Flexible joint modeling of mean and dispersion for the directional tuning of neuronal spike counts.

The study of how the number of spikes in a middle temporal visual area (MT/V5) neuron is tuned to the direction of a visual stimulus has attracted considerable attention over the years, but recent studies suggest that the variability of the number of spikes might also be influenced by the directional stimulus. This entails that Poisson regression models are not adequate for this type of data, as the observations usually present over/underdispersion (or both) with respect to the Poisson distribution. This paper makes use of the double exponential family and presents a flexible model to estimate, jointly, the mean and dispersion functions, accounting for the effect of a circular covariate.

Establishment of background pollution levels and spatial analysis of moss data on a regional scale.

The determination of background pollution levels is fundamental for the interpretation of the results obtained from environmental biomonitoring. In this paper we propose a new probabilistic method, based on a Gaussian mixture model, for determining the distribution of regional background levels of different pollutants. The distribution of the reference level is used to categorize the observations as "background" or "above-background" and spatial statistical techniques are then applied to determine the probability of the background level being exceeded.

iTRAQ-based proteomic analysis reveals potential serum biomarkers of allergic and nonallergic asthma.

Background: Asthma is heterogeneous disease with different phenotypes, endotypes and severities. Definition of these subgroups requires the identification of biomarkers in biological samples, and serum proteomics is a useful and minimally invasive method for this purpose. Therefore, the aim of this study was to detect serum proteins whose abundance is distinctively associated with different asthma phenotypes (allergic vs nonallergic) or severities.

Orthogonal Decomposition of the Genetic Variance for Epistatic Traits Under Linkage Disequilibrium-Applications to the Analysis of Bateson-Dobzhansky-Müller Incompatibilities and Sign Epistasis.

The one-century-old theory of orthogonal genetic variance decomposition originated the field of quantitative genetics and has kept on being improved ever since. Recently, serious concerns about the possibility of attaining a satisfactory implementation of genetic variance decomposition with linkage disequilibrium (LD) and epistasis have been raised. In this paper we dissipate such doubts by completing the classical theory of variance decomposition into additive, dominance and epistasis components with LD.

Postural changes associated with ageing on the sensory organization test and the limits of stability in healthy subjects.

Objective: Acknowledgement of the age effects on postural control and balance is essential to differentiate between physiological changes and actual pathological alterations of the elderly. The aim of this study is to establish the age-related postural changes recorded by the Computerized Dynamic Posturography.

Material And Methods: 70 healthy individuals (35 males and 35 females) with an average age of 44.

Can environmental constraints determine random patterns of plant species co-occurrence?

Plant community ecologists use the null model approach to infer assembly processes from observed patterns of species co-occurrence. In about a third of published studies, the null hypothesis of random assembly cannot be rejected. When this occurs, plant ecologists interpret that the observed random pattern is not environmentally constrained - but probably generated by stochastic processes.

Age-adjusted normality patterns for posturography by Sway Star system.

Technological advances have led to the development of new measurement techniques that have improved the evaluation, diagnosis, and treatment of patients with vertigo, dizziness and balance disorders. The objective of this study was to propose population normality patterns, adjusted for age, for summary option (balance control summary, BCS) of Sway Star system. Prospective study involving 70 healthy individuals (average age 44.

Comparative study of computerized dynamic posturography and the SwayStar system in healthy subjects.

Conclusions: For healthy subjects, posturography and SwayStar™ results are basically comparable, when they are obtained under the same sensory stimulation conditions. However, the management of the information and the mathematical analyses in the two systems are not comparable.

Objectives: Postural control represents man's ability to maintain the center of pressures inside the limits of stability.