scholarly journals Autopoiesis with or without cognition: defining life at its edge

2004 ◽  
Vol 1 (1) ◽  
pp. 99-107 ◽  
Author(s):  
Michel Bitbol ◽  
Pier Luigi Luisi
Keyword(s):  
Point Of View ◽  
Sufficient Condition ◽  
Metabolic Pattern ◽  
Biological Adaptation ◽  
Direct Form ◽  
A Cell ◽  
Living Unit ◽  
Definition Of ◽  
Necessary And Sufficient ◽  
Minimal Life

This paper examines two questions related to autopoiesis as a theory for minimal life: (i) the relation between autopoiesis and cognition; and (ii) the question as to whether autopoiesis is the necessary and sufficient condition for life. First, we consider the concept of cognition in the spirit of Maturana and Varela: in contradistinction to the representationalistic point of view, cognition is construed as interaction between and mutual definition of a living unit and its environment. The most direct form of cognition for a cell is thus metabolism itself, which necessarily implies exchange with the environment and therefore a simultaneous coming to being for the organism and for the environment. A second level of cognition is recognized in the adaptation of the living unit to new foreign molecules, by way of a change in its metabolic pattern. We draw here an analogy with the ideas developed by Piaget, who recognizes in cognition the two distinct steps of assimilation and accommodation. While assimilation is the equivalent of uptake and exchange of usual metabolites, accommodation corresponds to biological adaptation, which in turn is the basis for evolution. By comparing a micro-organism with a vesicle that uptakes a precursor for its own self-reproduction, we arrive at the conclusion that (a) the very lowest level of cognition is the condition for life, and (b) the lowest level of cognition does not reduce to the lowest level of autopoiesis. As a consequence, autopoiesis alone is only a necessary, but not sufficient, condition for life. The broader consequences of this analysis of cognition for minimal living systems are considered.

scholarly journals Lorentz Boosts and Wigner Rotations: Self-Adjoint Complexified Quaternions

Physics ◽  
2021 ◽  
Vol 3 (2) ◽  
pp. 352-366
Author(s):  
Thomas Berry ◽  
Matt Visser
Keyword(s):  
Point Of View ◽  
Sufficient Condition ◽  
Use Of Self ◽  
Necessary And Sufficient Condition ◽  
Wigner Rotation ◽  
Inertial Frames ◽  
Explicit Formulae ◽  
Specific Implementation ◽  
Necessary And Sufficient ◽  
Lorentz Boosts

In this paper, Lorentz boosts and Wigner rotations are considered from a (complexified) quaternionic point of view. It is demonstrated that, for a suitably defined self-adjoint complex quaternionic 4-velocity, pure Lorentz boosts can be phrased in terms of the quaternion square root of the relative 4-velocity connecting the two inertial frames. Straightforward computations then lead to quite explicit and relatively simple algebraic formulae for the composition of 4-velocities and the Wigner angle. The Wigner rotation is subsequently related to the generic non-associativity of the composition of three 4-velocities, and a necessary and sufficient condition is developed for the associativity to hold. Finally, the authors relate the composition of 4-velocities to a specific implementation of the Baker–Campbell–Hausdorff theorem. As compared to ordinary 4×4 Lorentz transformations, the use of self-adjoint complexified quaternions leads, from a computational view, to storage savings and more rapid computations, and from a pedagogical view to to relatively simple and explicit formulae.

scholarly journals A generalized inversion formula for the continuous Jacobi transform

1987 ◽  
Vol 10 (4) ◽  
pp. 671-692 ◽  
Author(s):  
Ahmed I. Zayed
Keyword(s):  
Analytic Function ◽  
Inversion Formula ◽  
Generalized Functions ◽  
Generalized Function ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Generalized Inversion ◽  
Definition Of ◽  
Necessary And Sufficient ◽  
Jacobi Transform

In this paper we extend the definition of the continuous Jacobi transform to a class of generalized functions and obtain a generalized inversion formula for it. As a by-product of our technique we obtain a necessary and sufficient condition for an analytic functionF(λ)inReλ>0to be the continuous Jacobi transform of a generalized function.

On the Indispensability of Intentionality

1972 ◽  
Vol 2 (1) ◽  
pp. 127-133
Author(s):  
Harold Morick
Keyword(s):  
Recent Literature ◽  
Essential Property ◽  
Sufficient Condition ◽  
Conceptual Scheme ◽  
Necessary And Sufficient Condition ◽  
Definition Of ◽  
Necessary And Sufficient

In the last two decades, there has been a great deal of interest in providing an intentional criterion of the psychological. Of the various ones proferred, it seems to me that the best was the earliest, which was Chisholm’s initial criterion in his 1955 essay “Sentences about Believing.” In this present paper I first single out a basic misconception pervading the recent literature on intentionality and suggest that a consequence of this misconception has been the futile attempt to use the notion of intentionality to provide a kind of definition of “mind”; that is, to use intentionality to provide a necessary and sufficient condition for the psychological. Secondly, I point out how intentionality as captured by my own criterion is indispensable in that it is an essential property of certain particulars (persons) which are basic to our conceptual scheme and apparently basic to any conceptual scheme whatsoever.

scholarly journals On the Option Pricing by the Binomial Model

2021 ◽  
Author(s):  
Nikos Halidias
Keyword(s):  
Sufficient Conditions ◽  
Fair Value ◽  
Point Of View ◽  
Binomial Model ◽  
No Arbitrage ◽  
Mathematical Arguments ◽  
Definition Of ◽  
Necessary And Sufficient ◽  
Probabilistic Point ◽  
Absence Of Arbitrage

In this note we study the binomial model applied to European, American and Bermudan type of derivatives. Our aim is to give the necessary and sufficient conditions under which we can define a fair value via replicating portfolios for any derivative using simple mathematical arguments and without using no arbitrage techniques. Giving suitable definitions we are able to define rigorously the fair value of any derivative without using concepts from probability theory or stochastic analysis therefore is suitable for students or young researchers. It will be clear in our analysis that if $e^{r \delta} \notin [d,u]$ then we can not define a fair value by any means for any derivative while if $d \leq e^{r \delta} \leq u$ we can. Therefore the definition of the fair value of a derivative is not so closely related with the absence of arbitrage. In the usual probabilistic point of view we assume that $d < e^{r \delta} < u$ in order to define the fair value but it is not clear what we can (or we can not) do in the cases where $e^{r \delta} \leq d$ or $e^{r \delta} \geq u$.

scholarly journals Some results concerning frames in Banach spaces

2007 ◽  
Vol 38 (3) ◽  
pp. 267-276 ◽  
Author(s):  
S. K. Kaushik
Keyword(s):  
Finite Number ◽  
Banach Spaces ◽  
Necessary Condition ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Linearly Independent ◽  
Banach Frame ◽  
Minimal Sequence ◽  
Definition Of ◽  
Necessary And Sufficient

A necessary and sufficient condition for the associated sequence of functionals to a complete minimal sequence to be a Banach frame has been given. We give the definition of a weak-exact Banach frame, and observe that an exact Banach frame is weak-exact. An example of a weak-exact Banach frame which is not exact has been given. A necessary and sufficient condition for a Banach frame to be a weak-exact Banach frame has been obtained. Finally, a necessary condition for the perturbation of a retro Banach frame by a finite number of linearly independent vectors to be a retro Banach frame has been given.

On the Modulii of Analytic Functions

1970 ◽  
Vol 13 (3) ◽  
pp. 325-327 ◽  
Author(s):  
Malcolm J. Sherman
Keyword(s):  
Analytic Functions ◽  
Point Of View ◽  
Sufficient Condition ◽  
Two Dimensional ◽  
Necessary And Sufficient Condition ◽  
Concrete Form ◽  
Norm Equality ◽  
Image Position ◽  
Necessary And Sufficient

The problem to be considered in this note, in its most concrete form, is the determination of all quartets f1, f2, g1, g2 of functions analytic on some domain and satisfying*where p > 0. When p = 2 the question can be reformulated in terms of finding a necessary and sufficient condition for (two-dimensional) Hilbert space valued analytic functions to have equal pointwise norms, and the answer (Theorem 1) justifies this point of view. If p ≠ 2, the problem is solved by reducing to the case p = 2, and the reformulation in terms of the norm equality of lp valued analytic functions gives no clue to the answer.

Anselm's Account of Freedom

2001 ◽  
Vol 31 (2) ◽  
pp. 221-244 ◽  
Author(s):  
Thomas Williams ◽  
Sandra Visser
Keyword(s):  
Moral Responsibility ◽  
Point Of View ◽  
Alternative Possibilities ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Freedom Of Choice ◽  
Necessary And Sufficient

According to Anselm's official definition, freedom of choice is ‘the power to preserve rectitude of will for the sake of that rectitude itself.’ From the point of view of contemporary metaphysics, this is one of the most unhelpful definitions imaginable. Does such freedom require alternative possibilities, for example? Is it compatible with causal determination? Is the exercise of such freedom a necessary and sufficient condition for moral responsibility? The definition sheds no light on these questions.And so we need to move on from Anselm's definition to Anselm's account of freedom. Here, though, we encounter the opposite problem. Where Anselm's definition seems not to answer these questions at all, Anselm's account seems to answer all these questions, sometimes with a yes and sometimes with a no. Consider the question about alternative possibilities. In De libertate arbitrii, Anselm seems clearly to deny that freedom involves alternative possibilities. God, the good angels, and the blessed dead cannot do otherwise than preserve rectitude, but they are still free- freer, in fact, than those who are capable of abandoning rectitude.

Analysis on Degree of Freedom and Singularity of Mechanism Based on Topological Graph Theory

2011 ◽  
Vol 393-395 ◽  
pp. 20-23
Author(s):  
Jian Guo Luo ◽  
Mao Yan He
Keyword(s):  
Graph Theory ◽  
Degree Of Freedom ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Topological Graph ◽  
Topological Graph Theory ◽  
Hybrid Mechanism ◽  
Definition Of ◽  
Necessary And Sufficient ◽  
Case Number

Based on the analysis of current developing state of graph theory, define the description of spacial moving capability of common couples and translation base and rotation base of mechanism, based on the new description method in topological graph theory. DOF(degree of freedom) of hybrid mechanism analysised with example based on the definition of dimensionity of branch spacial moving capability and mechanism spacial moving capability, necessary and sufficient condition of nonsingularity of mechanism presented, as well as the necessary and sufficient condition of singularity of mechanism deduced , in-phase and assimilation condition and in-phase and dissimilarity condition and asynchronism condition of limitation of input base of branch adopted, case number of position singularity and pose singularity and position and pose singularity obtained then, still the way of founding the combination and case number of common serial mechanism and parallel mechanism and hybrid mechanism mentioned.

What Is Conceptual Analysis?

2018 ◽  
Vol 10 (2) ◽  
pp. 131-142
Author(s):  
Hristo Ivanov Valchev ◽  
Keyword(s):  
Conceptual Analysis ◽  
Analytic Philosophy ◽  
Sufficient Condition ◽  
Definition Of ◽  
Necessary And Sufficient

In the present inquiry I explore the concept of conceptual analysis, looking for ways for it to be improved, and I come to the following conclusions. Conceptual analysis as ordinarily understood in analytic philosophy is a method which consists in drawing a conclusion about what the definition of a predicate is on the basis of an armchair investigation into whether the predicate is semantically applicable in different possible cases; but, the concept of conceptual analysis can be improved by making two changes to it: 1) the investigation into whether the predicate is semantically applicable in different possible cases is not to serve as a basis for a conclusion about what the definition of the predicate is, but as a basis for a conclusion about whether this-and-this is an only necessary, only sufficient, both necessary and sufficient, or neither necessary nor sufficient condition for the predicate’s semantic application; 2) the investigation into whether the predicate is semantically applicable in different possible cases is done not only from the armchair, but also empirically.

scholarly journals Rational valued and real valued projective characters of finite groups

1980 ◽  
Vol 21 (1) ◽  
pp. 23-28 ◽  
Author(s):  
J. F. Humphreys
Keyword(s):  
Symmetric Group ◽  
Finite Groups ◽  
General Information ◽  
Sufficient Condition ◽  
Necessary And Sufficient Condition ◽  
Complex Character ◽  
Definition Of ◽  
A Finite Group ◽  
Necessary And Sufficient ◽  
Spin Characters

It is well-known [3; V.13.7] that each irreducible complex character of a finite group G is rational valued if and only if for each integer m coprime to the order of G and each g ∈ G, g is conjugate to gm. In particular, for each positive integer n, the symmetric group on n symbols, S(n), has all its irreducible characters rational valued. The situation for projective characters is quite different. In [5], Morris gives tables of the spin characters of S(n) for n ≤ 13 as well as general information about the values of these characters for any symmetric group. It can be seen from these results that in no case are all the spin characters of S(n) rational valued and, indeed, for n ≥ 6 these characters are not even all real valued. In section 2 of this note, we obtain a necessary and sufficient condition for each irreducible character of a group G associated with a 2-cocycle α to be rational valued. A corresponding result for real valued projective characters is discussed in section 3. Section 1 contains preliminary definitions and notation, including the definition of projective characters given in [2].

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