Glossary of the key notions in Bionics and beyond

Four-pole → A network having an input and an output side. The input is called primer side, the output is called secunder side. The general four-pole is unequivocally characterized by four parameters.

Fovea → responsible for sharp central vision

Frame based neuronavigation → Brain neurosurgery when stereotactic apparatus is used

Frameless neuronavigation → Brain surgery when positions of the skull and the instruments are determined by ultrasound or infrared positioning technique.

Free induction decay (FID) → If transverse magnetization of the spins is produced, e.g., by a 90° pulse, a transient MR signal will result that will decay toward zero with a characteristic time constant T2 (or T2*); this decaying signal is the FID. In practice, the first part of the FID is not observable due to residual effects of the powerful exciting RF pulse on the electronics of the receiver, the receiver dead time.

Free parameters → The free parameters of the FFNN called weights can be set via learning or empirical methods. With theese parameters the FFNN can be customized.

Free running period → The time spent with wheel-running activity of experimental animals in the absence of any external “Zeitgebers”.

Free space propagation → When light travels in free space, in most cases it propagates as a transverse wave - the polarization is perpendicular to the wave’s direction of travel. In this case, the electric field may be oriented in a single direction (linear polarization), or it may rotate as the wave travels (circular or elliptical polarization).

Free-space loss → A signal propagating between two points with no attenuation or reflectionfollows the free space propagation law.

Frequency → ~ (unit: hertz, Hz, after German physicist Heinrich Hertz) is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency. The period is the duration of one cycle in a repeating event, so the period is the reciprocal of the frequency.

Frequency domain → ~ is a term used to describe the domain for analysis of mathematical functions or signals with respect to frequency, rather than time

Frequency encoding → Encoding the distribution of sources of MR signals along a direction by detecting the signal in the presence of a magnetic field gradient along that direction so that there is a corresponding gradient of resonance frequencies along that direction. In the absence of other position encoding, the Fourier transform of the resulting signal is a one-dimensional projection profile of the object.

Frequency meter → Frequency measuring instrument.

Friction machine → An electrical machine, generating static electricity by friction.

Front side illumination → Optics and photosensitive portion is on the top of the sensor chip.

Frontal plane → plane is a Y-X plane, perpendicular to the ground, which separates the anterior from the posterior (in standard Descartes coordinate system)

Frontier orbitals → ~ are the Highest-energy Occupied Molecular Orbital (HOMO) (filled or partly filled) and Lowest-energy Unoccupied Molecular Orbital (LUMO) (completely or partly vacant) of a molecular entity. Examination of the mixing of frontier molecular orbitals of reacting molecular entities affords an approach to the interpretation of reaction behaviour; this constitutes a simplified perturbation molecular orbital theory of chemical behaviour.

Function generator → A ~ is a piece of electronic test equipment or software used to generate electrical waveforms. These waveforms can be either repetitive or single-shot, in which case some kind of triggering source is required.

Function in systems theory → A role that an element plays within a system, or the role that a systems plays within a higher systems.

Functional analysis → ~ is a branch of mathematics concerned with infinite-dimensional vector spaces (mainly function spaces) and mappings between them. The spaces may be of different, and possibly infinite, dimensions. These mappings are called operators or, if the range is on the real line or in the complex plane, functionals.

Functional group → ~ is a group of atoms bounded in a particular way that is used to classify organic compounds into the various families; each ~ has specific properties and reactivity. That portion of a molecules where reactions are most likely to occur. In organic chemistry the organization and the grouping of molecules into families on the basis of the functional groups present within the molecule.

Functional group isomers → ~ are constitutional isomers with different functional groups.

Functional magnetic resonance imaging (fMRI) → ~ is used to demonstrate correlations between physical changes (as in blood flow) in the brain and mental functioning (as in performing cognitive tasks)

Fundamental interactions → The basic interactions between elementary particles: electromagnetism, strong and weak nuclear forces, and gravitations

Furan → ~ is a heterocyclic aromatic organic compound, consisting of a five-membered ring with four carbon atoms and one oxygen. (formula C4H4O)

Fusiform area (FFA) → The fusiform face area (FFA) is a part of the human visual system which might be specialized for facial recognition, although there is some evidence that it also processes categorical information about other objects, particularly familiar ones.

Fusion name → ~ is a composite name for a polycyclic parent structure having the maximum number of non-cumulative double bonds and at least one ortho fusion. Name formation involves the dissection of the structure into contiguous components having recognized trivial or semisystematic names, one of which is selected as the ‘base component’. Attachment of the other components is described by prefixes.

10. G

G protein-coupled receptor → A member of the family of transmembrane receptors, which are characterised by 7 transmembrane regions and coupled to intracellular signal transducers called G-proteins.

Galvanic cell → a cell that derives electrical energy from chemical reactions inside the cell

Galvanic isolation → The signal is transformed into a non-electric signal, then we percieve it and then it is transformed back into an electric signal. This can be done by transformator or optocoupler.

Galvanic skin response (GSR) → A change in the ability of the skin to conduct electricity.

Galvanometer → ~ is an instrument for detecting and measuring electric current. The first device was invented by Johann Schweiger (1779-1857) in 1820.

Gamma EEG band → EEG rhythm above 25-30 Hz.

Gamma knife → ~ makes possible noninvasive brain surgery by focusing large series of low intensity gamma radiation beams to one single point in the brain causing lesion of the tumor or malformation.

Gamma-aminobutyric acid (GABA) → A chemical substance, the major inhibitory neurotransmitter in the central nervous system.

Gamow → Georgy Antonovich Gamow (1904–1968), Russian-born American nuclear physicist and cosmologist who was one of the foremost advocates of the big-bang theory.

Gantry → Cylindrical scanner assembly in the bore of which the response of bodies or tissues to some specific exposure can be detected for 3D-imaging.

Gap junction → ~ or nexus is a specialized intercellular connection between cells. It connects directly the cytoplasm of two cells, through which molecules and ions can freely travel. Gap junctions are used in the electric synapse connecting two neurons via several connexin-built channels.

Gas → Gases are composed of particles that are not associated with each other and are moving rapidly. Gases have no definite volume or shape.

Gate array → Gate arrays are the basic elements of digital circuits. They are logical machines having inputs and outputs. Inputs are the independent logical variables, while the outputs are logical variables depending on the logical state of the inputs.

Gate level netlist → HDL contains only connecting wire descriptions and gates, IP blocks

Gauche effect → 1. The stabilization of the gauche (synclinal) conformation in a two carbon unit bonded vicinally to electronegative elements e.g. 1,2-difluoroethane. 2. The destabilization of the gauche (synclinal) conformation in a two carbon unit bonded vicinally to large, soft and polarizable elements such as sulfur and bromine.

Gauss → Johann Carl Friedrich Gauss (Gauß, Carolus Fridericus Gauss) (1777–1855) was a German mathematician and scientist who contributed significantly to many fields, including number theory, statistics, analysis, differential geometry, geodesy, geophysics, electrostatics, astronomy and optics.Sometimes referred to as the Princeps mathematicorum (Prince of Mathematicians/the foremost of mathematicians)

Gauss law → ~ is a law relating the distribution of electric charge to the resulting electric field. Gauss’s law states that the electric flux through any closed surface is proportional to the enclosed electric charge.

Gaussian function → The normal (or Gaussian) distribution is a continuous probability distribution that is often used as a first approximation to describe real-valued random variables that tend to cluster around a single mean value. The graph of a Gaussian is a characteristic symmetric “bell curve” shape that quickly falls off towards plus/minus infinity and is known as the Gaussian function. One parameter is the height of the curve’s peak, another is the position of the centre of the peak, and the third controls the width of the “bell”.

Gel electrophoresis → A laboratory method to separate charged (biological) macromolecules in a gel matrix by electric force.

Gene → A segment of the DNA molecule that encodes the information required for the synthesis of a gene product (protein or RNA).

Gene expression → Production of different types of RNAs or proteins from the information coding sequence of the genetic material.

General purpose graphical processing unit (GPU)+A960 → A special type of GPU which is able to solve arbitrary tasks specified in a special programming language.

General purpose processor → A processor to solve various different problem, with huge instruction set

Generalised orthogonal coordinates → Orthogonal coordinates are defined as a set of coordinates in which the coordinate surfaces all meet at right angles. A coordinate surface for a particular coordinate is the curve, surface, or hypersurface on which the particular coordinate is a constant.

Generalization capability → Ability to learn

Generalized coordinates → In the study of multibody systems, ~ are a set of coordinates used to describe the configuration of a system relative to some reference configuration. A restriction for a set of coordinates to serve as generalized coordinates is that they should uniquely define any possible configuration of the system relative to the reference configuration. Frequently the ~ are chosen to be independent of one another. The number of independent ~ is defined by the number of degrees of freedom of the system. The adjective “generalized” is a holdover from a period when Cartesian coordinates were the standard. Apart from practical reasons, any set of ~ is as good as another. The physics of the system is independent of the choice. However, there are more and less practical choices, that is, coordinates that are more or less optimally adapted to the system and make the solution of its equations of motion easier or more difficult.

Generalized dystonia → ~ affects most of the body, frequently involving the legs and back

Generalized hebbian algorithm → An iterative learning algorithm named after Donald O. Hebb which can perform the estimation of the weights without the knowledge of the correlation matrix

Generalized velocities → The ~ are the time derivatives of the generalized coordinates of the system.

Genetic code table → A table that shows the codon - amino acid encoding

Genome → All the genetic information encoded in the DNA or RNA of an organism.

Geometric isomerism (also known as cis-trans isomerism) → ~ is a stereoisomerism of olefins or cycloalkanes (or hetero-analogues) which differ in the positions of atoms (or groups) relative to a reference plane: in the cis-isomer the atoms are on the same side, in the trans-isomer they are on opposite sides.

Geometrical optics → ~, or ray optics, describes light propagation in terms of “rays”. The ray in geometric optics is an abstraction, which can be used to approximately model how light will propagate. Light rays are defined to propagate in a rectilinear path as far as they travel in a homogeneous medium. This is a significant simplification of optics that fails to account for optical effects such as diffraction and interference. It is an excellent approximation, however, when the wavelength is very small compared with the size of structures with which the light interacts. Geometric optics can be used to describe the geometrical aspects of imaging.

G-glutamyl cycle → The entry of an amino acid (AA) into a cell is catalyzed by a transferase enzyme. The AA reacts with glutathione, and in the cell AA is released. Glutathione, hydrolyzed is resinthesized in a cycle.

Gibbs free energy (G) or free enthalpy → A state function. Mathematically G=H-TS, where G is the free enthalpy, H is the enthalpy, S is the entropy and T is the temperature. The equilibrium of a system at constant temperature and pressure is characterized by the minimum of the Helmholtz free energy.

Gibbs phenomena → A convergence phenomenon occurring when a function with a discontinuity is approximated by a finite number of terms from a Fourier series

Gibbs-Duhem equation → ∑n_i dμ_i=0 where n_i is the number of moles of the i’th component of a solution and dμi is the change of the chemical potential of the i’th component of that solution.

Glass membrane → ~ are made of an ion-exchange type of silicate or chalcogenide glass.

Global alignment → Determines the measure of similarity from end to end

Global Positioning System (GPS)+A981 → It is a satelitte based radio navigation system that allows land, sea, and airborne users to determine their exact location and velocity anywhere (presicily any outdoors locations) in the world.

Glucogenic amino acids → Amino acids with carbon skeleton that can be used in glucose synthesis during gluconeogenesis (e.g. alanine, aspartate)

Gluconeogenesis → Synthesis of glucose from non-carbohydrate precursors

Gluon → Gluons (English glue) or gauge bosons are elementary particles. They mediate strong interactions of quarks in quantum chromodynamics (QCD). Unlike the electrically neutral photon of quantum electrodynamics (QED), ~ themselves carry color charge and therefore participate in the strong interaction in addition to mediating it, making QCD significantly harder to analyze than QED.

Glutamate → The main excitatory neurotransmitter in the central nervous system.

Glutamic acid decarboxylase (GAD) → The enzyme, which catalyses the decarboxylation of glutamate to GABA and carbon dioxide.

Glycerol → A trimer alcohol.

Glycine → An inhibitory neurotransmitter primarily in the spinal cord, but it also facilitates the NMDA receptor-mediated excitation.

Glycogen storage diseases → Inherited disorders characterized by abnormal quantity or type of glycogen in tissues

Glycogenolysis → Intracellular decomposition of glycogen

Glycolysis → Anaerobic degradation of glucose to lactate

Glycoprotein → Proteins containing carbohydrate groups

Glycosylation → Post-translational modification of proteins through which a sugar chain is covalently attached to the polypeptide.

Golgi tendon spindle → ~ is a proprioceptive sensory receptor organ located at the juction of the insertion of skeletal muscle fibers and tendons of skeletal muscle

Gradient amplifier → A ~ supplies power to a set of gradient coils, providing the variation in magnetic field strength required to obtain images and perform localization. MRI systems therefore require three gradient amplifiers, one for each set of gradient coils: x, y, and z. A ~ may use large amount of power and frequently require cooling with chilled water or forced air flow.

Gradient coils → Current carrying coils designed to produce a desired magnetic field gradient (so that the magnetic field will be stronger in some locations than others). Proper design of the size and configuration of the coils is necessary to produce a controlled and uniform gradient.

Gradient descent → ~ is a first-order optimization algorithm that finds a local minimum of a function.

Gradient, grad → ~ of a scalar field is a vector field that points in the direction of the greatest rate of increase of the scalar field, and whose magnitude is the greatest rate of change.

Gradient-echo pulse sequence → A pulse sequence that relies on gradient reversal to rephrase the transverse magnetization. Gradient-echo pulse sequences permit small flip-angle excitations, which preserve most of the longitudinal magnetization and therefore reduce or eliminate the time required for recovery of longitudinal magnetization before repeating the pulse sequence. Gradient echo pulse sequences have gained common use in 2DFT (planar) and 3DFT (volume) imaging, flow imaging, magnetic susceptibility imaging, and BOLD imaging.

Gravity → ~ is a natural phenomenon by which physical bodies attract with a force proportional to their mass. Gravitation is most familiar as the agent that gives weight to objects with mass. It is the weakest of the four fundamental forces

Gray code → The speciality of ~ is that only one number changes every time, so it is great to characterize rotations and displacements.

Ground fault circuit interrupter (GFCI) → Is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor.

Ground state → An atom, molecule or nucleus is in the ~ have no more energy than the absolute minimum. The ~ of an atom having the atom’s electrons in the lowest possible orbit.

Grounding → Ground or earth may be the reference point in an electrical circuit from which other voltages are measured, or a common return path for electric current, or a direct physical connection to the Earth.

GUARD → Connection to avoid the influence of the current leakage of the surface.

Gunn → John Battiscombe Gunn (1928–2008), was a British physicist, who spent most of his career in the United States.

Gunn effect → In some materials (III-V compounds), after an electric field in the material reaches a threshold level, the mobility of electrons decrease as the electric field is increased, thereby producing negative resistance. A two-terminal device made from such a material can produce microwave oscillations, the frequency of which is primarily determined by the characteristics of the specimen of the material and not by any external circuit.

Gyromagnetic ratio → The ratio of the magnetic moment to the angular momentum of a particle. This is a constant for a given nucleus.

Gyrus → A ridge on the cerebral cortex.

11. H

Haemodynamic response function (HRF) → The change in MR signal on T2* images following local neuronal activity as a function of time. The haemodynamic response results from a decrease in the amount of deoxygenated haemoglobin present within a voxel.

Hamilton → Sir William Rowan Hamilton (1805–1865) was an Irish physicist, astronomer, and mathematician, who made important contributions to classical mechanics, optics, and algebra. His greatest contribution is perhaps the reformulation of Newtonian mechanics, now called Hamiltonian mechanics.

Hamilton equations → The Hamilton(–Jacobi) equation is a reformulation of classical mechanics and, thus, equivalent to other formulations such as Newton’s laws of motion, Lagrangian mechanics and Hamiltonian mechanics. The Hamilton(–Jacobi) equation is particularly useful in identifying conserved quantities for mechanical systems, which may be possible even when the mechanical problem itself cannot be solved completely.

Hamilton’s principle → ~ states that the dynamics of a physical system is determined by a variational problem for a functional based on a single function, the Lagrangian, which contains all physical information concerning the system and the forces acting on it.

Hamiltonian cycle → B1650 visits every vertex in a graph exactly once

Hamiltonian operator → Mathematically, it is an operator which describes the energy of a particle.

Hamming distance → Number of positions differ in two sequences

Hammond principle (Hammond postulate) → The transition state is similar to the intermediate, thus if some-thing is stabilizing the intermediate, it is stabilizing the transi-tion state, too. On the other side, if something is destabilizing the intermediate, it is destabilizing the transition state.

Hantzsch–Widman name → Hantzsch–Widman name is a name for a heteromonocyclic parent hydride having no more than ten ring members formed by the citation of ‘a’ prefixes denoting the heteroatoms followed by an ending (the ‘stem’) defining the size of the ring.

Harm activity → ~ is due to the mechanical injury of the muscle fibers when the needle electrode is inserted or moved.

Harmonic oscillator → Its a model of the harmonic vibrational motion. In the ~, the potential energy of the system is proportional to the square of the displacement from its equilibrium point.

Hartree–Fock (HF) method → The ~ is an approximate method for the determination of the ground-state wave function and ground-state energy of a quantum many-body system. The ~ assumes that the exact, N-body wave function of the system can be approximated by a single Slater determinant (in the case where the particles are fermions) or by a single permanent (in the case of bosons) of N spin-orbitals. The ~ finds its typical application in the solution of the electronic Schrödinger equation of atoms, molecules.

HDL (Hardware description language) → ~ is any language from a class of computerlanguages for formal description of digital electronic circuits, for example, verilog, VHDL

Hearing aid → A ~ or traditional hearing aid is an electroacoustic device designed to amplify the sound in frequency ranges, where the hearing loss is the greatest. It is usually used to help people with conductive and sensorineural hearing loss.

Heart rate control → Generator: a small computer and an incorporated battery of many years of life.electrodes: special-coated wires connecting the heart muscles and the generator.The pacemaker - which is the size of a pocket watch - is usually placed under the skin layers in the recess of the shoulder, the clavicle and the large pectoral muscle. The electrodes are led through the blood vessels and fixed in the heart chambers, or in the case of open surgery, they are fixed to the outer surface of the heart. The generator has a small pouch under the skin. The device can also have programs that adapt to the functioning of the heart, or to physical activity. The more advanced devices allow for full and active life, even a regular sport.