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1.
Biomark Res ; 12(1): 25, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38355595

RESUMO

In recent decades, preterm birth (PTB) has become a significant research focus in the healthcare field, as it is a leading cause of neonatal mortality worldwide. Using five independent study cohorts including 1290 vaginal samples from 561 pregnant women who delivered at term (n = 1029) or prematurely (n = 261), we analysed vaginal metagenomics data for precise microbiome structure characterization. Then, a deep neural network (DNN) was trained to predict term birth (TB) and PTB with an accuracy of 84.10% and an area under the receiver operating characteristic curve (AUROC) of 0.875 ± 0.11. During a benchmarking process, we demonstrated that our DL model outperformed seven currently used machine learning algorithms. Finally, our results indicate that overall diversity of the vaginal microbiota should be taken in account to predict PTB and not specific species. This artificial-intelligence based strategy should be highly helpful for clinicians in predicting preterm birth risk, allowing personalized assistance to address various health issues. DeepMPTB is open source and free for academic use. It is licensed under a GNU Affero General Public License 3.0 and is available at https://deepmptb.streamlit.app/ . Source code is available at https://github.com/oschakoory/DeepMPTB and can be easily installed using Docker ( https://www.docker.com/ ).

2.
Artigo em Inglês | MEDLINE | ID: mdl-37417817

RESUMO

Major depression is a severe psychological disorder typically diagnosed using scale tests and through the subjective assessment of medical professionals. Along with the continuous development of machine learning techniques, computer technology has been increasingly employed to identify depression in recent years. Traditional methods of automatic depression recognition rely on using the patient's physiological data, such as facial expressions, voice, electroencephalography (EEG), and magnetic resonance imaging (MRI) as input. However, the acquisition cost of these data is relatively high, making it unsuitable for large-scale depression screening. Thus, we explore the possibility of utilizing a house-tree-person (HTP) drawing to automatically detect major depression without requiring the patient's physiological data. The dataset we used for this study consisted of 309 drawings depicting individuals at risk of major depression and 290 drawings depicting individuals without depression risk. We classified the eight features extracted from HTP sketches using four machine-learning models and used multiple cross-validations to calculate recognition rates. The best classification accuracy rate among these models reached 97.2%. Additionally, we conducted ablation experiments to analyze the association between features and information on depression pathology. The results of Wilcoxon rank-sum tests showed that seven of the eight features significantly differed between the major depression group and the regular group. We demonstrated significant differences in HTP drawings between patients with severe depression and everyday individuals, and using HTP sketches to identify depression automatically is feasible, providing a new approach for automatic identification and large-scale screening of depression.

3.
Sensors (Basel) ; 22(11)2022 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-35684728

RESUMO

Two-dimensional (2D) multi-person pose estimation and three-dimensional (3D) root-relative pose estimation from a monocular RGB camera have made significant progress recently. Yet, real-world applications require depth estimations and the ability to determine the distances between people in a scene. Therefore, it is necessary to recover the 3D absolute poses of several people. However, this is still a challenge when using cameras from single points of view. Furthermore, the previously proposed systems typically required a significant amount of resources and memory. To overcome these restrictions, we herein propose a real-time framework for multi-person 3D absolute pose estimation from a monocular camera, which integrates a human detector, a 2D pose estimator, a 3D root-relative pose reconstructor, and a root depth estimator in a top-down manner. The proposed system, called Root-GAST-Net, is based on modified versions of GAST-Net and RootNet networks. The efficiency of the proposed Root-GAST-Net system is demonstrated through quantitative and qualitative evaluations on two benchmark datasets, Human3.6M and MuPoTS-3D. On all evaluated metrics, our experimental results on the MuPoTS-3D dataset outperform the current state-of-the-art by a significant margin, and can run in real-time at 15 fps on the Nvidia GeForce GTX 1080.


Assuntos
Algoritmos , Imageamento Tridimensional , Humanos , Imageamento Tridimensional/métodos
4.
Sci Robot ; 3(21)2018 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-33141718

RESUMO

"Bad" humanoid robots just paying attention to human performance may energize attentional control-as does human presence.

5.
J Neurosci Methods ; 205(1): 96-109, 2012 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-22226742

RESUMO

Magnetic resonance (MR) provides a non-invasive way to investigate changes in the brain resulting from aging or neurodegenerative disorders such as Alzheimer's disease (AD). Performing accurate analysis for population studies is challenging because of the interindividual anatomical variability. A large set of tools is found to perform studies of brain anatomy and population analysis (FreeSurfer, SPM, FSL). In this paper we present a newly developed surface-based processing pipeline (MILXCTE) that allows accurate vertex-wise statistical comparisons of brain modifications, such as cortical thickness (CTE). The brain is first segmented into the three main tissues: white matter, gray matter and cerebrospinal fluid, after CTE is computed, a topology corrected mesh is generated. Partial inflation and non-rigid registration of cortical surfaces to a common space using shape context are then performed. Each of the steps was firstly validated using MR images from the OASIS database. We then applied the pipeline to a sample of individuals randomly selected from the AIBL study on AD and compared with FreeSurfer. For a population of 50 individuals we found correlation of cortical thickness in all the regions of the brain (average r=0.62 left and r=0.64 right hemispheres). We finally computed changes in atrophy in 32 AD patients and 81 healthy elderly individuals. Significant differences were found in regions known to be affected in AD. We demonstrated the validity of the method for use in clinical studies which provides an alternative to well established techniques to compare different imaging biomarkers for the study of neurodegenerative diseases.


Assuntos
Doença de Alzheimer/patologia , Mapeamento Encefálico/métodos , Córtex Cerebral/patologia , Processamento de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Adulto , Idoso , Algoritmos , Anatomia Transversal , Atrofia , Biomarcadores , Disfunção Cognitiva/patologia , Feminino , Lateralidade Funcional/fisiologia , Humanos , Imageamento Tridimensional , Pessoa de Meia-Idade , Doenças Neurodegenerativas/patologia , Reprodutibilidade dos Testes , Software
6.
Proc Biol Sci ; 279(1731): 1161-7, 2012 Mar 22.
Artigo em Inglês | MEDLINE | ID: mdl-21920973

RESUMO

Although laughter forms an important part of human non-verbal communication, it has received rather less attention than it deserves in both the experimental and the observational literatures. Relaxed social (Duchenne) laughter is associated with feelings of wellbeing and heightened affect, a proximate explanation for which might be the release of endorphins. We tested this hypothesis in a series of six experimental studies in both the laboratory (watching videos) and naturalistic contexts (watching stage performances), using change in pain threshold as an assay for endorphin release. The results show that pain thresholds are significantly higher after laughter than in the control condition. This pain-tolerance effect is due to laughter itself and not simply due to a change in positive affect. We suggest that laughter, through an endorphin-mediated opiate effect, may play a crucial role in social bonding.


Assuntos
Endorfinas/metabolismo , Riso , Limiar da Dor/psicologia , Comportamento Social , Feminino , Humanos , Masculino
7.
FEMS Microbiol Ecol ; 74(3): 669-81, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21044099

RESUMO

The microbial community response during the oxygen biostimulation process of aged oil-polluted soils is poorly documented and there is no reference for the long-term monitoring of the unsaturated zone. To assess the potential effect of air supply on hydrocarbon fate and microbial community structure, two treatments (0 and 0.056 mol h⁻¹ molar flow rate of oxygen) were performed in fixed bed reactors containing oil-polluted soil. Microbial activity was monitored continuously over 2 years throughout the oxygen biostimulation process. Microbial community structure before and after treatment for 12 and 24 months was determined using a dual rRNA/rRNA gene approach, allowing us to characterize bacteria that were presumably metabolically active and therefore responsible for the functionality of the community in this polluted soil. Clone library analysis revealed that the microbial community contained many rare phylotypes. These have never been observed in other studied ecosystems. The bacterial community shifted from Gammaproteobacteria to Actinobacteria during the treatment. Without aeration, the samples were dominated by a phylotype linked to the Streptomyces. Members belonging to eight dominant phylotypes were well adapted to the aeration process. Aeration stimulated an Actinobacteria phylotype that might be involved in restoring the ecosystem studied. Phylogenetic analyses suggested that this phylotype is a novel, deep-branching member of the Actinobacteria related to the well-studied genus Acidimicrobium.


Assuntos
Actinobacteria/isolamento & purificação , Gammaproteobacteria/isolamento & purificação , Hidrocarbonetos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Actinobacteria/classificação , Actinobacteria/genética , Biodegradação Ambiental , Reatores Biológicos , DNA Bacteriano/genética , Gammaproteobacteria/classificação , Gammaproteobacteria/genética , Oxigênio/metabolismo , Filogenia , Projetos Piloto , RNA Ribossômico 16S/genética , Solo/análise
8.
Hum Brain Mapp ; 30(4): 1310-27, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18537111

RESUMO

We compare three widely used brain volumetry methods available in the software packages FSL, SPM5, and FreeSurfer and evaluate their performance using simulated and real MR brain data sets. We analyze the accuracy of gray and white matter volume measurements and their robustness against changes of image quality using the BrainWeb MRI database. These images are based on "gold-standard" reference brain templates. This allows us to assess between- (same data set, different method) and also within-segmenter (same method, variation of image quality) comparability, for both of which we find pronounced variations in segmentation results for gray and white matter volumes. The calculated volumes deviate up to >10% from the reference values for gray and white matter depending on method and image quality. Sensitivity is best for SPM5, volumetric accuracy for gray and white matter was similar in SPM5 and FSL and better than in FreeSurfer. FSL showed the highest stability for white (<5%), FreeSurfer (6.2%) for gray matter for constant image quality BrainWeb data. Between-segmenter comparisons show discrepancies of up to >20% for the simulated data and 24% on average for the real data sets, whereas within-method performance analysis uncovered volume differences of up to >15%. Since the discrepancies between results reach the same order of magnitude as volume changes observed in disease, these effects limit the usability of the segmentation methods for following volume changes in individual patients over time and should be taken into account during the planning and analysis of brain volume studies.


Assuntos
Mapeamento Encefálico , Encéfalo/anatomia & histologia , Processamento Eletrônico de Dados/métodos , Imageamento por Ressonância Magnética/métodos , Idoso , Algoritmos , Simulação por Computador , Bases de Dados Bibliográficas/estatística & dados numéricos , Feminino , Humanos , Processamento de Imagem Assistida por Computador/métodos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Software
9.
Psychiatry Res ; 163(2): 106-15, 2008 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-18502618

RESUMO

In this study, a computational mapping technique was used to examine the three-dimensional profile of the lateral ventricles in autism. T1-weighted three-dimensional magnetic resonance images of the brain were acquired from 20 males with autism (age: 10.1+/-3.5 years) and 22 male control subjects (age: 10.7+/-2.5 years). The lateral ventricles were delineated manually and ventricular volumes were compared between the two groups. Ventricular traces were also converted into statistical three-dimensional maps, based on anatomical surface meshes. These maps were used to visualize regional morphological differences in the thickness of the lateral ventricles between patients and controls. Although ventricular volumes measured using traditional methods did not differ significantly between groups, statistical surface maps revealed subtle, highly localized reductions in ventricular size in patients with autism in the left frontal and occipital horns. These localized reductions in the lateral ventricles may result from exaggerated brain growth early in life.


Assuntos
Transtorno Autístico/diagnóstico , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Ventrículos Laterais/patologia , Imageamento por Ressonância Magnética , Adolescente , Mapeamento Encefálico , Criança , Dominância Cerebral/fisiologia , Lobo Frontal/patologia , Humanos , Masculino , Lobo Occipital/patologia , Valores de Referência
10.
Bioinformatics ; 23(19): 2550-7, 2007 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17698494

RESUMO

MOTIVATION: Microbial diversity is still largely unknown in most environments, such as soils. In order to get access to this microbial 'black-box', the development of powerful tools such as microarrays are necessary. However, the reliability of this approach relies on probe efficiency, in particular sensitivity, specificity and explorative power, in order to obtain an image of the microbial communities that is close to reality. RESULTS: We propose a new probe design algorithm that is able to select microarray probes targeting SSU rRNA at any phylogenetic level. This original approach, implemented in a program called 'PhylArray', designs a combination of degenerate and non-degenerate probes for each target taxon. Comparative experimental evaluations indicate that probes designed with PhylArray yield a higher sensitivity and specificity than those designed by conventional approaches. Applying the combined PhyArray/GoArrays strategy helps to optimize the hybridization performance of short probes. Finally, hybridizations with environmental targets have shown that the use of the PhylArray strategy can draw attention to even previously unknown bacteria.


Assuntos
Algoritmos , Sondas de DNA/genética , Marcação de Genes/métodos , Hibridização In Situ/métodos , Análise de Sequência com Séries de Oligonucleotídeos/métodos , Análise de Sequência de DNA/métodos , Software , Sequência de Bases , Dados de Sequência Molecular , Alinhamento de Sequência/métodos
11.
Comput Methods Programs Biomed ; 81(2): 174-80, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16423425

RESUMO

Microarray images push to their limits classical analysis methods, since gene spots are often poorly contrasted, ill defined and of irregular shapes. These characteristics hinder a robust quantification of corresponding values for red and green intensities as well as their R/G ratio. New approaches are thus needed to ensure accurate data extraction from these images. Herein we present an automatic non-supervised algorithm for a fast and accurate spot data extraction from DNA microarrays. The method is based on a split and merge algorithm, relying on a Delaunay triangulation process, allowing an incremental partition of the image into homogeneous polygons. Geometric properties of triangles as well as homogeneity criteria are defined according to the specificities of microarray image signals. The method is first assessed on simulated data, and then compared with GenePix and Jaguar Softwares. Results in segmentation and quantification are superior to those obtained from a number of standard techniques for spot extraction.


Assuntos
Algoritmos , Interpretação Estatística de Dados , Análise de Sequência com Séries de Oligonucleotídeos/estatística & dados numéricos , França , Perfilação da Expressão Gênica , Humanos
12.
Conf Proc IEEE Eng Med Biol Soc ; 2005: 4365-8, 2005.
Artigo em Inglês | MEDLINE | ID: mdl-17281202

RESUMO

Transcranial Magnetic Stimulation (TMS) is a technique for brain stimulation using magnetic field generated by an external coil. As another techniques like ECT or the implantation of electrodes into motor cortex, TMS has several applications in medical and clinical research. The main benefit of TMS is to be non invasive and painless. TMS use increases but stimulation process remains still empirical and pratician has to perform several stimulations to find the best coil position/direction. We propose to develop a simulator of transcranial magnetic stimulation which aims at computing the electromagnetic field induced in the cortex by TMS. We present in this article the first step of this tool, a parametrical coil model allowing the computation of potential magnetic field outside the head and some way to represent it.

13.
Comput Methods Programs Biomed ; 75(1): 1-9, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15158042

RESUMO

The large amount of data involved in DNA microarrays implies the development of efficient computer algorithms to analyze the gene expressions, and thus to study the transcriptome. Numerous techniques already exist and we propose a new method based on the key idea that gene profiles may be considered as continuous curves. The analysis of the set of curves stemming from the DNA microarray may be then performed using a functional analysis which can exhibit the main modes of variations in this set, gather genes with similar variations and extract characteristic parameters of gene profiles. We aim here at introducing this method, called the Functional Principal Component Analysis. A prospective study has been performed on two available datasets, concerning on the one hand the sporulation data of the Saccharomyces cerevisiae, and on the other hand data of tumor cell lines. Results are very promising: the method is able to extract characteristic parameters from the datasets, to extract significant modes of variations in the set of gene profiles, and to link these variations to biological processes already studied in literature.


Assuntos
Análise de Sequência com Séries de Oligonucleotídeos , Saccharomyces cerevisiae/genética , Algoritmos , Linhagem Celular Tumoral , Bases de Dados Genéticas , França , Humanos , Estudos Prospectivos , Transcrição Gênica
14.
Comput Methods Programs Biomed ; 68(3): 185-93, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12074845

RESUMO

Physical training is proved to induce changes in physical capacity and body composition. We propose in this article a fast, unsupervised and fully three-dimensional automatic method to extract muscle and fat volumes from magnetic resonance images of thighs in order to assess these changes. The technique relies on the use of a fuzzy clustering algorithm and post-processings to accurately process the body composition of thighs. Results are compared on 11 healthy voluntary elderly people with those provided on the same data by a validated method already published, and its reliability is assessed on repeated measures on three subjects. The two methods statistically agree when computing muscle and fat volumes, and clinical implications of this fully automatic method are important for medicine, physical conditioning, weight-loss programs and predictions of optimal body weight.


Assuntos
Algoritmos , Gorduras/análise , Músculos/diagnóstico por imagem , Coxa da Perna/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Radiografia , Reprodutibilidade dos Testes
15.
J Magn Reson Imaging ; 15(1): 16-22, 2002 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11793452

RESUMO

PURPOSE: To propose a method for the quantification of lateral ventricle (LV) volumes on a single sequence of 3D magnetic resonance (MR) images. MATERIALS AND METHODS: This algorithm, following a preliminary fuzzy tissue classification step, is based on the development of mathematical morphology processes allowing both the extraction of the LVs and the correction of partial volume effects on their boundaries. The procedure is fast and totally unsupervised. The method is tested on a phantom image, then applied to five patients diagnosed as potentially suffering from Alzheimer's disease, and finally applied on several MR acquisitions to show the genericness of the algorithm. RESULTS AND CONCLUSION: This technique yielded both an accurate estimation of ventricular volumes intra- and intersubject with respect to published data and a relevant management of partial volume effects. Numerous clinical applications are now expected, from the study of schizophrenia to the longitudinal follow-up of Alzheimer's patients.


Assuntos
Doença de Alzheimer/patologia , Ventrículos Laterais/patologia , Imageamento por Ressonância Magnética/métodos , Idoso , Algoritmos , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Masculino , Imagens de Fantasmas
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