New concepts may prove necessary to profit from the avalanche of sequence data on the genome, transcriptome, proteome and interactome and to relate this information to cell physiology. Here, we focus on the concept of large activity-based structures, or hyperstructures, in which a variety of types of molecules are brought together to perform a function. We review the evidence for the existence of hyperstructures responsible for the initiation of DNA replication, the sequestration of newly replicated origins of replication, cell division (...) and for metabolism. The processes responsible for hyperstructure formation include changes in enzyme affinities due to metabolite-induction, lipid-protein affinities, elevated local concentrations of proteins and their binding sites on DNA and RNA, and transertion. Experimental techniques exist that can be used to study hyperstructures and we review some of the ones less familiar to biologists. Finally, we speculate on how a variety of in silico approaches involving cellular automata and multi-agent systems could be combined to develop new concepts in the form of an Integrated cell (I-cell) which would undergo selection for growth and survival in a world of artificial microbiology. (shrink)
_ Source: _Volume 24, Issue 2, pp 300 - 317 This article examines R. Zvi Yehudah Kook’s reading of two earlier thinkers who were influential in the formulation of his thought—the Maharal of Prague and R. Avraham Azulai. I argue that his creative and unique reading of these texts exemplifies a fascinating dialogue he held with earlier sources, which he interpreted and infused with his own theological postulates. Here I explore his theory of the unique nature of the Jewish soul, (...) in both its collective and individual manifestations. The connection between R. Zvi Yehudah’s approach to interpreting earlier Jewish theological texts and that of his father, R. Avraham Itzhak HaCohen Kook, will also be discussed. (shrink)
In his exciting and original view of the universe, Itzhak Bentov has provided a new perspective on human consciousness and its limitless possibilities. Widely known and loved for his delightful humor and imagination, Bentov explains the familiar world of phenomena with perceptions that are as lucid as they are thrilling. He gives us a provocative picture of ourselves in an expanded, conscious, holistic universe. _.
This book offers a rigorous, concise, and nontechnical introduction to some of the fundamental insights of rational choice theory. It draws on formal theories of microeconomics, decision making, games, and social choice, and on ideas developed in philosophy, psychology, and sociology. Itzhak Gilboa argues that economic theory has provided a set of powerful models and broad insights that have changed the way we think about everyday life. He focuses on basic insights of the rational choice paradigm--the general conceptualization rather (...) than a particular theory--that survive recent critiques of economic theory's various failures. Gilboa explains the main concepts in language accessible to the nonspecialist, offering a nonmathematical guide to some of the main ideas developed in economic theory in the second half of the twentieth century. Chapters cover feasibility and desirability, utility maximization, constrained optimization, expected utility, probability and statistics, aggregation of preferences, games and equilibria, free markets, and rationality and emotions. Online appendixes offer additional material, including a survey of relevant mathematical concepts. (shrink)
Coordination games often have multiple equilibria. The selection of equilibrium raises the question of belief formation: how do players generate beliefs about the behavior of other players? This article takes the view that the answer lies in history, that is, in the outcomes of similar coordination games played in the past, possibly by other players. We analyze a simple model in which a large population plays a game that exhibits strategic complementarities. We assume a dynamic process that faces different populations (...) with such games for randomly selected values of a parameter. We introduce a belief formation process that takes into account the history of similar games played in the past, not necessarily by the same population. We show that when history serves as a coordination device, the limit behavior depends on the way history unfolds, and cannot be determined from a-priori considerations. (shrink)
Economic theory reduces the concept of rationality to internal consistency. As far as beliefs are concerned, rationality is equated with having a prior belief over a “Grand State Space”, describing all possible sources of uncertainties. We argue that this notion is too weak in some senses and too strong in others. It is too weak because it does not distinguish between rational and irrational beliefs. Relatedly, the Bayesian approach, when applied to the Grand State Space, is inherently incapable of describing (...) the formation of prior beliefs. On the other hand, this notion of rationality is too strong because there are many situations in which there is not sufficient information for an individual to generate a Bayesian prior. It follows that the Bayesian approach is neither sufficient not necessary for the rationality of beliefs. (shrink)
This note argues that, under some circumstances, it is more rational not to behave in accordance with a Bayesian prior than to do so. The starting point is that in the absence of information, choosing a prior is arbitrary. If the prior is to have meaningful implications, it is more rational to admit that one does not have sufficient information to generate a prior than to pretend that one does. This suggests a view of rationality that requires a compromise between (...) internal coherence and justification, similarly to compromises that appear in moral dilemmas. Finally, it is argued that Savage's axioms are more compelling when applied to a naturally given state space than to an analytically constructed one; in the latter case, it may be more rational to violate the axioms than to be Bayesian. (shrink)
We suggest to define objective probabilities by similarity-weighted empirical frequencies, where more similar cases get a higher weight in the computation of frequencies. This formula is justified intuitively and axiomatically, but raises the question, which similarity function should be used? We propose to estimate the similarity function from the data, and thus obtain objective probabilities. We compare this definition to others, and attempt to delineate the scope of situations in which objective probabilities can be used.
A decision maker has to choose one of several random variables whose distributions are not known. As a Bayesian, she behaves as if she knew the distributions. In this paper we suggest an axiomatic derivation of these (subjective) distributions, which is more economical than the derivations by de Finetti or Savage. Whereas the latter derive the whole joint distribution of all the available random variables, our approach derives only the marginal distributions. Correspondingly, the preference questionnaire needed in our case is (...) less smaller. (shrink)
Multicellular organisms are ensembles of quasi-two-dimensional structures (sheets) of various kinds. Why should the development of all organisms be mediated by a quasi-two-dimensional structure? Why does such development avoid a direct confrontation with the third dimension? In this paper, we accept the challenge of addressing this question from the perspective of computational geometry and suggest that the construction of three-dimensional organisms may be explained by the constraints imposed on a bottom-up construction process.
We assume that people have a need to make statements, and construct a model in which this need is the sole determinant of voting behavior. In this model, an individual selects a ballot that makes as close a statement as possible to her ideal point, where abstaining from voting is a possible (null) statement. We show that in such a model, a political system that adopts approval voting may be expected to enjoy a significantly higher rate of participation in elections (...) than a comparable system with plurality rule. (shrink)
Reverse Inference ( RI ) is an imaging-based type of inference from brain states to mental states, which has become highly widespread in neuroscience, most especially in neuroeconomics. Recent critical studies of RI may be taken to show that, if cautiously used, RI can help achieve research goals that may be difficult to achieve by way of behavior-based procedures alone. But can RI exceed the limits of these procedures and achieve research goals that are impossible for them to achieve alone? (...) By way of answering this question we show that a conception of the mind—type identity—under which the answer is in the positive, is untenable for reasons that strongly support another conception of the mind—functionalism—under which the answer must be in the negative. On this basis we then conclude that RI cannot exceed the limits of behavior-based procedures in cognitive psychology. (shrink)
Policyholders and other claimants in insurance companies are interested in solidity, i.e., the ability of insurers to meet their claims obligations in both the short run and the long run. Insurance regulators exist in order to represent the interests of consumers. Great emphasis is placed by the regulators of the market on the mandatory and uniform disclosure of relevant financial and operating aspects of insurers. This paper employs simple gametheoretic techniques to address two aspects of the general issue of the (...) desirability of establishing a regulator to assess the solidity of insurers. First, why would uniform information about insurers be desirable? Given that uniformity is desirable, it could be achieved by voluntary agreement of insurers or via regulation. The second issue is how that uniformity is to be achieved; that is, what is the value of a regulator in achieving uniformity? Insurance provides an interesting instance of the general problem. A key determinant is the structure of costs and benefits of securing voluntary agreements across firms. (shrink)
It is argued that, contrary to a rather prevalent view within economic theory, rationality does not imply Bayesianism. The note begins by defining these terms and justifying the choice of these definitions, proceeds to survey the main justification for this prevalent view, and concludes by highlighting its weaknesses.
This note documents Aumann's reason for omitting the “empty shells” argument for the common prior assumption from the final version of “Correlated Equilibrium as an Expression of Bayesian Rationality.” It then continues to discuss the argument and concludes that rational entities cannot learn their own identity; if they do not know it a priori, they never will.
In recent years the understanding of the cognitive foundations of economic behavior has become increasingly important. This volume contains contributions from such leading scholars as Adam Brandenburger, Michael Bacharach and Patrick Suppes. It will be of great interest to academics and researchers involved in the field of economics and psychology as well as those interested in political economy more generally.
Gilboa and Schmeidler provide a paradigm for modelling decision making under uncertainty. Unlike the classical theory of expected utility maximization, case-based decision theory does not assume that decision makers know the possible 'states of the world' or the outcomes, let alone the decision matrix attaching outcomes to act-state pairs. Case-based decision theory suggests that people make decisions by analogies to past cases: they tend to choose acts that performed well in the past in similar situations, and to avoid acts that (...) performed poorly. It is an alternative to expected utility theory when both states of the world and probabilities are neither given in the problem nor can be easily constructed. The authors describe the general theory and its relationship to planning, repeated choice problems, inductive inference, and learning; they highlight its mathematical and philosophical foundations and compare it with expected utility theory as well as with rule-based systems. (shrink)