In multicellular organisms, cells are frequently programmed to die. This makes good sense: cells that fail to, or are no longer playing important roles are eliminated. From the cell’s perspective, this also makes sense, since somatic cells in multicellular organisms require the cooperation of clonal relatives. In unicellular organisms, however, programmed cell death poses a difficult and unresolved evolutionary problem. The empirical evidence for PCD in diverse microbial taxa has spurred debates about what precisely PCD means in the case of (...) unicellular organisms. In this article, we survey the concepts of PCD in the literature and the selective pressures associated with its evolution. We show that definitions of PCD have been almost entirely mechanistic and fail to separate questions concerning what PCD fundamentally is from questions about the kinds of mechanisms that realize PCD. We conclude that an evolutionary definition is best able to distinguish PCD from closely related phenomena. Specifically, we define “true” PCD as an adaptation for death triggered by abiotic or biotic environmental stresses. True PCD is thus not only an evolutionary product but must also have been a target of selection. Apparent PCD resulting from pleiotropy, genetic drift, or trade-offs is not true PCD. We call this “ersatz PCD.”. (shrink)

Mates’s Puzzle has flown below many philosophers’ radar, despite its relations to both Frege’s Puzzle and the Paradox of Analysis. We explain the relations amongst these puzzles on the way to arguing that Mates’s Puzzle suggests a generalization of Frege’s Puzzle, and of the sense-reference distinction itself, in the form of hierarchy of senses. We explain how Mates’s Puzzle and the hierarchy, to different degrees, illuminate each other, and how their connection is missed in the literature. However, we argue that (...) the potential of Mates’s Puzzle to illuminate the hierarchy is yet to be fully actualised. We suggest that in order to do better, we need to formulate Mates’s Puzzle as a puzzle in the philosophy of thought and not as puzzle in the philosophy of language. What is needed, to which the present paper is a precursor, is an account of the cognitive significance of higher-order senses. (shrink)

The experiments reported herein probe the visual cortical mechanisms that control near–far percepts in response to two-dimensional stimuli. Figural contrast is found to be a principal factor for the emergence of percepts of near versus far in pictorial stimuli, especially when stimulus duration is brief. Pictorial factors such as interposition (Experiment 1) and partial occlusion Experiments 2 and 3) may cooperate, as generally predicted by cue combination models, or compete with contrast factors in the manner predicted by the FACADE model. (...) In particular, if the geometrical conŽ guration of an image favors activation of cortical bipole grouping cells, as at the top of a T-junction, then this advantage can cooperate with the contrast of the conŽ guration to facilitate a near–far percept at a lower contrast than at an X-junction. Varying the exposure duration of the stimuli shows that the more balanced bipole competition in the X-junction case takes longer exposure times to resolve than the bipole competition in the T-junction case (Experiment 3). (shrink)

Organismal death is foundational to the evolution of life, and many biological concepts such as natural selection and life history strategy are so fashioned only because individuals are mortal. Organisms, irrespective of their organization, are composed of basic functional units—cells—and it is our understanding of cell death that lies at the heart of most general explanatory frameworks for organismal mortality. Cell death can be exogenous, arising from transmissible diseases, predation, or other misfortunes, but there are also endogenous forms of death (...) that are sometimes the result of adaptive evolution. These endogenous forms of death—often labeled programmed cell death, PCD—originated in the earliest cells and are maintained across the tree of life. Here, we consider two problematic issues related to PCD (and cell mortality generally). First, we trace the original discoveries of cell death from the nineteenth century and place current conceptions of PCD in their historical context. Revisions of our understanding of PCD demand a reassessment of its origin. Our second aim is thus to structure the proposed origin explanations of PCD into coherent arguments. In our analysis we argue for the evolutionary concept of PCD and the viral defense-immunity hypothesis for the origin of PCD. We suggest that this framework offers a plausible account of PCD early in the history of life, and also provides an epistemic basis for the future development of a general evolutionary account of mortality. (shrink)

In 1952, Heinrich Scholz published a question in The Journal of Symbolic Logic asking for a characterization of spectra, i.e., sets of natural numbers that are the cardinalities of finite models of first order sentences. Günter Asser in turn asked whether the complement of a spectrum is always a spectrum. These innocent questions turned out to be seminal for the development of finite model theory and descriptive complexity. In this paper we survey developments over the last 50-odd years pertaining to (...) the spectrum problem. Our presentation follows conceptual developments rather than the chronological order. Originally a number theoretic problem, it has been approached by means of recursion theory, resource bounded complexity theory, classification by complexity of the defining sentences, and finally by means of structural graph theory. Although Scholz' question was answered in various ways, Asser's question remains open. (shrink)

Programmed cell death (PCD) in unicellular organisms is in some instances an altruistic trait. When the beneficiaries are clones or close kin, kin selection theory may be used to explain the evolution of the trait, and when the trait evolves in groups of distantly related individuals, group or multilevel selection theory is invoked. In mixed microbial communities, the benefits are also available to unrelated taxa. But the evolutionary ecology of PCD in communities is poorly understood. Few hypotheses have been offered (...) concerning the community role of PCD despite its far-reaching effects. The hypothesis we consider here is that PCD is a black queen. The Black Queen Hypothesis (BQH) outlines how public goods arising from a leaky function are exploited by other taxa in the community. Black Queen (BQ) traits are essential for community survival, but only some members bear the cost of possessing them, while others lose the trait In addition, BQ traits have been defined in terms of adaptive gene loss, and it is unknown whether this has occurred for PCD. Our conclusion is that PCD fulfils the two most important criteria of a BQ (leakiness and costliness), but that more empirical data are needed for assessing the remaining two criteria. In addition, we hold that for viewing PCD as a BQ, the original BQH needs to include social traits. Thus, despite some empirical and conceptual shortcomings, the BQH provides a helpful avenue for investigating PCD in microbial communities. (shrink)

This contribution presents an adult education workshop implemented in the field of early childhood education. One of the specificities of education and care practices lies in the competences of the professionals to give a central role to the detailed observation of situations, in order to adjust their modalities of action. How can such observational work be developed and transformed? A participatory research-training approach aims to support the co-construction of an analytical view on observable phenomena in the course of interactions. In (...) a perspective of interactional analysis, it focuses on the modalities that favor the construction of such an analytical posture. (shrink)

The devotion of a full article in the Paris Agreement to loss and damage was a major breakthrough for the world’s most vulnerable nations seeing to gain support for climate impacts beyond what can be adapted to. But how will loss and damage be paid for, and who will pay it? Will ethics be part of this decision? Here we ask what are the possible means of raising predictable and adequate levels of funding to address loss and damage? Utilizing a (...) framework developed by Marco Grasso, we argue that making the ethical connections between addressing climate impacts and finance mechanisms could significantly enhance their likelihood of being adopted. We briefly review insurance mechanisms and catastrophe bonds, and then move on to six “innovative finance” approaches to funding loss and damage. We utilize six criteria in assessing them: adequacy, predictability, technical feasibility, fairness, and indirect effects, and whether each has a clear link to loss and damage. Several mechanisms for gathering funds emerged as most promising. Three of the six financial mechanisms we reviewed to raise funding involved airline transport: clearly, there is a huge opportunity to tax this sector in one form or another, in recognition of airline emissions’ role in creating losses and damages in vulnerable nations from sea level rise, droughts, floods or hurricanes. Funding loss and damage response is a contentious issue that will get only more unwieldy if Parties’ conceptions of loss and damage are at odds: a common definition of loss and damage needs to be agreed upon under the UNFCCC. Most immediately, to meet any equity criteria, wealthy countries should do more to support the premiums of those who cannot afford insurance. (shrink)

In 2010, the Eurozone became the epicentre of the world crisis. The vulnerability of Europe appears to be linked to the specific institutional arrangement which organises monetary, financial and budgetary policies within the Eurozone. This article tries to understand the evolution of theeuduring a short but decisive historical sequence in a theoretical framework that puts elements of Gramsci’s reflections on the theme of crisis, and especially his notion of ‘Caesarism’, at its centre. It addresses the current debate concerning the relationships (...) between democratic politics and neoliberalism, while focusing on how the radicalisation of the crisis put at stake the co-construction of capitalism and representative democracy in the Western world sincewwii. (shrink)

Cet article vise à comprendre la théorie stoïcienne de la deixis afin d’expliquer l’importance accordée par les stoïciens aux pronoms démonstratifs et aux énoncés qu’ils composent, c’est-à-dire les propositions dites définitives. Nous montrons que ces propositions sont privilégiées pour des raisons à la fois ontologiques et épistémologiques en raison des propriétés sémantiques de leur sujet. Elles sont privilégiées d’un point de vue ontologique parce que la deixis grâce à laquelle leur sujet fait référence au réel crée une relation privilégiée à (...) la matière, la catégorie ontologique stoïcienne fondamentale. De plus, ces sujets requièrent que leur référent existe et soit présent et saisissable. Ces énoncés sont d’autre part privilégiés d’un point de vue épistémologique parce qu’ils sont fondamentaux dans l’acquisition de la connaissance. Nous suggérons enfin que tous les énoncés apparemment définis ne le sont pas en effet, et considérons quand et sous quelles conditions une référence déictique est réussie. (shrink)

El presente artículo busca mostrar la relevancia de la filosofía de Spinoza con respecto a la realización de la libertad. Su idea de libertad no rechaza las emociones, y las vincula con nuestra capacidad de ser seres racionales. Spinoza es de los primeros filósofos que aprecia una dimensión interna de las emociones y la considera como parte de nuestra propia naturaleza, pues afirma que la esencia humana es el deseo mismo. El ser humano es consciente de este deseo, el cual (...) lo lleva a buscar modos de afirmar su propia existencia. Su noción de libertad, por ende, debe considerar todos estos elementos para poder plasmarse como algo realizable sin dejar de lado lo que nos hace humanos. (shrink)

This paper is concerned with the description of the process of measurement within the context of a quantum theory of the physical world. It is noted that quantum mechanics permits a quasi-classical description of those macroscopic phenomena in terms of which the observer forms his perceptions. Thus, the process of measurement in quantum mechanics can be understood on the quasi-classical level by transcribing from the strictly classical observables of Newtonian physics to their quasi-classical counterparts the known rules for the measurement (...) of the former. The remaining physical problem is the delineation of the circumstances in which the correlation of a peculiarly quantum mechanical observable A with a classically measurable observable B can result in a significant measurement of A. This is undertaken within the context of quantum theory. The resulting clarification of the process of measurement has important implications relative to the philosophic interpretation of quantum mechanics. (shrink)

The Type VI secretion system is a multiprotein and mosaic apparatus that delivers protein effectors into prokaryotic or eukaryotic cells. Recent data on the enteroaggregative Escherichia coli T6SS have provided evidence that the TssA protein is a key component during T6SS biogenesis. The T6SS comprises a trans-envelope complex that docks the baseplate, a cytoplasmic complex that represents the assembly platform for the tail. The T6SS tail is structurally, evolutionarily and functionally similar to the contractile tails of bacteriophages. We have shown (...) that TssA docks to the membrane complex, recruits the baseplate complex and initiates and coordinates the polymerization of the inner tube with that of the sheath. Here, we review these recent findings, discuss the variations within TssA-like proteins, speculate on the role of EAEC TssA in T6SS biogenesis and propose future research perspectives. In the environment, bacteria have to cope with other microbial species and therefore have evolved anti-microbial mechanisms. The bacterial Type VI secretion system transports toxins into bacterial and/or eukaryotic cells using a contractile mechanism. At the architectural level, the T6SS could be viewed as a nano-speargun assembled in the bacterial cytoplasm and anchored to a trans-envelope complex. We describe and speculate on recent findings demonstrating that the TssA subunit is involved in the different stages of T6SS biogenesis. (shrink)

We study the minimal complexity of tilings of a plane with a given tile set. We note that every tile set admits either no tiling or some tiling with.

We study the extension of dependence logic \ by a majority quantifier \ over finite structures. We show that the resulting logic is equi-expressive with the extension of second-order logic by second-order majority quantifiers of all arities. Our results imply that, from the point of view of descriptive complexity theory, \\) captures the complexity class counting hierarchy. We also obtain characterizations of the individual levels of the counting hierarchy by fragments of \\).

The article argues the need to rehabilitate the concept of alienation within the post-Fordist model of production, insofar as it is the concept which – if we leave aside the general analysis of wage-labour within capitalist social structures – is best able to explain how the newly devised tools for the management of labour and, most importantly, for the mobilisation of the subjectivities of salaried workers, lead to a reduction both of their autonomy in work and of their opportunities for (...) escape from the stipulated behavioural norms. Finally, it is argued that the procedures for the organisation of production and labour, along with the mechanisms intrinsic to the mobilisation of labour, establish, to an unprecedented degree, the conditions for a denegation of alienation, thus consolidating it. (shrink)

L’objectif principal que nous poursuivons dans cet article est de montrer que pour un phénomène aussi complexe que le schwa, qui ne se laisse pas appréhender de manière triviale, la constitution de corpus s’appuyant sur une méthodologie rigoureuse et explicite est un élément indispensable de la construction des objets phonologiques. A cette fin, nous nous concentrons sur l’étude de la position finale, et plus spécifiquement de l’opposition /Cə#/ vs /C#/, à la lumière de trois enquêtes du projet « Phonologie du (...) français contemporain (PFC) : usages, variétés et structure » : un corpus de Douzens (Aude), un corpus de Biarritz (Pays Basque) et un corpus de Treize-Vents (Vendée). Après avoir resitué la problématique du schwa dans le débat général sur le traitement des positions finales, nous présentons le projet PFC, sa méthodologie et ses outils. Nous exposons enfin les résultats obtenus pour les trois corpus : le corpus de l’Aude représente un français du Midi très conservateur, où l’opposition /Cə#/ vs /C#/ est tenace malgré des variations entre générations ; le corpus du Pays Basque représente un français du Midi en évolution, où cette opposition tend à disparaître mais est résiduellement présente ; le corpus de Vendée (variété rarement décrite) se révèle plus proche du français de référence, et les données indiquent sans ambiguïté que l’opposition /Cə#/ vs /C#/ a été éliminée. Notre conclusion, si la démarche est correcte, est que ces résultats et les analyses qu’ils permettent (y compris l’étude des corrélations entre oral et écrit) seraient difficiles, voire impossible, à obtenir sur la base d’intuitions ou d’observations non contrôlées. (shrink)

In their book Spare Parts, published in 1992, Fox and Swazey criticized various aspects of organ transplantation, including the routinization of the procedure, ignorance regarding its inherent uncertainties, and the ethos of transplant professionals. Using this work as a frame of reference, we analyzed articles on organ transplantation published in internal medicine and transplantation journals between 1995 and 2008 to see whether Fox and Swazey’s critiques of organ transplantation were still relevant.

L’objectif de cet article est de faire le point sur le programme de recherche PFC (« Phonologie du français contemporain : usages, variétés et structure »), plus de quinze ans après son lancement et d’illustrer le travail mené dans ce cadre par la question du schwa, phénomène bien connu dans le domaine de la variation phonologique et central à la phonologie du français. Après avoir brièvement présenté le programme, nous abordons la question du schwa en français et expliquons son traitement (...) dans PFC. Nous illustrons ensuite le travail effectué en nous penchant tout d’abord sur les variétés méridionales, que nous opposons aux variétés septentrionales, avant d’aborder la question du schwa dans les variétés suisses romandes. (shrink)

De 1815 - avec le Congrès de Vienne qui inaugure une ère de Restauration - à mars 1848, avec les répercussions de la révolution de février en Europe, la période du Vormârz ("avant mars") se caractérise, au sein du monde germanique, par une vie intellectuelle d'une particulière effervescence. Les grandes philosophies qui se sont construites pour dépasser Kant, avec Fichte, Schelling et Hegel, autorisent bon nombre de penseurs allemands à considérer l'Allemagne comme étant philosophiquement en avance sur son temps, ou (...) tout au moins à la pointe de la modernité. Cette avance théorique tranche pourtant avec la réalité politique et sociale de l'époque, façonnée par Metternich. Une solution de cette contradiction dans laquelle se trouve l'Allemagne semble alors résider, aux yeux de certains auteurs, dans l'idée suivant laquelle il ne resterait plus à l'Allemagne qu'à réaliser sa philosophie. Le présent ouvrage entend contribuer à l'analyse de la façon dont le thème de la réalisation de la philosophie est élaboré par, ou à partir des réflexions de plusieurs auteurs de l'époque. Il s'agit des Jeunes Hégéliens, et principalement : Eduard Gans, Heinrich Heine, Arnold Ruge, Ludwig Feuerbach, Max Stirner, David Strauss, les frères Bruno et Edgar Bauer, Moses Hess, Michel Bakounine, August von Cieszkowski, Karl Marx et Friedrich Engels."--Page 4 of cover. (shrink)

Binding of antigen or lectin to the surface of a T lymphocyte initiates a complex sequence of events which result in both T cell proliferation and the acquisition of immunologic functions. This complex sequence of events is most likely programmed and precisely timed by a series of contingent gene activations in which one member of this series activates the next. The two most obvious examples of these stages are the set of genes activated when antigen interacts with the antigen receptor (...) and the set of genes activated when IL‐2 interacts with its receptor. However, it is likely that several other parallel pathways of gene activation are necessary to bring about T‐cell division. An example would be the antigen‐induced activation of the c‐myc gene, which in turn is likely to be involved in regulating an additional group of genes not directly controlled by either IL‐2 or antigen. A fundamental understanding of T‐lymphocyte activation necessitates identification of the factors involved in initiating each of these contingent levels of gene activation. (shrink)

Multicellular organisms develop on a predictable schedule that depends on both cell‐intrinsic timers and sequential cell‐cell interactions mediated by extracellular signals. The interplay between intracellular timers and extracellular signals is well illustrated by the development of oligodendrocytes, the cells that make the myelin in the vertebrate central nervous system. An intrinsic timing mechanism operates in each oligodendrocyte precursor cell to limit the length of time the cell divides before terminally differentiating. This mechanism consists of two components, a timing component, which (...) depends on the mitogen platelet‐derived growth factor (PDGF) and measures elapsed time, and an effector component, which depends on thyroid hormone and stops cell division and initiates differentiation at the appropriate time. The cell‐cycle inhibitor p27/Kip1 accumulates in the precursor cells as they proliferate and is part of both components of the timer. It seems likely that similar timing mechanisms operate in other cell lineages. BioEssays 22:64–71, 2000. ©2000 John Wiley & Sons, Inc. (shrink)

William C. Gentry was both an academic philosopher, perfectly willing to engage in the philosophical 'conversations' of the written word and, more importantly, a true philosopher, in the Platonic and Socratic style. Engaging with those around him in discourse, in live conversations, which are the vehicle of actual philosophical inquiry and discovery. These essays are the product of those conversations. Gentry's thoughts consisted of investigations into the deepest and most profound questions of human nature, ethics, and knowledge. This volume is (...) a tribute both to his role as a teacher and philosopher. As a teacher, friend, and colleague, Gentry was the epitome of the philosopher: questioning, exploring, critiquing, discovering. (shrink)

The paper describes the conceptual models used to understand the processes determining plant growth rates in response to environmental changes. A series of experiments and growth models were used at three organizational levels: the specific plant organs, the whole plant and the plant canopy. The energy conversion efficiency and the total plant carbon balance were first examined. The carbon partitioning amongst the plant parts was then studied. The energy conversion efficiency is generally understood. In modelling carbon partitioning it was first (...) necessary to establish the carbon demand for each plant organ. The carbon partitioned amongst plant organs was then calculated in two ways. The first one based on empirical data consisted in defining which organ received the carbon prior to other organs. The second one was based on the relationship between the carbon mass of specific organs and their trophic activity. This hypothesis allowed the optimization of the carbon partitioning in order to maximize the whole plant growth rate. The opportunities to use these theoretical approaches in plant growth modelling are discussed. (shrink)

Reprise d’un article initialement paru dans La création sociale, no 6 de 2001, p. 121-139. Aucune « culture humaine » n’est « pure » ni « définitive » ; toute culture est métissée et sans « fin » déterminée. Pour analyser les diverses formes du métissage culturel dans plusieurs civilisations, sept concepts différents sont ici présentés avec des exemples de leur application aussi bien en Orient qu’en Occident et du Moyen Âge qu’à nos jours. Reprint of an article originally published (...) in La création sociale, no. 6 of 2001, pp. 121–39. No “human culture” is “pure” or “final”. Any culture is mixed with another. To analyze the various forms of cultural miscegenation in many civilizations, seven different concepts are here presented with examples of their application both in the Eastern and the Western countries and from the middle ages to our days. (shrink)

This contribution reports on a study conducted as part of a research on early childhood educators’ vocational training in Geneva. We wish to better understand the interrelational positioning challenges that the students face during the activities in which they participate in the workplace. The multimodal analysis highlights the frequent shifts of the participants’ reciprocal positions in mentoring interactions, and shows the coexistence of two inverted asymmetrical relations in a form of “double-cross asymmetry”. In this context, the trainees’ positioning is vulnerable (...) to the professional events that emerge in the course of interaction. (shrink)