Search results for "Causa"
showing 10 items of 661 documents
Assessment of Granger causality by nonlinear model identification: application to short-term cardiovascular variability.
2007
A method for assessing Granger causal relationships in bivariate time series, based on nonlinear autoregressive (NAR) and nonlinear autoregressive exogenous (NARX) models is presented. The method evaluates bilateral interactions between two time series by quantifying the predictability improvement (PI) of the output time series when the dynamics associated with the input time series are included, i.e., moving from NAR to NARX prediction. The NARX model identification was performed by the optimal parameter search (OPS) algorithm, and its results were compared to the least-squares method to determine the most appropriate method to be used for experimental data. The statistical significance of…
Bicausative matrices to measure structural change: Are they a good tool?
1999
The causative-matrix method to analyze temporal change assumes that a matrix transforms one Markovian transition matrix into another by a left multiplication of the first matrix; the method is demand-driven when applied to input-output economics. An extension is presented without assuming the demand-driven or supply-driven hypothesis. Starting from two flow matrices X and Y, two diagonal matrices are searched, one premultiplying and the second postmultiplying X, to obtain a result the closer as possible to Y by least squares. The paper proves that the method is deceptive because the diagonal matrices are unidentified and the interpretation of results is unclear. Keywords : Input-Output ; Ch…
Cellular ionic alterations with age: relation to hypertension and diabetes.
2000
BACKGROUND: Cytosolic free calcium (Cai) and magnesium (Mgi) are vital to cellular homeostasis and function. OBJECTIVE: To evaluate cellular divalent cations in normal subjects at different ages and their relationship to ion levels in essential hypertension and diabetes. DESIGN: A cross-sectional study. SETTING: A university hospital in New York. PARTICIPANTS: A total of 103 subjects (32 older, 71.1 ± 1.2 y/o, and 71 young/middle aged subjects, 51.1 ± 2.3 y/o). INTERVENTION: Oral glucose tolerance test. MEASUREMENTS: 19F and 31P NMR spectroscopy were used to measure Cai and Mgi levels in erythrocytes from normal (>65 y/o, n = 11; 65 y/o, n = 9; 65 y/o, n = 12; <65 y/o, n = 15) subjects; the…
Towards understanding the complexity of cardiovascular oscillations: Insights from information theory.
2018
Abstract Cardiovascular complexity is a feature of healthy physiological regulation, which stems from the simultaneous activity of several cardiovascular reflexes and other non-reflex physiological mechanisms. It is manifested in the rich dynamics characterizing the spontaneous heart rate and blood pressure variability (HRV and BPV). The present study faces the challenge of disclosing the origin of short-term HRV and BPV from the statistical perspective offered by information theory. To dissect the physiological mechanisms giving rise to cardiovascular complexity in different conditions, measures of predictive information, information storage, information transfer and information modificati…
El Sáhara y la MPC
2007
Brain Activity Characterization Induced by Alcoholic Addiction: Spectral and Causality Analysis of Brain Areas Related to Control and Reinforcement o…
2014
Addiction to drugs generates modifications in the brain structure and its functions. In this work, an experimental model is described, using rats to characterize the brain activity induced by alcohol addiction. Four records were obtained using electrodes located in brain areas related to impulsivity control and reinforcement, i.e. the prelimbic (PL) and infralimbic (IL) cortex, together with the hippocampus (HPC). In the records, three main events related to the drinking action were selected: in the previous minute (T1), the first minute while drinking (T2) and the first minute after stopping drinking (T3).
Model development (conceptualisation)
2016
Chapter 2 provided the theoretical background for the development of the conceptual model. In this chapter, firstly, the constructs relevant for the model are conceptualised, and secondly, hypotheses regarding the relationships between those constructs are derived from theoretical considerations.
NESSO DI CAUSALITA'
2012
Credit risk transmission in the European banking sector: the case of the subprime and Eurozone debt crises
2014
El objetivo del presente trabajo es analizar en profundidad la transmisión del riesgo de crédito, aproximado por los CDS spreads, en el sector bancario europeo durante el periodo 2006-2012, intentando dar respuesta a diversas cuestiones: (i) ¿existe evidencia de transmisión del riesgo de crédito entre las entidades financieras europeas de la Eurozona y las que no pertenecen a dicha zona?, (ii) ¿es esta transmisión bidireccional o unidireccional?, (iii) concretamente, ¿qué países han liderado dicha transmisión?, y (iv) ¿cómo se ha visto afectada dicha transmisión con las recientes crisis financieras? Los resultados indican un cambio significativo en la transmisión del riesgo de crédito con e…
Expertise préalable à la création d’un tableau de maladie professionnelle ou à l’élaboration de recommandations aux comités régionaux de reconnaissan…
2022
L’amiante est classé en tant que substance cancérogène avérée pour l’humain (groupe 1 du Centre International de Recherche sur la Cancer (CIRC)) depuis les années 70 pour le poumon et la plèvre. La monographie sur l’amiante actualisée en 2012 indique que des preuves suffisantes sont maintenant disponibles pour démontrer le lien entre l’exposition à l’amiante et les cancers du larynx et de l'ovaire. Dans cette monographie, les cancers du pharynx, de l’estomac et les cancers colorectaux sont considérés comme possiblement liés à une exposition à l’amiante, mais avec un niveau de preuve limité.A ce jour, seuls les cancers broncho-pulmonaires provoqués par l'inhalation de poussières d'amiante [t…