A. Glossary of the key notions in Bionics and beyond
17. N
N100 component → N1 is a negative-going evoked
potential measured by electroencephalography; it peaks in adults between 80 and 120 milliseconds after the onset of a stimulus, and distributed mostly over the fronto-central region of the scalp. It is elicited by any unpredictable stimulus in the absence of task demands. While most research focuses on auditory stimuli, the N100 also occurs for visual, olfactory, heat, pain, balance, respiration blocking and somatosensory stimuli.
N400 component → The N400 is part of the normal brain
response to words and other meaningful (or potentially meaningful) stimuli, including visual and auditory words, sign language signs, pictures, faces, environmental sounds, and smells.
Na-K-Cl cotransporter 1 (NKCC1) → A transporter protein targeting sodium, potassium, and chloride into the cell from the blood. It is commonly found in organs secreting fluids.
Nanobio-technology → ~ refers to nanotechnology applied to
biology.
Nanotechnology → ~ is the study of manipulating matter
on an atomic and molecular scale. Generally, ~ deals with structures sized between 1 to 100 nm, in at least one dimension, and involves developing materials or devices possessing at least one dimension within that size.
Quantum mechanical effects are very important at this scale, which is in the quantum realm.
Narrowband channel → The narrowband implies that the
channel under consideration is sufficiently narrow that its frequency response can be considered flat.
Near field → The ―near-field‖, which is inside
about one wavelength distance from the antenna, is a region in which there are strong inductive and capacitative effects from the currents and charges in the antenna, which do not behave like far-field radiation. These effects decrease in power far more quickly with distance (with r2 and r3), than does the far-field radiation power. Also, absorption of radiated power in this region has effects which feed-back to the transmitter
Negative bit → This bit is set to the value of the most
significant bit (sign bit) of the result of the previous operation.
Negative cooperativity → Cooperativity, where the binding of one ligand decreases the binding affinity at other sites.
Negative logic → If logical 1 corresponds to voltage
level L (low), then it is called negative logic.
Neighborhood → The cells in a given radius of a cell are called neighborhood
Neighbor-joining algorithm → Finds pairs of leaves close to each other but far from other leaves (that is, finding pairs of neighboring leaves), developed by Saitou and Nei
Nernst equation → An equation which relates the
reversal potential of an ion to its concentration gradient
Nerve conduction velocity → The speed of propagation of an action potential along a peripheral nerve.
Network models → ~ are graph-representations of
various biological and technical systems in which entities are represented as nodes (vertices) and relationships are denoted with edges.
Neural hearing loss → ~ is a hearing disordes in which the auditory nerve or other brain structures in the auditory pathway are damaged.
Neural interface → ~ is a connection between the living
tissue and a man-made device, in most case a bioelectrode.
Neural Network → An artifical network, whereas the results in deafness if the tumor is not removed surgically.
Neuromorph → Neural-like motor control. (Control
based on the activity of motor neurons)
Neuromuscular junction → The ~ is the synapse of the axon terminal of a motor neuron with the motor end plate. After the release of the neurotransmitter acetylcholine action potentials are initiated in the muscle to contract.
Neuromuscular stimulation (NMS) → ~ is a form of electrical stimulation that attempts to strengthen muscles weakened by disuse using sub-contraction stimulus to promote muscle growth.
Neuron → A cell, which is the most important
communication entity in the nervous system
Neuron (Neural Networks) → The basic artificial element of neural networks
Neuron doctrine → It is a descriptive term for the
fundamental concept that the nervous system is made up of discrete individual cells, a discovery due to decisive neuro-anatomical work of Santiago Ramon y Cajal (1852-1934).
Neuron membrane → A phospholipid bilayer that separates
the intracellular and the extracellular fluids. Each phospholipid molecule consists of a hydrophilic and a hydrophobic part. Molecules are organized into layers such that hydrophobic parts are inside the membrane, and hydrophilic parts contact with the external world. This structure makes the membrane not permeable for ions and charged molecules, thus a good dielectric.
Neuronal parameter optimization → The process of identifying sets of parameters that lead to a desired electrical activity pattern in a neuron or neuronal network model that is not fully constrained by experimental data.
Neuropathy → The disease of the motor neurons.
Neuroprosthetics → ~ is a discipline related
to neuroscience and biomedical engineering, its main activity is the development and application of neural prostheses.
Neurostimulator → ~ is a pulse generator encased in a
titanium housing. It can be programmed by radiofrequency way. Its electrical pulses interfere with neural activity at the stimulated site. It is usually implanted under the skin of the chest, wires go under the skin to the electrodes implanted to the brain.
Neurotransmission → The way of infomation-transmission
between neurons; through synapses by means of neurotransmitters.
Neurotrophic electrode → Cortically implanted glass
microelectrode filled with neurotrophic growth factors.
Neurotropic → A characteristic of certain agents (i.e.
viruses) which are capable of infecting nerve cells.
Neutrino → A ~ (λ), meaning ―small neutral
one‖; is an elementary particle that usually travels close to the speed of light, is electrically neutral, and is able to pass through ordinary matter almost unaffected. This makes neutrinos extremely difficult to detect. Neutrinos have a very small, but nonzero mass.
Newman projection → The ~ is a representation formulated
by Melvin S. Newman and it shows the spatial relationship of the atoms in a molecule. In a molecule, one particular carbon–carbon bond selected as an axis and viewed down drawing a projection of the carbons. All the attached groups are in the plane of the paper. The bonds from the atoms attached to the front carbon are represented by solid lines meeting at a central point that represents the front carbon atom. The bonds from the atoms attached to the rear carbon atom are eclipsed by the front carbon, are represented by short lines from these atoms to the periphery of a circle drawn around the central point.
Newton → Sir Isaac Newton (1643–1727 was an
English physicist, mathematician, astronomer, natural philosopher, alchemist, and theologian. His Philosophiæ Naturalis Principia Mathematica, 1687 (Principia), is one of the most important scientific books ever written. It lays the groundwork for most of classical mechanics. Newton described universal gravitation and the three laws of motion, which dominated the scientific view of the physical universe for the next three centuries. Newton showed that the motions of objects on Earth and of celestial bodies are governed by the same set of natural laws, and his theory of gravitation; thus removing the last doubts about heliocentrism and advancing the Scientific Revolution.
Newton‟s equations → Newton‘s laws of motion are three
physical laws that form the basis for classical mechanics. They describe the relationship between the forces acting on a body and its motion due to those forces.First law: Every body remains in a state of constant velocity unless acted upon by an external unbalanced force.Second law: the total force applied on a body is equal to the time derivative of linear momentum of the body.Third law: The mutual forces of action and reaction (action and the reaction are simultaneous) between two bodies are equal, opposite and collinear.
Nissl staining → A general staining method, which
stains the negatively charged RNA and DNA-containing cellular organelles blue with basic dyes.
Nitro compounds → ~ are compounds having the nitro
group (–NO2), which may be attached to carbon, nitrogen (as in nitramines), or oxygen (as in nitrates), among other elements (in the absence of specification, C-nitro compounds are usually implied).
Nitrogen fixation → Nitrogen is abundant in the
atmosphere, but the biological systems (with a few exceptions) can use only reduced form of nitrogen. Nitrogen is reduced by a Nitrogenease enzyme.
NMDA receptor → A type of ion-channel-coupled synaptic receptor for the neurotransmitter glutamate, whose activation also depends on postsynaptic depolarization, and which leads to a slow excitatory response mediated by the influx of Na+ and Ca2+ ions.
N-methyl-D-aspartic acid (NMDA) → NMDA is an amino acid derivative which binds to the NMDA type of glutamate receptor only.
Nociceptive stimulus → Low-intensity stimuli gain access to the nociceptive pathway and begin to produce pain.
Noise figure → It is ratio of SNR on the input versus
on the output.
Noise-limited systems → Cellular systems (e.g. WLAN,
cellular mobile) operate in this mode if the user density is low and/or if no other BS is in the vicinity
Nonbonding molecular orbital → ~ is a molecular orbital whose occupation by electrons does not contribute (or contributes insignificantly) to the binding energy of the molecule. Generally, a nonbonding MO represents the highest occupied molecular orbital of a molecule.
Non-competitive inhibitor → A reversible inhibitor, which
decreases the Vmax value and does not change the Km value of the enzyme
Non-invazive → Not penetrating the body, as by
incision or injection
Nonlinear activation function → The activation fuction of the neurons are nonlinear
Nonlinear component → A circuit element whose
voltage-voltage function shows a non-linear characteristic.
Nonlinear regression → A form of regression analysis in
which the dependent variables are modeled as a nonlinear function of the independent variables. B1553
Nonlinear resistor → A resistor is a two-terminal passive
electronic component that resists an electric current by producing a voltage drop between its terminals in accordance with Ohm‘s law. A resistor is used to create a known voltage-to-current ratio in an electric circuit.
Nonlinear resistors have resistances that vary significantly with, for example, the applied current or voltage, temperature or light.
Non-REM sleep (NREM) → Sleep stages characterized by slow
EEG activity.
Norton equivalent circuit → According to Norton‘s law, any
two-poles made up of generators and resistances can be substituted by a current generator, and the inner resistance parallel to it.
Notch filter → It is a filter that passes all
frequencies except those in a stop band
Novelty P300 → If in an active oddball paradigm
additional unexpected novel stimuli are rarely presented an earlier P300 component called ―novelty P300‖
appear.
NPC1 → Nieman-Pick C1 protei+B1577n, an
intracellular carrier of cholesterol
NP-hard problem → A problem that cannot be solved
generally in guarantied polinomial execution time (solution time could be so long, that we are not able to wait it!)
N-type doped → The addition of pentavalent (donor) impurities such as antimony, arsenic or phosphorous contributes free electrons. In n-type material there are extra energy levels near the top of the band gap so that electrons can be easily excited into the conduction band.
N-type material → It contains an excess of conduction
band electrons
Nuclear Magnetic Resonance (NMR) Spectroscopy → NMR (Nuclear Magnetic Resonance) spectroscopy involves the interactions of atomic nuclei simultaneously with two different magnetic fields: a strong fixed magnetic field and a much weaker field oscillating perpendicular to the a strong fixed field at radio frequencies. The spectroscopic signals generated by the nuclear–magnetic interactions give detailed information about the molecular environment of each atom, which is equivalent to molecular structure information including connectivity, geometry, proximity, dynamics, etc. NMR is the most powerful spectroscopic technique for the elucidation of molecular structure and dynamics.
Nuclear planetary model → Rutherford‘s new model/planetary
model (instead of the so-called ―plum pudding model‖ of J. J. Thomson, which proved to be incorrect) based on the experimental results, had the new features of a relatively high central charge concentrated into a very small core in comparison to the rest of the atom and containing the bulk of the atomic mass (the nucleus of the atom).
Nucleophilic (nucleophile) → A nucleophile (or ~ reagent) is a reagent that forms a bond to its reaction partner (the electrophile) by donating both bonding electrons. A
‗nucleophilic substitution reaction‘ is a heterolytic reaction in which the reagent supplying the entering group acts as a nucleophile.
Nucleotide synthesis → The amount of nucleotides uptaken
by diet is not sufficient for several cells, therefore their synthesis is important. They are produced mainly from amino acids. Purin ring is produced by 2Gln, Gly, 2 Formyl THF, CO2 and Asp. Pyrimidine is synthesized from carbamoyl phosphate and Asp.
Nucleus, nuclei → The ~ is the very dense region
consisting of nucleons (protons and neutrons) at the center of an atom. Almost all of the mass in an atom is made up from the protons and neutrons in the ~, with a very small contribution from the orbiting electrons. The diameter of the nucleus is in the range of 1.75 fm (1 fm=10-15 m) for hydrogen (the diameter of a single proton) to about 15 fm for the heaviest atoms (uranium). These dimensions are much smaller than the diameter of the atom itself (nucleus + electronic cloud), by a factor of about 23,000 (uranium) to about 145,000 (hydrogen).
Nullcline → A ~ is a set of points where the
the amplitude and latency of the exogenous components of the auditory EPs depends on the stimulus intensity.
Observable → In quantum physics, a system ~ is a
property of the system state that can be determined by some sequence of physical operations. These operations might involve submitting the system to various electromagnetic fields and eventually reading a value off some gauge. In systems governed by classical mechanics, any experimentally observable value can be shown to be given by a real-valued function on the set of all possible system states. Physically meaningful observables must also satisfy transformation laws which relate observations performed by different observers in different frames of reference.
Occipital cortex → A part of the cerebral cortex located
in the posterior lobe of the brain.