Glossary of the key notions in Bionics and beyond

Thought Translation Device (TTD) → TTD is a Brain-Computer Interface for the completely paralyzed patients using slow-cortical brain potentials and consists of a training device and spelling program.

Through-silicon vias (TSVs) → Interconnection of layers via holes in the layer substrate filled with conductive material.

Tidal Volume → The volume of air inhaled and exhaled at rest. Normal value is approx. 500 ml.

Time constant → The time during which the 63% (1-1/e) of the maximal action potential amplitude is reached. The bigger the time constant, the slower the rising phase of AP.

Time domain → ~ is a term used to describe the analysis of a signal, what is represented by a periodic function depending on time.

Time invariance → A property of a system. The property tells us that the time shift operation on a system is interchangeable with the sytem operator.

Time shift → An elementary operation used in system theory. Causes the signal to be delayed with k samples. This is a memory unit, it remembers it’s input for k time steps and after k time step it puts the value to it’s output and forgets it.

Time synchronization → Common clock signal and physical time play crucial role for operation of networks (eg.: in energy-aware communication, data aggregation and in monitoring application).

Time to Echo (TE) → Echo time. Time between middle of exciting (e.g., 90°) RF pulse and middle of spin echo production. For multiple echos, use TE1, TE2, etc. When the RF spin echo and gradient echo are not coincident in time, TE refers to the time of the gradient spin echo.

Time-domain aliasing → This occurs when the number of DTFT samples is less than number of discrete-time signal samples.

Time-evolution of the wave-function → If the wavefunction for a physical system is at an initial time and the system is free of external interactions, then the evolution in time of the wavefunction is given by the Hamiltonian operator formed from the classical Hamiltonian by substituting for the classical observables their corresponding quantum mechanical operators. The role of the Hamiltonian in both space and time is contained in the Schrodinger equation.

Time-evolution operator → The Hamiltonian generates the time evolution of quantum states.

Time-harmonic analysis → The 2^nd order (in time) differential equations of a system have many solutions. However, the number of solutions can be reduced by consideration of a less general case - propagation of fixed frequency waves - using the so called: ~. The analysis calculates waves at first in a frequency domain and then converts them back in original time-domain. It separates the time invariant and variant part of field. For separation we need phasor.

Time-harmonic fields → One of the most important cases of time-varying electromagnetic fields are the ~. In this type of field, the excitation source varies sinusoidally in time with a single frequency. In a linear system, a sinusoidally varying source generates fields that vary also sinusoidally in time at all points in the system. For time-harmonic fields we can employ phasor analysis to obtain the single–frequency (monochromatic) steady-state response.

Time-independent perturbation → ~ theory is one of two categories of perturbation theory, the other being time-dependent perturbation. In ~ theory the perturbation Hamiltonian is static (i.e., possesses no time dependence). ~ theory was presented by Erwin Schrödinger.

Timing critical path → The critical path is defined as the path between an input and an output with the maximum delay of all possible paths.

Timing slack → The ~ is the difference between the required and the arrival time. 

TinyOS → It is an open source, BSD-licensed operating system designed for low-power wireless devices.

TMS mapping → Performed by changing the coil position above the head while observing its effects.

Tomography → An important characteristic of PET and other conventional imaging techniques (eg fMRI, SPECT) is that they do not feature anatomical relations, but the different functional characteristics of organs and tissues (eg, blood flow, metabolism) in a given moment. Since the onset of a disease first damages the functional characteristics of organs and tissues, and usually anatomical changes accompanythese secondarily, it is important that the functional imaging techniques indicate the onset of a disease much earlier, even before anatomical changes.

Tonic activity → Regularly occuring neuronal activity composed of single spikes.

Tonotopy → Tones close to each other in terms of frequency are represented in topologically neighbouring regions in the cochlea and brain.

Topological equivalence → We say that the functions A, and B are topologically equivalent, if there is a homeomorphism h:X->Y, mapping orbits of A to orbits of B homeomorphically, and preserving orientation of the orbits. Topologically equivalent systems have qualitatively similar phase portraits with identical types and numbers of fixed points.

Topology of the network → A special collection of neurons and related synaptic weights

Toposcope → The ~ is the first brain topography method developed by William Grey Walter (1910-1977) in collaboration with an electronic engineer Harold W. Shipton. The device displays the spatial organization of the EEG activity of the brain.

Toroid boundary conditions → The value of the virtual cell is copied from the opposing side’s cell

Torque → ~, also called moment or moment of force is the tendency of a force to rotate an object about an axis or pivot. The magnitude of torque depends on: a) the force applied; b) the length of the moment arm connecting the axis to the point of force application c) the angle betweenthe force and the moment arm. (Can be computed as the cross product of the moment arm and the force vectors)

Torsion angles → ~ are angles between amide planes.

Torsional angle (Dihedral angle) → In the nonlinear bond sequence A-B-C-D, the angle around the B-C bond between the A-B and the C-D bonds. Torsion angle is also refered as ‘dihedral angle’ (literally, the angle between two planes). Alternatively, it can be defined as the angle between the ABC and the BCD planes.

Total Lung Capacity → The sum of the vital capacity and the value of the residual air. In the sace of an adult male it is approx. 6000 ml.

Total reflection → ~ is an optical phenomenon that happens when a ray of light strikes a medium boundary at an angle larger than a particular critical angle with respect to the normal to the surface. If the refractive index is lower on the other side of the boundary, no light can pass through and all of the light is reflected.

Totally-implanted → The implanted device is completely concealed in the body.

Tourette syndrome → ~ is a neurological disorder with a strong genetic component and onset in childhood. It is characterized by multiple motor and phonic tics. Tics are repetitive stereotyped motor movements or vocalizations involving discrete muscle groups.

TR → Repetition Time between radio-frequency excitation pulses

Traceability → The result of a measurement is said to be traceable if, through an unbroken chain of comparisions, the result can be compared with a primary standard.

Training sequence (communication) → A predefined sequence, which is known by the sender and reciever either.

Training sequence (Neural Networks) → The weights of the network are set by the training sequence. A training clue is a pair of input and desired output.

Trajectory → Temporal path of consequent states

Transaminases → Enzymes catalyzing the reversible transfer of amino group from an amino acid to an oxo acid resulting a new amino acid and a new oxo acid

Transcranial magnetic stimulation (TMS) → A noninvasive method to cause depolarization in the neurons of the brain. TMS uses electromagnetic induction to induce weak electric currents using a rapidly changing magnetic field; this can cause activity in specific or general parts of the brain with minimal discomfort, allowing the functioning and interconnections of the brain to be studied.

Transcription → The process through which an RNA copy is synthesized from a template DNA molecule.

Transcriptome → All the RNA molecules that are present in a cell or organism at a given time.

Transducer → The ~ is a device which converts one type of energy into another. Examples are loudspeakers, microphones, thermometers, position sensors, pressure sensors and antenna.

Transfer delay → The difference between the centroids of the voltage response at an arbitrary location and the inducing current measured at the point of injection.

Transfer function → A mathematical statement that describes the transfer characteristics of a system, subsystem, or equipment

Transfer impedance → A complex-valued quantity characterizing the ratio of the voltage applied at one pair of terminals of a network to the resultant current at another pair of terminals, for sinusoidal input at a given frequency. In neurons, it is often defined as the ratio of the membrane potential change measured at some point in the cell and the amplitude of the injected current at another location, and contains information on both the ratio of amplitudes and the difference in phase.

Transfer resistance → The ratio of steady-state membrane potential change at some point in the cell and the amount of injected stationary current at another point. Transfer impedance at zero frequncy.

Transferase → An enzyme which catalyzes the transfer of composite chemical groups between two molecules

Transgenics → The study and practice of genetic modification by inserting genes from one species into the genetic material of another species.

Transient current → Fast current that lasts for a few milliseconds after an appropriate change in the membrane potential.

Transition probability → The changes of state of the system are called transitions, and the probabilities associated with various state-changes are called transition probabilities. We assume all possible states and transitions have been included in the definition of the processes, so there is always a next-state and the process goes on forever. The transition probabilities depend only on the current position, not on the way the position was reached.

Transition state → A ~ is a hypothetical thermodynamic state corresponding to the maximum in the reaction profile of a single reaction step.

Transition state analogues → Molecules which have a shape similar to that of the substrate.

Transition state fit → A model for substrate binding which assumes that it is the transition state which has a shape complementer to the binding surface.

Transition state theory → A model describing the reaction rate by assuming an activated complex with a short but finite lifetime and its equilibrium with the reactants. This theory is able to derive the rate constant from the quantum mechanical properties of the activated complex and the reactants.

Transition structure → A ~ is the hypothetical motionless assembly or arrangement of atoms which corresponds to the maximum in the potential energy profile (or the saddle point on the potential energy surface) describing the transformation of reactant(s) into product(s) in a single reaction step. This term is usually applied to structures which are the outcome of theoretical chemical calculations and corresponds to an arrangement of atoms without vibrational or rotational motion.

Translation (biology) → The process of protein synthesis on the ribosomes. The genetic information encoded in the mRNA is translated into a polypeptide sequence.

Transmembrance proteins → Membrane proteins which extend over the membrane.

Transmembrane (integral) proteins → Proteins embedded in the membrane, they reach both sides of the membrane. ~ means: through the membrane.

Transmitted wave → The refracted (transmitted) wave corresponding to a given incident ray represents the wave that is transmitted through the surface. The angle between this ray and the normal is known as the angle of refraction, and it is given by Snell’s Law.

Transmitter coil → The ~ is located in the external unit of the cochlear implant, outside the body, adjacent to the speech processor. It transmits data to the receiver coil and in some cases receives also back telemetry information from the implanted internal unit.

Transplantation → A medical intervention, when a part of an organ or the whole organ is moved from one organism to another.

Transverse Electric (TE) → TE modes (Transverse Electric) no electric field component in the direction of propagation.

Transverse ElectroMagnetic (TEM) → TEM modes (~) neither electric nor magnetic field component in the direction of propagation.

Transverse Magnetic (TM) → TM modes (~) no magnetic field component in the direction of propagation.

Transverse mode → A ~ of a beam of electromagnetic radiation is a particular electromagnetic field pattern of radiation measured in a plane perpendicular (i.e. transverse) to the propagation direction of the beam.

Tremor → A repeated contraction and relaxation of the muscle, which results in involuntary, shaking movement.

Triboelectric effect → A type of contact electrification in which certain materials become electrically charged after they come into contact with another different material and are then separated. For example rubbing amber with wool.

Trigger circuit → The ~ gives (trigger) pulses when the input signal voltage exceeds a given pre-set voltage value.

Triglycerids → ~ are compounds where a glycerol is esterized by three fatty acids on its hydroxyl groups.

Triple bond → ~ is a covalent bond formed when two atoms share three pairs of electrons.

Truncate → To shorten, to cut (from the latin word:B2663 truncare)

Truth table → We often make simple, bivalent decisions with simple, two possible conditions. This can be represented in a table. In this table, we simply write down under what conditions the decision will be true and false. This table is called ~.

Tumor necrosis factor-alpha (TNFα) → A cytokine, which promotes inflammation and stimulates the acute phase response.

Tuning curve → The average firing rate of a neuron as a function of the stimulus influencing the neuron.

Tunneling → It is a quantum-mechanical effect where a particle crosses through a classically-forbidden potential energy barrier. A particle approaching a potential step of height bigger then the electron’s own energy: classically the particle would be reflected by the step. An incident quantum particle has a nonzero probability for being found to the other side of the step.

Turn → Directional change of the waveform of the motor unit potential not necessarily crossing the baseline.

Turn → Non periodic, short but structured secondary structural elements.

Turnover number → The ~ of an enzyme is the number of molecules converted into product when the enzyme is fully saturated by substrate. It is often denoted as kcat.

Twisted Pair → The wires are twisted together in pairs, thus reducing the distorting effects of electromagnetic and radio frequency interference. Crosstalk between unshielded pairs is reduced by the different twisting of the pairs.

Twitch contraction → A short stimulation burst makes the muscle contracted but the duration is short in time thus the muscle begins its relaxing period before reaching peak force

Two body problem → It describes the motion of two particles as a motion of one particle around an other based on separating of relative motion and the motion of the centre of mass with respect to the system consisting of the two particles.

Two-state atom → A two-state system is a system which has two possible quantum states. More formally, the Hilbert space of a two-state system has two degrees of freedom, so a complete basis spanning the space must consist of two independent states. An example of a two-state system is the spin of a spin -1/2 particle such as an electron, whose spin can have values +½ or -½ in units of ħ. The physics of a quantum mechanical two-state system is trivial if both states are degenerate, that is, if the states have the same energy. However, if there is an energy difference between the two states, then nontrivial dynamics can occur.

Tympanic membrance → The tympanic membrane (eardrum) is a membrane sheet that separates the outer ear from the middle ear and transmits the sound vibrations from the air to the ossicles in the middle ear.

24. U

Ubiquitin → Intracellular 76-residue protein which can be covalently linked through its C-terminal residue to lysine side chains of other proteins and targets them to degradation by proteasomes

Ubiquitination → Addition to the side chain of a lysine residue of a polypeptide of a ubiquitin monomer already attached to a target protein

Ubiquitous communication → Ubiquitous wireless communications are developing as a part of next generation networks.

UI → User interface.

Ultrasound → Mechanical vibration, its frequency is higher than what a human’s ear can hear

Ultraviolet → ~ (UV) light is electromagnetic radiation with a wavelength shorter than that of visible light, but longer than X-rays, in the range 10 nm to 400 nm, and energies from 3eV to 124 eV. It is so named because the spectrum consists of electromagnetic waves with frequencies higher than those that humans identify as the color violet.

Ultraviolet catastrophe → The ~ was a prediction of late 19th century/early 20th century classical physics that an ideal black body at thermal equilibrium will emit radiation with infinite power.

Ultraviolet light (UV) → An electromagnetic radiation with a wavelength expanding from 40 nm to 400 nm (thus under the visible spectrum).

Ultraviolet Spectroscopy → UV (Ultraviolet) spectroscopy is an optical spectroscopy method which employs ultraviolet radiation. It provides structural information about the extent of π electron conjugation in compounds.

Ultrawideband (UWB) technology → It is a radio technology that can be used for short-range high-bandwidth communications.

Uncertainty relation → It states by precise inequalities that certain pairs of physical properties (such as position and momentum) cannot be simultaneously known to arbitrarily high precision.

Uncoupled template → The cell is not connect with itself, the a00 values is zero

Uncoupling → Oxidation (oxygen consumption) is not coupled to phosphorylation (ATP) synthesis. Oxidation is fast, ATP synthesis is slow or non-existent. P/O ratio is low, even could be zero.

Under sampling → For the bandpass signal one may sample below the Nyquist rate.

Uniform plane wave → Plane wave in which the electric and magnetic intensities have constant amplitude over the equiphase surfaces; such a wave can only be found in free space at an infinite distance from the source. The simplest electromagnetic waves are ~ propagating along some fixed direction in a lossless medium. The assumption of uniformity means that the fields have no dependence on the transverse coordinates.

Uniform quantization → The input values of quantizer has a linear relationship with the output value.

Unipennate muscle → All muscle fibres are on the same side of the tendon (hand muscles)

Uniport → Facilitated diffusion of a single substrate down its electrochemical gradient

Uniqueness theorem → ~ is a uniqueness result for linear partial differential equations with real analytic coefficients. If a solution is found, by whatever means, it is the solution.

Unit ramp function → A special DTS used for system analysis, where the elements value are equal with the value of the time instant for time instants greater or equal then 0 otherwise 0.

Unit step function → A special DTS used for system analysis, where the elements value are 1 for time instants greater or equal then 0 otherwise 0.

Unit vector → A ~ in a normed vector space is a vector (often a spatial vector) whose length is 1 (the unit length).

Univariate analysis → Methods for analyzing data on a single variable at a time.

Universal set → The complement of the empty set is the universial set in the Boolean algebra. The symbol of the universial set is 1. The complement of the ~ is the 0 set.

Unsaturated hydrocarbons → ~ are hydrocarbons that have double or triple covalent bonds between adjacent carbon atoms.

Unstable → A point in the phase space is ~, if the system moves away from this point, if left alone.

Unsupervised data mining → During the training process only the data collected in the experiment and no prior knowledge of classes are used

Unsupervised learning → A learning algorithm where the agent receives x1,x2,... inputs, but obtains neither target outputs, nor rewards from the environment. ~ can be thought of as finding patterns in the input data. Simple examples are clustering and dimensionality reduction.

Up-quark → The ~ or u quark (u) is the lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the down quark, forms the neutrons (one ~, two down quarks) and protons (two up quarks, one down quark) of atomic nuclei. It has an electric charge of +²⁄₃e and a bare mass of 1.5–3.3 MeV/c². The up quark is an elementary fermion with spin -¹⁄₂, and experiences all four fundamental interactions. The antiparticle of the ~ is the up antiquark.

Uptake of amino acids by human; protein digestion → diet proteins are hydrolyzed in the gastrointestinal tract by pepsin, trypsin, chymotrypsin, elastase and carboxypeptidase-A and the aminoacids released are transported into the blood circulation

25. V

Vacuum → ~ (Latin term for “empty”) is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. A perfect ~ would be one with no particles in it at all, which is impossible to achieve in practice. Physicists often discuss ideal test results that would occur in a perfect vacuum, which they simply call “vacuum” or “free space”, and use the term partial ~ to refer to real ~.

Vagus nerve → The tenth cranial nerve with mixed motor and sensory, somatic and autonomic functions.

Valence band → In solids, the valence band is the highest range of electron energies in which electrons are normally present at absolute zero temperature. The valence electrons are bound to individual atoms. The ~ below the conduction band, separated from it in insulators and semiconductors by a band gap. In metals, the conduction band has no energy gap separating it from the valence band.