Glossary of the key notions in Bionics and beyond

Alkyl halides → ~ (also known as alkyl halides or haloalkanes) are a group of chemical compounds derived from alkanes containing one or more halogens.

Alkyl/arylsulfonic acids → Sulfonic acids are compounds having the structure RS(=O)2OH.

Alkynes → ~ are acyclic (branched or unbranched) hydrocarbons having a carbon-carbon triple bond and the general formula CnH2n-2. Acyclic branched or unbranched hydrocarbons with more than one triple bond are called as alkadiynes, alkatriynes, etc.

All pass → A filter which magnitude response is a constant value, consequently it passes through every frequency component with the same amplitude. We do not have any restrictions on the phase characteristics of the filter.

Allostery → Property of an enzyme whereby non-covalent binding of a ligand to one site induces a conformational change that affects binding of a ligand at a different site

Allotropes → Two or more different forms of the same chemical element

Allowed band → The ranges of allowed energies of electrons in a solid are called allowed bands. Certain ranges of energies between two such allowed bands are called forbidden bands. Electrons within the solid may not possess these energies.

Alpha activity → EEG rhythm in the frequency band of 8-13 Hz.

Alphanumeric code → The description of the rule that transforms letters, numbers and other characters is called alphanumeric code.

Alternating current → The movement of electric charge periodically reverses direction(from positive to negative and vica-versa)

Alternative splicing → Different splicing reactions of the same pre mRNA that produce different mRNAs and may result in synthesis of different polypeptides.

AM1 → ~ (Austin Model 1) is a semi-empirical method for the quantum calculation of molecular electronic structure in computational chemistry. It is based on the Neglect of Differential Diatomic Overlap integral approximation. Specifically, it is a generalization of the modified neglect of differential diatomic overlap approximation.

Amide plane → A plane formed around a peptide bond by the α-carbon, the carboxyl carbon and carboxyl oxygen atoms of one amino acid and the amine nitrogen, the amine hydrogen and the α-carbon atoms of the other amino acid.

Amines → ~ are compounds formally derived from ammonia by replacing one, two or three hydrogen atoms by hydrocarbyl groups, and having the general structures RNH2 (primary amines), R2NH (secondary amines), R3N (tertiary amines).

Amino acid → Building blocks of proteins, which contain an amine and a carboxylic acid group and a variable side chain.

Amino acids → Amino acids are molecules containing an amine group, a carboxylic acid group and a side chain that varies between different amino acids.

Amino transferases (transaminases) → One aminoacid can be converted to another one via α-ketoacid formation. The reaction is catalyzed by aminotransferase. The determination of the amount aminotransferases in blood is useful in diagnosis of myocardial infarction and liver damage.

Ammonia elimination (Ornithine cycle) → High level of ammonia is dangerous, it should be eliminated. The main way is the ornithine cycle, where ammonia is converted to urea, which is removed by kidney

AMPA receptor → A type of ion-channel-coupled synaptic receptor for the neurotransmitter glutamate, whose activation leads to a fast excitatory response mediated by the influx of Na+ (and in some cases Ca2+) ions.

Ampere → André-Marie Ampère (1775–1836) was a French physicist and mathematician. He established the relations between electricity and magnetism, and developed the science of electromagnetism, or as he called it, electrodynamics. The SI unit of measurement of electric current, the ampere (A), is named after him.

Ampere’s law → ~ states that magnetic fields can be generated by electrical current (this was the original “Ampère’s law”) and by changing electric fields (this was “Maxwell’s correction”). Maxwell’s correction to Ampère’s law is particularly important: It means that a changing magnetic field creates an electric field, and a changing electric field creates a magnetic field.

Amphipathic → A molecule with both hydrophilic and hydrophobic characters

Amphoteric → Ampotheric chemical species are that behaves both as an acid and as a base is called amphoteric. This property depends upon the medium in which the species is investigated.

Amplifier → The ~ is a device for increasing the power of a signal.

Amplitude → ~ means the values of the time-varying signal along the vertical-axis. In case of bioelectric signals it is measured in mV, μV, mA, μA or fT.

Amplitude → Amplitude is the magnitude of the oscillating variable within an oscillating system.

Amygdala → An almond-shaped nucleus in the tip of the temporal lobe. It is part of the limbic system and has an important role in memory and controlling emotional reactions.

Amyotrophic lateral sclerosis (ALS) → ~ is a progressive, fatal, neurodegenerative disease caused by the degeneration of motor neurons, the nerve cells in the central nervous system that control voluntary muscle movement.

Anaerobic process → A metabolic process that can proceed in the absence of oxygen

Analog stimulation → The acoustic signal is filtered, compressed and transmitted as an analog signal to the electrode array.

Analog-to-digital converter (ADC) → An analog-to-digital converter is a device which converts a continuous quantity to a discrete time digital representation.

Analog-to-digital converter (ADC) → It is a device which converts a continuous quantity to a discrete time digital representation.

Analytical principle → Dividing into elemental parts or basic principles.

Analytical solution of a neuron → A method, where the weights of neurons can be calculated off-line

Anaplerotic → A reaction which can replenish the supply of intermediates in a metabolic pathway, e.g. in the citric acid cycle

Aneurysm → A localized abnormal widening of a blood vessel.

Angiography → Imaging technique used to visualize the inside, or lumen, of blood vessels and organs of the body.

Angular momentum → The ~ is a conserved vector quantity that can be used to describe the overall state of a physical system.

Angular velocity → The ~ is a vector quantity which specifies the angular speed of an object and the axis about which the object is rotating (radians per second).

Animal electricity → The term “~” (also referred as galvanism) comes form Luigi Galvani (1737-1798). It was the name of a theory in the 18th century used to explain the mechanisms in the nervous system. According to the theory electricity is flowing from the brain through the nerves to every organ, so to the muscles too. The muscles store this electricity and when a stimulus generates an electric discharge, the excitable muscles contract. Animal electricity also means the electricity that is developed in some animals, as the torpedo fish.

Anisotropic etching → Crystal plane dependent etching

Annihilation → ~ (destruction) is an event, when an elementary particle meets its antiparticle, both are destroyed, and the energy corresponding to their mass leaves in the form of photons.

Annotation → Literally, “providing with notes”, means i) the process in which functional, bibliographic information is added to structural data (like a sequence or a 3D structure), and ii) That part of a database record which contains the added data. This part can contain several structured fields.

Annulenes → ~ are monocyclic hydrocarbons having (formally) the maximum number of noncumulative double bonds, without side chains of the general formula CnHn (n is an even number) or CnHn+1 (n is an odd number). In systematic nomenclature an annulene with seven or more carbon atoms may be named [n]annulene, where n is the number of carbon atoms.

Anode → An ~ is apositive electrode through which electric current flows into the biological tissue

Antarafacial reaction → In an ~ the new bond is formed across the opposite sides of the π bond (or conjugated system) present in the substrate.

Antenna → ~ is an electrical device which couples electromagnetic waves in free space to an electrical current used by a receiver or transmitter. In reception, the antenna intercepts some of the power of an electromagnetic wave in order to produce a tiny voltage that the receiver can amplify. (Latin antenna ~ sail yard, Greek keraiai ~ horns of insects.) A dipole antenna can be made of a simple wire, with a center-fed driven element. It consists of two metal conductors of rod or wire, oriented parallel and collinear with each other, with a small space between them.

Antenna radiation → The near and far field regions around the source are defined simply for mathematical convenience, enabling certain simplifying approximations. The near field is the region within a radius small comaparable with the wavelength of the radiation, while the far field is the region for which the radius is much bigger than the wavelength. The radiation pattern from an oscillating electric dipole (linear antenna) is fairly complex, in far field it becomes fairly simple: a wave travels out radially from the source in all directions. The wave fronts here are expanding concentric spheres centered at the source.

Antenna rules → During plasma etching, electrical charge builds up in the long wires and destroy the connected gate electrodes (like metals in microwave oven). To avoid it, the length and perimeter of connected metals are restricted.

Anterior horn → The ~ of the spinal cord (also called the anterior cornu, anterior column or ventral horn) is the ventral (front) grey matter section of the spinal cord. The anterior horn contains motor neurons that affect the axial muscles while the posterior hornreceives information regarding touch and sensation. The anterior horn is where the cell bodies of alpha motorneurons are located.

Anterograde → From the cell body to the axon terminals.

Antiaromaticity → Those cyclic molecules for which cyclic electron delocalization provides for the reduction (in some cases, loss) of thermodynamic stability compared to acyclic structural analogues are classified as antiaromatic species. In contrast to aromatic compounds, antiaromatic ones are prone to reactions causing changes in their structural type, and display tendency to alternation of bond lengths and fluxional behavior (see fluxional molecules) both in solution and in the solid. Antiaromatic molecules possess negative (or very low positive) values of resonance energy and a small energy gap between their highest occupied and lowest unoccupied molecular orbitals.

Antibonding molecular orbital → ~ is the molecular orbital whose occupation by electrons decreases the total bonding (as usual, increases the total energy) of a molecule. The energy level of an antibonding MO lies higher than the average of the valence atomic orbitals of the atoms constituting the molecule.

Anticausal → ~ is a system property. A system is anticausal if it is only dependent on the future values of it’s input.

Antidromic → An ~ impulse refers to conduction along the axon away from the axon terminals towards the soma (conduction opposite of the normal, orthodromic direction). Antidromic activation is usually induced experimentally by direct electrical stimulation of a presumed target structure.

Anti-Markovnikov addition → Addition in the opposite sense of the Markovnikov addition. The addition of a hydrogen halide (HX) to an unsymmetrically substituted alkene occurs with attachment of the hydrogen to the carbon atom of the double bond having less hydrogens.

Antiport → Cotransport to the opposite direction.

Antiporter (exchanger) → ~ is a transporter which mediates passage of two substances in opposite directions, with strict stoichiometric coupling

Antisymmetric matrix → In linear algebra ~ is a square matrix whose transpose is equal to its negative.

Apical dendrite → A dendrite that emerges from the apex (peak) of a pyramidal cell.

Apolipoprotein → Protein component of a plasma lipoprotein freed from any associated lipids

Approximate → Close or be similar to something in quality, nature, or quantity

Approximation → Estimating a values of an unknown function

Apraxia → Inability to carry out a series of purposeful movements with preserved sensory and motor functions.

Aquaporin → A group of proteins serving as water channels. To be more precise: a transmembrane protein pore which allows fast passage of water molecules across biological membranes

Arenes → ~ are monoyclic and polycyclic aromatic hydrocarbons.

Arithmetic and logic unit → A digital circuit executing arithmetic and logic operations. A basic part of the central control unit of the computer.

Aromaticity → ~ is the concept of spatial and electronic structure of cyclic molecular systems displaying the effects of cyclic electron delocalization which provide for their enhanced thermodynamic stability (relative to acyclic structural analogues) and tendency to retain the structural type in the course of chemical transformations. A quantitative assessment of the degree of aromaticity is given by the value of the resonance energy. It may also be evaluated by the energies of relevant isodesmic and homodesmotic reactions. Along with energetic criteria of aromaticity, important and complementary are also a structural criterion (the lesser the alternation of bond lengths in the rings, the greater is the aromaticity of the molecule) and a magnetic criterion (existence of the diamagnetic ring current induced in a conjugated cyclic molecule by an external magnetic field and manifested by an exaltation and anisotropy of magnetic susceptibility).

Array → A data structure made up of a group of specific elements. These can be referenced by their indexes.

Arrhenius – Ostwald acid base theory → a theory where acids are defined as proton producers and bases as hydroxide ion producers

Arrhenius equation → k=A·exp(-E*/RT) where k is the rate coefficient, A is the so called preexponential factor which is a characteristic of a particular reaction, E* is the activation energy, R is the gas constant and T is temperature.

Artifact/artefact → ~ are unwanted alterations in the recordings that originate from sources other than the biological structure being studied. Artifacts can be electrical, mechanical or biological in nature.

Aryl diazonium compounds → ~ are having compounds of structure RN2+Y−, in which R is an aryl, and the cations of which are usually formulated as RN+≡N, E.g. PhN+≡N benzenediazonium chloride. They may also be named, from the canonical form RN=N+, hydrocarbyldiazenylium salts.

ASIC → Application Specific Integrated Circuits - ASICs, These are IC’s that are created for specific purposes.

Assistive technology → An ~ is a device or system designed to help persons with disabilities function more easily and independently. A BCI can be used as a type of assistive technology

Association constant → An equilibrium constant of an association reaction, for example between a receptor and its ligand.

Associative Memory → A memory which selects the most similar stored pattern to the input element

Associativity (math) → Let denote any (binary) operation by *. If A*B*C = A*(B*C) = (A*B)*C , then this operation is associative.

ASSP → ~ means Application Specific Standard Product

Asymmetric synthesis → A special way of synthesis by the formation one of the stereoisomers in higher ratio.

Asynchronous BCI → BCI in which the users can send information freely, without timing their commands to external cues. These BCIs are also called non-cue-based or non-cue-paced.

Asynchronous serial communication → Describes an asynchronous, serial transmission protocol in which a start signal is sent prior to each byte, character or code word and a stop signal is sent after each code word.

Atherosclerosis → an inflammatory disease of the arterial wall based on formation of lipid-rich plaques initiated by cholesterol deposition in the wall of large arteries

Atom → The ~ (Greek άτομος, α- ~ un- + τέμνω ~ to cut), means uncuttable, or indivisible, something that cannot be divided further. It is a basic unit of matter that consists of a dense, central nucleus surrounded by a cloud of negatively charged electrons.

Atomic model → Theoretical description of the nature of matter which states that all matter consists of small, indivisible units (atoms)

Atomic nucleus → A dense region at the center of the atom consisting of neutrons and protons

Atomic number (of an element) → Number of protons in the nucleus of an element

Atomic radius → The size of the typical radius of the atom from the nucleus to the boundary of its electron cloud

Attractor network → An ~ is a network of nodes (for example neurons in a biological network), often recurrently connected, whose temporal dynamics settle to a stable pattern.

Audio frequency → An ~ (AF), or audible frequency is characterized as a periodic vibration whose frequency is audible to the average human. While the range of frequencies that any individual can hear is largely related to environmental factors, the generally accepted standard range of audible frequencies is 20 to 20,000 hertz (Hz). Frequencies below 20 Hz can usually be felt rather than heard, assuming the amplitude of the vibration is high enough.

Audiometer → An ~ is a machine used for evaluating hearing loss.

Auditory brainstem implant → The ~t is a device similar to a cochlear implant, it uses electric stimulation to provide functional hearing in deafened persons. The difference is that the electrode array stimulates the cochlear nucleus in the brainstem instead of the cochlea. This experimental method can help people who have a damaged auditory nerve.

Auditory evoked potential (AEP) → Response of the brain to an auditory stimulus.

Auditory midbrain implant → The ~ is a device similar to a cochlear implant, it uses electric stimulation to provide functional hearing in deafened persons. The difference is that the electrode array stimulates the inferior colliculus in the midbrain instead of the cochlea. This experimental method can help people who have a damaged auditory nerve.

Auditory performance → ~ is the abitility to detect, identify, discriminate or recognize speech. It can be measured with the percent correct score on open-set speech-recognition tests.

Auditory steady-state response → ASSR is an auditory evoked potential, elicited with modulated tones that can be used to predict hearing sensitivity in patients of all ages. It will yield a frequency specific prediction of the hearing threshold.

Aufbau principle → A method used to determine the electron configuration of a given atom based on the order of orbital energy levels

Authentication → Examination of the appropriateness of a software or hardware according to a given set of criteria and the issuance of its certificate.

Auto-correlation → ~ is the cross-correlation of a signal with itself. It is the similarity between observations as a function of the time separation between them and is often used in signal processing.

Autonomic nervous systems → Part of the nervous system controlling visceral functions

Autoradiography → A technique which uses X-ray sensitive films to detect location of radioactively labeled substances.

Average Fade Duration (AFD) → The total percentage of time the fieldstrength is lower than the threshold value.

Average potential reference → Reference when all EEG electrodes are connected together through high resistances.

Avogadro constant → N_A=6.022·10²³ mol^-1

Axon hillock → Specialized part of the soma of a neuron that connects to the axon. As a result, the ~ is the last site in the soma where membrane potentials propagated from synaptic inputs are summated before being transmitted to the axon.

Axon terminal → Terminal part of the axon engaged in communication with receptors, effector structures and other neurons

Azeotrope → Such a composition of two or more compounds whose ratio cannot be changed by boiling or condensation, has a lower or higher (depending on the constituents) boiling point than any other composition

Azocoupling → ~ is an organic reaction between a diazonium compound and a dialkylaniline (C6H5NR2), phenol or other aromatic compound which produces an azo compound.

Azodyes → Azo compounds are derivatives of diazene (diimide), HN=NH, wherein both hydrogens are substituted by alkyl/aryl groups, e.g. PhN=NPh azobenzene or diphenyldiazene. As a consequence of п-delocalization, aryl azo compounds have vivid colors, especially reds, oranges, and yellows. Therefore, they are used as dyes, and are commonly known as azo dyes

Azoles → An azole is a class of five-membered nitrogen heterocyclic ring compounds containing at least one other non-carbon atom of either nitrogen, sulfur, or oxygen.

5. B

Back illumination → Optics and photosensitive portion is on the bottom of the sensor chip. The light goes through the substrate.

Back propagation → The empirical error is propagated in the opposite direction of the signal, to “distribute” the error between the neurons in the intermediate layers.

Backprojection → Original 3D structure reconstruction from 2D images taken from various angles.

Bacterial flagellum → A mainly filamentar structure of bacteria which is responsible for the movement of them. It is consisted of a basal body intergrated into the cell wall, a filament constituted by a protein called flagellin and a junction between them.

Bacteriorhodopsin → A membrane protein of some bacteria which can convert the energy of light into a proton gradient between the two sides of the plasma membrane.

Ballast resistor → A ~ compensates for normal or incidental changes in the physical state of a system.

Band gap → Describes the energy that needed to move an electron from the valance to the conduction band.

Band-pass filter → A band-pass filter is a device that passes frequencies within a certain range and rejects (attenuates) frequencies outside that range.

Bandpass filter → It is a device that passes frequencies within a certain range and blocks frequencies outside that range.

Band-stop filter → A band-stop filter or band-rejection filter is a filter that passes most frequencies unaltered, but attenuates those in a specific range to very low levels.