Search results for "ATTRACTION"
showing 10 items of 152 documents
Fatal attraction: Using distance to measure contagion in good times as well as bad
2007
This paper proposes a new measure of contagion that is good at anticipating future vulnerabilities. Building on previous work, it uses correlations of equity markets across countries to measure contagion, but in a departure from previous practice measures contagion using the relationship of these correlations with distance. Also in contrast to previous work, our test is good at identifying periods of “positive contagion,” in which capital flows to emerging markets in a herd-like manner largely unrelated to fundamentals. Identifying such periods of “fatal attraction” is important as they provide the essential ingredients for subsequent crises and rapid outflows of capital.
Sex pheromones are not always attractive: changes induced by learning and illness in mice
2014
A male-specific major urinary protein named darcin is attractive to female mice, Mus musculus, stimulates a learned attraction to volatile components of a male's urinary odour and induces spatial learning. In this article we show that darcin also induces learned attraction for a previously neutral olfactory stimulus (the odorant isoamyl acetate), acquired by repeated presentation of both stimuli together. We hypothesize that this is a case of olfactory–vomeronasal associative learning, in which darcin acts as the unconditioned reinforcer. However, the presence of darcin is not always attractive to adult female mice. Urine from males parasitized by the nematode Aspiculuris tetraptera has no …
Analysis of the Allee threshold via moving least square approximation
2016
Cooperation is a common behavior between the members of predators species, because it can improve theirs skill in hunt, especially in endangered eco-systems. This behavior it is well known to induce the Strong Allee effect, that can induce the extinction when the initial populations’ is under a critical density called ”Allee threshold ”. Here we investigate the impact of the pack hunting in a predator-prey system in which the predator suffers of an infectious disease with frequency and vertical transmission. The result is a three dimensional system with the predators population divided into susceptible and infected individuals. Studying the system dynamics a scenario was identified in which…
Attraction of Trichogramma Wasps to Butterfly Oviposition-Induced Plant Volatiles Depends on Brassica Species, Wasp Strain and Leaf Necrosis
2021
Within the Brassicaceae, wild as well as crop species are challenged by specialist herbivores including cabbage white butterflies (Pieris spp.). The wild crucifer Brassica nigra responds to oviposition by Pieris butterflies by the synergistic expression of two egg-killing traits. Genotypes that express a hypersensitive response (HR)-like necrosis (direct egg-killing) also emit oviposition-induced plant volatiles (OIPVs) attracting Trichogramma egg parasitoids (indirect egg-killing). This so-called double defense line can result in high butterfly egg mortalities. It remains unknown whether this strategy is unique to B. nigra or more common in Brassica species. To test this, we examined the r…
Les perceptions gustatives chez l'enfant
2005
As soon as the end of gestation, the gustatory system is stimulated by the taste-active compounds carried by the amniotic fluid and its maturation continues until mid-childhood. Facial expressions and relative ingestion methods show that the newborn can discriminate the various taste qualities (bitter, salty, sour, sweet and umami). The range of individual responses is wide. Neonatal reactions to sweet and umami are generally considered to express pleasure. The bitter and sour stimulations lead to hedonically negative reactions. The response to salt taste is less characteristic. Overall, the attraction towards sweet and the rejection of bitter and sour tastes become more pronounced during c…
Sur le rôle des singularités hamiltoniennes dans les systèmes contrôlés : applications en mécanique quantique et en optique non-linéaire.
2012
This thesis has two goals: the first one is to improve the control techniques in quantum mechanics, and more specifically in NMR, by using the tools of geometric optimal control. The second one is the study of the influence of Hamiltonian singularities in controlled systems. The chapter about optimal control study three classical problems of NMR : the inversion problem, the influence of the radiation damping term, and the steady state technique. Then, we apply the geometric optimal control to the problem of the population transfert in a three levels quantum system to recover the STIRAP scheme.The two next chapters study Hamiltonian singularities. We show that they allow to control the polar…
Implicit Interpersonal Attraction in Small Groups
2014
The present research investigated the nature and behavioral consequences of interpersonal attraction in small groups. In line with dual-process models of information processing, we studied the influence of implicit and explicit evaluations of interaction partners on actual friendly behavior in two social contexts. In two studies, 247 unacquainted same-sex participants ( N1 = 139; N2 = 108)—assigned to groups of four to six members—rated each other by completing a variant of the affective priming task to assess implicit interpersonal attraction and a self-report to measure explicit interpersonal attraction. Social relations analyses indicated that implicit and explicit interpersonal attract…
Behaviour-modifying compounds for management of the red palm weevil (Rhynchophorus ferrugineusOliver)
2015
BACKGROUND Populations of red palm weevil (RPW), a severe pest of palms in Mediterranean countries, might be limited by semiochemical-based behaviour-disrupting methods. We evaluated the effects of electroantennogram (EAG)-active plant volatiles on the behaviour of RPWs from Italy and Israel. In field experiments, α-pinene, citronellol, geraniol, citral and 1-octen-3-ol were tested for their ability to disrupt attraction to pheromone–kairomone and molasses baited traps. Those that were found to be disruptive in the field were evaluated in a laboratory choice bioassay in individual cages for their effect on RPW female feeding and oviposition. RESULTS Field experiments showed reduced captures…
Film Tourism – Locations Are the New Stars
2009
There once was a time when the actual attraction of a movie lied in the capability of the celluloid to let the spectators escape from the everyday, a spare time to leave the life-world environment behind and live the life of a thrilling armchair traveller. Foreign countries and remote regions could easily be mapped and visited without travelling to the actual location. Considering that “the modern world is very much a ‘seen’ phenomenon“ (Jenks 1995:2), one has to come to the assumption that present day travelling and watching movies are somehow connected. Tourism originally was perceived as visitors travelling, whether within their own country or internationally, for pleasure and relaxation…
Breeding near heterospecifics as a defence against brood parasites: can redstarts lower probability of cuckoo parasitism using neighbours?
2022
Breeding habitat choice based on the attraction to other species can provide valuable social information and protection benefits. In birds, species with overlapping resources can be a cue of good quality habitats; species with shared predators and/or brood parasites can increase joint vigilance or cooperative mobbing, while raptors may provide a protective umbrella against these threats. We tested whether the migratory common redstart (Phoenicurus phoenicurus) is attracted to breed near active nests of the great tit (Parus major), a keystone-information source for migrant passerine birds, or a top predator, the northern goshawk (Accipiter gentilis). This system is unique to test these quest…