Spelling suggestions: "subject:"biased""
121 |
The genetics of Pseudomonas fluorescens SBW25 : adaptation to a spatially structured environment : a thesis presented in partial fulfilment of the requirements for the degree of Doctor of Philosophy in Genetics at Massey University, Auckland CampusMcDonald, Michael Joseph January 2009 (has links)
Experimental microbial populations provide powerful models for testing the most challenging problems in evolutionary biology. In the midst of the genome sequencing revolution microbial evolutionary genetics has flourished; promising high-resolution explanations for the underlying causes of evolutionary phenomena. This thesis describes four investigations into the adaptation of Pseudomonas fluorescesns SBW25 to a spatially structured environment. The first builds upon a large body of experimental work characterising the genetic and phenotypic causes of the ability of divergent Wrinkley Spreader (WS) types to colonise the air-liquid interface in spatially structured microcosms. The mws and aws genetic loci are described, which together with the previously described wsp locus, account for the location of the causal mutation for all known WS genotypes. It was found that if these loci were deleted from the P. fluorescens genome, it could still evolve the WS phenotype via a previously undiscovered locus (sws). This study provides the first explicit evidence that genetic biases can influence the outcome of evolution. The second study used a novel method to sample WS genotypes without the biasing effects of natural selection; the distribution of the fitness effects of these genotypes was measured and analysed from a unique perspective. The distribution of fitness effects of new mutations is found to best fit the normal distribution, facilitating the extension of the mutational landscape model of adaptation to include all possible adaptive walks. The third study investigates the underlying causes of genetic biases on evolution; many WS genotypes are obtained at different time points during colonisation of the air-liquid interface (including WS obtained without selection) and the causal mutations of many of these mutants determined. Together these results allowed the elucidation of the relative effects of natural selection, genetic architecture and mutation rate on evolutionary outcomes. The final study considers the WS mat as the product of cooperative interactions, and uses a group selection experiment to investigate the potential of WS mats to evolve group level adaptations. A novel strategy is developed to overcome cheating types, considered the main barrier to the evolution of group level complexity. Furthermore, WS groups evolved specialised cell types, the first example of a de novo evolution of a division of labour, a hallmark of complexity.
|
122 |
Vliv situačních a osobnostních faktorů na ochotu platit za bezcenné informace / The influence of situational and personality factors on willingness to pay for worthless informationFrollová, Nikola January 2018 (has links)
Thesis presents recent relevant studies of cognitive biases and false perceiving of randomness. There is an ongoing general belief that past performance automatically predicts future performance even in the cases when the result is act of randomness. This became inspiration for the main topic of my scientific research. Based on recent relevant literature I study if it is possible to influence people buying valueless information by evoking feeling of loss. Also I am trying to answer question which personal factors stand behind this behaviour. The results shows, that the manipulation with loss had nothing to do with buying valueless information. However it seems that personality factors are connected with this phenomenon to a certain extent. I had identified one factor called 'Irrational Thinking', which partly explains why 71% of the participants were interested in valueless transaction.
|
123 |
Évaluation probabiliste de la fiabilité structurelle des digues fluviales à partir du jugement d’expert / Probabilistic evaluation of the structural reliability of river levees based on expert judgmentHathout, Michel 03 April 2018 (has links)
Les digues de protection contre les inondations sont d’une importance stratégique incontournable pour la sécurité des personnes et des biens. Une meilleure connaissance de leur fiabilité structurelle constitue un enjeu majeur pour les ingénieurs et pour les gestionnaires de ces ouvrages afin de répondre aux réglementations en vigueur et potentiellement les faire évoluer. La réglementation en France relative à la sûreté des ouvrages hydrauliques exige la réalisation d’études de dangers, au sein desquelles les démarches probabilistes d’évaluation de la sécurité prennent une place de plus en plus importante. De par la complexité de leurs mécanismes de rupture et l’absence de condition d’état-limite précis pour certains mécanismes de défaillance tels que l’érosion interne, la surverse ou l’affouillement, le calcul d’une probabilité de défaillance par des approches quantitatives demeure à ce jour impossible. Les digues induisent des problématiques particulières pour l’évaluation de leur fiabilité structurelle où l’intervention d’experts s’avère nécessaire et centrale. Ceux-ci doivent procéder à l’interprétation des données disponibles et la prise en compte de leurs incertitudes, pour pouvoir ensuite évaluer la fiabilité structurelle de digues en termes de probabilité de défaillance. L’objectif de la thèse est l’élaboration d’une démarche complète d’aide à l’évaluation probabiliste de la fiabilité structurelle des digues à partir du jugement expert. Une démarche scientifiquement justifiée pour le recueil et l’exploitation des évaluations expertes, incertaines mais quantitatives, de la fiabilité structurelle des ouvrages, sous la forme d’une probabilité de défaillance ou d’un coefficient de sécurité, assorti(e) d’une marge d’incertitude probabiliste. Afin de répondre à cet objectif, deux démarches ont été développée, « EiCAD » et « EiDA », toutes reposant (dans des ordres différents) sur les phases suivantes :- Une phase d’élicitation individuelle des avis experts (Ei) permettant le recueil des évaluations expertes probabilistes par la construction d’un formulaire de questionnement ;- Une phase de calibration (C) permettant de pondérer les évaluations expertes en fonction des degrés de précision et de justesse ;- Une phase d’agrégation (A) permettant une prise en compte simultanée de plusieurs évaluations expertes probabilistes ;- Une phase de débiaisage (D) permettant de traiter les biais susceptibles d’entacher les évaluations expertes probabilistes. Les démarches développées ont été mises en œuvre sur des cas de digues du Drac, dans l’agglomération grenobloise, pour évaluer la probabilité de défaillance, par jugement expert, vis-à-vis de mécanisme de rupture par glissement et par érosion interne / River levees as protective measures against flooding are a matter of utmost strategic importance for the security of people and property. A better knowledge of their structural reliability is a major challenge for engineers and managers of these structures in order to meet current regulations and potentially develop them. In France, the regulations relating to the safety of hydraulic structures require the realization of hazard studies, in which probabilistic safety evaluation procedures take on a more and more important role. Due to the complexity of their failure mechanisms and the lack of a specific condition of limit-state for some failure mechanisms such as internal erosion and overtopping or scour, calculating a probability of failure by quantitative approaches remains impossible to this day. Levees induce specific problems in evaluating their structural reliability where expert intervention is necessary and pivotal. They must interpret the available data and take into account the uncertainties in their analysis, in order to evaluate the structural reliability of levees in terms of probability of failure. The aim of the thesis is to develop and elaborate a complete approach for supporting probabilistic evaluation of structural reliability of levees based on expert judgments. It is designed as a scientifically justified approach to collect and use uncertain but quantitative expert evaluations of structural reliability, in the form of a failure probability or a safety factor, accompanied by a margin of probabilistic uncertainty. To meet this goal, two approaches have been developed, "EiCAD" and "EiDA" composed of the following phases (in different orders):- individual elicitation phase of expert judgment (Ei) allowing the collection of probabilistic expert evaluations by a constricted questionnaire ;- calibration phase (C) to weigh the probabilistic expert evaluations elicited depending on the degrees of precision and accuracy that can be provided;- aggregation phase (A) during which the probabilistic expert evaluations elicited by several experts are taken into account ;- debiasing phase (D) during which biases that may affect the probabilistic expert evaluations are removed. The developed approaches have been implemented for the cases of Drac levees, located in the Grenoble agglomeration, to assess the probability of failure, by expert judgment, with regard to sliding and internal erosion mechanism of failure
|
124 |
Gênero e educação superior: perspectivas de alunas de físicaAmorim, Valquiria Gila de 23 February 2017 (has links)
Submitted by Leonardo Cavalcante (leo.ocavalcante@gmail.com) on 2018-05-16T13:57:05Z
No. of bitstreams: 1
Arquivototal.pdf: 1290519 bytes, checksum: 35183282e57a26a6ec20882f9b86366b (MD5) / Made available in DSpace on 2018-05-16T13:57:05Z (GMT). No. of bitstreams: 1
Arquivototal.pdf: 1290519 bytes, checksum: 35183282e57a26a6ec20882f9b86366b (MD5)
Previous issue date: 2017-02-23 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Physics is a predominantly male field, and the reasons for this absence of women in the field are not sufficiently recognized or investigated, especially in Brazil. This dissertation aimed to analyze the experiences of inclusion and exclusion undergone by female students acquiring an undergraduate degree in Physics at Federal University of Paraíba (UFPB), Brazil. The theoretical approach was based on feminist and gender studies and cultural studies of science, which are interdisciplinary. The methodological approach was qualitative and two strategies of data collection were used in order to analyze the influence of family members and teachers in the choice of Physics, and their formative trajectory at the university: face-to-face and online structured interviews. However, male students’ perspectives were included to analyze the context of gender relations in the field of Physics, and how these relations may disadvantage women in contrast to men. Women's testimonies revealed embarrassing, debilitating and challenging experiences, as well as gender barriers, such as the chilly climate from the beginning, the male image of the Physicist, the lack of credibility of women in the field, and sexism and sexual harassment from male colleagues and professors. In conclusion, the data indicated that in order to remain in the Physics field, female students face gender stereotypes, prejudices, discrimination, sexism and sexual harassment, which remained invisible and naturalized in many situations. / A Física é um campo majoritariamente masculino, e as razões para essa ausência de mulheres não são suficientemente reconhecidas nem investigadas, principalmente no Brasil. Esta dissertação teve como objetivo analisar as experiências vivenciadas pelas alunas no curso de graduação de Física da Universidade Federal da Paraíba (UFPB), o que as inclui e as exclui, como mulheres, em suas trajetórias. Os aportes teóricos utilizados provêm dos estudos feministas e de gênero e dos estudos culturais da ciência, que são interdisciplinares. A metodologia utilizada foi qualitativa, sendo utilizadas duas estratégias de coleta de dados: entrevista estruturada presencial e online para analisar desde a influência dos familiares e professores/as na escolha do curso de Física até o percurso formativo na universidade. No entanto, foram incluídas vozes masculinas para colaborar a pensar sobre o contexto das relações de gênero no campo da Física e como essas relações podem desfavorecer as mulheres em contraste com os homens. As falas femininas revelaram experiências constrangedoras, debilitantes e desafiantes, bem como barreiras de gênero, entre elas: o clima frio na chegada ao curso, a imagem masculina do Físico, a falta de credibilidade das mulheres no campo, e a presença do sexismo e assédio sexual entre colegas e professores. Os dados apontam, em conclusão, que para permanecer no curso de Física as alunas enfrentam estereótipos de gênero, preconceitos, discriminações, sexismo e assédio sexual, que se apresentaram invisibilizados e naturalizados em muitas situações.
|
125 |
Mathematical modelling of the anchoring effect on the underconfidence bias / Modelado matemático del efecto del anclaje sobre el sesgo de subconfianzaMacbeth, Guillermo, Razumiejczyk, Eugenia 25 September 2017 (has links)
The anchoring effect is defined as the tendency of human thought to the fixation on certain pieces of information that affect decision-making. In the same context, the underconfidence bias is understood as an agent’s propensity to underestimate his or her own objective performance. While some aspects of these phenomena are well known, there are no formal models that specifically describe the relationship between both. This paper presents: i) an experiment that illustrates the anchoring effect on the underconfidence bias by both reducing and amplifying such bias in the domain of geographic decision tasks and ii) the foundations of a new mathematical model that promotes precision in the study of the relationship between anchoring and underconfidence. / Se define el efecto de anclaje como la tendencia del pensamiento humano a la fijación endeterminados fragmentos de información que afectan la toma de decisiones. El sesgo de subconfianza, por su parte, se entiende como la propensión de un agente a subestimar su desempeño objetivo. Si bien se conocen algunos aspectos de la interacción entre ambos efectos, no se dispone de modelos formales que describan tal relación específica. Este estudio presenta: i) un experimento que pone en evidencia el efecto que ejerce el anclaje tanto para reducir, como para amplificar la subconfianza en tareas de decisión geográfica y ii) los fundamentos de un modelo matemático novedoso que permite estudiar con mayor precisión la relación del anclaje con la subconfianza
|
126 |
Identifikace rizik a řízení celkového rizika domácností / Estimation of household total riskFrömel, Jaroslav January 2011 (has links)
The thesis focuses on estimation of household total risk exposure and factors affecting this estimation. The risk is represented with a financial loss of 20k CZK in the next month and with a financial loss of 50k CZK in the next 12 months. Nearly a half of participants in the survey (n=55) estimates the likelihood of this financial shock as being low, however the number of participants with high estimate increases for the next 12 months. The estimate of total risk exposure increases with age, for self-employed and single parents, next with income and assets, however overall wealth decreases the estimate. Significant factors are education, financial behaviour and cognitive abilities which all have a decreasing effect on the estimate. Availability is considered as significant having a positive effect while biased evaluation of risks has a negative effect. Time preferences can play an important role in the estimation of a long-term risk.
|
127 |
When the past becomes the “good old days”: adolescents underestimate pre-injury post-concussion-like symptoms by one month after mild traumatic brain injuryIrwin, Julie K. 26 July 2018 (has links)
Objectives: After mild traumatic brain injury (mTBI), psychological factors can contribute to persisting post-concussion symptoms (PCS). Consistent with constructive theories of memory, negative expectations for increased symptoms after mTBI may contribute to misattributing symptoms to the mTBI and underestimating pre-injury symptoms, called the “good old days’ bias” (Gunstad & Suhr, 2001). The good old days’ bias is not thought to be a general retrospective recall bias but studies to date have largely not controlled for normative memory processes including those that lead to a biased, more positive recall of the past. Therefore, the current study examines whether there is a good old days’ bias after mTBI above and beyond normal memory biases. This study also examines how soon after mTBI the good old days’ bias affects recall of pre-injury symptoms in the first month after mTBI in adolescents as well as whether the good old days’ bias causes pre-injury symptom severity to be underestimated or if symptoms are entirely forgotten. Finally, the clinical significance of symptom recall biases is investigated.
Method: The sample is 42 adolescents who sustained an mTBI (ages 13-18 years; 24 males) and 42 uninjured adolescents (ages 13-18 years; 24 males, ). The mTBI group rated current and retrospective post-concussion symptom ratings within one week and again, at one month, post-injury. The control group rated current and retrospective post-concussion symptoms at baseline and one month later. Cross-sectional and longitudinal comparisons using non-parametric statistical tests were used.
Results: Wilcoxon signed-rank tests showed that, by one month post-mTBI, adolescents report fewer total, physical, and emotional pre-injury symptoms than they had reported within one week of their concussion. The control group did not demonstrate this good old days’ bias. There were no between-group differences in retrospective PCS ratings at either time point. Chi-square analyses found that the mTBI group was as likely as the control group to recall “no” pre-injury/past symptoms one month post-injury after having initially reported some pre-injury symptoms. Only four more adolescents were classified as “recovered” if their one-month PCS ratings were compared with pre-injury PCS ratings made within 1-week post-concussion rather than pre-injury ratings from 1-month post-injury.
Discussion: There was mixed evidence for a good old days’ bias by one month post-concussion. This bias was not demonstrated in healthy adolescents, suggesting that the good old days’ bias is found specifically after concussion. During the acute post-injury period, the good old days’ bias may only be apparent by studying changes in concussed individuals’ own PCS ratings. The good old days’ bias leads to underestimating the severity of pre-injury symptoms rather than forgetting them entirely. The good old days’ bias does not greatly affect symptom recovery tracking by one month post-concussion. Future studies should directly examine expectations about concussion and their effect on current and retrospective symptom reporting. / Graduate / 2019-07-10
|
128 |
Využití nekonvenčních pozorování v asimilaci dat do numerického předpovědního modelu počasí ve vysokém rozlišení spojení se studiem pomalého podprostoru řešení modelu / Non-conventional data assimilation in high resolution numerical weather prediction model with study of the slow manifold of the modelBenáček, Patrik January 2019 (has links)
Satellite instruments currently provide the largest source of infor- mation to today's data assimilation (DA) systems for numerical weather predic- tion (NWP). With the development of high-resolution models, the efficient use of observations at high density is essential to improve small-scale information in the weather forecast. However, a large amount of satellite radiances has to be removed from DA by horizontal data thinning due to uncorrelated observation error assumptions. Moreover, satellite radiances include systematic errors (biases) that may be even larger than the observation signal itself, and must be properly removed prior to DA. Although the Variational Bias Correction (VarBC) scheme is widely used by global NWP centers, there are still open questions regarding its use in Limited-Area Models (LAMs). This thesis aims to tackle the obser- vation error difficulties in assimilating polar satellite radiances in the meso-scale ALADIN system. Firstly, we evaluate spatial- and inter-channel error correla- tions to enhance the positive effect of data thinning. Secondly, we study satellite radiance bias characteristics with the key aspects of the VarBC in LAMs, and we compare the different VarBC configurations with regards to forecast performance. This work is a step towards improving the...
|
129 |
Teacher Biases as an Influence on Early Childhood AssessmentsMason, Crystal 01 January 2019 (has links)
Teacher perspectives and judgments of students' race and gender are known to influence their assessment of primary and secondary students' academic achievements. However, little is known about the effect on children's academic achievement of preschool teacher perspectives and judgments of students' race and gender, which forms the basis for this study. The purpose of this study was to analyze teacher assessment of preschool children's mathematics and science skills on the Desired Results Developmental Profile (DRDP) and Teacher Strategies GOLD (TSG), along with teacher comments written in preparation for each child's parent-teacher conference, to determine if there was a relationship between preschool teachers' assessment and comments and the race and gender of the child. Wason's theory of confirmation bias formed the theoretical foundation of this study. The research questions addressed the relationship between preschool teacher assessments recorded on the DRDP and TSG regarding children's mathematics and science skill and teacher comments coded from Racasens linguistic model and those children's race and gender. Archival data from 2 Head Start centers in a western and southwestern state were analyzed using the Mann-Whitney U test, and the point-biserial Pearson correlation. The Mann-Whitney U test found no statistically significant differences in DRDP and TSG scores by students' race and gender. The point-biserial Pearson correlation found no statistically significant correlation between race or gender and teacher comments. This study contributes to positive social change by confirming observational assessments to be free from teacher bias, supporting their continued use with preschool children to promote their learning and development.
|
130 |
The Lynching of Christopher Davis: A History of Race Relations in Athens, OhioZdinak, Jordan L. 03 June 2020 (has links)
No description available.
|
Page generated in 0.0568 seconds