Disk Asymmetries Research Articles

First ALMA observations of the HD 105211 debris disc: A warm dust component close to a gigayear-old star

Most debris discs consist of a gas-poor, cold dust belt located tens to hundreds of astronomical units away from the host star. Many cold dust belts exhibit distinct structures attributed to the dynamic interaction of planetary systems. Moreover, in a few systems, additional warm components can be found closer to the central star, resembling the asteroid belt or zodiacal dust in our Solar System. In this work, we investigate the structure of the disc surrounding the nearby F2V star HD 105211 (eta Cru, HIP 59072), which has a warm excess (seen with Spitzer /MIPS at 24 mu m) and a potential asymmetry in the cold belt (seen in the Herschel /PACS images). We applied the CASA pipeline to obtain the ALMA 1.3 mm continuum images of HD105211. Then we constructed the spectral energy distribution (SED) of the system and performed Markov Chain Monte Carlo (MCMC) simulations to fit a model to the ALMA visibility data. To characterise the disc asymmetry, we analysed the ALMA images of two individual observation blocks (OB1, conducted on 2017 March 28, and OB2, conducted on 2018 May 9) and compared them to the previous Herschel images. Our modelling reveals that the disc around HD105211 is a narrow ring (23.6pm 4.6 au) with low eccentricity ($e positioned at a distance of 133.7pm 1.6 au from the central star, which differs from the broad disc ($100 au) starting at an inner edge of $87 au, inferred from the Herschel images. We found that both observation blocks show excess emission at the stellar position ($>3 while OB1 shows an offset between the star and the phase centre ($ and OB2 shows brightness clumps ($ We used a two-temperature model to fit the infrared SED and used the ALMA detection to constrain the warm component to a nearly pure blackbody model. The relatively low ratio of actual radius to blackbody radius of the HD105211 debris disc indicates that this system is depleted in small grains, which could indicate that it is dynamically cold. The excess emission from the stellar position suggests that there should be a warm millimetre-sized dust component close to the star, for which we suggest two possible origins: in situ asteroid belt or comet delivery.

Dual-band Observations of the Asymmetric Ring around CIDA 9A: Dead or Alive?

While the most exciting explanation of the observed dust asymmetries in protoplanetary disks is the presence of protoplanets, other mechanisms can also form the dust features. This paper presents dual-wavelength Atacama Large Millimeter/submillimeter Array observations of a large asymmetric dusty ring around the M-type star CIDA 9A. We detect a dust asymmetry in both 1.3 and 3.1 mm data. To characterize the asymmetric structure, a parametric model is used to fit the observed visibilities. We report a tentative azimuthal shift of the dust emission peaks between the observations at the two wavelengths. This shift is consistent with a dust trap caused by a vortex, which may be formed by an embedded protoplanet or other hydrodynamical instabilities, such as a dead zone. Deep high-spatial-resolution observations of dust and molecular gas are needed to constrain the mechanisms that formed the observed millimeter cavity and dust asymmetry in the protoplanetary disk around CIDA 9A.

SO and SiS Emission Tracing an Embedded Planet and Compact 12CO and 13CO Counterparts in the HD 169142 Disk

Planets form in dusty, gas-rich disks around young stars, while at the same time, the planet formation process alters the physical and chemical structure of the disk itself. Embedded planets will locally heat the disk and sublimate volatile-rich ices, or in extreme cases, result in shocks that sputter heavy atoms such as Si from dust grains. This should cause chemical asymmetries detectable in molecular gas observations. Using high-angular-resolution ALMA archival data of the HD 169142 disk, we identify compact SO J = 88 − 77 and SiS J = 19 − 18 emission coincident with the position of a ∼ 2 M Jup planet seen as a localized, Keplerian NIR feature within a gas-depleted, annular dust gap at ≈38 au. The SiS emission is located along an azimuthal arc and has a morphology similar to that of a known 12CO kinematic excess. This is the first tentative detection of SiS emission in a protoplanetary disk and suggests that the planet is driving sufficiently strong shocks to produce gas-phase SiS. We also report the discovery of compact 12CO and 13CO J = 3 − 2 emission coincident with the planet location. Taken together, a planet-driven outflow provides the best explanation for the properties of the observed chemical asymmetries. We also resolve a bright, azimuthally asymmetric SO ring at ≈24 au. While most of this SO emission originates from ice sublimation, its asymmetric distribution implies azimuthal temperature variations driven by a misaligned inner disk or planet–disk interactions. Overall, the HD 169142 disk shows several distinct chemical signatures related to giant planet formation and presents a powerful template for future searches of planet-related chemical asymmetries in protoplanetary disks.

On the origin of the anomalous gas, non-declining rotation curve, and disc asymmetries in NGC 253

ABSTRACT We present a multiwavelength (from far-ultraviolet to ${\rm H}\, \rm {\small I}$ emission) study of star formation feedback on the kinematics of the interstellar medium in the Sculptor galaxy, NGC 253. Its three well-known features (a disrupted stellar disc, a previously reported declining rotation curve, and anomalous ${\rm H}\, \rm {\small I}$ gas) are studied in a common context of disc asymmetries. About 170 h of on-source ATCA observations are collected and reduced into two versions of ${\rm H}\, \rm {\small I}$ data cubes of different angular resolution (30 arcsec/2 arcmin) and H i column density sensitivity (7.4 × 1019 cm−2/4 × 1018 cm−2). We separate the anomalous gas from the disc using a custom-made line profile fitting toolkit called FMG. Two star formation tracers (H α, FUV emission) are carefully processed and studied. We find that at R > 7.5 kpc, the star formation activity is strongly lopsided (SFRNE > SFRSW), and investigate several other properties (H α/FUV, dust temperature, stellar age, and disc stability parameters). We also find that the declining nature of the rotation curve perceived by previous studies is not intrinsic but a combined effect of kinematical asymmetries at R = 7.5–16 kpc. This is likely the consequence of star formation triggered outflow. The mass distribution and the time-scale of the anomalous gas also imply that it originates from gas outflow, which is perhaps caused by galaxy–galaxy interaction considering the crowded environment of NGC 253.

Morphologic aspects of the cervical (C3-C7) annular epiphysis: a skeletal study

BACKGROUND CONTEXTThe annular epiphysis (AE) is a peripheral ring of cortical bone that forms a secondary ossification center in the superior and inferior surfaces of vertebral bodies (VBs). The AE is the last ossification site in the skeleton, typically forming at about the 25th year of life. The AE functions jointly with vertebral endplates to anchor the intervertebral discs to the VBs. PURPOSETo establish accurate data on the sizes of the AE of the cervical spine (C3–C7); to compare the ratios between areas and the ratios of the AE to VBs; to compare the ratios between the superior and inferior VB surface areas; and to compare AE lengths between the posterior and anterior midsagittal areas. STUDY DESIGNMeasurement of 424 cervical spines (C3–C7) obtained from the skeletal collection of the Natural History Museum, Cleveland, Ohio (USA). METHODSThe sample was characterized by sex, age, and ethnic origin. The following measurements were recorded for each vertebra: (1) the surface area of the VBs and the AE, (2) the midsagittal anterior and posterior length of the AE, (3) the ratios between the AE and VB surface areas, and (4) the ratios between the superior and inferior disc surface areas. RESULTSThe study revealed that the AE and VBs in men were larger than in women. With age, the AE and VBs became larger; the ratio between the AE and VB surface was approximately 0.5 throughout the middle to lower cervical spine. The ratio of superior to inferior VBs was approximately 0.8. We found no differences between African Americans versus European Americans or between the anterior versus the posterior midsagittal length of the AE of the superior and inferior VBs. CONCLUSIONSThe ratios between the superior and inferior VBs are ≥0.8, and the ratio is the same for the entire middle to lower spine. Thus, the ratio between the superior and inferior VBs to the AE is ≥ 0.5. Men had larger AEs and VBs than women did, with both VBs and AEs becoming larger with age. Knowing these relationships are important so that orthopedic surgeons can best correct these issues in young patients (<25 years old) during spine surgery. The data reported here provide, for the first time, all the relevant sizes of the AE and VB. In future studies, AEs and VBs of living patients can be measured with computed tomography. CLINICAL SIGNIFICANCEThe ER location and function are clinically significant showing any changes during life that might lead to clinical issues related to intervertebral discs such as intervertebral disc asymmetry, disc herniation, nerve pressure, cervical osteophytes and neck pain.

The burst mode of accretion in massive star formation with stellar inertia

ABSTRACT The burst mode of accretion in massive star formation is a scenario linking the initial gravitational collapse of parent pre-stellar cores to the properties of their gravitationally unstable discs and of their accretion-driven bursts. In this study, we present a series of high-resolution 3D radiation-hydrodynamics numerical simulations for young massive stars formed out of collapsing $100{\rm M}_{\odot }$ molecular cores, spinning with several values of the ratio of rotational-to-gravitational energies $\beta =5{{-}9\ per cent}$. The models include the indirect gravitational potential caused by disc asymmetries. We find that this modifies the barycentre of the disc, causing significant excursions of the central star position, which we term stellar wobbling. The stellar wobbling slows down and protracts the development of gravitational instability in the disc, reducing the number and magnitude of the accretion-driven bursts undergone by the young massive stars, whose properties are in good agreement with that of the burst monitored from the massive protostar M17 MIR. Including stellar wobbling is therefore important for accurate modelling disc structures. Synthetic alma interferometric images in the millimetre waveband show that the outcomes of efficient gravitational instability such as spiral arms and gaseous clumps can be detected for as long as the disc is old enough and has already entered the burst mode of accretion.

The Role of Bending Films in the Lowest Instrumented Vertebra Selection in Adolescent Idiopathic Scoliosis Lenke Type 1A,B Based on Asymmetrical Disc Loading and Decompensation

Patients with severe adolescent idiopathic scoliosis (AIS) require instrumented spinal fusion surgery. The range of instrumented vertebra is still questioned, especially the selection of the lowest instrumented vertebra (LIV). This single institution retrospective consecutive study is to provide real-world data on outcomes. The study aims to assess whether bending films can determine the LIV. The method of determination of the lower tilted vertebra (LTV) is presented. The selection of the LTV was identified on standing PA (LTVs) and on bending X-rays (LTVb). Group A is a reference group, with less flexible curves. Groups B and C contained patients with more flexible curves. Group B covered patients with instrumentation ending at the LTVs and group C with shorter instrumentation ending at LTVb. The disc angle below the LIV was monitored for postoperative decompensation. Sixty-eight subjects with AIS Lenke 1A and 1B types underwent selective fusion. The decompensation criteria of the unfused disc below the fusion were determined as a wedging disk of &gt;5° of the Cobb angle. The patients were monitored during the postoperative period with 5.8 years average followup (minimum of 2 years). The rate of decompensation was comparable in groups A and B (31% and 33%, respectively). In contrast, the rate of decompensation was doubled in group C (60%). Caudal fusion shortening in more flexible curves according to bending films is associated with the first free disc asymmetry, which leads to decompensation below the fusion. This method should be considered in addition to other LIV selection criteria.

Modeling the arc and ring structures in the HD 143006 disk

Rings and asymmetries in protoplanetary disks are considered as signposts of ongoing planet formation. In this work, we conduct three-dimensional radiative transfer simulations to model the intriguing disk around HD 143006 that has three dust rings and a bright arc. A complex geometric configuration, with a misaligned inner disk, is assumed to account for the asymmetric structures. The two-dimensional surface density is constructed by iteratively fitting the ALMA data. We find that the dust temperature displays a notable discontinuity at the boundary of the misalignment. The ring masses range from 0.6 to 16Mearth that are systematically lower than those inferred in the younger HL Tau disk. The arc occupies nearly 20% of the total dust mass. Such a high mass fraction of dust grains concentrated in a local region is consistent with the mechanism of dust trapping into vortices. Assuming a gas-to-dust mass ratio of 30 that is constant throughout the disk, the dense and cold arc is close to the threshold of being gravitationally unstable, with the Toomre parameter Q~1.3. Nevertheless, our estimate of Q relies on the assumption for the unknown gas-to-dust mass ratio. Adopting a lower gas-to-dust mass ratio would increase the inferred Q value. Follow-up high resolution observations of dust and gas lines are needed to clarify the origin of the substructures.

Feeding a Protostar with 10 000 au Scale Streamers

Dense cores are the places where stars are formed within the supersonic Molecular Clouds. These dense regions (n ∼ 105 cc) are cold (T ∼10 K) and display subsonic levels of turbulence (Mach ∼ 0.5), and represent the initial conditions for both star and disk formation. However, the influence of the parental core properties on the disk formation process is still not well constrained, and it is therefore crucial to study dense cores with interferometers to better understand the dense core and disk connection. We present NOEMA observations of a Class 0 object, which has been suggested to present a disk under gravitational instability (GI) (asymmetrical features in ALMA high resolution dust continuum emission). Our new data reveal a previously unseen large scale (∼10,000 au, or 33′′) streamer of fresh gas from the surrounding dense core down to the disk scales. This streamer is almost perpendicular to the outflow, and it contains material with subsonic levels of turbulence, and therefore unperturbed by the outflow. Based on the total mass in the streamer and the free-fall timescale, we estimate infall rates to the disk scales, which clearly show that accretion via streamer can have an important role in the disk formation. Moreover, these results show that previously observed disk asymmetries could also be driven by large scale asymmetric flows instead of GI. This result shows the power and importance of studying dense cores with interferometers to provide a complete and proper picture of star and disk formation.

High-resolution ALMA observations of V4046 Sgr: a circumbinary disc with a thin ring

ABSTRACT The nearby V4046 Sgr spectroscopic binary hosts a gas-rich disc known for its wide cavity and dusty ring. We present high resolution (∼20 mas or 1.4 au) ALMA observations of the 1.3 mm continuum of V4046 Sgr which, combined with SPHERE–IRDIS polarised images and a well-sampled spectral energy distribution (SED), allow us to propose a physical model using radiative transfer predictions. The ALMA data reveal a thin ring at a radius of 13.15 ± 0.42 au (Ring13), with a radial width of 2.46 ± 0.56 au. Ring13 is surrounded by a ∼10 au-wide gap, and it is flanked by a mm-bright outer ring (Ring24) with a sharp inner edge at 24 au. Between 25 and ∼35 au the brightness of Ring24 is relatively flat and then breaks into a steep tail that reaches out to ∼60 au. In addition, central emission is detected close to the star which we interpret as a tight circumbinary ring made of dust grains with a lower size limit of 0.8 mm at 1.1 au. In order to reproduce the SED, the model also requires an inner ring at ∼5 au (Ring5) composed mainly of small dust grains, hiding under the IRDIS coronagraph, and surrounding the inner circumbinary disc. The surprisingly thin Ring13 is nonetheless roughly 10 times wider than its expected vertical extent. The strong near-far disc asymmetry at 1.65 $\rm{\mu m}$ points at a very forward-scattering phase function, and requires grain radii of no less than 0.4 $\rm{\mu m}$.

New Families in our Solar Neighborhood: Applying Gaussian Mixture Models for Objective Classification of Structures in the Milky Way and in Simulations

AbstractThe standard picture of galaxy formation motivates the decomposition of the Milky Way into 3–4 stellar populations with distinct kinematic and elemental abundance distributions: the thin disk, thick disk, bulge, and stellar halo. To test this idea, we construct a Gaussian mixture model (GMM) for both simulated and observed stars in the solar neighborhood, using measured velocities and iron abundances (i.e., an augmented Toomre diagram) as the distributions to be decomposed. We compare results for the Gaia−APOGEE DR16 crossmatch catalog of the solar neighborhood with those from a suite of synthetic Gaia−APOGEE crossmatches constructed from FIRE-2 cosmological simulations of Milky Way mass galaxies. We find that in both the synthetic and real data, the best-fit GMM usesfiveindependent components, some of whose properties resemble the standard populations predicted by galaxy formation theory. Two components can be identified unambiguously as the thin disk and another as the halo. However, instead of a single counterpart to the thick disk, there are three intermediate components with different age and alpha abundance distributions (although these data are not used to construct the model). We use decompositions of the synthetic data to show that the classified components indeed correspond to stars with different origins. By analogy with the simulated data, we show that our mixture model of the real Gaia−APOGEE crossmatch distinguishes the following components: (1) a classic thin disk of young stars on circular orbits (46%), (2) thin disk stars heated by interactions with satellites (22%), (3, 4) two components representing the velocity asymmetry of the alpha-enhanced thick disk (27%), and (5) a stellar halo consistent with early, massive accretion (4%).

A holistic review of a galactic interaction

ABSTRACT Our situation as occupants of the Milky Way (MW) Galaxy, bombarded by the Sagittarius dwarf galaxy, provides an intimate view of physical processes that can lead to the dynamical heating of a galactic disc. While this evolution is instigated by Sagittarius, it is also driven by the intertwined influences of the dark matter halo and the disc itself. We analyse an N-body simulation following a Sagittarius-like galaxy interacting with a MW-like host to disentangle these different influences during the stages of a minor merger. The accelerations in the disc plane from each component are calculated for each snapshot in the simulation, and then decomposed into Fourier series on annuli. The analysis maps quantify and compare the scales of the individual contributions over space and through time: (i) accelerations due to the satellite are only important around disc passages; (ii) the influence around these passages is enhanced and extended by the distortion of the dark matter halo; (iii) the interaction drives disc asymmetries within and perpendicular to the plane and the self-gravity of these distortions increase in importance with time eventually leading to the formation of a bar. These results have interesting implications for identifying different influences within our own Galaxy. Currently, Sagittarius is close enough to a plane crossing to search for localized signatures of its effect at intermediate radii, the distortion of the MW’s dark matter halo should leave its imprint in the outer disc and the disc’s own self-consistent response is sculpting the intermediate and inner disc.

Deployed Dimensions of the GORE® CARDIOFORM ASD Occluder as Function of Defect Size.

The GORE® CARDIOFORM ASD occluder (ASDO) is approved for closure of ASDs up to 35mm diameter. With an adaptable central waist, each device size is suitable over a range of defect diameters. Understanding deployed dimensions across various defect sizes will assist operators. Therefore, this study investigates the deployed dimensions of the ASDO as a function of defect size. A 2-mm-thick ASD model with circular defects ranging from 5 to 35mm was 3D printed. Diameter, width, and left-right disc diameter were measured by fluoroscopy after ASDO devices were deployed in applicable defects. Linear regression evaluated relationships between device size, defect size, and deployed dimensions. Six ASDOs of each size (27, 32, 37, 44, and 48 mm) were deployed in all applicable defects. There was significant ASDO size-defect size interaction in determining deployed ASDO diameter. Diameter was positively associated with defect size for 48-mm (B = 0.13, p < 0.001) and 44-mm (B = 0.11, p < 0.001) ASDOs, while no association was seen for 27-mm, 32-mm, or 37-mm ASDOs. No such interaction existed for deployed width or left-right disc difference. Controlling for ASDO size, width (B = -0.12, p < 0.001) and left-right disc difference (B = -0.06, p < 0.001) were negatively associated with defect size. In smaller defects, the 44-mm and 48-mm ASDOs display progressive diameter foreshortening, and all devices display progressive increase in width and left-right disc asymmetry. Anticipating the degree of diameter foreshortening may be critical when attempting closure of fenestrated lesions and/or in patients with limited total atrial septal length.

Stability of asymmetric rotors with asymmetric flexible disks

The presented work examines the dynamic behavior of an asymmetric rotor with asymmetric flexible disk, contrary to previous works on the subject, where researchers examined the effect of either rigid disk asymmetry or disk flexibility at a time. Account for the asymmetry of flexible disk in rotors constitutes the new contribution in this work. The suggested mathematical model combines Lagrangian approach with Rayleigh–Ritz method to derive the governing equations of motion of the rotor. Account for asymmetry of the flexible disk results in complicated and lengthy expressions for the potential and kinetic energies of the rotor, required in the adopted Lagrangian approach. Using symbolic computation simplified the derivation of the governing equations of motion with constant coefficients in terms of rotating coordinate system. Solution of the resulting eigenvalue problem provided numerical results for rotors with symmetric and asymmetric flexible disks, required to assess the effect of disk flexibility and asymmetry on the resulting frequencies and stability boundaries of the examined rotor system.

The asymmetric inner disk of the Herbig Ae star HD 163296 in the eyes of VLTI/MATISSE: evidence for a vortex?

Context. A complex environment exists in the inner few astronomical units of planet-forming disks. High-angular-resolution observations play a key role in our understanding of the disk structure and the dynamical processes at work. Aims. In this study we aim to characterize the mid-infrared brightness distribution of the inner disk of the young intermediate-mass star HD 163296 from early VLTI/MATISSE observations taken in the L- and N-bands. We put special emphasis on the detection of potential disk asymmetries. Methods. We use simple geometric models to fit the interferometric visibilities and closure phases. Our models include a smoothed ring, a flat disk with an inner cavity, and a 2D Gaussian. The models can account for disk inclination and for azimuthal asymmetries as well. We also perform numerical hydrodynamical simulations of the inner edge of the disk. Results. Our modeling reveals a significant brightness asymmetry in the L-band disk emission. The brightness maximum of the asymmetry is located at the NW part of the disk image, nearly at the position angle of the semimajor axis. The surface brightness ratio in the azimuthal variation is 3.5 ± 0.2. Comparing our result on the location of the asymmetry with other interferometric measurements, we confirm that the morphology of the r &lt; 0.3 au disk region is time-variable. We propose that this asymmetric structure, located in or near the inner rim of the dusty disk, orbits the star. To find the physical origin of the asymmetry, we tested a hypothesis where a vortex is created by Rossby wave instability, and we find that a unique large-scale vortex may be compatible with our data. The half-light radius of the L-band-emitting region is 0.33 ±0.01 au, the inclination is 52°−7°+5°, and the position angle is 143° ± 3°. Our models predict that a non-negligible fraction of the L-band disk emission originates inside the dust sublimation radius for μm-sized grains. Refractory grains or large (≳10 μm-sized) grains could be the origin of this emission. N-band observations may also support a lack of small silicate grains in the innermost disk (r ≲ 0.6 au), in agreement with our findings from L-band data.

Impact of binocular integrated visual field defects on healthy related quality of life in glaucoma.

To investigate the impact of different types of binocular integrated visual field defects on the quality of life in glaucoma.Ninety-six patients with primary glaucoma were divided into 5 groups with 25, 24, 11, 15, and 21 patients according to types of the binocular integrated visual field (BVF) defects. The criteria for BVF grouping included mild visual field defect in binocular eyes, mild visual field defect in 1 eye and moderate or advanced defect in the other, moderate and non-overlapping visual field defect in both eyes, overlapping and moderate visual field defect in binocular eyes, and severe defect in both eyes, respectively. The visual field (VF) evaluation was based on H-P-A visual field grading system. Visual acuity, visual field tests and Glaucoma Quality of Life-15 Questionnaire (GQL-15) were performed for enrolled patients, and binocular visual field results were integrated. The changes and correlations of the Visual field index values and quality of life scores were compared among the 5 groups. The main factors affecting the quality of life in glaucoma were analyzed by multiple regression analysis.The best binocular integrated visual field index (BVFI) and optimal quality of life were observed in group A. The BVFI of group B was better than that of group C or group D, but the peripheral vision glare and dark adaptation were worse. No significant difference was noted between group C and group D in terms of BVFI. However, the glare and dark adaptation in group C were better than that in group D. The BVFI was the lowest and the quality of life was the worst in group E. In all, BVFI and decibels (dB) values were negatively correlated with GQL-15 scores and positively correlated with patients’ quality of life.Binocular integrated visual field accurately reflects the visual function in glaucoma. Higher binocular integrated visual field indices represent a better quality of life for patients with glaucoma. Mild to moderate synchronous or complementary binocular VF defects had a slight effect on the quality of life, while severe and non-compensated VF loss significantly impacts on quality of life in glaucoma patients.

Appearance of stagnation points in skyrmion-based STNO due to geometric asymmetries

In this work, we investigated the motion of a skyrmion on an asymmetric disk induced by an out-of-plane spin-polarized current. The appearance of two movement regimes based on disk asymmetry was reported. A tangential component is induced in the restoration force by the asymmetry, which in turn competes with the tangential component of the STT force. For a disk with low asymmetry, a precession motion was obtained and for a disk with high asymmetry, a convergent movement to points of stagnation was reported. These regimes can be understood as a result of competition between restoration forces and STT forces.

Prevalence and risk factors of diabetic retinopathy in diabetic patients

In China, there is a significant lack of awareness of diabetes and its complications. Screening of diabetic retinopathy has important for early detection, prevention, and treatment. This large, cross-sectional study aimed to characterize the demographic, physical, serological, and ocular characteristics of subjects with diabetes mellitus in Shijiazhuang, China. It also aimed to associate these characteristics with the presence of diabetic retinopathy.From May 2, 2018 to August 25, 2019, under diabetes care program, the diabetic patients (n = 1008) were subjected to standardized questionnaires to collect demographical characteristics. Also, telescreens and laboratory tests were performed for the enrolled patients. Multivariate logistic regression analysis was used to evaluate factors associated with diabetic retinopathy.Forty percent of diabetics in its population had some form of diabetic retinopathy. Diabetic retinopathic patients were likely to be elder (P = .0003), men (P = .018), hypertensive (P < .0001), and had high body mass index (P < .0001), metabolic abnormalities, and longer duration of diabetes (P < .0001). Higher intraocular pressure (P = .0008), fasting blood glucose (P < .0001), serum total cholesterol (P < .0001), serum triglyceride (P = .0006), % glycated hemoglobin (HbA1c) (P < .0001), and disc asymmetry including cup–disc ratio (P = .041) reported in patients with diabetic retinopathy. Age (P = .049), male sex (P = .048), hypertension (P = .048), duration of diabetes (P = .012), diabetic neuropathy (P = .048), diabetic nephropathy (P = .048), diabetic foot ulcer (P = .041), foot amputation (P = .042), fasting blood glucose (P = .022), serum total cholesterol (P = .028), serum triglyceride (P = .035), and HbA1c (P = .042) were associated with diabetic retinopathy.Diabetic retinopathy was the most common ocular fundus disease in diabetic patients. Also, aging, the other comorbidities, and metabolic syndrome are associated with diabetic retinopathy.Level of Evidence: III.

Unilateral Nevus of Ota with Palatal and Optic Disc Pigmentation with Coincidental Preauricular Tag- A Case Report

Nevus of Ota also known as oculodermal melanosis presents as hyperpigmentation of face involving ophthalmic and maxillary branches of trigeminal nerve associated with ocular hyperpigmentation. It is due to confinement of melanocytes in the dermis. Most commonly it is unilateral but sometimes it may have bilateral presentation. Typically, it presents at birth but can also be an acquired condition. Frequently seen in Japanese and rarely in Indian subcontinent. It has more predilection towards females. Less frequently, hyperpigmentation is seen in other sites like oral mucosa, tympanum and nasal mucosa. These patients are at high risk of developing glaucoma and malignancy. The author reported a case of 12-year-old male child with unilateral pigmentation of left side face involving forehead, periorbital and cheek, along with ocular pigmentation. Hyperpigmentation of conjunctiva, iris and angles is present in left eye with intraocular pressure being normal in both eyes. Fundus showing optic disc pigmentation in the left eye with cup disc asymmetry in both eyes. Child has coexistent preauricular tag on the left side.

Mapping the Galactic Disk with the LAMOST and Gaia Red Clump Sample. III. A New Velocity Substructure and Time Stamps of the Galactic Disk Asymmetry in the Disk between 12 and 15 kpc

Abstract We investigate the three-dimensional asymmetrical kinematics and present time stamps of the Milky Way disk between Galactocentric distances of R = 12 and 15 kpc, using red clump stars selected from the LAMOST Galactic survey, also with proper motion measurements provided by the Gaia DR2. We discover velocity substructure above the Galactic plane corresponding to a density dip found recently (“South-middle opposite” density structure [R ∼ 12–15 kpc, Z ∼ 1.5 kpc] discovered in Wang et al.) in the radial and azimuthal velocity. For the vertical velocity, we detect clear vertical bulk motions or bending mode motions, which has no clear North–South asymmetry corresponding to the in-plane asymmetrical features. In the subsample of stars with different ages, we find that there is little temporal evolution of the in-plane asymmetry from 0 to 14 Gyr, which means the structure is possibly sensitive to the perturbations in almost cosmic time. We propose that the possible scenario of this asymmetric velocity structure is caused by the mechanisms generated in-plane, rather than vertical perturbations.