Gravitational waves from extreme mass-ratio inspirals in Dynamical Chern-Simons gravity

Dynamical Chern-Simons gravity is an interesting extension of General Relativity, which finds its way in many different contexts, including string theory, cosmological settings and loop quantum gravity. In this theory, the gravitational field is coupled to a scalar field by a parity-violating term, which gives rise to characteristic signatures. Here we investigate how Chern-Simons gravity would affect the quasi-circular inspiralling of a small, stellar-mass object into a large non-rotating supermassive black hole, and the accompanying emission of gravitational and scalar waves. We find the relevant equations describing the perturbation induced by the small object, and we solve them through the use of Green's function techniques. Our results show that for a wide range of coupling parameters, the Chern-Simons coupling gives rise to an increase in total energy flux, which translates into a fewer number of gravitational-wave cycles over a certain bandwidth. For space-based gravitational-wave detectors such as LISA, this effect can be used to constrain the coupling parameter effectively.Comment: RevTex4, 18 pages, 7 figures, 1 tabl

Optical Coherence Tomography May Be Used to Predict Visual Acuity in Patients with Macular Edema

Purpose. To determine whether the volume of retinal tissue passing between the inner and outer retina in macular edema could be used as an indicator of visual acuity. Methods. Diabetic and uveitic patients with cystoid macular edema (81 subjects, 129 eyes) were recruited. Best corrected logMAR visual acuity and spectral optical coherence tomography (OCT/SLO; OTI, Toronto, ONT, Canada) were performed in all patients. Coronal OCT scans obtained from a cross section of the retina between the plexiform layers were analyzed with a grid of five concentric radii (500, 1000, 1500, 2000, and 2500 μm centered on the fovea). The images were analyzed to determine the amount of retinal tissue present within each ring. A linear regression model was developed to determine the relationship between tissue integrity and logMAR visual acuity. Results. A linear relationship between tissue integrity and VA was demonstrated. The volume of retinal tissue between the plexiform layers in rings 1 and 2 (up to 1000 μm from the foveal center) predicted 80% of visual acuity. By contrast, central macular thickness within the central 1000 μm predicted only 14% of visual acuity. Conclusions. This study showed that the cross-sectional area of retinal tissue between the plexiform layers in cystoid macular edema, as imaged by OCT, is the best indicator of visual function at baseline. Further prospective treatment trials are needed to investigate this parameter as a predictor of visual outcome after intervention

Antidepressant exposure in pregnancy and child sensorimotor and visuospatial development

Motor development underlies many aspects of education and learning. There has been uncertainty about the impact of exposure of antidepressant medication in pregnancy on child motor outcomes. This paper examines whether exposure to antidepressants in utero increases the risk of poorer motor development in two areas: sensorimotor and visuospatial processing. Data were obtained from 195 women and children across 3 groups: women with untreated depression in pregnancy, women treated with antidepressants and control women. Data were collected across pregnancy, postpartum and until 4 years for mother and child. Maternal depression was established at baseline with the Structured Clinical Interview for DSM-IV. Antidepressant exposure, including type, dose and timing, was measured through repeated self-report across pregnancy and the postpartum, medical records at delivery and in cord blood samples collected at delivery. Child sensorimotor and visuospatial outcomes were assessed at 4 years of age with four subtests from the NEPSY-II. Our study found for sensorimotor development, visuomotor precision completion time was associated with better performance for antidepressant exposed children compared to those with mothers with untreated depression. Yet another measure of sensorimotor development, motor manual sequences, was poorer in those exposed to antidepressants. One subtest for visuospatial processing, block construction, was associated with poorer performance in antidepressant-exposed children who had poor neonatal adaptation and those exposed to a higher dose of antidepressant. These findings suggest an inconsistent association between sensorimotor development and antidepressant use in pregnancy. However, the findings for visuospatial processing would support further exploration of antidepressant associated poor neonatal adaption and later motor development

Volatiles in High Titanium Basalts from the Moon

No abstract availabl

Bilateral symmetry breaking in a nonlinear Fabry-Perot cavity exhibiting optical tristability

We show the existence of a region in the parameter space that defines the field dynamics in a Fabry-Perot cylindrical cavity, where three output stable stationary states of the light are possible for a given localized incident field. Two of these states do not preserve the bilateral (i.e. left-right) symmetry of the entire system. These broken-symmetry states are the high-transmission nonlinear modes of the system. We also discuss how to excite these states.Comment: 5 pages, 5 figure