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Animatic of a Rotating Hemihelix Animatic of a Rotating Hemihelix.gif
Animatic of a Rotating Hemihelix
Video recording for a hemihelix with one perversion under water. Both ends are free to rotate.

A hemihelix is a curved geometric shape consisting of a series of helices with alternating chirality, connected by a perversion at the reversals. [1] [2]

The formation of hemihelices with periodic distributions of perversions in slender structures is understood in terms of competing buckling instabilities generated by in-plane stresses. [3]

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Alpha helix Type of secondary structure of proteins

The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group hydrogen bonds to the backbone C=O group of the amino acid located three or four residues earlier along the protein sequence.

PLOS Nonprofit open-access publisher

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Helix Type of smooth space curve

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Perversion is a type of human behavior that deviates from that which is understood to be orthodox or normal. Although the term perversion can refer to a variety of forms of deviation, it is most often used to describe sexual behaviors that are considered particularly abnormal, repulsive or obsessive. Perversion differs from deviant behavior, in that the latter covers areas of behavior for which perversion would be too strong a term. It is often considered derogatory, and, in psychological literature, the term paraphilia has been used as a replacement, though this term is controversial, and deviation is sometimes used in its place.

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In botany, a tendril is a specialized stem, leaf or petiole with a threadlike shape that is used by climbing plants for support, attachment and cellular invasion by parasitic plants, generally by twining around suitable hosts found by touch. They do not have a lamina or blade, but they can photosynthesize. They can be formed from modified shoots, modified leaves, or auxiliary branches and are sensitive to chemicals, often determining the direction of growth, as in species of Cuscuta.


An eraser is an article of stationery that is used for removing marks from paper or skin. Erasers have a rubbery consistency and come in a variety of shapes, sizes and colours. Some pencils have an eraser on one end. Less expensive erasers are made from synthetic rubber and synthetic soy-based gum, but more expensive or specialized erasers are made from vinyl, plastic, or gum-like materials.

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Tendril perversion

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  1. Amina Khan (April 24, 2014). "With a little rubber, scientists make weird, twisted hemihelix". Los Angeles Times.
  2. Lydia Smith (April 24, 2014). "Scientists Discover New Rare 'Hemihelix' Shape Using Rubber Bands". International Business Times.
  3. Liu, J.; Huang, J.; Su, T.; Bertoldi, K.; Clarke, D. R. (2014). "Structural Transition from Helices to Hemihelices". PLOS ONE. 9 (4): e93183. Bibcode:2014PLoSO...993183L. doi:10.1371/journal.pone.0093183. PMC   3997338 . PMID   24759785.