Self-Inverse and Exchangeable Random Variables

A random variable Z will be called self-inverse if it has the same distribution as its reciprocal 1/Z. It is shown that if Z is defined as a ratio, X/Y, of two rv's X and Y (with Pr[X=0]=Pr[Y=0]=0), then Z is self-inverse if and only if X and Y are (or can be chosen to be) exchangeable. In general, however, there may not exist iid X and Y in the ratio representation of Z.Comment: Statistics and Probability Letters (to appear, 6 pages

Distributions generated by perturbation of symmetry with emphasis on a multivariate skew tt distribution

A fairly general procedure is studied to perturbate a multivariate density satisfying a weak form of multivariate symmetry, and to generate a whole set of non-symmetric densities. The approach is general enough to encompass a number of recent proposals in the literature, variously related to the skew normal distribution. The special case of skew elliptical densities is examined in detail, establishing connections with existing similar work. The final part of the paper specializes further to a form of multivariate skew $t$ density. Likelihood inference for this distribution is examined, and it is illustrated with numerical examples.Comment: full-length version of the published paper, 31 pages with 9 figure

Alien Registration- Jones, Arnold (Fort Fairfield, Aroostook County)

https://digitalmaine.com/alien_docs/36387/thumbnail.jp

Two-dimensional topological gravity and equivariant cohomology

In this paper, we examine the analogy between topological string theory and equivariant cohomology. We also show that the equivariant cohomology of a topological conformal field theory carries a certain algebraic structure, which we call a gravity algebra. (Error on page 9 corrected: BRS current contains total derivatives.)Comment: 18 page

Mechanical Faraday effect for orbital angular momentum-carrying beams

When linearly polarised light is transmitted through a spinning window, the plane of polarisation is rotated. This rotation arises through a phase change that is applied to the circularly polarised states corresponding to the spin angular momentum (SAM). Here we show an analogous effect for the orbital angular momentum (OAM), where a differential phase between the positive and negative modes (±ℓ) is observed as a rotation of the transmitted image. For normal materials, this rotation is on the order of a micro radian, but by using a slow-light medium, we show a rotation of a few degrees. We also note that, within the bounds of our experimental parameters, this rotation angle does not exceed the scale of the spatial features in the beam profile

Taxonomy of the spring dwelling amphipod Synurella ambulans (Crustacea: Crangonyctidae) in West Russia: with notes on its distribution and ecology

This study deals with taxonomic problems of the semi-subterranean crangonyctid amphipod Synurella ambulans (F. Müller, 1846), well-known from various freshwater habitats in Europe. The taxonomy of the species S. ambulans and the generic diagnosis for the genus Synurella are revised. A new synonymy is proposed: Synurella ambulans (F. Müller, 1846) = Synurella ambulans meschtscherica Borutzky, 1929, syn. nov. The affinity with the related groups, distribution and ecology of the species are examined

Axially Symmetric U-O-Ln and U-O-U containing molecules from the control of uranyl reduction with simple f-block halides

The reduction of UVI uranyl halides or amides with simple LnII or UIII salts forms highly symmetric, linear, oxo-bridged trinuclear UV/LnIII/UV, LnIII/UIV/LnIII, and UIV/UIV/UIV complexes or linear LnIII/UV polymers depending on the stoichiometry and solvent. The reactions can be tuned to give the products of one- or two-electron uranyl reduction. The reactivity and magnetism of these compounds are discussed in the context of using a series of strongly oxo-coupled homo- and heterometallic poly(f-block) chains to better understand fundamental electronic structure in the f-block.JRC.G.I.5-Advanced Nuclear Knowledg

Penicillin in the Treatment of an Open Joint

On the evening of April 18, 1947 an albino 3 year old mare was entered at the Stange Memorial Clinic with the history that the right hock had been cut on a fence the morning of April 17, 1947. The veterinarians who first attended the animal had applied a pressure bandage infiltrated with powdered sulfanilamide to control hemorrhage and administered tetanus antitoxin

Distributions that are both log-symmetric and R-symmetric

Two concepts of symmetry for the distributions of positive random variables Y are log-symmetry (symmetry of the distribution of logY) and R-symmetry. In this paper, we characterise the distributions that have both properties, which we call doubly symmetric. It turns out that doubly symmetric distributions constitute a subset of those distributions that are moment-equivalent to the lognormal distribution. They include the lognormal, some members of the Berg/Askey class of distributions, and a number of others for which we give an explicit construction (based on work of A.J. Pakes) and note some properties; Stieltjes classes, however, are not doubly symmetric