Explore the vast range of titles available.

The refined multiscale entropy (RMSE) approach is commonly applied to assess complexity as a function of the time scale. RMSE is normally based on the computation of sample entropy (SampEn) estimating complexity as conditional entropy. However, SampEn is dependent on the length and standard deviation of the data. Recently, fuzzy entropy (FuzEn) has been proposed, including several refinements, as an alternative to counteract these limitations. In this work, FuzEn, translated FuzEn (TFuzEn), translated-reflected FuzEn (TRFuzEn), inherent FuzEn (IFuzEn), and inherent translated FuzEn (ITFuzEn) were exploited as entropy-based measures in the computation of RMSE and their performance was compared to that of SampEn. FuzEn metrics were applied to synthetic time series of different lengths to evaluate the consistency of the different approaches. In addition, electroencephalograms of patients under sedation-analgesia procedure were analyzed based on the patient’s response after the application of painful stimulation, such as nail bed compression or endoscopy tube insertion. Significant differences in FuzEn metrics were observed over simulations and real data as a function of the data length and the pain responses. Findings indicated that FuzEn, when exploited in RMSE applications, showed similar behavior to SampEn in long series, but its consistency was better than that of SampEn in short series both over simulations and real data. Conversely, its variants should be utilized with more caution, especially whether processes exhibit an important deterministic component and/or in nociception prediction at long scales.

The study assesses complexity of the cardiac control directed to the sinus node and to ventricles in long QT syndrome type 1 (LQT1) patients with KCNQ1-A341V mutation. Complexity was assessed via refined multiscale entropy (RMSE) computed over the beat-to-beat variability series of heart period (HP) and QT interval. HP and QT interval were approximated respectively as the temporal distance between two consecutive R-wave peaks and between the R-wave apex and T-wave end. Both measures were automatically taken from 24-hour electrocardiographic Holter traces recorded during daily activities in non mutation carriers (NMCs, n = 14) and mutation carriers (MCs, n = 34) belonging to a South African LQT1 founder population. The MC group was divided into asymptomatic (ASYMP, n = 11) and symptomatic (SYMP, n = 23) patients according to the symptom severity. Analyses were carried out during daytime (DAY, from 2PM to 6PM) and nighttime (NIGHT, from 12PM to 4AM) off and on beta-adrenergic blockade (BBoff and BBon). We found that the complexity of the HP variability at short time scale was under vagal control, being significantly increased during NIGHT and BBon both in ASYMP and SYMP groups, while the complexity of both HP and QT variability at long time scales was under sympathetic control, being smaller during NIGHT and BBon in SYMP subjects. Complexity indexes at long time scales in ASYMP individuals were smaller than those in SYMP ones regardless of therapy (i.e. BBoff or BBon), thus suggesting that a reduced complexity of the sympathetic regulation is protective in ASYMP individuals. RMSE analysis of HP and QT interval variability derived from routine 24-hour electrocardiographic Holter recordings might provide additional insights into the physiology of the cardiac control and might be fruitfully exploited to improve risk stratification in LQT1 population.

Background: Despite the known impact of propofol and remifentanil on hemodynamics and patient outcomes, there is a lack of comprehensive quantitative analysis, particularly in surgical settings, considering the influence of noxious stimuli. The aim of this study was to develop a quantitative semi-mechanistic population model that characterized the time course changes in mean arterial pressure (MAP) and heart rate (HR) due to the effects of propofol, remifentanil, and different types of noxious stimulation related to the clinical routine. Methods: Data from a prospective study were used; the study analyzed the effects of propofol and remifentanil general anesthesia on female patients in physical status of I-II according to the American Society of Anesthesiologists (ASA I-II) undergoing gynecology surgery. Patients were consecutively assigned to different administration schemes of propofol and remifentanil targeted at different effect-site concentrations. Esophageal instrumentation, laryngeal mask airway insertion, hysteroscopy, and tetanus stimuli were applied. Data from patients with chronic hypertension were discarded. Results: MAP and HR observations from 77 patients were analyzed. The hemodynamic effects were described using turn-over models incorporating feedback mechanisms. Analyses revealed that propofol and remifentanil elicited effects on the turn-over of MAP and HR, respectively, with estimates of plasma drug concentrations causing an inhibition-half of the maximum effect (C50) of 8.79 µg∙mL−1 and 4.57 ng∙mL−1. Hysteroscopy exerted an increase in MAP (but not in HR), which was well-characterized by the model, with a predicted typical increase of 28 mmHg and a dissipation half-life of 33 min. The impact of other noxious stimuli on MAP or HR could not be identified. Model simulations indicated that propofol and remifentanil, titrated to inhibit the motor response to noxious stimuli, regardless of dose combinations, cause a significant risk of hypotension, especially following induction and at the end of surgery (when surgical intervention is completed, before the awakening phase). Conclusions: The developed semi-mechanistic and fully identifiable model provides quantitative information on how propofol, remifentanil, and surgical stimulus (hysteroscopy) interact to produce the hemodynamic changes (of MAP and HR) commonly observed in clinical practice.

Intraoperative targeting of the analgesic effect still lacks an optimal solution. Opioids are currently the main drug used to achieve antinociception, and although underdosing can lead to an increased stress response, overdose can also lead to undesirable adverse effects. To better understand how to achieve the optimal analgesic effect of opioids, we studied the influence of remifentanil on the pupillary reflex dilation (PRD) and its relationship with the reflex movement response to a standardized noxious stimulus. The main objective was to generate population pharmacodynamic models relating remifentanil predicted concentrations to movement and to pupillary dilation during general anesthesia. A total of 78 patients undergoing gynecological surgery under general anesthesia were recruited for the study. PRD and movement response to a tetanic stimulus were measured multiple times before and after surgery. We used nonlinear mixed effects modeling to generate a population pharmacodynamic model to describe both the time profiles of PRD and movement responses to noxious stimulation. Our model demonstrated that movement and PRD are equally depressed by remifentanil. Using the developed model, we changed the intensity of stimulation and simulated remifentanil predicted concentrations maximizing the probability of absence of movement response. An estimated effect site concentration of 2 ng/ml of remifentanil was found to inhibit movement to a tetanic stimulation with a probability of 81%.

The level of sedation in patients undergoing medical procedures is decided to assure unconsciousness and prevent pain. The monitors of depth of anesthesia, based on the analysis of the electroencephalogram (EEG), have been progressively introduced into the daily practice to provide additional information about the state of the patient. However, the quantification of analgesia still remains an open problem. The purpose of this work was to analyze the capability of prediction of nociceptive responses based on refined multiscale entropy (RMSE) and auto mutual information function (AMIF) applied to EEG signals recorded in 378 patients scheduled to undergo ultrasonographic endoscopy under sedation-analgesia. Two observed categorical responses after the application of painful stimulation were analyzed: the evaluation of the Ramsay Sedation Scale (RSS) after nail bed compression and the presence of gag reflex (GAG) during endoscopy tube insertion. In addition, bispectrum (BIS), heart rate (HR), predicted concentrations of propofol (CeProp) and remifentanil (CeRemi) were annotated with a resolution of 1 s. Results showed that functions based on RMSE, AMIF, HR and CeRemi permitted predicting different stimulation responses during sedation better than BIS.

The use of more abstract language to describe expected behaviors as opposed to unexpected behaviors has traditionally been considered a way of stereotype maintenance. This tendency is known as linguistic expectancy bias. Two experiments examined the influence of approach and avoidance motivational orientations on the production of this linguistic expectancy bias. It was predicted that approach strategic orientation is likely to describe expectancy consistent behaviors at a higher level of linguistic abstraction than expectancy inconsistent behaviors. In contrast, avoidance strategic orientation is likely to describe both expectancy consistent behaviors and expectancy inconsistent behaviors at a lower level of linguistic abstraction, thus facilitating the disappearance of linguistic expectancy bias. Two experiments confirmed these expectations, using strategic orientation manipulations based either on communication goals or on motor action, and measuring linguistic abstraction either on forced-choice answer format or on free descriptions. Implications for the generalisation of linguistic expectancy bias are discussed. El uso de un lenguaje más abstracto para describir los comportamientos congruentes con las expectativas que los comportamientos incongruentes con las expectativas es una forma de mantener los estereotipos. Esta tendencia se conoce como el sesgo lingüístico de expectativa. Dos experimentos analizan la influencia de las orientaciones motivacionales de aproximación y evitación en la producción del sesgo lingüístico de expectativa. Se predijo que la orientación estratégica de aproximación promovería que comportamientos consistentes con la expectativa se describiesen con un mayor nivel de abstracción lingüística que los comportamientos inconsistentes con la expectativa. En cambio, la orientación estratégica de evitación induciría a que tanto los comportamientos consistentes como los inconsistentes con las expectativas se describiesen a un menor nivel de abstracción, facilitando con ello la desaparición del sesgo lingüístico de expectativa. Los dos experimentos que se presentan confirmaron dichas predicciones utilizando manipulaciones de orientación estratégica de aproximación y evitación formuladas en forma de metas comunicativas y en forma de acción motora. Además, se midió la abstracción lingüística tanto en formato de respuesta de elección múltiple como en descripción libre. El artículo debate las implicaciones de los estudios para la generalización del sesgo lingüístico de expectativa.

Basándose en la teoría del núcleo central (Abric, 1976, 1987), el objetivo del estudio fue analizar la representación social que jóvenes en formación profesional tienen sobre el desempleo masculino y femenino. En el estudio participaron 231 jóvenes de 3 centros de formación tecnológica elegidos intencionadamente del Departamento de los Pirineos Atlánticos en Francia, los que respondieron a un cuestionario con preguntas de evocación y de refutación. Los resultados del análisis lexicográfico y categorial mostraron las especificidades del desempleo femenino, organizado en relación a la dimensión familiar, y las del masculino, organizado en relación a la dimensión individual. Los porcentajes de refutación, por su parte, mostraron que los elementos centrales del desempleo femenino y del masculino son los mismos. Estos resultados evidencian la organización en base al género de la representación social del desempleo, en la que sigue vigente la asignación tradicional de los roles de género.

El uso de un lenguaje más abstracto para describir los comportamientos congruentes con las expectativas que los comportamientos incongruentes con las expectativas es una forma de mantener los estereotipos. Esta tendencia se conoce como el sesgo lingüístico de expectativa. Dos experimentos analizan la influencia de las orientaciones motivacionales de aproximación y evitación en la producción del sesgo lingüístico de expectativa. Se predijo que la orientación estratégica de aproximación promovería que comportamientos consistentes con la expectativa se describiesen con un mayor nivel de abstracción lingüística que los comportamientos inconsistentes con la expectativa. En cambio, la orientación estratégica de evitación induciría a que tanto los comportamientos consistentes como los inconsistentes con las expectativas se describiesen a un menor nivel de abstracción, facilitando con ello la desaparición del sesgo lingüístico de expectativa. Los dos experimentos que se presentan confirmaron dichas predicciones utilizando manipulaciones de orientación estratégica de aproximación y evitación formuladas en forma de metas comunicativas y en forma de acción motora. Además, se midió la abstracción lingüística tanto en formato de respuesta de elección múltiple como en descripción libre. El artículo debate las implicaciones de los estudios para la generalización del sesgo lingüístico de expectativa.

La segmentación del iris es una de las etapas más importantes en los sistemas de reconocimiento del iris. En este trabajo se aplican algoritmos de preprocesamiento de la imagen con el objetivo de evaluar su impacto en los porcentajes de segmentación exitosa del iris. Los algoritmos utilizados se basan en el ajuste del histograma, filtros Gaussianos y en la eliminación del reflejo especular en imágenes del ojo humano. Se aplica el método de segmentación introducido por Masek a 199 imágenes tomadas bajo condiciones no controladas, pertenecientes a la base de datos CASIA-irisV3, antes y después de aplicar los algoritmos de preprocesamiento. Posteriormente se evalúa el impacto de los algoritmos de preprocesamiento en el porcentaje de segmentación exitosa del iris por medio de una inspección visual de las imágenes, para determinar si las circunferencias detectadas del iris y de la pupila corresponden adecuadamente con el iris y la pupila de la imagen real. El algoritmo que generó uno de los mayores incrementos de los porcentajes de segmentación exitosa (pasa de 59% a 73%) es aquel que combina la eliminación de reflejos especulares, seguido por la aplicación de un filtro Gaussiano con máscara 5x5. Los resultados obtenidos señalan la importancia de una etapa previa de preprocesamiento de la imagen como paso previo para garantizar una mayor efectividad en el proceso de detección de bordes y segmentación del iris.

Basándose en la teoría del núcleo central (Abric, 1976, 1987), el objetivo del estudio fue analizar la representación social que jóvenes en formación profesional tienen sobre el desempleo masculino y femenino. En el estudio participaron 231 jóvenes de 3 centros de formación tecnológica elegidos intencionadamente del Departamento de los Pirineos Atlánticos en Francia, los que respondieron a un cuestionario con preguntas de evocación y de refutación. Los resultados del análisis lexicográfico y categorial mostraron las especificidades del desempleo femenino, organizado en relación a la dimensión familiar, y las del masculino, organizado en relación a la dimensión individual. Los porcentajes de refutación, por su parte, mostraron que los elementos centrales del desempleo femenino y del masculino son los mismos. Estos resultados evidencian la organización en base al género de la representación social del desempleo, en la que sigue vigente la asignación tradicional de los roles de género.Based on the theory of the central core (Abric, 1976, 1987), the aim of the study was to analyze the social representation of male and female unemployment held by young people with vocational training studies. In the study 231 students from 3 purposively chosen technology training centers in the Pyrénées-Atlantiques Department in France completed a questionnaire containing evocation and refutation items. The results of the lexicographic and categorical analysis showed the specificities of female unemployment, organized along the family dimension and of male unemployment, organized around the individual dimension. In contrast, percentages related to the refutation questionnaires showed the same core elements in both female and male unemployment. These results suggest that the social representation of unemployment is differently organized as a function of gender, thus implying that the traditional views of gender roles still persist.