Vertical Disc Research Articles

Inter-eye Comparison of the Lamina Cribrosa Depth in Patients with Bilateral Normal-tension Glaucoma with Asymmetrical Damage

Purpose: To evaluate the association between lamina cribrosa depth (LCD) and the severity of glaucomatous damage in patients with normal-tension glaucoma (NTG).Methods: The optic nerve heads (ONHs) of patients with bilateral NTG showing asymmetrical damage were scanned using spectral-domain optical coherence tomography. LCDs were measured on ONH horizontal B-scan images at three locations equidistant across the vertical optic disc diameter and compared between the more damaged and contralateral eyes. Conditional logistic regression analysis was performed to identify ocular risk factors associated with more severe damage between the eyes.Results: One hundred and four eyes of 52 patients with bilateral NTG were included. The mean age was 66.0 ± 15.0 years; there were 31 males and 21 females. The more damaged eyes exhibited a higher baseline intraocular pressure (IOP) (p < 0.001), a thinner global retinal nerve fiber layer thickness (p < 0.001), and worse visual field mean deviation (p < 0.001) and a pattern standard deviation (p < 0.001), than the contralateral eyes. In contrast, we found no significant inter-eye difference in either the spherical equivalent or the axial length. The average LCD was significantly larger in the more damaged eyes (529.4 ± 116.7 vs. 482.9 ± 107.5 μm, p < 0.001). On conditional logistic regression analysis, the higher the baseline IOP (p = 0.006) and the larger the LCD (p = 0.003), the higher the risk of having more severe damage compared to the contralateral eye under similar systemic conditions.Conclusions: The LCD was significantly larger in the more damaged eyes of patients with bilateral NTG, suggesting that LC deformation might be associated with glaucomatous ONH damage in NTG eyes.

OPTIMUM DESIGN OF SEED HOLDING RING OF VERTICAL DISC SEED-METERING DEVICE

In this paper, the vertical disk mechanical seed-metering device is taken as the object to optimize the design of seed holding ring. The laboratory test is carried out with seed-metering test bench and high-speed camera system; and the influence law of starting and ending angle, front inclination angle and flexible buffer of seed holding ring on the seed filling performance is studied. The ending angle of seed holding ring shall be consistent with seed throwing angle of seed-metering device, and the starting angle of seed holding ring has a significant effect on seed filling performance. The quality of fill index will first increase and then decrease, reaching the maximum at 35.7°; while miss fill index will first decrease and then increase, and the multiple fill index will be 0% when the starting angle is greater than 50°; and seed damage index will first decrease and then increase. In order to improve seed filling performance, the front end of seed holding ring is treated with inner chamfering. The larger the angle is, the lower the quality of fill index, the higher the multiple fill index and the lower the miss fill index, but the seed damage index will also increase. By setting a flexible buffer in the front end of seed holding ring, the seed damage index can be effectively reduced. When the buffer is 60 mm, the seed can be cleaned smoothingly, and the seed damage index will be 0%.

Entropy optimized radiative heat transfer of hybrid nanofluid over vertical moving rotating disk with partial slip

Hybrid nanofluids are a mixture of two types of nanomaterials in the base fluid. These nanofluids have novel characteristics that benefit many industrial applications like fuel cells, refrigerators, heat exchangers, etc. The present study examined entropy optimized Cu−TiO2/Water flow over vertically moving rotating disk with thermal radiation and partial slip. Also, Dufour and Soret’s effects are utilized in the modeling of the energy equation. The highly non-linear system of differential equations is solved by the BVP Midrich scheme employed in Maple software. The effects of embedded non-dimensional parameters on velocity, concentration, and temperature profiles are analyzed graphically along with the examination of entropy generation. It is observed that vertical disk movement and rotation have a contrasting impact on velocity, concentration, and temperature profiles compared to existing literature. Also entropy rate rises with radiation parameter, diffusion factor and temperature ratio parameter but declines with slip coefficient. The local skin friction coefficients, Nusselt number and Sherwood number are plotted with respect to different involved parameters. The current work can be utilized in various engineering applications to improve their efficiency.

Quantification of an oval optic disc in relation to myopic foveoschisis using swept-source optical coherence tomography

BackgroundTo investigate the relationship between an oval optic disc and the occurrence of myopic foveoschisis (MF) using swept-source optic coherence tomography (SS-OCT).MethodsFifty eyes of 25 patients with unilateral MF were included in this retrospective observational study. The biometric features of the optic disc and peripapillary structures were evaluated using SS-OCT.ResultsThe ovality index (OI) of the optic disc was significantly smaller (P = 0.003) and the optic disc tilt angle was greater (P = 0.023) in the eyes with MF than in the contralateral eyes. The optic disc tilt angle was significantly correlated with the OI (P = 0.000). Generalized estimating equation (GEE) model (linear regression) demonstrated that spherical equivalent refraction (P = 0.001), narrow macular staphyloma (P = 0.001) and the occurrence of MF (P = 0.026) were the independent factors associated with the OI. Narrow macular staphyloma was more frequent (P = 0.020) and the staphyloma was deeper (P = 0.006) in eyes with MF. GEE model (logistic regression) revealed that narrow macular staphyloma was the only independent factor related to the occurrence of MF (P = 0.013).ConclusionsAn oval optic disc in eyes with MF resulted from the increased tilt around the vertical disc axis. The optic disc tilt was related to narrow macular staphyloma, which was the only independent factor associated with the occurrence of MF. The clinical relevance needs further exploration through longitudinal analysis.

Morphologic Changes in the Lamina Cribrosa Upon Intraocular Pressure Lowering in Patients With Normal Tension Glaucoma.

PurposeThe purpose of this study was to investigate whether the lamina cribrosa (LC) curve changes in response to intraocular pressure (IOP) reduction following administration of topical ocular hypotensive eye drops in eyes with normal tension glaucoma (NTG).MethodsNinety-three eyes of 93 patients with treatment naïve NTG at initial examination and with ≥20% reduction from baseline IOP following administration of topical ocular hypotensive eye drops were included. Serial horizontal B-scan images of the optic nerve head (ONH) were obtained from each eye using enhanced depth imaging spectral domain optical coherence tomography (OCT) before and 1 year after IOP-lowering treatment. The LC curvature in each eye was assessed by measuring the LC curvature index (LCCI) in horizontal OCT B-scan images obtained at three (superior, central, and inferior) locations spaced equidistantly across the vertical optic disc diameter before and after IOP-lowering treatment. We evaluated the OCT detectible change in the LC curvature based on the interval change of LCCI to exceed the intersession standard deviation of 1.96 times and factors associated with the magnitude of the LCCI change in the eyes showing significant LC change.ResultsIOP decreased from 15.7 ± 2.5 mm Hg at baseline to 11.2 ± 1.7 mm Hg after topical glaucoma medication. Among the 93 subjects, 62 (66.7%) eyes showed the significant reduction of the LCCI (interssetional change over 1.5) after the treatment; greater interssessional change of the LCCI after IOP reduction was associated with younger age (P = 0.020) and larger baseline LCCI (P < 0.001).ConclusionsThe OCT detectible changes in LC curvature occurred in response to a modest decrease in the IOP in the naïve NTG eyes. The therapeutic benefit of these changes need to be assessed in longitudinal studies.

Combining spectral domain optical coherence tomography of retinal nerve fiber layer and noncontact tonometry in mass glaucoma screening during the World Glaucoma Week

This study reports the combination of noncontact tonometry and spectral domain optical coherence tomography (SD-OCT) in mass glaucoma screening in the Lebanese population. This cross-sectional study included Lebanese individuals who participated in a glaucoma screening campaign in March 2018 and March 2019 for World Glaucoma Week. Intraocular pressure (IOP) was measured by noncontact tonometry. Optic nerve head (ONH) and retinal nerve fiber layer (RNFL) scans were obtained using SD-OCT. Glaucoma suspects were defined as individuals having an IOP above 21mmHg in at least one eye and/or RNFL thinning in either the superior or the inferior quadrant. Among the 1116 individuals who were examined, 15.5% were found to be glaucoma suspects based upon their IOP readings, 15.5% based on OCT, and 3.0% based on both criteria combined. The mean vertical and horizontal disc diameter was 1.75±0.23mm and 1.57±0.22mm, respectively. Eyes that were suspects by OCT with normal IOP had thinner corneas when compared to eyes with normal OCT and high IOP (512.25μm vs. 559.12μm, P<0.0001). SD-OCT can be an easy and relatively fast component of mass glaucoma screening in addition to IOP measurement. Further studies are needed to establish this combination as a valid glaucoma screening method.

Collective effect of thermal plumes on temperature fluctuations in a closed Rayleigh–Bénard convection cell

We report a systematic study of the collective effect of thermal plumes on the probability density function (p.d.f.) $P(\delta T)$ of temperature fluctuations $\delta T(t)$ in turbulent Rayleigh–Bénard convection. By decomposing $\delta T(t)$ into four basic fluctuation modes associated with single and multiple warm and cold plumes and a turbulent background, we derive an analytic form of $P(\delta T)$ based on the convolutions of the five independent modes. To test the derived form of $P(\delta T)$ in the multiple-plume regions, where the thermal plumes are heavily populated, we conduct time series measurements of temperature fluctuations in two convection cells; one is a vertical thin disk and the other is an upright cylinder of aspect ratio unity. For a given normalized position in most regions of the convection cell, all of the measured p.d.f.s $P(\delta T)$ for different Rayleigh numbers fall onto a single master curve, once $\delta T$ is normalized by its root-mean-square (r.m.s.) value $\sigma _T$ . It is found that the measured $P(\delta T/\sigma _T)$ at different locations along the symmetric horizontal and vertical axes of the convection cells can all be well described by the derived form of $P(\delta T/\sigma _T)$ . The fitted values of the parameters associated with the number of plumes in multiple plume clusters and their relative strengths and degrees of intermittency are closely linked to the spatial distribution of thermal plumes and local dynamics of the large-scale circulation in a closed convection cell. Our work thus provides a unified theoretical approach for understanding scalar p.d.f.s in a turbulent field, which is very useful not only for the present study but also for the study of many turbulent mixing problems of practical interest.

RETRACTED: Non-axisymmetric Homann stagnation-point flow of unsteady Walter's B nanofluid over a vertical cylindrical disk

Particular non-axisymmetric Homann stagnation point flow of Walter’s B fluid over a vertical cylindrical disk is considered in this work. Important physical aspects of newly transient state problem are described by incorporating the effects of magnetic field and mixed convection. Additionally, the temperature and solute concentration are expressed with new parameters in the form of Brownian motion, thermophoretic force, thermal radiation, and 1st order chemical reaction. Furthermore, the problem is modeled with non-linear PDE’s, and which are further converted into ODE’s along with the proposed geometric conditions. Exploration of new physical impacts are described in the form of velocity, temperature, concentration, and displacement thicknesses by applying numerical scheme. However, the momentum equation subjected to the insufficient boundary conditions converting us to apply perturbation technique to reduce the order of ODE accordingly. It is conducted that displacement thicknesses [Formula: see text] and [Formula: see text] tends to its asymptotic value, as [Formula: see text] On the other hand, the displacement thickness [Formula: see text] is found in reverse trends, for the same escalating values of viscoelastic parameter. The skin friction [Formula: see text] variation against viscoelastic parameter is noticed with uplifting trend when [Formula: see text] and vice versa, for [Formula: see text] Outcomes for the Nusselt and Sherwood numbers and rate of heat and mass transfer have been obtained and discussed for parametric variations of the buoyancy parameter ξ, magnetic parameter M, temperature ratio parameter, Brownian motion parameter [Formula: see text], thermophoresis parameter [Formula: see text] and 1st order chemical reaction Rc. Also, shows relative growth for the momentum and concentration profiles.

蔬菜株间火焰除草机器人工作空间分析与丙烷燃烧数值模拟

In order to improve the seed filling performance of mechanical hole type seed metering device with high speed, a vertical disc metering device was designed with seed agitator to improve the seed filling probability. Discrete element simulation method and physical prototype bench tests were used to simulate and analyse the seed metering process. The structure parameters of the seed agitators were optimized by the quadratic orthogonal rotation central composite design test. The results showed that: 1) the addition of seed agitator had a significant influence on the MIS (miss index), among which the concave type had the lowest MIS, and it was the highest without agitator; 2) for concave type agitator, the optimal value of depth and angle were 3.1 mm and 60.5°, respectively; 3) the physical prototype tests showed that the QFI (quality of feed index) was more than 95% under the speed of 2-10 km/h, and the MIS was less than 1%, which meets the requirements of precision sowing.

The Effect of Hounsfield Unit Value with Conventional Computed Tomography and Intraoperative Distraction on Postoperative Intervertebral Height Reduction in Patients Following Stand-Alone Anterior Cervical Discectomy and Fusion.

ObjectiveThe most common complication of anterior cervical discectomy and fusion (ACDF) is cage subsidence and maintenance of disc height affects postoperative clinical outcomes. We considered cage subsidence as an inappropriate indicator for evaluating preservation of disc height. Thus, this study aimed to consider patients with complications such as reduced total disc height compared to that before surgery and evaluate the relevance of several factors before ACDF. MethodsWe retrospectively reviewed the medical records of 40 patients who underwent stand-alone single-level ACDF using a polyetheretherketone (PEEK) cage at our institution between January 2012 and December 2018. Our study population comprised 19 male and 21 female patients aged 24–70 years. The minimum follow-up period was 1 year. Twenty-seven patients had preoperative bone mineral density (BMD) data on dual-energy X-ray absorptiometry. Clinical parameters included sex, age, body mass index, smoking history, and prior medical history. Radiologic parameters included the C2-7 cobb angle, segmental angle, sagittal vertical axis, disc height, and total intervertebral height (TIH) at the preoperative and postoperative periods. Cage decrement was defined as the reduction in TIH at the 6-month follow-up compared to preoperative TIH. To evaluate the bone quality, Hounsfield unit (HU) value was calculated in the axial and sagittal images of conventional computed tomography. ResultsLumbar BMD values and cervical HU values were significantly correlated (r=0.733, p<0.001). We divided the patients into two groups based on cage decrement, and 47.5% of the total patients were regarded as cage decrement. There were statistically significant differences in the parameters of measuring the HU value of the vertebra and intraoperative distraction between the two groups. Using these identified factors, we performed a receiver operating characteristic (ROC) curve analysis. Based on the ROC curve, the cut-off point was 530 at the HU value of the upper cortical and cancellous vertebrae (p=0.014; area under the curve [AUC], 0.727; sensitivity, 94.7%; specificity, 42.9%) and 22.41 at intraoperative distraction (p=0.017; AUC, 0.722; sensitivity, 85.7%; specificity, 57.9%). Using this value, we converted these parameters into a bifurcated variable and assessed the multinomial regression analysis to evaluate the risk factors for cage decrement in ACDF. Intraoperative distraction and HU value of the upper vertebral body were independent factors of postoperative subsidence. ConclusionInsufficient intraoperative distraction and low HU value showed a strong relationship with postoperative intervertebral height reduction following single stand-alone PEEK cage ACDF.

Mesin Pengiris Tempe Semi Otomatis Jenis Disc Cutter Vertical

Rempeyek Ilham is one of the Micro, Small and Medium Enterprises (MSMEs) in Jambi City which is engaged in the production of tempeh peanut brittle. The increase in the capacity of the tempeh slices is done by making an automatic tempeh slicing machine using a vertical disc cutter. The slicing method is to use a crankshaft mechanism which produces a reciprocating motion with a 2-way movement direction, namely the transfersal direction and the longitudinal direction. The thickness of the wedge is regulated by a stopper with the help of a spring push mechanism. The results showed that the tempe cutting machine with a cutting time of 1 minute 37 seconds, the average number of slices obtained with a size of 2 mm was 83.8 slices and for sizes above 2 mm (2.1 mm-3 mm) as many as 68 slices, and the rest of the tempeh pieces are 5.6 cm long.

Optic disc morphology in preterm children. Influence of gestational age and birth weight

The characteristics of the optic disc and the development of the optic nerve can affect visual function in children. The purpose of our study was to assess optic disc morphology in preterm infants and to determine whether it is influenced by gestational age, birth weight and the presence of a retinopathy of prematurity. In a retrospective study, RetCam fundus images of 109 premature newborns admitted to our tertiary-level neonatal intensive care unit were reviewed. We evaluated the cup to disc ratio (C/D), optic disc diameter, cup diameter, shape of the optic disc, adherence to the ISNT rule, and presence of a peripapillary atrophy. Of 218 photos, we found the following results: mean±SD gestational age 28.5±2.7 weeks, mean±SD birth weight 1122±394g, mean C/D 0.32. There was no significant correlation between C/D and gestational age or birth weight. Vertical disc diameter was greater than horizontal disc diameter, with a mean ratio (horizontal/vertical) of 4/5, lending an oval shape to the optic disc. Nineteen infants had retinopathy of prematurity in both eyes; ninety-three percent had peripapillary atrophy. In our study, optic disc morphology in premature newborns was not influenced by gestational age, birth weight or presence of premature retinopathy.

Visual measurement of milling surface roughness based on Xception model with convolutional neural network

At present, machine vision roughness detection mostly needs to design roughness related indexes based on images, and the index design has human intervention and is heavily dependent on the light source environment. To solve this problem, the paper classifies the surface roughness based on the deep convolutional neural network method, which can realize the roughness detection without index design. The most important thing is that the detection method has good light source robustness under different light source environments. The study adopts an end-to-end image analysis method, by means of image enhancement pre-processing of a small number of source images, after multi-layer convolution and pooling operations, as well as comprehensive processing of fully connected and classification layers, the convolutional kernel can automatically extract the features of the image, and finally the surface roughness obtained by vertical disc cutter milling can be classified and predicted. In addition, based on the experimental light source environment with two different luminance of night and day, by comparing with the technically mature ResNet50 and DenseNet121 convolutional neural network models, the deep convolutional neural network Xception model not only has high roughness classification accuracy, but also has more light source environment robustness. This method makes the online measurement of visual roughness possible.

Full waveform inversion to estimate the material properties of a layered half-space

Estimations of material properties of layered infinite media have been considered in a variety of problems, including geophysical subsurface imaging, geotechnical site investigations, and nondestructive tests. The full waveform inversion (FWI) approach can be employed because it is versatile when used to estimate the properties of complicated systems. A rigorous formulation of the FWI approach used in conjunction with the thin-layer method, which is accurate and efficient for wave-propagation in a layered medium, is developed to estimate the material parameters of a layered half-space. We measure the vertical displacements of a layered half-space subjected to a harmonic vertical disk load on its surface. The responses are compared with those calculated using the estimated material properties of the considered medium. The estimated responses are obtained using a thin-layer model of the system. The thin-layer model is composed of mid-point integrated finite elements, the thickness of which can be complex, and perfectly matched discrete layers, which are appropriate for the representation of a layered half-space. An objective function, which is defined as the L2-norm of the difference between the measured and estimated responses, is minimized by means of gradient-based optimization. The gradient of the objective function is derived in terms of the derivatives of the eigenvectors and eigenvalues of the thin-layer representation of the considered medium. We then estimate the material properties by solving the optimization problem. The proposed approach is applied to various examples to estimate the profiles of shear-wave velocities of layered half-spaces. We demonstrate that the developed FWI strategy can estimate the material properties of layered half-spaces with satisfactory accuracy.

基于离散元法的垂直圆盘侧充排种器种群结构特性研究

The vertical disc seed metering device was selected to study the influence of the structural characteristics of seed group on the filling performance of seed metering device. The working process of seed metering device was simulated by discrete element software to study the influence of seed quantity and structure characteristics of seed chamber on seed movement and filling results. The seed group was divided into four zones: ascending zone, relative static zone, collapse zone and recirculation zone. The number of seeds and the rotation speed of disk have no effect on the inclination angle of the recirculation zone upper surface, which was always about 35°. But they had a significant effect on the filling performance. When the number of seeds was 500-1500, QFI (quality of feed index) decreased, MIS (miss index) increased and MUL (multiple index) did not change significantly. However, when the number of seeds was 2000, the change trend of filling performance was completely opposite. Inner surface inclination angle and axial width of the seed chamber have significant effects on the filling performance. QFI first increased and then decreased with the increase of inclination angle, reaching the maximum at 20° and MIS showed the opposite trend. QFI increases with the increase of thickness and tends to be stable at 40mm. Similarly, MIS has the opposite trend.

Solar still with rotating parts: a review.

Access to freshwater is narrowed down every day in the world. Many diseases of human beings are related to water supplies contaminated or unpurified. Nowadays, there are massive water shortages in developed and developing nations due to unplanned mechanisms and water pollution caused by human behavior. Water desalination with no impact on the environment is the necessity of the hour. The distillation of saline or brackish water using free solar energy such as solar still is one of the techniques of water purification providing ultrapure distilled water. Besides, solar still is an economical and eco-friendly method, particularly in arid areas. Solar distillers also provide renewable equipment for freshwater productivity. The still design was affected by several operating and environmental factors. The low productivity of the solar still is its major drawback, so many researchers have studied various models to enhance solar still productivity. This paper aims to review the numerous studies of solar still incorporated with rotating parts that are deemed to be effective and efficient design because rotating parts break water surface tension, increase evaporation area, and improve the still performance. Throughout this detailed review, the scholars intend to present, clarify, and analyze the status of several solar distillers with various rotary component arrangements such as a fan, rotating wick, shaft, drum, disc... etc. In addition, based on the entire work, it was confirmed and recommended that the solar still with rotating parts should be continuously followed to supply potable water efficiently and economically. Different results showed the importance of part rotation (best daily yield & improvement) such as vertical disc distiller (16.5 L/m2/d & 617.4%), drum distiller (9.22 L/m2/d & 350%), moving wick solar still (9.17 L/m2/d & 315%), shaft still (0.83 L/m2/d & 39.49%), and vibratory distiller (5.8 L/m2/d & 132%). These important results obtain the importance of embedding rotating parts into the solar stills.

Estimation of the Radial Scale Length and Vertical Scale Height of the Galactic Thin Disk from Cepheids

Up-to-date data on 2214 classical Cepheids have been used. The model of an exponential matter density distribution in the Galactic thin disk has been applied. New estimates of the radial disk scale length $h_R,$ the distance of the Sun from the symmetry plane $z_\odot$, and the vertical disk scale height $h_z$ have been obtained. Based on samples of 1087 Cepheids younger than 120 Myr and 1127 Cepheids older than 120 Myr, we have found $h_R=2.30\pm0.09$ kpc and $h_R=1.96\pm0.12$ kpc, respectively. It has turned out that an unambiguous estimate of $h_R$ cannot be obtained from their overall radial distribution. However, we have constructed the radial distribution of 806 Cepheids of different ages at the time of their birth from which we have found $h_R=2.36\pm0.24$ kpc. We show that $h_z$ depends strongly on the age of stars. For example, from 705 Cepheids younger than 120 Myr with heliocentric distances $r<6$ kpc we have found $z_\odot=-17\pm4$ pc and $h_z=75\pm5$ pc. From 393 Cepheids older than 120 Myr at $r<6$ kpc, we have found $z_\odot=-39\pm11$ pc and $h_z=131\pm10$ pc.

Maxwell Points of Dynamical Control Systems Based on Vertical Rolling Disc—Numerical Solutions

We study two nilpotent affine control systems derived from the dynamic and control of a vertical rolling disc that is a simplification of a differential drive wheeled mobile robot. For both systems, their controllable Lie algebras are calculated and optimal control problems are formulated, and their Hamiltonian systems of ODEs are derived using the Pontryagin maximum principle. These optimal control problems completely determine the energetically optimal trajectories between two states. Then, a novel numerical algorithm based on optimisation for finding the Maxwell points is presented and tested on these control systems. The results show that the use of such numerical methods can be beneficial in cases where common analytical approaches fail or are impractical.

Role of Visual Field Testing and OCT in Evaluation of Brimonidine as a Neuroprotector in Primary Open Angle Glaucoma

Background: Glaucoma is the leading cause of global irreversible blindness optic neuropathy and retinal ganglion cell (RGC) death are the hallmarks of glaucoma. If intraocular pressure (IOP) is held within “normal” ranges, the disease process and RGC death can still progress in some patients. Neuroprotective therapies for glaucoma should aim to halt RGC loss thus preventing further structural and functional damage of the optic nerve Objective: The aim of the current work was to study the ability of visual field testing and optical coherence tomography to reveal the neuroprotective role of brimonidine. Patients and Methods: This prospective randomized controlled trial study included a total of 98 eyes from 50 patients affected by primary open-angle glaucoma (POAG). They were recruited from a larger population of 70 POAG patients, attending at Menofiya University Hospitals. Results: The use of visual field-testing parameters have revealed that brimonidine had insignificantly halted glaucoma progression: MD (-0.1115 dB and -.2465 dB), VFI (-0.5882 and-1.1471) and PSD (0.1729 and 0.1894). On the other hand, some OCT parameters: average RNFL thickness (-0.7273 u and-2.2121 u), inferior RNFL thickness (-0.735 u and -1.559 u), superior RNFL thickness (-0.6364u and -1.4848 u), rim area (-0.0162 mm2 and-0.0797 mm2), average cup disc ratio (-0.01765 and 0.01824) and vertical cup disc ratio (-0.0167 and 0.0321) for study and control groups respectively, gave promising neuroprotective results for brimonidine. Conclusion: It could be concluded that the use of visual field-testing parameters (MD, VFI and PSD) has revealed that brimonidine had insignificantly halted glaucoma progression.

Symmetries in geometric control theory using Maple

We focus on the role of symmetries in geometric control theory from the Hamiltonian viewpoint. We demonstrate the power of Ian Anderson’s package DifferentialGeometry in CAS software Maple for dealing with control problems on Lie groups. We apply the tools to the problem of vertical rolling disc, however, anyone can modify our approach and tools to other control problems.