146 research outputs found
Brain connectivity analysis: a short survey
This short survey the reviews recent literature on brain connectivity studies. It encompasses all forms of static and dynamic
connectivity whether anatomical, functional, or effective. The last decade has seen an ever increasing number of studies devoted
to deduce functional or effective connectivity, mostly from functional neuroimaging experiments. Resting state conditions have
become a dominant experimental paradigm, and a number of resting state networks, among them the prominent default mode
network, have been identified. Graphical models represent a convenient vehicle to formalize experimental findings and to closely
and quantitatively characterize the various networks identified. Underlying these abstract concepts are anatomical networks, the
so-called connectome, which can be investigated by functional imaging techniques as well. Future studies have to bridge the gap between anatomical neuronal connections and related functional or effective connectivities
A full-scale timbrel cross vault subjected to vertical cyclical displacements in one of its supports
[EN] Up-and-down cyclical displacement of supports-foundations, due for example to the presence of expansive soils, can affect the integrity of a structure and may even lead to its collapse. A recent study carried out at the ICITECH laboratories of the Universitat Politècnica de València analysed the effects of earth settlements on the behaviour of masonry cross vaults. One of the tests involved the construction and testing of a full-scale timbrel cross vault, one of whose supports was subjected to up-and-down vertical displacement cycles. The 4×4 m2 vault was composed of four 3.6 m diameter arches supporting a masonry web. Vertical displacements were applied to one of the supports by means of two synchronised mechanical jacks. The results of the tests provide valuable information to the scientific community, architects and engineers on the behaviour of timbrel cross vaults when one of their supports is subjected to cyclical movements.The authors wish to express their gratitude to the Spanish Ministry of Economy, Industry and Competitiveness for the funding provided through Project BIA 2014-59036-R, and also to LIC-Levantina Ingenieria y Construction and the Grupo Puma for their invaluable assistance.
The second author (Elisa Bertolesi) would like to thank the Universitat Politecnica de Valencia for funding received for her postdoctoral grant (PAID-10-17).Torres Górriz, B.; Bertolesi, E.; Calderón García, PA.; Moragues, JJ.; Adam, JM. (2019). A full-scale timbrel cross vault subjected to vertical cyclical displacements in one of its supports. Engineering Structures. 183:791-804. https://doi.org/10.1016/j.engstruct.2019.01.054S79180418
Robust Ensemble Classification Methodology for I123-Ioflupane SPECT Images and Multiple Heterogeneous Biomarkers in the Diagnosis of Parkinson’s Disease
In last years, several approaches to develop an effective Computer-Aided-Diagnosis
(CAD) system for Parkinson’s Disease (PD) have been proposed. Most of these methods
have focused almost exclusively on brain images through the use of Machine-Learning
algorithms suitable to characterize structural or functional patterns. Those patterns
provide enough information about the status and/or the progression at intermediate
and advanced stages of Parkinson’s Disease. Nevertheless this information could be
insufficient at early stages of the pathology. The Parkinson’s ProgressionMarkers Initiative
(PPMI) database includes neurological images along with multiple biomedical tests.
This information opens up the possibility of comparing different biomarker classification
results. As data come from heterogeneous sources, it is expected that we could include
some of these biomarkers in order to obtain new information about the pathology. Based
on that idea, this work presents an Ensemble Classification model with Performance
Weighting. This proposal has been tested comparing Healthy Control subjects (HC)
vs. patients with PD (considering both PD and SWEDD labeled subjects as the same
class). This model combines several Support-Vector-Machine (SVM) with linear kernel
classifiers for different biomedical group of tests—including CerebroSpinal Fluid (CSF),
RNA, and Serum tests—and pre-processed neuroimages features (Voxels-As-Features
and a list of definedMorphological Features) fromPPMI database subjects. The proposed
methodology makes use of all data sources and selects the most discriminant features
(mainly from neuroimages). Using this performance-weighted ensemble classification
model, classification results up to 96% were obtained.This work was supported by the MINECO/FEDER under
the TEC2015-64718-R project and the Ministry of Economy,
Innovation, Science and Employment of the Junta de Andalucía
under the Excellence Project P11-TIC-7103
Automatic ROI Selection in Structural Brain MRI Using SOM 3D Projection
This paper presents a method for selecting Regions of Interest (ROI) in brain Magnetic Resonance Imaging (MRI) for diagnostic purposes, using statistical learning and vector quantization techniques. The proposed method models the distribution of GM and WM tissues grouping the voxels belonging to each tissue in ROIs associated to a specific neurological disorder. Tissue distribution of normal and abnormal images is modelled by a Self-Organizing map (SOM), generating a set of representative prototypes, and the receptive field (RF) of each SOM prototype defines a ROI. Moreover, the proposed method computes the relative importance of each ROI by means of its discriminative power. The devised method has been assessed using 818 images from the Alzheimer's disease Neuroimaging Initiative (ADNI) which were previously segmented through Statistical Parametric Mapping (SPM). The proposed algorithm was used over these images to parcel ROIs associated to the Alzheimer's Disease (AD). Additionally, this method can be used to extract a reduced set of discriminative features for classification, since it compresses discriminative information contained in the brain. Voxels marked by ROIs which were computed using the proposed method, yield classification results up to 90% of accuracy for controls (CN) and Alzheimer's disease (AD) patients, and 84% of accuracy for Mild Cognitive Impairment (MCI) and AD patients.This work was partly supported by the MICINN under the TEC2012-34306 project and the Consejería de Innovación, Ciencia y Empresa (Junta de Andalucía, Spain) under the Excellence Projects P09-TIC-4530 and P11-TIC-7103. Data collection and sharing for this project was funded by the Alzheimer's Disease Neuroimaging Initiative (ADNI) (National Institutes of Health Grant U01 AG024904) and DOD ADNI (Department of Defense award number W81XWH-12-2-0012). ADNI is funded by the National Institute on Aging, the National Institute of Biomedical Imaging and Bioengineering, and through generous contributions from the following: Alzheimer's Association; Alzheimer's Drug Discovery Foundation; BioClinica, Inc.; Biogen Idec Inc.; Bristol-Myers Squibb Company; Eisai Inc.; Elan Pharmaceuticals, Inc.; Eli Lilly and Company; F. Hoffmann-La Roche Ltd and its affiliated company Genentech, Inc.; GE Healthcare; Innogenetics, N.V.; IXICO Ltd.; Janssen Alzheimer Immunotherapy Research & Development, LLC.; Johnson & Johnson Pharmaceutical Research & Development LLC.; Medpace, Inc.; Merck & Co., Inc.; Meso Scale Diagnostics, LLC.; NeuroRxResearch; Novartis Pharmaceuticals Corporation; Pfizer Inc.; Piramal Imaging; Servier; Synarc Inc.; and Takeda Pharmaceutical Company. The Canadian Institutes of Health Research is providing funds to support ADNI clinical sites in Canada. Private sector contributions are facilitated by the Foundation for the National Institutes of Health (www.fnih.org). The grantee organization is the Northern California Institute for Research and Education, and the study is coordinated by the Alzheimer's Disease Cooperative Study at the University of California, San Diego. ADNI data are disseminated by the Laboratory for Neuro Imaging at the University of Southern California
A Structural Parametrization of the Brain Using Hidden Markov Models Based Paths in Alzheimer's Disease
The usage of biomedical imaging in the diagnosis of dementia is increasingly widespread. A number of works explore the possibilities of computational techniques and algorithms in what is called Computed Aided Diagnosis. Our work presents an automatic parametrization of the brain structure by means of a path generation algorithm based on Hidden Markov Models. The path is traced using information of intensity and spatial orientation in each node, adapting to the structural changes of the brain. Each path is itself a useful way to extract features from the MRI image, being the intensity levels at each node the most straightforward. However, a further processing consisting of a modification of the Gray Level Co-occurrence Matrix can be used to characterize the textural changes that occur throughout the path, yielding more meaningful values that could be associated to the structural changes in Alzheimer's Disease, as well as providing a significant feature reduction. This methodology achieves high performance, up to 80.3\% of accuracy using a single path in differential diagnosis involving Alzheimer-affected subjects versus controls belonging to the Alzheimer's Disease Neuroimaging Initiative (ADNI).TIC218, MINECO TEC2008-02113 and TEC2012-34306 projects, Consejería de Economía, Innovación, Ciencia y Empleo de la Junta de Andalucía P09-TIC-4530 and P11-TIC-71
Computational approaches to Explainable Artificial Intelligence: Advances in theory, applications and trends
Financiado para publicación en acceso aberto: Universidad de Granada / CBUA.[Abstract]: Deep Learning (DL), a groundbreaking branch of Machine Learning (ML), has emerged as a driving force in both theoretical and applied Artificial Intelligence (AI). DL algorithms, rooted in complex and non-linear artificial neural systems, excel at extracting high-level features from data. DL has demonstrated human-level performance in real-world tasks, including clinical diagnostics, and has unlocked solutions to previously intractable problems in virtual agent design, robotics, genomics, neuroimaging, computer vision, and industrial automation. In this paper, the most relevant advances from the last few years in Artificial Intelligence (AI) and several applications to neuroscience, neuroimaging, computer vision, and robotics are presented, reviewed and discussed. In this way, we summarize the state-of-the-art in AI methods, models and applications within a collection of works presented at the 9th International Conference on the Interplay between Natural and Artificial Computation (IWINAC). The works presented in this paper are excellent examples of new scientific discoveries made in laboratories that have successfully transitioned to real-life applications.Funding for open access charge: Universidad de Granada / CBUA. The work reported here has been partially funded by many public and private bodies: by the MCIN/AEI/10.13039/501100011033/ and FEDER “Una manera de hacer Europa” under the RTI2018-098913-B100 project, by the Consejeria de Economia, Innovacion, Ciencia y Empleo (Junta de Andalucia) and FEDER under CV20-45250, A-TIC-080-UGR18, B-TIC-586-UGR20 and P20-00525 projects, and by the Ministerio de Universidades under the FPU18/04902 grant given to C. Jimenez-Mesa, the Margarita-Salas grant to J.E. Arco, and the Juan de la Cierva grant to D. Castillo-Barnes.
This work was supported by projects PGC2018-098813-B-C32 & RTI2018-098913-B100 (Spanish “Ministerio de Ciencia, Innovacón y Universidades”), P18-RT-1624, UMA20-FEDERJA-086, CV20-45250, A-TIC-080-UGR18 and P20 00525 (Consejería de econnomía y conocimiento, Junta de Andalucía) and by European Regional Development Funds (ERDF). M.A. Formoso work was supported by Grant PRE2019-087350 funded by MCIN/AEI/10.13039/501100011033 by “ESF Investing in your future”. Work of J.E. Arco was supported by Ministerio de Universidades, Gobierno de España through grant “Margarita Salas”.
The work reported here has been partially funded by Grant PID2020-115220RB-C22 funded by MCIN/AEI/10.13039/501100011033 and, as appropriate, by “ERDF A way of making Europe”, by the “European Union” or by the “European Union NextGenerationEU/PRTR”.
The work of Paulo Novais is financed by National Funds through the Portuguese funding agency, FCT - Fundaça̋o para a Ciência e a Tecnologia within project DSAIPA/AI/0099/2019.
Ramiro Varela was supported by the Spanish State Agency for Research (AEI) grant PID2019-106263RB-I00.
José Santos was supported by the Xunta de Galicia and the European Union (European Regional Development Fund - Galicia 2014–2020 Program), with grants CITIC (ED431G 2019/01), GPC ED431B 2022/33, and by the Spanish Ministry of Science and Innovation (project PID2020-116201GB-I00). The work reported here has been partially funded by Project Fondecyt 1201572 (ANID).
The work reported here has been partially funded by Project Fondecyt 1201572 (ANID).
In [247], the project has received funding by grant RTI2018-098969-B-100 from the Spanish Ministerio de Ciencia Innovación y Universidades and by grant PROMETEO/2019/119 from the Generalitat Valenciana (Spain). In [248], the research work has been partially supported by the National Science Fund of Bulgaria (scientific project “Digital Accessibility for People with Special Needs: Methodology, Conceptual Models and Innovative Ecosystems”), Grant Number KP-06-N42/4, 08.12.2020; EC for project CybSPEED, 777720, H2020-MSCA-RISE-2017 and OP Science and Education for Smart Growth (2014–2020) for project Competence Center “Intelligent mechatronic, eco- and energy saving sytems and technologies”BG05M2OP001-1.002-0023.
The work reported here has been partially funded by the support of MICIN project PID2020-116346GB-I00.
The work reported here has been partially funded by many public and private bodies: by MCIN/AEI/10.13039/501100011033 and “ERDF A way to make Europe” under the PID2020-115220RB-C21 and EQC2019-006063-P projects; by MCIN/AEI/10.13039/501100011033 and “ESF Investing in your future” under FPU16/03740 grant; by the CIBERSAM of the Instituto de Salud Carlos III; by MinCiencias project 1222-852-69927, contract 495-2020.
The work is partially supported by the Autonomous Government of Andalusia (Spain) under project UMA18-FEDERJA-084, project name Detection of anomalous behavior agents by DL in low-cost video surveillance intelligent systems. Authors gratefully acknowledge the support of NVIDIA Corporation with the donation of a RTX A6000 48 Gb.
This work was conducted in the context of the Horizon Europe project PRE-ACT, and it has received funding through the European Commission Horizon Europe Program (Grant Agreement number: 101057746). In addition, this work was supported by the Swiss State Secretariat for Education, Research and Innovation (SERI) under contract nummber 22 00058.
S.B Cho was supported by Institute of Information & Communications Technology Planning & Evaluation (IITP) grant funded by the Korean government (MSIT) (No. 2020-0-01361, Artificial Intelligence Graduate School Program (Yonsei University)).Junta de Andalucía; CV20-45250Junta de Andalucía; A-TIC-080-UGR18Junta de Andalucía; B-TIC-586-UGR20Junta de Andalucía; P20-00525Junta de Andalucía; P18-RT-1624Junta de Andalucía; UMA20-FEDERJA-086Portugal. Fundação para a Ciência e a Tecnologia; DSAIPA/AI/0099/2019Xunta de Galicia; ED431G 2019/01Xunta de Galicia; GPC ED431B 2022/33Chile. Agencia Nacional de Investigación y Desarrollo; 1201572Generalitat Valenciana; PROMETEO/2019/119Bulgarian National Science Fund; KP-06-N42/4Bulgaria. Operational Programme Science and Education for Smart Growth; BG05M2OP001-1.002-0023Colombia. Ministerio de Ciencia, Tecnología e Innovación; 1222-852-69927Junta de Andalucía; UMA18-FEDERJA-084Suíza. State Secretariat for Education, Research and Innovation; 22 00058Institute of Information & Communications Technology Planning & Evaluation (Corea del Sur); 2020-0-0136
Probabilistic combination of eigenlungs-based classifiers for COVID-19 diagnosis in chest CT images
The outbreak of the COVID-19 (Coronavirus disease 2019) pandemic has changed
the world. According to the World Health Organization (WHO), there have been
more than 100 million confirmed cases of COVID-19, including more than 2.4
million deaths. It is extremely important the early detection of the disease,
and the use of medical imaging such as chest X-ray (CXR) and chest Computed
Tomography (CCT) have proved to be an excellent solution. However, this process
requires clinicians to do it within a manual and time-consuming task, which is
not ideal when trying to speed up the diagnosis. In this work, we propose an
ensemble classifier based on probabilistic Support Vector Machine (SVM) in
order to identify pneumonia patterns while providing information about the
reliability of the classification. Specifically, each CCT scan is divided into
cubic patches and features contained in each one of them are extracted by
applying kernel PCA. The use of base classifiers within an ensemble allows our
system to identify the pneumonia patterns regardless of their size or location.
Decisions of each individual patch are then combined into a global one
according to the reliability of each individual classification: the lower the
uncertainty, the higher the contribution. Performance is evaluated in a real
scenario, yielding an accuracy of 97.86%. The large performance obtained and
the simplicity of the system (use of deep learning in CCT images would result
in a huge computational cost) evidence the applicability of our proposal in a
real-world environment.Comment: 15 pages, 9 figure
Assisted Diagnosis of Parkinsonism Based on the Striatal Morphology
Parkinsonism is a clinical syndrome characterized by the progressive loss of striatal dopamine. Its diagnosis
is usually corroborated by neuroimaging data such as DaTSCAN neuroimages that allow visualizing
the possible dopamine deficiency. During the last decade, a number of computer systems have been
proposed to automatically analyze DaTSCAN neuroimages, eliminating the subjectivity inherent to the
visual examination of the data. In this work, we propose a computer system based on machine learning
to separate Parkinsonian patients and control subjects using the size and shape of the striatal region,
modeled from DaTSCAN data. First, an algorithm based on adaptative thresholding is used to parcel
the striatum. This region is then divided into two according to the brain hemisphere division and characterized
with 152 measures, extracted from the volume and its three possible 2-dimensional projections.
Afterwards, the Bhattacharyya distance is used to discard the least discriminative measures and, finally,
the neuroimage category is estimated by means of a Support Vector Machine classifier. This method was
evaluated using a dataset with 189 DaTSCAN neuroimages, obtaining an accuracy rate over 94%. This
rate outperforms those obtained by previous approaches that use the intensity of each striatal voxel as
a feature.This work was supported by the MINECO/
FEDER under the TEC2015-64718-R project, the
Ministry of Economy, Innovation, Science and
Employment of the Junta de Andaluc´ıa under the
P11-TIC-7103 Excellence Project and the Vicerectorate
of Research and Knowledge Transfer of the
University of Granada
POS-255 EFFECT OF DAPAGLIFLOZIN ON BLOOD PRESSURE IN PATIENTS WITH CKD: A PRE-SPECIFIED ANALYSIS FROM DAPA-CKD
Introduction: Hypertension is common in patients with chronic kidney disease (CKD). Sodium-glucose cotransporter 2 inhibitors decrease blood pressure in patients with type 2 diabetes, but the consistency and magnitude of blood pressure lowering with dapagliflozin in patients with CKD is unknown. We performed a pre-specified analysis of the DAPA-CKD trial to investigate the effect of dapagliflozin on systolic blood pressure in patients with CKD, with and without type 2 diabetes.
Methods: We randomized 4,304 adults with baseline eGFR 25–75 mL/min/1.73m2and urinary albumin-to-creatinine ratio (UACR) 200–5,000 mg/g to either dapagliflozin 10 mg or placebo once daily; median follow-up was 2.4 years. The primary outcome was a composite of sustained ≥50% eGFR decline, end-stage kidney disease, or death from a kidney or cardiovascular cause. Change in systolic blood pressure was a pre-specified endpoint. Subgroup analyses were performed according to baseline type 2 diabetes status.
Results: Baseline mean (SD) systolic blood pressure was 137.1 mmHg (17.4); in participants with and without type 2 diabetes 139.2 mmHg (17.3) and 132.6 mmHg (16.7), respectively. By week 2, dapagliflozin compared to placebo reduced systolic blood pressure by 3.6 mmHg (95%CI 2.8, 4.4; p\u3c0.001), an effect maintained over the duration of the trial, with similar reductions in patients with and without type 2 diabetes (Table). The reduction in systolic blood pressure with dapagliflozin explained 7.6% (95%CI 1.8, 20.9) of the effect on the primary composite outcome, with similar proportions explained in patients with and without type 2 diabetes.
Conclusions: In participants with CKD, dapagliflozin lowered systolic blood pressure with a consistent effect in participants with and without type 2 diabetes. The modest reduction in blood pressure explained a small proportion of the benefit of dapagliflozin on the primary outcome. Conflict of interest Potential conflict of interest: HLH received grant funding and honoraria for consultancy as a member of the steering committee of the DAPA-CKD trial from AstraZeneca. Honoraria for steering committee membership paid to his institution from Janssen, Gilead, Bayer, Chinook, CSL Pharma honoraria for consultancy paid to his institution from Abbvie, Boehringer Ingleheim, Retrophin, Novo Nordisk honoraria for advisory board participation paid to his institution from Janssen, Merck, Mitsubishi Tanabe and Munipharma lecture fees received from AstraZeneca and Mitsubishi Tanabe and grant support received from Boehringer Ingelheim
- …