Self‐Assembly of a β‐Peptide Foldamer: The Role of the Surfactant in Three‐Dimensional Shape Selection

Previous research has shown that infants as young as the first few months of life perceive several aspects of the three-dimensional environment. Yet we know relatively little about the visual depth information which serves as a basis for their spatial capacities. A study is reported in which a visual habituation procedure was used to examine what types of optical depth information four-month-old infants find useful in visually perceiving solid (three-dimensional) shape. Results imply that in the absence of binocular depth cues four-month-olds rely on kinetic depth information to perceive solid shape.

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Cellular geometry controls the efficiency of motile sperm aggregates

10.1101/330316 ◽

2018 ◽

Author(s):

D. J. G. Pearce ◽

L. Hoogerbrugge ◽

K. A. Hook ◽

H. S. Fisher ◽

L. Giomi

Keyword(s):

Three Dimensional ◽

Cell Binding ◽

Head Shape ◽

Random Walker ◽

Muroid Rodents ◽

Dimensional Shape ◽

Biochemical Mechanisms ◽

The Stability ◽

Three Dimensional Shape

Teams of cooperating sperm have been found across several vertebrate and invertebrate species, ranging from sperm pairs to massive aggregates containing hundreds of cells. Although the biochemical mechanisms involved in sperm-sperm adhesion are unclear, aggregation can enhance the motility of the cells. Here, we report a thorough computational investigation on the role of cellular geometry in the performance of sperm aggregates. The sperm head is modeled as a persistent random walker characterized by a non-trivial three-dimensional shape and equipped with an adhesive region where cell-cell binding occurs. By considering both a simple parametric head shape and a computer reconstruction of a real head shape based on morphometric data, we demonstrate that the geometry of the head and the structure of the adhesive region crucially affect both the stability and motility of the aggregates. Our analysis further suggests that the apical hook, commonly found in the sperm of most muroid rodents, might serve to shield portions of the adhesive region and promote efficient alignment of the velocities of the interacting cells.

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Cellular geometry controls the efficiency of motile sperm aggregates

Journal of The Royal Society Interface ◽

10.1098/rsif.2018.0702 ◽

2018 ◽

Vol 15 (148) ◽

pp. 20180702 ◽

Cited By ~ 5

Author(s):

D. J. G. Pearce ◽

L. A. Hoogerbrugge ◽

K. A. Hook ◽

H. S. Fisher ◽

L. Giomi

Keyword(s):

Molecular Mechanisms ◽

Three Dimensional ◽

Cell Binding ◽

Head Shape ◽

Random Walker ◽

Muroid Rodents ◽

Dimensional Shape ◽

The Stability ◽

Three Dimensional Shape

Sperm that swim collectively to the fertilization site have been observed across several vertebrate and invertebrate species, with groups ranging in size from sperm pairs to massive aggregates containing hundreds of cells. Although the molecular mechanisms that regulate sperm–sperm adhesion are still unclear, aggregation can enhance sperm motility and thus offer a fertilization advantage. Here, we report a thorough computational investigation on the role of cellular geometry in the performance of sperm aggregates. The sperm head is modelled as a persistent random walker characterized by a non-trivial three-dimensional shape and equipped with an adhesive region where cell–cell binding occurs. By considering both, a simple parametric head shape and a computer reconstruction of a real head shape based on morphometric data, we demonstrate that the geometry of the head and the structure of the adhesive region crucially affects both the stability and motility of the aggregates. Our analysis further suggests that the apical hook commonly found in the sperm of muroid rodents might serve to shield portions of the adhesive region and promote efficient alignment of the velocities of the interacting cells.

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Three-dimensional shape perception from chromatic orientation flows

Visual Neuroscience ◽

10.1017/s0952523806233170 ◽

2006 ◽

Vol 23 (3-4) ◽

pp. 323-330 ◽

Cited By ~ 10

Author(s):

QASIM ZAIDI ◽

ANDREA LI

Keyword(s):

Three Dimensional ◽

Shape Perception ◽

Retinal Images ◽

Accurate Perception ◽

Dimensional Shape ◽

Three Dimensional Shape

The role of chromatic information in 3-D shape perception is controversial. We resolve this controversy by showing that chromatic orientation flows are sufficient for accurate perception of 3-D shape. Chromatic flows required less cone contrast to convey shape than did achromatic flows, thus ruling out luminance artifacts as a problem. Luminance artifacts were also ruled out by a protanope's inability to see 3-D shape from chromatic flows. Since chromatic orientation flows can only be extracted from retinal images by neurons that are responsive to color modulations and selective for orientation, the psychophysical results also resolve the controversy over the existence of such neurons. In addition, we show that identification of 3-D shapes from chromatic flows can be masked by luminance modulations, indicating that it is subserved by orientation-tuned neurons sensitive to both chromatic and luminance modulations.

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A Three-dimensional Shape Measurement Method Requiring only a Single Observation Image Based on Pattern Projection Technique

IEEJ Transactions on Electronics Information and Systems ◽

10.1541/ieejeiss.131.2224 ◽

2011 ◽

Vol 131 (12) ◽

pp. 2224-2225

Author(s):

Ke Sun ◽

Cunwei Lu

Keyword(s):

Measurement Method ◽

Three Dimensional ◽

Shape Measurement ◽

Projection Technique ◽

Single Observation ◽

Pattern Projection ◽

Dimensional Shape ◽

Three Dimensional Shape

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Four Dimensions of Diamond T: Combination Trade Marks of Colours And Shapes

Victoria University of Wellington Law Review ◽

10.26686/vuwlr.v37i4.5584 ◽

2006 ◽

Vol 37 (4) ◽

pp. 583

Author(s):

Michael McGowan

Keyword(s):

Three Dimensional ◽

Trade Mark ◽

Fourth Dimension ◽

Trade Marks ◽

Four Dimensions ◽

Trade Mark Law ◽

Dimensional Shape ◽

Three Dimensional Shape

This article examines the relatively new fields of colour and shape trade marks. It was initially feared by some academics that the new marks would encroach on the realms of patent and copyright. However, the traditional requirements of trade mark law, such as functionality and descriptiveness, have meant that trade marks in colour and shape are extremely hard to acquire if they do not have factual distinctiveness. As colour and shape trade marks have no special restrictions, it is proposed that the combination trade mark theory and analysis from the Diamond T case should be used as a way to make them more accessible. The combination analysis can be easily applied because every product has a three dimensional shape and a fourth dimension of colour.

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