Rim Shape Research Articles

Myopia and Other Refractive Error and Their Relationships to Glaucoma Screening.

A large disk, a large parapapillary delta zone and a long axial length may be used as screening criteria to detect glaucomatous optic neuropathy in highly myopic eyes. To describe aspects for screening of glaucomatous optic neuropathy in dependence of refractive error, under special consideration of high myopia. Studies on the anatomy of the myopic optic nerve head and results of investigations on the relationship between glaucomatous optic neuropathy and axial myopia were included. In the range from hyperopia to moderate myopia, refractive error is not a strong glaucoma risk factor and may not be included in glaucoma screening strategies. Care should be taken, that in moderate myopia, a shift of Bruch´s membrane opening usually into the temporal direction leads to parapapillary gamma zone and a corresponding shortening of the horizontal disk diameter. In these moderately myopic eyes, a secondarily small optic disk with a correspondingly small optic cup should not lead to an overlooking of intrapapillary glaucomatous changes. Prevalence of glaucomatous or glaucoma-like optic nerve atrophy (GOA) steeply increases with longer axial length in highly myopic eyes (cutoff approximately -8 diopters/axial length 26.5mm), with prevalences higher than 50% in extremely high myopia. Besides longer axial length, morphological parameters associated with GOA in highly myopic eyes are a secondarily enlarged disk and large parapapillary delta zone. Both parameters, together with long axial length, may be used as screening criteria in high myopia for GOA. The latter is characterized by an abnormal neuroretinal rim shape, that is, vessel kinking close to the intrapapillary disk border. Factors associated with nonglaucomatous optic neuropathy are larger gamma zone and longer axial length, potentially due to an axial elongation-related retinal nerve fiber stretching.

Automatic analysis of pottery sherds based on structure from motion scanning: The case of the Phoenician carinated-shoulder amphorae from Tell el-Burak (Lebanon)

Over the last few years, significant interest has been addressed in developing computer-based methods to document and analyze fragments of ceramics sherds in archaeology. This is because traditional manual processes do not allow for an objective, repeatable, and reproducible analysis of the large quantities of material needed to fully understand and explain human practices in various cultural contexts, such as the economy, daily life, and the material expression of religious beliefs.In that context, this paper proposes a fully digital methodology resulting from the constitution of an international research group coming from different scientific backgrounds: archaeologists with specific skills and experience in fast 3D geometry acquisition methods and researchers who developed and published the only available computer-based process for recognizing the geometric and morphological sherds features analyzed by archaeologists. The proposed methodology consists of two main parts: 1. 3D acquisition of sherds with the construction of the discrete 3D manifold model based on the Structure for Motion technologies; 2. recognition, segmentation, and dimensional characterization of morphological and geometrical features based on the codification and algorithmic implementation of the knowledge used by the archeologists in the traditional method. The method was applied to analyze a set of 133 sherds excavated at Tell el-Burak (Lebanon) to obtain, through the analysis of the namely Phoenician carinated-shoulder amphorae, new insights into the economic organization of the Phoenician homeland. The method demonstrated the potential for objectively, repeatedly, and reproducibly analyzing large quantities of sherds. Furthermore, it allowed studying sherds by generating new high-level knowledge from those acquired from 3D models; in particular, this paper introduces new morphological features that help the archaeologist classify fragments from an analysis of the rim's shape.

Design of A Novel Wheel-Legged Robot with Rim Shape Changeable Wheels

The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain. However, most of the wheel-legged robots only have one-directional obstacle-crossing ability. During the motion, most of the wheel-legged robots’ centroid fluctuates violently, which damages the stability of the load. What’s more, many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled, which limits its optimal performance in both aspects. This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel, which has a bi-directional and smooth obstacle-crossing ability. Based on the kinematic model, the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately. The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels. A prototype is made according to the optimal parameters. Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.

What Is a Polygonal Impact Crater? A Proposed Framework Toward Quantifying Crater Shapes

AbstractImpact craters are used for a wide array of investigations of planetary surfaces. A crater form that is somewhat rare, forming only ∼10% of impact craters, is the polygonal impact crater (or PIC). These craters have been visually, manually identified as having at least two rim segments that are best represented as straight lines. Such straight lines or edges are most often used to infer details about the subsurface crust where faults control the structure of the crater cavity as it formed. The PIC literature is scant, but almost exclusively these craters are identified manually, and the potentially straight edges are classified and measured manually. The reliance on human subjectivity in both the identification and measurement motivated us to design a more objective algorithm to fit the crater rim shape, measure any straight edges, and measure joint angles between straight edges. The developed code uses a Monte Carlo approach from a user‐input number of edges to first find a reasonable shape from purely random possible shapes; it then uses an iterative Monte Carlo approach to improve the shape until a minimum difference between the shape and rim trace is found. It returns the result in a concise, parameterized form. This code is presented as a first step because, while we experimented with several different metrics, we could not find one that could consistently, objectively return an answer that stated which shape for a given crater was the best; this objective metric is an area for future improvement.

Reconstruction of a full-thickness upper third defect of the helix ear using a single-stage chondrocutaneous composite transposition flap.

The external ear is a crucial part of the ear's anatomy for both functional and aesthetic purposes. We present a defect after the extirpation of an invasive squamous cell carcinoma, where the final defect involved the superior third of the outer ear, missing both cartilage and skin. The regional chondrocutaneous composite transposition flap of the ipsilateral auricular concha is a one-stage technique that successfully preserves the helical rim's shape and size.

Do Anatomical Differences of the Volar Rim of the Distal Radius Affect Implant Design? A Three-Dimensional Analysis of Its Anatomy and Need for Personalized Medicine

The distal radius, one of the frequent sites of upper extremity fractures, includes unique anatomy referred to as the volar rim. Few studies have addressed its interindividual differences. Additionally, implants for osteosynthesis must match the anatomical structures to prevent soft tissue invasion, but no implants have focused on that so far. In this study, three-dimensional surface models were created from CT images of 101 cases. Analysis of the distal radius, including the volar rim anatomy, was performed to design plates to minimize the discrepancy between the bone anatomy and the implant. The results showed that there were considerable interindividual differences in the morphology of the distal radius, particularly in the degree of palmar protrusion of the volar rim. A moderate correlation between the width of the distal radius and the shape of the volar rim was demonstrated. Considering that variations in plate width are available for treatment of normal distal radius fractures and that the shape of the volar rim changes in correlation with the width of the bone, we infer that simply adding volar rim shape information to the current variations should suffice in preventing complications. We conclude that individualized design according to the shape of the volar rim is unnecessary in fracture surgery.

Stereoscopic vs. monoscopic photographs on optic disc evaluation and glaucoma diagnosis among general ophthalmologists: A cloud-based real-world multicenter study.

PurposeTo investigate whether stereoscopic vs. monoscopic viewing condition influences the evaluation of optic disc photographs for morphologic features and glaucoma likelihood in a general ophthalmologist population from multicenters on a cloud-based platform.MethodsA cross-sectional study of 519 pairs of stereoscopic and monoscopic photographs of optic discs with adequate quality were selected and presented using a cloud-based platform. A total of 21 general ophthalmologists from 14 centers assessed 15 morphologic features based on 5R's rules and estimated glaucoma likelihood for each assigned photograph. There were 93 pairs of stereoscopic and monoscopic photographs evaluated by a panel of glaucoma specialists and set as ground truth. The main outcome measures were the agreement between estimates and ground truth and the inter-grader agreements.ResultsThere were good agreements between ground truth and both monoscopic and stereoscopic estimates (stereo κ 0.532 and mono κ 0.494). There was also a substantial intra-grader agreement between monoscopic and stereoscopic evaluation of glaucoma likelihood (κ 0.636). In eyes with probable glaucoma, the accuracy of the stereo method was greater than that of the mono method (stereo 0.238 vs. mono 0.118) When compared with ground truth, stereoscopic photographs had a better agreement for disc size (stereo κ 0.447 vs. mono κ 0.183), disc color (stereo κ 0.612 vs. mono κ 0.549), neuroretinal rim shape (stereo κ 0.356 vs. mono κ 0.274) on the whole. The stereoscopic method also had a better inter-grade agreement for disc size, disc color, neuroretinal rim shape, and glaucoma likelihood (stereo κ 0.402 vs. mono κ 0.359) on the whole.ConclusionsIn the evaluation of optic disc photographs for morphologic features and glaucoma likelihood, the stereoscopic method showed superiority compared to the monoscopic method for general ophthalmologists. The stereoscopic method is more likely to identify glaucomatous eyes which need medical intervention.

Impact of dust diffusion on the rim shape of protoplanetary disks

Context. Multiple mechanisms are known to give rise to turbulence in protoplanetary disks, which facilitates the accretion onto the central star. Small dust particles that are well coupled to the gas undergo diffusion due to this turbulent motion. Aims. This paper investigates the influence of turbulence-induced dust diffusion on the equilibrium of protoplanetary disks. Methods. The model accounts for dust sublimation, radiative transfer with the flux-limited diffusion approximation, and dust diffusion. It predicts the density and temperature profiles as well as the dust-to-gas ratio of the disk. Results. It is shown that dust diffusion can have a large impact: Assuming the dust survives for 104 s or longer before it can be evaporated, this leads the dust diffusion to widen the inner disk considerably. This effect is generated through a feedback mechanism as the diffusion length is much shorter than the disk width. With increasing dust diffusion, the inclination of the inner rim toward the stellar radiation becomes steeper until it is almost vertical. The temperature range of evaporation and condensation, which is linked to the dust composition, has no influence on this effect. Conclusions. For realistic parameters, dust diffusion cannot be neglected when determining the equilibrium of the disk. Stronger turbulence inside the disk induces more dust diffusion. Therefore, the dust density grows more gradually over a greater distance and less radiation reaches the disk surface. The new equilibrium shape of the disk is more inclined toward the star. This effect is universal and independent of the specific dust composition.

Comparison of resuspended road dust concentration for identifying optimum sampling position on a mobile laboratory vehicle

The accurate measurement of resuspended road dust from driving vehicles is key to assessing its role in air pollution. In this study, we used numerical analysis to investigate the behavior of resuspended road dust and selected the optimum sampling positions for use in a mobile laboratory (ML) to measure resuspended road dust emissions. Transient simulation of vehicle driving was performed by depicting wheel rim shape and tire tread pattern in detail. The resuspended road dust distributions generated around the vehicle wheels and the flow around the vehicle were analyzed according to the vehicle speed. Based on the analysis, four sampling positions with concentrated distributions of resuspended road dust were selected. To verify the simulation results, sampling inlets were installed on a ML in the selected positions, and resuspended road dust was collected at each position using a Teflon filter at vehicle speeds of 30, 40, and 50 km/h. Mass measurements of the resuspended road dust collected at the four locations showed that the most dust was collected at the position at the bottom of the vehicle immediately behind the wheel, and the overall trend was similar to the simulation results. Therefore, when measuring resuspended road dust using a ML, sampling inlets installed at the locations derived in this study are expected to yield more effective measurements for representing the pollution level of the road.Copyright © 2021 American Association for Aerosol Research

Mathematical Modeling of alloy wheel rim shape optimization using metaheuristic method

For the all automobile, wheel rim is very important part to control it. The wheel rims are only contact with both dynamic load and impact load. Dynamic load is rotation and the impact load is comes from road condition like speed breakers. Since we try alloy materials to the wheel rim. This alloy wheels are more safety and lighter than the other materials. In this paper, the alloy wheel rim is shape analyzed by the metaheuristic method using ansys workbench software. By using solidworks the 3d model of the wheel rim made. Based on the final deformation of all materials, the best material is selected.

Pottery of the late 16th — first quarter of the 18th c. from the Sofia yard of the Tobolsk Kremlin and the Upper town: comparative morphological analysis

The article presents morphological analysis of ceramic complexes from excavations in 2006 and 2017 in the city of Tobolsk. The pottery came from two areas: the Tobolsk Kremlin and the Upper town (9 Oktyabrskaya st.). Within this research, we aimed to conduct comparative analysis of morphology of the tableware from these sites to assess its similarities. From the two areas, 2261 ceramic fragments have been analyzed, and 200 vessels (counted by rims) from the late 16th c. — first quarter of the 18th c. layers have been identified. By the production technology, the dishes are non-glazed, made mainly on the pottery wheel. Hand-made ceramics have also been found in small quantity (less than 2 %). The assemblage is dominated by pot-like dishes (94.5 %). The proportion of cupped dishes is small. Other types of dishes (large pot, washbasin pot) have been found in single numbers. Based on the appearance of rims and necks, three types of pots and five types of bowls have been identified. Comparison has been made between the diameter of the mouth and the type of pot. Further examined were the frequency of occurrence of dishes with different colors and type of surface treatment, dimensions of bottoms, frequency of adding of sand to the surface of the pottery wheel. The assemblages have been compared to the late medieval ceramics of the northern, north-western and central regions of Russia, as well as the Urals and Siberia. Comparisons have been also made with the results of other studies of the Tobolsk ceramics. Statistics show that the pottery complexes are very similar to each other, both in large groups (pot-shaped and cup-shaped ware) and by other parameters (color and type of surface treatment, rim shape, mouth and bottom size, the ratio between types and diameters of pot mouths). Differences have been identified in the proportion of higher quality light gray dishes, being 2.5 times larger in the territory of the Upper town than in the Sofia yard. The difference is also expressed in proportions of the three types of pots. Type I prevails in the territory of the Upper town, and types II and III — in the Sofia court. Bowl-shaped dishes are diverse (3 types) and are present in both parts of the town. The quality light gray and black-glazed vessels of this type have been classified as tableware, partially for the lack of traces of soot. With this classification, the proportion of bowls defined as tableware constitutes 3 %. Comparison of the assemblages with the late medieval pottery from other regions of Russia revealed close analogies. But in terms of the general range of dishes, Tobolsk stands behind the cities of the European part of the country.

THE BRONZE CAULDRON OF AVRĂMENI (BOTOȘANI COUNTY). ASPECTS OF COLLECTIVE AND INDIVIDUAL MOBILITY DURING THE LATE IRON AGE IN THE TERRITORIES BETWEEN THE CARPATHIANS AND THE VOLGA

In 1942, following readjustment works of the road connecting the Saveni and Avrameni communes, a barrow was destroyed, resulting the find of a bronze cauldron. A. Nițu deemed the vessel of Avrameni as part of the series of cauldrons coinciding with the civilisation and expansion of the Sarmatians by the Don and Lower and Mid Danube in the 1st – 4th century AD and dated it to this chronological span. Gh. Bichir argued that the Avrameni cauldron is somewhat later than that of Piatra Șoimului (Calu), which the scholar dated to the 1st century BC. The vessel’s shape resembles that of a “bell” cast together with its handles, while the biconical foot was made separately, the two parts being attached by a bronze cast-made plug. On the body, the vessel displays several repair traces. According to its features and specificities, the Avrameni cauldron belongs to type Demidenko II.1.B, being the single of the type in the area between the Don and the Carpathians. The remaining resembling specimens come from 2nd – 1st century BC complexes from territories left of the Lower Don and the Kuban region. The author believes that according to its shape, the curved vertical handles decorated each with a knob as well as its making manner and foot attachment, the Avrameni vessel is an artefact joining elements specific to the Sauromatian cauldrons used in the Volga and Lower Don area, but also in the Kuban region also in the 2nd – 1st century BC. Within the context of its analysis are also discussed the cauldrons of Bubueci and Velikoploskoe, both from “ritual hoards/deposits” part of a larger group of such features of the 3rd – 1st century BC from territories comprised between the Volga – the pre-mountain area from North Caucasus in the east and the Lower Danube - Prut to the west. The cauldron of Bubueci belongs to type Demidenko I.3.A. It has a body cast together with the handles, while the iconical foot, surviving fragmentarily, was cast separately. Similarly to the Avrameni vessel, that of Bubueci is the most western find of a cauldron of the type. The body shape, curved vertical handles decorated each with three knobs, the lip shape and its making manner, how the handles start from the cauldron rim as well as how they were made, indicate that the vessel combines elements specific to the Sauromatian and early Sarmatian cauldrons. In the case of the Avrameni and Bubueci cauldrons, as well as those similar, the author concludes they are either a continuation of ancient casting traditions or were produced sometime earlier, yet continued to be used for a good period of time after their production cease. The exhibited repair traces and presence far from their territories of origin, where they were made and used, as well as their find together with 2nd – 1st century BC artefacts confirm, according to the author, their use for a longer time span. In the case of the Avrameni vessel, its deposition might have occurred sometime during the 2nd century BC as well as between the end of the 2nd – first decades of the 1st century BC. With respect to the dating of the “ritual hoard/deposit” of Bubueci, the author believes it dates no earlier than the 2nd century BC, and that its framing sometime between mid 2nd century BC and early 1st century BC is very likely. In the case of the Velikoploskoe cauldron, its body shape and sizes resemble those of the Demidenko VI type cauldrons emerging in the 2nd century BC, yet the remaining elements specific to this vessel type are missing. The rudimentary attachment procedure of the foot to the body, rim shape, its making manner, as well as how the handles start from the vessel rim, are according to the author, specific to the Sauromatae and early Sarmatian cauldrons (types Demidenko I-III, V) used in the first centuries BC, which hinders its ascribing to a certain type. Therefore, it was concluded that the Velikoploskoe vessel seems to be intermediary between the 5th - 3rd century BC cauldrons, mainly Sauromatae, and those of the early and mid armatian periods between the 2nd century BC and mid 2nd century AD. Its elements and making manner allow, according to the author, for its dating to the 2nd – 1st century BC, likely only sometime during the 2nd century BC, which is not contradicted by the remaining artefacts in the find.

Substrate counts: Quantitative effects of surface roughness on fingering pattern and rim shape of an impacting drop

Rim perturbations during the spreading of an impacting water drop are studied to provide quantitative insight into the effects of the substrate surface on the drop spreading process. Water drop impingement experiments on different surfaces confirm that undulations over the spreading rim are affected by surface characteristics. We have obtained a new relation to predict the number of fingers at the maximum spreading, providing a quantitative proof for substrate effects on evolution of the frontal shape. The valid range of the Weber number for this relation is 130–397. Moreover, we suggest a dimensionless “abnormality degree” for estimating the deformation of the rim shape due to instabilities and subsequent undulations. This parameter is quantitatively studied. Through a curve-fitting approach, we show that it can be expressed as a polynomial of three variables, namely, the Weber number and two roughness parameters. This study reveals the role of the solid surface in drop impingement and provides a comprehensive view of this process. The range of average surface roughness in this study is varied between 0.016 μm and 5.894 μm, and the characteristic slope ranges from 0.49 × 10−3 to 53.39 × 10−3.

Комплекс с «псевдо-самосской» амфорой из раскопок Фанагории

The article discusses the problems of localization and chronology of a group of the Ionian trans- port amphorae which production is referred to the workshops of Samos, Miletus or Erythrai. The basic event behind these questions was the uncovering of a ground ditch at the Acropolis of Phanagoria in which fragments of ceramic containers of Chios, Mende and an amphora were unearthed. The rim shape and the foot of the amphora are closely associated with Samian amphorae, but the shape of its body is distinguished from them.

The influence of the rim depth to the aerodynamic performances of a wheel: a numerical study

Summary  The aerodynamic drag and side force of five different wheels are evaluated by means of Computational Fluid Dynamics (CFD). The wheels are identical with the exception of the depth of the rim, which varies from 20 to 100 mm (Figure 1a).  Introduction  Aerodynamic drag is responsible for about 90 % of the total resistance of a cyclist travelling at racing speeds (Kyle & Burke, 1984). The bike contribution to the total drag ranges from 28% to 36% of the total drag depending on his or her position (Defraeye et al., 2010a). Earlier research has shown that the wheels’ contribution to the total drag is within 10% i€­ 15% and that an overall reduction in aerodynamic drag of 2-3% is possible solely by optimizing the wheels (Greenwell et al. 1995).  Therefore, a correct selection of the wheel can make a difference in the final result of a cycling race. In this paper the aerodynamics of spoked wheels as the most commonly used wheels in cycling races are investigated. The aerodynamic performances of spoked wheels are mainly affected by three factors: i) spoke count; ii) spoke shape and iii) rim depth. The first two parameters are kept fixed in this study while the rim depth is varied in order to better understand its effect on the aerodynamic forces generated on the wheel. To do so, an elliptical rim shape is adopted for all wheels.  Methods 3D steady Reynolds-Averaged Navier-Stokes (RANS) CFD simulations are performed to investigate the aerodynamic forces acting on five wheels with different rim depth at different yaw angles. The evaluation is based on validation with wind-tunnel measurements of Zipp Speed Weaponry, Indiana, USA, as presented in Godo et al., 2010.  The wheel considered for the validation study is the Zipp 404. Detailed characteristics of the wheel are provided in Godo et al. (2010). Subsequently, five wheels are created with elliptical rim shape of different depth.  The fluid domain is split in three regions. The first zone is built around the hub, the spokes and the internal part of the rim, and is later modelled as a moving reference frame (Figure 1b). The second zone is built externally to the wheel and has a cylindrical shape, which can be rotated to obtain different yaw angles for the wheel. The third zone is a parallelepiped representing the far-field domain.  The wheels are first drawn using the Computer-Aided Design (CAD) program PTC-Creo. The computational grid is then built using ANSYS/Fluent Meshing (Figure 1c). The volume grids consist of prismatic cells in the boundary layer region near the wheel and the ground while tetrahedral cells are employed nearby the wheel. Moreover, hexahedral cells are used in the far-field. The rotation of the wheel is imposed using a moving reference frame in the volume zone near the spokes. In the rest of the wheel, a rotational moving wall boundary condition is applied. The wheel-ground contact is modelled extruding the wheel’s footprint for 7mm. The k-I‰ SST turbulence model is used. Note that the good performance of this turbulence model for cyclist aerodynamics has been shown in several occasions in the past, e.g. Defraeye et al., 2010b. Results Earlier research results (Godo et al. 2010), have shown that for spoked wheels a decrease occurs in the drag coefficient, C D , when the yaw angle is increased up to 10 degrees. For larger yaw angles, C D increases. The expected effect of increasing the rim depth is to decrease the aerodynamic drag of the wheel, but an increase of the side force for large yaw angles is also expect. Â

The Development of the Method for the Calculation of the Shaping Force in the Production of Vehicle Wheel Rims

The objective of the paper is the development of the method for the calculation of the required force of shaping of a horizontal shape-forming machine used in the preproduction workflow. The design of a machine for horizontal shape-forming of wheel steel rims enables quick readjusting and transfer to another rim shape, which is significant under the conditions of frequent alteration of the product nomenclature. We developed the calculation method based on the assumptions of the deformations continuity, the constancy of the volume at plastic deformation and axisymmetric stressed state as well as the local application of the load. The research resulted in obtaining the analytical dependences for the calculation of the force of shaping of a wheel rim, taking into account the degree of deformation, the mechanical characteristics of the metal, hardening as well as the design and technological factors of the process. The topicality of the development consists in the necessity for the high-quality and the least expensive choice of the equipment of the required rated power when designing a new workflow. The experimental data, carried out both under the production and laboratory conditions, confirmed the adequacy of the theoretical formulas. It is determined by the assumptions and solutions obtained based on the mathematical apparatus of the technical theory of the shells of revolution. The clearness of the method will make it possible to algorithmize the calculation process quite easily and to use it as a subprogram in an applied complex of technical preproduction. It will also allow determining the shaping process most significant factors influencing the value of the force without the direct use of the calculation. We recommend to use it at enterprises producing vehicle steel wheels by the method of radial-rotation shaping.

Ancestral Variation in Orbital Rim Shape: A Three-Dimensional Pilot Study.

Traditional nonmetric methods of ancestry assessment posit orbital rim shape varies among ancestral groups. This pilot study uses morphometric analysis of 3D orbital variation to test discrimination among individuals of primarily European, African, and Asian ancestry. Although the size and nature of the sample analyzed limit inferences for other samples, principal components analysis suggests ancestry has a significant effect on rim shape (p = 2.93e-04). European orbits display more marked folding of the orbit in the sagittal plane than either African or Asian orbits, while the lateral margin of African orbits lies further posterior relative to the medial margin when compared to Asian orbits. The findings suggest curviplanar relationships are the most ancestrally informative aspect of orbital rim shape; these relationships may be distorted by perspective based on orientation of the skull relative to the viewer in traditional nonmetric analyses. Additional studies on geometric morphometric approaches to ancestry assessment are therefore warranted.

Optic Disc - Fovea Angle: The Beijing Eye Study 2011

PurposeTo determine the optic disc-fovea angle (defined as angle between the horizontal and the line between the optic disc center and the fovea) and to assess its relationships with ocular and systemic parameters.MethodsThe population-based cross-sectional Beijing Eye Study 2011 included 3468 individuals. A detailed ophthalmic examination was carried out. Using fundus photographs, we measured the disc-fovea angle.ResultsReadable fundus photographs were available for 6043 eyes of 3052 (88.0%) individuals with a mean age of 63.6±9.3 years (range: 50–91 years) and a mean axial length of 23.2±1.0 mm (range: 18.96–28.87 mm). Mean disc-fovea angle was 7.76 ± 3.63° (median: 7.65°; range: -6.3° to 28.9°). The mean inter-eye difference was 4.01 ± 2.94° (median: 3.49°; range: 0.00–22.3°). In multivariate analysis, larger disc-fovea angle was associated (regression coefficient r2: 0.08) with older age (P = 0.009; standardized regression coefficient beta: 0.05), thinner RNFL in the nasal superior sector (P<0.001; beta: -0.17), superior sector (P<0.001; beta: -0.10) and temporal superior sector (P<0.001; beta: -0.11) and thicker RNFL in the inferior sector (P<001; beta: 0.13), nasal inferior sector (P<001; beta: 0.13) and nasal sector (P = 0.007; beta: 0.06), higher prevalence of retinal vein occlusion (P = 0.02; beta: 0.04), and with larger cylindrical refractive error (P = 0.04; beta: 0.04).ConclusionsThe optic disc-fovea angle markedly influences the regional distribution of the RNFL thickness pattern. The disc-fovea angle may routinely be taken into account in the morphological glaucoma diagnosis and in the assessment of structure-function relationship in optic nerve diseases. Future studies may address potential associations between a larger disc-fovea angle and retinal vein occlusions and between the disc-fovea angle and the neuroretinal rim shape.

THE TIMBUL SITE, BALI, AND THE TRANSFORMATIONS PROJECT: MATERIAL REMAINS AND CONSIDERATIONS OF CHRONOLOGY AND TYPOLOGY

The project, Transformations in the Landscapes of South-Central Bali: An Archaeological Investigation of Early Balinese States, undertaken with Drs John Schoenfelder and I Wayan Ardika, was initiated to investigate, through a program of survey and excavation, changes and continuities in aspects of the political, religious and economic landscapes of south-central Bali during the mid-late first millennium AD and into the second millennium AD. This paper first presents a brief discussion of the theoretical background to the project and of the 2000 survey season, followed by a brief overview of the 2004 excavations at the Timbul site and a discussion of the dating of the several periods of occupation. Analysis of the smaller assemblage of non-earthenware artifacts, including the Chinese materials and their dating, as well as of the lithic artifacts, are next discussed. The paper then presents the morphological analyses of the earthenware pottery and also compares the resulting rim shape types and vessel shapes to those from other dated sites on Bali. The paper concludes with a discussion of the excavated Timbul deposits in the context of current archaeological knowledge of the relevant periods on Bali.

Evaluation of the Optic Nerve Head in Glaucoma.

ABSTRACTGlaucoma is an optic neuropathy leading to changes in the intrapaillary and parapaillary regions of the optic disk. Despite technological advances, clinical identification of optic nerve head characteristics remains the first step in diagnosis.Careful examination of the disk parameters including size, shape, neuroretinal rim shape and pallor; size of the optic cup in relation to the area of the disk; configuration and depth of the optic cup; ratios of cup-to-disk diameter and cup-to-disk area; presence and location of splinter-shaped hemorrhages; occurrence, size, configuration, and location of parapapillary chorioretinal atrophy; and visibility of the retinal nerve fiber layer (RNFL) is important to differentiate between the glaucomatous and nonglaucomatous optic neuropathy.How to cite this article: Gandhi M, Dubey S. Evaluation of the Optic Nerve Head in Glaucoma. J Current Glau Prac 2013;7(3):106-114.