We hypothesize that as one of the most consequential events in evolution, primary endosymbiosis accelerates lineage divergence, a process we refer to as the endosymbiotic ratchet. Our proposal is supported by recent work on the photosynthetic amoeba, Paulinella, that underwent primary plastid endosymbiosis about 124 Mya. This amoeba model allows us to explore the early impacts of photosynthetic organelle (plastid) origin on the host lineage. The current data point to a central role for effective population size (Ne) in accelerating divergence (...) post‐endosymbiosis due to limits to dispersal and reproductive isolation that reduce Ne, leading to local adaptation. We posit that isolated populations exploit different strategies and behaviors and assort themselves in non‐overlapping niches to minimize competition during the early, rapid evolutionary phase of organelle integration. The endosymbiotic ratchet provides a general framework for interpreting post‐endosymbiosis lineage evolution that is driven by disruptive selection and demographic and population shifts. Also see the video abstract here: https://youtu.be/gYXrFM6Zz6Q. (shrink)

AbstractThe Green Revolution still exerts an important influence on agricultural policy as a technology-centred development strategy. A main policy narrative underpinning the Green Revolution was first expounded in Transforming Traditional Agriculture, a book published in 1964 by Nobel Prize-winning economist Ted Schultz. He famously argued that traditional farmers were ‘poor but efficient’. As farmers responded to economic incentives, technology-driven strategies would transform traditional agriculture into an engine of economic growth. Schultz relied on published ethnographic data and his own calculations to (...) construct this policy narrative. My reanalysis of TTA focuses on its main case study, Panajachel, a village in Guatemala. I follow a narrative approach, evaluating whether Schultz’s story relates a plausible account of agricultural development in Panajachel and its region. I show how Schultz deliberately tried to hide that Mayan farmers in Panajachel were not challenged in technological terms and were able to reach relatively high economic returns. His interpretation of the Guatemalan rural economy ignored ethnic tensions dominating market exchange, a main barrier for agricultural development. I evaluate Schultz’s narrative further by tracing the subsequent evolution of Panajachel and its wider region. High-input strategies had to address ethnic barriers and change agents became embroiled in violent conflict along ethnic lines. Assessing the adequacy of Schultz’s contribution, from a narrative approach, shows how he ‘got the story wrong’ and that the Green Revolution policy narrative has an excessively narrow intellectual basis. New narratives should reserve a much more important place for institutional change in agricultural development. (shrink)

In this book two of the leading figures in argumentation theory present a view of argumentation as a means of resolving differences of opinion by testing the acceptability of the disputed positions. Their model of a 'critical discussion' serves as a theoretical tool for analysing, evaluating and producing argumentative discourse. They develop a method for the reconstruction of argumentative discourse that takes into account all aspects that are relevant to a critical assessment. They also propose a practical code of behaviour (...) for discussants who want to resolve their differences in a reasonable way. This is a major contribution to the study of argumentation and will be of particular value to professionals and graduate students in speech communication, informal logic, rhetoric, critical thinking, linguistics, and philosophy. (shrink)

Feedback control in neural systems is ubiquitous. Here we study the mathematics of nonlinear feedback control. We compare models in which the input is multiplied by a dynamic gain (multiplicative control) with models in which the input is divided by a dynamic attenuation (divisive control). The gain signal (resp. the attenuation signal) is obtained through a concatenation of an instantaneous nonlinearity and a linear low-pass filter operating on the output of the feedback loop. For input steps, the dynamics of gain (...) and attenuation can be very different, depending on the mathematical form of the nonlinearity and the ordering of the nonlinearity and the filtering in the feedback loop. Further, the dynamics of feedback control can be strongly asymmetrical for increment versus decrement steps of the input. Nevertheless, for each of the models studied, the nonlinearity in the feedback loop can be chosen such that immediately after an input step, the dynamics of feedback control is symmetric with respect to increments versus decrements. Finally, we study the dynamics of the output of the control loops and find conditions under which overshoots and undershoots of the output relative to the steady-state output occur when the models are stimulated with low-pass filtered steps. For small steps at the input, overshoots and undershoots of the output do not occur when the filtering in the control path is faster than the low-pass filtering at the input. For large steps at the input, however, results depend on the model, and for some of the models, multiple overshoots and undershoots can occur even with a fast control path. (shrink)

The objective of the new series, "Molecular Biology, Biochemistry and Biophysics", of which this brochure forms the first volume, is to produce more than another compilation of data. It is hoped that the new series will help the individual "specialist" keep abreast of important developments in the natural sciences at the molecular and subcellular level in fields complementary to his own. The predominant aim is not so much to increase the ever-growing body of information in an encyclopedic fashion but rather (...) to give, in addition to a well rounded factual presentation of subjects which have reached a degree of maturation, a leitmotiv developed by the individual authors from a more personal point of view. The reader should thus be able to use these mono graphs not only for acquisition of knowledge but as a source of further motiva tion in his own work. This latter and more consequential aim of the monograph series is one of the reasons for presenting here a most unusual talk which should enable the reader to sit back and view his own efforts in the context of science and creative attempts as a whole. The lecture is the virtually unknown inaugural address of the Dutch physical chemist JACOBUS HENRICUS VAN'T HOFF. As is shown in his short biography presented on pages 3 and 4 the principal thoughts of the molecular biologist of today are akin to his own and he clearly recognized the universality of molecular life processes. (shrink)

Despite the proliferation of research on ethical leadership, there remains a limited understanding of how specifically the assumingly moral component of this leadership style affects employee behavior. Taking an identity perspective, we integrate the ethical leadership literature with research on the dynamics of the moral self-concept to posit that ethical leadership will foster a sense of moral identity among employees, which then inspires followers to adopt more ethical actions, such as increased organization citizenship behavior. We further argue that these identity (...) effects should be more pronounced when leaders are perceived to be group prototypical, as their actions then speak louder to followers’ sense of identity. Two studies—a scenario experiment with 138 participants and a field study with 225 employees—provided support for our hypothesized moderated mediation model. Perceived ethical leadership positively affected OCB via followers’ moral identity but only under conditions of high perceived leader group prototypicality. We discuss how the identity pathway of ethical leadership can facilitate novel theorizing about moral transference. Our findings also suggest that, when hiring external ethical leaders or training internal managers, practitioners are well advised to consider that these individuals may only be effective in morally transforming followers when they are perceived as prototypical for the group. (shrink)

We explore why people feel the socially improper emotions of schadenfreude and gluckschmerz. One explanation follows from sentiment relations. Prior dislike leads to both schadenfreude and gluckschmerz. A second explanation relates to concerns over justice. Deserved misfortune is pleasing and undeserved good fortune is displeasing. A third explanation concerns appraisal of the good or bad fortunes of others as creating either benefit or harm for the self or in-group. Especially in competitive situations and when envy is present, gain is pleasing (...) and loss is displeasing. Both emotions have important implications for understanding human relations at the individual and group levels. (shrink)

Objectives: To investigate why physicians label end-of-life acts as either ‘euthanasia/ending of life’ or ‘alleviation of symptoms/palliative or terminal sedation’, and to study the association of such labelling with intended reporting of these acts. Methods: Questionnaires were sent to a random, stratified sample of 2100 Dutch physicians. They were asked to label six hypothetical end-of-life cases: three ‘standard’ cases and three cases randomly selected, that varied according to type of medication, physician’s intention, type of patient request, patient’s life expectancy and (...) time until death. We identified the extent to which characteristics of cases are associated with physician’s labelling, with multilevel multivariable logistic regression. Results: The characteristics that contributed most to labelling cases as ‘euthanasia/ending of life’ were the administration of muscle relaxants or disproportional morphine. Other important factors were an intention to hasten death and a life expectancy of several months. Physicians were much more willing to report cases labelled as ‘euthanasia’ or ‘ending of life’ than other cases. Conclusions: Similar cases are not uniformly labelled. However, a physicians’ label is strongly associated with their willingness to report their acts. Differences in how physicians label similar acts impede complete societal control. Further education and debate could enhance the level of agreement about what is physician-assisted dying, and thus should be reported, and what not. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Kinship:The Relationship Between Johnstone's Ideas about Philosophical Argument and the Pragma-Dialectical Theory of ArgumentationFrans H. van Eemeren and Peter Houtlosser1. Johnstone on the Nature of Philosophical ArgumentAs he himself declared in Validity and Rhetoric in Philosophical Argument (1978, 1), the late philosopher Henry W. Johnstone Jr. devoted a long period of his professional life to clarifying the nature of philosophical argument. His well-known view was that philosophical arguments are (...) sui generis, i.e., not to be judged by the standards of argumentation in science or everyday discourse. Philosophical arguments are not ad rem, but are based on premises that are expressed or implied commitments of a party in dialogue. This is why philosophical argumentation is, according to Johnstone, always ad hominem. In philosophical argumentation, every ad rem argument begs the question.Usually, ad hominem argumentation is dismissed as invalid. Johnstone, however, maintains that making use of argumentum ad hominem is the only way to establish a philosophical conclusion. In an argumentum ad hominem, inferences are drawn from propositions stated or implied by the other party and critical questions are raised about the conclusions that were drawn, so that it can be used to refute a philosophical position by showing that this position is inconsistent. As Walton (2001) rightly observes, this type of ad hominem argumentation boils down to arguing from commitments of the other party, i.e., ex concessis.The use of ad hominem argumentation as the criticism of a position in terms of its own presuppositions is, in Johnstone's view, the only valid argument in philosophy, if any philosophical argument is indeed valid. All philosophical polemic is in this perspective in fact addressed ad hominem. This applies not only to philosophical argumentation that concerns self-referential refutation but also to other ad hominem types of philosophical argumentation, including the tu quoque argument (1978, 11–12).According to Johnstone, there is no objective criterion for determining the validity of ad hominem argumentation. Validity must, says Johnstone in the [End Page 51] epilogue of his collected essays on philosophical argument, be viewed as "a regulative ideal" (135). Much earlier, Johnstone had already come to the conclusion that "the valid argument is the one that maintains philosophical discussion" (38). It is this self-perpetuating feature that is the distinctive rationality of philosophy. By forcing the interlocutor to elaborate his philosophical position rather than just repeat it, the gap between the interlocutors is bridged.In order to distinguish between constructive persuasive argumentation and mere repetition or other forms of paralyzing the discourse, the line must be drawn between responsible and irresponsible persuasion. This is a problem for Johnstone. Where the Ancients solved the problem by insisting that the persuader be virtuous, Johnstone proposed to base the distinction between responsible and irresponsible persuasion on the attitude of the philosopher and his interest in maintaining the philosophical enterprise. The philosopher is a critic who criticizes con amore. His intention to do so, however, is revealed "only in the way he goes about his work" (84).A more down to earth criterion for responsible persuasion that Johnstone proposed is that the discourse should not tend to degenerate. Logic, as the discipline concerned with reason, serves to prevent the discussion from degenerating, but it can do so only if the parties concerned have jointly committed themselves to certain logical principles. If in philosophical argument a defendant is under no obligation to acknowledge an inconsistency when the other party points out an inconsistency in his position, then the other party's criticism cannot count as valid. According to Johnstone, however, it will depend on the parties' presuppositions whether or not they consider two statements as being inconsistent. In other words, what is inconsistent for the one party may not be inconsistent for the other party.Few obligations are imposed on everyone; most obligations arise from commitments made by specific individuals or groups of individuals. As Johnstone says, "Even the cogent philosophical argument is not, of course, absolutely cogent; it is cogent only relatively to interlocutors who maintain the premises on which it depends" (27). Once we abandon the search for objective conditions under which philosophical arguments can be valid, according... (shrink)

Introduction: Placebo and nocebo effects are positive and negative health outcomes that can be elicited by the psychosocial context. They can be mediated by expectations, and may emerge in somatic symptoms even when people are aware of these effects. Interindividual differences could impact placebo and nocebo responding, but findings are inconsistent.Methods: The current work examined expectation as a mediator of the association between verbal placebo and nocebo suggestions and histamine-induced itch across three experimental studies. Moreover, we examined whether interindividual differences, (...) body ignorance) modulated: the direct association between VSs and itch, and the indirect, expectation-mediated association between VSs and itch. Positive VSs were compared to neutral instructions or negative VSs in an open-label or closed-label context using PROCESS. First, mediation of VSs effects on itch by expectations was tested. Next, moderation by individual traits was explored using conditional process analyses.Results: The effects of VSs on itch were significantly mediated by expectation in Study 1 and in the open-label contexts of Studies 2 and 3. Ignorance of bodily signals marginally moderated the direct effects of VSs on itch when closed-label suggestions were given: at low levels of body ignorance, effects of positive and negative VSs were stronger. Moreover, moderated mediation was observed in the open-label groups of Studies 2 and 3: The expectation-mediated effects of VSs on itch were stronger when BAS drive was lower.Conclusion: Overall, the effects of VSs on itch were mediated by expectations in the open-label, but not the closed-label context. Moreover, the current work suggests that placebo and nocebo effects may be moderated by ignorance of bodily signals and the BAS. There was limited evidence that other interindividual differences modulated placebo and nocebo responding in itch. (shrink)

Results of two survey studies are presented. It is shown that attitudes of the public about "technology in general" are not stable and can easily be affected by how the subject is introduced. Eight areas of technology are compared on the basis of empirical relations in attitudinal judgments, in attribute ratings, in self- assigned importance weights of attributes, and in importance of reference groups and persons. On the basis of similarities in these four kinds of judgments, three clusters of technology (...) areas were identified: a cluster of modern reproductive technologies, an information cluster containing automation, computer, and communication technologies, and a cluster containing nuclear energy and military technology. The attitude toward "technology in general" can not be considered as an aggregation of attitudes toward these areas of technology: The relations between general attitude and specific attitudes are only moderate to negligible. (shrink)

Lysophosphatidic acid (LPA) is a lipid mediator with a wide variety of biological actions, particularly as an inducer of cell proliferation, migration and survival. LPA binds to specific G‐protein‐coupled receptors and thereby activates multiple signal transduction pathways, including those initiated by the small GTPases Ras, Rho, and Rac. LPA signaling has been implicated in such diverse processes as wound healing, brain development, vascular remodeling and tumor progression. Knowledge of precisely how and where LPA is produced has long proved elusive. Excitingly, (...) it has recently been discovered that LPA is generated from precursors by ‘autotaxin’, a once enigmatic exo‐phosphodiesterase implicated in tumor cell motility. Exogenous phospholipases D can also produce LPA, which may contribute to their toxicity. Here we review recent progress in our understanding of LPA bioactivity, signaling and synthesis. BioEssays 26:870–881, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

In the present article we argue that emotional interactions are not appropriately captured in present emotion research and theorizing. Emotional stimuli or antecedents are dynamic and change over time because they often interact and have a specific relationship with the subject. Earlier emotional interactions may, for example, intensify later emotional reactions to a specific person, or our anger reactions towards powerful or powerless others may differ considerably. Thus, we suggest that such social factors not only affect the intensity, but also (...) the nature of emotional experiences and expressions, and specifically the nature of the social movement (e.g., moving towards, away, or against). We discuss different processes that are implicated in the relation between the social environment and our emotions, describe how emotional expressions shape social behavior, and provide suggestions for incorporating the social dimension of emotion in future research. (shrink)

In ‘The making of argumentation theory’ van Eemeren and van Haaften describe the contributions made to the five components of a full-fledged research program of argumentation theory by four prominent approaches to the discipline: formal dialectics, rhetoric/pragmalinguistics, informal logic, and pragma-dialectics. Most of these approaches do not contribute to all components, but to some in particular. Starting from the pragma-dialectical view of the relationship between dialectical reasonableness and rhetorical effectiveness – the crucial issue in argumentation theory – van Eemeren and (...) van Haaften explain the positions taken by representatives from the approaches discussed and indicate where they differ from the pragma-dialectical approach. It transpires that approaches focusing on dialectical reasonableness are, next to pragma-dialectics, formal dialectics and informal logic; approaches focusing on rhetorical effectiveness are, next to pragma-dialectics, rhetoric and pragmalinguistics, and the informal logician Tindale. When it comes to the relationship between dialectical reasonableness and rhetorical effectiveness, some interest in it is shown in rhetoric and pragmalinguistics, but only in pragma-dialectics and in Tindale’s work is it a real focus. The main difference between Tindale’s view and the pragma-dialectical view is that in pragma-dialectics the decisive role in deciding about reasonableness is assigned to a code of conduct for reasonable argumentative discourse and in Tindale’s approach this role is assigned to Tindale’s interpretation of the Perelmanian universal audience. (shrink)

Pragmatics and dialectics are two disciplines which have been amongst the first and most important partners for argument studies in the exploration of the complex realm of communication. Treating argumentation as a construct consisting of premises and conclusion allows for investigating some interesting properties of the phenomenon of reasoning, but does not capture a variety of aspects related to the usage of natural language and dialogical context in which real-life argumentation is typically embedded. This special issue explores some of the (...) fascinating research questions which emerge when we move beyond logic into the territory of the pragmatics and dialectics of argument. (shrink)

This contribution is a gentle introduction to so-called dynamic epistemic logics, that can describe how agents change their knowledge and beliefs. We start with a concise introduction to epistemic logic, through the example of one, two and finally three players holding cards; and, mainly for the purpose of motivating the dynamics, we also very summarily introduce the concepts of general and common knowledge. We then pay ample attention to the logic of public announcements, wherein agents change their knowledge as the (...) result of public announcements. One crucial topic in that setting is that of unsuccessful updates: formulas that become false when announced. The Moore-sentences that were already extensively discussed at the conception of epistemic logic in Hintikka’s ‘Knowledge and Belief’ give rise to such unsuccessful updates. After that, we present a few examples of more complex epistemic updates. Our closing observations are on recent developments that link the ‘standard’ topic of belief revision, as in ‘On the Logic of Theory Change: partial meet contraction and revision functions’, by Alchourron et al. , to the dynamic epistemic logics introduced here. (shrink)