392 research outputs found
Multiple hypothesis testing and clustering with mixtures of non-central t-distributions applied in microarray data analysis
Multiple testing analysis, based on clustering methodologies, is usually applied in Microarray Data Analysis for comparisons between pair of groups. In this paper, we generalize this methodology to deal with multiple comparisons among more than two groups obtained from microarray expressions of genes. Assuming normal data, we define a statistic which depends on sample means and sample variances, distributed as a non-central t-distribution. As we consider multiple comparisons among groups, a mixture of non-central t-distributions is derived. The estimation of the components of mixtures is obtained via a Bayesian approach, and the model is applied in a multiple comparison problem from a microarray experiment obtained from gorilla, bonobo and human cultured fibroblasts.Clustering, MCMC computation, Microarray analysis, Mixture distributions, Multiple hypothesis testing, Non-central t-distribution
Leibnizian, Galilean and Newtonian structures of spacetime
The following three geometrical structures on a manifold are studied in
detail: (1) Leibnizian: a non-vanishing 1-form plus a Riemannian
metric \h on its annhilator vector bundle. In particular, the possible
dimensions of the automorphism group of a Leibnizian G-structure are
characterized. (2) Galilean: Leibnizian structure endowed with an affine
connection (gauge field) which parallelizes and \h. Fixed
any vector field of observers Z (), an explicit Koszul--type
formula which reconstruct bijectively all the possible 's from the
gravitational and vorticity fields
(plus eventually the torsion) is provided. (3) Newtonian: Galilean structure
with \h flat and a field of observers Z which is inertial (its flow preserves
the Leibnizian structure and ). Classical concepts in Newtonian
theory are revisited and discussed.Comment: Minor errata corrected, to appear in J. Math. Phys.; 22 pages
including a table, Late
Bayesian inference and data cloning in population projection matrices
Discrete time models are used in Ecology for describing the evolution of an agestructured
population. Usually, they are considered from a deterministic viewpoint but,
in practice, this is not very realistic.
The statistical model we propose in this article is a reasonable model for the case in
which the evolution of the population is described by means of a projection matrix.
In this statistical model, fertility rates and survival rates are unknown parameters and
they are estimated by using a Bayesian approach. Usual Bayesian and data cloning methods (based on Bayesian methodology) are applied
to real data from the population of the Steller sea lions located in the Alaska coast since
1978 to 2004. The estimates obtained from these methods show a good behavior when
they are compared to the actual value
A note on the existence of standard splittings for conformally stationary spacetimes
Let be a spacetime which admits a complete timelike conformal Killing
vector field . We prove that splits globally as a standard
conformastationary spacetime with respect to if and only if is
distinguishing (and, thus causally continuous). Causal but non-distinguishing
spacetimes with complete stationary vector fields are also exhibited. For the
proof, the recently solved "folk problems" on smoothability of time functions
(moreover, the existence of a {\em temporal} function) are used.Comment: Metadata updated, 6 page
Excited-state quantum phase transitions in the anharmonic Lipkin-Meshkov-Glick model: Static aspects
The basic Lipkin-Meshkov-Glick model displays a second-order ground-state quantum phase transition and
an excited-state quantum phase transition (ESQPT). The inclusion of an anharmonic term in the Hamiltonian
implies a second ESQPT of a different nature. We characterize this ESQPT using the mean field limit of the
model. The alternative ESQPT, associated with the changes in the boundary of the finite Hilbert space of
the system, can be properly described using the order parameter of the ground-state quantum phase transition,
the energy gap between adjacent states, the participation ratio, and the quantum fidelity susceptibility.I + D + i Projects - MCIN/AEI PID2019-104002GB-C21
PID2019104002GB-C22
PID2020-114687GB-I00
MCIN/AEI/10.13039/501100011033Junta de AndaluciaEuropean Commission UHU-1262561
US-1380840Junta de Andalucia P20_01247ERDF-A Way of Making Europe
European CommissionSpanish Government UNHU-15CE-2848European Union NextGenerationEU/PRT
The Effects of 6 Weeks of Tribulus terrestris L. Supplementation on Body Composition, Hormonal Response, Perceived Exertion, and CrossFit® Performance: A Randomized, Single-Blind, Placebo-Controlled Study
[EN] Tribulus terrestris L. (TT) supplementation have been shown to enhance sports performance in many but not all studies. Moreover, data regarding the potential impact of TT supplementation on CrossFit® endurance is limited. This study aimed to determine whether TT supplementation improve body composition, hormonal response, and performance among CrossFit® athletes. In a randomized, single-blind, placebo-controlled trial, a total of 30 healthy CrossFit®-trained males were randomly allocated to receive either 770 mg of TT supplementation or a placebo daily for 6 weeks. Body mass, fat mass, fat composition, testosterone and cortisol levels, and CrossFit® performance (5 common Workouts of the Day: back squat, bench press, dead lift, Grace, and CrossFit® Total) were assessed before and after intervention. There were no significant group x time interactions for the outcomes of the study except for testosterone levels and bench press performance (p < 0.05). TT supplementation did not impact enhance performance or body composition in CrossFit® male athletes. However, TT supplementation may act as a testosterone booster helping the recovery after physical loads and mitigating fatigueS
Pancreas agenesis mutations disrupt a lead enhancer controlling a developmental enhancer cluster.
Sequence variants in cis-acting enhancers are important for polygenic disease, but their role in Mendelian disease is poorly understood. Redundancy between enhancers that regulate the same gene is thought to mitigate the pathogenic impact of enhancer mutations. Recent findings, however, have shown that loss-of-function mutations in a single enhancer near PTF1A cause pancreas agenesis and neonatal diabetes. Using mouse and human genetic models, we show that this enhancer activates an entire PTF1A enhancer cluster in early pancreatic multipotent progenitors. This leading role, therefore, precludes functional redundancy. We further demonstrate that transient expression of PTF1A in multipotent progenitors sets in motion an epigenetic cascade that is required for duct and endocrine differentiation. These findings shed insights into the genome regulatory mechanisms that drive pancreas differentiation. Furthermore, they reveal an enhancer that acts as a regulatory master key and is thus vulnerable to pathogenic loss-of-function mutations
The effects of 6 weeks of Tribulus terrestris L. supplementation on body composition, hormonal response, perceived exertion, and CrossFit® performance: A randomized, single-blind, placebo-controlled study
Producción CientíficaTribulus terrestris L. (TT) supplementation have been shown to enhance sports performance in many but not all studies. Moreover, data regarding the potential impact of TT supplementation on CrossFit® endurance is limited. This study aimed to determine whether TT supplementation improve body composition, hormonal response, and performance among CrossFit® athletes. In a randomized, single-blind, placebo-controlled trial, a total of 30 healthy CrossFit®-trained males were randomly allocated to receive either 770 mg of TT supplementation or a placebo daily for 6 weeks. Body mass, fat mass, fat composition, testosterone and cortisol levels, and CrossFit® performance (5 common Workouts of the Day: back squat, bench press, dead lift, Grace, and CrossFit® Total) were assessed before and after intervention. There were no significant group x time interactions for the outcomes of the study except for testosterone levels and bench press performance (p < 0.05). TT supplementation did not impact enhance performance or body composition in CrossFit® male athletes. However, TT supplementation may act as a testosterone booster helping the recovery after physical loads and mitigating fatigue
Heart Rate Variability Analysis Guided by Respiration in Major Depressive Disorder
In this study a Heart Rate Variability (HRV) analysis guided by respiration to evaluate different patterns of Autonomic Nervous System (ANS) in response to a cognitive stressor between Major Depressive Disorder (MDD) and control (CT) subjects is presented. Cardiorespiratory Time Frequency Coherence (TFC) reveals the local coupling of HRV and respiration signal which is essential and usually not included in estimation of ANS measures derived by HRV. Parasympathetic activity of ANS is measured as the power at the frequencies where TFC between HRV and respiration is significant, whereas sympathetic dominance is measured as the normalized power in the low frequency band [0.04,0.15] Hz of HRV excluding the power of those frequencies related to respiration. Results showed significantly lower (p <; 0.05) sympathetic dominance in MDD with respect to CT subjects during stress, suggesting that ANS reactivity as response to stress stimuli is lower in MDD patients. The study of ANS reactivity to a stressor may serve as a biomarker useful for the early diagnosis and monitoring of MDD patients
A windows application that supports the teaching of the calculation of fertilizer requirements
En el actual contexto de rápidos e incesantes desarrollos tecnológicos, existe una necesidad creciente de
incorporar nuevas herramientas basadas en las Tecnologías de la Información y la Comunicación (TIC) en
los procesos de enseñanza-aprendizaje en ingeniería. Este artículo describe las principales características
de FertiliCalc, una novedosa aplicación Windows concebida como herramienta de apoyo en la docencia
del cálculo de necesidades de nutrientes y fertilizantes de los cultivos. La aplicación permite al usuario
determinar las cantidades estacionales requeridas de nitrógeno, potasio y fósforo y la combinación más
barata de fertilizantes comerciales para 149 cultivos. Más aún, se han desarrollado versiones de
FertiliCalc y videos tutoriales de uso en hasta 25 idiomas, haciendo posible su empleo en diferentes
universidades alrededor del mundo y que cualquier estudiante pueda aprender la terminología relacionada
en otros idiomas. Las primeras evaluaciones del uso de la aplicación en un curso reducido perteneciente
al Grado de Ingeniería Agroalimentaria de la Universidad de Córdoba han revelado mayores tasas de
éxito por parte de los estudiantes en el cálculo de las necesidades de fertilizantes en relación a ediciones
pasadas del mismo. Se concluye que FertiliCalc representa una prometedora y potente herramienta para
la docencia.Under the current context of fast and constant technological developments, there is a major call for the
introduction of new tools based on the new available Information and Communication Technologies (TIC)
in the processes of teaching-learning in engineering. This article describes the main characteristics of
FertiliCalc, a novel Windows application conceived as a support tool for teaching the calculation of nutrient
and fertilizer requirements of crops. The application allows the user to calculate the seasonal amounts of
nitrogen, potassium and phosphorous needed and the most cost-effective combination of commercial
fertilizers for up to 149 crops. Moreover, versions of FertiliCalc and video tutorials have been developed in
up to 25 languages, so that it can be used in different universities across the world and allows students to
learn the related terminology in foreign languages. The first assessments of the use of the application in a
course belonging to the Degree on Agricultural Engineering of the University of Córdoba revealed a higher
success rate among students in the calculation of fertilizer requirements in relation to past editions of that
course. It is concluded that FertiliCalc represents a promising and powerful tool for teaching
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