Resolution of Spike Overlapping by Biogeography-Based Optimization

There are many cases in which the separation of different sources from single channel recordings is important, for example, in fluorescence spectral overlap compensation, electrical impedance signaling, intramuscular electromyogram decomposition or in the case of spike sorting of neuron potentials from microelectrode arrays (MEA). Focusing on the latter, the problem can be faced by identifying spikes emerging from the background and clustering into different groups, indicating the activity of different neurons. Problems are found when more spikes are superimposed in overlapped waveforms. We discuss the application of Biogeography-Based Optimization (BBO) to resolve this specific problem. Our algorithm is compared with three spike-sorting methods (SpyKING Circus, Common Basis Pursuit and Klusta), showing statistically better performance (in terms of F1 score, True Positive Rate—TPR and Positive Predictive Value—PPV) in resolving overlaps in realistic, simulated data. Specifically, BBO showed median F1, TPR and PPV of 100%, 100% and about 75%, respectively, considering a simulated noise with the same spectral density as the experimental one and a similar power with highly statistically significant improvements of at least two performance indexes over each of the other three tested algorithm

Functional Connectivity of EEG in Encephalitis during Slow Biphasic Complexes

The electroencephalogram (EEG) of patients suffering from inflammatory diseases of the brain may show specific waveforms called slow biphasic complexes (SBC). Recent studies indicated a correlation between the severity of encephalitis and some features of SBCs, such as location, amplitude and frequency of appearance. Moreover, EEG rhythms were found to vary before the onset of an SBC, as if the brain was preparing to the discharge (actually with a slowing down of the EEG oscillation). Here, we investigate possible variations of EEG functional connectivity (FC) in EEGs from pediatric patients with different levels of severity of encephalitis. FC was measured by the maximal crosscorrelation of EEG rhythms in different bipolar channels. Then, the indexes of network patterns (namely strength, clustering coefficient, efficiency and characteristic path length) were estimated to characterize the global behavior when they are measured during SBCs or far from them. EEG traces showed statistical differences in the two conditions: clustering coefficient, efficiency and strength are higher close to an SBC, whereas the characteristic path length is lower. Moreover, for more severe conditions, an increase in clustering coefficient, efficiency and strength and a decrease in characteristic path length were observed in the delta–theta band. These outcomes support the hypothesis that SBCs result from the anomalous coordination of neurons in different brain areas affected by the inflammation process and indicate FC as an additional key for interpreting the EEG in encephalitis patients

Tecniche di marketing quantitativo

ope

NO

openFenomeno del Gioco d'Azzardo Patologico letto in chiave relazionale, rimarcando l'importanza delle relazioni sociali e la necessità dei Servizi di un adeguamento delle azioni che devono avere necessariamente come focus principale la persona e la sua rete di supporto personale e sociale

Connectivity Analysis in EEG Data: A Tutorial Review of the State of the Art and Emerging Trends

Understanding how different areas of the human brain communicate with each other is a crucial issue in neuroscience. The concepts of structural, functional and effective connectivity have been widely exploited to describe the human connectome, consisting of brain networks, their structural connections and functional interactions. Despite high-spatial-resolution imaging techniques such as functional magnetic resonance imaging (fMRI) being widely used to map this complex network of multiple interactions, electroencephalographic (EEG) recordings claim high temporal resolution and are thus perfectly suitable to describe either spatially distributed and temporally dynamic patterns of neural activation and connectivity. In this work, we provide a technical account and a categorization of the most-used data-driven approaches to assess brain-functional connectivity, intended as the study of the statistical dependencies between the recorded EEG signals. Different pairwise and multivariate, as well as directed and non-directed connectivity metrics are discussed with a pros-cons approach, in the time, frequency, and information-theoretic domains. The establishment of conceptual and mathematical relationships between metrics from these three frameworks, and the discussion of novel methodological approaches, will allow the reader to go deep into the problem of inferring functional connectivity in complex networks. Furthermore, emerging trends for the description of extended forms of connectivity (e.g., high-order interactions) are also discussed, along with graph-theory tools exploring the topological properties of the network of connections provided by the proposed metrics. Applications to EEG data are reviewed. In addition, the importance of source localization, and the impacts of signal acquisition and pre-processing techniques (e.g., filtering, source localization, and artifact rejection) on the connectivity estimates are recognized and discussed. By going through this review, the reader could delve deeply into the entire process of EEG pre-processing and analysis for the study of brain functional connectivity and learning, thereby exploiting novel methodologies and approaches to the problem of inferring connectivity within complex networks

Genetic Features of Metachronous Esophageal Cancer Developed in Hodgkin's Lymphoma or Breast Cancer Long-Term Survivors: An Exploratory Study.

Background Development of novel therapeutic drugs and regimens for cancer treatment has led to improvements in patient long-term survival. This success has, however, been accompanied by the increased occurrence of second primary cancers. Indeed, patients who received regional radiotherapy for Hodgkin's Lymphoma (HL) or breast cancer may develop, many years later, a solid metachronous tumor in the irradiated field. Despite extensive epidemiological studies, little information is available on the genetic changes involved in the pathogenesis of these solid therapy-related neoplasms. Methods Using microsatellite markers located in 7 chromosomal regions frequently deleted in sporadic esophageal cancer, we investigated loss of heterozygosity (LOH) and microsatellite instability (MSI) in 46 paired (normal and tumor) samples. Twenty samples were of esophageal carcinoma developed in HL or breast cancer long-term survivors: 14 squamous cell carcinomas (ESCC) and 6 adenocarcinomas (EADC), while 26 samples, used as control, were of sporadic esophageal cancer (15 ESCC and 11 EADC). Results We found that, though the overall LOH frequency at the studied chromosomal regions was similar among metachronous and sporadic tumors, the latter exhibited a statistically different higher LOH frequency at 17q21.31 (p = 0.018). By stratifying for tumor histotype we observed that LOH at 3p24.1, 5q11.2 and 9p21.3 were more frequent in ESCC than in EADC suggesting a different role of the genetic determinants located nearby these regions in the development of the two esophageal cancer histotypes. Conclusions Altogether, our results strengthen the genetic diversity among ESCC and EADC whether they occurred spontaneously or after therapeutic treatments. The presence of histotype-specific alterations in esophageal carcinoma arisen in HL or breast cancer long-term survivors suggests that their transformation process, though the putative different etiological origin, may retrace sporadic ESCC and EADC carcinogenesis

Primary Subcutaneous B-cell Lymphoma : Case Report and Literature Review

Primary cutaneous B-cell lymphomas are defined as malignant B-cell proliferations presenting with cutaneous involvement alone and no evidence of extracutaneous manifestations when complete staging has been performed. It has been shown that the infiltrate in some cases could involve the underlying subcutaneous tissues, but primary localization in this compartment has been rarely reported. We describe here the case of a 53-year-old woman who noticed a nodular lesion on the left shoulder that rapidly enlarged in a few months. The histological and immunophenotypical features were compatible with a subcutaneous B-cell lymphoma. The tumoural mass was confined predominantly to the subcutaneous compartment, as confirmed by computed tomography. No other tumour localizations were found. Thus, primary B-cell lymphoma of the subcutis was diagnosed. We report a review of the literature indicating that B-cell lymphomas that are primarily localized to the subcutaneous tissue represent a very rare modality of presentation with a biological behaviour different from conventional cutaneous B-cell lymphoma

Speech-language pathology performance in patients with acquired immunodeficiency syndrome and complaint of swallowing : retrospective analysis of medical records

Objetivo: Verificar e caracterizar a deglutição de pacientes internados, diagnosticados com Síndrome da Imunodeficiência Adquirida (SIDA), com queixas de deglutição. Métodos: Análise retrospectiva de 17 prontuários de pacientes com SIDA, atendidos em um hospital escola, entre 2011 e 2012, submetidos a protocolos de avaliação e tratamento da deglutição em beira de leito. Os dados coletados foram referentes à avaliação da deglutição em beira de leito, por meio de protocolos específicos, no momento inicial e na alta fonoaudiológica ou hospitalar. Os pacientes foram divididos em dois grupos: Grupo de alta fonoaudiológica (GAF): pacientes que receberam alta fonoaudiológica antes da alta hospitalar; Grupo de alta hospitalar (GAH): pacientes que receberam alta hospitalar sem terem recebido alta fonoaudiológica. Resultados: Os grupos não se diferenciaram em relação à idade e gênero. Quanto à classificação da disfagia: 1) ambos os grupos apresentaram escores significativamente melhores no momento da alta, em relação ao momento inicial (GAH - p=0,024; GAF - p=0,011); 2) os grupos não se diferenciaram no mo¬mento inicial (p=0,349); 3) no momento de alta, os grupos apresentaram diferença significativa (p=0,002), com melhores resultados para o GAF. A análise dos sinais clínicos sugestivos de disfagia e de penetração/aspiração apontou que, na comparação intragrupos (ambos os grupos), houve diferença significativa somente para a presença de deglutições múltiplas, com redução do número de deglutições após o tratamento. Conclusão: Os grupos obtiveram melhora na escala de classificação da disfagia e na remissão de sinais clínicos sugestivos de disfagia orofaríngea e/ou penetração/aspiração, sendo que o GAF alcançou melhores resultados.Purpose: To verify and characterize the function of swallowing in Acquired Immunodeficiency Syndrome (AIDS) patients with a complaint of dysphagia. Methods: We performed a retrospective analysis of the medical records of 17 AIDS patients treated in a school hospital between 2011 and 2012, who underwent a bedside evaluation and treatment of swallowing. The data were related to the results of the bedside evalu¬ation that followed specific protocols, both at baseline and discharge. Patients were divided into two groups: 1) patients who completed the swallowing intervention during the admission (GCSI); and 2) patients who did not complete the swallowing intervention during the admission (GNCSI). Results: The groups did not differ in age and gender. For the classification of swallowing: 1) both groups had significantly better scores at discharge compared to those at baseline (GNCSI: p=0.024; GCSI: p=0.011); 2) the scores did not differ between groups at baseline (p=0.349); 3) at discharge, the scores were different between groups (p=0.002), with better results in the GCSI group. The analysis of the clinical signs and symptoms of oropharyngeal dysphagia or penetration/ aspiration indicated that in both groups, there was a statistically significant difference between baseline and discharge only in the presence of multiple swallows (a decrease in the number of swallows after intervention). Conclusion: Swallowing ability improved after intervention. Additionally, clinical signs and symptoms suggestive of oropharyngeal dysphagia or penetration/aspiration resolved. The GCSI group showed better results than GNCSI after intervention

Fluency shaping with surface electromyography: a pilot study

TEMA: utilização de recursos tecnológicos para promoção da fluência. OBJETIVO: verificar a efetividade de um tratamento para gagueira baseado exclusivamente no uso da eletromiografia de superfície (EMGS). MÉTODO: participaram desse estudo quatro adultos gagos de ambos os sexos. A avaliação pré e pós-tratamento consistiu de uma sessão para coleta de amostra de fala, análise da tensão muscular de repouso e do tempo de reação para fala. O tratamento consistiu de 12 sessões de 20 minutos, monitoradas pela EMGS. RESULTADOS: observou-se redução estatisticamente significante das disfluências gagas e comuns. Os demais parâmetros, bem como a variação dos dados eletromiográficos, não apresentaram variação estatisticamente significante. CONCLUSÃO: a EMGS mostrou-se eficaz na redução da gagueira, sem a necessidade de associação com outras técnicas de promoção da fluência.BACKGROUND: the use of a technological resource in fluency promotion. AIM: to verify the effectiveness of a stuttering treatment based on the use of surface electromyography (SEMG) exclusively. METHOD: participants were four stuttering adults of both genders. Assessment, pre and post-treatment, consisted of a speech gathering session and the analyses of the rest tension and of the reaction time for speech. Treatment consisted of twelve twenty minute training sessions monitored by SEMG. RESULTS: there was a statistically significant reduction in the number of stuttering-like disfluencies (p = 0.094) and in the number of other disfluencies (p = 0.014). The other parameters, as well as differences in the electromyographic measurements, did not present significant variation. CONCLUSION: SEMG proved to be effective in the reduction of stuttering, with no need of association to other techniques