Search results for "void"
showing 10 items of 435 documents
The cross-lagged relations between children’s academic skill development, task-avoidance, and parental beliefs about success.
2011
Abstract This longitudinal study investigated the cross-lagged associations between children’s academic skill development, task-avoidant behaviour in the context of homework, and parental beliefs about their child’s success from kindergarten to Grade 2. The participants were 1267 children. The children’s pre-skills were assessed at the end of the kindergarten year, and math and reading skills at the end of Grade 1 and Grade 2. Parents provided ratings of their beliefs about their children’s school success and task-avoidant behaviour with regard to homework at the end of Grades 1 and 2. The results showed that children’s math and reading skills predicted children’s task-avoidant behaviour re…
Reforming a complicated income tax system: The political economy perspective
2006
Abstract In this paper we analyze the political economy of revenue-neutral income tax reforms when a government aims at cutting back deduction possibilities in exchange for lower tax rates (“tax-cut-cum-base-broadening”). We show that the individual decision whether to support or reject a reform proposal depends on how strongly the voter is affected by all available exemptions, even if the cut of only one single exemption is at stake. The voting outcome in the society depends on the joint distribution of the deductible characteristics. Due to implicit logrolling there are cases where only symmetrical tax reforms are possible, whereas for other properties of the joint distribution only asymm…
No evidence for prezygotic postcopulatory avoidance of kin despite high inbreeding depression.
2018
11 pages; International audience; Offspring resulting from mating among close relatives can suffer from impaired fitness through the expression of recessive alleles with deleterious effects. Postcopulatory sperm selection (a prezygotic mechanism of cryptic female choice) has been suggested to be an effective way to avoid inbreeding. To investigate whether postcopulatory female choice allows the avoidance of fertilization by close kin, we performed artificial inseminations in a promiscuous bird, the houbara bustard (Chlamydotis undulata undulata). Females were inseminated with a mix of sperm from triads of males, each constituted of a male genetically unrelated to the female, a first cousin …
Genetic and potential non-genetic benefits increase offspring fitness of polyandrous females in non-resource based mating system
2010
Abstract Background The adaptive significance of female polyandry is currently under considerable debate. In non-resource based mating systems, indirect, i.e. genetic benefits have been proposed to be responsible for the fitness gain from polyandry. We studied the benefits of polyandry in the Arctic charr (Salvelinus alpinus) using an experimental design in which the material investments by the sires and maternal environmental effects were controlled. Results Embryonic mortality showed a strong paternal genetic component, and it was lower in polyandrously fertilized offspring (sperm competition of two males) than in monandrous fertilizations. We also found that high sperm velocity was assoc…
Reward-related limbic memory and stimulation of the cannabinoid system: An upgrade in value attribution?
2018
While a lot is known about the mechanisms promoting aversive learning, the impact of rewarding factors on memory has received comparatively less attention. This research investigates reward-related explicit memory in male rats, by taking advantage of the emotional-object recognition test. This is based on the prior association, during conditioned learning, between a rewarding experience (the encounter with a receptive female rat) and an object; afterwards rat discrimination and recognition of the â emotional objectâ is recorded in the presence of a novel object, as a measure of positive limbic memory formation. Since endocannabinoids are critical for processing reward and motivation, the co…
Gender differences in the effects of haloperidol on avoidance conditioning in mice
1995
Abstract Gender differences in the effects of haloperidol (0.07S mg/kg per day for 5 days) on avoidance conditioning were evaluated. We also studied performance of the subjects free of the drug and the acute effects of haloperidol in animals trained without drug 48 h after the last haloperidol administration. Latencies of escape and avoidance responses, number of nonresponses, escapes, avoidances, crossings during the adaptation period, crossings during intertrial intervals, and total crossings per minute were analyzed. This dosage impaired conditioning of the male animals but did not attain the same effects on females. Haloperidol did not deteriorate performance of the task when it had bee…
Obstacles to intergroup contact: When outgroup partner's anxiety meets perceived ethnic discrimination
2013
Emerging research suggests that outgroup partner's anxiety can disrupt intergroup rapport-building. This study extends previous findings by investigating the interactive effects of anticipated outgroup partner's anxiety and perceived ethnic discrimination on self-anxiety and intergroup contact avoidance. A sample of immigrant adolescents belonging to different ethnic minorities in Italy (N = 118) was considered. Results showed that when participants expected to interact with an anxious outgroup (Italian) versus in-group partner, self-anxiety increased and, as a consequence, their intentions to avoid future encounters. However, these effects were observed only for participants with higher (v…
Communication deficits and avoidance of angry faces in children with autism spectrum disorder.
2017
Abstract Background Understanding how emotional faces are processed is important to help characterize the social deficits in Autism Spectrum Disorder (ASD). Aims We examined: (i) whether attention is modulated by emotional facial expression; (ii) the time course of the attentional preferences (short vs. long stimulus presentation rates); and (iii) the association between attentional biases and autistic symptomatology. Method and procedures We applied a dot-probe experiment with emotional faces (happy, sad, and angry). The sample was composed of ASD children without additional language and/or intellectual impairments (n = 29) and age-matched Typically Developing (TD) children (n = 29). Outco…
Endocannabinoids render exploratory behaviour largely independent of the test aversiveness: role of glutamatergic transmission.
2009
To investigate the impact of averseness, controllability and familiarity of a test situation on the involvement of the endocannabinoid system in the regulation of exploratory behaviour, we tested conventional and conditional cannabinoid receptor type 1 (CB1)-deficient mice in behavioural paradigms with different emotional load, which depended on the strength of illumination and the ability of the animals to avoid the light stimulus. Complete CB1 null-mutant mice (Total-CB1-KO) showed an anxiogenic-like phenotype under circumstances where they were able to avoid the bright light such as the elevated plus-maze and the light/dark avoidance task. Conditional mutant mice lacking CB1 expression s…
The Higher the Dose, the Greater the Sex Differences in Escape–Avoidance Response in Mice After Acute Administration of Haloperidol
1998
Abstract MONLEON, S. AND A. PARRA. The higher the dose, the greater the sex differences in escape–avoidance response in mice after acute administration of haloperidol . PHARMACOL BIOCHEM BEHAV 60 (1) 279–284, 1998.—Sex differences in the effects of haloperidol in the escape–avoidance response have previously been found in various studies carried out in our laboratory in which mice were used as experimental subjects. Males were more affected than females by the disruptive effects of this neuroleptic of frequent clinical use. In the present work these sex differences were evaluated in a unique training session using several doses of the drug (0.075, 0.25, and 0.75 mg/kg IP). The number of avo…