Glossary of the key notions in Bionics and beyond

Stereotaxic frame → The Horsley-Clarke apparatus invented by Sir Victor A. H. Horsley (1857-1916) and Robert C. Clarke in 1908 was the first stereotaxic frame. The device is used for animal experimentation by implementing a Cartesian coordinate system.

Stereotaxic technique → Surgical technique which makes use of of a three-dimensional coordinates system to locate small targets inside the body

Steric acceleration → ~ is a steric effect on a rate process may result in a rate increase.

Steric effect → The effect on a chemical or physical property (structure, rate or equilibrium constant) upon introduction of substituents having different steric requirements. The ~ in a reaction is ascribed to the difference in steric energy between, on the one hand, reactants and, on the other hand, a transition state (or products). A ~ on a rate process may result in a rate increase (‘steric acceleration’) or a decrease (‘steric retardation’).

Steric hindrance → ~ is steric effect arising from crowding of substituents.

Sterochemistry → The subdiscipline of chemistry dealing with the spatial (i.e., three-dimensional) relarelationships between the atoms in molecules.

Steroids → A group of lipid some members of which take also part in the building of biological membranes.

Stiffness → The resistance of an elastic material to deformation by a force along a given degree of freedom

Stimulated emission → ~ is the process by which an atomic electron (or an excited molecular state) interacting with an electromagnetic wave of a certain frequency, may drop to a lower energy level transferring its energy to that field. A photon created in this manner has the same phase, frequency, polarization, and direction of travel as the photons of the incident wave.

Stimulating electrodes → ~ elicit excitation electrically in neural or muscle tissue by charge injection.

Stimulation rate → The ~ is the number of pulses per second used in case of pulsatile stimulation. It is measured in Hz.

Stirling → James Stirling (1692–1770) was a Scottish mathematician.

Stirling approximation → Stirling’s approximation is an approximation for large factorials. Stirling’s approximation gives an approximate value for the factorial function or the gamma function

Stoichiometry (chemistry) → Describes the ratio of the constituents (see law of definite proportions)

Stopping criteria → The predefined condition when the learning loop is finished.

Stopping potential → In the photoelectric effect or thermionic action, a current, the outward movement of electrons can be produced. The ~ is the voltage that reduces this current to zero.

Storage capacity → The maximum number of patterns, which can be stored in the network.

Strain gauge → A ~ is a device that measures the elongation of a body. Its main type is made of an elastic electric insulating film, which is covered by an electricity conducting layer of the appropriate shape. Is the body is going through a change of shape, the ~ undergoes a deformation, too, and the conductor’s resistance changes.

Strained silicon → The silicon crystal is strained by SiGe to increase electron mobility.

Strech reflex → ~ is a muscle contraction in response to stretching within the muscle. It is a monosynaptic reflex which provides automatic regulation of skeletal muscle length.

Stress test → Before the test, ECG electrodes are connected to the body, and a blood pressure cuff is placed on the arm. The patient is asked to perform treadmill or exercise bike move. The ECG machine records the electrical signals from the heart on a paper tape. Before the test, a target heart rate per minute was set. The load, i.e. the difficulty of turning the pedal or the speed of the runner may be increased gradually. The test is over, if the test person has reached the prescribed heart rate, or if during the test, chest pain (angina) occurs, if blood pressure is too high or ECG abnormalities occur.

Stroke → A rapidly developing loss of brain function(s) due to disturbance in the blood supply of the brain.

Strong acid → Strong acids are ionizing completley in water. Ka >> [H2O]

Strong base → Strong bases are ionizing completley in water.

Strong nuclear force → The strong interaction/strong force/strong nuclear force/colour force is one of the four fundamental interactions of nature. It is a non-contact force. At atomic scale, it is about 100 times stronger than electromagnetism, which in turn is orders of magnitude stronger than the weak force and gravitation. The strong interaction is observable in two areas: on the larger scale, it is the force that binds protons and neutrons together to form the nucleus of an atom. On the smaller scale, it is also the force that holds quarks and gluons together to form the proton, the neutron and other particles. The strong force is thought to be mediated by gluons, acting upon quarks, antiquarks, and the gluons themselves. This is detailed in the theory of quantum chromodynamics (QCD).

Structure in systems theory → An arrangement of the elements or relationships of a system that is constant in space and time.

Subdural electrode grid → Electrodes are fiuxed in a plastic plate forming an electrode matrix. Grids are usually implanted subdually in patients to localize epileptic focus.

Submaximal stimulation → ~ means maintaining a lower current or voltage intensity than used in case of supramaximal stimulation.

Subretinal → A approach to threat the retina near the photoreceptors.

Subroutine → Part of the code of a bigger program, which executes a given task, it is relatively independent of the other parts of the code, and it can be used several times.

Subset → A ~ is the group of the elements of a set that are characterized by further characteristics, and also considering as a set.

Substituent → Atom or group of atoms in an organic compound that are not part of the main chain or ring but are bounded to it.

Substituent effects → ~ result from the size of the substituent on the reaction site. Steric hindrance (steric resistance) occurs when the size of groups within a molecule prevents chemical reactions that are observed in related smaller molecules. Although steric hindrance is sometimes a problem, it can also be a very useful tool, and is often exploited by chemists to change the reactivity pattern of a molecule by stopping unwanted side-reactions (steric protection). (Substituents may also have inductive and mesomeric effect as well)

Substitution reaction → Substitution is a reaction (elementary or stepwise), in which one atom or group in a molecular entity is replaced by another atom or group.

Substitutive name → ~ is a name which indicates the exchange of one or more hydrogen atoms attached to a skeletal atom of a parent structure or to an atom of a characteristic group for another atom or group, which may be expressed by a suffix or by prefixes.

Substitutive nomenclature → ~ is a system of naming compounds. The name of the substituted compound is derived by the formal replacement of a hydrogen atom the substituted compound is derived by the formal replacement of a hydrogen atom. The name of the functional or replacement group, called the substituent, provides the suffix after the name of the parent hydrocarbon.

Substrate → It is converted by enzymes.

Substrate coupling → Cross effects between devices through the substrate

Substrate level phosphorylation → Formation of ATP by phosphoryl group transfer from a compound having high energy bound

Subtractive name → Subtractive is a name for a modified parent structure in which prefixes and/or suffixes indicate the removal of atoms or groups and, where required, replacement by an appropriate number of hydrogen atoms.

Successive Approximation Register (SAR) → A successive approximation is a type of analog-to-digital converter (ADC) that converts a continuous analog waveform into a discrete digital representation via a binary search through all possible quantization levels before finally converging upon a digital output for each conversion.

Successive ionization energy → The amounts of energy that are required to remove one electron after another from an atom

Sulcus → A depression or fissure in the surface of the brain.

Sulfonamides → ~ are amides of sulfonic acids, having the structure RS(=O)2NR’2.

Sulfones → ~ are compounds having the structure, RS(=O)2R .

Sulfoxides → ~ are compounds having the structure R2S=O.

Superacids → Acids that have acidity greater than pure sulfuric acid (pKa=-3)

Superconducting quantum interference device (SQUID) → SQUID is a very sensitive magnetometer used to measure extremely weak magnetic fields, based on superconducting loops.

Superposition → The theory of ~ says that in a network of many generators, the resultant excitation can be calculated as the sum of the partial excitements made by the individual generators.

Supervised data mining → During the training process prior knowledge of classes is used

Supervised learning → A learning task or algorithm where the agent is given inputs x1,x2,..., as well as desired outputs y1,y2,..., and the goal of the agent is to learn to produce the correct output given a new input.

Suprachiasmatic nucleus (SCN) → A group of neurons located in the hypothalamus dorsal to the optic chiasm. The master pacemaker controlling circadian rhythms.

Suprafacial reaction → In a ~ the new bond is formed on the same side of the π bond (or conjugated system) present in the substrate.

Supramaximal stimulation → ~ means that the stimulation current or voltage intensity is slowly increased until the recorded response potential is at its maximum.

Surface EMG (SEMG) → Electrical activity of muscles measured through the skin.

Surface micromachining → Not the substrate is manufactured, but structures are build on top of it

Surface tension → The amount of work required to create new area on the surface of a liquid

Surfactant → Secretioncontaining phospholipids and several specific proteins that coats the surface of lung alveoli preventing their collapse through lowering their surface pressure

SVM (Support vector machine) → ~ is a type of classificator algorithm.

Symbolic analysis → Based on simplified empirical models, than symbolic mathematics helps to simplify dependences (e.g. Maple, Matlab, Mathematica)

Symmetric → Symmetry (Greek συμμετρειν ~to measure together), meaning is a precise and well-defined concept of balance or “patterned self-similarity” that can be demonstrated or proved according to the rules of a formal system: by geometry, through physics or otherwise.

Symport → Cotransport to the same direction.

Symporter (cotransporter) → A transporter which mediates passage of two substances in the same direction, with strict stoichiometric coupling

Synapse → The contact point where neurons transfer information to a target structure

Synaptic kernel → A function that describes the time course of the synaptic current or conductance in response to a synaptic spike arriving at t=0.

Synaptic potential → Alteration in the membrane potential of a cell resulting from activation of a synaptic input.

Synaptic vesicle → A vesicle in the vicinity of presynaptic membrane, which contains neurotransmitter molecules.

Synaptobrevin → Membrane protein associated with synaptic vesicles

Synaptotagmin → Membrane protein associated with synaptic vesicles

Synchronized EEG → The term used to describe EEG with high amplitude low frequency rhythmic activity.

Synchronous → Having the same frequency and zero phase difference.

Synchronous BCI → BCI in which the users can only send messages or commands time locked to a cue given by the system. These BCIs are also called cue-based or cue-paced.

Synchronous reaction → Synchronous is the term applied to two or more changes occurring at exactly the same time in a single step reaction; such changes are necessarily concerted.

Synergy → the cooperation (collaboration) of individual parts of a system.

Synthesis (chemistry) → An enzyme-catalyzed chemical process resulting in complex products formed out of substrates.

Synthesis (VLSI methods) → Mapping of logic functions to gates.

Systemic psychophysiology → Description of areas of psychophysiology in terms of physiologial systems. Cardiovascular, respiratory, gastrointestinal.

Systems → Any part of reality that can be approximately separated from the environment by a boundary and consists of interacting parts can be considered as a system. Examples include, living ~, social ~, technological ~ etc.

Systems biology → The branch of science that studies the complex interaction network (between genes and gene products) in biological systems.

Systems theory → A general theory that tries to explain the commonalities in the systems defined in various fields of science. ~ is not a science but an approach or paradigm that helps to define concepts and trends within various sciences. It was founded by Austrian born biologist Ludwig von Bertalanffy (1901-1972)

23. T

T1 (Spin-lattice or longitudinal relaxation time, nuclear physics) → ~ is the characteristic time constant for spins to tend to align themselves with the external magnetic field. Starting from zero magnetization in the z direction, the z magnetization will grow to 63% of its final maximum value in a time ~.

T1-weighted (T1W, biomedical imaging) → Often used to indicate an image where most of the contrast between tissues or tissue states is due to differences in tissue T1. This term may be misleading in that the potentially important effects of tissue density differences and the range of tissue T1 values are ignored. A T1 contrast state is approached by imaging with a TR short compared to the longest tissue T1 of interest and TE short compared to tissue T2 (to reduce T2 contributions to image contrast). Due to the wide range of T1 and T2 and tissue density values that can be found in the body, an image that is T1-weighted for some tissues may not be so for others.

T2 (Spin-spin or transverse relaxation time, nuclear physics) → ~ is the characteristic time constant for loss of phase coherence among spins oriented at an angle to the static magnetic field, due to interactions between the spins, with resulting loss of transverse magnetization and MR signal. Starting from a nonzero value of the magnetization in the xy plane, the xy magnetization will decay so that it loses 63% of its initial values in a time T2, if relaxation is characterized by a simple single exponential decay.

T2* (T2-weighted (T2W). → The observed time constant of the FID due to loss of phase coherence among spins oriented at an angle to the static magnetic field, commonly due to a combination of magnetic field inhomogeneities, ΔB, and spin-spin transverse relaxation with resultant more rapid loss in transverse magnetization and MR signal. MR signals can usually still be recovered as a spin echo in times less than or on the order of T2. 1/T2* ≅ 1/T2 + Δω/2; Δω = γΔB. Note that the FID will generally not be an exponential, so that T2* will not be unique.

T2-weighted image (T2W) → ~ often used to indicate an image where most of the contrast between tissues or tissue states is due to differences in tissue T2. This term may be misleading in that the potentially important effects of tissue density differences and the range of tissue T2 values are often ignored. A T2 contrast state is approached by imaging with a TR long compared to tissueT1 (to reduce T1 contribution to image contrast) and a TE between the longest and shortest tissue T2s of interest.

Talairach coordinates → Human brain coordinate system developed by French neurosurgeon Jean Talairach

Tandem mass spectrometer (MS/MS) → Involves two steps of mass spectrometry: fragmentation of peptides and then acceleration of the fragmentd ions

Tapped delay line → A delay-line tap extracts a signal output from somewhere within the delay line, optionally scales it, and usually sums with other taps for form an output signal.

Technology node → A ~ is defined by the smallest feature printed in a repetitive array.

Telemetry → ~ allows the remote measurement and reporting of information. In case of cochlear implants telemetry is a feedback loop that monitors critical electric and neural activities in the implant and transmits these information back to the external unit. Back ~ allows the external unit to check status of the internal unit and to measure and monitor critical information regarding the electrode-tissue interface.

Telencephalon → The anterior subdivision of the embryonic forebrain or the corresponding part of the adult forebrain that includes the cerebral hemispheres and associated structures

Template (CNN) → Operator - weights of the connections, there are two templates A and B feedback, and input synaptic cloning template

Temporal resolution → The shortest time duration between two events that can be measured with an MR experiment.

Tendon → A ~ is a tough band of fibrous connective tissue that connects muscle to bone and is capable of withstanding tension.

TENS (Transcutaneous electrical nerve stimulation) → ~ is the use of electric current produced by a device to stimulate the nerves for therapeutic purposes

Tensor → Tensors are geometric entities introduced into mathematics and physics to extend the notion of scalars, geometric vectors, and matrices to higher orders. Tensors were first conceived as part of the absolute differential calculus. Many physical quantities are naturally regarded not as vectors themselves, but as correspondences between one set of vectors and another. Because they express a relationship between vectors, tensors themselves are independent of a particular choice of coordinate system. The coordinate-independence of a ~ then takes the form of a “covariant” transformation law that relates the array computed in one coordinate system to that computed in another one.

Terc-amino effect → ~ operates in some ortho-substituted tertiary anilines: an unusual cyclization reaction proceeds with formation of a new bond to afford a fused-ring system.

Tertiary alcohol → ~ is an alcohol that has three alkyl group bounded to the carbon atom with the hydroxyl group.

Test board → A device used for circuit testing. Circuit elements can easily connect to this device. Its contact points are pre-wired for different purposes.

Testing set → Training samples for testing the FFNN after the learning procedure

Tetanic contraction → The stimulation is long enough so that the muscle may reach the peak force and stays at maximum level

Tetrad → A 4 long binary sequence.

Tetrode → An electronic device having four active electrodes. The idea is that the four electrodes are spaced close enough to each other to detect overlapping populations of neurons, but wide enough so that the exact waveform of the individual neurons are different on each of the electrodes.

Tetrodotoxin (TTX) → The neurotoxin, which inhibits the action potential firing of neurons by blocking the sodium channels.

Thematic psychophysiology → Organized in terms of topics to study. Cognitive psychophysiology, developmental psychophysiology, social psychophysiology, clinical psychophysiology.

Theoretical error (Neural Network) → The difference of the F function to be taught to the network and the actual approximation of the F function.

Thermal equilibrium → A higher temperature object which is in contact with a lower temperature object will transfer heat to the lower temperature object. The objects will approach the same temperature, and in the absence of loss to other objects, they will then maintain a constant temperature. They are then said to be in thermal equilibrium.

Thermal noise → It is electronic noise generated by the thermal agitation of the charge carriers (usually the electrons) inside an electrical conductor at equilibrium, which happens regardless of any applied voltage

Thermionic electron emission → Thermionic emission is the heat-induced flow of charge carriers from a surface or over a potential-energy barrier. This occurs because the thermal energy given to the carrier overcomes the binding potential, also known as work function of the metal.

Thermodynamic control → ~ is the term characterizes conditions that lead to reaction products in a proportion governed by the equilibrium constant for their interconversion and/or for the interconversion of reaction intermediates formed in or after the rate-limiting step.

Thermodynamic equilibrium → It is a state of a system, where the thermodynamic variables do not change and no macroscopical processes can be observed.

Thermodynamic system → A system being investigated thermodynamically in a particular study.

Thermodynamic variables → Measures that characterize the state of a macroscopic system. Their values only depend on the state itself regardless the route through which the system reaches it. Mathematically, they are exact differentials. They can be extensive or intensive properties.

Thermodynamics → ~ is the science of energy conversion involving heat and other forms of energy, most notably mechanical work. It studies and interrelates the macroscopic variables, such as temperature, volume and pressure, which describe physical, thermodynamic systems.

Theta EEG band → EEG activity with frequency between 4 and 8 Hz.

Thevenin equivalent circuit → Any electrical circuits containing current-, voltage generators or resistances can be replaced by its equivalent voltage generator.

Thiazole → ~ is a heterocyclic aromatic organic compound with three carbon atoms and one sulfur (at position 1) an one nitrogen (at position 3). (formula C3H3NS)

Thioethers → ~ (sulfides) are compounds having the structure RSR.

Thiols → ~ are compounds having the structure RSH. They are also known by the term mercaptans.

Thiophene → ~ is a heterocyclic aromatic organic compound, consisting of a five-membered ring with four carbon atoms and one sulfur. (formula C4H4S)

Third law of thermodynamics → The entropy of homogeneous material systems is zero at temperature T=0.

Thoracic injuries → Generally causes paraplegia. Normal movement functions of the neck, hand and thorax are usually not effected. (damage (motor/sensory) of the lower limb)