The Role of Dysfunctional Myths in a Decision-Making Process under Bounded Rationality: A Complex Dynamical Systems Perspective.

PubMed

Stamovlasis, Dimitrios; Vaiopoulou, Julie

2017-07-01

The present study examines the factors influencing a decision-making process, with specific focus on the role of dysfunctional myths (DM). DM are thoughts or beliefs that are rather irrational, however influential to people's decisions. In this paper a decision-making process regarding the career choice of university students majoring in natural sciences and education (N=496) is examined by analyzing survey data taken via Career Decision Making Difficulties Questionnaire (CDDQ). The difficulty of making the choice and the certainty about one's decision were the state variables, while the independent variables were factors related to the lack of information or knowledge needed, which actually reflect a bounded rationality. Cusp catastrophe analysis, based on both least squares and maximum likelihood procedures, showed that the nonlinear models predicting the two state variables were superior to linear alternatives. Factors related to lack of knowledge about the steps involved in the process of career decision-making, lack of information about the various occupations, lack of information about self and lack of motivation acted as asymmetry, while dysfunctional myths acted as bifurcation factor for both state variables. The catastrophe model, grounded in empirical data, revealed a unique role for DM and a better interpretation within the context of complexity and the notion of bounded rationality. The analysis opens the nonlinear dynamical systems (NDS) perspective in studying decision-making processes. Theoretical and practical implications are discussed.

Bounded rationality alters the dynamics of paediatric immunization acceptance

PubMed Central

Oraby, Tamer; Bauch, Chris T.

2015-01-01

Interactions between disease dynamics and vaccinating behavior have been explored in many coupled behavior-disease models. Cognitive effects such as risk perception, framing, and subjective probabilities of adverse events can be important determinants of the vaccinating behaviour, and represent departures from the pure “rational” decision model that are often described as “bounded rationality”. However, the impact of such cognitive effects in the context of paediatric infectious disease vaccines has received relatively little attention. Here, we develop a disease-behavior model that accounts for bounded rationality through prospect theory. We analyze the model and compare its predictions to a reduced model that lacks bounded rationality. We find that, in general, introducing bounded rationality increases the dynamical richness of the model and makes it harder to eliminate a paediatric infectious disease. In contrast, in other cases, a low cost, highly efficacious vaccine can be refused, even when the rational decision model predicts acceptance. Injunctive social norms can prevent vaccine refusal, if vaccine acceptance is sufficiently high in the beginning of the vaccination campaign. Cognitive processes can have major impacts on the predictions of behaviour-disease models, and further study of such processes in the context of vaccination is thus warranted. PMID:26035413

What Information Theory Says About Best Response and About Binding Contracts

NASA Technical Reports Server (NTRS)

Wolpert, David H.

2004-01-01

Product Distribution (PD) theory is the information-theoretic extension of conventional full- rationality game theory to bounded rational games. Here PD theory is used to investigate games in which the players use bounded rational best-response strategies. This investigation illuminates how to determine the optimal organization chart for a corporation, or more generally how to order the sequence of moves of the players / employees so as to optimize an overall objective function. It is then shown that in the continuum-time limit, bounded rational best response games result in a variant of the replicator dynamics of evolutionary game theory. This variant is then investigated for team games, in which the players share the same utility function, by showing that such continuum- limit bounded rational best response is identical to Newton-Raphson iterative optimization of the shared utility function. Next PD theory is used to investigate changing the coordinate system of the game, i.e., changing the mapping from the joint move of the players to the arguments in the utility functions. Such a change couples those arguments, essentially by making each players move be an offered binding contract.

Computational rationality: linking mechanism and behavior through bounded utility maximization.

PubMed

Lewis, Richard L; Howes, Andrew; Singh, Satinder

2014-04-01

We propose a framework for including information-processing bounds in rational analyses. It is an application of bounded optimality (Russell & Subramanian, 1995) to the challenges of developing theories of mechanism and behavior. The framework is based on the idea that behaviors are generated by cognitive mechanisms that are adapted to the structure of not only the environment but also the mind and brain itself. We call the framework computational rationality to emphasize the incorporation of computational mechanism into the definition of rational action. Theories are specified as optimal program problems, defined by an adaptation environment, a bounded machine, and a utility function. Such theories yield different classes of explanation, depending on the extent to which they emphasize adaptation to bounds, and adaptation to some ecology that differs from the immediate local environment. We illustrate this variation with examples from three domains: visual attention in a linguistic task, manual response ordering, and reasoning. We explore the relation of this framework to existing "levels" approaches to explanation, and to other optimality-based modeling approaches. Copyright © 2014 Cognitive Science Society, Inc.

Emergence of scale-free characteristics in socio-ecological systems with bounded rationality

PubMed Central

Kasthurirathna, Dharshana; Piraveenan, Mahendra

2015-01-01

Socio–ecological systems are increasingly modelled by games played on complex networks. While the concept of Nash equilibrium assumes perfect rationality, in reality players display heterogeneous bounded rationality. Here we present a topological model of bounded rationality in socio-ecological systems, using the rationality parameter of the Quantal Response Equilibrium. We argue that system rationality could be measured by the average Kullback–-Leibler divergence between Nash and Quantal Response Equilibria, and that the convergence towards Nash equilibria on average corresponds to increased system rationality. Using this model, we show that when a randomly connected socio-ecological system is topologically optimised to converge towards Nash equilibria, scale-free and small world features emerge. Therefore, optimising system rationality is an evolutionary reason for the emergence of scale-free and small-world features in socio-ecological systems. Further, we show that in games where multiple equilibria are possible, the correlation between the scale-freeness of the system and the fraction of links with multiple equilibria goes through a rapid transition when the average system rationality increases. Our results explain the influence of the topological structure of socio–ecological systems in shaping their collective cognitive behaviour, and provide an explanation for the prevalence of scale-free and small-world characteristics in such systems. PMID:26065713

Emergence of scale-free characteristics in socio-ecological systems with bounded rationality.

PubMed

Kasthurirathna, Dharshana; Piraveenan, Mahendra

2015-06-11

Socio-ecological systems are increasingly modelled by games played on complex networks. While the concept of Nash equilibrium assumes perfect rationality, in reality players display heterogeneous bounded rationality. Here we present a topological model of bounded rationality in socio-ecological systems, using the rationality parameter of the Quantal Response Equilibrium. We argue that system rationality could be measured by the average Kullback--Leibler divergence between Nash and Quantal Response Equilibria, and that the convergence towards Nash equilibria on average corresponds to increased system rationality. Using this model, we show that when a randomly connected socio-ecological system is topologically optimised to converge towards Nash equilibria, scale-free and small world features emerge. Therefore, optimising system rationality is an evolutionary reason for the emergence of scale-free and small-world features in socio-ecological systems. Further, we show that in games where multiple equilibria are possible, the correlation between the scale-freeness of the system and the fraction of links with multiple equilibria goes through a rapid transition when the average system rationality increases. Our results explain the influence of the topological structure of socio-ecological systems in shaping their collective cognitive behaviour, and provide an explanation for the prevalence of scale-free and small-world characteristics in such systems.

Information Theory - The Bridge Connecting Bounded Rational Game Theory and Statistical Physics

NASA Technical Reports Server (NTRS)

Wolpert, David H.

2005-01-01

A long-running difficulty with conventional game theory has been how to modify it to accommodate the bounded rationality of all red-world players. A recurring issue in statistical physics is how best to approximate joint probability distributions with decoupled (and therefore far more tractable) distributions. This paper shows that the same information theoretic mathematical structure, known as Product Distribution (PD) theory, addresses both issues. In this, PD theory not only provides a principle formulation of bounded rationality and a set of new types of mean field theory in statistical physics; it also shows that those topics are fundamentally one and the same.

A Reward-Maximizing Spiking Neuron as a Bounded Rational Decision Maker.

PubMed

Leibfried, Felix; Braun, Daniel A

2015-08-01

Rate distortion theory describes how to communicate relevant information most efficiently over a channel with limited capacity. One of the many applications of rate distortion theory is bounded rational decision making, where decision makers are modeled as information channels that transform sensory input into motor output under the constraint that their channel capacity is limited. Such a bounded rational decision maker can be thought to optimize an objective function that trades off the decision maker's utility or cumulative reward against the information processing cost measured by the mutual information between sensory input and motor output. In this study, we interpret a spiking neuron as a bounded rational decision maker that aims to maximize its expected reward under the computational constraint that the mutual information between the neuron's input and output is upper bounded. This abstract computational constraint translates into a penalization of the deviation between the neuron's instantaneous and average firing behavior. We derive a synaptic weight update rule for such a rate distortion optimizing neuron and show in simulations that the neuron efficiently extracts reward-relevant information from the input by trading off its synaptic strengths against the collected reward.

Reference Service and Bounded Rationality: Helping Students with Research.

ERIC Educational Resources Information Center

Chu, Felix T.

1994-01-01

In university libraries, reference librarians often get ambiguous questions to which they try to give appropriate answers. Because of limitations on resources, time, and mental capability for information processing, the decision-making process involved in answering reference questions becomes bounded by the rationality of these constraints.…

Bounded Rationality and Satisficing in Young People's Web-Based Decision Making.

ERIC Educational Resources Information Center

Agosto, Denise E.

2002-01-01

Investigated behavioral decision-making theories of bounded rationality and satisficing in relation to young people's decision making in the World Wide Web and considered the role of personal preferences. Results of this study of ninth- and tenth-grade females consider time constraints, information overload, physical constraints, reduction…

The anchoring bias reflects rational use of cognitive resources.

PubMed

Lieder, Falk; Griffiths, Thomas L; M Huys, Quentin J; Goodman, Noah D

2018-02-01

Cognitive biases, such as the anchoring bias, pose a serious challenge to rational accounts of human cognition. We investigate whether rational theories can meet this challenge by taking into account the mind's bounded cognitive resources. We asked what reasoning under uncertainty would look like if people made rational use of their finite time and limited cognitive resources. To answer this question, we applied a mathematical theory of bounded rationality to the problem of numerical estimation. Our analysis led to a rational process model that can be interpreted in terms of anchoring-and-adjustment. This model provided a unifying explanation for ten anchoring phenomena including the differential effect of accuracy motivation on the bias towards provided versus self-generated anchors. Our results illustrate the potential of resource-rational analysis to provide formal theories that can unify a wide range of empirical results and reconcile the impressive capacities of the human mind with its apparently irrational cognitive biases.

Local stability condition of the equilibrium of an oligopoly market with bounded rationality adjustment

NASA Astrophysics Data System (ADS)

Ibrahim, Adyda; Saaban, Azizan; Zaibidi, Nerda Zura

2017-11-01

This paper considers an n-firm oligopoly market where each firm produces a single homogenous product under a constant unit cost. Nonlinearity is introduced into the model of this oligopoly market by assuming the market has an isoelastic demand function. Furthermore, instead of the usual assumption of perfectly rational firms, they are assumed to be boundedly rational in adjusting their outputs at each period. The equilibrium of this n discrete dimensional system is obtained and its local stability is calculated.

Simon and the Sirens: A Commentary.

PubMed

Daston, Lorraine

2015-09-01

Even in its extended usage, the concept of bounded rationality bears the birthmark of its origins in economics. First and most obviously, it is about seeking the most efficient (not necessarily the best) means toward a given end, whether that is curing patients or proving theorems. Second, the means are whittled down to the most parsimonious possible, not only acknowledging cognitive limitations but actually imposing them, whether in the form of Morgan's canon, Methodist agnosticism about causes, or Entscheidungsproblem-like restrictions on the acceptable formulation of mathematical proofs. Third, these parsimonious restrictions all tend to minimize the role of reasonable deliberation in rationality, albeit in different ways. As an object of inquiry for the history of science, bounded rationality has great promise. But as a model of the history of science, as one long exercise in bounded rationality, its utility may apply more to future than past science.

Bounded rationality leads to equilibrium of public goods games.

PubMed

Xu, Zhaojin; Wang, Zhen; Zhang, Lianzhong

2009-12-01

In this work, we introduce a degree of rationality to the public goods games in which players can determine whether or not to participate, and with it a new mechanism has been established. Existence of the bounded rationality would lead to a new equilibrium which differs from the Nash equilibrium and qualitatively explains the fundamental role of loners' payoff for maintaining cooperation. Meanwhile, it is shown how the potential strategy influences the players' decision. Finally, we explicitly demonstrate a rock-scissors-paper dynamics which is a consequence of this model.

Bounded rationality leads to equilibrium of public goods games

NASA Astrophysics Data System (ADS)

Xu, Zhaojin; Wang, Zhen; Zhang, Lianzhong

2009-12-01

In this work, we introduce a degree of rationality to the public goods games in which players can determine whether or not to participate, and with it a new mechanism has been established. Existence of the bounded rationality would lead to a new equilibrium which differs from the Nash equilibrium and qualitatively explains the fundamental role of loners’ payoff for maintaining cooperation. Meanwhile, it is shown how the potential strategy influences the players’ decision. Finally, we explicitly demonstrate a rock-scissors-paper dynamics which is a consequence of this model.

Many faces of rationality: Implications of the great rationality debate for clinical decision-making.

PubMed

Djulbegovic, Benjamin; Elqayam, Shira

2017-10-01

Given that more than 30% of healthcare costs are wasted on inappropriate care, suboptimal care is increasingly connected to the quality of medical decisions. It has been argued that personal decisions are the leading cause of death, and 80% of healthcare expenditures result from physicians' decisions. Therefore, improving healthcare necessitates improving medical decisions, ie, making decisions (more) rational. Drawing on writings from The Great Rationality Debate from the fields of philosophy, economics, and psychology, we identify core ingredients of rationality commonly encountered across various theoretical models. Rationality is typically classified under umbrella of normative (addressing the question how people "should" or "ought to" make their decisions) and descriptive theories of decision-making (which portray how people actually make their decisions). Normative theories of rational thought of relevance to medicine include epistemic theories that direct practice of evidence-based medicine and expected utility theory, which provides the basis for widely used clinical decision analyses. Descriptive theories of rationality of direct relevance to medical decision-making include bounded rationality, argumentative theory of reasoning, adaptive rationality, dual processing model of rationality, regret-based rationality, pragmatic/substantive rationality, and meta-rationality. For the first time, we provide a review of wide range of theories and models of rationality. We showed that what is "rational" behaviour under one rationality theory may be irrational under the other theory. We also showed that context is of paramount importance to rationality and that no one model of rationality can possibly fit all contexts. We suggest that in context-poor situations, such as policy decision-making, normative theories based on expected utility informed by best research evidence may provide the optimal approach to medical decision-making, whereas in the context-rich circumstances other types of rationality, informed by human cognitive architecture and driven by intuition and emotions such as the aim to minimize regret, may provide better solution to the problem at hand. The choice of theory under which we operate is important as it determines both policy and our individual decision-making. © 2017 The Authors Journal of Evaluation in Clinical Practice Published by John Wiley & Sons Ltd.

Many faces of rationality: Implications of the great rationality debate for clinical decision‐making

PubMed Central

Elqayam, Shira

2017-01-01

Abstract Given that more than 30% of healthcare costs are wasted on inappropriate care, suboptimal care is increasingly connected to the quality of medical decisions. It has been argued that personal decisions are the leading cause of death, and 80% of healthcare expenditures result from physicians' decisions. Therefore, improving healthcare necessitates improving medical decisions, ie, making decisions (more) rational. Drawing on writings from The Great Rationality Debate from the fields of philosophy, economics, and psychology, we identify core ingredients of rationality commonly encountered across various theoretical models. Rationality is typically classified under umbrella of normative (addressing the question how people “should” or “ought to” make their decisions) and descriptive theories of decision‐making (which portray how people actually make their decisions). Normative theories of rational thought of relevance to medicine include epistemic theories that direct practice of evidence‐based medicine and expected utility theory, which provides the basis for widely used clinical decision analyses. Descriptive theories of rationality of direct relevance to medical decision‐making include bounded rationality, argumentative theory of reasoning, adaptive rationality, dual processing model of rationality, regret‐based rationality, pragmatic/substantive rationality, and meta‐rationality. For the first time, we provide a review of wide range of theories and models of rationality. We showed that what is “rational” behaviour under one rationality theory may be irrational under the other theory. We also showed that context is of paramount importance to rationality and that no one model of rationality can possibly fit all contexts. We suggest that in context‐poor situations, such as policy decision‐making, normative theories based on expected utility informed by best research evidence may provide the optimal approach to medical decision‐making, whereas in the context‐rich circumstances other types of rationality, informed by human cognitive architecture and driven by intuition and emotions such as the aim to minimize regret, may provide better solution to the problem at hand. The choice of theory under which we operate is important as it determines both policy and our individual decision‐making. PMID:28730671

Assessment: Give Me a Place to Stand, and I Will Move the Earth

DTIC Science & Technology

2012-06-01

Theory , and Policy Keywords: C2 agility, bounded rationality, heuristics, uncertainty, assessment Authors: Erik Bjurström Mälardalen...of making decisions. Although the notion of bounded rationality and its associated theory rendered Herbert Simon the 1978 Nobel prize in economics...future and represents a more structuralistic approach. While making predictions about the future is often necessary it is not feasible as a general

Cognitive Architectures and Rational Analysis: Comment

DTIC Science & Technology

1989-03-17

These last three are assumptions- about the structure of the task 12 Architectures and Rationality 17 March 1989 environment , and are empirically... rationality is what cognitive psychology is all about. And the study of bounded rationality is not the study of optimization in relation tc tPok environments ...one must 16 Architectures and Rationality 17 March 1989 consider both the task environment and the limits upon the adaptive Powers of the system. Only

Rational Budgeting? The Stanford Case.

ERIC Educational Resources Information Center

Chaffee, Ellen Earle

The budget decision making process at Stanford University, California, from 1970 through 1979 was evaluated in relation to the allocation of general funds to 38 academic departments. Using Simon's theory of bounded rationality and an organizational level of analysis, the Stanford decision process was tested for its rationality through…

Molecular targeting of growth factor receptor-bound 2 (Grb2) as an anti-cancer strategy.

PubMed

Dharmawardana, Pathirage G; Peruzzi, Benedetta; Giubellino, Alessio; Burke, Terrence R; Bottaro, Donald P

2006-01-01

Growth factor receptor-bound 2 (Grb2) is a ubiquitously expressed adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway. As such, it has been implicated in the oncogenesis of several important human malignancies. In addition to this function, research over the last decade has revealed other fundamental roles for Grb2 in cell motility and angiogenesis--processes that also contribute to tumor growth, invasiveness and metastasis. This functional profile makes Grb2 a high priority target for anti-cancer drug development. Knowledge of Grb2 protein structure, its component Src homology domains and their respective structure-function relationships has facilitated the rapid development of sophisticated drug candidates that can penetrate cells, bind Grb2 with high affinity and potently antagonize Grb2 signaling. These novel compounds offer considerable promise in our growing arsenal of rationally designed anti-cancer therapeutics.

A Model for Determining Optimal Governance Structure in DoD Acquisition Projects in a Performance-Based Environment

DTIC Science & Technology

2010-04-30

combating market dynamism (Aldrich, 1979; Child, 1972), which is a result of evolving technology, shifting prices, or variance in product availability... principles : (1) human beings are bounded rationally, and (2), as a result of being rationally bound, will always choose to further their own self... principles to govern the relationship among the buyers and suppliers. Our conceptual model aligns the alternative governance structures derived

Approaching system equilibrium with accurate or not accurate feedback information in a two-route system

NASA Astrophysics Data System (ADS)

Zhao, Xiao-mei; Xie, Dong-fan; Li, Qi

2015-02-01

With the development of intelligent transport system, advanced information feedback strategies have been developed to reduce traffic congestion and enhance the capacity. However, previous strategies provide accurate information to travelers and our simulation results show that accurate information brings negative effects, especially in delay case. Because travelers prefer to the best condition route with accurate information, and delayed information cannot reflect current traffic condition but past. Then travelers make wrong routing decisions, causing the decrease of the capacity and the increase of oscillations and the system deviating from the equilibrium. To avoid the negative effect, bounded rationality is taken into account by introducing a boundedly rational threshold BR. When difference between two routes is less than the BR, routes have equal probability to be chosen. The bounded rationality is helpful to improve the efficiency in terms of capacity, oscillation and the gap deviating from the system equilibrium.

What is epistemic value in free energy models of learning and acting? A bounded rationality perspective.

PubMed

Ortega, Pedro A; Braun, Daniel A

2015-01-01

Free energy models of learning and acting do not only care about utility or extrinsic value, but also about intrinsic value, that is, the information value stemming from probability distributions that represent beliefs or strategies. While these intrinsic values can be interpreted as epistemic values or exploration bonuses under certain conditions, the framework of bounded rationality offers a complementary interpretation in terms of information-processing costs that we discuss here.

Person perception and the bounded rationality of social judgment.

PubMed

Wright, J C; Dawson, V L

1988-11-01

In this article, we develop a bounded rationality view of the relation between person perception and social behavior. Two theses of this approach are that behaviors vary in their significance to observers, and that observers pursue bounded rather than global utility in forming personality impressions. Observers are expected to be sensitive to targets' overall behavioral tendencies and to the variability of their behavior across situations, but both sensitivities are bounded, being greater for behaviors that directly affect observers' outcomes. In two investigations involving extensive hourly and 6-s observations, we examined the bounded utility of people's impressions of personality, demonstrating how impression accuracy is linked to the significance of behaviors. Observers were sensitive to the organization of aggressive behaviors, but less sensitive to the organization of withdrawn behaviors, even when the consistency of those behaviors was comparable. The results clarify the relation between people's inferential shortcomings in laboratory paradigms and the bounded utility of person perception in the natural environment.

Dynamics of market structure driven by the degree of consumer’s rationality

NASA Astrophysics Data System (ADS)

Yanagita, Tatsuo; Onozaki, Tamotsu

2010-03-01

We study a simple model of market share dynamics with boundedly rational consumers and firms interacting with each other. As the number of consumers is large, we employ a statistical description to represent firms’ distribution of consumer share, which is characterized by a single parameter representing how rationally the mass of consumers pursue higher utility. As the boundedly rational firm does not know the shape of demand function it faces, it revises production and price so as to raise its profit with the aid of a simple reinforcement learning rule. Simulation results show that (1) three phases of market structure, i.e. the uniform share phase, the oligopolistic phase, and the monopolistic phase, appear depending upon how rational consumers are, and (2) in an oligopolistic phase, the market share distribution of firms follows Zipf’s law and the growth-rate distribution of firms follows Gibrat’s law, and (3) an oligopolistic phase is the best state of market in terms of consumers’ utility but brings the minimum profit to the firms because of severe competition based on the moderate rationality of consumers.

The use of artificially intelligent agents with bounded rationality in the study of economic markets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rajan, V.; Slagle, J.R.

The concepts of {open_quote}knowledge{close_quote} and {open_quote}rationality{close_quote} are of central importance to fields of science that are interested in human behavior and learning, such as artificial intelligence, economics, and psychology. The similarity between artificial intelligence and economics - both are concerned with intelligent thought, rational behavior, and the use and acquisition of knowledge - has led to the use of economic models as a paradigm for solving problems in distributed artificial intelligence (DAI) and multi agent systems (MAS). What we propose is the opposite; the use of artificial intelligence in the study of economic markets. Over the centuries various theories ofmore » market behavior have been advanced. The prevailing theory holds that an asset`s current price converges to the risk adjusted value of the rationally expected dividend stream. While this rational expectations model holds in equilibrium or near-equilibrium conditions, it does not sufficiently explain conditions of market disequilibrium. An example of market disequilibrium is the phenomenon of a speculative bubble. We present an example of using artificially intelligent agents with bounded rationality in the study of speculative bubbles.« less

Focus: Bounded Rationality and the History of Science. Introduction.

PubMed

Cowles, Henry M; Deringer, William; Dick, Stephanie; Webster, Colin

2015-09-01

Historians of science see knowledge and its claimants as constrained by myriad factors. These limitations range from the assumptions and commitments of scientific practitioners to the material and ideational contexts of their practice. The precise nature of such limits and the relations among them remains an open question in the history of science. The essays in this Focus section address this question by examining one influential portrayal of constraints--Herbert Simon's theory of "bounded rationality"--as well as the responses to which it has given rise over the last half century.

Comparable Stocks, Boundedly Rational Stock Markets and IPO Entry Rates

PubMed Central

Chok, Jay; Qian, Jifeng

2013-01-01

In this study, we examine how initial public offerings (IPO) entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO) entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses. PMID:23690924

Comparable stocks, boundedly rational stock markets and IPO entry rates.

PubMed

Chok, Jay; Qian, Jifeng

2013-01-01

In this study, we examine how initial public offerings (IPO) entry rates are affected when stock markets are boundedly rational and IPO firms infer information from their counterparts in the market. We hypothesize a curvilinear relationship between the number of comparable stocks and initial public offerings (IPO) entry rates into the NASDAQ Stock Exchange. Furthermore, we argue that trading volume and changes in stock returns partially mediates the relationship between the number of comparable stocks and IPO entry rates. The statistical evidence provides strong support for the hypotheses.

Differential proteomics analysis of the surface heterogeneity of dextran iron oxide nanoparticles and the implications for their in vivo clearance

PubMed Central

Simberg, Dmitri; Park, Ji-Ho; Karmali, Priya P.; Zhang, Wan-Ming; Merkulov, Sergei; McCrae, Keith; Bhatia, Sangeeta; Sailor, Michael; Ruoslahti, Erkki

2009-01-01

In order to understand the role of plasma proteins in the rapid liver clearance of dextran-coated superparamagnetic iron oxide (SPIO) in vivo, we analyzed the full repertoire of SPIO-binding blood proteins using novel two-dimensional differential mass spectrometry approach. The identified proteins showed specificity for surface domains of the nanoparticles: mannan-binding lectins bound to the dextran coating, histidine-rich glycoprotein and kininogen bound to the iron oxide part, and the complement lectin and contact clotting factors were secondary binders. Nanoparticle clearance studies in knockout mice suggested that these proteins, as well as several previously identified opsonins, do not play a significant role in the SPIO clearance. However, both the dextran coat and the iron oxide core remained accessible to specific probes after incubation of SPIO in plasma, suggesting that the nanoparticle surface could be available for recognition by macrophages, regardless of protein coating. These data provide guidance to rational design of bioinert, long-circulating nanoparticles. PMID:19394687

Differential proteomics analysis of the surface heterogeneity of dextran iron oxide nanoparticles and the implications for their in vivo clearance.

PubMed

Simberg, Dmitri; Park, Ji-Ho; Karmali, Priya P; Zhang, Wan-Ming; Merkulov, Sergei; McCrae, Keith; Bhatia, Sangeeta N; Sailor, Michael; Ruoslahti, Erkki

2009-08-01

In order to understand the role of plasma proteins in the rapid liver clearance of dextran-coated superparamagnetic iron oxide (SPIO) in vivo, we analyzed the full repertoire of SPIO-binding blood proteins using novel two-dimensional differential mass spectrometry approach. The identified proteins showed specificity for surface domains of the nanoparticles: mannan-binding lectins bound to the dextran coating, histidine-rich glycoprotein and kininogen bound to the iron oxide part, and the complement lectin and contact clotting factors were secondary binders. Nanoparticle clearance studies in knockout mice suggested that these proteins, as well as several previously identified opsonins, do not play a significant role in the SPIO clearance. However, both the dextran coat and the iron oxide core remained accessible to specific probes after incubation of SPIO in plasma, suggesting that the nanoparticle surface could be available for recognition by macrophages, regardless of protein coating. These data provide guidance to rational design of bioinert, long-circulating nanoparticles.

Clinical reasoning in the real world is mediated by bounded rationality: implications for diagnostic clinical practice guidelines.

PubMed

Bonilauri Ferreira, Ana Paula Ribeiro; Ferreira, Rodrigo Fernando; Rajgor, Dimple; Shah, Jatin; Menezes, Andrea; Pietrobon, Ricardo

2010-04-20

Little is known about the reasoning mechanisms used by physicians in decision-making and how this compares to diagnostic clinical practice guidelines. We explored the clinical reasoning process in a real life environment. This is a qualitative study evaluating transcriptions of sixteen physicians' reasoning during appointments with patients, clinical discussions between specialists, and personal interviews with physicians affiliated to a hospital in Brazil. FOUR MAIN THEMES WERE IDENTIFIED: simple and robust heuristics, extensive use of social environment rationality, attempts to prove diagnostic and therapeutic hypothesis while refuting potential contradictions using positive test strategy, and reaching the saturation point. Physicians constantly attempted to prove their initial hypothesis while trying to refute any contradictions. While social environment rationality was the main factor in the determination of all steps of the clinical reasoning process, factors such as referral letters and number of contradictions associated with the initial hypothesis had influence on physicians' confidence and determination of the threshold to reach a final decision. Physicians rely on simple heuristics associated with environmental factors. This model allows for robustness, simplicity, and cognitive energy saving. Since this model does not fit into current diagnostic clinical practice guidelines, we make some propositions to help its integration.

Clinical Reasoning in the Real World Is Mediated by Bounded Rationality: Implications for Diagnostic Clinical Practice Guidelines

PubMed Central

Bonilauri Ferreira, Ana Paula Ribeiro; Ferreira, Rodrigo Fernando; Rajgor, Dimple; Shah, Jatin; Menezes, Andrea; Pietrobon, Ricardo

2010-01-01

Background Little is known about the reasoning mechanisms used by physicians in decision-making and how this compares to diagnostic clinical practice guidelines. We explored the clinical reasoning process in a real life environment. Method This is a qualitative study evaluating transcriptions of sixteen physicians' reasoning during appointments with patients, clinical discussions between specialists, and personal interviews with physicians affiliated to a hospital in Brazil. Results Four main themes were identified: simple and robust heuristics, extensive use of social environment rationality, attempts to prove diagnostic and therapeutic hypothesis while refuting potential contradictions using positive test strategy, and reaching the saturation point. Physicians constantly attempted to prove their initial hypothesis while trying to refute any contradictions. While social environment rationality was the main factor in the determination of all steps of the clinical reasoning process, factors such as referral letters and number of contradictions associated with the initial hypothesis had influence on physicians' confidence and determination of the threshold to reach a final decision. Discussion Physicians rely on simple heuristics associated with environmental factors. This model allows for robustness, simplicity, and cognitive energy saving. Since this model does not fit into current diagnostic clinical practice guidelines, we make some propositions to help its integration. PMID:20421920

Healthcare rationing: issues and implications.

PubMed

Cypher, D P

1997-01-01

What methods, if any, should be used to practice healthcare rationing? This article looks at healthcare rationing in the United States, identifies ethical issues associated with implementing healthcare rationing, and addresses legal implications. The author utilizes sources from published literature and her own experience. Society must recognize that it does not have the resources available to fulfill all healthcare needs of all its members. Resolution will bring conflict and compromise.

A theoretical perspective on road safety communication campaigns.

PubMed

Elvik, Rune

2016-12-01

This paper proposes a theoretical perspective on road safety communication campaigns, which may help in identifying the conditions under which such campaigns can be effective. The paper proposes that, from a theoretical point of view, it is reasonable to assume that road user behaviour is, by and large, subjectively rational. This means that road users are assumed to behave the way they think is best. If this assumption is accepted, the best theoretical prediction is that road safety campaigns consisting of persuasive messages only will have no effect on road user behaviour and accordingly no effect on accidents. This theoretical prediction is not supported by meta-analyses of studies that have evaluated the effects of road safety communication campaigns. These analyses conclude that, on the average, such campaigns are associated with an accident reduction. The paper discusses whether this finding can be explained theoretically. The discussion relies on the distinction made by many modern theorists between bounded and perfect rationality. Road user behaviour is characterised by bounded rationality. Hence, if road users can gain insight into the bounds of their rationality, so that they see advantages to themselves of changing behaviour, they are likely to do so. It is, however, largely unknown whether such a mechanism explains why some road safety communication campaigns have been found to be more effective than others. Copyright © 2015 Elsevier Ltd. All rights reserved.

James Moffett's Mistake: Ignoring the Rational Capacities of the Other

ERIC Educational Resources Information Center

Donehower, Kim

2013-01-01

Using Alasdair MacIntyre's theory of tradition-bound rationalities, this essay analyses James Moffett's depiction of the censors who opposed his "Interactions" textbook series in the Kanawha County, West Virginia, schools. Many reviewers have found Moffett's analysis of the censors in "Storm in the Mountains" even-handed and…

Generalized Skyrme model with the loosely bound potential

NASA Astrophysics Data System (ADS)

Gudnason, Sven Bjarke; Zhang, Baiyang; Ma, Nana

2016-12-01

We study a generalization of the loosely bound Skyrme model which consists of the Skyrme model with a sixth-order derivative term—motivated by its fluidlike properties—and the second-order loosely bound potential—motivated by lowering the classical binding energies of higher-charged Skyrmions. We use the rational map approximation for the Skyrmion of topological charge B =4 , calculate the binding energy of the latter, and estimate the systematic error in using this approximation. In the parameter space that we can explore within the rational map approximation, we find classical binding energies as low as 1.8%, and once taking into account the contribution from spin-isospin quantization, we obtain binding energies as low as 5.3%. We also calculate the contribution from the sixth-order derivative term to the electric charge density and axial coupling.

The origin of bounded rationality and intelligence.

PubMed

Lo, Andrew W

2013-09-01

Rational economic behavior in which individuals maximize their own self-interest is only one of many possible types of behavior that arise from natural selection. Given an initial population of individuals, each assigned a purely arbitrary behavior with respect to a binary choice problem, and assuming that offspring behave identically to their parents, only those behaviors linked to reproductive success will survive, and less successful behaviors will disappear exponentially fast. This framework yields a single evolutionary explanation for the origin of several behaviors that have been observed in organisms ranging from bacteria to humans, including risk-sensitive foraging, risk aversion, loss aversion, probability matching, randomization, and diversification. The key to understanding which types of behavior are more likely to survive is how behavior affects reproductive success in a given population's environment. From this perspective, intelligence is naturally defined as behavior that increases the likelihood of reproductive success, and bounds on rationality are determined by physiological and environmental constraints.

The Rational Unconscious: Implications for Mental Illness and Psychotherapy.

PubMed

Bowins, Brad

2018-05-15

Rational and reality-congruent unconscious processes facilitate adaptive functioning and have implications for mental illness and psychotherapy. With this knowledge, psychotherapists can more effectively guide interventions to improve mental health.

Broadening the Debate: Comments on Michael J. Feuer's "Moderating the Debate"

ERIC Educational Resources Information Center

Robertson, Emily

2009-01-01

In "Moderating the Debate: Rationality and the Promise of American Education", Michael Feuer argues that insights from cognitive science and the theory of bounded rationality can help us understand why educational policy makers overreach in seeking optimal solutions to educational problems. In this essay, Emily Robertson argues that cognitive…

Dynamic pricing of network goods with boundedly rational consumers.

PubMed

Radner, Roy; Radunskaya, Ami; Sundararajan, Arun

2014-01-07

We present a model of dynamic monopoly pricing for a good that displays network effects. In contrast with the standard notion of a rational-expectations equilibrium, we model consumers as boundedly rational and unable either to pay immediate attention to each price change or to make accurate forecasts of the adoption of the network good. Our analysis shows that the seller's optimal price trajectory has the following structure: The price is low when the user base is below a target level, is high when the user base is above the target, and is set to keep the user base stationary once the target level has been attained. We show that this pricing policy is robust to a number of extensions, which include the product's user base evolving over time and consumers basing their choices on a mixture of a myopic and a "stubborn" expectation of adoption. Our results differ significantly from those that would be predicted by a model based on rational-expectations equilibrium and are more consistent with the pricing of network goods observed in practice.

Modeling pedestrian shopping behavior using principles of bounded rationality: model comparison and validation

NASA Astrophysics Data System (ADS)

Zhu, Wei; Timmermans, Harry

2011-06-01

Models of geographical choice behavior have been dominantly based on rational choice models, which assume that decision makers are utility-maximizers. Rational choice models may be less appropriate as behavioral models when modeling decisions in complex environments in which decision makers may simplify the decision problem using heuristics. Pedestrian behavior in shopping streets is an example. We therefore propose a modeling framework for pedestrian shopping behavior incorporating principles of bounded rationality. We extend three classical heuristic rules (conjunctive, disjunctive and lexicographic rule) by introducing threshold heterogeneity. The proposed models are implemented using data on pedestrian behavior in Wang Fujing Street, the city center of Beijing, China. The models are estimated and compared with multinomial logit models and mixed logit models. Results show that the heuristic models are the best for all the decisions that are modeled. Validation tests are carried out through multi-agent simulation by comparing simulated spatio-temporal agent behavior with the observed pedestrian behavior. The predictions of heuristic models are slightly better than those of the multinomial logit models.

Dynamic pricing of network goods with boundedly rational consumers

PubMed Central

Radner, Roy; Radunskaya, Ami; Sundararajan, Arun

2014-01-01

We present a model of dynamic monopoly pricing for a good that displays network effects. In contrast with the standard notion of a rational-expectations equilibrium, we model consumers as boundedly rational and unable either to pay immediate attention to each price change or to make accurate forecasts of the adoption of the network good. Our analysis shows that the seller’s optimal price trajectory has the following structure: The price is low when the user base is below a target level, is high when the user base is above the target, and is set to keep the user base stationary once the target level has been attained. We show that this pricing policy is robust to a number of extensions, which include the product’s user base evolving over time and consumers basing their choices on a mixture of a myopic and a “stubborn” expectation of adoption. Our results differ significantly from those that would be predicted by a model based on rational-expectations equilibrium and are more consistent with the pricing of network goods observed in practice. PMID:24367101

Max Weber's Types of Rationality: Cornerstones for the Analysis of Rationalization Processes in History.

ERIC Educational Resources Information Center

Kalberg, Stephen

1980-01-01

Explores rationality in Max Weber's works and identifies four types of rationality which play major roles in his writing--practical, theoretical, substantive, and formal. Implications for society and education are discussed. (DB)

Rationing health care: its impact and implications for hematology-oncology.

PubMed Central

Duffy, T. P.

1992-01-01

Rationing of health care in the United States currently exists via the covert mechanism of restricting significant segments of medical care for many of those who cannot afford it. Provision of universal health care would necessitate explicit rationing of certain interventions and technologies, even though an individual could afford them. The British and Canadian experiences provide lessons from which America can profit, and the Oregon health plan is an experiment in this direction. The progressive "graying" of America has raised the question of the need for intergenerational charity as a form of rationing. The implications of these rationing plans would result in a major restructuring of the practice of hematology-oncology. PMID:1519379

Rational and Boundedly Rational Behavior in a Binary Choice Sender-Receiver Game

ERIC Educational Resources Information Center

Landi, Massimiliano; Colucci, Domenico

2008-01-01

The authors investigate the strategic rationale behind the message sent by Osama bin Laden on the eve of the 2004 U.S. Presidential elections. They model this situation as a signaling game in which a population of receivers takes a binary choice, the outcome is decided by majority rule, sender and receivers have conflicting interests, and there is…

When does "economic man" dominate social behavior?

PubMed

Camerer, Colin F; Fehr, Ernst

2006-01-06

The canonical model in economics considers people to be rational and self-regarding. However, much evidence challenges this view, raising the question of when "Economic Man" dominates the outcome of social interactions, and when bounded rationality or other-regarding preferences dominate. Here we show that strategic incentives are the key to answering this question. A minority of self-regarding individuals can trigger a "noncooperative" aggregate outcome if their behavior generates incentives for the majority of other-regarding individuals to mimic the minority's behavior. Likewise, a minority of other-regarding individuals can generate a "cooperative" aggregate outcome if their behavior generates incentives for a majority of self-regarding people to behave cooperatively. Similarly, in strategic games, aggregate outcomes can be either far from or close to Nash equilibrium if players with high degrees of strategic thinking mimic or erase the effects of others who do very little strategic thinking. Recently developed theories of other-regarding preferences and bounded rationality explain these findings and provide better predictions of actual aggregate behavior than does traditional economic theory.

Rational Suicide and the Crisis of Terminal Illness.

ERIC Educational Resources Information Center

Lokhandwala, Tasneem M.; Westefeld, John S.

1998-01-01

Whether or not suicide may be considered a rational choice for clients with terminal illness is controversial. Rational suicide and the literature and statistics pertaining to suicide and terminal illness are reviewed. Implications of accepting rational suicide as a treatment option, including moral and ethical issues, are addressed. (Author/EMK)

Are We Rational or Not? The Exploration of Voter Choices during the 2016 Presidential and Legislative Elections in Taiwan

PubMed Central

Lee, I-Ching; Chen, Eva E.; Yen, Nai-Shing; Tsai, Chia-Hung; Cheng, Hsu-Po

2017-01-01

The decisions voters make—and whether those decisions are rational—have profound implications on the functionality of a democratic society. In this study, we delineated two criteria in evaluating voter rationality and weigh evidence of voter rationality versus irrationality. Furthermore, we compared models in two different elections in Taiwan to explore the reasons behind the irrational choices voters can make. Survey questions and an implicit association test (IAT) were administered prior to both elections among 197 voters in Taipei. These voters then reported their actual votes post-election. Model testing suggests that voters often are rational, but are more likely to make irrational choices in more important elections. Our findings indicate that voters generally aim to be diligent and to optimize their choices, even if they make less rational choices in the end. Further implications regarding elections and human rationality are discussed. PMID:29075215

DNA binding triggers tetramerization of the glucocorticoid receptor in live cells

PubMed Central

Presman, Diego M.; Ganguly, Sourav; Schiltz, R. Louis; Johnson, Thomas A.; Karpova, Tatiana S.; Hager, Gordon L.

2016-01-01

Transcription factors dynamically bind to chromatin and are essential for the regulation of genes. Although a large percentage of these proteins appear to self-associate to form dimers or higher order oligomers, the stoichiometry of DNA-bound transcription factors has been poorly characterized in vivo. The glucocorticoid receptor (GR) is a ligand-regulated transcription factor widely believed to act as a dimer or a monomer. Using a unique set of imaging techniques coupled with a cell line containing an array of DNA binding elements, we show that GR is predominantly a tetramer when bound to its target DNA. We find that DNA binding triggers an interdomain allosteric regulation within the GR, leading to tetramerization. We therefore propose that dynamic changes in GR stoichiometry represent a previously unidentified level of regulation in steroid receptor activation. Quaternary structure analysis of other members of the steroid receptor family (estrogen, androgen, and progesterone receptors) reveals variation in oligomerization states among this family of transcription factors. Because GR’s oligomerization state has been implicated in therapy outcome, our findings open new doors to the rational design of novel GR ligands and redefine the quaternary structure of steroid receptors. PMID:27382178

When Information Improves Information Security

NASA Astrophysics Data System (ADS)

Grossklags, Jens; Johnson, Benjamin; Christin, Nicolas

This paper presents a formal, quantitative evaluation of the impact of bounded-rational security decision-making subject to limited information and externalities. We investigate a mixed economy of an individual rational expert and several naïve near-sighted agents. We further model three canonical types of negative externalities (weakest-link, best shot and total effort), and study the impact of two information regimes on the threat level agents are facing.

Complex Nonlinear Dynamic System of Oligopolies Price Game with Heterogeneous Players Under Noise

NASA Astrophysics Data System (ADS)

Liu, Feng; Li, Yaguang

A nonlinear four oligopolies price game with heterogeneous players, that are boundedly rational and adaptive, is built using two different special demand costs. Based on the theory of complex discrete dynamical system, the stability and the existing equilibrium point are investigated. The complex dynamic behavior is presented via bifurcation diagrams, the Lyapunov exponents to show equilibrium state, bifurcation and chaos with the variation in parameters. As disturbance is ubiquitous in economic systems, this paper focuses on the analysis of delay feedback control method under noise circumstances. Stable dynamics is confirmed to depend mainly on the low price adjustment speed, and if all four players have limited opportunities to stabilize the market, the new adaptive player facing profits of scale are found to be higher than the incumbents of bounded rational.

Evolutionary game analysis and regulatory strategies for online group-buying based on system dynamics

NASA Astrophysics Data System (ADS)

Jiang, Zhong-Zhong; He, Na; Qin, Xuwei; Ip, W. H.; Wu, C. H.; Yung, K. L.

2018-07-01

The emergence of online group-buying provides a new consumption pattern for consumers in e-commerce era. However, many consumers realize that their own interests sometimes can't be guaranteed in the group-buying market due to the lack of being regulated. This paper aims to develop effective regulation strategies for online group-buying market. To the best of our knowledge, most existing studies assume that three parties in online group-buying market, i.e. the retailer, the group-buying platform and the consumer, are perfectly rational. To better understand the decision process, in this paper, we incorporate the concept of bounded rationality into consideration. Firstly, a three-parties evolutionary game model is established to study each player's game strategy based on bounded rationality. Secondly, the game model is simulated as a whole by adopting system dynamics to analyze its stability. Finally, theoretical analysis and extensive computational experiments are conducted to obtain the managerial insights and regulation strategies for online group-buying market. Our results clearly demonstrate that a suitable bonus-penalty measure can promote the healthy development of online group-buying market.

An evolutionary model of bounded rationality and intelligence.

PubMed

Brennan, Thomas J; Lo, Andrew W

2012-01-01

Most economic theories are based on the premise that individuals maximize their own self-interest and correctly incorporate the structure of their environment into all decisions, thanks to human intelligence. The influence of this paradigm goes far beyond academia-it underlies current macroeconomic and monetary policies, and is also an integral part of existing financial regulations. However, there is mounting empirical and experimental evidence, including the recent financial crisis, suggesting that humans do not always behave rationally, but often make seemingly random and suboptimal decisions. Here we propose to reconcile these contradictory perspectives by developing a simple binary-choice model that takes evolutionary consequences of decisions into account as well as the role of intelligence, which we define as any ability of an individual to increase its genetic success. If no intelligence is present, our model produces results consistent with prior literature and shows that risks that are independent across individuals in a generation generally lead to risk-neutral behaviors, but that risks that are correlated across a generation can lead to behaviors such as risk aversion, loss aversion, probability matching, and randomization. When intelligence is present the nature of risk also matters, and we show that even when risks are independent, either risk-neutral behavior or probability matching will occur depending upon the cost of intelligence in terms of reproductive success. In the case of correlated risks, we derive an implicit formula that shows how intelligence can emerge via selection, why it may be bounded, and how such bounds typically imply the coexistence of multiple levels and types of intelligence as a reflection of varying environmental conditions. Rational economic behavior in which individuals maximize their own self interest is only one of many possible types of behavior that arise from natural selection. The key to understanding which types of behavior are more likely to survive is how behavior affects reproductive success in a given population's environment. From this perspective, intelligence is naturally defined as behavior that increases the probability of reproductive success, and bounds on rationality are determined by physiological and environmental constraints.

An Evolutionary Model of Bounded Rationality and Intelligence

PubMed Central

Brennan, Thomas J.; Lo, Andrew W.

2012-01-01

Background Most economic theories are based on the premise that individuals maximize their own self-interest and correctly incorporate the structure of their environment into all decisions, thanks to human intelligence. The influence of this paradigm goes far beyond academia–it underlies current macroeconomic and monetary policies, and is also an integral part of existing financial regulations. However, there is mounting empirical and experimental evidence, including the recent financial crisis, suggesting that humans do not always behave rationally, but often make seemingly random and suboptimal decisions. Methods and Findings Here we propose to reconcile these contradictory perspectives by developing a simple binary-choice model that takes evolutionary consequences of decisions into account as well as the role of intelligence, which we define as any ability of an individual to increase its genetic success. If no intelligence is present, our model produces results consistent with prior literature and shows that risks that are independent across individuals in a generation generally lead to risk-neutral behaviors, but that risks that are correlated across a generation can lead to behaviors such as risk aversion, loss aversion, probability matching, and randomization. When intelligence is present the nature of risk also matters, and we show that even when risks are independent, either risk-neutral behavior or probability matching will occur depending upon the cost of intelligence in terms of reproductive success. In the case of correlated risks, we derive an implicit formula that shows how intelligence can emerge via selection, why it may be bounded, and how such bounds typically imply the coexistence of multiple levels and types of intelligence as a reflection of varying environmental conditions. Conclusions Rational economic behavior in which individuals maximize their own self interest is only one of many possible types of behavior that arise from natural selection. The key to understanding which types of behavior are more likely to survive is how behavior affects reproductive success in a given population’s environment. From this perspective, intelligence is naturally defined as behavior that increases the probability of reproductive success, and bounds on rationality are determined by physiological and environmental constraints. PMID:23185602

Fluoride mechanisms.

PubMed

ten Cate, J M; van Loveren, C

1999-10-01

This article discusses fluoride mechanisms in relation to dental caries. The authors specifically address firmly bound versus loosely bound fluoride; different fluoride active ingredients; fluoride and demineralization and remineralization; fluoride slow-release devices and F-releasing dental materials; antimicrobial effects of fluoride; the uptake of fluoride by oral bacteria; inhibition of enolase, protein-intruding ATPase and sugar transport; the various aspects of plaque as it relates to fluoride; and the rational use of fluoride.

Administrative gatekeeping - a third way between unrestricted patient advocacy and bedside rationing.

PubMed

Lauridsen, Sigurd

2009-06-01

The inevitable need for rationing of healthcare has apparently presented the medical profession with the dilemma of choosing the lesser of two evils. Physicians appear to be obliged to adopt either an implausible version of traditional professional ethics or an equally problematic ethics of bedside rationing. The former requires unrestricted advocacy of patients but prompts distrust, moral hazard and unfairness. The latter commits physicians to rationing at the bedside; but it is bound to introduce unfair inequalities among patients and lack of political accountability towards citizens. In this paper I shall argue that this dilemma is false, since a third intermediate alternative exists. This alternative, which I term 'administrative gatekeeping', makes it possible for physicians to be involved in rationing while at the same time being genuine advocates of their patients. According to this ideal, physicians are required to follow fair rules of rationing adopted at higher organizational levels within healthcare systems. At the same time, however, they are prohibited from including considerations of cost in their clinical decisions.

Re-visions of rationality?

PubMed

Newell, Ben R

2005-01-01

The appeal of simple algorithms that take account of both the constraints of human cognitive capacity and the structure of environments has been an enduring theme in cognitive science. A novel version of such a boundedly rational perspective views the mind as containing an 'adaptive toolbox' of specialized cognitive heuristics suited to different problems. Although intuitively appealing, when this version was proposed, empirical evidence for the use of such heuristics was scant. I argue that in the light of empirical studies carried out since then, it is time this 'vision of rationality' was revised. An alternative view based on integrative models rather than collections of heuristics is proposed.

Prospect balancing theory: Bounded rationality of drivers' speed choice.

PubMed

Schmidt-Daffy, Martin

2014-02-01

This paper introduces a new approach to model the psychological determinants of drivers' speed choice: prospect-balancing theory. The theory transfers psychological insight into the bounded rationality of human decision-making to the field of driving behaviour. Speed choice is conceptualized as a trade-off between two options for action: the option to drive slower and the option to drive faster. Each option is weighted according to a subjective value and a subjectively weighted probability attributed to the achievement of the associated action goal; e.g. to avoid an accident by driving more slowly. The theory proposes that the subjective values and weightings of probability differ systematically from the objective conditions and thereby usually favour a cautious speed choice. A driving simulation study with 24 male participants supports this assumption. In a conflict between a monetary gain in case of fast arrival and a monetary loss in case of a collision with a deer, participants chose a velocity lower than that which would maximize their pay-out. Participants' subjective certainty of arriving in time and of avoiding a deer collision assessed at different driving speeds diverged from the respective objective probabilities in accordance with the observed bias in choice of speed. Results suggest that the bounded rationality of drivers' speed choice might be used to support attempts to improve road safety. Thus, understanding the motivational and perceptual determinants of this intuitive mode of decision-making might be a worthwhile focus of future research. Copyright © 2013 Elsevier Ltd. All rights reserved.

Abnormality, rationality, and sanity.

PubMed

Hertwig, Ralph; Volz, Kirsten G

2013-11-01

A growing body of studies suggests that neurological and mental abnormalities foster conformity to norms of rationality that are widely endorsed in economics and psychology, whereas normality stands in the way of rationality thus defined. Here, we outline the main findings of these studies, discuss their implications for experimental design, and consider how 'sane' some benchmarks of rationality really are. Copyright © 2013 Elsevier Ltd. All rights reserved.

A Feminist Critique of Rational-Choice Theories: Implications for Sociology.

ERIC Educational Resources Information Center

England, Paula

1989-01-01

Provides a feminist critique of rational-choice theory and the interdisciplinary feminist theories of sociology. Applies the separative model of self to four assumptions of the neoclassical economics version of rational-choice theory. Uses research on marital power to illustrate how removing distorting assumptions can help illuminate sociological…

Rational Emotive Behavior Therapy: Origins, Constructs, and Applications.

ERIC Educational Resources Information Center

Watson, Joshua C.

In 1956, Dr. Albert Ellis presented his seminal work on Rational Therapy, subsequently renamed Rational Emotive Behavior Therapy (REBT) in 1993. This paper explores the origins, theoretical foundations, applications, and implications of REBT and provides a look at the empirical research available in support of the approach's efficacy. REBT is…

Are Grade Expectations Rational? A Classroom Experiment

ERIC Educational Resources Information Center

Hossain, Belayet; Tsigaris, Panagiotis

2015-01-01

This study examines students' expectations about their final grade. An attempt is made to determine whether students form expectations rationally. Expectations in economics, rational or otherwise, carry valuable information and have important implications in terms of both teaching effectiveness and the role of grades as an incentive structure for…

The Integration of Extrarational and Rational Learning Processes: Moving Towards the Whole Learner.

ERIC Educational Resources Information Center

Puk, Tom

1996-01-01

Discusses the dichotomy between rational and nonrational learning processes, arguing for an integration of both. Reviews information processing theory and related learning strategies. Presents a model instructional strategy that fully integrates rational and nonrational processes. Describes implications for teaching and learning of the learning…

AIDS and Rational Suicide: A Counseling Psychology Perspective or a Slide on the Slippery Slope.

ERIC Educational Resources Information Center

Rogers, James R.; Britton, Paula J.

1994-01-01

Responds to Werth's (1992) arguing for rational suicide for individuals diagnosed with Acquired Immune Deficiency Syndrome (AIDS). Commends Werth's willingness to address issue of rational suicide for individuals diagnosed with AIDS, but expresses concerns about data supporting his rationale and implications for counseling psychology and society…

Developing and Testing Rational Models of Message Design.

ERIC Educational Resources Information Center

O'Keefe, Barbara J.

1992-01-01

Responds to an article in the same issue regarding research methods for conversational cognition. Argues for a noncognitive view of rational models in communication research. Sets out an analysis of the kinds of claims made by rational models of message design. Discusses the implications of this analysis for studies of the cognitive processes…

Adolescent Identity: Rational vs. Experiential Processing, Formal Operations, and Critical Thinking Beliefs.

ERIC Educational Resources Information Center

Klaczynski, Paul A.; Fauth, James M.; Swanger, Amy

1998-01-01

The extent to which adolescents rely on rational versus experiential information processing was studied with 49 adolescents administered multiple measures of formal operations, two critical thinking questionnaires, a measure of rational processing, and a measure of ego identity status. Implications for studies of development are discussed in terms…

An investigation into the unusual linkage isomerization and nitrite reduction activity of a novel tris(2-pyridyl) copper complex

NASA Astrophysics Data System (ADS)

Roger, Isolda; Wilson, Claire; Senn, Hans M.; Sproules, Stephen; Symes, Mark D.

2017-08-01

The copper-containing nitrite reductases (CuNIRs) are a class of enzymes that mediate the reduction of nitrite to nitric oxide in biological systems. Metal-ligand complexes that reproduce the salient features of the active site of CuNIRs are therefore of fundamental interest, both for elucidating the possible mode of action of the enzymes and for developing biomimetic catalysts for nitrite reduction. Herein, we describe the synthesis and characterization of a new tris(2-pyridyl) copper complex ([Cu1(NO2)2]) that binds two molecules of nitrite, and displays all three of the common binding modes for NO2-, with one nitrite bound in an asymmetric quasi-bidentate κ2-ONO manner and the other bound in a monodentate fashion with a linkage isomerism between the κ1-ONO and κ1-NO2 binding modes. We use density functional theory to help rationalize the presence of all three of these linkage isomers in one compound, before assessing the redox activity of [Cu1(NO2)2]. These latter studies show that the complex is not a competent nitrite reduction electrocatalyst in non-aqueous solvent, even in the presence of additional proton donors, a finding which may have implications for the design of biomimetic catalysts for nitrite reduction.

Backstepping Design of Adaptive Neural Fault-Tolerant Control for MIMO Nonlinear Systems.

PubMed

Gao, Hui; Song, Yongduan; Wen, Changyun

In this paper, an adaptive controller is developed for a class of multi-input and multioutput nonlinear systems with neural networks (NNs) used as a modeling tool. It is shown that all the signals in the closed-loop system with the proposed adaptive neural controller are globally uniformly bounded for any external input in . In our control design, the upper bound of the NN modeling error and the gains of external disturbance are characterized by unknown upper bounds, which is more rational to establish the stability in the adaptive NN control. Filter-based modification terms are used in the update laws of unknown parameters to improve the transient performance. Finally, fault-tolerant control is developed to accommodate actuator failure. An illustrative example applying the adaptive controller to control a rigid robot arm shows the validation of the proposed controller.In this paper, an adaptive controller is developed for a class of multi-input and multioutput nonlinear systems with neural networks (NNs) used as a modeling tool. It is shown that all the signals in the closed-loop system with the proposed adaptive neural controller are globally uniformly bounded for any external input in . In our control design, the upper bound of the NN modeling error and the gains of external disturbance are characterized by unknown upper bounds, which is more rational to establish the stability in the adaptive NN control. Filter-based modification terms are used in the update laws of unknown parameters to improve the transient performance. Finally, fault-tolerant control is developed to accommodate actuator failure. An illustrative example applying the adaptive controller to control a rigid robot arm shows the validation of the proposed controller.

Regulating Hazardous-materials Transportation with Behavioral Modeling of Drivers

DOT National Transportation Integrated Search

2018-01-29

Changhyun Kwon (ORCID ID 0000-0001-8455-6396) This project considers network regulation problems to minimize the risk of hazmat accidents and potential damages to the environment, while considering bounded rationality of drivers. We consider governme...

Context as Relevance-Driven Abduction and Charitable Satisficing

PubMed Central

Attardo, Salvatore

2016-01-01

It has been widely assumed that the full meaning of a linguistic expression can be grasped only within a situation, the context of the utterance. There is even agreement that certain factors within the situation are particularly significant, including gestures and facial expressions of the participants, their social roles, the setting of the exchange, the objects surrounding the participants, the linguistic, cultural and educational backgrounds of the participants, their beliefs, including those concerning the situation, the social procedures and conventions that regulate the situation. Finally, there is some agreement that context is dynamic, reflexive (the speakers are mutually aware of their beliefs), not limited to linguistics actions, and last but not least, a psychological construct. This definition of context is not (very) controversial, but it leaves out two major problems, which will be addressed in this paper: how is context arrived at? And, since a perfectly natural interpretation of the above definition could be that the context of each utterance is the entire universe, how is the relevant context delimited? Four related concepts will provide the answer to both questions: abductive reasoning, driven by relevance and cooperation, and bounded rationality and the principle of charity. Simply put, context is derived abductively by the speakers assuming that for the speakers to behave the way they behave and do so rationally, a given context must be available to them. The context is bounded by the simple requirement that speakers not try to optimize their interpretation/calculation, but rather satisfice, i.e., find the first acceptable solution and by the need to follow the principle of charity, which forces intersubjective agreement. Thus, abductive reasoning and bounded rationality will be shown to be sufficient to calculate the relevant context of utterances (or other rationality-driven interactions) and to effectively delimit the potentially infinite search space that must be explored to do so. PMID:27014123

Context as Relevance-Driven Abduction and Charitable Satisficing.

PubMed

Attardo, Salvatore

2016-01-01

It has been widely assumed that the full meaning of a linguistic expression can be grasped only within a situation, the context of the utterance. There is even agreement that certain factors within the situation are particularly significant, including gestures and facial expressions of the participants, their social roles, the setting of the exchange, the objects surrounding the participants, the linguistic, cultural and educational backgrounds of the participants, their beliefs, including those concerning the situation, the social procedures and conventions that regulate the situation. Finally, there is some agreement that context is dynamic, reflexive (the speakers are mutually aware of their beliefs), not limited to linguistics actions, and last but not least, a psychological construct. This definition of context is not (very) controversial, but it leaves out two major problems, which will be addressed in this paper: how is context arrived at? And, since a perfectly natural interpretation of the above definition could be that the context of each utterance is the entire universe, how is the relevant context delimited? Four related concepts will provide the answer to both questions: abductive reasoning, driven by relevance and cooperation, and bounded rationality and the principle of charity. Simply put, context is derived abductively by the speakers assuming that for the speakers to behave the way they behave and do so rationally, a given context must be available to them. The context is bounded by the simple requirement that speakers not try to optimize their interpretation/calculation, but rather satisfice, i.e., find the first acceptable solution and by the need to follow the principle of charity, which forces intersubjective agreement. Thus, abductive reasoning and bounded rationality will be shown to be sufficient to calculate the relevant context of utterances (or other rationality-driven interactions) and to effectively delimit the potentially infinite search space that must be explored to do so.

Additive equivalence in turbulent drag reduction by flexible and rodlike polymers.

PubMed

Benzi, Roberto; Ching, Emily S C; Lo, T S; L'vov, Victor S; Procaccia, Itamar

2005-07-01

We address the additive equivalence discovered by Virk and co-workers: drag reduction affected by flexible and rigid rodlike polymers added to turbulent wall-bounded flows is limited from above by a very similar maximum drag reduction (MDR) asymptote. Considering the equations of motion of rodlike polymers in wall-bounded turbulent ensembles, we show that although the microscopic mechanism of attaining the MDR is very different, the macroscopic theory is isomorphic, rationalizing the interesting experimental observations.

Understanding the Current 30-Year Shipbuilding Plan Through Three Models

DTIC Science & Technology

2014-12-01

to what the Navy can ultimately build in ten years and beyond due to the fact that this plan is revised annually. In a political game this...the game and each one hoping for a different outcome. Though not currently possible with the FY2015 Long Range Plan it is possible to analyze the...to make a choice while the bounded rationality theory acknowledges the limits of human capabilities, knowledge, and capacity. Therefore, bounded

Inaugurating Rationalization: Three Field Studies Find Increased Rationalization When Anticipated Realities Become Current.

PubMed

Laurin, Kristin

2018-04-01

People will often rationalize the status quo, reconstruing it in an exaggeratedly positive light. They will even rationalize the status quo they anticipate, emphasizing the upsides and minimizing the downsides of sociopolitical realities they expect to take effect. Drawing on recent findings on the psychological triggers of rationalization, I present results from three field studies, one of which was preregistered, testing the hypothesis that an anticipated reality becoming current triggers an observable boost in people's rationalizations. San Franciscans rationalized a ban on plastic water bottles, Ontarians rationalized a targeted smoking ban, and Americans rationalized the presidency of Donald Trump, more in the days immediately after these realities became current compared with the days immediately before. Additional findings show evidence for a mechanism underlying these behaviors and rule out alternative accounts. These findings carry implications for scholarship on rationalization, for understanding protest behavior, and for policymakers.

Nutritional Implications of High-Tech Foods, Should Combat Rations be High Fat or Low Fat

DTIC Science & Technology

1988-10-06

storage. It is self-evident that an individual that has energy stored for later use when energy intake does not meet energy expenditure will have a competitive advantage . Keywords: Symposia; Nutrition; Military rations.

The etiology of social change.

PubMed

Carley, Kathleen M; Martin, Michael K; Hirshman, Brian R

2009-10-01

A fundamental aspect of human beings is that they learn. The process of learning and what is learned are impacted by a number of factors, both cognitive and social; that is, humans are boundedly rational. Cognitive and social limitations interact, making it difficult to reason about how to provide information to impact what humans know, believe, and do. Herein, we use a multi-agent dynamic-network simulation system, Construct, to conduct such reasoning. In particular, we ask, What media should be used to provide information to most impact what people know, believe, and do, given diverse social structures? All simulated agents are boundedly rational both at the cognitive and social level, and so are subject to factors such as literacy, education, and the breadth of their social network. We find that there is no one most effective intervention; rather, to be effective, messages and the media used to spread the message need to be selected for the population being addressed. Typically, a multimedia campaign is critical. Copyright © 2009 Cognitive Science Society, Inc.

Changing crops in response to climate: virtual Nang Rong, Thailand in an agent based simulation

PubMed Central

Malanson, George P.; Verdery, Ashton M.; Walsh, Stephen J.; Sawangdee, Yothin; Heumann, Benjamin W.; McDaniel, Philip M.; Frizzelle, Brian G.; Williams, Nathalie E.; Yao, Xiaozheng; Entwisle, Barbara; Rindfuss, Ronald R.

2014-01-01

The effects of extended climatic variability on agricultural land use were explored for the type of system found in villages of northeastern Thailand. An agent based model developed for the Nang Rong district was used to simulate land allotted to jasmine rice, heavy rice, cassava, and sugar cane. The land use choices in the model depended on likely economic outcomes, but included elements of bounded rationality in dependence on household demography. The socioeconomic dynamics are endogenous in the system, and climate changes were added as exogenous drivers. Villages changed their agricultural effort in many different ways. Most villages reduced the amount of land under cultivation, primarily with reduction in jasmine rice, but others did not. The variation in responses to climate change indicates potential sensitivity to initial conditions and path dependence for this type of system. The differences between our virtual villages and the real villages of the region indicate effects of bounded rationality and limits on model applications. PMID:25061240

Looking Across and Looking Beyond the Knowledge Frontier: Intellectual Distance, Novelty, and Resource Allocation in Science

PubMed Central

Boudreau, Kevin J.; Guinan, Eva C.; Lakhani, Karim R.; Riedl, Christoph

2016-01-01

Selecting among alternative projects is a core management task in all innovating organizations. In this paper, we focus on the evaluation of frontier scientific research projects. We argue that the “intellectual distance” between the knowledge embodied in research proposals and an evaluator’s own expertise systematically relates to the evaluations given. To estimate relationships, we designed and executed a grant proposal process at a leading research university in which we randomized the assignment of evaluators and proposals to generate 2,130 evaluator–proposal pairs. We find that evaluators systematically give lower scores to research proposals that are closer to their own areas of expertise and to those that are highly novel. The patterns are consistent with biases associated with boundedly rational evaluation of new ideas. The patterns are inconsistent with intellectual distance simply contributing “noise” or being associated with private interests of evaluators. We discuss implications for policy, managerial intervention, and allocation of resources in the ongoing accumulation of scientific knowledge. PMID:27746512

Looking Across and Looking Beyond the Knowledge Frontier: Intellectual Distance, Novelty, and Resource Allocation in Science.

PubMed

Boudreau, Kevin J; Guinan, Eva C; Lakhani, Karim R; Riedl, Christoph

2016-10-01

Selecting among alternative projects is a core management task in all innovating organizations. In this paper, we focus on the evaluation of frontier scientific research projects. We argue that the "intellectual distance" between the knowledge embodied in research proposals and an evaluator's own expertise systematically relates to the evaluations given. To estimate relationships, we designed and executed a grant proposal process at a leading research university in which we randomized the assignment of evaluators and proposals to generate 2,130 evaluator-proposal pairs. We find that evaluators systematically give lower scores to research proposals that are closer to their own areas of expertise and to those that are highly novel. The patterns are consistent with biases associated with boundedly rational evaluation of new ideas. The patterns are inconsistent with intellectual distance simply contributing "noise" or being associated with private interests of evaluators. We discuss implications for policy, managerial intervention, and allocation of resources in the ongoing accumulation of scientific knowledge.

Capped RNA primer binding to influenza polymerase and implications for the mechanism of cap-binding inhibitors

PubMed Central

Pflug, Alexander; Gaudon, Stephanie; Resa-Infante, Patricia; Lethier, Mathilde; Reich, Stefan; Schulze, Wiebke M

2018-01-01

Abstract Influenza polymerase uses short capped primers snatched from nascent Pol II transcripts to initiate transcription of viral mRNAs. Here we describe crystal structures of influenza A and B polymerase bound to a capped primer in a configuration consistent with transcription initiation (’priming state’) and show by functional assays that conserved residues from both the PB2 midlink and cap-binding domains are important for positioning the capped RNA. In particular, mutation of PB2 Arg264, which interacts with the triphosphate linkage in the cap, significantly and specifically decreases cap-dependent transcription. We also compare the configuration of the midlink and cap-binding domains in the priming state with their very different relative arrangement (called the ‘apo’ state) in structures where the potent cap-binding inhibitor VX-787, or a close analogue, is bound. In the ‘apo’ state the inhibitor makes additional interactions to the midlink domain that increases its affinity beyond that to the cap-binding domain alone. The comparison suggests that the mechanism of resistance of certain mutations that allow virus to escape from VX-787, notably PB2 N510T, can only be rationalized if VX-787 has a dual mode of action, direct inhibition of capped RNA binding as well as stabilization of the transcriptionally inactive ‘apo’ state. PMID:29202182

Against the magnanimous in medical ethics.

PubMed

Kottow, M H

1990-09-01

Supererogatory acts are considered by some to be part of medicine, whereas others accept supererogation to be a gratuitous virtue, to be extolled when present, but not to be demanded. The present paper sides with those contending that medicine is duty-bound to benefit patients and that supererogation/altruism must per definition remain outside and beyond any role-description of the profession. Medical ethics should be bound by rational ethics and steer away from separatist views which grant exclusive privileges but also create excessive demands, way beyond what physicians perform or are willing and able to offer.

Communication: An exact bound on the bridge function in integral equation theories.

PubMed

Kast, Stefan M; Tomazic, Daniel

2012-11-07

We show that the formal solution of the general closure relation occurring in Ornstein-Zernike-type integral equation theories in terms of the Lambert W function leads to an exact relation between the bridge function and correlation functions, most notably to an inequality that bounds possible bridge values. The analytical results are illustrated on the example of the Lennard-Jones fluid for which the exact bridge function is known from computer simulations under various conditions. The inequality has consequences for the development of bridge function models and rationalizes numerical convergence issues.

Emerging Perspectives on Planning and Change Processes.

ERIC Educational Resources Information Center

Beach, Robert H.

1993-01-01

During the past 50 years, educational planning has evolved into a recognized, somewhat esoteric field of study. The four major planning models are rationalism (comprehensive and bounded), incrementalism (or muddling through), mixed or environmental scanning, and goal-free (developmental) planning. Sound educational planning is people-oriented and…

An SH2 domain model of STAT5 in complex with phospho-peptides define ``STAT5 Binding Signatures''

NASA Astrophysics Data System (ADS)

Gianti, Eleonora; Zauhar, Randy J.

2015-05-01

The signal transducer and activator of transcription 5 (STAT5) is a member of the STAT family of proteins, implicated in cell growth and differentiation. STAT activation is regulated by phosphorylation of protein monomers at conserved tyrosine residues, followed by binding to phospho-peptide pockets and subsequent dimerization. STAT5 is implicated in the development of severe pathological conditions, including many cancer forms. However, nowadays a few STAT5 inhibitors are known, and only one crystal structure of the inactive STAT5 dimer is publicly available. With a view to enabling structure-based drug design, we have: (1) analyzed phospho-peptide binding pockets on SH2 domains of STAT5, STAT1 and STAT3; (2) generated a model of STAT5 bound to phospho-peptides; (3) assessed our model by docking against a class of known STAT5 inhibitors (Müller et al. in ChemBioChem 9:723-727, 2008); (4) used molecular dynamics simulations to optimize the molecular determinants responsible for binding and (5) proposed unique "Binding Signatures" of STAT5. Our results put in place the foundations to address STAT5 as a target for rational drug design, from sequence, structural and functional perspectives.

Optimization through satisficing with prospects

NASA Astrophysics Data System (ADS)

Oyo, Kuratomo; Takahashi, Tatsuji

2017-07-01

As the broadening scope of reinforcement learning calls for a rational and more efficient heuristics, we test a satisficing strategy named RS, based on the theory of bounded rationality that considers the limited resources in agents. In K-armed bandit problems, despite its simpler form than the previous formalization of satisficing, RS shows better-than-optimal performances when the optimal aspiration level is given. We also show that RS shows a scalability for the number of actions, K, and an adaptability in the face of an infinite number of actions. It may be an efficient means for online learning in a complex or real environments.

Treatment of Childhood Depression: The State of the Art.

ERIC Educational Resources Information Center

Clarizio, Harvey F.

1986-01-01

This article reviews various aspects of seven approaches to the treatment of childhood depression--psychoanalytic, behavioral, cognitive, familial, rational-emotive, multimodal, and drug interventions. Implications for practitioners are considered in terms of target selection, choice of treatment methods, rational evaluation based on developmental…

Pharmacodynamics of nicotine: implications for rational treatment of nicotine addiction.

PubMed

Benowitz, N L

1991-05-01

Rational treatment of the pharmacologic aspects of tobacco addiction includes nicotine substitution therapy. Understanding the pharmacodynamics of nicotine and its role in the addiction process provides a basis for rational therapeutic intervention. Pharmacodynamic considerations are discussed in relation to the elements of smoking cessation therapy: setting objectives, selecting appropriate medication and dosing form, selecting the optimal doses and dosage regimens, assessing therapeutic outcome, and adjusting therapy to optimize benefits and minimize risks.

Kodiak: An Implementation Framework for Branch and Bound Algorithms

NASA Technical Reports Server (NTRS)

Smith, Andrew P.; Munoz, Cesar A.; Narkawicz, Anthony J.; Markevicius, Mantas

2015-01-01

Recursive branch and bound algorithms are often used to refine and isolate solutions to several classes of global optimization problems. A rigorous computation framework for the solution of systems of equations and inequalities involving nonlinear real arithmetic over hyper-rectangular variable and parameter domains is presented. It is derived from a generic branch and bound algorithm that has been formally verified, and utilizes self-validating enclosure methods, namely interval arithmetic and, for polynomials and rational functions, Bernstein expansion. Since bounds computed by these enclosure methods are sound, this approach may be used reliably in software verification tools. Advantage is taken of the partial derivatives of the constraint functions involved in the system, firstly to reduce the branching factor by the use of bisection heuristics and secondly to permit the computation of bifurcation sets for systems of ordinary differential equations. The associated software development, Kodiak, is presented, along with examples of three different branch and bound problem types it implements.

Problems of Change: Bounded Rationality--What do Teachers Really Do?

ERIC Educational Resources Information Center

Hatcher, Catherine W.

Through an integration of teacher effectiveness and reading research, this paper proposes ways for improving classroom reading instruction. The first part of the paper reviews teacher effectiveness research, noting the shifts that have occurred in that area from the early efforts, which focused on identifying and describing teacher characteristics…

Estimating the Volumes of Solid Figures with Curved Surfaces.

ERIC Educational Resources Information Center

Cohen, Donald

1991-01-01

Several examples of solid figures that calculus students can use to exercise their skills at estimating volume are presented. Although these figures are bounded by surfaces that are portions of regular cylinders, it is interesting to note that their volumes can be expressed as rational numbers. (JJK)

Rational models as theories - not standards - of behavior.

PubMed

McKenzie, Craig R.M.

2003-09-01

When people's behavior in laboratory tasks systematically deviates from a rational model, the implication is that real-world performance could be improved by changing the behavior. However, recent studies suggest that behavioral violations of rational models are at least sometimes the result of strategies that are well adapted to the real world (and not necessarily to the laboratory task). Thus, even if one accepts that certain behavior in the laboratory is irrational, compelling evidence that real-world behavior ought to change accordingly is often lacking. It is suggested here that rational models be seen as theories, and not standards, of behavior.

Internationally Minded Schools as Cultural Artefacts: Implications for School Leadership

ERIC Educational Resources Information Center

Hill, Ian

2014-01-01

This article adopts a non-rational, existential, subjective approach to school leadership, on the assumption that rational models provide useful pointers on mechanics such as time management, coaching and staff evaluation, but are less appropriate for grasping the essence of leadership which resides in managing interpersonal relationships and the…

Rational decision making in medicine: Implications for overuse and underuse.

PubMed

Djulbegovic, Benjamin; Elqayam, Shira; Dale, William

2018-06-01

In spite of substantial spending and resource utilization, today's health care remains characterized by poor outcomes, largely due to overuse (overtesting/overtreatment) or underuse (undertesting/undertreatment) of health services. To a significant extent, this is a consequence of low-quality decision making that appears to violate various rationality criteria. Such suboptimal decision making is considered a leading cause of death and is responsible for more than 80% of health expenses. In this paper, we address the issue of overuse or underuse of health care interventions from the perspective of rational choice theory. We show that what is considered rational under one decision theory may not be considered rational under a different theory. We posit that the questions and concerns regarding both underuse and overuse have to be addressed within a specific theoretical framework. The applicable rationality criterion, and thus the "appropriateness" of health care delivery choices, depends on theory selection that is appropriate to specific clinical situations. We provide a number of illustrations showing how the choice of theoretical framework influences both our policy and individual decision making. We also highlight the practical implications of our analysis for the current efforts to measure the quality of care and link such measurements to the financing of health care services. © 2017 The Authors. Journal of Evaluation in Clinical Practice Published by John Wiley & Sons Ltd.

Economic rationality and health and lifestyle choices for people with diabetes.

PubMed

Baker, Rachel Mairi

2006-11-01

Economic rationality is traditionally represented by goal-oriented, maximising behaviour, or 'instrumental rationality'. Such a consequentialist, instrumental model of choice is often implicit in a biomedical approach to health promotion and education. The research reported here assesses the relevance of a broader conceptual framework of rationality, which includes 'procedural' and 'expressive' rationality as complements to an instrumental model of rationality, in a health context. Q methodology was used to derive 'factors' underlying health and lifestyle choices, based on a factor analysis of the results of a card sorting procedure undertaken by 27 adult respondents with type 2 diabetes in Newcastle upon Tyne, UK. These factors were then compared with the rationality framework and the appropriateness of an extended model of economic rationality as a means of better understanding health and lifestyle choices was assessed. Taking a wider rational choice perspective, choices which are rendered irrational within a narrow-biomedical or strictly instrumental model, can be understood in terms of a coherent rationale, grounded in the accounts of respondents. The implications of these findings are discussed in terms of rational choice theory and diabetes management and research.

The Rational Patient and Beyond: Implications for Treatment Adherence in People with Psychiatric Disabilities

PubMed Central

Corrigan, Patrick W.; Rüsch, Nicolas; Ben-Zeev, Dror; Sher, Tamara

2014-01-01

Purpose/Objective Many people with psychiatric disabilities do not benefit from evidence-based practices because they often do not seek out or fully adhere to them. One way psychologists have made sense of this rehabilitation and health decision process and subsequent behaviors (of which adherence might be viewed as one) is by proposing a “rational patient;” namely, that decisions are made deliberatively by weighing perceived costs and benefits of intervention options. Social psychological research, however, suggests limitations to a rational patient theory that impact models of health decision making. Design The research literature was reviewed for studies of rational patient models and alternative theories with empirical support. Special focus was on models specifically related to decisions about rehabilitation strategies for psychiatric disability. Results Notions of the rational patient evolved out of several psychological models including the health belief model, protection motivation theory, and theory of planned behavior. A variety of practice strategies evolved to promote rational decision making. However, research also suggests limitations to rational deliberations of health. (1) Rather than carefully and consciously considered, many health decisions are implicit, potentially occurring outside awareness. (2) Decisions are not always planful; often it is the immediate exigencies of a context rather than an earlier balance of costs and benefits that has the greatest effects. (3) Cool cognitions often do not dictate the process; emotional factors have an important role in health decisions. Each of these limitations suggests additional practice strategies that facilitate a person’s health decisions. Conclusions/Implications Old models of rational decision making need to be supplanted by multi-process models that explain supra-deliberative factors in health decisions and behaviors. PMID:24446671

Against the magnanimous in medical ethics.

PubMed Central

Kottow, M H

1990-01-01

Supererogatory acts are considered by some to be part of medicine, whereas others accept supererogation to be a gratuitous virtue, to be extolled when present, but not to be demanded. The present paper sides with those contending that medicine is duty-bound to benefit patients and that supererogation/altruism must per definition remain outside and beyond any role-description of the profession. Medical ethics should be bound by rational ethics and steer away from separatist views which grant exclusive privileges but also create excessive demands, way beyond what physicians perform or are willing and able to offer. PMID:2231634

Runge-Lenz vector, accidental SU(2) symmetry, and unusual multiplets for motion on a cone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Al-Hashimi, M.H.; Wiese, U.-J.

2008-01-15

We consider a particle moving on a cone and bound to its tip by 1/r or harmonic oscillator potentials. When the deficit angle of the cone divided by 2{pi} is a rational number, all bound classical orbits are closed. Correspondingly, the quantum system has accidental degeneracies in the discrete energy spectrum. An accidental SU(2) symmetry is generated by the rotations around the tip of the cone as well as by a Runge-Lenz vector. Remarkably, some of the corresponding multiplets have fractional 'spin' and unusual degeneracies.

Modelling body weight, dieting and obesity traps

NASA Astrophysics Data System (ADS)

Barbieri, Paolo Nicola

2017-02-01

This paper presents a theoretical investigation into why losing weight is so difficult even in the absence of rational addiction, time-inconsistent preferences or bounded rationality. We add to the existing literature by focusing on the role that individual metabolism has on weight loss. The results from the theoretical model provide multiple steady states and a threshold revealing a situation of "obesity traps" that the individual must surpass in order to successfully lose weight. Any weight-loss efforts that the individual undertakes have to surpass such threshold in order to result in permanent weight loss, otherwise the individual will gradually regain weight and converge to his or her previous body weight.

A Perspective on Judgment and Choice: Mapping Bounded Rationality

ERIC Educational Resources Information Center

Kahneman, Daniel

2003-01-01

Early studies of intuitive judgment and decision making conducted with the late Amos Tversky are reviewed in the context of two related concepts: an analysis of accessibility, the ease with which thoughts come to mind; a distinction between effortless intuition and deliberate reasoning. Intuitive thoughts, like percepts, are highly accessible.…

Benzothiophene inhibitors of MK2. Part 2: Improvements in kinase selectivity and cell potency

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, David R.; Meyers, Marvin J.; Kurumbail, Ravi G.

2010-10-01

Optimization of kinase selectivity for a set of benzothiophene MK2 inhibitors provided analogs with potencies of less than 500 nM in a cell based assay. The selectivity of the inhibitors can be rationalized by examination of X-ray crystal structures of inhibitors bound to MK2.

How High School Students Construct Decision-Making Strategies for Choosing Colleges

ERIC Educational Resources Information Center

Govan, George V.; Patrick, Sondra; Yen, Cherng-Jyn

2006-01-01

This study examined how high school seniors construct decision-making strategies for choosing a college to attend. To comprehend their decision-making strategies, we chose to examine this process through the theoretical lens of bounded rationality, which brings to light the complexity in constructing a college choice decision-making strategy…

Barriers to Energy Efficiency and the Uptake of Green Revolving Funds in Canadian Universities

ERIC Educational Resources Information Center

Maiorano, John; Savan, Beth

2015-01-01

Purpose: The purpose of this paper is to investigate the barriers to the implementation of energy efficiency projects in Canadian universities, including access to capital, bounded rationality, hidden costs, imperfect information, risk and split incentives. Methods to address these barriers are investigated, including evaluating the efficacy of…

The College-Choice Process of High Achieving Freshmen: A Comparative Case Study

ERIC Educational Resources Information Center

Dale, Amanda

2010-01-01

The purpose of this study was to examine the college-choice process of high achieving students. Employing current literature and previous research, it combined current models of college choice and the influential factors identified throughout the literature while utilizing the concept of bounded rationality to create a conceptual framework to…

A Hybrid Trust-Based Recommender System for Online Communities of Practice

ERIC Educational Resources Information Center

Zheng, Xiao-Lin; Chen, Chao-Chao; Hung, Jui-Long; He, Wu; Hong, Fu-Xing; Lin, Zhen

2015-01-01

The needs for life-long learning and the rapid development of information technologies promote the development of various types of online Community of Practices (CoPs). In online CoPs, bounded rationality and metacognition are two major issues, especially when learners face information overload and there is no knowledge authority within the…

A mechanism for social selection and successful altruism.

PubMed

Simon, H A

1990-12-21

Within the framework of neo-Darwinism, with its focus on fitness, it has been hard to account for altruism behavior that reduces the fitness of the altruist but increases average fitness in society. Many population biologists argue that, except for altruism to close relatives, human behavior that appears to be altruistic amounts to reciprocal altruism, behavior undertaken with an expectation of reciprocation, hence incurring no net cost to fitness. Herein is proposed a simple and robust mechanism, based on human docility and bounded rationality that can account for the evolutionary success of genuinely altruistic behavior. Because docility-receptivity to social influence-contributes greatly to fitness in the human species, it will be positively selected. As a consequence, society can impose a "tax" on the gross benefits gained by individuals from docility by inducing docile individuals to engage in altruistic behaviors. Limits on rationality in the face of environmental complexity prevent the individual from avoiding this "tax." An upper bound is imposed on altruism by the condition that there must remain a net fitness advantage for docile behavior after the cost to the individual of altruism has been deducted.

Multi-agent fare optimization model of two modes problem and its analysis based on edge of chaos

NASA Astrophysics Data System (ADS)

Li, Xue-yan; Li, Xue-mei; Li, Xue-wei; Qiu, He-ting

2017-03-01

This paper proposes a new framework of fare optimization & game model for studying the competition between two travel modes (high speed railway and civil aviation) in which passengers' group behavior is taken into consideration. The small-world network is introduced to construct the multi-agent model of passengers' travel mode choice. The cumulative prospect theory is adopted to depict passengers' bounded rationality, the heterogeneity of passengers' reference point is depicted using the idea of group emotion computing. The conceptions of "Langton parameter" and "evolution entropy" in the theory of "edge of chaos" are introduced to create passengers' "decision coefficient" and "evolution entropy of travel mode choice" which are used to quantify passengers' group behavior. The numerical simulation and the analysis of passengers' behavior show that (1) the new model inherits the features of traditional model well and the idea of self-organizing traffic flow evolution fully embodies passengers' bounded rationality, (2) compared with the traditional model (logit model), when passengers are in the "edge of chaos" state, the total profit of the transportation system is higher.

[Nudge strategies at a glance: an overview. More freedom or new paternalism?

PubMed

Leone, Luca

2016-01-01

Under the theoretical assumptions of individual bounded rationality and of behavioural psychology about human actions and agency, nudge has been promoted as an alternative to traditional regulatory tools, characterized by being inexpensive, choice-preserving, and bound to promote legitimate goals and citizens' welfare within through specific choice architectures. Applicable to several domains, health included, the nudging approach runs in connection with requests and needs arising from marketing strategies, with the aim of maximizing economic rationality and efficiency. However, as nudge was framed having in mind the notion of consumer, it fails to fully meet the values connected to the idea of citizenship. Most nudges strategies seem to imply a top-down vision - though soft paternalistic - where pre-defined and often black-boxed values pretend to define individual and collective directions. The representational and ethical issues surrounding nudge, the psychological mechanisms working behind it, and the correlated legal issues request a precise and accurate scrutiny, if we want nudging interventions to be legitimately and democratically framed within policy strategies and human agency not to be disregarded, but empowered by behaviourally-based actions.

Identifying optimum performance trade-offs using a cognitively bounded rational analysis model of discretionary task interleaving.

PubMed

Janssen, Christian P; Brumby, Duncan P; Dowell, John; Chater, Nick; Howes, Andrew

2011-01-01

We report the results of a dual-task study in which participants performed a tracking and typing task under various experimental conditions. An objective payoff function was used to provide explicit feedback on how participants should trade off performance between the tasks. Results show that participants' dual-task interleaving strategy was sensitive to changes in the difficulty of the tracking task and resulted in differences in overall task performance. To test the hypothesis that people select strategies that maximize payoff, a Cognitively Bounded Rational Analysis model was developed. This analysis evaluated a variety of dual-task interleaving strategies to identify the optimal strategy for maximizing payoff in each condition. The model predicts that the region of optimum performance is different between experimental conditions. The correspondence between human data and the prediction of the optimal strategy is found to be remarkably high across a number of performance measures. This suggests that participants were honing their behavior to maximize payoff. Limitations are discussed. Copyright © 2011 Cognitive Science Society, Inc.

Kant on euthanasia and the duty to die: clearing the air.

PubMed

Cholbi, Michael

2015-08-01

Thanks to recent scholarship, Kant is no longer seen as the dogmatic opponent of suicide that he appears to be at first glance. However, some interpreters have recently argued for a Kantian view of the morality of suicide with surprising, even radical, implications. More specifically, they have argued that Kantianism (1) requires that those with dementia or other rationality-eroding conditions end their lives before their condition results in their loss of identity as moral agents and (2) requires subjecting the fully demented or those confronting future dementia to non-voluntary euthanasia. Properly understood, Kant's ethics have neither of these implications (1) wrongly assumes that rational agents' duty of self-preservation entails a duty of self-destruction when they become non-rational, (2) further neglects Kant's distinction between duties to self and duties to others and wrongly assumes that duties can be owed to rational agents only during the time of their existence. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The neural basis of belief updating and rational decision making

PubMed Central

Achtziger, Anja; Hügelschäfer, Sabine; Steinhauser, Marco

2014-01-01

Rational decision making under uncertainty requires forming beliefs that integrate prior and new information through Bayes’ rule. Human decision makers typically deviate from Bayesian updating by either overweighting the prior (conservatism) or overweighting new information (e.g. the representativeness heuristic). We investigated these deviations through measurements of electrocortical activity in the human brain during incentivized probability-updating tasks and found evidence of extremely early commitment to boundedly rational heuristics. Participants who overweight new information display a lower sensibility to conflict detection, captured by an event-related potential (the N2) observed around 260 ms after the presentation of new information. Conservative decision makers (who overweight prior probabilities) make up their mind before new information is presented, as indicated by the lateralized readiness potential in the brain. That is, they do not inhibit the processing of new information but rather immediately rely on the prior for making a decision. PMID:22956673

The neural basis of belief updating and rational decision making.

PubMed

Achtziger, Anja; Alós-Ferrer, Carlos; Hügelschäfer, Sabine; Steinhauser, Marco

2014-01-01

Rational decision making under uncertainty requires forming beliefs that integrate prior and new information through Bayes' rule. Human decision makers typically deviate from Bayesian updating by either overweighting the prior (conservatism) or overweighting new information (e.g. the representativeness heuristic). We investigated these deviations through measurements of electrocortical activity in the human brain during incentivized probability-updating tasks and found evidence of extremely early commitment to boundedly rational heuristics. Participants who overweight new information display a lower sensibility to conflict detection, captured by an event-related potential (the N2) observed around 260 ms after the presentation of new information. Conservative decision makers (who overweight prior probabilities) make up their mind before new information is presented, as indicated by the lateralized readiness potential in the brain. That is, they do not inhibit the processing of new information but rather immediately rely on the prior for making a decision.

Continuous punishment and the potential of gentle rule enforcement.

PubMed

Erev, Ido; Ingram, Paul; Raz, Ornit; Shany, Dror

2010-05-01

The paper explores the conditions that determine the effect of rule enforcement policies that imply an attempt to punish all the visible violations of the rule. We start with a simple game-theoretic analysis that highlights the value of gentle COntinuous Punishment (gentle COP) policies. If the subjects of the rule are rational, gentle COP can eliminate violations even when the rule enforcer has limited resources. The second part of the paper uses simulations to examine the robustness of gentle COP policies to likely deviations from rationality. The results suggest that when the probability of detecting violations is sufficiently high, gentle COP policies can be effective even when the subjects of the rule are boundedly rational adaptive learners. The paper concludes with experimental studies that clarify the value of gentle COP policies in the lab, and in attempt to eliminate cheating in exams. Copyright (c) 2009 Elsevier B.V. All rights reserved.

Predicting differences in the perceived relevance of crime's costs and benefits in a test of rational choice theory.

PubMed

Bouffard, Jeffrey A

2007-08-01

Previous hypothetical scenario tests of rational choice theory have presented all participants with the same set of consequences, implicitly assuming that these consequences would be relevant for each individual. Recent research demonstrates that those researcher-presented consequences do not accurately reflect those considered by study participants and that there is individual variation in the relevance of various consequences. Despite this and some theoretical propositions that such differences should exist, little empirical research has explored the possibility of predicting such variation. This study allows participants to develop their own set of relevant consequences for three hypothetical offenses and examines how several demographic and theoretical variables impact those consequences' relevance. Exploratory results suggest individual factors impact the perceived relevance of several cost and benefit types, even among a relatively homogenous sample of college students. Implications for future tests of rational choice theory, as well as policy implications are discussed.

The discrepancy between emotional vs. rational estimates of body size, actual size, and ideal body ratings: theoretical and clinical implications.

PubMed

Thompson, J K; Dolce, J J

1989-05-01

Thirty-two asymptomatic college females were assessed on multiple aspects of body image. Subjects' estimation of the size of three body sites (waist, hips, thighs) was affected by instructional protocol. Emotional ratings, based on how they "felt" about their body, elicited ratings that were larger than actual and ideal size measures. Size ratings based on rational instructions were no different from actual sizes, but were larger than ideal ratings. There were no differences between actual and ideal sizes. The results are discussed with regard to methodological issues involved in body image research. In addition, a working hypothesis that differentiates affective/emotional from cognitive/rational aspects of body size estimation is offered to complement current theories of body image. Implications of the findings for the understanding of body image and its relationship to eating disorders are discussed.

Pre-University Students' Errors in Integration of Rational Functions and Implications for Classroom Teaching

ERIC Educational Resources Information Center

Yee, Ng Kin; Lam, Toh Tin

2008-01-01

This paper reports on students' errors in performing integration of rational functions, a topic of calculus in the pre-university mathematics classrooms. Generally the errors could be classified as those due to the students' weak algebraic concepts and their lack of understanding of the concept of integration. With the students' inability to link…

On the Psychology of the Recognition Heuristic: Retrieval Primacy as a Key Determinant of Its Use

ERIC Educational Resources Information Center

Pachur, Thorsten; Hertwig, Ralph

2006-01-01

The recognition heuristic is a prime example of a boundedly rational mind tool that rests on an evolved capacity, recognition, and exploits environmental structures. When originally proposed, it was conjectured that no other probabilistic cue reverses the recognition-based inference (D. G. Goldstein & G. Gigerenzer, 2002). More recent studies…

Teaching as Goal-Less and Reflective Design: A Conversation with Herbert A. Simon and Donald Schon

ERIC Educational Resources Information Center

Go, Johnny C.

2012-01-01

This paper examines Donald Schon's critique of Herbert Simon's "science of design" to determine whether later developments in Simon's thought--particularly, his theories of "bounded rationality" and "goal-less designing"--can contribute to an appreciation of Schon's notion of reflective practice. The paper then argues, that viewed through the…

Fluency Heuristic: A Model of How the Mind Exploits a By-Product of Information Retrieval

ERIC Educational Resources Information Center

Hertwig, Ralph; Herzog, Stefan M.; Schooler, Lael J.; Reimer, Torsten

2008-01-01

Boundedly rational heuristics for inference can be surprisingly accurate and frugal for several reasons. They can exploit environmental structures, co-opt complex capacities, and elude effortful search by exploiting information that automatically arrives on the mental stage. The fluency heuristic is a prime example of a heuristic that makes the…

Should informed consent be based on rational beliefs?

PubMed Central

Savulescu, J; Momeyer, R W

1997-01-01

Our aim is to expand the regulative ideal governing consent. We argue that consent should not only be informed but also based on rational beliefs. We argue that holding true beliefs promotes autonomy. Information is important insofar as it helps a person to hold the relevant true beliefs. But in order to hold the relevant true beliefs, competent people must also think rationally. Insofar as information is important, rational deliberation is important. Just as physicians should aim to provide relevant information regarding the medical procedures prior to patients consenting to have those procedures, they should also assist patients to think more rationally. We distinguish between rational choice/action and rational belief. While autonomous choice need not necessarily be rational, it should be based on rational belief. The implication for the doctrine of informed consent and the practice of medicine is that, if physicians are to respect patient autonomy and help patients to choose and act more rationally, not only must they provide information, but they should care more about the theoretical rationality of their patients. They should not abandon their patients to irrationality. They should help their patients to deliberate more effectively and to care more about thinking rationally. We illustrate these arguments in the context of Jehovah's Witnesses refusing life-saving blood transfusions. Insofar as Jehovah's Witnesses should be informed of the consequences of their actions, they should also deliberate rationally about these consequences. PMID:9358347

Should informed consent be based on rational beliefs?

PubMed

Savulescu, J; Momeyer, R W

1997-10-01

Our aim is to expand the regulative ideal governing consent. We argue that consent should not only be informed but also based on rational beliefs. We argue that holding true beliefs promotes autonomy. Information is important insofar as it helps a person to hold the relevant true beliefs. But in order to hold the relevant true beliefs, competent people must also think rationally. Insofar as information is important, rational deliberation is important. Just as physicians should aim to provide relevant information regarding the medical procedures prior to patients consenting to have those procedures, they should also assist patients to think more rationally. We distinguish between rational choice/action and rational belief. While autonomous choice need not necessarily be rational, it should be based on rational belief. The implication for the doctrine of informed consent and the practice of medicine is that, if physicians are to respect patient autonomy and help patients to choose and act more rationally, not only must they provide information, but they should care more about the theoretical rationality of their patients. They should not abandon their patients to irrationality. They should help their patients to deliberate more effectively and to care more about thinking rationally. We illustrate these arguments in the context of Jehovah's Witnesses refusing life-saving blood transfusions. Insofar as Jehovah's Witnesses should be informed of the consequences of their actions, they should also deliberate rationally about these consequences.

New perspectives on the computational characterization of the kinetics of binding-unbinding in drug design: implications for novel therapies.

PubMed

Moreno-Vargas, Liliana M; Prada-Gracia, Diego

The efficiency and the propensity of a drug to be bound to its target protein have been inseparable concepts for decades now. The correlation between the pharmacological activity and the binding affinity has been the first rule to design and optimize a new drug rationally. However, this argument does not prove to be infallible when the results of in vivo assays have to be confronted. Only recently, we understand that other magnitudes as the kinetic rates of binding and unbinding, or the mean residence time of the complex drug-protein, are equally relevant to draw a more accurate model of the mechanism of action of a drug. It is in this scenario where new computational techniques to simulate the all-atom dynamics of the biomolecular system find its valuable place on the challenge of designing new molecules for more effective and less toxic therapies. Copyright © 2016 Hospital Infantil de México Federico Gómez. Publicado por Masson Doyma México S.A. All rights reserved.

New Hardness Results for Diophantine Approximation

NASA Astrophysics Data System (ADS)

Eisenbrand, Friedrich; Rothvoß, Thomas

We revisit simultaneous Diophantine approximation, a classical problem from the geometry of numbers which has many applications in algorithms and complexity. The input to the decision version of this problem consists of a rational vector α ∈ ℚ n , an error bound ɛ and a denominator bound N ∈ ℕ + . One has to decide whether there exists an integer, called the denominator Q with 1 ≤ Q ≤ N such that the distance of each number Q ·α i to its nearest integer is bounded by ɛ. Lagarias has shown that this problem is NP-complete and optimization versions have been shown to be hard to approximate within a factor n c/ loglogn for some constant c > 0. We strengthen the existing hardness results and show that the optimization problem of finding the smallest denominator Q ∈ ℕ + such that the distances of Q·α i to the nearest integer are bounded by ɛ is hard to approximate within a factor 2 n unless {textrm{P}} = NP.

Quadrature formula for evaluating left bounded Hadamard type hypersingular integrals

NASA Astrophysics Data System (ADS)

Bichi, Sirajo Lawan; Eshkuvatov, Z. K.; Nik Long, N. M. A.; Okhunov, Abdurahim

2014-12-01

Left semi-bounded Hadamard type Hypersingular integral (HSI) of the form H(h,x) = 1/π √{1+x/1-x }∫-1 **1√{1-t/1+t }h(t)/(t-x)2 dt,x∈(-1.1), Where h(t) is a smooth function is considered. The automatic quadrature scheme (AQS) is constructed by approximating the density function h(t) by the truncated Chebyshev polynomials of the fourth kind. Numerical results revealed that the proposed AQS is highly accurate when h(t) is choosing to be the polynomial and rational functions. The results are in line with the theoretical findings.

Distributed Optimization

NASA Technical Reports Server (NTRS)

Macready, William; Wolpert, David

2005-01-01

We demonstrate a new framework for analyzing and controlling distributed systems, by solving constrained optimization problems with an algorithm based on that framework. The framework is ar. information-theoretic extension of conventional full-rationality game theory to allow bounded rational agents. The associated optimization algorithm is a game in which agents control the variables of the optimization problem. They do this by jointly minimizing a Lagrangian of (the probability distribution of) their joint state. The updating of the Lagrange parameters in that Lagrangian is a form of automated annealing, one that focuses the multi-agent system on the optimal pure strategy. We present computer experiments for the k-sat constraint satisfaction problem and for unconstrained minimization of NK functions.

The Oil Drop Experiment: A Rational Reconstruction of the Millikan-Ehrenhaft Controversy and Its Implications for Chemistry Textbooks.

ERIC Educational Resources Information Center

Niaz, Mansoor

2000-01-01

Develops a history and philosophy of science framework based on a rational reconstruction of experimental observations that led to the Millikan-Ehrenhaft controversy, and evaluates 31 chemistry books for coverage of the controversy. Finds that most books lacked a history and philosophy of science perspective and did not adequately address several…

Dilemmas in rationing health care services: the case for implicit rationing.

PubMed

Mechanic, D

1995-06-24

With tension between the demand for health services and the cost of providing them, rationing is increasingly evident in all medical systems. Until recently, rationing was primarily through the ability to pay or achieved implicitly by doctors working within fixed budgets. Such forms of rationing are commonly alleged to be inequitable and inefficient and explicit rationing is advocated as more appropriate. Utilisation management in the United States and quasi-markets separating purchasing from provision in the United Kingdom are seen as ways of using resources more efficiently and are increasingly explicit. There is also advocacy to ration explicitly at the point of service. Mechanic reviews the implications of these developments and explains why explicit approaches are likely to focus conflict and dissatisfaction and be politically unstable. Explicit rationing is unlikely to be as equitable as its proponents argue and is likely to make dissatisfaction and perceived deprivation more salient. Despite its limitations, implicit rationing at the point of service is more sensitive to the complexity of medical decisions and the needs and personal and cultural preferences of patients. All systems use a mix of rationing devices, but the clinical allocation of services should substantially depend on the discretion of professionals informed by practice guidelines, outcomes research, and other informational aids.

Dilemmas in rationing health care services: the case for implicit rationing.

PubMed Central

Mechanic, D.

1995-01-01

With tension between the demand for health services and the cost of providing them, rationing is increasingly evident in all medical systems. Until recently, rationing was primarily through the ability to pay or achieved implicitly by doctors working within fixed budgets. Such forms of rationing are commonly alleged to be inequitable and inefficient and explicit rationing is advocated as more appropriate. Utilisation management in the United States and quasi-markets separating purchasing from provision in the United Kingdom are seen as ways of using resources more efficiently and are increasingly explicit. There is also advocacy to ration explicitly at the point of service. Mechanic reviews the implications of these developments and explains why explicit approaches are likely to focus conflict and dissatisfaction and be politically unstable. Explicit rationing is unlikely to be as equitable as its proponents argue and is likely to make dissatisfaction and perceived deprivation more salient. Despite its limitations, implicit rationing at the point of service is more sensitive to the complexity of medical decisions and the needs and personal and cultural preferences of patients. All systems use a mix of rationing devices, but the clinical allocation of services should substantially depend on the discretion of professionals informed by practice guidelines, outcomes research, and other informational aids. Images p1657-a p1659-a PMID:7795458

Discovery of a small-molecule HIV-1 integrase inhibitor-binding site | Center for Cancer Research

Cancer.gov

The lowest energy-binding conformation of an inhibitor bound to the dimeric interface of HIV-1 integrase core domain. The yellow region represents a unique allosteric binding site identified by affinity labeling and mass spectrometry and validated through mutagenesis. This site can provide a potential platform for the rational design of inhibitors selective for disruption of

Nonlinear Dynamics and Heterogeneous Interacting Agents

NASA Astrophysics Data System (ADS)

Lux, Thomas; Reitz, Stefan; Samanidou, Eleni

Economic application of nonlinear dynamics, microscopic agent-based modelling, and the use of artificial intelligence techniques as learning devices of boundedly rational actors are among the most exciting interdisciplinary ventures of economic theory over the past decade. This volume provides us with a most fascinating series of examples on "complexity in action" exemplifying the scope and explanatory power of these innovative approaches.

Stochastic Evolution Dynamic of the Rock-Scissors-Paper Game Based on a Quasi Birth and Death Process

NASA Astrophysics Data System (ADS)

Yu, Qian; Fang, Debin; Zhang, Xiaoling; Jin, Chen; Ren, Qiyu

2016-06-01

Stochasticity plays an important role in the evolutionary dynamic of cyclic dominance within a finite population. To investigate the stochastic evolution process of the behaviour of bounded rational individuals, we model the Rock-Scissors-Paper (RSP) game as a finite, state dependent Quasi Birth and Death (QBD) process. We assume that bounded rational players can adjust their strategies by imitating the successful strategy according to the payoffs of the last round of the game, and then analyse the limiting distribution of the QBD process for the game stochastic evolutionary dynamic. The numerical experiments results are exhibited as pseudo colour ternary heat maps. Comparisons of these diagrams shows that the convergence property of long run equilibrium of the RSP game in populations depends on population size and the parameter of the payoff matrix and noise factor. The long run equilibrium is asymptotically stable, neutrally stable and unstable respectively according to the normalised parameters in the payoff matrix. Moreover, the results show that the distribution probability becomes more concentrated with a larger population size. This indicates that increasing the population size also increases the convergence speed of the stochastic evolution process while simultaneously reducing the influence of the noise factor.

Stochastic Evolution Dynamic of the Rock-Scissors-Paper Game Based on a Quasi Birth and Death Process.

PubMed

Yu, Qian; Fang, Debin; Zhang, Xiaoling; Jin, Chen; Ren, Qiyu

2016-06-27

Stochasticity plays an important role in the evolutionary dynamic of cyclic dominance within a finite population. To investigate the stochastic evolution process of the behaviour of bounded rational individuals, we model the Rock-Scissors-Paper (RSP) game as a finite, state dependent Quasi Birth and Death (QBD) process. We assume that bounded rational players can adjust their strategies by imitating the successful strategy according to the payoffs of the last round of the game, and then analyse the limiting distribution of the QBD process for the game stochastic evolutionary dynamic. The numerical experiments results are exhibited as pseudo colour ternary heat maps. Comparisons of these diagrams shows that the convergence property of long run equilibrium of the RSP game in populations depends on population size and the parameter of the payoff matrix and noise factor. The long run equilibrium is asymptotically stable, neutrally stable and unstable respectively according to the normalised parameters in the payoff matrix. Moreover, the results show that the distribution probability becomes more concentrated with a larger population size. This indicates that increasing the population size also increases the convergence speed of the stochastic evolution process while simultaneously reducing the influence of the noise factor.

Endogenous Market-Clearing Prices and Reference Point Adaptation

NASA Astrophysics Data System (ADS)

Dragicevic, Arnaud Z.

When prices depend on the submitted bids, i.e. with endogenous market-clearing prices in repeated-round auction mechanisms, the assumption of independent private values that underlines the property of incentive-compatibility is to be brought into question; even if these mechanisms provide active involvement and market learning. In its orthodox view, adaptive bidding behavior imperils incentive-compatibility. We relax the assumption of private values' independence in the repeated-round auctions, when the market-clearing prices are made public at the end of each round. Instead of using game-theory learning models, we introduce a behavioral model that shows that bidders bid according to the anchoring-and-adjustment heuristic, which neither ignores the rationality and incentive-compatibility constraints, nor rejects the posted prices issued from others' bids. Bidders simply weight information at their disposal and adjust their discovered value using reference points encoded in the sequential price weighting function. Our model says that bidders and offerers are sincere boundedly rational utility maximizers. It lies between evolutionary dynamics and adaptive heuristics and we model the concept of inertia as high weighting of the anchor, which stands for truthful bidding and high regard to freshly discovered preferences. Adjustment means adaptive rule based on adaptation of the reference point in the direction of the posted price. It helps a bidder to maximize her expected payoff, which is after all the only purpose that matters to rationality. The two components simply suggest that sincere bidders are boundedly rational. Furthermore, by deviating from their anchor in the direction of the public signal, bidders operate in a correlated equilibrium. The correlation between bids comes from the commonly observed history of play and each bidder's actions are determined by the history. Bidders are sincere if they have limited memory and confine their reference point adaptation to their anchor and the latest posted price. S-shaped weighting mechanism reflects such a bidding strategy.

Universal bounds on charged states in 2d CFT and 3d gravity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Benjamin, Nathan; Dyer, Ethan; Fitzpatrick, A. Liam

2016-08-04

We derive an explicit bound on the dimension of the lightest charged state in two dimensional conformal field theories with a global abelian symmetry. We find that the bound scales with c and provide examples that parametrically saturate this bound. We also prove that any such theory must contain a state with charge-to-mass ratio above a minimal lower bound. As a result, we comment on the implications for charged states in three dimensional theories of gravity.

Comparative effectiveness research as choice architecture: the behavioral law and economics solution to the health care cost crisis.

PubMed

Korobkin, Russell

2014-02-01

With the Patient Protection and Affordable Care Act ("ACA") set to dramatically increase access to medical care, the problem of rising costs will move center stage in health law and policy discussions. "Consumer directed health care" proposals, which provide patients with financial incentives to equate marginal costs and benefits of care at the point of treatment, demand more decisionmaking ability from consumers than is plausible due to bounded rationality. Proposals that seek to change the incentives of health care providers threaten to create conflicts of interest between doctors and patients. New approaches are desperately needed. This Article proposes a government-facilitated but market-based approach to improving efficiency in the private market for medical care that I call "relative value health insurance." This approach focuses on the "choice architecture" necessary to enable even boundedly rational patients to contract for an efficient level of health care services through their health insurance purchase decisions. It uses comparative effectiveness research, which the ACA funds at a significant level for the first time, to rate medical treatments on a scale of one to ten based on their relative value, taking into account expected costs and benefits. These relative value ratings would enable consumers to contract with insurers for different levels of medical care at different prices, reflecting different cost-quality trade-offs. The Article describes both the benefits of relative value health insurance and the impediments to its implementation. It concludes with a brief discussion of how relative value ratings could also help to rationalize expenditures on public health insurance programs.

Testing two mechanisms by which rational and irrational beliefs may affect the functionality of inferences.

PubMed

Bond, F W; Dryden, W; Briscoe, R

1999-12-01

This article describes a role playing experiment that examined the sufficiency hypothesis of Rational Emotive Behaviour Therapy (REBT). This proposition states that it is sufficient for rational and irrational beliefs to refer to preferences and musts, respectively, if those beliefs are to affect the functionality of inferences (FI). Consistent with the REBT literature (e.g. Dryden, 1994; Dryden & Ellis, 1988; Palmer, Dryden, Ellis & Yapp, 1995) results from this experiment showed that rational and irrational beliefs, as defined by REBT, do affect FI. Specifically, results showed that people who hold a rational belief form inferences that are significantly more functional than those that are formed by people who hold an irrational belief. Contrary to REBT theory, the sufficiency hypothesis was not supported. Thus, results indicated that it is not sufficient for rational and irrational beliefs to refer to preferences and musts, respectively, if those beliefs are to affect the FI. It appears, then, that preferences and musts are not sufficient mechanisms by which rational and irrational beliefs, respectively, affect the FI. Psychotherapeutic implications of these findings are considered.

Zero-point energy effects in anion solvation shells.

PubMed

Habershon, Scott

2014-05-21

By comparing classical and quantum-mechanical (path-integral-based) molecular simulations of solvated halide anions X(-) [X = F, Cl, Br and I], we identify an ion-specific quantum contribution to anion-water hydrogen-bond dynamics; this effect has not been identified in previous simulation studies. For anions such as fluoride, which strongly bind water molecules in the first solvation shell, quantum simulations exhibit hydrogen-bond dynamics nearly 40% faster than the corresponding classical results, whereas those anions which form a weakly bound solvation shell, such as iodide, exhibit a quantum effect of around 10%. This observation can be rationalized by considering the different zero-point energy (ZPE) of the water vibrational modes in the first solvation shell; for strongly binding anions, the ZPE of bound water molecules is larger, giving rise to faster dynamics in quantum simulations. These results are consistent with experimental investigations of anion-bound water vibrational and reorientational motion.

A Rational Reconstruction of the Kinetic Molecular Theory of Gases Based on History and Philosophy of Science and Its Implications for Chemistry Textbooks.

ERIC Educational Resources Information Center

Niaz, Mansoor

2000-01-01

Describes a study that was designed to develop a framework for examining the way in which chemistry textbooks describe the kinetic theory and related issues. The framework was developed by a rational reconstruction of the kinetic molecular theory of gases based on historians and philosophers of science. (Contains 102 references.)(Author/LRW)

When is diagnostic testing inappropriate or irrational? Acceptable regret approach.

PubMed

Hozo, Iztok; Djulbegovic, Benjamin

2008-01-01

The authors provide a new model within the framework of theories of bounded rationality for the observed physicians' behavior that their ordering of diagnostic tests may not be rational. Contrary to the prevailing thinking, the authors find that physicians do not act irrationally or inappropriately when they order diagnostic tests in usual clinical practice. When acceptable regret (i.e., regret that a decision maker finds tolerable upon making a wrong decision) is taken into account, the authors show that physicians tend to order diagnostic tests at a higher level of pretest probability of disease than predicted by expected utility theory. They also show why physicians tend to overtest when regret about erroneous decisions is extremely small. Finally, they explain variations in the practice of medicine. They demonstrate that in the same clinical situation, different decision makers might have different acceptable regret thresholds for withholding treatment, for ordering a diagnostic test, or for administering treatment. This in turn means that for some decision makers, the most rational strategy is to do nothing, whereas for others, it may be to order a diagnostic test, and still for others, choosing treatment may be the most rational course of action.

More Fair Play in an Ultimatum Game after Resettlement in Zimbabwe: A Field Experiment and a Structural Model

PubMed Central

Kohler, Stefan

2013-01-01

Zimbabwean villagers of distinct background have resettled in government-organized land reforms for more than three decades. Against this backdrop, I assess the level of social cohesion in some of the newly established communities by estimating the average preferences for fairness in a structural model of bounded rationality. The estimations are based on behavioral data from an ultimatum game field experiment played by 234 randomly selected households in 6 traditional and 14 resettled villages almost two decades after resettlement. Equal or higher degrees of fairness are estimated in all resettlement schemes. In one, or arguably two, out of three distinct resettlement schemes studied, the resettled villagers exhibit significantly higher degrees of fairness ( ) and rationality ( ) than those who live in traditional villages. Overall, villagers appear similarly rational, but the attitude toward fairness is significantly stronger in resettled communities ( ). These findings are consistent with the idea of an increased need for cooperation required in recommencement. PMID:23724095

More fair play in an ultimatum game after resettlement in Zimbabwe: a field experiment and a structural model.

PubMed

Kohler, Stefan

2013-01-01

Zimbabwean villagers of distinct background have resettled in government-organized land reforms for more than three decades. Against this backdrop, I assess the level of social cohesion in some of the newly established communities by estimating the average preferences for fairness in a structural model of bounded rationality. The estimations are based on behavioral data from an ultimatum game field experiment played by 234 randomly selected households in 6 traditional and 14 resettled villages almost two decades after resettlement. Equal or higher degrees of fairness are estimated in all resettlement schemes. In one, or arguably two, out of three distinct resettlement schemes studied, the resettled villagers exhibit significantly higher degrees of fairness (p ≤ 0.11) and rationality (p ≤ 0.04) than those who live in traditional villages. Overall, villagers appear similarly rational, but the attitude toward fairness is significantly stronger in resettled communities (p ≤ 0.01). These findings are consistent with the idea of an increased need for cooperation required in recommencement.

Social Learning in the Ultimatum Game

PubMed Central

Zhang, Boyu

2013-01-01

In the ultimatum game, two players divide a sum of money. The proposer suggests how to split and the responder can accept or reject. If the suggestion is rejected, both players get nothing. The rational solution is that the responder accepts even the smallest offer but humans prefer fair share. In this paper, we study the ultimatum game by a learning-mutation process based on quantal response equilibrium, where players are assumed boundedly rational and make mistakes when estimating the payoffs of strategies. Social learning is never stabilized at the fair outcome or the rational outcome, but leads to oscillations from offering 40 percent to 50 percent. To be precise, there is a clear tendency to increase the mean offer if it is lower than 40 percent, but will decrease when it reaches the fair offer. If mutations occur rarely, fair behavior is favored in the limit of local mutation. If mutation rate is sufficiently high, fairness can evolve for both local mutation and global mutation. PMID:24023950

A DESCRIPTION OF HANKEL OPERATORS OF CLASS \\mathfrak{S}_p FOR p>0, AN INVESTIGATION OF THE RATE OF RATIONAL APPROXIMATION, AND OTHER APPLICATIONS

NASA Astrophysics Data System (ADS)

Peller, V. V.

1985-02-01

The main result is the following description of Hankel operators in the Schatten-von Neumann class \\mathfrak{S}_p when 0: \\displaystyle \\Gamma_\\varphi\\in\\mathfrak{S}_p\\Leftrightarrow \\varphi\\in B_p^{1/p},where \\Gamma_\\varphi is the Hankel operator with symbol \\varphi, and B_p^{1/p} is the Besov class. This result extends results obtained earlier for 1\\leqslant p<+\\infty by the author to the case 0. Also described are the Hankel operators in the Schatten-Lorentz classes \\mathfrak{S}_{pq}, 0, 0. Precise descriptions of classes of functions defined in terms of rational approximation in the bounded mean oscillation norm are given as an application, along with a complete investigation of the case where the decrease is of power order, and some precise results on rational approximation in the L^\\infty-norm. Certain other applications are also considered.Bibliography: 57 titles.

Evolution of Cooperation in Public Goods Games

NASA Astrophysics Data System (ADS)

Xia, Cheng-Yi; Zhang, Juan-Juan; Wang, Yi-Ling; Wang, Jin-Song

2011-10-01

We investigate the evolution of cooperation with evolutionary public goods games based on finite populations, where four pure strategies: cooperators, defectors, punishers and loners who are unwilling to participate are considered. By adopting approximate best response dynamics, we show that the magnitude of rationality not only quantitatively explains the experiment results in [Nature (London) 425 (2003) 390], but also it will heavily influence the evolution of cooperation. Compared with previous results of infinite populations, which result in two equilibriums, we show that there merely exists a special equilibrium and the relevant high value of bounded rationality will sustain cooperation. In addition, we characterize that loner's payoff plays an active role in the maintenance of cooperation, which will only be warranted for the low and moderate values of loner's payoff. It thus indicates the effects of rationality and loner's payoff will influence the cooperation. Finally, we highlight the important result that the introduction of voluntary participation and punishment will facilitate cooperation greatly.

Adolescent rationality.

PubMed

Moshman, David

2013-01-01

Adolescents are commonly seen as irrational, a position supported to varying degrees by many developmentalists, who often appeal to recent research on adolescent brains. Careful review of relevant evidence, however, shows that (1) adults are less rational than is generally assumed, (2) adolescents (and adults) are categorically different from children with respect to the attainment of advanced levels of rationality and psychological functioning, and (3) adolescents and adults do not differ categorically from each other with respect to any rational competencies, irrational tendencies, brain structures, or neurological functioning. Development often continues in adolescence and beyond but categorical claims about adolescents as distinct from adults cannot be justified. A review of U.S. Supreme Court decisions concerning intellectual freedom, reproductive freedom, and criminal responsibility shows ongoing ambivalence and confusion about the rationality of adolescents. Developmental theory and research suggest that adolescents should be conceptualized as young adults, not immature brains, with important implications for their roles, rights, and responsibilities.

An analytic study on bounds for the associated Legendre functions. [for truncation of geopotential series in spherical harmonics in orbital analyses

NASA Technical Reports Server (NTRS)

Payne, M. H.

1973-01-01

The bounds for the normalized associated Legendre functions P sub nm were studied to provide a rational basis for the truncation of the geopotential series in spherical harmonics in various orbital analyses. The conjecture is made that the largest maximum of the normalized associated Legendre function lies in the interval which indicates the greatest integer function. A procedure is developed for verifying this conjecture. An on-line algebraic manipulator, IAM, is used to implement the procedure and the verification is carried out for all n equal to or less than 2m, for m = 1 through 6. A rigorous proof of the conjecture is not available.

Development of a scale to assess Hwa-Byung, a Korean culture-bound syndrome, using the Korean MMPI-2.

PubMed

Roberts, Miguel E; Han, Kyunghee; Weed, Nathan C

2006-09-01

This study documents the development of an MMPI-2 scale designed to assess features of the Korean culture-bound syndrome, Hwa-Byung (HB). An American research team and psychiatric practitioners in Korea created an 18-item HB scale via rational item selection and psycho-metric refinement. Principal components analysis of scale items revealed four components, reflecting content domains of general health, gastrointestinal symptoms, hopelessness, and anger. This four-component solution applied well to both Korean men and women, but not to an American sample. Although some findings were encouraging, future studies employing clinical samples are needed to provide further validation of this scale.

Cosmographic analysis with Chebyshev polynomials

NASA Astrophysics Data System (ADS)

Capozziello, Salvatore; D'Agostino, Rocco; Luongo, Orlando

2018-05-01

The limits of standard cosmography are here revised addressing the problem of error propagation during statistical analyses. To do so, we propose the use of Chebyshev polynomials to parametrize cosmic distances. In particular, we demonstrate that building up rational Chebyshev polynomials significantly reduces error propagations with respect to standard Taylor series. This technique provides unbiased estimations of the cosmographic parameters and performs significatively better than previous numerical approximations. To figure this out, we compare rational Chebyshev polynomials with Padé series. In addition, we theoretically evaluate the convergence radius of (1,1) Chebyshev rational polynomial and we compare it with the convergence radii of Taylor and Padé approximations. We thus focus on regions in which convergence of Chebyshev rational functions is better than standard approaches. With this recipe, as high-redshift data are employed, rational Chebyshev polynomials remain highly stable and enable one to derive highly accurate analytical approximations of Hubble's rate in terms of the cosmographic series. Finally, we check our theoretical predictions by setting bounds on cosmographic parameters through Monte Carlo integration techniques, based on the Metropolis-Hastings algorithm. We apply our technique to high-redshift cosmic data, using the Joint Light-curve Analysis supernovae sample and the most recent versions of Hubble parameter and baryon acoustic oscillation measurements. We find that cosmography with Taylor series fails to be predictive with the aforementioned data sets, while turns out to be much more stable using the Chebyshev approach.

Where do moral decisions come from?

PubMed

Crigger, Bette-Jane

1996-01-01

[Mark] Johnson asks us to take seriously theory as an imaginative construction that offers, not an objective account of the world, but a dynamic, intersubjective construal of it....A common feature [of the four books discussed] is the conviction that moral universals are somehow bound up with dynamic processes that have their origin in the human form, not with disembodied rules or rational arguments per se.

Neutron diffraction of acetazolamide-bound human carbonic anhydrase II reveals atomic details of drug binding

PubMed Central

Fisher, S. Zoë; Aggarwal, Mayank; Kovalevsky, Andrey Y.; Silverman, David N.; McKenna, Robert

2012-01-01

Carbonic anhydrases (CAs) catalyze the hydration of CO2 forming HCO3− and a proton, an important reaction for many physiological processes including respiration, fluid secretion, and pH regulation. As such, CA isoforms are prominent clinical targets for treating various diseases. The clinically used acetazolamide (AZM) is a sulfonamide that binds with high affinity to human CA isoform II (HCA II). There are several X-ray structures available of AZM bound to various CA isoforms, but these complexes do not show the charged state of AZM, or hydrogen (H) atom positions of the protein and solvent. Neutron diffraction is a useful technique for directly observing H atoms and the mapping of H-bonding networks that can greatly contribute to rational drug design. To this end the neutron structure of H/D exchanged HCA II crystals in complex with AZM was determined. The structure reveals the molecular details of AZM binding and the charged state of the bound drug. This represents the first determined neutron structure of a clinically used drug bound to its target. PMID:22928733

Rational desires and the limitation of life-sustaining treatment.

PubMed

Savulescu, Julian

1994-07-01

It is accepted that treatment of previously competent, now incompetent patients can be limited if that is what the patient would desire, if she were now competent. Expressed past preferences or an advance directive are often taken to constitute sufficient evidence of what a patient would now desire. I distinguish between desires and rational desires. I argue that for a desire to be an expression of a person's autonomy, it must be or satisfy that person's rational desires. A person rationally desires a course of action if that person desires it while being in possession of all available relevant facts, without committing relevant error of logic, and "vividly imagining" what its consequences would be like for her. I argue that some competent, expressed desires obstruct autonomy. I show that several psychological mechanisms operate to prevent a person rationally evaluating what future life in a disabled state would be like. Rational evaluation is difficult. However, treatment limitation, if it is to respect autonomy, must be in accord with a patient's rational desires, and not merely her expressed desires. I illustrate the implications of these arguments for the use of advance directives and for the treatment of competent patients.

Bonds or Bargains: Relationship Paradigms and Their Significance for Marital Therapy.

ERIC Educational Resources Information Center

Johnson, Sue

1986-01-01

Discusses contrasting conceptual paradigms describing the nature of intimate relationships. Relationships may be viewed in terms of a rational bargain or as an emotional bond. The implications of each paradigm for the process of marital therapy and the role of bonding and attachment in adult intimacy are prescribed. Implications for marital…

Rational-number comparison across notation: Fractions, decimals, and whole numbers.

PubMed

Hurst, Michelle; Cordes, Sara

2016-02-01

Although fractions, decimals, and whole numbers can be used to represent the same rational-number values, it is unclear whether adults conceive of these rational-number magnitudes as lying along the same ordered mental continuum. In the current study, we investigated whether adults' processing of rational-number magnitudes in fraction, decimal, and whole-number notation show systematic ratio-dependent responding characteristic of an integrated mental continuum. Both reaction time (RT) and eye-tracking data from a number-magnitude comparison task revealed ratio-dependent performance when adults compared the relative magnitudes of rational numbers, both within the same notation (e.g., fractions vs. fractions) and across different notations (e.g., fractions vs. decimals), pointing to an integrated mental continuum for rational numbers across notation types. In addition, eye-tracking analyses provided evidence of an implicit whole-number bias when we compared values in fraction notation, and individual differences in this whole-number bias were related to the individual's performance on a fraction arithmetic task. Implications of our results for both cognitive development research and math education are discussed. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Bound Rationality and Organizational Learning.

DTIC Science & Technology

1989-09-23

psychology of people living In an organizational environment. The complaint was usually registered by sociologists, and was not without merit. We need...species of what Bill Starbuck has called "knowledge intensive organizations." Let us take the case of a university that wants to innovate along some...control gear would be an example, a considerable fraction of Ideas for new products originates with a knowledge or customers ’ needs and problems - the

Socially Coherent Negotiation for Cooperative Multiagent Systems

DTIC Science & Technology

2008-07-16

of altruism by substituting the preferences of others for one’s own. • It is assumed that each member will...approximation) — it is not a species of bounded rationality. (c) It naturally extends to the multi-agent case, thereby providing a natural frame- work...are mass functions, permits a natural way to aggregate the preference orderings of the individuals to form a group preference ordering. As is well

The structure of a market containing boundedly rational firms

NASA Astrophysics Data System (ADS)

Ibrahim, Adyda; Zura, Nerda; Saaban, Azizan

2017-11-01

The structure of a market is determined by the number of active firms in it. Over time, this number is affected by the exit of existing firms, called incumbents, and entries of new firms, called entrant. In this paper, we considered a market governed by the Cobb-Douglas utility function such that the demand function is isoelastic. Each firm is assumed to produce a single homogenous product under a constant unit cost. Furthermore, firms are assumed to be boundedly rational in adjusting their outputs at each period. A firm is considered to exit the market if its output is negative. In this paper, the market is assumed to have zero barrier-to-entry. Therefore, the exiting firm can reenter the market if its output is positive again, and new firms can enter the market easily. Based on these assumptions and rules, a mathematical model was developed and numerical simulations were run using Matlab. By setting certain values for the parameters in the model, initial numerical simulations showed that in the long run, the number of firms that manages to survive the market varies between zero to 30. This initial result is consistent with the idea that a zero barrier-to-entry may produce a perfectly competitive market.

Transition in the waiting-time distribution of price-change events in a global socioeconomic system

NASA Astrophysics Data System (ADS)

Zhao, Guannan; McDonald, Mark; Fenn, Dan; Williams, Stacy; Johnson, Nicholas; Johnson, Neil F.

2013-12-01

The goal of developing a firmer theoretical understanding of inhomogeneous temporal processes-in particular, the waiting times in some collective dynamical system-is attracting significant interest among physicists. Quantifying the deviations between the waiting-time distribution and the distribution generated by a random process may help unravel the feedback mechanisms that drive the underlying dynamics. We analyze the waiting-time distributions of high-frequency foreign exchange data for the best executable bid-ask prices across all major currencies. We find that the lognormal distribution yields a good overall fit for the waiting-time distribution between currency rate changes if both short and long waiting times are included. If we restrict our study to long waiting times, each currency pair’s distribution is consistent with a power-law tail with exponent near to 3.5. However, for short waiting times, the overall distribution resembles one generated by an archetypal complex systems model in which boundedly rational agents compete for limited resources. Our findings suggest that a gradual transition arises in trading behavior between a fast regime in which traders act in a boundedly rational way and a slower one in which traders’ decisions are driven by generic feedback mechanisms across multiple timescales and hence produce similar power-law tails irrespective of currency type.

Design and application of a CA-BDI model to determine farmers' land-use behavior.

PubMed

Liang, Xiaoying; Chen, Hai; Wang, Yanni; Song, Shixiong

2016-01-01

The belief-desire-intention (BDI) model has been widely used to construct reasoning systems for complex tasks in dynamic environments. We have designed a capabilities and abilities (CA)-BDI farmer decision-making model, which is an extension of the BDI architecture and includes internal representations for farmer household Capabilities and Abilities. This model is used to explore farmer learning mechanisms and to simulate the bounded rational decisions made by farmer households. Our case study focuses on the Gaoqu Commune of Mizhi County, Shaanxi Province, China, where scallion is one of the main cash crops. After comparing the differences between actual land-use changes from 2007 to 2009 and the simulation results, we analyze the validity of the model and discuss the potential and limitations of the farmer land-use decision-making model under three scenarios. Based on the design and implementation of the model, the following conclusions can be drawn: (1) the CA-BDI framework is an appropriate model for exploring learning mechanisms and simulating bounded rational decisions; and (2) local governments should encourage scallion planting by assisting scallion farmer cooperatives and farmers to understand the market risk, standardize the rules of their cooperation, and supervise the contracts made between scallion cooperatives and farmers.

Identification and calculation of the universal asymptote for drag reduction by polymers in wall bounded turbulence.

PubMed

Benzi, Roberto; De Angelis, Elisabetta; L'vov, Victor S; Procaccia, Itamar

2005-11-04

Drag reduction by polymers in wall turbulence is bounded from above by a universal maximal drag reduction (MDR) velocity profile that is a log law, estimated experimentally by Virk as V+(y+) approximately 11.7logy+ - 17. Here V+(y+) and y+ are the mean streamwise velocity and the distance from the wall in "wall" units. In this Letter we propose that this MDR profile is an edge solution of the Navier-Stokes equations (with an effective viscosity profile) beyond which no turbulent solutions exist. This insight rationalizes the universality of the MDR and provides a maximum principle which allows an ab initio calculation of the parameters in this law without any viscoelastic experimental input.

Optimal inference with suboptimal models: Addiction and active Bayesian inference

PubMed Central

Schwartenbeck, Philipp; FitzGerald, Thomas H.B.; Mathys, Christoph; Dolan, Ray; Wurst, Friedrich; Kronbichler, Martin; Friston, Karl

2015-01-01

When casting behaviour as active (Bayesian) inference, optimal inference is defined with respect to an agent’s beliefs – based on its generative model of the world. This contrasts with normative accounts of choice behaviour, in which optimal actions are considered in relation to the true structure of the environment – as opposed to the agent’s beliefs about worldly states (or the task). This distinction shifts an understanding of suboptimal or pathological behaviour away from aberrant inference as such, to understanding the prior beliefs of a subject that cause them to behave less ‘optimally’ than our prior beliefs suggest they should behave. Put simply, suboptimal or pathological behaviour does not speak against understanding behaviour in terms of (Bayes optimal) inference, but rather calls for a more refined understanding of the subject’s generative model upon which their (optimal) Bayesian inference is based. Here, we discuss this fundamental distinction and its implications for understanding optimality, bounded rationality and pathological (choice) behaviour. We illustrate our argument using addictive choice behaviour in a recently described ‘limited offer’ task. Our simulations of pathological choices and addictive behaviour also generate some clear hypotheses, which we hope to pursue in ongoing empirical work. PMID:25561321

Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings

PubMed Central

Ayres, Cory M.; Corcelli, Steven A.; Baker, Brian M.

2017-01-01

Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic “energy landscapes” of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology. PMID:28824655

Peptide and Peptide-Dependent Motions in MHC Proteins: Immunological Implications and Biophysical Underpinnings.

PubMed

Ayres, Cory M; Corcelli, Steven A; Baker, Brian M

2017-01-01

Structural biology of peptides presented by class I and class II MHC proteins has transformed immunology, impacting our understanding of fundamental immune mechanisms and allowing researchers to rationalize immunogenicity and design novel vaccines. However, proteins are not static structures as often inferred from crystallographic structures. Their components move and breathe individually and collectively over a range of timescales. Peptides bound within MHC peptide-binding grooves are no exception and their motions have been shown to impact recognition by T cell and other receptors in ways that influence function. Furthermore, peptides tune the motions of MHC proteins themselves, which impacts recognition of peptide/MHC complexes by other proteins. Here, we review the motional properties of peptides in MHC binding grooves and discuss how peptide properties can influence MHC motions. We briefly review theoretical concepts about protein motion and highlight key data that illustrate immunological consequences. We focus primarily on class I systems due to greater availability of data, but segue into class II systems as the concepts and consequences overlap. We suggest that characterization of the dynamic "energy landscapes" of peptide/MHC complexes and the resulting functional consequences is one of the next frontiers in structural immunology.

Considering rational self-interest as a disposition: organizational implications of other orientation.

PubMed

Meglino, Bruce M; Korsgaard, Audrey

2004-12-01

In contrast with major theories of attitudes and behavior, the authors propose that individuals are not equally motivated to pursue their self-interests. The authors show that differences in other orientation affect the extent to which actions and attitudes reflect self-interested calculation (instrumental rationality) and the extent to which beliefs represent their external environment (epistemic rationality). These differences have consequences for processes underlying a wide range of attitudes and behavior typically assumed to be rationally self-interested. Thus, the authors' model exposes a common explanation for diverse organizational phenomena. It also clarifies inconsistencies surrounding the validity of certain attitudinal and motivational models, the relationship between job attitudes and actions, cross-cultural differences in attitudes and behavior, escalation of commitment, and the relationship between chief executive officer characteristics and organizational performance. 2004 APA, all rights reserved

Rational and mechanistic perspectives on reinforcement learning.

PubMed

Chater, Nick

2009-12-01

This special issue describes important recent developments in applying reinforcement learning models to capture neural and cognitive function. But reinforcement learning, as a theoretical framework, can apply at two very different levels of description: mechanistic and rational. Reinforcement learning is often viewed in mechanistic terms--as describing the operation of aspects of an agent's cognitive and neural machinery. Yet it can also be viewed as a rational level of description, specifically, as describing a class of methods for learning from experience, using minimal background knowledge. This paper considers how rational and mechanistic perspectives differ, and what types of evidence distinguish between them. Reinforcement learning research in the cognitive and brain sciences is often implicitly committed to the mechanistic interpretation. Here the opposite view is put forward: that accounts of reinforcement learning should apply at the rational level, unless there is strong evidence for a mechanistic interpretation. Implications of this viewpoint for reinforcement-based theories in the cognitive and brain sciences are discussed.

Adversarial Collaboration Decision-Making: An Overview of Social Quantum Information Processing

DTIC Science & Technology

2002-01-01

collaborative decision - making (CDM) to solve problems is an aspect of human behavior least yielding to rational predictions. To reduce the complexity of CDM...increases. Implications for C2 decision - making are discussed. Overview of research Game theory was one of the first rational approaches to the study of...Psychologist, 36, 343-356. Lawless, W.F. (2001), The quantum of social action and the function of emotion in decision - making , Proceedings, Emotional and

[What did bachelard mean by "applied rationalism" ?].

PubMed

Tiles, Mary

2013-01-01

Bachelard was concerned with the processes whereby scientific knowledge is acquired, including the activity of knowing subjects. He did not equate reasoning with logic but rather argued that reasoning resulted from the use of mathematics in organizing both thought and experimental practices, which is why he conceived science as applied mathematics. This had material and technical implications, for Bachelard was concerned with the element of reason inherent in technical materialism as well as the concrete reality inherent in applied rationalism.

Rational Degenerations of M-Curves, Totally Positive Grassmannians and KP2-Solitons

NASA Astrophysics Data System (ADS)

Abenda, Simonetta; Grinevich, Petr G.

2018-03-01

We establish a new connection between the theory of totally positive Grassmannians and the theory of M-curves using the finite-gap theory for solitons of the KP equation. Here and in the following KP equation denotes the Kadomtsev-Petviashvili 2 equation [see (1)], which is the first flow from the KP hierarchy. We also assume that all KP times are real. We associate to any point of the real totally positive Grassmannian Gr^{tp} (N,M) a reducible curve which is a rational degeneration of an M-curve of minimal genus {g=N(M-N)} , and we reconstruct the real algebraic-geometric data á la Krichever for the underlying real bounded multiline KP soliton solutions. From this construction, it follows that these multiline solitons can be explicitly obtained by degenerating regular real finite-gap solutions corresponding to smooth M-curves. In our approach, we rule the addition of each new rational component to the spectral curve via an elementary Darboux transformation which corresponds to a section of a specific projection Gr^{tp} (r+1,M-N+r+1)\\mapsto Gr^{tp} (r,M-N+r).

Neutrino mass implications for muon decay parameters

DOE Office of Scientific and Technical Information (OSTI.GOV)

Erwin, Rebecca J.; Kile, Jennifer; Ramsey-Musolf, Michael J.

2007-02-01

We use the scale of neutrino mass and naturalness considerations to obtain model-independent expectations for the magnitude of possible contributions to muon decay Michel parameters from new physics above the electroweak symmetry-breaking scale. Focusing on Dirac neutrinos, we obtain a complete basis of dimension four and dimension six effective operators that are invariant under the gauge symmetry of the standard model and that contribute to both muon decay and neutrino mass. We show that - in the absence of fine tuning - the most stringent neutrino-mass naturalness bounds on chirality-changing vector operators relevant to muon decay arise from one-loop operatormore » mixing. The bounds we obtain on their contributions to the Michel parameters are 2 orders of magnitude stronger than bounds previously obtained in the literature. In addition, we analyze the implications of one-loop matching considerations and find that the expectations for the size of various scalar and tensor contributions to the Michel parameters are considerably smaller than derived from previous estimates of two-loop operator mixing. We also show, however, that there exist gauge-invariant operators that generate scalar and tensor contributions to muon decay but whose flavor structure allows them to evade neutrino-mass naturalness bounds. We discuss the implications of our analysis for the interpretation of muon-decay experiments.« less

Playing Games and Making Decisions with Complex State Spaces, Resource-Bounded Agents, and Unforeseen Contingencies

DTIC Science & Technology

2012-01-20

t) = ∑ ~a∈A(σ1(t1)(a1) × . . . × σm(tm)(am))ui(~t,~a). Player i’s expected utility if ~σ is played, denoted Ui(~σ), is then just EPr [u ~σ i ] = ∑ ~t∈T...well-known Traveler’s Dilemma (K. Basu, The traveler’s dilemma: paradoxes of rationality in game theory, American Economic Review 84:2, 1994, pp. 391

Applying theories to better understand socio-political challenges in implementing evidence-based work disability prevention strategies.

PubMed

Ståhl, Christian; Costa-Black, Katia; Loisel, Patrick

2018-04-01

This article explores and applies theories for analyzing socio-political aspects of implementation of work disability prevention (WDP) strategies. For the analysis, theories from political science are explained and discussed in relation to case examples from three jurisdictions (Sweden, Brazil and Québec). Implementation of WDP strategies may be studied through a conceptual framework that targets: (1) the institutional system in which policy-makers and other stakeholders reside; (2) the ambiguity and conflicts regarding what to do and how to do it; (3) the bounded rationality, path dependency and social systems of different stakeholders; and (4) coalitions formed by different stakeholders and power relations between them. In the case examples, the design of social insurance systems, the access to and infrastructure of healthcare systems, labor market policies, employers' level of responsibility, the regulatory environment, and the general knowledge of WDP issues among stakeholders played different roles in the implementation of policies based on scientific evidence. Future research may involve participatory approaches focusing on building coalitions and communities of practice with policy-makers and stakeholders, in order to build trust, facilitate cooperation, and to better promote evidence utilization. Implications for Rehabilitation Implementation of work disability prevention policies are subject to contextual influences from the socio-political setting and from relationships between stakeholders Stakeholders involved in implementing strategies are bound to act based on their interests and previous courses of action To promote research uptake on the policy level, stakeholders and researchers need to engage in collaboration and translational activities Political stakeholders at the government and community levels need to be more directly involved as partners in the production and utilization of evidence.

"Leaky" Rationality: How Research on Behavioral Decision Making Challenges Normative Standards of Rationality.

PubMed

Keys, Daniel J; Schwartz, Barry

2007-06-01

For more than 30 years, decision-making research has documented that people often violate various principles of rationality, some of which are so fundamental that theorists of rationality rarely bother to state them. We take these characteristics of decision making as a given but argue that it is problematic to conclude that they typically represent departures from rationality. The very psychological processes that lead to "irrational" decisions (e.g., framing, mental accounting) continue to exert their influence when one experiences the results of the decisions. That is, psychological processes that affect decisions may be said also to "leak" into one's experience. The implication is that formal principles of rationality do not provide a good enough normative standard against which to assess decision making. Instead, what is needed is a substantive theory of rationality-one that takes subjective experience seriously, considers both direct and indirect consequences of particular decisions, considers how particular decisions fit into life as a whole, and considers the effects of decisions on others. Formal principles may play a role as approximations of the substantive theory that can be used by theorists and decision makers in cases in which the formal principles can capture most of the relevant considerations and leakage into experience is negligible. © 2007 Association for Psychological Science.

Environmental risk, precaution, and scientific rationality in the context of WTO/NAFTA trade rules.

PubMed

Crawford-Brown, Douglas; Pauwelyn, Joost; Smith, Kelly

2004-04-01

This article considers the role of scientific rationality in understanding statements of risk produced by a scientific community. An argument is advanced that, while scientific rationality does impose constraints on valid scientific justifications for restrictions on products and practices, it also provides flexibility in the judgments needed to both develop and apply characterizations of risk. The implications of this flexibility for the understanding of risk estimates in WTO and NAFTA deliberations are explored, with the goal of finding an intermediate ground between the view that science unambiguously justifies or rejects a policy, and the view that science is yet another cultural tool that can be manipulated in support of any decision. The result is a proposal for a dialogical view of scientific rationality in which risk estimates are depicted as confidence distributions that follow from a structured dialogue of scientific panels focused on judgments of evidence, evidential reasoning, and epistemic analysis.

Classical Physics and the Bounds of Quantum Correlations.

PubMed

Frustaglia, Diego; Baltanás, José P; Velázquez-Ahumada, María C; Fernández-Prieto, Armando; Lujambio, Aintzane; Losada, Vicente; Freire, Manuel J; Cabello, Adán

2016-06-24

A unifying principle explaining the numerical bounds of quantum correlations remains elusive, despite the efforts devoted to identifying it. Here, we show that these bounds are indeed not exclusive to quantum theory: for any abstract correlation scenario with compatible measurements, models based on classical waves produce probability distributions indistinguishable from those of quantum theory and, therefore, share the same bounds. We demonstrate this finding by implementing classical microwaves that propagate along meter-size transmission-line circuits and reproduce the probabilities of three emblematic quantum experiments. Our results show that the "quantum" bounds would also occur in a classical universe without quanta. The implications of this observation are discussed.

Laws of cognition and the cognition of law.

PubMed

Kahan, Dan M

2015-02-01

This paper presents a compact synthesis of the study of cognition in legal decisionmaking. Featured dynamics include the story-telling model (Pennington & Hastie, 1986), lay prototypes (Smith, 1991), motivated cognition (Sood, 2012), and coherence-based reasoning (Simon, Pham, Le, & Holyoak, 2001). Unlike biases and heuristics understood to bound or constrain rationality, these dynamics identify how information shapes a variety of cognitive inputs-from prior beliefs to perceptions of events to the probative weight assigned new information-that rational decisionmaking presupposes. The operation of these mechanisms can be shown to radically alter the significance that jurors give to evidence, and hence the conclusions they reach, within a Bayesian framework of information processing. How these dynamics interact with the professional judgment of lawyers and judges, the paper notes, remains in need of investigation. Copyright © 2014 Elsevier B.V. All rights reserved.

PAYING FOR PERFORMANCE: THE POWER OF INCENTIVES OVER HABITS

PubMed Central

Sindelar, Jody L.

2010-01-01

New evidence suggests that individuals do not always make rational decisions, especially with regard to health habits. Smoking, misuse of alcohol, overeating and illicit drug use are leading causes of morbidity and mortality. Thus, influencing health habits is critical for improving overall health and well-being. This editorial argues that economists should take a more active role in shaping individuals’ health habits. Two recent innovations in economic theory pave the way. One change is that some economists now view rationality as bounded and willpower in short supply. Another, related to the first, is a more accepting perspective on paternalism, authorizing economists to help individuals make better choices when the neoclassical model breaks down. Findings from psychology offer incentive-based approaches; specifically, contingency management (CM). Economists could use this approach as a basis for developing public and private policies. PMID:18348117

Design, Synthesis and Affinity Properties of Biologically Active Peptide and Protein Conjugates of Cotton Cellulose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, J. V.; Goheen, Steven C.

The formation of peptide and protein conjugates of cellulose on cotton fabrics provides promising leads for the development of wound healing, antibacterial, and decontaminating textiles. An approach to the design, synthesis, and analysis of bioconjugates containing cellulose peptide and protein conjugates includes: 1) computer graphic modeling for a rationally designed structure; 2) attachment of the peptide or protein to cotton cellulose through a linker amino acid, and 3) characterization of the resulting bioconjugate. Computer graphic simulation of protein and peptide cellulose conjugates gives a rationally designed biopolymer to target synthetic modifications to the cotton cellulose. Techniques for preparing these typesmore » of conjugates involve both sequential assembly of the peptide on the fabric and direct crosslinking of the peptide or protein as cellulose bound esters or carboxymethylcellulose amides.« less

Heterocyclic periphery in the design of carbonic anhydrase inhibitors: 1,2,4-Oxadiazol-5-yl benzenesulfonamides as potent and selective inhibitors of cytosolic hCA II and membrane-bound hCA IX isoforms.

PubMed

Krasavin, Mikhail; Shetnev, Anton; Sharonova, Tatyana; Baykov, Sergey; Tuccinardi, Tiziano; Kalinin, Stanislav; Angeli, Andrea; Supuran, Claudiu T

2018-02-01

A series of novel aromatic primary sulfonamides decorated with diversely substituted 1,2,4-oxadiazole periphery groups has been prepared using a parallel chemistry approach. The compounds displayed a potent inhibition of cytosolic hCA II and membrane-bound hCA IX isoforms. Due to a different cellular localization of the two target enzymes, the compounds can be viewed as selective inhibition tools for either isoform, depending on the cellular permeability profile. The SAR findings revealed in this study has been well rationalized by docking simulation of the key compounds against the crystal structures of the relevant hCA isoforms. Copyright © 2017. Published by Elsevier Inc.

The nature of thinking, shallow and deep.

PubMed

Brase, Gary L

2014-01-01

Because the criteria for success differ across various domains of life, no single normative standard will ever work for all types of thinking. One method for dealing with this apparent dilemma is to propose that the mind is made up of a large number of specialized modules. This review describes how this multi-modular framework for the mind overcomes several critical conceptual and theoretical challenges to our understanding of human thinking, and hopefully clarifies what are (and are not) some of the implications based on this framework. In particular, an evolutionarily informed "deep rationality" conception of human thinking can guide psychological research out of clusters of ad hoc models which currently occupy some fields. First, the idea of deep rationality helps theoretical frameworks in terms of orienting themselves with regard to time scale references, which can alter the nature of rationality assessments. Second, the functional domains of deep rationality can be hypothesized (non-exhaustively) to include the areas of self-protection, status, affiliation, mate acquisition, mate retention, kin care, and disease avoidance. Thus, although there is no single normative standard of rationality across all of human cognition, there are sensible and objective standards by which we can evaluate multiple, fundamental, domain-specific motives underlying human cognition and behavior. This review concludes with two examples to illustrate the implications of this framework. The first example, decisions about having a child, illustrates how competing models can be understood by realizing that different fundamental motives guiding people's thinking can sometimes be in conflict. The second example is that of personifications within modern financial markets (e.g., in the form of corporations), which are entities specifically constructed to have just one fundamental motive. This single focus is the source of both the strengths and flaws in how such entities behave.

Rational thinking and cognitive sophistication: development, cognitive abilities, and thinking dispositions.

PubMed

Toplak, Maggie E; West, Richard F; Stanovich, Keith E

2014-04-01

We studied developmental trends in 5 important reasoning tasks that are critical components of the operational definition of rational thinking. The tasks measured denominator neglect, belief bias, base rate sensitivity, resistance to framing, and the tendency toward otherside thinking. In addition to age, we examined 2 other individual difference domains that index cognitive sophistication: cognitive ability (intelligence and executive functioning) and thinking dispositions (actively open-minded thinking, superstitious thinking, and need for cognition). All 5 reasoning domains were consistently related to cognitive sophistication regardless of how it was indexed (age, cognitive ability, thinking dispositions). The implications of these findings for taxonomies of developmental trends in rational thinking tasks are discussed. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Competency to stand trial: rationalism, "contextualism" and other modest theories.

PubMed

Jan Brakel, S

2003-01-01

Determinations of competency to stand trial in criminal cases are complicated and rendered unpredictable by two sub-surface issues that are rarely articulated: (i) the place of the defendant's rationality in the substantive standard(s) for competency and (ii) the level or degree of incompetency required to stop the criminal process. The rare references to these issues, mostly indirect, that are made in the cases, commentary, and competency testing instruments devised (including those civil as well as criminal) are examined. The conclusion that emerges is that the level of capacity and rationality required of the defendant depends much on context-the type of case, its relative complexity, and the values and stakes implicated in the outcome. Copyright 2003 John Wiley & Sons, Ltd.

On the error probability of general tree and trellis codes with applications to sequential decoding

NASA Technical Reports Server (NTRS)

Johannesson, R.

1973-01-01

An upper bound on the average error probability for maximum-likelihood decoding of the ensemble of random binary tree codes is derived and shown to be independent of the length of the tree. An upper bound on the average error probability for maximum-likelihood decoding of the ensemble of random L-branch binary trellis codes of rate R = 1/n is derived which separates the effects of the tail length T and the memory length M of the code. It is shown that the bound is independent of the length L of the information sequence. This implication is investigated by computer simulations of sequential decoding utilizing the stack algorithm. These simulations confirm the implication and further suggest an empirical formula for the true undetected decoding error probability with sequential decoding.

What does the Sr-substituted 2.1 Å resolution crystal structure of photosystem II reveal about the water oxidation mechanism?

PubMed

Terrett, Richard; Petrie, Simon; Pace, Ron J; Stranger, Robert

2014-03-25

A density functional study of the Sr-substituted photosystem II water oxidising complex demonstrates that its recent X-ray crystal structure is consistent with a (Mn(III))4 oxidation state pattern, and with a Sr-bound hydroxide ion. The Sr-water-hydroxide interactions rationalize differences in the exchange rates of substrate water and kinetics of dioxygen bond formation relative to the Ca-containing structure.

Matching games with partial information

NASA Astrophysics Data System (ADS)

Laureti, Paolo; Zhang, Yi-Cheng

2003-06-01

We analyze different ways of pairing agents in a bipartite matching problem, with regard to its scaling properties and to the distribution of individual “satisfactions”. Then we explore the role of partial information and bounded rationality in a generalized Marriage Problem, comparing the benefits obtained by self-searching and by a matchmaker. Finally we propose a modified matching game intended to mimic the way consumers’ information makes firms to enhance the quality of their products in a competitive market.

Rational design of orally-active, pyrrolidine-based progesterone receptor partial agonists

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Scott K.; Washburn, David G.; Frazee, James S.

2010-09-03

Using the X-ray crystal structure of an amide-based progesterone receptor (PR) partial agonist bound to the PR ligand binding domain, a novel PR partial agonist class containing a pyrrolidine ring was designed. Members of this class of N-alkylpyrrolidines demonstrate potent and highly selective partial agonism of the progesterone receptor, and one of these analogs was shown to be efficacious upon oral dosing in the OVX rat model of estrogen opposition.

The impact of loss sensitivity on a mobile phone supply chain system stability based on the chaos theory

NASA Astrophysics Data System (ADS)

Ma, Junhai; Xie, Lei

2018-02-01

This paper, based on the China's communications and the current situation of the mobile phone industry, focuses on the stability of a supply chain system that consists of one supplier and one bounded rational retailer. We explore the influence of the decision makers' loss sensitivity and decision adjustment speed on the stability of the supply chain. It is found that when the retailer is not sensitive to the loss or adjusts decisions cautiously, the system can be stable. The single-retailer model is extended to a multi-retailer one to study the influence of competition on the system stability. The results show that the market share of each retailer does not affect the system stability when it is fixed. The decision of each retailer does not affect that of any other retailer and the system stability. We present two decision adjustment rules (;bounded rationality expectation (BRE); and "adaptive exponential smoothing (AES)") and compare their performances on the system stability, and find that the AES rule does not affect the system stability, while the BRE rule will make the system stability be sensitive to the retailers' loss sensitivity and the decision adjustment speed. We also reveal the unstable system's negative impact on the retailers' decisions and profits, to emphasize the importance to maintain the system stability.

On one-dimensional compressible Navier-Stokes equations for a reacting mixture in unbounded domains

NASA Astrophysics Data System (ADS)

Li, Siran

2017-10-01

In this paper we consider the one-dimensional Navier-Stokes system for a heat-conducting, compressible reacting mixture which describes the dynamic combustion of fluids of mixed kinds on unbounded domains. This model has been discussed on bounded domains by Chen (SIAM J Math Anal 23:609-634, 1992) and Chen-Hoff-Trivisa (Arch Ration Mech Anal 166:321-358, 2003), among others, in which the reaction rate function is a discontinuous function obeying the Arrhenius' law of thermodynamics. We prove the global existence of weak solutions to this model on one-dimensional unbounded domains with large initial data in H^1. Moreover, the large-time behaviour of the weak solution is identified. In particular, the uniform-in-time bounds for the temperature and specific volume have been established via energy estimates. For this purpose we utilise techniques developed by Kazhikhov-Shelukhin (cf. Kazhikhov in Siber Math J 23:44-49, 1982; Solonnikov and Kazhikhov in Annu Rev Fluid Mech 13:79-95, 1981) and refined by Jiang (Commun Math Phys 200:181-193, 1999, Proc R Soc Edinb Sect A 132:627-638, 2002), as well as a crucial estimate in the recent work by Li-Liang (Arch Ration Mech Anal 220:1195-1208, 2016). Several new estimates are also established, in order to treat the unbounded domain and the reacting terms.

Précis of bayesian rationality: The probabilistic approach to human reasoning.

PubMed

Oaksford, Mike; Chater, Nick

2009-02-01

According to Aristotle, humans are the rational animal. The borderline between rationality and irrationality is fundamental to many aspects of human life including the law, mental health, and language interpretation. But what is it to be rational? One answer, deeply embedded in the Western intellectual tradition since ancient Greece, is that rationality concerns reasoning according to the rules of logic--the formal theory that specifies the inferential connections that hold with certainty between propositions. Piaget viewed logical reasoning as defining the end-point of cognitive development; and contemporary psychology of reasoning has focussed on comparing human reasoning against logical standards. Bayesian Rationality argues that rationality is defined instead by the ability to reason about uncertainty. Although people are typically poor at numerical reasoning about probability, human thought is sensitive to subtle patterns of qualitative Bayesian, probabilistic reasoning. In Chapters 1-4 of Bayesian Rationality (Oaksford & Chater 2007), the case is made that cognition in general, and human everyday reasoning in particular, is best viewed as solving probabilistic, rather than logical, inference problems. In Chapters 5-7 the psychology of "deductive" reasoning is tackled head-on: It is argued that purportedly "logical" reasoning problems, revealing apparently irrational behaviour, are better understood from a probabilistic point of view. Data from conditional reasoning, Wason's selection task, and syllogistic inference are captured by recasting these problems probabilistically. The probabilistic approach makes a variety of novel predictions which have been experimentally confirmed. The book considers the implications of this work, and the wider "probabilistic turn" in cognitive science and artificial intelligence, for understanding human rationality.

Discrimination Between Human Leukocyte Antigen Class I-Bound and Co-Purified HIV-Derived Peptides in Immunopeptidomics Workflows

PubMed Central

Partridge, Thomas; Nicastri, Annalisa; Kliszczak, Anna E.; Yindom, Louis-Marie; Kessler, Benedikt M.; Ternette, Nicola; Borrow, Persephone

2018-01-01

Elucidation of novel peptides presented by human leukocyte antigen (HLA) class I alleles by immunopeptidomics constitutes a powerful approach that can inform the rational design of CD8+ T cell inducing vaccines to control infection with pathogens such as human immunodeficiency virus type 1 (HIV-1) or to combat tumors. Recent advances in the sensitivity of liquid chromatography tandem mass spectrometry instrumentation have facilitated the discovery of thousands of natural HLA-restricted peptides in a single measurement. However, the extent of contamination of class I-bound peptides identified using HLA immunoprecipitation (IP)-based immunopeptidomics approaches with peptides from other sources has not previously been evaluated in depth. Here, we investigated the specificity of the IP-based immunopeptidomics methodology using HLA class I- or II-deficient cell lines and membrane protein-specific antibody IPs. We demonstrate that the 721.221 B lymphoblastoid cell line, widely regarded to be HLA class Ia-deficient, actually expresses and presents peptides on HLA-C*01:02. Using this cell line and the C8166 (HLA class I- and II-expressing) cell line, we show that some HLA class II-bound peptides were co-purified non-specifically during HLA class I and membrane protein IPs. Furthermore, IPs of “irrelevant” membrane proteins from HIV-1-infected HLA class I- and/or II-expressing cells revealed that unusually long HIV-1-derived peptides previously reported by us and other immunopeptidomics studies as potentially novel CD8+ T cell epitopes were non-specifically co-isolated, and so constitute a source of contamination in HLA class I IPs. For example, a 16-mer (FLGKIWPSYKGRPGNF), which was detected in all samples studied represents the full p1 segment of the abundant intracellular or virion-associated proteolytically-processed HIV-1 Gag protein. This result is of importance, as these long co-purified HIV-1 Gag peptides may not elicit CD8+ T cell responses when incorporated into candidate vaccines. These results have wider implications for HLA epitope discovery from abundant or membrane-associated antigens by immunopeptidomics in the context of infectious diseases, cancer, and autoimmunity. PMID:29780384

Extending Romanovski polynomials in quantum mechanics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Quesne, C.

2013-12-15

Some extensions of the (third-class) Romanovski polynomials (also called Romanovski/pseudo-Jacobi polynomials), which appear in bound-state wavefunctions of rationally extended Scarf II and Rosen-Morse I potentials, are considered. For the former potentials, the generalized polynomials satisfy a finite orthogonality relation, while for the latter an infinite set of relations among polynomials with degree-dependent parameters is obtained. Both types of relations are counterparts of those known for conventional polynomials. In the absence of any direct information on the zeros of the Romanovski polynomials present in denominators, the regularity of the constructed potentials is checked by taking advantage of the disconjugacy properties ofmore » second-order differential equations of Schrödinger type. It is also shown that on going from Scarf I to Scarf II or from Rosen-Morse II to Rosen-Morse I potentials, the variety of rational extensions is narrowed down from types I, II, and III to type III only.« less

Bounded rationality in volunteering public goods games.

PubMed

Xu, Zhaojin; Wang, Zhen; Zhang, Lianzhong

2010-05-07

It is one of the fundamental problems in biology and social sciences how to maintain high levels of cooperation among selfish individuals. Theorists present an effective mechanism promoting cooperation by allowing for voluntary participation in public goods games. But Nash's theory predicts that no one can do better or worse than loners (players unwilling to join the public goods game) in the long run, and that the frequency of participants is independent of loners' payoff. In this paper, we introduce a degree of rationality and investigate the model by means of an approximate best response dynamics. Our research shows that the payoffs of the loners have a significant effect in anonymous voluntary public goods games by this introduction and that the dynamics will drive the system to a fixed point, which is different from the Nash equilibrium. In addition, we also qualitatively explain the existing experimental results. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

Modulating bacterial and gut mucosal interactions with engineered biofilm matrix proteins.

PubMed

Duraj-Thatte, Anna M; Praveschotinunt, Pichet; Nash, Trevor R; Ward, Frederick R; Joshi, Neel S

2018-02-22

Extracellular appendages play a significant role in mediating communication between bacteria and their host. Curli fibers are a class of bacterial fimbria that is highly amenable to engineering. We demonstrate the use of engineered curli fibers to rationally program interactions between bacteria and components of the mucosal epithelium. Commensal E. coli strains were engineered to produce recombinant curli fibers fused to the trefoil family of human cytokines. Biofilms formed from these strains bound more mucins than those producing wild-type curli fibers, and modulated mucin rheology as well. When treated with bacteria producing the curli-trefoil fusions mammalian cells behaved identically in terms of their migration behavior as when they were treated with the corresponding soluble trefoil factors. Overall, this demonstrates the potential utility of curli fibers as a scaffold for the display of bioactive domains and an untapped approach to rationally modulating host-microbe interactions using bacterial matrix proteins.

A geometric modeler based on a dual-geometry representation polyhedra and rational b-splines

NASA Technical Reports Server (NTRS)

Klosterman, A. L.

1984-01-01

For speed and data base reasons, solid geometric modeling of large complex practical systems is usually approximated by a polyhedra representation. Precise parametric surface and implicit algebraic modelers are available but it is not yet practical to model the same level of system complexity with these precise modelers. In response to this contrast the GEOMOD geometric modeling system was built so that a polyhedra abstraction of the geometry would be available for interactive modeling without losing the precise definition of the geometry. Part of the reason that polyhedra modelers are effective is that all bounded surfaces can be represented in a single canonical format (i.e., sets of planar polygons). This permits a very simple and compact data structure. Nonuniform rational B-splines are currently the best representation to describe a very large class of geometry precisely with one canonical format. The specific capabilities of the modeler are described.

Endogenous Price Bubbles in a Multi-Agent System of the Housing Market

PubMed Central

2015-01-01

Economic history shows a large number of boom-bust cycles, with the U.S. real estate market as one of the latest examples. Classical economic models have not been able to provide a full explanation for this type of market dynamics. Therefore, we analyze home prices in the U.S. using an alternative approach, a multi-agent complex system. Instead of the classical assumptions of agent rationality and market efficiency, agents in the model are heterogeneous, adaptive, and boundedly rational. We estimate the multi-agent system with historical house prices for the U.S. market. The model fits the data well and a deterministic version of the model can endogenously produce boom-and-bust cycles on the basis of the estimated coefficients. This implies that trading between agents themselves can create major price swings in absence of fundamental news. PMID:26107740

The original risk: overtheologizing ethics and undertheologizing sin.

PubMed

Müller, Denis

2007-01-01

The project of articulating a theological ethics on the basis of liturgical anthropology is bound to fail if the necessary consequence is that one has to quit the forum of critical modern rationality. The risk of Engelhardt's approach is to limit rationality to a narrow vision of reason. Sin is not to be understood as the negation of human holiness, but as the negation of divine holiness. The only way to renew theological ethics is to understand sin as the anthropological and ethical expression of the biblical message of the justification by faith only. Sin is therefore a secondary category, which can only by interpreted in light of the positive manifestation of liberation, justification, and grace. The central issue of Christian ethics is not ritual purity or morality, but experience, confession and recognition of our own injustice in our dealing with God and men.

A novel, bounding gait in swimming turtles: implications for aquatic locomotor diversity.

PubMed

Mayerl, Christopher J; Blob, Richard W

2017-10-15

Turtles are an iconic lineage in studies of animal locomotion, typifying the use of slow, alternating footfalls during walking. Alternating movements of contralateral limbs are also typical during swimming gaits for most freshwater turtles. Here, we report a novel gait in turtles, in which the pleurodire Emydura subglobosa swims using a bounding gait that coordinates bilateral protraction of both forelimbs with bilateral retraction of both hindlimbs. Use of this bounding gait is correlated with increased limb excursion and decreased stride frequency, but not increased velocity when compared with standard swimming strokes. Bounding by E. subglobosa provides a second example of a non-mammalian lineage that can use bounding gaits, and may give insight into the evolution of aquatic flapping. Parallels in limb muscle fascicle properties between bounding turtles and crocodylids suggest a possible musculoskeletal mechanism underlying the use of bounding gaits in particular lineages. © 2017. Published by The Company of Biologists Ltd.

Topological defects in mixtures of superconducting condensates with different charges

NASA Astrophysics Data System (ADS)

Garaud, Julien; Babaev, Egor

2014-06-01

We investigate the topological defects in phenomenological models describing mixtures of charged condensates with commensurate electric charges. Such situations are expected to appear for example in liquid metallic deuterium. This is modeled by a multicomponent Ginzburg-Landau theory where the condensates are coupled to the same gauge field by different coupling constants whose ratio is a rational number. We also briefly discuss the case where electric charges are incommensurate. Flux quantization and finiteness of the energy per unit length dictate that the different condensates have different winding and thus different number of (fractional) vortices. Competing attractive and repulsive interactions lead to molecule-like bound states between fractional vortices. Such bound states have finite energy and carry integer flux quanta. These can be characterized by the CP1 topological invariant that motivates their denomination as skyrmions.

Modular constraints on conformal field theories with currents

NASA Astrophysics Data System (ADS)

Bae, Jin-Beom; Lee, Sungjay; Song, Jaewon

2017-12-01

We study constraints coming from the modular invariance of the partition function of two-dimensional conformal field theories. We constrain the spectrum of CFTs in the presence of holomorphic and anti-holomorphic currents using the semi-definite programming. In particular, we find the bounds on the twist gap for the non-current primaries depend dramatically on the presence of holomorphic currents, showing numerous kinks and peaks. Various rational CFTs are realized at the numerical boundary of the twist gap, saturating the upper limits on the degeneracies. Such theories include Wess-Zumino-Witten models for the Deligne's exceptional series, the Monster CFT and the Baby Monster CFT. We also study modular constraints imposed by W -algebras of various type and observe that the bounds on the gap depend on the choice of W -algebra in the small central charge region.

Lower bound buckling loads for design of laminate composite cylinders

NASA Astrophysics Data System (ADS)

Croll, James G. A.; Wang, Hongtao

2017-01-01

Over a period of more than 45 years, an extensive research program has allowed a series of very simple propositions, relating to the safe design of shells experiencing imperfection sensitive buckling, to be recast in the form of a series of lemmas. These are briefly summarized and their practical use is illustrated in relation to the prediction of safe lower bounds to the imperfection sensitive buckling of axially loaded, fiber reinforced polymeric, laminated cylinders. With a fundamental aspect of the approach, sometimes referred to as the reduced stiffness method, being the delineation of the various shell membrane and bending stiffness (or perhaps more appropriately energy) components contributing to the buckling resistance, the method will be shown to also provide a powerful way of making rational design decisions to optimize the use of fiber reinforcement.

Robust allocation of a defensive budget considering an attacker's private information.

PubMed

Nikoofal, Mohammad E; Zhuang, Jun

2012-05-01

Attackers' private information is one of the main issues in defensive resource allocation games in homeland security. The outcome of a defense resource allocation decision critically depends on the accuracy of estimations about the attacker's attributes. However, terrorists' goals may be unknown to the defender, necessitating robust decisions by the defender. This article develops a robust-optimization game-theoretical model for identifying optimal defense resource allocation strategies for a rational defender facing a strategic attacker while the attacker's valuation of targets, being the most critical attribute of the attacker, is unknown but belongs to bounded distribution-free intervals. To our best knowledge, no previous research has applied robust optimization in homeland security resource allocation when uncertainty is defined in bounded distribution-free intervals. The key features of our model include (1) modeling uncertainty in attackers' attributes, where uncertainty is characterized by bounded intervals; (2) finding the robust-optimization equilibrium for the defender using concepts dealing with budget of uncertainty and price of robustness; and (3) applying the proposed model to real data. © 2011 Society for Risk Analysis.

Structures of human ADAR2 bound to dsRNA reveal base-flipping mechanism and basis for site selectivity

DOE PAGES

Matthews, Melissa M.; Thomas, Justin M.; Zheng, Yuxuan; ...

2016-04-11

Adenosine deaminases acting on RNA (ADARs) are editing enzymes that convert adenosine to inosine in duplex RNA, a modification reaction with wide-ranging consequences in RNA function. Understanding of the ADAR reaction mechanism, the origin of editing-site selectivity, and the effect of mutations is limited by the lack of high-resolution structural data for complexes of ADARs bound to substrate RNAs. In this paper, we describe four crystal structures of the human ADAR2 deaminase domain bound to RNA duplexes bearing a mimic of the deamination reaction intermediate. These structures, together with structure-guided mutagenesis and RNA-modification experiments, explain the basis of the ADARmore » deaminase domain's dsRNA specificity, its base-flipping mechanism, and its nearest-neighbor preferences. In addition, we identified an ADAR2-specific RNA-binding loop near the enzyme active site, thus rationalizing differences in selectivity observed between different ADARs. In conclusion, our results provide a structural framework for understanding the effects of ADAR mutations associated with human disease.« less

Discovery and gram-scale synthesis of BMS-593214, a potent, selective FVIIa inhibitor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Priestley, E. Scott; De Lucca, Indawati; Zhou, Jinglan

A 6-amidinotetrahydroquinoline screening hit was driven to a structurally novel, potent, and selective FVIIa inhibitor through a combination of library synthesis and rational design. An efficient gram-scale synthesis of the active enantiomer BMS-593214 was developed, which required significant optimization of the key Povarov annulation. Importantly, BMS-593214 showed antithrombotic efficacy in a rabbit arterial thrombosis model. A crystal structure of BMS-593214 bound to FVIIa highlights key contacts with Asp 189, Lys 192, and the S2 pocket.

On the dynamics of disobedience: experimental investigations of defying unjust authority

PubMed Central

Bocchiaro, Piero; Zimbardo, Philip

2017-01-01

Across six Experimental conditions with university student participants (N=600), we examined some of the dynamics underlying expressed defiance to unjust authority. Results revealed disobedience was best enacted by participants low in right-wing authoritarianism and was more likely to occur when: 1) in physical proximity of other rebels, 2) the authority made two demanding requests instead of one, and 3) there had been an earlier opposition to injustice. Results are discussed within the theoretical framework of bounded rationality. PMID:28761383

On the dynamics of disobedience: experimental investigations of defying unjust authority.

PubMed

Bocchiaro, Piero; Zimbardo, Philip

2017-01-01

Across six Experimental conditions with university student participants (N=600), we examined some of the dynamics underlying expressed defiance to unjust authority. Results revealed disobedience was best enacted by participants low in right-wing authoritarianism and was more likely to occur when: 1) in physical proximity of other rebels, 2) the authority made two demanding requests instead of one, and 3) there had been an earlier opposition to injustice. Results are discussed within the theoretical framework of bounded rationality.

The Changing Strategic Balance and US Defense Planning.

DTIC Science & Technology

1984-02-01

that ’,+, :., -nuclear war is unthinkable and that the application of force is V 3 prima facie evidence of failure of rational analysis and patient...University. Dr. Kennedy served on active duty briefly with the Army and !hen with the Air Force from 1958 to 1971 and is currently a reserve officer...pursuing a war-winning capability designed to give them a strategic advantage they woule be " duty bound" to exploit." In the wake of his participation

Cognitive synergy in groups and group-to-individual transfer of decision-making competencies

PubMed Central

Curşeu, Petru L.; Meslec, Nicoleta; Pluut, Helen; Lucas, Gerardus J. M.

2015-01-01

In a field study (148 participants organized in 38 groups) we tested the effect of group synergy and one's position in relation to the collaborative zone of proximal development (CZPD) on the change of individual decision-making competencies. We used two parallel sets of decision tasks reported in previous research to test rationality and we evaluated individual decision-making competencies in the pre-group and post-group conditions as well as group rationality (as an emergent group level phenomenon). We used multilevel modeling to analyze the data and the results showed that members of synergetic groups had a higher cognitive gain as compared to members of non-synergetic groups, while highly rational members (members above the CZPD) had lower cognitive gains compared to less rational group members (members situated below the CZPD). These insights extend the literature on group-to-individual transfer of learning and have important practical implications as they show that group dynamics influence the development of individual decision-making competencies. PMID:26441750

Cognitive synergy in groups and group-to-individual transfer of decision-making competencies.

PubMed

Curşeu, Petru L; Meslec, Nicoleta; Pluut, Helen; Lucas, Gerardus J M

2015-01-01

In a field study (148 participants organized in 38 groups) we tested the effect of group synergy and one's position in relation to the collaborative zone of proximal development (CZPD) on the change of individual decision-making competencies. We used two parallel sets of decision tasks reported in previous research to test rationality and we evaluated individual decision-making competencies in the pre-group and post-group conditions as well as group rationality (as an emergent group level phenomenon). We used multilevel modeling to analyze the data and the results showed that members of synergetic groups had a higher cognitive gain as compared to members of non-synergetic groups, while highly rational members (members above the CZPD) had lower cognitive gains compared to less rational group members (members situated below the CZPD). These insights extend the literature on group-to-individual transfer of learning and have important practical implications as they show that group dynamics influence the development of individual decision-making competencies.

Structural Basis of Resistance to Anti-Cytochrome bc1 Complex Inhibitors: Implication for Drug Improvement

PubMed Central

Esser, Lothar; Yu, Chang-An; Xia, Di

2016-01-01

The emergence of drug resistance has devastating economic and social consequences, a testimonial of which is the rise and fall of inhibitors against the respiratory component cytochrome bc1 complex, a time tested and highly effective target for disease control. Unfortunately, the mechanism of resistance is a multivariate problem, including primarily mutations in the gene of the cytochrome b subunit but also activation of alternative pathways of ubiquinol oxidation and pharmacokinetic effects. There is a considerable interest in designing new bc1 inhibitors with novel modes of binding and lower propensity to induce the development of resistance. The accumulation of crystallographic data of bc1 complexes with and without inhibitors bound provides the structural basis for rational drug design. In particular, the cytochrome b subunit offers two distinct active sites that can be targeted for inhibition - the quinol oxidation site and the quinone reduction site. This review brings together available structural information of inhibited bc1 by various quinol oxidation- and reduction-site inhibitors, the inhibitor binding modes, conformational changes upon inhibitor binding of side chains in the active site and large scale domain movements of the iron-sulfur protein subunit. Structural data analysis provides a clear understanding of where and why existing inhibitors fail and points towards promising alternatives. PMID:23688079

Entrepreneurial "mining" of the dying: viatical transactions, tax strategies and mind games.

PubMed

Trinkaus, John; Giacalone, Joseph A

2002-03-01

Conceptually, entrepreneurship is seen as the engine that drives a robust economy, promotes a favorable quality of life, and assures the availability of the attributes needed for meaningful living. However, like many popular concepts in this world, its limitations are normally not well acknowledged. A grouping of entrepreneurial ventures which as recently come into existence deals with the personal fiscal issues associated with the end-of-life phase of the human cycle. While generally praised as humanitarian services for society, that are assuredly within legal bounds, these activities have potentially significant negative implications. When examined from an ethical perspective, some questionable practices became apparent. Three such undertakings in particular have to do with the terminally ill and are examined in this paper. The first, viatical transactions, is defined as the transfer of a life insurance policy's ownership to someone who does not have an insurable interest in the life of the insured individual. The second, creative tax shelters for wealthy people involved in estate planning, involves hiring unrelated parties, particularly those who are young and in failing health, to do the dying for the principal. The third, mind games, involves curtailing the use of medical resources for the dying. The justification for this is rationing scarce medical resources.

Impacts of changing food webs in Lake Ontario: Implications of dietary fatty acids on growth of alewives

USGS Publications Warehouse

Snyder, R.J.; Demarche, C.J.; Honeyfield, D.C.

2011-01-01

Declines in the abundance and condition of Great Lakes Alewives have been reported periodically during the last two decades, and the reasons for these declines remain unclear. To better understand how food web changes may influence Alewife growth and Wisconsin growth model predictions, we fed Alewives isocaloric diets high in omega-6 fatty acids (corn oil) or high in omega-3 fatty acids (fish oil). Alewives were fed the experimental diets at either 1% (“low ration”) or 3% (“high ration”) of their wet body weight per day. After six weeks, Alewives maintained on the high ration diets were significantly larger than those fed the low ration diets. Moreover, Alewives given the high ration fish oil diet were significantly larger than those maintained on the high ration corn oil diet after six weeks of growth. Body lipid, energy density and total body energy of Alewives on the high ration diets were significantly higher than those fed the low ration diets, and total body energy was significantly higher in Alewives given the high ration fish oil diet compared to those on the high ration corn oil diet. The current Wisconsin bioenergetics model underestimated growth and overestimated food consumption by Alewives in our study. Alewife thiaminase activity was similar among treatment groups. Overall, our results suggest that future food web changes in Lake Ontario, particularly if they involve decreases in the abundance of lipid rich prey items such as Mysis, may reduce Alewife growth rates and total body energy due to reductions in the availability of dietary omega-3 fatty acids.

Approaches to rationing antiretroviral treatment: ethical and equity implications.

PubMed Central

Bennett, Sara; Chanfreau, Catherine

2005-01-01

Despite a growing global commitment to the provision of antiretroviral therapy (ART), its availability is still likely to be less than the need. This imbalance raises ethical dilemmas about who should be granted access to publicly-subsidized ART programmes. This paper reviews the eligibility and targeting criteria used in four case-study countries at different points in the scale-up of ART, with the aim of drawing lessons regarding ethical approaches to rationing. Mexico, Senegal, Thailand and Uganda have each made an explicit policy commitment to provide antiretrovirals to all those in need, but are achieving this goal in steps--beginning with explicit rationing of access to care. Drawing upon the case-studies and experiences elsewhere, categories of explicit rationing criteria have been identified. These include biomedical factors, adherence to treatment, prevention-driven factors, social and economic benefits, financial factors and factors driven by ethical arguments. The initial criteria for determining eligibility are typically clinical criteria and assessment of adherence prospects, followed by a number of other factors. Rationing mechanisms reflect several underlying ethical theories and the ethical underpinnings of explicit rationing criteria should reflect societal values. In order to ensure this alignment, widespread consultation with a variety of stakeholders, and not only policy-makers or physicians, is critical. Without such explicit debate, more rationing will occur implicitly and this may be more inequitable. The effects of rationing mechanisms upon equity are critically dependent upon the implementation processes. As antiretroviral programmes are implemented it is crucial to monitor who gains access to these programmes. PMID:16175829

Boundary implications for frequency response of interval FIR and IIR filters

NASA Technical Reports Server (NTRS)

Bose, N. K.; Kim, K. D.

1991-01-01

It is shown that vertex implication results in parameter space apply to interval trigonometric polynomials. Subsequently, it is shown that the frequency responses of both interval FIR and IIR filters are bounded by the frequency responses of certain extreme filters. The results apply directly in the evaluation of properties of designed filters, especially because it is more realistic to bound the filter coefficients from above and below instead of determining those with infinite precision because of finite arithmetic effects. Illustrative examples are provided to show how the extreme filters might be easily derived in any specific interval FIR or IIR filter design problem.

Selected approaches for rational drug design and high throughput screening to identify anti-cancer molecules.

PubMed

Hedvat, Michael; Emdad, Luni; Das, Swadesh K; Kim, Keetae; Dasgupta, Santanu; Thomas, Shibu; Hu, Bin; Zhu, Shan; Dash, Rupesh; Quinn, Bridget A; Oyesanya, Regina A; Kegelman, Timothy P; Sokhi, Upneet K; Sarkar, Siddik; Erdogan, Eda; Menezes, Mitchell E; Bhoopathi, Praveen; Wang, Xiang-Yang; Pomper, Martin G; Wei, Jun; Wu, Bainan; Stebbins, John L; Diaz, Paul W; Reed, John C; Pellecchia, Maurizio; Sarkar, Devanand; Fisher, Paul B

2012-11-01

Structure-based modeling combined with rational drug design, and high throughput screening approaches offer significant potential for identifying and developing lead compounds with therapeutic potential. The present review focuses on these two approaches using explicit examples based on specific derivatives of Gossypol generated through rational design and applications of a cancer-specificpromoter derived from Progression Elevated Gene-3. The Gossypol derivative Sabutoclax (BI-97C1) displays potent anti-tumor activity against a diverse spectrum of human tumors. The model of the docked structure of Gossypol bound to Bcl-XL provided a virtual structure-activity-relationship where appropriate modifications were predicted on a rational basis. These structure-based studies led to the isolation of Sabutoclax, an optically pure isomer of Apogossypol displaying superior efficacy and reduced toxicity. These studies illustrate the power of combining structure-based modeling with rational design to predict appropriate derivatives of lead compounds to be empirically tested and evaluated for bioactivity. Another approach to cancer drug discovery utilizes a cancer-specific promoter as readouts of the transformed state. The promoter region of Progression Elevated Gene-3 is such a promoter with cancer-specific activity. The specificity of this promoter has been exploited as a means of constructing cancer terminator viruses that selectively kill cancer cells and as a systemic imaging modality that specifically visualizes in vivo cancer growth with no background from normal tissues. Screening of small molecule inhibitors that suppress the Progression Elevated Gene-3-promoter may provide relevant lead compounds for cancer therapy that can be combined with further structure-based approaches leading to the development of novel compounds for cancer therapy.

Implications of Weltanschauungen for Value Formulation by Guidance Personnel

ERIC Educational Resources Information Center

Weinstock, Henry R.; O'Dowd, Peter S.

1970-01-01

Examines two divergent world-views (empiricism and ration alism) of human values, presenting definitions from many philosophers. Anticipates possibility of confluence of beliefs on nature of man which may offer guidance personnel more accurate tools for direction. (CJ)

Interaction of staphylococcal delta-toxin and synthetic analogues with erythrocytes and phospholipid vesicles. Biological and physical properties of the amphipathic peptides.

PubMed

Alouf, J E; Dufourcq, J; Siffert, O; Thiaudiere, E; Geoffroy, C

1989-08-01

Staphylococcal delta-toxin, a 26-residue amphiphilic peptide is lytic for cells and phospholipid vesicles and is assumed to insert as an amphipathic helix and oligomerize in membranes. For the first time, the relationship between these properties and toxin structure is investigated by means of eight synthetic peptides, one identical in sequence to the natural toxin, five 26-residue analogues and two shorter peptides corresponding to residues 1-11 and 11-26. These peptides were designed by the Edmundson wheel axial projection in order to maintain: (a) the hydrophilic/hydrophobic balance while rationalizing the sequence, (b) the alpha-helical configuration and (c) the common epitopic structure. The fluorescence of the single Trp residue was used to monitor the behaviour of the natural toxin and analogues. All 26-residue analogues were hemolytically active although to a lesser extent than natural toxin. The peptide of residues 11-26 bound lipids weakly and was hemolytic at high concentration. The peptide of residues 1-11 did not bind lipids and was hemolytically inactive. All peptides except the latter cross-reacted in immunoprecipitation tests with the natural toxin. The study of a 26-residue analogue by circular dichroism revealed an alpha-helical configuration in both the free and lipid-bound state. Changes in the fluorescence of the peptides in the presence of lipid micelles and bilayers varied according to the position of the reporter group. When bound to lipids, Trp5, Trp16 and the Fmoc-1 positions of the analogues became buried while Trp15 of the natural toxin and its synthetic replicate remained more exposed. All changes are rationalized by the proposal of an amphipathic helix whose hydrophobic face is embedded within the apolar core of bilayers while the hydrophilic and charged face remains more exposed to solvent.

An Extended Chemical Plant Environmental Protection Game on Addressing Uncertainties of Human Adversaries.

PubMed

Zhu, Zhengqiu; Chen, Bin; Qiu, Sihang; Wang, Rongxiao; Chen, Feiran; Wang, Yiping; Qiu, Xiaogang

2018-03-27

Chemical production activities in industrial districts pose great threats to the surrounding atmospheric environment and human health. Therefore, developing appropriate and intelligent pollution controlling strategies for the management team to monitor chemical production processes is significantly essential in a chemical industrial district. The literature shows that playing a chemical plant environmental protection (CPEP) game can force the chemical plants to be more compliant with environmental protection authorities and reduce the potential risks of hazardous gas dispersion accidents. However, results of the current literature strictly rely on several perfect assumptions which rarely hold in real-world domains, especially when dealing with human adversaries. To address bounded rationality and limited observability in human cognition, the CPEP game is extended to generate robust schedules of inspection resources for inspection agencies. The present paper is innovative on the following contributions: (i) The CPEP model is extended by taking observation frequency and observation cost of adversaries into account, and thus better reflects the industrial reality; (ii) Uncertainties such as attackers with bounded rationality, attackers with limited observation and incomplete information (i.e., the attacker's parameters) are integrated into the extended CPEP model; (iii) Learning curve theory is employed to determine the attacker's observability in the game solver. Results in the case study imply that this work improves the decision-making process for environmental protection authorities in practical fields by bringing more rewards to the inspection agencies and by acquiring more compliance from chemical plants.

Concepts and Bounded Rationality: An Application of Niestegge's Approach to Conditional Quantum Probabilities

NASA Astrophysics Data System (ADS)

Blutner, Reinhard

2009-03-01

Recently, Gerd Niestegge developed a new approach to quantum mechanics via conditional probabilities developing the well-known proposal to consider the Lüders-von Neumann measurement as a non-classical extension of probability conditionalization. I will apply his powerful and rigorous approach to the treatment of concepts using a geometrical model of meaning. In this model, instances are treated as vectors of a Hilbert space H. In the present approach there are at least two possibilities to form categories. The first possibility sees categories as a mixture of its instances (described by a density matrix). In the simplest case we get the classical probability theory including the Bayesian formula. The second possibility sees categories formed by a distinctive prototype which is the superposition of the (weighted) instances. The construction of prototypes can be seen as transferring a mixed quantum state into a pure quantum state freezing the probabilistic characteristics of the superposed instances into the structure of the formed prototype. Closely related to the idea of forming concepts by prototypes is the existence of interference effects. Such inference effects are typically found in macroscopic quantum systems and I will discuss them in connection with several puzzles of bounded rationality. The present approach nicely generalizes earlier proposals made by authors such as Diederik Aerts, Andrei Khrennikov, Ricardo Franco, and Jerome Busemeyer. Concluding, I will suggest that an active dialogue between cognitive approaches to logic and semantics and the modern approach of quantum information science is mandatory.

Dynamic route guidance strategy in a two-route pedestrian-vehicle mixed traffic flow system

NASA Astrophysics Data System (ADS)

Liu, Mianfang; Xiong, Shengwu; Li, Bixiang

2016-05-01

With the rapid development of transportation, traffic questions have become the major issue for social, economic and environmental aspects. Especially, during serious emergencies, it is very important to alleviate road traffic congestion and improve the efficiency of evacuation to reduce casualties, and addressing these problems has been a major task for the agencies responsible in recent decades. Advanced road guidance strategies have been developed for homogeneous traffic flows, or to reduce traffic congestion and enhance the road capacity in a symmetric two-route scenario. However, feedback strategies have rarely been considered for pedestrian-vehicle mixed traffic flows with variable velocities and sizes in an asymmetric multi-route traffic system, which is a common phenomenon in many developing countries. In this study, we propose a weighted road occupancy feedback strategy (WROFS) for pedestrian-vehicle mixed traffic flows, which considers the system equilibrium to ease traffic congestion. In order to more realistic simulating the behavior of mixed traffic objects, the paper adopted a refined and dynamic cellular automaton model (RDPV_CA model) as the update mechanism for pedestrian-vehicle mixed traffic flow. Moreover, a bounded rational threshold control was introduced into the feedback strategy to avoid some negative effect of delayed information and reduce. Based on comparisons with the two previously proposed strategies, the simulation results obtained in a pedestrian-vehicle traffic flow scenario demonstrated that the proposed strategy with a bounded rational threshold was more effective and system equilibrium, system stability were reached.

An Extended Chemical Plant Environmental Protection Game on Addressing Uncertainties of Human Adversaries

PubMed Central

Wang, Rongxiao; Chen, Feiran; Wang, Yiping; Qiu, Xiaogang

2018-01-01

Chemical production activities in industrial districts pose great threats to the surrounding atmospheric environment and human health. Therefore, developing appropriate and intelligent pollution controlling strategies for the management team to monitor chemical production processes is significantly essential in a chemical industrial district. The literature shows that playing a chemical plant environmental protection (CPEP) game can force the chemical plants to be more compliant with environmental protection authorities and reduce the potential risks of hazardous gas dispersion accidents. However, results of the current literature strictly rely on several perfect assumptions which rarely hold in real-world domains, especially when dealing with human adversaries. To address bounded rationality and limited observability in human cognition, the CPEP game is extended to generate robust schedules of inspection resources for inspection agencies. The present paper is innovative on the following contributions: (i) The CPEP model is extended by taking observation frequency and observation cost of adversaries into account, and thus better reflects the industrial reality; (ii) Uncertainties such as attackers with bounded rationality, attackers with limited observation and incomplete information (i.e., the attacker’s parameters) are integrated into the extended CPEP model; (iii) Learning curve theory is employed to determine the attacker’s observability in the game solver. Results in the case study imply that this work improves the decision-making process for environmental protection authorities in practical fields by bringing more rewards to the inspection agencies and by acquiring more compliance from chemical plants. PMID:29584679

Organizational Behavior in Disasters and Implications for Disaster Planning. Volume 1, Number 2

DTIC Science & Technology

1986-07-01

the personal challenges presented by the disaster. There may be expectations of panic, but what almost always occurs is rational behavior . For many...Similarly, there may be expectations of disorder, but what appears is a great deal of prosocial instead of antisocial behavior . To inexperienced...FEMA 104/July 1986 (5-1 Organizational Behavior in Disasters and IMpliCations for Disaster Planning - ii;~1COPBy Enrico L. Quarante~l , Ph. D

Beyond Positivity Bounds and the Fate of Massive Gravity

NASA Astrophysics Data System (ADS)

Bellazzini, Brando; Riva, Francesco; Serra, Javi; Sgarlata, Francesco

2018-04-01

We constrain effective field theories by going beyond the familiar positivity bounds that follow from unitarity, analyticity, and crossing symmetry of the scattering amplitudes. As interesting examples, we discuss the implications of the bounds for the Galileon and ghost-free massive gravity. The combination of our theoretical bounds with the experimental constraints on the graviton mass implies that the latter is either ruled out or unable to describe gravitational phenomena, let alone to consistently implement the Vainshtein mechanism, down to the relevant scales of fifth-force experiments, where general relativity has been successfully tested. We also show that the Galileon theory must contain symmetry-breaking terms that are at most one-loop suppressed compared to the symmetry-preserving ones. We comment as well on other interesting applications of our bounds.

Beyond Positivity Bounds and the Fate of Massive Gravity.

PubMed

Bellazzini, Brando; Riva, Francesco; Serra, Javi; Sgarlata, Francesco

2018-04-20

We constrain effective field theories by going beyond the familiar positivity bounds that follow from unitarity, analyticity, and crossing symmetry of the scattering amplitudes. As interesting examples, we discuss the implications of the bounds for the Galileon and ghost-free massive gravity. The combination of our theoretical bounds with the experimental constraints on the graviton mass implies that the latter is either ruled out or unable to describe gravitational phenomena, let alone to consistently implement the Vainshtein mechanism, down to the relevant scales of fifth-force experiments, where general relativity has been successfully tested. We also show that the Galileon theory must contain symmetry-breaking terms that are at most one-loop suppressed compared to the symmetry-preserving ones. We comment as well on other interesting applications of our bounds.

Bound entangled states with a private key and their classical counterpart.

PubMed

Ozols, Maris; Smith, Graeme; Smolin, John A

2014-03-21

Entanglement is a fundamental resource for quantum information processing. In its pure form, it allows quantum teleportation and sharing classical secrets. Realistic quantum states are noisy and their usefulness is only partially understood. Bound-entangled states are central to this question--they have no distillable entanglement, yet sometimes still have a private classical key. We present a construction of bound-entangled states with a private key based on classical probability distributions. From this emerge states possessing a new classical analogue of bound entanglement, distinct from the long-sought bound information. We also find states of smaller dimensions and higher key rates than previously known. Our construction has implications for classical cryptography: we show that existing protocols are insufficient for extracting private key from our distributions due to their "bound-entangled" nature. We propose a simple extension of existing protocols that can extract a key from them.

The Othello Syndrome

PubMed Central

Famuyiwa, Oluwole O.; Ekpo, Micheal

1983-01-01

A case of the Othello syndrome is presented. In its classical form the syndrome is rare, but as with other allied paranoid states, its medicosocial implications are great. Rational management should include pharmacotherapy, conjoint family therapy after symptom remission, and long-term individual psychotherapy. PMID:6827614

Immigrant Aspirations

ERIC Educational Resources Information Center

Portes, Alejandro; And Others

1978-01-01

Examines occupational, income, and educational aspirations among recent Mexican and Cuban immigrants to the United States. Aspirations appear to be set through a rational assessment of past attainments and skills. Reviews implications for immigrants'"dreams of fantasy" when they first arrive in the United States. (Author/AV)

Some Implications for Afro-American Culture: Rationalism and Western Music

ERIC Educational Resources Information Center

Walton, Ortiz M.

1973-01-01

Will the computer or instruments powered by electrical energy become the most efficient means by which to produce Western music, replacing the live performer? If so, what will be the effects of electronic, mechanical music on society? (Author/RJ)

Creativity, Management, and the Minds of Man

ERIC Educational Resources Information Center

Suojanen, Waino W.

1976-01-01

Describes recent neurophysical theories regarding the different functions of the brain's left hemisphere (linear, time-oriented, rational, and analytic) and right hemisphere (intuitive, artistic, and creative) and discusses their implications for management science. (Available from Office of Publications, Graduate School of Business…

Techno-Science, Rationality, and the University: Lyotard on the "Postmodern Condition."

ERIC Educational Resources Information Center

Peters, Michael

1989-01-01

This article explores Lyotard's contribution to the modernism vs. postmodernism debate and the educational implications of his hypothesis that the status of knowledge is altered as societies enter the postindustrial age and cultures enter the postmodern age. (IAH)

Education as Literacy for Freedom: Implications for Latin America and the Caribbean from an Upward Bound Project.

ERIC Educational Resources Information Center

Dottin, Erskine S.

The Upward Bound Project for low income youth in Florida emphasizes humanistic education rather than education based on the capitalistic model of production, consumption, and competition. The project, which can serve as a model for education in developing countries, focuses on creating self-concepts and values to counteract those of an acquisitive…

Do framing effects reveal irrational choice?

PubMed

Mandel, David R

2014-06-01

Framing effects have long been viewed as compelling evidence of irrationality in human decision making, yet that view rests on the questionable assumption that numeric quantifiers used to convey the expected values of choice options are uniformly interpreted as exact values. Two experiments show that when the exactness of such quantifiers is made explicit by the experimenter, framing effects vanish. However, when the same quantifiers are given a lower bound (at least) meaning, the typical framing effect is found. A 3rd experiment confirmed that most people spontaneously interpret the quantifiers in standard framing tests as lower bounded and that their interpretations strongly moderate the framing effect. Notably, in each experiment, a significant majority of participants made rational choices, either choosing the option that maximized expected value (i.e., lives saved) or choosing consistently across frames when the options were of equal expected value. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Designed Long‐Lived Emission from CdSe Quantum Dots through Reversible Electronic Energy Transfer with a Surface‐Bound Chromophore

PubMed Central

La Rosa, Marcello; Denisov, Sergey A.

2018-01-01

Abstract The size‐tunable emission of luminescent quantum dots (QDs) makes them highly interesting for applications that range from bioimaging to optoelectronics. For the same applications, engineering their luminescence lifetime, in particular, making it longer, would be as important; however, no rational approach to reach this goal is available to date. We describe a strategy to prolong the emission lifetime of QDs through electronic energy shuttling to the triplet excited state of a surface‐bound molecular chromophore. To implement this idea, we made CdSe QDs of different sizes and carried out self‐assembly with a pyrene derivative. We observed that the conjugates exhibit delayed luminescence, with emission decays that are prolonged by more than 3 orders of magnitude (lifetimes up to 330 μs) compared to the parent CdSe QDs. The mechanism invokes unprecedented reversible quantum dot to organic chromophore electronic energy transfer. PMID:29383800

Bounds on invisible Higgs boson decays extracted from LHC ttH production data.

PubMed

Zhou, Ning; Khechadoorian, Zepyoor; Whiteson, Daniel; Tait, Tim M P

2014-10-10

We present an upper bound on the branching fraction of the Higgs boson to invisible particles by recasting a CMS Collaboration search for stop quarks decaying to tt + E(T)(miss). The observed (expected) bound, BF(H → inv.) < 0.40(0.65) at 95% C.L., is the strongest direct limit to date, benefiting from a downward fluctuation in the CMS data in that channel. In addition, we combine this new constraint with existing published constraints to give an observed (expected) bound of BF(H → inv.) < 0.40(0.40) at 95% C.L., and we show some of the implications for theories of dark matter which communicate through the Higgs portal.

Cosmological implications of Dark Matter bound states

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mitridate, Andrea; Redi, Michele; Smirnov, Juri

2017-05-01

We present generic formulæ for computing how Sommerfeld corrections together with bound-state formation affects the thermal abundance of Dark Matter with non-abelian gauge interactions. We consider DM as a fermion 3plet (wino) or 5plet under SU(2) {sub L} . In the latter case bound states raise to 11.5 TeV the DM mass required to reproduce the cosmological DM abundance and give indirect detection signals such as (for this mass) a dominant γ-line around 70 GeV. Furthermore, we consider DM co-annihilating with a colored particle, such as a squark or a gluino, finding that bound state effects are especially relevant inmore » the latter case.« less

Strategic implications of the succession of Kim Jong IL for US foreign policy towards North Korea. Master`s thesis, 2 August 1994-2 June 1995

DOE Office of Scientific and Technical Information (OSTI.GOV)

McElree, J.A.

1995-06-02

This study analyzes the strategic implications of the dynastic succession of Kim Jong IL for U.S. foreign policy towards North Korea. The proliferation of nuclear weapons by North Korea threatens vital U.S. interests in Northeast Asia and challenges U.S. regional and global leadership. In order to properly respond to the North Korean nuclear threat, it is essential to understand the man who will dictate North Korean actions--Kim Jong IL. The study examines Kim Jong Il`s background, training, experience, personality, leadership characteristics, and the challenges he will face. The analysis of Kim Jong IL indicates that he is a rational actormore » who has and will continue to act in a rational manner in pursuit of his desired ends. The framework for analysis is the Strategic Estimate Process. Alternative courses of action are developed using the four elements of national power. The study identifies the strategic implications of probable North Korean actions and recommends appropriate U.S. courses of action on the basis of feasibility, acceptability, and suitability in achieving U.S. objectives in support of U.S. interests.« less

The impact of chief executive officer optimism on hospital strategic decision making.

PubMed

Langabeer, James R; Yao, Emery

2012-01-01

Previous strategic decision making research has focused mostly on the analytical positioning approach, which broadly emphasizes an alignment between rationality and the external environment. In this study, we propose that hospital chief executive optimism (or the general tendency to expect positive future outcomes) will moderate the relationship between comprehensively rational decision-making process and organizational performance. The purpose of this study was to explore the impact that dispositional optimism has on the well-established relationship between rational decision-making processes and organizational performance. Specifically, we hypothesized that optimism will moderate the relationship between the level of rationality and the organization's performance. We further suggest that this relationship will be more negative for those with high, as opposed to low, optimism. We surveyed 168 hospital CEOs and used moderated hierarchical regression methods to statically test our hypothesis. On the basis of a survey study of 168 hospital CEOs, we found evidence of a complex interplay of optimism in the rationality-organizational performance relationship. More specifically, we found that the two-way interactions between optimism and rational decision making were negatively associated with performance and that where optimism was the highest, the rationality-performance relationship was the most negative. Executive optimism was positively associated with organizational performance. We also found that greater perceived environmental turbulence, when interacting with optimism, did not have a significant interaction effect on the rationality-performance relationship. These findings suggest potential for broader participation in strategic processes and the use of organizational development techniques that assess executive disposition and traits for recruitment processes, because CEO optimism influences hospital-level processes. Research implications include incorporating greater use of behavior and cognition constructs to better depict decision-making processes in complex organizations like hospitals.

The rational patient and beyond: implications for treatment adherence in people with psychiatric disabilities.

PubMed

Corrigan, Patrick W; Rüsch, Nicolas; Ben-Zeev, Dror; Sher, Tamara

2014-02-01

Many people with psychiatric disabilities do not benefit from evidence-based practices because they often do not seek out or fully adhere to them. One way psychologists have made sense of this rehabilitation and health decision process and subsequent behaviors (of which adherence might be viewed as one) is by proposing a "rational patient"; namely, that decisions are made deliberatively by weighing perceived costs and benefits of intervention options. Social psychological research, however, suggests limitations to a rational patient theory that impact models of health decision making. The research literature was reviewed for studies of rational patient models and alternative theories with empirical support. Special focus was on models specifically related to decisions about rehabilitation strategies for psychiatric disability. Notions of the rational patient evolved out of several psychological models including the health belief model, protection motivation theory, and theory of planned behavior. A variety of practice strategies evolved to promote rational decision making. However, research also suggests limitations to rational deliberations of health. (1) Rather than carefully and consciously considered, many health decisions are implicit, potentially occurring outside awareness. (2) Decisions are not always planful; often it is the immediate exigencies of a context rather than an earlier balance of costs and benefits that has the greatest effects. (3) Cool cognitions often do not dictate the process; emotional factors have an important role in health decisions. Each of these limitations suggests additional practice strategies that facilitate a person's health decisions. Old models of rational decision making need to be supplanted by multiprocess models that explain supradeliberative factors in health decisions and behaviors. PsycINFO Database Record (c) 2014 APA, all rights reserved.

Post-Doctoral Training Program in Bio-Behavioral Breast Cancer Research

DTIC Science & Technology

2005-05-01

therapy with a particular interest in Rational Emotive- Behavior Therapy ( REBT ) and its application to clinical populations, including breast cancer...Implication for my idiosyncratic practice of REBT . Psychological Annals of Oradea State University (Annalele Universitatii din Oradea-Psihologie), 4: 29-55

The role of cognitive, emotional and personality factors in the experience of fatigue in a university and community sample.

PubMed

Kangas, Maria; Montgomery, Guy H

2011-05-01

The aim of this study was to investigate the contribution of cognitive, emotional and personality factors to the experience of fatigue severity in healthy adult individuals. Specifically, the study examined whether fatigue catastrophising and emotional distress mediated the relationships between neuroticism, general irrational and rational thoughts to fatigue severity. One hundred and eighty nine university students and community volunteers completed self-report questionnaires assessing fatigue catastrophising and symptom severity, neuroticism, general rational and irrational thoughts and emotional distress. A series of correlational and path analyses were conducted to test the study hypotheses. Neuroticism and more general negative, irrational cognitions were associated with elevated fatigue catastrophising and fatigue severity, whereas more adaptive, rational cognitions were related to lower fatigue catastrophising and fatigue severity. Both elevated fatigue catastrophising and emotional distress uniquely and simultaneously mediated the relationships between irrational and rational cognitions and neuroticism to fatigue severity. These findings demonstrate that cognitions play a role in fatigue severity. The results have implications in the assessment and treatment of fatigue disturbances in the general community.

Risk, rationality, and community: Psychology, ethnography, and transactions in the risk management process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cantor, R.; Schoepfle, M.

Communities at risk are confronted by an increasingly complex array of opportunities and need for involvement in decisions affecting them. Policy analysis often demands from researchers insights into the complicated process of how best to account for community involvement in decision making. Often, this requires additional understanding of how decisions are made by community members. Researchers trying to capture the important features of decision making will necessarily make assumptions regarding the rationality underlying the decision process. Two implicit and often incompatible sets of research assumptions about decision processes have emerged: outcome rationality and process rationality. Using outcome rationality, the principalmore » goal of risk research often is to predict how people will react to risk regardless of what they say they would do. Using process rationality, the research goal is to determine how people perceive the risks to which they are exposed and how perceptions actually influence responses. The former approach is associated with research in risk communication, conducted by economists and cognitive psychologists; the latter approach is associated with the field of risk negotiation and acceptance, conducted by anthropologists, some sociologists, and planners. This article describes (1) the difference between the assumptions behind outcome and process rationality regarding decision making and the problems resulting from these differences; (2) the promise and limitations of both sets of assumptions; (3) the potential contributions from cognitive psychology, cognitive ethnography, and the theory of transaction costs in reconciling the differences in assumptions and making them more complementary; and (4) the implications of such complementarity.« less

Sacred bounds on rational resolution of violent political conflict

PubMed Central

Ginges, Jeremy; Atran, Scott; Medin, Douglas; Shikaki, Khalil

2007-01-01

We report a series of experiments carried out with Palestinian and Israeli participants showing that violent opposition to compromise over issues considered sacred is (i) increased by offering material incentives to compromise but (ii) decreased when the adversary makes symbolic compromises over their own sacred values. These results demonstrate some of the unique properties of reasoning and decision-making over sacred values. We show that the use of material incentives to promote the peaceful resolution of political and cultural conflicts may backfire when adversaries treat contested issues as sacred values. PMID:17460042

Leveraging structure determination with fragment screening for infectious disease drug targets: MECP synthase from Burkholderia pseudomallei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Begley, Darren W.; Hartley, Robert C.; Davies, Douglas R.

As part of the Seattle Structural Genomics Center for Infectious Disease, we seek to enhance structural genomics with ligand-bound structure data which can serve as a blueprint for structure-based drug design. We have adapted fragment-based screening methods to our structural genomics pipeline to generate multiple ligand-bound structures of high priority drug targets from pathogenic organisms. In this study, we report fragment screening methods and structure determination results for 2C-methyl-D-erythritol-2,4-cyclo-diphosphate (MECP) synthase from Burkholderia pseudomallei, the gram-negative bacterium which causes melioidosis. Screening by nuclear magnetic resonance spectroscopy as well as crystal soaking followed by X-ray diffraction led to the identification ofmore » several small molecules which bind this enzyme in a critical metabolic pathway. A series of complex structures obtained with screening hits reveal distinct binding pockets and a range of small molecules which form complexes with the target. Additional soaks with these compounds further demonstrate a subset of fragments to only bind the protein when present in specific combinations. This ensemble of fragment-bound complexes illuminates several characteristics of MECP synthase, including a previously unknown binding surface external to the catalytic active site. These ligand-bound structures now serve to guide medicinal chemists and structural biologists in rational design of novel inhibitors for this enzyme.« less

Modeling ligand recognition at the P2Y12 receptor in light of X-ray structural information

NASA Astrophysics Data System (ADS)

Paoletta, Silvia; Sabbadin, Davide; von Kügelgen, Ivar; Hinz, Sonja; Katritch, Vsevolod; Hoffmann, Kristina; Abdelrahman, Aliaa; Straßburger, Jens; Baqi, Younis; Zhao, Qiang; Stevens, Raymond C.; Moro, Stefano; Müller, Christa E.; Jacobson, Kenneth A.

2015-08-01

The G protein-coupled P2Y12 receptor (P2Y12R) is an important antithrombotic target and of great interest for pharmaceutical discovery. Its recently solved, highly divergent crystallographic structures in complex either with nucleotides (full or partial agonist) or with a nonnucleotide antagonist raise the question of which structure is more useful to understand ligand recognition. Therefore, we performed extensive molecular modeling studies based on these structures and mutagenesis, to predict the binding modes of major classes of P2Y12R ligands previously reported. Various nucleotide derivatives docked readily to the agonist-bound P2Y12R, but uncharged nucleotide-like antagonist ticagrelor required a hybrid receptor resembling the agonist-bound P2Y12R except for the top portion of TM6. Supervised molecular dynamics (SuMD) of ticagrelor binding indicated interactions with the extracellular regions of P2Y12R, defining possible meta-binding sites. Ureas, sulfonylureas, sulfonamides, anthraquinones and glutamic acid piperazines docked readily to the antagonist-bound P2Y12R. Docking dinucleotides at both agonist- and antagonist-bound structures suggested interactions with two P2Y12R pockets. Thus, our structure-based approach consistently rationalized the main structure-activity relationships within each ligand class, giving useful information for designing improved ligands.

The Mystery of Io's Warm Polar Regions: Implications for Heat Flow

NASA Technical Reports Server (NTRS)

Matson, D. L.; Veeder, G. J.; Johnson, T. V.; Blaney, D. L.; Davies, A. G.

2002-01-01

Unexpectedly warm polar temperatures further support the idea that Io is covered virtually everywhere by cooling lava flows. This implies a new heat flow component. Io's heat flow remains constrained between a lower bound of (approximately) 2.5 W m(exp -2) and an upper bound of (approximately) 13 W m(exp -2). Additional information is contained in the original extended abstract.

The nature of thinking, shallow and deep

PubMed Central

Brase, Gary L.

2014-01-01

Because the criteria for success differ across various domains of life, no single normative standard will ever work for all types of thinking. One method for dealing with this apparent dilemma is to propose that the mind is made up of a large number of specialized modules. This review describes how this multi-modular framework for the mind overcomes several critical conceptual and theoretical challenges to our understanding of human thinking, and hopefully clarifies what are (and are not) some of the implications based on this framework. In particular, an evolutionarily informed “deep rationality” conception of human thinking can guide psychological research out of clusters of ad hoc models which currently occupy some fields. First, the idea of deep rationality helps theoretical frameworks in terms of orienting themselves with regard to time scale references, which can alter the nature of rationality assessments. Second, the functional domains of deep rationality can be hypothesized (non-exhaustively) to include the areas of self-protection, status, affiliation, mate acquisition, mate retention, kin care, and disease avoidance. Thus, although there is no single normative standard of rationality across all of human cognition, there are sensible and objective standards by which we can evaluate multiple, fundamental, domain-specific motives underlying human cognition and behavior. This review concludes with two examples to illustrate the implications of this framework. The first example, decisions about having a child, illustrates how competing models can be understood by realizing that different fundamental motives guiding people’s thinking can sometimes be in conflict. The second example is that of personifications within modern financial markets (e.g., in the form of corporations), which are entities specifically constructed to have just one fundamental motive. This single focus is the source of both the strengths and flaws in how such entities behave. PMID:24860542

Is poker a skill game? New insights from statistical physics

NASA Astrophysics Data System (ADS)

Javarone, Marco Alberto

2015-06-01

During last years poker has gained a lot of prestige in several countries and, besides being one of the most famous card games, it represents a modern challenge for scientists belonging to different communities, spanning from artificial intelligence to physics and from psychology to mathematics. Unlike games like chess, the task of classifying the nature of poker (i.e., as “skill game” or gambling) seems really hard and it also constitutes a current problem, whose solution has several implications. In general, gambling offers equal winning probabilities both to rational players (i.e., those that use a strategy) and to irrational ones (i.e., those without a strategy). Therefore, in order to uncover the nature of poker, a viable way is comparing performances of rational vs. irrational players during a series of challenges. Recently, a work on this topic revealed that rationality is a fundamental ingredient to succeed in poker tournaments. In this study we analyze a simple model of poker challenges by a statistical physics approach, with the aim to uncover the nature of this game. As main result we found that, under particular conditions, few irrational players can turn poker into gambling. Therefore, although rationality is a key ingredient to succeed in poker, also the format of challenges has an important role in these dynamics, as it can strongly influence the underlying nature of the game. The importance of our results lies on the related implications, as for instance in identifying the limits within which poker can be considered as a “skill game” and, as a consequence, which kind of format must be chosen to devise algorithms able to face humans.

The effects of mortality salience and conceptual focus in CISM providers: implications for mental health response to mass fatality disasters.

PubMed

Morrow, Hope E; Haussmann, Robert

2012-01-01

On the basis of terror management theory (TMT) and cognitive-experiential self-theory (CEST), research has demonstrated that when individuals are experientially (rather than rationally)focused, mortality salience (MS) can engender world view defense in the form of increased in-group bias, increased favoritism toward others who uphold cultural values, and greater derogation of those who threaten them. The goal of the present study was to replicate previously observed effects of mortality salience on world view defense in a sample of disaster responders, specifically Criticallncident Stress Management (CISM) providers, and to examine the potential moderating effect of conceptual mode (rational versus experiential) on these effects. Sixty-two participants at the International Critical Incident Stress Foundation's 2011 World Congress were selected for participation in the study. Subsequent manipulation checks revealed that neither,manipulation (mortality salience: MS versus non-MS or conceptual mode: rational versus experiential) was effective. This failure is discussed in terms of the potentially mortality salient nature of conference proceedings that preceded data collection, the depletion of self-control resources required to maintain a rational focus on conference presentations, participants 'need to maintain their focus during future conference presentations, and profession-related practice effects that may have made it easier for some participants to maintain a rational focus.

Rapid humanitarian assessments and rationality: a value-of-information study from Iraq, 2003-04.

PubMed

Benini, Aldo; Conley, Charles

2007-03-01

Rapid assessments are one of the standard informational tools in humanitarian response and are supposed to contribute to rational decision-making.(1) The extent to which the assessment organisation itself behaves rationally, however, is an open question. This can be evaluated against multiple criteria, such as the cost and value of the information it collects and its ability to adapt flexibly design or samples when the survey environment changes unforeseeably. An unusual data constellation from two concurrent recent (2003-04) rapid assessments in northern Iraq permits us to model part of the actual assessment behaviour in terms of geographical, community and prior substantive information attributes. The model correctly predicts the decisions, in 79 per cent of the 2,425 local communities in focus, that data collector teams in the Emergency Mine Action Survey made to visit or not to visit. The analysis demonstrates variably rational behaviour under conditions of insecurity, repeated regrouping and incomplete sampling frames. A pronounced bias towards very small rural settlements is irrational for the overall results, but may be a rational strategy of individual survey workers seeking to prolong their employment. Implications for future assessments are sketched in the areas of tools for urban surveys, greater adaptability, including early feedback from users, and sensibility to value-of-information concepts.

Irrational reactions to negative outcomes: evidence for two conceptual systems.

PubMed

Epstein, S; Lipson, A; Holstein, C; Huh, E

1992-02-01

According to cognitive-experiential self-theory (CEST), individuals have 2 systems for processing information, a rational system and an experiential system. Research conducted under norm theory (NT) has provided impressive evidence of an if only (IO) effect associated with postoutcome processing of aversive events that are highly consistent with formulations in CEST. Two studies involving vignettes adapted from NT were conducted that tested 4 hypotheses and corollaries derived from CEST. It was demonstrated, in support of hypotheses, that the IO effect can be obtained with ratings of one's own and of a protagonist's specific behaviors, as well as with ratings of a protagonist's diffuse emotions (the usual procedure); that a rational orientation decreases the IO effect; that increasing the intensity of outcomes increases it; and that priming the experiential system reduces people's ability to subsequently think rationally. The theoretical and research implications of these findings are discussed.

Uncomfortable realities: the challenge of creating real change in Europe's consolidating hospital sector.

PubMed

Jeurissen, Patrick; Duran, Antonio; Saltman, Richard B

2016-05-24

This article examines uncomfortable realities that the European hospital sector currently faces and the potential impact of wide-spread rationalization policies such as (hospital) payment reform and privatization. Review of relevant international literature. Based on the evidence we present, rationalization policies such as (hospital) payment reform and privatization will probably fall short in delivering better quality of care and lower growth in health expenses. Reasons can be sought in a mix of evidence on the effectiveness of these rationalization policies. Nevertheless, pressures for different business models will gradually continue to increase and it seems safe to assume that more value-added process business and facilitated network models will eventually emerge. The overall argument of this article holds important implications for future research: how can policymakers generate adequate leverage to introduce such changes without destroying necessary hospital capacity and the ability to produce quality healthcare.

Old Wine in New Bottles--Nursing in the 21st Century.

ERIC Educational Resources Information Center

Bulger, Roger J.

1996-01-01

Discusses what constitutes health care in society, the nature of the healer and healing, and rationing of health care. Outlines foundational values for a health care system: justice, patient autonomy, hope, and mercy, and suggests implications for health professions education. (SK)

Native and Nonnative Speakers' Pragmatic Interpretations of English Texts.

ERIC Educational Resources Information Center

Hinkel, Eli

1994-01-01

Considering the complicating effect of cultural differences in writing conventions, this study examines discourse tradition as influenced by Confucian/Taoist precepts and those of U.S. academic environments, the latter requiring rational argumentation, justification, and proof. Pedagogical implications of native-speaker and nonnative-speaker…

Depression, anxiety, and personal finance behavior: implications for the classical economic conception of humans as rational decision-makers.

PubMed

Lester, David; Yang, Bijou; Spinella, Marcello

2006-12-01

In a sample of 138 college students, the personal finance behaviors of impulse control and organization were negatively associated with the use of recreational drugs and with scores on measures of depression, mania, and anxiety.

Organizational rationality, performance, and social responsibility: results from the hospital industry.

PubMed

Becker, Edmund R; Potter, Sharyn J

2002-01-01

Drawing on stakeholder theory and Weber's distinction between formal and substantive rationality, we posit that: (1) for-profit organizations manage stakeholders in ways that result in the organization being more efficient and less socially responsible than organizations that are not as profit oriented, and (2) organizations with major corporate relationships that are not local manage stakeholders in a manner that results in the organization being more efficient and less socially responsible than organizations without such arrangements. We test these hypotheses with 1994 data on 4,705 of the nation's short-term general hospitals using two measures of hospital efficiency and four measures of social responsibility. Results confirm that for-profit hospitals and hospitals lacking local ties are managing stakeholder relationships in ways that increases the efficiency of these hospitals but decreases their social responsiveness. We conclude by speculating that organizational efficiency and social responsibility may be inversely related and then summarize some of the academic, managerial, and policy implications, with emphasis on the implications for stakeholder theory.

Weak gravity conjecture as a razor criterium for exotic D-brane instantons

NASA Astrophysics Data System (ADS)

Addazi, Andrea

2017-01-01

We discuss implications of weak gravity conjecture (WGC) for exotic D-brane instantons. In particular, WGC leads to indirect stringent bounds on non-perturbative superpotentials generated by exotic instantons with many implications for phenomenology: R-parity violating processes, neutrino mass, μ-problem, neutron-antineutron transitions and collider physics.

Upper bounds on the photon mass

DOE Office of Scientific and Technical Information (OSTI.GOV)

Accioly, Antonio; Group of Field Theory from First Principles, Sao Paulo State University; Instituto de Fisica Teorica

2010-09-15

The effects of a nonzero photon rest mass can be incorporated into electromagnetism in a simple way using the Proca equations. In this vein, two interesting implications regarding the possible existence of a massive photon in nature, i.e., tiny alterations in the known values of both the anomalous magnetic moment of the electron and the gravitational deflection of electromagnetic radiation, are utilized to set upper limits on its mass. The bounds obtained are not as stringent as those recently found; nonetheless, they are comparable to other existing bounds and bring new elements to the issue of restricting the photon mass.

Adsorbate-mediated strong metal–support interactions in oxide-supported Rh catalysts

DOE PAGES

Matsubu, John C.; Zhang, Shuyi; DeRita, Leo; ...

2016-09-19

The optimization of supported metal catalysts predominantly focuses on engineering the metal site, for which physical insights based on extensive theoretical and experimental contributions have enabled the rational design of active sites. Although it is well known that supports can influence the catalytic properties of metals, insights into how metal–support interactions can be exploited to optimize metal active-site properties are lacking. Here in this paper, we utilize in situ spectroscopy and microscopy to identify and characterize a support effect in oxide-supported heterogeneous Rh catalysts. This effect is characterized by strongly bound adsorbates (HCO x) on reducible oxide supports (TiO 2more » and Nb 2O 5) that induce oxygen-vacancy formation in the support and cause HCO x-functionalized encapsulation of Rh nanoparticles by the support. The encapsulation layer is permeable to reactants, stable under the reaction conditions and strongly influences the catalytic properties of Rh, which enables rational and dynamic tuning of CO 2-reduction selectivity.« less

Structure of the Escherichia coli phosphonate binding protein PhnD and rationally optimized phosphonate biosensors.

PubMed

Alicea, Ismael; Marvin, Jonathan S; Miklos, Aleksandr E; Ellington, Andrew D; Looger, Loren L; Schreiter, Eric R

2011-12-02

The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate (Pn) uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by ~70° between the two states. Extensive hydrogen bonding and electrostatic interactions stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into Pn uptake by bacteria and facilitated the rational design of high signal-to-noise Pn biosensors based on both coupled small-molecule dyes and autocatalytic fluorescent proteins. Copyright © 2011 Elsevier Ltd. All rights reserved.

Structure of the Escherichia coli Phosphonate Binding Protein PhnD and Rationally Optimized Phosphonate Biosensors

PubMed Central

Alicea, Ismael; Marvin, Jonathan S.; Miklos, Aleksandr E.; Ellington, Andrew D.; Looger, Loren L.; Schreiter, Eric R.

2012-01-01

The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by ~70° between the two states. Extensive hydrogen bonding and electrostatic interactions stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into phosphonate uptake by bacteria and facilitated the rational design of high signal-to-noise phosphonate biosensors based both on coupled small molecule dyes and autocatalytic fluorescent proteins. PMID:22019591

Attention and choice: a review on eye movements in decision making.

PubMed

Orquin, Jacob L; Mueller Loose, Simone

2013-09-01

This paper reviews studies on eye movements in decision making, and compares their observations to theoretical predictions concerning the role of attention in decision making. Four decision theories are examined: rational models, bounded rationality, evidence accumulation, and parallel constraint satisfaction models. Although most theories were confirmed with regard to certain predictions, none of the theories adequately accounted for the role of attention during decision making. Several observations emerged concerning the drivers and down-stream effects of attention on choice, suggesting that attention processes plays an active role in constructing decisions. So far, decision theories have largely ignored the constructive role of attention by assuming that it is entirely determined by heuristics, or that it consists of stochastic information sampling. The empirical observations reveal that these assumptions are implausible, and that more accurate assumptions could have been made based on prior attention and eye movement research. Future decision making research would benefit from greater integration with attention research. Copyright © 2013 Elsevier B.V. All rights reserved.

Structure of the Escherichia coli Phosphonate Binding Protein PhnD and Rationally Optimized Phosphonate Biosensors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alicea, Ismael; Marvin, Jonathan S.; Miklos, Aleksandr E.

2012-09-17

The phnD gene of Escherichia coli encodes the periplasmic binding protein of the phosphonate (Pn) uptake and utilization pathway. We have crystallized and determined structures of E. coli PhnD (EcPhnD) in the absence of ligand and in complex with the environmentally abundant 2-aminoethylphosphonate (2AEP). Similar to other bacterial periplasmic binding proteins, 2AEP binds near the center of mass of EcPhnD in a cleft formed between two lobes. Comparison of the open, unliganded structure with the closed 2AEP-bound structure shows that the two lobes pivot around a hinge by {approx}70{sup o} between the two states. Extensive hydrogen bonding and electrostatic interactionsmore » stabilize 2AEP, which binds to EcPhnD with low nanomolar affinity. These structures provide insight into Pn uptake by bacteria and facilitated the rational design of high signal-to-noise Pn biosensors based on both coupled small-molecule dyes and autocatalytic fluorescent proteins.« less

Antigenicity and Immunogenicity in HIV-1 Antibody-Based Vaccine Design

PubMed Central

Kong, Leopold; Sattentau, Quentin J

2012-01-01

Neutralizing antibodies can protect from infection by immunodeficiency viruses. However, the induction by active vaccination of antibodies that can potently neutralize a broad range of circulating virus strains is a goal not yet achieved, despite more than 2 decades of research. Here we review progress made in the field, from early empirical studies to today’s rational structure-based vaccine antigen design. We discuss the existence of broadly neutralizing antibodies, their implications for epitope discovery and recent progress made in antigen design. Finally, we consider the relationship between antigenicity and immunogenicity for B cell recognition and antibody production, a major hurdle for rational vaccine design to overcome. PMID:23227445

Communication strategies in cosmetic surgery websites: an application of Taylor's six-segment message strategy wheel.

PubMed

Ahn, Ho-Young Anthony; Wu, Lei; Taylor, Ronald E

2013-01-01

Using Taylor's six-segment message strategy wheel as a theoretical framework, this study examines the communication approach (transmission or ritual) and message strategy (ego, social, sensory, routine, acute need, or ration) of cosmetic surgery websites. A content analysis revealed a fairly even division between transmission and ritual approaches. Ration strategy was the exclusive strategy in the websites adopting a transmission approach. No routine or acute need strategies were observed. Websites incorporating the ritual approach used ego, social, and sensory strategies. Human female models and natural objects were incorporated to deliver emotional persuasion. Implications for cosmetic surgery web marketers are discussed.

Bound states of moving potential wells in discrete wave mechanics

NASA Astrophysics Data System (ADS)

Longhi, S.

2017-10-01

Discrete wave mechanics describes the evolution of classical or matter waves on a lattice, which is governed by a discretized version of the Schrödinger equation. While for a vanishing lattice spacing wave evolution of the continuous Schrödinger equation is retrieved, spatial discretization and lattice effects can deeply modify wave dynamics. Here we discuss implications of breakdown of exact Galilean invariance of the discrete Schrödinger equation on the bound states sustained by a smooth potential well which is uniformly moving on the lattice with a drift velocity v. While in the continuous limit the number of bound states does not depend on the drift velocity v, as one expects from the covariance of ordinary Schrödinger equation for a Galilean boost, lattice effects can lead to a larger number of bound states for the moving potential well as compared to the potential well at rest. Moreover, for a moving potential bound states on a lattice become rather generally quasi-bound (resonance) states.

On Emotion and Rationality: A Response to Barrett.

ERIC Educational Resources Information Center

Steutel, Jan; Dam, Ellis van

1996-01-01

Maintains that recent criticism of cognitive psychologists' conception of irrational emotions as marginal and ephemeral is misguided and inaccurate. Argues that this interpretation is a misstatement of the psychologists' position and analyzes the process resulting in this misinterpretation. Discusses the implications of these arguments for moral…

Left Brain to Right Brain: Notes from the Human Laboratory.

ERIC Educational Resources Information Center

Baumli, Francis

1982-01-01

Examines the implications of the left brain-right brain theory on communications styles in male-female relationships. The author contends that women tend to use the vagueness of their emotional responses manipulatively. Men need to apply rational approaches to increase clarity in communication. (AM)

Thomas S. Kuhn: Revolutionary Theorist of Science

ERIC Educational Resources Information Center

Wade, Nicholas

1977-01-01

Kuhn's theory, that science is heavily influenced by non-rational procedures, and that new theories are viewed as being more complex than those they usurp but do not stand any closer to the truth, is outlined. Included are implications of this theory and criticisms of it. (AJ)

Backbone conformational preferences of an intrinsically disordered protein in solution.

PubMed

Espinoza-Fonseca, L Michel; Ilizaliturri-Flores, Ian; Correa-Basurto, José

2012-06-01

We have performed a 4-μs molecular dynamics simulation to investigate the native conformational preferences of the intrinsically disordered kinase-inducible domain (KID) of the transcription factor CREB in solution. There is solid experimental evidence showing that KID does not possess a bound-like structure in solution; however, it has been proposed that coil-to-helix transitions upon binding to its binding partner (CBP) are template-driven. While these studies indicate that IDPs possess a bias towards the bound structure, they do not provide direct evidence on the time-dependent conformational preferences of IDPs in atomic detail. Our simulation captured intrinsic conformational characteristics of KID that are in good agreement with experimental data such as a very small percentage of helical structure in its segment α(B) and structural disorder in solution. We used dihedral principal component analysis dPCA to map the conformations of KID in the microsecond timescale. By using principal components as reaction coordinates, we further constructed dPCA-based free energy landscapes of KID. Analysis of the free energy landscapes showed that KID is best characterized as a conformational ensemble of rapidly interconverting conformations. Interestingly, we found that despite the conformational heterogeneity of the backbone and the absence of substantial secondary structure, KID does not randomly sample the conformational space in solution: analysis of the (Φ, Ψ) dihedral angles showed that several individual residues of KID possess a strong bias toward the helical region of the Ramachandran plot. We suggest that the intrinsic conformational preferences of KID provide a bias toward the folded state without having to populate bound-like conformations before binding. Furthermore, we argue that these conformational preferences do not represent actual structural constraints which drive binding through a single pathway, which allows for specific interactions with multiple binding partners. Based on this evidence, we propose that the backbone conformational preferences of KID provide a thermodynamic advantage for folding and binding without negatively affecting the kinetics of binding. We further discuss the relation of our results to previous studies to rationalize the functional implications of the conformational preferences of IDPs, such as the optimization of structural disorder in protein-protein interactions. This study illustrates the importance in obtaining atomistic information of intrinsically disordered proteins in real time to reveal functional features arising from their complex conformational space.

A Cross-Cultural Investigation of Gender-Bound Language Use in Turkish and English Plays: Implications for Foreign Language Education

ERIC Educational Resources Information Center

Genc, Zubeyde Sinem; Armagan, Kiymet Selin

2018-01-01

The aim of the study is to investigate gender-bound language use in Turkish and English languages and to identify the differences and similarities across cultures and genders in the plays with family and social themes. Four English and five Turkish plays were chosen randomly for comparison. The number of words in the plays were taken into…

Bohr-Sommerfeld quantization condition for Dirac states derived from an Ermakov-type invariant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thylwe, Karl-Erik; McCabe, Patrick

2013-05-15

It is shown that solutions of the second-order decoupled radial Dirac equations satisfy Ermakov-type invariants. These invariants lead to amplitude-phase-type representations of the radial spinor solutions, with exact relations between their amplitudes and phases. Implications leading to a Bohr-Sommerfeld quantization condition for bound states, and a few particular atomic/ionic and nuclear/hadronic bound-state situations are discussed.

Bounding entanglement spreading after a local quench

NASA Astrophysics Data System (ADS)

Drumond, Raphael C.; Móller, Natália S.

2017-06-01

We consider the variation of von Neumann entropy of subsystem reduced states of general many-body lattice spin systems due to local quantum quenches. We obtain Lieb-Robinson-like bounds that are independent of the subsystem volume. The main assumptions are that the Hamiltonian satisfies a Lieb-Robinson bound and that the volume of spheres on the lattice grows at most exponentially with their radius. More specifically, the bound exponentially increases with time but exponentially decreases with the distance between the subsystem and the region where the quench takes place. The fact that the bound is independent of the subsystem volume leads to stronger constraints (than previously known) on the propagation of information throughout many-body systems. In particular, it shows that bipartite entanglement satisfies an effective "light cone," regardless of system size. Further implications to t density-matrix renormalization-group simulations of quantum spin chains and limitations to the propagation of information are discussed.

Exploring the Influence of Smallholders' Perceptions Regarding Water Availability on Crop Choice and Water Allocation Through Socio-Hydrological Modeling

NASA Astrophysics Data System (ADS)

Kuil, L.; Evans, T.; McCord, P. F.; Salinas, J. L.; Blöschl, G.

2018-04-01

While it is known that farmers adopt different decision-making behaviors to cope with stresses, it remains challenging to capture this diversity in formal model frameworks that are used to advance theory and inform policy. Guided by cognitive theory and the theory of bounded rationality, this research develops a novel, socio-hydrological model framework that can explore how a farmer's perception of water availability impacts crop choice and water allocation. The model is informed by a rich empirical data set at the household level collected during 2013 in Kenya's Upper Ewaso Ng'iro basin that shows that the crop type cultivated is correlated with water availability. The model is able to simulate this pattern and shows that near-optimal or "satisficing" crop patterns can emerge also when farmers were to make use of simple decision rules and have diverse perceptions on water availability. By focusing on farmer decision making it also captures the rebound effect, i.e., as additional water becomes available through the improvement of crop efficiencies it will be reallocated on the farm instead of flowing downstream, as a farmer will adjust his (her) water allocation and crop pattern to the new water conditions. This study is valuable as it is consistent with the theory of bounded rationality, and thus offers an alternative, descriptive model in addition to normative models. The framework can be used to understand the potential impact of climate change on the socio-hydrological system, to simulate and test various assumptions regarding farmer behavior and to evaluate policy interventions.

Reasoning and memory: People make varied use of the information available in working memory.

PubMed

Hardman, Kyle O; Cowan, Nelson

2016-05-01

Working memory (WM) is used for storing information in a highly accessible state so that other mental processes, such as reasoning, can use that information. Some WM tasks require that participants not only store information, but also reason about that information to perform optimally on the task. In this study, we used visual WM tasks that had both storage and reasoning components to determine both how ideally people are able to reason about information in WM and if there is a relationship between information storage and reasoning. We developed novel psychological process models of the tasks that allowed us to estimate for each participant both how much information they had in WM and how efficiently they reasoned about that information. Our estimates of information use showed that participants are not all ideal information users or minimal information users, but rather that there are individual differences in the thoroughness of information use in our WM tasks. However, we found that our participants tended to be more ideal than minimal. One implication of this work is that to accurately estimate the amount of information in WM, it is important to also estimate how efficiently that information is used. This new analysis contributes to the theoretical premise that human rationality may be bounded by the complexity of task demands. (PsycINFO Database Record (c) 2016 APA, all rights reserved).

Emerging strategies for EphA2 receptor targeting for cancer therapeutics.

PubMed

Tandon, Manish; Vemula, Sai Vikram; Mittal, Suresh K

2011-01-01

High mortality rates with cancers warrant further development of earlier diagnostics and better treatment strategies. Membrane-bound erythropoietin-producing hepatocellular receptor tyrosine kinase class A2 (EphA2) is overexpressed in breast, prostate, urinary bladder, skin, lung, ovary and brain cancers. EphA2 overexpression in cancers, its signaling mechanisms and strategies to target its deregulation. High EphA2 expression in cancer cells is correlated with a poor prognosis associated with recurrence due to enhanced metastasis. Interaction of the EphA2 receptor with its ligand (e.g., ephrinA1) triggers events that are deregulated and implicated in carcinogenesis. EphrinA1-independent oncogenic activity and ephrinA1-dependent tumor suppressor roles for EphA2 are described. Molecular interactions of EphA2 with signaling proteins are associated with the modulation of cytoskeleton dynamics, cell adhesion, proliferation, differentiation and metastasis. The deregulated signaling by EphA2 and its involvement in oncogenesis provide multiple avenues for the rational design of intervention approaches. EphA2 has been tested as a drug target using multiple approaches such as agonist antibodies, RNA interference, immunotherapy, virus vector-mediated gene transfer, small-molecule inhibitors and nanoparticles. With over a decade of research, encouraging results with targeting of EphA2 expression in various pre-clinical cancer models necessitate further studies.

Reasoning and memory: People make varied use of the information available in working memory

PubMed Central

Hardman, Kyle O.; Cowan, Nelson

2015-01-01

Working memory (WM) is used for storing information in a highly-accessible state so that other mental processes, such as reasoning, can use that information. Some WM tasks require that participants not only store information, but also reason about that information in order to perform optimally on the task. In this study, we used visual WM tasks that had both storage and reasoning components in order to determine both how ideally people are able to reason about information in WM and if there is a relationship between information storage and reasoning. We developed novel psychological process models of the tasks that allowed us to estimate for each participant both how much information they had in WM and how efficiently they reasoned about that information. Our estimates of information use showed that participants are not all ideal information users or minimal information users, but rather that there are individual differences in the thoroughness of information use in our WM tasks. However, we found that our participants tended to be more ideal than minimal. One implication of this work is that in order to accurately estimate the amount of information in WM, it is important to also estimate how efficiently that information is used. This new analysis contributes to the theoretical premise that human rationality may be bounded by the complexity of task demands. PMID:26569436

Evolutionary continuity and personhood: Legal and therapeutic implications of animal consciousness and human unconsciousness.

PubMed

Benvenuti, Anne

Convergent lines of research in the biological sciences have made obsolete the commonly held assumption that humans are distinct from and superior to all other animals, a development predicted by evolutionary science. Cumulative evidence has both elevated other animals from the status of "dumb brutes" to that of fully sentient and intentional beings and has simultaneously discredited elevated claims of human rationality, intentionality, and freedom from the constraints experienced by other animals. It follows then that any theoretical model in which humans occupy the top of an imagined evolutionary hierarchy is untenable. This simple fact calls for a rethinking of foundational concepts in law and health sciences. A further cultural fallacy that is exposed by these converging lines of scientific evidence is the notion that the subjective inner and abstract dimension of human beings is the most true and valuable level of analysis for organizing human lives. In fact, our individual and collective minds are particularly vulnerable to elaborated false narratives that may be definitive of the particular forms of suffering that humans experience and seek to heal with modalities like psychoanalytic psychotherapies. I conclude with the suggestion that other animals may have the capacity to help us with this healing project, even as we are ethically bound to heal the suffering that we have collectively imposed upon them. Copyright © 2016 Elsevier Ltd. All rights reserved.

Experiential and rational decision making: a survey to determine how emergency physicians make clinical decisions.

PubMed

Calder, Lisa A; Forster, Alan J; Stiell, Ian G; Carr, Laura K; Brehaut, Jamie C; Perry, Jeffrey J; Vaillancourt, Christian; Croskerry, Patrick

2012-10-01

Dual-process psychological theories argue that clinical decision making is achieved through a combination of experiential (fast and intuitive) and rational (slower and systematic) cognitive processes. To determine whether emergency physicians perceived their clinical decisions in general to be more experiential or rational and how this compared with other physicians. A validated psychometric tool, the Rational Experiential Inventory (REI-40), was sent through postal mail to all emergency physicians registered with the College of Physicians and Surgeons of Ontario, according to their website in November 2009. Forty statements were ranked on a Likert scale from 1 (Definitely False) to 5 (Definitely True). An initial survey was sent out, followed by reminder cards and a second survey to non-respondents. Analysis included descriptive statistics, Student t tests, analysis of variance and comparison of mean scores with those of cardiologists from New Zealand. The response rate in this study was 46.9% (434/925). The respondents' median age was 41-50 years; they were mostly men (72.6%) and most had more than 10 years of clinical experience (66.8%). The mean REI-40 rational scores were higher than the experiential scores (3.93/5 (SD 0.35) vs 3.33/5 (SD 0.49), p<0.0001), similar to the mean scores of cardiologists from New Zealand (mean rational 3.93/5, mean experiential 3.05/5). The mean experiential scores were significantly higher for female respondents than for male respondents (3.40/5 (SD 0.49) vs 3.30/5 (SD 0.48), p=0.003). Overall, emergency physicians favoured rational decision making rather than experiential decision making; however, female emergency physicians had higher experiential scores than male emergency physicians. This has important implications for future knowledge translation and decision support efforts among emergency physicians.

Making Citizens Governable? The Crick Report as Governmental Technology

ERIC Educational Resources Information Center

Pykett, Jessica

2007-01-01

This paper considers the recent introduction of Citizenship Education in England from a governmental perspective, drawing on the later work of Foucault to offer a detailed account of the political rationalities, technologies and subjectivities implicated in contemporary education policy in the formation and governance of citizen-subjects. This is…

The Autonomous Self vs. the Relational Self: Implications for Clinical Assessment and Treatment in Child Psychotherapy.

ERIC Educational Resources Information Center

Atwood, Richard; Safyer, Andrew W.

1993-01-01

Reviews and discusses the debate between the traditional psychoanalytic perspective on separation-individuation and the newer "rational" view of self-development. Finds each have equal importance both for understanding psychopathology and for providing effective and empathically-attuned psychotherapy. Provides clinical vignettes derived…

Humanism and the Sciences: Monogamy, Polygamy, and Sociobiology.

ERIC Educational Resources Information Center

Saladin, Kenneth S.

1981-01-01

Portrays sociobiology in a rational light and examines its human implications in the area of sexual selection and mating systems. Sociobiology is the analysis of social behavior in terms of its revolutionary and genetic origins and consequences. Concludes with a discussion of the potential contributions of sociobiology toward understanding of…

The Interplay of Scientific Activity, Worldviews and Value Outlooks

ERIC Educational Resources Information Center

Lacey, Hugh

2009-01-01

Scientific activity tends to reflect particular worldviews and their associated value outlooks; and scientific results sometimes have implications for worldviews and the presuppositions of value outlooks. Even so, scientific activity per se neither presupposes nor provides sound rational grounds to accept any worldview or value outlook. Moreover,…

Toward an Expanded Definition of Adaptive Decision Making.

ERIC Educational Resources Information Center

Phillips, Susan D.

1997-01-01

Uses the lifespan, life-space model to examine the definition of adaptive decision making. Reviews the existing definition of adaptive decision making as "rational" decision making and offers alternate perspectives on decision making with an emphasis on the implications of using the model. Makes suggestions for future theory, research,…

Emerging Perspectives on Organizational Behavior: Implications for Institutional Researchers.

ERIC Educational Resources Information Center

Schmidtlein, Frank A.

1999-01-01

Examines common assumptions about the rationality or irrationality of organizational behavior and finds that decision making occurs in a complex context that successful college/university institutional research offices must recognize and work with. Finds that emerging organizational theories suggest there are limitations on the use of data and…

Carelessness: A Hidden Doxa of Higher Education

ERIC Educational Resources Information Center

Lynch, Kathleen

2010-01-01

This article explores the implications of new public sector "reforms" for the culture of higher education. It argues that a culture of carelessness, grounded in Cartesian rationalism, has been exacerbated by new managerialism. The article challenges a prevailing sociological assumption that the character of higher education culture is primarily…

The Option of Rationality in the Source of Joy of Life.

ERIC Educational Resources Information Center

Bondergaard, Jette

1998-01-01

Examines challenges arising from a growing consciousness of environmental problems and their implications for education in general and for early childhood education specifically. Argues that cultures should consider both human rights and environmental protection, that they need to develop solidarity and create peaceful ways of living. Maintains…

Economic theory and evidence on smoking behavior of adults.

PubMed

Sloan, Frank A; Wang, Yang

2008-11-01

To describe: (i) three alternative conceptual frameworks used by economists to study addictive behaviors: rational, imperfectly rational and irrational addiction; (ii) empirical economic evidence on each framework and specific channels to explain adult smoking matched to the frameworks; and (iii) policy implications for each framework. A systematic review and appraisal of important theoretical and empirical economic studies on smoking. There is some empirical support for each framework. For rational and imperfectly rational addiction there is some evidence that anticipated future cigarette prices influence current cigarette consumption, and quitting costs are high for smokers. Smokers are more risk-tolerant in the financial domain than are others and tend to attach a lower value to being in good health. Findings on differences in rates of time preference by smoking status are mixed; however, short-term rates are higher than long-term rates for both smokers and non-smokers, a stylized fact consistent with hyperbolic discounting. The economic literature lends no empirical support to the view that mature adults smoke because they underestimate the probability of harm to health from smoking. In support of the irrationality framework, smokers tend to be more impulsive than others in domains not related directly to smoking, implying that they may be sensitive to cues that trigger smoking. Much promising economic research uses the imperfectly rational addiction framework, but empirical research based on this framework is still in its infancy.

The Impact of Menstrual Cycle Phase on Economic Choice and Rationality.

PubMed

Lazzaro, Stephanie C; Rutledge, Robb B; Burghart, Daniel R; Glimcher, Paul W

2016-01-01

It is well known that hormones affect both brain and behavior, but less is known about the extent to which hormones affect economic decision-making. Numerous studies demonstrate gender differences in attitudes to risk and loss in financial decision-making, often finding that women are more loss and risk averse than men. It is unclear what drives these effects and whether cyclically varying hormonal differences between men and women contribute to differences in economic preferences. We focus here on how economic rationality and preferences change as a function of menstrual cycle phase in women. We tested adherence to the Generalized Axiom of Revealed Preference (GARP), the standard test of economic rationality. If choices satisfy GARP then there exists a well-behaved utility function that the subject's decisions maximize. We also examined whether risk attitudes and loss aversion change as a function of cycle phase. We found that, despite large fluctuations in hormone levels, women are as technically rational in their choice behavior as their male counterparts at all phases of the menstrual cycle. However, women are more likely to choose risky options that can lead to potential losses while ovulating; during ovulation women are less loss averse than men and therefore more economically rational than men in this regard. These findings may have market-level implications: ovulating women more effectively maximize expected value than do other groups.

The Impact of Menstrual Cycle Phase on Economic Choice and Rationality

PubMed Central

Lazzaro, Stephanie C.; Rutledge, Robb B.; Burghart, Daniel R.; Glimcher, Paul W.

2016-01-01

It is well known that hormones affect both brain and behavior, but less is known about the extent to which hormones affect economic decision-making. Numerous studies demonstrate gender differences in attitudes to risk and loss in financial decision-making, often finding that women are more loss and risk averse than men. It is unclear what drives these effects and whether cyclically varying hormonal differences between men and women contribute to differences in economic preferences. We focus here on how economic rationality and preferences change as a function of menstrual cycle phase in women. We tested adherence to the Generalized Axiom of Revealed Preference (GARP), the standard test of economic rationality. If choices satisfy GARP then there exists a well-behaved utility function that the subject’s decisions maximize. We also examined whether risk attitudes and loss aversion change as a function of cycle phase. We found that, despite large fluctuations in hormone levels, women are as technically rational in their choice behavior as their male counterparts at all phases of the menstrual cycle. However, women are more likely to choose risky options that can lead to potential losses while ovulating; during ovulation women are less loss averse than men and therefore more economically rational than men in this regard. These findings may have market-level implications: ovulating women more effectively maximize expected value than do other groups. PMID:26824245

Optimal vaccination choice, vaccination games, and rational exemption: an appraisal.

PubMed

Manfredi, Piero; Posta, Pompeo Della; d'Onofrio, Alberto; Salinelli, Ernesto; Centrone, Francesca; Meo, Claudia; Poletti, Piero

2009-12-10

A threat for vaccination policies might be the onset of "rational" exemption, i.e. the family's decision not to vaccinate children after a seemingly rational comparison between the perceived risk of infection and the perceived risk of vaccine side effects. We study the implications of rational exemption by models of vaccination choice. By a simple model of individual choice we first prove the "elimination impossible" result in presence of informed families, i.e. aware of herd immunity, and suggest that limited information might explain patterns of universal vaccination. Next, we investigate vaccination choice in a game-theoretic framework for communities stratified into two groups, "pro" and "anti" vaccinators, having widely different perceived costs of infection and of vaccine side effects. We show that under informed families neither a Nash nor a Stackelberg behaviour (characterized, respectively, by players acting simultaneously and by an asymmetric situation with a "leader" and a "follower) allow elimination, unless "pro-vaccinators" assign no costs to vaccine side effects. Elimination turns out to be possible when cooperation is encouraged by a social planner, provided, however, he incorporates in the "social loss function" the preferences of anti-vaccinators only. This allows an interpretation of the current Italian vaccination policy.

Modeling Human Decision Processes in Command and Control

DTIC Science & Technology

1983-02-14

principle , calculus of variations, least squares, etc. 7 SALPHATECH, INC. Thus, the...34"""~~~~~~~~~~~~~~~~~. ." -. " ""’./’ ’ • "" -" - -".. "-.... •..... ""........."-. -....... -.............. r ALPHATECH, INC. to equate what a human does with what he should do. Employing this principle "of bounded rationality, the norm’tive-descriptive...mechanism to describe these salient task features. In essence, the SHOR paradigm is derived from the stimulus-response (S-R) principle

Emotion-affected decision making in human simulation.

PubMed

Zhao, Y; Kang, J; Wright, D K

2006-01-01

Human modelling is an interdisciplinary research field. The topic, emotion-affected decision making, was originally a cognitive psychology issue, but is now recognized as an important research direction for both computer science and biomedical modelling. The main aim of this paper is to attempt to bridge the gap between psychology and bioengineering in emotion-affected decision making. The work is based on Ortony's theory of emotions and bounded rationality theory, and attempts to connect the emotion process with decision making. A computational emotion model is proposed, and the initial framework of this model in virtual human simulation within the platform of Virtools is presented.

Modeling the stylized facts in finance through simple nonlinear adaptive systems

PubMed Central

Hommes, Cars H.

2002-01-01

Recent work on adaptive systems for modeling financial markets is discussed. Financial markets are viewed as evolutionary systems between different, competing trading strategies. Agents are boundedly rational in the sense that they tend to follow strategies that have performed well, according to realized profits or accumulated wealth, in the recent past. Simple technical trading rules may survive evolutionary competition in a heterogeneous world where prices and beliefs co-evolve over time. Evolutionary models can explain important stylized facts, such as fat tails, clustered volatility, and long memory, of real financial series. PMID:12011401

Rotation sets and phase-locking in an electronic three oscillator system

NASA Astrophysics Data System (ADS)

Ashwin, Peter; Guaschi, John; Phelps, J. M.

1993-07-01

The parameter space of an electronic three oscillator system is investigated and various codimension one and two bifurcations predicted by Baesens, Guckenheimer, Kim and MacKay are identified. Sampled time-series from the experimental systems are recorded and analysed for partial mode-locking or resonance (one or two independent rational relations between the average rates of change of the angles describing the system) using knowledge of where the invariant torus lies and the torus unfolding scheme of Ashwin and Swift. Examples of toroidal and annular chaos are investigated by finding bounds on the size and shape of the rotation set.

Design of a small molecule against an oncogenic noncoding RNA.

PubMed

Velagapudi, Sai Pradeep; Cameron, Michael D; Haga, Christopher L; Rosenberg, Laura H; Lafitte, Marie; Duckett, Derek R; Phinney, Donald G; Disney, Matthew D

2016-05-24

The design of precision, preclinical therapeutics from sequence is difficult, but advances in this area, particularly those focused on rational design, could quickly transform the sequence of disease-causing gene products into lead modalities. Herein, we describe the use of Inforna, a computational approach that enables the rational design of small molecules targeting RNA to quickly provide a potent modulator of oncogenic microRNA-96 (miR-96). We mined the secondary structure of primary microRNA-96 (pri-miR-96) hairpin precursor against a database of RNA motif-small molecule interactions, which identified modules that bound RNA motifs nearby and in the Drosha processing site. Precise linking of these modules together provided Targaprimir-96 (3), which selectively modulates miR-96 production in cancer cells and triggers apoptosis. Importantly, the compound is ineffective on healthy breast cells, and exogenous overexpression of pri-miR-96 reduced compound potency in breast cancer cells. Chemical Cross-Linking and Isolation by Pull-Down (Chem-CLIP), a small-molecule RNA target validation approach, shows that 3 directly engages pri-miR-96 in breast cancer cells. In vivo, 3 has a favorable pharmacokinetic profile and decreases tumor burden in a mouse model of triple-negative breast cancer. Thus, rational design can quickly produce precision, in vivo bioactive lead small molecules against hard-to-treat cancers by targeting oncogenic noncoding RNAs, advancing a disease-to-gene-to-drug paradigm.

Précis of Simple heuristics that make us smart.

PubMed

Todd, P M; Gigerenzer, G

2000-10-01

How can anyone be rational in a world where knowledge is limited, time is pressing, and deep thought is often an unattainable luxury? Traditional models of unbounded rationality and optimization in cognitive science, economics, and animal behavior have tended to view decision-makers as possessing supernatural powers of reason, limitless knowledge, and endless time. But understanding decisions in the real world requires a more psychologically plausible notion of bounded rationality. In Simple heuristics that make us smart (Gigerenzer et al. 1999), we explore fast and frugal heuristics--simple rules in the mind's adaptive toolbox for making decisions with realistic mental resources. These heuristics can enable both living organisms and artificial systems to make smart choices quickly and with a minimum of information by exploiting the way that information is structured in particular environments. In this précis, we show how simple building blocks that control information search, stop search, and make decisions can be put together to form classes of heuristics, including: ignorance-based and one-reason decision making for choice, elimination models for categorization, and satisficing heuristics for sequential search. These simple heuristics perform comparably to more complex algorithms, particularly when generalizing to new data--that is, simplicity leads to robustness. We present evidence regarding when people use simple heuristics and describe the challenges to be addressed by this research program.

Time scales of supercooled water and implications for reversible polyamorphism

NASA Astrophysics Data System (ADS)

Limmer, David T.; Chandler, David

2015-09-01

Deeply supercooled water exhibits complex dynamics with large density fluctuations, ice coarsening and characteristic time scales extending from picoseconds to milliseconds. Here, we discuss implications of these time scales as they pertain to two-phase coexistence and to molecular simulations of supercooled water. Specifically, we argue that it is possible to discount liquid-liquid criticality because the time scales imply that correlation lengths for such behaviour would be bounded by no more than a few nanometres. Similarly, it is possible to discount two-liquid coexistence because the time scales imply a bounded interfacial free energy that cannot grow in proportion to a macroscopic surface area. From time scales alone, therefore, we see that coexisting domains of differing density in supercooled water can be no more than nanoscale transient fluctuations.

IR signature of the photoionization-induced hydrophobic-->hydrophilic site switching in phenol-Arn clusters

NASA Astrophysics Data System (ADS)

Ishiuchi, Shun-ichi; Sakai, Makoto; Tsuchida, Yuji; Takeda, Akihiro; Kawashima, Yasutake; Dopfer, Otto; Müller-Dethlefs, Klaus; Fujii, Masaaki

2007-09-01

IR spectra of phenol-Arn (PhOH-Arn) clusters with n =1 and 2 were measured in the neutral and cationic electronic ground states in order to determine the preferential intermolecular ligand binding motifs, hydrogen bonding (hydrophilic interaction) versus π bonding (hydrophobic interaction). Analysis of the vibrational frequencies of the OH stretching motion, νOH, observed in nanosecond IR spectra demonstrates that neutral PhOH-Ar and PhOH -Ar2 as well as cationic PhOH +-Ar have a π-bound structure, in which the Ar atoms bind to the aromatic ring. In contrast, the PhOH +-Ar2 cluster cation is concluded to have a H-bound structure, in which one Ar atom is hydrogen-bonded to the OH group. This π →H binding site switching induced by ionization was directly monitored in real time by picosecond time-resolved IR spectroscopy. The π-bound νOH band is observed just after the ionization and disappears simultaneously with the appearance of the H-bound νOH band. The analysis of the picosecond IR spectra demonstrates that (i) the π →H site switching is an elementary reaction with a time constant of ˜7ps, which is roughly independent of the available internal vibrational energy, (ii) the barrier for the isomerization reaction is rather low(<100cm-1), (iii) both the position and the width of the H-bound νOH band change with the delay time, and the time evolution of these spectral changes can be rationalized by intracluster vibrational energy redistribution occurring after the site switching. The observation of the ionization-induced switch from π bonding to H bonding in the PhOH +-Ar2 cation corresponds to the first manifestation of an intermolecular isomerization reaction in a charged aggregate.

Designed Long-Lived Emission from CdSe Quantum Dots through Reversible Electronic Energy Transfer with a Surface-Bound Chromophore.

PubMed

La Rosa, Marcello; Denisov, Sergey A; Jonusauskas, Gediminas; McClenaghan, Nathan D; Credi, Alberto

2018-03-12

The size-tunable emission of luminescent quantum dots (QDs) makes them highly interesting for applications that range from bioimaging to optoelectronics. For the same applications, engineering their luminescence lifetime, in particular, making it longer, would be as important; however, no rational approach to reach this goal is available to date. We describe a strategy to prolong the emission lifetime of QDs through electronic energy shuttling to the triplet excited state of a surface-bound molecular chromophore. To implement this idea, we made CdSe QDs of different sizes and carried out self-assembly with a pyrene derivative. We observed that the conjugates exhibit delayed luminescence, with emission decays that are prolonged by more than 3 orders of magnitude (lifetimes up to 330 μs) compared to the parent CdSe QDs. The mechanism invokes unprecedented reversible quantum dot to organic chromophore electronic energy transfer. © 2018 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matthews, Melissa M.; Thomas, Justin M.; Zheng, Yuxuan

Adenosine deaminases acting on RNA (ADARs) are editing enzymes that convert adenosine to inosine in duplex RNA, a modification reaction with wide-ranging consequences in RNA function. Understanding of the ADAR reaction mechanism, the origin of editing-site selectivity, and the effect of mutations is limited by the lack of high-resolution structural data for complexes of ADARs bound to substrate RNAs. In this paper, we describe four crystal structures of the human ADAR2 deaminase domain bound to RNA duplexes bearing a mimic of the deamination reaction intermediate. These structures, together with structure-guided mutagenesis and RNA-modification experiments, explain the basis of the ADARmore » deaminase domain's dsRNA specificity, its base-flipping mechanism, and its nearest-neighbor preferences. In addition, we identified an ADAR2-specific RNA-binding loop near the enzyme active site, thus rationalizing differences in selectivity observed between different ADARs. In conclusion, our results provide a structural framework for understanding the effects of ADAR mutations associated with human disease.« less

Parametric symmetries in exactly solvable real and PT symmetric complex potentials

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yadav, Rajesh Kumar, E-mail: rajeshastrophysics@gmail.com; Khare, Avinash, E-mail: khare@physics.unipune.ac.in; Bagchi, Bijan, E-mail: bbagchi123@gmail.com

In this paper, we discuss the parametric symmetries in different exactly solvable systems characterized by real or complex PT symmetric potentials. We focus our attention on the conventional potentials such as the generalized Pöschl Teller (GPT), Scarf-I, and PT symmetric Scarf-II which are invariant under certain parametric transformations. The resulting set of potentials is shown to yield a completely different behavior of the bound state solutions. Further, the supersymmetric partner potentials acquire different forms under such parametric transformations leading to new sets of exactly solvable real and PT symmetric complex potentials. These potentials are also observed to be shape invariantmore » (SI) in nature. We subsequently take up a study of the newly discovered rationally extended SI potentials, corresponding to the above mentioned conventional potentials, whose bound state solutions are associated with the exceptional orthogonal polynomials (EOPs). We discuss the transformations of the corresponding Casimir operator employing the properties of the so(2, 1) algebra.« less

[The effect of copper on the metabolism of iodine, carbohydrates and proteins in rats].

PubMed

Esipenko, B E; Marsakova, N V

1990-01-01

Experiments on 156 rats maintained at ration with copper deficiency have demonstrated a decrease in the values of iodine metabolism in organs and tissues excluding the liver where a sharp increase in the concentration and content of inorganic iodine was observed. A disturbance in indices of carbohydrate and proteins metabolism in the organism of animals is marked. A direct relationship with a correlation coefficient equaling 0.87-1.00 is determined between changes in the concentration of protein-bound iodine in blood and concentration of glycogen in the liver, skeletal muscles, albumins, alpha 1-, alpha 2-globulins, urea concentration; an inverse relationship with glucose, activity of blood lipo-dehydrogenase and liver mitochondria, aldolase, concentration of pyruvic and lactic acids is established as well. It is concluded that copper deficiency can exert both a direct effect on metabolic processes (as data from literature testify) and an indirect one disturbing iodine metabolism, i. e. sharply decreasing protein-bound iodine production by the thyroid gland.

Thermodynamic dissection of the binding energetics of proline-rich peptides to the Abl-SH3 domain: implications for rational ligand design.

PubMed

Palencia, Andrés; Cobos, Eva S; Mateo, Pedro L; Martínez, Jose C; Luque, Irene

2004-02-13

The inhibition of the interactions between SH3 domains and their targets is emerging as a promising therapeutic strategy. To date, rational design of potent ligands for these domains has been hindered by the lack of understanding of the origins of the binding energy. We present here a complete thermodynamic analysis of the binding energetics of the p41 proline-rich decapeptide (APSYSPPPPP) to the SH3 domain of the c-Abl oncogene. Isothermal titration calorimetry experiments have revealed a thermodynamic signature for this interaction (very favourable enthalpic contributions opposed by an unfavourable binding entropy) inconsistent with the highly hydrophobic nature of the p41 ligand and the Abl-SH3 binding site. Our structural and thermodynamic analyses have led us to the conclusion, having once ruled out any possible ionization events or conformational changes coupled to the association, that the establishment of a complex hydrogen-bond network mediated by water molecules buried at the binding interface is responsible for the observed thermodynamic behaviour. The origin of the binding energetics for proline-rich ligands to the Abl-SH3 domain is further investigated by a comparative calorimetric analysis of a set of p41-related ligands. The striking effects upon the enthalpic and entropic contributions provoked by conservative substitutions at solvent-exposed positions in the ligand confirm the complexity of the interaction. The implications of these results for rational ligand design are discussed.

New Insights into the Pathogenesis of MDS and the rational therapeutic opportunities.

PubMed

Abou Zahr, Abdallah; Bernabe Ramirez, Carolina; Wozney, Jocelyn; Prebet, Thomas; Zeidan, Amer M

2016-01-01

Myelodysplastic syndromes (MDS) include a heterogeneous group of acquired hematopoietic malignancies characterized by ineffective hematopoiesis, peripheral cytopenias, and a varying propensity for progression to acute myeloid leukemia. The clinical heterogeneity in MDS is a reflection of its molecular heterogeneity. Better understanding of aberrant epigenetics, dysregulation of immune responses, and del(5q) MDS has provided the rationale for well-established treatments in MDS. Further understanding of abnormal signal transduction and aberrant apoptosis pathways has led to development of new rational therapies that are in advanced phases of clinical translation. This review seeks to describe recent developments in our understanding of the pathogenesis of MDS and the potential therapeutic implications of these observations.

Rosetta comparative modeling for library design: Engineering alternative inducer specificity in a transcription factor.

PubMed

Jha, Ramesh K; Chakraborti, Subhendu; Kern, Theresa L; Fox, David T; Strauss, Charlie E M

2015-07-01

Structure-based rational mutagenesis for engineering protein functionality has been limited by the scarcity and difficulty of obtaining crystal structures of desired proteins. On the other hand, when high-throughput selection is possible, directed evolution-based approaches for gaining protein functionalities have been random and fortuitous with limited rationalization. We combine comparative modeling of dimer structures, ab initio loop reconstruction, and ligand docking to select positions for mutagenesis to create a library focused on the ligand-contacting residues. The rationally reduced library requirement enabled conservative control of the substitutions by oligonucleotide synthesis and bounding its size within practical transformation efficiencies (∼ 10(7) variants). This rational approach was successfully applied on an inducer-binding domain of an Acinetobacter transcription factor (TF), pobR, which shows high specificity for natural effector molecule, 4-hydroxy benzoate (4HB), but no native response to 3,4-dihydroxy benzoate (34DHB). Selection for mutants with high transcriptional induction by 34DHB was carried out at the single-cell level under flow cytometry (via green fluorescent protein expression under the control of pobR promoter). Critically, this selection protocol allows both selection for induction and rejection of constitutively active mutants. In addition to gain-of-function for 34DHB induction, the selected mutants also showed enhanced sensitivity and response for 4HB (native inducer) while no sensitivity was observed for a non-targeted but chemically similar molecule, 2-hydroxy benzoate (2HB). This is unique application of the Rosetta modeling protocols for library design to engineer a TF. Our approach extends applicability of the Rosetta redesign protocol into regimes without a priori precision structural information. © 2015 Wiley Periodicals, Inc.

Bounds on graviton mass using weak lensing and SZ effect in galaxy clusters

NASA Astrophysics Data System (ADS)

Rana, Akshay; Jain, Deepak; Mahajan, Shobhit; Mukherjee, Amitabha

2018-06-01

In General Relativity (GR), the graviton is massless. However, a common feature in several theoretical alternatives of GR is a non-zero mass for the graviton. These theories can be described as massive gravity theories. Despite many theoretical complexities in these theories, on phenomenological grounds the implications of massive gravity have been widely used to put bounds on graviton mass. One of the generic implications of giving a mass to the graviton is that the gravitational potential will follow a Yukawa-like fall off. We use this feature of massive gravity theories to probe the mass of graviton by using the largest gravitationally bound objects, namely galaxy clusters. In this work, we use the mass estimates of galaxy clusters measured at various cosmologically defined radial distances measured via weak lensing (WL) and Sunyaev-Zel'dovich (SZ) effect. We also use the model independent values of Hubble parameter H (z) smoothed by a non-parametric method, Gaussian process. Within 1σ confidence region, we obtain the mass of graviton mg < 5.9 ×10-30 eV with the corresponding Compton length scale λg > 6.82 Mpc from weak lensing and mg < 8.31 ×10-30 eV with λg > 5.012 Mpc from SZ effect. This analysis improves the upper bound on graviton mass obtained earlier from galaxy clusters.

Dual processing and organizational justice: the role of rational versus experiential processing in third-party reactions to workplace mistreatment.

PubMed

Skarlicki, Daniel P; Rupp, Deborah E

2010-09-01

The moral perspective of justice proposes that when confronted by another person's mistreatment, third parties can experience a deontic response, that is, an evolutionary-based emotional reaction that motivates them to engage in retribution toward the transgressor. In this article, we tested whether the third party's deontic reaction is less strong when a rational (vs. experiential) processing frame is primed. Further, we tested whether third parties high (vs. low) in moral identity are more resistant to the effects of processing frames. Results from a sample of 185 French managers revealed that following an injustice, managers primed to use rational processing reported lower retribution tendencies compared with managers primed to use experiential processing. Third parties high in moral identity, however, were less affected by the framing; they reported a high retribution response regardless of processing frame. Theoretical and practical implications of these findings are discussed. Copyright 2010 APA, all rights reserved

The effects of rational and experiential information processing of expert testimony in death penalty cases.

PubMed

Krauss, Daniel A; Lieberman, Joel D; Olson, Jodi

2004-01-01

Past research examining the effects of actuarial and clinical expert testimony on defendants' dangerousness in Texas death penalty sentencing has found that jurors are more influenced by less scientific pure clinical expert testimony and less influenced by more scientific actuarial expert testimony (Krauss & Lee, 2003; Krauss & Sales, 2001). By applying cognitive-experiential self-theory (CEST) to juror decision-making, the present study was undertaken in an attempt to offer a theoretical rationale for these findings. Based on past CEST research, 163 mock jurors were either directed into a rational mode or experiential mode of processing. Consistent with CEST and inconsistent with previous research using the same stimulus materials, results demonstrate that jurors in a rational mode of processing more heavily weighted actuarial expert testimony in their dangerousness assessments, while those jurors in the experiential condition were more influenced by clinical expert testimony. The policy implications of these findings are discussed. Copyright 2004 John Wiley & Sons, Ltd.

Assessing Irrational Beliefs and Emotional Distress: Evidence and Implications of Limited Discriminant Validity.

ERIC Educational Resources Information Center

Zurawski, Raymond M.; Smith, Timothy W.

1987-01-01

Examined the disciminant validity of measures of irrational beliefs. The Irrational Beliefs Test and the Rational Behavior Inventory were highly correlated but were equally highly correlated with self-report measures of depression and anxiety. Thus, rather than assessing beliefs correlated with emotional distress, the measures may actually assess…

Development of partial ontogenic resistance to powdery mildew in Hop cones and its management implications

USDA-ARS?s Scientific Manuscript database

Knowledge of processes leading to crop damage is central to devising rational approaches to disease management. Multiple experiments established that infection of hop cones by Podosphaera macularis was most severe if inoculation occurred within 15 to 21 days after bloom. This period of infection was...

The Barriers to Achieving the Wider Goals of General Education and Their Implications for the British Educational Research Association.

ERIC Educational Resources Information Center

Raven, John

1990-01-01

Advocates revamping the British educational system from technical-rational content model to student-centered process programs designed to promote critical thinking, individual initiative, and communication skills. Discusses obstacles to this educational reform, emphasizing research orientation. Urges the British Educational Research Association to…

Educational Planning and Models of Decision-Making.

ERIC Educational Resources Information Center

Crowson, Robert L.

This paper suggests that a first, important, step toward a broadening of the skills of the educational planner is a clear conceptualization of some implications that accompany differing styles of decision-making. It has been suggested that planning traditionally employs a rational decision model that leaves the planner poorly equipped to deal with…

Globalization and Education: Exploring Pedagogical and Curricular Issues and Implications. Introductory Essay.

ERIC Educational Resources Information Center

Smits, Hans

2000-01-01

A continuation of colonialism, globalization's narrow focus on economics and free-market thinking reinforces modernist rationality and individualism and discounts how deeply all life is interconnected. Its effects on education are reflected in high stakes testing, emphasis on information technologies, and a discounting of non-Western cultures.…

A Democracy of All Learners: Ethical Rationality and the Affective Roots of Democratic Leadership

ERIC Educational Resources Information Center

Woods, Philip A.

2006-01-01

This article contends that it is important for educational leaders to understand and reown the historical roots of modern democracy. In particular, it highlights a foundational human capacity for shared ethical insight which characterizes the rich conception of democracy that can be traced in this historical development. Implications for…

The Distributional and Cost Implications of Negative Expected Family Contributions

ERIC Educational Resources Information Center

Kelchen, Robert

2017-01-01

Eligibility for many federal, state, and institutional financial aid programs is determined by the expected family contribution (EFC) from the Free Application for Federal Student Aid (FAFSA), which functions as a tool to ration scarce aid dollars. The lowest possible EFC under current rules is zero, but this obscures a wider distribution of…

Creating School Change: Discovering a Choice of Lenses for the School Administrator.

ERIC Educational Resources Information Center

Amatea, Ellen S.; And Others

1996-01-01

Proposes a variety of epistemological lenses for viewing the school change process for school administrators' use. Applies these lenses in an actual case study depicting school change, illustrating how administrators can shift focus, position, and mode of inquiry from their usual rational viewpoint. Analyzes implications of using such lenses for…

Language Implications for Advertising in International Markets: A Model for Message Content and Message Execution.

ERIC Educational Resources Information Center

Beard, John; Yaprak, Attila

A content analysis model for assessing advertising themes and messages generated primarily for United States markets to overcome barriers in the cultural environment of international markets was developed and tested. The model is based on three primary categories for generating, evaluating, and executing advertisements: rational, emotional, and…

Econophysics and individual choice

NASA Astrophysics Data System (ADS)

Bordley, Robert F.

2005-08-01

The subjectivist theory of probability specifies certain axioms of rationality which together lead to both a theory of probability and a theory of preference. The theory of probability is used throughout the sciences while the theory of preferences is used in economics. Results in quantum physics challenge the adequacy of the subjectivist theory of probability. As we show, answering this challenge requires modifying an Archimedean axiom in the subjectivist theory. But changing this axiom modifies the subjectivist theory of preference and therefore has implications for economics. As this paper notes, these implications are consistent with current empirical findings in psychology and economics. As we show, these results also have implications for pricing in securities markets. This suggests further directions for research in econophysics.

Adaptive Multi-Agent Systems for Constrained Optimization

NASA Technical Reports Server (NTRS)

Macready, William; Bieniawski, Stefan; Wolpert, David H.

2004-01-01

Product Distribution (PD) theory is a new framework for analyzing and controlling distributed systems. Here we demonstrate its use for distributed stochastic optimization. First we review one motivation of PD theory, as the information-theoretic extension of conventional full-rationality game theory to the case of bounded rational agents. In this extension the equilibrium of the game is the optimizer of a Lagrangian of the (probability distribution of) the joint state of the agents. When the game in question is a team game with constraints, that equilibrium optimizes the expected value of the team game utility, subject to those constraints. The updating of the Lagrange parameters in the Lagrangian can be viewed as a form of automated annealing, that focuses the MAS more and more on the optimal pure strategy. This provides a simple way to map the solution of any constrained optimization problem onto the equilibrium of a Multi-Agent System (MAS). We present computer experiments involving both the Queen s problem and K-SAT validating the predictions of PD theory and its use for off-the-shelf distributed adaptive optimization.

Probing the effects of surface hydrophobicity and tether orientation on antibody-antigen binding

NASA Astrophysics Data System (ADS)

Bush, Derek B.; Knotts, Thomas A.

2017-04-01

Antibody microarrays have the potential to revolutionize molecular detection for many applications, but their current use is limited by poor reliability, and efforts to change this have not yielded fruitful results. One difficulty which limits the rational engineering of next-generation devices is that little is known, at the molecular level, about the antibody-antigen binding process near solid surfaces. Atomic-level structural information is scant because typical experimental techniques (X-ray crystallography and NMR) cannot be used to image proteins bound to surfaces. To overcome this limitation, this study uses molecular simulation and an advanced, experimentally validated, coarse-grain, protein-surface model to compare fab-lysozyme binding in bulk solution and when the fab is tethered to hydrophobic and hydrophilic surfaces. The results show that the tether site in the fab, as well as the surface hydrophobicity, significantly impacts the binding process and suggests that the optimal design involves tethering fabs upright on a hydrophilic surface. The results offer an unprecedented, molecular-level picture of the binding process and give hope that the rational design of protein-microarrays is possible.

Ultimate energy density of observable cold baryonic matter.

PubMed

Lattimer, James M; Prakash, Madappa

2005-03-25

We demonstrate that the largest measured mass of a neutron star establishes an upper bound to the energy density of observable cold baryonic matter. An equation of state-independent expression satisfied by both normal neutron stars and self-bound quark matter stars is derived for the largest energy density of matter inside stars as a function of their masses. The largest observed mass sets the lowest upper limit to the density. Implications from existing and future neutron star mass measurements are discussed.

Some Fundamental Limits on SAW RFID Tag Information Capacity and Collision Resolution

NASA Technical Reports Server (NTRS)

Barton, Richard J.

2013-01-01

In this paper, we apply results from multi-user information theory to study the limits of information capacity and collision resolution for SAW RFID tags. In particular, we derive bounds on the achievable data rate per tag as a function of fundamental parameters such as tag time-bandwidth product, tag signal-to-noise ratio (SNR), and number of tags in the environment. We also discuss the implications of these bounds for tag waveform design and tag interrogation efficiency

Children's understanding of fraction and decimal symbols and the notation-specific relation to pre-algebra ability.

PubMed

Hurst, Michelle A; Cordes, Sara

2018-04-01

Fraction and decimal concepts are notoriously difficult for children to learn yet are a major component of elementary and middle school math curriculum and an important prerequisite for higher order mathematics (i.e., algebra). Thus, recently there has been a push to understand how children think about rational number magnitudes in order to understand how to promote rational number understanding. However, prior work investigating these questions has focused almost exclusively on fraction notation, overlooking the open questions of how children integrate rational number magnitudes presented in distinct notations (i.e., fractions, decimals, and whole numbers) and whether understanding of these distinct notations may independently contribute to pre-algebra ability. In the current study, we investigated rational number magnitude and arithmetic performance in both fraction and decimal notation in fourth- to seventh-grade children. We then explored how these measures of rational number ability predicted pre-algebra ability. Results reveal that children do represent the magnitudes of fractions and decimals as falling within a single numerical continuum and that, despite greater experience with fraction notation, children are more accurate when processing decimal notation than when processing fraction notation. Regression analyses revealed that both magnitude and arithmetic performance predicted pre-algebra ability, but magnitude understanding may be particularly unique and depend on notation. The educational implications of differences between children in the current study and previous work with adults are discussed. Copyright © 2017 Elsevier Inc. All rights reserved.

Deleting 'irrational' responses from discrete choice experiments: a case of investigating or imposing preferences?

PubMed

Lancsar, Emily; Louviere, Jordan

2006-08-01

Investigation of the 'rationality' of responses to discrete choice experiments (DCEs) has been a theme of research in health economics. Responses have been deleted from DCEs where they have been deemed by researchers to (a) be 'irrational', defined by such studies as failing tests for non-satiation, or (b) represent lexicographic preferences. This paper outlines a number of reasons why deleting responses from DCEs may be inappropriate after first reviewing the theory underpinning rationality, highlighting that the importance placed on rationality depends on the approach to consumer theory to which one ascribes. The aim of this paper is not to suggest that all preferences elicited via DCEs are rational. Instead, it is to suggest a number of reasons why it may not be the case that all preferences labelled as 'irrational' are indeed so. Hence, deleting responses may result in the removal of valid preferences; induce sample selection bias; and reduce the statistical efficiency and power of the estimated choice models. Further, evidence suggests random utility theory may be able to cope with such preferences. Finally, we discuss a number of implications for the design, implementation and interpretation of DCEs and recommend caution regarding the deletion of preferences from stated preference experiments. Copyright 2006 John Wiley & Sons, Ltd.

The effects of bound state motion on macromolecular diffusion

NASA Astrophysics Data System (ADS)

Hough, Loren; Stefferson, Michael; Norris, Samantha; Maguire, Laura; Vernerey, Franck; Betterton, Meredith

The diffusion of macromolecules is modified in crowded environments by both inert obstacles and interaction sites. Molecules are generally slowed in their movement inducing transient anomalous subdiffusion. Obstacles also modify the kinetics and equilibrium behavior of interaction between mobile proteins. In some biophysical contexts, bound molecules can still experience mobility, for example transcription factors sliding along DNA, membrane proteins with some entry and diffusion within lipid domains, or proteins that can enter into non-membrane bound compartments such as the nucleolus. We used lattice and continuum models to study the diffusive behavior of tracer particles which bind to obstacles and can diffuse within them. We show that binding significantly alters the motion of tracers. The type and degree of motion while bound is a key determinant of the tracer mobility. Our work has implications for protein-protein movement and interactions within living cells, including those involving intrinsically disordered proteins.

"(Un)informed College and Major Choice": Verification in an Alternate Setting. CEDR Working Paper. WP #2015-11

ERIC Educational Resources Information Center

Huntington-Klein, Nick

2015-01-01

The decision to pursue formal education has significant labor market implications. To approach the decision rationally, a student must consider the costs and benefits of each available option. However, mounting empirical evidence suggests that reported expectations of costs and benefits are uncertain and vary across students. Hastings et al.…

The Epistemic of Aesthetic Knowledge and Knowing: Implications for Aesthetic Education Curricula and Rational Pedagogy in Nigerian Secondary Schools

ERIC Educational Resources Information Center

Aghaosa, Ike P.

2015-01-01

Using essentially the philosophical and documentary, methodologies of language and logical analysis and deductions, analogical inference; and historical inspection of documents, the paper examined the issues and arguments involved in Aesthetics as an epistemological concept. These were in terms of aesthetic: knowledge, faculty of knowing and…

Avenues of Influence Cross-Cultural Implications (Briefing Charts)

DTIC Science & Technology

2012-11-01

cultural , Social Influence, Communication modality, Emotional contagion, Individualistic , Collectivistic , Group orientation, Behavioral influences 16...appeals to take additional training – Culture groups: Individualistic and Collectivistic – Six persuasive appeals will be used in the stimuli: rational...between media type and emotional contagion Does culture influence the impact of social proof? H4: Collectivistic cultures will engage in

The Reindustrialization of the United States: Implications for Vocational Education Research and Development. Occasional Paper No. 71.

ERIC Educational Resources Information Center

Striner, Herbert E.

Reindustrialization problems in the United States (U.S.) include unemployment, low productivity, inflation, and inadequate economic growth. To determine how to improve economic performance, a careful, rational evaluation must be made of such factors as tax policy, spirit of risk, managerial effectiveness, rates of innovation, research and…

Child Abuse: Principles and Implications of Current Pediatric Practice.

ERIC Educational Resources Information Center

Newberger, Eli H.; Hyde, James N., Jr.

This paper summarizes data and experience with child abuse pertinent to child health practice. It goal is to foster sound and rational medical management. Because of the complex origins of child abuse, however, and of the institutional and social changes which shall have to accompany excellent practice if child abuse is effectively to be treated…

Inactive Lifestyles and Obesity in Chilean Youth: Individual Costs in Health-Related Choices

ERIC Educational Resources Information Center

Correa-Burrows, Paulina; Burrows, Raquel A.

2014-01-01

Objective: A recent economic approach suggests that people do not account for the long-term implications of unhealthy behaviours, preventing them from performing a fully rational trade-off between current benefits and future costs, leading to negative health outcomes. We examined whether the current allocation of time to physical activity among…

Reconsideration of Rorty's View of the Liberal Ironist and Its Implications for Postmodern Civic Education

ERIC Educational Resources Information Center

Kwak, Duck-Joo

2004-01-01

There have been persistent criticisms of Rorty's "liberal ironist" as the postmodern picture of the educated in the liberal utopia. While the modernist (Enlightenment) liberal Thomas McCarthy, who believes in universal rationality as the basis of public morality, criticizes Rorty's view of the liberal ironist for fostering the poverty of public…

Rules for Rational Decision Making: An Experiment with 15- and 16-Year Old Students

ERIC Educational Resources Information Center

Guerra, Ana Teresa Antequera; Febles, Maria Candelaria Espinel

2012-01-01

Multicriteria analysis constitutes a way to model decision processes, which allow the decision maker to assess the possible implications each course of action may entail. A multicriteria problem is chosen from the Programme for International Student Assessment 2003 Report and then extended to include questions involving a choice of preferences and…

Space outside the market: implications of NTFP certification for subsistence use (US)

Treesearch

Marla R. Emery

2002-01-01

Non-timber forest product (NTFP) certification is a market mechanism that is advanced to attain the dual goals of protecting global forests and promoting economic development (Nepstad and Schwartzman, 1992; Pierce, 1999; Viana et al, 1996). Certification criteria and indicators emphasize the rationalization and control of each step of the NTFP process from forest to...

Does Studying Political Science Affect Civic Attitudes?: A Panel Comparison of Students of Politics, Law, and Mass Communication

ERIC Educational Resources Information Center

Esaiasson, Peter; Persson, Mikael

2014-01-01

The article evaluates the civic implications of studying political science. Previous research has argued that learning rational choice models of political behavior could be detrimental to civic outcomes. However, results from our two panel surveys of students at Swedish universities show the opposite: studying political science has positive…

"With human health it's a global thing": Canadian perspectives on ethics in the global governance of an influenza pandemic.

PubMed

Thompson, Alison K; Smith, Maxwell J; McDougall, Christopher W; Bensimon, Cécile; Perez, Daniel Felipe

2015-03-01

We live in an era where our health is linked to that of others across the globe, and nothing brings this home better than the specter of a pandemic. This paper explores the findings of town hall meetings associated with the Canadian Program of Research on Ethics in a Pandemic (CanPREP), in which focus groups met to discuss issues related to the global governance of an influenza pandemic. Two competing discourses were found to be at work: the first was based upon an economic rationality and the second upon a humanitarian rationality. The implications for public support and the long-term sustainability of new global norms, networks, and regulations in global public health are discussed.

Publics in the making: mediating different methods of engagement and the publics these construct : commentary on: "Technologies of democracy: experiments and demonstrations".

PubMed

Mohr, Alison

2011-12-01

The potential for public engagement to democratise science has come under increasing scrutiny amid concerns that conflicting motivations have led to confusion about what engagement means to those who mediate science and publics. This raises important yet relatively unexplored questions regarding how publics are constituted by different forms of engagement used by intermediary scholars and other actors. It is possible to identify at least two possible 'rationalities of mediation' that mobilise different versions of the public and the roles they are assumed to play, as 'citizens' or 'users', in discussions around technology. However, combinations of rationalities are found in practice and these have significant implications for the 'new' scientific democracy.

Structural rearrangements occurring upon cofactor binding in the Mycobacterium smegmatis β-ketoacyl-acyl carrier protein reductase MabA.

PubMed

Küssau, Tanja; Flipo, Marion; Van Wyk, Niel; Viljoen, Albertus; Olieric, Vincent; Kremer, Laurent; Blaise, Mickaël

2018-05-01

In mycobacteria, the ketoacyl-acyl carrier protein (ACP) reductase MabA (designated FabG in other bacteria) catalyzes the NADPH-dependent reduction of β-ketoacyl-ACP substrates to β-hydroxyacyl-ACP products. This first reductive step in the fatty-acid biosynthesis elongation cycle is essential for bacteria, which makes MabA/FabG an interesting drug target. To date, however, very few molecules targeting FabG have been discovered and MabA remains the only enzyme of the mycobacterial type II fatty-acid synthase that lacks specific inhibitors. Despite the existence of several MabA/FabG crystal structures, the structural rearrangement that occurs upon cofactor binding is still not fully understood. Therefore, unlocking this knowledge gap could help in the design of new inhibitors. Here, high-resolution crystal structures of MabA from Mycobacterium smegmatis in its apo, NADP + -bound and NADPH-bound forms are reported. Comparison of these crystal structures reveals the structural reorganization of the lid region covering the active site of the enzyme. The crystal structure of the apo form revealed numerous residues that trigger steric hindrance to the binding of NADPH and substrate. Upon NADPH binding, these residues are pushed away from the active site, allowing the enzyme to adopt an open conformation. The transition from an NADPH-bound to an NADP + -bound form is likely to facilitate release of the product. These results may be useful for subsequent rational drug design and/or for in silico drug-screening approaches targeting MabA/FabG.

The Search for Proton Decay.

ERIC Educational Resources Information Center

Marshak, Marvin L.

1984-01-01

Provides the rationale for and examples of experiments designed to test the stability of protons and bound neutrons. Also considers the unification question, cosmological implications, current and future detectors, and current status of knowledge on proton decay. (JN)

Universal Trade-Off between Power, Efficiency, and Constancy in Steady-State Heat Engines

NASA Astrophysics Data System (ADS)

Pietzonka, Patrick; Seifert, Udo

2018-05-01

Heat engines should ideally have large power output, operate close to Carnot efficiency and show constancy, i.e., exhibit only small fluctuations in this output. For steady-state heat engines, driven by a constant temperature difference between the two heat baths, we prove that out of these three requirements only two are compatible. Constancy enters quantitatively the conventional trade-off between power and efficiency. Thus, we rationalize and unify recent suggestions for overcoming this simple trade-off. Our universal bound is illustrated for a paradigmatic model of a quantum dot solar cell and for a Brownian gyrator delivering mechanical work against an external force.

New leads in speculative behavior

NASA Astrophysics Data System (ADS)

Kindler, A.; Bourgeois-Gironde, S.; Lefebvre, G.; Solomon, S.

2017-02-01

The Kiyotaki and Wright (1989) (henceforth KW) model of money emergence as a medium of exchange has been studied from various perspectives in recent papers. In the present work we propose a minimalistic model for the behavior of agents in the KW framework, which may either reproduce the theoretical predictions of Kiyotaki and Wright (1989) on the emerging Nash equilibria, or (less closely) the empirical results of Brown (1996), Duffy and Ochs (1999) and our own, introduced in a first part of the present paper. The main import is the systematic computer scanning of speculative monetary equilibria under drastic bounded rationality of agents, based on behavior previously observed in the lab.

Emerging strategies for EphA2 receptor targeting for cancer therapeutics

PubMed Central

Tandon, Manish; Vemula, Sai Vikram; Mittal, Suresh K.

2010-01-01

Importance of the field High mortality rates with cancers warrant further development of earlier diagnostics and better treatment strategies. Membrane-bound hepatocellular receptor tyrosine kinase class A2 (EphA2) is overexpressed in breast, prostate, urinary bladder, skin, lung, ovary and brain cancers. Areas covered in this review This review describes EphA2 overexpression in cancers, its signaling mechanisms and strategies to target its deregulation. What will the reader will gain High EphA2 expression in cancer cells is correlated to a poor prognosis associated with recurrence due to enhanced metastasis. Interaction of the EphA2 receptor with its ligand (e.g., EphrinA1) triggers events that are deregulated and implicated in carcinogenesis. Both EphrinA1-independent oncogenic activity and EphrinA1-dependent tumor suppressor roles for EphA2 are described. Molecular interactions of EphA2 with signaling proteins are associated with the modulation of cytoskeleton dynamics, cell adhesion, proliferation, differentiation and metastasis. The deregulated signaling by EphA2 and its involvement in oncogenesis provide multiple avenues for the rational design of intervention approaches. Take home message EphA2 has been tested as a drug target using multiple approaches such as agonist antibodies, RNA interference, immunotherapy, virus vectors-mediated gene transfer, small molecule inhibitors and nanoparticles. With over a decade of research, encouraging results with successful targeting of EphA2 expression in various pre-clinical cancer models necessitate further studies. PMID:21142802

Sulphur-bound steroid and phytane carbon skeletons in geomacromolecules: Implications for the mechanism of incorporation of sulphur into organic matter

NASA Astrophysics Data System (ADS)

Kohnen, Math E. L.; Sinninghe Damsté, Jaap S.; Baas, Marianne; Dalen, A. C. Kock-van; de Leeuw, Jan W.

1993-06-01

Sulphur-bound steroid and phytane moieties in macromolecules present in the polar fractions of six immature samples (both crude oils and sediment extracts) have been analyzed using S-selective chemolysis methods and analytical pyrolysis. The identifications of the methylthioethers released from the macromolecule-containing fractions after MeLi/MeI treatment are based on comparison of mass spectral data and chromatographic data with those for synthesized methylthioethers. Evidence is presented that di- or polysulphide linkages are present in geomacromolecules in both sediments and oils and that the location of di- or polysulphide linkages in macromolecularly S-bound moieties is the same as that of monosulphide linkages. Macromolecularly S-bound phytanyl moieties are chiefly bound with S linkages located at the tertiary positions of their carbon skeletons, which indicates that the S incorporation mechanism(s) involve(s) intermediate carbocations. The macromolecularly S-bound steroids are bound with S linkages located mainly at C-2, C-3, C-4, or C-5 of their carbon skeletons, which indicates that the S incorporation took place into sterenes or steradienes - the dehydration products of stanols and stenols, respectively. However, it remains possible that the macromolecularly S-bound steroids with an axial S linkage at C-3 are, in part, resulting from a S N2 reaction of inorganic S species with steryl esters or stanols.

Kant on mental disorder. Part 2: philosophical implications of Kant's account.

PubMed

Frierson, Patrick

2009-09-01

This paper considers various philosophical problems arising from Kant's account of mental disorder. Starting with the reasons why Kant considered his theory of mental disorder important, I then turn to the implications of this theory of Kant's metaphysics, epistemology and ethics. Given Kant's account of insanity as 'a totally different standpoint... from which one sees all objects differently' (7: 216), the Critique of Pure Reason should be read as offering a more social epistemology than typically recognized. Also, mental disorders that seem to undermine human freedom and rationality raise problems for Kant's moral philosophy that his pragmatic anthropology helps to mitigate. Finally, I propose some implications of Kant's account of mental disorder for contemporary work on mental illness.

Design of a small molecule against an oncogenic noncoding RNA

PubMed Central

Velagapudi, Sai Pradeep; Cameron, Michael D.; Haga, Christopher L.; Rosenberg, Laura H.; Lafitte, Marie; Duckett, Derek R.; Phinney, Donald G.; Disney, Matthew D.

2016-01-01

The design of precision, preclinical therapeutics from sequence is difficult, but advances in this area, particularly those focused on rational design, could quickly transform the sequence of disease-causing gene products into lead modalities. Herein, we describe the use of Inforna, a computational approach that enables the rational design of small molecules targeting RNA to quickly provide a potent modulator of oncogenic microRNA-96 (miR-96). We mined the secondary structure of primary microRNA-96 (pri-miR-96) hairpin precursor against a database of RNA motif–small molecule interactions, which identified modules that bound RNA motifs nearby and in the Drosha processing site. Precise linking of these modules together provided Targaprimir-96 (3), which selectively modulates miR-96 production in cancer cells and triggers apoptosis. Importantly, the compound is ineffective on healthy breast cells, and exogenous overexpression of pri-miR-96 reduced compound potency in breast cancer cells. Chemical Cross-Linking and Isolation by Pull-Down (Chem-CLIP), a small-molecule RNA target validation approach, shows that 3 directly engages pri-miR-96 in breast cancer cells. In vivo, 3 has a favorable pharmacokinetic profile and decreases tumor burden in a mouse model of triple-negative breast cancer. Thus, rational design can quickly produce precision, in vivo bioactive lead small molecules against hard-to-treat cancers by targeting oncogenic noncoding RNAs, advancing a disease-to-gene-to-drug paradigm. PMID:27170187

Dynamics of bleomycin interaction with a strongly bound hairpin DNA substrate, and implications for cleavage of the bound DNA.

PubMed

Bozeman, Trevor C; Nanjunda, Rupesh; Tang, Chenhong; Liu, Yang; Segerman, Zachary J; Zaleski, Paul A; Wilson, W David; Hecht, Sidney M

2012-10-31

Recent studies involving DNAs bound strongly by bleomycins have documented that such DNAs are degraded by the antitumor antibiotic with characteristics different from those observed when studying the cleavage of randomly chosen DNAs in the presence of excess Fe·BLM. In the present study, surface plasmon resonance has been used to characterize the dynamics of BLM B(2) binding to a strongly bound hairpin DNA, to define the effects of Fe(3+), salt, and temperature on BLM-DNA interaction. One strong primary DNA binding site, and at least one much weaker site, were documented. In contrast, more than one strong cleavage site was found, an observation also made for two other hairpin DNAs. Evidence is presented for BLM equilibration between the stronger and weaker binding sites in a way that renders BLM unavailable to other, less strongly bound DNAs. Thus, enhanced binding to a given site does not necessarily result in increased DNA degradation at that site; i.e., for strongly bound DNAs, the facility of DNA cleavage must involve other parameters in addition to the intrinsic rate of C-4' H atom abstraction from DNA sugars.

Identification of a GTP-bound Rho specific scFv molecular sensor by phage display selection

PubMed Central

Goffinet, Marine; Chinestra, Patrick; Lajoie-Mazenc, Isabelle; Medale-Giamarchi, Claire; Favre, Gilles; Faye, Jean-Charles

2008-01-01

Background The Rho GTPases A, B and C proteins, members of the Rho family whose activity is regulated by GDP/GTP cycling, function in many cellular pathways controlling proliferation and have recently been implicated in tumorigenesis. Although overexpression of Rho GTPases has been correlated with tumorigenesis, only their GTP-bound forms are able to activate the signalling pathways implicated in tumorigenesis. Thus, the focus of much recent research has been to identify biological tools capable of quantifying the level of cellular GTP-bound Rho, or determining the subcellular location of activation. However useful, these tools used to study the mechanism of Rho activation still have limitations. The aim of the present work was to employ phage display to identify a conformationally-specific single chain fragment variable (scFv) that recognizes the active, GTP-bound, form of Rho GTPases and is able to discriminate it from the inactive, GDP-bound, Rho in endogenous settings. Results After five rounds of phage selection using a constitutively activated mutant of RhoB (RhoBQ63L), three scFvs (A8, C1 and D11) were selected for subsequent analysis. Further biochemical characterization was pursued for the single clone, C1, exhibiting an scFv structure. C1 was selective for the GTP-bound form of RhoA, RhoB, as well as RhoC, and failed to recognize GTP-loaded Rac1 or Cdc42, two other members of the Rho family. To enhance its production, soluble C1 was expressed in fusion with the N-terminal domain of phage protein pIII (scFv C1-N1N2), it appeared specifically associated with GTP-loaded recombinant RhoA and RhoB via immunoprecipitation, and endogenous activated Rho in HeLa cells as determined by immunofluorescence. Conclusion We identified an antibody, C1-N1N2, specific for the GTP-bound form of RhoB from a phage library, and confirmed its specificity towards GTP-bound RhoA and RhoC, as well as RhoB. The success of C1-N1N2 in discriminating activated Rho in immunofluorescence studies implies that this new tool, in collaboration with currently used RhoA and B antibodies, has the potential to analyze Rho activation in cell function and tumor development. PMID:18377644

Development of a Preventive HIV Vaccine Requires Solving Inverse Problems Which Is Unattainable by Rational Vaccine Design

PubMed Central

Van Regenmortel, Marc H. V.

2018-01-01

Hypotheses and theories are essential constituents of the scientific method. Many vaccinologists are unaware that the problems they try to solve are mostly inverse problems that consist in imagining what could bring about a desired outcome. An inverse problem starts with the result and tries to guess what are the multiple causes that could have produced it. Compared to the usual direct scientific problems that start with the causes and derive or calculate the results using deductive reasoning and known mechanisms, solving an inverse problem uses a less reliable inductive approach and requires the development of a theoretical model that may have different solutions or none at all. Unsuccessful attempts to solve inverse problems in HIV vaccinology by reductionist methods, systems biology and structure-based reverse vaccinology are described. The popular strategy known as rational vaccine design is unable to solve the multiple inverse problems faced by HIV vaccine developers. The term “rational” is derived from “rational drug design” which uses the 3D structure of a biological target for designing molecules that will selectively bind to it and inhibit its biological activity. In vaccine design, however, the word “rational” simply means that the investigator is concentrating on parts of the system for which molecular information is available. The economist and Nobel laureate Herbert Simon introduced the concept of “bounded rationality” to explain why the complexity of the world economic system makes it impossible, for instance, to predict an event like the financial crash of 2007–2008. Humans always operate under unavoidable constraints such as insufficient information, a limited capacity to process huge amounts of data and a limited amount of time available to reach a decision. Such limitations always prevent us from achieving the complete understanding and optimization of a complex system that would be needed to achieve a truly rational design process. This is why the complexity of the human immune system prevents us from rationally designing an HIV vaccine by solving inverse problems. PMID:29387066

Modeling discrete and continuous entities with fractions and decimals.

PubMed

Rapp, Monica; Bassok, Miriam; DeWolf, Melissa; Holyoak, Keith J

2015-03-01

When people use mathematics to model real-life situations, their use of mathematical expressions is often mediated by semantic alignment (Bassok, Chase, & Martin, 1998): The entities in a problem situation evoke semantic relations (e.g., tulips and vases evoke the functionally asymmetric "contain" relation), which people align with analogous mathematical relations (e.g., the noncommutative division operation, tulips/vases). Here we investigate the possibility that semantic alignment is also involved in the comprehension and use of rational numbers (fractions and decimals). A textbook analysis and results from two experiments revealed that both mathematic educators and college students tend to align the discreteness versus continuity of the entities in word problems (e.g., marbles vs. distance) with distinct symbolic representations of rational numbers--fractions versus decimals, respectively. In addition, fractions and decimals tend to be used with nonmetric units and metric units, respectively. We discuss the importance of the ontological distinction between continuous and discrete entities to mathematical cognition, the role of symbolic notations, and possible implications of our findings for the teaching of rational numbers. PsycINFO Database Record (c) 2015 APA, all rights reserved.

Beyond the Humanism/Posthumanism Debate: The Educational Implications of Said's Critical, Humane Praxis

ERIC Educational Resources Information Center

Chatelier, Stephen

2017-01-01

The late Edward Said sought to place critique and, indeed, self-critique at the heart of humanism. While the posthuman critiques surrounding the (im)possibility of humanism in postmodern times tend to focus on human autonomy, rationality, and essentialism, Stephen Chatelier here explores the idea that Said's writing on humanism could help us shift…

Naturalising Ethics: The Implications of Darwinism for the Study of Moral Philosophy

ERIC Educational Resources Information Center

Cartwright, John

2010-01-01

The nature of moral values has occupied philosophers and educationalists for centuries and a variety of claims have been made about their origin and status. One tradition suggests they may be thoughts in the mind of God; another that they are eternal truths to be reached by rational reflection (much like the truths of mathematics) or alternatively…

The Politics of Reform of Teachers' Work and the Consequences for Schools: Some Implications for Teacher Education

ERIC Educational Resources Information Center

Smyth, John

2006-01-01

This paper argues that we are currently experiencing a debilitating overload of political interference and media hyperbole in respect of teaching and teacher education, and that much of this blitzkrieg amounts to a "political spectacle" and blatant neo-liberal ideology dressed up as rational analysis. The politics of disparagement being unleashed…

The Contribution of "Cool" and "Hot" Components of Decision-Making in Adolescence: Implications for Developmental Psychopathology

ERIC Educational Resources Information Center

Seguin, Jean R.; Arseneault, Louise; Tremblay, Richard E.

2007-01-01

Impairments in either "cool" or "hot" processes may represent two pathways to deficient decision-making. Whereas cool processes are associated with cognitive and rational decisions, hot processes are associated with emotional, affective, and visceral processes. In this study, 168 boys were administered a card-playing task at ages 13 and 14 years…

Specific noncovalent interactions at protein-ligand interface: implications for rational drug design.

PubMed

Zhou, P; Huang, J; Tian, F

2012-01-01

Specific noncovalent interactions that are indicative of attractive, directional intermolecular forces have always been of key interest to medicinal chemists in their search for the "glue" that holds drugs and their targets together. With the rapid increase in the number of solved biomolecular structures as well as the performance enhancement of computer hardware and software in recent years, it is now possible to give more comprehensive insight into the geometrical characteristics and energetic landscape of certain sophisticated noncovalent interactions present at the binding interface of protein receptors and small ligands based on accumulated knowledge gaining from the combination of two quite disparate but complementary approaches: crystallographic data analysis and quantum-mechanical ab initio calculation. In this perspective, we survey massive body of published works relating to structural characterization and theoretical investigation of three kinds of strong, specific, direct, enthalpy-driven intermolecular forces, including hydrogen bond, halogen bond and salt bridge, involved in the formation of protein-ligand complex architecture in order to characterize their biological functions in conferring affinity and specificity for ligand recognition by host protein. In particular, the biomedical implications of raised knowledge are discussed with respect to potential applications in rational drug design.

Dopamine dysregulation syndrome: implications for a dopamine hypothesis of bipolar disorder.

PubMed

Berk, M; Dodd, S; Kauer-Sant'anna, M; Malhi, G S; Bourin, M; Kapczinski, F; Norman, T

2007-01-01

Rational therapeutic development in bipolar is hampered by a lack of pathophysiological model. However, there is a wealth of converging data on the role of dopamine in bipolar disorder. This paper therefore examines the possibility of a dopamine hypothesis for bipolar disorder. A literature search was conducted using standard search engines Embase, PyschLIT, PubMed and MEDLINE. In addition, papers and book chapters known to the authors were retrieved and examined for further relevant articles. Collectively, in excess of 100 articles were reviewed from which approximately 75% were relevant to the focus of this paper. Pharmacological models suggest a role of increased dopaminergic drive in mania and the converse in depression. In Parkinson's disease, administration of high-dose dopamine precursors can produce a 'maniform' picture, which switches into a depressive analogue on withdrawal. It is possible that in bipolar disorder there is a cyclical process, where increased dopaminergic transmission in mania leads to a secondary down regulation of dopaminergic receptor sensitivity over time. This may lead to a period of decreased dopaminergic transmission, corresponding with the depressive phase, and the repetition of the cycle. This model, if verified, may have implications for rational drug development.

Structural basis of GSK-3 inhibition by N-terminal phosphorylation and by the Wnt receptor LRP6.

PubMed

Stamos, Jennifer L; Chu, Matthew Ling-Hon; Enos, Michael D; Shah, Niket; Weis, William I

2014-03-18

Glycogen synthase kinase-3 (GSK-3) is a key regulator of many cellular signaling pathways. Unlike most kinases, GSK-3 is controlled by inhibition rather than by specific activation. In the insulin and several other signaling pathways, phosphorylation of a serine present in a conserved sequence near the amino terminus of GSK-3 generates an auto-inhibitory peptide. In contrast, Wnt/β-catenin signal transduction requires phosphorylation of Ser/Pro rich sequences present in the Wnt co-receptors LRP5/6, and these motifs inhibit GSK-3 activity. We present crystal structures of GSK-3 bound to its phosphorylated N-terminus and to two of the phosphorylated LRP6 motifs. A conserved loop unique to GSK-3 undergoes a dramatic conformational change that clamps the bound pseudo-substrate peptides, and reveals the mechanism of primed substrate recognition. The structures rationalize target sequence preferences and suggest avenues for the design of inhibitors selective for a subset of pathways regulated by GSK-3. DOI: http://dx.doi.org/10.7554/eLife.01998.001.

Bound on the Slope of Steady Water Waves with Favorable Vorticity

NASA Astrophysics Data System (ADS)

Strauss, Walter A.; Wheeler, Miles H.

2016-12-01

We consider the angle {θ} of inclination (with respect to the horizontal) of the profile of a steady two dimensional inviscid symmetric periodic or solitary water wave subject to gravity. Although {θ} may surpass 30° for some irrotational waves close to the extreme wave, Amick (Arch Ration Mech Anal 99(2):91-114, 1987) proved that for any irrotational wave the angle must be less than 31.15°. Is the situation similar for periodic or solitary waves that are not irrotational? The extreme Gerstner wave has infinite depth, adverse vorticity and vertical cusps ( θ = 90°). Moreover, numerical calculations show that even waves of finite depth can overturn if the vorticity is adverse. In this paper, on the other hand, we prove an upper bound of 45° on {θ} for a large class of waves with favorable vorticity and finite depth. In particular, the vorticity can be any constant with the favorable sign. We also prove a series of general inequalities on the pressure within the fluid, including the fact that any overturning wave must have a pressure sink.

[TORCH syndrome: Rational approach of pre and post natal diagnosis and treatment. Recommendations of the Advisory Committee on Neonatal Infections Sociedad Chilena de Infectología, 2016].

PubMed

Cofre, Fernanda; Delpiano, Luis; Labraña, Yenis; Reyes, Alejandra; Sandoval, Alejandra; Izquierdo, Giannina

2016-04-01

There is a lot of bacterial, viral or parasite infections who are able to be transmitted vertically from the mother to the fetus or newborn which implicates an enormous risk for it. The TORCH acronym is used universally to refer to a fetus or newborn which presents clinical features compatible with a vertically acquired infection and allows a rational diagnostic and therapeutic approach. The traditional "TORCH test" is nowadays considered not appropriate and it has been replaced for specific test for specific pathogens under well defined circumstances. The present document reviews the general characteristics, epidemiology, pathogenesis, diagnostic and therapeutic options for the most frequently involved pathogens in the fetus or newborn with TORCH suspicion.

Who Should Ration?

PubMed

Rosoff, Philip M

2017-02-01

A principal component of physician decision making is judging what interventions are clinically appropriate. Due to the inexorable and steady increase of health care costs in the US, physicians are constantly being urged to exercise judicious financial stewardship with due regard for the financial implications of what they prescribe. When applied on a case-by-case basis, this otherwise reasonable approach can lead to either inadvertent or overt and arbitrary restriction of interventions for some patients rather than others on the basis of clinically irrelevant characteristics such as ethnicity, gender, age, or skin color. In the absence of systemwide reform in which the resources saved from one patient or group of patients are reallocated for the benefit of others, prudence is urged in the application of "bedside rationing." © 2017 American Medical Association. All Rights Reserved.

Acute Pancreatitis Etiology Investigation: A Workup Algorithm Proposal

PubMed Central

da Silva, Sílvia; Rocha, Mónica; Pinto-de-Sousa, João

2017-01-01

Background Acute pancreatitis represents a significant number of hospital admissions. Most of the patients are admitted in an acute setting. Early identification of its etiology is an essential step toward the rational approach, both for its implications in the immediate therapy and the prevention of recurrence. Although often obvious, the etiological workup of acute pancreatitis can be challenging. Conclusion There are several studies emphasizing the multiple etiologies underlying acute pancreatitis but lacking structured diagnostic workups to allow a rational and organized study. The main goal of this work is to develop an algorithm proposal, which aims to serve as a guide for the investigation of the etiology of acute pancreatitis based on a review of already published literature, adjusted to the reality of our hospital and the available resources. PMID:28848797

Differentiating drugs by harm potential: the rational versus the feasible.

PubMed

Kalant, H

1999-01-01

In an ideal harm reduction model, drugs would be ranked according to their potential to cause harm, with varying implications for control policies and interventions. In such a public health oriented approach, the maximum protection of the public from harm would be balanced with the least possible restriction of freedom. In reality, however, the accuracy and completeness of the necessary information for such a ranking is highly limited. Many other factors not readily incorporated in a rational model, such as values, beliefs, and traditions, also affect drug policy decisions. Thus, rather than relying on acquisition of the necessary knowledge, it may be preferable to focus efforts on developing effective nonlegal measures to reduce drug use and harm. [Translations are provided in the International Abstracts Section of this issue.

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tews, Ingo; Lattimer, James M.; Ohnishi, Akira

We propose the existence of a lower bound on the energy of pure neutron matter (PNM) on the basis of unitary-gas considerations. We discuss its justification from experimental studies of cold atoms as well as from theoretical studies of neutron matter. We demonstrate that this bound results in limits to the density-dependent symmetry energy, which is the difference between the energies of symmetric nuclear matter and PNM. In particular, this bound leads to a lower limit to the volume symmetry energy parameter S {sub 0}. In addition, for assumed values of S {sub 0} above this minimum, this bound impliesmore » both upper and lower limits to the symmetry energy slope parameter L , which describes the lowest-order density dependence of the symmetry energy. A lower bound on neutron-matter incompressibility is also obtained. These bounds are found to be consistent with both recent calculations of the energies of PNM and constraints from nuclear experiments. Our results are significant because several equations of state that are currently used in astrophysical simulations of supernovae and neutron star mergers, as well as in nuclear physics simulations of heavy-ion collisions, have symmetry energy parameters that violate these bounds. Furthermore, below the nuclear saturation density, the bound on neutron-matter energies leads to a lower limit to the density-dependent symmetry energy, which leads to upper limits to the nuclear surface symmetry parameter and the neutron-star crust–core boundary. We also obtain a lower limit to the neutron-skin thicknesses of neutron-rich nuclei. Above the nuclear saturation density, the bound on neutron-matter energies also leads to an upper limit to the symmetry energy, with implications for neutron-star cooling via the direct Urca process.« less

Symmetry Parameter Constraints from a Lower Bound on Neutron-matter Energy

NASA Astrophysics Data System (ADS)

Tews, Ingo; Lattimer, James M.; Ohnishi, Akira; Kolomeitsev, Evgeni E.

2017-10-01

We propose the existence of a lower bound on the energy of pure neutron matter (PNM) on the basis of unitary-gas considerations. We discuss its justification from experimental studies of cold atoms as well as from theoretical studies of neutron matter. We demonstrate that this bound results in limits to the density-dependent symmetry energy, which is the difference between the energies of symmetric nuclear matter and PNM. In particular, this bound leads to a lower limit to the volume symmetry energy parameter S 0. In addition, for assumed values of S 0 above this minimum, this bound implies both upper and lower limits to the symmetry energy slope parameter L ,which describes the lowest-order density dependence of the symmetry energy. A lower bound on neutron-matter incompressibility is also obtained. These bounds are found to be consistent with both recent calculations of the energies of PNM and constraints from nuclear experiments. Our results are significant because several equations of state that are currently used in astrophysical simulations of supernovae and neutron star mergers, as well as in nuclear physics simulations of heavy-ion collisions, have symmetry energy parameters that violate these bounds. Furthermore, below the nuclear saturation density, the bound on neutron-matter energies leads to a lower limit to the density-dependent symmetry energy, which leads to upper limits to the nuclear surface symmetry parameter and the neutron-star crust-core boundary. We also obtain a lower limit to the neutron-skin thicknesses of neutron-rich nuclei. Above the nuclear saturation density, the bound on neutron-matter energies also leads to an upper limit to the symmetry energy, with implications for neutron-star cooling via the direct Urca process.

An exercise in rational taxonomy.

PubMed

Ho, M W

1990-11-07

The quest for a rational taxonomy of living forms began in the 17th century. Since the general acceptance of Darwin's theory of descent with modification, however, students of morphology became preoccupied with a systematics based on the genealogy of groups; and the rise of molecular phylogenies in recent years results in a further decline in the science of morphology. Reconstructing phylogenies by itself brings us no closer to the goal of rational taxonomy, which is to uncover the natural order inherent in the forms of living things. It is proposed that the rational taxonomy of forms should be derived from a study of development, much as von Baer had envisaged. To illustrate the method, a set of segmentation abnormalities in Drosophila larvae (previously exposed to either vapour) is considered, which can be individually classified as distinct disturbances in the process responsible for establishing normal segmental pattern. The process consists of a hierarchy of four successive bifurcations dividing the embryo's body first into two parts, then four, eight, and finally 16 subdivisions or segments. This gives rise to a taxonomic map of all possible transformations which contains the "phylogeny" of the actual forms and provides a natural system for classifying them. Attempts to recover the "true" phylogeny by various numerical methods are summarized and their implications for the validity of the basic assumptions of contemporary systematics discussed.

Cognitive factors associated with facial pain.

PubMed

Schwartz, S M; Gramling, S E

1997-07-01

Most well-accepted etiological models of facial pain (e.g., temporomandibular disorders and headache) implicate emotional distress as an important factor in the development and maintenance of pain. Data exists to support the notion that some facial pain sufferers are more emotionally distressed than no pain controls. However, many of these dependent measures of emotional distress are either lengthy assessment batteries, lack clear cut psychotherapeutic treatment implications, or focus exclusively on pain related sequela. As cognitive-behavioral interventions become more integrated into the treatment of chronic pain conditions, including various facial pain conditions, it becomes more imperative that the tools used to assess psychological functioning provide the clinician with specific cognitive/behavioral targets for change. The purpose of this study was to assess the degree to which symptomatic treatment seeking facial pain sufferers (N = 25), symptomatic non-treatment seeking facial pain sufferers (N = 48), and healthy pain-free controls (N = 70) differed on the Rational Beliefs Inventory (RBI). The RBI is a reliable, valid questionnaire assessing rational beliefs that are operationalized within a Rational Emotive Therapy (RET) framework. RET is a cognitive-behavioral treatment paradigm that focuses on how an individual's maladaptive cognitive errors or distortions exacerbate emotional distress. Group differences were assessed using a oneway Analysis of Covariance (ANCOVA) with the total RBI score serving as the dependent measure, and a Multivariate Analysis of Covariance (MANCOVA) using individual RBI belief subscales as dependent measures. These results indicated that groups differed significantly on the total score and several of the individual belief subscales. These findings indicated that facial pain sufferers generally hold maladaptive beliefs that may be of clinical significance for cognitive/behavioral treatment approaches.

Distributed Constrained Optimization with Semicoordinate Transformations

NASA Technical Reports Server (NTRS)

Macready, William; Wolpert, David

2006-01-01

Recent work has shown how information theory extends conventional full-rationality game theory to allow bounded rational agents. The associated mathematical framework can be used to solve constrained optimization problems. This is done by translating the problem into an iterated game, where each agent controls a different variable of the problem, so that the joint probability distribution across the agents moves gives an expected value of the objective function. The dynamics of the agents is designed to minimize a Lagrangian function of that joint distribution. Here we illustrate how the updating of the Lagrange parameters in the Lagrangian is a form of automated annealing, which focuses the joint distribution more and more tightly about the joint moves that optimize the objective function. We then investigate the use of "semicoordinate" variable transformations. These separate the joint state of the agents from the variables of the optimization problem, with the two connected by an onto mapping. We present experiments illustrating the ability of such transformations to facilitate optimization. We focus on the special kind of transformation in which the statistically independent states of the agents induces a mixture distribution over the optimization variables. Computer experiment illustrate this for &sat constraint satisfaction problems and for unconstrained minimization of NK functions.

Rational design of crystal contact-free space in protein crystals for analyzing spatial distribution of motions within protein molecules.

PubMed

Matsuoka, Rei; Shimada, Atsushi; Komuro, Yasuaki; Sugita, Yuji; Kohda, Daisuke

2016-03-01

Contacts with neighboring molecules in protein crystals inevitably restrict the internal motions of intrinsically flexible proteins. The resultant clear electron densities permit model building, as crystallographic snapshot structures. Although these still images are informative, they could provide biased pictures of the protein motions. If the mobile parts are located at a site lacking direct contacts in rationally designed crystals, then the amplitude of the movements can be experimentally analyzed. We propose a fusion protein method, to create crystal contact-free space (CCFS) in protein crystals and to place the mobile parts in the CCFS. Conventional model building fails when large amplitude motions exist. In this study, the mobile parts appear as smeared electron densities in the CCFS, by suitable processing of the X-ray diffraction data. We applied the CCFS method to a highly mobile presequence peptide bound to the mitochondrial import receptor, Tom20, and a catalytically relevant flexible segment in the oligosaccharyltransferase, AglB. These two examples demonstrated the general applicability of the CCFS method to the analysis of the spatial distribution of motions within protein molecules. © 2016 The Protein Society.

Dynamic route and departure time choice model based on self-adaptive reference point and reinforcement learning

NASA Astrophysics Data System (ADS)

Li, Xue-yan; Li, Xue-mei; Yang, Lingrun; Li, Jing

2018-07-01

Most of the previous studies on dynamic traffic assignment are based on traditional analytical framework, for instance, the idea of Dynamic User Equilibrium has been widely used in depicting both the route choice and the departure time choice. However, some recent studies have demonstrated that the dynamic traffic flow assignment largely depends on travelers' rationality degree, travelers' heterogeneity and what the traffic information the travelers have. In this paper, we develop a new self-adaptive multi agent model to depict travelers' behavior in Dynamic Traffic Assignment. We use Cumulative Prospect Theory with heterogeneous reference points to illustrate travelers' bounded rationality. We use reinforcement-learning model to depict travelers' route and departure time choosing behavior under the condition of imperfect information. We design the evolution rule of travelers' expected arrival time and the algorithm of traffic flow assignment. Compared with the traditional model, the self-adaptive multi agent model we proposed in this paper can effectively help travelers avoid the rush hour. Finally, we report and analyze the effect of travelers' group behavior on the transportation system, and give some insights into the relation between travelers' group behavior and the performance of transportation system.

Navigating the poverty of heroin addiction treatment and recovery opportunity in Kenya: access work, self-care and rationed expectations.

PubMed

Rhodes, Tim; Ndimbii, James; Guise, Andy; Cullen, Lucy; Ayon, Sylvia

2015-01-01

Drawing on the analyses of qualitative interview accounts of people who inject heroin in Kenya, we describe the narration of addiction treatment access and recovery desire in conditions characterised by a 'poverty of drug treatment opportunity'. We observe the performance of addiction recovery narrative in the face of heavy social constraints limiting access to care. Fee-based residential rehabilitation ('rehab') is the only treatment locally available and inaccessible to most. Its recovery potential is doubted, given normative expectations of relapse. Treating drug use is a product of tightly bounded agency. Individuals enact strategies to maximise their slim chances of treatment access ('access work'), develop self-care alternatives when these fail to materialise and ration their care expectations. The use of rehab as a primary means of respite and harm reduction rather than recovery and the individuation of care in the absence of an enabling recovery environment are key characteristics of drug treatment experience. The recent incorporation of 'harm reduction' into policy discourses may trouble the primacy of recovery narrative in addiction treatment and in how treatment desires are voiced. The diversification of drug treatments in combination with social interventions enabling their access are fundamental.

Product Distribution Theory for Control of Multi-Agent Systems

NASA Technical Reports Server (NTRS)

Lee, Chia Fan; Wolpert, David H.

2004-01-01

Product Distribution (PD) theory is a new framework for controlling Multi-Agent Systems (MAS's). First we review one motivation of PD theory, as the information-theoretic extension of conventional full-rationality game theory to the case of bounded rational agents. In this extension the equilibrium of the game is the optimizer of a Lagrangian of the (probability distribution of) the joint stare of the agents. Accordingly we can consider a team game in which the shared utility is a performance measure of the behavior of the MAS. For such a scenario the game is at equilibrium - the Lagrangian is optimized - when the joint distribution of the agents optimizes the system's expected performance. One common way to find that equilibrium is to have each agent run a reinforcement learning algorithm. Here we investigate the alternative of exploiting PD theory to run gradient descent on the Lagrangian. We present computer experiments validating some of the predictions of PD theory for how best to do that gradient descent. We also demonstrate how PD theory can improve performance even when we are not allowed to rerun the MAS from different initial conditions, a requirement implicit in some previous work.

Monoamines and assessment of risks.

PubMed

Takahashi, Hidehiko

2012-12-01

Over the past decade, neuroeconomics studies utilizing neurophysiology methods (fMRI or EEG) have flourished, revealing the neural basis of 'boundedly rational' or 'irrational' decision-making that violates normative theory. The next question is how modulatory neurotransmission is involved in these central processes. Here I focused on recent efforts to understand how central monoamine transmission is related to nonlinear probability weighting and loss aversion, central features of prospect theory, which is a leading alternative to normative theory for decision-making under risk. Circumstantial evidence suggests that dopamine tone might be related to distortion of subjective reward probability and noradrenaline and serotonin tone might influence aversive emotional reaction to potential loss. Copyright © 2012 Elsevier Ltd. All rights reserved.

Accelerating lattice QCD simulations with 2 flavors of staggered fermions on multiple GPUs using OpenACC-A first attempt

NASA Astrophysics Data System (ADS)

Gupta, Sourendu; Majumdar, Pushan

2018-07-01

We present the results of an effort to accelerate a Rational Hybrid Monte Carlo (RHMC) program for lattice quantum chromodynamics (QCD) simulation for 2 flavors of staggered fermions on multiple Kepler K20X GPUs distributed on different nodes of a Cray XC30. We do not use CUDA but adopt a higher level directive based programming approach using the OpenACC platform. The lattice QCD algorithm is known to be bandwidth bound; our timing results illustrate this clearly, and we discuss how this limits the parallelization gains. We achieve more than a factor three speed-up compared to the CPU only MPI program.

Adversarial risk analysis with incomplete information: a level-k approach.

PubMed

Rothschild, Casey; McLay, Laura; Guikema, Seth

2012-07-01

This article proposes, develops, and illustrates the application of level-k game theory to adversarial risk analysis. Level-k reasoning, which assumes that players play strategically but have bounded rationality, is useful for operationalizing a Bayesian approach to adversarial risk analysis. It can be applied in a broad class of settings, including settings with asynchronous play and partial but incomplete revelation of early moves. Its computational and elicitation requirements are modest. We illustrate the approach with an application to a simple defend-attack model in which the defender's countermeasures are revealed with a probability less than one to the attacker before he decides on how or whether to attack. © 2011 Society for Risk Analysis.

Bodily Moral Disgust: What It Is, How It Is Different from Anger, and Why It Is an Unreasoned Emotion

ERIC Educational Resources Information Center

Russell, Pascale Sophie; Giner-Sorolla, Roger

2013-01-01

With the recent upswing in research interest on the moral implications of disgust, there has been uncertainty about what kind of situations elicit moral disgust and whether disgust is a rational or irrational player in moral decision making. We first outline the benefits of distinguishing between bodily violations (e.g., sexual taboos, such as…

Older Voters and the 2010 U.S. Election: Implications for 2012 and beyond?

ERIC Educational Resources Information Center

Binstock, Robert H.

2012-01-01

Purpose: To analyze the extent to which Americans aged 65 and older may have voted as an old age-benefits bloc in the 2010 midterm election in response to threats of Medicare rationing. Methods: Analysis of age group data from the Edison Research 2010 Election Day exit polls, complemented by data published elsewhere. Results: For the first time in…

In situ catalyst improvement in the proline-mediated alpha-amination of aldehydes.

PubMed

Iwamura, Hiroshi; Mathew, Suju P; Blackmond, Donna G

2004-09-29

Kinetic investigations show that the proline-mediated alpha-amination of aldehydes exhibits autoinductive rate behavior and amplification of product enantiomeric excess. Further experiments highlight the role of product, offering suggestions for the design of catalysts of improved efficiency for such transformations. The unusual characteristics exhibited by these reactions implicate amino acid catalysis in rationalizations of the origin of biological homochirality.

A Rational Approach to Historiography: Misuses and Abuses of History. Symposium on Historiography: the Revisionist and the Progressive Historical Interpretations of Vocational Education andCurrent Implications.

ERIC Educational Resources Information Center

Greenwood, Katy Lee Brown

To knowledgeably debate with revisionist historians regarding the early history of vocational education and the social intentions of early leaders, vocational educators should focus attention on three general questions regarding (l) the validity of historical research, (2) motives of historical researchers, and (3) the kind of research…

Socratic suicide.

PubMed

Warren, J

2001-01-01

When is it rational to commit suicide? More specifically, when is it rational for a Platonist to commit suicide, and more worryingly, is it ever not rational for a Platonist to commit suicide? If the Phaedo wants us to lear that the soul is immortal, and that philosophy is a preparation for a state better than incarnation, then why does it begin with a discussion defending the prohibition of suicide? In the course of that discussion, Socrates offers (but does not necessarily endorse) two arguments for the prohibition of self-killing, at least in most circumstances, which have exerted a long and powerful influence over subsequent discussion of the topic, particularly in theist contexts. In the context of the Phaedo itself, however, this introductory conversation plays a crucial role in setting the agenda for the remainder of the dialogue and offering an initial discussion of the major concerns of the argument as a whole. In par- ticular, the discussion of thte nature of suicide is intimately bound up with Socrates' conception of true philosophy as a 'preparation for death', the relationship between soul and body, and the immortality of the soul. My intention is to provide a reading of that passage (61e-69e) which asks whether the Phaedo can offer a philosophically satisfying distinction between suicide and philosophy and how it relates to other ancient philosophical attitudes to self-killing. I argue that Socrates does not think that being dead is always preferable to being alive, and that the religious views expressed in the passage are consistent with his general stance on the benevolence of the gods.

Populations of High-Luminosity Density-Bounded HII Regions in Spiral Galaxies? Evidence and Implications

NASA Technical Reports Server (NTRS)

Beckman, J. E.; Rozas, M.; Zurita, A.; Watson, R. A.; Knapen, J. H.

2000-01-01

In this paper we present evidence that the H II regions of high luminosity in disk galaxies may be density bounded, so that a significant fraction of the ionizing photons emitted by their exciting OB stars escape from the regions. The key piece of evidence is the presence, in the Ha luminosity functions (LFs) of the populations of H iI regions, of glitches, local sharp peaks at an apparently invariant luminosity, defined as the Stromgren luminosity Lstr), LH(sub alpha) = Lstr = 10(sup 38.6) (+/- 10(sup 0.1)) erg/ s (no other peaks are found in any of the LFs) accompanying a steepening of slope for LH(sub alpha) greater than Lstr This behavior is readily explicable via a physical model whose basic premises are: (a) the transition at LH(sub alpha) = Lstr marks a change from essentially ionization bounding at low luminosities to density bounding at higher values, (b) for this to occur the law relating stellar mass in massive star-forming clouds to the mass of the placental cloud must be such that the ionizing photon flux produced within the cloud is a function which rises more steeply than the mass of the cloud. Supporting evidence for the hypothesis of this transition is also presented: measurements of the central surface brightnesses of H II regions for LH(sub alpha) less than Lstr are proportional to L(sup 1/3, sub H(sub alpha)), expected for ionization bounding, but show a sharp trend to a steeper dependence for LH(sub alpha) greater than Lstr, and the observed relation between the internal turbulence velocity parameter, sigma, and the luminosity, L, at high luminosities, can be well explained if these regions are density bounded. If confirmed, the density-bounding hypothesis would have a number of interesting implications. It would imply that the density-bounded regions were the main sources of the photons which ionize the diffuse gas in disk galaxies. Our estimates, based on the hypothesis, indicate that these regions emit sufficient Lyman continuum not only to ionize the diffuse medium, but to cause a typical spiral to emit significant ionizing flux into the intergalactic medium. The low scatter observed in Lstr, less than 0.1 mag rms in the still quite small sample measured to date, is an invitation to widen the data base, and to calibrate against primary standards, with the aim of obtaining a precise, approx. 10(exp 5) solar luminosity widely distributed standard candle.

Mapping out past and future minds: The perceived trajectory of rationality versus emotionality over time.

PubMed

O'Brien, Ed

2015-06-01

Who do we see when envisioning our "past self" and "future self"? Extant research finds a motivation to perceive improvement over time, such that past selves are seen as worse versions, and future selves as better versions, of current selves. However, the broader components comprising "worse" or "better" beyond domain-specific achievement (e.g., "Last year I failed at dieting, but next year I'll succeed") are less well understood. Are there more general qualities ascribed to the person we recall versus imagine being? Six studies suggest so, extending the 2-dimensional mind perception framework to the self: Past selves seem to possess highly emotional but not very rational minds, whereas future selves seem to possess highly rational but not very emotional minds (Studies 1a, 1b, 1c). Consistent with motivated improvement, this asymmetry does not emerge in evaluating others and applies uniquely to self-judgment (Study 2). Thus, our pervasive belief in changing for the "better" specifically means becoming more rational types of people. This observation has asymmetric consequences. Participants who brought to mind future selves sought intellectual enrichment (Study 3) and performed better on a self-control task (Study 4); however, participants who brought to mind past selves sought emotional enrichment and performed better on the same task when allegedly measuring enjoyment. These findings build a bridge between mind perception and intertemporal dynamics, raising novel implications for the present. Thinking about the future may not uniformly "improve" decisions and behaviors; rather, it mostly facilitates rational-related pursuits, whereas thinking about the past may enhance feeling-related experiences. (c) 2015 APA, all rights reserved).

Uncertainty relations as Hilbert space geometry

NASA Technical Reports Server (NTRS)

Braunstein, Samuel L.

1994-01-01

Precision measurements involve the accurate determination of parameters through repeated measurements of identically prepared experimental setups. For many parameters there is a 'natural' choice for the quantum observable which is expected to give optimal information; and from this observable one can construct an Heinsenberg uncertainty principle (HUP) bound on the precision attainable for the parameter. However, the classical statistics of multiple sampling directly gives us tools to construct bounds for the precision available for the parameters of interest (even when no obvious natural quantum observable exists, such as for phase, or time); it is found that these direct bounds are more restrictive than those of the HUP. The implication is that the natural quantum observables typically do not encode the optimal information (even for observables such as position, and momentum); we show how this can be understood simply in terms of the Hilbert space geometry. Another striking feature of these bounds to parameter uncertainty is that for a large enough number of repetitions of the measurements all V quantum states are 'minimum uncertainty' states - not just Gaussian wave-packets. Thus, these bounds tell us what precision is achievable as well as merely what is allowed.

Production of a Purified Marine Neurotoxin and Demonstration of its Binding Affinity to Ion Channel Receptors

DTIC Science & Technology

1989-06-10

the ciguatera Implicated toxins, maitotoxin, does not displace brevetoxin from its unique receptor and therefore must produce its toxic 49octs with a...James R. Balthrop, John A. Babinchak, Penny B. Travis, Teresa L. Herring and Pam Y. Brown-Eyo Ciguatera is a tropical fish-borne disease in which both a...synaptosome bound toxin from free toxin following in vitro bindina. we have demonstruted that one of the ciguatera implicated toxins, maitotoxin

The mediation effect of experiential avoidance between coping and psychopathology in chronic pain.

PubMed

Costa, Joana; Pinto-Gouveia, José

2011-01-01

This study explores experiential avoidance as a mediator in the relationship between coping (rational coping, avoidant coping and detached/ emotional coping) and psychopathology (depression, anxiety and stress). A battery of self-report questionnaires was used to assess coping, experiential avoidance and depression, anxiety and stress in 70 participants with a chronic pain from Portuguese primary health care units. Regression analyses were performed and showed preliminary evidence supporting the mediation role of experiential avoidance in a Portuguese sample with chronic pain. Results show that experiential avoidance partially or fully mediate the effects of rational coping and detached/emotional coping on depression and stress. Implications for clinical practice were discussed and suggest that psychopathology is not necessary direct product of coping and other processes, such as experiential avoidance, are likely involved. Copyright © 2010 John Wiley & Sons, Ltd.

Considerations for the rational design of a Chlamydia vaccine.

PubMed

Liang, Steven; Bulir, David; Kaushic, Charu; Mahony, James

2017-04-03

Chlamydia trachomatis is the leading cause of preventable blindness and the most common bacterial sexually transmitted infection. Remarkable progress in vaccine research over the past six decades has led to the advancement of novel C. trachomatis vaccine candidates into clinical trials. However, many questions regarding the role of specific cellular populations and molecular mechanisms in protective immunity against human C. trachomatis genital tract infections remain unanswered. Biomarkers of vaccine induced protective immunity are elusive in humans, while a cautionary message on the translatability of data obtained from current animal models has emanated from vaccine research and development efforts against other important human pathogens. In this commentary, we highlight recent advances in Chlamydia vaccine development and discuss their implications in the context of a rational approach to the design of a human C. trachomatis vaccine.

Reciprocity, Punishment, Institutions: The Streets to Social Collaboration -- New Theories on How Emerging Social Artifacts Control Our Lives in Society

NASA Astrophysics Data System (ADS)

Gerace, Giuliana

What mechanisms induce and support cooperation in social interaction? Traditional rational-choice perspective has resulted ineffective to keep track of complex real-world dynamics of cooperation. On the other hand, perspectives based on the justification of fairness preferences as internalized behavioural forces driving realistic cooperative interactions are notoriously incomplete and rather fuzzy with respect to their theoretical foundations. After considering recognized evolutionary accounts of the emergence and resilience of social standards, we endorse the view according to which the key to understanding evolutionary dynamics of social engagement is to be found in individual motivational attitudes to interaction. But, beyond any psychological implications, we suggest not exiting from the "logic of reciprocity" in considering the rationality of preferences for social interaction. Preliminary supporting experimental evidence is provided.

Conflicting Online Health Information and Rational Decision Making: Implication for Cancer Survivors.

PubMed

Yoon, Heesoo; Sohn, Minsung; Choi, Mankyu; Jung, Minsoo

Although people in the social media age can access health information easier, they have difficulty judging conflicting rational information or summarizing the large amounts of health information available. Conflicting health information occurs when contrary assertions or information about a certain health issue comes from different information sources. This study examined the background knowledge and the current phenomenon of why conflicting health information occurs in real-world conditions. We also reviewed causes and solutions by reviewing the literature. In particular, we recommend a method that solves problems that patients have including cancer survivors who cannot themselves be active in seeking health information. Thus, we categorized the specific types of conflicting health information and analyzed the sociodemographic factors and information carrier factors that have an impact on the health information-seeking behavior of individuals.

Activation of Two Sequential H-transfers in the Thymidylate Synthase Catalyzed Reaction

PubMed Central

Islam, Zahidul; Strutzenberg, Timothy S.; Ghosh, Ananda K.; Kohen, Amnon

2015-01-01

Thymidylate synthase (TSase) catalyzes the de novo biosynthesis of thymidylate, a precursor for DNA, and is thus an important target for chemotherapeutics and antibiotics. Two sequential C-H bond cleavages catalyzed by TSase are of particular interest: a reversible proton abstraction from the 2′-deoxy-uridylate substrate, followed by an irreversible hydride transfer forming the thymidylate product. QM/MM calculations of the former predicted a mechanism where the abstraction of the proton leads to formation of a novel nucleotide-folate intermediate that is not covalently bound to the enzyme (Wang, Z.; Ferrer, S.; Moliner, V.; Kohen, A. Biochemistry 2013, 52, 2348–2358). Existence of such intermediate would hold promise as a target for a new class of drugs. Calculations of the subsequent hydride transfer predicted a concerted H-transfer and elimination of the enzymatic cysteine (Kanaan, N.; Ferrer, S.; Marti, S.; Garcia-Viloca, M.; Kohen, A.; Moliner, V. J. Am. Chem. Soc. 2011, 133, 6692–6702). A key to both C-H activations is a highly conserved arginine (R166) that stabilizes the transition state of both H-transfers. Here we test these predictions by studying the R166 to lysine mutant of E. coli TSase (R166K) using intrinsic kinetic isotope effects (KIEs) and their temperature dependence to assess effects of the mutation on both chemical steps. The findings confirmed the predictions made by the QM/MM calculations, implicate R166 as an integral component of both reaction coordinates, and thus provide critical support to the nucleotide-folate intermediate as a new target for rational drug design. PMID:26576323

EXTRACTION OF SEDIMENT-BOUND CHLORINATED ORGANIC COMPOUNDS: IMPLICATIONS ON FATE AND HAZARD ASSESSMENT. (R825513C007)

EPA Science Inventory

Five methods were used for the extraction of hexachlorobutadiene and chlorobenzenes from a contaminated estuarine sediment. The following extraction methods were used: Soxhlet extraction, sonication and solvent extraction, sequential solvent extraction, saponification and solv...

Plant-specific multisubunit RNA polymerase in gene silencing.

PubMed

Lahmy, Sylvie; Bies-Etheve, Natacha; Lagrange, Thierry

2010-01-01

In recent years, a major breakthrough in the study of epigenetic silencing in eukaryotes came with the discovery that the RNA-interference pathway (RNAi) is generally implicated in heterochromatin assembly and gene silencing. An important and paradoxical feature of the RNAi-mediated heterochromatin pathways is their requirement for some form of transcription. In fission yeast, Schizosaccharomyces pombe, centromeric siRNAs have been shown to derive from chromatin-bound nascent transcripts produced by RNA polymerase II (PolII) at the site of heterochromatin formation. Likewise, chromatin-bound nascent transcripts generated by a PolII-related DNA-dependent RNA polymerase, known as PolIVb/PolV, have recently been implicated in RNA-directed DNA methylation (RdDM), the prominent RNAi-mediated chromatin pathway in plants. In this review we discuss recent work on the plant-specific PolII variant enzymes and discuss the mechanistic convergences that have been observed in the role of these enzymes in their respective siRNA-mediated heterochromatin formation pathways.

Governator vs. Hunter and Aggregator: A simulation of party competition with vote-seeking and office-seeking rules.

PubMed

Lehrer, Roni; Schumacher, Gijs

2018-01-01

The policy positions parties choose are central to both attracting voters and forming coalition governments. How then should parties choose positions to best represent voters? Laver and Sergenti show that in an agent-based model with boundedly rational actors a decision rule (Aggregator) that takes the mean policy position of its supporters is the best rule to achieve high congruence between voter preferences and party positions. But this result only pertains to representation by the legislature, not representation by the government. To evaluate this we add a coalition formation procedure with boundedly rational parties to the Laver and Sergenti model of party competition. We also add two new decision rules that are sensitive to government formation outcomes rather than voter positions. We develop two simulations: a single-rule one in which parties with the same rule compete and an evolutionary simulation in which parties with different rules compete. In these simulations we analyze party behavior under a large number of different parameters that describe real-world variance in political parties' motives and party system characteristics. Our most important conclusion is that Aggregators also produce the best match between government policy and voter preferences. Moreover, even though citizens often frown upon politicians' interest in the prestige and rents that come with winning political office (office pay-offs), we find that citizens actually receive better representation by the government if politicians are motivated by these office pay-offs in contrast to politicians with ideological motivations (policy pay-offs). Finally, we show that while more parties are linked to better political representation, how parties choose policy positions affects political representation as well. Overall, we conclude that to understand variation in the quality of political representation scholars should look beyond electoral systems and take into account variation in party behavior as well.

Governator vs. Hunter and Aggregator: A simulation of party competition with vote-seeking and office-seeking rules

PubMed Central

2018-01-01

The policy positions parties choose are central to both attracting voters and forming coalition governments. How then should parties choose positions to best represent voters? Laver and Sergenti show that in an agent-based model with boundedly rational actors a decision rule (Aggregator) that takes the mean policy position of its supporters is the best rule to achieve high congruence between voter preferences and party positions. But this result only pertains to representation by the legislature, not representation by the government. To evaluate this we add a coalition formation procedure with boundedly rational parties to the Laver and Sergenti model of party competition. We also add two new decision rules that are sensitive to government formation outcomes rather than voter positions. We develop two simulations: a single-rule one in which parties with the same rule compete and an evolutionary simulation in which parties with different rules compete. In these simulations we analyze party behavior under a large number of different parameters that describe real-world variance in political parties’ motives and party system characteristics. Our most important conclusion is that Aggregators also produce the best match between government policy and voter preferences. Moreover, even though citizens often frown upon politicians’ interest in the prestige and rents that come with winning political office (office pay-offs), we find that citizens actually receive better representation by the government if politicians are motivated by these office pay-offs in contrast to politicians with ideological motivations (policy pay-offs). Finally, we show that while more parties are linked to better political representation, how parties choose policy positions affects political representation as well. Overall, we conclude that to understand variation in the quality of political representation scholars should look beyond electoral systems and take into account variation in party behavior as well. PMID:29394268

Post-September 11Th Perspectives on Religion, Spirituality, and Philosophy in the Personal and Professional Lives of Selected REBT Cognoscenti

ERIC Educational Resources Information Center

Weinrach, Stephen G.; Dryden, Windy; DiMattia, Dominic J.; Doyle, Kristene A.; MacLaren, Catherine; O'Kelly, Monica; Malkinson, Ruth

2004-01-01

The purpose of this article was for selected Rational Emotive Behavior Therapy (REBT) cognoscenti to examine the impact of the events of September 11th, 2001, on their beliefs about religion, spirituality and their personal philosophy--including the role of evil in the universe and the implications of these issues on their use of REBT. The degree…

A perspective on reagent diversity and non-covalent binding of reactive carbonyl species (RCS) and effector reagents in nonenzymatic glycation (NEG): Mechanistic considerations and implications for future research

NASA Astrophysics Data System (ADS)

Rodnick, Kenneth J.; Holman, R. W.; Ropski, Pamela S.; Huang, Mingdong; Swislocki, Arthur L. M.

2017-06-01

This perspective focuses on illustrating the underappreciated connections between reactive carbonyl species (RCS), initial binding in the nonenzymatic glycation (NEG) process, and nonenzymatic covalent protein modification (here termed NECPM). While glucose is the central species involved in NEG, recent studies indicate that the initially-bound glucose species in the NEG of human hemoglobin (HbA) and human serum albumin (HSA) are non-RCS ring-closed isomers. The ring-opened glucose, an RCS structure that reacts in the NEG process, is most likely generated from previously-bound ring-closed isomers undergoing concerted acid/base reactions while bound to protein. The generation of the glucose RCS can involve concomitantly-bound physiological species (e.g., inorganic phosphate, water, etc.); here termed effector reagents. Extant NEG schemes do not account for these recent findings. In addition, effector reagent reactions with glucose in the serum and erythrocyte cytosol can generate RCS (e.g., glyoxal, glyceraldehyde, etc.). Recent research has shown that these RCS covalently modify proteins in vivo via NECPM mechanisms. A general scheme that reflects both the reagent and mechanistic diversity that can lead to NEG and NECPM is presented here. A perspective that accounts for the relationships between RCS, NEG, and NECPM can facilitate the understanding of site selectivity, may help explain overall glycation rates, and may have implications for the clinical assessment/control of diabetes mellitus. In view of this perspective, concentrations of ribose, fructose, Pi, bicarbonate, counter ions, and the resulting RCS generated within intracellular and extracellular compartments may be of importance and of clinical relevance. Future research is also proposed.

Upper bounds on secret-key agreement over lossy thermal bosonic channels

NASA Astrophysics Data System (ADS)

Kaur, Eneet; Wilde, Mark M.

2017-12-01

Upper bounds on the secret-key-agreement capacity of a quantum channel serve as a way to assess the performance of practical quantum-key-distribution protocols conducted over that channel. In particular, if a protocol employs a quantum repeater, achieving secret-key rates exceeding these upper bounds is evidence of having a working quantum repeater. In this paper, we extend a recent advance [Liuzzo-Scorpo et al., Phys. Rev. Lett. 119, 120503 (2017), 10.1103/PhysRevLett.119.120503] in the theory of the teleportation simulation of single-mode phase-insensitive Gaussian channels such that it now applies to the relative entropy of entanglement measure. As a consequence of this extension, we find tighter upper bounds on the nonasymptotic secret-key-agreement capacity of the lossy thermal bosonic channel than were previously known. The lossy thermal bosonic channel serves as a more realistic model of communication than the pure-loss bosonic channel, because it can model the effects of eavesdropper tampering and imperfect detectors. An implication of our result is that the previously known upper bounds on the secret-key-agreement capacity of the thermal channel are too pessimistic for the practical finite-size regime in which the channel is used a finite number of times, and so it should now be somewhat easier to witness a working quantum repeater when using secret-key-agreement capacity upper bounds as a benchmark.

Effects of soft interactions and bound mobility on diffusion in crowded environments: a model of sticky and slippery obstacles

NASA Astrophysics Data System (ADS)

Stefferson, Michael W.; Norris, Samantha L.; Vernerey, Franck J.; Betterton, Meredith D.; E Hough, Loren

2017-08-01

Crowded environments modify the diffusion of macromolecules, generally slowing their movement and inducing transient anomalous subdiffusion. The presence of obstacles also modifies the kinetics and equilibrium behavior of tracers. While previous theoretical studies of particle diffusion have typically assumed either impenetrable obstacles or binding interactions that immobilize the particle, in many cellular contexts bound particles remain mobile. Examples include membrane proteins or lipids with some entry and diffusion within lipid domains and proteins that can enter into membraneless organelles or compartments such as the nucleolus. Using a lattice model, we studied the diffusive movement of tracer particles which bind to soft obstacles, allowing tracers and obstacles to occupy the same lattice site. For sticky obstacles, bound tracer particles are immobile, while for slippery obstacles, bound tracers can hop without penalty to adjacent obstacles. In both models, binding significantly alters tracer motion. The type and degree of motion while bound is a key determinant of the tracer mobility: slippery obstacles can allow nearly unhindered diffusion, even at high obstacle filling fraction. To mimic compartmentalization in a cell, we examined how obstacle size and a range of bound diffusion coefficients affect tracer dynamics. The behavior of the model is similar in two and three spatial dimensions. Our work has implications for protein movement and interactions within cells.

The Online Learner: Characteristics and Pedagogical Implications

ERIC Educational Resources Information Center

Dabbagh, Nada

2007-01-01

Globalization has stretched the scope of the online learner population from a homogeneous profile of mostly adult, mostly employed, place-bound, goal-oriented, and intrinsically motivated to one that is heterogeneous, younger, dynamic, and responsive to rapid technological innovations. This paper describes the emerging characteristics of the…

GAS- AND SOLID-PHASE PARTITIONING OF PCDDS/FS ON MSWI FLY ASH AND THE EFFECTS OF SAMPLING

EPA Science Inventory

Semi-volatile organic compounds (SOCs), including polychlorinated dibenzo-p-dioxins/dibenzofurans (PCDDs/Fs), are partitioned as gas-phase and particle-bound products of many industrial combustion processes. This gas/particle partitioning of SOCs has severe implications on both ...

On confidence and consequence: the certainty and importance of self-knowledge.

PubMed

Pelham, B W

1991-04-01

Belief certainty and belief importance represent 2 relatively independent forms of investment in the self-concept. Three studies suggested that whereas certainty is associated with epistemic (i.e., rational or informational) factors, importance is more closely associated with emotive (i.e., emotional and motivational) factors. A 4th study explored the implications of certainty and importance for the temporal stability of people's self-views and revealed that whereas belief certainty was associated with the stability of both positive and negative beliefs, belief importance was associated with the stability of positive beliefs only. The implications of belief investment for the verification-enhancement debate and for the structure and measurement of the self-concept are discussed.

Stress-induced EGFR trafficking: mechanisms, functions, and therapeutic implications

PubMed Central

Tan, Xiaojun; Lambert, Paul F.; Rapraeger, Alan C.; Anderson, Richard A.

2016-01-01

Epidermal growth factor receptor (EGFR) has fundamental roles in normal physiology and in cancer, making it a rational target for cancer therapy. Surprisingly, however, inhibitors that target canonical, ligand-stimulated EGFR signaling have proven to be largely ineffective in treating many EGFR-dependent cancers. Recent evidence indicates that both intrinsic and therapy-induced cellular stress triggers robust, non-canonical pathways of ligand-independent EGFR trafficking and signaling, which provides cancer cells with a survival advantage and resistance to therapeutics. Here we review the mechanistic regulation of non-canonical EGFR trafficking and signaling, the pathological and therapeutic stresses that activate it, and discuss the implications of this pathway in clinical treatment of EGFR-overexpressing cancers. PMID:26827089

Conflict monitoring in dual process theories of thinking.

PubMed

De Neys, Wim; Glumicic, Tamara

2008-03-01

Popular dual process theories have characterized human thinking as an interplay between an intuitive-heuristic and demanding-analytic reasoning process. Although monitoring the output of the two systems for conflict is crucial to avoid decision making errors there are some widely different views on the efficiency of the process. Kahneman [Kahneman, D. (2002). Maps of bounded rationality: A perspective on intuitive judgement and choice. Nobel Prize Lecture. Retrieved January 11, 2006, from: http://nobelprize.org/nobel_prizes/economics/laureates/2002/kahnemann-lecture.pdf] and Evans [Evans, J. St. B. T. (1984). Heuristic and analytic processing in reasoning. British Journal of Psychology, 75, 451-468], for example, claim that the monitoring of the heuristic system is typically quite lax whereas others such as Sloman [Sloman, S. A. (1996). The empirical case for two systems of reasoning. Psychological Bulletin, 119, 3-22] and Epstein [Epstein, S. (1994). Integration of the cognitive and psychodynamic unconscious. American Psychologists, 49, 709-724] claim it is flawless and people typically experience a struggle between what they "know" and "feel" in case of a conflict. The present study contrasted these views. Participants solved classic base rate neglect problems while thinking aloud. In these problems a stereotypical description cues a response that conflicts with the response based on the analytic base rate information. Verbal protocols showed no direct evidence for an explicitly experienced conflict. As Kahneman and Evans predicted, participants hardly ever mentioned the base rates and seemed to base their judgment exclusively on heuristic reasoning. However, more implicit measures of conflict detection such as participants' retrieval of the base rate information in an unannounced recall test, decision making latencies, and the tendency to review the base rates indicated that the base rates had been thoroughly processed. On control problems where base rates and description did not conflict this was not the case. Results suggest that whereas the popular characterization of conflict detection as an actively experienced struggle can be questioned there is nevertheless evidence for Sloman's and Epstein's basic claim about the flawless operation of the monitoring. Whenever the base rates and description disagree people will detect this conflict and consequently redirect attention towards a deeper processing of the base rates. Implications for the dual process framework and the rationality debate are discussed.

Decision theory with resource-bounded agents.

PubMed

Halpern, Joseph Y; Pass, Rafael; Seeman, Lior

2014-04-01

There have been two major lines of research aimed at capturing resource-bounded players in game theory. The first, initiated by Rubinstein (), charges an agent for doing costly computation; the second, initiated by Neyman (), does not charge for computation, but limits the computation that agents can do, typically by modeling agents as finite automata. We review recent work on applying both approaches in the context of decision theory. For the first approach, we take the objects of choice in a decision problem to be Turing machines, and charge players for the "complexity" of the Turing machine chosen (e.g., its running time). This approach can be used to explain well-known phenomena like first-impression-matters biases (i.e., people tend to put more weight on evidence they hear early on) and belief polarization (two people with different prior beliefs, hearing the same evidence, can end up with diametrically opposed conclusions) as the outcomes of quite rational decisions. For the second approach, we model people as finite automata, and provide a simple algorithm that, on a problem that captures a number of settings of interest, provably performs optimally as the number of states in the automaton increases. Copyright © 2014 Cognitive Science Society, Inc.

The anatomy of choice: dopamine and decision-making

PubMed Central

Friston, Karl; Schwartenbeck, Philipp; FitzGerald, Thomas; Moutoussis, Michael; Behrens, Timothy; Dolan, Raymond J.

2014-01-01

This paper considers goal-directed decision-making in terms of embodied or active inference. We associate bounded rationality with approximate Bayesian inference that optimizes a free energy bound on model evidence. Several constructs such as expected utility, exploration or novelty bonuses, softmax choice rules and optimism bias emerge as natural consequences of free energy minimization. Previous accounts of active inference have focused on predictive coding. In this paper, we consider variational Bayes as a scheme that the brain might use for approximate Bayesian inference. This scheme provides formal constraints on the computational anatomy of inference and action, which appear to be remarkably consistent with neuroanatomy. Active inference contextualizes optimal decision theory within embodied inference, where goals become prior beliefs. For example, expected utility theory emerges as a special case of free energy minimization, where the sensitivity or inverse temperature (associated with softmax functions and quantal response equilibria) has a unique and Bayes-optimal solution. Crucially, this sensitivity corresponds to the precision of beliefs about behaviour. The changes in precision during variational updates are remarkably reminiscent of empirical dopaminergic responses—and they may provide a new perspective on the role of dopamine in assimilating reward prediction errors to optimize decision-making. PMID:25267823

The anatomy of choice: dopamine and decision-making.

PubMed

Friston, Karl; Schwartenbeck, Philipp; FitzGerald, Thomas; Moutoussis, Michael; Behrens, Timothy; Dolan, Raymond J

2014-11-05

This paper considers goal-directed decision-making in terms of embodied or active inference. We associate bounded rationality with approximate Bayesian inference that optimizes a free energy bound on model evidence. Several constructs such as expected utility, exploration or novelty bonuses, softmax choice rules and optimism bias emerge as natural consequences of free energy minimization. Previous accounts of active inference have focused on predictive coding. In this paper, we consider variational Bayes as a scheme that the brain might use for approximate Bayesian inference. This scheme provides formal constraints on the computational anatomy of inference and action, which appear to be remarkably consistent with neuroanatomy. Active inference contextualizes optimal decision theory within embodied inference, where goals become prior beliefs. For example, expected utility theory emerges as a special case of free energy minimization, where the sensitivity or inverse temperature (associated with softmax functions and quantal response equilibria) has a unique and Bayes-optimal solution. Crucially, this sensitivity corresponds to the precision of beliefs about behaviour. The changes in precision during variational updates are remarkably reminiscent of empirical dopaminergic responses-and they may provide a new perspective on the role of dopamine in assimilating reward prediction errors to optimize decision-making.

Indazole-based potent and cell-active Mps1 kinase inhibitors: rational design from pan-kinase inhibitor anthrapyrazolone (SP600125).

PubMed

Kusakabe, Ken-ichi; Ide, Nobuyuki; Daigo, Yataro; Tachibana, Yuki; Itoh, Takeshi; Yamamoto, Takahiko; Hashizume, Hiroshi; Hato, Yoshio; Higashino, Kenichi; Okano, Yousuke; Sato, Yuji; Inoue, Makiko; Iguchi, Motofumi; Kanazawa, Takayuki; Ishioka, Yukichi; Dohi, Keiji; Kido, Yasuto; Sakamoto, Shingo; Yasuo, Kazuya; Maeda, Masahiro; Higaki, Masayo; Ueda, Kazuo; Yoshizawa, Hidenori; Baba, Yoshiyasu; Shiota, Takeshi; Murai, Hitoshi; Nakamura, Yusuke

2013-06-13

Monopolar spindle 1 (Mps1) is essential for centrosome duplication, the spindle assembly check point, and the maintenance of chromosomal instability. Mps1 is highly expressed in cancer cells, and its expression levels correlate with the histological grades of cancers. Thus, selective Mps1 inhibitors offer an attractive opportunity for the development of novel cancer therapies. To design novel Mps1 inhibitors, we utilized the pan-kinase inhibitor anthrapyrazolone (4, SP600125) and its crystal structure bound to JNK1. Our design efforts led to the identification of indazole-based lead 6 with an Mps1 IC50 value of 498 nM. Optimization of the 3- and 6-positions on the indazole core of 6 resulted in 23c with improved Mps1 activity (IC50 = 3.06 nM). Finally, application of structure-based design using the X-ray structure of 23d bound to Mps1 culminated in the discovery of 32a and 32b with improved potency for cellular Mps1 and A549 lung cancer cells. Moreover, 32a and 32b exhibited reasonable selectivities over 120 and 166 kinases, respectively.

Transport in the barrier billiard

NASA Astrophysics Data System (ADS)

Saberi Fathi, S. M.; Ettoumi, W.; Courbage, M.

2016-06-01

We investigate transport properties of an ensemble of particles moving inside an infinite periodic horizontal planar barrier billiard. A particle moves among bars and elastically reflects on them. The motion is a uniform translation along the bars' axis. When the tangent of the incidence angle, α , is fixed and rational, the second moment of the displacement along the orthogonal axis at time n , , is either bounded or asymptotic to K n2 , when n →∞ . For irrational α , the collision map is ergodic and has a family of weakly mixing observables, the transport is not ballistic, and autocorrelation functions decay only in time average, but may not decay for a family of irrational α 's. An exhaustive numerical computation shows that the transport may be superdiffusive or subdiffusive with various rates or bounded strongly depending on the values of α . The variety of transport behaviors sounds reminiscent of well-known behavior of conservative systems. Considering then an ensemble of particles with nonfixed α , the system is nonergodic and certainly not mixing and has anomalous diffusion with self-similar space-time properties. However, we verified that such a system decomposes into ergodic subdynamics breaking self-similarity.

The 2.5 Å Crystal Structure of the SIRT1 Catalytic Domain Bound to Nicotinamide Adenine Dinucleotide (NAD + ) and an Indole (EX527 Analogue) Reveals a Novel Mechanism of Histone Deacetylase Inhibition

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhao, Xun; Allison, Dagart; Condon, Bradley

2013-02-14

The sirtuin SIRT1 is a NAD+-dependent histone deacetylase, a Sir2 family member, and one of seven human sirtuins. Sirtuins are conserved from archaea to mammals and regulate transcription, genome stability, longevity, and metabolism. SIRT1 regulates transcription via deacetylation of transcription factors such as PPARγ, NFκB, and the tumor suppressor protein p53. EX527 (27) is a nanomolar SIRT1 inhibitor and a micromolar SIRT2 inhibitor. To elucidate the mechanism of SIRT inhibition by 27, we determined the 2.5 Å crystal structure of the SIRT1 catalytic domain (residues 241–516) bound to NAD+ and the 27 analogue compound 35. 35 binds deep in themore » catalytic cleft, displacing the NAD+ nicotinamide and forcing the cofactor into an extended conformation. The extended NAD+ conformation sterically prevents substrate binding. The SIRT1/NAD+/35 crystal structure defines a novel mechanism of histone deacetylase inhibition and provides a basis for understanding, and rationally improving, inhibition of this therapeutically important target by drug-like molecules.« less

The role of endocytic pathways in cellular uptake of plasma non-transferrin iron

PubMed Central

Sohn, Yang-Sung; Ghoti, Hussam; Breuer, William; Rachmilewitz, Eliezer; Attar, Samah; Weiss, Guenter; Cabantchik, Z. Ioav

2012-01-01

Background In transfusional siderosis, the iron binding capacity of plasma transferrin is often surpassed, with concomitant generation of non-transferrin-bound iron. Although implicated in tissue siderosis, non-transferrin-bound iron modes of cell ingress remain undefined, largely because of its variable composition and association with macromolecules. Using fluorescent tracing of labile iron in endosomal vesicles and cytosol, we examined the hypothesis that non-transferrin-bound iron fractions detected in iron overloaded patients enter cells via bulk endocytosis. Design and Methods Fluorescence microscopy and flow cytometry served as analytical tools for tracing non-transferrin-bound iron entry into endosomes with the redox-reactive macromolecular probe Oxyburst-Green and into the cytosol with cell-laden calcein green and calcein blue. Non-transferrin-bound iron-containing media were from sera of polytransfused thalassemia major patients and model iron substances detected in thalassemia major sera; cell models were cultured macrophages, and cardiac myoblasts and myocytes. Results Exposure of cells to ferric citrate together with albumin, or to non-transferrin-bound iron-containing sera from thalassemia major patients caused an increase in labile iron content of endosomes and cytosol in macrophages and cardiac cells. This increase was more striking in macrophages, but in both cell types was largely reduced by co-exposure to non-transferrin-bound iron-containing media with non-penetrating iron chelators or apo-transferrin, or by treatment with inhibitors of endocytosis. Endosomal iron accumulation traced with calcein-green was proportional to input non-transferrin-bound iron levels (r2=0.61) and also preventable by pre-chelation. Conclusions Our studies indicate that macromolecule-associated non-transferrin-bound iron can initially gain access into various cells via endocytic pathways, followed by iron translocation to the cytosol. Endocytic uptake of plasma non-transferrin-bound iron is a possible mechanism that can contribute to iron loading of cell types engaged in bulk/adsorptive endocytosis, highlighting the importance of its prevention by iron chelation. PMID:22180428

Speculative and Hedging Interaction Model in Oil and U.S. Dollar Markets—Phase Transition

NASA Astrophysics Data System (ADS)

Campbell, Michael; Carfì, David

2018-01-01

We show that there is a phase transition in the bounded rational Carfì-Musolino model, and the possibility of a market crash. This model has two types of operators: a real economic subject (Air) and one or more investment banks (Bank). It also has two markets: oil spot market and US dollar futures. Bank agents react to Air and equilibrate much more quickly than Air. Thus Air is an acting external agent due to its longer-term investing, whereas the action of the banks equilibrates before Air makes its next transaction. This model constitutes a potential game, and agents crowd their preferences into one of the markets at a critical temperature when air makes no purchases of oil futures.

Cultural heuristics in risk assessment of HIV/AIDS.

PubMed

Bailey, Ajay; Hutter, Inge

2006-01-01

Behaviour change models in HIV prevention tend to consider that risky sexual behaviours reflect risk assessments and that by changing risk assessments behaviour can be changed. Risk assessment is however culturally constructed. Individuals use heuristics or bounded cognitive devices derived from broader cultural meaning systems to rationalize uncertainty. In this study, we identify some of the cultural heuristics used by migrant men in Goa, India to assess their risk of HIV infection from different sexual partners. Data derives from a series of in-depth interviews and a locally informed survey. Cultural heuristics identified include visual heuristics, heuristics of gender roles, vigilance and trust. The paper argues that, for more culturally informed HIV/AIDS behaviour change interventions, knowledge of cultural heuristics is essential.

A Learning-Based Approach to Reactive Security

NASA Astrophysics Data System (ADS)

Barth, Adam; Rubinstein, Benjamin I. P.; Sundararajan, Mukund; Mitchell, John C.; Song, Dawn; Bartlett, Peter L.

Despite the conventional wisdom that proactive security is superior to reactive security, we show that reactive security can be competitive with proactive security as long as the reactive defender learns from past attacks instead of myopically overreacting to the last attack. Our game-theoretic model follows common practice in the security literature by making worst-case assumptions about the attacker: we grant the attacker complete knowledge of the defender's strategy and do not require the attacker to act rationally. In this model, we bound the competitive ratio between a reactive defense algorithm (which is inspired by online learning theory) and the best fixed proactive defense. Additionally, we show that, unlike proactive defenses, this reactive strategy is robust to a lack of information about the attacker's incentives and knowledge.

Control mechanisms for stochastic biochemical systems via computation of reachable sets.

PubMed

Lakatos, Eszter; Stumpf, Michael P H

2017-08-01

Controlling the behaviour of cells by rationally guiding molecular processes is an overarching aim of much of synthetic biology. Molecular processes, however, are notoriously noisy and frequently nonlinear. We present an approach to studying the impact of control measures on motifs of molecular interactions that addresses the problems faced in many biological systems: stochasticity, parameter uncertainty and nonlinearity. We show that our reachability analysis formalism can describe the potential behaviour of biological (naturally evolved as well as engineered) systems, and provides a set of bounds on their dynamics at the level of population statistics: for example, we can obtain the possible ranges of means and variances of mRNA and protein expression levels, even in the presence of uncertainty about model parameters.

Control mechanisms for stochastic biochemical systems via computation of reachable sets

PubMed Central

Lakatos, Eszter

2017-01-01

Controlling the behaviour of cells by rationally guiding molecular processes is an overarching aim of much of synthetic biology. Molecular processes, however, are notoriously noisy and frequently nonlinear. We present an approach to studying the impact of control measures on motifs of molecular interactions that addresses the problems faced in many biological systems: stochasticity, parameter uncertainty and nonlinearity. We show that our reachability analysis formalism can describe the potential behaviour of biological (naturally evolved as well as engineered) systems, and provides a set of bounds on their dynamics at the level of population statistics: for example, we can obtain the possible ranges of means and variances of mRNA and protein expression levels, even in the presence of uncertainty about model parameters. PMID:28878957

Are transaction taxes a cause of financial instability?

NASA Astrophysics Data System (ADS)

Fontini, Fulvio; Sartori, Elena; Tolotti, Marco

2016-05-01

We analyze a stylized market where N boundedly rational agents may decide to trade or not a share of a risky asset at subsequent trading dates. Agents' payoff depends on returns, which are endogenously determined taking into account observed and forecasted demand and an exogenous transaction tax. We study the time evolutions of demand, returns and market activity. We show that the introduction of a transaction tax generally helps in reducing variability of returns and market activity. On the other hand, there are market conditions under which a low taxation may lead the market into a very unstable phase characterized by the fluctuation of the fundamentals around two different regimes; indeed, under these circumstances, heteroscedasticity of time series is detected and statistically analyzed.

Can Limiting Choice Increase Social Welfare? The Elderly and Health Insurance

PubMed Central

Hanoch, Yaniv; Rice, Thomas

2006-01-01

Herbert Simon's work on bounded rationality has had little impact on health policy discourse, despite numerous supportive findings. This is particularly surprising in regard to the elderly, a group marked by a decline in higher cognitive functions. Elders' cognitive capacity to make decisions will be challenged even further with the introduction of the new Medicare prescription drug benefit program, mainly because of the many options available. At the same time, a growing body of evidence points to the perils of having too many choices. By combining research from decision science, economics, and psychology, we highlight the potential problems with the expanding health insurance choices facing the elderly and conclude with some policy suggestions to alleviate the problem. PMID:16529568

A note on bound constraints handling for the IEEE CEC'05 benchmark function suite.

PubMed

Liao, Tianjun; Molina, Daniel; de Oca, Marco A Montes; Stützle, Thomas

2014-01-01

The benchmark functions and some of the algorithms proposed for the special session on real parameter optimization of the 2005 IEEE Congress on Evolutionary Computation (CEC'05) have played and still play an important role in the assessment of the state of the art in continuous optimization. In this article, we show that if bound constraints are not enforced for the final reported solutions, state-of-the-art algorithms produce infeasible best candidate solutions for the majority of functions of the IEEE CEC'05 benchmark function suite. This occurs even though the optima of the CEC'05 functions are within the specified bounds. This phenomenon has important implications on algorithm comparisons, and therefore on algorithm designs. This article's goal is to draw the attention of the community to the fact that some authors might have drawn wrong conclusions from experiments using the CEC'05 problems.

Quantum discord bounds the amount of distributed entanglement.

PubMed

Chuan, T K; Maillard, J; Modi, K; Paterek, T; Paternostro, M; Piani, M

2012-08-17

The ability to distribute quantum entanglement is a prerequisite for many fundamental tests of quantum theory and numerous quantum information protocols. Two distant parties can increase the amount of entanglement between them by means of quantum communication encoded in a carrier that is sent from one party to the other. Intriguingly, entanglement can be increased even when the exchanged carrier is not entangled with the parties. However, in light of the defining property of entanglement stating that it cannot increase under classical communication, the carrier must be quantum. Here we show that, in general, the increase of relative entropy of entanglement between two remote parties is bounded by the amount of nonclassical correlations of the carrier with the parties as quantified by the relative entropy of discord. We study implications of this bound, provide new examples of entanglement distribution via unentangled states, and put further limits on this phenomenon.

Change and Continuity in Experiential Education: A Case Study.

ERIC Educational Resources Information Center

James, Thomas

1989-01-01

Traces program development at the North Carolina Outward Bound school from 1967 to 1987. Describes changes in the standard three-week challenge course, evolution of short intensive courses, and introduction of tailored contract courses in response to changing market demands. Discusses implications for institutional mission, identity, and…

Planning Responses to Demographic Change. AIR 1986 Annual Forum Paper.

ERIC Educational Resources Information Center

Taylor, Bryan J. R.; Taylor, Elizabeth A.

A method for forecasting the number of college graduates in the United Kingdom is described, and suggestions are offered about ways that society should react to influence declining enrollments and potential reductions in technologically skilled graduates. Consideration is given to the implications of recruiting noncollege-bound individuals to…

Pro-environmental behavior: rational choice meets moral motivation.

PubMed

Turaga, Rama Mohana R; Howarth, Richard B; Borsuk, Mark E

2010-01-01

The determinants of individual behaviors that provide shared environmental benefits are a longstanding theme in social science research. Alternative behavioral models yield markedly different predictions and policy recommendations. This paper reviews and compares the literatures from two disciplines that appear to be moving toward a degree of convergence. In social psychology, moral theories of pro-environmental behavior have focused on the influence of personal moral norms while recognizing that external factors, such as costs and incentives, ultimately limit the strength of the norm-behavior relationship. Rational choice models, such as the theory of planned behavior in social psychology and the theories of voluntary provision of public goods in economics, have sought to incorporate the effects of personal norms and to measure their importance in explaining behaviors, such as recycling and the demand for green products. This paper explores the relationship between these approaches and their implications for the theory and practice of ecological economics.

Structural basis of a rationally rewired protein-protein interface critical to bacterial signaling

PubMed Central

Podgornaia, Anna I.; Casino, Patricia; Marina, Alberto; Laub, Michael T.

2013-01-01

Summary Two-component signal transduction systems typically involve a sensor histidine kinase that specifically phosphorylates a single, cognate response regulator. This protein-protein interaction relies on molecular recognition via a small set of residues in each protein. To better understand how these residues determine the specificity of kinase-substrate interactions, we rationally rewired the interaction interface of a Thermotoga maritima two-component system, HK853-RR468, to match that found in a different two-component system, E. coli PhoR-PhoB. The rewired proteins interacted robustly with each other, but no longer interacted with the parent proteins. Analysis of the crystal structures of the wild-type and mutant protein complexes, along with a systematic mutagenesis study, reveals how individual mutations contribute to the rewiring of interaction specificity. Our approach and conclusions have implications for studies of other protein-protein interactions, protein evolution, and the design of novel protein interfaces. PMID:23954504

A social information processing approach to job attitudes and task design.

PubMed

Salancik, G R; Pfeffer, J

1978-06-01

This article outlines a social information processing approach to explain job attitudes. In comparison with need-satisfaction and expectancy models to job attitudes and motivation, the social information processing perspective emphasizes the effects of context and the consequences of past choices, rather than individual predispositions and rational decision-making processes. When an individual develops statements about attitude or needs, he or she uses social information--information about past behavior and about what others think. The process of attributing attitudes or needs from behavior is itself affected by commitment processes, by the saliency and relevance of information, and by the need to develop socially acceptable and legitimate rationalizations for actions. Both attitudes and need statements, as well as characterizations of jobs, are affected by informational social influence. The implications of the social information processing perspective for organization development efforts and programs of job redesign are discussed.

Reference-dependent risk sensitivity as rational inference.

PubMed

Denrell, Jerker C

2015-07-01

Existing explanations of reference-dependent risk sensitivity attribute it to cognitive imperfections and heuristic choice processes. This article shows that behavior consistent with an S-shaped value function could be an implication of rational inferences about the expected values of alternatives. Theoretically, I demonstrate that even a risk-neutral Bayesian decision maker, who is uncertain about the reliability of observations, should use variability in observed outcomes as a predictor of low expected value for outcomes above a reference level, and as a predictor of high expected value for outcomes below a reference level. Empirically, I show that combining past outcomes using an S-shaped value function leads to accurate predictions about future values. The theory also offers a rationale for why risk sensitivity consistent with an inverse S-shaped value function should occur in experiments on decisions from experience with binary payoff distributions. (c) 2015 APA, all rights reserved).

A rational model for maximizing the effects of therapeutic relationship regulation in personality disorders with poor metacognition and over-regulation of affects.

PubMed

Dimaggio, Giancarlo; Carcione, Antonino; Salvatore, Giampaolo; Semerari, Antonio; Nicolò, Giuseppe

2010-11-01

The therapeutic relationship plays a key role in personality disorder (PD) psychotherapy. Some aspects of therapeutic relationship regulation appear important for treatment of PD clients, including those with constricted relational schemas, poor metacognition, and over-regulation of affects described here. AIM.: To propose a rational model for how and when to work on the therapeutic relationship by treating the underlying personality pathology. Formalize a step-by-step procedure for performing operations such as validation of clients' experiences, creating a sense of sharedness, assessing the quality of the therapeutic relationship in order to prevent and repair ruptures in the alliance, self-disclosing by the therapist, and metacommunication on the basis of clients' responses to treatment. We discuss the implications of this model for further research into the PD therapy process. 2010 The British Psychological Society.

Clearing the smoke around medical marijuana.

PubMed

Ware, M A

2011-12-01

The hazy world of "medical marijuana" continues to cry out for clear data on which to base medical decision making and rational policy design. In this issue of Clinical Pharmacology & Therapeutics, Abrams and colleagues report that vaporized cannabis does not meaningfully affect opioid plasma levels and may even augment the efficacy of oxycodone and morphine in patients with chronic non-cancer pain. This Commentary considers the implications of this work for clinical practice and further research initiatives.

Irrational beliefs, optimism, pessimism, and psychological distress: a preliminary examination of differential effects in a college population.

PubMed

Chang, E C; Bridewell, W B

1998-02-01

The present study compared the effects of irrational beliefs measured by the Survey of Personal Beliefs (SPB) and optimism and pessimism as measured by the revised Life Orientation Test (LOT-R) on depressive and anxious symptoms 6 weeks later. Results of analysis of variances for both measures of psychological distress indicated a significant main effect for pessimism only. Implications for Ellis Rational Emotive Therapy are discussed.

Potent selective nonpeptidic inhibitors of human lung tryptase

PubMed Central

Burgess, Laurence E.; Newhouse, Bradley J.; Ibrahim, Prabha; Rizzi, James; Kashem, Mohammed A.; Hartman, Ann; Brandhuber, Barbara J.; Wright, Clifford D.; Thomson, David S.; Vigers, Guy P. A.; Koch, Kevin

1999-01-01

Human lung tryptase, a homotetrameric serine protease unique to mast cell secretory granules, has been implicated in the pathogenesis of asthma. A hypothesis that tethered symmetrical inhibitors might bridge two adjacent active sites was explored via a rationally designed series of bisbenzamidines. These compounds demonstrated a remarkable distanced-defined structure–activity relationship against human tryptase with one series possessing subnanomolar potencies. Additional evidence supporting the concept of active-site bridging is also presented. PMID:10411878

The Problem of Pseudoscience in Science Education and Implications of Constructivist Pedagogy

NASA Astrophysics Data System (ADS)

Mugaloglu, Ebru Z.

2014-04-01

The intrusion of pseudoscience into science classrooms is a problem in science education today. This paper discusses the implications of constructivist pedagogy, which relies on the notions of viability and inter-subjectivity, in a context favourable to the acceptance of pseudoscience. Examples from written statements illustrate how prospective science teachers in Turkey readily accept pseudoscientific explanations of the origin of species. Constructivist pedagogy underestimates, if not ignores, the difficulty of holding rational discussions in the presence of pseudoscientific or absolute beliefs. Moreover, it gives a higher priority to learners' exposure to alternative constructions through social negotiation than to furthering their appreciation of science. Under these circumstances, self-confirmation and social pressure to accept existing pseudoscientific beliefs may be unanticipated consequences of social negotiation. Considering the aim of science education to foster an appreciation of science, the implications of constructivist pedagogy are, or should be, of great concern to science educators.

Tailored coating of gold nanostars: rational approach to prototype of theranostic device based on SERS and photothermal effects at ultralow irradiance.

PubMed

Bassi, B; Dacarro, G; Galinetto, P; Giulotto, E; Marchesi, N; Pallavicini, P; Pascale, A; Perversi, S; Taglietti, A

2018-06-08

The last decade has come across an increasing demand for theranostic biocompatible nanodevices possessing the double ability of diagnosis and therapy. In this work, we report the design, synthesis and step-by-step characterization of rationally coated gold nanostars (GNSs) for the SERS imaging and photothermal therapy of HeLa cancer cells. The nanodevices were realized by synthesizing GNSs with a seed growth approach, coating them with a controlled mixture of thiols composed of a Raman reporter and a polyethylene glycol with a terminal amino group, and then reacting these amino groups with folic acid (FA), in order to impart selectivity towards cancer cells which overexpress folate receptors on their membranes. After a complete characterization, we demonstrate that these FA-functionalized GNSs (FA-GNSs) are able to bind selectively to the membranes of HeLa cells, acting as SERS tags and allowing SERS imaging. Moreover, we demonstrate that once bound to HeLa cell membranes, FA-GNSs exhibit photothermal effect which can be exploited to kill the same cells in vitro using laser irradiation in the NIR at a very low and safe irradiance. We thus demonstrate that the FA-GNSs designed following the described approach are an efficient prototype of theranostic nanodevices.

Cooperation in memory-based prisoner's dilemma game on interdependent networks

NASA Astrophysics Data System (ADS)

Luo, Chao; Zhang, Xiaolin; Liu, Hong; Shao, Rui

2016-05-01

Memory or so-called experience normally plays the important role to guide the human behaviors in real world, that is essential for rational decisions made by individuals. Hence, when the evolutionary behaviors of players with bounded rationality are investigated, it is reasonable to make an assumption that players in system are with limited memory. Besides, in order to unravel the intricate variability of complex systems in real world and make a highly integrative understanding of their dynamics, in recent years, interdependent networks as a comprehensive network structure have obtained more attention in this community. In this article, the evolution of cooperation in memory-based prisoner's dilemma game (PDG) on interdependent networks composed by two coupled square lattices is studied. Herein, all or part of players are endowed with finite memory ability, and we focus on the mutual influence of memory effect and interdependent network reciprocity on cooperation of spatial PDG. We show that the density of cooperation can be significantly promoted within an optimal region of memory length and interdependent strength. Furthermore, distinguished by whether having memory ability/external links or not, each kind of players on networks would have distinct evolutionary behaviors. Our work could be helpful to understand the emergence and maintenance of cooperation under the evolution of memory-based players on interdependent networks.

Tailored coating of gold nanostars: rational approach to prototype of theranostic device based on SERS and photothermal effects at ultralow irradiance

NASA Astrophysics Data System (ADS)

Bassi, B.; Dacarro, G.; Galinetto, P.; Giulotto, E.; Marchesi, N.; Pallavicini, P.; Pascale, A.; Perversi, S.; Taglietti, A.

2018-06-01

The last decade has come across an increasing demand for theranostic biocompatible nanodevices possessing the double ability of diagnosis and therapy. In this work, we report the design, synthesis and step-by-step characterization of rationally coated gold nanostars (GNSs) for the SERS imaging and photothermal therapy of HeLa cancer cells. The nanodevices were realized by synthesizing GNSs with a seed growth approach, coating them with a controlled mixture of thiols composed of a Raman reporter and a polyethylene glycol with a terminal amino group, and then reacting these amino groups with folic acid (FA), in order to impart selectivity towards cancer cells which overexpress folate receptors on their membranes. After a complete characterization, we demonstrate that these FA-functionalized GNSs (FA-GNSs) are able to bind selectively to the membranes of HeLa cells, acting as SERS tags and allowing SERS imaging. Moreover, we demonstrate that once bound to HeLa cell membranes, FA-GNSs exhibit photothermal effect which can be exploited to kill the same cells in vitro using laser irradiation in the NIR at a very low and safe irradiance. We thus demonstrate that the FA-GNSs designed following the described approach are an efficient prototype of theranostic nanodevices.

Bound of dissipation on a plane Couette dynamo

NASA Astrophysics Data System (ADS)

Alboussière, Thierry

2009-06-01

Variational turbulence is among the few approaches providing rigorous results in turbulence. In addition, it addresses a question of direct practical interest, namely, the rate of energy dissipation. Unfortunately, only an upper bound is obtained as a larger functional space than the space of solutions to the Navier-Stokes equations is searched. Yet, in some cases, this upper bound is in good agreement with experimental results in terms of order of magnitude and power law of the imposed Reynolds number. In this paper, the variational approach to turbulence is extended to the case of dynamo action and an upper bound is obtained for the global dissipation rate (viscous and Ohmic). A simple plane Couette flow is investigated. For low magnetic Prandtl number Pm fluids, the upper bound of energy dissipation is that of classical turbulence (i.e., proportional to the cubic power of the shear velocity) for magnetic Reynolds numbers below Pm-1 and follows a steeper evolution for magnetic Reynolds numbers above Pm-1 (i.e., proportional to the shear velocity to the power of 4) in the case of electrically insulating walls. However, the effect of wall conductance is crucial: for a given value of wall conductance, there is a value for the magnetic Reynolds number above which energy dissipation cannot be bounded. This limiting magnetic Reynolds number is inversely proportional to the square root of the conductance of the wall. Implications in terms of energy dissipation in experimental and natural dynamos are discussed.

Updated estimates of the climate response to emissions and their policy implications (Invited)

NASA Astrophysics Data System (ADS)

Allen, M. R.; Otto, A.; Stocker, T. F.; Frame, D. J.

2013-12-01

We review the implications of observations of the global energy budget over recent decades, particularly the 'warming hiatus' period over the 2000s, for key climate system properties including equilibrium climate sensitivity (ECS), transient climate response (TCR) and transient climate response to cumulative carbon emissions (TCRE). We show how estimates of the upper bound of ECS remain, as ever, sensitive to prior assumptions and also how ECS, even if it were better constrained, would provide much less information about the social cost of carbon than TCR or TCRE. Hence the excitement over recent, apparently conflicting, estimates of ECS, is almost entirely misplaced. Of greater potential policy significance is the fact that recent observations imply a modest (of order 25%) downward revision in the upper bound and most likely values of TCR and TCRE, as compared to some, but not all, of the estimates published in the mid-2000s. This is partly due to the recent reduced rate of warming, and partly due to revisions in estimates of total anthropogenic forcing to date. Both of these developments may turn out to be short-lived, so the policy implications of this modest revision in TCR/TCRE should not be over-sold: nevertheless, it is interesting to explore what they are. The implications for climate change adaptation of a 25% downward revision in TCR and TCRE are minimal, being overshadowed by uncertainty due to internal variability and non-CO2 climate forcings over typical timescales for adaptation planning. We introduce a simple framework for assessing the implications for mitigation in terms of timing of peak emissions average rates of emission reduction required to avoid specific levels of peak warming. We show that, as long as emissions continue to increase approximately exponentially, the implications for mitigation of any revisions in the climate response are surprisingly small.

Action understanding as inverse planning.

PubMed

Baker, Chris L; Saxe, Rebecca; Tenenbaum, Joshua B

2009-12-01

Humans are adept at inferring the mental states underlying other agents' actions, such as goals, beliefs, desires, emotions and other thoughts. We propose a computational framework based on Bayesian inverse planning for modeling human action understanding. The framework represents an intuitive theory of intentional agents' behavior based on the principle of rationality: the expectation that agents will plan approximately rationally to achieve their goals, given their beliefs about the world. The mental states that caused an agent's behavior are inferred by inverting this model of rational planning using Bayesian inference, integrating the likelihood of the observed actions with the prior over mental states. This approach formalizes in precise probabilistic terms the essence of previous qualitative approaches to action understanding based on an "intentional stance" [Dennett, D. C. (1987). The intentional stance. Cambridge, MA: MIT Press] or a "teleological stance" [Gergely, G., Nádasdy, Z., Csibra, G., & Biró, S. (1995). Taking the intentional stance at 12 months of age. Cognition, 56, 165-193]. In three psychophysical experiments using animated stimuli of agents moving in simple mazes, we assess how well different inverse planning models based on different goal priors can predict human goal inferences. The results provide quantitative evidence for an approximately rational inference mechanism in human goal inference within our simplified stimulus paradigm, and for the flexible nature of goal representations that human observers can adopt. We discuss the implications of our experimental results for human action understanding in real-world contexts, and suggest how our framework might be extended to capture other kinds of mental state inferences, such as inferences about beliefs, or inferring whether an entity is an intentional agent.

The roles of emotional competence and social problem-solving in the relationship between physical abuse and adolescent suicidal ideation in China.

PubMed

Kwok, Sylvia Y C L; Yeung, Jerf W K; Low, Andrew Y T; Lo, Herman H M; Tam, Cherry H L

2015-06-01

The study investigated the relationship among physical abuse, positive psychological factors including emotional competence and social problem-solving, and suicidal ideation among adolescents in China. The possible moderating effects of emotional competence and social problem-solving in the association between physical abuse and adolescent suicidal ideation were also studied. A cross-sectional survey employing convenience sampling was conducted and self-administered questionnaires were collected from 527 adolescents with mean age of 14 years from the schools in Shanghai. Results showed that physical abuse was significantly and positively related to suicidal ideation in both male and female adolescents. Emotional competence was not found to be significantly associated with adolescent suicidal ideation, but rational problem-solving, a sub-scale of social problem-solving, was shown to be significantly and negatively associated with suicidal ideation for males, but not for females. However, emotional competence and rational problem-solving were shown to be a significant and a marginally significant moderator in the relationship between physical abuse and suicidal ideation in females respectively, but not in males. High rational problem-solving buffered the negative impact of physical abuse on suicidal ideation for females. Interestingly, females with higher empathy and who reported being physically abused by their parents have higher suicidal ideation. Findings are discussed and implications are stated. It is suggested to change the attitudes of parents on the concept of physical abuse, guide them on appropriate attitudes, knowledge and skills in parenting, and enhance adolescents' skills in rational problem-solving. Copyright © 2015 Elsevier Ltd. All rights reserved.

Josephson junctions of multiple superconducting wires

NASA Astrophysics Data System (ADS)

Deb, Oindrila; Sengupta, K.; Sen, Diptiman

2018-05-01

We study the spectrum of Andreev bound states and Josephson currents across a junction of N superconducting wires which may have s - or p -wave pairing symmetries and develop a scattering matrix based formalism which allows us to address transport across such junctions. For N ≥3 , it is well known that Berry curvature terms contribute to the Josephson currents; we chart out situations where such terms can have relatively large effects. For a system of three s -wave or three p -wave superconductors, we provide analytic expressions for the Andreev bound-state energies and study the Josephson currents in response to a constant voltage applied across one of the wires; we find that the integrated transconductance at zero temperature is quantized to integer multiples of 4 e2/h , where e is the electron charge and h =2 π ℏ is Planck's constant. For a sinusoidal current with frequency ω applied across one of the wires in the junction, we find that Shapiro plateaus appear in the time-averaged voltage across that wire for any rational fractional multiple (in contrast to only integer multiples in junctions of two wires) of 2 e /(ℏ ω ) . We also use our formalism to study junctions of two p -wave and one s -wave wires. We find that the corresponding Andreev bound-state energies depend on the spin of the Bogoliubov quasiparticles; this produces a net magnetic moment in such junctions. The time variation of these magnetic moments may be controlled by an external voltage applied across the junction. We discuss experiments which may test our theory.

The role of ions in the self-healing behavior of soft particle suspensions

PubMed Central

Scotti, Andrea; Gasser, Urs; Herman, Emily S.; Pelaez-Fernandez, Miguel; Han, Jun; Menzel, Andreas; Lyon, L. Andrew; Fernández-Nieves, Alberto

2016-01-01

Impurities in crystals generally cause point defects and can even suppress crystallization. This general rule, however, does not apply to colloidal crystals formed by soft microgel particles [Iyer ASJ, Lyon LA (2009) Angew Chem Int Ed 48:4562–4566], as, in this case, the larger particles are able to shrink and join the crystal formed by a majority of smaller particles. Using small-angle X-ray scattering, we find the limit in large-particle concentration for this spontaneous deswelling to persist. We rationalize our data in the context of those counterions that are bound to the microgel particles as a result of the electrostatic attraction exerted by the fixed charges residing on the particle periphery. These bound counterions do not contribute to the suspension osmotic pressure in dilute conditions, as they can be seen as internal degrees of freedom associated with each microgel particle. In contrast, at sufficiently high particle concentrations, the counterion cloud of each particle overlaps with that of its neighbors, allowing these ions to freely explore the space outside the particles. We confirm this scenario by directly measuring the osmotic pressure of the suspension. Because these counterions are then no longer bound, they create an osmotic pressure difference between the inside and outside of the microgels, which, if larger than the microgel bulk modulus, can cause deswelling, explaining why large, soft microgel particles feel the squeeze when suspended with a majority of smaller particles. We perform small-angle neutron scattering measurements to further confirm this remarkable behavior. PMID:27125854

Revisiting the structures of several antibiotics bound to the bacterial ribosome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bulkley, David; Innis, C. Axel; Blaha, Gregor

2010-10-08

The increasing prevalence of antibiotic-resistant pathogens reinforces the need for structures of antibiotic-ribosome complexes that are accurate enough to enable the rational design of novel ribosome-targeting therapeutics. Structures of many antibiotics in complex with both archaeal and eubacterial ribosomes have been determined, yet discrepancies between several of these models have raised the question of whether these differences arise from species-specific variations or from experimental problems. Our structure of chloramphenicol in complex with the 70S ribosome from Thermus thermophilus suggests a model for chloramphenicol bound to the large subunit of the bacterial ribosome that is radically different from the prevailing model.more » Further, our structures of the macrolide antibiotics erythromycin and azithromycin in complex with a bacterial ribosome are indistinguishable from those determined of complexes with the 50S subunit of Haloarcula marismortui, but differ significantly from the models that have been published for 50S subunit complexes of the eubacterium Deinococcus radiodurans. Our structure of the antibiotic telithromycin bound to the T. thermophilus ribosome reveals a lactone ring with a conformation similar to that observed in the H. marismortui and D. radiodurans complexes. However, the alkyl-aryl moiety is oriented differently in all three organisms, and the contacts observed with the T. thermophilus ribosome are consistent with biochemical studies performed on the Escherichia coli ribosome. Thus, our results support a mode of macrolide binding that is largely conserved across species, suggesting that the quality and interpretation of electron density, rather than species specificity, may be responsible for many of the discrepancies between the models.« less

Revisiting the Structures of Several Antibiotics Bound to the Bacterial Ribosome

DOE Office of Scientific and Technical Information (OSTI.GOV)

D Bulkley; C Innis; G Blaha

2011-12-31

The increasing prevalence of antibiotic-resistant pathogens reinforces the need for structures of antibiotic-ribosome complexes that are accurate enough to enable the rational design of novel ribosome-targeting therapeutics. Structures of many antibiotics in complex with both archaeal and eubacterial ribosomes have been determined, yet discrepancies between several of these models have raised the question of whether these differences arise from species-specific variations or from experimental problems. Our structure of chloramphenicol in complex with the 70S ribosome from Thermus thermophilus suggests a model for chloramphenicol bound to the large subunit of the bacterial ribosome that is radically different from the prevailing model.more » Further, our structures of the macrolide antibiotics erythromycin and azithromycin in complex with a bacterial ribosome are indistinguishable from those determined of complexes with the 50S subunit of Haloarcula marismortui, but differ significantly from the models that have been published for 50S subunit complexes of the eubacterium Deinococcus radiodurans. Our structure of the antibiotic telithromycin bound to the T. thermophilus ribosome reveals a lactone ring with a conformation similar to that observed in the H. marismortui and D. radiodurans complexes. However, the alkyl-aryl moiety is oriented differently in all three organisms, and the contacts observed with the T. thermophilus ribosome are consistent with biochemical studies performed on the Escherichia coli ribosome. Thus, our results support a mode of macrolide binding that is largely conserved across species, suggesting that the quality and interpretation of electron density, rather than species specificity, may be responsible for many of the discrepancies between the models.« less

Emotions and Decisions: Beyond Conceptual Vagueness and the Rationality Muddle.

PubMed

Volz, Kirsten G; Hertwig, Ralph

2016-01-01

For centuries, decision scholars paid little attention to emotions: Decisions were modeled in normative and descriptive frameworks with little regard for affective processes. Recently, however, an "emotions revolution" has taken place, particularly in the neuroscientific study of decision making, putting emotional processes on an equal footing with cognitive ones. Yet disappointingly little theoretical progress has been made. The concepts and processes discussed often remain vague, and conclusions about the implications of emotions for rationality are contradictory and muddled. We discuss three complementary ways to move the neuroscientific study of emotion and decision making from agenda setting to theory building. The first is to use reverse inference as a hypothesis-discovery rather than a hypothesis-testing tool, unless its utility can be systematically quantified (e.g., through meta-analysis). The second is to capitalize on the conceptual inventory advanced by the behavioral science of emotions, testing those concepts and unveiling the underlying processes. The third is to model the interplay between emotions and decisions, harnessing existing cognitive frameworks of decision making and mapping emotions onto the postulated computational processes. To conclude, emotions (like cognitive strategies) are not rational or irrational per se: How (un)reasonable their influence is depends on their fit with the environment. © The Author(s) 2015.

(Ir)rationality in action: do soccer players and goalkeepers fail to learn how to best perform during a penalty kick?

PubMed

Bar-Eli, Michael; Azar, Ofer H; Lurie, Yotam

2009-01-01

This chapter discusses penalty kicks in soccer, interpreted within the framework of behavioral economics. We present two behaviors of professional soccer players during penalty kicks that seem nonoptimal, and possibly indicate biases in decision making. We ask whether, despite the huge incentives involved in professional soccer and the possibility of learning through feedback from the outcomes of previous penalty kicks, goalkeepers and penalty kickers are not optimizing their actions. We suggest that they do indeed learn to optimize, but have a different utility function; goalkeepers are not solely interested in minimizing the chances of the goal, and kickers are not solely interested in maximizing these chances. We believe that, in general, in cases where decision makers have the ability to learn through feedback about the outcome of their actions but exhibit behavior that seems nonoptimal, it is possible that they do optimize, but that their utility function is different from the one assumed. We propose that such decision makers' behavior be reconceived as "socially rational," in the sense that their social environment seems to be incorporated into their utility functions. Finally, the concept of "socio-emotional rationality" is suggested to account for possible implications in future studies of motion-cognition interactions.

The Development of CK2 Inhibitors: From Traditional Pharmacology to in Silico Rational Drug Design

PubMed Central

Cozza, Giorgio

2017-01-01

Casein kinase II (CK2) is an ubiquitous and pleiotropic serine/threonine protein kinase able to phosphorylate hundreds of substrates. Being implicated in several human diseases, from neurodegeneration to cancer, the biological roles of CK2 have been intensively studied. Upregulation of CK2 has been shown to be critical to tumor progression, making this kinase an attractive target for cancer therapy. Several CK2 inhibitors have been developed so far, the first being discovered by “trial and error testing”. In the last decade, the development of in silico rational drug design has prompted the discovery, de novo design and optimization of several CK2 inhibitors, active in the low nanomolar range. The screening of big chemical libraries and the optimization of hit compounds by Structure Based Drug Design (SBDD) provide telling examples of a fruitful application of rational drug design to the development of CK2 inhibitors. Ligand Based Drug Design (LBDD) models have been also applied to CK2 drug discovery, however they were mainly focused on methodology improvements rather than being critical for de novo design and optimization. This manuscript provides detailed description of in silico methodologies whose applications to the design and development of CK2 inhibitors proved successful and promising. PMID:28230762

The rationality of resistance: alternatives for engagement in complex emergencies.

PubMed

Gilgan, M

2001-03-01

The different conceptualisations of conflict in the complex emergency literature have profound implications on the perception of the agency of different groups and the prospects for conflict management. While much recent analysis has focused on the rational political and economic functions of violence, relatively little analysis has focused on why the majority of people chose not to resort to violence. Using Foucault's analysis of power relations, a new framework for conflict analysis is proposed which includes non-violent resistance as well as violence as a means of domination. Non-violent resistance is explored as a rational, highly adaptable response to acts of domination. A comprehensive understanding of conflict must recognise local forms of resistance and identify the barriers and opportunities for the engagement of the international humanitarian community with these groups. This engagement can be used to foster capacities for the creation of legitimate, inclusive, non-violent political and economic processes in the attempt to provide alternatives for everyone in the conflict. If the purpose of the study of complex emergencies is to understand the nature of various conflicts and, based on that understanding, make recommendations for possible routes to conflict management, the analysis of local resistance and efforts to foster it must become a major aspect of the research agenda.

Decision-Making Capacity and Unusual Beliefs: Two Contentious Cases : Australasian Association of Bioethics and Health Law John McPhee (Law) Student Essay Prize 2016.

PubMed

Hyslop, Brent

2017-09-01

Decision-making capacity is a vital concept in law, ethics, and clinical practice. Two legal cases where capacity literally had life and death significance are NHS Trust v Ms T [2004] and Kings College Hospital v C [2015]. These cases share another feature: unusual beliefs. This essay will critically assess the concept of capacity, particularly in relation to the unusual beliefs in these cases. Firstly, the interface between capacity and unusual beliefs will be examined. This will show that the "using and weighing of information" is the pivotal element in assessment. Next, this essay will explore the relationship between capacity assessment and a decision's "rationality." Then, in light of these findings, the essay will appraise the judgments in NHS v T and Kings v C, and consider these judgments' implications. More broadly, this essay asks: Does capacity assessment examine only the decision-making process (as the law states), or is it also influenced by a decision's rationality? If influenced by rationality, capacity assessment has the potential to become "a search and disable policy aimed at those who are differently orientated in the human life-world" (Gillett 2012, 233). In contentious cases like these, this potential deserves attention.

The database search problem: a question of rational decision making.

PubMed

Gittelson, S; Biedermann, A; Bozza, S; Taroni, F

2012-10-10

This paper applies probability and decision theory in the graphical interface of an influence diagram to study the formal requirements of rationality which justify the individualization of a person found through a database search. The decision-theoretic part of the analysis studies the parameters that a rational decision maker would use to individualize the selected person. The modeling part (in the form of an influence diagram) clarifies the relationships between this decision and the ingredients that make up the database search problem, i.e., the results of the database search and the different pairs of propositions describing whether an individual is at the source of the crime stain. These analyses evaluate the desirability associated with the decision of 'individualizing' (and 'not individualizing'). They point out that this decision is a function of (i) the probability that the individual in question is, in fact, at the source of the crime stain (i.e., the state of nature), and (ii) the decision maker's preferences among the possible consequences of the decision (i.e., the decision maker's loss function). We discuss the relevance and argumentative implications of these insights with respect to recent comments in specialized literature, which suggest points of view that are opposed to the results of our study. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

End-of-life decision making is more than rational.

PubMed

Eliott, Jaklin A; Olver, Ian N

2005-01-01

Most medical models of end-of-life decision making by patients assume a rational autonomous adult obtaining and deliberating over information to arrive at some conclusion. If the patient is deemed incapable of this, family members are often nominated as substitutes, with assumptions that the family are united and rational. These are problematic assumptions. We interviewed 23 outpatients with cancer about the decision not to resuscitate a patient following cardiopulmonary arrest and examined their accounts of decision making using discourse analytical techniques. Our analysis suggests that participants access two different interpretative repertoires regarding the construct of persons, invoking a 'modernist' repertoire to assert the appropriateness of someone, a patient or family, making a decision, and a 'romanticist' repertoire when identifying either a patient or family as ineligible to make the decision. In determining the appropriateness of an individual to make decisions, participants informally apply 'Sanity' and 'Stability' tests, assessing both an inherent ability to reason (modernist repertoire) and the presence of emotion (romanticist repertoire) which might impact on the decision making process. Failure to pass the tests respectively excludes or excuses individuals from decision making. The absence of the romanticist repertoire in dominant models of patient decision making has ethical implications for policy makers and medical practitioners dealing with dying patients and their families.

Your Choice Beyond a Degree.

ERIC Educational Resources Information Center

Crowther, Roger, Ed.

A major aim of this book (part of the Careers Research and Advisory Centre Choice Series) is to assist college bound students in England who are about to choose their degree course of study, to understand the implications, especially those reflecting recent employment trends for graduates, of their choice in career terms. Section I contains two…

Nonlinear dynamics in ecosystem response to climatic change: case studies and policy implications.

Treesearch

Virginia R. Burkett; Douglas A. Wilcox; Robert Stottlemeyer; Wylie Barrow; Dan Fagre; Jill Baron; Jeff Price; Jennifer L. Nielsen; Craig D. Allen; David L. Peterson; Greg Ruggerone; Thomas Doyle

2005-01-01

Many biological, hydrological, and geological processes are interactively linked in ecosystems. These ecological phenomena normally vary within bounded ranges, but rapid, nonlinear changes to markedly different conditions can be triggered by even small differences if threshold values are exceeded. Intrinsic and extrinsic ecological thresholds can lead to effects that...

A Study of Online Exams Procrastination Using Data Analytics Techniques

ERIC Educational Resources Information Center

Levy, Yair; Ramim, Michelle M.

2012-01-01

Procrastination appears to be an inevitable part of daily life, especially for activities that are bounded by deadlines. It has implications for performance and is known to be linked to poor personal time management. Although research related to procrastination as a general behavior has been well established, studies assessing procrastination in…

Helping Students Cross the Threshold: Implications from a University Writing Assessment

ERIC Educational Resources Information Center

Brockman, Elizabeth; Taylor, Marcy; Crawford, MaryAnn K.; Kreth, Melinda

2010-01-01

Some "English Journal" ("EJ") readers may fondly (or not so fondly) remember reading lists for college-bound students, which were once routinely distributed to promote the reading of "The Scarlet Letter," "Pride and Prejudice," "The Pearl," and other noteworthy classics. Today, virtually any English teacher would recognize that a focus on solely…

Cultural Trends and the Implications for the Transformation of the Bundeswehr

DTIC Science & Technology

2006-06-01

another--is much more intensive than ever before; due to modern mass and communication media, cultural changes proceed much faster and in part more...Weltbevölkerungsbericht 2005. Retrieved 6/2/06 from www.dsw- online.de/kopf1/wbbericht/b_wbb2001_1.html. 9 globalization of mass communication (e.g., in the...modern age, i.e. pluralism and rationality, human rights, tolerance, openness and differentiation, with the means of modern organization, communication

Food distribution as a guarantee for nutrition and health: China's experience.

PubMed

Wang, V L

1976-01-01

In China, agriculture, health, education, and welfare are intricately woven as part of the development and its relationship to health programs, the strategy of food rationing and the "private plot" to improve nutrition and health, and the balance of food and population in the Chinese society. China's nutritional experience contributes significantly to understanding the role of "energy food" in the struggle against protein malnutrition and hunger. The author has outlined the implications for the developing countries.

Exploration of charge states of balanol analogues acting as ATP-competitive inhibitors in kinases.

PubMed

Hardianto, Ari; Yusuf, Muhammad; Liu, Fei; Ranganathan, Shoba

2017-12-28

(-)-Balanol is an ATP mimic that inhibits protein kinase C (PKC) isozymes and cAMP-dependent protein kinase (PKA) with limited selectivity. While PKA is a tumour promoter, PKC isozymes act as tumour promoters or suppressors, depending on the cancer type. In particular, PKCε is frequently implicated in cancer promotion, making it a potential target for anticancer drugs. To improve isozyme selectivity of balanol, exhaustive structural and activity relationship (SAR) studies have been performed in the last two decades, but with limited success. More recently, fluorination on balanol has shown improved selectivity for PKCε, although the fluorine effect is not yet clearly understood. Understanding the origin to this fluorine-based selectivity will be valuable for designing better balanol-based ATP mimicking inhibitors. Computational approaches such as molecular dynamics (MD) simulations can decipher the fluorine effect, provided that correct charges have been assigned to a ligand. Balanol analogues have multiple ionisable functional groups and the effect of fluorine substitutions on the exact charge state of each analogue bound to PKA and to PKCε needs to be thoroughly investigated in order to design highly selective inhibitors for therapeutic applications. We explored the charge states of novel fluorinated balanol analogues using MD simulations. For different potential charge states of these analogues, Molecular Mechanics Generalized Born Surface Area (MMGBSA) binding energy values were computed. This study suggests that balanol and the most potent fluorinated analogue (5S fluorine substitution on the azepane ring), have charges on the azepane ring (N1), and the phenolic (C6''OH) and the carboxylate (C15''O 2 H) groups on the benzophenone moiety, when bound to PKCε as well as PKA. To the best our knowledge, this is the first study showing that the phenolate group is charged in balanol and its analogues binding to the ATP site of PKCε. Correct charge assignments of ligands are important to obtain predicted binding energy values from MD simulations that reflect experimental values. Both fluorination and the local enzymatic environment of the ATP site can influence the exact charge states of balanol analogues. Overall, this study is highly valuable for further rational design of potent balanol analogues selective to PKCε.

Cryo-Trapping the Distorted Octahedral Reaction Intermediate of Manganese Superoxide Dismutase

NASA Technical Reports Server (NTRS)

Borgstahl, Gloria; Snell, Edward H.; Rose, M. Franklin (Technical Monitor)

2000-01-01

Superoxide dismutase protects organisms from potentially damaging oxygen radicals by catalyzing the disproportion of superoxide to oxygen and hydrogen peroxide. We report the use of cryogenic temperatures to kinetically trap the 6th ligand bound to the active site of manganese superoxide dismutase. Using cryocrystallography and synchrotron radiation, we describe at 1.55A resolution the six-coordinate, distorted octahedral geometry assumed by the active site during catalysis and compare it to the room temperature, five-coordinate trigonal-bipyramidal active site. Gateway residues Tyr34, His30 and a tightly bound water molecule are implicated in closing off the active site and blocking the escape route of superoxide during dismutation.

Cosmological bounds on neutrino statistics

NASA Astrophysics Data System (ADS)

de Salas, P. F.; Gariazzo, S.; Laveder, M.; Pastor, S.; Pisanti, O.; Truong, N.

2018-03-01

We consider the phenomenological implications of the violation of the Pauli exclusion principle for neutrinos, focusing on cosmological observables such as the spectrum of Cosmic Microwave Background anisotropies, Baryon Acoustic Oscillations and the primordial abundances of light elements. Neutrinos that behave (at least partly) as bosonic particles have a modified equilibrium distribution function that implies a different influence on the evolution of the Universe that, in the case of massive neutrinos, can not be simply parametrized by a change in the effective number of neutrinos. Our results show that, despite the precision of the available cosmological data, only very weak bounds can be obtained on neutrino statistics, disfavouring a more bosonic behaviour at less than 2σ.

The Structural Basis for Activation and Inhibition of ZAP-70 Kinase Domain.

PubMed

Huber, Roland G; Fan, Hao; Bond, Peter J

2015-10-01

ZAP-70 (Zeta-chain-associated protein kinase 70) is a tyrosine kinase that interacts directly with the activated T-cell receptor to transduce downstream signals, and is hence a major player in the regulation of the adaptive immune response. Dysfunction of ZAP-70 causes selective T cell deficiency that in turn results in persistent infections. ZAP-70 is activated by a variety of signals including phosphorylation of the kinase domain (KD), and binding of its regulatory tandem Src homology 2 (SH2) domains to the T cell receptor. The present study investigates molecular mechanisms of activation and inhibition of ZAP-70 via atomically detailed molecular dynamics simulation approaches. We report microsecond timescale simulations of five distinct states of the ZAP-70 KD, comprising apo, inhibited and three phosphorylated variants. Extensive analysis of local flexibility and correlated motions reveal crucial transitions between the states, thus elucidating crucial steps in the activation mechanism of the ZAP-70 KD. Furthermore, we rationalize previously observed staurosporine-bound crystal structures, suggesting that whilst the KD superficially resembles an "active-like" conformation, the inhibitor modulates the underlying protein dynamics and restricts it in a compact, rigid state inaccessible to ligands or cofactors. Finally, our analysis reveals a novel, potentially druggable pocket in close proximity to the activation loop of the kinase, and we subsequently use its structure in fragment-based virtual screening to develop a pharmacophore model. The pocket is distinct from classical type I or type II kinase pockets, and its discovery offers promise in future design of specific kinase inhibitors, whilst mutations in residues associated with this pocket are implicated in immunodeficiency in humans.

The Structural Basis for Activation and Inhibition of ZAP-70 Kinase Domain

PubMed Central

Huber, Roland G.; Fan, Hao; Bond, Peter J.

2015-01-01

ZAP–70 (Zeta-chain-associated protein kinase 70) is a tyrosine kinase that interacts directly with the activated T-cell receptor to transduce downstream signals, and is hence a major player in the regulation of the adaptive immune response. Dysfunction of ZAP–70 causes selective T cell deficiency that in turn results in persistent infections. ZAP–70 is activated by a variety of signals including phosphorylation of the kinase domain (KD), and binding of its regulatory tandem Src homology 2 (SH2) domains to the T cell receptor. The present study investigates molecular mechanisms of activation and inhibition of ZAP–70 via atomically detailed molecular dynamics simulation approaches. We report microsecond timescale simulations of five distinct states of the ZAP–70 KD, comprising apo, inhibited and three phosphorylated variants. Extensive analysis of local flexibility and correlated motions reveal crucial transitions between the states, thus elucidating crucial steps in the activation mechanism of the ZAP–70 KD. Furthermore, we rationalize previously observed staurosporine-bound crystal structures, suggesting that whilst the KD superficially resembles an “active-like” conformation, the inhibitor modulates the underlying protein dynamics and restricts it in a compact, rigid state inaccessible to ligands or cofactors. Finally, our analysis reveals a novel, potentially druggable pocket in close proximity to the activation loop of the kinase, and we subsequently use its structure in fragment-based virtual screening to develop a pharmacophore model. The pocket is distinct from classical type I or type II kinase pockets, and its discovery offers promise in future design of specific kinase inhibitors, whilst mutations in residues associated with this pocket are implicated in immunodeficiency in humans. PMID:26473606

Coupling of active motion and advection shapes intracellular cargo transport.

PubMed

Khuc Trong, Philipp; Guck, Jochen; Goldstein, Raymond E

2012-07-13

Intracellular cargo transport can arise from passive diffusion, active motor-driven transport along cytoskeletal filament networks, and passive advection by fluid flows entrained by such cargo-motor motion. Active and advective transport are thus intrinsically coupled as related, yet different representations of the same underlying network structure. A reaction-advection-diffusion system is used here to show that this coupling affects the transport and localization of a passive tracer in a confined geometry. For sufficiently low diffusion, cargo localization to a target zone is optimized either by low reaction kinetics and decoupling of bound and unbound states, or by a mostly disordered cytoskeletal network with only weak directional bias. These generic results may help to rationalize subtle features of cytoskeletal networks, for example as observed for microtubules in fly oocytes.

Charge Carriers Modulate the Bonding of Semiconductor Nanoparticle Dopants As Revealed by Time-Resolved X-ray Spectroscopy

DOE PAGES

Hassan, Asra; Zhang, Xiaoyi; Liu, Xiaohan; ...

2017-08-28

Understanding the electronic structure of doped semiconductors is essential to realize advancements in electronics and in the rational design of nanoscale devices. Here, we report the results of time-resolved X-ray absorption studies on copper-doped cadmium sulfide nanoparticles that provide an explicit description of the electronic dynamics of the dopants. The interaction of a dopant ion and an excess charge carrier is unambiguously observed via monitoring the oxidation state. The experimental data combined with DFT calculations demonstrate that dopant bonding to the host matrix is modulated by its interaction with charge carriers. Additionally, the transient photoluminescence and the kinetics of dopantmore » oxidation reveal the presence of two types of surface-bound ions that create mid-gap states.« less

Hyperspherical nuclear motion of H3 + and D3 + in the electronic triplet state, a 3Sigmau +.

PubMed

Ferreira, Tiago Mendes; Alijah, Alexander; Varandas, António J C

2008-02-07

The potential energy surface of H(3) (+) in the lowest electronic triplet state, a (3)Sigma(u) (+), shows three equivalent minima at linear nuclear configurations. The vibrational levels of H(3) (+) and D(3) (+) on this surface can therefore be described as superimposed linear molecule states. Owing to such a superposition, each vibrational state characterized by quantum numbers of an isolated linear molecule obtains a one- and a two-dimensional component. The energy splittings between the two components have now been rationalized within a hyperspherical picture. It is shown that nuclear motion along the hyperangle phi mainly accounts for the splittings and provides upper bounds. This hyperspherical motion can be considered an extension of the antisymmetric stretching motion of the individual linear molecule.

Robust consensus algorithm for multi-agent systems with exogenous disturbances under convergence conditions

NASA Astrophysics Data System (ADS)

Jiang, Yulian; Liu, Jianchang; Tan, Shubin; Ming, Pingsong

2014-09-01

In this paper, a robust consensus algorithm is developed and sufficient conditions for convergence to consensus are proposed for a multi-agent system (MAS) with exogenous disturbances subject to partial information. By utilizing H∞ robust control, differential game theory and a design-based approach, the consensus problem of the MAS with exogenous bounded interference is resolved and the disturbances are restrained, simultaneously. Attention is focused on designing an H∞ robust controller (the robust consensus algorithm) based on minimisation of our proposed rational and individual cost functions according to goals of the MAS. Furthermore, sufficient conditions for convergence of the robust consensus algorithm are given. An example is employed to demonstrate that our results are effective and more capable to restrain exogenous disturbances than the existing literature.

Does the market maker stabilize the market?

NASA Astrophysics Data System (ADS)

Zhu, Mei; Chiarella, Carl; He, Xue-Zhong; Wang, Duo

2009-08-01

The market maker plays an important role in price formation, but his/her behavior and stabilizing impact on the market are relatively unclear, in particular in speculative markets. This paper develops a financial market model that examines the impact on market stability of the market maker, who acts as both a liquidity provider and an active investor in a market consisting of two types of boundedly rational speculative investors-the fundamentalists and trend followers. We show that the market maker does not necessarily stabilize the market when he/she actively manages the inventory to maximize profits, and that rather the market maker’s impact depends on the behavior of the speculators. Numerical simulations show that the model is able to generate outcomes for asset returns and market inventories that are consistent with empirical findings.

Charge Carriers Modulate the Bonding of Semiconductor Nanoparticle Dopants As Revealed by Time-Resolved X-ray Spectroscopy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hassan, Asra; Zhang, Xiaoyi; Liu, Xiaohan

Understanding the electronic structure of doped semiconductors is essential to realize advancements in electronics and in the rational design of nanoscale devices. Here, we report the results of time-resolved X-ray absorption studies on copper-doped cadmium sulfide nanoparticles that provide an explicit description of the electronic dynamics of the dopants. The interaction of a dopant ion and an excess charge carrier is unambiguously observed via monitoring the oxidation state. The experimental data combined with DFT calculations demonstrate that dopant bonding to the host matrix is modulated by its interaction with charge carriers. Additionally, the transient photoluminescence and the kinetics of dopantmore » oxidation reveal the presence of two types of surface-bound ions that create mid-gap states.« less

On a class of nonlinear dispersive-dissipative interactions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rosenau, P.

1997-07-29

The authors study the prototypical, genuinely nonlinear, equation; u{sub t} + a(u{sup m}){sub x} + (u{sup n}){sub xxx} = {mu}(u{sup k}){sub xx}, a, {mu} = consts., which encompasses a wide variety of dissipative-dispersive interactions. The parametric surface k = (m + n)/2 separates diffusion dominated from dissipation dominated phenomena. On this surface dissipative and dispersive effects are in detailed balance for all amplitudes. In particular, the m = n + 2 = k + 1 subclass can be transformed into a form free of convection and dissipation making it accessible to theoretical studies. Both bounded and unbounded oscillations are foundmore » and certain exact solutions are presented. When a = (2{mu}3/){sup 2} the map yields a linear equation; rational, periodic and aperiodic solutions are constructed.« less

Bounds on area and charge for marginally trapped surfaces with a cosmological constant

NASA Astrophysics Data System (ADS)

Simon, Walter

2012-03-01

We sharpen the known inequalities AΛ ⩽ 4π(1 - g) (Hayward et al 1994 Phys. Rev. D 49 5080, Woolgar 1999 Class. Quantum Grav. 16 3005) and A ⩾ 4πQ2 (Dain et al 2012 Class. Quantum Grav. 29 035013) between the area A and the electric charge Q of a stable marginally outer-trapped surface (MOTS) of genus g in the presence of a cosmological constant Λ. In particular, instead of requiring stability we include the principal eigenvalue λ of the stability operator. For Λ* = Λ + λ > 0, we obtain a lower and an upper bound for Λ*A in terms of Λ*Q2, as well as the upper bound Q \\le 1/(2\\sqrt{\\Lambda ^{*}}) for the charge, which reduces to Q \\le 1/(2\\sqrt{\\Lambda }) in the stable case λ ⩾ 0. For Λ* < 0, there only remains a lower bound on A. In the spherically symmetric, static, stable case, one of our area inequalities is saturated iff the surface gravity vanishes. We also discuss implications of our inequalities for ‘jumps’ and mergers of charged MOTS.

Preventing skin cancer through behavior change. Implications for interventions.

PubMed

Rossi, J S; Blais, L M; Redding, C A; Weinstock, M A

1995-07-01

Sun exposure is the only major causative factor for skin cancer for which prevention is feasible. Both individual and community-based interventions have been effective in changing sun exposure knowledge and attitudes but generally have not been effective in changing behaviors. An integrative model of behavior change is described that has been successful in changing behavior across a wide range of health conditions. This model holds promise for developing a rational public health approach to skin cancer prevention based on sound behavioral science.

Heat flow bounds over the Cascadia margin derived from bottom simulating reflectors and implications for thermal models of subduction

NASA Astrophysics Data System (ADS)

Phrampus, Benjamin J.; Harris, Robert N.; Tréhu, Anne M.

2017-09-01

Understanding the thermal structure of the Cascadia subduction zone is important for understanding megathrust earthquake processes and seismogenic potential. Currently our understanding of the thermal structure of Cascadia is limited by a lack of high spatial resolution heat flow data and by poor understanding of thermal processes such as hydrothermal fluid circulation in the subducting basement, sediment thickening and dewatering, and frictional heat generation on the plate boundary. Here, using a data set of publically available seismic lines combined with new interpretations of bottom simulating reflector (BSR) distributions, we derive heat flow estimates across the Cascadia margin. Thermal models that account for hydrothermal circulation predict BSR-derived heat flow bounds better than purely conductive models, but still over-predict surface heat flows. We show that when the thermal effects of in-situ sedimentation and of sediment thickening and dewatering due to accretion are included, models with hydrothermal circulation become consistent with our BSR-derived heat flow bounds.

Health sciences librarians and mental health laws.

PubMed Central

Hartz, F R

1978-01-01

Two U.S. Supreme Court decisions, O'Connor v. Donaldson and Bounds v. Smith, hold important implications for health sciences librarians serving in mental health facilities. The first, O'Connor, with its many ancillary holdings, puts mental health personnel on notice that patients have certain basic rights, which courts all over the country will now be required to enforce. In Bounds the court has ruled that prison authorities must assist prison inmates in preparing and filing legal papers. The ruling will most likely benefit all mentally disabled prisoners, and future litigation may expand this category to include: (1) persons committed under the criminal code, (2) persons under involuntary commitment not related to the criminal code, and (3) persons voluntarily committed. A selective annotated bibliography, consisting of background readings in mental health and the law, basic rights, law library materials, and mental health legal services, has been compiled to help librarians establish and develop legal collections in anticipation of court decisions that will expand the conditions of Bounds to include all mentally disabled patients. PMID:361117

Enumeration of Extended m-Regular Linear Stacks.

PubMed

Guo, Qiang-Hui; Sun, Lisa H; Wang, Jian

2016-12-01

The contact map of a protein fold in the two-dimensional (2D) square lattice has arc length at least 3, and each internal vertex has degree at most 2, whereas the two terminal vertices have degree at most 3. Recently, Chen, Guo, Sun, and Wang studied the enumeration of [Formula: see text]-regular linear stacks, where each arc has length at least [Formula: see text] and the degree of each vertex is bounded by 2. Since the two terminal points in a protein fold in the 2D square lattice may form contacts with at most three adjacent lattice points, we are led to the study of extended [Formula: see text]-regular linear stacks, in which the degree of each terminal point is bounded by 3. This model is closed to real protein contact maps. Denote the generating functions of the [Formula: see text]-regular linear stacks and the extended [Formula: see text]-regular linear stacks by [Formula: see text] and [Formula: see text], respectively. We show that [Formula: see text] can be written as a rational function of [Formula: see text]. For a certain [Formula: see text], by eliminating [Formula: see text], we obtain an equation satisfied by [Formula: see text] and derive the asymptotic formula of the numbers of [Formula: see text]-regular linear stacks of length [Formula: see text].

1H, 15N and 13C resonance assignments for free and IEEVD peptide-bound forms of the tetratricopeptide repeat domain from the human E3 ubiquitin ligase CHIP.

PubMed

Zhang, Huaqun; McGlone, Cameron; Mannion, Matthew M; Page, Richard C

2017-04-01

The ubiquitin ligase CHIP catalyzes covalent attachment of ubiquitin to unfolded proteins chaperoned by the heat shock proteins Hsp70/Hsc70 and Hsp90. CHIP interacts with Hsp70/Hsc70 and Hsp90 by binding of a C-terminal IEEVD motif found in Hsp70/Hsc70 and Hsp90 to the tetratricopeptide repeat (TPR) domain of CHIP. Although recruitment of heat shock proteins to CHIP via interaction with the CHIP-TPR domain is well established, alterations in structure and dynamics of CHIP upon binding are not well understood. In particular, the absence of a structure for CHIP-TPR in the free form presents a significant limitation upon studies seeking to rationally design inhibitors that may disrupt interactions between CHIP and heat shock proteins. Here we report the 1 H, 13 C, and 15 N backbone and side chain chemical shift assignments for CHIP-TPR in the free form, and backbone chemical shift assignments for CHIP-TPR in the IEEVD-bound form. The NMR resonance assignments will enable further studies examining the roles of dynamics and structure in regulating interactions between CHIP and the heat shock proteins Hsp70/Hsc70 and Hsp90.

Approaching rational epitope vaccine design for hepatitis C virus with meta-server and multivalent scaffolding

NASA Astrophysics Data System (ADS)

He, Linling; Cheng, Yushao; Kong, Leopold; Azadnia, Parisa; Giang, Erick; Kim, Justin; Wood, Malcolm R.; Wilson, Ian A.; Law, Mansun; Zhu, Jiang

2015-08-01

Development of a prophylactic vaccine against hepatitis C virus (HCV) has been hampered by the extraordinary viral diversity and the poor host immune response. Scaffolding, by grafting an epitope onto a heterologous protein scaffold, offers a possible solution to epitope vaccine design. In this study, we designed and characterized epitope vaccine antigens for the antigenic sites of HCV envelope glycoproteins E1 (residues 314-324) and E2 (residues 412-423), for which neutralizing antibody-bound structures are available. We first combined six structural alignment algorithms in a “scaffolding meta-server” to search for diverse scaffolds that can structurally accommodate the HCV epitopes. For each antigenic site, ten scaffolds were selected for computational design, and the resulting epitope scaffolds were analyzed using structure-scoring functions and molecular dynamics simulation. We experimentally confirmed that three E1 and five E2 epitope scaffolds bound to their respective neutralizing antibodies, but with different kinetics. We then investigated a “multivalent scaffolding” approach by displaying 24 copies of an epitope scaffold on a self-assembling nanoparticle, which markedly increased the avidity of antibody binding. Our study thus demonstrates the utility of a multi-scale scaffolding strategy in epitope vaccine design and provides promising HCV immunogens for further assessment in vivo.

The Multi/Plural Turn, Postcolonial Theory, and Neoliberal Multiculturalism: Complicities and Implications for Applied Linguistics

ERIC Educational Resources Information Center

Kubota, Ryuko

2016-01-01

In applied linguistics and language education, an increased focus has been placed on plurality and hybridity to challenge monolingualism, the native speaker norm, and the modernist view of language and language use as unitary and bounded. The multi/plural turn parallels postcolonial theory in that they both support hybridity and fluidity while…

Scenes of Chaos and Joy: Playing and Performing Selves in Digitally Virtu/Real Places

ERIC Educational Resources Information Center

Szafran, Denice Joy

2012-01-01

Since the creation of the World Wide Web, researchers have attempted to understand the larger cultural and societal implications of this "space that is not a space" on identity, community, expression, and behavior. Ethnographies and analyses of bounded online gathering spaces, however, contain little concern focused on the expressions of play and…

Islamic Reformation: A History of "Madrasa" Reform and Legal Change in Egypt

ERIC Educational Resources Information Center

Gesink, Indira Falk

2006-01-01

According to contemporary media opinion, the problem with Islam, and by implication, with Islamic education, is that it never underwent a reformation that freed individual religious inquiry from the control of a religious hierarchy. Thus, it has been assumed that Islam and Islamic education remain bound to rigid seventh-century codes of belief.…

Recent Innovations in the Changing Criterion Design: Implications for Research and Practice in Special Education

ERIC Educational Resources Information Center

McDougall, Dennis; Hawkins, Jacqueline; Brady, Michael; Jenkins, Amelia

2006-01-01

This article illustrates (a) 2 recent innovations in the changing criterion research design, (b) how these innovations apply to research and practice in special education, and (c) how clinical needs influence design features of the changing criterion design. The first innovation, the range-bound changing criterion, is a very simple variation of…

Upper and lower bounds of ground-motion variabilities: implication for source properties

NASA Astrophysics Data System (ADS)

Cotton, Fabrice; Reddy-Kotha, Sreeram; Bora, Sanjay; Bindi, Dino

2017-04-01

One of the key challenges of seismology is to be able to analyse the physical factors that control earthquakes and ground-motion variabilities. Such analysis is particularly important to calibrate physics-based simulations and seismic hazard estimations at high frequencies. Within the framework of the development of ground-motion prediction equation (GMPE) developments, ground-motions residuals (differences between recorded ground motions and the values predicted by a GMPE) are computed. The exponential growth of seismological near-source records and modern GMPE analysis technics allow to partition these residuals into between- and a within-event components. In particular, the between-event term quantifies all those repeatable source effects (e.g. related to stress-drop or kappa-source variability) which have not been accounted by the magnitude-dependent term of the model. In this presentation, we first discuss the between-event variabilities computed both in the Fourier and Response Spectra domains, using recent high-quality global accelerometric datasets (e.g. NGA-west2, Resorce, Kiknet). These analysis lead to the assessment of upper bounds for the ground-motion variability. Then, we compare these upper bounds with lower bounds estimated by analysing seismic sequences which occurred on specific fault systems (e.g., located in Central Italy or in Japan). We show that the lower bounds of between-event variabilities are surprisingly large which indicates a large variability of earthquake dynamic properties even within the same fault system. Finally, these upper and lower bounds of ground-shaking variability are discussed in term of variability of earthquake physical properties (e.g., stress-drop and kappa_source).

Human γ-Glutamyl Transpeptidase 1: STRUCTURES OF THE FREE ENZYME, INHIBITOR-BOUND TETRAHEDRAL TRANSITION STATES, AND GLUTAMATE-BOUND ENZYME REVEAL NOVEL MOVEMENT WITHIN THE ACTIVE SITE DURING CATALYSIS.

PubMed

Terzyan, Simon S; Burgett, Anthony W G; Heroux, Annie; Smith, Clyde A; Mooers, Blaine H M; Hanigan, Marie H

2015-07-10

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within the active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. These data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Human γ-glutamyl transpeptidase 1: Structures of the free enzyme, inhibitor-bound tetrahedral transition states, and glutamate-bound enzyme reveal novel movement within the active site during catalysis [Human gamma-glutamyl transpeptidase: Inhibitor binding and movement within the active site

DOE PAGES

Terzyan, Simon S.; Burgett, Anthony W. G.; Heroux, Annie; ...

2015-05-26

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within themore » active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. Lastly,tThese data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use.« less

Human γ-glutamyl transpeptidase 1: Structures of the free enzyme, inhibitor-bound tetrahedral transition states, and glutamate-bound enzyme reveal novel movement within the active site during catalysis [Human gamma-glutamyl transpeptidase: Inhibitor binding and movement within the active site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Terzyan, Simon S.; Burgett, Anthony W. G.; Heroux, Annie

γ-Glutamyl transpeptidase 1 (GGT1) is a cell surface, N-terminal nucleophile hydrolase that cleaves glutathione and other γ-glutamyl compounds. GGT1 expression is essential in cysteine homeostasis, and its induction has been implicated in the pathology of asthma, reperfusion injury, and cancer. In this study, we report four new crystal structures of human GGT1 (hGGT1) that show conformational changes within the active site as the enzyme progresses from the free enzyme to inhibitor-bound tetrahedral transition states and finally to the glutamate-bound structure prior to the release of this final product of the reaction. The structure of the apoenzyme shows flexibility within themore » active site. The serine-borate-bound hGGT1 crystal structure demonstrates that serine-borate occupies the active site of the enzyme, resulting in an enzyme-inhibitor complex that replicates the enzyme's tetrahedral intermediate/transition state. The structure of GGsTop-bound hGGT1 reveals its interactions with the enzyme and why neutral phosphonate diesters are more potent inhibitors than monoanionic phosphonates. These structures are the first structures for any eukaryotic GGT that include a molecule in the active site covalently bound to the catalytic Thr-381. The glutamate-bound structure shows the conformation of the enzyme prior to release of the final product and reveals novel information regarding the displacement of the main chain atoms that form the oxyanion hole and movement of the lid loop region when the active site is occupied. Lastly,tThese data provide new insights into the mechanism of hGGT1-catalyzed reactions and will be invaluable in the development of new classes of hGGT1 inhibitors for therapeutic use.« less

A rational account of pedagogical reasoning: teaching by, and learning from, examples.

PubMed

Shafto, Patrick; Goodman, Noah D; Griffiths, Thomas L

2014-06-01

Much of learning and reasoning occurs in pedagogical situations--situations in which a person who knows a concept chooses examples for the purpose of helping a learner acquire the concept. We introduce a model of teaching and learning in pedagogical settings that predicts which examples teachers should choose and what learners should infer given a teacher's examples. We present three experiments testing the model predictions for rule-based, prototype, and causally structured concepts. The model shows good quantitative and qualitative fits to the data across all three experiments, predicting novel qualitative phenomena in each case. We conclude by discussing implications for understanding concept learning and implications for theoretical claims about the role of pedagogy in human learning. Copyright © 2014 Elsevier Inc. All rights reserved.

Blood transfusion: implications of treating a Jehovah's Witness patient.

PubMed

Effa-Heap, Gladys

Jehovah's Witnesses believe that an individual's life is contained within blood, and that accepting transfusion of blood and blood products is sinful. The administration of blood to a Jehovah's Witness who has refused to accept transfusion may lead to criminal or civil proceedings. From an ethical viewpoint, if a rational adult who has been fully apprised of the consequences of not receiving this treatment persists in a refusal, the decision should be respected. Medical and nursing staff faced with such a problem should explore fully with the patient any transfusion alternatives that the patient might find acceptable, such as cell salvage, volume expanders, antifibrinolytics and pharmaceutical options, such as erythropoietin. This article examines the legal and consent issues around blood transfusion in Jehovah's Witness patients and their implications for medical and surgical management.

Cigarette Smoke and Inflammation: Role in Cerebral Aneurysm Formation and Rupture

PubMed Central

Chalouhi, Nohra; Ali, Muhammad S.; Starke, Robert M.; Jabbour, Pascal M.; Tjoumakaris, Stavropoula I.; Gonzalez, L. Fernando; Rosenwasser, Robert H.; Koch, Walter J.; Dumont, Aaron S.

2012-01-01

Smoking is an established risk factor for subarachnoid hemorrhage yet the underlying mechanisms are largely unknown. Recent data has implicated a role of inflammation in the development of cerebral aneurysms. Inflammation accompanying cigarette smoke exposure may thus be a critical pathway underlying the development, progression, and rupture of cerebral aneurysms. Various constituents of the inflammatory response appear to be involved including adhesion molecules, cytokines, reactive oxygen species, leukocytes, matrix metalloproteinases, and vascular smooth muscle cells. Characterization of the molecular basis of the inflammatory response accompanying cigarette smoke exposure will provide a rational approach for future targeted therapy. In this paper, we review the current body of knowledge implicating cigarette smoke-induced inflammation in cerebral aneurysm formation/rupture and attempt to highlight important avenues for future investigation. PMID:23316103

New fluorescent labels with tunable hydrophilicity for the rational design of bright optical probes for molecular imaging.

PubMed

Pauli, Jutta; Licha, Kai; Berkemeyer, Janis; Grabolle, Markus; Spieles, Monika; Wegner, Nicole; Welker, Pia; Resch-Genger, Ute

2013-07-17

The rational design of bright optical probes and dye-biomolecule conjugates in the NIR-region requires fluorescent labels that retain their high fluorescence quantum yields when bound to a recognition unit or upon interaction with a target. Because hydrophilicity-controlled dye aggregation in conjunction with homo-FRET presents one of the major fluorescence deactivation pathways in dye-protein conjugates, fluorescent labels are required that enable higher labeling degrees with minimum dye aggregation. Aiming at a better understanding of the factors governing dye-dye interactions, we systematically studied the signal-relevant spectroscopic properties, hydrophilicity, and aggregation behavior of the novel xS-IDCC series of symmetric pentamethines equipped with two, four, and six sulfonic acid groups and selected conjugates of these dyes with IgG and the antibody cetuximab (ctx) directed against the cancer-related epidermal growth factor (EGF) receptor in comparison to the gold standard Cy5.5. With 6S-IDCC, which displays a molar absorption coefficient of 190 000 M(-1) cm(-1) and a fluorescence quantum yield (Φf) of 0.18 in aqueous media like PBS and nearly no aggregation, we could identify a fluorophore with a similarly good performance as Cy5.5. Bioconjugation of 6S-IDCC and Cy5.5 yielded highly emissive targeted probes with comparable Φf values of 0.29 for a dye-to-protein (D/P) ratio <1 and a reduced number of protein-bound dye aggregates in the case of 6S-IDCC. Binding studies of the ctx conjugates of both dyes performed by fluorescence microscopy and FACS revealed that the binding strength between the targeted probes and the EGF receptor at the cell membrane is independent of D/P ratio. These results underline the importance of an application-specific tuning of dye hydrophilicity for the design of bright fluorescent reporters and efficient optical probes. Moreover, we could demonstrate the potential of fluorescence spectroscopy to predict the size of fluorescence signals resulting for other fluorescence techniques such as FACS.