Search results for "Linear model"

Comparing subjective intoxication with risky single-occasion drinking in a European sample.

2020

In most epidemiological literature, harmful drinking—a drinking pattern recognized as closely linked to alcohol-attributable diseases—is recorded using the measure risky single-occasion drinking (RSOD), which is based on drinking above a certain quantity. In contrast, subjective intoxication (SI) as an alternative measure can provide additional information, including the drinker’s subjective perceptions and cultural influences on alcohol consumption. However, there is a lack of research comparing both. The current article investigates this comparison, using data from the Standardized European Alcohol Survey from 2015. We analysed the data of 12,512 women and 12,516 men from 17 European coun…

Quantification of the Fabry marker lysoGb3 in human plasma by tandem mass spectrometry

2011

Morbus Fabry is a hereditary metabolic disorder with low prevalence and late clinical manifestation. A defect in the α-galactosidase gene leads to lysosomal accumulation of the glycolipid globotriaosylceramide (Gb3). Gb3 may be used for monitoring of enzyme replacement therapy (ERT), but diagnostic sensitivity is limited. Recently, globotriaosylsphingosine (lysoGb3) was introduced as a promising new marker with significantly better sensitivity. For Fabry diagnosis, clinical studies and possible therapy monitoring, we established a fast and reliable LC-MS/MS assay for quantification of lysoGb3 in human plasma. Protein precipitation and glycolipid extraction from EDTA plasma was performed usi…

Comparison of prognostic models in patients with advanced Hodgkin disease

2001

Several prognostic systems have been elaborated for patients with Hodgkin disease (HD) over the last 12 years, but early identification of a reasonably large group of both low and high risk, advanced stage patients remains unsatisfactory.Seven well known models were applied to 516 patients with advanced HD, with 315 patients used for the study sample and 201 patients used for the test sample. Individual performances as well as joint performances were analyzed univariately and multivariately in relation to overall survival, recurrence free survival, and time to treatment failure by means of a proportional hazards model.None of the models identified a group containing10% of patients from the …

MicroRNA hsa-miR-4717-5p regulates RGS2 and may be a risk factor for anxiety-related traits

2015

Regulator of G-protein Signaling 2 (RGS2) is a key regulator of G-protein-coupled signaling pathways involved in fear and anxiety. Data from rodent models and genetic analysis of anxiety-related traits and disorders in humans suggest down-regulation of RGS2 expression to be a risk factor for anxiety. Here we investigated, whether genetic variation in microRNAs mediating posttranscriptional down-regulation of RGS2 may be a risk factor for anxiety as well. 75 microRNAs predicted to regulate RGS2 were identified by four bioinformatic algorithms and validated experimentally by luciferase reporter gene assays. Specificity was confirmed for six microRNAs (hsa-miR-1271-5p, hsa-miR-22-3p, hsa-miR-3…

Distributed BOLD-response in association cortex vector state space predicts reaction time during selective attention.

2006

Human cortical information processing is thought to be dominated by distributed activity in vector state space (Churchland, P.S., Sejnowski, T.J., 1992. The Computational Brain. MIT Press, Cambridge.). In principle, it should be possible to quantify distributed brain activation with independent component analysis (ICA) through vector-based decomposition, i.e., through a separation of a mixture of sources. Using event-related functional magnetic resonance imaging (fMRI) during a selective attention-requiring task (visual oddball), we explored how the number of independent components within activated cortical areas is related to reaction time. Prior to ICA, the activated cortical areas were d…

k-Nearest neighbour local linear prediction of scalp EEG activity during intermittent photic stimulation

2011

The characterization of the EEG response to photic stimulation (PS) is an important issue with significant clinical relevance. This study aims to quantify and map the complexity of the EEG during PS, where complexity is measured as the degree of unpredictability resulting from local linear prediction. EEG activity was recorded with eyes closed (EC) and eyes open (EO) during resting and PS at 5, 10, and 15. Hz in a group of 30 healthy subjects and in a case-report of a patient suffering from cerebral ischemia. The mean squared prediction error (MSPE) resulting from k-nearest neighbour local linear prediction was calculated in each condition as an index of EEG unpredictability. The linear or …

Surrogate data analysis of sleep electroencephalograms reveals evidence for nonlinearity

1996

We tested the hypothesis of whether sleep electroencephalographic (EEG) signals of different time windows (164 s, 82 s, 41 s and 20.5 s) are in accordance with linear stochastic models. For this purpose we analyzed the all-night sleep electroencephalogram of a healthy subject and corresponding Gaussian-rescaled phase randomized surrogates with a battery of five non-linear measures. The following nonlinear measures were implemented: largest Lyapunov exponent L1, correlation dimension D2, and the Green-Savit measures delta 2, delta 4 and delta 6. The hypothesis of linear stochastic data was rejected with high statistical significance. L1 and D2 yielded the most pronounced effects, while the G…

Oxidative status in nondiabetic middle-aged subjects with metabolic syndrome: preliminary data.

2013

Influence of social cognition as a mediator between cognitive reserve and psychosocial functioning in patients with first episode psychosis

2019

This work was supported by the Carlos III Institute of Health and European Fund for Regional Development (PI08/1213, PI11/01977, PI14/01900, PI08/01026, PI11/02831, PI14/01621, PI08/1161, PI16/00359, PI16/01164, PI18/00805), the Basque Foundation for Health Innovation and Research (BIOEF), the Secretaria d´Universitats I Recerca del Departament d´Economia I Coneixement (2017 SGR 1365), and R&D activities in Biomedicine, Madrid Regional Government and Structural Funds of the European Union (S2017/BMD-3740 (AGES-CM 2-CM)).

Causal transfer function analysis to describe closed loop interactions between cardiovascular and cardiorespiratory variability signals

2004

Although the concept of transfer function is intrinsically related to an input-output relationship, the traditional and widely used estimation method merges both feedback and feedforward interactions between the two analyzed signals. This limitation may endanger the reliability of transfer function analysis in biological systems characterized by closed loop interactions. In this study, a method for estimating the transfer function between closed loop interacting signals was proposed and validated in the field of cardiovascular and cardiorespiratory variability. The two analyzed signals x and y were described by a bivariate autoregressive model, and the causal transfer function from x to y w…