Picture of the low-dimensional structure in chaotic dripping faucets

Chaotic dynamics of the dripping faucet was investigated both experimentally and theoretically. We measured continuous change in drop position and velocity using a high-speed camera. Continuous trajectories of a low-dimensional chaotic attractor were reconstructed from these data, which was not previously obtained but predicted in our fluid dynamic simulation. From the simulation, we further obtained an approximate potential function with only two variables, the drop mass and its position of the center of mass. The potential landscape helps one to understand intuitively how the dripping dynamics can exhibit low-dimensional chaos.Comment: 8 pages, 3 figure

Promoting patient utilization of outpatient cardiac rehabilitation: A joint International Council and Canadian Association of Cardiovascular Prevention and Rehabilitation position statement

Background: Cardiac Rehabilitation (CR) is a recommendation in international clinical practice guidelines given its’ benefits, however use is suboptimal. The purpose of this position statement was to translate evidence on interventions that increase CR enrolment and adherence into implementable recommendations. Methods: The writing panel was constituted by representatives of societies internationally concerned with preventive cardiology, and included disciplines that would be implementing the recommendations. Patient partners served, as well as policy-makers. The statement was developed in accordance with AGREE II, among other guideline checklists. Recommendations were based on our update of the Cochrane review on interventions to promote patient utilization of CR. These were circulated to panel members, who were asked to rate each on a 7-point Likert scale in terms of scientific acceptability, actionability, and feasibility of assessment. A web call was convened to achieve consensus and confirm strength of the recommendations (based on GRADE). The draft underwent external review and public comment. Results: The 3 drafted recommendations were that to increase enrolment, healthcare providers, particularly nurses (strong), should promote CR to patients face-to-face (strong), and that to increase adherence part of CR could be delivered remotely (weak). Ratings for the 3 recommendations were 5.95±0.69 (mean ± standard deviation), 5.33±1.12 and 5.64±1.08, respectively. Conclusions: Interventions can significantly increase utilization of CR, and hence should be widely applied. We call upon cardiac care institutions to implement these strategies to augment CR utilization, and to ensure CR programs are adequately resourced to serve enrolling patients and support them to complete programs

Apego terapéutico. Informe a la comunidad cardiológica

La falta de apego al tratamiento de las enfermedades cardiovasculares crónicas es un problema clínico. Trasciende de la relación médico-paciente a lo social y es nuevo en la salud pública. No existe una solución integral, pero está el potencial de resolverlo con la colaboración amplia de médicos, pacientes y las facilidades que brinde la acción comunitaria organizada. La Sociedad Mexicana de Cardiología, consciente de su papel rector en el asunto, ha tomado la iniciativa de conocer a fondo el problema. Este artículo es el informe inicial que contiene una revisión del tema y de un Estudio de Investigación Cualitativa. Se ha enfocado a la interpretación de las declaraciones públicas de un debate organizado ex profeso en el reciente Congreso de Cardiología. Destaca la necesidad de organizarse, fomentar la cultura de la salud, actuar en la readaptación de la relación médico-paciente de acuerdo a las nuevas exigencias de cambios radicales que la modernidad involucra

Calculation of matrix elements in relativistic quantum mechanics

Employing a relativistic version of a hypervirial result, recurrence relations for arbitrary nondiagonal radial hydrogenic matrix elements have recently been obtained in Dirac relativistic quantum mechanics. In this contribution honoring Professor Lowdin, we report on a new relation we have recently discovered between the matrix elements and -where beta is a Dirac matrix and the numbers distiguish between different radial eigenstates-that allow for a simplification and hence for a more convenient way of expressing the recurrence relations. We additionally derive another relation that can be employed for simplifying two-center matrix element calculations in relativistic atomic or molecular calculations. (C) 2002 Wiley Periodicals, Inc. Int

Dp71, utrophin and beta-dystroglycan expression and distribution in PC12/L6 cell cocultures.

International audienceFunction of dystrophin Dp71 isoforms is unknown but seems related to neurite outgrowth and synapse formation. To evaluate Dp71 role in myoneural synapses, we established a coculture model using PC12 cells and L6 myotubes and analyzed expression and localization of Dp71 and related proteins, utrophin and beta-dystroglycan, in PC12 cells. Confocal microscopy showed Dp71d isoform in PC12 nuclei, golgi-complex-like and endoplasmic reticulum-like structures, whereas Dp71ab concentrates at neurite tips and cytoplasm, colocalizing with beta-dystroglycan, utrophin, synaptophysin and acetylcholine receptors. Evidences suggest that Dp71ab isoform, unlike Dp71d, may take part in neurite-related processes. This is the first work on Dp and members of Dp-associated protein complex roles in a cell-line based coculturing system, which may be useful in determining Dp71 isoforms associations

Association between premature ventricular complexes during exercise, long-term occurrence of life-threatening arrhythmia and mortality

Objective: Exercise-induced premature ventricular complexes (EiPVCs) are often considered as benign arrhythmias, although they are associated with a high risk of all-cause death in the general healthy population. However, an intermediate pathophysiological process remains unclear, particularly in patients with known cardiovascular disease. The aim of this study was to find an association between EiPVCs, the occurrence of life-threatening ventricular arrhythmias (LACO), and all-cause mortality in patients with cardiovascular disease. Methods: This was an observational study of a cohort of patients with coronary artery disease (CAD) or idiopathic cardiomyopathy (ICM). Stress testing was performed as a part of the routine cardiovascular evaluation. The occurrence of EiPVCs was evaluated during exercise testing (ET). At follow-up, long-term occurrence of LACO was evaluated. A bivariate and multivariate analysis was performed. Results: Out of the total of 1442 patients analysed, 700 (49%) had EiPVCs. During 14 years of following-up after ET, 106 LACO outcomes were observed. Long-term all-cause mortality was 4% (n = 61). A bivariate analysis showed that patients with EiPVCs had an increased risk for LACO (RR = 2.81, 95% CI; 1.9–4.3, P < .001), and for mortality (RR = 2.1, CI95% 1.2–3.4, P < .01). Occurrence of LACO was also associated with a higher mortality risk (RR = 5.7, 95% CI; 3.4–9.4, P < .001). After a post hoc analysis, LACO remained as a highly predictive variable for mortality. Conclusion: Patients with EiPVCs have a high risk of LACO and all-cause mortality. The presence of LACO could be an intermediate stage between EiPVCs and mortality in subjects with cardiovascular disease. Resumen: Objetivo: La extrasistolia ventricular inducida por ejercicio (EVIE) suele considerarse una arritmia benigna, sin embargo, ha sido asociada a mayor mortalidad en población general. Hasta hoy no se ha encontrado el proceso fisiopatológico involucrado, particularmente en pacientes con enfermedad cardiovascular. El objetivo del estudio fue establecer una asociación entre EVIE con la ocurrencia de arritmias ventriculares potencialmente malignas (APM) y letalidad a largo plazo, en sujetos con enfermedad cardiovascular. Método: Estudiamos una cohorte de pacientes con enfermedad coronaria o miocardiopatía dilatada, que realizaron una prueba de ejercicio al inicio del estudio. Inicialmente evaluamos la ocurrencia de EVIE, APM y letalidad a largo plazo y posteriormente se realizó un estudio bivariable y multivariable. Resultados: Se incluyeron 1,442 pacientes de los cuales 700 presentaron EVIE (49%). Durante 14 años de seguimiento, 106 sujetos presentaron APM y la mortalidad total fue de 61 casos (4%). El estudio bivariable mostró que aquellos pacientes con EVIE tuvieron un riesgo de presentar APM de 2.81 (IC95% de 1.9 a 4.3, p < 0.001) y de mortalidad de 2.1 (IC95% de 1.2 a 3.4, p < 0.01). Los individuos con APM tuvieron mayor riesgo de mortalidad (RR= 5.7, IC95% de 3.4 a 9.4, p < 0.001). Después de un análisis multivariable, la APM continuó siendo una variable altamente predictiva de mortalidad. Conclusión: Los pacientes con EVIE tienen un riesgo elevado de presentar APM y de mortalidad a largo plazo. Los resultados sugieren que las APM podrían representar un estado intermedio entre la presencia de EVIE y la mortalidad en pacientes con enfermedad cardiovascular. Keywords: Cardiovascular disease, Arrhythmias, Exercise testing, Cardiovascular risk, Mortality, Mexico, Palabras clave: Enfermedad cardiovascular, Arritmia, Prueba de esfuerzo, Riesgo cardiovascular, Mortalidad, Méxic

Iduronic Acid in chondroitin/dermatan sulfate affects directional migration of aortic smooth muscle cells

Contains fulltext : 119303.pdf (publisher's version ) (Open Access)Aortic smooth muscle cells produce chondroitin/dermatan sulfate (CS/DS) proteoglycans that regulate extracellular matrix organization and cell behavior in normal and pathological conditions. A unique feature of CS/DS proteoglycans is the presence of iduronic acid (IdoA), catalyzed by two DS epimerases. Functional ablation of DS-epi1, the main epimerase in these cells, resulted in a major reduction of IdoA both on cell surface and in secreted CS/DS proteoglycans. Downregulation of IdoA led to delayed ability to re-populate wounded areas due to loss of directional persistence of migration. DS-epi1-/- aortic smooth muscle cells, however, had not lost the general property of migration showing even increased speed of movement compared to wild type cells. Where the cell membrane adheres to the substratum, stress fibers were denser whereas focal adhesion sites were fewer. Total cellular expression of focal adhesion kinase (FAK) and phospho-FAK (pFAK) was decreased in mutant cells compared to control cells. As many pathological conditions are dependent on migration, modulation of IdoA content may point to therapeutic strategies for diseases such as cancer and atherosclerosis