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Abstract: This work proposes a method to characterize the respiratory pattern of patients with chronic heart failure (CHF) to determine non-periodic breathing (nPB), periodic breathing (PB) and Cheyne-Stokes respiration (CSR) through non-linear, symbolic analysis of biological signals. A total of 43 patients were examined for their cardiorespiratory profiles, their ECG and respiratory pattern signals were processed, analyzed and studied for parameters that could be of potential use in clinical decision making, specifically in patient classification. Patients in the study were characterized through their cardiorespiratory signals, applying joint symbolic dynamics (JSD) analysis to cardiac beat and respiratory interval durations. The most statistically significant parameters across all groups were identified through a Kruskal-Wallis two tailed test (α = 0.05) and a linear discriminant analysis (LDA) classification method based on such parameters was developed. The best result achieved with this classification method uses 10 features to discriminate patients with a 97.67% Accuracy (Acc). The best features to discriminate among groups are related to cardiorespiratory interaction rather than just respiration patterns alone. Results further support the idea that abnormal breathing patterns derive from physiological abnormalities in chronic heart failure.

Resumen: El trabajo propone un método para identificar el patrón respiratorio de pacientes con insuficiencia cardiaca crónica (CHF) con la finalidad de determinar respiración no periódica (NPB), respiración periódica (PB) y respiración de Cheyne-Stokes (CSR) a través de análisis simbólico no lineal de señales biológicas. Se examinaron los perfiles cardiorrespiratorios de 43 pacientes; sus señales de ECG y patrón respiratorio fueron procesados, analizados y estudiados en busca de parámetros que pudieran ser de utilidad, específicamente en la clasificación de pacientes. Estos pacientes se caracterizaron por medio de sus señales cardiorrespiratorias, aplicando un análisis de dinámica simbólica de conjuntos al ritmo cardíaco y a la duración de los intervalos respiratorios. Los parámetros de mayor significancia estadística entre todos los grupos se identificaron a través de una prueba Kruskal-Wallis de dos colas ( α = 0,05) y mediante un método de clasificación por análisis discriminante lineal (LDA). El mejor resultado conseguido con este método utiliza 10 características para discriminar a los pacientes con una precisión de 97,67% (Acc). Las características para discriminar entre grupos estuvieron relacionados con la interacción cardiorrespiratoria más que con solo los patrones de respiración, respaldando así la idea de que los patrones de respiración anormales derivan de anomalías fisiológicas presentes en la insuficiencia cardíaca crónica.

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The aim of this study was to determine the trophic structure and nycthemeral variations in the diet of dominant fish species (Ariopsis felis, Bairdiella chrysoura, Micropogonias undulatus, Eucinostomus gula, Eucinostomus argenteus, Lagodon rhomboides and Sphoeroides testudineus) in Celestun Lagoon, a biosphere reserve located in the southern Gulf of Mexico, and influenced by freshwater seeps. A total of 1473 stomachs were analysed and nine trophic groups were recorded. Bray-Curtis analyses with analyses of similarity (ANOSIM) statistical tests were used to determine two groups of feeding guilds: zoobenthivores and omnivores, with significant differences between time and habitat. The relationships between fish feeding habits, size class and environmental variables were investigated using canonical correspondence analysis (CCA). Most of the species showed a low niche breadth with high specialization towards amphipod consumption, with the exception of L. rhomboides (0·60), which indicated generalist feeding. This study in a protected area is an important source of information for drawing up conservation policies in relation to the management of aquatic resources, and will aid in the establishment of priority areas for conservation.

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This report analyse the results about forty three (43) patients, thirty six (36) of which showed an extrahepatic obstructive biliary Syndrome was made evident by ultrasonography, five (5) with a cholecistolithiasis and doubtful history of jaundice were evaluated to carry out a video-surgery procedure and two (2) patients whom hepatic-yeyunostomy had been practiced, a control of anastomosis in postoperative period was required. Nuclear Magnetic Resonance and Operative Cholangiography findings were correlated and afterward with the anatomopathological studies when they arrived. In all cases the Nuclear Magnetic Cholangio Resonance (NMCR) let us prove the diagnosis of extrahepatic biliary obstruction determining with precision furthermore the topographical site of the lesion. Respecting the aetiology of obstruction, NMCR was accurate in 34 out of 36 cases (94.4%). In conclusion Cholangio-Resonance is an excellent diagnostic method to evaluate biliary ductal system including anatomic changes. However, there are some limitations yet in order to determine the aetiology of lesions about extrahepatic biliary via extremes. We emphasize its features such as non-invasive, little operating dependent, and without morbimortality that become it as a method of choice to study the biliary via from a diagnostic viewpoint.

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