dont les résultats principaux sont
décrits dans ce résumé, visait trois objectifs différents:
a) mieux comprendre l'évolution de la
consommation de substances durant l'adolescence;
b) mesurer les représentations sociales, par
rapport à la consommation, dans une population
de consommateurs comparée à une population
«tout-venant»; c) valider un instrument de dépistage
de la consommation.
L'échantillon, sur lequel porte l'observation du
suivi, est représentatif d'une population de
consommateurs de substances. Le suivi a été
réalisé sur une période de quatre ans, l'âge des
sujets variant entre 15 et 20 ans au moment du
premier entretien. Pour l'évaluation des représentations
sociales, une population «tout-venant» a
été recrutée, afin de pouvoir comparer les attitudes
et opinions des adolescents en relation avec
la consommation. Enfin, pour la validation de
l'instrument de screening, les deux populations,
suivi et «tout-venant», ont été réunies
On the Fourier transform of the characteristic functions of domains with -smooth boundary
We consider domains with -smooth boundary and
study the following question: when the Fourier transform of the
characteristic function belongs to ?Comment: added two references; added footnotes on pages 6 and 1
Victim Precipitation: some fresh evidence on nonverbally mediated perceptions of vulnerability.
Bio+mine project: empowering the community to develop a site-specific system for the rehabilitation of a legacy mine
The rehabilitation of legacy mines continues to be a big challenge because of the difficulties in returning them to safe and stable conditions and ensuring that the mined-out areas become productive to support the economic activity of the host community. Previous efforts are often focused on purely technical and environmental aspects, leading to resistance from the local community due to their exclusion from the rehabilitation process. To address the issues associated with legacy mines and lack of participation of the community, we have developed a project, Biodiversity Positive Mining For The Net Zero Challenge (Bio + Mine), focusing on the abandoned Sto. Niño copper mine (Benguet, Philippines). The mine was closed in 1982 without a plan involving local stakeholders and leaving a significant ongoing negative legacy. Using the social-ecological-technological system framework, we will explore the intersections of the structure and functions of socio-economicdemographic, ecological, and technological data useful in devising a more inclusive mitigation strategy for the reconstruction of the supporting ecosystem. We aim to develop a site-specific system, underpinned by the local community's knowledge and practices, that can be a model for wider implementation in other legacy and active mines worldwide
Semiquinone Radicals from Oxygenated Polychlorinated Biphenyls: Electron Paramagnetic Resonance Studies
Composantes transgénérationnelles dans les toxicomanies et les troubles des conduites alimentaires à l'adolescence.
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