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Dissertations / Theses on the topic 'SSCEP'

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Published: 4 June 2021
Last updated: 19 February 2022

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1

Wingi, Hereuwar Walipe, and n/a. "A review and analysis of Secondary Schools Community Extension Project (SSCEP)." University of Canberra. Education, 1991. http://erl.canberra.edu.au./public/adt-AUC20061110.163118.

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2

Baker, Mark. "Differentiation of dermatophyte fungi using SSCP." Thesis, University of Kent, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498820.

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3

Talevi, Luca. "Sviluppo e test di un sistema BCI SSVEP-based." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/11636/.

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Una Brain Computer Interface (BCI) è un dispositivo che permette la misura e l’utilizzo di segnali cerebrali al fine di comandare software e/o periferiche di vario tipo, da semplici videogiochi a complesse protesi robotizzate. Tra i segnali attualmente più utilizzati vi sono i Potenziali Evocati Visivi Steady State (SSVEP), variazioni ritmiche di potenziale elettrico registrabili sulla corteccia visiva primaria con un elettroencefalogramma (EEG) non invasivo; essi sono evocabili attraverso una stimolazione luminosa periodica, e sono caratterizzati da una frequenza di oscillazione pari a quella di stimolazione. Avendo un rapporto segnale rumore (SNR) particolarmente favorevole ed una caratteristica facilmente studiabile, gli SSVEP sono alla base delle più veloci ed immediate BCI attualmente disponibili. All’utente vengono proposte una serie di scelte ciascuna associata ad una stimolazione visiva a diversa frequenza, fra le quali la selezionata si ripresenterà nelle caratteristiche del suo tracciato EEG estratto in tempo reale. L’obiettivo della tesi svolta è stato realizzare un sistema integrato, sviluppato in LabView che implementasse il paradigma BCI SSVEP-based appena descritto, consentendo di: 1. Configurare la generazione di due stimoli luminosi attraverso l’utilizzo di LED esterni; 2. Sincronizzare l’acquisizione del segnale EEG con tale stimolazione; 3. Estrarre features (attributi caratteristici di ciascuna classe) dal suddetto segnale ed utilizzarle per addestrare un classificatore SVM; 4. Utilizzare il classificatore per realizzare un’interfaccia BCI realtime con feedback per l’utente. Il sistema è stato progettato con alcune delle tecniche più avanzate per l’elaborazione spaziale e temporale del segnale ed il suo funzionamento è stato testato su 4 soggetti sani e comparato alle più moderne BCI SSVEP-based confrontabili rinvenute in letteratura.
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4

Hodgskiss, Dean Leslie. "Towards improved visual stimulus discrimination in an SSVEP BCI." Master's thesis, University of Cape Town, 2010. http://hdl.handle.net/11427/11283.

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The dissertation investigated the influence of stimulus characteristics, electroencephalographic (EEG) electrode location and three signal processing methods on the spectral signal to noise ratio (SNR) of Steady State Visual Evoked Potentials (SSVEPs) with a view for use in Brain-Computer Interfaces (BCIs). It was hypothesised that the new spectral baseline processing method introduced here, termed the 'activity baseline', would result in an improved SNR.
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5

Raza, Asim. "SSVEP based EEG Interface for Google Street View Navigation." Thesis, Linköpings universitet, Medie- och Informationsteknik, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-104276.

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Brain-computer interface (BCI) or Brain Machine Interface (BMI) provides direct communication channel between user’s brain and an external device without any requirement of user’s physical movement. Primarily BCI has been employed in medical sciences to facilitate the patients with severe motor, visual and aural impairments. More recently many BCI are also being used as a part of entertainment. BCI differs from Neuroprosthetics, a study within Neuroscience, in terms of its usage; former connects the brain with a computer or external device while the later connects the nervous system to an implanted device. A BCI receives the modulated input from user either invasively or non-invasively. The modulated input, concealed in the huge amount of noise, contains distinct brain patterns based on the type of activity user is performing at that point in time. Primary task of a typical BCI is to find out those distinct brain patterns and translates them to meaningful communication command set. Cursor controllers, Spellers, Wheel Chair and robot Controllers are classic examples of BCI applications. This study aims to investigate an Electroencephalography (EEG) based non-invasive BCI in general and its interaction with a web interface in particular. Different aspects related to BCI are covered in this work including feedback techniques, BCI frameworks, commercial BCI hardware, and different BCI applications. BCI paradigm Steady State Visually Evoked Potentials (SSVEP) is being focused during this study. A hybrid solution is developed during this study, employing a general purpose BCI framework OpenViBE, which comprised of a low-level stimulus management and control module and a web based Google Street View client application. This study shows that a BCI can not only provide a way of communication for the impaired subjects but it can also be a multipurpose tool for a healthy person. During this study, it is being established that the major hurdles that hamper the performance of a BCI system are training protocols, BCI hardware and signal processing techniques. It is also observed that a controlled environment and expert assistance is required to operate a BCI system.
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6

Mgijima-Msindwana, Mirriam Miranda Nomso. "Implementing Educational Innovations: The case of the Secondary School Curriculum Diversification Programme in Lesotho." University of the Western Cape, 1991. http://hdl.handle.net/11394/8434.

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Philosophiae Doctor - PhD
Between 1974 and 1982 the MOE introduced in two phases the diversification programme [SSCDP] which sought to establish practical subjects in the secondary school curriculum. This study examines the sustainability of implementation efforts beyond project expiry. It was hypothesised that SSCDP is not working as originally intended. The broad research problem was framed thus: What implementation response arises from an open-ended innovation policy? Subsidiary questions are: 1. How far have the policy-makers communicated the meaning of SSCDP and what factors account for mismatches between policy intentions and innovation practice? 2. What is the response of Project schools and what factors explain variation in response? 3. What is their significance for the sustainability of SSCDP? The analysis draws key concepts from the innovation literature on models and strategies of planned change; relationships in the implementation hierarchy; determinants of and orientations to the implementation process. Centred around qualitative research methods, the investigation utilises data from project documents, semi-structured interviews and from observations during school visits. Findings show an overall low level of implementation that varies among project schools. This is attributed to: Poor interpretation of SSCDP goals; Deficiencies in the implementation management; Idiosyncratic school behaviours. The study concludes that the 'practitioner-policy-maker' discrepancy is significant, hence the gap between policy intents and innovation practice. The gap is not regarded so much as an ultimate failure of the programme but as a necessary condition that allows for mutual adaptation between the innovation and its setting. This is reflected in the varied patterns of implementation response, classified as the: faithful; negotiators; selective adaptors; expansionists; and reductionist. As a policy-oriented study aiming at providing an 'improvement value', the findings lead to a proposal of improvements in the strategies of managing change in three areas: shifting focus from an adoption to an implementation perspective. Recognising implementation as a process dependent on a mutual linkage relationship among participants. Recognising schools as important bearers of change. These three are crucial factors in the implementation-sustainability relationship.
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7

Lüth, Thorsten [Verfasser]. "Individualisierte Kalibrierung in einem SSVEP-basierten Brain-Computer Interface / Thorsten Lüth." Aachen : Shaker, 2016. http://d-nb.info/1098042409/34.

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8

TELLO, R. J. M. G. "A Novel Approach Of Independent Brain-computer Interface Based On SSVEP." Universidade Federal do Espírito Santo, 2016. http://repositorio.ufes.br/handle/10/9683.

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Durante os últimos dez anos, as Interfaces Cérebro Computador (ICC) baseadas em Potenciais Evocados Visuais de Regime Permanente (SSVEP) têm chamado a atenção de muitos pesquisadores devido aos resultados promissores e as altas taxas de precisão atingidas. Este tipo de ICC permite que pessoas com dificuldades motoras severas possam se comunicar com o mundo exterior através da modulação da atenção visual a luzes piscantes com frequência determinada. Esta Tese de Doutorado tem o intuito de desenvolver um novo enfoque dentro das chamadas ICC Independentes, nas quais os usuários não necessitam executar tarefas neuromusculares para seleção visual de objetivos específicos, característica que a distingue das tradicionais ICCs-SSVEP. Assim, pessoas com difculdades motoras severas, como pessoas com Esclerose Lateral Amiotrófca (ELA), contam com uma nova alternativa de se comunicar através de sinais cerebrais. Diversas contribuições foram realizadas neste trabalho, como, por exemplo, melhoria do algoritmo extrator de características, denominado Índice de Sincronização Multivariável (ou MSI, do Inglês), para a detecção de potenciais evocados; desenvolvimento de um novo método de detecção de potenciais evocados através da correlação entre modelos multidimensionais (tensores); o desenvolvimento do primeiro estudo sobre a influência de estímulos coloridos na detecção de SSVEPs usando LEDs; a aplicação do conceito de Compressão na detecção de SSVEPs; e, fnalmente, o desenvolvimento de uma nova ICC independente que utiliza o enfoque de Percepção Fundo-Figura (ou FGP, do Inglês).
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9

Rogers, Michael. "PCR-SSCP analysis of microbial communities in a model system." Thesis, University of Kent, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.270818.

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10

Cotrina, A. "A Novel Stimulation Paradigm For a Brain-computer Interface Based On Ssvep." Universidade Federal do Espírito Santo, 2015. http://repositorio.ufes.br/handle/10/9719.

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11

Giovanini, Renato de Macedo [UNESP]. "SSVEP-EEG signal pattern recognition system for real-time brain-computer interfaces applications." Universidade Estadual Paulista (UNESP), 2017. http://hdl.handle.net/11449/151710.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
There are, nowadays, about 110 million people in the world who live with some type of severe motor disability. Specifically in Brazil, about 2.2% of the population are estimated to live with a condition of difficult locomotion. Aiming to help these people, a vast variety of devices, techniques and services are currently being developed. Among those, one of the most complex and challenging techniques is the study and development of Brain-Computer Interfaces (BCIs). BCIs are systems that allow the user to communicate with the external world controlling devices without the use of muscles or peripheral nerves, using only his decoded brain activity. To achieve this, there is a need to develop robust pattern recognition systems, that must be able to detect the user’s intention through electroencephalography (EEG) signals and activate the corresponding output with reliable accuracy and within the shortest possible processing time. In this work, different EEG signal processing techniques were studied, and it is presented the development of a EEG under visual stimulation (Steady-State Visual Evoked Potentials - SSVEP) pattern recognition system. Using only Open Source tools and Python programming language, modules to manage datasets, reduce noise, extract features and perform classification of EEG signals were developed, and a comparative study of different techniques was performed, using filter banks and Discrete Wavelet Transforms (DWT) as feature extraction approaches, and the classifiers K-Nearest Neighbors, Multilayer Perceptron and Random Forests. Using DWT approach with Random Forest and Multilayer Perceptron classifiers, high accuracy rates up to 92 % were achieved in deeper decomposition levels. Then, the small-size microcomputer Raspberry Pi was used to perform time processing evaluation, obtaining short processing times for every classifiers. This work is a preliminary study of BCIs at the Laboratório de Instrumentação e Engenharia Biomédica, and, in the future, the system here presented may be part of a complete SSVEP-BCI system.
Existem, atualmente, cerca de 110 milhões de pessoas no mundo que vivem com algum tipo de deficiência motora severa. Especificamente no Brasil, é estimado que cerca de 2.2% da população conviva com alguma condição que dificulte a locomoção. Com o intuito de auxiliar tais pessoas, uma grande variedade de dispositivos, técnicas e serviços são atualmente desenvolvidos. Dentre elas, uma das técnicas mais complexas e desafiadoras é o estudo e o desenvolvimento de Interfaces Cérebro-Computador (ICMs). As ICMs são sistemas que permitem ao usuário comunicar-se com o mundo externo, controlando dispositivos sem o uso de músculos ou nervos periféricos, utilizando apenas sua atividade cerebral decodificada. Para alcançar isso, existe a necessidade de desenvolvimento de sistemas robustos de reconhecimento de padrões, que devem ser capazes de detectar as intenções do usuáro através dos sinais de eletroencefalografia (EEG) e ativar a saída correspondente com acurácia confiável e o menor tempo de processamento possível. Nesse trabalho foi realizado um estudo de diferentes técnicas de processamento de sinais de EEG, e o desenvolvimento de um sistema de reconhecimento de padrões de sinais de EEG sob estimulação visual (Potenciais Evocados Visuais de Regime Permanente - PEVRP). Utilizando apenas técnicas de código aberto e a linguagem Python de programação, foram desenvolvidos módulos para realizar o gerenciamento de datasets, redução de ruído, extração de características e classificação de sinais de EEG, e um estudo comparativo de diferentes técnicas foi realizado, utilizando-se bancos de filtros e a Transformada Wavelet Discreta (DWT) como abordagens de extração de características, e os classificadores K-Nearest Neighbors, Perceptron Multicamadas e Random Forests. Utilizando-se a DWT juntamente com Random Forests e Perceptron Multicamadas, altas taxas de acurácia de até 92 % foram obtidas nos níveis mais profundos de decomposição. Então, o computador Raspberry Pi, de pequenas dimensões, foi utilizado para realizar a avaliação do tempo de processamento, obtendo um baixo tempo de processamento para todos os classificadores. Este trabalho é um estudo preliminar em ICMs no Laboratório de Instrumentação e Engenharia Biomédica e, no futuro, pode ser parte de um sistema ICM completo.
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12

Giovanini, Renato de Macedo. "SSVEP-EEG signal pattern recognition system for real-time brain-computer interfaces applications /." Ilha Solteira, 2017. http://hdl.handle.net/11449/151710.

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Orientador: Aparecido Augusto de Carvalho
Resumo: There are, nowadays, about 110 million people in the world who live with some type of severe motor disability. Specifically in Brazil, about 2.2% of the population are estimated to live with a condition of difficult locomotion. Aiming to help these people, a vast variety of devices, techniques and services are currently being developed. Among those, one of the most complex and challenging techniques is the study and development of Brain-Computer Interfaces (BCIs). BCIs are systems that allow the user to communicate with the external world controlling devices without the use of muscles or peripheral nerves, using only his decoded brain activity. To achieve this, there is a need to develop robust pattern recognition systems, that must be able to detect the user’s intention through electroencephalography (EEG) signals and activate the corresponding output with reliable accuracy and within the shortest possible processing time. In this work, different EEG signal processing techniques were studied, and it is presented the development of a EEG under visual stimulation (Steady-State Visual Evoked Potentials - SSVEP) pattern recognition system. Using only Open Source tools and Python programming language, modules to manage datasets, reduce noise, extract features and perform classification of EEG signals were developed, and a comparative study of different techniques was performed, using filter banks and Discrete Wavelet Transforms (DWT) as feature extraction approach... (Resumo completo, clicar acesso eletrônico abaixo)
Mestre
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13

Évain, Andéol. "Optimizing the use of SSVEP-based brain-computer interfaces for human-computer interaction." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S083/document.

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Cette thèse porte sur la conception et l'évaluation de systèmes interactifs utilisant des interfaces cerveau-machine (BCI pour Brain-Computer Interfaces). Ce type d'interfaces s'est développé dans les années récentes tout d'abord dans le domaine du handicap, afin de fournir aux grands handicapés des moyens d'interaction et de communication, et plus récemment dans d'autres domaines comme celui des jeux vidéo. Néanmoins, la plupart des travaux ont porté sur l'identification des signaux du cerveau susceptibles de porter une information utile, et sur les traitements nécessaires à l'extraction de cette information. Peu de travaux ont porté sur les aspects d'utilisabilité et de prise en compte des facteurs humains dans l'ensemble du système interactif. Cette thèse se concentre sur les systèmes basées sur SSVEP (steady-state visually evoked potentials), et se propose d'étudier l'ensemble du système interactif cerveau-machine, selon les critères de l'interaction homme-machine (IHM). Plus précisément, les points étudiés portent sur la demande cognitive, la frustration de l'utilisateur, les conditions de calibration, et les BCI hybrides
This PhD deals with the conception and evaluation of interactive systems based on Brain-Computer Interfaces (BCI). This type of interfaces has developed in recent years, first in the domain of handicaps, in order to provide disabled people means of interaction and communication, and more recently in other fields as video games. However, most of the research so far focused on the identification of cerebral pattern carrying useful information, a on signal processing for the detection of these patterns. Less attention has been given to usability aspects. This PhD focuses on interactive systems based on Steady-State Visually Evoked Potentials (SSVEP), and aims at considering the interactive system as a whole, using the concepts of Human-Computer Interaction. More precisely, a focus is made on cognitive demand, user frustration, calibration conditions, and hybrid BCIs
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14

Sommer, Ulrike. "Mutationsanalyse bei Patienten mit Nephronophthise Typ 1 mittels SSCP und Sequenzierung." [S.l.] : [s.n.], 2000. http://deposit.ddb.de/cgi-bin/dokserv?idn=963841246.

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15

Aydin, Atakan. "Universelle Multifluoreszenz-unterstützte PCR-SSCP für den Nachweis von genetischen Variationen." [S.l.] : [s.n.], 2005. http://www.diss.fu-berlin.de/2005/109/index.html.

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16

Oliveira, Taíse Lima de. "Caracterização clínica e molecular de pacientes com hipotireodismo congênito de Monte Santo-Bahia-Brasil." reponame:Repositório Institucional da FIOCRUZ, 2010. https://www.arca.fiocruz.br/handle/icict/4308.

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Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2012-08-30T20:27:31Z No. of bitstreams: 1 Taise Lima de Oliveira Caracterização clínica e molecular de pacientes com hipertireodismo....pdf: 583769 bytes, checksum: 1d1d8e16ece954c3ead88d0648b4eeea (MD5)
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Fundação Oswaldo Cruz. Centro de Pesquisas Gonçalo Moniz. Salvador, Bahia, Brasil
O hipotireoidismo congênito (HC) é uma das doenças metabólicas mais comuns na infância, com incidência de HC é de 1:3.000 a 1:5.000 nascidos-vivos. Quando primário, o HC caracteriza-se por altos níveis de TSH podendo ser originado por disormonogênese, deficiente produção hormonal ou decorre de disgenesia tireoidiana, defeito embriológico que leva a agenesia, hemiagenesia ou ectopia. Na ausência do tratamento hormonal, o HC leva a grave retardo mental, além de outras alterações clínicas. A interação do hormônio TSH com o seu receptor (TSHR) tem importante função biológica estimulando o crescimento, diferenciação e função tireoidiana. Mutações no gene do TSHR têm sido identificadas como causa de HC hereditário ou congênito, mas parecem ser raras. Objetivos: 1) Obter genealogia das famílias afetadas para determinação do padrão de herança, identificação de afetados e possíveis portadores; 2) Descrever as características clínica-demográficas dos pacientes com HC; 3) Determinar a distribuição mutacional no gene do receptor do hormônio estimulante da tireoide (TSHR) nos afetados; 4) Sugerir ações de saúde pública e de otimização do aconselhamento genético. Material e Métodos: Foram estudados 12 pacientes provenientes de Monte Santo-BA, sendo oito diagnosticados pela triagem neonatal e quatro diagnosticados tardiamente durante expedição à cidade. Estes últimos foram identificados durante a coleta dos dados genealógicos das famílias dos afetados. Todos foram investigados para mutações no gene do TSHR. Toda a região codificadora do gene foi amplificada através do DNA genômico, seguido de SSCP e sequenciamento. Resultados: À época da primeira avaliação, os pacientes apresentaram níveis elevados de TSH, confirmando o caráter primário da doença, associados a sinais e sintomas do HC. Observou-se grande heterogeneidade clínica entre os pacientes mesmo aqueles com grau de parentesco muito próximo. Nenhuma mutação patogênica foi encontrada no gene TSHR. Conclusão: a análise das genealogias permitiu observar a heterogeneidade clínica e genética da doença. Não foi encontrada nenhuma mutação no gene TSHR. O estudo de outros genes poderá ajudar no esclarecimento do HC na região.
Congenital hypothyroidism (CH) is one of the most common metabolic disease in childhood, with an incidence of HC is 1:3,000 to 1:5,000 live births. When primary, CH is characterized by high levels of TSH and may be caused by dyshormonogenesis deficient hormone production, or due to thyroid dysgenesis, embryological defect that leads to agenesis, ectopic or hypoplastic. In the absence of hormonal treatment leads to the CH severe mental retardation and other clinical manifestations. The interaction of stimulanting thyroid growth, differentiation and function. Mutations in the TSHR gene have been identified as a cause of hereditary or congenital CH, but appear to be rare. Objectives: 1) Get genealogy of the affected families to detemine the pattern of inheritance, and possible identification of affected patients; 2) Describe the clinical and demographic characteristics of patients witc CH; 3) Determine the mutational distribution in the TSHR gene in the affected individuals; 4) Suggest public health actions and for genetic counseling optimization. Methods: We studied 12 patients from Monte Santo-Bahia, eight were diagnosed by newborn screening and four diagnosed late during an expedition to the city. The latter were identified during the collection of genealogical data of families those affected. All were investigated for mutations in the TSHR. The entire coding region of the gene was amplified using genomic DNA followed by SSCP and sequencing. Results: At first evaluation, all patients had elevated TSH levels, confirming the primary nature of the disease, associated with signs and/or symptoms of CH. As there was a familial recurrence of the disease, we noticed a large clinical heterogeneity among patients, even those with close family relationship. No pathogenic mutation was found in the TSHR gene. Conclusion: The analysis of pedigrees allowed to observe the clinical and genetic heterogeneity of the disease. We not found mutation in the TSHR. The study of other genes may help in clarifying the CH i the region.
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Mitchell, Adam Scott. "A pilot study toward the development of ERD and SSVEP based hybrid brain computer interface." Thesis, University of Strathclyde, 2015. http://oleg.lib.strath.ac.uk:80/R/?func=dbin-jump-full&object_id=26432.

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Brain-computer interfaces (BCI) are devices that allow for the brain to communicate information to a computer. In situations where a victim of brain trauma or disease has suffered damage causing paralysis or impaired movement, BCIs may be the answer in providing assistance to neurological function. Development of BCIs continues to increase, but literature suggests the next step is the hybrid brain computer interface (hBCI). The simplified concept behind the hBCI is by having two BCIs, in which both signals can be detected simultaneously, creates the situation that if one BCI is to fail to show user intent the other may succeed. Using a non-invasive method such as surface electroencephalogram (sEEG), able to detect signals from brain activity, this pilot study will look into the development of a hBCI combining the modalities of event-related de-synchronisation (ERS) and steady-state visual evoked potentials (SSVEP). The aim of this project is to show the hBCI proposed works, to find where improvements can be made and to identify the synergies of SSVEP and ERD modalities. A duel task experiment was performed on 4 healthy subject, ages 22-35, in which they must look at a flickering LED and move their wrist in the direction corresponding to that LED. Four LEDs are setup about a point, providing intuitive directions for wrist movement, and only one will flicker at any time. Results show that the SSVEP and ERD hBCI can work, but there may be limitations. The main limitation suggested by the results have also been found in other literature and is known as 'dual-task interference'. The cause of dual-task interference hasn't been well documented and only suggested or speculated so far. Future experiments should validate the cause of this dual-task interference in hBCIs.
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Silva, Andrei Damian da. "Desenvolvimento de um dispositivo SSVEP rápido e confiável utilizando eletrodos a seco e frequências acima de 25 Hz." Universidade Federal de Goiás, 2018. http://repositorio.bc.ufg.br/tede/handle/tede/8215.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
This paper presents a new approach for the processing and classification of visual evoked potentials of steady state (SSVEP). It introduces a ensemble tree model that combines canonical correlation analysis data with methods based on estimation of power spectral density. The stimuli were created using LEDs, from 7.04 Hz to 38.46 Hz. Data were collected using the Texas Instruments ADS1299EEG-Fe and three electrodes. The tests were performed for different distances and light intensities to evaluate the performance of the algorithm under different conditions. In all, 22 participants were recruited, and the average classification was 99.1 ± 2.27% with fixed decision time of 1 second.
Este trabalho apresenta uma nova abordagem para o processamento e classificação de potenciais evocados visuais de estado estacionário (SSVEP). Este trabalho introduz um modelo de em aprendizagem por agrupamento de árvores de decisão que combina dados de análise da correlação canônica com métodos baseados na estimativa da densidade espectral de potência. Os estímulos foram criados utilizando LEDs, com frequência de 7.04 Hz até 38.46 Hz. Os dados foram coletados utilizando a placa ADS1299EEG-Fe da Texas Instruments e três eletrodos. Os testes foram realizados para diferentes distâncias e intensidades luminosas com o objetivo de avaliar o desempenho do algoritmo em condições diversas. Ao todo, 22 participantes foram recrutados e a taxa de acertos média foi de 99.1±2.27% com tempo de decisão fixo em 1 segundo.
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19

Dorn-In, Samart. "Untersuchungen zur Rekonstruktion der ursprünglichen Pilzflora hitzebehandelter Lebensmittel mittels qPCR und PCR-SSCP." Diss., lmu, 2012. http://nbn-resolving.de/urn:nbn:de:bvb:19-148578.

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20

Huber, Jair. "Pesquisa de mutações no gene CDKN2A em pacientes com critérios clínicos de melanoma hereditário." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/17/17135/tde-21082007-081727/.

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A incidência do melanoma, tumor maligno que se origina dos melanócitos, vem crescendo em todo o mundo. História familial positiva da doença tem sido relatada em 8 a 14% dos pacientes afetados. Muitos estudos sugeriram o envolvimento da região 9p21, onde se encontra o gene CDKN2A, no surgimento dessa neoplasia. Este é um gene supressor tumoral clássico e a inativação dos dois alelos tem sido detectadas em linhagens celulares tumorais de famílias com melanoma hereditário e esporádico. Mutações em linhagens germinativas do gene CDKN2A têm sido identificadas em aproximadamente 20% das famílias com melanoma familial. Utilizando técnicas de biologia molecular como Reação em Cadeia da Polimerase (PCR), Conformação Estrutural de Fita Simples (SSCP) e seqüenciamento, este projeto estudou 22 pacientes com critérios clínicos de melanoma hereditário e encontrou uma mutação (P48T) em um paciente numa família de três afetados. Em 13 casos foi identificado pelo menos um dos três polimorfismos: 500 C>G (31,9%), 540 C>T (27,3%) e A148T (4,5%). Os resultados demonstram a importância da pesquisa de mutações no gene CDKN2A principalmente em famílias com dois ou mais membros afetados pela doença.
The incidence of melanoma, malign tumor that originates from melanocytes, is increasing all over the world. Positive familial history of disease has been related in 8 to 14% of affected patients. Several studies have suggest the 9p21 region evolvement, where is located the CDKN2A gene, in the arising of this neoplasia. It is a classic tumor suppressor gene and the inactivation of two alleles has been detected in tumor cells lines of families with hereditary and sporadic melanoma. Nowadays germeline mutations in CDKN2A gene have been identified in almost 20% of families with familial melanoma. Using molecular biology techniques like Polymerase Chain Reaction (PCR), Single Strand Conformational Polymorphism (SSCP) and sequencing, this project studied 22 patients with clinical pattern of hereditary melanoma and it found one mutation (P48T) in one patient belonged to a three affected family. Thirteen cases had at least one of the three polymorphisms: 500 C>G (31,9%), 540 C>T (27,3%) e A148T (4,5%). The results show the importance of the search for mutations in the CDKN2A gene mainly in families with two or more affected by disease.
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21

FLORIANO, A. S. P. "Desenvolvimento de uma Interface Cérebro-Computador Não Invasiva Baseada em Potenciais Evocados Visuais de Regime Permanente Aplicada à Comunicação Alternativa e Robô de Telepresença." Universidade Federal do Espírito Santo, 2016. http://repositorio.ufes.br/handle/10/9673.

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Uma parcela da população é composta por pessoas que são acometidas de doenças ou vítimas de acidentes graves que as impossibilitam de interagir e se comunicar. Novas tecnologias têm surgido para prover a essas pessoas um canal de comunicação alternativo através de sinais cerebrais. Esses sistemas são conhecidos como Interfaces Cérebro-Computador (ICCs). Este trabalho descreve o desenvolvimento de uma ICC baseada no paradigma de Potenciais Evocados Visuais de Regime Permanente (Steady State Visual Evoked Potential - SSVEP) aplicada à Comunicação Alternativa e Robô de Telepresença. A interface foi construída para quatro comandos de seleção atráves de estímulos visuais desenvolvidos em um software utilizando a biblioteca gráfica OpenGL e executados em frequências distintas (5,6Hz, 6,4Hz, 6,9Hz e 8,0Hz). Todos os voluntários avaliados nos testes utilizando o sistema online conseguiram completar as tarefas propostas com uma taxa de acerto média de 88,3% ± 5,4%, tempo de classificação de 5,6s ± 0,5s e ITR média de 14,2 bits/min ± 3,5 bits/min, não necessitando de treinamento e utilizando apenas um canal para aquisição do sinal eletroencefalográfico. Os resultados demonstraram a possibilidade da construção de uma ICC que poderá ser utilizada nos futuros projetos de tecnologias assistivas desenvolvidos no Laboratório de Automação Inteligente da Universidade Federal do Espírito Santo (LAI-UFES).
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Splendore, Alessandra Della Casa. "Estudo molecular do gene TCOF1 em pacientes portadores da síndrome de Treacher Collins." Universidade de São Paulo, 2002. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-22092004-222503/.

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A síndrome de Treacher Collins (STC) é um distúrbio do desenvolvimento craniofacial de herança autossômica dominante causada por mutações no gene TCOF1, localizado no cromossomo 5 (5q32). Utilizando as técnicas de SSCP e seqüenciamento, estabelecemos um método eficiente para a detecção de mutações no gene TCOF1, o que permitiu oferecer o teste diagnóstico aos pacientes com suspeita clínica de STC. Identificamos a mutação responsável pela síndrome em 39/43 (90,7%) dos pacientes atendidos pelo Centro de Estudos do Genoma Humano e em 23/48 (48%) dos pacientes encaminhados pelo Johns Hopkins Medical Institute. Desse modo, caracterizamos 43 novas mutações patogênicas e 16 novos polimorfismos no gene TCOF1. A detecção de uma troca de aminoácido de caráter patogênica em uma região conservada da proteína nos levou a propor a existência de um domínio funcional importante nessa região. Realizamos triagem de mutações no gene TCOF1 em 24 pacientes com anomalias faciais em estruturas derivadas do 1o e 2o arcos branquiais, mas sem diagnóstico de STC. Nenhuma mutação patogênica foi encontrada nesses casos, indicando que a STC, apesar de apresentar uma grande variabilidade clínica, é uma entidade circunscrita. Triamos também, pela primeira vez, duas famílias cujo padrão de segregação do quadro clínico sugere um padrão de herança autossômico recessivo. Também nesse caso não encontramos mutação no gene TCOF1, apesar de uma análise de segregação com marcadores da região 5q31-q34 não ter excluído essa região de uma possível relação com a síndrome. Testamos, empregando pela primeria vez ferramentas moleculares, a hipótese que as mutações esporádicas que causam a STC têm origem preferencial na linhagem germinativa de homens mais velhos. Ao contrário do sugerido pela literatura, em dez casos informativos encontramos 70% das mutações no cromossomo herdado do pai e 30% de origem materna e nenhuma correlação com aumento de idade paterna.
Treacher Collins syndrome (TCS) is an autosomal dominant disorder affecting craniofacial development. The syndrome is caused by mutations in the TCOF1 gene, located in chromosome 5 (5q32). Combining SSCP and sequencing, we established an efficient method of screening for mutations in the TCOF1 gene, allowing us to offer diagnostic tests to patients with clinical signs of TCS. We detected a pathogenic mutation in 39/43 (90.7%) of patients ascertained at the Centro de Estudos do Genoma Humano and in 23/48 (48%) of patients referred to Johns Hopkins Medical Institute. We therefore characterized 43 novel pathogenic mutations and 16 novel polymorphisms in the TCOF1 gene. We described a pathogenic missense mutation located in a conserved region of the protein, which led us to propose the existence of a critical function domain in its N-terminus. After screening 24 patients with craniofacial anomalies resembling TCS but without a precise clinical diagnosis for mutations in the TCOF1 gene, we found no pathogenic mutation and concluded that, despite its broad clinical spectrum, TCS is well characterized in clinical grounds. We also screened, for the first time, two families in which the segregation of the phenotype suggested autosomal recessive inheritance. No mutation was detected in these families, despite linkage analysis with markers from 5q31-34 not excluding this region. We used molecular techniques for the first time to test the hypothesis that sporadic mutations in TCS arise preferentially in the male germ line and their frequency increases with age. As opposed to what the literature suggested, in ten informative cases we had 7 mutations of paternal origin and 3 originating in the female germ line, with no detectable age effect.
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23

Mouli, Surej. "Design of portable led visual stimulus and SSVEP analysis for visual fatigue reduction and improved accuracy." Thesis, University of Kent, 2017. https://kar.kent.ac.uk/66503/.

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Brain-computer interface (BCI) applications have emerged as an innovative communication channel between computers and human brain as it circumvents peripheral limbs thereby creating a direct interface between brain thoughts and the external world. This research focuses on non-invasive BCI to improve the design of visual stimuli in eliciting steady-state visual evoked potential (SSVEP) for BCI applications. To evoke SSVEP in the brain, the user needs to focus on a visual stimulus flickering at a constant frequency. Traditionally in research studies, the visual stimulus for SSVEP uses LCD screens where the flicker is generated using black or white patterns, which alternates the colour to produce a flickering effect. However, there are drawbacks for LCD based visual stimuli systems that limit the user acceptance of SSVEP applications. The main limitations are: (i) choice of flicker frequency is limited to the LCDs vertical refresh rate (ii) flickers are mainly limited to black/white patterns (iii) higher visual fatigue for the user due to LCDs background flicker (iv) reduced visual stimulus portability (v) Inaccurate flickers generated and controlled by the software (vi) influence of adjacent flickers causing attention shift when multiple flickers are used for classification and also not being easily adaptable for user requirements. The impediments in eliciting and utilising SSVEP responses for designing a near real-time platform for controlling external applications are addressed from five main perspectives here: (i) design of standalone LED visual stimulus hardware for precise generation of any frequency for replacing the LCD based visual stimulus (ii) eliciting maximal response by choosing most responsive colour, orientation and shape of visual stimulus (iii) identification of the best luminance level for visual stimulus to improve the comfortability of the user and for improved SSVEP response (iv) control of the duration of ON/OFF period for the visual stimulus to reduce eyestrain for the user (i.e. visual fatigue), and (v) hybrid BCI paradigm using SSVEP and P300 to improve the classification accuracy for controlling external applications. The experimental study involved the development of various visual stimulus designs based on LEDs and microcontrollers to minimise the visual fatigue and improve the SSVEP responses. The signal analysis results from the studies with five to ten participants show SSVEP elicitation is influenced by colour, orientation, the shape of stimulus, the luminance level of stimulus and the duration of ON/OFF period for the stimulus. The participants also commented that choosing the correct luminance and ON/OFF periods of the stimulus considerably reduce the eyestrain, improve the attention levels and reduce the visual fatigue. Taken together, these finding leads to more user acceptance in SSVEP based BCI as an assistive mechanism for controlling external applications with improved comfort, portability and reduced visual fatigue.
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24

Wess, Christian. "Wertigkeit der simultanen intraoperativen Ableitung von subduralem EEG und SSEP während vaskulärer neurochirurgischer Operationen." kostenfrei, 2008. http://nbn-resolving.de/urn/resolver.pl?urn=nbn:de:bvb:20-opus-34855.

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Fielmuth, Stefan. "Validierung SSEP-generierter Shuntkriterien in der Karotis-Chirurgie durch klinisch-neurologisches Monitoring des regionalanaesthesierten Patienten." [S.l.] : [s.n.], 2002. http://deposit.ddb.de/cgi-bin/dokserv?idn=972323325.

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Almeida, Lorena Schneider. "Análise molecular do gene CRTAP através da técnica de PCR-SSCP-sequenciamento em pacientes com osteogênese imperfeita do Espírito Santo." Universidade Federal do Espírito Santo, 2013. http://repositorio.ufes.br/handle/10/5746.

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The Osteogenesis Imperfecta (OI) is a genetic disease characterized by structural defects of type I collagen protein or by reducing its biosynthesis causing decreased bone mass and predisposition to fractures and bone deformities. Approximately 90% of individuals with OI exhibit autosomal dominant inheritance caused by mutations in the genes COL1A1 and COL1A2. However, the number of genes linked to autosomal recessive forms of OI is increasing in the literature. The CRTAP gene was the second identified causing recessive inheritance OI. This gene has 6622 bp, seven exons and encodes a protein of 46.5 kDa. The CRTAP encoding the protein cartilage associated (CRTAP) which is part of the collagen 3-hydroxylation complex, responsible for post-translational modifications during the biosynthesis of collagen molecule. CRTAP mutations are related to severe and lethal form of the disease. The target of this research was evaluating the exons of CRTAP and its adjacent regions in OI patients from Espírito Santo thought the Single-Stranded Conformation Polymorphism (SSCP) screening of mutations and sequencing. We studied 24 patients with clinical diagnosis of OI from Hospital Infantil Nossa Senhora da Glória de Vitória, Brazil. The patients/ ages ranged from 2 to 16 years (median: 14.5). The sex proportion of the patients was 15 males and 9 females. Eleven patients have mild clinical symptoms of the disease, 5 show moderate symptoms and 9 were severe cases. The lethal OI cases were not obtained by methodological difficulties. We found the polymorphisms c.534C> T previously reported in exon 2 of the CRTAP gene in patients from sample. No pathogenic mutations were found in this study. The results of this study suggest that mutations in CRTAP are rare in ES population. These data may assist in developing more efficient methodological strategies for molecular diagnosis of OI
A Osteogênese Imperfeita (OI) é uma doença genética caracterizada por defeitos estruturais da proteína do colágeno tipo I ou por redução da sua biossíntese causando diminuição da massa óssea e a predisposição a fraturas e deformidades ósseas. Aproximadamente 90% dos indivíduos com OI apresentam herança autossômica dominante causada por mutações nos genes COL1A1 ou COL1A2. Contudo, é crescente o número de genes ligados à herança autossômica recessiva da OI descritos na literatura. O gene CRTAP foi o segundo gene identificado causando OI com herança recessiva. Este gene possui 6.622 pb, 7 exons e codifica uma proteína de 46,5 KDa. O gene CRTAP codifica a proteína da cartilagem associada (CRTAP) que faz parte do complexo prolil 3-hidroxilação, responsável por modificações pós-traducionais fundamentais durante a biossíntese da molécula de colágeno. Mutações no gene CRTAP estão relacionadas à forma grave ou letal da doença. Esta pesquisa teve como objetivo avaliar as porções codificantes do gene CRTAP e suas regiões adjacentes em pacientes com OI do estado do Espírito Santo por meio da técnica de triagem de mutações de Polimorfismo Conformacional de Fita Simples (SSCP) e sequenciamento. Foram estudados 24 pacientes com diagnóstico clínico de OI do Hospital Infantil Nossa Senhora da Glória de Vitória, Brasil. As idades dos pacientes variaram de 2 a 16 anos (mediana: 14,5 anos) sendo 15 indivíduos do sexo masculino e 9 do sexo feminino, 11 pacientes apresentam a forma leve da doença, 5 a forma moderada e 9 a forma grave da doença. Os casos letais de OI não foram obtidos por dificuldades metodológicas. Foi encontrado o polimorfismos c.534C>T no exon 2 do gene CRTAP, previamente relatado na literatura, em pacientes da amostra. Não foram identificadas mutações patogênicas neste estudo. Os resultados desse trabalho sugerem que mutações no gene CRTAP são raras na população com OI do ES, corroborando dados da literatura. Esses dados poderão auxiliar na elaboração de estratégias metodológicas mais eficientes para o diagnóstico molecular de OI
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Whitlock, Sharon E. "The Effects of Single-Sex and Coeducational Environments on the Self-Efficacy of Middle School Girls." Diss., Virginia Tech, 2006. http://hdl.handle.net/10919/28041.

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The purpose of this study was to investigate the effects of class type, coeducational or same-sex, on the self-efficacy of middle school girls in a unit of volleyball. Four intact certified physical education specialists from two Middle Schools were used in the study. All of the teachers were female. In two of the classes, students were split out according to gender with males being taught by one instructor and the females being taught by the other instructor. For the coeducational classes, the students were randomly assigned to either of the teachers, with boys and girls evenly divided between the two classes. Essentially two new classes were created at each school. Quantitative and qualitative methods were used for the study. Two questionnaires were administered to the students. Analysis of data from the questionnaire showed the student variables that were measured quantitatively for determining girls' self-efficacy for learning volleyball were found to be significant at the 05 level, favoring girls in single-sex environments. Data from the post-intervention questionnaire and student and teacher interviews were analyzed to provide insight into student preferences for these contexts. It is concluded from the qualitative data that single-sex classes have a more supportive learning environment, and have better conduct than coeducational classes.
Ed. D.
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Kühnel, Dana. "Histologische und molekulargenetische Analyse von Darmgeweben aus mit dem humanrelevanten Kanzerogen 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) behandelten F344-Ratten." Phd thesis, Universität Potsdam, 2005. http://opus.kobv.de/ubp/volltexte/2006/695/.

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Die Entwicklung von Dickdarmkrebs wird durch eine Reihe von Lebens- und Essgewohnheiten sowie Umweltfaktoren begünstigt. Den letzteren beiden sind Substanzen zuzurechnen, die bei der Zubereitung der Nahrung entstehen und mit ihr aufgenommen werden. Zu diesen Verbindungen gehört das 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridin (PhIP) aus der Substanzklasse der heterozyklischen aromatischen Amine. Es entsteht bei der Erhitzung zahlreicher proteinhaltiger Nahrungsmittel und die Zielorgane in Nagerstudien stimmen mit der Häufung von Krebsinzidenzen in westlichen Industrienationen überein. Dieser Zusammenhang konnte jedoch bis heute nicht endgültig bewiesen werden. Fütterungsversuche mit Ratten wurden mit Konzentrationen der Substanz durchgeführt, die weit über der menschlichen Exposition liegen. Durch das Verfüttern einer humanrelevanten Dosis PhIP sollte geklärt werden, ob auch geringe Konzentrationen dickdarmkrebstypische Mutationen, präneoplastische Läsionen oder Tumore induzierten. Die mit humanrelevanten Dosen gefütterten Tiere wiesen weniger Läsionen als die Hoch-Dosis-PhIP-Gruppe auf, in der allerdings keinerlei maligne Tumoren des Dickdarms auftraten. Hinweise auf dickdarmkrebstypische Mutationen fanden sich ebenfalls in beiden Gruppen, wobei hier keine Dosisabhängigkeit beobachtet werden konnte. Die Sequenzierung ergab ein deutlich von Literaturdaten abweichendes Spektrum. In Bezug auf das verwendete Tiermodell wurden erhebliche Abweichungen in der Empfindlichkeit der Tiere gegenüber der Substanz im Vergleich zu ähnlichen Studien festgestellt. Beide Fütterungsgruppen zeigten deutlich weniger Läsionen; als mögliche Gründe wurden Unterschiede in der Futterzusammensetzung und –zubereitung sowie in der Tierhaltung und –herkunft ausgemacht. Es konnte erstmalig ein Zusammenhang zwischen PhIP in niedrigen Dosen in der Nahrung und der Induktion von Entzündungen gezeigt werden. Diese waren sowohl makroskopisch als auch histologisch sichtbar, der genaue Mechanismus ihrer Entstehung ist jedoch unbekannt.

Die zusammenfassende Betrachtung aller Ergebnisse lässt vermuten, dass PhIP allein über lange Zeiträume aber in geringen Dosen verabreicht nicht für die hohe Zahl an Krebserkrankungen in westlichen Industrienationen ursächlich ist.
The development of colon cancer is associated with several nutritional, life style, and environmental factors. Among the environmental factors probably involved are substances formed during food processing and taken up with food. One of these substances is the heterocyclic aromatic amine (HAA) 2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP), which is formed during the heating of proteinaceous food such as meat and fish. In rodent studies the target organs for HAA-derived cancer development are identical with human organs showing high tumor incidences in western countries. Whether there is an association between exposure to PhIP and high tumor incidences in humans is still uncertain. The amount of PhIP administred to rodents in several studies was far above the levels of human exposure towards HAA. Thus, the aim of this study was to elucidate whether low concentrations of the substance are able to induce finger-print colon cancer gene mutations, preneoplastic lesions or tumors in rats. Animals fed with high amounts of PhIP developed fewer lesions than animals fed with a human-relevant concentration of PhIP. However none of the groups developed tumors of the colon. Both groups showed finger-print mutations for colon cancer, but not in a dose-dependent manner. Sequencing showed that the mutations were different from the known mutation spectum of PhIP. The susceptibility of the F344 rats to PhIP used in this study differed from that in previous feeding studies, with both groups showing much less lesions of the colon. Differences in composition and processing of the animal diets as well as animal maintenance and –origin may explain this discrepancy. For the first time an association between low doses of PhIP in the diet and induction of inflammation was shown. Signs of inflammation were observed macroscopically as well as in histological slices, but the mechanism of its induction remains to be clarified.

Taken together the results suggest that a chronical exposure to low doses of PhIP alone is not sufficient to explain the high incidences of colon cancer in western countries.
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29

Fabbri, Alan. "Studio degli effetti della stimolazione transcranica a corrente diretta (tdcs) sui potenziali evocati visivi steady state." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2014. http://amslaurea.unibo.it/7014/.

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I potenziali evocati visivi steady state (ssVEPs) consistono in una perturbazione dell’attività elettrica cerebrale spontanea e insorgono in presenza di stimoli visivi come luci monocromatiche modulate sinusoidalmente. Nel tracciato EEG si instaurano oscillazioni di piccola ampiezza ad una frequenza pari a quella dello stimolo. L’analisi nel dominio delle frequenze permette di mettere in evidenza queste oscillazioni che si presentano con un picco ben distinto in corrispondenza della frequenza dello stimolo. L’obiettivo di questo lavoro è quello di capire se la stimolazione transcranica in corrente continua (tDCS) ha degli effetti a breve e a medio termine sui SSVEPs. Si è studiato gli effetti della stimolazione anodica utilizzando un montaggio di stimolazione extra-cefalico (anodo posizionato su Oz e catodo sul braccio destro). L’esperimento prevede il flickering a 3 frequenze di interesse (12, 15, 20 Hz) di 3 quadrati colorati (rosso e giallo) su sfondo nero. Sono state quindi messe a confronto 4 condizioni operative: baseline, stimolazione sham, stimolazione anodica, condizione Post Anodica.L’esperimento è stato sottoposto a 6 soggetti di età tra i 21 e i 51 anni. Il segnale è stato acquisito da due canali bipolari localizzati nella regione occipitale (O1-PO7 e O2-PO8). È stato effettuato un filtraggio tra 3-60 Hz e a 50 Hz. Si sono stimate le PSD normalizzate rispetto alla condizione di riposo in baseline e le potenze nell’intorno della frequenze di interesse (12,15,20 Hz). I dati chiaramente artefattuali sono stati scartati mediante un’analisi esplorativa. Da qui è stato deciso di non includere nella statistica la stimolazione anodica. L’analisi statistica considera tre aspetti: effetto stimolazione, effetto frequenza ed effetto colore. In alcune configurazioni la stimolazione post anodica si è rivelata significativamente differente con ranghi medi delle colonne inferiori alle altre stimolazioni. Non ci sono differenze significative tra le frequenze. Il colore giallo è risultato significativamente maggiore al colore rosso.
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Genini, Sem. "Establishment of quick-methods to reveal DNA-polymorphisms single strand conformational polymorphism (SSCP) and heteroduplex analysis (HA) /." Zurich : Swiss Federal Institute of Technology, Department of Animal Sciences, Breeding Biology, 2002. http://e-collection.ethbib.ethz.ch/show?type=dipl&nr=50.

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31

Silva, Aline Correa da. "Polimorfismo do gene SPi2 na obstrução recorrente das vias aéreas e na doença inflamatória das vias aéreas em cavalos puro sangue de corrida." Universidade Federal de Santa Maria, 2008. http://repositorio.ufsm.br/handle/1/10026.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Recurrent airway obstruction (RAO) and inflammatory airway disease (IAD) show high prevalence and are economically important in equine athletes. RAO is considered a multifactorial disease due to genetic and environmental components in their patophysiology. The aim of this study was to determine the presence of polymorphism at exons 2, 3, 4 and 5 of the SPi2 gene and a possible association between them and ORA or IAD on 51 thoroughbred horses through single-strand conformational polymorphism (SSCP). Exons 2, 3 and 4 of the Spi2 gene showed no polymorphism. On exon 5, 3 alleles and 6 genotypes were identified. Frequency of allele A (0.6388) and genotype AA (0.3888) were higher in horses affected by RAO but no association was found between any polymorphism and horses with RAO or IAD.
A obstrução recorrente das vias aéreas (ORA) e a doença inflamatória das vias aéreas (DIVA) são doenças de alta prevalência e economicamente importantes em cavalos atletas. A ORA é considerada uma enfermidade multifatorial por apresentar componentes ambientais e genéticos em sua fiosiopatologia. O presente trabalho teve por objetivo determinar a presença de polimorfismos nos éxons 2, 3, 4 e 5 do gene SPi2 e verificar uma possível associação destes com a ORA e/ou DIVA em 51 cavalos Puro Sangue de Corrida através da técnica de polimorfismo conformacional de fita simples (SSCP). Os éxons 2, 3 e 4 não apresentaram polimorfismo. No éxon 5 do gene Spi2 foram identificados três alelos e seis genótipos. Apesar do alelo A e o genótipo AA apresentarem freqüência (0,6388 e 0,3888, respectivamente) mais elevada nos animais com ORA, não houve associação entre os polimorfismos observados e ORA ou DIVA.
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32

Dorn-In, Samart [Verfasser], and Erwin [Akademischer Betreuer] Märtlbauer. "Untersuchungen zur Rekonstruktion der ursprünglichen Pilzflora hitzebehandelter Lebensmittel mittels qPCR und PCR-SSCP / Samart Dorn-In. Betreuer: Erwin Märtlbauer." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2012. http://d-nb.info/1026653568/34.

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Jorge, Simone Bordignon de. "Otimização da tecnica de SSCP (Single Strand Conformation Polymorphism) para triagem de mutações nos genes da globina [alfa] humana." [s.n.], 2002. http://repositorio.unicamp.br/jspui/handle/REPOSIP/310884.

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Orientadores : Maria de Fatima Sonati, Monica Barbosa de Melo
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas
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Resumo: Mutações de ponto e pequenas inserções ou deleções nos genes da globina a humana podem produzir variantes estruturais de cadeia a e a-talassemia. As mutações podem ser identificadas tanto pelo sequenciamento total dos genes, como por métodos de triagem, os quais selecionam o exon mutado para, então, ser seqüenciado. Embora sejam pequenos (cerca de 1Kb, com 3 exons e 2 introns), os genes da globina a são duplicados (a2 and a1) e extremamente ricos em ligações G-C, o que torna difícil a desnaturação e reduz a eficiência do sequenciamento, causando freqüentes artefatos e necessidade de repetições. Como o sequenciamento é ainda um método demorado e de custo elevado para muitos laboratórios, nós modificamos algumas condições do Single Strand Conformation Polymorphism (SSCP) com o intuito de otimizar a triagem de mutações nos genes da globina a humana
Abstract: Point mutations and small insertions or deletions in the human a-globin genes may produce a-chain structural variants and a-thalassemia. Mutations can be detected either by direct sequencing of the whole gene or by screening methods, which select the mutated exon for sequencing. Although small (around 1 Kb, 3 exons and 2 introns), the a-globin genes are duplicate (a2 and a1) and extremely G-C rich, what makes them difficult to denature and reduces sequencing efficiency, causing frequent artifacts and the need of repetitions. As DNA sequencing is still a time-consuming and expensive method for many laboratories, we modified some conditions of the Single Strand Conformation Polymorphism (SSCP) in order to optimize mutation detection in the a-globin genes
Mestrado
Ciencias Biomedicas
Mestre em Ciências Médicas
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34

Almeida, Márcio Germello de. "Mutações na região aminoterminal do gene col1a2 e a manifestação da osteogênese imperfeita." Universidade Federal do Espírito Santo, 2011. http://repositorio.ufes.br/handle/10/5753.

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Osteogenesis Imperfecta (OI) is a genetic disease associated with alterations in the type I collagen molecule. OI is clinically characterized by skeletal fragility and deformity. The majority of OI cases are caused by dominant autosomal mutations on COL1A1 and COL1A2 genes, responsible for the synthesis of the type I collagen molecule. However, there are isolated cases and new cases of recessive autosomal forms of OI. Thus OI is a clinically and genetically heterogeneous group, and it justifies the importance of molecular studies related to this desease. The objective of this research was to characterize the mutation pattern of the beginning region of the COL1A2 gene of OI patients. We studied the exons 1 to 26 of the COL1A2 gene on 33 non-related patients of Vitoria-ES with OI diagnosed using PCR-SSCP and sequencing techniques. We detected an alteration on the exon 16 of a female OI with moderate form of the disease, identified as c.739 G>C (p.Gly247Arg). The clinical report of our patient differs from another one already described on literature. These results may contribute to the understanding of the disease, leading to the development of more efficient treatment methods to patients with OI.
A Osteogênese Imperfeita (OI) é uma doença genética associada a alterações na molécula do colágeno tipo I, sendo caracterizada clinicamente por fragilidade e deformidade ósseas. A maioria dos relatos de OI são alterações autossômicas dominantes nos genes COL1A1 e COL1A2, codificadores da molécula do colágeno tipo I. Também há relatos de casos isolados e de manifestação autossômica recessiva da OI. A diversidade clínica e genética apresentada pelos pacientes com OI evidencia a necessidade de estudos moleculares dos genes associados à OI. Essa pesquisa teve como objetivo caracterizar o padrão de mutações da região inicial do gene COL1A2 em pacientes com OI. Foram estudados os exons 1 a 26 em 33 pacientes não aparentados com OI de Vitória-ES por PCR-SSCP e sequenciamento automatizado. Uma alteração no padrão de bandas de DNA, localizada no fragmento do exon 16 do gene COL1A2, foi dectada na amostra de um paciente do sexo feminino com quadro clínico moderado de OI. O sequenciamento dessa amostra permitiu a identificação da transversão c.739 G>C (p.Gly247Arg) com descrição clínica distinta de um relato prévio na literatura portador da mesma alteração genética. Os resultados dessa pesquisa poderão contribuir com o entendimento clínico da doença, e, consequentemente, auxiliar no desenvolvimento de tratamentos mais adequados aos pacientes.
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Almeida, Vera Sofia Teles. "Aplicação das técnicas PCR, SSCP e sequenciação automática na análise de polimorfismos no TLR7 em lesões do colo do útero." Master's thesis, Universidade de Aveiro, 2009. http://hdl.handle.net/10773/3120.

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Mestrado em Métodos Biomoleculares
Os factores imunológicos do hospedeiro são muito importantes na susceptibilidade à infecção e na persistência de infecções por HPV e, consequentemente, no desenvolvimento de cancro do colo do útero. As infecções persistentes por HPV de alto risco são o principal factor de risco para o desenvolvimento de cancro do colo do útero. Embora a infecção por HPV seja necessária, não é suficiente para causar este tipo de cancro. As respostas imunológicas inata e adquirida são importantes na prevenção e regressão das lesões causadas por HPV. O sistema imunológico inato reconhece características que identificam antigénios estranhos ao organismo, através de receptores de reconhecimento de padrões (PRRs), e inicia uma resposta apropriada. Os receptores tipo-Toll (TLR), nomeadamante os TLR7 e 9, são PRRs que podem estar envolvidos no reconhecimento de vírus. A activação de TLRs por componentes virais estimula a resposta imunológica inata através da estimulação da síntese de citoquinas, como interferons (IFNs) do tipo I, IL-1β e IL-6, que podem actuar directamente na replicação viral. Estes sinais levam também ao recrutamento de células imunológicas para os locais de infecção e à activação de células dendríticas, que desencadeiam a resposta imunológica adquirida. Alterações/ polimorfismos em genes que codificam factores imunológicos do hospedeiro como os TLRs, podem comprometer a resposta imunológica. A investigação de factores genéticos ligados à resposta imunológica poderá ser importante para a compreensão da capacidade distinta de diferentes mulheres para controlar e eliminar a infecção por HPV. O objectivo deste trabalho foi tentar determinar se alterações genéticas no TLR7 actuariam como factores de risco, ou de protecção, para infecção por HPV e/ou desenvolvimento de cancro do colo do útero. Estas alterações foram pesquisadas e analisadas utilizando técnicas biomoleculares como a PCR, o SSCP e a sequenciação automática de DNA. Foram pesquisadas alterações na região codificante, zonas de splicing e UTRs do TLR7 em amostras citológicas em que foram identificadas diferentes lesões do colo do útero: células escamosas atípicas de significado indeterminado (ASCUS), lesões de baixo grau (LBG), lesões de alto grau (LAG) e carcinomas, bem como amostras de controlo. Foram identificadas catorze possíveis alterações neste gene, treze na região codificante e uma na 3’UTR. Das alterações identificadas neste estudo, cinco são alterações missense, cinco são alterações sinónimas e três são inserções com alteração da pauta de leitura (frameshift). O polimorfismo mais estudado neste trabalho, Gln11Leu, já se encontra descrito na literatura. Não foram observadas quaisquer diferenças significativas, quer no que respeita às frequências alélicas, quer genotípicas, relativamente a indivíduos com e sem infecção, ou com diferentes graus de lesão. Uma vez que este polimorfismo se encontra localizado numa região que inclui o ectodomínio do TLR7, pode ser importante para a resposta imunológica contra o HPV, já que pode comprometer a activação das células através do TLR7. Nas restantes alterações não foi possível estabelecer qualquer relação entre a infecção por HPV e o grau de lesão já que não nos foi possível determinar o genótipo de um número suficiente de amostras devido a limitações técnicas. Estas poderão ser futuramente ultrapassadas com recurso a uma série de procedimentos que são discutidos neste trabalho. ABSTRACT: The host immune factors are very important in susceptibility to infection and persistence of HPV infections and, thus, in the development of the cervical cancer. Persistent infections by high-risk HPV are the main risk factor for the development of cervical cancer. Although HPV infection is necessary, it is not sufficient to cause this type of cancer. The innate and acquired immune responses are important in the prevention and regression of lesions caused by HPV. The innate immune system recognizes foreign antigens through pattern recognition receptors (PRR) and initiates an appropriate response. Toll-like receptors (TLR), in particular TLR7 and 9, are PRRs that may be involved in virals recognition. Activation of TLRs by viral components stimulates the innate immune response by promoting the synthesis of cytokines, such as type I interferons (IFNs), IL-1β and IL-6, which can act directly on viral replication. These signals also lead to the recruitment of immune cells to the infection sites and to activation of dendritic cells, which trigger the acquired immune response. Single nucleotide polymorphisms (SNPs) in genes encoding host immune factors, such as TLRs, may compromise the immune response. The investigation of genetic factors related to the host immune response may be important for understanding the distinctive ability of different women to control and eliminate HPV infection. The aim of this study was to determine if genetic changes in TLR7 could act as risk factors for HPV infection and/or development of cervical cancer. TLR7 genetic changes were screened and analyzed using molecular techniques such as PCR, SSCP and automatic DNA sequencing. We have analysed the TLR7 coding region, splicing areas and UTRs in cytologic samples of women that harboured cervical lesions of different grades: atypical squamous cells of undetermined significance (ASCUS), low-grade lesions (LSIL), high-grade lesions (HSIL) and carcinomas; as well as control samples. Fourteen putative genetic changes were found, thirteen of which were located in the coding region and one in the 3'UTR. Five of them were missense changes, five were synonymous changes and three were frameshift insertions. The polymorphism that was more extensively studied in this work, Gln11Leu, was already described in the literature. No significant differences were found in allelic and genotypic frequencies with regard to HPV infection and/or grade of cervical lesion. Since this polymorphism is located in a region that includes the ectodomain of the TLR7, it may be important for the immune response against HPV as it may compromise cell activation through TLR7. With regard to the other TLR7 genetic changes, it was not possible to establish any association between any of these changes and HPV infection and/or cervical cancer development, as the number of genotyped sample was too small. This was due to technical limitations. In this work we discuss a set of procedures that may be used in the future to overcome these limitations.
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36

Rezgui, Awatef. "Étude de la microflore colonisant les tissus ligneux de Vitis vinifera : Intérêt pour le développement d’agents de biocontrôle contre une maladie du bois de la vigne, l’esca." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0449/document.

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Les maladies du bois de la vigne (MDBs) et plus particulièrement l’esca, sont devenues en l’espace de deux décennies l’objet de préoccupations majeures puisqu’elles mettent en danger la pérennité de nombreux vignobles partout dans le monde. En Tunisie, ces maladies sont peu connues mais elles semblent être en pleine expansion et, en France, environ 13% du vignoble est improductif à cause des dépérissements qu’elles provoquent. Pour lutter contre les MDBs, les filières viticoles françaises et tunisiennes sont actuellement dans une impasse technique car elles ne disposent d’aucune méthode de lutte chimique « curative ». Dans ce contexte, l’objectif de cette thèse est de (i) déterminer quels agents pathogènes sont responsables des dégradations du bois de la vigne en Tunisie ? Les symptômes correspondent-ils à ceux de l’esca ? Existe-t-il une spécificité des agents pathogènes chez les ceps tunisiens ? Aussi (ii) afin de lutter contre ces maladies du bois (MDBs), de potentiels agents de biocontrôle bactériens ont été recherchés dans les parties ligneuses de ceps sélectionnés dans des vignobles tunisiens. Ils ont été caractérisés et des essais de protection in planta ont été réalisés. [...] Ces champignons ont été identifiés au niveau morphologique et moléculaire. Leur pathogénicité a été confirmée après inoculation sur jeunes plants de vigne. Des travaux originaux basés sur la co-inoculation de plants de vigne par ces 3 pathogènes ont montré qu’ils pouvaient rentrer en compétition entre eux au sein du végétal. Par ailleurs, sur le même thème, 2 autres pathogènes des MDBs, i.e. Phomopsis viticola et Diploidia seriata, ont été isolés dans une autre étude à partir de ceps prélevés dans la même région en Tunisie. Dans une deuxième étape, la microflore bactérienne colonisant les tissus ligneux de vignes prélevées dans le nord de la Tunisie a été étudiée afin de rechercher des agents de lutte biologique potentiels. La technique d’empreinte moléculaire Single-Strand Conformation Polymorphism (SSCP) a d’abord montré que les communautés bactériennes étaient différentes en fonction des tissus qu’elles colonisaient, i.e. le bois nécrosé ou sain. Soixante-neuf souches bactériennes ont été isolées par méthode pasteurienne, et les 19 souches les plus abondantes ont fait la suite de l’étude. L’identification moléculaire de ces souches par séquençage de l’ARNr 16S et du gène rpoB a montré l’existence de 4 genres colonisant les ceps de vignes : Bacillus, Curtobacterium, Pantoea et Pseudomonas. Ces bactéries ont été également caractérisées au niveau biochimique, métabolique et génétique. Des tests de sélection in vitro contre les trois pathogènes fongiques ont été effectués, suite auxquels, une souche B6 de B. subtilis a été sélectionnée pour des essais de protection in planta en serre. Par la suite, une étude combinant deux bactéries antagonistes isolées de bois de vigne tunisien, i.e. B. subtilis B6, et français, i.e. Pantoea agglomerans S5, a été réalisée pour lutter contre 2 agents pathogènes, Phaeomoniella chlamydospora (isolé des vignobles français) et N. parvum (isolé des vignobles tunisiens), impliqués dans les MDBs. Deux cépages, un fréquent en Tunisie, le Muscat d’Italie, et l’autre en France, le Cabernet Sauvignon, ont été utilisés. En effet, suivant l’agent pathogène et le cépage utilisés, les résultats de protection obtenus étaient différents. Les meilleurs résultats de protection ont été obtenus en combinant les bactéries et en les appliquant sur Muscat d’Italie contre les 2 champignons pathogènes. La spécificité et l’efficacité de la protection biologique a ici été démontrée
Grapevine trunk diseases (GTDs) such as esca are of major concern for viticulture worldwide. In Tunisia, knowledge about the symptoms of this disease and the microflora associated with, is still incomplete despite their ability to cause considerable damage to vineyards. In France, around 13% of whole vineyard is unproductive because of GTDs, and no effective treatment currently exists. In that context, the objectives of the present PhD study were: (i) to characterize the fungal microflora inhabiting the wood tissues of Tunisian esca-foliar symptomatic vines in order to identify the pathogens responsible for wood decay. (ii) To investigate the bacterial microflora colonizing the wood tissues of Tunisian grapevines cv. Muscat d’Italie in order to find a suitable Biological Control Agent (BCA) that can be applied to vineyards. First, in order to better characterize the microflora colonizing the wood tissues of vine, samples were collected from 10 vineyards in the north of Tunisia. Fungal isolates were obtained from trunk of grapevines showing decline, small and distorted leaves and chloroses. To identify the isolated fungal species, sequencing of the Internal Transcribed Spacer region of the rDNA was performed (ITS1 and ITS4 primers). Three pathogens, i.e. Lasidiodiplodia pseudotheobromae, Neofusicoccum parvum and Schizophyllum commune, described in the literature as involved in GTDs were isolated for the first time in Tunisia. Their pathogenicity was confirmed in planta. Moreover, the coinoculation of these 3 fungi in planta, showed that they displayed a competitive inhibition effect on each other. In another study, two others pathogens involved in GTDs, i.e. Phomopsis viticola and Diploidia seriata were also isolated from the same region. This PhD also aimed at identifying the bacterial microflora inhabiting the wood tissues of escafoliar symptomatic vines, i.e. necrotic and non-necrotic wood, using microbiological and molecular approaches. Complex bacterial communities, as shown by Single-Strand Conformation Polymorphism (SSCP) analyses, colonize both types of wood tissues. After isolation, the 19 most abundant cultivable strains were sequenced (16S rRNA and rpoB genes) and identified as belonging to four genera: Bacillus, Pantoea, Pseudomonas and Curtobacterium. They were then screened for their in vitro antagonistic traits against the three pathogenic fungi L. pseudotheobromae, N. parvum and S. commune. Based on the results obtained, two bacterial strains were selected: B. subtilis (strain B6) and Pantoea agglomerans (strain S5), respectively isolated from Tunisian and French grapevines. They were then tested in planta on young vines of cv Muscat d’Italie and Cabernet Sauvignon against two fungal pathogens involved in GTDs, i.e. N. parvum (isolated from Tunisian wood) and Phaeomoniella chlamydospora (isolated from French vines). Young vines of both cultivars were inoculated by B. subtilis B6, P. agglomerans S5 or the combination of B6+S5, singly or in combination with N. parvum and P. chlamydospora. In terms of plant protection, the most efficient condition to reduce in planta necrosis caused by the fungal pathogens in the two cultivars was the combination of the two bacteria. However, bacterial treatments were significantly more efficient to reduce necrosis caused by N. parvum or P. chlamydospora in Muscat d’Italie than in Cabernet Sauvignon
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37

Michelland, Rory. "Caractérisation moléculaire des procaryotes et facteurs de variation des écosystèmes digestifs chez deux mammifères herbivores : approche comparée vache/lapin." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT006A/document.

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L’objectif de ce travail était de caractériser la variabilité spécifique (Bos taurus vs Oryctolagus cuniculus), individuelle, spatiale (inter- et intra- fermenteurs digestifs) et temporelle (en conditions non perturbée ou perturbée) des écosystèmes digestifs des mammifères herbivores (communautés procaryotiques et biotope) en comparant deux modèles animaux, la vache et le lapin, et en utilisant des outils moléculaires (CE-SSCP et qPCR). D’un point de vue méthodologique, nous avons développé un programme informatique, StatFingerprints, pour améliorer le traitement et l’analyse statistique des profils CE-SSCP et ainsi mieux extraire l’information écologique qu’ils contiennent en termes de structure et de diversité des communautés. Nous avons également mis au point des systèmes de qPCR plus spécifiques (Firmicutes et Bacteroides Prevotella) que ceux précédemment décrits. D’un point de vue cognitif, nos travaux démontrent une forte influence de l’espèce hôte sur les caractéristiques de son écosystème : les communautés sont plus riches (+8 %, +12 % pour les bactéries et les Archaea, respectivement), plus diverse (+19 % pour les bactéries) mais moins abondantes (-4.9 % de bactéries) dans le rumen de la vache que dans le caecum du lapin. Le biotope ruminal est moins acide (+0.6 unité pH), plus réducteur (-30 mV), et contient moins d’acides gras volatils (-19%) et plus de NH3-N (+39%) que le biotope caecal. Cela suggère un rôle déterminant de la physiologie digestive de l’hôte et/ou des phénomènes de coévolution hôte/microbiote. Nos travaux n’ont pas permis de mettre en évidence un effet de « l’individu hôte » sur les caractéristiques de sa communauté microbienne suggérant que la proximité génétique entre les individus (race) et/ou la forte standardisation des conditions d’élevage (logement, alimentation etc.) tendent à uniformiser l’influence des individus sur le déterminisme de leurs communautés procaryotiques. Nous avons montré qu’il existe une évolution des communautés microbiennes le long du tractus digestif en relation avec la physiologie et les conditions environnementales des différents compartiments à laquelle s’additionne, dans le rumen, une variabilité liée à la fraction, liquide ou solide, considérée. Nos données suggèrent qu’à l’état basal et en situation de perturbation, les communautés procaryotiques des deux espèces hôtes n’évoluent pas de la même façon dans le temps. Ainsi, dans le rumen de la vache, la communauté bactérienne fluctue de façon sporadique suggérant un état d’équilibre dynamique alors qu’elle reste dans un état d’équilibre statique dans le caecum du lapin. Les deux communautés réagissent de façon rapide (< 2jours) et s’adaptent rapidement à une augmentation du ratio amidon/fibres pour atteindre un nouvel équilibre, dynamique dans le rumen et statique dans le caecum. En revanche, nos travaux n’ont pas mis en évidence de corrélations importantes entre les communautés bactériennes et les paramètres de leur environnement. D’un point de vue finalisé, ces données confirment que la nutrition est une voie d’action pertinente pour essayer de réorienter le fonctionnement des écosystèmes digestifs chez ces espèces d’intérêt zootechnique, vers une meilleure santé et/ou efficacité digestive
The aim of this work was to characterize the specific (Bos taurus vs Oryctolagus cuniculus), individual, spatial (inter- and intra- digestive fermentors) and temporal (in undisturbed or disturbed conditions) variability of the digestive ecosystems (prokaryotic communities and biotope) in herbivorous mammals by comparing two animal models, cow and rabbit, and by using molecular methods (CE-SSCP and qPCR). Concerning methodology, we developed the StatFingerprints program to improve processing and statistical analysis of CE-SSCP profiles and better extract ecological information they contained about structure and diversity of communities. We also developed more specific (Firmicutes and Bacteroides Prevotella) primers than those available. From a cognitive point of view, our work demonstrated a strong effect of host species on ecosystem: communities presented a higher richness (+8 %, +12 % for bacteria and Archaea, respectively), a greater diversity (+19 % for bacteria) but are less abundant (-4.9 % bacteria) in cow rumen than in rabbit caecum. The rumen biotope is less acid (+0.6 pH unit), more reductive (-30 mV), and contains a lower concentration of fatty acids (-19%) and a higher concentration of NH3-N (+39%) than caecal biotope. Taken together, these results suggested a determining role of the digestive physiology of the host and of coevolution phenomena between the host and its microbiota. Our results did not permit to evidence an individual effect on the procaryotic communities suggesting that the genetic similarity between animals we used and/or the strong standardization of breeding conditions (housing, food etc) tended to reduce the influence of the individuals on their prokaryotic communities. We showed that the procaryotic communities evolved along the digestive tract in relation to the physiology and the environmental conditions of the various compartments in which they live. In addition, in the rumen, we evidenced a variability of the bacterial community related to the fraction considered, liquid or solid. Our data suggested that, both in basal and disturbed situations, the bacterial communities of the two host species did not evolve in the same way in time. Indeed, in the rumen of the cow and basal condition, the bacterial community fluctuated sporadically suggesting a dynamic balance whereas it remains in a stable state in the caecum of the rabbit. The two communities reacted quickly (< 2 days) and adapted quickly to an increased ratio starch/fibres to reach a new balance, dynamic in the rumen and stable in the caecum. On the other hand, our work did not highlight important correlations between the bacterial communities and the parameters of their environments. From a finalized point of view, these data confirmed that the nutrition is a relevant way to try to reorientate the functioning of digestive ecosystems in these two species, toward a better digestive health and/or efficiency
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Contador, Luciana. "Etude de la structure chimique et microbiologique de l'interface air-mer en baie de Guanabara (Rio de Janeiro, Brésil)." Paris 6, 2006. http://www.theses.fr/2006PA066158.

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La microcouche de surface (SML) correspond au premier millimètre de la colonne d’eau. Située à l’interface air-eau, la SML est un environnement unique, riche en microorganismes, en matières organiques, en hydrocarbures et présentant des conditions extrêmes par l’impact des radiations UV et les fortes concentrations de polluants. Les échantillons ont été prélevés dans la SML et dans l’eau sous-jacente (UW) à 7 stations de la Baie de Guanabara, Brésil. Cette étude a permis de caractériser l’abondance et la diversité des bactéries et des hydrocarbures présents dans la SML de la baie. L’origine des hydrocarbures a été analysée par des marqueurs chimiques par chromatographie en phase gazeuse. Sur le plan microbiologique, 43 souches bactériennes ont été isolées et identifiées. Leur résistance aux radiations UV a été évaluée à l’aide d’un simulateur solaire. La SML de la baie est bien définie par rapport à l’UW et enrichie en hydrocarbures et en bactéries. Le bactérioneuston est plus diversifié que le bactérioplancton. La plupart des souches testées sont très résistantes aux UV et sont des espèces potentiellement intéressantes sur le plan biotechnologique.
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39

Le, Goff Olivier. "Identification et dispersion des bioaérosols générés lors du compostage." Thesis, Montpellier 2, 2010. http://www.theses.fr/2010MON20094/document.

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Cette étude porte sur l'identification et la dispersion des bioaérosols générés sur les plates-formes de compostage et plus précisément lors du retournement des andains en cours de fermentation. L'analyse des bioaérosols émis sur cinq plates-formes par des inventaires moléculaires (ADNr 16S et ADNr 18S) a permis de montrer la dominance de deux phyla bactériens Firmicutes et Actinobacteria et du phylum fongique Ascomycota. En comparant la structure de la population microbienne des cinq bioaérosols, une signature a été identifiée. Dix phylotypes microbiens sont communs à au moins quatre bioaérosols. Deux sont présents dans les cinq bioaérosols : NA07 appartenant à l'espèce Saccharopolyspora rectivirgula et représentant 7% des séquences bactériennes totales et EQ07 affiliée à Thermomyces (49% des séquences fongiques). Un second phylotype bactérien, NC38, affilié à la famille des Thermoactinomycetaceae a été sélectionné du fait q u'il n'ait été identifié que dans le compost. Des systèmes de PCRq ont été développés pour quantifier ces trois indicateurs potentiels. Ces derniers ont été validés expérimentalement par des mesures sur sites industriels. La dispersion des bioaérosols a ensuite été caractérisée en utilisant plusieurs méthodologies, dont les trois indicateurs conçus et une technique d'empreinte moléculaire, la SSCP. Lors d'une activité de retournement, la concentration des indicateurs est supérieure à leur niveau basal dans l'air (bruit de fond). Les indicateurs présentent des profils de dispersion différents d'où l'intérêt de les coupler afin d'obtenir une meilleure vision de la dispersion des bioaérosols de compostage
The aim of this work was to analyze the diversity and the dispersal of composting bioaerosol emitted during the turning of compost windrows in thermophilic phase on composting platforms. The study of the microbial diversity of aerosols emitted on five composting plants was realized by 16S and 18S rDNA molecular inventories. Two bacterial phyla Firmicutes and Actinobacteria and one fungal phylum Ascomycota dominated. A common microbial signature emerged from the five composting bioaerosols: ten microbial phylotypes (seven bacterial and three fungal) were common to at least four bioaerosols. Two have been identified in five bioaerosols: NA07 belonging to the species Saccharopolyspora rectivirgula, and representing 7% of total number of bacterial sequences, and EQ05,affiliated to Thermomyces (49% of total number of fungal sequences). A second bacterial phylotype, NC38, affiliated to the Thermoactinomycetaceae family, was selected because it was id entified only in the environmental source compost'. qPCR systems were then designed for each phylotype. Measurements performed on industrial composting sites validated the use of these microorganisms as indicators of composting bioaerosols. The dispersal of composting bioaerosols was then characterized using the three indicators developed and a fingerprint technique, the SSCP
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40

Jordaan, Karen. "The evaluation of multiplex PCR and DNA profiling methods (DGGE and SSCP) for the detection of mycotoxigenic Fusarium species / by Karen Jordaan." Thesis, North-West University, 2008. http://hdl.handle.net/10394/2117.

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41

Peyruchaud, Olivier. "Analyse des polymorphismes du complexe glycoprotéique GPIIb-IIIa plaquettaire par PCR-SSCP : application à la Thrombasthénie de Glanzmann et aux systèmes alloantigéniques." Bordeaux 2, 1995. http://www.theses.fr/1995BOR28356.

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42

Silva, Junior José Inácio da. "Comparativo de desempenho de sistemas BCI-SSVEP off-line e em tempo de execução utilizando técnicas de estimação de espectro e análise de correlação canônica." reponame:Repositório Institucional da UFABC, 2017.

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Orientador: Prof. Dr. Diogo Coutinho Soriano
Dissertação (mestrado) - Universidade Federal do ABC. Programa de Pós-Graduação em Engenharia Biomédica, 2017.
Interfaces cérebro-computador (BCIs) definem canais de comunicação capazes de mapear sinais cerebrais em sinais de controle para dispositivos externos, sem utilização dos eferentes biológicos, utilizando comumente estratégias não invasivas para tanto, tal como obtido pela eletroencefalografia de superfície. Dentre os principais paradigmas BCI têm-se os potenciais visualmente evocados em regime estacionário (SSVEP - steady state visually evoked potential), o qual se baseia no sincronismo da atividade elétrica do córtex visual com estímulos visuais externos, permitindo assim a identificação dos eletrodos e frequências estimulatórias mais eficientes para a discriminação dos estímulos escolhidos pelo usuário via modulação da sua atenção. Tal paradigma de sistema BCI tem sido utilizado como uma importante estratégia no âmbito do desenvolvimento de tecnologias assistivas, as quais visam aumentar a qualidade de vida de pacientes com severas limitações motoras e de comunicação. Neste contexto, o presente trabalho apresenta contribuições à implementação de sistemas BCI-SSVEP operando de modo off-line e em tempo de execução (on-line). Para tanto, analisa-se aqui um conjunto de estruturas de processamento de sinais que levam ao melhor desempenho na tarefa de reconhecimento de padrões considerando técnicas clássicas de estimação de espectro e análise de correlação canônica (CCA - Canonical Correlation Analysis), um método comumente referenciado por seus bons resultados. Comparativos envolvendo variantes de pré-processamento baseados na filtragem espacial e na seleção de atributos também são apresentados. Dois conjuntos de dados foram analisados em ambiente off-line e um em tempo de execução. O primeiro conjunto de dados off-line foi analisado a partir da coleta de dados em cooperação científica no contexto do projeto DesTiNe, enquanto o segundo conjunto envolveu coleta de dados off-line e em tempo de execução no próprio laboratório de Métodos Computacionais para a Bioengenharia da UFABC. Como contribuições centrais podem-se mencionar: 1) comparativo de desempenho utilizando variantes de técnicas de filtragem espacial, extração e seleção de características em ambiente off-line; 2) implementação de um setup completo experimental para realização de experimentos BCI-SSVEP com neuro-feedback visual e auditivo; 3) Disponibilização de uma base de dados BCI-SSVEP contendo aquisições de 15 sujeitos com 12 sessões de 6 segundos para cada uma das 4 frequências (10, 11, 12 e 13 Hz), totalizando 48 sessões por sujeito, i.e. um total de 720 sessões de 6 s ou 4.320 s de dados disponibilizados para a comunidade científica; 4) Comparação de 3 métodos de extração de características em âmbito off-line (FFT, Welch e CCA); 5) Comparação de 2 métodos de extração de características em âmbito on-line, FFT e CCA; 6) Análise de desempenho on-line versus off-line.
Brain-computer interfaces (BCIs) define communication channels capable of mapping brain signals in control signals to external devices, without the use of biological efferents, using commonly non-invasive strategies for both, as obtained by surface electroencephalography. Among the main BCI paradigms are the steady state visually evoked potentials (SSVEP), which is based on the synchronization of the electrical activity of the visual cortex with external visual stimuli, thus allowing the identification of the electrodes and frequencies stimulus for discriminating the stimuli chosen by the user by modulating its attention. This BCI system paradigm has been widely used in the development of assistive technologies, which aim to increase the quality of life of patients with severe motor and communication limitations. In this context, this work presents contributions to the implementation of BCI-SSVEP systems operating offline and at run-time. To do so, we analyze here a set of signal processing structures that lead to the best pattern recognition performance considering classical techniques as spectrum estimation and Canonical Correlation Analysis (CCA), a commonly cited method for its good results. Comparisons involving preprocessing variants based on spatial filtering and attribute selection are also presented. Two sets of data were analyzed in an offline environment and one at run time. The first set of off-line data was analyzed from data collection in scientific cooperation in the context of DesTiNe project, while the second set involved off-line and run time data analysis in the Laboratory of Computational Methods for Bioengineering at UFABC. As central contributions may be mentioned: 1) comparative performance using variants of techniques of spatial filtering, feature extraction and feature selection in an offline environment; 2) implementation of a complete experimental setup to perform BCI-SSVEP experiments with visual and auditory neuro-feedback; 3) Availability of a BCI-SSVEP database containing acquisitions of 15 subjects with 12 sessions of 6 seconds for each of the 4 frequencies (10, 11, 12 and 13 Hz), totaling 48 sessions per subject, ie a total of 720 sessions of 6 s or 4,320 s of data made available to the scientific community; 4) Comparison of 3 methods of feature extraction in off-line environment (FFT, Welch and CCA); 5) Comparison of 2 methods of feature extraction in online scope, FFT and CCA; 6) Analysis of performance online versus offline.
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43

Weitzel, Stephan [Verfasser], Markus Wolfgang [Akademischer Betreuer] Ferrari, Christoph [Akademischer Betreuer] Redecker, and Stefan [Akademischer Betreuer] Isenmann. "Individuelle zerebrale Prognose nach Herzstillstand - ist die Bewertung der Medianus-SSEP Untersucher abhängig? / Stephan Weitzel. Gutachter: Markus Wolfgang Ferrari ; Christoph Redecker ; Stefan Isenmann." Jena : Thüringer Universitäts- und Landesbibliothek Jena, 2012. http://d-nb.info/1023683857/34.

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44

Marques, Martins Guilherme. "Communautés microbiennes de la baie de raisin : Incidence des facteurs biotiques et abiotiques." Thesis, Bordeaux 2, 2012. http://www.theses.fr/2012BOR21924/document.

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L’étude des communautés microbiennes de la baie de raisin dans des conditions de production à l’échelle de la parcelle montre une dynamique temporelle des populations cultivables, qui se traduit par une augmentation des niveaux de population à partir des stades de début véraison et début maturité. Concernant la communauté bactérienne cultivable, 44 espèces appartenant à 21 genres ont été identifiées. Parmi les huit genres identifiés pour la population fongique, les espèces appartenant au genre Aureobasidium sont les plus abondantes, contrairement aux espèces fermentaires qui restent minoritaires. L’incidence des facteurs biotiques et abiotiques sur différents paramètres de population microbienne tels que la structure, la densité et l’activité métabolique a été analysée. Nous avons observé que les zones climatiques plus fraîches et humides, favorisent le développement des microorganismes. Ces travaux mettent en évidence l’impact écotoxique du cuivre sur la communauté microbienne, en particulier dans sa fraction bactérienne. Le développement de Botrytis cinerea sur la grappe modifie la communauté microbienne des baies de raisin sain : le nombre d’espèces bactériennes augmente ainsi que leur diversité. La communauté bactérienne de la baie de raisin est proche de celle des feuilles d’un point de vue de sa structure, et mais éloignée de celles des écorces et du sol, avec des indices de diversité et de richesse plus faibles
The study of microbial communities associated with wine grapes under field conditions revealed changes in the size and structure during the berry ripening process, with levels rising gradually and reaching their highest value when the berries were over ripe. During this work several bacteria and fungi species, including fermentative yeast, have been isolated and identified. From cultured bacteria, over 44 species were identified from 21 genera. Concerning fungi population, among eight genera identified, the genus Aureobasidium was the most abundant. Our study reveals the impact of different abiotic and biotic factors over microbial community structure, density and metabolic activity. Comparing different vineyards in the same region, we observed that areas presenting more humid and colder climate favor the growth of microorganisms. Our results also show that the farming system has a clear impact on the microbial community, especially in the bacterial fraction. One of the reasons is the inhibiting effect of copper-based fungicides, frequently used in both organic and conventional farming systems. The presence of Botrytis cinerea in grape berries without visual symptoms of infection can change the microbial community of the grapes, increasing bacterial population density and diversity
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45

Koenig, Roger. "Comment le sens est-il extrait de l'information visuelle ? Le système visuel exploré des catégories à la conscience." Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00736494.

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Comment le sens est-il extrait de l'information visuelle ? Cette thèse est focalisée sur la capacité du système visuel d'humains et de singes à extraire et représenter l'information visuelle sur différents niveaux de complexité. Nous avons étudié différent niveaux de représentations visuelles, de la production de représentations visuelles primaires jusqu'à l'élaboration de représentations visuelles conscientes. Ce manuscrit présente six travaux dans lesquels nous avons exploré : (1) les attributs visuels nécessaires pour réaliser la tâche de catégorisation ultra-rapide chez l'homme et le singe au moyen de méthodes psychophysiques, (2) la dynamique spatio-temporelle de l'attention visuelle chez l'homme au moyen de méthodes psychophysiques, (3) les corrélats neuronaux des représentations de haut niveau en EEG grâce au développement d'une nouvelle technique appelée SWIFT, (4) les corrélats neuronaux de la conscience visuelle dans la rivalité binoculaire en EEG, (5) la synchronie des signaux cérébraux en fonction de la reconnaissance consciente au moyen d'enregistrements intracrâniens chez des patients épileptiques et (6) les corrélats neuronaux associés à la prise de conscience chez le singe au moyen d'enregistrements intracrâniens. Les résultats de ces travaux nous ont permis d'ébaucher un modèle de la perception visuelle, cherchant à dissocier l'attention et la conscience.
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46

Koenig, Alexis Roger. "Comment le sens est-il extrait de l'information visuelle ? : le système visuel exploré des catégories à la conscience." Toulouse 3, 2012. http://thesesups.ups-tlse.fr/1749/.

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Comment le sens est-il extrait de l'information visuelle ? Cette thèse est focalisée sur la capacité du système visuel d'humains et de singes à extraire et représenter l'information visuelle sur différents niveaux de complexité. Nous avons étudié différent niveaux de représentations visuelles, de la production de représentations visuelles primaires jusqu'à l'élaboration de représentations visuelles conscientes. Ce manuscrit présente six travaux dans lesquels nous avons exploré : (1) les attributs visuels nécessaires pour réaliser la tâche de catégorisation ultra rapide chez l'homme et le singe au moyen de méthodes psychophysiques, (2) la dynamique spatio-temporelle de l'attention visuelle chez l'homme au moyen de méthodes psychophysiques, (3) les corrélats neuronaux des représentations de haut niveau en EEG grâce au développement d'une nouvelle technique appelée SWIFT, (4) les corrélats neuronaux de la conscience visuelle dans la rivalité binoculaire en EEG, (5) la synchronie des signaux cérébraux en fonction de la reconnaissance consciente au moyen d'enregistrements intracrâniens chez des patients épileptiques et (6) les corrélats neuronaux associés à la prise de conscience chez le singe au moyen d'enregistrements intracrâniens. Les résultats de ces travaux nous ont permis d'ébaucher un modèle de la perception visuelle cherchant à dissocier l'attention et la conscience
How does sense emerges in the visual system? In this thesis we will be focused on the visual system of human and non-human primates and their large capacity of extract and represent visual information. We studied several levels of visual representations from those related to the extraction of coarse visual features to the emergence of conscious visual representations. This manuscript presents six works in which we explored: (1) the visual features necessary to perform ultra-rapid visual categorization in monkeys and humans using psychophysics, (2) the spatio-temporal dynamics of visual attention in humans using psychophysics, (3) the neural correlates of high-level visual representations using EEG tanks to the development of an innovative technique called SWIFT, (4) the neural correlates of visual consciousness under binocular rivalry using EEG, (5) the synchrony of brain signals as a function of conscious recognition using intracranial electrodes implanted in epileptic patients and (6) the neural correlates associated with conscious perception in monkeys using intracranial electrodes. The results of these works allowed outlining a tentative model of visual perception aimed to dissociate attention and consciousness
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47

Janke, Tobias [Verfasser], Johann Akademischer Betreuer] Bauer, and Erika von [Akademischer Betreuer] [Mutius. "Molekularbiologische Untersuchungen zur Pilzdiversität in Stall- und Hausstaubproben mittels PCR-SSCP und Parallelsequenzierung / Tobias Janke. Gutachter: Erika von Mutius ; Johann Bauer. Betreuer: Johann Bauer." München : Universitätsbibliothek der TU München, 2013. http://d-nb.info/1048677222/34.

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48

Méndez, Aranda Melissa Marlene. "Aplicación de la prueba polimorfismo conformacional de la hebra simple de ADN (SSCP) en la determinación de la susceptibilidad a pirazinamida en Mycobacterium tuberculosis." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2008. https://hdl.handle.net/20.500.12672/3168.

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La pirazinamida (PZA) es una droga antituberculosa de primera línea, presenta gran actividad in vivo, sin embargo in vitro no es evidente a menos que el pH del medio sea ácido, lo que hace que la susceptibilidad sea difícil de determinar por métodos convencionales. Por lo tanto, el objetivo del presente estudio fue evaluar la prueba molecular Polimorfismo Conformacional de la Hebra simple de ADN (SSCP) en cepas clínicas de Mycobacterium tuberculosis, así como comparar su desempeño con otras pruebas como son el BACTECÔ-460TB, el test de Wayne y el secuenciamiento. Se utilizó la prueba molecular del SSCP para la determinación de la susceptibilidad a PZA trabajando con 157 aislamientos clínicos de M. tuberculosis provenientes del Área de Tuberculosis del Laboratorio de Enfermedades Infecciosas de la Universidad Peruana Cayetano Heredia.
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49

Cavalcante, Roberta Barroso. "Altera??es nos genes da E-caderina e ?-catenina em adenoma pleom?rfico e carcinoma aden?ide c?stico: estudo molecular e imuno-histoqu?mico." Universidade Federal do Rio Grande do Norte, 2008. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17140.

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Made available in DSpace on 2014-12-17T15:32:27Z (GMT). No. of bitstreams: 1 RobertaBC.pdf: 1065704 bytes, checksum: 6e6f9aa3d97c1150d7b5fd4167469597 (MD5) Previous issue date: 2008-08-30
Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico
Pleomorphic adenoma and adenoid cystic carcinoma represent a benign and malignant salivary gland neoplasm, respectively, that shares the same histological origin, however with distinct biological behavior. The aim of the present study was identify the -160 C/A polymorphism in the gene CDH1, mutational analysis of CTNNB1 gene and evaluation the expression of the E-cadherin and ?-catenin in pleomorphic adenomas and adenoid cystic carcinomas. Furthermore, it was proposed correlate the immunochemistry staining patterns with the polymorphism and mutations. Twenty-four pleomorphic adenomas and 24 adenoid cystic carcinomas were retrieved. The polymorphism analysis was performed by restriction fragment length polymorphism (RFLP), using the restriction enzymes HphI or AflIII and the mutational screening was performed by PCR-single strand conformational polymorphism (PCR-SSCP). The immunohistochemical analysis was taken by the counting of cells, recorded as the Hscore index, and considering the presence or absence, intensity, distribution and localization of proteins expression. Comparing the two neoplasms, the results demonstrated statistically significant difference for the E-cadherin and ?-catenin expression, with pleomorphic adenoma presenting weaker immunostaining. Was observed statistical correlation between E-cadherin and ?-catenin expression. CDH1 heterozigotic polymorphism was seen in two cases and 13 cases displayed abnormal mobility electrophoretic shifts, suggesting CTNNB1 gene mutation. The immunohistochemical expression was not statistically correlated with the polymorphism or suggested mutations. In conclusion this study supports that the E-cadherin/?-catenin complex immunohistochemical expression might be related with the myoepithelial component amount and differentiation neither the tumor biological behavior. The cases that showed E-cadherin gene polymorphism presented reduced protein expression and, moreover, CTNNB1 suggested mutations seem not influence in the ?-catenin protein expression
O adenoma pleom?rfico e o carcinoma aden?ide c?stico representam neoplasias de gl?ndula salivar benigna e maligna, respectivamente, que compartilham a mesma origem histol?gica, por?m com comportamentos biol?gicos distintos. O prop?sito deste estudo consistiu na identifica??o do polimorfismo -160 C/A da regi?o promotora do gene CDH1 (E-caderina), na triagem de muta??es no gene CTNNB1 (?-catenina), e ainda na an?lise da express?o imuno-histoqu?mica das prote?nas E-caderina e ?-catenina em adenomas pleom?rficos e carcinomas aden?ides c?sticos. Al?m disso, objetivou-se correlacionar os achados imuno-histoqu?micos com as poss?veis muta??es e polimorfismo. Foram selecionados 24 casos de adenoma pleom?rfico e 24 casos de carcinoma aden?ide c?stico. Para a identifica??o do polimorfismo no gene da E-caderina empregou-se a t?cnica RFLP (restriction fragment length polymorphism) utilizando-se enzimas de restri??o HphI e AflIII. A triagem de muta??es no exon 3 do gene da ?-catenina foi realizada por meio de SSCP (single strand conformational polymorphism). Para a an?lise imuno-histoqu?mica, procedeu-se contagem de c?lulas, por meio do ?ndice HScore e verificou-se presen?a ou aus?ncia, intensidade, padr?o de distribui??o e localiza??o celular e tecidual das prote?nas. Os resultados demonstraram diferen?a estatisticamente significativa quando a marca??o imuno-histoqu?mica, tanto da E-caderina quanto ?-catenina, foi comparada entre as duas neoplasias estudadas, apresentando o adenoma pleom?rfico express?o reduzida. Observou-se correla??o estatisticamente significativa entre a imuno-marca??o da E-caderina e ?-catenina. Dois casos (1 adenoma pleom?rfico e 1 carcinoma aden?ide c?stico) apresentaram polimorfismo heterozig?tico no gene CDH1 e 13 casos (6 adenomas pleom?rficos e 7 carcinomas aden?ides c?sticos) exibiram varia??o no padr?o de corrida eletrofor?tica, sugerindo muta??o do gene CTNNB1. N?o houve correla??o estatisticamente significativa entre a marca??o imuno-histoqu?mica e presen?a de polimorfismo ou poss?veis muta??es. Conclui-se que a express?o imuno-histoqu?mica do complexo E-caderina/?-catenina pode estar relacionada com a quantidade e diferencia??o do componente mioepitelial e n?o ao comportamento biol?gico dos tumores. Os casos que exibiram polimorfismo no gene da E-caderina apresentaram redu??o na express?o prot?ica e, por fim, as poss?veis muta??es no gene CTNNB1 parecem n?o influenciar na express?o da prote?na ?-catenina
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50

Degueurce, Axelle. "La méthanisation par voie sèche agricole appliquée aux fumiers de bovins : optimisation de la recirculation des lixiviats." Thesis, Rennes 1, 2016. http://www.theses.fr/2016REN1S016/document.

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Abstract:
Avec 67 Mt de fumiers de bovins récupérés chaque année, la France possède un gisement considérable de substrats agricoles mobilisables et valorisables par méthanisation. Le procédé de méthanisation par voie sèche, discontinu, avec recirculation de lixiviat semble être le mieux adapté à la valorisation de ce type de substrats à forte teneur en matière sèche (>20%). A l’heure actuelle, ce procédé est cependant rare sur le territoire. Afin de permettre et de pérenniser le développement de cette technologie, des verrous techniques et scientifiques doivent être levés, notamment ceux qui portent sur la recirculation des lixiviats. L’objectif de cette thèse est d’optimiser le procédé de méthanisation par voie sèche appliquée aux effluents agricoles (principalement fumiers de bovins), afin d’atteindre les conditions les plus favorables à la production d’un maximum de biogaz, de façon constante et en un minimum de temps en considérant les contraintes relatives à un tel procédé. Dans un premier temps, l’objectif a été de comprendre le rôle du lixiviat dans ce procédé de digestion anaérobie discontinu, d’un point de vue biologique. Pour se faire quatre lixiviats ayant différentes origines ont été utilisés. Deux d’entre eux étaient biologiquement actifs (lixiviats provenant de méthaniseurs) et les deux autres stérilisés. Du point de vue abiotique, il a été montré que pour favoriser la digestion anaérobie, le lixiviat devait avoir un pH adéquat, présenter une concentration suffisante de nutriments et un fort pouvoir tampon. D’un point de vue biotique, deux communautés distinctes de microorganismes évoluent dans le lixiviat et dans le fumier, sans aucun transfert entre ces deux environnements, limitant ainsi le rôle d’inoculation souvent attribué au lixiviat. Dans un deuxième temps, la réalisation d’un plan d’expérience a permis d’identifier, au laboratoire sur pilotes instrumentés, des paramètres de recirculation du lixiviat qui influencent les vitesses de production de méthane. Ainsi, le temps entre les recirculations, le volume recirculé et le ratio lixiviat/substrat initialement introduit jouent sur la forme des cinétiques de production. En actionnant l’un ou l’autre de ces leviers, il serait potentiellement possible d’adapter la production de méthane, en fonction des besoins des systèmes de valorisation du biogaz en place sur ces installations. Enfin, la méthode de tomographie de résistivité électrique a été utilisée, à grande échelle, pour suivre la percolation du lixiviat à travers le massif et mettre en évidence les disparités de distribution du lixiviat dans le massif. Cette étude a montré que la géométrie du réseau de recirculation du lixiviat, consistant en un tuyau perforé parcourant la surface du massif dans le sens de la longueur, ne permettait pas un écoulement homogène du lixiviat dans les digesteurs. Certaines zones n’ayant jamais été humidifiées, la production de méthane se trouve réduite et les rendements amoindris. Cette thèse s’articule autour de plusieurs analyses multi-échelles et complémentaires permettant de mieux comprendre le rôle du lixiviat, d’améliorer sa mise en œuvre et son utilisation pour la digestion anaérobie des fumiers de bovins
With 67 Mt of cattle manure recovered every year, France has a significant source of agricultural waste to be valorised through anaerobic digestion. Batch mode solid state anaerobic digestion (SSAD) process with leachate recirculation seems to be the most suitable technique to valorise that kind of waste, which contains high total solid content (>20%). Currently, this process is rare on French territory. To develop batch mode SSAD, various technical and scientific barriers must be straightened out, and particularly those concerning leachate recirculation. The objective of this work is to optimize SSAD of agricultural was (mostly cattle manure) by pointing out the most favorable settings that allow producing high volumes of biogas, steadily and within a short time, taking into account the particular technical constraints of this process. First of all, the objective was to better understand the biological role of leachate in the batch mode SSAD process. For that purpose, four leachates with different origins were used. Two of them were biologically active (from existing digesters) while the two others were sterilized. It was demonstrated an effective anaerobic digestion was favored by using a leachate gathering the following abiotic characteristics: an adequate pH, a strong buffer capacity and the presence of the right concentration of nutrients. From the biotic point of view, dedicated communities of microbes were in progress in each liquid and solid environment with nested relationship. The role of leachate as inoculum was then limited. In a second part, the influent parameters of leachate recirculation were identified at laboratory scale, by setting up a design of experiment. It was found that the elapsed time between two recirculations, the recirculated volume of leachate and the initial leachate to substrate ratio introduced in the reactor could modify the shape of methane production rate. By changing one or several of those parameters, it would be possible to control and adapt methane production rate to the specific constraints of one SSAD plant. In the last part, the Electrical Resistivity Tomography (ERT) method was used, at full scale, to monitor the leachate percolation through the solid waste and highlight leachate distribution disparities. It was shown the leachate injection system consisting of a perforated pipe laying on the solid top surface was not efficient to evenly moisten the solid waste. From that observation, it was concluded that cumulated methane production could be improved if areas that were not in contact with leachate could be moistened by using another leachate injection system. This manuscript was based on several multi-scale and complementary analyses that allow a better understanding of the role of leachate during SSAD process and an improvement of its utilization for the anaerobic digestion of cattle manure
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