Fractional Brownian fields, duality, and martingales

In this paper the whole family of fractional Brownian motions is constructed as a single Gaussian field indexed by time and the Hurst index simultaneously. The field has a simple covariance structure and it is related to two generalizations of fractional Brownian motion known as multifractional Brownian motions. A mistake common to the existing literature regarding multifractional Brownian motions is pointed out and corrected. The Gaussian field, due to inherited ``duality'', reveals a new way of constructing martingales associated with the odd and even part of a fractional Brownian motion and therefore of the fractional Brownian motion. The existence of those martingales and their stochastic representations is the first step to the study of natural wavelet expansions associated to those processes in the spirit of our earlier work on a construction of natural wavelets associated to Gaussian-Markov processes.Comment: Published at http://dx.doi.org/10.1214/074921706000000770 in the IMS Lecture Notes Monograph Series (http://www.imstat.org/publications/lecnotes.htm) by the Institute of Mathematical Statistics (http://www.imstat.org

Collagen organization, polarization sensitivity and image quality in human corneas using second harmonic generation microscopy

In this paper, a Second-Harmonic-Generation (SHG) microscope was used to study the relationship between collagen structural arrangement, image quality and polarization sensitivity in human corneas with different organizations. The degree of order (or alternatively, the Structural Dispersion, SD) was quantified using the structure tensor method. SHG image quality was evaluated with different objective metrics. Dependence with polarization was quantified by means of a parameter defined as polarimetric modulation, which employs polarimetric SHG images acquired with four independent polarization states. There is a significant exponential relationship between the quality of the SHG images and the SD of the samples. Moreover, polarization sensitivity strongly depends on collagen arrangement. For quasi- or partially organized specimens, there is a polarization state that noticeably improves the image quality, providing additional information often not seen in other SHG images. This does not occur in non-organized samples. This fact is closely related to polarimetric modulation, which linearly decreases with the SD. Understanding in more detail the relationships that take place between collagen distribution, image quality and polarization sensitivity brings the potential to enable the development of optimized SHG image acquisition protocols and novel objective strategies for the analysis and detection of pathologies related to corneal collagen disorders, as well as surgery follow-ups

Impact of Physical Activity and Exercise on the Epigenome in Skeletal Muscle and Effects on Systemic Metabolism

Julio Plaza-Diaz and Concepcion M. Aguilera are part of the "UGR Plan Propio de Investigacion 2016" and the "Excellence actions: Unit of Excellence on Exercise and Health (UCEES), University of Granada". Julio Plaza-Diaz is supported by a fellowship to postdoctoral researchers at foreign universities and research centers from the "Fundacion Ramon Areces", Madrid, Spain. Francisco Javier Ruiz-Ojeda is supported by a fellowship from Spanish Government "Agencia Estatal de Investigacion-Juan de la Cierva-Incorporacion" program (IJC2020-042739-I). Alvaro TorresMartos is supported by the Project "Transductores Moleculares del Ejercicio Fisico y la Activacion del Tejido Adiposo Pardo: en Busca de Nuevas Dianas Terapeuticas en la Comunicacion Intercelular" funded by "Consejeria de Economia, Conocimiento, Empresas y Universidad (PY18-4455), Junta de Andalucia", Spain.Exercise and physical activity induces physiological responses in organisms, and adaptations in skeletal muscle, which is beneficial for maintaining health and preventing and/or treating most chronic diseases. These adaptations are mainly instigated by transcriptional responses that ensue in reaction to each individual exercise, either resistance or endurance. Consequently, changes in key metabolic, regulatory, and myogenic genes in skeletal muscle occur as both an early and late response to exercise, and these epigenetic modifications, which are influenced by environmental and genetic factors, trigger those alterations in the transcriptional responses. DNA methylation and histone modifications are the most significant epigenetic changes described in gene transcription, linked to the skeletal muscle transcriptional response to exercise, and mediating the exercise adaptations. Nevertheless, other alterations in the epigenetics markers, such as epitranscriptomics, modifications mediated by miRNAs, and lactylation as a novel epigenetic modification, are emerging as key events for gene transcription. Here, we provide an overview and update of the impact of exercise on epigenetic modifications, including the well-described DNA methylations and histone modifications, and the emerging modifications in the skeletal muscle. In addition, we describe the effects of exercise on epigenetic markers in other metabolic tissues; also, we provide information about how systemic metabolism or its metabolites influence epigenetic modifications in the skeletal muscle."Fundacion Ramon Areces", Madrid, SpainSpanish Government "Agencia Estatal de Investigacion-Juan de la Cierva-Incorporacion" program IJC2020-042739-IProject "Transductores Moleculares del Ejercicio Fisico y la Activacion del Tejido Adiposo Pardo: en Busca de Nuevas Dianas Terapeuticas en la Comunicacion Intercelular" - "Consejeria de Economia, Conocimiento, Empresas y Universidad, Junta de Andalucia", PY18-445

Quantitative optical spectroscopy of 87^{87}Rb vapour in the Voigt geometry in DC magnetic fields up to 0.4T

We present a detailed spectroscopic investigation of a thermal ⁸⁷Rb atomic vapour in magnetic fields up to 0.4T in the Voigt geometry. We fit experimental spectra with our theoretical model ElecSus and find excellent quantitative agreement, with RMS errors of backsim0.3%. We extract the magnetic field strength and the angle between the polarisation of the light and the magnetic field from the atomic signal and find excellent agreement to within backsim1% with a commercial Hall probe. Finally, we present an investigation of the relative sensitivity of this technique to variations in the field strength and angle with a view to enabling atom-based high-field vector magnetometry

Aplicación de medidas de linealidad del gráfico p-p al problema de dos muestras

Se presenta un estadístico no-paramétrico para el problema de dos muestras, basado en una medida de linealidad del gráfico P-P. El estadístico propuesto es la adaptación de una idea bien conocida en la literatura en el contexto de bondad de ajuste a una familia paramétrica. Se lleva a cabo una comparación Monte Carlo con los métodos clásicos de Wilcoxon y Ansari-Bradley, Kolmogorov-Smirnov y Cramér-von Mises para el probelam de dos muestras. Dicha comparación demuestra que el método propuesto ofrece uma potencia superior frente a ciertas alternativas relevantes. Desde el punto de vista teórico, se estudia la consistencia del método propuesto y se establece un Teorema del Límite Central para su distribución.We present a non-parametric statistic based on a linearity measure of the P-P plot for the two-sample problem by adapting a known statistic proposed for goodness of fit to a univariate parametric family. A Monte Carlo comparison is carried out to compare the method proposed with the classical Wilcoxon and Ansari-Bradley statistics and the Kolmogorov-Smirnov and Cramér-von Mises statistics the two-sample problem, showing that, for certain relevant alternatives, the proposed method offers advantages, in terms of power, over its classical counterparts. Theoretically, the consistency of the statistic proposed is studied and a Central Limit Theorem is established for its distribution

Gender differences in clinical presentation and 1-year outcomes in atrial fibrillation

Objectives Our objective was to examine gender differences in clinical presentation, management and prognosis of atrial fibrillation (AF) in a contemporary cohort. Methods In 6412 patients, 39.7% women, of the PREvention oF thromboembolic events – European Registry in Atrial Fibrillation, we examined gender differences in symptoms, risk factors, therapies and 1-year incidence of adverse outcomes. Results Men with AF were on average younger than women (mean±SD: 70.1±10.7 vs 74.1±9.7 years, p<0.0001). Women more frequently had at least one AF-related symptom at least occasionally compared with men (95.4% in women, 89.8% in men, p<0.0001). Prescription of oral anticoagulation was similar, with an increase of non-vitamin K antagonist oral anticoagulants from 5.9% to 12.6% in women and from 6.2% to 12.6% in men, p<0.0001 for both. Men were more frequently treated with electrical cardioversion and ablation (20.6% and 6.3%, respectively) than women (14.9% and 3.3%, respectively), p<0.0001. Women had 65% (OR: 0.35; 95% CI (0.22 to 0.56)) lower age-adjusted and country-adjusted odds of coronary revascularisation, 40% (OR: 0.60; (0.38 to 0.93)) lower odds of acute coronary syndrome and 20% (OR: 0.80; (0.68 to 0.96)) lower odds of heart failure at 1 year. There were no statistically significant gender differences in 1-year stroke/transient ischaemic attack/arterial thromboembolism and major bleeding events. Conclusion In a ‘real-world’ European AF registry, women were more symptomatic but less likely to receive invasive rhythm control therapy such as electrical cardioversion or ablation. Further study is needed to confirm that these differences do not disadvantage women with AF

High-intensity high-volume swimming induces more robust signaling through PGC-1α and AMPK activation than sprint interval swimming in <i>m. triceps brachii</i>

We aimed to test whether high-intensity high-volume training (HIHVT) swimming would induce more robust signaling than sprint interval training (SIT) swimming within the m. triceps brachii due to lower metabolic and oxidation. Nine well-trained swimmers performed the two training procedures on separate randomized days. Muscle biopsies from m. triceps brachii and blood samples were collected at three different time points: a) before the intervention (pre), b) immediately after the swimming procedures (post) and c) after 3 h of rest (3 h). Hydroperoxides, creatine kinase (CK), and lactate dehydrogenase (LDH) were quantified from blood samples, and peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α) and the AMPKpTHR172/AMPK ratio were quantified by Western blot analysis. PGC-1α, sirtuin 3 (SIRT3), superoxide-dismutase 2 (SOD2), and vascular endothelial growth factor (VEGF) mRNA levels were also quantified. SIT induced a higher release of LDH (

Quality More Than Quantity: The Use of Carbohydrates in High-Fat Diets to Tackle Obesity in Growing Rats

This research was supported by funds provided by the Abbott Laboratories S.A.Childhood obesity prevention is important to avoid obesity and its comorbidities into adulthood. Although the energy density of food has been considered a main obesogenic factor, a focus on food quality rather that the quantity of the different macronutrients is needed. Therefore, this study investigates the effects of changing the quality of carbohydrates from rapidly to slowly digestible carbohydrates on metabolic abnormalities and its impact on obesity in growing rats fed a high-fat diet (HFD). Growing rats were fed on HFD containing carbohydrates with different digestion rates: a HFD containing rapid-digesting carbohydrates (OBE group) or slow-digesting carbohydrates (ISR group), for 4 weeks and the effect on the metabolism and signaling pathways were analyzed in different tissues. Animals from OBE group presented an overweight/obese phenotype with a higher body weight gain and greater accumulation of fat in adipose tissue and liver. This state was associated with an increase of HOMA index, serum diacylglycerols and triacylglycerides, insulin, leptin, and pro-inflammatory cytokines. In contrast, the change of carbohydrate profile in the diet to one based on slow digestible prevented the obesity-related adverse effects. In adipose tissue, GLUT4 was increased and UCPs and PPARg were decreased in ISR group respect to OBE group. In liver, GLUT2, FAS, and SRBP1 were lower in ISR group than OBE group. In muscle, an increase of glycogen, GLUT4, AMPK, and Akt were observed in comparison to OBE group. In conclusion, this study demonstrates that the replacement of rapidly digestible carbohydrates for slowly digestible carbohydrates within a highfat diet promoted a protective effect against the development of obesity and its associated comorbidities.Abbott Laboratories S.A

Melatonin administration in diabetes: regulation of plasma Cr, V, and Mg in young male Zucker diabetic fatty rats

The use of melatonin, a neurohormone present in plants, represents an exciting approach for the maintenance of optimum health conditions. Melatonin administration ameliorates glucose homeostasis in Zucker diabetic fatty (ZDF) rats. The objective of this study was to investigate the effects of melatonin in diabetes in relation to the levels and regulation of plasma chromium (Cr), vanadium (V), and magnesium (Mg) in Zucker diabetic fatty (ZDF) and Zucker lean (ZL) rats. At the age of 6 weeks, ZDF (n ¼ 30) and ZL (n ¼ 30) groups were each subdivided into three groups: control (C) (n ¼ 10), vehicle-treated (V 0 ) (n ¼ 10) and melatonin-treated (M) (10 mg kg À1 per day; n ¼ 10) groups for a 6 week period. After treatment, plasma mineral concentrations were measured by flame (Mg) and electrothermal (Cr and V) atomic absorption spectrometry. No significant differences were found between the C and V 0 groups (p &gt; 0.05). Plasma Mg levels were significantly lower in C-ZDF vs. C-ZL rats, demonstrating the presence of hypomagnesemia in this diabetes mellitus model. Plasma V and Cr levels were significantly higher in M-ZDF vs. C-ZDF rats. Plasma Mg levels in ZDF rats were not affected by melatonin treatment (p &gt; 0.05). Melatonin administration ameliorates the diabetic status of ZDF rats by enhancing plasma Cr and V concentrations. This appears to be the first report of a beneficial effect of melatonin treatment on plasma Cr and V regulation in ZDF rats