A First-Principle Analysis of Ethylene Chemisorption on Copper Chloride Clusters

The structure of the laboratory population of green microalgae Scenedesmus quadricauda (Turp.) Breb (=Desmodesmus communis E. Hegew.) was studied at different stages of its growth (lag-phase, log-phase and stationary phase) at low concentrations of copper chloride and silver nitrate by the method microculture, allowing to monitor the state and development of single cells having different physiological status. The response of the culture of S. quadricauda - the change in the number of cells and the fractional composition (the fraction of dividing, «dormant» and dying cells) depended not only on the concentration of the toxicant in the medium, but also on the physiological state of the culture: the level of synchronization and the growth phase. Silver ions at low concentrations had a more pronounced toxic effect on the culture than copper ions at different phases of its development, especially at a concentration of 0.001 mg/l (10-9 M). The main mechanism of the toxic effect of metals is to inhibit the process of cell division. At low concentrations of toxicants, especially at a concentration of 0.001 mg/l, a «paradoxical» effect expressed in the predominance of the fraction of «dormant» cells was revealed. The temporary inhibition of the process of cell division can be regarded as a protective mechanism that allows preserving the integrity of the population and its ability to survive in a changing environment. The obtained data explain the effect of action of low concentrations of substances due to their inclusion in the cell, the subsequent accumulation in the cell and their low excretion.

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First Principle Study of Oxygen Diffusion on Uranium Nitride UN (001) Surface with Uranium or Nitrogen Vacancies

Micro and Nanosystems ◽

10.2174/1876402908666151112224733 ◽

2015 ◽

Vol 7 (2) ◽

pp. 124-130 ◽

Cited By ~ 1

Author(s):

T. Zergoug ◽

S. E.H. Abaidia ◽

A. Nedjar

Keyword(s):

Oxygen Diffusion ◽

First Principle ◽

Uranium Nitride ◽

Nitrogen Vacancies

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Freedom and Responsibility in Neoplatonist Thought

10.1093/oso/9780198824831.001.0001 ◽

2020 ◽

Author(s):

Ursula Coope

Keyword(s):

First Principle ◽

Human Beings ◽

Human Soul ◽

The One ◽

Freedom And Responsibility

The Neoplatonists have a perfectionist view of freedom: an entity is free to the extent that it succeeds in making itself good. Free entities are wholly in control of themselves: they are self-determining, self-constituting, and self-knowing. Neoplatonist philosophers argue that such freedom is only possible for nonbodily things. The human soul is free insofar as it rises above bodily things and engages in intellection, but when it turns its desires to bodily things, it is drawn under the sway of fate and becomes enslaved. This book discusses this notion of freedom, and its relation to questions about responsibility. It explains the important role of notions of self-reflexivity in Neoplatonist accounts of both freedom and responsibility. Part I sets out the puzzles Neoplatonist philosophers face about freedom and responsibility and explains how these puzzles arise from earlier discussions. Part II looks at the metaphysical underpinnings of the Neoplatonist notion of freedom (concentrating especially on the views of Plotinus and Proclus). In what sense (if any) is the ultimate first principle of everything (the One) free? If everything else is under this ultimate first principle, how can anything other than the One be free? What is the connection between freedom and nonbodiliness? Part III looks at questions about responsibility, arising from this perfectionist view of freedom. Why are human beings responsible for their behaviour, in a way that other animals are not? If we are enslaved when we act viciously, how can we be to blame for our vicious actions and choices?

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