Aperiodicity in one-way Markov cycles and repeat times of large earthquakes in faults

A common use of Markov Chains is the simulation of the seismic cycle in a fault, i.e. as a renewal model for the repetition of its characteristic earthquakes. This representation is consistent with Reid's elastic rebound theory. Here it is proved that in {\it any} one-way Markov cycle, the aperiodicity of the corresponding distribution of cycle lengths is always lower than one. This fact concurs with observations of large earthquakes in faults all over the world

Individual variability in cardiac biomarker release after 30 min of high-intensity rowing in elite and amateur athletes

This study had two objectives: (i) to examine individual variation in the pattern of cardiac troponin I (cTnI) and N-terminal pro-brain natriuretic peptide (NT-proBNP) release in response to high-intensity rowing exercise, and (ii) to establish whether individual heterogeneity in biomarker appearance was influenced by athletic status (elite vs. amateur). We examined cTnI and NT-proBNP in 18 elite and 14 amateur rowers before and 5 min, 1, 3, 6, 12, and 24 h after a 30-min maximal rowing test. Compared with pre-exercise levels, peak postexercise cTnI (pre: 0.014 ± 0.030 μg·L–1; peak post: 0.058 ± 0.091 μg·L–1; p = 0.000) and NT-proBNP (pre: 15 ± 11 ng·L–1; peak post: 31 ± 19 ng·L–1; p = 0.000) were elevated. Substantial individual heterogeneity in peak and time-course data was noted for cTnI. Peak cTnI exceeded the upper reference limit (URL) in 9 elite and 3 amateur rowers. No rower exceeded the URL for NT-proBNP. Elite rowers had higher baseline (0.019 ± 0.038 vs. 0.008 ± 0.015 μg·L–1; p = 0.003) and peak postexercise cTnI (0.080 ± 0.115 vs. 0.030 ± 0.029 μg·L–1; p = 0.022) than amateur rowers, but the change with exercise was similar between groups. There were no significant differences in baseline and peak postexercise NT-proBNP between groups. In summary, marked individuality in the cTnI response to a short but high-intensity rowing bout was observed. Athletic status did not seem to affect the change in cardiac biomarkers in response to high-intensity exercise

Mutations affecting the actin regulator WD repeat–containing protein 1 lead to aberrant lymphoid immunity

Background: The actin-interacting protein WD repeat–containing protein 1 (WDR1) promotes cofilin-dependent actin filament turnover. Biallelic WDR1 mutations have been identified recently in an immunodeficiency/autoinflammatory syndrome with aberrant morphology and function of myeloid cells. Objective: Given the pleiotropic expression of WDR1, here we investigated to what extent it might control the lymphoid arm of the immune system in human subjects. Methods: Histologic and detailed immunologic analyses were performed to elucidate the role of WDR1 in the development and function of B and T lymphocytes. Results: Here we identified novel homozygous and compound heterozygous WDR1 missense mutations in 6 patients belonging to 3 kindreds who presented with respiratory tract infections, skin ulceration, and stomatitis. In addition to defective adhesion and motility of neutrophils and monocytes, WDR1 deficiency was associated with aberrant T-cell activation and B-cell development. T lymphocytes appeared to develop normally in the patients, except for the follicular helper T-cell subset. However, peripheral T cells from the patients accumulated atypical actin structures at the immunologic synapse and displayed reduced calcium flux and mildly impaired proliferation on T-cell receptor stimulation. WDR1 deficiency was associated with even more severe abnormalities of the B-cell compartment, including peripheral B-cell lymphopenia, paucity of B-cell progenitors in the bone marrow, lack of switched memory B cells, reduced clonal diversity, abnormal B-cell spreading, and increased apoptosis on B-cell receptor/Toll-like receptor stimulation. Conclusion: Our study identifies a novel role for WDR1 in adaptive immunity, highlighting WDR1 as a central regulator of actin turnover during formation of the B-cell and T-cell immunologic synapses

RICORS2040 : The need for collaborative research in chronic kidney disease

Chronic kidney disease (CKD) is a silent and poorly known killer. The current concept of CKD is relatively young and uptake by the public, physicians and health authorities is not widespread. Physicians still confuse CKD with chronic kidney insufficiency or failure. For the wider public and health authorities, CKD evokes kidney replacement therapy (KRT). In Spain, the prevalence of KRT is 0.13%. Thus health authorities may consider CKD a non-issue: very few persons eventually need KRT and, for those in whom kidneys fail, the problem is 'solved' by dialysis or kidney transplantation. However, KRT is the tip of the iceberg in the burden of CKD. The main burden of CKD is accelerated ageing and premature death. The cut-off points for kidney function and kidney damage indexes that define CKD also mark an increased risk for all-cause premature death. CKD is the most prevalent risk factor for lethal coronavirus disease 2019 (COVID-19) and the factor that most increases the risk of death in COVID-19, after old age. Men and women undergoing KRT still have an annual mortality that is 10- to 100-fold higher than similar-age peers, and life expectancy is shortened by ~40 years for young persons on dialysis and by 15 years for young persons with a functioning kidney graft. CKD is expected to become the fifth greatest global cause of death by 2040 and the second greatest cause of death in Spain before the end of the century, a time when one in four Spaniards will have CKD. However, by 2022, CKD will become the only top-15 global predicted cause of death that is not supported by a dedicated well-funded Centres for Biomedical Research (CIBER) network structure in Spain. Realizing the underestimation of the CKD burden of disease by health authorities, the Decade of the Kidney initiative for 2020-2030 was launched by the American Association of Kidney Patients and the European Kidney Health Alliance. Leading Spanish kidney researchers grouped in the kidney collaborative research network Red de Investigación Renal have now applied for the Redes de Investigación Cooperativa Orientadas a Resultados en Salud (RICORS) call for collaborative research in Spain with the support of the Spanish Society of Nephrology, Federación Nacional de Asociaciones para la Lucha Contra las Enfermedades del Riñón and ONT: RICORS2040 aims to prevent the dire predictions for the global 2040 burden of CKD from becoming true

Incidencia predictiva de las variables intelectuales en el rendimiento académico durante el período inicial de escolarización

Análisis de la incidencia de las variables intelectuales en el rendimiento académico, con la finalidad de comprobar en qué medida las diferencias pueden explicarse a través de la ejecución de tests aptitudinales y, en su caso, qué factores y/o variables responden mejor a este fenómeno. Hipótesis 1: las diferencias en rendimiento académico son más acusadas a medida que el nivel de las variables intelectuales de los sujetos presentan mayor variabilidad en sus ejecuciones. Hipótesis 2: las variables intelectuales inciden y nos ayudan a predecir el rendimiento académico y las diferencias que en él se observen. 232 alumnos del ciclo inicial de escolarización, conformada a partir del criterio basado en la media de las puntuaciones en los distintos tests y sus desviaciones típicas. Se extraen tres grupos: el de puntuaciones más bajas, el de puntuaciones intermedias y el de puntuaciones más altas. Variables predictoras: tratan de establecer las características personales aptitudinales y las habilidades psicolingüísticas. Variable criterio: se centra en la calificación escolar final. Test de Boehm. Wisc. MPC de Raven. Test de habilidades psicolingüísticas de Illinois. Calificación escolar final. Se confirma la hipótesis 1. La hipótesis 2 se confirma solamente para las asignaturas instrumentales. Las diferencias observadas entre los grupos de puntuaciones extremas indican la posibilidad de que estas se agraven progresivamente durante la escolarización. Las materias no instrumentales parecen conformar un currículo suplementario, en tanto que ponen de manifiesto la incidencia de otros factores. Las variables intelectuales muestran incidencia predictiva en este período de escolarización. Los porcentajes parciales de varianza explicada por cada una de las variables intelectuales, tomadas individualmente, indican la presencia de dos tipos de materias distintas: de un lado, las instrumentales, en las que se pondrían en juego las enseñanzas del razonamiento, solución de problemas y aptitudes verbales y, de otro lado, las no instrumentales, en las que se mantiene una orientación curricular diferente. Los resultados obtenidos indican la posibilidad, de un lado, de que en estas materias no se enseñe lo que realmente debe enseñarse o, de otro lado, que los resultados, al tomar una calificación 'subjetiva' proporcionada por el profesor que imparte la docencia, esté sesgada por algo que no deja de ser un número, sin reflejar para nada la verdadera adquisición que de esta materia se produce.AsturiasES

Stress-strain curves of concrete under monotonic uniaxial compression: a systematic review

La existencia de más de una treintena de expresiones matemáticas distintas que pretenden representar la evolución tenso- deformacional de una probeta de hormigón sometida a compresión uniaxial monotónica (incluidas las propuestas en las normativas oficiales de los distintos países que tienen regulado por ley el empleo del hormigón como material estructural), parece requerir un esfuerzo adicional a la hora de formular una expresión universalmente aceptada. Como primer paso hacia ese objetivo, en este trabajo se muestran y analizan de manera sistemática las distintas dinastías de ecuaciones publicadas, desde las primeras propuestas de Ritter y Bach (1897- 1899), pasando por los truncamientos polinómicos más o menos complejos de la ecuación de Smith y Young (1956), hasta las aportaciones basadas en distribuciones estadísticas del modelo de daño, concluyendo con el análisis del tratamiento dado a la cuestión por las distintas versiones del Código Modelo y la Instrucción de Hormigón Estructural española (EHE-08).The existence of more than thirty different mathematical expressions that claims to represent the stress-strain relationship of a concrete specimen under monotonic and uniaxial compression (including those proposed in the official regulations of different countries that have regulated by law the use of concrete as structural material), seems to require an additional effort in formulating a universally accepted equation. As a first step toward that goal, in this paper we show and analyze systematically the different dynasties of equations that have been published, since the first proposals of Ritter and Bach (1897-1899), through the, more or less complicated, polynomial truncations of the Smith and Young’s equation (1956), continuing with the contributions based on statistical distributions of the damage model, and concluding with the analysis of the approach to the issue by the successive versions of the Model Code and the Spanish Structural Concrete Instruction (EHE-08)

Enhanced variational image dehazing

Images obtained under adverse weather conditions, such as haze or fog, typically/nexhibit low contrast and faded colors, which may severely limit the visibility within the scene. Unveiling/nthe image structure under the haze layer and recovering vivid colors out of a single image/nremains a challenging task, since the degradation is depth-dependent and conventional methods are/nunable to overcome this problem. In this work, we extend a well-known perception-inspired variational/nframework for single image dehazing. Two main improvements are proposed. First, we replace/nthe value used by the framework for the grey-world hypothesis by an estimation of the mean of/nthe clean image. Second, we add a set of new terms to the energy functional for maximizing the/ninter-channel contrast. Experimental results show that the proposed Enhanced Variational Image/nDehazing (EVID) method outperforms other state-of-the-art methods both qualitatively and quantitatively./nIn particular, when the illuminant is uneven, our EVID method is the only one that recovers/nrealistic colors, avoiding the appearance of strong chromatic artifacts.D. Pardo was partially funded by the Project of the Spanish Ministry of Economy and Competitiveness with reference MTM2013-40824-P, the BCAM “Severo Ochoa” accreditation of excellence SEV-2013-0323, the CYTED 2011 project 712RT0449, and the Basque Government/nConsolidated Research Group Grant IT649-13 on “Mathematical Modeling, Simulation, and Industrial Applications (M2SI)”

Optimal Output Vector Feedback Control Strategy for Wind Power Systems

This article presents the design of optimal output feedback controllers to enhance the dynamic performance of wind turbine generator supplying an infinite bus through transmission line. Efforts have been made to propose optimal regulators based on feedback of output state variables, which are easily accessible and available for the measurement. The designed optimal output feedback controllers are implemented in the wake of step disturbance in the system. The system dynamic responses and pattern of closed loop system eigenvalues for various system states are obtained with the designed optimal regulators to investigate the system dynamic performance. The investigations of the results obtained reveal that the reduction in system states used for feedback has resulted in degradation of system dynamic performance. However, for a particular set of output variables used as feedback; five states are used for feedback for an eighth order original system. The system dynamic performance is the same as offered by optimal controllers based on full state vector feedback control strategy.http://www.tandfonline.com/loi/uemp202016-06-30hb2016Electrical, Electronic and Computer Engineerin