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[[File:Rabbit or duck.jpg|right|300px|thumb|'''Graphical ambiguity:''' ''Fliegende Blätter'' (1892-10-23): Perception versus interpretation (Ludwig Wittgenstein) or paradigm shift (Thomas Kuhn)]]
The '''ambiguity crisis''' is a contemporary crisis comparable to the credibility or [[reproducibility crisis]] in the biomedical sciences. The term 'crisis' is rooted etymologically in the Greek word ''krinein'': meaning to 'separate, decide, judge'. In this sense, science and communication in general are a continuous crisis at the edge of separating clarity or certainty from confusing double meaning, or obscure 'alchemical' gibberish, or even fake-news. Reproducibility relates to the condition of repeating and confirming calculations or experiments presented in a published resource. While ambiguity is linked to relevant issues of reproducibility, it extends to the communications space of terminological and graphical representations of concepts. Type 1 ambiguities are the inevitable consequence of conceptual evolution, in the process of which ambiguities are replaced by experimentally and theoretically supported paradigm shifts to clear-cut theorems. In contrast, type 2 ambiguities are traced in publications that reflect merely a disregard and ignorance of established concepts without an attempt to justify the inherent deviations from high-quality science. There are many shades of grey between these types of ambiguity. +
'''Concentrated ammonia solution''' (25 % - 30 % ammonium hydroxide solution, ammonia) is used for the service of the polarographic oxygen sensor OroboPOS. After opening the commercial solution, the concentration of ammonia may decline during storage and may render the ammonia stock ineffective for sensor service.
'''Source:''' A commercially available solution from a drugstore is sufficient for this cleaning purpose +
The '''amount of substance''' ''n'' is a base physical quantity, and the corresponding SI unit is the [[mole]] [mol]. Amount of substance (sometimes abbreviated as 'amount' or 'chemical amount') is proportional to the number ''N''<sub>''X''</sub> of specified elementary entities ''X'', and the universal proportionality constant is the reciprocal value of the [[Avogadro constant]] ([[Bureau International des Poids et Mesures_2019_The International System of Units (SI) |SI]]),
''n''<sub>''X''</sub> = ''N''<sub>''X''</sub>·''N''<sub>A</sub><sup>-1</sup>
''n''<sub>''X''</sub> contained in a system can change due to internal and external transformations,
d''n''<sub>''X''</sub> = d<sub>i</sub>''n''<sub>''X''</sub> + d<sub>e</sub>''n''<sub>''X''</sub>
In the absence of nuclear reactions, the amount of any atom is conserved, ''e.g.'', for carbon d<sub>i</sub>''n''<sub>C</sub> = 0. This is different for chemical substances or ionic species which are produced or consumed during the [[advancement]] of a reaction r,
:::: [[File:Amount dn.png|100px]]
A change in the amount of ''X''<sub>''i''</sub>, d''n''<sub>''i''</sub>, in an open system is due to both the internal formation in chemical transformations, d<sub>r</sub>''n''<sub>''i''</sub>, and the external transfer, d<sub>e</sub>''n''<sub>''i''</sub>, across the system boundaries. d''n''<sub>''i''</sub> is positive if ''X''<sub>''i''</sub> is formed as a product of the reaction within the system. d<sub>e</sub>''n''<sub>''i''</sub> is negative if ''X''<sub>''i''</sub> flows out of the system and appears as a product in the surroundings ([[Cohen 2008 IUPAC Green Book]]). +
'''Amp calibration''' indicates the calibration of the amperometric O2k-channel. +
The ampere, symbol A, is the SI unit of electric current. It is defined by taking the fixed numerical value of the elementary charge ''e'' to be 1.602 176 634 × 10<sup>−19</sup> when expressed in the unit C, which is equal to A s, where the second is defined in terms of Δ''ν''<sub>Cs</sub>. +
After selection of the Amperometric, Amp channel in the '''[[O2k configuration]]''', an Amperometric, Amp tab will appear in the '''O2k control''' [F7] window. Set the desired light intensity (0-1600) in the field ´Fluo intensity´ and the desired amplification of the signal (1-1000) in the field ´Gain for Fluo sensor´in the Amperometric, Amp window followed by a left-click '''Send to O2k'''. Switching off the [[Illumination on/off|illumination]] before each fluorometric measurement is routinely required. +
'''Amplex<sup>®</sup> UltraRed''' (AmR) is used as an [[extrinsic fluorophores |extrinsic fluorophore]] for measurement of [[hydrogen peroxide]] production ([[ROS]]) by cells or mitochondrial preparations. The reaction of H<sub>2</sub>O<sub>2</sub> and AmR is catalyzed by [[horseradish peroxidase]] to produce the red fluorescent compound [[resorufin]] (excitation wavelength 563 nm, emission 587 nm; the fluorescent product according to the supplier is called UltroxRed in the case of Amplex<sup>®</sup> UltraRed which has a similar structure to resorufin). The change of emitted fluorescence intensity is directly proportional to the concentration of H<sub>2</sub>O<sub>2</sub> added, whereby the H<sub>2</sub>O<sub>2</sub> is consumed. +
The '''amplitude''' of the [[absorbance spectrum]] can be described in terms of the [[absorbance]] differences between the characteristic peaks (absorbance maxima) and troughs (absorbance minima) (see [[absorbance spectrum]]) for substances present in the sample. +
'''Amytal''' sodium salt (synonym: amobarbital; 5-Ethyl-5-isoamylbarbituric acid) is a barbiturate drug and an inhibitor of [[Complex I]]. +
'''Anaerobic''' metabolism takes place without the use of molecular oxygen, in contrast to '''[[aerobic]]''' metabolism. The capacity for energy assimilation and growth under '''[[anoxic]]''' conditions is the ultimate criterion for '''facultative anaerobiosis'''. Anaerobic ''metabolism'' may proceed not only under [[anoxic]] ''conditions'' or ''states'', but also under [[hyperoxic]] and [[normoxic]] conditions ('''aerobic glycolysis'''), and under [[hypoxic]] and [[microxic]] conditions below the [[limiting oxygen pressure]]. +
'''Anaplerosis''' is the process of formation of intermediates of the [[tricarboxylic acid cycle]]. [[Malic enzyme]] (mtME), [[phosphoenolpyruvate carboxykinase]] (PEPCK), propionyl-CoA carboxylase, [[pyruvate carboxylase]] and [[proline dehydrogenase]] play important roles in anaplerosis. +
'''Anaplerotic pathway control states''' are fuelled by single substrates which are transported into the mitochondrial matrix and increase the pool of intermediates of the [[tricarboxylic acid cycle]]. [[Malic enzyme]] (mtME), phosphoenopyruvate carboxykinase (PEPCK), propionyl-CoA carboxylase, and pyruvate carboxylase play important roles in [[anaplerosis]]. The [[glutamate-anaplerotic pathway control state]] and [[malate-anaplerotic pathway control state]] are the most important anaplerotic substrate control states (aN). +
Ideally the terms '''anoxia''' and anoxic (anox, without oxygen) should be restricted to conditions where molecular oxygen is strictly absent. Practically, effective anoxia is obtained when a further decrease of experimental oxygen levels does not elicit any physiological or biochemical response. The practical definition, therefore, depends on (i) the techiques applied for oxygen removal and minimizing oxygen diffusion into the experimental system, (ii) the sensitivity and limit of detection of analytical methods of measuring oxygen (O<sub>2</sub> concentration in the nM range), and (iii) the types of diagnostic tests applied to evaluate effects of trace amounts of oxygen on physiological and biochemical processes. The difficulties involved in defining an absolute limit between anoxic and [[microxic]] conditions are best illustrated by a logarithmic scale of oxygen pressure or oxygen concentration. In the '''''anoxic state''''' ([[State 5]]), any aerobic type of metabolism cannot take place, whereas '''''[[anaerobic]] metabolism''''' may proceed under oxic or anoxic conditions. +
'''Antimycin A''' is an inhibitor of [[Complex III]] (CIII). It binds to the Qi site of CIII and inhibits the transfer of electrons from heme ''b''<sub>H</sub> to oxidized Q (Qi site inhibitor). High concentrations of antimycin A also inhibit acyl-CoA oxidase and D-amino acid oxidase. +
'''P1,P5-Di(adenosine-5')pentaphosphate (Ap5A)''' is an inhibitor of [[adenylate kinase]] (ADK), the enzyme which rephosphorylates AMP to ADP, consuming ATP (ATP + AMP ↔ 2 ADP). +
'''Aqua destillata''' (a.d.) is the Latin name for '''distilled [[water]]''', H<sub>2</sub>O. When a.d. is used in various solution protocols, it may indicate that water with the highest possible quality or lowest possible level of impurities should be used, as may be reached not only with distilled water but also with high-purity deionised water. +
'''arXiv''' is a classic preprint server initiated in 1991 by Paul Ginsparg. {''Quote''} arXiv.org is a highly-automated electronic archive and distribution server for research articles. Covered areas include physics, mathematics, computer science, nonlinear sciences, quantitative biology, quantitative finance, statistics, electrical engineering and systems science, and economics. arXiv is maintained and operated by Cornell University with guidance from the arXiv Scientific Advisory Board and the arXiv Member Advisory Board, and with the help of numerous subject moderators. {''end of Quote''}. arXiv rejects abstracts that are submitted without accompanying paper. +
'''Artemisinin''' and various derivatives are potent anti-malaria drugs which have additionally anti-tumorigenic effects, particularly when targeted at mitochondria. The anti-malaria effect is associated with artemisinin's action on heme. Mitochondria are involved in the synthesis of heme, and may play additional roles in the anti-tumorigenic effect of artemisinin. +
In respiratory assays for cytochrome ''c'' oxidase activity ([[Complex IV|Complex IV, CIV]]), '''ascorbate''' is added as regenerating system to maintain [[TMPD]] in a reduced state. It has to be titrated into the respiration medium prior to the addition of TMPD, otherwise the [[autoxidation]] reaction velocity is permanently elevated. +
[[File:ASMRM LOGO.JPG|200px|left]]The '''Asia Society for Mitochondrial Research and Medicine''' (ASMRM) was founded in 2003 to share the latest knowledge on mitochondrial research. +
-20was-20founded-20in-202003-20to-20share-20the-20latest-20knowledge-20on-20mitochondrial-20research.){kind=link}