12 research outputs found

    Automatic ROI Selection in Structural Brain MRI Using SOM 3D Projection

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    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

    Association of candidate gene polymorphisms with chronic kidney disease : Results of a case-control analysis in the NEFRONA cohort

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    Chronic kidney disease (CKD) is a major risk factor for end-stage renal disease, cardiovascular disease and premature death. Despite classical clinical risk factors for CKD and some genetic risk factors have been identified, the residual risk observed in prediction models is still high. Therefore, new risk factors need to be identified in order to better predict the risk of CKD in the population. Here, we analyzed the genetic association of 79 SNPs of proteins associated with mineral metabolism disturbances with CKD in a cohort that includes 2,445 CKD cases and 559 controls. Genotyping was performed with matrix assisted laser desorption ionization-time of flight mass spectrometry. We used logistic regression models considering different genetic inheritance models to assess the association of the SNPs with the prevalence of CKD, adjusting for known risk factors. Eight SNPs (rs1126616, rs35068180, rs2238135, rs1800247, rs385564, rs4236, rs2248359, and rs1564858) were associated with CKD even after adjusting by sex, age and race. A model containing five of these SNPs (rs1126616, rs35068180, rs1800247, rs4236, and rs2248359), diabetes and hypertension showed better performance than models considering only clinical risk factors, significantly increasing the area under the curve of the model without polymorphisms. Furthermore, one of the SNPs (the rs2248359) showed an interaction with hypertension, being the risk genotype affecting only hypertensive patients. We conclude that 5 SNPs related to proteins implicated in mineral metabolism disturbances (Osteopontin, osteocalcin, matrix gla protein, matrix metalloprotease 3 and 24 hydroxylase) are associated to an increased risk of suffering CKD

    Association of a single nucleotide polymorphism combination pattern of the Klotho gene with non-cardiovascular death in patients with chronic kidney disease

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    Chronic kidney disease (CKD) is associated with an elevated risk of all-cause mortality, with cardiovascular death being extensively investigated. However, non-cardiovascular mortality represents the biggest percentage, showing an evident increase in recent years. Klotho is a gene highly expressed in the kidney, with a clear influence on lifespan. Low levels of Klotho have been linked to CKD progression and adverse outcomes. Single nucleotide polymorphisms (SNPs) of the Klotho gene have been associated with several diseases, but studies investigating the association of Klotho SNPs with noncardiovascular death in CKD populations are lacking. The main aim of this study was to assess whether 11 Klotho SNPs were associated with non-cardiovascular death in a subpopulation of the National Observatory of Atherosclerosis in Nephrology (NEFRONA) study (n ¼ 2185 CKD patients). After 48 months of follow-up, 62 cardiovascular deaths and 108 non-cardiovascular deaths were recorded. We identified a high non-cardiovascular death risk combination of SNPs corresponding to individuals carrying the most frequent allele (G) at rs562020, the rare allele (C) at rs2283368 and homozygotes for the rare allele (G) at rs2320762 (rs562020 GG/AG þ rs2283368 CC/CT þ rs2320762 GG). Among the patients with the three SNPs genotyped (n ¼ 1016), 75 (7.4%) showed this combination. Furthermore, 95 (9.3%) patients showed a low-risk combination carrying all the opposite genotypes (rs562020 AA þ rs2283368 TT þ rs2320762 GT/TT). All the other combinations [n ¼ 846 (83.3%)] were considered as normal risk. Using competing risk regression analysis, we confirmed that the proposed combinations are independently associated with a higher fhazard ratio [HR] 3.28 [confidence interval (CI) 1.51-7.12]g and lower [HR 6 × 10- (95% CI 3.3 × 10--1.1 × 10-)] risk of suffering a non-cardiovascular death in the CKD population of the NEFRONA cohort compared with patients with the normal-risk combination. Determination of three SNPs of the Klotho gene could help in the prediction of non-cardiovascular death in CKD

    Diseño de software educativo en el área de Ciencias Naturales para el Ciclo Superior de EGB

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    Diseñar modos de utilización de ordenadores en el aula que ayuden eficazmente a alcanzar, al final del período de Educación Obligatoria, el nivel de destrezas básico que el cambio social y tecnológico demanda en los alumnos. El objeto de trabajo es la informática en la enseñanza de las Ciencias Experimentales en la segunda etapa de EGB. Investigación teórica y aplicada con fin prospectivo que sigue el proceso: I. Aspectos teóricos del problema: Desarrollo de la didáctica. Desarrollo de la Psicología educacional y Ciencia Cognitiva. II. Revisión y selección de las teorías de aprendizaje más válidas y estudio de los modelos de instrucción derivados. III. Estudio de la herramienta informática: A. Desde su característica lingüística como sistema. B. De procesamiento formal de símbolos. IV. Propuesta metodológica para la integración de actividades con ordenador en unidades didácticas de Ciencia: lenguaje logo adaptado a los aspectos conceptuales específicos. Aplicación al caso de fuerza gravitatoria. 1. Ni en España ni en el entorno europeo existen bancos de software educativo para equipos PC-compatibles susceptibles de ser analizados. 2. Los países vecinos siguen con Thomson y BBC y avanzan lentamente hacia PC Standar. 3. La calidad del software es en conjunto baja y no vale la pena adaptarlos al castellano. 4. Los modelos de aprendizaje/enseñanza que subyacen son en su mayoría esquemas conductistas, excepción hecha de ejemplos de simulación (BBC) y programación anexa a la utilización de micros en el laboratorio. 1. No se esperan cambios sustanciales repentinos. Se tiende a un uso más explícito de la Ciencia Cognitiva aplicada a implementaciones de inteligencia artificial con ordenadores más potentes. 2. Se manifiesta una doble evolución: A. La utilización telemática de acceso a bancos de datos y comunicación de centros entre sí. B. Uso de ordenadores en tecnologías de control. 3. Se propone que se estudien usos del ordenador en la enseñanza de las ciencias que corrijan la carencia de un software específico. Deben ser coherentes con los modelos cognitivos de aprendizaje y con las posibilidades de los micros actuales, se recomienda la utilización de microentornos formalizados con el lenguaje logo, tal y como se expone en el modelo.NavarraES

    Feature selection using factor analysis for Alzheimer’s diagnosis using 18F-FDG PET images

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    Purpose: This article presents a computer-aided diagnosis technique for improving the accuracy of the early diagnosis of Alzheimer’s disease (AD). Two hundred and ten 18F-FDG PET images from the ADNI initiative [52 normal controls (NC), 114 mild cognitive impairment (MCI), and 53 AD subjects] are studied

    Reconstructive social innovation cycles in women-led initiatives in rural areas

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    Abstract Social innovations can tackle various challenges related to gender equity in rural areas, especially when such innovations are initiated and developed by women themselves. We examine cases located in rural areas of Canada, Italy, Lebanon, Morocco, and Serbia, where women are marginalized by gender roles, patriarchal values, male dominated economy and policy, and lack of opportunities for education and employment. Our objective is to analyze five case studies on how women-led social innovation processes can tackle gender equity related challenges manifested at the levels of everyday practice, institutions, and cognitive frames. The analyses are based on interviews, workshops, literature screening, and are examined via the qualitative abductive method. Results summarize challenges that rural women are facing, explore social innovation initiatives as promising solutions, and analyze their implications on gender equity in the five case studies. Based on our results we propose a new concept: reconstructive social innovation cycle. It refers to is defined as cyclical innovation processes that engage women via civil society initiatives. These initiatives reconstruct the existing state of affairs, by questioning marginalizing and discriminative practices, institutions, and cognitive frames that are often perceived as normal. The new concept helps with to assessing the implications that women-led social innovations have for gender equity

    Vitamin D and Chronic Kidney Disease Association with Mineral and Bone Disorder: An Appraisal of Tangled Guidelines

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    Chronic kidney disease (CKD) is a highly prevalent condition worldwide in which the kidneys lose many abilities, such as the regulation of vitamin D (VD) metabolism. Moreover, people with CKD are at a higher risk of multifactorial VD deficiency, which has been extensively associated with poor outcomes, including bone disease, cardiovascular disease, and higher mortality. Evidence is abundant in terms of the association of negative outcomes with low levels of VD, but recent studies have lowered previous high expectations regarding the beneficial effects of VD supplementation in the general population. Although controversies still exist, the diagnosis and treatment of VD have not been excluded from nephrology guidelines, and much data still supports VD supplementation in CKD patients. In this narrative review, we briefly summarize evolving controversies and useful clinical approaches, underscoring that the adverse effects of VD derivatives must be balanced against the need for effective prevention of progressive and severe secondary hyperparathyroidism. Guidelines vary, but there seems to be general agreement that VD deficiency should be avoided in CKD patients, and it is likely that one should not wait until severe SHPT is present before cautiously starting VD derivatives. Furthermore, it is emphasized that the goal should not be the complete normalization of parathyroid hormone (PTH) levels. New developments may help us to better define optimal VD and PTH at different CKD stages, but large trials are still needed to confirm that VD and precise control of these and other CKD-MBD biomarkers are unequivocally related to improved hard outcomes in this population
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