Spatial evolutionary game theory explains how cooperative traits can survive the intense competition in biological systems. If the spatial distribution allows cooperators to interact with each other frequently, the benefits of cooperation will outweigh the losses due to exploitation by selfish organisms. However, for a cooperative behavior to get established in a system, it needs to be found initially in a sufficiently large cluster to allow a high frequency of intracooperator interactions. Since mutations are rare events, this poses the question (...) of how cooperation can arise in a biological system in the first place. We present a simple model which captures two concepts from genetics that can explain how evolution overcomes the emergence problem. The first concept is, often in nature, a gene may not express its phenotype except under specific environmental conditions, rendering it to be a “silent” gene. The second key idea is that a neutral gene, one that does not harm or improve an organism’s survival chances, can still spread through a population if it is physically near to another gene that is positively selected. Through these two ideas, our model offers a possible solution to the fundamental problem of emergence of cooperation in biological systems. (shrink)

Positive frequency dependent selection is a natural selection regime where the fitness of a phenotype increases with its frequency in the population. Examples can be typically found in the spread of disease tolerance strategies in a population. A characterizing feature of PFDS is that the focal allele may experience favorable selection only when it becomes more frequent in the population, while being selected against when it is rare. In this paper, by applying a solution concept from evolutionary game theory, we (...) hypothesize that the process of emergence of such alleles triggers selection for silence, where the emergence of alleles that can stay unexpressed for a period of time will be favored by selection forces. We illustrate our hypothesis using a mathematical model of a population of single locus diploid organisms with two alleles where a single mutant of an allele that experiences positive frequency dependent selection appears in a population where the other allele is a dominant. The model results show that the longer the silence interval of the new mutant before its expression, the better its chances of getting fixed in the population. However, this effect will be observable only to a certain limit after which further increase in the interval will not have an effect on the expected fixation rate. Two divergences from the simple scenario are also investigated: the nonsynchronous expression of the focal allele and its emergence in a spatial grid limited by a migration bottleneck. In all cases, it is shown that there is an evolutionary pressure inherent in the dynamics of positive frequency dependent selection on the genes to have a delayed expression. It is hypothesized that the regulation systems of such traits will be under selection for either internal silencing mechanisms or to be triggered by an external environmental condition. (shrink)

When people comprehend language, they mentally represent object shape. Previous research has shown that objects that are mentioned in a simile construction are represented as similarly shaped. The present study examined object shape in mental representations of negated similes. In our experiment participants read negated similes or control sentences without a comparison structure. After having read the sentence, they judged whether two presented objects, which were either similarly or dissimilarly shaped, were previously mentioned. Our findings showed that for the negated (...) similes, verification latencies were shorter for similarly shaped than for dissimilarly shaped objects. This shows that the expected situation, rather than the actual situation is represented. For the control sentences, we did not find such an effect of similarity in shape. We discuss our findings in the light of processing theories of negation and comparison. (shrink)

People mentally represent the shapes of objects. For instance, the mental representation of an eagle is different when one thinks about a flying or resting eagle. This study examined the role of shape in mental representations of similes (i.e., metaphoric comparisons). We tested the prediction that when people process a simile they will mentally represent the entities of the comparison as having a similar shape. We conducted two experiments in which participants read sentences that either did (experimental sentences) or did (...) not (control sentences) invite comparing two entities. For the experimental sentences, the ground of the comparison was explicit in Experiment 1 (“X has the ability to Z, just like Y”) and implicit in Experiment 2 (“X is like Y”). After having read the sentence, participants were presented with line drawings of the two objects, which were either similarly or dissimilarly shaped. They judged whether both objects were mentioned in the preceding sentence. For the experimental sentences, recognition latencies were shorter for similarly shaped objects than for dissimilarly shaped objects. For the control sentences, we did not find such an effect of similarity in shape. These findings suggest that a perceptual symbol of shape is activated when processing similes. (shrink)

A referendum was held on October 1st, 1978 at Andenne, a municipality in the French-speaking part of Belgium, on the settlement of a nuclear plant. A referendum on the settlement of an ecologically noxiousindustry was held at Tessenderlo, a municipality in the Dutch-speaking part of Belgium, on March 25th, 1979. These referenda are unique in their kind in Belgium. They show a very large similarity bath in theirset-up and their results. The turn-out can be considered satisfying high, especially since compulsory (...) voting could not be imposed. The votes cast were mainly nays. (shrink)

This article on the evolution of economic and monetary policy in Belgium, which turned the "sick man of Europe" into one of the stronger European economies and allowed it to enter into EMU, stresses the role of the monetary authorities as a stabilising force in Belgium. It gives a detailed analysis of how these changes have allowed Belgium to regain the confidence of both monetary authorities and international investors after the devaluation of 1982. The policy responses to the oil shock (...) at the beginning of the seventies broke with the policy mix which had until then been practised. Both the wage formation process andf iscal policy clearly spiralled out of control, the chiefresult of which was a drastic loss in international competitiveness. As a consequence, the current account showed a large deficit, the traditional level at which public deficit had stood rose dramatically, unemployment exploded and the financial structure of most corporations became fragile.A drastic realignment of economic policy started with the devaluation of the Belgian franc in 1982. This devaluation was accompanied by a series of measures aimed at preventing the inflationary pressures from triggering further devaluations, and hence at restoring credibility. These measures included restrictive fiscal policies and real wage cuts. By 1987 this recovery policy had successfully restored Belgian competitiveness, reduced the government deficit and restored the balance ofpayments equilibrium. Although public policies became less restrictive during the period 1988-1993, the central bank continued to gain international credibility. Significant stepsin this process were the abolition of the dual exchange rate system, the decision to peg the Belgian franc to the most stable currency in the ERM and the reform of the money markets in Belgium. The latter in particular helped to increase the central bank's independence, since this reform implied total control by the central bank over short term interest rates, it reduced significantly the automatic credit lines of the fiscal authorities with the central bank and it stipulated that revaluations of gold reserves should no langer be used to finance government budget deficits. By 1992 international credibility had been restored to such a degree that the Belgian franc became a strong currency during the 1992 crisis, obliging the central bank to come to the rescue of the weaker currencies under attack in September 1992 with a speculative inflow of capital of about 200 billion BEF. However this restored credibility continued to be fragile, as became evident during the 1993 exchange rate crisis when the Belgian franc was vigorously attacked by international speculation.The insufficient alignment of public and monetary policies proved to be at the heart of the financial problems of the 1993 crises. The Belgian government relaunched its policies of budgetary restriction and wage moderation, brought together in what was called the 'Global Plan'. This realignment of public policies to monetary policy swiftly restored the credibility of the Belgian franc, so that as early as January 1994 the Belgian franc converged to its central parity with an interest differential vis-à-vis the German mark of only about 2 %. This differential declined progressively. Indeed the global plan restored the confidence of the investors in Belgian economic policy. Financial markets now fully believed in the entry of Belgium into EMU and from then on no major difficulties were to arise. (shrink)

Feigning symptoms distorts diagnostic evaluations. Therefore, dedicated tools known as symptom validity tests have been developed to help clinicians differentiate feigned from genuine symptom presentations. While a deviant SVT score is an indicator of a feigned symptom presentation, a non-deviant score provides support for the hypothesis that the symptom presentation is valid. Ideally, non-deviant SVT scores should temper suspicion of feigning even in cases where the patient fits the DSM’s stereotypical yet faulty profile of the “antisocial” feigner. Across three studies, (...) we tested whether non-deviant SVT scores, indeed, have this corrective effect. We gave psychology students and clinical experts a case alluding to the DSM profile of feigning. In successive steps, they received information about the case, among which non-deviant SVT outcomes. After each step, participants rated how strongly they suspected feigning and how confident they were about their judgment. Both students and experts showed suspicion rates around the midpoint of the scale and did not respond to non-deviant SVT outcomes with lowered suspicion rates. In Study 4, we educated participants about the shortcomings of the DSM’s antisocial typology of feigning and the importance of the negative predictive power of SVTs, after which they processed the case information. Judgments remained roughly similar to those in Studies 1–3. Taken together, our findings suggest that students and experts alike have difficulties understanding that non-deviant scores on SVTs reduce the probability of feigning as a correct differential diagnosis. (shrink)

Tekst jest wyborem fragmentów przypisywanych Janowi Potockiemu. Jean Potocki, mistrz ironii, twardo usadowiony w nieuchwytnym na pozór miejscu pomiędzy oświeceniem a romantyzmem, pozostaje najczęściej plagiatowanym autorem Europy. Zapewne przysłużył się pośmiertnie sprawie praw autorskich, ale i stało się tak, jakby oryginalność i płodność jego myśli była na tyle inna, że nie sposób przedstawić go inaczej jak wymazując jego imię, jeśli po prostu nie niszcząc. Choć historia jego francuskich i amerykańskich plagiatów jest wyczerpująco udokumentowana, nie istnieje jeszcze definitywne wydanie jego arcydzieła: (...) Rękopisu znalezionego w Saragossie, już w 1809 roku przełożonego po części na niemiecki, a w 1847, również w Lipsku, zapewne z udziałem Societas Jablonoviana, w całości na polski. W latach pięćdziesiątych XX wieku trud przywrócenia należnego mu miejsca podjęli R. Caillois, L. Kukulski, W. Has, Emanuel Rostworowski i Maria-Ewelina Żółtowska-Weintraub, której wciąż nieopublikowany doktorat stanowi najpełniejszą biografię hrabiego Jana, powiązaną z karierą bohatera Rękopisu. Skromny ów oficer gwardii walońskiej: Alfons van Worden, po wielu straszliwych próbach, które w gruncie rzeczy niczym innym dla niego nie były jak straszliwymi, teatralnie zaaranżowanymi opowieściami, awansował na gubernatora Saragossy, gdzie wiódł spokojny żywot troszcząc się o córeczkę swą Fatimę. […]. (shrink)

Pleidooi voor de beleving als kennis-instrument.

b> Critical thinking is highly valued but difficult to teach effectively. The Reason! project at the University of Melbourne has developed the Reason!Able software as part of a general method aimed at enhancing critical thinking skills. Students using Reason!Able appear to make dramatic gains. This paper describes the challenge involved, the theoretical basis of the Reason! project, the Reason!Able software, and results of intensive evaluation of the Reason! approach.

This book offers a new description of the significance of Hesiod's 'myth of the races' for ancient Greek and Roman authors, showing how the most detailed responses to this story go far beyond nostalgia for a lost 'Golden' age or hope of its return. Through a series of close readings, it argues that key authors from Plato to Juvenal rewrite the story to reconstruct 'Hesiod' more broadly as predecessor in forming their own intellectual and rhetorical projects; disciplines such as philosophy, (...) didactic poetry and satire all engage in implicit questions about 'Hesiodic' teaching. The first chapter introduces key issues; the second re-evaluates the account in Hesiod's Works and Days. A major chapter outlines Plato's use of Hesiod through close study of the Protagoras, Republic and Statesman. Subsequent chapters focus on Aratus' Phaenomena and Ovid's Metamorphoses; the final chapter, on the Octavia attributed to Seneca and Juvenal's sixth Satire, broadens ideas of Hesiod's reception in Rome. (shrink)

Discourse Representation Theory is a specific name for the work of Hans Kamp in the area of dynamic interpretation of natural language. Also, it has gradually become a generic term for proposals for dynamic interpretation of natural language in the same spirit. These proposals have in common that each new sentence is interpreted in terms of the contribution it makes to an existing piece of interpreted discourse. The interpretation conditions for sentences are given as instructions for updating the representation of (...) the discourse. (shrink)

This is a fully revised and updated version of Hans van der Doel"s Democracy and Welfare Economics.

Can the straight line be analysed mathematically such that it does not fall apart into a set of discrete points, as is usually done but through which its fundamental continuity is lost? And are there objects of pure mathematics that can change through time? The mathematician and philosopher L.E.J. Brouwer argued that the two questions are closely related and that the answer to both is "yes''. To this end he introduced a new kind of object into mathematics, the choice sequence. (...) But other mathematicians and philosophers have been voicing objections to choice sequences from the start. This book aims to provide a sound philosophical basis for Brouwer's choice sequences by subjecting them to a phenomenological critique in the style of the later Husserl. "It is almost as if one could hear the two rebels arguing their case in a European café or on a terrace, and coming to a common understanding, with both men taking their hat off to the other, in admiration and gratitude. Dr. van Atten has convincingly applied Husserl's method to Brouwer's program, and has equally convincingly applied Brouwer's intuition to Husserl's program. Both programs have come out the better." Piet Hut, professor of Interdisciplinary Studies, Institute for Advanced Study, Princeton, U.S.A. (shrink)

De werkelijkheid is dat wat niet verdwijnt ook als we er niet meer in geloven. Het is niet erg om dingen niet te weten, maar het is ook niet nodig om deze werkelijkheid in twijfel te trekken wanneer dit geloof aan het wankelen wordt gebracht. Om de weg niet kwijt te raken is het van belang om zo goed en zo kwaad als we kunnen te blijven onderscheiden tussen zinnig en onzinnig, tussen verstandig en ondoordacht, tussen goed geïnformeerd en de (...) kluts kwijt. Dit boek helpt de lezer onderscheid te maken tussen propaganda en betrouwbare experts, om de werkelijkheid zo nooit uit het oog te verliezen."--Publisher information. (shrink)

Guarded actions are changes with preconditions acting as a guard. Guarded action models are multimodal Kripke models with the valuations replaced by guarded actions. Call guarded action logic the result of adding product updates with guarded action models to PDL (propositional dynamic logic). We show that guarded action logic reduces to PDL.

In this paper I assess the relation between philosophy of chemistry and philosophy of science, focusing on those themes in the philosophy of chemistry that may bring about major revisions or extensions of current philosophy of science. Three themes can claim to make a unique contribution to philosophy of science: first, the variety of materials in the world; second, extending the world by making new stuff; and, third, specific features of the relations between chemistry and physics.

Most philosophers still tend to believe that mathematics is basically about producing formal proofs. A consequence of this view is that some aspects of mathematical practice are entirely lost from view. My contention is that it is precisely in those aspects that similarities can be found between practices in the exact sciences and in mathematics. Hence, if we are looking for a (more) unified treatment of science and mathematics it is necessary to incorporate these elements into our view of what (...) mathematics is about. As a helpful tool I introduce the notion of a mathematical argument as a more liberalized version of the notion of mathematical proof. (shrink)

In his own day, the name of Pierre Bayle was as famous as that of any philosopher in Europe. Yet despite his vast influence on the eighteenth century and the Enlightenment, Bayle's name was eclipsed by those of other, more methodical thinkers of his age, eliciting the following remark from one modern scholar, J.C. Laursen: 'Why do professional philosophers spend so much time on Descartes and so little time on Pierre Bayle, when Bayle was clearly the better philosopher?'In the past (...) decades a surge of new interest in Bayle has led to the rediscovery of the depth of his philosophical thought as well as the extent of his influence-yet the scholarly debate is shadowed by deep uncertainty as to how to tackle his eclectic writings, especially the expansive historical-philosophical publication that became one of the Enlightenment's best-sellers: the Dictionnaire Historique et Critique, first published in 1696 and counting more than six million words.This volume provides an important new study of both Bayle and the Dictionnaire. (shrink)