To see the other types of publications on this topic, follow the link: Causal role.
Dissertations / Theses on the topic 'Causal role'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Causal role.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
1
Wachter, Daniel von. "Modality, causality, and God." Thesis, University of Oxford, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.289017.
Full text
2
Williams, Cara. "The causal role of mood in confabulation." Master's thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/6042.
Full textAbstract:
Bibliography: leaves 35-40.Following a presumed haemorrhage in the hyplthalamic area during an operation to remove a tumour from the diencephalon and frontal lobes, a man (CA) presented with confabulatory amnesia. Previous research papers have shown that confabulations (CA's included) have a positive emotional bias and Turnbull et al. (in press) have demonstrated that low mood appears to co-occur with confabulation. This paper explores the mood of CA across time.
3
Ding, Peng. "Exploring the Role of Randomization in Causal Inference." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:17467349.
Full textAbstract:
This manuscript includes three topics in causal inference, all of which are under the randomization inference framework (Neyman, 1923; Fisher, 1935a; Rubin, 1978). This manuscript contains three self-contained chapters.
Chapter 1. Under the potential outcomes framework, causal effects are defined as comparisons between potential outcomes under treatment and control. To infer causal effects from randomized experiments, Neyman proposed to test the null hypothesis of zero average causal effect (Neyman’s null), and Fisher proposed to test the null hypothesis of zero individual causal effect (Fisher’s null). Although the subtle difference between Neyman’s null and Fisher’s null has caused lots of controversies and confusions for both theoretical and practical statisticians, a careful comparison between the two approaches has been lacking in the literature for more than eighty years. I fill in this historical gap by making a theoretical comparison between them and highlighting an intriguing paradox that has not been recognized by previous re- searchers. Logically, Fisher’s null implies Neyman’s null. It is therefore surprising that, in actual completely randomized experiments, rejection of Neyman’s null does not imply rejection of Fisher’s null for many realistic situations, including the case with constant causal effect. Furthermore, I show that this paradox also exists in other commonly-used experiments, such as stratified experiments, matched-pair experiments, and factorial experiments. Asymptotic analyses, numerical examples, and real data examples all support this surprising phenomenon. Besides its historical and theoretical importance, this paradox also leads to useful practical implications for modern researchers.
Chapter 2. Causal inference in completely randomized treatment-control studies with binary outcomes is discussed from Fisherian, Neymanian and Bayesian perspectives, using the potential outcomes framework. A randomization-based justification of Fisher’s exact test is provided. Arguing that the crucial assumption of constant causal effect is often unrealistic, and holds only for extreme cases, some new asymptotic and Bayesian inferential procedures are proposed. The proposed procedures exploit the intrinsic non-additivity of unit-level causal effects, can be applied to linear and non- linear estimands, and dominate the existing methods, as verified theoretically and also through simulation studies.
Chapter 3. Recent literature has underscored the critical role of treatment effect variation in estimating and understanding causal effects. This approach, however, is in contrast to much of the foundational research on causal inference; Neyman, for example, avoided such variation through his focus on the average treatment effect and his definition of the confidence interval. In this chapter, I extend the Ney- manian framework to explicitly allow both for treatment effect variation explained by covariates, known as the systematic component, and for unexplained treatment effect variation, known as the idiosyncratic component. This perspective enables es- timation and testing of impact variation without imposing a model on the marginal distributions of potential outcomes, with the workhorse approach of regression with interaction terms being a special case. My approach leads to two practical results.
First, I combine estimates of systematic impact variation with sharp bounds on over- all treatment variation to obtain bounds on the proportion of total impact variation explained by a given model—this is essentially an R2 for treatment effect variation. Second, by using covariates to partially account for the correlation of potential out- comes problem, I exploit this perspective to sharpen the bounds on the variance of the average treatment effect estimate itself. As long as the treatment effect varies across observed covariates, the resulting bounds are sharper than the current sharp bounds in the literature. I apply these ideas to a large randomized evaluation in educational research, showing that these results are meaningful in practice.Statistics
4
James, Nathalie. "The role of subjective input in causal category formation." Diss., Restricted to subscribing institutions, 2008. http://proquest.umi.com/pqdweb?did=1781954331&sid=6&Fmt=2&clientId=1564&RQT=309&VName=PQD.
Full text
5
Pepper, Rebecca. "The causal role of attentional control within depressive rumination." Thesis, University of Exeter, 2017. http://hdl.handle.net/10871/28821.
Full textAbstract:
Objectives: Due to a number of conceptual and methodological limitations, existing research has provided only equivocal evidence that deficits/biases in attentional control (AC) are causally implicated in depressive rumination and/or that Cognitive Control Training (CCT) can be used to remediate such vulnerabilities. By using a well-validated training task and ensuring adequate training exposure, the current study aimed to examine the hypothesis that daily CCT would reduce rumination and improve mood among participants with elevated ruminative disposition. Method: Using a multiple baseline design (MBD), eight high-ruminating university participants rated their daily levels of rumination and mood before and after the randomly-determined introduction of daily CCT, designed to enhance their level of AC. Daily ratings were compared before and after the introduction of CCT, using systematic visual analysis and randomisation tests for significance at the group level. Results: No evidence was found to support the hypothesis that daily CCT reduces rumination and/or improve mood. While participants improved in their performance within the CCT across the training period, there was no evidence of near- or far-transfer, visual analysis revealed no impact of the introduction of daily training, and all group-level analyses were non-significant (p ≥ .05). Conclusion: Despite addressing a number of conceptual/methodological concerns, the current study provides no further support for AC theories of rumination or the use of CCT-based treatments for depression. Such conclusions must be interpreted in light of other methodological limitations, however, including the use of a non-clinical sample and the use of MBD to detect delayed treatment effects.
6
Wittchen, Hans-Ulrich, Katja Beesdo, Antje Bittner, and Renee D. Goodwin. "Depressive episodes - evidence for a causal role of primary anxiety disorders?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-110116.
Full textAbstract:
Anxiety and depressive disorders are common mental disorders in general population, imposing tremendous burden on both affected persons and society. Moreover, comorbidity between anxiety and depressive conditions is high, leading to substantial disability and functional impairment. Findings consistently suggest that anxiety disorders are primary to depression in the majority of comorbid cases. Yet, the question of whether anxiety disorders are risk factors for depression, and potentially even causal risk factors for the first onset of depression, remains unresolved. Recent results have shown that anxiety disorders increase the risk for subsequent depression, and also affect the course of depression, resulting in a poorer prognosis. Further, some results suggest a dose–response-relationship in revealing that a higher number of anxiety disorders and more severe impairment associated with anxiety disorders additionally increase the risk for subsequent depression. The goal of this paper is to review recent literature, summarize implications of previous findings, and suggest directions for future research regarding preventive and intervention strategies.
7
Alm, Charlotte. "The Role of Causal Attribution and Self-Focused Attention for Shyness." Doctoral thesis, Linköping : Department of Behavioural Sciences, Linköpings universitet, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-6455.
Full text
8
Wittchen, Hans-Ulrich, Katja Beesdo, Antje Bittner, and Renee D. Goodwin. "Depressive episodes - evidence for a causal role of primary anxiety disorders?" Technische Universität Dresden, 2003. https://tud.qucosa.de/id/qucosa%3A26812.
Full textAbstract:
Anxiety and depressive disorders are common mental disorders in general population, imposing tremendous burden on both affected persons and society. Moreover, comorbidity between anxiety and depressive conditions is high, leading to substantial disability and functional impairment. Findings consistently suggest that anxiety disorders are primary to depression in the majority of comorbid cases. Yet, the question of whether anxiety disorders are risk factors for depression, and potentially even causal risk factors for the first onset of depression, remains unresolved. Recent results have shown that anxiety disorders increase the risk for subsequent depression, and also affect the course of depression, resulting in a poorer prognosis. Further, some results suggest a dose–response-relationship in revealing that a higher number of anxiety disorders and more severe impairment associated with anxiety disorders additionally increase the risk for subsequent depression. The goal of this paper is to review recent literature, summarize implications of previous findings, and suggest directions for future research regarding preventive and intervention strategies.
9
Cleveland, Simon. "A Causal Model to Predict Organizational Knowledge Sharing via Information and Communication Technologies." NSUWorks, 2014. http://nsuworks.nova.edu/gscis_etd/16.
Full textAbstract:
Knowledge management literature identifies numerous barriers that inhibit employees' knowledge seeking and knowledge contributing practices via information and communication technologies (ICTs). Presently, there is a significant gap in the literature that explains what factors promote common knowledge sharing barriers. To bridge this gap, this study examined two research questions: 1) What are the potential factors that contribute to the commonly accepted barriers to knowledge sharing?, and 2) How do these factors impact employees' use of ICTs for knowledge seeking and knowledge contributing? Literature review of 103 knowledge management articles identified three major barriers to knowledge sharing practices (lack of time, poor communication skills, and lack of trust) and three underlying factors that promoted these barriers (role conflict, role ambiguity, and locus of control). A six-stage content analysis study of the 103 knowledge articles identified 199 references to the observed contributors.
To address the second research question, a causal knowledge sharing model was developed and seven hypotheses proposed. A survey consisting of 41 questions was distributed to 1,368 full-time analysts from a variety of industries, and 314 useful responses were analyzed using confirmatory factor analysis and structural equation modeling. The results confirmed that role conflict, role ambiguity, and locus of control predicted knowledge seeking and knowledge contributing behaviors via ICTs. Moreover, type of ICTs used was found to moderate the strength of these predictors.
10
Keaton, Douglas. "Realization and Causal Role-Playing: an Essay on the Mind/Body Problem." University of Cincinnati / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1280777209.
Full text
11
Barbo, Elizabeth Jane. "Causal influences of mental overload and self-efficacy on academic performance." CSUSB ScholarWorks, 1997. https://scholarworks.lib.csusb.edu/etd-project/1179.
Full textAbstract:
In the past, literature has proposed relationships between several different factors. Multiple roles influence performance and stress, good performance increases self-efficacy, high self-efficacy increases performance, and increased amounts of stress decrease performance. While performance can be measured in different ways, the literature has supported using academic achievement as a performance indicator.
12
Alfano, Candice Ann. "Does negative self-imagery play a causal role in social phobia among adolescents?" College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2858.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Psychology. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
13
Greville, William. "Beyond contiguity : the role of temporal distributions and predictability in human causal learning." Thesis, Cardiff University, 2011. http://orca.cf.ac.uk/17847/.
Full textAbstract:
Most contemporary theories of causal learning identify three primary cues to causality; temporal order, contingency and contiguity. It is well-established in the literature that a lack of temporal contiguity – a delay between cause and effect – can have an adverse effect on causal induction. However research has tended to focus almost exclusively on the extent of delay while ignoring the potential influence of delay variability. This thesis aimed to address this oversight. Since humans tend to experience causal relations repeatedly over time, we accordingly experience multiple cause-effect intervals. If intervals are constant, it becomes possible to predict when the effect will occur following the cause. Fixed delays thus confer temporal predictability, which may contribute to successful causal inference by creating an impression of a stable underlying mechanism. Five experiments confirmed the facilitatory effect of predictability in instrumental causal learning. Two experiments involving a different aspect of causal judgment found no effects of interval variability, but two further experiments demonstrated that predictability facilitates elemental causal induction from observation. These results directly conflict with findings from studies of animal conditioning, where preference for variable- interval reinforcement is routinely exhibited, and a simple associative account struggles to explain this disparity. However both a temporal coding associative account, and higher-level cognitive perspectives such as Bayesian structural inference, are compatible with these findings. Overall, this thesis indicates that causal learning involves processes above and beyond simple associations.
14
Schultz, David Arthur. "Children's Decision to Help: The Effects of Causal Attributions and Affective Role-Taking." W&M ScholarWorks, 1995. https://scholarworks.wm.edu/etd/1539626009.
Full text
15
Krynski, Tevye Rachelson. "The role of temporal factors and prior knowledge in causal learning and judgment." Thesis, Massachusetts Institute of Technology, 2006. http://hdl.handle.net/1721.1/37967.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Brain and Cognitive Sciences, 2006.Includes bibliographical references (leaves 189-193).
Causal relationships are all around us: wine causes stains; matches cause flames; foods cause allergic reactions. Next to language, it is hard to imagine a cognitive process more indicative of human intelligence than causal reasoning. To understand how people accomplish these feats, two major questions must be addressed: how do people acquire knowledge of causal relationships (causal learning), and how do people use that knowledge to make predictions and draw inferences (causal judgment)? The first part of this thesis is concerned with causal learning, and draws on the foundation of Bayesian inferential frameworks (e.g., Tenenbaum, Griffiths, & Kemp, 2006) to explain how observable data can be used to infer causal relationships between events. I will argue that rapid causal learning from small samples can be understood as rational inference over a representation of causality that includes a temporal delay between cause and effect. Experimentally, I show that people learn causal relationships faster when the temporal delay between cause and effect is less variable, just as is predicted by a rational statistical model of event causation. I argue that people's tendency to learn better from short delays is an artifact of the fact that short delays are inherently less variable.
(cont.) The second part of this thesis is concerned with causal judgment, and draws on the foundation of knowledge-based Bayesian networks to show that it is often more rational to make judgments using causal frameworks than purely statistical frameworks. Deviations from traditional norms of judgment, such as "base-rate neglect" (Tversky & Kahneman, 1974), can be explained in terms of a mismatch between the statistics given to people and the causal models they intuitively construct to support probabilistic reasoning. Experimentally, I provide evidence that base-rate neglect may be an artifact of applying causal reasoning to purely statistical problems. Six experiments show that when a clear mapping can be established from given statistics to the parameters of an intuitive causal model, people are more likely to use the statistics appropriately, and that when the classical and causal Bayesian norms differ in their prescriptions, people's judgments are more consistent with causal Bayesian norms.
by Tevye Rachelson Krynski.
Ph.D.
16
Houstis, Nicholas E. "Reactive oxygen species play a causal role in multiple forms of insulin resistance." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/38631.
Full textAbstract:
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Biology, 2007.Includes bibliographical references.
Insulin resistance is a cardinal feature of type 2 diabetes and is characteristic of a wide range of other clinical and experimental settings. Little is known about why insulin resistance occurs in so many contexts. Do the various insults that trigger insulin resistance act through a common mechanism? Or, as has been suggested, do they utilize distinct cellular pathways? Here, we report a genomic analysis of two cellular models of insulin resistance, induced by treatment with tumor necrosis factor-a and dexamethasone. Gene expression analysis suggested that reactive oxygen species (ROS) levels were elevated in both models, and this was confirmed through measures of cellular redox state. ROS have been previously proposed to be involved in insulin resistance, although evidence for a causal role has been scant. To test this hypothesis, six treatments designed to alter ROS levels, including two small molecules and four transgenes, were tested in cell culture; all ameliorated insulin resistance to varying degrees. One treatment was tested in obese, insulin resistant mice and was shown to improve insulin sensitivity and glucose homeostasis. Our results suggest that elevated ROS levels are an important trigger for insulin resistance in multiple settings.
by Nicholas E. Houstis.
Ph.D.
17
Chadwick, Michèle. "Cognitive mechanisms underlying the determining of relevance : the causal role of body states." Thesis, Paris 8, 2015. http://www.theses.fr/2015PA080036/document.
Full textAbstract:
La quantité d’informations à laquelle nous sommes chaque jour confrontésconditionne notre survie à la capacité de détecter rapidement ce qui est le pluspertinent dans notre environnement. Nos cerveaux ont ainsi évolué afin dedéclencher, en réponse aux stimuli pertinents, des changements d’état affectif quinous informent alors de l’existence et de la nature de ces stimuli. Or, tandis que lesétats émotionnels, induits par des états corporels, impactent notre perception desstimuli émotionnels, l’influence de ces états corporels sur l’évaluation de lapertinence de stimuli externes est méconnue. Nous avons ici examiné le rôle queces états du corps, transitoires et socialement signifiants, jouent dans l'évaluation dela pertinence des expressions faciales de menace. Lors de nos testscomportementaux, où variaient le degré de pertinence des stimuli et le focusattentionnel, nous avons modulé l'état corporel des participants à l’aide de posturesdominantes ou non dominantes réalisées avant les tâches. Nous avons alorsdémontré que ces postures influencent l'évaluation de la pertinence des expressionsde menace, en accord avec le statut social qu’elles incarnent. De plus, ceci n’a étérévélé que lorsque le traitement de ces stimuli était implicite, soulignant alors lasaillance de ces derniers. Ainsi, nos résultats démontrent que les états corporelsinfluencent non seulement l'évaluation de la pertinence, mais la déterminent, car desstimuli par ailleurs pertinents ne sont plus évalués comme tels selon la postureadoptée. Ces résultats suggèrent que l’état du corps interagit avec nos états affectifspour signaler à l’observateur quels indices sociaux sont pertinentsGiven the quantity of information with which we are constantly confronted, our survival depends on the ability to rapidly detect and attend to what is most relevant. To this end, our brains have evolved to trigger changes in our affective state in response to relevant objects and events, which inform us of their existence and of their nature. While body-induced affective states impact the perception of congruent emotional stimuli, it is still unknown whether body-induced affective states influence the manner in which the relevance of external stimuli is determined and therefore perceived. Here, we examined the role that socially meaningful transient body states play in the evaluation of relevance of facial displays of threat. In a series of behavioral experiments, we modulated participants’ body state, instructing them to hold dominant or non-dominant postures prior to behavioral tests, in which we varied the degree of relevance of the stimuli and the focus of attention. We first demonstrated that these body postures, in accordance with the social status they embody, influenced the evaluation of the relevance of threatening facial displays. Moreover, this impact occurred where facial displays were processed implicitly, highlighting the saliency of these social cues. Overall, our studies demonstrate, that body states, not only influence the evaluation of relevance, but determine it, as otherwise relevant social cues, were no longer evaluated as such. These findings suggest that body states interact with affective states to signal which social cues are relevant to the observer
18
Zajkowski, Wojciech K., Malgorzata Kossut, and Robert C. Wilson. "A causal role for right frontopolar cortex in directed, but not random, exploration." ELIFE SCIENCES PUBLICATIONS LTD, 2017. http://hdl.handle.net/10150/626036.
Full textAbstract:
The explore-exploit dilemma occurs anytime we must choose between exploring unknown options for information and exploiting known resources for reward. Previous work suggests that people use two different strategies to solve the explore-exploit dilemma: directed exploration, driven by information seeking, and random exploration, driven by decision noise. Here, we show that these two strategies rely on different neural systems. Using transcranial magnetic stimulation to inhibit the right frontopolar cortex, we were able to selectively inhibit directed exploration while leaving random exploration intact. This suggests a causal role for right frontopolar cortex in directed, but not random, exploration and that directed and random exploration rely on (at least partially) dissociable neural systems.
19
Williams, Kate Victoria. "The causal role of appraisal biases upon negative repetitive thinking and emotional reactivity." Thesis, University of Exeter, 2016. http://hdl.handle.net/10871/23468.
Full textAbstract:
Attributional style is hypothesised to causally contribute to depression vulnerability through influencing both emotional response and rumination following life events. Consistent with this hypothesis, Peters et al. (2011) found that training individuals towards a pessimistic attributional style, characterised by internal-stable attributions for negative events and external-unstable attributions for positive events, resulted in greater negative mood and emotional reactivity to perceived failure, relative to training a resilient attributional style characterized by the reverse pattern of attributions. To date, however, the relative contribution of the internal-external and stable-unstable dimensions, their interaction, and their application to positive or negative events upon influencing emotional response and, by theoretical extension, risk for depression, remains unresolved. To resolve this question, 80 participants received training manipulating attributional style along four dimensions (i.e., internal versus external attributions for negative events; internal versus external attributions for positive events; stable versus unstable attributions for negative events; stable versus unstable attributions for positive events) in a 24 orthogonal factorial design. Participants then completed a perceived failure induction task. Measures of emotion and state rumination were completed pre-manipulation, post- manipulation, and post-induction. The internality dimension for positive and, separately, negative events influenced both immediate emotional response and emotional reactivity. Stable attributions for negative events increased negative emotional response and moderated the effect of internal attributions for negative events: internal attributions to negative resulted in greater emotional reactivity relative to external attributions, but only in the context of stable attributions for negative events. Both internal and stable dimensions also had independent effects. These findings identifying the active components driving the effect of attributional style upon emotional reactivity suggest slight revisions and refinements to attribution models of depression vulnerability. Furthermore, it provides further evidence that attributional style can be modified and furthers understanding of how CBM-attribution training could be developed as a potential intervention for the treatment of depression.
20
Brunner, Ryan P. "The Role of Memory Perspective in the Maintenance of Causal Uncertainty Beliefs Over Time." The Ohio State University, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=osu1245255022.
Full text
21
Morris, Martin. "The role of causal perception of movement in the early social development of autistic children." Thesis, University of Plymouth, 1995. http://hdl.handle.net/10026.1/2558.
Full textAbstract:
Autistic children often lack social behaviours which are normally present by 8-12 months (Klin et al, 1992; Mundy et al, 1986), although current 'top down' theories about autism hypothesise later-developing conceptual difficulties in social cognition. Research indicates that there are abnormal 'bottom up' perceptual processes in autism (Moore, Hobson & Lee, 1995). Processing of unexpected dynamic visual information may occur to a diminished extent (Courchesne, 1987), whilst in normal infancy, causal perception of the movements of animate. and inanimate objects is likely to be important for social cognition and affective relationships (Shultz, 1989; Premack & Dasser, 1990). It has been suggested that autistic children have difficulties with the unpredictable nature of perceived social information (Moody & Sigman, 1989b; Dawson & Lewy, 1989). On the basis of such previous research, it was proposed that the early social abnormalities of autistic children are a result -of them tending not to notice, or process further, brief dynamic visual information about events unless these follow simple predictable patterns. To test this hypothesis, seven young autistic and seven developmentally delayed children, matched pairwise for verbal comprehension, were initially habituated to two computer-generated displays, of a cartoon-like 'boy' (Runner) running up to a 'wall' and back, and of a 'ball' moving towards the wall and apparently re-bounding back. Visual habituation was reliable and due to information encoding. The autistic children looked relatively less at the Runner habituation display, perhaps due to relatively diminished processing of animate dynamic information. After habituation criterion was reached, a time delay was introduced prolonging contact with the wall, so that the Ball display became 'impossible' whereas the Runner remained 'possible'. As predicted, recovery of visual fixation indicated that the delay was discriminated, and the autistic children recovered relatively less to the novel Ball display compared with the developmentally delayed children. The autistic children may not have perceived the anomaly in the novel 'impossible' Ball event. They either may have had a general expectation for inanimate objects to move independently, or a tendency not to notice altered significance in a repetitive visual event. However, the group differences could also have been due to the autistic children tending not to have real life expectations of cartoon images. Consistent with the hypothesis, the scores of all 14 children both for pre-11 month social behaviours and for joint attention, were associated with relative recovery for the novel Ball display. As predicted from previous research, the autistic children engaged infrequently in these social behaviours. It is proposed that how children perceive the dynamic animate and inanimate world affects how they develop socially during their first year of life. Relevant areas for future research and implications for early interventions are discussed.
22
Chrobak, Quin M. "The Role of Causal Connections in the Development of False Memories for Entire Fabricated Events." Kent State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=kent1278623190.
Full text
23
Turner, Nicholas. "Modifiable risk factors for depression in adolescence : understanding the causal role of obesity and physical activity." Thesis, University of Bristol, 2018. http://hdl.handle.net/1983/c57cda62-9848-43e8-a71c-8e3308b002ae.
Full textAbstract:
Background: Adolescent depression is a significant burden to individuals, families and healthcare systems. Understanding modifiable risk factors, such as obesity and physical activity (PA), is key to informing preventative strategies. The aim of this project was to examine the causal relationships between obesity, PA and depression in adolescents. Methods: Longitudinal data on obesity, PA and depression in adolescents came from 3 large international cohorts (ALSPAC N=7457, TRAILS N=2230 and NDIT=1294). Linear regression and generalised estimating equations (longitudinal) were used to model effects of obesity on future depression. Cross-lagged structural equation modelling was used to investigate a bi-directional relationship between obesity and depression. Mendelian Randomization analysis was used to address residual confounding. The same analytical approaches were used to examine the association between PA and depression. Partial least squares regression was used to identify aspect(s) of PA important in adolescent depression. SEM was used to investigate the role of biological and psychosocial factors as mediators of the obesity-depression relationship. Results: There was (inconsistent) evidence of a positive relationship between obesity and depression in females; a 1 SD increase in obesity was associated with a 0.035 SD (95% CI 0.003, 0.067) increase in depression at the next time point. There was evidence (in one cohort) that this relationship may be mediated by body image. There was no consistent evidence of any association between PA and subsequent depression (e.g. a 1 SD increase in PA was associated with a -0.006 SD (SE 0.016) decrease in depression at the next time point). Conclusion: Reducing obesity may improve the mental health of adolescent females, alongside having physical health benefits. There is little evidence that increased levels of PA are beneficial for depression. Embedding data collection within existing cohorts approaching adolescence will further research in this area and potentially improve outcomes for future generations.
24
Rohlman, James E. "Attribution to Deviant and Nondeviant Social Roles." Thesis, University of North Texas, 1999. https://digital.library.unt.edu/ark:/67531/metadc2178/.
Full textAbstract:
A questionnaire was used to study causal attribution to social roles as influenced by perceived deviance of the role, instructions to identify with the role, and participant gender. The perceived deviance or nondeviance of the roles was determined by a pilot study. The roles were varied randomly through 12 hypothetical events, and identification or nonidentification instructions randomly assigned. The participants were 194 male and female university students. Participants gave the cause of each event and rated the cause on five dimensions: internality, externality, stability, globality, and controllability. Causal attribution to deviant social roles was found to result in a significantly higher across-scales score and to be more internal, less external, and more global than attribution to nondeviant roles. Participant gender showed an interaction with deviance overall and on the dimensions of stability and globality due to significantly higher ratings by women participants than those by men. Identification instructions did not produce a significant effect.
25
Naanyu, Violet. "Social context, stigma, and the role of causal attributions public evaluations of mental illness in South Africa /." [Bloomington, Ind.] : Indiana University, 2009. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3378374.
Full textAbstract:
Thesis (Ph.D.)--Indiana University, Dept. of Sociology, 2009.Title from PDF t.p. (viewed on Jul 7, 2010). Source: Dissertation Abstracts International, Volume: 70-10, Section: A, page: 4077. Advisers: Bernice Pescosolido; Eliza Pavalko.
26
Kauke, Leonie, and Laura Noack. "Perceived Psychological Safety and Causal Attributions of Errors of Working Students: The Mediating Role of Error Orientation." Thesis, Linnéuniversitetet, Institutionen för psykologi (PSY), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-95666.
Full textAbstract:
Given that causal attributions of errors contain different motivational and behavioral implications for learning from errors, it is highly relevant for organizations to thoroughly understand the factors that promote functional attributions. This study set out to investigate whether perceived psychological safety is an antecedent of functional and dysfunctional causal attributions of errors and whether this association is mediated by error orientation. A total of 148 German and Swedish working students served as a convenience sample for the current cross-sectional survey study. Participants answered an online survey measuring their perception of psychological safety, error orientation, and causal attributions of errors. Partial correlation analysis, hierarchical multiple regression, and hierarchical binary logistic regression were performed to analyze the data. It was found that perceived psychological safety negatively predicted the orientation toward covering errors as well as the avoidant error orientation, whereas it did not predict the learning from errors orientation. No evidence of error orientation being related to causal attributions of errors, nor a direct or indirect link between perceived psychological safety and causal attributions was found. The results imply that organizations benefit from creating a psychologically safe work environment in that it reduces the counterproductive error orientations.
27
Revell, Elizabeth R. "Readiness to change in alcohol-related illness : the role of perceived control, causal attributions and illness beliefs." Thesis, University of Leicester, 1999. http://hdl.handle.net/2381/31278.
Full textAbstract:
This research thesis is based on an exploratory study that investigated the influence of health- and drinking-related factors on motivation to change drinking behaviour in alcohol-related illness. Key factors relevant to behavioural intentions to change were drawn together from health and substance-dependency literature. The aim was to demonstrate links between causal, control and efficacy beliefs and readiness to change. Specific hypotheses were proposed for relationships between causal attributions, perceived control, abstinence self-efficacy, health value, alcohol dependency and stage of change. The study involved 33 male and female participants diagnosed with an alcohol-related illness. The sample included hospital in-patients and those seeking help from community agencies. Participants completed a semi-structured interview and six questionnaire measures, administered by the researcher. Relationships between variables were examined using bivariate analyses. The relative power of variables as predictors of readiness to change were examined using regression analysis. Significant differences were found between those classified as 'ready to change' and those 'not ready to change' in terms of alcohol dependency and abstinence self-efficacy. Perceived dependency was a significant and strong predictor of readiness to change. Behavioural self-blame, perceived control, and health-value were not significantly related to readiness to change. No significant relationships were found between perceived control and either self-efficacy or behavioural self-blame. However, significant relationships were found between alcohol dependency and both abstinence self-efficacy and perceived control over illness. The intensity, timing and type of intervention should be responsive to the motivational stage of the individual. The clinician needs to assess clients' beliefs about the nature of their drinking problem. Problem drinkers need knowledge about how to regulate their behaviour and firm belief in their personal efficacy to take effective action and personal control over outcomes.
28
Hung, Woei. "An investigation of the role of causal reasoning methods in facilitating conceptual understanding of college students in physics /." free to MU campus, to others for purchase, 2003. http://wwwlib.umi.com/cr/mo/fullcit?p3101025.
Full text
29
Hammond, Jane Anne. "The role of syntax and contextual frame in children's use of a causal theory in reasoning about natural kinds." College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2653.
Full textAbstract:
Thesis (Ph. D.) -- University of Maryland, College Park, 2005.Thesis research directed by: Human Development. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
30
Etyang, A. O. "Determining the causal role of malaria in elevating blood pressure and pulse wave velocity in Kenyan adolescents and adults." Thesis, London School of Hygiene and Tropical Medicine (University of London), 2018. http://researchonline.lshtm.ac.uk/4646135/.
Full textAbstract:
Introduction: High blood pressure is recognized as a leading risk factor for stroke and death in sub-Saharan Africa (sSA). While many studies have examined the role of established risk factors such as obesity and salt consumption, less is known about other factors, such as infection, that could be of particular importance in sSA. Ambulatory blood pressure measurement has emerged as the optimal method in recent years in Western settings, but there has been limited use to date in sSA. This work presents the results of a study investigating whether malaria, which is widespread in sSA could contribute to the development of high blood pressure using ambulatory measurements. Methods: Preliminary work involved determining the prevalence of hypertension in Kilifi, Kenya and examining the population-level effects of using ambulatory blood pressure monitoring (ABPM) for diagnosing hypertension. A literature review outlining the basis of the malaria-high blood pressure hypothesis and the Mendelian randomization method for testing the hypothesis was conducted. Sickle cell trait and alpha (+) thalassemia were chosen as instrumental variables to represent malaria exposure because they protect against malaria. Two studies were performed in Nairobi, Kenya among the same cohort to confirm that sickle-cell trait and alpha-thalassemia do not influence blood pressure in the absence of malaria and were therefore valid instrumental variables to test the malaria-high blood pressure hypothesis in Kilifi where there is malaria transmission. A Mendelian randomization study was then conducted in Kilifi, Kenya where 24-hour blood pressure and arterial 4 stiffness indices were compared in individuals with and without sickle cell trait and alpha thalassemia. Results: The prevalence of hypertension in Kilifi, a rural area, was found to be as high as in urban areas of Kenya despite the low frequency of classical risk factors such as obesity and excessive salt consumption. Use of ambulatory blood pressure monitoring for diagnosing hypertension was found to improve the accuracy of detection of high blood pressure. Neither Sickle-cell trait (SCT) nor alpha+ thalassemia influenced blood pressure or arterial stiffness indices among adolescents that had been lifelong residents of Nairobi, where there is no malaria transmission. Among individuals that had been lifelong residents of Kilifi, Kenya where there has been on-going malaria transmission, blood pressure was found to be lower among individuals with SCT, which protects against malaria episodes compared to those without SCT. The difference in BP by SCT status was larger in women than in men. There were no significant differences in arterial stiffness based on SCT status. Conclusion: This work suggests that malaria contributes to the burden of hypertension in sSA, and the control of malaria may lead to a reduction in blood pressure in this group. Future work should focus on confirming the findings using alternative study designs such as examining blood pressure in cohorts born before and after complete malaria elimination in parts of the world where this has been achieved. Subsequent work would involve delineating the pathophysiological mechanisms involved in malaria induced BP elevation with a view to generating new drugs to control hypertension.
31
Kinyanjui, George Kariuki. "Altruism and the role of affect: an investigation into the causal effects of positive emotions and its rationality on altruism." Doctoral thesis, Faculty of Commerce, 2021. http://hdl.handle.net/11427/33813.
Full textAbstract:
There is now well established evidence that shows that growing up in poor neighbourhoods can keep people locked in poverty. One response to neighbourhood distress – i.e., situations in which neighbourhoods serves as poverty traps – is to move people out of such situations. Experiments conducted in the United States of America (for example, the Moving to Opportunity experiment) provides a compelling case for this approach. However, when the scale of neighbourhood distress reaches a majority of the population, as is does in South Africa, where the legacy of Apartheid spatial inequality persists, alternative approaches are necessary. One such alternative is to seek to better understand the behavioural mechanisms at work that tilt communities toward the low level equilibria characterising a poverty trap and to target those behaviours that can aggregate to produce neighbourhood distress. Behaviour modification programmes attempt to do this, for example, by targeting the underlying drivers of crime, violence, risky sexual behaviour and fatalism that characterises so many marginalised communities in South Africa. This dissertation uses data from a rare lab-in-the-field experiment to investigate one important mechanism of behaviour modification: the impact of emotions on pro-social preferences. The results show that positive emotions causes an increase in individual altruism and do not imply irrationality according to standard axiomatic frameworks in economics. This contrasts with the view of earlier investigators that emotions are disruptive in decision making. This dissertation is divided into five chapters. Chapter one focuses on a general introduction of endogenous preferences, the link between emotions, pro-social preferences and decision making. In chapter two I discuss the novel behaviour modification experiment that this dissertation is based on: the Activate! Change Driver's programme (hereafter, simply referred to as Activate!), an empowerment programme aimed at youth that live in distressed neighbourhoods in South Africa. Activate! consists of a nexus of interventions that aims to promote prosocial preferences (i.e., preferences for altruism, trust, and commitment to the public good), as well as interventions that are aimed at changing mindsets and perceptions that foster destructive risk-taking, myopia and civic apathy. The programme runs as a series of three modularised workshops covering self-belief, goal-orientation, creative thinking, problem solving, resilience, communication skills, trust building, project management, and political engagement. These interventions are theorised to lead to an actualisation of greater pro-social preferences as well as better outcomes in terms of risk taking, tolerance for delayed gratification, civic engagement, and economic opportunity. In chapter three, I investigate the causal effect of positive affect on altruism. I employed two estimation strategies where in the first strategy, I used an instrumental variable approach to estimate the effects of affect on altruism. In the second strategy, I relaxed the assumption that affect does not directly impact altruism by using a mood inducement experiment to vary affect within the subjects. Both identification strategies support the same conclusion: positive affect is shown to be a significant and positive cause of altruism. Subjects in the positive affect treatment send significantly more tokens to anonymous others in a dictator game as compared to subjects in the mild neutral affect treatment. This result is robust in all specifications considered. Chapter four focuses on characterising whether emotions disrupt rational choices in altruism. In psychology, emotions are theorised to influence decision making since they influence a person's decision to exert effort and be productive at work. There is also evidence indicating that emotions reduce time preferences over money, that they can increase cognitive flexibility, reduce spending and willingness to pay as well as increase reciprocity in gift exchange. I made use of data from a modified dictator game experiment and employed the axioms of revealed preferences to test for economic rationality. I found that subjects treated to positive affect elicited altruistic preferences that are indifferent to subjects treated to neutral affect and that their preferences fit the standard economic definition of rationality. Thus, by this account even though emotions are seen to be disruptive, they do not imply irrationality. In summary, the dissertation presents a number of implications. First, behaviour modification programmes especially in the context of marginalised communities may result in increasing pro-social outcomes and therefore have the potential to reverse fatalistic preferences among young people. Second, behaviour modification and ultimately belief updating towards pro-social preferences has the potential to spark civic mindedness among young people. Third, positive emotions mediate pro-sociality and do not blur individual rationality in decision making.
32
Bajaj, Sahil, Stephen N. Housley, David Wu, Mukesh Dhamala, G. A. James, and Andrew J. Butler. "Dominance of the Unaffected Hemisphere Motor Network and Its Role in the Behavior of Chronic Stroke Survivors." FRONTIERS MEDIA SA, 2016. http://hdl.handle.net/10150/622772.
Full textAbstract:
Balance of motor network activity between the two brain hemispheres after stroke is crucial for functional recovery. Several studies have extensively studied the role of the affected brain hemisphere to better understand changes in motor network activity following stroke. Very few studies have examined the role of the unaffected brain hemisphere and confirmed the testretest reliability of connectivity measures on unaffected hemisphere. We recorded blood oxygenation level dependent functional magnetic resonance imaging (fMRI) signals from nine stroke survivors with hemiparesis of the left or right hand. Participants performed a motor execution task with affected hand, unaffected hand, and both hands simultaneously. Participants returned for a repeat fMRI scan 1 week later. Using dynamic causal modeling (DCM), we evaluated effective connectivity among three motor areas: the primary motor area (M1), the premotor cortex (PMC) and the supplementary motor area for the affected and unaffected hemispheres separately. Five participants manual motor ability was assessed by Fugl-Meyer Motor Assessment scores and root-mean square error of participants tracking ability during a robot-assisted game. We found (i) that the task performance with the affected hand resulted in strengthening of the connectivity pattern for unaffected hemisphere, (ii) an identical network of the unaffected hemisphere when participants performed the task with their unaffected hand, and (iii) the pattern of directional connectivity observed in the affected hemisphere was identical for tasks using the affected hand only or both hands. Furthermore, paired t-test comparison found no significant differences in connectivity strength for any path when compared with one-week follow-up. Brain-behavior linear correlation analysis showed that the connectivity patterns in the unaffected hemisphere more accurately reflected the behavioral conditions than the connectivity patterns in the affected hemisphere. Above findings enrich our knowledge of unaffected brain hemisphere following stroke, which further strengthens our neurobiological understanding of stroke-affected brain and can help to effectively identify and apply stroke-treatments.
33
Annus, Agnes M. "MANIPULATION OF THINNESS AND RESTRICTING EXPECTANCIES: FURTHER EVIDENCE FOR A CAUSAL ROLE OF THINNESS AND RESTRICTING EXPECTANCIES IN THE ETIOLOGY OF EATING DISORDERS." Lexington, Ky. : [University of Kentucky Libraries], 2006. http://lib.uky.edu/ETD/ukypcps2006t00477/AgnesMAnnusThesis.pdf.
Full textAbstract:
Thesis (M.S.)--University of Kentucky, 2006.Title from document title page (viewed on November 2, 2006). Document formatted into pages; contains: vii, 25 p. : ill. (some col.). Includes abstract and vita. Includes bibliographical references (p. 21-23).
34
Maingret, Nicolas. "A causal role for the hippocampo-cortical dialogue in memory consolidation : temporal coupling of rhythmic patterns and cortical network reorganization during sleep in rats." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066620.
Full textAbstract:
La théorie de la formation de la mémoire "en deux étapes" postule que la consolidation mnésique repose sur un dialogue pendant le sommeil entre l'hippocampe, où les traces mnésiques sont initialement formées, et le néocortex (notamment le cortex préfrontal médian, CPm), où elles seraient stockées à long terme. En particulier, la coordination entre oscillations au sein du réseau hippocampo-cortical pendant le sommeil apparaît comme un mécanisme plausible pour la consolidation. Nous avons augmenté la coordination temporelle entre ces deux structures pendant le sommeil suivant un apprentissage d'une tâche de mémoire spatiale limité en temps n'induisant pas de consolidation. Les rats ayant suivi le protocole permettant l'augmentation des intéractions entre ondulations hippocampiques, ondes delta corticales et fuseaux thalamo-corticaux par le biais d'impulsions électriques intra-corticales ont fait preuve d'un haut niveau de performance de rappel 24 h plus tard, contrairement à des rats de contrôle qui ne faisaient pas mieux que le hasard. Ainsi, cette augmentation des intéractions hippocampo-corticales pendant le sommeil a-t-elle stabilisé des traces mnésiques qui autrement n'auraient pas subsisté entre l'entraînement et le test. De plus, nous avons observé une réorganisation des réseaux neuronaux du CPm pendant le sommeil, ainsi qu'une réponse accrue du CPm à la tâche le lendemain. Ces travaux constituent une mise en évidence directe du rôle causal du dialogue hippocampo-cortical pendant le sommeil dans la consolidation mnésique, dont les mécanismes sous-jacents impliquent une coordination temporelle précise entre ondulations, ondes delta et fuseaux (Maingret et al., 2016)The `two-stage' theory of memory posits that memory consolidation involves a dialogue during sleep between the hippocampus, where traces are initially formed, and the neocortex (notably the prefrontal cortex), where they are stored for long-term retention. Temporally coordinated oscillations in the hippocampo-cortical network could be a key mechanism for sleep-dependent memory consolidation. We dynamically manipulated the temporal coordination between the two structures during sleep following training on a spatial memory task specifically designed to trigger encoding, but not memory consolidation. Reinforcing the endogenous coordination between hippocampal sharp wave-ripples, cortical delta waves and spindles by timed electrical stimulation resulted in a high recall performance on the next day, contrary to control rats which performed at chance levels. Thus, this enhancement of hippocampo-cortical interactions during sleep stabilized memory traces that would have otherwise vanished between training and test. In addition, we observed a reorganization of prefrontal cortical networks during sleep, along with subsequent increased prefrontal responsivity to the task on the next day. These results provide direct evidence for a causal role of a hippocampo-cortical dialogue during sleep in memory consolidation, and indicate that the underlying mechanism involves a fine-tuned coordination between sharp wave-ripples, delta waves and spindles (Maingret et al., 2016)
35
Guo, Yuhua. "The role of the basal ganglia in memory and motor inhibition." Thesis, University of Cambridge, 2017. https://www.repository.cam.ac.uk/handle/1810/268489.
Full textAbstract:
This PhD thesis investigated the role of the basal ganglia in memory and motor inhibition. Recent neuroimaging evidence suggests a supramodal network of inhibition involving the lateral prefrontal cortex. Here we examined whether this supramodal network also includes subcortical structures, such as the basal ganglia. Despite their well-established role in motor control, the basal ganglia are repeatedly activated but never interpreted during memory inhibition. We first used a series of meta-analyses to confirm the consistent involvement of the basal ganglia across studies using memory and motor inhibition tasks (including the Go/No-Go, Think/No-Think, and Stop-signal tasks), and discovered that there may be different subprocesses of inhibition. For instance, while the Go/No-Go task may require preventing a response from taking place, the Think/No-Think and Stop-signal tasks may require cancelling an emerging or ongoing response. We then conducted an fMRI study to examine how the basal ganglia interact with other putative supramodal regions (e.g., DLPFC) to achieve memory and motor inhibition during prevention and cancellation. Through dynamic causal modelling (DCM), we found that both DLPFC and basal ganglia play effective roles to achieve inhibition in the task-specific regions (hippocampus for memory inhibition; primary motor cortex (M1) for motor inhibition). Specifically, memory inhibition requires a DLPFC-basal ganglia-hippocampus pathway, whereas motor inhibition requires a basal ganglia-DLPFC-M1 pathway. We correlated DCM coupling parameters with behavioural indices to examine the relationship between network dynamics during prevention and cancellation and the successfulness of inhibition. However, due to constraints with DCM parameter estimates, caution is necessary when interpreting these results. Finally, we used diffusion weighted imaging to explore the anatomical connections supporting functions and behaviour. Unfortunately, we were unable to detect any white matter variability in relation to effective connectivity or behaviour during the prevention or cancellation processes of memory and motor inhibition at this stage. This PhD thesis provides essential INITIAL evidence that not only are the basal ganglia consistently involved in memory and motor inhibition, but these structures are effectively engaged in these tasks, achieving inhibition through task-specific pathways. We will discuss our findings, interpretations, and future directions in the relevant chapters.
36
Horton, Johan. "Help-seeking for Attention Deficit Hyperactivity Disorder (ADHD) : the role of causal attributions and knowledge in determining whether parents and teachers seek help for ADHD." Thesis, University of Leicester, 2006. http://hdl.handle.net/2381/8241.
Full textAbstract:
Literature Review - Past surveys suggest that there is a low use of specialist services and an underdiagnosis of ADHD (Meltzer et al., 2000). Understanding the variables that facilitate or prevent help-seeking occurring is considered to be crucial. This review sets out to examine the role causal attributions play in determining whether parents and teachers seek help for a child displaying symptoms of ADHD. Attribution theory is applied to this area to present a conceptual model in attempt to understand the psychological factors influencing help-seeking for ADHD, highlighting the need future research. Research Report - Objectives: To examine the role causal attributions and knowledge have in predicting whether parents and teacher seek help for the core symptoms of ADHD. Method: The study recruited 131 participants, 63 parents and 69 teachers. Each completed a demographic questionnaire, the Knowledge of Attention Deficit Disorder (KADDS) and were presented with written descriptions of a child displaying inattentive and hyperactive-impulsive behaviours for which they rated on the causal dimensions of locus, controllability, globality and stability and the likelihood that they would seek help. Results: Perceptions regarding the problematic nature of ADHD behaviours predicted whether parents and teachers sought help. Teachers were found to perceive hyperactive-impulsive behaviours as more problematic and in need of help, whilst parents perceived inattentive behaviours as more a problem and requiring of help. Causal attributions had a significant role in predicting help-seeking. Conclusions: Identification of the role the perceptions and attributions parents and teachers hold towards the causes of ADHD have important clinical implications not only in the recognition of this disorder and subsequent decisions to seek help, but also for diagnosis and treatment of this condition. Critical Appraisal - The appraisal details a personal account of the research, from the planning stages to implementation and writing up. An exploration of this journey and subsequent learning outcomes are discussed.
37
Cohn, Andrew. "An investigation into the role of causal attributions, expectancy of control and coping strategies in psychological adjustment to basic military training in the Australian Army / Andrew Cohn." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18464.pdf.
Full text
38
Jenczmionka, Nicole Joan. "The role of mitogen-activated protein kinases for developmental and pathogenic processes of Fusarium graminearum, the causal agent of the head blight disease of small grain cereals." [S.l. : s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=971440352.
Full text
39
Comrie, Emma L. "Explaining the role of Twitter in the amplification and attenuation of risk during health risk events through causal loop diagrams : a comparative study of Nova Scotia and Scotland." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=24950.
Full textAbstract:
The goal of the research is to support the development of an effective communication strategy within public health through social media. Drawing upon the Social Amplification of Risk Framework (SARF), developed by Kasperson et al. (1988) as the theoretical basis, this research explores and compares the use of Twitter by health organisations during health risk events. The research focuses on Twitter as an information channel and its role in the amplification and attenuation of risk events. The empirical research employs a two case comparative case study approach in which data was collected from participants in health organisations in Nova Scotia and Scotland. The data collection method was semi-structured interviews. The interview data was analysed through a thematic analysis to identify the main themes emerging from the data. Lastly, a causal loop diagram was developed to model the interdependencies among factors during a risk event. The research found that health organisations were using Twitter as a means of strengthening risk communication strategies. The use of Twitter had an increasingly important role within communication showing that it had a role in increasing credibility and trust in the organisation; a way of pushing and pulling information and a means of direct communication. However, the participatory, interactive nature of Twitter provided challenges for these organisations. Theoretical contributions are made to the extant body of research relating to SARF, extending the application of the framework to Twitter. Also, more widely, to the field of risk communication identifying that Twitter is a medium through which information can both be pushed and pulled by organisations. Methodological contributions are made by applying causal loop diagramming to SARF. The use of causal loop diagrams enhances the SARF tool-kit providing a tool that models relationships between factors during a risk event. This methodology could be used by others and applied in other areas related to SARF.
40
Graf, Nicolas. "The Moderating Role of the Industry Structure on the Causal Relationships between Remote Risks, Task Risks, and Industry Performance: Empirical Study of the U.S. Casual Theme Restaurant Industry." Diss., Virginia Tech, 2007. http://hdl.handle.net/10919/30149.
Full textAbstract:
The purpose of this study was to investigate the concepts of remote and task risks in relation to the structure of the casual theme restaurant industry, and to examine the performance consequences of their relationships. This study proposed a framework of analysis that will enable industry participants to develop an improved understanding of the relationships among environmental risk drivers, and of the influence of their strategic decisions on the environment-performance connection.
Specifically, it was proposed that task risk factors could be identified, and that they would mediate the influence that some identifiable remote risk factors would have on the performance of the industry. It was also expected that this mediated relationship would be moderated by the influence of the structure of industry.
The primary unit of analysis was at the industry sector level as the performance construct was operationalized using a portfolio of 24 casual theme restaurant firms. Exploratory factor analysis was used to identify the remote and task risk factors. The analysis suggested that three remote factors and three task factors represent the two environmental constructs: â Interest ratesâ , â Expectationsâ and â Exchange ratesâ for the remote environment, and â Input quantitiesâ , â Input restaurantâ and â Input pricesâ for the task environment.
A number of time-series regression analyses were subsequently conducted for the 1993-2006 period to investigate the various proposed relationships. The results indicated that a number of significant direct effects of the remote and task risk factors on the cash flow returns on invested capital of the industry portfolio existed. Also, a significant mediated relationship was found: the â Input pricesâ mediated the influence of the â Expectationsâ on changes in the cash flow returns on invested capital. However, and despite numerous significant direct effects between the industry structure variables and the performance variables, no moderation could be established.
The present study paved the way for future research on the relationships between the remote and task environment and the performance of firms. In particular, further research should be conducted that delves into the role of the cyclical nature of environmental risk factors. Besides, additional investigations of the influence of the structure of the industry should be conducted by attempting to compare more contrasted states of the industry.Ph. D.
41
Nguyen, Phuong. "Ethnic gap, household businesses and social networks in Vietnam The role of Social Networks on Household Business Performance in Vietnam: A qualitative assessment." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLED080.
Full textAbstract:
Au cours des deux dernières décennies, les deux groupes vulnérables des ethnies minoritaires et des entreprises familiales ont contribué à la croissance économique, mais n’ont pas été en mesure de bénéficier de la croissance économique autant que d’autres groupes au Vietnam. Le caractère moins inclusif de ces deux groupes dans la croissance économique demande une étude sur l'écart ethnique de bien être et des performances des entreprises familiales au point de vue des réseaux sociaux. Cette recherche étudie le rôle des réseaux sociaux en utilisant la méthode Q-square sur une base de données originale, les données quantitatives et qualitatives des relations sociales d'une entreprise familiale, et avec un instrument innovant: être le fils l'aîné. Le chapitre 1 mesure et analyse les déterminants principaux de l’écart ethnique pendant les dix ans derniers. Le chapitre 2 identifie les effects de cause entre les réseaux sociaux et la performance des entreprises familiales. Enfin, le chapitre 3 présente une étude qualitative de l'impact des réseaux sociaux sur les performances des entrepreneurs informels. Cette étude se centre sur une dimension particulière des réseaux qui est la force des liens. Elle distingue par ailleurs l’utilisation des réseaux à la création de l’entreprise et à un stade plus avancé de son développementOver the past two decades, the two vulnerable groups of ethnic minorities and household businesses have participated in the economic growth but could not benefit from the growth process as much as the other groups in Vietnam. The inadequate inclusiveness of these two groups in the economic growth calls for an investigation of the ethnic gap and household businesses' performance with a lens of social networks. This study aims to examine the role of social networks, using a Q-squared method to analyze an original dataset, which combined both the quantitative and qualitative datasets on social networks of household businesses. In doing so, the study employs an innovative instrument of being the first son in the family. Chapter 1 measures and analyses the main drivers of the ethnic gap over the last ten years. Chapter 2 identifies the causal effects of social networks on household businesses' performance. Chapter 3 presents a qualitative analysis of the impact of social networks on business performance by the content and the strength of social relationships, and the business phase
42
Flint, Abigail Louise. "Reindeer herding as a high-level buffering mechanism : the role of climate change in a multi-causal model of the emergence of reindeer herding among the Sami of northern Sweden." Thesis, University of Sheffield, 2011. http://etheses.whiterose.ac.uk/14548/.
Full textAbstract:
This thesis takes a critical examination of current theories of the emergence of reindeer herding, during the sixteenth and seventeenth century, amongst Sami communities in northern Sweden. This period coincides with the latter part of the Little Ice Age, a period of extremely variable climate in northern Europe, which has not been addressed in current theories of the emergence of herding. Using a bottom-up approach, gathering evidence of the nature of the environmental change and its impact on reindeer, human populations, and subsistence activities, it is suggested this had a profound effect on subsistence strategies. These impacts are considered in context to provide a multi-causal model of cultural change during this period. The evidence suggests that reindeer herding did not represent a radical and large-scale cultural change, and that Sami subsistence strategies do not fit neatly into categories of hunting or herding. The intensification of reliance on domestic reindeer emerged, from the preceding mixed economy, as a high-level buffering mechanism to cope with increased local environmental variability and a disruption In the wild reindeer popUlation, and was facilitated by interactions with the Swedish state through trade and taxation.
43
Medlow, Sharon Denise. "Mechanisms of mental causation: An examination of the theories of Anomalous Monism and Direct Realism with regard to their proposals concerning the causal role of human mentality in the natural world." University of Sydney. Psychology, 2004. http://hdl.handle.net/2123/678.
Full textAbstract:
One of the most interesting developments in recent psychological theorising has been a growing appreciation of the need for a viable theory of mental causation. Hitherto, the prospects for reconciling what seems to be the uniquely rational character of human thought and action with the non-rational mechanistic workings of the natural world have appeared to be limited or even illusory, and the pursuit of reconciliation of this sort has therefore formerly been dismissed as being either impossible of completion or inappropriate for contemplation. Much of the scepticism concerning the role of causal processes in human thought and action was dispelled, however, by the philosopher Donald Davidson, who argues that not only is human action capable of being caused by the actor�s thoughts and desires, but that only when such action is so caused, can it be rational. Davidson�s proposal for the reconciliation of human rationality with causal necessitation is articulated in his theory of Anomalous Monism. According to this theory, there exists what may be termed an ontological-conceptual distinction between events themselves and the characters or properties that are attributed to events by human observers, and it is through recognition of this distinction that one discovers how mental events, that is, events that are amenable to description in the psychological vocabulary, are causally efficacious yet free from the constraints typically associated with the necessity and sufficiency of causal laws. Anomalous Monism, if it were workable, would therefore resolve the paradox according to which human mentality is at once integrated in, and yet unconstrained by, the mechanistic natural world, by demonstrating the compatibility of the facts of causation with the intuitions of folk psychology. However, close examination of Anomalous Monism reveals it to rely on logically flawed anti-realist principles concerning the characters of events, properties and causation. It follows from this that the theory itself must be rejected, but the task that it was devised to undertake, the formulation of a viable theory of mental causation, need not be similarly discarded. Rather, what remains is the challenge of delineating an alternative theory, one that withstands logical scrutiny whilst addressing what is characteristic of human mental processes, and thereby what is characteristic of mental causation. The theory of Direct Realism that is derived from the broader philosophical realism of John Anderson provides the materials for meeting this challenge. According to Direct Realism, mental phenomena are relational situations obtaining between certain organisms (including humans) and their environments. As such, mental phenomena are included in the range of phenomena occurring in the natural world and they are therefore subject to all of its ways of working, including its deterministic mechanisms. The particular challenge that a Direct Realist theory of mental causation faces, that of demonstrating that relational situations can be causal, is revealed upon examination of the character of causation to be unproblematic. Furthermore, the seeming incompatibility between human rationality and natural necessitation is resolved when it is acknowledged that, rather than be an inherent feature of thought and action, logical structure is a characteristic of the natural environment that organisms are at times sensitive to, as revealed by its effects on the characters of their thoughts and actions. Far from being remote or illusory, the prospects for reconciling human mentality with the causal mechanisms of the natural world are discovered in the present thesis to be favourable when a realist approach to the characters of both mental events and causation is adopted.
44
Medlow, Sharon. "Mechanisms of mental causation an examination of the theories of Anomalous Monism and Direct Realism with regard to their proposals concerning the causal role of human mentality in the natural world /." Connect to full text, 2004. http://hdl.handle.net/2123/678.
Full textAbstract:
Thesis (Ph. D.)--University of Sydney, 2004.Title from title screen (viewed 14 May 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the School of Psychology, Faculty of Science. Includes bibliographical references. Also available in print form.
45
Van, Houten Lucas Jon. "Structuralist Qualia." Scholarship @ Claremont, 2014. http://scholarship.claremont.edu/cmc_theses/967.
Full textAbstract:
Structuralist theories of properties state that properties are individuated by their nomological or causal roles. It has previously been suggested that structuralism is incompatible with robust conceptions of qualia. In this paper, I argue that structuralism should be taken as a theory of de re representation, and under this formulation it is able to accommodate qualia as intrinsic, introspectable properties of experiences. I then turn to various thought experiments used by qualia theorists to expand the notion of qualia, and find the majority of these compatible with structuralism as well. I conclude that the structuralists and qualia theorists need not be at odds with each other.
46
Di, Bello Patrick Louis. "Understanding the Causal Agent of Rose rosette disease." Thesis, University of Arkansas, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1605371.
Full textAbstract:
A number viruses are known to infect roses, ranging from those in the genera Nepovirus, and Ilarvirus, which have been reported since the inception of rose virology, to recently discovered viruses in the genera Carmovirus, Closterovirus, Emaravirus, Luteovirus, Rosadnavirus, and Potyvirus. Of the viral diseases in rose, arguably the most damaging is Rose rosette (RRD), which is associated with the Emaravirus, Rose rosette virus (RRV). The objective of this thesis is to fill in the gaps in knowledge on the epidemiological aspects of RRD and RRV. There has been significant progress in the epidemiology of the RRD agent prior to the discovery of Rose rosette virus (RRV). The elusive agent was known to be graft transmissible, vectored by the eriophyid mite, Phyllocoptes fructiphilus in an uncharacterized manner, and associated with virus-like double membrane-bound bodies. RRV, the putative casual agent, was detected in all plants with RRD symptoms. However, this correlation does not prove causation of the disease. Given the complex symptomology observed the question of whether RRV causes RRD solely or as part of a virus complex, as is the case of numerous disorders of perennial plants, once thought to be caused by a single virus, was still unclear. Resistance is an important first line of defense when managing any disease, and here we identified potential sources resistance for producers, rosarians, and breeders. To date few viruses, believed to be transmitted by eriophyid viruses have been conclusively demonstrated to do so. The mode of transmission is elucidated for an even smaller subset of those viruses. In this study Koch’s postulates were fulfilled for RRV; additional RRV genome segments were discovered; Phyllocoptes fructiphillus was verified as a vector of RRV; resistant rose varieties were identified; and the acquisition and inoculation access periods (AAP and IAP respectively) for RRV were determined.
47
Kancharala, Ashok Kumar. "The role of flexibility on propulsive performance of flapping fins." Diss., Virginia Tech, 2015. http://hdl.handle.net/10919/56563.
Full textAbstract:
The versatility of the fish to adapt to diverse swimming requirements has attracted the attention of researchers in studying bioinspired propulsion for developing efficient underwater robotics. The tail/caudal fin is a major source of thrust generation and is believed that the fish modulates its fin stiffness to optimize the propulsive performance. Inspired by the stiffness modulation of fish fins, the objective of this research is to predict and evaluate the effect of flexibility on propulsive performance of flapping fins. The stiffness of the fins vary along their length and optimization studies have been performed to predict the stiffness profiles that maximize performance. Experiments performed on the real fish caudal fins to measure the stiffness variation along their length validate the theoretical optimal stiffness profiles and provide an insight about the evolution of fish fins for optimal performance. Along with the fin stiffness, the stiffness of the joint (caudal peduncle) connecting the fish body to the tail plays a major role in the generation of thrust. The numerical and experimental investigation has shown that there exists an optimal combination of fin and joint stiffness for each operating condition, thus providing the motivation for active stiffness control during locomotion to optimize efficiency.
Inspired by nature's ability to modulate stiffness and shape for different operating conditions, an investigation has been carried out on active control of flapping foils for thrust tailoring using Macro Fiber Composites (MFCs). It has been observed that the performance can be enhanced by controlling the deformation, and distributed actuation along fin produces maximum performance through proper selection of the phase difference between heaving and voltage. Flapping fins produce forces which are oscillatory in nature causing center of mass (COM) oscillations of the attached bodies posing problems of control and maneuverability. Optimization studies have revealed that flexibility of the fin plays a major role in reducing the COM oscillations along with the other operating parameters. Based on these studies, the design principles and guidelines that control the performance have been proposed which aid in the development of aerial and underwater robotic vehicles. Additionally, these studies provide some insight in to how fish might modulate its stiffness based on the requirements.Ph. D.
48
Arnold-Reed, Diane Elizabeth. "The caudal neurosecretory system and its role in fish osmoregulatory physiology." Thesis, University of Manchester, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.329615.
Full text
49
Aragón, Manresa Ferran. "The role of vHnf1 and Fgf Signaling in the caudal Hindbrain Patterning." Doctoral thesis, Universitat Pompeu Fabra, 2008. http://hdl.handle.net/10803/7147.
Full textAbstract:
Durant els primers estadis del desenvolupament embrionari dels metazous els teixits embrionaris son progressivament regionalitzats fins que adquireixen destins específics. En els vertebrats, el tub neural, que és el primordi del sistema nerviós central, es tempranament regionalitzat en el seu eix antero-posterior i queda dividit en les tres vesícules cerebrals i la medul·la espinal. La vesícula cerebral més posterior rep el nom de rombencèfal. En el rombencèfal un següent estadi de regionalització condueix cap a una organització en una serie de segments anomenats rombomers. Aquesta organització primària serveix de patró per les estructures que es van generant en el rombencèfal. A part d'unitats morfològiques els rombomers també son compartiments que observen restricció del llinatge cel·lular i expressen combinacions específiques de gens que els hi confereixen una identitat posicional. L'assoliment d'una identitat posicional per part de cadascun dels rombomers implica un procés jeràrquic i gradual en el qual intervenen tota una serie de factors de transcripció de tipus Hox i no Hox així com diferents molècules de senyalitzacióvHnf1 es un dels primers factors de transcripció expressats en el rombencèfal. En aquest projecte s'ha estudiat el paper de vHnf1 així com la implicació de la senyalització FGF en la regionalització del rombencèfal caudal del embrió de pollet. Els resultats mostren que vHnf1 s'expressa tempranament en el rombencèfal amb un límit rostral d'expressió coincident amb la frontera prospectiva entre els rombomers 4 i 5. Experiments de sobrexpressió mostren que vHnf1 es capaç de conferir caràcter caudal a rombomers rostrals tot induint Krox20 in MafB i reprimint Hoxb1 a r4. Les induccions de Krox20 i MafB resultaren ésser dependents de la senyalització per FGFs. Sorprenentment, els nostres resultats també mostren que vHnf1 indueix fortament la expressió de Fgf3. És més, anàlisis per RT-PCRs semiquantitatives demostraren que aquesta inducció es molt ràpida suggerint que Fgf3 és directament regulat per vHnf1. En aquest projecte també es presenta l'anàlisi dels perfils d'expressió d'alguns gens del grup de "sinexpressió" dels FGFs en el rombencéfal caudal. Finalment es determina que la senyalització FGF funciona a través de la via intracel·lular Ras-MAPK en el procés de regionalització del rombencéfal caudal sense implicació de la via PI3K-Akt.
Aquests resultats ofereixen nova informació sobre els mecanismes moleculars implicats en la regionalització del rombencèfal caudal en vertebrats. De manera interessant aquests resultats posen de manifest certes diferencies en els mecanismes de regulació que operen en la regionalització del rombencéfal de diferents especies.
During early embryonic development of chordates, the hindbrain, which is the caudalmost brain vesicle, is transiently organized along the AP axis in a series of segments called rhombomeres (r). This segmental organization serves as scaffold for several structures that develop within the hindbrain in repeated patterns. Each rhombomere has a molecular identity given by a specific combination of gene expression. Rhombomeric identity is the result of a progressively refined patterning that involves the interplay of different cell signaling pathways and rhombomere-specific transcription factors.
In the present project the role of vHnf1, one of the earliest transcription factors expressed in the hindbrain, and its interplay with FGF signaling has been analyzed during the chick embryo development. The results show that vHnf1 is very early expressed in the chick neuroepithelium with a sharp boundary of expression coinciding with the presumptive r4/r5 interrhombomeric boundary. Gain-of-function experiments demonstrated that vHnf1 is able to confer partial caudal character to rostral rhombomeres through the mediation of FGF signaling. We also analyzed the expression of genes of the FGF synexpression group in the caudal hindbrain. Finally, we determined that the role of FGF signaling in regulating the caudal rhombomeric markers Krox20 and MafB is mediated through the Ras-ERK1/2 intracellular pathway.
The results of this project provide new information about the molecular mechanisms involved in patterning the vertebrate caudal hindbrain. Interestingly, while requirement of vHnf1 and FGF signaling for caudal hindbrain patterning is an evolutionary conserved feature, the ways by which FGF signals are regulated during this process differ across species.
50
Petrof, Iraklis. "Behavioural analysis of the role of caudal thalamic reticular nucleus in attention /." St Andrews, 2007. http://hdl.handle.net/10023/373.
Full text