Probability boxes, also called p-boxes, correspond to sets of probability distributions bounded by a pair distribution functions. They belong the class models known as imprecise probabilities. One central issues related probabilities is intervals values corresponding expectations random variables, and in particular interval bounds. In general, these are reached at extreme points credal sets, wh...

The determination of the relative numbers of different cone types in the human retina is fundamental to our understanding of visual sensitivity and color vision; yet direct measurement which provide this basic information have not previously been made for all cone types. Here we present a model which links the detection of a test light of small dimension to the number of cones contributing to d...

PURPOSE To characterize photoreceptor structure and mosaic integrity in subjects with ​RGS9- and R9AP-associated retinal dysfunction (bradyopsia) and compare to previous observations in other cone dysfunction disorders such as oligocone trichromacy. DESIGN Observational case series. METHODS setting: Moorfields Eye Hospital (United Kingdom) and Medical College Wisconsin (USA). STUDY POPULA...

PURPOSE To test the hypothesis that Regulator of G-protein Signaling 9 (RGS9-1) is necessary for the normal inactivation of retinal cones. METHODS Mice having the gene RGS9-1 inactivated in both alleles (RGS9-1 -/-) were tested between the ages 8-10 weeks with electroretinographic (ERG) protocols that isolate cone-driven responses. Immunohistochemistry was performed with a primary antibody ag...

We study the quantitative relationship between the cones of nonnegative polynomials, cones of sums of squares and cones of sums of powers of linear forms. We derive bounds on the volumes (raised to the power reciprocal to the ambient dimension) of compact sections of the three cones. We show that the bounds are asymptotically exact if the degree is fixed and number of variables tends to infinit...

In the mouse retina, three different types of photoreceptors provide input to 14 bipolar cell (BC) types. Classically, most BC types are thought to contact all cones within their dendritic field; ON-BCs would contact cones exclusively via so-called invaginating synapses, while OFF-BCs would form basal synapses. By mining publically available electron microscopy data, we discovered interesting v...