The Peripheral Hearing Mechanism: A Biochemical and Biological Approach

A new approach is described to the problem of hearing at energy levels near threshold. Models depending on the macro-physics of levers are rejected. Instead, evidence is presented for frequency analysis, signal placement and energy transduction by the properties (known or experimentally determined) of the cochlea and of the structures within the scala media. The hypothesis developed rests on the established theorems of Gabor and Brillouin, and at the same time is based on the data of enzymology. Care is taken not only that the hypothesis does not conflict but that it is actually consonant with recent solid state physics. The cochlea by virtue of its internal geometry and contained column of fluid is considered to perform a Fourier analysis to a first approximation. This crude “placement” of the acoustic signal is refined by the semi-solid-state lattice of the tectorial membrane which far from permitting dissipation of the signal energy actually “concentrates” the energy at the membrane surface of the hair processes of a hair cell. Here biochemical transduction, akin to the processes known for other sensory cells, transforms acoustic energy through an ion-shuttling mechanism to the form of energy characteristic of living cells, viz. enzyme conformational changes.

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Quantum Bit Modalities/Architectures

Oxford Research Encyclopedia of Physics ◽

10.1093/acrefore/9780190871994.013.29 ◽

2018 ◽

Author(s):

Cornelius Hempel

Keyword(s):

Quantum Mechanics ◽

Solid State ◽

Quantum Information Processing ◽

Energy Levels ◽

Building Blocks ◽

Physical Parameters ◽

Solid State Physics ◽

Forthcoming Article ◽

Quantum Bit ◽

Quantum Bits

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Physics. Please check back later for the full article. The theory of quantum mechanics provides an accurate description of nature at the fundamental level of elementary particles, such as photons, electrons, and larger objects like atoms, molecules, and more macroscopic systems. Any such physical system with two distinct energy levels can be used to represent a quantum bit, or qubit, which provides the equivalent to a classical bit within the context of quantum mechanics. As such, a qubit can be in a well-defined physical state representing one “classical bit” of information. Yet, it also allows for fundamental quantum phenomena such as superposition and mutual entanglement, making these effects available as a resource. Quantum information processing aims to use qubits and quantum effects to attain an advantage in computation and simulation, communication, or the measurement of physical parameters. Much like the classical bits realized by transistors in silicon are at the foundation of many modern devices, quantum bits form the building blocks out of which quantum devices can be constructed that allow for the use of qubits as a resource. Since the 1990s, many physical systems have been investigated and prototyped as quantum bits, leading to implementations that range from photonics, to atoms and , as well as solid state devices in the form of tailored impurities in a material or superconducting electrical circuits. Each physical approach differs in how the quantum bits are stored, how they are being manipulated, and how quantum states are read out. Research in this area is often cross-cutting between different areas of physics, often covering atomic, optical, and solid state physics and combining fundamental with applied science and engineering. Tying these efforts together is a joint set of metrics that describes the qubits’ ability to retain a quantum mechanical state and the ability to manipulate and read out this state. Examples are phase coherence and fidelity of measurement and operations. Further aspects include the scalability with respect to current technological capabilities, speed, and amenability to error correction.

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Role of spectrin in membrane fusion and in shape change of human erythrocyte ghost

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100082509 ◽

1978 ◽

Vol 36 (2) ◽

pp. 328-329

Author(s):

Hideo Hayashi ◽

Yoshikazu Hirai ◽

John T. Penniston

Keyword(s):

Conformational Changes ◽

Human Erythrocyte ◽

Shape Change ◽

Membrane Surface ◽

Slight Modification ◽

Active Role ◽

Main Role ◽

Bank Blood ◽

Human Erythrocyte Ghost

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.

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