Search results for "void"
showing 10 items of 435 documents
Unavoidable sets and circular splicing languages
2017
Circular splicing systems are a formal model of a generative mechanism of circular words, inspired by a recombinant behaviour of circular DNA. They are defined by a finite alphabet A, an initial set I of circular words, and a set R of rules. In this paper, we focus on the still unknown relations between regular languages and circular splicing systems with a finite initial set and a finite set R of rules represented by a pair of letters ( ( 1 , 3 ) -CSSH systems). When R = A × A , it is known that the set of all words corresponding to the splicing language belongs to the class of pure unitary languages, introduced by Ehrenfeucht, Haussler, Rozenberg in 1983. They also provided a characteriza…
Avoidant coping style and verbal-cardiovascular response dissociation
1996
Abstract This study explored the relationship between an avoidant coping style and three responses during three experimental periods (i.e., speech preparation, speech delivery, and recovery). One response was cardiovascular reactivity, the two other responses were subjective in nature: self-reports of anxiety and self-estimations of blood pressure. Subjects were 20 male and 20 female students who scored either in the upper third (i.e., high-avoiders) or lower third (i.e., low-avoiders) on cognitive avoidance (Krohne, 1989). When compared to subjects scoring low on avoidance, those high on avoidance showed greater systolic blood pressure (SBP) reactivity and evidenced verbal-autonomic respon…
Monte Carlo simulation of many-arm star polymers in two-dimensional good solvents in the bulk and at a surface
1991
A Monte Carlo technique is proposed for the simulation of statistical properties of many-arm star polymers on lattices. In this vectorizing algorithm, the length of each arml is increased by one, step by step, from a starting configuration withl=1 orl=2 which is generated directly. This procedure is carried out for a large sample (e.g., 100,000 configurations). As an application, we have studied self-avoiding stars on the square lattice with arm lengths up tol max=125 and up tof=20 arms, both in the bulk and in the geometry where the center of the star is adsorbed on a repulsive surface. The total number of configurations, which behaves asN∼l γ G–1μ fl , whereμ=2.6386 is the usual effective…
The red tooth hypothesis: A computational model of predator-prey relations, protean escape behavior and sexual reproduction
2009
This paper presents an extension of the Red Queen Hypothesis (hereafter, RQH) that we call the Red Tooth Hypothesis (RTH). This hypothesis suggests that predator-prey relations may play a role in the maintenance of sexual reproduction in many higher animals. RTH is based on an interaction between learning on the part of predators and evolution on the part of prey. We present a simple predator-prey computer simulation that illustrates the effects of this interaction. This simulation suggests that the optimal escape strategy from the prey's standpoint would be to have a small number of highly reflexive, largely innate (and, therefore, very fast) escape patterns, but that would also be unlearn…
Inhibitory avoidance learning in CD1 mice: Effects of chronic social defeat stress
2015
Chronic social defeat stress (CSDS) is an animal model widely used to determine the neurobiological mechanisms of stress and its associated pathologies. In this study, the effects of CSDS on inhibitory avoidance (IA) were evaluated in post-pubertal and adult male CD1 mice, instead of the C57BL/6J strain used in the CSDS standard protocol. CSDS consisted of daily 5-min (experiments 1 and 2) or 10-min (experiment 3) agonistic encounters on 21 consecutive days. Twenty four hours after the last session of CSDS, all the mice were tested for IA. They were also evaluated in an elevated plus-maze, obtaining complementary measures of locomotor activity and emotionality. In experiments 1 and 2, IA le…
Cognitive and behavioural effects induced by social stress plus MDMA administration in mice
2017
Adverse life experiences such as social stress may make an individual more vulnerable to drug addiction and mental disorders associated with drug consumption. The present work aimed to evaluate the effects of stress induced by acute social defeat combined with the administration of 3,4-methylenedioxymethamphetamine (MDMA) on depression-like behaviour, memory function and motor response to drug in late adolescent male mice. Two groups of mice were exposed to social defeat (SD) during four encounters with an aggressive co-specific, which took place on alternate days. Immediately after defeat, animals were treated with saline or MDMA 10mg/kg (SD+SAL and SD+MDMA). In control groups, mice were p…
Should all the world be taxed?
1997
Governments are beginning to fear that the establishment of the “information society” will cause their revenue from taxation to shrink: economic activities in the virtual world of the Internet could escape the application of value added tax. Are these fears justified? Would a “bit tax” solve the problem?
Tax Evasion and Tax Progressivity
2003
In a pure tax evasion framework in which the monetary penalty is a function of the evaded tax, more progressive income taxes will reduce tax evasion if income has to be declared. However, if tax payments have to be declared, higher tax progressivity will have no effects. Thus, the relationship between tax evasion and tax progressivity depends on whether income or taxes have to be divulged to tax authorities. If the fine is a function of undeclared income, higher tax progressivity will always raise evasion.
Instructional support predicts children’s task avoidance in kindergarten
2011
Abstract This study examined the role of observed classroom quality in children's task-avoidant behavior and math skills in kindergarten. To investigate this, 1268 children were tested twice on their math skills during their kindergarten year. Kindergarten teachers ( N = 137) filled in questionnaires measuring their professional experience and also rated the children on their task-avoidant versus task-focused behaviors. Trained observers used the CLASS instrument ( Pianta, La Paro, & Hamre, 2008 ) to observe 49 kindergarten teachers (out of 137) on their emotional support, classroom organization, and instructional support. The results of multilevel modeling showed that kindergarten classro…
The cross-lagged associations between classroom interactions and children’s achievement behaviors
2014
This study examined the cross-lagged associations between the quality of classroom interactions and children’s behaviors in achievement situations. The achievement behaviors in challenging test situations of 166 Finnish children from 70 classrooms were rated by trained testers in grades 1 and 2. The quality of classroom interactions in terms of emotional support, classroom organization, and instructional support were observed in 25 classrooms (out of 70) in grades 1 and 2. The results of multilevel modeling showed that classroom teachers’ low emotional support predicted children’s subsequent high passive avoidance, whereas high classroom organization and instructional support predicted chil…