Large Disk Research Articles

Epiretinal large disc of blue-stained lyophilized amniotic membrane to treat complex macular holes: a 1-year follow-up.

To report the long-term outcomes of large diameter epiretinal lyophilized amniotic membranes (lAMs) in recurrent or persistent macular holes (MHs) with or without rhegmatogenous retinal detachment (RRD), in a prospective interventional case series. Ten eyes of 10 patients underwent pars plana vitrectomy for MH-associated RRD (n = 5) or persistent MH without RRD (n = 5), in a university Hospital. A 3 or 4 mm diameter disc of lAM, stained with 0.06% trypan blue, was inserted with a catheter through a sclerotomy and positioned over the MH. Gas or silicone-oil tamponade was used. At 1 year, the main outcome was anatomic success defined as complete MH closure. Secondary outcomes were best corrected visual acuity (BCVA) recovery, changes in ellipsoid zone (EZ) and external limiting membrane (ELM) defects, complications. Mean follow-up was 13.8 ± 2.9 months (range, 12-18). Mean baseline data were minimum and maximum diameters, respectively, 945 ± 330 and 1507 ± 717 μm; axial length 26.58 ± 3.38 mm; and number of prior surgeries 1.4 ± 0.96. At 1 year, anatomic success was achieved in eight eyes (80%), and two had reduced diameter of MH. All RRDs were reattached without recurrence. Mean logMAR BCVA improved from 1.92 ± 0.58 to 1.17 ± 0.57 (p < 0.001), with nine eyes (90%) achieving ≥0.3 logMAR improvement. Mean EZ and ELM defects decreased (p = 0.004, p = 0.003, respectively). Postoperative complications were RRD (n = 1) reattached by subsequent surgery, lAM slightly retracted under silicone (n = 1), foveal atrophy after early lAM displacement (n = 1). A 1-year follow-up highlighted that epiretinal large discs of blue-stained lAM can help safely close refractory MHs, and provide satisfactory visual recovery.

Fluctuations for zeros of Gaussian Taylor series

We study fluctuations in the number of zeros of random analytic functions given by a Taylor series whose coefficients are independent complex Gaussians. When the functions are entire, we find sharp bounds for the asymptotic growth rate of the variance of the number of zeros in large disks centered at the origin. To obtain a result that holds under no assumptions on the variance of the Taylor coefficients, we employ the Wiman–Valiron theory. We demonstrate the sharpness of our bounds by studying well-behaved covariance kernels, which we call admissible (after Hayman).

Translaminar Pressure Difference and Ocular Perfusion Pressure in Glaucomatous Eyes with Different Optic Disc Sizes.

Purpose Intracranial pressure (ICP) and ocular perfusion pressure (OPP) are both involved with the pathogenesis of glaucoma. The orbital ICP determines a retrolaminar counter pressure that is antagonistic to the intraocular pressure (IOP). The purpose of this study is to evaluate whether the translaminar pressure difference (TLPD) and the OPP varies in glaucoma patients with different optic disc sizes.Methods In this university hospital-based, observational, cross-sectional clinical study, all patients underwent an ophthalmic evaluation. Blood pressure, height, weight, and the results of retinal nerve fiber layer examination with optical coherence tomography examination were recorded. TLPD and OPP were calculated for each patient using proxy algorithms to attain indirect surrogate parameter values. Patients' eyes were stratified into three quantiles according to optic disc sizes and the differences compared. Data from both eyes were used after using the appropriate correction for inter-eye dependency.ResultsThe sample consisted of 140 eyes of 73 patients with primary open-angle glaucoma and suspects. Patients with large disc size presented with higher TLPD as compared to those with average and small-sized discs (2.4 4.5, 2.8 3.8, and 3.7 4.7 mmHg for first, second, and third tertile, respectively (P 0.000). OPP did not vary according to the optic disc size.ConclusionGlaucoma patients with larger optic discs have higher TLPD. The pathological significance of this finding warrants further investigation.

Intradural Disc Herniation in the Setting of Congenital Lumbar Spinal Stenosis

IntroductionAccounting for an estimated 1.10-1.76% of all lumbar herniations, lumbar intradural disc herniation (IDH) occurs primarily in males during the fourth to fifth decades of life. While not validated, congenital lumbar spinal stenosis (CLSS) is implicated as one precipitating factor for IDH. Case reportWe report 28-year-old Hispanic female with CLSS, severe obesity, and degenerative disk disease, with a history of minimally invasive surgical (MIS) decompression for a large paracentral L4-5 disc herniation at 25. After three years, the patient developed sudden burning dysesthesias in the L4-5 dermatomes bilaterally and temporary leg weakness. Lumbar magnetic resonance imaging exhibited severe L4-5 spinal stenosis, and the patient underwent repeat MIS decompression, which again provided her with adequate symptom resolution. However, 20 days postoperatively she developed cauda equina syndrome with anal dysfunction, and bilateral leg and foot weakness. Upon open surgical exploration we discovered a tense L4-5 dural protrusion. After a dorsal durotomy, a large IDH with a ventral dural tear was identified. Subsequent to adequate debulking of the IDH, the ventral tear was repaired, and an expansile duraplasty was performed. Overall, the patient's bladder and bowel function, pain, hypoesthesia, and motor strength all improved. Two weeks after surgery she presented with a lumbar pseudomeningocele that was managed conservatively. ConclusionThis report not only highlights an atypical presentation of IDH and is the first case of CLSS linked with IDH, lending support to the hypothesis that CLSS can lead to IDH, but also provides a comprehensive review of IDHs.

The Be/neutron star system Swift J004929.5-733107 in the Small Magellanic Cloud–X-ray characteristics and optical counterpart candidates

ABSTRACT Swift J004929.5-733107 is an X-ray source in the Small Magellanic Cloud (SMC) that has been reported several times, but the optical counterpart has been unclear due to source confusion in a crowded region of the SMC. Previous works proposed [MA93] 302 as the counterpart, however we show here, using data obtained from the S-CUBED project, that the X-ray position is inconsistent with that object. Instead we propose a previously unclassified object which has all the indications of being a newly identified Be star exhibiting strong H α emission. Evidence for the presence of significant I-band variability strongly suggest that this is, in fact, a Be type star with a large circumstellar disc. Over 18 yr worth of optical monitoring by the OGLE project reveal a periodic modulation at a period of 413 d, probably the binary period of the system. A SALT optical spectrum shows strong Balmer emission and supports a proposed spectral classification of B1-3 III-IVe. The X-ray data obtained from the S-CUBED project reveal a time-averaged spectrum well fitted by a photon index Γ = 0.93 ± 0.16. Assuming the known distance to the SMC, the flux corresponds to a luminosity ∼1035 erg s−1. All of these observational facts suggest that this is confirmed as a Be star–neutron star X-ray binary (BeXRB) in the SMC, albeit one with an unusually long binary period at the limits of the Corbet Diagram.

Research on plastic deformation law and forming technology of rotary forging with multi-cone rolls

With the development of industrial technology, the application of large diameter-thickness ratio integral discs in various high precision vessels is becoming more and more important. At present, the forming processes of large-diameter disc mainly includes welding and multiple local upsetting, but these processes exhibit large defects and cannot meet the requirements of industry. Therefore, a new metal plastic forming technology, namely rotary forging with multi-cone rolls (MCRs) is proposed to integrally form large diameter and ultra-thin discs. The forming process was simulated by DEFORM-3D finite element analysis software, and the deformation characteristics of MCRs disc were revealed. The results show that the axial plastic deformation of disc can be divided into three stages. In the first stage, the plastic deformation area was basically symmetrical, and the deformation was relatively stable. In the second stage, the plastic deformation area on both sides was different, which was in the unstable stage and easy to produce defects. In the third stage, the plastic deformation area was approximately symmetrical for a long time, and the plastic deformation was stable. At the same time, the influence of process parameters on the form characteristics of MCRs, the main defects in the deformation process and the preventive measures were studied. The research results are helpful to better understand the metal plastic forming technology of MCRs and promote the further development of MCRs.

HD 142527: quantitative disk polarimetry with SPHERE

Aims. We present high-precision photometry and polarimetry based on visual and near-infrared imaging data for the protoplanetary disk surrounding the Herbig Ae/Be star HD 142527, with a strong focus on determining the light scattering parameters of the dust located at the surface of the large outer disk. Methods. We re-reduced existing polarimetric differential imaging data of HD 142527 in the VBB (735 nm) and H-band (1625 nm) from the ZIMPOL and IRDIS subinstruments of SPHERE at the VLT. With polarimetry and photometry based on reference star differential imaging (RDI), we were able to measure the linearly polarized intensity and the total intensity of the light scattered by the circumstellar disk with high precision. We used simple Monte Carlo simulations of multiple light scattering by the disk surface to derive constraints for three scattering parameters of the dust: the maximum polarization of the scattered light Pmax, the asymmetry parameter g, and the single-scattering albedo ω. Results. We measure a reflected total intensity of 51.4 ± 1.5 mJy and 206 ± 12 mJy and a polarized intensity of 11.3 ± 0.3 mJy and 55.1 ± 3.3 mJy in the VBB and H-band, respectively. We also find in the visual range a degree of polarization that varies between 28% on the far side of the disk and 17% on the near side. In the H-band, the degree of polarization is consistently higher by about a factor of 1.2. The disk also shows a red color for the scattered light intensity and the polarized intensity, which are about twice as high in the near-infrared when compared to the visual. We determine with model calculations the scattering properties of the dust particles and find evidence for strong forward scattering (g ≈ 0.5–0.75), relatively low single-scattering albedo (ω ≈ 0.2–0.5), and high maximum polarization (Pmax ≈ 0.5–0.75) at the surface on the far side of the disk for both observed wavelengths. The optical parameters indicate the presence of large aggregate dust particles, which are necessary to explain the high maximum polarization, the strong forward-scattering nature of the dust, and the observed red disk color.

Properties of large scale ultra-high temperature ceramic matrix composites made by filament winding and spark plasma sintering

In this paper, for the first time, we report the manufacturing and characterization of large UHTCMCs discs, made of a ZrB2/SiC matrix reinforced with PyC-coated PAN-based carbon fibres. This work was the result of a long term collaboration between different institutions and shows how it is possible to scale-up the production process of UHTCMCs for the fabrication of large components. 150 mm large discs were produced by filament winding and consolidated by spark plasma sintering and specimens were machined to test a large set of material properties at room and elevated temperature (up to 1800 °C). The extensive characterization revealed a new material with mechanical behaviour similar to CMCs, but with intrinsic higher thermal stability. Furthermore, the scale-up demonstrated in this work increases the appeal of UHTCMCs in sectors such as aerospace, where severe operating conditions limit the application of conventional materials.

Total disconnectedness of Julia sets of random quadratic polynomials

AbstractFor a sequence of complex parameters $(c_n)$ we consider the composition of functions $f_{c_n} (z) = z^2 + c_n$ , the non-autonomous version of the classical quadratic dynamical system. The definitions of Julia and Fatou sets are naturally generalized to this setting. We answer a question posed by Brück, Büger and Reitz, whether the Julia set for such a sequence is almost always totally disconnected, if the values $c_n$ are chosen randomly from a large disc. Our proof is easily generalized to answer a lot of other related questions regarding typical connectivity of the random Julia set. In fact we prove the statement for a much larger family of sets than just discs; in particular if one picks $c_n$ randomly from the main cardioid of the Mandelbrot set, then the Julia set is still almost always totally disconnected.

Raid Storage Dynamic Tendency of its Levels &amp; Types: A Survey Study

Raid storage is a data storage visualization technology for storing more data than common hard drives; for data redundancy, performance enhancement, or both, it integrates several physical disk drive components into one or more logical drives. In comparison to earlier idea of reliable mainframe disk drives, this was called "Single Large Expensive Disk" (SLED).

Domino Tilings of Cylinders: Connected Components under Flips and Normal Distribution of the Twist

We consider domino tilings of $3$-dimensional cubiculated regions. A three-dimensional domino is a $2\times 1\times 1$ rectangular cuboid. We are particularly interested in regions of the form $\mathcal{R}_N = \mathcal{D} \times [0,N]$ where $\mathcal{D} \subset \mathbb{R}^2$ is a fixed quadriculated disk. In dimension $3$, the twist associates to each tiling $\mathbf{t}$ an integer $\operatorname{Tw}(\mathbf{t})$. We prove that, when $N$ goes to infinity, the twist follows a normal distribution.&#x0D; A flip is a local move: two neighboring parallel dominoes are removed and placed back in a different position. The twist is invariant under flips. A quadriculated disk $\mathcal{D}$ is regular if, whenever two tilings $\mathbf{t}_0$ and $\mathbf{t}_1$ of $\mathcal{R}_N$ satisfy $\operatorname{Tw}(\mathbf{t}_0) = \operatorname{Tw}(\mathbf{t}_1)$, $\mathbf{t}_0$ and $\mathbf{t}_1$ can be joined by a sequence of flips provided some extra vertical space is allowed.&#x0D; Many large disks are regular, including rectangles $\mathcal{D} = [0,L] \times [0,M]$ with $LM$ even and $\min\{L,M\} \ge 3$. For regular disks, we describe the larger connected components under flips of the set of tilings of the region $\mathcal{R}_N = \mathcal{D} \times [0,N]$. As a corollary, let $p_N$ be the probability that two random tilings $\mathbf{T}_0$ and $\mathbf{T}_1$ of $\mathcal{D} \times [0,N]$ can be joined by a sequence of flips conditional to their twists being equal. Then $p_N$ tends to $1$ if and only if $\mathcal{D}$ is regular.&#x0D; Under a suitable equivalence relation, the set of tilings has a group structure, the {\em domino group} $G_{\mathcal{D}}$. These results illustrate the fact that the domino group dictates many properties of the space of tilings of the cylinder $\mathcal{R}_N = \mathcal{D} \times [0,N]$, particularly for large $N$.

Formation and evolution of protostellar accretion discs – I. Angular-momentum budget, gravitational self-regulation, and numerical convergence

ABSTRACT We investigate the formation and early evolution of a protostellar disc from a magnetized prestellar core using non-ideal magnetohydrodynamic (MHD) simulations including ambipolar diffusion and Ohmic dissipation. The dynamical contraction of the prestellar core ultimately leads to the formation of a first hydrostatic core, after ambipolar diffusion decouples the magnetic field from the predominantly neutral gas. The hydrostatic core accumulates angular momentum from the infalling material, evolving into a rotationally supported torus; this ‘first hydrostatic torus’ then forms an accreting protostar and a rotationally supported disc. The disc spreads out by gravitational instability, reaching ∼30 au in diameter at ∼3 kyr after protostar formation. The total mass and angular momentum of the protostar–disc system are determined mainly by accretion of gas from an infalling pseudo-disc, which has low specific angular momentum because of magnetic braking; their removal from the protostar–disc system by outflow and disc magnetic braking are negligible, in part because the magnetic field is poorly coupled there. The redistribution of angular momentum within the protostar–disc system is facilitated mainly by gravitational instability; this allows formation of relatively large discs even when the specific angular momentum of infalling material is low. We argue that such discs should remain marginally unstable as they grow (with Toomre Q ∼ 1–2), an idea that is broadly consistent with recent observational estimates for Class 0/I discs. We discuss the numerical convergence of our results, and show that properly treating the inner boundary condition is crucial for achieving convergence at an acceptable computational cost.

Fiber-optic silicon Fabry-Perot interferometric bolometer with improved detection limit for magnetic confinement fusion.

Fiber-optic bolometers (FOBs) intended for plasma radiation measurement in magnetically confined fusion have been previously developed using a silicon pillar that functions as both a Fabry-Perot interferometer (FPI) for temperature measurement and an absorber for the radiation. We report an FOB design that can significantly improve the detection sensitivity over earlier designs by engineering the absorber of the FOB. Our design uses the fact that, compared with a silicon pillar, a gold film with the same x-ray absorption thickness will show a much higher temperature rise from a given power density of the radiation. Therefore, the responsivity of an FOB can be improved by attaching a large gold disk to the silicon FPI as the absorber. We have developed a fabrication method for FOBs of such design and obtained an FOB with a 4-µm-thick, 0.6-mm-diameter gold disk attached to a 200-µm-diameter, 100-µm-thick silicon FPI. We have characterized the noise, responsivity, response time, and noise-equivalent power density (NEPD) and compared these with the earlier design where the absorber is mainly the silicon FPI itself. The experimental result suggests that the FOB with the gold disk achieves a responsivity of ∼2.8 mK/(W/m2) and a noise-equivalent-power-density of 0.13 W/m2, which are, respectively, more than nine times larger and six times smaller compared to the FOB using a previous design. Improved NEPD and good absorption over a broad frequency range will make the FOB more attractive for applications in magnetic-confinement fusion devices.

Resumption of virtual machines after adaptive deduplication of virtual machine images in live migration

In cloud computing, load balancing, energy utilization are the critical problems solved by virtual machine (VM) migration. Live migration is the live movement of VMs from an overloaded/underloaded physical machine to a suitable one. During this process, transferring large disk image files take more time, hence more migration and down time. In the proposed adaptive deduplication, based on the image file size, the file undergoes both fixed, variable length deduplication processes. The significance of this paper is resumption of VMs with reunited deduplicated disk image files. The performance measured by calculating the percentage reduction of VM image size after deduplication, the time taken to migrate the deduplicated file and the time taken for each VM to resume after the migration. The results show that 83%, 89.76% reduction overall image size and migration time respectively. For a deduplication ratio of 92%, it takes an overall time of 3.52 minutes, 7% reduction in resumption time, compared with the time taken for the total QCOW2 files with original size. For VMDK files the resumption time reduced by a maximum 17% (7.63 mins) compared with that of for original files.

Imaging characteristics of intradural disc herniation: A comparison with large disc extrusion

ObjectiveTo compare the computed tomography (CT) and magnetic resonance imaging (MRI) findings of lumbar intradural disc herniation (IDH) and disc extrusion mimicking IDH. Materials and methodsBetween January 2015 and August 2018, 32 with surgically confirmed IDH or disc extrusion mimicking IDH were included. Age, sex, symptoms, herniated disc level, history of discectomy at the same site, and operative findings were investigated through the medical records. We evaluated the direction, type, migration, margin, and shape of disc herniation, the presence of an abrupt discontinuity of the posterior longitudinal ligament (PLL), Y-sign of ventral dura, disc material beyond the PLL, and disc calcification or ossification. In addition, maximum herniated disc diameter to central canal diameter (MHDD/CCD) ratios were calculated. ResultsTwelve patients (8 males, 4 females; mean age 53.3 [21–83] years) were surgically confirmed to have lumbar IDH and 20 (11 males, 9 females; mean age 52 [19–78] years) had disc extrusion mimicking lumbar IDH. Margins and beak-like shapes of herniated discs, abrupt discontinuity of the PLL, Y-sign of ventral dura, disc material beyond the PLL, calcification or ossification of herniated discs, and MHDD/CCD ratios were significantly different in the IDH and non-IDH groups (p < 0.05). ConclusionImaging findings of an ill-defined margin, a beak-like shape, herniated disc calcification or ossification, abrupt PLL discontinuity, Y-sign of ventral dura, disc material beyond the PLL and a high MHDD/CCD ratio were found to predict the presence of IDH.

Analysis of the rub-impact forces between a controlled nonlinear rotating shaft system and the electromagnet pole legs

This article aimed to investigate the dynamical behaviours of a controlled asymmetric rotating shaft system when the rub-impact forces between the rotor and stator occur. A nonlinear position-velocity controller is proposed to control the system's lateral vibrations. The suggested control algorithm is integrated into the shaft system via four electromagnetic poles that are fixed on a fixed frame and act as active actuators. The dynamics of the asymmetric shaft, the electromagnetic coupling between the magnetic poles and the rotating shaft, and the rub-impact forces between the rotating shaft and the stator are included in the studied model. The derived dynamical model is firstly analyzed as a continuous nonlinear dynamical system utilizing the asymptotic analysis while neglecting the rub-impact forces. Different response curves are plotted to predict the conditions under which the rotating shaft may suffer from the rub-impact forces. Secondly, the whole system model is analyzed numerically as a discontinuous nonlinear dynamical system utilizing the bifurcation diagram, Poincaré map, and frequency spectrum. The main obtained results illustrated that the rub-impact forces occurrence between the uncontrolled rotating shaft and the stator induces unbounded oscillation that can destruct the rotating shaft. However, the suggested control algorithm has improved the vibratory behaviours of the considered system via minimizing the oscillation amplitudes and preventing the rub-impact forces for a wide range of the disk eccentricities. Moreover, it was found that the rotating shaft can whirl in a full annular rub mode with bounded oscillations if the proposed controller fails to prevent the rub-impact forces occurrence due to either the large disk eccentricity or the large asymmetric stiffness coefficients.

Posterior staphyloma is associated with the microvasculature and microstructure of myopic eyes

ObjectiveTo investigate the microvasculature and structural characteristics of the eyes of myopic patients and their association with posterior staphyloma (PS).MethodsThis was a retrospective, case-control study comprising of 106 eyes from 72 individuals. Using 1:1 matching of axial length (AL) of their eyes, patients were allocated into a PS group or no posterior staphyloma (NPS) group. All patients were examined using ultra-widefield fundus imaging, optical coherence tomography angiography, and ocular biometry to acquire microvasculature and microstructure parameters.ResultsThe anterior chamber depth (ACD) of the PS group was significantly different from that of the NPS group (3.56 mm vs 3.76 mm, P < 0.001), as was 1ens thickness (3.72 mm vs 3.57 mm, P = 0.005) and spherical equivalent (SE)(-10.11D vs -8.80D, P = 0.014). The PS group had reduced choriocapillaris flow, subfoveal choroidal thickness (SFCT), and a thinner retinal layer compared with the NPS group. No difference in retinal blood flow between the two groups was observed. The PS group exhibited a smaller disc area (15082.89 vs 17,043.32, P = 0.003) and angle α between temporal retinal arterial vascular arcades (113.29°vs 128.39°, P = 0.003), a larger disc tilt ratio (1.41 vs 1.24, P < 0.001) and parapapillary atrophy (PPA) area (13840.98 vs 8753.86, P = 0.020), compared with the NPS group. Multivariate regression analysis indicated that disc tilt ratio (P = 0.031) and SFCT (P = 0.015) were significant predictors of PS. In addition, PS (P = 0.049), AL (P = 0.003), corneal refractive power (P < 0.001), ACD (P = 0.022), relative lens position (P = 0.045), and disc area (P = 0.011) were significant predictors of SE.ConclusionsPS was found to be closely linked to a reduction in choriocapillaris perfusion and anatomical abnormalities including posterior and anterior segments. Furthermore, PS exacerbated the progression of myopia.

Retrospective study of effectiveness in transforminal nerve root block in lumbar disc disease

Introduction: Among chronic conditions, back problems are the most frequent cause of limitations of activity in persons less than 45 years of age. Sciatic neuralgia is a nerve root oedema because of the inflammatory, immunological, and mechanical factors. The lifetime prevalence of lumbar radiculopathy has been reported to be 5.3% in men and 3.7% in women. Steroid injections play an important role in the management of sciatic radiculopathy. Steroids act by reducing the oedema around the nerve roots and decreasing pain having the advantage of reduced dosage and targeted delivery around the nerve roots forming the basis of transforaminal nerve root block injections. In this study we want to study the effectiveness of transforaminal nerve root block in 30 patients post block and 3 months later. Aims and objectives: Aims and objectives of the study are as follows: 1. To study the effectiveness in relief of symptoms in transforaminal nerve root block in lumbar disc disease. Materials and Methods: The clinical and follow-up data of 30 patients having lumbar disc disease causing sciatic neuralgia were taken from May 2019 to December 2019 in MGM medical college and hospital Kamothe Navi Mumbai were retrospectively analysed in this study. Follow-up was conducted immediately after the administration of block, as well as 3 months post the administration of the root block. Preoperative VAS scoring and was done and same were repeated post block and at 3 months to observe the functional outcome of transforaminal root block. Results: The average follow-up was 6 months. At 2 to 3 weeks’ follow-up, 28 of 30 patients reported successful pain reduction. In 25 patients, this pain reduction was obtained immediately and in a further 3 patients within 4 days. In 2 patients, the nerve root block did not show a sufficient pain reduction. In total with 6months of follow up 26 patients with pain relief after the first injection had a permanent and substantial pain reduction, 16 did not require surgery, 6 had disc herniation and the remaining 3 had foraminal stenosis for which operative procedures were planned. Conclusion: From our study we can conclude that transforaminal Root block should be the first choice in treating and diagnosing patients with disc herniation. Root block is more effective in patients with disc herniation rather than canal stenosis. We also understand from our study that transforaminal Root block is more effective in early course of disease, within 6 weeks of onset of symptoms. So we conclude that larger discs should later be planned for an open or endoscopic decompression and mild and moderate disc can also be managed conservatively after a transforaminal root block. The patient’s clinical course remains the most important determinant for treatment decision in disc herniation.

The JCMT BISTRO Survey: Alignment between Outflows and Magnetic Fields in Dense Cores/Clumps

Abstract We compare the directions of molecular outflows of 62 low-mass Class 0 and I protostars in nearby (&lt;450 pc) star-forming regions with the mean orientations of the magnetic fields on 0.05–0.5 pc scales in the dense cores/clumps where they are embedded. The magnetic field orientations were measured using the JCMT POL-2 data taken by the BISTRO-1 survey and from the archive. The outflow directions were observed with interferometers in the literature. The observed distribution of the angles between the outflows and the magnetic fields peaks between 15° and 35°. After considering projection effects, our results could suggest that the outflows tend to be misaligned with the magnetic fields by 50° ± 15° in three-dimensional space and are less likely (but not ruled out) randomly oriented with respect to the magnetic fields. There is no correlation between the misalignment and the bolometric temperatures in our sample. In several sources, the small-scale (1000–3000 au) magnetic field is more misaligned with the outflow than the large-scale magnetic field, suggesting that the small-scale magnetic field has been twisted by the dynamics. In comparison with turbulent MHD simulations of core formation, our observational results are more consistent with models in which the energy densities in the magnetic field and the turbulence of the gas are comparable. Our results also suggest that the misalignment alone cannot sufficiently reduce the efficiency of magnetic braking to enable formation of the observed number of large Keplerian disks with sizes larger than 30–50 au.

Effect of myopia and optic disc area on ganglion cell-inner plexiform layer and retinal nerve fiber layer thickness.

Purpose:The aim of this work was to study the impact of myopia and different optic disc areas on ganglion cell-inner plexiform layer (GCIPL) and retinal nerve fiber layer (RNFL) thickness profiles in myopic patients by spectral-domain optical coherence tomography (SD-OCT).Methods:This was a cross-sectional study of 100 eyes of 50 myopic individuals. All patients underwent complete ophthalmic evaluation and SD-OCT examination. According to spherical equivalent (SE), patients were divided into M1, M2, and M3 (low, moderate, and high myopia group). According to optic disc area values, patients were divided into D1, D2 and D3 (small, medium and large disc groups). Average GCIPL and RNFL thickness recorded globally and separately for all quadrants and also according to 12 clock hours and analyzed with respect to different myopic groups, optic disc area groups, and axial length.Results:Quadrantic RNFL thickness profiles and their average RNFL thickness were significantly thinner in high myopic group compared to low myopic group, except for the temporal quadrant (P < 0.05). Average RNFL and RNFL thickness of all quadrants were significantly thicker in the large disc group than in the small disc group (P < 0.05). Average GCIPL and GCIPL thicknesses of all sectors were significantly thinner in high myopic group compared to low myopic group (P < 0.05). No significant correlation was observed between GCIPL and disc area changes. Average RNFL thickness correlated significantly with SE (3.667 μm/diopter), axial length (–5.3805 μm/mm) and optic disc area (9.4617 μm/mm2). Also, average GCIPL thickness correlated statistically significantly with SE (1.6807 μm/diopter) and axial length (–2.626 μm/mm).Conclusion:Myopia and axial length significantly reduce RNFL and GCIPL thickness profiles but the optic disc area significantly increases RNFL thickness, but not GCIPL thickness.