Choroidal hemangioma (CH) is a benign vascular tumor dependent on the choroid. Two types of lesions are distinguished: circumscribed (CCH), the most frequent variant, and diffuse (DCH), normally ...associated with Sturge-Weber syndrome. HCC appears as an orange mass that can present asymptomatically, however, when it produces symptoms, the most frequent is decreased visual acuity due to neurosensory retinal detachment. Due to its benign nature, only those that produce symptoms should be eligible for treatment. Knowledge of this pathology and its correct differential diagnosis is very relevant to establish the appropriate diagnosis and treatment, avoiding unnecessary treatments. There is currently a wide variety of multimodal diagnostic imaging tests that allow us to identify and adequately monitor this tumor. In addition, in recent years, there has been a change in the paradigm of the treatment of these tumors thanks to the use of photodinamic therapy, which has led to a significant improvement in the visual prognosis of these patients. This has been due to the use of photodynamic therapy as the treatment of choice for HCC.
To analyse the association between the thickness of the circumpapillary retinal nerve fibre layer (cpRNFL) and the thickness of the inner macular layers with the mean deviation of the visual field ...(MD) in children with primary congenital glaucoma (PCG).
A total of 41 children with PGC were included in the study. They all had a complete ophthalmological examination, including visual acuity, intraocular pressure, funduscopy, Octopus™ visual field, as well as circumpapillar and macular spectral domain optical coherence tomography (SD-OCT). SD-OCT with automated segmentation was used to measure the thicknesses and volumes of the macular retinal nerve fibre layer (mRNFL), ganglion cell layer (GCL), and inner plexiform layer.
The mean age was 11.2±3.86 years, and the mean MD was 8.85±6.76dB. The visual field was classified as normal in 46% of the patients, and 20% of the patients had a concentrical restriction of the visual field. A positive correlation was found between between the cup-to-disc ratio and the MD, r=0.51 (P=.004). The correlation between the MD and the cpRNFL was r=-0.63 (P<.001), and r=-0.69 (P<.001) with the GCL.
Inner macular layers thickness and cpRNFL thickness show a good correlation with the mean deviation of the visual field in children with primary congenital glaucoma.
The gravitational-wave signal GW150914 was first identified on September 14, 2015, by searches for short-duration gravitational-wave transients. These searches identify time-correlated transients in ...multiple detectors with minimal assumptions about the signal morphology, allowing them to be sensitive to gravitational waves emitted by a wide range of sources including binary black hole mergers. Over the observational period from September 12 to October 20, 2015, these transient searches were sensitive to binary black hole mergers similar to GW150914 to an average distance of ~ 600Mpc. In this paper, we describe the analyses that first detected GW150914 as well as the parameter estimation and waveform reconstruction techniques that initially identified GW150914 as the merger of two black holes. We find that the reconstructed waveform is consistent with the signal from a binary black hole merger with a chirp mass of ~ 30M? and a total mass before merger of ~ 70M? in the detector frame.
We compare GW150914 directly to simulations of coalescing binary black holes in full general relativity, including several performed specifically to reproduce this event. Our calculations go beyond ...existing semianalytic models, because for all simulations-including sources with two independent, precessing spins-we perform comparisons which account for all the spin-weighted quadrupolar modes, and separately which account for all the quadrupolar and octopolar modes. Consistent with the posterior distributions reported by Abbott et al. Phys. Rev. Lett. 116, 241102 (2016) (at the 90% credible level), we find the data are compatible with a wide range of nonprecessing and precessing simulations. Follow-up simulations performed using previously estimated binary parameters most resemble the data, even when all quadrupolar and octopolar modes are included. Comparisons including only the quadrupolar modes constrain the total redshifted mass Mz∈64 M⊙−82 M⊙, mass ratio 1/q=m2/m1∈0.6,1, and effective aligned spin χeff∈−0.3,0.2, where χeff=(S1/m1+S2/m2)·L^/M. Including both quadrupolar and octopolar modes, we find the mass ratio is even more tightly constrained. Even accounting for precession, simulations with extreme mass ratios and effective spins are highly inconsistent with the data, at any mass. Several nonprecessing and precessing simulations with similar mass ratio and χeff are consistent with the data. Though correlated, the components’ spins (both in magnitude and directions) are not significantly constrained by the data: the data is consistent with simulations with component spin magnitudes a1,2 up to at least 0.8, with random orientations. Further detailed follow-up calculations are needed to determine if the data contain a weak imprint from transverse (precessing) spins. For nonprecessing binaries, interpolating between simulations, we reconstruct a posterior distribution consistent with previous results. The final black hole’s redshifted mass is consistent with Mf,z in the range 64.0 M⊙−73.5 M⊙ and the final black hole’s dimensionless spin parameter is consistent with af=0.62–0.73. As our approach invokes no intermediate approximations to general relativity and can strongly reject binaries whose radiation is inconsistent with the data, our analysis provides a valuable complement to Abbott et al. Phys. Rev. Lett. 116, 241102 (2016).
Around the globe several observatories are seeking the first direct detection of gravitational waves (GWs). These waves are predicted by Einstein's general theory of relativity and are generated, for ...example, by black-hole binary systems. Present GW detectors are Michelson-type kilometre-scale laser interferometers measuring the distance changes between mirrors suspended in vacuum. The sensitivity of these detectors at frequencies above several hundred hertz is limited by the vacuum (zero-point) fluctuations of the electromagnetic field. A quantum technology--the injection of squeezed light--offers a solution to this problem. Here we demonstrate the squeezed-light enhancement of GEO 600, which will be the GW observatory operated by the LIGO Scientific Collaboration in its search for GWs for the next 3-4 years. GEO 600 now operates with its best ever sensitivity, which proves the usefulness of quantum entanglement and the qualification of squeezed light as a key technology for future GW astronomy.
We present results from a semicoherent search for continuous gravitational waves from the low-mass x-ray binary Scorpius X-1, using a hidden Markov model (HMM) to track spin wandering. This search ...improves on previous HMM-based searches of LIGO data by using an improved frequency domain matched filter, the J -statistic, and by analyzing data from Advanced LIGO's second observing run. In the frequency range searched, from 60 to 650 Hz, we find no evidence of gravitational radiation. At 194.6 Hz, the most sensitive search frequency, we report an upper limit on gravitational wave strain (at 95% confidence) of h95%0 = 3.47 × 10−25 when marginalizing over source inclination angle. This is the most sensitive search for Scorpius X-1, to date, that is specifically designed to be robust in the presence of spin wandering.
In Advanced LIGO, detection and astrophysical source parameter estimation of the binary black hole merger GW150914 requires a calibrated estimate of the gravitational-wave strain sensed by the ...detectors. Producing an estimate from each detector’s differential arm length control loop readout signals requires applying time domain filters, which are designed from a frequency domain model of the detector’s gravitational-wave response. The gravitational-wave response model is determined by the detector’s opto-mechanical response and the properties of its feedback control system. The measurements used to validate the model and characterize its uncertainty are derived primarily from a dedicated photon radiation pressure actuator, with cross-checks provided by optical and radio frequency references. We describe how the gravitational-wave readout signal is calibrated into equivalent gravitational-wave-induced strain and how the statistical uncertainties and systematic errors are assessed. Detector data collected over 38 calendar days, from September 12 to October 20, 2015, contain the event GW150914 and approximately 16 days of coincident data used to estimate the event false alarm probability. The calibration uncertainty is less than 10% in magnitude and 10° in phase across the relevant frequency band, 20 Hz to 1 kHz.
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