Prescription opioid (PO) abuse is a growing public health concern worldwide as evidenced by an increasing number of opioid-related hospital admissions with a striking lack of research examining the neural basis underlying cognitive symptomatology. Drugs of abuse, through their impact on the dopaminergic system, are thought to disrupt the cognitive network regulating impulse control and incentive salience through inhibition of goal-oriented behaviour and drug-induced attentional biases. The objective of the present study is to examine neurocognitive processes in PO abusers (vs. healthy controls) by relying on the enhanced temporal resolution (1ms) of event-related potentials (ERPs) to track information processing abnormalities associated with cognitive control. In a naturalistic clinical study, 16 patients actively using prescription opioids and 16 healthy controls (matched for age, gender, educational level and smoking status) were assessed using a Go/NoGo and cue reactivity paradigm. Analysis revealed no significant differences in N2 or P3 amplitude, measures of inhibitory control, between groups after successful NoGo trials and no significant differences in ERN or Pe amplitude, measures of error processing, between groups after unsuccessful NoGo trials. Cue reactivity analysis of attention-related ERP components in patients demonstrated significantly (p<0.005) smaller P2 amplitudes, indexing the commencement of attentional processing, for drug pictures compared to neutral and affective pictures. Furthermore, stimulus type did not significantly modulate LPP amplitudes, indexing sustained attention, in patients however arousal ratings for drug pictures were positively correlated with LPP amplitudes in patients. These ERP results of altered cognitive control and incentive salience suggest the neural mechanisms underlying these cognitions are affected by chronic opioid abuse. Investigating the cognitive abnormalities experienced by PO abusers is an important factor in understanding the neural correlates of substance abuse and in predicting successful outcomes to ensure the best chance at long-term recovery for addicted individuals.

Ma thèse porte sur une dimension fondamentale de la structure des groupes sociaux : la hiérarchie. Chez l'être humain, les hiérarchies sociales régissent en profondeur les interactions. Pour naviguer avec succès dans son environnement, il doit être en mesure de repérer précisément les positions hiérarchiques des autres membres de son groupe. Ce travail de thèse vise à caractériser certains mécanismes neuronaux, comportementaux et physiologiques impliqués dans l'analyse d'un indice hiérarchique. Pour préciser la nature du traitement de la hiérarchie, j'ai exploré son influence sur différentes étapes de la perception des visages. Je me suis tout d'abord intéressée au décours temporel du traitement neuronal des visages dans un contexte hiérarchique. Deux études menées en électroencéphalographie m'ont permis d'identifier les potentiels neuronaux et les composants oscillatoires évoqués par la perception de visages associés soit, à un rang hiérarchique établi à l'issue d'une compétition, soit à un statut social induit par la profession. Une étude réalisée ensuite en oculométrie avait pour but de capturer l'influence de la hiérarchie sur des mécanismes fins du contrôle de l'attention visuelle. J'ai étudié à la fois l'exploration visuelle de classements hiérarchiques incluant le participant, et celle de visages associés à des rangs hiérarchiques différents. Enfin, j'ai tenté de déterminer si un signal ou une situation d'asymétrie hiérarchique véhicule une valence émotionnelle et motivationnelle non neutre susceptible d'induire des variations de certains paramètres physiologiques, comme le rythme cardiaque ou la réponse électrodermale / Hierarchy is a key organizational feature of social groups. In order to successfully navigate their social environment, humans must precisely read the hierarchical position of other during social interaction. This present thesis intends to characterize the neural correlates as well as the early physiological and behavioral mechanisms involved in the processing of social rank. The influence of hierarchy was mainly investigated in the context of face perception. To begin, my focus was on the time course of neuronal processing of faces embedded in a hierarchical context. Using eletroencephalography in two studies, it has been possible to identify evoked neuronal potentials and oscillatory components in response to faces varying in hierarchical rank, established through competition or social status induced by profession. The next study used eye-tracking methodology to explore the influence of hierarchy on the subtle mechanisms of visual attention control. I aimed at characterizing the visual scanning pattern of hierarchical rankings (during a competition) and of faces associated with different hierarchical ranks. Finally, I tried to determine if a hierarchical signal or a social asymmetrical situation conveyed an emotional/motivational valence. During face perception and a minimal social interaction, I examined if this particular dimension of hierarchy generated variations of physiological activity, such as heart rate and skin conductance response

La combustion prévaporisée prémélangée pauvre est une piste de choix pour réduire les émissions polluantes des moteurs d'avions mais peut conduire à l'apparition d'instabilités thermo-acoustiques. Afin d'améliorer la stabilité de telles flammes, l'étagement du combustible consiste à contrôler la distribution spatiale du carburant. Une telle procédure s'accompagne cependant d'une complexité accrue du système pouvant déboucher sur des phénomènes inattendus.Un brûleur à l'échelle de laboratoire alimenté par du dodécane liquide est utilisé dans cette thèse. Le combustible est injecté dans deux étages séparés, permettant ainsi de contrôler sa distribution. Cette particularité permet l'observation de différentes formes de flammes et notamment de points bistables pour lesquels deux flammes différentes peuvent exister malgré des conditions opératoires identiques.L'utilisation de diagnostics optiques à haute cadence (diffusion de Mie des gouttes de combustible et émission spontanée de la flamme) est couplée à des méthodes de post-traitement avancées comme la Décomposition en Modes Dynamiques. Ainsi, des mécanismes pilotant la stabilisation des flammes ainsi que leurs changements de forme sont proposés. Ils mettent notamment en lumière les interactions entre l'écoulement gazeux, les gouttes de combustible et la flamme. / A promising way to reduce jet engines pollutant emissions is the use of lean premixed prevaporized combustion but it tends to trigger thermo-acoustic instabilities. To improve the stability of these flames, a procedure called staging consists in splitting the fuel injection to control its spatial distribution. This however leads to an increased complexity and unexpected phenomena can occur.In the present work, a model gas turbine combustor fed with liquid dodecane is used. It is equipped with two fuel injection stages to control the fuel distribution in the burner. Different flame stabilizations can be observed and a bistable case where two flame shapes can exist for the same operating conditions is highlighted.High-speed optical diagnostics (fuel droplets Mie scatering and chemiluminescence measurements) are coupled with advanced post-processing methods like Dynamic Mode Decomposition. The results enable to propose mechanisms leading to flame stabilization and flame shape transitions. They show a strong interplay between the gaseous flow, the fuel droplets and the flame itself.

<p>Bacterial outer membrane vesicles (OMVs) are spherical buds of the outer membrane (OM) containing periplasmic lumenal components. OMVs have been demonstrated to play a critical part in the transmission of virulence factors, immunologically active compounds, and bacterial survival, however vesiculation also appears to be a ubiquitous physiological process for Gram-negative bacteria. Despite their characterized biological roles, especially for pathogens, very little is known about their importance for the originating organism as well as regulation and mechanism of production. Only when we have established their biogenesis can we fully uncover their roles in pathogenesis and bacterial physiology. The overall goal of this research was to characterize bacterial mutants which display altered vesiculation phenotypes using genetic and biochemical techniques, and thereby begin to elucidate the mechanism of vesicle production and regulation. One part of this work elucidated a synthetic genetic growth defect for a strain with reduced OMV production (&#916;nlpA, inner membrane lipoprotein with a minor role in methionine transport) and envelope stress (&#916;degP, dual function periplasmic chaperone/ protease responsible for managing proteinaceous waste). This research showed that the growth defect of &#916;nlpA&#916;degP correlated with reduced OMV production with respect to the hyprevesiculator &#916;degP and the accumulation of protein in the periplasm and DegP substrates in the lumen of OMVs. We further demonstrated that OMVs do not solely act as a stress response pathway to rid the periplasm of otherwise damaging misfolded protein but also of accumulated peptidoglycan (PG) fragments and lipopolysaccharide (LPS), elucidating OMVs as a general stress response pathway critical for bacterial well-being. The second part of this work, focused on the role of PG structure, turnover and covalent crosslinks to the OM in vesiculation. We established a direct link between PG degradation and vesiculation: Mutations in the OM lipoprotein nlpI had been previously established as a very strong hypervesiculation phenotype. In the literature NlpI had been associated with another OM lipoprotein, Spr that was recently identified as a PG hydrolase. The data presented here suggest that NlpI acts as a negative regulator of Spr and that the &#916;nlpI hypervesiculation phenotype is a result of rampantly degraded PG by Spr. Additionally, we found that changes in PG structure and turnover correlate with altered vesiculation levels, as well as non-canonical D-amino acids, which are secreted by numerous bacteria on the onset of stationary phase, being a natural factor to increase OMV production. Furthermore, we discovered an inverse relationship between the concentration of Lpp-mediated, covalent crosslinks and the level of OMV production under conditions of modulated PG metabolism and structure. In contrast, situations that lead to periplasmic accumulation (protein, PG fragments, and LPS) and consequent hypervesiculation the overall OM-PG crosslink concentration appears to be unchanged. Form this work, we conclude that multiple pathways lead to OMV production: Lpp concentration-dependent and bulk driven, Lpp concentration-independent.</p> / Dissertation

The construction industry is facing challenges when it comes to increased costs, defective timetables and inadequate material handling. The purpose of the study is to highlight and propose possible improvements to the process of using plasterboards in the construction industry. The aim of the survey is to investigate how the use of plasterboards can be made more efficient through better collaboration between stakeholders in the construction industry and to identify shortcomings in the current construction process. Interviews were used to produce improvements and shortcomings. The result showed that there is a lack of communication between actors and when handling plasterboards. Other shortcomings in the industry are documentation of changes made during production and cooperation between actors. / Byggbranschen står inför utmaningar när det kommer till ökade kostnader, bristande tidsplaner och bristfällig materialhantering.Syftet med studien är att belysa och föreslå möjliga förbättringar av processen kring gipsanvändning i byggbranschen. Målet med undersökningen är att undersöka hur användningen av gipsskivor kan effektiviseras genom ett bättre samarbete mellan aktörer i byggbranschen samt att identifiera brister i nuvarande byggprocess. Intervjuer användes för att få fram brister och förbättringsmöjligheter.Intervjuerna visade att det finns brister i kommunikationen mellan aktörer samt vid hantering av gipsskivor. Andra brister i branschen är dokumentation av ändringar gjorda under produktionen och samarbete mellan aktörer.

Previous studies support that the relative width of the upper face (facial width-to-height ratio; fWHR) has evolved to signal threat, but these studies rely greatly on subjective facial ratings and measurements prone to confounds. The present study objectively quantifies threat perception to the magnitude of the observers’ electrophysiological reaction, specifically the event-related potential (ERP) called the late positive potential (LPP), and investigate if brow height and jaw width could have confounded previous fWHR studies. Swedish and international students (N = 30, females = 11, Mage = 24 years, SDage = 2.9) were shown computer-generated neutral faces created with the underlying skeletal morphology varying in brow ridge height, cheekbone width and jaw width. Participants first rated how threatening each face was and then viewed 12 blocks of 64 faces while their electroencephalography (EEG) was recorded. The results supported that the LPP could be used to index threat perception and showed that only brow height significantly affected both facial ratings (p &lt; .001, ɳp2 = .698) and magnitude of the LPP within the 400 to 800 ms latency (p = .02, d = .542). Hence, brow height, not facial width, could explain previous findings. The results contradict the hypothesis that fWHR is an evolved cue of threat and instead support the overgeneralisation hypothesis in that faces with similar features to anger will be perceived as more threatening.

Distraction and cognitive reappraisal are two widely used types of emotional regulation strategies that are thought to be reliable when down-regulating our emotions to negative or unpleasant stimuli. Gross‘s process model of emotion generation (Gross, 1998) holds that they differ in the time they intervene in the emotiongenerative process and also how they impact emotional responses when they are used to regulate negative emotions. Distraction which involves attentional deployment is expected to operate earlier than reappraisal that entails meaning evaluation and reevaluation. Cognitive reappraisal encompasses various strategies that are used to regulate our emotions through reinterpretation. Self-focused and situation-focused reappraisal are two of them. The former is considered more efficient and thus would lead to a greater attenuation of the LPPthan the latter. To test this prediction, electrocortical responses to angry faces when using these strategies were measured using the late positive potential (LPP). Twenty four healthy participants were recruited for the study and were cued to down-regulate their emotions using these strategies while angry and neutral facial stimuli were seen on a computer screen. Contrary to prediction, distraction did not modulate the LPP earlier than reappraisal. However, supporting our hypothesis self-focused strategies largely modulated the LPP than situation-focused strategy. The pattern of result suggests that reappraisal might have an influence on the early neural processes of emotion generation and that the subcategories of cognitive reappraisal have a differential effect on emotional regulation.

Syfte och frågeställningar Syftet med denna studie är att undersöka några idrottslärares tolkning av den nationella kursplanen för idrott och hälsa och hur denna tar sig i uttryck genom LPP. Studien utgår från nedanstående frågeställningar 1. Vad innehåller en LPP? 2. Hur skiljer sig LPP från den nationella kursplanen? Metod I studien har vi utgått från en kvalitativ textanalys ifrån tio olika LPP, med hjälp av Googles-sökmotor har vi sökt på ”pedagogisk planering åk 7-9 idrott och hälsa” för att få tillgång till det material som skall analyseras. Studien utgick ifrån de tio första LPP som dök upp i resultatet från sökningen. Resultat Genom analys av LPP har det visat sig att idrottsläraren har olika stora möjligheter att fritt formulera en egen LPP som inte alls behöver vara identisk med den nationella kursplanen. En tolkning vid arbetet med LPP, är att se det som ett uttryck eller försök till att förändra skolans styrning av ämnet. Överlag tolkas det som att lärare runt om i Sverige har använt sig av LPP för att förenkla och förtydliga ämnets mål. Genom att ha skrivit en LPP fick lärarna en annan typ av ansvar då de inte bara följde kursplanen utan även tolkade den på ett eget sätt. En LPP kunde vara nästan ”identisk” som den nationella kursplanen, men även ha fria tolkningar av kursplanen. Detta berodde på hur långt utanför ramarna läraren valde att gå. Slutsats Utifrån resultatet av studien kan det sammanfattas att det varierar väldigt mycket hur skolornas LPP ser ut. Generellt sett är det svårt att få fram ett tydligt svar för hur det ser ut i hela landet. Detta beror på att den insamlade data från nätet var väldigt begränsad och i liten omfattning. Det kan tolkas att Skolverket inte uppmanar lärarna att skriva LPP då det inte förekommer på deras hemsida överhuvudtaget.

BACKGROUND: Food-related visual cues may affect eating behavior and energy intake. The purpose of this study was to determine the neural response to pictures of food and whether or not the neural responses were associated with energy intake. METHODS: Using a cross-sectional design, 60 adults participated in this study. Each participant reported to the laboratory in a fasted state, were fitted with a 128-electrode electroencephalogram (EEG) net, and were shown pictures grouped into three categories: high-calorie foods, low-calorie foods, and distractor pictures. These pictures were shown in random order. Furthermore, participants were shown these pictures in one passive condition and two active conditions (also in random order). The passive condition required participants to view pictures in a relaxed state while neural responses were recorded. The active conditions required participants to be actively engaged with the picture by pressing or withholding a specified button on a keyboard (go/no go task). The active conditions included only high- and low-calorie foods. Event Related Potentials (ERP) of interest were the N2, P300, and late positive potential (LPP). The National Cancer Institute's Automated Self-administered 24-hour Dietary Recall (ASA24) was used to assess energy and macronutrient intake. RESULTS: The N2 amplitude, when amplitude for high-calorie pictures is subtracted from the amplitude of low-calorie pictures, was significantly different for each active condition (F = 41.23; p < 0.0001). However, neural responses to picture-type for the N2, P300 and LPP were not different (p > 0.05). The difference in N2 amplitude, for the high-calorie no go condition that results from the amplitude for low and high-calorie pictures being subtracted from each other, was significantly associated with carbohydrate intake (r = -0.263) and significantly predicted carbohydrate intake (regression coefficient = -56.821; p = 0.043) but not energy, fat, or protein intake (p > 0.05). Neither the P300 nor the LPP was correlated with or predicted energy and macronutrient intake (p > 0.05). CONCLUSION: The N2 differentiates depending on the no go stimulus. The difference in N2 amplitude, for the high-calorie no go condition, may be an index of carbohydrate intake. The P300 and LPP do not appear to differentiate between pictures of high- and low-calorie foods, nor do they correlate with energy or macronutrient intake.

In order to follow increasingly strict regulation of pollutant emissions, a new concept of Lean Premixed pre-vaporized (LPP) combustion has been proposed for turbines. In LPP combustion, controlled atomization, dispersion and vaporization of different types of liquid fuel in the premixer are the key factors required to stabilize the combustion process and improve the efficiency. A numerical study is conducted for the fundamental understanding of the liquid fuel dispersion and vaporization process in pre-mixers using both cross-flow and co-flow injection methods. First, the vaporization model is validated by comparing the numerical data to existing experiments of single droplet vaporization under both low and high convective air temperatures. Next, the dispersion and vaporization process for biofuels and conventional fuels injected transversely into a typical simplified version of rectangular pre-mixer are simulated and results are analyzed with respect to vaporization performance, degree of mixedness and homogeneity. Finally, collision model has been incorporated to predict more realistic vaporization performance. Four fuels, Ethanol, Rapeseed Methyl Esters (RME), gasoline and jet-A have been investigated. For mono-disperse spray with no collision model, the droplet diameter reduction and surface temperature rise were found to be strongly dependent on the fuel properties. The diameter histogram near the pre-mixer exit showed a wide droplet diameter distribution for all the fuels. In general, pre-heating of the fuels before injection improved the vaporization performance. An improvement in the drag model with Stefan flow correction showed that a low speed injection and high cone angle improved performance. All fuels achieved complete vaporization under a iv spray cone angle of 140°. In general, it was found that cross-flow injection achieved better vaporization performance than co-flow injection. A correlation is derived for jet-A‟s total vaporization performance as a function of non-dimensional inlet air temperature and fuel/air momentum flux ratio. This is achieved by curve-fitting the simulated results for a broad range of inlet air temperatures and fuel/air momentum flux ratios. The collision model, based on no-time-counter method (NTC) proposed by Schmidt and Rutland, was implemented to replace O‟Rourke‟s collision algorithm to improve the results such that the unphysical numerical artifact in a Cartesian grid was removed and the results were found to be grid-independent. The dispersion and vaporization processes for liquid fuel sprays were simulated in a cylindrical pre-mixer using co-flow injection method. Results for jet-A and Rapeseed Methyl Esters (RME) showed acceptable grid independence. At relatively low spray cone angle and injection velocity, it was found that the collision effect on the average droplet size and the vaporization performance were very high due to relatively high coalescence rate induced by droplet collisions. It was also found that the vaporization performance and the level of homogeneity of fuel-air mixture could be significantly improved when the dispersion level is high, which can be achieved by increasing the spray cone angle and injection velocity. In order to compare the performance between co-flow and cross-flow injection methods, the fuels were injected at an angle of 40° with respect to the stream wise direction to avoid impacting on the wall. The cross-flow injection achieved similar vaporization performance as co-flow because a higher coalescence rate induced by droplet collisions cancelled off its higher heat transfer efficiency between two phases for cross-flow injections.