A bayesian model for the analysis of transgenerational epigenetic variation

477-485Epigenetics has become one of the major areas of biological research. However, the degree of phenotypic variability that is explained by epigenetic processes still remains unclear. From a quantitative genetics perspective, the estimation of variance components is achieved by means of the information provided by the resemblance between relatives. In a previous study, this resemblance was described as a function of the epigenetic variance component and a reset coefficient that indicates the rate of dissipation of epigenetic marks across generations. Given these assumptions, we propose a Bayesian mixed model methodology that allows the estimation of epigenetic variance from a genealogical and phenotypic database. The methodology is based on the development of a T matrix of epigenetic relationships that depends on the reset coefficient. In addition, we present a simple procedure for the calculation of the inverse of this matrix (T-1) and a Gibbs sampler algorithm that obtains posterior estimates of all the unknowns in the model. The new procedure was used with two simulated data sets and with a beef cattle database. In the simulated populations, the results of the analysis provided marginal posterior distributions that included the population parameters in the regions of highest posterior density. In the case of the beef cattle dataset, the posterior estimate of transgenerational epigenetic variability was very low and a model comparison test indicated that a model that did not included it was the most plausible

Linkage disequilibrium, persistence of phase, and effective population size in Spanish local beef cattle breeds assessed through a high-density single nucleotide polymorphism chip

We have used the BovineHD Genotyping BeadChip to obtain high density genotypes (>700, 000 SNP after quality control) from 116 trios in five Spanish local beef cattle breeds. Linkage disequilibrium (LD) was meas- ured through the r2 statistic. Average r2 for adjacent markers in the five breeds were very close, around 0.52, and de- creased with increasing distance between markers, although in long distances some LD remained (0.07 and 0.05 for markers 200 kb and 1000 kb apart, respectively). At all distances the standard deviations were large and the shape of the distribution varied depending upon the marker dis- tance. Average r2 varied also between chromosomes. Pair- wise correlations between the r’s estimated in two breeds at short distances (5 kb) was in the rank of 0.6 – 0.7. Similarly to r2 estimates, this correlation decreased with increasing marker distance

Weighted norm inequalities for polynomial expansions associated to some measures with mass points

Fourier series in orthogonal polynomials with respect to a measure $\nu$ on $[-1,1]$ are studied when $\nu$ is a linear combination of a generalized Jacobi weight and finitely many Dirac deltas in $[-1,1]$. We prove some weighted norm inequalities for the partial sum operators $S_n$, their maximal operator $S^*$ and the commutator $[M_b, S_n]$, where $M_b$ denotes the operator of pointwise multiplication by b \in \BMO. We also prove some norm inequalities for $S_n$ when $\nu$ is a sum of a Laguerre weight on $\R^+$ and a positive mass on $0$

Non-Linear Numerical Models for Predicting the Bond Strength of Fibre-Reinforced Concrete at High Temperatures

The steel to concrete bond mechanism is critical to address the behaviour of reinforced concrete structural members. Although this mechanism can be compromised during a fire, it may be one of the least researched phenomena in concrete technology and is not addressed in the design codes and standards. In this work, we present a thorough review of the experimental data available on this topic, focusing on fibre-reinforced concrete. The data allow us to study the evolution of the bond strength as a function of three variables: the exposure temperature, the type of fibre and the volume fraction. A linear multiple regression is initially carried out, followed by a series of non-linear numerical models. These models are built using a methodology based on the finite element method combined with the formulation of the Galerkin method. The numerical models have been developed for different degrees of complexity. The error measurements obtained with the linear regression and the numerical models are compared in order to present a prediction model. The selected model is then validated for different values of the independent variables. This process supports the discussion of the influence that the independent variables have in the evolution of the bond strength between steel reinforcement and fibre-reinforced concretes exposed to high temperatures.The authors want to acknowledge Generalitat Valenciana, which has made possible this piece of research through the grant GV/2018/015

Tendon Immune Regeneration: Insights on the Synergetic Role of Stem and Immune Cells during Tendon Regeneration

Tendon disorders represent a very common pathology in today’s population, and tendinopathies that account 30% of tendon-related injuries, affect yearly millions of people which in turn cause huge socioeconomic and health repercussions worldwide. Inflammation plays a prominent role in the development of tendon pathologies, and advances in understanding the underlying mechanisms during the inflammatory state have provided additional insights into its potential role in tendon dis-orders. Different cell compartments, in combination with secreted immune modulators, have shown to control and modulate the inflammatory response during tendinopathies. Stromal compartment represented by tenocytes has shown to display an important role in orchestrating the inflammatory response during tendon injuries due to the interplay they exhibit with the immune-sensing and infiltrating compartments, which belong to resident and recruited immune cells. The use of stem cells or their derived secretomes within the regenerative medicine field might represent synergic new therapeutical approaches that can be used to tune the reaction of immune cells within the damaged tissues. To this end, promising opportunities are headed to the stimulation of macrophages polarization towards anti-inflammatory phenotype together with the recruitment of stem cells, that possess immunomodulatory properties, able to infiltrate within the damaged tissues and improve tendinopathies resolution. Indeed, the comprehension of the interactions between tenocytes or stem cells with the immune cells might considerably modulate the immune reaction solving hence the inflammatory response and preventing fibrotic tissue formation. The purpose of this review is to compare the roles of distinct cell compartments during tendon homeostasis and injury. Furthermore, the role of immune cells in this field, as well as their interactions with stem cells and tenocytes during tendon regeneration, will be discussed to gain insights into new ways for dealing with tendinopathies

Detección de regiones genómicas con elevado desequilibrio de ligamiento en poblaciones de vacuno de carne españolas con análisis de BovineHD BeadChip

Mouresan, E. F. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.González Rodríguez, A. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Munilla, Sebastián. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Moreno, C. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Altarriba, J. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Díaz, C. Instituto Nacional de Tecnología Agraria y Alimentaria (INIA). Mejora Genética Animal. Madrid, España.Baro, J. A. Universidad de Valladolid. Departamento de Ciencias Agroforestales. Producción Animal. Valladolid. España.Piedrafita, J. Universitad Autónoma de Barcelona. Ciencia Animal y de los Alimentos. Barcelona, España.Molina, A. Universidad de Córdoba. Departamento de Genética. Córdoba. Spain.Cañas Alvarez, J. J. Universitad Autónoma de Barcelona. Ciencia Animal y de los Alimentos. Barcelona, España.Varona, L. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.59-65El objetivo de este trabajo fue evaluar el patrón de desequilibrio de ligamiento a lo largo del genoma en siete poblaciones españolas autóctonas de vacuno de carne (Asturiana de los Valles, Avileña Negra - Ibérica, Bruna dels Pirineus, Morucha, Pirenaica, Retinta y Rubia Gallega). Para ello, se utilizó el BovineHD BeadChip con el que se genotiparon 171 tríos formados por individuo/padre/madre. Después del filtrado, se dispuso de 573.134 SNP. A partir de esta información se definió un parámetro que mide el desequilibrio medio del genoma por regiones de 1Mb en cada una de las poblaciones. Los resultados mostraron que el desequilibrio de ligamiento es muy heterogéneo a lo largo del genoma y que, además, esta heterogeneidad es consistente entre poblaciones. Las causas de esta heterogeneidad pueden ser, o bien estructurales y atribuibles a una menor tasa de mutación y/o recombinación, o bien consecuencia de procesos de selección estabilizadora

Dynamical principles in neuroscience

Dynamical modeling of neural systems and brain functions has a history of success over the last half century. This includes, for example, the explanation and prediction of some features of neural rhythmic behaviors. Many interesting dynamical models of learning and memory based on physiological experiments have been suggested over the last two decades. Dynamical models even of consciousness now exist. Usually these models and results are based on traditional approaches and paradigms of nonlinear dynamics including dynamical chaos. Neural systems are, however, an unusual subject for nonlinear dynamics for several reasons: (i) Even the simplest neural network, with only a few neurons and synaptic connections, has an enormous number of variables and control parameters. These make neural systems adaptive and flexible, and are critical to their biological function. (ii) In contrast to traditional physical systems described by well-known basic principles, first principles governing the dynamics of neural systems are unknown. (iii) Many different neural systems exhibit similar dynamics despite having different architectures and different levels of complexity. (iv) The network architecture and connection strengths are usually not known in detail and therefore the dynamical analysis must, in some sense, be probabilistic. (v) Since nervous systems are able to organize behavior based on sensory inputs, the dynamical modeling of these systems has to explain the transformation of temporal information into combinatorial or combinatorial-temporal codes, and vice versa, for memory and recognition. In this review these problems are discussed in the context of addressing the stimulating questions: What can neuroscience learn from nonlinear dynamics, and what can nonlinear dynamics learn from neuroscience?This work was supported by NSF Grant No. NSF/EIA-0130708, and Grant No. PHY 0414174; NIH Grant No. 1 R01 NS50945 and Grant No. NS40110; MEC BFI2003-07276, and Fundación BBVA

Detección de regiones genómicas con elevado desequilibrio de ligamiento en poblaciones de vacuno de carne españolas con análisis de BovineHD BeadChip

Mouresan, E. F. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.González Rodríguez, A. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Munilla, Sebastián. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Moreno, C. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Altarriba, J. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.Díaz, C. Instituto Nacional de Tecnología Agraria y Alimentaria (INIA). Mejora Genética Animal. Madrid, España.Baro, J. A. Universidad de Valladolid. Departamento de Ciencias Agroforestales. Producción Animal. Valladolid. España.Piedrafita, J. Universitad Autónoma de Barcelona. Ciencia Animal y de los Alimentos. Barcelona, España.Molina, A. Universidad de Córdoba. Departamento de Genética. Córdoba. Spain.Cañas Alvarez, J. J. Universitad Autónoma de Barcelona. Ciencia Animal y de los Alimentos. Barcelona, España.Varona, L. Universidad de Zaragoza. Facultad de Veterinaria. Unidad de Mejora Genética. Zaragoza, España.59-65El objetivo de este trabajo fue evaluar el patrón de desequilibrio de ligamiento a lo largo del genoma en siete poblaciones españolas autóctonas de vacuno de carne (Asturiana de los Valles, Avileña Negra - Ibérica, Bruna dels Pirineus, Morucha, Pirenaica, Retinta y Rubia Gallega). Para ello, se utilizó el BovineHD BeadChip con el que se genotiparon 171 tríos formados por individuo/padre/madre. Después del filtrado, se dispuso de 573.134 SNP. A partir de esta información se definió un parámetro que mide el desequilibrio medio del genoma por regiones de 1Mb en cada una de las poblaciones. Los resultados mostraron que el desequilibrio de ligamiento es muy heterogéneo a lo largo del genoma y que, además, esta heterogeneidad es consistente entre poblaciones. Las causas de esta heterogeneidad pueden ser, o bien estructurales y atribuibles a una menor tasa de mutación y/o recombinación, o bien consecuencia de procesos de selección estabilizadora