Direction-Oriented Line Interpolation Using Geometric Duality

1. We recorded responses from neurons in area V1 of the alert macaque monkey to textured patterns modeled after stimuli used in psychophysical experiments of pop-out. Neuronal responses to a single oriented line segment placed within a cell's classical receptive field (CRF) were compared with responses in which the center element was surrounded by rings of elements placed entirely outside the CRF. The orientations of the surround elements either matched the center element, were orthogonal to it, or were random. 2. The addition of the textured surround tended to suppress the response to the center element by an average of 34%. Overall, almost 80% of the 122 cells analyzed in detail were significantly suppressed by at least one of the texture surrounds. 3. Cells tended to respond more strongly to a stimulus in which there was a contrast in orientation between the center and surround than to a stimulus lacking such contrast. The average difference was 9% of the response to the optimally oriented center element alone. For the 32% of the cells showing a statistically significant orientation contrast effect, the average difference was 28%. 4. Both the general suppression and orientation contrast effects originated from surround regions at the ends of the center bar as well as regions along the sides of the center bar. 5. The amount of suppression induced by the texture surround decreased as the density of the texture elements decreased. 6. Both the general suppression and the orientation contrast effects appeared early in the population response to the stimuli. The general suppression effect took approximately 7 ms to develop, whereas the orientation contrast effect took 18-20 ms to develop. 7. These results are consistent with a possible functional role of V1 cells in the mediation of perceptual pop-out and in the segregation of texture borders. Possible anatomic substrates of the effects are discussed.

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Hemicentin, a conserved extracellular member of the immunoglobulin superfamily, organizes epithelial and other cell attachments into oriented line-shaped junctions

Development ◽

10.1242/dev.128.6.883 ◽

2001 ◽

Vol 128 (6) ◽

pp. 883-894 ◽

Cited By ~ 8

Author(s):

B.E. Vogel ◽

E.M. Hedgecock

Keyword(s):

Matrix Protein ◽

Chromosome Instability ◽

Basement Membranes ◽

Extracellular Matrix Protein ◽

Immunoglobulin Superfamily ◽

Cell Contact ◽

Chromosome Loss ◽

Oriented Line ◽

Escape Reflex ◽

Epithelial Basement

him-4 mutations cause a novel syndrome of tissue fragility, defective cell migration and chromosome instability in Caenorhabditis elegans. Null mutants have abnormal escape reflex, mispositioning of the vas deferens and uterus, and mitotic chromosome loss and multinucleate cells in the germline. The him-4 gene product, hemicentin, is a conserved extracellular matrix protein with 48 tandem immunoglobulin repeats flanked by novel terminal domains. Secreted from skeletal muscle and gonadal leader cells, hemicentin assembles into fine tracks at specific sites, where it contracts broad regions of cell contact into oriented linear junctions. Some tracks organize hemidesmosomes in the overlying epidermis. Hemicentin tracks facilitate mechanosensory neuron anchorage to the epidermis, gliding of the developing gonad along epithelial basement membranes and germline cellularization.

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N-Point Hough Transform Derived by Geometric Duality

Advances in Image and Video Technology - Lecture Notes in Computer Science ◽

10.1007/11949534_15 ◽

2006 ◽

pp. 148-157

Author(s):

Yoshihiko Mochizuki ◽

Akihiko Torii ◽

Atsushi Imiya

Keyword(s):

Hough Transform ◽

Geometric Duality

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Service-Oriented Line Planning and Timetabling for Passenger Trains

Transportation Science ◽

10.1287/trsc.1120.0424 ◽

2013 ◽

Vol 47 (3) ◽

pp. 295-311 ◽

Cited By ~ 47

Author(s):

Mor Kaspi ◽

Tal Raviv

Keyword(s):

Line Planning ◽

Oriented Line ◽

Service Oriented ◽

Passenger Trains

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The Delaunay tessellation in hyperbolic space

Mathematical Proceedings of the Cambridge Philosophical Society ◽

10.1017/s0305004116000827 ◽

2016 ◽

Vol 164 (1) ◽

pp. 15-46 ◽

Cited By ~ 3

Author(s):

JASON DEBLOIS

Keyword(s):

Hyperbolic Space ◽

Finite Subset ◽

Voronoi Tessellation ◽

Invariant Sets ◽

Convex Hulls ◽

Delaunay Tessellation ◽

Locally Finite ◽

Euclidean Setting ◽

Geometric Duality

AbstractThe Delaunay tessellation of a locally finite subset of the hyperbolic space ℍnis constructed via convex hulls in ℝn+1. For finite and lattice-invariant sets it is proven to be a polyhedral decomposition, and versions (necessarily modified from the Euclidean setting) of the empty circumspheres condition and geometric duality with the Voronoi tessellation are proved. Some pathological examples of infinite, non lattice-invariant sets are exhibited.

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