PACHYCHOROID: an inherited condition?

PURPOSE: Thick choroid (pachychoroid) is associated with central serous chorioretinopathy (CSC), but whether pachychoroid is inherited is unknown. METHODS: In a prospective observational study, first- or second-degree relatives (16 individuals) of 5 patients with CSC had refraction and visual acuity measurement, fundus examination, nonmydriatic photography, and autofluorescence photography. Eyes were graded using the following criteria: 0: normal fundus and autofluorescence photography, 1: focal retinal pigment epithelium hyperfluorescence and/or hypofluorescence and/or retinal pigment epithelial detachment, 2: CSC or diffuse retinal epitheliopathy. Choroid thickness was measured by enhanced depth imaging mode on optical coherence tomography. RESULTS: Considering 395 μm as the threshold limit for normal subfoveal choroidal thickness, 50% of the eyes from relatives had a thick choroid. Nine eyes of Grade 0 (28%) with an isolated pachychoroid would thus have been considered normal, if choroidal thickness was not included as a screening sign predisposing for CSC. CONCLUSION: Our observation suggests that pachychoroid could be an inherited condition with potentially a dominant transmission mode. Its inclusion in the phenotype of CSC for genetic studies should be considered

Detailed studies of non-linear magneto-optical resonances at D1 excitation of Rb-85 and Rb-87 for partially resolved hyperfine F-levels

Experimental signals of non-linear magneto-optical resonances at D1 excitation of natural rubidium in a vapor cell have been obtained and described with experimental accuracy by a detailed theoretical model based on the optical Bloch equations. The D1 transition of rubidium is a challenging system to analyze theoretically because it contains transitions that are only partially resolved under Doppler broadening. The theoretical model took into account all nearby transitions, the coherence properties of the exciting laser radiation, and the mixing of magnetic sublevels in an external magnetic field and also included averaging over the Doppler profile. Great care was taken to obtain accurate experimental signals and avoid systematic errors. The experimental signals were reproduced very well at each hyperfine transition and over a wide range of laser power densities, beam diameters, and laser detunings from the exact transition frequency. The bright resonance expected at the F_g=1 --> F_e=2 transition of Rb-87 has been observed. A bright resonance was observed at the F_g=2 --> F_e=3 transition of Rb-85, but displaced from the exact position of the transition due to the influence of the nearby F_g=2 --> F_e=2 transition, which is a dark resonance whose contrast is almost two orders of magnitude larger than the contrast of the bright resonance at the F_g=2 --> F_e=3 transition. Even in this very delicate situation, the theoretical model described in detail the experimental signals at different laser detunings.Comment: 11 pages, 9 figure

A quantitative analysis of measures of quality in science

Condensing the work of any academic scientist into a one-dimensional measure of scientific quality is a difficult problem. Here, we employ Bayesian statistics to analyze several different measures of quality. Specifically, we determine each measure's ability to discriminate between scientific authors. Using scaling arguments, we demonstrate that the best of these measures require approximately 50 papers to draw conclusions regarding long term scientific performance with usefully small statistical uncertainties. Further, the approach described here permits the value-free (i.e., statistical) comparison of scientists working in distinct areas of science.Comment: 11 pages, 8 figures, 4 table

Formation and evolution of clumpy tidal tails around globular clusters

We present some results of numerical simulations of a globular cluster orbiting in the central region of a triaxial galaxy on a set of 'loop' orbits. Tails start forming after about a quarter of the globular cluster orbital period and develop, in most cases, along the cluster orbit, showing clumpy substructures as observed, for example, in Palomar 5. If completely detectable, clumps can contain about 7,000 solar masses each, i.e. about 10% of the cluster mass at that epoch. The morphology of tails and clumps and the kinematical properties of stars in the tails are studied and compared with available observational data. Our finding is that the stellar velocity dispersion tends to level off at large radii, in agreement to that found for M15 and Omega Centauri.Comment: LaTeX 2e, uses AASTeX v5.x, 40 pages with 18 figures. Submitted to The Astronomical Journa

The Mangum terrace

Caption title.Digitized 2007 AES MoU

The study of bronze statuettes with the help of neutron-imaging techniques

Until recently fabrication techniques of Renaissance bronzes have been studied only with the naked eye, microscopically, videoscopically and with X-radiography. These techniques provide information on production techniques, yet much important detail remains unclear. As part of an interdisciplinary study of Renaissance bronzes undertaken by the Rijksmuseum Amsterdam, neutron-imaging techniques have been applied with the aim of obtaining a better understanding of bronze workmanship during the Renaissance period. Therefore, an explanation of the fabrication techniques is given to better understand the data collected by these neutron-imaging techniques. The data was used for tomography studies, which reveal hidden aspects that could not at all or scarcely be seen using X-radiography. For this specific study, the representative bronze ‘Hercules Pomarius’ of Willem van Tetrode (ca 1520–1588) has been examined, along with 20 other Renaissance bronzes from the Rijksmuseum collection