scholarly journals Parietal Neurons Represent Surface Orientation From the Gradient of Binocular Disparity

2000 ◽  
Vol 83 (5) ◽  
pp. 3140-3146 ◽  
Author(s):  
Masato Taira ◽  
Ken-Ichiro Tsutsui ◽  
Min Jiang ◽  
Kazuo Yara ◽  
Hideo Sakata
Keyword(s):  
Binocular Disparity ◽  
Three Dimensional ◽  
Surface Orientation ◽  
Orientation Tuning ◽  
Surface Perception ◽  
Order Processing ◽  
Input Signals ◽  
Dmts Task ◽  
Random Dot Stereogram ◽  
Almost All

In order to elucidate the neural mechanisms involved in the perception of the three-dimensional (3D) orientation of a surface, we trained monkeys to discriminate the 3D orientation of a surface from binocular disparity cues using a Go/No-go type delayed-matching-to-sample (DMTS) task and examined the properties of the surface-orientation–selective (SOS) neurons. We recorded 57 SOS neurons from the caudal part of the lateral bank of the intraparietal sulcus (area CIP) of three hemispheres of two Japanese monkeys ( Macaca fuscata). We tested 29 of 57 SOS neurons using the square plate of a solid figure stereogram (SFS) and random-dot stereogram (RDS) without perspective cues; almost all of the tested neurons (28/29) showed surface orientation selectivity for the SFS and/or the RDS without perspective cues. Eight of these 28 neurons (28.6%) showed selectivity for both the RDS and SFS, 7 (25.0%) were dominantly selective for the RDS, and 13 (46.4%) were dominantly selective for the SFS. These results suggest that neurons that show surface orientation tuning for the RDS without perspective cues compute surface orientation from the gradient of the binocular disparity given by the random-dot across the surface. On the other hand, neurons that show surface orientation tuning for the SFS without perspective cues may represent surface orientation primarily from the gradient of the binocular disparity along the contours. In conclusion, the SOS neurons in the area CIP are likely to operate higher order processing of disparity signals for surface perception by integrating the input signals from many disparity-sensitive neurons with different disparity tuning.

Integration of Perspective and Disparity Cues in Surface-Orientation–Selective Neurons of Area CIP

2001 ◽  
Vol 86 (6) ◽  
pp. 2856-2867 ◽  
Author(s):  
Ken-Ichiro Tsutsui ◽  
Min Jiang ◽  
Kazuo Yara ◽  
Hideo Sakata ◽  
Masato Taira
Keyword(s):  
Single Unit ◽  
Binocular Disparity ◽  
Three Dimensional ◽  
Surface Orientation ◽  
Linear Perspective ◽  
Orientation Tuning ◽  
Single Unit Recording ◽  
Unit Recording ◽  
Depth Cues ◽  
3D Surface

We investigated the effects of linear perspective and binocular disparity, as monocular and binocular depth cues, respectively, on the response of surface-orientation–selective (SOS) neurons in the caudal part of the lateral bank of the intraparietal sulcus (area CIP). During the single-unit recording, monkeys were required to perform the delayed-matching-to-sample (successive same/different discrimination) of discriminating surface orientation in stereoscopic computer graphics. Of 211 visually responsive neurons, 66 were intensively tested using the solid-figure stereogram (SFS) of a square plate with both disparity and perspective cues (D+P condition), and 62 of these were identified as SOS neurons for responding selectively to the orientation of stimuli. All these neurons were further tested using a solid figure with perspective cues alone (P-only condition), and 58% (36/62) of these showed selective response to the orientation of the stimuli. Of the 62 SOS neurons, 35 neurons were also tested using SFS with disparity cues alone (D-only condition) in addition to the D+P and P-only conditions. We classified these 35 neurons into four groups by comparing the response selectivity under the P-only and D-only conditions. More than one-half of these (19/35) were sensitive to both perspective and disparity cues (DP neurons), and nearly one-third (11/35) of these were sensitive to disparity cues alone (D neurons), but a few (2/35) were sensitive to perspective cues alone (P neurons). The remaining (3/35) neurons exhibited orientation selectivity only when both cues were present. In DP neurons, the preferred orientation under the D+P condition was correlated to those under the D-only and P-only conditions, and the response magnitude under the D+P condition was greater than those under the D-only and P-only conditions, suggesting the integration of both cues for the perception of surface orientation. However, in these neurons, the orientation tuning sharpness under the D+P and D-only conditions was higher than that under the P-only condition, suggesting the dominance of disparity cues. After the single-unit recording experiments, muscimol was microinjected into the recording site to temporarily inactivate its function. In all three effective cases out of six microinjection experiments, discrimination of a three-dimensional (3D) surface orientation was impaired when disparity cues alone were present. In only one effective case, when a relatively large amount of muscimol was microinjected, discrimination of a 3D surface orientation was impaired even when both disparity and perspective cues were present. These results suggest that linear perspective is an important cue for representations of a 3D surface of SOS neurons in area CIP, although it is less effective than binocular disparity, and that both of these depth cues may be integrated in area CIP for the perception of surface orientation in depth.

scholarly journals Integration of texture and disparity cues to surface slant in dorsal visual cortex

2013 ◽  
Vol 110 (1) ◽  
pp. 190-203 ◽  
Author(s):  
Aidan P. Murphy ◽  
Hiroshi Ban ◽  
Andrew E. Welchman
Keyword(s):  
Single Neuron ◽  
Binocular Disparity ◽  
Three Dimensional ◽  
Surface Orientation ◽  
Cortical Circuits ◽  
Depth Cues ◽  
3D Objects ◽  
Surface Slant ◽  
Cortical Responses ◽  
Multivariate Pattern

Reliable estimation of three-dimensional (3D) surface orientation is critical for recognizing and interacting with complex 3D objects in our environment. Human observers maximize the reliability of their estimates of surface slant by integrating multiple depth cues. Texture and binocular disparity are two such cues, but they are qualitatively very different. Existing evidence suggests that representations of surface tilt from each of these cues coincide at the single-neuron level in higher cortical areas. However, the cortical circuits responsible for 1) integration of such qualitatively distinct cues and 2) encoding the slant component of surface orientation have not been assessed. We tested for cortical responses related to slanted plane stimuli that were defined independently by texture, disparity, and combinations of these two cues. We analyzed the discriminability of functional MRI responses to two slant angles using multivariate pattern classification. Responses in visual area V3B/KO to stimuli containing congruent cues were more discriminable than those elicited by single cues, in line with predictions based on the fusion of slant estimates from component cues. This improvement was specific to congruent combinations of cues: incongruent cues yielded lower decoding accuracies, which suggests the robust use of individual cues in cases of large cue conflicts. These data suggest that area V3B/KO is intricately involved in the integration of qualitatively dissimilar depth cues.

scholarly journals 3D Reconstruction of Cultural Heritage Sites as an Educational Approach. The Sanctuary of Delphi

2021 ◽  
Vol 11 (8) ◽  
pp. 3635
Author(s):  
Ioannis Liritzis ◽  
Pantelis Volonakis ◽  
Spyros Vosinakis
Keyword(s):  
University Students ◽  
3D Reconstruction ◽  
Cultural Heritage ◽  
New Technology ◽  
Three Dimensional ◽  
Computer Gaming ◽  
Educational Approach ◽  
Heritage Sites ◽  
3D Environment ◽  
Almost All

In the field of cultural heritage, three-dimensional (3D) reconstruction of monuments is a usual activity for many professionals. The aim in this paper focuses on the new technology educational application combining science, history, and archaeology. Being involved in almost all stages of implementation steps and assessing the level of participation, university students use tools of computer gaming platform and participate in ways of planning the virtual environment which improves their education through e-Learning. The virtual 3D environment is made with different imaging methods (helium-filled balloon, Structure for motion, 3D repository models) and a developmental plan has been designed for use in many future applications. Digital tools were used with 3D reconstructed buildings from the museum archive to Unity 3D for the design. The pilot study of Information Technology work has been employed to introduce cultural heritage and archaeology to university syllabuses. It included students with a questionnaire which has been evaluated accordingly. As a result, the university students were inspired to immerse themselves into the virtual lab, aiming to increasing the level of interaction. The results show a satisfactory learning outcome by an easy to use and real 3D environment, a step forward to fill in needs of contemporary online sustainable learning demands.

scholarly journals Functional Assessment of 12 Rare Allelic CYP2C9 Variants Identified in a Population of 4773 Japanese Individuals

2021 ◽  
Vol 11 (2) ◽  
pp. 94
Author(s):  
Masaki Kumondai ◽  
Akio Ito ◽  
Evelyn Marie Gutiérrez Rico ◽  
Eiji Hishinuma ◽  
Akiko Ueda ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Three Dimensional ◽  
Warfarin Dose ◽  
Catalytic Efficiency ◽  
Therapeutic Window ◽  
Wild Type ◽  
Drug Metabolizing Enzyme ◽  
Novel Variants ◽  
Metabolizing Enzyme ◽  
Almost All

Cytochrome P450 2C9 (CYP2C9) is an important drug-metabolizing enzyme that contributes to the metabolism of approximately 15% of clinically used drugs, including warfarin, which is known for its narrow therapeutic window. Interindividual differences in CYP2C9 enzymatic activity caused by CYP2C9 genetic polymorphisms lead to inconsistent treatment responses in patients. Thus, in this study, we characterized the functional differences in CYP2C9 wild-type (CYP2C9.1), CYP2C9.2, CYP2C9.3, and 12 rare novel variants identified in 4773 Japanese individuals. These CYP2C9 variants were heterologously expressed in 293FT cells, and the kinetic parameters (Km, kcat, Vmax, catalytic efficiency, and CLint) of (S)-warfarin 7-hydroxylation and tolbutamide 4-hydroxylation were estimated. From this analysis, almost all novel CYP2C9 variants showed significantly reduced or null enzymatic activity compared with that of the CYP2C9 wild-type. A strong correlation was found in catalytic efficiencies between (S)-warfarin 7-hydroxylation and tolbutamide 4-hydroxylation among all studied CYP2C9 variants. The causes of the observed perturbation in enzyme activity were evaluated by three-dimensional structural modeling. Our findings could clarify a part of discrepancies among genotype–phenotype associations based on the novel CYP2C9 rare allelic variants and could, therefore, improve personalized medicine, including the selection of the appropriate warfarin dose.

scholarly journals Symmetric Boundary Condition for Laplacian on Net of Regular Hexagons

2017 ◽  
Vol 9 (3) ◽  
pp. 46
Author(s):  
Daniel Lee
Keyword(s):  
Boundary Condition ◽  
Matrix Theory ◽  
Three Dimensional ◽  
Cardiac Tissues ◽  
Energy Product ◽  
Symmetric Boundary Condition ◽  
Almost All ◽  
Wave Phenomena ◽  
Dimensional Cell ◽  
Theory Series

Hexagonal grid methods are found useful in many research works, including numerical modeling in spherical coordinates, in atmospheric and ocean models, and simulation of electrical wave phenomena in cardiac tissues. Almost all of these used standard Laplacian and mostly on one configuration of regular hexagons. In this work, discrete symmetric boundary condition and energy product for anisotropic Laplacian are investigated firstly on general net of regular hexagons, and then generalized to its most extent in two- or three-dimensional cell-center finite difference applications up to the usage of symmetric stencil in central differences. For analysis of Laplacian related applications, this provides with an approach in addition to the M-matrix theory, series method, functional interpolations and Fourier vectors.

Bioprinting in ophthalmology: current advances and future pathways

2019 ◽  
Vol 25 (3) ◽  
pp. 496-514 ◽  
Author(s):  
Nataraj Poomathi ◽  
Sunpreet Singh ◽  
Chander Prakash ◽  
Rajkumar V. Patil ◽  
P.T. Perumal ◽  
...  
Keyword(s):  
3D Printing ◽  
Cardiac Tissue ◽  
Human Life ◽  
Three Dimensional ◽  
3D Models ◽  
Eye Diseases ◽  
Biological Research ◽  
Content Type ◽  
Almost All ◽  
Time Of Operation

Purpose Bioprinting is a promising technology, which has gained a recent attention, for application in all aspects of human life and has specific advantages in different areas of medicines, especially in ophthalmology. The three-dimensional (3D) printing tools have been widely used in different applications, from surgical planning procedures to 3D models for certain highly delicate organs (such as: eye and heart). The purpose of this paper is to review the dedicated research efforts that so far have been made to highlight applications of 3D printing in the field of ophthalmology. Design/methodology/approach In this paper, the state-of-the-art review has been summarized for bioprinters, biomaterials and methodologies adopted to cure eye diseases. This paper starts with fundamental discussions and gradually leads toward the summary and future trends by covering almost all the research insights. For better understanding of the readers, various tables and figures have also been incorporated. Findings The usages of bioprinted surgical models have shown to be helpful in shortening the time of operation and decreasing the risk of donor, and hence, it could boost certain surgical effects. This demonstrates the wide use of bioprinting to design more precise biological research models for research in broader range of applications such as in generating blood vessels and cardiac tissue. Although bioprinting has not created a significant impact in ophthalmology, in recent times, these technologies could be helpful in treating several ocular disorders in the near future. Originality/value This review work emphasizes the understanding of 3D printing technologies, in the light of which these can be applied in ophthalmology to achieve successful treatment of eye diseases.

Three-Dimensional Microfabrication System for Biodegradable Microdevices With High-Resolution and Bio-Applicability

2005 ◽  
Author(s):  
Akira Yamada ◽  
Fuminori Niikura ◽  
Koji Ikuta
Keyword(s):  
Tensile Strength ◽  
Biodegradable Polymers ◽  
Conventional Method ◽  
Three Dimensional ◽  
Single Layer ◽  
Batch Process ◽  
Potential Applications ◽  
A Cell ◽  
The One ◽  
Almost All

Biodegradable polymers are employed in medicine and its further application is expected with eagerness. But the lack of an appropriate processing method retards the progress. To overcome this problem, we have developped a novel three-dimensional microfabrication system. The system design allows us the processing of the free three-dimensional micro-level forms by stacking up melted polymers from the nozzle. Different from the conventional method, we adopted a batch process to supply materials in order to eliminate the prior process that required toxic solvents. In addition, it is possible to handle almost all biodegradable thermoplastic resins by adopting this system. A single layer from the piled-up layers of extruded lines was observed to evaluate the resolution. The lateral and depth resolutions attained are 40 μm and 45 μm, respectively. Biodegradable polymers enable three-dimensional microstructures such as micro-pipes, micro-bends, and micro-coil springs to be manufactured in less than 15 min. The biocompatibility of the newly fabricated structure was evaluated using a cell line (PC12). For this purpose, a small vessel, with a transparent base, was fabricated using PLA and cells were cultivated in it. The results were then compared with the results obtained using the standard method. The mechanical strength of our microstructures was evaluated using a tensile strength test. The tensile strength of the microstructure was lower than the one obtained from the conventional method, but has enough strength for fabrication of medical devices. Our system renders it possible to produce toxic-free, as well as transparent and leakage-free devices. Our system is expected to have potential applications in optimum design and fabrication of implantable devices, especially in tissue engineering.

scholarly journals Three-dimensional technologies used for patient specific applications in orthopedics

2021 ◽  
Vol 67 (2) ◽  
pp. 77-85
Author(s):  
Flaviu Moldovan ◽  
Tiberiu Bataga
Keyword(s):  
Orthopedic Surgery ◽  
Three Dimensional ◽  
Medical Application ◽  
Surgical Instruments ◽  
Patient Specific ◽  
Innovative Technology ◽  
Clinical Environment ◽  
Clinical Practices ◽  
Content Description ◽  
Almost All

Abstract Background: Three-dimensional (3D) technologies have numerous medical applications and have gained a lot of interest in medical world. After the advent of three-dimensional printing technology, and especially in last decade, orthopedic surgeons began to apply this innovative technology in almost all areas of orthopedic traumatic surgery. Objective: The aim of this paper is to give an overview of 3D technologies current usage in orthopedic surgery for patient specific applications. Methods: Two major databases PubMed and Web of Science were explored for content description and applications of 3D technologies in orthopedic surgery. It was considered papers presenting controlled studies and series of cases that include descriptions of 3D technologies compatible with applications to human medical purposes. Results: First it is presented the available three-dimensional technologies that can be used in orthopedic surgery as well as methods of integration in order to achieve the desired medical application for patient specific orthopedics. Technology starts with medical images acquisition, followed by design, numerical simulation, and printing. Then it is described the state of the art clinical applications of 3D technologies in orthopedics, by selecting the latest reported articles in medical literature. It is focused on preoperative visualization and planning, trauma, injuries, elective orthopedic surgery, guides and customized surgical instrumentation, implants, orthopedic fixators, orthoses and prostheses. Conclusion: The new 3D digital technologies are revolutionizing orthopedic clinical practices. The vast potential of 3D technologies is increasingly used in clinical practice. These technologies provide useful tools for clinical environment: accurate preoperative planning for cases of complex trauma and elective cases, personalized surgical instruments and personalized implants. There is a need to further explore the vast potential of 3D technologies in many other areas of orthopedics and to accommodate healthcare professionals with these technologies, as well as to study their effectiveness compared to conventional methods.

scholarly journals INTEGRATION OF SURVEYING TECHNIQUES TO DETECT THE IDEAL SHAPE OF A DOME: THE CASE OF THE ESCUELAS PÍAS CHURCH IN VALENCIA

2019 ◽  
Vol XLII-2/W9 ◽  
pp. 39-43
Author(s):  
S. Artese ◽  
J. L. Lerma ◽  
J. Aznar Molla ◽  
R. M. Sánchez ◽  
R. Zinno
Keyword(s):  
Laser Scanning ◽  
3D Model ◽  
Three Dimensional ◽  
Historical Building ◽  
Software Packages ◽  
Similarities And Differences ◽  
3D Documentation ◽  
Almost All ◽  
The Church ◽  
The Ideal

<p><strong>Abstract.</strong> The three-dimensional (3D) documentation and surveying of cultural heritage can be carried out following several geomatics techniques such as laser scanning and thermography in order to detect the original 3D shape after applying reverse engineering solutions. In almost all cases, the integration of data collected by different instruments is needed to achieve a successful and comprehensive 3D model of the as-built architectural shape of the historical building. This paper describes the operations carried out by the authors to determine the as-built 3D model of the Escuelas Pias Church, related namely to the dome and circular nave. After the description of the church and historical notes, attention will be driven to the indirect registration results obtained with three different laser scanning software packages, highlighting similarities and differences, and the consequences while generating meshes. The 3D model carried out will then be described and the results of some investigations with regard to the hypotheses about the design of the dome and the origin of the alterations will be presented.</p>

scholarly journals ANALISIS PENERAPAN PENGGUNAAN GRAPHIC EDITOR PADA PEMBUATAN OBJEK 3 DIMENSI

2017 ◽  
Vol 7 (2) ◽  
pp. 13
Author(s):  
Nurcahyani Dewi Retnowati
Keyword(s):  
Three Dimensional ◽  
Research Model ◽  
3D Object ◽  
Graphic Editor ◽  
Almost All ◽  
Selection Of ◽  
Production Games

Three-dimensional applications has evolved penetrated in almost all areas of work, especially in the field of multimedia and other virtual media. Offeature films, television, print design to production games. LightWave 3D is a software that can model an object once animate. This research model a 3D object using LightWave Modeler then analyzed the results of modeling using graphic editors in LightWave Layout. To connect between LightWave Modeler and LightWave Layout used LightWave Hub. Analysis using the graphic editor can make a better model for the selection of each layer more detail.

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