Inferring CRCs progression dynamic with HyperTraPS

Masteroppgave i statistikkSTAT399MAMN-STA

Social cognitive and neural mechanisms of food choice under the influence of food-related information

Food is the fuel of life. As such food stimuli are intensively processed by the human brain and the consequences of these processes, resulting in our food choice, have an essential impact on our life. Research suggested that food choice is largely guided by predominantly learned preference, and is likely to be influenced by information regarding the food (e.g., nutritional value) as well as by learned beliefs and associations (e.g., between a given food and its health value). This project aims at understanding at both behavioral and neural levels how these non-physiological factors might influence the food/drink choice and how they can be modified to improve our choice. Chapter 1 includes the literature review on 1) how semantic information influences implicit/explicit associations toward food/drink, 2) the predictive validity implicit/explicit associations on food/drink choice, 3) the behavioral and neural evidence of changing associations, choices, and impulsivity control toward food/drink by implementing a conditioning paradigm (e.g. evaluative conditioning). The motivation and the objectives of my Ph.D. project are also presented here. Chapter 2 contains Study 1 (Experiment 1 and 2). The first aim of the thesis is to understand how the association between a certain food and different concepts may guide our choices. This is addressed in Experiment 1 where I investigated how our choices can be predicted by preference and/or implicit associations between different constructs of interest (e.g., social status) and coffee and/or tea. People\u2019s self-report preference, implicit and explicit associations between different social constructs and tea/coffee were measured. Results based on 22 Italian healthy adults indicate that they possess strong implicit associations between tea and low social status, and this association significantly predicted choice of tea. The second aim of the thesis is to investigate whether the associations between food/drink and certain constructs can be changed through a classical learning paradigm, evaluative conditioning (EC), in which the associations between target drinks/food and food-related information was manipulated. This approach allowed us to investigate a possible strategy of intervention that could improve drink/food choices. This is addressed in Experiment 2 whereby a within-subject design is employed with participants going through both EC-condition and control condition. Results based on 68 healthy adults show that the implicit associations between tea and high-social-status, as well as the preference towards tea, significantly increase after EC. Most importantly, the difference in implicit associations across conditions significantly predict the difference in choices of tea between conditions, indicating that changes in implicit associations determine changes in choice. Chapter 3 is dedicated to the third aim which is to identify the neural mechanisms underlying the changes in association after EC between foods and the concepts of healthiness and sustainability. To this end changes in neural markers were related to changes in food choice as well as personal eating habits and individual difference in restraint eating and impulsive behavior. In Study 2, I experimentally strengthened the association between the concept of unhealthiness/unsustainability and heavily-processed food, and between healthiness/sustainability and minimally-processed food. A semantic congruency task combined with the Electroencephalography (EEG) technique was used to investigate changes in neural activity of the N400 in incongruent trials. Results on 18 healthy adults derived by comparing neural signatures of incongruent trials between conditions demonstrated that the magnitude of the N400 in left dorsal lateral prefrontal cortex (DLPFC) for minimally-processed high-calorie food significantly increased after EC. Thus, EC can be considered as an effective method to strengthen the semantic association between foods and a given concept, indexed by the change of neural signature tracking the semantic conflict. This increased magnitude also positively correlated with the Barratt Impulsiveness Scale score, indicating that the more impulsive a person is, the greater the change in magnitude of the N400. Chapter 4 is devoted to address the fourth aim of the thesis that is to understand whether control of impulsivity over unhealthy food choice can be improved through the evaluative priming (EP) that is a variation of EC used in Study 2. Thus in Study 3, 15 healthy adults went through a pre-EP and a post-EP test including a Go/NoGo task combined with EEG. During EP, an increased subjective liking was found for Minimally-Processed Low-Calorie food images in evaluative block. For GNG tasks, at neural level, the averaged amplitude at left DLPFC for food images with evaluative priming was more negative in post-EP than in pre-EP GNG task. More negative N200 amplitudes were consistently found at left DLPFC in post-EP GNG task for Heavily-Processed Low-Calorie food as well as for Minimally-Processed Low-Calorie food. The behavioral and neural evidence showed the improvement of self-control towards food stimuli through evaluative priming. The possible role of left dorsal lateral prefrontal region in online value modulation and in integrating the stimulus feature with related information was identified, suggesting the self-control process based on deliberated thinking with symbolic representations and information operations. In Chapter 5 I summarized and discussed the main findings of my thesis. In short, my project provides the basic roadmap for understanding how food/drink related information affects cognitive and neural underpinnings of food/drink choices. Indeed, choices can be improved through modifying associations between food/drink and related information and thus healthy diets are encouraged. These results provide a potentially interesting research avenue well as possible interventions to modify and improve food/drink choices that could possibly be applied to individuals with eating disorders

Genetic Similarity of Colchicine-induced Grass-type Mutants in Sorghum

The induction of true-breeding diploid mutants in certain varieties of Sorghum Vulgare Pers. by application of 0.5 per cent colchicine in lanolin to the coleoptile of the seedlings has been previously reported. Both cytological and genetical evidences obtained by various investigators have indicated the occurrence of gene mutations previous to or concurrent with the reduction division. The repeated occurrence of mutants with identical phenotypes involving whole complexes of characters raises the problem of whether identical major chromatin rearrangements or identical mutagenic effects are responsible. This study was designed to determine whether the phenotypically similar mutants are also genotypically similar. Genetical and cytological observations were made on three phenotypically similar grass mutants which arose from the sorghum variety Experimental 3 after colchicine treatment in different years. For this study, three phenotypically similar grass-type mutants derived from one variety after colchicine treatments by C. J. Franzke in 1948 and 1955, and by M. E. Sanders and C. J. Franzke in 1957, respectively, and the original variety, Experimental 3, were involved in this study. The modes of inheritance of cour different contrasting characters, namely, red vs. green seedling base, dry vs. juicy midrib, purple vs. non-purple spotting on leaf blade, and awnless vs. awned, were analyzed from the results obtained from five categories of crosses

Assessment of Professional Competence in a Construction Management Problem-based Learning Setting

This paper discusses the congruence between problem-based learning (PBL) and competencybased assessment and describes how competency based assessment has been implementedin a professional construction management programme. The design andunderlying principles of assessment approaches used to determine students' professionalcompetence through use of professional standards to frame learning and assessment arediscussed. Through presentation of preliminary findings of a case study that explores staffand student experiences in the construction management programme, the authors describethe issues and challenges they have encountered in implementing competencybased assessment in a PBL programme within the context of higher education

The Effects of Product Knowledge and Internet Experience on Online Shopping Behavior

Thanks to tremendous growth of e-commerce and the advancement of Internet infrastructure, the online shopping medium has become a staple in many world economies. The present study examines how the consumer’s product knowledge and Internet experience affect the level of uncertainty and perceived risk. Potential dimensions of product knowledge and Internet experience are developed and examined. Their effects on uncertainty and risk perception are proposed. An add-on model linking product knowledge, Internet experience, uncertainty, risk, trust, and purchase intention is developed. The add-on model is incorporated into an existing model of online shopping process (NetShop). The revised overall model suggests how online shopping intention can be affected by the level of product knowledge and Internet experience, via their effects on uncertainty and perceived risk, as well as the three original factors, interactivity, transaction, and fulfillment

Improving HIV Detection at Malawian Sexually Transmitted Infections Clinics

HIV diagnosis is the essential first step for persons living with HIV (PLWH) to access HIV care, which can improve health outcomes and prevent onward transmission. Synergy between HIV and other sexually transmitted infections (STI) makes STI clinics effective settings to reach PLWH and to find persons unaware of their HIV infection. We assessed the efficacy of an intervention incorporating acute HIV infection (AHI) screening, contract partner notification, and social contact referral on HIV detection among the sociosexual networks of PLWH seeking STI care in Lilongwe, Malawi.We conducted a randomized controlled trial to evaluate the combination intervention relative to the Malawian standard of care of rapid serological HIV tests and passive partner notification. Enrollment occurred in two STI clinics between 2015 and 2019. We also standardized the intervention and standard-of-care outcomes to six months of patient visits at Bwaila District Hospital’s STI Clinic to assess potential real-world clinical impacts. We used the SEDIA LAg avidity assay to assess the stage of HIV infection among participants.During study enrollment, 1230 HIV-seropositive persons received control arm procedures and 655 received intervention arm procedures, including 94 persons with AHI. The intervention was efficacious in increasing the total number of new HIV diagnoses made per index participant (ratio: 1.9 (95% confidence interval (CI): 1.2, 3.1)) versus the standard of care. When we standardized the trial outcomes to 4730 patient visits at Bwaila STI Clinic, we found estimated that the intervention would yield 6.7 times the number of new HIV diagnoses relative to the standard of care, including index participants diagnosed with AHI. Among STI patients seeking care, we found that only 6% of patients newly diagnosed with HIV had a recent HIV infection, with a mean duration of infection of 130 days.The combination intervention was efficacious in increasing HIV detection among the sociosexual networks of PLWH seeking STI care. Furthermore, when the acute HIV diagnoses among index participants were considered, the intervention greatly improved HIV detection beyond the standard of care. Integrating novel referral and HIV testing strategies can improve HIV detection, which is the first step to ending the HIV epidemic.Doctor of Philosoph