A meta-analysis of machine learning classification tools using rs-fmri data for autism spectrum disorder diagnosis

The Autism Spectrum Disorder (ASD) is a complex and heterogeneous neurodevelopmental condition characterized by cognitive, behavioral, and social dysfunction. Much effort is being made to identify brain imaging biomarkers and develop tools that could facilitate its diagnosis - currently based on behavioral criteria through a lengthy and timeconsuming process. In particular, the use of Machine Learning (ML) classifiers based on resting-state functional Magnetic Resonance Imaging (rs-fMRI) data is promising, but there is an ongoing need for further research on their accuracy. Therefore, we conducted a systematic review and meta-analysis to summarize and aggregate the available evidence in the literature so far. The systematic search resulted in the selection of 93 articles, whose data were extracted and analyzed through the systematic review. A bivariate randomeffects meta-analytic model was implemented to investigate the sensitivity and specificity across the 55 studies (132 independent samples) that offered sufficient information for a quantitative analysis. Our results indicated overall summary sensitivity and specificity estimates of 73.8% (95% CI: 71.8-75.8%) and 74.8% (95% CI: 72.3-77.1%), respectively, and Support Vector Machine (SVM) stood out as the most used classifier, presenting summary estimates above 76%. Studies with bigger samples tended to obtain worse accuracies, except in the subgroup analysis for Artificial Neural Network (ANN) classifiers. The use of other brain imaging or phenotypic data to complement rs-fMRI information seem to be promising, achieving specially higher sensitivities (p = 0.002) when compared to rs-fMRI data alone (84.7% - 95% CI: 78.5-89.4% - versus 72.8% - 95% CI: 70.6-74.8%). Lower values of sensitivity/specificity were found when the number of Regions of Interest (ROIs) increased. We also highlight the performance of the approaches using the Automated Anatomical Labelling atlas with 116 ROIs (AAL116). Regarding the features used to train the classifiers, we found better results using the Pearson Correlation (PC) Fishertransformed or other features in comparison to the use of the PC without modifications. Finally, our analysis showed AUC values between acceptable and excellent, but given the many limitations indicated in our study, further well-designed studies are warranted to extend the potential use of those classification algorithms to clinical settings.Agência 1O Transtorno do Espectro Autista (TEA) é uma condição complexa e heterogênea que afeta o desenvolvimento cerebral e é caracterizada por disfunções cognitivas, comportamentais e sociais. Muito esforço vem sendo feito para identificar biomarcadores baseados em imagens cerebrais e desenvolver ferramentas que poderiam facilitar o diagnóstico do TEA - atualmente baseado em critérios comportamentais, através de um processo longo e demorado. Em particular, o uso de algoritmos de Aprendizado de Máquina para classificação de dados de Imagens de Ressonância Magnética funcional em estado de repouso (rs-fMRI) é promissor, mas há uma necessidade contínua de pesquisas adicionais a respeito da precisão desses classificadores. Assim, este trabalho realiza uma revisão sistemática e meta-análise de modo a resumir e agregar as evidências disponíveis na literatura da área até o momento. A busca sistemática por artigos resultou na seleção de 93 deles, que tiveram seus dados extraídos e analisados através da revisão sistemática. Um modelo meta-analítico bivariado de efeitos aleatórios foi implementado para investigar a sensibilidade e especificidade dos 55 estudos (132 amostras independentes) que ofereceram informação suficiente para serem utilizados na análise quantitativa. Os resultados obtidos indicaram estimativas gerais de sensibilidade e especificidade de 73.8% (95% IC: 71.8- 75.8%) e 74.8% (95% IC: 72.3-77.1%), respectivamente, e os classificadores baseados em SVM (do inglês, Support Vector Machine) se destacaram como os mais utilizados, apresentando estimativas acima de 76%. Estudos que utilizaram amostras maiores tenderam a obter piores resultados de precisão, com exceção do subgrupo composto por classificadores baseados em Redes Neurais Artificiais. O uso de outros tipos de imagens cerebrais ou dados fenotípicos para complementar as informações obtidas através da rs-fMRI se mostrou promissor, alcançando especialmente sensibilidades mais altas ( = 0.002) em relação aos estudos que utilizaram apenas dados de rs-fMRI (84.7% - 95% IC: 78.5-89.4% - versus 72.8% - 95% IC: 70.6-74.8%). Valores menores de sensibilidade/especificidade foram encontrados quando o número de Regiões de Interesse (ROIs, do inglês Regions of Interest) aumentou. Vale destacar também o desempenho das abordagens utilizando o atlas AAL (do inglês, Automated Anatomical Labelling) com 116 ROIs. Em relação às features usadas para treinar os classificadores, foram encontrados melhores resultados nos estudos que utilizaram a correlação de Pearson em conjunto com a transformação Z de Fisher ou outras features em comparação ao uso da correlação de Pearson sem modifica- ções. Finalmente, a análise revelou valores da área sob a curva ROC (do inglês, Receiver Operating Characteristic) entre aceitável e excelente. Entretanto, considerando as várias limitações que são indicadas no estudo, mais estudos bem desenhados são necessários para estender o uso potencial desses algoritmos de classificação a ambientes clínicos

Using fuzzy logic to integrate neural networks and knowledge-based systems

Outlined here is a novel hybrid architecture that uses fuzzy logic to integrate neural networks and knowledge-based systems. The author's approach offers important synergistic benefits to neural nets, approximate reasoning, and symbolic processing. Fuzzy inference rules extend symbolic systems with approximate reasoning capabilities, which are used for integrating and interpreting the outputs of neural networks. The symbolic system captures meta-level information about neural networks and defines its interaction with neural networks through a set of control tasks. Fuzzy action rules provide a robust mechanism for recognizing the situations in which neural networks require certain control actions. The neural nets, on the other hand, offer flexible classification and adaptive learning capabilities, which are crucial for dynamic and noisy environments. By combining neural nets and symbolic systems at their system levels through the use of fuzzy logic, the author's approach alleviates current difficulties in reconciling differences between low-level data processing mechanisms of neural nets and artificial intelligence systems

Modelling domain knowledge using explicit conceptualization

Applications are characterized by the tasks and domains involved. Knowledge modeling can be divided into two conceptual subactivities: modeling the task and modeling the domain knowledge. An explicit conceptualization of the domain knowledge at the heart of its organization is discussed. A conceptualization is the objects presumed to exist and the relationships and functions among them. The annotations and the conceptualization guide the construction of applications and support flexible reasoning during problem solving. It also lets domain knowledge be reused

Chapter 6: Assessing Applicability of Medical Test Studies in Systematic Reviews

Use of medical tests should be guided by research evidence about the accuracy and utility of those tests in clinical care settings. Systematic reviews of the literature about medical tests must address applicability to real-world decision-making. Challenges for reviews include: (1) lack of clarity in key questions about the intended applicability of the review, (2) numerous studies in many populations and settings, (3) publications that provide too little information to assess applicability, (4) secular trends in prevalence and the spectrum of the condition for which the test is done, and (5) changes in the technology of the test itself. We describe principles for crafting reviews that meet these challenges and capture the key elements from the literature necessary to understand applicability

Physical examination tests of the shoulder: a systematic review and meta-analysis of diagnostic test performance

Background: Physical examination tests of the shoulder (PETS) are clinical examination maneuvers designed to aid the assessment of shoulder complaints. Despite more than 180 PETS described in the literature, evidence of their validity and usefulness in diagnosing the shoulder is questioned. Methods: This meta-analysis aims to use diagnostic odds ratio (DOR) to evaluate how much PETS shift overall probability and to rank the test performance of single PETS in order to aid the clinician’s choice of which tests to use. This study adheres to the principles outlined in the Cochrane guidelines and the PRISMA statement. A fixed effect model was used to assess the overall diagnostic validity of PETS by pooling DOR for different PETS with similar biomechanical rationale when possible. Single PETS were assessed and ranked by DOR. Clinical performance was assessed by sensitivity, specificity, accuracy and likelihood ratio. Results: Six thousand nine-hundred abstracts and 202 full-text articles were assessed for eligibility; 20 articles were eligible and data from 11 articles could be included in the meta-analysis. All PETS for SLAP (superior labral anterior posterior) lesions pooled gave a DOR of 1.38 [1.13, 1.69]. The Supraspinatus test for any full thickness rotator cuff tear obtained the highest DOR of 9.24 (sensitivity was 0.74, specificity 0.77). Compression-Rotation test obtained the highest DOR (6.36) among single PETS for SLAP lesions (sensitivity 0.43, specificity 0.89) and Hawkins test obtained the highest DOR (2.86) for impingement syndrome (sensitivity 0.58, specificity 0.67). No single PETS showed superior clinical test performance. Conclusions: The clinical performance of single PETS is limited. However, when the different PETS for SLAP lesions were pooled, we found a statistical significant change in post-test probability indicating an overall statistical validity. We suggest that clinicians choose their PETS among those with the highest pooled DOR and to assess validity to their own specific clinical settings, review the inclusion criteria of the included primary studies. We further propose that future studies on the validity of PETS use randomized research designs rather than the accuracy design relying less on well-established gold standard reference tests and efficient treatment options

The Computational Diet: A Review of Computational Methods Across Diet, Microbiome, and Health.

Food and human health are inextricably linked. As such, revolutionary impacts on health have been derived from advances in the production and distribution of food relating to food safety and fortification with micronutrients. During the past two decades, it has become apparent that the human microbiome has the potential to modulate health, including in ways that may be related to diet and the composition of specific foods. Despite the excitement and potential surrounding this area, the complexity of the gut microbiome, the chemical composition of food, and their interplay in situ remains a daunting task to fully understand. However, recent advances in high-throughput sequencing, metabolomics profiling, compositional analysis of food, and the emergence of electronic health records provide new sources of data that can contribute to addressing this challenge. Computational science will play an essential role in this effort as it will provide the foundation to integrate these data layers and derive insights capable of revealing and understanding the complex interactions between diet, gut microbiome, and health. Here, we review the current knowledge on diet-health-gut microbiota, relevant data sources, bioinformatics tools, machine learning capabilities, as well as the intellectual property and legislative regulatory landscape. We provide guidance on employing machine learning and data analytics, identify gaps in current methods, and describe new scenarios to be unlocked in the next few years in the context of current knowledge

Knowledge-based diagnosis for aerospace systems

The need for automated diagnosis in aerospace systems and the approach of using knowledge-based systems are examined. Research issues in knowledge-based diagnosis which are important for aerospace applications are treated along with a review of recent relevant research developments in Artificial Intelligence. The design and operation of some existing knowledge-based diagnosis systems are described. The systems described and compared include the LES expert system for liquid oxygen loading at NASA Kennedy Space Center, the FAITH diagnosis system developed at the Jet Propulsion Laboratory, the PES procedural expert system developed at SRI International, the CSRL approach developed at Ohio State University, the StarPlan system developed by Ford Aerospace, the IDM integrated diagnostic model, and the DRAPhys diagnostic system developed at NASA Langley Research Center

Machine learning and its applications in reliability analysis systems

In this thesis, we are interested in exploring some aspects of Machine Learning (ML) and its application in the Reliability Analysis systems (RAs). We begin by investigating some ML paradigms and their- techniques, go on to discuss the possible applications of ML in improving RAs performance, and lastly give guidelines of the architecture of learning RAs. Our survey of ML covers both levels of Neural Network learning and Symbolic learning. In symbolic process learning, five types of learning and their applications are discussed: rote learning, learning from instruction, learning from analogy, learning from examples, and learning from observation and discovery. The Reliability Analysis systems (RAs) presented in this thesis are mainly designed for maintaining plant safety supported by two functions: risk analysis function, i.e., failure mode effect analysis (FMEA) ; and diagnosis function, i.e., real-time fault location (RTFL). Three approaches have been discussed in creating the RAs. According to the result of our survey, we suggest currently the best design of RAs is to embed model-based RAs, i.e., MORA (as software) in a neural network based computer system (as hardware). However, there are still some improvement which can be made through the applications of Machine Learning. By implanting the 'learning element', the MORA will become learning MORA (La MORA) system, a learning Reliability Analysis system with the power of automatic knowledge acquisition and inconsistency checking, and more. To conclude our thesis, we propose an architecture of La MORA