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Estudo das respostas para o potencial evocado auditivo de estado estável em lactentes; Auditory steady state evoked response in young-infants

Ribeiro, Flávia Giuli Santi Martins
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 15/08/2008 PT
Relevância na Pesquisa
35.88%
Introdução: O potencial evocado auditivo de estado estável (PEAEE) é uma técnica promissora no diagnóstico precoce da surdez, tratando-se de um método objetivo, que estima o grau de sensibilidade em diferentes freqüências e oferece recursos diferenciais como: o emprego da avaliação dicótica e simultânea para diferentes freqüências, tornando o teste mais rápido, além da detecção automática da resposta garantindo a confiabilidade dos resultados. Objetivo: obter limiares para o PEAEE, em lactentes nascidos a termo e pré-termo, com audição normal, a fim de investigar o processo de maturação das respostas e verificar possíveis ajustes no protocolo, para aplicação clínica no diagnóstico precoce da surdez. Método: estudo coorte e prospectivo para análise dos limiares obtidos no PEAEE para 60 orelhas (30 para cada grupo) utilizando o programa Master®, com análise automática da resposta, pela aplicação do F-teste, com p-valor < 0,01, pesquisa de limiar em 5-5 dB, com estimulação monótica e simultânea para 500, 1000, 2000 e 4000 Hz. Resultados e discussão: Os limiares encontrados, em dB NPS foram mais elevados para o grupo Pré-termo sendo, em média, 49,11 (± 9,44), 26,38 (± 6,59), 26,74 (± 7,57) e 35...

Detecção de dano em estruturas via inteligência computacional e análise dinâmica ; Structural damage detection by means of computational intelligence techniques and dynamic analysis

Villalba Morales, Jesús Daniel
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 29/11/2012 PT
Relevância na Pesquisa
35.72%
Nesta tese doutoral estudam-se formas de resolver o problema de detecção de dano em estruturas a partir da aplicação de técnicas de inteligência computacional e da resposta dinâmica da estrutura. Duas opções para a formulação do problema são consideradas. Primeiro, um problema de otimização é estabelecido a partir da minimização da diferença entre os parâmetros dinâmicos experimentais da estrutura na condição com dano e aqueles calculados utilizando um modelo de elementos finitos que representa tal condição. Diferentes técnicas metaheurísticas (algoritmos genéticos, particle swarm optimization, evolução diferencial), algumas em versões com adaptação de parâmetros, são empregadas. Estuda-se, ainda, a formulação do problema de otimização como um com múltiplos objetivos. Uma nova forma de avaliar o desempenho de uma metodologia de detecção de dano é proposta, que está baseada na capacidade da metodologia para obter um nível determinado de exatidão no cálculo da extensão do dano e na presença de falso-negativos e falso-positivos nos resultados. Segundo, aplicam-se redes neurais para determinar o mapeamento entre os parâmetros dinâmicos experimentais da condição atual da estrutura e a extensão ou posição do dano nesta. Estruturas do tipo viga e treliça foram submetidas a diferentes cenários de dano com o intuito de determinar o desempenho das metodologias propostas. Resultados mostram a habilidade de técnicas de inteligência computacional para detecção de cenários de dano com uns poucos elementos danificados; porém não é possível garantir que as metodologias terão sucesso para o 100% dos casos. Recomenda-se a utilização de técnicas de busca local para melhorar a solução encontrada pelos algoritmos globais. Finalmente...

Fluorescence spectroscopy for tongue carcinoma detection: Study in an animal model

Kurachi, C.; Fontana, C. R.; Melo, C. A S; Rosa, L. E B; Bagnato, V. S.
Fonte: Universidade Estadual Paulista Publicador: Universidade Estadual Paulista
Tipo: Conferência ou Objeto de Conferência Formato: 210-217
ENG
Relevância na Pesquisa
35.65%
Fluorescence diagnosis of malignant lesions has been showed as an attractive optical technique due especially to its real-time response and a more objective and quantitative evaluation. Even though the oral cavity allows a direct examination many lesions are diagnosed when it is already in advanced stage, compromising the patient prognosis. In this study, the fluorescence spectroscopy was used to the detection of chemically induced carcinoma at the lateral border of the tongue in a hamster model. Two excitations wavelengths in visible region were applied: 442 and 532 nm. All the spectra results were analyzed comparing with the histopathological diagnosis. The better results were achieved with the 442 nm laser excitation. The spectra from carcinoma showed new emission bands and these were used to determined different ratios for a quantitative analysis. Using the 625-645 nm fluorescence range under 442 nm excitation (A3 coefficient) the percentage of false negative was of 9.1%, however the false positive percentage was of 18.5%. The 532 nm excitation provided a better normal tissue detection compared to 442 nm excitation. The ideal clinical condition is probably the use of multiple wavelengths excitation for a broader tissue fluorescence investigation.

Detecção de fugas em tubulações atraves do metodo de resposta em frequencia e reflexões de pulsos de alta frequencia; Leak detection pipes by frequency response method and reflections high frequency pulses

Juliana Barbosa Palhares
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 25/08/2005 PT
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35.74%
Nos sistemas de transporte de fluido líquido, têm-se a preocupação em combater às fugas ou vazamentos. Dessa fonna, este trabalho tem como objetivo aperfeiçoar o método de detecção de fugas em tubulações pelo método de resposta nos domínios fteqüência e tempo, utilizando como ferramentas matemáticas o Método da Matriz Transferência / Resposta em Freqüência e o Método das Características / Transfonnada Rápida de Fourier, sendo demonstradas as vantagens e desvantagens de cada método. E, como contribuição original, propõe um método de detecção de fugas através da análise de pulso de Alta Freqüência, localizando as fugas através da detenninação do tempo que um pulso emitido pela válvula leva para percorrer toda a tubulação e retomar à esta, denominado como Pulso Refletido; In liquid fluid transport systems, there is a concem about avoiding leaks. Thus, this work has as objective to improve the leak detection method in pipes by úequency and time domains response method, being used as mathematical tools the method ofTransfer-Matrix / by úequency response and the Method of Characteristics / the Fast Fourier Transform, being demonstrated the advantages and disadvantages of each method. And, as new contribution...

Atuação do time de resposta rápida nos indicadores de melhoria da qualidade assistencial; Action of the rapid response team in improving the quality indicators assistance

Viviane Cordeiro Veiga
Fonte: Biblioteca Digital da Unicamp Publicador: Biblioteca Digital da Unicamp
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 19/02/2013 PT
Relevância na Pesquisa
35.71%
Introdução: A segurança do paciente tornou-se prioridade estratégica para o sistema de saúde. Ações têm sido implantadas nas Instituições, na tentativa de reduzir a mortalidade hospitalar e os eventos não previsíveis. Objetivo: O objetivo deste trabalho é avaliar a atuação do time de resposta rápida nos indicadores de melhoria da qualidade assistencial, comparando dois períodos de seguimento. Casuística e Método: No período de maio de 2010 a dezembro de 2012, foram avaliados os atendimentos realizados pelo time de resposta rápida, em pacientes com idade maior ou igual a 18 anos. O estudo foi dividido em dois períodos, denominado "antes" e "depois", sendo que o primeiro compreendeu o intervalo de maio de 2010 a julho de 2011 e o segundo, entre agosto de 2011 e dezembro de 2012. O acionamento do grupo era feito por qualquer profissional da equipe assistencial, baseado em critérios preestabelecidos e amplamente divulgados na Instituição. Após 15 meses de seguimento, optou-se pela alteração nos critérios de acionamento (período "depois"), visando à detecção precoce da deterioração clínica e baseados no perfil epidemiológico da Instituição. No período, foram atendidos 8009 pacientes, sendo 1830 no "antes" e 6179 no "depois"...

Topographic distribution of the tibial somatosensory evoked potential using coherence

Melges,D.B.; Infantosi,A.F.C.; Miranda de Sá,A.M.F.L.
Fonte: Associação Brasileira de Divulgação Científica Publicador: Associação Brasileira de Divulgação Científica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2008 EN
Relevância na Pesquisa
55.88%
The objective of the present study was to determine the adequate cortical regions based on the signal-to-noise ratio (SNR) for somatosensory evoked potential (SEP) recording. This investigation was carried out using magnitude-squared coherence (MSC), a frequency domain objective response detection technique. Electroencephalographic signals were collected (International 10-20 System) from 38 volunteers, without history of neurological pathology, during somatosensory stimulation. Stimuli were applied to the right posterior tibial nerve at the rate of 5 Hz and intensity slightly above the motor threshold. Response detection was based on rejecting the null hypothesis of response absence (significance level α= 0.05 and M = 500 epochs). The best detection rates (maximum percentage of volunteers for whom the response was detected for the frequencies between 4.8 and 72 Hz) were obtained for the parietal and central leads mid-sagittal and ipsilateral to the stimulated leg: C4 (87%), P4 (82%), Cz (89%), and Pz (89%). The P37-N45 time-components of the SEP can also be observed in these leads. The other leads, including the central and parietal contralateral and the frontal and fronto-polar leads, presented low detection capacity. If only contralateral leads were considered...

A SIMPLE EXPERIMENTAL MODEL OF HEAT SHOCK RESPONSE IN RATS

Meyer,Tufi Neder; Silva,Alcino Lázaro da
Fonte: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia Publicador: Sociedade Brasileira para o Desenvolvimento da Pesquisa em Cirurgia
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/1998 EN
Relevância na Pesquisa
35.7%
Objective: To obtain a simple model for the elicitation of the heat shock response in rats. Design: Laboratory study. Setting: University research laboratories. Sample: Seventy-nine adult male albino rats (weight range 200 g to 570 g). Procedures: Exposure to heat stress by heating animals in a warm bath for 5 min after their rectal temperatures reached 107.60 F (420 C). Liver and lung samples were collected for heat-shock protein 70 (HSP70) detection (Western analysis). Results: Western analysis was positive for HSP70 in the liver and in the lungs of heated animals. There was a temporal correlation between heating and HSP70 detection: it was strongest 1 day after heating and reduced afterwards. No heated animals died. Conclusion: These data show that heating rats in a warm (45o C) bath, according to parameters set in this model, elicits efficiently the heat shock response.

Detection of determinant genes and diagnostic via Item Response Theory

Tavares,Héliton Ribeiro; Andrade,Dalton Francisco de; Pereira,Carlos Alberto de Bragança
Fonte: Sociedade Brasileira de Genética Publicador: Sociedade Brasileira de Genética
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2004 EN
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35.58%
This work presents a method to analyze characteristics of a set of genes that can have an influence in a certain anomaly, such as a particular type of cancer. A measure is proposed with the objective of diagnosing individuals regarding the anomaly under study and some characteristics of the genes are analyzed. Maximum likelihood equations for general and particular cases are presented.

Rice detector: proposal of a novel objective response detection technique

Farina Júnior,Paulo Danilo; Melges,Danilo Barbosa; Infantosi,Antonio Fernando Catelli; Sá,Antonio Mauricio Ferreira Leite Miranda de
Fonte: SBEB - Sociedade Brasileira de Engenharia Biomédica Publicador: SBEB - Sociedade Brasileira de Engenharia Biomédica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
95.91%
INTRODUCTION: The detection of the somatosensory response (SR) is an important tool for the neurophysiological evaluation in the intra and post-operative period of some vascular and spine surgeries. Particularly, the SR identification with a maximum false positive ratio by means of Objective Response Detection (ORD) techniques could lead to a less subjective procedure. In this work a novel ORD, the Rice Detector (RD), is presented and its theoretical critical value is obtained. METHODS: The probability of detection (PD) of RD is assessed for different numbers of eletroencephalographic (EEG) signal epochs (M = 30, 60, 120, 240) and signal-to-noise ratios (-20 to 10 dB, in steps of 1 dB) by means of simulation. The simulated PD curves (PDc) are compared with the theoretical ones and with the PDc of the Magnitude-Squared Coherence (MSC), a well-known ORD technique. The performance of RD and MSC are also compared for real EEG data. The comparison is based on the DP for estimates calculated with M = 30, 60, 120 and 240 epochs. RESULTS: The results showed that the simulated PDc follow the theoretical ones and both the MSC and RD present similar performance, with slight advantage for this latter at low M-values. However, for real data, no statistical significant difference (proportion test with alpha=0.05) was found between MSC and RD. CONCLUSION: Both techniques presented mean detection rates varying from 70% to 90%...

Association between chemotherapy response and rate of disease progression in disseminated melanoma.

Joensuu, H.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /01/1991 EN
Relevância na Pesquisa
35.69%
Fifty-five evaluable patients with disseminated malignant melanoma were treated with the combination of dacarbazine (DTIC) 400 mg i.v. on days 1 to 3 and lomustine (CCNU) 50 to 80 mg m-2 orally on day 1 with intervals of 6 weeks as the first line chemotherapy. Three (5%) patients had complete and 6 (11%) partial response, and 7 (13%) patients had stable disease at least for 3 months. The patients with an objective response (n = 9) survived longer than the rest of the patients if the length of survival was calculated from the start of chemotherapy (P = 0.0006). However, the responding patients also had longer time interval from the diagnosis to the detection of distant metastases (P = 0.05), and survival time from disease progression following DTIC and CCNU therapy (P = 0.005). These findings suggest that patients with an objective response to DTIC-CCNU therapy have melanoma with a slow progression rate, and prolonged survival in such patients may in part result from the less aggressive biological nature of their tumours.

Flow cytometric analysis of DNA ploidy and S-phase fraction from prostatic carcinomas: implications for prognosis and response to endocrine therapy.

Visakorpi, T.; Kallioniemi, O. P.; Paronen, I. Y.; Isola, J. J.; Heikkinen, A. I.; Koivula, T. A.
Fonte: PubMed Publicador: PubMed
Tipo: Artigo de Revista Científica
Publicado em /09/1991 EN
Relevância na Pesquisa
35.58%
We analysed ploidy and S-phase fraction (SPF) from 78 paraffin-embedded primary prostatic carcinomas by DNA flow cytometry. DNA aneuploidy and above median (4.2%) SPF were both associated with high tumour grade, large size of prostate and presence of distant metastases. Both aneuploidy and high SPF (greater than 4.2%) indicated short 10-year progression-free (P = 0.01 for ploidy and P = 0.0002 for SPF), overall (P = 0.004 and P less than 0.0001) as well as prostate cancer survival (P = 0.002 and P less than 0.0001). Ten-year overall survival rate was 45% in cases with SPF below 4.2% and 0% in those with higher values, whereas the corresponding prostate cancer-specific survival rates were 80% and 11%, respectively. None of the seven tumours with SPF above 12% showed an objective response to endocrine therapy, whereas 26/49 (52%) of those with lower SPF values responded (P = 0.01). DNA ploidy, tumour grade, T-stage or M-stage did not significantly correlate with endocrine responsiveness. SPF was also the best predictor of progression free survival in patients treated hormonally. In conclusion, detection of high SPF in prostate cancer may indicate lack of hormonal responsiveness and poor prognosis.

Enhanced Detection of Host Response Antibodies to Borrelia burgdorferi Using Immuno-PCR

Halpern, Micah D.; Jain, Sunny; Jewett, Mollie W.
Fonte: American Society for Microbiology Publicador: American Society for Microbiology
Tipo: Artigo de Revista Científica
Publicado em /03/2013 EN
Relevância na Pesquisa
25.86%
Lyme disease is the fastest-growing zoonotic disease in North America. Current methods for detection of Borrelia burgdorferi infection are challenged by analysis subjectivity and standardization of antigen source. In the present study, we developed an immuno-PCR (iPCR)-based approach employing recombinant in vivo-expressed B. burgdorferi antigens for objective detection of a host immune response to B. burgdorferi infection. iPCR is a liquid-phase protein detection method that combines the sensitivity of PCR with the specificity and versatility of immunoassay-based protocols. Use of magnetic beads coated with intact spirochetes provided effective antigen presentation and allowed detection of host-generated antibodies in experimentally infected mice at day 11 postinoculation, whereas host-generated antibodies were detected at day 14 by enzyme-linked immunosorbent assay (ELISA) and day 21 by immunoblotting. Furthermore, magnetic beads coated with recombinant B. burgdorferi in vivo-expressed antigen OspC or BmpA demonstrated positive detection of host-generated antibodies in mice at day 7 postinoculation with markedly increased iPCR signals above the background, with the quantification cycle (Cq) value for each sample minus the mean background Cq plus 3 standard deviations (ΔCq) being 4 to 10...

Peripheral Blood for Epidermal Growth Factor Receptor Mutation Detection in Non-Small Cell Lung Cancer Patients

Li, Xuefei; Ren, Ruixin; Ren, Shengxiang; Chen, Xiaoxia; Cai, Weijing; Zhou, Fei; Zhang, Yishi; Su, Chunxia; Zhao, Chao; Li, Jiayu; Cheng, Ningning; Zhao, Mingchuan; Zhou, Caicun
Fonte: Neoplasia Press Publicador: Neoplasia Press
Tipo: Artigo de Revista Científica
Publicado em 17/06/2014 EN
Relevância na Pesquisa
35.82%
OBJECTIVE: It is important to analyze and track Epidermal Growth Factor Receptor (EGFR) mutation status for predicting efficacy and monitoring resistance throughout EGFR-tyrosine kinase inhibitors (TKIs) treatment in non-small cell lung cancer (NSCLC) patients. The objective of this study was to determine the feasibility and predictive utility of EGFR mutation detection in peripheral blood. METHODS: Plasma, serum and tumor tissue samples from 164 NSCLC patients were assessed for EGFR mutations using Amplification Refractory Mutation System (ARMS). RESULTS: Compared with matched tumor tissue, the concordance rate of EGFR mutation status in plasma and serum was 73.6% and 66.3%, respectively. ARMS for EGFR mutation detection in blood showed low sensitivity (plasma, 48.2%; serum, 39.6%) but high specificity (plasma, 95.4%; serum, 95.5%). Treated with EGFR-TKIs, patients with EGFR mutations in blood had significantly higher objective response rate (ORR) and insignificantly longer progression-free survival (PFS) than those without mutations (ORR: plasma, 68.4% versus 38.9%, P = 0.037; serum, 75.0% versus 39.5%, P = 0.017; PFS: plasma, 7.9 months versus 6.1 months, P = 0.953; serum, 7.9 months versus 5.7 months, P = 0.889). In patients with mutant tumors...

Detection of K-ras Mutations in Predicting Efficacy of Epidermal Growth Factor Receptor Tyrosine Kinase (EGFR-TK) Inhibitor in Patients with Metastatic Colorectal Cancer

Li, Ze; Liu, Xue-Wei; Chi, Zhao-Cheng; Sun, Bao-Sheng; Cheng, Ying; Cheng, Long-Wei
Fonte: Public Library of Science Publicador: Public Library of Science
Tipo: Artigo de Revista Científica
Publicado em 07/05/2015 EN
Relevância na Pesquisa
35.52%
Epidermal growth factor receptor tyrosine kinase (EGFR-TK) inhibitors are useful in treating different advanced human cancers; however, their clinical efficacy varies. This study detected K-ras mutations to predict the efficacy of EGFR-TK inhibitor cetuximab treatment on Chinese patients with metastatic colorectal cancer (mCRC). A total of 87 patients with metastatic colorectal cancer were treated with cetuximab for 2-16 months, in combination with chemotherapy between August 2008 and July 2012, and tissue samples were used to detect K-ras mutations. The data showed that K-ras mutation occurred in 27/87 (31%). The objective response rates and disease control rate in K-ras wild type and mutant patients were 42% (25/60) versus 11% (3/27) (p<0.05) and 60% (36/60) versus 26% (7/27) (p<0.05), respectively. Patients with the wild-type K-ras had significantly higher median survival times and progression-free survival, than patients with mutated K-ras (21 months versus 17 months, p=0.017; 10 months versus 6 months, p=0.6). These findings suggest that a high frequency of K-ras mutations occurs in Chinese mCRC patients and that K-ras mutation is required to select patients for eligibility for cetuximab therapy. Further prospective studies using a large sample size are needed to confirm these preliminary findings.

Detection of methotrexate using surface plasmon resonance biosensors for chemotherapy monitoring

Zhao, Sandy Shuo
Fonte: Université de Montréal Publicador: Université de Montréal
Tipo: Thèse ou Mémoire numérique / Electronic Thesis or Dissertation
EN
Relevância na Pesquisa
35.65%
Le méthotrexate (MTX), un agent anti-cancéreux fréquemment utilisé en chimiothérapie, requiert généralement un suivi thérapeutique de la médication (Therapeutic Drug Monitoring, TDM) pour surveiller son niveau sanguin chez le patient afin de maximiser son efficacité tout en limitant ses effets secondaires. Malgré la fenêtre thérapeutique étroite entre l’efficacité et la toxicité, le MTX reste, à ce jour, un des agents anti-cancéreux les plus utilisés au monde. Les techniques analytiques existantes pour le TDM du MTX sont coûteuses, requièrent temps et efforts, sans nécessairement fournir promptement les résultats dans le délai requis. Afin d’accélérer le processus de dosage du MTX en TDM, une stratégie a été proposée basée sur un essai compétitif caractérisé principalement par le couplage plasmonique d’une surface métallique et de nanoparticules d’or. Plus précisément, l’essai quantitatif exploite la réaction de compétition entre le MTX et une nanoparticule d’or fonctionnalisée avec l’acide folique (FA-AuNP) ayant une affinité pour un récepteur moléculaire, la réductase humaine de dihydrofolate (hDHFR), une enzyme associée aux maladies prolifératives. Le MTX libre mixé avec les FA-AuNP...

Collision detection and post-processing for physical cloth simulation; Kollisionsdetektion und Nachbearbeitung bei der physikalischen Textilsimulation

Kimmerle, Stefan
Fonte: Universidade de Tubinga Publicador: Universidade de Tubinga
Tipo: Dissertação
DE_DE
Relevância na Pesquisa
35.81%
Um deformierbare Materialien wie Textilien oder menschliches Gewebe physikalisch simulieren zu können, muss eine Reihe komplexer Probleme gelöst werden. Diese Arbeit befasst sich dabei im Speziellen mit der Detektion und Behandlung von auftretenden Kollisionen sowie der Nachbearbeitung simulierter Netze zur Steigerung der visuellen Qualität. Dabei werden Anwendungen aus dem Bereich simulierter Textilien und der virtuellen Anprobe von Kleidung vorgestellt. Insbesondere wird auf das am WSI/GRIS entwickelte Textilsimulationssystem TüTex eingegangen. Zunächst wird der State of the Art zur Kollisionsdetektion deformierbarer Objekte vorgestellt, und es wird ausführlich diskutiert, welches Verfahren am besten für welche Anwendung geeignet ist. Für die Anforderungen, die TüTex an die Kollisionsdetektion stellt, wird gezeigt, dass sich dafür besonders Bounding-Volume-Hierarchien eignen. Diese werden im Weiteren mit einem stochastischen Sampling zu einer neuen Kollisionsdetektionsmethode kombiniert. Dieses neue Verfahren erlaubt eine Abwägung zwischen Geschwindigkeit und Qualität der Detektion und erhöht damit auch deutlich ihre Performance. Im Folgenden wird eine Impuls-basierte Methode zur Auflösung komplexer Kollisionen und Selbstkollisionen vorgestellt...

Attacks against intrusion detection networks: evasion, reverse engineering and optimal countermeasures

Pastrana Portillo, Sergio
Fonte: Universidade Carlos III de Madrid Publicador: Universidade Carlos III de Madrid
Tipo: Tese de Doutorado
ENG
Relevância na Pesquisa
35.71%
Intrusion Detection Networks (IDNs) constitute a primary element in current cyberdefense systems. IDNs are composed of different nodes distributed among a network infrastructure, performing functions such as local detection --mostly by Intrusion Detection Systems (IDS) --, information sharing with other nodes in the IDN, and aggregation and correlation of data from different sources. Overall, they are able to detect distributed attacks taking place at large scale or in different parts of the network simultaneously. IDNs have become themselves target of advanced cyberattacks aimed at bypassing the security barrier they offer and thus gaining control of the protected system. In order to guarantee the security and privacy of the systems being protected and the IDN itself, it is required to design resilient architectures for IDNs capable of maintaining a minimum level of functionality even when certain IDN nodes are bypassed, compromised, or rendered unusable. Research in this field has traditionally focused on designing robust detection algorithms for IDS. However, almost no attention has been paid to analyzing the security of the overall IDN and designing robust architectures for them. This Thesis provides various contributions in the research of resilient IDNs grouped into two main blocks. The first two contributions analyze the security of current proposals for IDS nodes against specific attacks...

Statistical evaluation of a novel SSVEP-BCI stimulation setup based on depth-of-field

Cotrina,Anibal; Benevides,Alessandro Botti; Castillo-Garcia,Javier; Ferreira,Andre; Bastos Filho,Teodiano Freire
Fonte: Sociedade Brasileira de Engenharia Biomédica Publicador: Sociedade Brasileira de Engenharia Biomédica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
Relevância na Pesquisa
45.63%
AbstractIntroductionThe main drawback of a Brain-computer Interface based on Steady-State Visual Evoked Potential (SSVEP-BCI) that detects the emergence of visual evoked potentials (VEP) in reaction to flickering stimuli is its muscular dependence due to users must redirect their gaze to put the target stimulus in their field of view. In this work, a novel setup is evaluated in which two stimuli are placed together in the center of users' field of view, but with dissimilar distances from them, so that the target selection is performed by focus shifting instead of head, neck and/or eyeball movements.MethodsA model of VEP generation for the novel setup was developed. The Spectral F-test based on Bartett periodogram was used to evaluate the null hypothesis of absence of effects of the non-focused stimulus (NFS) within the VEP elicited by the focused stimulus (FS). To reinforce that there is not statistical evidence to support the presence of NFS effects, the PSDA detection method was employed to find the frequency of FS. Electroencephalographic signals of nine subjects were recorded.ResultsApproximately in 80% of the tests, the null hypothesis with 5% level of significance was non-rejected at the fundamental frequency of NFS. The average of the accuracy rate attained with PSDA detection method was 79.4%.ConclusionResults of this work become further evident to state that if the focused stimulus (FS) will be able to elicit distinguishable VEP pattern regardless the non-focused stimulus (NFS) is also present.

Estudio de la evasión de la respuesta inmune citotóxica por el Virus de la Inmunodeficiencia Humana Tipo-1 (HIV-1) y su relación con el tratamiento antirretroviral; Study of the evasion from the cytotoxic immune response by the Human Immunodeficiency Virus Type-1 (HIV-1) and its relationship with the antiretroviral therapy

Dilernia, Darío A.
Fonte: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires Publicador: Facultad de Ciencias Exactas y Naturales. Universidad de Buenos Aires
Tipo: info:eu-repo/semantics/doctoralThesis; tesis doctoral; info:eu-repo/semantics/publishedVersion Formato: application/pdf
Publicado em //2010 SPA
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35.65%
Introducción. El HIV es el agente causal del SIDA. Entender las formas en las que evade la respuesta inmune del hospedador es crítico para el desarrollo racional de una vacuna efectiva. Aunque la amplia extensión del tratamiento antirretroviral es capaz de impactar significativamente en los procesos naturales de selección y escape, pocos trabajos han estudiado esta temática. El objetivo de esta tesis fue identificar aquellas regiones virales sometidas a presión de selección inmune y evaluar el impacto del tratamiento antirretroviral en su selección y persistencia. Metodología y resultados. Mediante análisis estadístico se identificaron 12 mutaciones virales asociadas a escape inmune, 6 de ellas en regiones no caracterizadas previamente como epítopes. El análisis de secuencias obtenidas en los últimos 20 años de epidemia sugirió que varias de ellas han incrementado su frecuencia hasta estar presentes en la mayoría de las cepas virales actuales. La evaluación de la respuesta inmune péptido específica mostró reconocimiento principalmente de dos péptidos con restricción para el alelo HLA A02 (A02P65 y A02P84), uno para el alelo HLA A03 (A03P28) y uno para el alelo HLA B07 (B07P357). Para los dos últimos y para A02P65 se demostró que la variante de escape disminuía el reconocimiento por la respuesta inmune mientras que...

Detection of movement intention using EEG in a human-robot interaction environment

Lana,Ernesto Pablo; Adorno,Bruno Vilhena; Tierra-Criollo,Carlos Julio
Fonte: Sociedade Brasileira de Engenharia Biomédica Publicador: Sociedade Brasileira de Engenharia Biomédica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/01/2015 EN
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Introduction: This paper presents a detection method for upper limb movement intention as part of a brain-machine interface using EEG signals, whose final goal is to assist disabled or vulnerable people with activities of daily living. Methods EEG signals were recorded from six naïve healthy volunteers while performing a motor task. Every volunteer remained in an acoustically isolated recording room. The robot was placed in front of the volunteers such that it seemed to be a mirror of their right arm, emulating a Brain Machine Interface environment. The volunteers were seated in an armchair throughout the experiment, outside the reaching area of the robot to guarantee safety. Three conditions are studied: observation, execution, and imagery of right arm’s flexion and extension movements paced by an anthropomorphic manipulator robot. The detector of movement intention uses the spectral F test for discrimination of conditions and uses as feature the desynchronization patterns found on the volunteers. Using a detector provides an objective method to acknowledge for the occurrence of movement intention. Results When using four realizations of the task, detection rates ranging from 53 to 97% were found in five of the volunteers when the movement was executed...