Feature selection and classification of imbalanced datasets. Application to PET images of children with Autistic Spectrum Disorders

Learning with discriminative methods is generally based on minimizing themisclassification of training samples, which may be unsuitable for imbalanceddatasets where the recognition might be biased in favor of the most numerousclass. This problem can be addressed with a generative approach, which typicallyrequires more parameters to be determined leading to reduced performances inhigh dimension. In such situations, dimension reduction becomes a crucial issue.We propose a feature selection / classification algorithm based on generativemethods in order to predict the clinical status of a highly imbalanced datasetmade of PET scans of forty-five low-functioning children with autism spectrumdisorders (ASD) and thirteen non-ASD low-functioning children. ASDs aretypically characterized by impaired social interaction, narrow interests, andrepetitive behaviours, with a high variability in expression and severity. Thenumerous findings revealed by brain imaging studies suggest that ASD isassociated with a complex and distributed pattern of abnormalities that makesthe identification of a shared and common neuroimaging profile a difficult task.In this context, our goal is to identify the rest functional brain imagingabnormalities pattern associated with ASD and to validate its efficiency inindividual classification. The proposed feature selection algorithm detected acharacteristic pattern in the ASD group that included a hypoperfusion in theright Superior Temporal Sulcus (STS) and a hyperperfusion in the contralateralpostcentral area. Our algorithm allowed for a significantly accurate (88\%),sensitive (91\%) and specific (77\%) prediction of clinical category. For thisimbalanced dataset, with only 13 control scans, the proposed generativealgorithm outperformed other state-of-the-art discriminant methods. The highpredictive power of the characteristic pattern, which has been automaticallyidentified on whole brains without any priors, confirms previous findingsconcerning the role of STS in ASD. This work offers exciting possibilities forearly autism detection and/or the evaluation of treatment response in individualpatients

Atypical coordination of cortical oscillations in response to speech in autism.

Subjects with autism often show language difficulties, but it is unclear how they relate to neurophysiological anomalies of cortical speech processing. We used combined EEG and fMRI in 13 subjects with autism and 13 control participants and show that in autism, gamma and theta cortical activity do not engage synergistically in response to speech. Theta activity in left auditory cortex fails to track speech modulations, and to down-regulate gamma oscillations in the group with autism. This deficit predicts the severity of both verbal impairment and autism symptoms in the affected sample. Finally, we found that oscillation-based connectivity between auditory and other language cortices is altered in autism. These results suggest that the verbal disorder in autism could be associated with an altered balance of slow and fast auditory oscillations, and that this anomaly could compromise the mapping between sensory input and higher-level cognitive representations

Água e saúde: fluoretação e revogação da Lei Federal n. 6.050/1974

Ao contrário de muitos países, o Brasil dispõe de um instrumento legal que ampara a fluoretação da água (uma tecnologia de saúde pública eficaz para prevenir a cárie dentária em nível populacional): a Lei Federal n. 6.050/1974. Como não há objeções científicas à medida, o país deveria proteger esse instrumento. Contudo, a Câmara dos Deputados tem acolhido iniciativas parlamentares que pedem a revogação da lei brasileira que torna a medida obrigatória onde haja estação de tratamento de água. Tal é o caso dos projetos de lei n. 510/2003 e n. 6.359/2013. Neste artigo, são analisados os argumentos que justificam esses projetos de leis, à luz de evidências científicas. Constatou-se estreita semelhança entre os conteúdos dos dois projetos: os argumentos utilizados para justificar a revogação da lei não têm embasamento científico e se apoiam apenas em crendices e no senso comum. A fluoretação de águas de abastecimento tornou-se, ao longo do século XX, a ação de maior impacto na prevenção da cárie. No Brasil, a referida lei tornou-se um referencial jurídico importante para a implantação da fluoretação em boa parte do território nacional, beneficiando milhões de pessoas de todas as idades e contribuindo para atenuar as limitações de acesso às ações de prevenção individuais e à assistência odontológica. Conclui-se que a revogação da lei implicaria, em muitos casos, a suspensão dessa importante medida sanitária, configurando-se um ato de injustiça, com o aprofundamento de desigualdades decorrente da previsível piora do quadro epidemiológico bucal.Unlike many countries, Brazil has a legal instrument that endorses water fluoridation, an effective public health technology to prevent tooth decay of the population: Federal Law 6050/1974. As there are no scientific objections to the measure, the country should protect this instrument. However, the Chamber of Deputies has welcomed parliamentary initiatives calling for the repeal of the Brazilian law which mandates fluoridation wherever there is a water treatment plant. Such were the cases of the Bill 510, in 2003, and the Bill 6359, in 2013. In this article we analyze the arguments justifying these bills, in the light of scientific evidence. It was found close similarity between the contents of the two bills: the arguments used to justify the repeal of the law have no scientific basis and rely only on beliefs and common sense. The supply of water fluoridation has become the action with the greatest impact in preventing tooth decay, throughout the twentieth century. In Brazil, this law has become an important legal frame of reference for its implementation in much of the country, benefiting millions of people of all ages, helping to mitigate the limitations of access to individual preventative actions and dental care. It was concluded that the repeal of this law would imply in the suspension of an important health measure representing an injustice and bringing about inequalities and a foreseeable worsening of the oral epidemiological framework

Biotecnologia e saúde pública:suas interfaces teórico-conceituais e contribuições para pensar a Odontologia neste diálogo

This essay intends to discuss issues related to biotechnological practices aiming the improvements aimed of public health services and population needs. One focus of this discussion involves Dentistry and includes the following question: is there a place for this field in the dialogue between biotechnology and public health? According to many authors, it is necessary to analyze the applicability of biotechnological products in dental public health, as well as the guarantee of social and economical relevance related to the advancement of knowledge and application of the results especially relate to the solution of priority health problems and adapting them to the National Policy on Science, Technology and Innovation in Health (NPSTIH) and the National Agenda of Priorities in Health Research (NAPHR). Therefore, the dental community needs to understand and appropriate of this subject considering it represents a challenge for the development of a public oral health, in the largest universal health system in the world.Este es un ensayo que analiza aspectos de las prácticas biotecnológicas para ayudar a los servicios de salud pública y las necesidades de la población. El principal objetivo de esta discusión refiere a la Odontología y a la Siguiente pregunta: ¿hay lugar para la Odontología en el diálogo entre la biotecnología y la salud pública? Según los autores, existe la necesidad de un análisis de la aplicación de los productos  biotecnológicos dentales en la salud pública como también garantizar su pertinencia social y económica, relacionándolos con el avance del conocimiento y aplicando sus resultados, especialmente a la solución de los problemas prioritarios de la salud apuntados por la Política Nacional de Ciencia, Tecnología e Innovación en Salud (PNCTIS) y la Agenda Nacional de Prioridades de Investigación en Salud (ANPPS). En este sentido, la comunidad odontológica debería apropiarse de los conocimientos relacionados con este tema que, en la actualidad, se convierte en un desafío más para la implementación de una salud bucal pública y de calidad en el mayor sistema de salud universal del mundo.Trata-se de um ensaio que visa discutir aspectos relativos às práticas biotecnológicas em prol de melhorias destinadas aos serviços de saúde pública e às necessidades das populações. Um dos focos desta discussão orbita ao redor da Odontologia e inclui o seguinte questionamento: há espaço para esta área no diálogo entre biotecnologia e saúde pública? Diversos estudiosos indicam a necessidade da análise da aplicabilidade dos produtos biotecnológicos à realidade da Odontologia na saúde pública, bem como da garantia de relevância social e econômica relacionada com o avanço do conhecimento e aplicação dos resultados, especialmente no que tange a solução de problemas prioritários de saúde, adequando-os à Política Nacional de Ciência, Tecnologia e Inovação em Saúde (PNCTIS) e à Agenda Nacional de Prioridades de Pesquisa em Saúde (ANPPS). Neste sentido, caberia, portanto, à comunidade odontológica entender e apropriar-se do conhecimento relativo a este tema que, na atualidade, se torna mais um desafio à implantação de uma saúde bucal pública e de qualidade no maior sistema de saúde universal do mundo

Impaired identification of impoverished animate but not inanimate objects in adults with high-functioning autism spectrum disorder

The ability to identify animate and inanimate objects from impoverished images was investigated in adults with high-functioning autism spectrum disorder (HFA) and in matched typically developed (TD) adults, using a newly developed task. Consecutive frames were presented containing Gabor elements that slightly changed orientation from one frame to the next. For a subset of elements, the changes were such that these elements gradually formed the outline of an object. Elements enclosed within the object's outline gradually adopted one and the same orientation, outside elements adopted random orientations. The subjective experience was that of an object appearing out of a fog. The HFA group required significantly more frames to identify the impoverished objects than the TD group. Crucially, this difference depended on the nature of the objects: the HFA group required significantly more frames to identify animate objects, but with respect to the identification of inanimate objects the groups did not differ. The groups also did not differ with respect to the number and type of incorrect guesses they made. The results suggest a specific impairment in individuals with HFA in identifying animate objects. A number of possible explanations are discussed

Oral health and access to dental care services in relation to the Health Necessities Index: São Paulo, Brazil, 2008

A Secretaria Municipal de Saúde de São Paulo desenvolveu o Índice de Necessidades em Saúde (INS) para identificar áreas prioritárias para a oferta de serviços. Em 2008 realizou um Levantamento das Condições de Saúde Bucal. Pretende-se, neste estudo ecológico, analisar o perfil de saúde bucal em relação ao INS. As variáveis, estratificadas para as idades de 5, 12 e 15 anos, foram: porcentagem de indivíduos com dificuldade no acesso ao serviço odontológico; média do ceod e CPOD; prevalência da necessidade de extração e de livres de cárie. As informações foram analisadas para as 25 Supervisões Técnicas de Saúde (STS). Empregou-se o teste estatístico de covariância, o coeficiente de correlação de Pearson e o modelo de regressão linear. Observou-se uma correlação positiva entre maiores INS e a dificuldade de acesso aos serviços. Nas STS com maiores INS houve maior experiência de cárie, maior necessidade de exodontias e menor prevalência de livres de cárie. Reforça-se a necessidade de priorizar as áreas de privação social para melhorar a condição de saúde da população

Projeto Cananéia: Atividade de Extensão Universitária que Integra Graduação, Serviço e Comunidade

Academic extension is an educational, cultural and scientific process that articulates teaching and research in an indivisible way and enables the transforming relation between university and society. This is an experience report of The Cananéia Project (southern coast of the State of São Paulo), idealized in 1992 by the undergraduate students of the São Paulo State University Dental School (FO-USP). The project proposes a set of primary oral health care activities. It is expected that students get acquaintance with the health policy of Cananéia; check the living conditions of the target population; conduct epidemiological survey in oral health; provide primary oral health care and promote actions of oral health education. Permitting the students to get acquainted with the real condition of health of the population can evoke on them a more conscious approach of the importance of these practices, providing support to a better academic background. This also serves as a stimulus for a critical reflection about their learning process.A extensão universitária é o processo educativo, cultural e científico que viabiliza a relação transformadora entre a universidade e a sociedade. Este trabalho é um relato da experiência do Projeto Cananéia, idealizado em 1992 e coordenado desde 2007 pelo Departamento de Odontologia Social da Faculdade de Odontologia da USP. Propõe-se um conjunto de atividades de atenção primária para que os alunos conheçam a política de saúde municipal e as condições de vida da população, promovendo ações de educação, levantamento epidemiológico e atendimento odontológico básico. A aproximação com a realidade sensibiliza o aluno sobre a importância dessas ações, fornecendo subsídios para uma melhor formação acadêmica, com estímulo para a reflexão crítica em relação ao seu próprio processo formativo

Pupil dilation reflects the dynamic integration of audiovisual emotional speech

Emotional speech perception is a multisensory process. When speaking with an individual we concurrently integrate the information from their voice and face to decode e.g., their feelings, moods, and emotions. However, the physiological reactions—such as the reflexive dilation of the pupil—associated to these processes remain mostly unknown. That is the aim of the current article, to investigate whether pupillary reactions can index the processes underlying the audiovisual integration of emotional signals. To investigate this question, we used an algorithm able to increase or decrease the smiles seen in a person’s face or heard in their voice, while preserving the temporal synchrony between visual and auditory channels. Using this algorithm, we created congruent and incongruent audiovisual smiles, and investigated participants’ gaze and pupillary reactions to manipulated stimuli. We found that pupil reactions can reflect emotional information mismatch in audiovisual speech. In our data, when participants were explicitly asked to extract emotional information from stimuli, the first fixation within emotionally mismatching areas (i.e., the mouth) triggered pupil dilation. These results reveal that pupil dilation can reflect the dynamic integration of audiovisual emotional speech and provide insights on how these reactions are triggered during stimulus perception

Autism Spectrum Traits in the Typical Population Predict Structure and Function in the Posterior Superior Temporal Sulcus

Autism spectrum disorders (ASDs) are typically characterized by impaired social interaction and communication, narrow interests, and repetitive behaviors. The heterogeneity in the severity of these characteristics across individuals with ASD has led some researchers to suggest that these disorders form a continuum which extends into the general, or “typical,” population, and there is growing evidence that the extent to which typical adults display autistic traits, as measured using the autism-spectrum quotient (AQ), predicts performance on behavioral tasks that are impaired in ASD. Here, we show that variation in autism spectrum traits is related to cortical structure and function within the typical population. Voxel-based morphometry showed that increased AQ scores were associated with decreased white matter volume in the posterior superior temporal sulcus (pSTS), a region important in processing socially relevant stimuli and associated with structural and functional impairments in ASD. In addition, AQ was correlated with the extent of cortical deactivation of an adjacent area of pSTS during a Stroop task relative to rest, reflecting variation in resting state function. The results provide evidence that autism spectrum characteristics are reflected in neural structure and function across the typical (non-ASD) population

MRI Findings in 77 Children with Non-Syndromic Autistic Disorder

International audienceBACKGROUND: The clinical relevance of MR scanning in children with autism is still an open question and must be considered in light of the evolution of this technology. MRI was judged to be of insufficient value to be included in the standard clinical evaluation of autism according to the guidelines of the American Academy of Neurology and Child Neurology Society in 2000. However, this statement was based on results obtained from small samples of patients and, more importantly, included mostly insufficient MRI sequences. Our main objective was to evaluate the prevalence of brain abnormalities in a large group of children with a non-syndromic autistic disorder (AD) using T1, T2 and FLAIR MRI sequences. METHODOLOGY: MRI inspection of 77 children and adolescents with non-syndromic AD (mean age 7.4+/-3.6) was performed. All met the DSM-IV and ADI -R criteria for autism. Based on recommended clinical and biological screenings, we excluded patients with infectious, metabolic or genetic diseases, seizures or any other neurological symptoms. Identical MRI inspections of 77 children (mean age 7.0+/-4.2) without AD, developmental or neurological disorders were also performed. All MRIs were acquired with a 1.5-T Signa GE (3-D T1-FSPGR, T2, FLAIR coronal and axial sequences). Two neuroradiologists independently inspected cortical and sub-cortical regions. MRIs were reported to be normal, abnormal or uninterpretable. PRINCIPAL FINDINGS: MRIs were judged as uninterpretable in 10% (8/77) of the cases. In 48% of the children (33/69 patients), abnormalities were reported. Three predominant abnormalities were observed, including white matter signal abnormalities (19/69), major dilated Virchow-Robin spaces (12/69) and temporal lobe abnormalities (20/69). In all, 52% of the MRIs were interpreted as normal (36/69 patients). CONCLUSIONS: An unexpectedly high rate of MRI abnormalities was found in the first large series of clinical MRI investigations in non-syndromic autism. These results could contribute to further etiopathogenetic research into autism