Search results for "correlation"

Validation of the Hungarian PHQ-15. A latent variable approach

2021

Somatic symptoms without a clear-cut organic or biomedical background, also called "medically unexplained" or "somatoform" symptoms, are frequent in primary and secondary health care. They are often accompanied by depression and/or anxiety, and cause functional impairment. The Patient Health Question-naire Somatic Symptom Scale (PHQ-15) was developed to measure somatic symptom distress based on the frequency and bothersomeness of non-specific somatic symptoms. The study aimed to (1) evaluate the Hungarian version of the PHQ-15 from a psychometric point of view; (2) replicate the bifactor structure and associations with negative affect described in the literature; and (3) provide the Hungari…

Nonlinear Dynamics Techniques for the Detection of the Brain Areas Using MER Signals

2008

A methodology for identifying brain areas from the brain MER signals (microelectrode recordings) is presented, which is based on a nonlinear feature set. We propose nonlinear dynamics measures such as correlation dimension, Hurst exponent and the largest Lyapunov exponent to characterize the dynamic structure. The MER records belong to the Polytechnical University of Valencia, 24 records for each zone (black substance, thalamus, subthalamus nucleus and uncertain area). The detection of each area using characteristics derived from complexity analysis was obtained through a classifier (support vector machine). The joint information between areas is remarkable and the best accuracy result was …

Monitoring human parvovirus B19 virus-like particles and antibody complexes in solution by fluorescence correlation spectroscopy

2004

AbstractFluorescence correlation spectroscopy (FCS) was used in monitoring human parvovirus B19 virus-like particle (VLP) antibody complexes from acute phase and pastimmunity serum samples. The Oregon Green 488-labeled VLPs gave an average diffusion coefficient of 1.7x10exp-7 cm(2)s(-1) with an apparent hydrodynamic radius of 14 nm. After incubation of the fluorescent VLPs with an acute phase serum sample, the mobility information obtained from the fluorescence intensity fluctuation by autocorrelation analysis showed an average diffusion coefficient of 1.5x10exp-8 cm(2)s(-1), corresponding to an average radius of 157 nm. In contrast, incubation of the fluorescent VLPs with a pastimmunity se…

Interannual persistence effects in vegetation dynamics of semi-arid Africa

2005

[1] Over 15 years of Normalized Difference Vegetation Index (NDVI) data from the Advanced Very High Resolution Radiometers (AVHRR) are used to study the response of vegetation activity to rainfall in three semi-arid regions of Africa. The relationships between annual NDVI and annual precipitation (PPT) time series are examined using statistical approaches (simple and partial correlations, linear multiple regressions). It appears that annual NDVI highly depends on PPT of the concurrent year and the previous year. An analysis of particularly dry and wet years enables to better diagnose two distinct responses of vegetation activity to rainfall. The “recovery” effect represents the difficulty o…

Isoerosivity and erosion risk map for Sicily

1991

This paper reviews simplified methods for evaluating the rainfall erosivity index and proposes two relationships for estimating the annual value of Wischmeier's rainfall erosivity index at sites equipped with recording and non-recording raingauges. For the Sicilian region, the FAO index was also found to represent the erosion risk. A regional relationship to estimate the standard deviation of the annual erosivity index is proposed. The isoerosivity map is plotted by using 41 values of the rainfall erosivity index calculated by Wischmeier's procedure and 128 values estimated according to a relationship proposed by the authors. Finally, for each of 169 sites, an erosion risk index is calculat…

Exploring the influence of vegetation cover, sediment storage capacity and channel dimensions on stone check dam conditions and effectiveness in a la…

2018

Abstract Check dams are widely used for soil conservation at the watershed scale. When structurally sound, these engineering control works retain sediment as planned. However, there is limited information describing the influence of site characteristics on post-construction condition including structural stability and sediment retention capacity. More specifically, the effects of channel morphology, check dam geometry and vegetation characteristics as potentially influencing factors on sediment retention capacity at the watershed level are poorly understood. Thus, an investigation applying field and remotely sensed measurements, multi-regression models, redundancy and sensitivity analysis, …

Temperamentos afectivos y edad de inicio en pacientes bipolares tipo II

2016

Actualmente es imperante contar con indicadores que posibiliten realizar una detección temprana y correcta del trastorno bipolar en general, y del tipo II, en particular. Los temperamentos afectivos constituyen estilos de reactividad emocional temporalmente estables a lo largo del ciclo vital, con una importante base biológica. Dada la escasez de investigaciones al respecto, se exploraron posibles asociaciones entre la edad de inicio de 32 pacientes eutímicos con diagnóstico de trastorno bipolar tipo II y los temperamentos afectivos ciclotímico, depresivo, irritable, ansioso e hipertímico. Los participantes presentaron una edad media de 51,5 años (rango intercuartil 8) y el 65,6% de la mues…

Hypertrophic Lichen Planus: Importance of Follow-Up and Clinicopathologic Correlation

2021

Intuitive eating: A novel eating style? Evidence from a Spanish sample

2020

Contains fulltext : 217000.pdf (Publisher’s version ) (Closed access) Intuitive eating is defined as an adaptive way of eating that maintains a strong connection with the internal physiological signs of hunger and satiety. It has four elements: unconditional permission to eat whenever and whatever food is desired, eating for physical rather than for emotional reasons, reliance on hunger and satiety cues to determine when and how much to eat, and body-food choice congruence. In this study, we assessed the differences and similarities between intuitive eating, as measured with the Intuitive Eating Scale-2, and eating styles (restrained, emotional, and external eating), as assessed with the Du…

Dominating Clasp of the Financial Sector Revealed by Partial Correlation Analysis of the Stock Market

2010

What are the dominant stocks which drive the correlations present among stocks traded in a stock market? Can a correlation analysis provide an answer to this question? In the past, correlation based networks have been proposed as a tool to uncover the underlying backbone of the market. Correlation based networks represent the stocks and their relationships, which are then investigated using different network theory methodologies. Here we introduce a new concept to tackle the above question--the partial correlation network. Partial correlation is a measure of how the correlation between two variables, e.g., stock returns, is affected by a third variable. By using it we define a proxy of stoc…