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Same Probability (same + probability)
Selected AbstractsContingent application of the cancellation editing operation: the role of semantic relatedness between risky outcomesJOURNAL OF BEHAVIORAL DECISION MAKING, Issue 2 2004Nicolao Bonini Abstract This article presents findings on the restructuring component of the decision process. Two experiments are described employing hypothetical vacation choice dilemmas. The aim was to explore the conditions under which outcomes common to two risky prospects with the same probabilities of occurrence are or are not cancelled and how consequent decisions are influenced. The design of the options presented to participants was based on pilot work to establish appropriate contexts. The key independent variable was the semantic relatedness between outcomes of the same risky prospect. The main finding was that the participants did not cancel the outcome shared by two prospects when it was semantically related to another outcome within the same prospect. In this case, the prospect with greater risk was chosen significantly more frequently in comparison to when the common outcome was unrelated to other outcomes. An interpretation of the findings is presented in terms of contingent editing processes. Copyright © 2004 John Wiley & Sons, Ltd. [source] Verbal probabilities: a question of frame?JOURNAL OF BEHAVIORAL DECISION MAKING, Issue 1 2003Karl Halvor Teigen Abstract Verbal expressions of probability and uncertainty are of two kinds: positive (,probable', ,possible') and negative (,not certain', ,doubtful'). Choice of term has implications for predictions and decisions. The present studies show that positive phrases are rated to be more optimistic (when the target outcome is positive), and more correct, when the target outcome actually occurs, even in cases where positive and negative phrases are perceived to convey the same probabilities (Experiments 1 and 2). Selection of phrase can be determined by linguistic frame. Positive quantifiers (,some', ,several') support positive probability phrases, whereas negative quantifiers (,not all') suggest negative phrases (Experiment 3). Positive frames induced by numeric frequencies (e.g. the number of students to be admitted) imply positive probability phrases, whereas negative frames (e.g. the number of students to be rejected) call for negative probability phrases (Experiment 4). It is concluded that choice of verbal phrase is based not only on level of probability, but also on situational and linguistic cues. Copyright © 2002 John Wiley & Sons, Ltd. [source] Haplotype analysis in the presence of informatively missing genotype dataGENETIC EPIDEMIOLOGY, Issue 4 2006Nianjun Liu Abstract It is common to have missing genotypes in practical genetic studies, but the exact underlying missing data mechanism is generally unknown to the investigators. Although some statistical methods can handle missing data, they usually assume that genotypes are missing at random, that is, at a given marker, different genotypes and different alleles are missing with the same probability. These include those methods on haplotype frequency estimation and haplotype association analysis. However, it is likely that this simple assumption does not hold in practice, yet few studies to date have examined the magnitude of the effects when this simplifying assumption is violated. In this study, we demonstrate that the violation of this assumption may lead to serious bias in haplotype frequency estimates, and haplotype association analysis based on this assumption can induce both false-positive and false-negative evidence of association. To address this limitation in the current methods, we propose a general missing data model to characterize missing data patterns across a set of two or more markers simultaneously. We prove that haplotype frequencies and missing data probabilities are identifiable if and only if there is linkage disequilibrium between these markers under our general missing data model. Simulation studies on the analysis of haplotypes consisting of two single nucleotide polymorphisms illustrate that our proposed model can reduce the bias both for haplotype frequency estimates and association analysis due to incorrect assumption on the missing data mechanism. Finally, we illustrate the utilities of our method through its application to a real data set. Genet. Epidemiol. 2006. © 2006 Wiley-Liss, Inc. [source] Age-dependent reproductive performance in Northern Goshawks Accipiter gentilisIBIS, Issue 1 2003Jan Tøttrup Nielsen The age-specific reproductive performance of Northern Goshawks Accipiter gentilis was studied over 22 years in Denmark. The age of the breeding female in relation to the number of young raised was known in 929 breeding attempts, while the age of both the male and the female was known in 496 breeding attempts. The number of fledglings raised per breeding attempt increased with both male and female age, but only for females was it possible to conduct a detailed analysis of this age-dependent relationship. The annual production of fledglings increased with female age from 1 to 7 years of age, whereupon it started to decline. A longitudinal analysis showed that this mean population trend could be attributed to similar age-related trends in individual females. Previous breeding experience did not influence the number of fledglings produced by individual females, and poorly performing females apparently survived with the same probability as well performing ones. The most likely explanation for the age-dependent reproductive performance in the observed Goshawk population appeared to be age-related improvements in competence, such as foraging efficiency. [source] Discrete numerical modelling of rockfill damsINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 11 2006R. Deluzarche Abstract The aim of this study is to obtain quantitative information on the behaviour of rockfill used in embankment dams, and particularly on the influence of block breakage on the displacement field, from a numerical analysis using the Distinct element method. A methodology is set up to define the resistance of the 2D particles so that the same probability of breaking blocks may be reproduced as in a 3D material. The model uses the discrete element code PFC2D (Itasca Consulting Group Inc., PFC2D (Particle Flow Code in Two Dimensions), Version 3.0, 2002) and considers breakable clusters of 2D balls. The different parameters are determined from experimental data obtained from laboratory tests performed on rock blocks. The model is validated by comparing the results of the simulation of shearing tests with actual triaxial tests on rockfill material published in the literature. The numerical analysis of block crushing in an actual dam is proposed in the last part of this paper. Copyright © 2006 John Wiley & Sons, Ltd. [source] Experimental Evidence of Discrimination in the Hiring of First- and Second-generation ImmigrantsLABOUR, Issue 3 2010Magnus Carlsson Previous field experiments that study ethnic discrimination in the labour market are extended in this paper, which outlines a study comparing discrimination of first- and second-generation immigrants. Qualitatively identical resumes, belonging to first- and second-generation immigrants from the Middle East, were sent to employers in Sweden that had advertised for labour. The findings suggest, somewhat unexpectedly, that first- and second-generation immigrants have essentially the same probability of being invited to a job interview, which in turn is significantly lower than the probability of invitation to interview for natives. [source] Neuropsychological impairment and gender differences in HIV-1 infectionPSYCHIATRY AND CLINICAL NEUROSCIENCES, Issue 5 2008José M. Faílde-Garrido phd Aims:, Research into neuropsychological consequences of HIV has focused mainly on male subjects, and therefore very little is known about the disease in female subjects and, of course, about gender differences. The aim of the present research was therefore to investigate neuropsychological impairment rates and pattern in HIV male and female patients, with regard to the study of gender differences in tasks assessing attention, memory for texts, digits and words, psychomotor speed, verbal intelligence and abstract reasoning. Methods:, A clinical sample was recruited consisting of 122 subjects, divided into four groups: (i) 57 HIV+ men; (ii) 31 HIV+ women; (iii) 18 HIV, men and (iv) 16 HIV, women. All the subjects had more than 18 years, being the average of age of 34.08 for men and 33.35 for women. The evaluation of each subject consisted of a semistructured interview investigating sociodemographic, clinical and toxicological aspects and a neuropsychological assessment, with a battery of tests specifically selected for this study and chosen for their validity and because they have been shown to be sensitive to neuropsychological impairment in HIV-infected patients in other studies. Results:, None of HIV, male and female groups fulfilled impairment criteria. Regarding the HIV+ group, a rate of neuropsychological impairment of 51.9% was obtained for the men and 54.8% for the women, but there were no significant differences between groups. Nevertheless, were detected significant differences in neuropsychological impairment rates between HIV+ and HIV, women, and also between HIV+ and HIV, men. Although HIV+ women presented multiple factors that could increase their neuropsychological vulnerability to the effects of HIV, HIV+ men had the same probability of having neuropsychological impairment as HIV+ women. Conclusions:, A different neuropsychological impairment pattern was detected between genders: while HIV+ men had greater impairment in visual memory, attention, psychomotor speed and abstract reasoning, HIV+ women had greater impairment on attention, psychomotor speed and verbal memory for texts. [source] Relationship between floral tube length and nectar robbing in Duranta erecta L. (Verbenaceae)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 2 2009LUIS NAVARRO Although nectar robbing is a common phenomenon in plant species with tubular flowers or flowers with nectar spurs, the potential effect of this illegitimate interaction on plant reproductive success has not received the deserved attention. In the present study, we analysed the functional relationship between flower morphology and nectar robbing, and examined the reproductive consequences of the interaction in a population of Duranta erecta (Verbenaceae) on the island of Cuba. The results show that nectar robbing is conducted by the carpenter bees Xylocopa cubaecola and affects up to 44% of flowers in the studied population. However, not all the flowers have the same probability of being robbed. The chance of flowers being robbed increases with flower length and flower diameter. Moreover, nectar robbing significantly decreases the chance that flowers will set fruit. Also, the impact of nectar robbing on the probability of flowers to set fruits is dependent on the plant. We suggest that nectar robbing may represent an opposite selective force that balances the selection for longer corollas often imposed by pollinators specializing in visiting tubular flowers. Such a relationship with nectar robbers would have obvious implications for the evolution of tubular or closed flowers. This preliminary finding deserves further research in light of the ecological and evolutionary consequences of nectar robbing in tubular flowers. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 392,398. [source] Theoretical Determination of the Vibrational Raman Optical Activity Signatures of Helical Polypropylene ChainsCHEMPHYSCHEM, Issue 11 2006Ewa Lamparska Abstract Raman and vibrational Raman optical activity (VROA) spectra of helical conformers of polypropylene chains are simulated using ab initio methods to unravel the relationships between the vibrational signatures and the primary and secondary structures of the chains. For a polypropylene chain containing three units, conformational effects are shown to lead to more acute signatures for VROA than for Raman spectra. In addition to regular polypropylene chains, which can display right and left helicities with the same probability, chirality and therefore helicity are enforced by substituting one chain end with a phenyl group. The simulations predict that the threefold helical structures, which correspond to (TG)N conformations of the backbone, have a specific VROA backward signature in the form of an intense couplet around 1100 cm,1. This couplet is associated with collective wagging and twisting motions, while most of its intensity comes from the anisotropic invariants combining normal coordinate derivatives of the electric dipole,electric dipole polarizability and of the electric dipole,magnetic dipole polarizability. A similar signature has already been found in model helical polyethylene chains, whereas it is very weak in forward VROA. [source] | |||||||||||||