Teses / dissertações: "Pain network"

1

Rissacher, Daniel J. "Neural network recognition of pain state in EEG recordings". Thesis, Georgia Institute of Technology, 2002. http://hdl.handle.net/1853/16646.

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Boshoff, Susan. "Absenteeism and musculoskeletal pain : an interactive network of variables". Master's thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/3367.

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3

Awang, Mahmud Awang Bulgiba. "Application of statistical and neural network techniques to chest pain diagnosis". Thesis, University of East Anglia, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.430583.

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4

Samineni, Vijaya K. "The role of the periaqueductal gray in modulation of acute and chronic pain: Actions of drugs with analgesic properties on periaqueductal gray neuronal network". OpenSIUC, 2013. https://opensiuc.lib.siu.edu/dissertations/701.

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Considerable evidence suggests the involvement of the ventrolateral periaqueductal gray (PAG) in both inhibitory and facilitatory actions within modulatory pathways for pain, The PAG is a critical nucleus in these pain networks and receives and sends extensive projections within these networks. Chronic pain is a major side effect in 30-70% of cancer patients receiving chemotherapeutic regimen. Endocannabinoids, such as anandamide (AEA), are lipid neuromodulators in the CNS that affect nociception. AEA is known to activate cannabinoid (CB1) as well as transient receptor potential vanilloid 1 (TRPV1) receptors, which are involved in nociception. Previous studies have shown that PAG is a crucial site for EC- mediated analgesia. Hypothesis one of my project is blockade of AEA uptake in the PAG will induce analgesic effects, which are mediated by CB1 and/or TRPV1 receptors. My results indicate that focal bilateral microinjection of AM404, an AEA uptake inhibitor, into the PAG induced analgesia to noxious thermal stimuli (radiant heat) both in normal and paclitaxel-treated (2 mg/kg i.p. for 4 alternate days). This analgesia was mainly mediated by both CB1 and TRPV1 receptors in the PAG in normal and by CB1 receptors in paxlitaxel-treated rats. Several studies have demonstrated that post-ictal analgesia is observed following drug-induced generalized seizures in rats. My second hypothesis is that post-ictal analgesia will occur after audiogenic seizure (AGS) induction, in genetically epilepsy prone rats (GEPR-9s), and blockade of CB1 receptors in the PAG will inhibit the analgesic effects that occur during the post-ictal period. My results indicate that induction of AGS resulted in post-ictal analgesia in GEPR-9s to noxious thermal stimuli, which was blocked upon microinjection of a CB1 receptor antagonist into the PAG suggesting a crucial role of PAG in post-ictal analgesia in GEPR-9s. Hypothesis three of my project is that, neuroplastic changes will occur in the PAG, leading to increases in neuronal firing during neuropathic pain, which will be altered by analgesic drugs. To evaluate this hypothesis, I studied the firing pattern of PAG neurons in awake behaving rats to noxious thermal stimuli. This involved evaluation of extracellular single unit activity using 8 channel microwire electrodes chronically-implanted in the PAG of unrestrained awake rats and examining responses to noxious thermal stimulation (Peltier device). The results indicate the presence of the three types of neuronal populations in the PAG that exhibit either "excitatory" or "Inhibitory" responses or were "non-responsive", to noxious thermal stimulus administered to the paw. Subsequently, I also investigated effects of pentobarbital on spontaneous and thermal stimulus evoked PAG neuronal firing, as has often been done in previous pain studies. Administration of low doses of pentobarbital significantly decreased PAG spontaneous firing and evoked excitatory and inhibitory PAG neuronal responses. These results suggest that the use of barbiturates to study PAG neuronal responses might have resulted in significant un-intended modifications of the fundamental properties of PAG neuron, as compared to the unanesthetized state. The PAG is important part of pain modulatory network, but the electrophysiological characteristics of PAG neurons in chronic neuropathic pain conditions are still unclear. This issue was addressed by administering a standard chronic pain protocol, using the cancer chemotherapeutic drug, paclitaxel, (2 mg/kg i.p. for 4 alternate days) which induced chronic neuropathic pain, Ten days after treatment, mean spontaneous firing rates of PAG neurons were increased significantly after paclitaxel treatment compared to the pre-paclitaxel treatment levels. PAG neurons in the neuropathic state exhibited significantly increased excitatory neuronal responses to non-noxious stimulus, similar to noxious thermal stimulation and significantly increased excitatory-like neuronal responses as compared to pre-treatment levels. Gabapentin is an anticonvulsant that acts on N type voltage sensitive calcium channels and possesses analgesic properties in chronic pain syndromes. Gabapentin did not significantly affect PAG neuronal responses to acute pain in my initial studies However, gabapentin did produce significant changes in spontaneous and thermal stimuli evoked PAG neuronal firing in paclitaxel-treated rats. Gabapentin induced significant dose-dependent decreases in the elevated spontaneous and evoked PAG neuronal firing to both non-noxious and noxious thermal stimuli in the paclitaxel model of neuropathic pain. I also investigated effects of AM404 on spontaneous and thermal stimuli evoked PAG neuronal firing in paclitaxel-treated rats, I observed that AM404 dose-dependently inhibited elevated spontaneous and evoked PAG neuronal firing in paclitaxel-treated rats. These effects were blocked by pre-treatment with CB1 receptor antagonist (AM251) suggesting a crucial role of CB1 receptor in AM404 mediated analgesic effects. These findings suggest that paclitaxel treatment could lead to plasticity in the PAG that might contribute to generation and maintenance of neuropathic pain. These findings provide the evidence that targeting endogenous cannabinoid system or inhibiting presynaptic calcium channels may be effective in treating neuropathic pain, in part, by actions on the PAG.

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Rogoz, Katarzyna. "Signaling Mechanisms in the Neuronal Networks of Pain and Itch". Doctoral thesis, Uppsala universitet, Genetisk utvecklingsbiologi, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-183255.

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Glutamate is the essential neurotransmitters in pain pathways. The discovery of the vesicular glutamate transporters (VGLUT1-3) has been a fundamental step on the way to describe glutamate-dependent pain pathways. We used the Cre-lox system to construct conditional knockouts with deficient Vglut2 transmission in specific neuronal populations. We generated a Vglut2f/f;Ht-Pa-Cre line to selectively delete Vglut2 from the peripheral nervous system. These Vglut2 deficient mice showed decreased acute nociceptive responses and were less prone to develop an inflammatory state. They did not develop cold allodynia, or heat hyperalgesia and were less hypersensitive to mechanical stimuli in the PSNL chronic pain model. Further analyses of genes with altered expression after nerve injury, revealed candidates for future studies of chronic pain biomarkers. Interestingly, the Vglut2f/f;Ht-Pa-Cre mice developed an elevated itch behavior. To investigate more specific neuronal populations, we analyzed mice lacking Vglut2 in the Nav1.8 population, as inflammatory hyperalgesia, cold pain, and noxious mechanosensation have been shown to depend upon Nav1.8Cre positive sensory neurons. We showed that deleting Vglut2 in Nav1.8Cre positive neurons abolished thermal hyperalgesia in persistent inflammatory models and responses to noxious mechanical stimuli. We also demonstrated that substance P and VGLUT2-dependent glutamatergic transmission are co-required for the development of formalin-induced inflammatory pain and heat hyperalgesia in persistent inflammatory states. Deletion of Vglut2 in a subpopulation of neurons overlapping with the vanilloid receptor (TRPV1) primary afferents in the dorsal root ganglia resulted in a dramatic increase in itch behavior accompanied by a reduced responsiveness to thermal pain. Substance P signaling and VGLUT2-mediated glutamatergic transmission in TRPV1 neurons was co-required for the development of inflammatory pain states. Analyses of an itch phenotype uncovered the pathway within TRPV1 neurons, with VGLUT2 playing a regulatory role and GRPR neurons, which are to plausible converge the itch signal in the spinal cord. These studies confirmed the essential role of VGLUT2-dependent glutamatergic transmission in acute and persistent pain states and identified the roles of specific subpopulations of primary afferent neurons. Additionally, a novel pain and itch transmission pathway in TRPV1/VGLUT2 positive neurons was identified, which could be part of the gate control of pain.

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6

English, Amber. "The relationship between pain and arousal: The modulation of noxious sensation by the brain’s alerting network". Thesis, English, Amber (2017) The relationship between pain and arousal: The modulation of noxious sensation by the brain’s alerting network. Honours thesis, Murdoch University, 2017. https://researchrepository.murdoch.edu.au/id/eprint/40612/.

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The literature indicates that pain is decreased by arousal in healthy individuals. Conversely, arousal has been observed to increase pain in those with chronic pain. The present study explored the relationship between psychological arousal and pain in healthy adults (N=30). To elucidate this interaction, this study utilised an acoustic startle stimulus and electrically-induced pain, while also manipulating stimulus timing. The acoustic startle was presented prior to electrical stimulation, to act as the arousal induction. The reverse stimulus timing, the acoustic startle presented after electrical stimulation, acted as the experimental control. Using a repeated-measures design, timing effects were evaluated according to physiological responses and subjective self-ratings. The main hypothesis was that the presentation of the acoustic startle before electrical stimulation would result in significantly lower pain ratings, in comparison to electrical stimulation alone. Not only was this inhibitory effect supported but it extended to both pain and sharpness ratings, in comparison to the reverse stimulus timing. In line with predictions, pupillary responses supported that there was adequate physiological arousal in all conditions. Contradictory to predictions, stimulus timing did not significantly alter pupillary responses or spinal nociceptive reflexes. These physiological outcomes were inconsistent with the interaction found between stimulus timing and participant ratings. Additionally, Pain Catastrophizing did not correlate with the other pain measures and thus was not included in the other analyses. Together, these findings suggest that prior activation of arousal significantly inhibits the experience of pain in healthy individuals’, at a purely supra-spinal level. Keywords: pain, nociception, arousal, descending inhibition, spinal reflex, pupillometry

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7

Snyder, Kristian. "Utilizing Convolutional Neural Networks for Specialized Activity Recognition: Classifying Lower Back Pain Risk Prediction During Manual Lifting". University of Cincinnati / OhioLINK, 2020. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1583999458096255.

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8

Alharbi, Ghaleb. "Evidence-based medicine in neuropathic pain : a systematic review, meta-analysis, sequential analysis and network meta-analysis of randomised controlled trials". Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/55427/.

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Background Many randomised controlled trials (RCTs) are available to support using different pharmacotherapy agents in the management of various neuropathic pain conditions. However, choosing these pharmacotherapy agents for neuropathic pain is challenging, due to the limited evidence-based knowledge to support the use of different pharmacotherapy agents in different neuropathic pain conditions. Aims The aim of this PhD is to evaluate the efficacy and safety of oral and topical pharmacotherapies for managing neuropathic pain by deriving placebo and active comparative efficacy and safety evidence from RCTs. Methods This research used three approaches to summarise and synthesise evidence from randomised controlled studies including: a systematic review of placebo and active control RCTs to summarise and criticise the current evidence in neuropathic pain; a meta-analysis and sequential analysis of eligible studies to provide a more precise estimate of the overall treatment effects; and a network meta-analysis to estimate the relative effectiveness of the most commonly used interventions in neuropathic pain. Results Systematic review Two hundred placebo and active-controlled trials met the inclusion criteria. A wide range of different treatments were studied in these trials, including anticonvulsants, antidepressants, opioids and topical capsaicin and lidocaine. Most of the included studies were parallel placebo-controlled trials and commonly lasted for 3 to 12 weeks. In addition, the vast majority of the included RCTs were conducted in participants with painful diabetic neuropathy and post-herpetic neuralgia, while only a few trials were conducted in participants with central neuropathic pain conditions. Pairwise meta-analysis Sixty seven trials were eligible for the pairwise meta analysis of efficacy outcomes. Of the anticonvulsants group pregabalin and gabapentin compared with placebo demonstrated efficacy for 50% and 30% pain reduction and global improvement in patients with neuropathic pain. The efficacy of anticonvulsants varied in different types of neuropathic pain. Gabapentin when compared against a placebo was better than a placebo in PHN and PDN, while pregabalin was significantly effective in patients with post-herpetic neuralgia (PHN) and painful diabetic neuropathy (PDN) but not in patients with HIV associated neuropathic pain. Others anticonvulsant agents, such as lamotrigine, valproic acid, topiramate, levetiracetam and oxcarbazepine, were tested in a small number of trials. These did not provide useful benefits compared with a placebo for a 50% and 30% pain reduction. Of the antidepressant group, duloxetine when compared to a placebo demonstrated efficacy for 50% and 30% pain reduction in diabetic neuropathic pain. A few active comparison trials failed to demonstrate superior efficacy of one drug over another for a 50% and 30% reduction in neuropathic pain. Trial sequential analysis To examine the reliability and conclusiveness of the available evidence, trialsequential analysis has been applied in this study. The results show convincing evidence of the efficacy of some interventions (e.g. pregabalin, gabapentin and duloxetine) to reduce pain by 50% in some neuropathic pain conditions (e.g. diabetic neuropathic pain and post-herpetic neuralgia). The continuation of RCTs of pregabalin and duloxetine in diabetic neuropathy and gabapentin in post-herpetic neuralgia is not necessary as there appears to be sufficient evidence of the efficacy of these treatments in the management diabetic neuropathic pain and post herpetic neuralgia. Further RCTs of duloxetine, pregabalin and gabapentin are however required for central neuropathic pain. In contrast, the analysis failed to provide evidence that opioids and high concentration capsaicin demonstrate a 50% pain reduction. Network meta-analysis Twenty-eight trials were eligible for the network meta-analysis. The results incorporating both direct-comparison and indirect-comparison evidence suggested that there is no superiority of duloxetine over amitriptyline, pregabalin and gabapentin in achieving at least a 30% and 50% pain reduction with a treatment duration of 7 to 12 weeks in patients with neuropathic pain conditions, such as diabetic neuropathic pain, postherpetic neuralgia and spinal cord injury. Conclusions In summary, this research has found that some good quality trials provide good evidence regarding the efficacy of duloxetine, pregabalin and gabapentin in a minority of patients with neuropathic pain. Until advancements in developing mechanism-based approaches and improved clinical trial design become available, the routine use of these medications is unlikely to be changed. This may support the hypothesis that traditional RCTs might not be a suitable method of choice to address provisional health questions in routine clinical practice.

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9

Cazzanelli, Silvia. "Functional ultrasound (fUS) imaging of brain functional connectivity alterations in a mouse model of neuropathic pain : impact of nociceptive symptoms and associated comorbidities". Electronic Thesis or Diss., Université Paris sciences et lettres, 2024. http://www.theses.fr/2024UPSLS010.

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La douleur neuropathique est une sensation de douleur anormale qui persiste au-delà du cours temporel de la guérison naturelle. Elle interfère avec la qualité de vie du patient et est associée à plusieurs comorbidités telles que l'anxiété et la dépression. Des études antérieures ont suggéré que la douleur chronique pourrait résulter d’une plasticité neuronale anormale et inadaptée dans les structures connues pour être impliquées dans la perception de la douleur (Bliss et al. 2016). Cela signifie qu'une lésion nerveuse déclencherait une potentialisation à long terme de la transmission synaptique dans les aires cérébrales liées à la douleur (Zhuo et al. 2014). Comme ces régions sont également impliquées dans les aspects émotionnels de la douleur, notre hypothèse est que la plasticité inadaptée susmentionnée dans ces zones cérébrales pourrait constituer un mécanisme clé pour le développement de comorbidités, telles que l'anxiété et la dépression.Au cours de ma thèse, nous avons choisi de tester cette hypothèse de travail par l’étude des altérations de la connectivité fonctionnelle (CF) intrinsèque des réseaux cérébraux par imagerie fonctionnelle ultrasonore (fUS) dans un modèle murin de douleur neuropathique. Cette technique de neuro-imagerie relativement récente a permis de nombreuses avancées en neurosciences, grâce à sa haute résolution spatio-temporelle, à sa sensibilité, mais aussi son adaptabilité, permettant des études chez l’animal anesthésié ou éveillé.Dans une première étude, j’ai mis au point un protocole expérimental permettant d’imager le cerveau des souris éveillées de façon reproductible et avec un minimum de stress et d artefacts de mouvements et ai également été impliquée dans le développement d’un nouvel algorithme d’analyse des signaux générées par ces acquisitions. Cette première approche étant réalisée avec une sonde linéaire en mouvement qui ne permet pas de visualiser l’entièreté du cerveau, dans une seconde étude, j’ai participe au développement d’une nouvelle technologie de sonde compilées et motorisée.Fort de ces développements technologiques, j’ai alors utilisé ces nouvelles approches pour tester mon hypothèse neurobiologique. J’ai entrepris deux études en parallèle chez des animaux anesthésiés pour l’une et éveillés pour la seconde, chez lesquelles nous avons étudié le lien temporel entre les altérations de la CF cérébrale et le développement de la douleur neuropathique et/ou des comorbidités associées. Pour cela, nous avons mesuré la CF (en période de repos) chez des souris atteintes de douleur neuropathique, à trois moments différents : I) 2 semaines après l’induction de la douleur neuropathique (manchon autour du nerf sciatique) II) à 8 semaines post-induction, lorsque l'anxiété émerge et III) à 12 semaines post-induction, lorsque la dépression apparait (12W). Ce suivi longitudinal a également été réalisé en parallèle sur un groupe d’animaux contrôles.Nos résultats indiquent des changements significatifs de la CF dans les principales régions cérébrales impliquées dans la transmission ou la modulation de la sensibilité ou de la douleur, suggérant la mise en place d’une plasticité inadaptée du réseau de la douleur, suite à la lésion nerveuse. De plus, nous observons une évolution temporelle de ces altérations, potentiellement corrélée à l'apparition des comorbidités associées. Ainsi, ces mécanismes pourraient participer à la chronicisation de la douleur
Neuropathic pain is an abnormal pain sensation that persists longer than the temporal course of natural healing. It interferes with the patient’s quality of life and leads to several comorbidities, such as anxiety and depression. It has been suggested that chronic pain may result from abnormal and maladaptive neuronal plasticity in the structures known to be involved in pain perception (Bliss et al. 2016). This means that nerve injury would trigger long-term potentiation of synaptic transmission in pain-related areas (Zhuo et al. 2014). Since these regions are also involved in the emotional aspects of pain, our hypothesis is that the aforementioned maladaptive plasticity in these brain areas could constitute a key mechanism for the development of comorbidities such as anxiety and depression.My PhD aimed at testing this working hypothesis, through the study of brain resting state functional connectivity (FC) using functional ultrasound imaging (fUS) in a mouse model of neuropathic pain. FUS is a relatively recent neuroimaging technique that enabled numerous advances in neuroscience, thanks to its high spatio-temporal resolution, its sensitivity, but also its adaptability, allowing studies in anesthetized or awake animals.In a first study, I developed an experimental protocol allowing the brains of awake mice to be imaged in a reproducible manner and with minimal stress and movement artifacts and was also involved in the development of a new algorithm for the analysis of the signals generated by these acquisitions. As this first approach was carried out with a moving linear probe which does not allow the entire brain to be visualized, in a second study, I participated in the development of a new compiled and motorized probe technology.Building on these technological developments, I then used these new approaches to test my neurobiological hypothesis. I undertook two parallel studies in animals anesthetized for one and awake for the second, in which we studied the temporal link between alterations in cerebral FC and the development of neuropathic pain and/or associated comorbidities. To do this, we measured the resting-state functional connectivity (FC) in anesthetized and in awake head-fixed mice, at three time points: I) 2 weeks after induction of neuropathic pain (cuff around the sciatic nerve), II) at 8 weeks post-induction during the emergence of anxiety (8W) and III) at 12 weeks post-induction during the emergence of depression. This longitudinal follow-up has been conducted concurrently on a control group.Our results show significant changes in FC in major pain-related brain regions in accordance with the development of neuropathic pain symptoms. These findings suggest that the pain network undergoes maladaptive plasticity following nerve injury which could contribute to pain chronification. Moreover, the time course of these connectivity alterations between regions of the pain network could be correlated with the subsequent apparition of associated comorbidities

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10

Morabit, Safaa El. "New Artificial Intelligence techniques for Computer vision based medical diagnosis". Electronic Thesis or Diss., Valenciennes, Université Polytechnique Hauts-de-France, 2023. http://www.theses.fr/2023UPHF0013.

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La capacité à ressentir la douleur est cruciale pour la vie, car elle sert de système d’alerteprécoce en cas de dommages potentiels pour le corps. La majorité des évaluations dela douleur reposent sur les rapports des patients. En revanche, les patients incapablesd’exprimer leur douleur doivent plutôt se fier aux rapports de tierces personnes sur leursouffrance. En raison des biais potentiel de l’observateur, les rapports sur la douleurpeuvent contenir des inexactitudes. En outre, il serait impossible de surveiller les patients 24 heures sur 24. Afin de mieux gérer la douleur, notamment chez les patients avec des difficultés de communication, des techniques de détection automatique de la douleur pourraient être mises en œuvre pour aider les soignants et compléter leur service. Les expressions faciales sont utilisées par la plupart des systèmes d’évaluation de la douleur basés sur l’observation, car elles constituent un indicateur fiable de la douleur et peuvent être interprétées à distance.En considérant que la douleur génère généralement un comportement facial spontané, les expressions faciales pourraient être utilisées pour détecter la présence de la douleur. Dans cette thèse, nous analysons les expressions faciales de la douleur afin d’aborder l’estimation de la douleur. Tout d’abord, nous présentons une analyse approfondie du problème en comparant de nombreuses architectures CNN (réseau de neurones convolutifs) courantes, telles que MobileNet, GoogleNet, ResNeXt-50, ResNet18et DenseNet-161. Nous utilisons ces réseaux dans deux modes uniques : autonome et extraction de caractéristiques. En mode autonome, les modèles (c’est-à-dire les réseaux)sont utilisés pour estimer directement la douleur. En mode extracteur de caractéristiques, les "valeurs" de la couche intermédiaire sont extraites et introduites dans desclassificateurs tels que la régression à vecteur de support (SVR) et la régression à forêtsd’arbres décisionnels (RFR).Les CNN ont obtenu des résultats significatifs dans la classification d’images et ontconnu un grand succès. Plus récemment, l’efficacité des Transformers en vision par ordinateur a été démontrée par plusieurs études. Des architectures basées sur les Transformers ont été proposées dans la deuxième section de cette thèse. Ces deux architectures distinctes ont été présentées pour répondre à deux problèmes distincts liés àla douleur : la détection de la douleur (douleur vs absence de douleur) et la distinction entre la douleur authentique et la douleur simulée. L’architecture innovante pourl’identification binaire de la douleur faciale est basée sur des transformateurs d’imagesefficaces en termes de données (Deit). Deux bases de données, UNBC-McMaster shoulder pain et BioVid heat pain, ont été utilisées pour affiner et évaluer le modèle formé. Ladeuxième architecture proposée, repose sur des transformateurs de vision pour la détection de douleurs authentiques et simulées à partir des expressions faciales (ViT). Pour distinguer la douleur authentique de la douleur simulée, le modèle doit accorder uneattention particulière aux changements subtils des expressions faciales dans le temps.L’approche employée prend en compte l’aspect séquentiel et capture les variations des expressions faciales. Les expériences ont été menées sur la base de données BioVid HeatPain démontrent l’efficacité de notre stratégie
The ability to feel pain is crucial for life, since it serves as an early warning system forpotential harm to the body. The majority of pain evaluations rely on patient reports. Patients who are unable to express their own pain must instead rely on third-party reportsof their suffering. Due to potential observer bias, pain reports may contain inaccuracies. In addition, it would be impossible for people to keep watch around the clock. Inorder to better manage pain, especially in noncommunicative patients, automatic paindetection technologies might be implemented to aid human caregivers and complementtheir service. Facial expressions are used by all observer-based pain assessment systemsbecause they are a reliable indicator of pain and can be interpreted from a distance.Taking into consideration that pain generally generates spontaneous facial behavior,these facial expressions could be used to detect the presence of pain. In this thesis, weanalyze facial expressions of pain in order to address pain estimation. First, we presenta thorough analysis of the problem by comparing numerous common CNN (Convolutional Neural Network) architectures, such as MobileNet, GoogleNet, ResNeXt-50, ResNet18, and DenseNet-161. We employ these networks in two unique modes: standalone and feature extraction. In standalone mode, models (i.e., networks) are utilized to directly estimate pain. In feature extractor mode, "values" from the middle layer are extracted and fed into classifiers like Support Vector Regression (SVR) and Random Forest Regression (RFR).CNNs have achieved significant results in image classification and have achievedgreat success. The effectiveness of Transformers in computer vision has been demonstrated through recent studies. Transformer-based architectures were proposed in the second section of this thesis. Two distinct Transformer-based frameworks were presented to address two distinct pain issues: pain detection (pain vs no pain) and thedistinction between genuine and posed pain. The innovative architecture for binaryidentification of facial pain is based on data-efficient image transformers (Deit). Twodatasets, UNBC-McMaster shoulder pain and BioVid heat pain, were used to fine-tuneand assess the trained model. The suggested architecture is built on Vision Transformers for the detection of genuine and simulated pain from facial expressions (ViT). Todistinguish between Genuine and Posed Pain, the model must pay particular attentionto the subtle changes in facial expressions over time. The employed approach takes intoaccount the sequential aspect and captures the variations in facial expressions. Experiments on the publicly accessible BioVid Heat Pain Database demonstrate the efficacy of our strategy

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11

Silva, Adriana Ferreira. "Efeito da estimulação transcraniana de corrente contínua com a tarefa neurocognitiva na capacidade atencional e na dor de pacientes com fibromialgia". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2015. http://hdl.handle.net/10183/129673.

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Introdução: Fibromialgia (FM) é uma síndrome que acomete entre 1-6% da população, com maior frequência em mulheres. Costuma cursar com dor crônica, alterações de sono, sintomas depressivos e prejuízo de memória. Seu impacto na vida das pacientes está relacionado às limitações para atividades da vida diária, incluindo as funções executivas. A disfunção das redes neurais envolvidas no sistema de excitabilidade e de inibição tem repercussões cognitivas que comprometem a atenção e o desempenho de atividades laborais. A dor é o sintoma que governa esta síndrome e é capaz de afetar a capacidade atencional de pacientes com FM e prejudicar realizações cotidianas. No entanto, pouco se conhece sobre as vias e os processos envolvidos nesse conjunto de sintomas. Faz-se necessário, portanto, compreender esses processos e buscar estratégias terapêuticas com efeito nesses mecanismos. Dentre os tratamentos, pode-se citar a estimulação transcraniana de corrente continua (ETCC), intervenção com feito modulador da atividade neuronal, cujo potencial beneficio tem sido demonstrado na FM. A integração do efeito excitatório da ETCC ao efeito inibitório das tarefas neurocogntivas em áreas envolvidas no processamento afetivo-motivacional, incluindo a dor crônica, não foi profundamente explorada. O objetivo do presente estudo foi comparar o efeito da ETCC-ativa (a) com ETCC-sham (s) combinada a tarefa neurocognitva inibitória (Go- noGo Task) na dor e capacidade atencional de pacientes com FM. Métodos: Foram selecionadas pacientes com diagnóstico de FM de acordo com o American College of Rheumatology (ACR) 2010. A amostra foi composta por 40 pacientes, subdivididas em dois grupos- ETCC-a ou ETCC-s- num ensaio clínico do tipo cruzado, duas sessões com intervalo de sete dias entre uma intervenção e outra. A estimulação ETCC foi anódica pré-frontal dorsolateral (DLPFC) de 1 mA por 20 minutos. As intervenções utilizadas foram Go- noGo Task (GNG), Attention Network Task (ANT) e ETCC. Resultados: Houve significativa diferença entre os grupos ETCC-a e ETCC-s nos resultados de ANT. ETCC-a combinada a tarefa GNG foi capaz de potencializar a rede de atenção executiva e amenizar a sensação de dor. Em ANT os dados relacionados à orientação foram -14,63 de diferença média, com 95% intervalo de confiança (IC) (de -18,89 a -0,37). Quanto à execução, foi verificada média de 21.00 com 95% de IC (4.11 a 37.89). Em relação ao alerta não houve diferença, apresentando a média de -3,17; com 95% de IC (-3,17 a 4,88). Pacientes com maior nível de catastrofização e dor apresentaram diminuição da atenção executiva em comparação com os demais pacientes do estudo. Conclusão: Os efeitos sobre a rede neuronal induzida por uma tarefa inibitória combinada com ETCC-a apresentou maior desempenho na execução atencional e redução da dor.
Introduction: Fibromyalgia (FM) is a syndrome that affects 1-6% of the population, mostly women. It usually courses with chronic pain, sleep disturbance, symptoms of depression and memory loss. Its impact on the female patients’ life is related to the limitations in everyday activities, including executive functions. The dysfunction of the neural networks involved in the excitability and inhibition systems has cognitive repercussions that compromise attention and the performance of work-related activities. Pain is the symptom that rules this syndrome and can affect the attentional capacity of patients with FM and impair daily achievements. However, little is known about the pathways and the processes involved in this set of symptoms. It is, therefore, necessary to understand these processes and look for therapeutic strategies that have an effect on these mechanisms. Among these treatments we can mention Transcranial direct current stimulation (tDCS) an intervention with a modulating effect of neuronal activity, whose potential benefit has been demonstrated in FM. The integration of the excitatory effect of tDCS on the inhibitory effect of neurocognitive tasks in areas involved in the affective-motivational processing, including chronic pain, has not been profoundly explored. The purpose of the present study was to compare the effect of active tDCS(a) with sham tDCS(s) combining the inhibitory neurocognitive task (Go- noGo Task) in pain and in the attentional capacity of patients with FM. Methods: Patients with a diagnosis of FM according to the American College of Rheumatology (ACR) 2010 were selected. The sample was composed by 40 patients, subdivided into two groups - tDCS-a or tDCS-s - in a clinical assay of the cross-matched type, two sessions with a seven-day interval between one intervention and another. The tDCS stimulation was anodyne (DLPFC) of 1mA for 20 minutes. The interventions used were Go- noGo Task (GNG), Attention Network Task (ANT) and tDCS. Results: There was a significant difference betweeen the tDCS-a and tDCS-s groups in the ANT results. tDCS-a combined with the GNG task was able to potentiate the network of executive attention and attenuate the feeling of pain. In ANT the data related to orientation were -14.63 of mean difference, with a 95% confidence interval (CI) (from -18.89 to -0.37). As to execution, a mean of 21.00 was found with 95% CI (4.11 to 37.89). As to the alert, there was no difference, and the mean was -3.17; with 95% CI (-3.17 to 4.88). Patients with a higher level of catastrophization and pain presented reduced executive attention compared to the other patients in the study. Conclusion: The effects on the neuronal network induced by an inhibtory task combined with tDCS-a presented a greater performance in attentional execution and pain reduction.

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Narula, Vaibhav, Antonio Giuliano Zippo, Alessandro Muscoloni, Gabriele Eliseo M. Biella e Carlo Vittorio Cannistraci. "Can local-community-paradigm and epitopological learning enhance our understanding of how local brain connectivity is able to process, learn and memorize chronic pain?" Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-230803.

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The mystery behind the origin of the pain and the difficulty to propose methodologies for its quantitative characterization fascinated philosophers (and then scientists) from the dawn of our modern society. Nowadays, studying patterns of information flow in mesoscale activity of brain networks is a valuable strategy to offer answers in computational neuroscience. In this paper, complex network analysis was performed on the time-varying brain functional connectomes of a rat model of persistent peripheral neuropathic pain, obtained by means of local field potential and spike train analysis. A wide range of topological network measures (14 in total, the code is publicly released at: https://github.com/biomedical-cybernetics/topological_measures_wide_analysis) was employed to quantitatively investigate the rewiring mechanisms of the brain regions responsible for development and upkeep of pain along time, from three hours to 16 days after nerve injury. The time trend (across the days) of each network measure was correlated with a behavioural test for rat pain, and surprisingly we found that the rewiring mechanisms associated with two local topological measure, the local-community-paradigm and the power-lawness, showed very high statistical correlations (higher than 0.9, being the maximum value 1) with the behavioural test. We also disclosed clear functional connectivity patterns that emerged in association with chronic pain in the primary somatosensory cortex (S1) and ventral posterolateral (VPL) nuclei of thalamus. This study represents a pioneering attempt to exploit network science models in order to elucidate the mechanisms of brain region re-wiring and engram formations that are associated with chronic pain in mammalians. We conclude that the local-community-paradigm is a model of complex network organization that triggers a local learning rule, which seems associated to processing, learning and memorization of chronic pain in the brain functional connectivity. This rule is based exclusively on the network topology, hence was named epitopological learning.

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Kambrun, Charline. "Contrôle des réseaux spinaux de la lamina II de la moelle épinière par les fibres C-LTMRs : approches optogénétique et pharmacologique". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0869/document.

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La perception de la douleur résulte de l'intégration dans la moelle épinière des informations sensorielles et nociceptives transmises par les afférences primaires. Parmi celles-ci, les Mechanorécepteurs C à bas seuil (C-LTMR), exprimant la chimiokine TAFA4, ont été identifiés comme des modulateurs de la douleur. Cependant, les mécanismes sous-jacents au contrôle de l'intégration sensori-nociceptive par TAFA4 restent mal compris. Grâce aux enregistrements obtenus in vitro par patch clamp chez des souris naïves, nous montrons que l'application exogène de TAFA4 induit une diminution de la fréquence des courants post-synaptiques excitateurs spontanés (CPSE). A l’inverse nous observons une augmentation de la fréquence des événements synaptiques inhibiteurs spontanés (CPSI). Cette modulation de l'activité synaptique est préservée avec TTX, indiquant que TAFA4 modifie la transmission synaptique par des mécanismes présynaptiques. En stimulant les fibres nociceptives à haut seuil d’activation, nous démontrons que TAFA4 induit une augmentation du ratio des réponses synaptiques des interneurones évoquées par des stimulations d’impulsions pairées. Par conséquent, TAFA4 renforce l'inhibition présynaptique des fibres nociceptives. Nous démontrons également que les effets de TAFA4 sur la transmission excitatrice spontanée et évoquée sont bloqués par des antagonistes des récepteurs GABA, indiquant que les C-LTMRs interagissent principalement avec les neurones GABAergiques. De plus, des expériences de microscopie électronique ont révélé la présence de contacts synaptiques directs entre les C-LTMRs et les terminaisons GABAergiques dans la lamina IIi. Pour aller plus loin dans la caractérisation des effets de TAFA4 sur la transmission de la douleur, nous avons induit une inflammation de la patte arrière des souris (modèle CFA). Chez ces souris, l'effet de TAFA4 sur la fréquence EPSC et IPSC est conservé. Nous constatons que chez les souris CFA, TAFA4 diminue la décharge neuronale enregistrée in vivo suite à une stimulation mécanique nociceptive de la patte inflammée. Cet effet est bloqué par une injection d'antagonistes des récepteurs GABA. En effectuant le test Von Frey sur des souris inflammées, nous montrons que l’action anti-allodynique induite par l'injection intrathécale de TAFA4 est bloquée par les antagonistes des récepteurs GABA. Nous avançons l’hypothèse que les C-LTMRs contactent directement les interneurones GABAergiques de la corne dorsale et, via la libération de TAFA4, renforcent l'activité synaptique inhibitrice participant à l’effet anti-nociceptif de TAFA4. En outre, TAFA4 favorise la rétraction microgliale chez les animaux inflammés, ainsi qu'une augmentation du nombre de synapses inhibitrices sur les somas des neurones de la lamina IIi. En conclusion, ces résultats identifient les interneurones GABAergiques comme premier relais d'intégration pour les C-LTMRs et mettent en évidence une nouvelle interaction entre les neurones sensoriels, les cellules microgliales et les interneurones de la moelle épinière, permettant une modulation fine de l'activité inhibitrice et de la transmission nociceptive en situation pathologique
Pain elaboration results from the integration within dorsal spinal cord of sensory and nociceptive information conveyed by primary afferents. Among these, C low-threshold Mechano Receptors (C-LTMR), expressing the chemokine TAFA4, were identified as modulators of pain. However, mechanisms underlying the control of sensori-nociceptive integration by TAFA4 remains poorly understood. Using in vitro patch clamp recording on spinal cord slices of naïve mice we show that, bath application of TAFA4 induces a decrease in frequency of spontaneous excitatory post synaptic currents (EPSCs). This effect is mirrored by an increase in frequency of spontaneous inhibitory synaptic events (IPSCs). This modulation of synaptic activity is preserved with TTX, indicating that TAFA4 alters synaptic transmission through presynaptic mechanisms. By recruiting high threshold nociceptive fibers, we demonstrate that TAFA4 induces an increase in the paired pulse ratio of evoked synaptic responses in interneurons, and thus, reinforces presynaptic inhibition of nociceptive fibers. We also demonstrate that the effects of TAFA4 on spontaneous and evoked excitatory transmission are blocked by antagonists of GABA receptors, indicating that -C-LTMRs mainly interact with GABAergic neurons. Moreover, Electron Microscopy provides evidence of direct synaptic contacts between C-LTMRs and GABAergic terminals in lamina IIi. To further characterize the effects of TAFA4 on pain transmission, we inflamed mice using Complete Freund Adjuvant (CFA). In CFA mice, the effect of TAFA4 on EPSC and IPSC frequency is preserved. We find that in CFA mice, TAFA4 decreases the neuronal discharge recorded in vivo following a nociceptive mechanical stimulation in inflamed hindpaw. This effect is blocked by an injection of GABA receptors antagonists. By performing Von Frey test on inflamed mice, we show that intrathecal injection of TAFA4 provides anti-allodynic effects blocked by GABA receptors antagonists. We propose that C-LTMR directly contact GABAergic interneurons in dorsal horn, and, through the liberation of TAFA4 reinforce inhibitory synaptic activity which may in turn promote their anti-nociceptive activity. Furthermore, TAFA4 promotes microglial retraction in CFA inflamed animals, together with an increase in the number of inhibitory synapses on lamina IIi somata. Altogether, these results identify GABAergic interneurons as the first integration relay for C-LTMRs and highlight a novel interplay between sensory neurons, microglial cells and spinal interneurons leading to a fine tuning of inhibitory activity and nociceptive transmission in pathological conditions

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Pautrat, Arnaud. "Traitement nociceptif sous-cortical : Implications dans les douleurs Parkinsoniennes. Approche expérimentale chez le rat Revealing a novel nociceptive network that links the subthalamic nucleus to pain processing Abnormal Subcortical Nociceptive Processing in Rodent Models of Parkinson's Disease". Thesis, Université Grenoble Alpes (ComUE), 2019. http://www.theses.fr/2019GREAV042.

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La maladie de Parkinson (MP) est une maladie neurodégénérative caractérisée par la perte progressive des neurones dopaminergiques de la substance noire compacte. Cette dégénérescence engendre de profonds dysfonctionnements au sein d’un réseau cérébral essentiel pour de nombreuses fonctions, les ganglions de la base (GB). Bien que ce réseau soit classiquement associé au contrôle du mouvement, de plus en plus d’études lui prêtent également un rôle dans la nociception. Il est intéressant de constater que les patients Parkinsoniens présentent une symptomatologie douloureuse complexe, améliorée par la stimulation cérébrale profonde du noyau subthalamique (NST), une des régions clé des GB. De ce fait, l’objectif principal de cette thèse a été de préciser le rôle des GB dans la nociception et d’évaluer l’impact d’une dégénérescence dopaminergique sur cette fonction. Pour cela, nous avons, dans une première étude, effectué des enregistrements électrophysiologiques chez le rat, et démontré que les neurones du NST s’activent toniquement et phasiquement à la présentation de stimulations douloureuses. Nous avons ensuite identifié le noyau parabrachial (PBN), comme étant la structure principale relayant l’information nociceptive au NST. Dans une deuxième étude, nous avons recherché d’éventuels dysfonctionnements au sein de ce réseau chez des animaux modèles de la MP. Nous décrivons ainsi une altération du traitement du signal nociceptif avec un fort degré de déplétion dopaminergique, et reportons la présence de phénomènes de compensation neuroplastiques efficaces au sein du PBN avec un degré moyen de déplétion dopaminergique. Ces résultats apportent un nouveau regard sur les douleurs Parkinsoniennes, qui pourraient provenir de phénomènes neuroplastiques pathologiques associés à une activité et un traitement anormal du signal nociceptif par le réseau des GB
Parkinson's disease (PD) is a neurodegenerative disease characterized by a progressive loss of dopaminergic neurons from the substantia nigra compacta. This degeneration leads to profound dysfunctions in a brain network essential for many functions, called the basal ganglia (BG). Although this network is traditionally associated with movement control, many studies have also attributed it a role in nociception. It is interesting to note that PD patients suffer from a complex painful symptomatology, improved by deep brain stimulation of the subthalamic nucleus (STN), one of the key regions of the BG. Therefore, the main objective of this thesis was to clarify the role of BG in nociception and to evaluate the impact of a dopaminergic degeneration on this function. In this purpose in a first study, we carried out electrophysiological recordings in rats and demonstrated that STN neurons are activated tonically and phasically by noxious stimuli. We then identified the parabrachial nucleus (PBN) as the main structure relaying the nociceptive information to the STN. In a second study, we investigated possible dysfunctions in this network in PD rat models. We thus describe an alteration of nociceptive signal processing in this network with a high degree of dopaminergic depletion, and report the presence of effective neuroplastic compensation mechanisms within PBN neurons with a moderate dopaminergic depletion. These results provide a new perspective on Parkinsonian pain that could result from pathological neuroplastic phenomena associated with abnormal activity and nociceptive signal processing by the BG network

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Ghasemi, Ghaleh Bahmani Afsaneh. "Machine perception of human emotions using motion patterns". Thesis, Queensland University of Technology, 2017. https://eprints.qut.edu.au/104297/1/Afsaneh_Ghasemi%20Ghaleh%20Bahmani_Thesis.pdf.

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We propose novel, intelligent facial expression recognition systems as well as unique encoding of the dynamics of facial actions, enabling machines to have the ability to sense and understand human visual interaction signals. Various methodologies have been proposed to address the existing limitations in performance as well as the computing resource constraints, to advance the field of automatic human emotion recognition.

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Brawn, Jennifer. "Neuroimaging functional pain networks in health and disease". Thesis, University of Oxford, 2017. https://ora.ox.ac.uk/objects/uuid:6c5c88a1-be58-4f45-b3ce-d209fd1aa85b.

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Chronic pelvic pain (CPP) is considered a significant public health problem. In the United Kingdom, it has been estimated that 24% of women suffer from CPP. Using neuroimaging, this dissertation aims to characterise the pain experience by examining functional changes in critical pain networks. I begin by examining the functional correlates of capsaicin-induced central sensitisation in healthy individuals. Most of the results did not reach significance, largely due to the use of early 7T data and small sample sizes. In an exploratory analysis, amygdala - anterior insula connectivity is positively correlated with pain intensity. The remaining experimental chapters examine mechanisms of pain in women with CPP. I begin by attempting to better characterise this diverse patient population. I demonstrate correlations between measures of the pain experience and psychological scores. Following this, I examine clinically-relevant changes in functional connectivity. I demonstrate that there are potentially different underlying modulatory mechanisms in women with neuropathic components to their pelvic pain. Furthermore, women who experience pain for longer than 24 months have increased functional connectivity between the hippocampus and periaqueductal gray, suggesting pain-related alterations in central circuitry. The final experimental chapters explore surgical and pharmaceutical treatments for CPP and endometriosis; however, due to small sample sizes and nonsignificant findings, limited conclusions can be drawn from the results. In this dissertation, I found changes in important pain networks that could either represent the maintenance of the pain state or are consequence of the pain itself. These findings may serve as an indicator of underlying central changes that relate to relevant components of the clinical pain experience.

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Löfstrand, Emelie. "Empathy for Pain : And its Neural Correlates". Thesis, Högskolan i Skövde, Institutionen för biovetenskap, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:his:diva-12795.

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The phenomenon of empathy has been fascinating laymen and scholars for centuries and has recently been an important subject for cognitive neuroscientific study. Empathy refers to the ability to understand and share others’ emotions and a characteristic of this ability is the capacity to empathize with others in pain. This review intends to examine and read up on the current state of the field of the neural and behavioral mechanisms associated with empathy for pain. The neural underpinnings of the first-hand experience of pain have been shown to be activated in a person observing the suffering individual, and this similarity in brain activity has been referred to as shared networks. This phenomenon plays an important role in the study of empathy. However, different factors have been shown to influence empathy for pain, such as age, gender, affective link between observer and sufferer, as well as phylogenetic similarity. This thesis discusses these differences, as well as atypical aspects affecting the empathic ability such as synaesthesia for pain, psychopathy and Asperger’s disease. Further, empathy for pain can be modulated by the individual observing someone in pain. For example, caregivers often down-regulate their empathic response to patients in pain, possibly in order to focus on their treatment and assistance. Also, paying attention to harmful stimuli heightens the perception of pain; therefore, the painful experience can be less remarkable when focusing on something else. The effect of empathy from others directed to oneself when suffering is discussed, as well as the consistency and limitations of presented research.

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Yusoff, Nooraini. "Pair-associate learning in spiking neural networks". Thesis, University of Surrey, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.576162.

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We propose associative learning models that integrate spike-time dependent plasticity (STDP) and firing rate in two semi-supervised paradigms, Pavlovian and reinforcement learning. Through the Pavlovian approach, the learning rule associates paired stimuli (stimulus-stimulus) known as the predictor-choice pair. Synaptic plasticity is dependent on the timing and the rate of pre- and post synaptic spikes within a time window. The contribution of our learning model can be attributed to the implementation of the proposed learning rules using integration of STDP and firing rate in spatio-temporal neural networks, with Izhikevich's spiking neurons. There is no such model yet found in the literature. The model has been tested in recognition of real visual images. As a result of learning, synchronisation of activity among inter- and intra-subpopulation neurons demonstrates association between two stimulus groups. As an improvement to the stimulus-stimulus (S-S) association model, we extend the algorithm for stimulus-stimulus- response (S-S-R) association using a reinforcement approach with reward-modulated STDP. In the later model, firing rate in response groups determines a reward signal that modulates synaptic changes derived from STDP processes. The S-S-R model has been successfully tested in a visual recognition task with real images and simulation of the colour word Stroop effect. The learning algorithm is able to perform pair-associate learning as well as to recognise the sequence of the presented stimuli. Unlike other existing gradient-based learning models, the S-S-R model implements temporal sequence learning in more natural way through reward-based learning whose protocol follows a behavioural experiment from a psychology study. The key novelty of our S-S-R model can be ascribed to its lateral inhibition mechanism through a minimal anatomical constraint that enables learning in high competitive environments (e.g. temporal logic AND and XOR problems). The S-S model models for example the retrospective and prospective activity in the brain, whilst the S-S-R model exhibits reward acquisition behaviour in human learning. Furthermore, we have proven than, a goal directed learning can be implemented via a generic neural network with rich realistic dynamics based on neurophysiological data. Hence the loose dependency between the model's anatomical properties and functionalities could offer a wide range of applications especially in complex learning environments. Keywords: spiking neural network, spike timing dependent plasticity, associate learning, reinforcement learning, cognitive modelling

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Fernández, Peña Rosario. "El estudio del apoyo social y la calidad de vida desde las redes personales: el caso del dolor crónico". Doctoral thesis, Universitat Autònoma de Barcelona, 2015. http://hdl.handle.net/10803/377765.

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Esta investigación se ha centrado en el estudio del apoyo social y la calidad de vida en situación de dolor crónico. En este contexto de cronicidad, el ambiente social ocupa un papel relevante por los recursos que contiene para hacer frente a las limitaciones provocadas por la enfermedad. Entre estos recursos cabe destacar la cantidad y calidad de las relaciones sociales de carácter informal, tanto por su papel en la evaluación de la dimensión social de la calidad de vida como por su capacidad de garantizar la prolongación de los cuidados fuera de las instituciones socio-sanitarias. Esta investigación ha optado por un enfoque de métodos mixtos, combinando información cualitativa obtenida a través de entrevistas semi-estructuradas y datos cuantitativos de la calidad de vida obtenidos a través del cuestionario SF-36. También se han obtenido datos cuantitativos de apoyo social aplicando la perspectiva teórica y metodológica del análisis de redes sociales (ARS). Esta perspectiva ha permitido identificar el papel que desempeña la estructura y la composición de la red personal en la provisión y satisfacción con el apoyo social recibido. Así, se han estudiado las redes personales y de apoyo de 30 personas con dolor crónico tratadas en la Unidad de Dolor de un hospital público español (20 relaciones de cada uno de ellos, 600 relaciones en total). Desde el punto de vista de los informantes, la experiencia dolorosa se ha caracterizado por el severo impacto en diferentes aspectos de la vida, especialmente en el estado físico por su limitación de la movilidad, las actividades de autocuidado, el mantenimiento del hogar, el cuidado de otros miembros de la familia, la afectación a las esferas psicológica y laboral, la reducción de la participación en actividades sociales y la consecuente limitación de la vida relacional. Los resultados de calidad de vida arrojan resultados por debajo de la media poblacional de referencia en todas sus dimensiones y componentes sumarios, de forma especial para las dimensiones de Rol Emocional y Funcionamiento Social relacionados con el Componente Sumario Mental y las dimensiones Rol Físico y Dolor Corporal para el Componente Sumario Físico. En la investigación hemos identificado, mediante un análisis de clúster una tipología de perfiles en función de la satisfacción con el apoyo social recibido a partir de las variables de estructura, composición y apoyo de las relaciones estudiadas. Las relaciones proveedoras de un apoyo más satisfactorio se caracterizan por ser recíprocas, mantener un vínculo fuerte con ego, estar ocupadas por mujeres, familiares cercanos, con una localización geográfica próxima a ego y ser proveedores de un apoyo social múltiple, presencial y frecuente que se mantiene o aumenta a lo largo del tiempo. En la comparación de medias, la satisfacción aumenta a medida que lo hace la densidad de la red y la centralidad de grado por un lado y la centralidad de intermediación por otro y disminuye a medida que aumenta el número de aislados y componentes. El estudio de la vida relacional de la persona en situación de dolor crónico, sus cambios, necesidades y recursos, permite la evaluación de la cara social del dolor y posibilita el diseño de estrategias de intervención con el objetivo de mejorar la calidad de vida en situación de enfermedad.
This research has focused on the study of social support and quality of life in situations of chronic pain. In this context of chronicity, social environment plays a relevant role due to the resources it offers for coping with the limitations caused by an illness. Of importance among these resources are the quantity and quality of informal social relationships, both because of their role in the evaluation of the social dimension of the quality of life and because of their capacity to guarantee the prolongation of care outside of healthcare institutions. This study opted for a mixed methodological focus that combines qualitative information obtained from semi-structured interviews with quantitative data on quality of life obtained by applying the SF-36 questionnaire. Quantitative data on social support was also obtained by applying the theoretical and methodological perspective of social network analysis (SNA), which made it possible to identify the role played by the structure and composition of the personal network in the provision of social support and satisfaction with the same. The personal and support networks of 30 people with chronic pain being treated in the Pain Unit at a Spanish public hospital were studied (20 relations for each of them, 600 relations in all). In the opinion of the informants, the experience of pain was characterised by severe impact on different aspects of life, especially in terms of physical shape due to limited mobility, self-care activities, household chores, caring for other members of the family, affectation of psychological and work-related spheres, reduced participation in social activities and the consequent limitations on relational life. The results for quality of life are below the average for the reference population in all summary components and dimensions, especially in the dimensions of Emotional Role and Social Functioning related with the Mental Component Summary score and the dimensions of Physical Role and Bodily Pain for the Physical Component Summary score. In this research, we have identified, by means of cluster analysis, a typology of profiles in accordance with satisfaction with the social support received on the basis of the structure, composition and support variables of the studied relations. Relations that provide the most satisfactory support are characterised as being reciprocal, maintaining a strong ties with the subject, being occupied by women, being close family members, being located geographically close to the subject and being providers of multiple, face-to-face and frequent social support that is maintained or increased over time. In the comparison of means, satisfaction increases along with the density of the network and the degree centrality, on the one hand, and the betweenness centrality on the other, and it decreases in line with an increase in the number of isolates and components. The study of the relational life of people in situations of chronic pain, their changes, needs and resources, enables evaluation of the social aspect of pain and the design of intervention strategies to improve the quality of life during situations of illness.

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Veglia, Paolo. "Applications TV pair-à-pair conscientes du réseau". Phd thesis, Télécom ParisTech, 2011. http://pastel.archives-ouvertes.fr/pastel-00647980.

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Ce travail a origine dans le contexte du projet européen Napa-Wine et son premier but est de rendre les applications pair-a-pair conscientes du réseau qui est au dessous. Cette information (e.g. capacité du chemin, latence, etc.) aide a optimiser le trafic P2P et ses bénéfices sont duplices : d'un coté les operateurs peuvent limiter le trafic sur les " peering links " en le confinant dans leur Autonomous System. De l'autre coté les utilisateurs peuvent connaître une meilleure qualité du service due à la proximité des autres noeds. Pour maitriser le problème, nous analysons les applications existantes d'abord, et nous évaluons leur niveau de conscience du réseau : comme plusieurs systèmes sont " closed source ", nous les étudions comme des boites noires au moyen d'une analyse purement passive, puis nous mettons en place un banc d'essai complètement contrôlé et finalement nous utilisons des sondes actives en parallèle pour déduire les propriétés dynamiques du voisinage. Dans une seconde étape, nous vérifions l'état de l'art des algorithmes de diffusion des morceaux vidéo dans un simulateur réaliste où nous modelons latences et débit d'accès selon résultats académiques. Dans un tel scenario, nous étudions comment la diffusion des morceaux vidéo subit une dégradation de performance en présence d'erreurs de mesure et une connaissance obsolète de l'état du système. Finalement nous développons un scenario d'émulation dans lequel nous pouvons tester des vraies applications. Notre banc d'essai peut gérer jusqu'à 200 instances d'applications réelles et émuler la topologie du réseau de recherche existant Abilene ; il permet aussi de exécuter algorithmes d'ingénierie du trafic que nous exploitons pour analyser phénomènes de couplage entre couche IP et routage applicatif.

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Butte, Atul J. "Mutual information relevance networks : functional genomic networks built from pair-wise entropy measurements". Thesis, Massachusetts Institute of Technology, 2002. https://hdl.handle.net/1721.1/128565.

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This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.
Thesis (S.M.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2002.
Includes bibliographical references (leaves 27-28).
by Atul Janardhan Butte.
Thesis (S.M.)--Harvard--Massachusetts Institute of Technology Division of Health Sciences and Technology, 2002.

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Dias, Sandra Cristina Camisão. "Capacitação de pais de pessoas com deficiência : Projeto oficinas de pais". Doctoral thesis, ISPA - Instituto Universitário das Ciências Psicológicas, Sociais e da Vida, 2014. http://hdl.handle.net/10400.12/3410.

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Tese de Doutoramento apresentada ao ISPA - Instituto Universitário
Este trabalho pretende dar uma panorâmica das necessidades, competências parentais e redes de apoio dos pais de filhos com deficiência, em Portugal, e perceber quais os processos cognitivos e emocionais ocorridos nas Oficinas de Pais e os impactos da participação neste projeto, centrado na família. Foram efetuados 3 estudos empíricos que trataram os dados recolhidos aos 279 participantes das Oficinas de Pais, entre 2011 e 2012: no estudo 1, os dados dos questionários de caracterização das famílias, de identificação das necessidades dos pais e das redes de apoio, obtidos no início e no final do 1.º nível das Oficinas (GAE), foram analisados com técnicas estatísticas inferenciais; no estudo 2, os dados do questionário sobre competências parentais percebidas, preenchido por 54 pais, no início do 2.º nível das Oficinas (COR), e do questionário de auto-percepção da evolução dessas competências, preenchido no final do COR, foram analisados com técnicas estatísticas descritivas, e; no estudo 3, os conteúdos de 25 entrevistas presenciais foram analisados qualitativamente com vista à compreensão dos processos ocorridos, da adequação e dos impactos do projeto. Quanto às necessidades de apoio, considerando a amostra global, os pais raramente necessitam de ajuda para explicar o problema do filho e frequentemente precisam de alguém para falar de coisas que os preocupam. A análise sincrónica confirma que as necessidades de apoio se diferenciam consoante a idade e patologia do filho. A análise diacrónica, antes e depois do GAE, confirma que as necessidades de apoio se alteram. Quanto às redes de apoio, considerando a amostra global, os pais recorrem sempre ao cônjuge. A este juntam-se, nas necessidades práticas, os familiares, nas técnicas, os profissionais e, nas emocionais, os amigos. A análise sincrónica confirma que as redes de apoio se diferenciam consoante a idade e a patologia do filho. A análise diacrónica, evidencia, a nível global, a sua diversificação e consequente alívio do cônjuge e confirma que a participação nesta ação influenciou alterações nas redes de apoio social. A análise da competência parental percebida, antes do COR, indica uma avaliação global positiva nas competências de orientação e de controlo, negativa nas de resistência ao stress e mista nas emocionais. A autoavaliação da mudança na competência parental percebida, no final do COR, confirma que a mudança positiva foi influenciada pela participação nesta ação e que ela se diferencia com a idade e patologia do filho. A análise do conteúdo das entrevistas presenciais destaca: nos GAE, a processos de partilha, de reflexão, de consciencialização e de aprendizagens; no COR, a processos de consciencialização e de aprendizagens. Os entrevistados apreciaram positivamente as Oficinas de Pais e destacam como factores distintivos o ser uma escola de pais de filhos com diagnósticos diversos, que partilham em grupo as suas preocupações, reflexões e experiências, e o foco da capacitação ser a pessoa-pai e não só só o pai de filho com deficiência. Os impactos no participante são avaliados positivamente e refletem-se em equilíbrio emocional, alteração de perspetiva da deficiência, identificação e partilha com outros pais e reposicionamento social e familiar.
ABSTRACT: The aim of this work is to trace a panoramic of the needs, parental abilities and support network of families with disabled sons, in Portugal, and to try to perceive the cognitive and emotional processes occurred in the Oficinas de Pais project and the impact in the participants of this family centered project. Three empirical studies were developed with the data collected from the 279 participants in the Oficinas de Pais project, between 2011 and 2012: In study 1, the data had been collected with questionnaires of family`s characterization, parent`s needs identification and the support network that they use, the questionnaires had been filled at the beginning and in the end of 1.º level of Oficinas de Pais (GAE); the statistical treatment had been done with inferential statistical techniques; in study 2, the data collected in the questionnaire on the perception of the parental abilities, filled by 54 parents at the beginning of 2.º level of Oficinas de Pais (COR), and in the questionnaire of auto-perception of the evolution of these abilities, filled in the end of COR; in study 3, analysis of the content of interviews, were made to 25 parents, with sight to understand the processes and the impacts occurred as well as the adequacy of the parent`s qualification. About the needs, regarding the global sample, parents rarely need help to explain their son`s problem and frequently need somebody to speak about things that worry them. The synchronic analysis confirms that the support needs differs consonant the age and pathology of the son. The diachronic analysis, before and after GAE, confirms that the support needs modifies. About the support network , regarding the global sample, the parents always appeal to the spouse. To this join, in the practical necessities, the family ones, in the techniques, the professionals and, in the emotional ones, the friends. The synchronic analysis confirms that the support network differs consonant the age and pathology of the son. The diachronic analysis evidences, in the global sample, its diversification and consequent relief of the spouse and confirms that the participation in this project influenced alterations in the support network. The analysis of the perceived parental ability, before the COR, indicates positive evaluation in the control and orientation abilities, negative in the ones of resistance to stress and mixed evaluation in the emotional ones. The auto-evaluation change in the perceived parental ability, in the end of the COR, confirms that the positive change was influenced by the participation in this action and that it differentiates with the age and pathology of the son. The analysis of the content of the interviews concluded: in the GAE, the processes of sharing, reflection, awareness and learning; in the COR, the processes of awareness and learning. The interviewed ones appreciated Oficinas de Pais positively and indicated as distinctive factors the fact that it`s a school of parents of children with diverse diagnostic, that share their concerns, reflections and experiences, and that the focus of the empowerment was the person and not only the person as the father of a disabled son. The impacts in the participants were evaluated positively and are reflected in the emotional balance, alteration of perspective of the deficiency, identification and sharing with other parents and social and familiar repositioning.

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Esnault, Armel. "Systèmes pair-à-pair pour l’informatique opportuniste". Thesis, Lorient, 2017. http://www.theses.fr/2017LORIS432/document.

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La multiplication du nombre d'objets, qui ont vocation à être connectés à Internet (e.g., smartphones, capteurs), et la croissance des échanges de données effectués par des individus en situation de mobilité ont conduit, et conduiront encore, à une augmentation significative du trafic de données dans les réseaux, et en particulier dans les réseaux cellulaires. Les récents progrès réalisés au niveau de la couche physique pour accroître les débits dans ces réseaux pourraient s'avérer insuffisants dans le futur avec l'émergence d'un Internet des objets. Il nous semble dès lors intéressant d'étudier des architectures réseau alternatives ou complémentaires. Les réseaux hybrides à connectivité intermittente (RHCI), qui sont constitués d'une infrastructure et de parties formées par des objets fixes ou mobiles communiquant en mode ad hoc, font partie de ces architectures qui méritent d'être étudiées. Dans cette thèse, nous étudions les bénéfices que pourrait apporter l'utilisation des techniques des réseaux pair-à-pair et des communications opportunistes dans les RHCI. Nous proposons une architecture pair-à-pair décentralisée et non structurée qui permet d'assurer les communications entre des objets dans des RHCI de grande taille via différents modes de communication. Un prototype de plateforme, baptisé Nephila a été développé, pour évaluer cette approche en simulation
The number of devices that are likely to get connected to the Internet (e.g., smartphones, sensors), and the amount of data produced by people using these devices grow continuously, especially in cellular networks. Latest developments performed on the physical layer to increase the networks' bandwidth might be insufficient in the future, because of the emergence of the Internet of things. Therefore, it seems to be interesting to study new or complementary network architectures. Intermittently-Connected Hybrid Networks (ICHN), which are composed both of an infrastructure part and of parts formed by mobile device communicating using ad hoc mode, are examples of those architectures that deserve to be studied. In this thesis, we study benefits that peer-to-peer mechanisms and opportunistic networking techniques could bring to ICHN. We propose a decentralized unstructured peer-to-peer overlay architecture that supports communications between devices in wide ICHNs. A prototype named Nephila has been developed to evaluate this approach in simulation

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Enright, Nadine. "Testing the pair-wise network model: Does it accurately predict the dynamics of STIs on a network?" Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28193.

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Background. Mathematical models are an essential tool in infectious disease epidemiology. The most fundamental, and still widely used mathematical model for looking at infectious diseases, is the simple SIS (susceptible-infected-susceptible) compartmental model. However, this type of model does not integrate the local contact network of individuals making them inappropriate for studying sexually transmitted infections (STIs). Goal. To evaluate the accuracy of the pair-wise network model, proposed by Eames & Keeling (2002), which incorporates the sexual contact network. Results. Compared to observed data, the predictions of the pair-wise model were a much better fit to the prevalence of chlamydia than those of the traditional simple SIS model. Conclusions. The results demonstrate the critical role of the network structure in the spread of chlamydia and other STIs. If decision-makers continue to rely on the simple SIS model, they could underestimate the effectiveness of prevention and control strategies, actually hindering our efforts to eliminate chlamydia. Also, good quality data on the sexual network structure of the target population is necessary in order to make accurate and useful predictions.

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Ploghaus, Alexander. "A functional magnetic resonance analysis of the neural networks mediating pain and its prediction". Thesis, University of Oxford, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.393471.

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Guellier, Antoine. "Strongly Private Communications in a Homogeneous Network". Thesis, CentraleSupélec, 2017. http://www.theses.fr/2017SUPL0001/document.

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L’avènement de l’ère digitale a changé la façon dont les individus communiquent à travers le monde, et a amené de nouvelles problématiques en terme de vie privée. La notion d’anonymat la plus répandue pour les communications sur Internet consiste à empêcher tout acteur du réseau de connaître à la fois l’expéditeur d’un message et son destinataire. Bien que ce niveau de protection soit adéquat pour l’utilisateur d’Internet moyen, il est insuffisant lorsqu’un individu peut être condamné pour le simple envoi de documents à une tierce partie. C’est le cas en particulier des lanceurs d’alerte, prenant des risques personnels pour informer le public de pratiques illégales ou antidémocratiques menées par de grandes organisations. Dans cette thèse, nous envisageons un niveau d’anonymat plus fort, où l’objectif est de dissimuler le fait même qu’un utilisateur envoie ou reçoive des données. Pour cela, nous délaissons l’architecture client-serveur couramment utilisée dans les réseaux anonymes, en faveur d’une architecture entièrement distribuée et homogène, où chaque utilisateur remplit également le rôle de serveur relai, lui permettant de dissimuler son propre trafic dans celui qu’il relai pour les autres. Dans cette optique, nous proposons un nouveau protocole pour les communications pairs à pairs sur Internet. À l’aide de récents outils de preuves cryptographiques, nous prouvons que ce protocole réalise les propriétés d’anonymat désirées. De plus, nous montrons par une étude pratique que, bien que le protocole induise une grande latence dans les communications, il assure un fort anonymat, même pour des réseaux de petite taille
With the development of online communications in the past decades, new privacy concerns have emerged. A lot of research effort have been focusing on concealing relationships in Internet communications. However, most works do not prevent particular network actors from learning the original sender or the intended receiver of a communication. While this level of privacy is satisfactory for the common citizen, it is insufficient in contexts where individuals can be convicted for the mere sending of documents to a third party. This is the case for so-called whistle-blowers, who take personal risks to alert the public of anti-democratic or illegal actions performed by large organisations. In this thesis, we consider a stronger notion of anonymity for peer-to-peer communications on the Internet, and aim at concealing the very fact that users take part in communications. To this end, we deviate from the traditional client-server architecture endorsed by most existing anonymous networks, in favor of a homogeneous, fully distributed architecture in which every user also acts as a relay server, allowing it to conceal its own traffic in the traffic it relays for others. In this setting, we design an Internet overlay inspired from previous works, that also proposes new privacy-enhancing mechanisms, such as the use of relationship pseudonyms for managing identities. We formally prove with state-of-the-art cryptographic proof frameworks that this protocol achieves our privacy goals. Furthermore, a practical study of the protocol shows that it introduces high latency in the delivery of messages, but ensures a high anonymity level even for networks of small size

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Gioftsos, George. "The use of artificial neural networks and other approaches to the classification of common patterns of human movement". Thesis, University College London (University of London), 1994. http://discovery.ucl.ac.uk/1317946/.

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This thesis aims to apply neural networks in the classification of human patterns of movement and to compare the accuracy of this technique with existing methods (conventional statistics and clinical assessment). Three different examples of human movement and one of posture were chosen for study and a variety of biomechanical parameters used to describe them. The temporal parameters of gait patterns, related to speed of walking and walking with splinted knee or weighted leg, were recorded. The angular displacement of both hips and knees was measured during stepping up or down steps of five different heights. Different standing postures were studied by measuring the disposition of body landmarks associated with imagined moods of human subjects. Finally, changes of the sit-stand-sit manoeuvre due to chronic low back pain, expressed as joint movement and forces exerted on the ground, were recorded. Patterns were classified by neural networks, linear discriminant analysis and, in the case of sit-stand patterns, by qualified clinicians. By altering the number of variables to discriminate between patterns, benefits of the above classifiers were identified. The success in classification of the measured patterns by neural networks was found to have an accuracy at least as high as that of linear discriminant analysis. A neural network is a useful tool for the discrimination of patterns of human movements; its main advantage is the ability to deal with a large number of predictor variables. A successfully trained and tested neural networks can easily be set up in a computer and, on the evidence presented, could be used to help clinicians diagnose or assess pathological patterns of movement.

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Houmadi, Sherri F. "THE APPLICATION OF CONVOLUTIONAL NEURAL NETWORKS TO CLASSIFY PAINT DEFECTS". OpenSIUC, 2020. https://opensiuc.lib.siu.edu/dissertations/1807.

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AN ABSTRACT OF THE DISSERTATION OFSherri Houmadi, for the Doctor of Philosophy degree in Engineering Science, presented on March 27, 2020, at Southern Illinois University Carbondale. TITLE: THE APPLICATION OF CONVOLUTIONAL NEURAL NETWORKS TO CLASSIFY PAINT DEFECTSMAJOR PROFESSOR: Dr. Julie DunstonDespite all of the technological advancements in computer vision, many companies still utilize human visual inspection to determine whether parts are good or bad. It is particularly challenging for humans to inspect parts in a fast-moving manufacturing environment. Such is the case at Aisin Manufacturing Illinois where this study will be testing the use of convolutional neural networks (CNNs) to classify paint defects on painted outside door handles and caps for automobiles. Widespread implementation of vision systems has resulted in advancements in machine learning. As the field of artificial intelligence (AI) evolves and improvement are made, diverse industries are adopting AI models for use in their applications. Medical imaging classification using neural networks has exploded in recent years. Convolutional neural networks have proven to scale very well for image classification models by extracting various features from the images. A goal of this study is to create a low-cost machine learning model that is able to quickly classify paint defects in order to identify rework parts that can be repaired and shipped. The central thesis of this doctoral work is to test a machine learning model that can classify the paint defects based on a very small dataset of images, where the images are taken with a smartphone camera in a manufacturing setting. The end goal is to train the model for an overall accuracy rate of at least 80%. By using transfer learning and balancing the class datasets, the model was trained to achieve an overall accuracy rate of 82%.

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Witham, Kevin J. "The Relationship Between Hostility and Social Support with Chronic Pain and Health Indicators". Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc278882/.

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The purposes of the study were to examine the psychosocial variables of hostility and social support, and their independent relationships with resting physiological levels and chronic pain symptoms, and to examine the independent relationships of chronic pain chronicity and social support with hostility.

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Öhberg, Fredrik. "Biomechanical methods and error analysis related to chronic musculoskeletal pain /". Umeå : Department of Radiation Sciences, Umeå University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-18470.

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Fernandes, Macedo Daniel. "Self-configuration of multi-hop wireless networks". Paris 6, 2009. http://www.theses.fr/2009PA066498.

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Aux changements de l’environnement. Nous proposons ainsi une nouvelle Les réseaux sans fil à multi-sauts se communiquent par des liens hertziens par le relayage de paquets (les sauts). La très haute dynamique dans cet environnement force l’utilisation des approches d’auto-configuration, c’est-à-dire des approches où les paramètres des terminaux sont adaptés automatiquement face approche de partage d'informations d'auto-configuration et de cross-layer, basée sur le concept du plan de d'information, ainsi que deux algorithmes de auto-configuration qui les utilisent. Nous commençons la thèse avec l'architecture et l'évaluation du logiciel du plan d'information. Ensuite nous présentons et évaluons les deux algorithmes d'auto-configuration proposés. Le premier algorithme améliore le routage en prenant en compte la bande passante et la puissance de transmission des liens sans fil hertziens. Nous présentons un modèle mathématique pour ce problème comme support à notre proposition. Le deuxième algorithme utilise la théorie de contrôle et la logique floue pour adapter le mécanisme d'enquêtes d'une application pair à pair à la charge du réseau.

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Guerreiro, covita João. "Role of relaxin-3/RXFP3 forebrain networks in the descending control of pain in the mouse". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0121.

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La douleur est un processus biologique complexe qui alerte sur les changements potentiellement délétères de l’environnement et s’avère nécessaire à la survie de l’organisme. Toutefois, l’activation continue de ce système de signalisation peut provoquer des changements maladaptifs qui se caractérisent par des altérations anatomiques et fonctionnelles. La douleur est considérée comme chronique lorsque sa durée dépasse 3 mois. Les douleurs chroniques sont accompagnées de problèmes économiques et sociaux qui font de leur traitement une priorité de santé publique.Le cerveau décode les composantes sensori-discriminatives et affectives de la douleur. Il détermine ainsi le type de douleur (pincement, brûlure, etc.), et sa localisation dans l’organisme, et sa valeur aversive, respectivement. Le cerveau transmet ensuite à la périphérie des informations en accord avec les stimuli reçus, et qui tiennent aussi compte des expériences présentes et passées de l’individu.Le signal nociceptif est modulé à toutes les étapes de sa transmission par la mise en jeu de nombreux systèmes neurochimiques, et en particulier par des neuropeptides. La présence de neuropeptides et de leurs récepteurs dans des aires du système nerveux central (SNC) impliquées dans la transmission douloureuse suggère que les systèmes peptidergiques participent au contrôle de la nociception.La relaxine-3 est un neuropeptide principalement synthétisée dans une région du rhombencéphale appelée Nucleus Incertus (NI). Depuis sa découverte, la relaxine-3 a été impliquée, via l’activation de son récepteur RXFP3, dans le contrôle d’une large variété de comportements tels que l’anxiété, l’éveil, la recherche de récompense. Ces rôles de la signalisation relaxine-3/RXFP3 suggèrent que l’activation du récepteur RXFP3 pourrait contribuer à la modulation de la sensibilité douloureuse.Mes travaux visaient initialement à évaluer les effets de l’activation et de l’inhibition du récepteur RXFP3 sur la sensibilité thermique et mécanique dans des conditions normales et en situation de douleurs persistantes. Nos travaux ont démontré que l’administration centrale, par injection intracérébroventriculaire (icv), de l’agoniste peptidique A2 du récepteur RXFP3, provoquaient une diminution de la sensibilité mécanique mais pas thermique. De plus, l’injection icv de l’antagoniste peptidique R3(B1-22)R augmente la sensibilité mécanique et thermique. Ces données suggèrent que la signalisation relaxine-3/RXFP3 exerce un effet tonique inhibiteur sur la sensibilisation mécanique et thermique, et que la mise en jeu du récepteur RXFP3 pourrait avoir des propriétés antalgiques.De plus, j’ai étudié la mise en jeu de différentes aires cérébrales en comparant l’immunoréactivité c-Fos dans différentes régions après injection de l’agoniste A2. Toutefois, ces travaux n’ont pas révélé de différence dans le nombre des cellules marquées ni dans l’intensité du marquage.L’hybridation in situ de différentes aires cérébrales a permis d’identifier les populations exprimant les ARNm de RXFP3. J’ai analysé la coexpression des ARNm de marqueurs spécifiques, parvalbumine et somatostatine, et déterminé l’expression relative des ARNm de RXFP3 parmi ces populations.Enfin, j’ai examiné une possible anxiété comorbide chez des souris en conditions de douleur inflammatoire. De manière surprenante, le comportement anxieux n’était pas modifié chez ces souris suggérant que ce modèle ne développe pas d’anxiété et que l’activation du RXFP3 cible spécifiquement la transmission nociceptive.L’ensemble de mes résultats montre l’implication du système relaxine-3/RXFP3 dans le contrôle de la douleur, offrant de nouvelles possibilités pour le développement d’outils thérapeutiques en ciblant un système peptidergique susceptible d’impacter plusieurs comportements altérés en conditions de douleurs chroniques
Pain is a complex biological phenomenon that is beneficial and necessary for our survival, warning of changes and hazards in the environment that compromise optimal function. However, continuous activation of pain signalling systems results in maladaptive changes characterized by altered tissue and organ structure and activity. Pain lasting more than 3 months is termed chronic pain and it is under these conditions that it becomes a major burden for affected individuals. Chronic pain is also accompanied by serious social and economic burdens, making research in this field a high priority globally.The central nervous system (CNS) acts as a major control centre for nociceptive signal transmission, decoding pain for its sensory-discriminative and aversive components, i.e., deciphering the type of pain (pinch, burn, etc.), its location in the body, and its associated hedonic value, respectively. Once the information is decrypted, neural signals from the brain to the periphery act in accordance with the provided stimulus based on past and current experiences.The nociceptive signal is modulated at every step of this process by an abundance of neurochemical signals, including neuropeptides. The presence of neuropeptides and/or their receptors in areas linked to nociceptive processing and transmission suggests putative roles for these systems in the control of nociception.Relaxin-3 is a neuropeptide that is mainly synthesized in a hindbrain region known as the nucleus incertus (NI). Since its discovery, relaxin-3 has been linked to the control of a wide range of behaviours such as anxiety-like behaviours, arousal, and reward-seeking, through activation of the Gi/o-protein-coupled receptor, RXFP3. These putative roles of relaxin-3/RXFP3 signalling suggest a possible link between RXFP3 activation and modulation of pain sensitivity.Therefore, my initial studies assessed the effect of RXFP3 activation and inhibition on mechanical and thermal pain sensitivity in normal and persistent pain conditions. These studies demonstrated that central administration of the RXFP3 agonist peptide, RXFP3-A2, via intracerebroventricular (icv) injection, produced relief of mechanical, but not thermal, pain sensation. Moreover, icv injection of the RXFP3 antagonist peptide, R3(B1-22)R, augmented mechanical and thermal pain sensitivity. These data suggest that relaxin-3/RXFP3 signalling has a tonic action in maintaining mechanical and thermal pain thresholds, and the potential for activation of RXFP3 to produce pain relief.Additionally, I examined the possible involvement of different brain areas in these effects, by assessing the number of c-Fos-positive cell nuclei under different conditions. However, these studies revealed no difference in the number of c-Fos-positive cell nuclei or staining intensity in the vehicle- and RXFP3 agonist-treated mice.Further characterization of pain circuit-related brain areas using multiplex in situ hybridization revealed that RXFP3 mRNA is expressed within discrete populations of neurons in these areas. I also evaluated possible co-expression of RXFP3 mRNA with somatostatin and parvalbumin mRNA, and determined the relative proportion of RXFP3 mRNA expression in populations of neurons that express these transcripts.Finally, I examined the possible presence of comorbid anxiety in mice subjected to the persistent pain protocol. However, anxiety-like behaviour was not altered in mice with persistent hindpaw pain, suggesting this model does not display produce anxiety, and that effects of RXFP3 modulation observed specifically targeted nociceptive transmission.Overall, my findings implicate the relaxin-3/RXFP3 system in control of pain transmission, providing new opportunities for the development of therapeutic tools for pain management, by targeting a neuropeptide system that impacts several behaviours that are altered in chronic pain conditions

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Augustian, Midhumol. "Neural network based fault detection on painted surface". Thesis, Umeå universitet, Institutionen för tillämpad fysik och elektronik, 2017. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-141070.

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Machine vision systems combined with classification algorithms are being increasingly used for different applications in the age of automation. One such application would be the quality control of the painted automobile parts. The fundamental elements of the machine vision system include camera, illumination, image acquisition software and computer vision algorithms. Traditional way of thinking puts too much importance on camera systems and ignores other elements while designing a machine vision system. In this thesis work, it is shown that selecting an appropriate illumination for illuminating the surface being examined is equally important in case of machine vision system for examining specular surface. Knowledge about the nature of the surface, type and properties of the defect to be detected and classified are important factors while choosing the illumination system for the machine vision system. The main illumination system tested were bright field, dark field and structured illumination and out of the three, dark field and structured illumination gave best results. This thesis work proposes a dark field illumination based machine vision system for fault detection on specular painted surface. A single layer Artificial Neural Network model is employed for the classification of defects in intensity images of painted surface acquired with this machine vision system. The results of this research work proved that the quality of the images and size of data set used for training the Neural Network model play a vital role in the performance of the classifier algorithm.

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Eisenbarth, Jean-Philippe. "Analyse, valorisation et protection des réseaux pair-à-pair de blockchains publiques". Electronic Thesis or Diss., Université de Lorraine, 2022. http://www.theses.fr/2022LORR0213.

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Les blockchains reposent sur des réseaux P2P essentiels à leur bon fonctionnement puisqu'ils assurent la dissémination des transactions et des blocs à l'ensemble des parties. Alors que Bitcoin et Ethereum - les deux principales blockchains publiques - capitalisent aujourd'hui des milliers de milliards de dollars, attirant chaque jour de nouveaux utilisateurs, peu d'études s'intéressent aux aspects réseau bien que la littérature montre que de nombreux problèmes peuvent réduire la fiabilité des réseaux P2P publics. Dans cette thèse, nous nous sommes intéressés dans un premier temps à la supervision des réseaux P2P des blockchains Bitcoin et Ethereum. Nous avons implanté un crawler pour chaque réseau capable de découvrir tous les pairs connectés et avons analysé les données issues de campagnes de mesure de plusieurs mois. Différents critères pouvant affecter la fiabilité du réseau ont été étudiés, tels que le nombre de pairs, leur distribution du point de vue géographique ou du réseau IP, leur taux d'attrition, la proportion de clients aux vulnérabilités connues, l'existence de motifs journaliers de connexion ou encore la capacité d'inférer la topologie. Il apparaît que les deux réseaux montrent de bonnes propriétés sur tous ces points. Partant du constat que, d'une part, le réseau P2P d'Ethereum basé sur une table de hachage distribuée (DHT) est largement inexploité, car aucune donnée n'est stockée dans la DHT, et que, d'autre part, le stockage des données de la blockchain ne fait que croître (ce qui posera des problèmes à terme), nous avons étudié dans un second temps le stockage des données du principal client d'Ethereum (Geth) et sa manière de synchroniser l'état de la blockchain entre les pairs. Nous avons conçu une nouvelle architecture distribuée de stockage pour Ethereum tirant parti de la DHT, rétrocompatible avec les clients actuels et pouvant réduire l'espace disque, utilisé pour le stockage long terme, de 95% (58% du stockage total) sans impact sur les garanties ou les performances de la blockchain Ethereum. Le stockage des données sur la DHT la rend cependant plus intéressante à attaquer, en particulier par des attaques Sybil localisées. Nous avons donc analysé les pairs d'Ethereum à la recherche de motifs pouvant traduire des attaques Sybil et montré l'existence de milliers de nœuds suspects regroupant un grand nombre d'identifiants pour une même adresse IP (jusqu'à 10000/IP). Nous avons finalement conçu et implanté une architecture de protection contre les attaques Sybils. Celle-ci se base sur un crawler détectant les nœuds suspects en temps réel, un smart contract structurant l'information et la distribuant à tous les pairs, et enfin une révocation complètement distribuée, chaque pair constatant lui-même l'attaque et coupant ses connexions aux nœuds Sybils. La mise en œuvre sur un réseau de test Ethereum a montré l'efficacité de l'architecture proposée
Blockchains rely on P2P networks that are essential to their proper functioning, as they ensure the dissemination of transactions and blocks to all parties.While Bitcoin and Ethereum - the two main public blockchains - are now worth trillions of dollars, attracting new users every day, few studies focus on the network aspects, although the literature shows that many problems can reduce the reliability of public P2P networks.In this thesis, we first focused on the monitoring of the P2P networks of the Bitcoin and Ethereum blockchains.We implemented a crawler for each network able to discover all connected peers and analyzed data from several months of measurement campaigns.Different criteria that can affect the reliability of the network were studied, such as the number of peers, their geographical distribution, their distribution over the IP network, the churn, the proportion of clients with known vulnerabilities, the existence of daily connection patterns or the ability to infer topology. It appears that both networks show good properties on all these points.Starting from the observation that, on the one hand, the Ethereum P2P network based on a distributed hash table (DHT) is largely untapped, as no data is stored in the DHT, and on the other hand, thestorage of the blockchain data is only growing (which will eventually be problematic),we studied in a second time the data storage of the main client of Ethereum(Geth) and its way of synchronizing the state of the blockchain between the peers. We have designeda new distributed storage architecture for Ethereum taking advantage of the DHT, backward compatible with the current clients and able to reduce the disk space, used for long-term storage, by 95% (58% of the total storage) without impacting the guarantees or the performances of the Ethereum blockchain.However, storing data on the DHT makes it more prone to attacks, especially Sybil attacks.We therefore analyzed Ethereum peers for patterns that could reflect Sybil attacks and showed the existence of thousands of suspicious nodes grouping many identifiers for a single IP address (up to 10000/IP).We finally designed and implemented a protection architecture against Sybil attacks. It is based on a crawler detecting suspicious nodes in real time, a smart contract structuring the information and distributing it to all peers, and finally a fully-distributed revocation system, each peer noticing itself the attack and removing its connections.The deployment on an Ethereum test network has shown the effectiveness of the proposed architecture

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Yoho, Jason Jon. "Physically-Based Realizable Modeling and Network Synthesis of Subscriber Loops Utilized in DSL Technology". Diss., Virginia Tech, 2001. http://hdl.handle.net/10919/29738.

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Performance analysis of Digital Subscriber Line (DSL) technologies, which are implemented on existing telephone subscriber loops, is of vital importance to DSL service providers. This type of analysis requires accurate prediction of the local loop structure and precise identification of the cable parameters. These cables are the main components of the loop and are typically comprised of multi-conductor twisted pair type currently being used on existing telephone subscriber loops. This system identification problem was investigated through the application of single port measurements, with preference being placed on measurements taken from the service provider's end of the loop under investigation. Once the cabling system has been identified, the performance analysis of the loop was obtained through simulation. Accurate modeling is an important aspect of any system identification solution; therefore, the modeling of the twisted pair cables was thoroughly investigated in this research. Early modeling attempts of twisted pair cabling systems for use with (DSL) technology has not been vigorously investigated due to the difficulty in obtaining wideband physical data necessary for the task as well as the limitations of simulators to accurately model the skin effects of the conductors. Models are developed in this research that produce a wideband representation of the twisted pair cables through the use of the data measured in high frequency spectra. The twisted-pair cable models were then applied to the system identification problem through a de-embedding type approach. The identification process accurately characterizes the sections of the subscriber loop closest to the measurements node, and these identified sections were then modeled and de-embedded from the system measurement in a layer removing, or "peeling", type process. After each identified section was de-embedded from the system measurement, the process was repeated until the entire system was identified. Upon completion of the system identification process, the resulting system model was simulated between the central office (CO) and resulting identified customer nodes for the evaluation of performance analysis. The performance analysis allows the providers to identify points where the DSL technology is feasible, and where so, the rates of the data transfer to the nodes that can be expected.
Ph. D.

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Marginean, Radu. "Measurement of the top pair production cross section at CDF using neural networks". Connect to this title online, 2004. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1101831484.

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Thesis (Ph. D.)--Ohio State University, 2004.
Title from first page of PDF file. Document formatted into pages; contains xiii, 110 p.; also includes graphics (some col.). Includes bibliographical references (p. 106-110).

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Tazawa, Nilson. "Modelagem da dor utilizando-se redes neurais artificiais". Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/3/3140/tde-14122006-153805/.

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Este trabalho apresenta os resultados obtidos na elaboração de dois modelos para o fenômeno da dor utilizando-se redes neurais artificiais, de forma a simular computacionalmente as prováveis respostas de um indivíduo na presença de dor. Os modelos são fundamentados na Teoria de Controle da Comporta de dor, onde são analisados os principais componentes envolvidos na percepção/inibição da dor, bem como o funcionamento dos mecanismos biológicos e cognitivos participantes do processo. A escolha do tipo de rede neural é feita a partir das observações realizadas, considerando-se também o número de fatores envolvidos e o comportamento esperado frente a cada conjunto de entrada. O método de treinamento das redes neurais baseia-se no algoritmo de retropropagação. O foco do processamento da rede é responder adequadamente, considerando-se a influência das entradas envolvidas, a eventos posteriores à ocorrência de uma lesão gerando um sinal de alerta a ser utilizado como uma resposta natural do organismo a este dano tecidual. O desempenho de cada modelo é avaliado comparando-se as saídas obtidas com aquelas esperadas para cada padrão de entrada.
This work presents the results of two models that were developed to describe the phenomenon of pain using Artificial Neural Networks, with the final goal to simulate computationally possible answers of an individual in the presence of pain. The models are based on The Gate Control Theory, where the main components involved in the perception/inhibition of pain were analysed, as well as the operation of the biological and cognitive mechanisms involved in the process. The type of neural network was chosen based on accumulated knowledge, considering also the number of involved factors and the expected behaviour response to each set of patterns. The neural networks were trained based on the backpropagation algorithm. The major focus of the network processing was to answer adequately to the occurrence of an injury, considering the role of the involved inputs, and generating an alert signal to this tecidual damage, which could replace the natural reply of the organism. The performance of each model is evaluated comparing the outputs obtained with those expected for each pattern.

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Pham, Khoa Ngoc. "Conformational Dynamics and Stability Associated with Magnesium or Calcium Binding to DREAM in the Regulation of Interactions between DREAM and DNA or Presenilins". FIU Digital Commons, 2016. http://digitalcommons.fiu.edu/etd/2589.

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Downstream regulatory element antagonist modulator (DREAM) is involved in various interactions with targets both inside and outside of the nucleus. In the cytoplasm, DREAM interacts with the C-terminal fragments of presenilins to facilitate the production of β-amyloid plaques in Alzheimer’s disease. In the nucleus, Ca2+ free DREAM directly binds to specific downstream regulatory elements of prodynorphin/c-fos gene to repress the gene transcription in pain modulation. These interactions are regulated by Ca2+ and/or Mg2+ association at the EF-hands in DREAM. Therefore, understanding the conformational dynamics and stability associated with Ca2+ and/or Mg2+ binding to DREAM is crucial for elucidating the mechanisms of interactions of DREAM with DNA or presenilins. The critical barrier for envisioning the mechanisms of these interactions lies in the lack of NMR/crystal structures of Apo and Mg2+DREAM. Using a combination of fluorescence spectroscopy, circular dichroism, isothermal titration calorimetry, photothermal spectroscopy, and computational approaches, I showed that Mg2+ association at the EF-hand 2 structurally stabilizes the N-terminal alpha-helices 1, 2, and 5, facilitating the interaction with DNA. Binding of Ca2+ at the EF-hand 3 induces significant structural changes in DREAM, mediated by several hydrophobic residues in both the N- and C-domains. These findings illustrate the critical role of EF-hand 3 for Ca2+ signal transduction from the C- to N-terminus in DREAM. The Ca2+ association at the EF-hand 4 stabilizes the C-terminus by forming a cluster consisting of several hydrophobic residues in C-terminal domain. I also demonstrated that association of presenilin-1 carboxyl peptide with DREAM is Ca2+ dependent and the complex is stabilized by aromatic residues F462 and F465 from presenilin-1 and F252 from DREAM. Stabilization is also provided by residues R200 and R207 in the loop connecting a7 and a8 in DREAM and the residues D450 and D458 in presenilin-1. These findings provide a structural basis for the development of new drugs for chronic pain and Alzheimer’s disease treatments.

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Lok, Peter Yin Cheung. "Development of a novel minimally invasive scaffold system for spinal disc repair". Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/12583.

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Debilitating chronic back pain caused by severe spinal disc degeneration leads to loss of mobility, affecting quality of life, a significant loss of productivity for the employee and the employer. Currently available surgical intervention options, such as spinal fusion and total disc replacement, seeking only to alleviate pain, are not only invasive, but fail to address the underlying biological causes of spinal disc degeneration, or restore normal physiological spinal motion. Recently proposed tissue engineering approaches focus on stopping and reversing the degenerative cascade, which has a promising regenerative effect, though not without significant challenges before a clinical application is made available, including tumourigenesis risks and proof of efficacy. A minimally invasive nucleus pulposus replacement option, which preserves the competent annulus fibrosis, while replacing the removed degenerated nucleus tissue with a prosthesis, provides an alternative for early disc degeneration, though most commercially available types are at clinical trial stages. There is an opportunity for developing a minimally invasive nucleus pulposus replacement type spinal implant system that restores disc biomechanics and addresses biological degenerative causes. This body of work details the design, development, fabrication, prototyping, verification and validation of this novel implant system. The implant system consisted of a configuration of scaffold and hydrogel interpenetrating polymer network composite delivered minimally invasively via a cannula system, after the nucleus pulposus is removed in a nucleotomy with a set of specialised tools. Implantation of the novel prosthesis was shown to be successful in various spinal disc models, in meeting identified design and functional requirements, including biomechanical loading, resistance to expulsion and radiopacity.

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40

Yeferny, Taoufik. "Proposition d'approches de routage de requêtes dans les systèmes pair-à-pair non structurés". Phd thesis, Institut National des Télécommunications, 2014. http://tel.archives-ouvertes.fr/tel-01048671.

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Ces deux dernières décennies les systèmes P2P de partage de fichiers sont devenus très populaires grâce aux accès à des ressources diverses, distribuées sur Internet. Parallèlement à l'évolution de cette catégorie de systèmes, les dispositifs mobiles (téléphones cellulaires, PDA et autres appareils portatifs) ont eu un grand succès sur le marché. Équipés d'une technologie de communication sans fil (Bluetooth, et Wifi), ils peuvent communiquer sans nécessiter une infrastructure particulière en utilisant un réseau mobile adhoc (Mobile Adhoc NETwork -MANET). De la même manière, les systèmes P2P peuvent être aussi déployés sur ce type de réseau et deviennent des systèmes P2P mobiles (Mobile 2P systems). Dans le cadre de cette thèse, nous nous intéressons essentiellement à la recherche d'information dans les systèmes P2P et plus précisément au problème de routage de requêtes. La première partie de la thèse, s'est focalisée sur le routage de requêtes dans les systèmes P2P sur Internet. Nous avons proposé (i) un modèle de routage sémantique basé sur l'historique des requêtes. Ce modèle est ensuite instancié pour définir une nouvelle méthode de routage par apprentissage. Pour pallier le problème de démarrage à froid, (ii) nous avons proposé une méthode prédictive de l'intention de l'utilisateur qui construit une base de connaissances à priori pour chaque pair. Enfin, (iii) nous avons proposé une méthode de routage hybride pour traiter le problème d'échec de sélection. Cette méthode est basée sur l'historique des requêtes et le regroupement de pairs dans des groupes sémantiques. La deuxième partie de la thèse, s'est focalisée sur le routage de requêtes dans les systèmes P2P mobiles. L'apparition des MANETs, a soulevé de nouveaux challenges de routage. Ces réseaux souffrent de plusieurs contraintes liées aux supports de transmission ou bien aux dispositifs mobiles. Dans ce cadre, nous avons proposé une méthode de routage pour les systèmes P2P non structurés mobiles basée sur le contexte de l'utilisateur. D'un point de vue technique, toutes ces propositions ont été développées, validées et évaluées grâce aux simulateurs PeerSim et NS2

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Nikoloski, Zoran. "Graph-theoretic Approach to Modeling Propagation and Control of Network Worms". Doctoral diss., University of Central Florida, 2005. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/3164.

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In today's network-dependent society, cyber attacks with network worms have become the predominant threat to confidentiality, integrity, and availability of network computing resources. Despite ongoing research efforts, there is still no comprehensive network-security solution aimed at controling large-scale worm propagation. The aim of this work is fivefold: (1) Developing an accurate combinatorial model of worm propagation that can facilitate the analysis of worm control strategies, (2) Building an accurate epidemiological model for the propagation of a worm employing local strategies, (3) Devising distributed architecture and algorithms for detection of worm scanning activities, (4) Designing effective control strategies against the worm, and (5) Simulation of the developed models and strategies on large, scale-free graphs representing real-world communication networks. The proposed pair-approximation model uses the information about the network structure--order, size, degree distribution, and transitivity. The empirical study of propagation on large scale-free graphs is in agreement with the theoretical analysis of the proposed pair-approximation model. We, then, describe a natural generalization of the classical cops-and-robbers game--a combinatorial model of worm propagation and control. With the help of this game on graphs, we show that the problem of containing the worm is NP-hard. Six novel near-optimal control strategies are devised: combination of static and dynamic immunization, reactive dynamic and invariant dynamic immunization, soft quarantining, predictive traffic-blocking, and contact-tracing. The analysis of the predictive dynamic traffic-blocking, employing only local information, shows that the worm can be contained so that 40\% of the network nodes are not affected. Finally, we develop the Detection via Distributed Blackholes architecture and algorithm which reflect the propagation strategy used by the worm and the salient properties of the network. Our distributed detection algorithm can detect the worm scanning activity when only 1.5% of the network has been affected by the propagation. The proposed models and algorithms are analyzed with an individual-based simulation of worm propagation on realistic scale-free topologies.
Ph.D.
School of Computer Science
Engineering and Computer Science
Computer Science

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42

Desai, Pratikkumar U. "Localization and Surveillance using Wireless Sensor Network and Pan/Tilt Camera". Wright State University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=wright1240284866.

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ABHYANKAR, SACHIN ARUN. "TRAFFIC ENGINEERING OVER BLUETOOTH-BASED WIRELESS AD HOC NETWORKS". University of Cincinnati / OhioLINK, 2003. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1054754764.

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44

Ngo, Hoang Giang. "De l'Interconnexion des Réseaux de Recouvrement à la Cooperation des Systèmes Pair-à-Pair". Phd thesis, Université Nice Sophia Antipolis, 2013. http://tel.archives-ouvertes.fr/tel-00921367.

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Les systèmes pair-à-pair (P2P) sont utilisés par des millions d'usagers tous les jours. Dans beaucoup de cas, un usager souhaite communiquer, échanger du contenu ou des services à travers différents systèmes P2P. Cela requiert de la coopération entre les différents systèmes P2P, ce qui est très souvent difficile ou même impossible à obtenir, à cause des raisons suivantes; in primis, l'absence d'une infrastructure de routage entre les réseaux, ce qui rend la communication étanche et, in secundis, l'incompatibilité des protocoles et des opérations des susdits systèmes. L'objectif principal de cette thèse est celui de permettre la coopération entre systèmes P2P. La thèse introduit un cadre de coopération rétro-compatible entre systèmes P2P hétérogènes constitué de deux parties. La première est un cadre de routage intra-réseaux permettant à des réseaux hétérogènes de communiquer. La deuxième est une application coopérative, conçue à l'aide et au travers du cadre de routage, dont l'objectif est celui de résoudre les incompatibilités protocolaires des systèmes P2P sous-jacents. A cause des différences intrinsèques des domaines d'applications - dans la description du cadre de coopération - la thèse se focalise essentiellement sur les principes fondateurs de la construction du cadre de coopération. Comme étude de cas de notre cadre de coopération, on présente une solution complète permettant une coopération entre des réseaux P2P spécialisés dans l'échange des fichiers pouvant s'appliquer aux réseaux P2P actuels. La solution proposée serait composée par une application de coopération, devant fonctionner à l'aide d'un protocole d'échange de fichiers inter-réseaux (IFP), et qui devrait être à la base du cadre de routage inter-protocolaire. A travers des expérimentations en taille réelle, on montre l'efficacité du cadre de routage inter-réseaux ainsi que l'efficacité de la solution proposée, pour permettre la coopération entre réseaux d'échange des fichiers P2P. Pendant l'étude des protocoles de routages inter-réseaux, on a observé que l'interconnexion des systèmes P2P pourrait donner une réponse à des problématiques communes aux systèmes P2P, comme le passage à l'échelle, la localisation, la tolérance aux pannes, et l'auto-organisation. Notre conviction est qu'un système possédant toutes ces caractéristiques pourrait être à la base de la conception de plusieurs systèmes ''cyber-physiques'' (CPS). En fait, dans la deuxième partie de la thèse, on présente une étude de cas d'usage de notre architecture d'interconnexion des réseaux P2P appliquée à un cas typique de CPS, notamment les réseaux d'électricité intelligents. Dans cette étude de cas, une collection des ''tables de hachage distribuées'' et organisées de façon hiérarchique est à la base d'une infrastructure de communication entre de compteurs d'électricité intelligents (AMI). L'analyse et les expérimentations montrent le passage à l'échelle et l'efficacité de communication de l'architecture proposée.

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Alberts, Marthinus. "Analysis of the IEEE 802.15.4a ultra wideband physical layer through wireless sensor network simulations in OMNET++". Diss., University of Pretoria, 2011. http://hdl.handle.net/2263/23103.

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Wireless Sensor Networks are the main representative of pervasive computing in large-scale physical environments. These networks consist of a large number of small, wireless devices embedded in the physical world to be used for surveillance, environmental monitoring or other data capture, processing and transfer applications. Ultra wideband has emerged as one of the newest and most promising concepts for wireless technology. Considering all its advantages it seems a likely communication technology candidate for future wireless sensor networks. This paper considers the viability of ultra wideband technology in wireless sensor networks by employing an IEEE 802.15.4a low-rate ultra wideband physical layer model in the OMNET++ simulation environment. An elaborate investigation into the inner workings of the IEEE 802.15.4a UWB physical layer is performed. Simulation experiments are used to provide a detailed analysis of the performance of the IEEE 802.15.4a UWB physical layer over several communication distances. A proposal for a cognitive, adaptive communication approach to optimize for speed and distance is also presented. AFRIKAANS : Draadlose Sensor Netwerke is die hoof verteenwoordiger vir deurdringende rekenarisering in groot skaal fisiese omgewings. Hierdie tipe netwerke bestaan uit ’n groot aantal klein, draadlose apparate wat in die fisiese wêreld ingesluit word vir die doel van bewaking, omgewings monitering en vele ander data opvang, verwerk en oordrag applikasies. Ultra wyeband het opgestaan as een van die nuutste en mees belowend konsepte vir draadlose kommunikasie tegnologie. As al die voordele van dié kommunikasie tegnologie in ag geneem word, blyk dit om ’n baie goeie kandidaat te wees vir gebruik in toekomstige draadlose sensor netwerke. Hierdie verhandeling oorweeg die vatbaarheid van die gebruik van die ultra wyeband tegnologie in draadlose sensor netwerke deur ’n IEEE 802.15.4a lae-tempo ultra wyeband fisiese laag model in die OMNET++ simulasie omgewing toe te pas. ’n Breedvoerige ondersoek word geloots om die fyn binneste werking van die IEEE 802.15.4a UWB fisiese laag te verstaan. Simulasie eksperimente word gebruik om ’n meer gedetaileerde analiese omtrent die werkverrigting van die IEEE 802.15.4a UWB fisiese laag te verkry oor verskillende kommunikasie afstande. ’n Voorstel vir ’n omgewings bewuste, aanpasbare kommunikasie tegniek word bespreek met die doel om die spoed en afstand van kommunikasie te optimiseer.
Dissertation (MEng)--University of Pretoria, 2011.
Electrical, Electronic and Computer Engineering
unrestricted

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46

Dogan, Torgay. "An Analysis Of The Pan-european Transport Network". Master's thesis, METU, 2005. http://etd.lib.metu.edu.tr/upload/12606564/index.pdf.

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This thesis analyses the process of the creation of the Pan-European Transport Network connecting the European Union with the neighbouring regions and Caucasus and Central Asia in the long run. The thesis focuses on the incentives in establishing a continental transport network stemming from the nature of the capitalist relations between market and national and supranational forces in the margins of the global economy. In this context, the parallel processes of the acceleration of the European integration and the establishment of the Pan-European Transport Network are explored. Furthermore, in the thesis, the components of the Pan-European Transport Network, namely the Trans-European Transport Networks (TEN-T), the Pan-European Transport Corridors and Areas (including Turkey), and the Eurasian transport routes are analysed. The thesis seeks to show that the Pan-European Transport Network has been planned to ensure the economic and political cohesion of the European Union and regulate the trade relations between Europe and Asia, including the transportation of the energy resources. The lack of specific analyses on the main problem of the thesis and the incrementalism in the processes of the European integration and development of the Pan-European Transport Network induce the interpretation of the raw and first hand information, such as technical reports, intergovernmental declarations, official documents, speeches and press releases.

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Schoenberg, Lisa Maire. "Assessing North Dakota Nurse Practitioners' Knowledge of the National Comprehensive Cancer Network's Treatment Guidelines for Adult Cancer Pain". Diss., North Dakota State University, 2013. https://hdl.handle.net/10365/26928.

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The purpose of this project was to determine if access to the National Comprehensive Cancer Network's guidelines on the treatment of adult cancer related pain increased nurse practitioner knowledge and utilization in practice. The guidelines were provided to nurse practitioners who practiced within an oncology setting in North Dakota to assess whether their knowledge of pain management increased and if they found the guidelines to be a useful tool to have in practice. A pre-intervention questionnaire was sent to the participants to gain demographic information, including, age and gender, type of certification, primary area of practice, number of years practicing as an nurse practitioner, hours spent in clinical practice per week, and the average number of oncology patients seen per week. In addition, the pre-intervention questionnaire evaluated current treatment modalities the participants utilized in treating cancer related pain. After receiving the pre-intervention questionnaires, the National Comprehensive Cancer Network's guidelines were distributed to the participants who agreed to utilize them for the duration of this project. The participants were given the full guidelines, a pocketbook of the guideline's algorithms, and instructions for utilizing the phone application of the guidelines. A post-intervention questionnaire was sent out three months after the guidelines were distributed assessing their impact on nurse practitioner practice. Overall, the participants felt that the guidelines increased their knowledge on treatment modalities for cancer related pain and found them to be a useful resource in practice. From this project we can assume that the evidence based guidelines provided from the National Comprehensive Cancer Network are beneficial for novice and experienced nurse practitioners practicing in oncology.

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48

Kang, Hai-zhuang. "Assessment of paint appearance quality in the automotive industry". Thesis, Brunel University, 2000. http://bura.brunel.ac.uk/handle/2438/7900.

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In the modern automotive industry, more and more manufacturers recognise that vehicle paint appearance makes an important contribution to customer satisfaction. Attractive appearance has become one of the important factors for customers in making a decision to purchase a car. Objective measurement of the quality of autobody paint appearance, as perceived by the customer, in a repeatable, reproducible, continuous scale manner is an important requirement for improving the paint appearance. It can provide car manufacturers a standard reference to evaluate the quality of the paint appearance. This thesis mainly deals with the measurement of paint appearance quality in the automotive industry by investigating, identifying and developing measurement methods in this area. First of all, the 'state of the art' in the area of paint appearance measurement was presented, which summarised the concept of appearance, models, attributes and definitions. To further identify the parameters and instruments used in the automotive industry, a round robin test was launched to perform visual assessment and instrument measurements on a set of panels in some European car manufacturers. A summary of the correlation found between measurable parameters and visual assessment provided the basis of the further work. Based on the literature survey and round robin test results, the next work is mainly concentrated on the two most important parameters, 'orange peel' and 'metal texture effect', how to separate and evaluate them. Digital signal processing technique, FFT and Filtering, have been employed to separate them and a set of measures have been provided for evaluation. At the same time, the technique for texture pattern recognition was introduced to evaluate the texture effect when a fine texture comparison was needed. A set of computable textural parameters based on grey-tone spatial-dependence matrices gives good correlation directly corresponding to visual perception. To resolve the overall appearance modelling problem, two novel and more powerful modelling tools, artificial neural networks and fuzzy logic, are introduced to model the overall appearance. The test results showed that both of them are able to reflect the correlation between overall appearance and the major parameters measured from a painted surface. Finally, an integrated measurement system, 'Smart Appearance', was developed using the image processing techniques and the artificial neural network model. The implement results show that this system can measure the major attributes of paint appearance and provide an overall appearance index corresponding to human visual perception. This system is helpful to product quality control on car body paint. It also could be used on the paint production line for dynamic measurement.

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Deng, Guodong. "SYNTHESIS AND CHARACTERIZATION OF IONICALLY CROSS-LINKED NETWORKS THROUGH THE USE OF ION-PAIR COMONOMERS". University of Akron / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=akron1534124831858723.

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Draidi, Fady. "Recommandation Pair-à-Pair pour Communautés en Ligne à Grande Echelle". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2012. http://tel.archives-ouvertes.fr/tel-00766963.

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Les systèmes de recommandation (RS) et le pair-à-pair (P2) sont complémen-taires pour faciliter le partage de données à grande échelle: RS pour filtrer et person-naliser les requêtes des utilisateurs, et P2P pour construire des systèmes de partage de données décentralisés à grande échelle. Cependant, il reste beaucoup de difficultés pour construire des RS efficaces dans une infrastructure P2P. Dans cette thèse, nous considérons des communautés en ligne à grande échelle, où les utilisateurs notent les contenus qu'ils explorent et gardent dans leur espace de travail local les contenus de qualité pour leurs sujets d'intérêt. Notre objectif est de construire un P2P-RS efficace pour ce contexte. Nous exploitons les sujets d'intérêt des utilisateurs (extraits automatiquement des contenus et de leurs notes) et les don-nées sociales (amitié et confiance) afin de construire et maintenir un overlay P2P so-cial. La thèse traite de plusieurs problèmes. D'abord, nous nous concentrons sur la conception d'un P2P-RS qui passe à l'échelle, appelé P2Prec, en combinant les ap-proches de recommandation par filtrage collaboratif et par filtrage basé sur le contenu. Nous proposons alors de construire et maintenir un overlay P2P dynamique grâce à des protocoles de gossip. Nos résultats d'expérimentation montrent que P2Prec per-met d'obtenir un bon rappel avec une charge de requêtes et un trafic réseau accep-tables. Ensuite, nous considérons une infrastructure plus complexe afin de construire et maintenir un overlay P2P social, appelé F2Frec, qui exploite les relations sociales entre utilisateurs. Dans cette infrastructure, nous combinons les aspects filtrage par contenu et filtrage basé social, pour obtenir un P2P-RS qui fournit des résultats de qualité et fiables. A l'aide d'une évaluation de performances extensive, nous mon-trons que F2Frec améliore bien le rappel, ainsi que la confiance dans les résultats avec une surcharge acceptable. Enfin, nous décrivons notre prototype de P2P-RS que nous avons implémenté pour valider notre proposition basée sur P2Prec et F2Frec.

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