In spite of the importance of point mutations for evolution and human diseases, their natural spectrum of incidence in different species is not known. Here I propose to determine these spectra by comparing consecutive sequence periods in stretches of repetitive DNA. The article presents the analysis of more than 51,000 such point mutations identified by this approach in the genomes of human, chimpanzee, rat, mouse, pufferfish, zebrafish, and sea squirt. I propose to explain the observed spectra by auto‐mutagenic (...) mechanisms of genome variation involving the inter‐conversions of nucleotides, single base‐pair inversions and their combinations. (shrink)

We have achieved a residue‐level resolution of genetic interaction mapping – a technique that measures how the function of one gene is affected by the alteration of a second gene – by analyzing point mutations. Here, we describe how to interpret point mutant genetic interactions, and outline key applications for the approach, including interrogation of protein interaction interfaces and active sites, and examination of post‐translational modifications. Genetic interaction analysis has proven effective for characterizing cellular processes; however, to date, (...) systematic high‐throughput genetic interaction screens have relied on gene deletions or knockdowns, which limits the resolution of gene function analysis and poses problems for multifunctional genes. Our point mutant approach addresses these issues, and further provides a tool for in vivo structure‐function analysis that complements traditional biophysical methods. We also discuss the potential for genetic interaction mapping of point mutations in human cells and its application to personalized medicine. (shrink)

Here, we propose that the heterogeneity of mutational types in populations underpins alternative pathways of evolutionary adaptation. Point mutations, deletions, insertions, transpositions and duplications cause different biological effects and provide distinct adaptive possibilities. Experimental evidence for this notion comes from the mutational origins of adaptive radiations in large, clonal bacterial populations. Independent sympatric lineages with different phenotypes arise from distinct genetic events including gene duplication, different insertion sequence movements and several independent point mutations. The breadth of the mutational (...) spectrum in the ancestral population should be viewed as a form of bet‐hedging, reducing the risk of evolutionary dead ends and complementing the phenotypic and epigenetic heterogeneities that improve the survival capabilities of a population. Different mutational events arise from distinct cellular processes and are subject to separate environmental impacts, so the availability of any particular type of mutation may constrain or promote adaptive pathways in populations. (shrink)

The fifth base in human DNA, 5‐methylcytosine, is inherently mutagenic. This has led to marked changes in the distribution of the CpG methyl acceptor site and an 80% depletion in its frequency of occurrence in vertebrate DNA. The coding regions of many genes contain CpGs which are methylated in sperm and serve as hot spots for mutation in human genetic diseases. Fully 30–40% of all human germline point mutations are thought to be methylation induced even though the CpG (...) dinucleotide is under‐represented and efficient cellular repair systems exist. Importantly, tumor suppressor genes such as p53 also contain methylated CpGs and these serve as hot spots for mutations in some, but not all, human cancers. Comparison of the spectrum of mutations present in this gene in different human cancers allows for predictions to be made on the molecular mechanisms of tumorigenesis. (shrink)

Historians go to great lengths to avoid confronting discontinuity, searching for explanations as to why such events as the fall of the Berlin Wall, George W. Bush's invasion of Iraq, and the introduction of the euro logically develop from what came before. _Moved by the Past_ radically breaks with this tradition of predating the past, incites us to fully acknowledge the discontinuous nature of discontinuities, and proposes to use the fact that history is propelled by unforeseeable leaps and bounds as (...) a starting point for a truly evolutionary conception of history. Integrating research from a variety of disciplines, Eelco Runia identifies two modes of being "moved by the past": regressive and revolutionary. In the regressive mode, the past may either overwhelm us--as in nostalgia--or provoke us to act out what we believe to be solidly dead. When we are moved by the past in a revolutionary sense, we may be said to embody history: we burn our bridges behind us and create accomplished facts we have no choice but to live up to. In the final thesis of _Moved by the Past_, humans energize their own evolution by habitually creating situations ("catastrophes" or sublime historical events) that put a premium on mutations. This book therefore illuminates how every now and then we chase ourselves away from what we were and force ourselves to become what we are. Proposing a simple yet radical change in perspective, Runia profoundly reorients how we think and theorize about history. (shrink)

We address two points. First, one must explain how different, rare mutations ultimately lead to common psychopathological conditions. The developmental instability model offers one solution. Second, Keller & Miller perhaps miss the major processes other than variation fueled by rare deleterious mutations that account for interesting genetic variation in psychopathology, particularly when single alleles have non-negligible effects: Red Queen processes.

Somatic mutation plays a key role in transforming normal cells into cancerous cells. The analysis of cancer progression therefore requires the study of how point mutations and chromosomal mutations accumulate in cellular lineages. The spread of somatic mutations depends on the mutation rate, the number of cell divisions in the history of a cellular lineage, and the nature of competition between different cellular lineages. We consider how various aspects of tissue architecture and cellular competition affect the pace (...) of mutation accumulation. We also discuss the rise and fall of somatic mutation rates during cancer progression. BioEssays 26:291–299, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Oncogenesis is manifested as uncontrolled cellular proliferation and in some situations a failure of normal differentiation in the transformed cell. This has led to speculation that the normal role of proto‐oncogenes during development may be to mediate the relationship between proliferation and differentiation. The advent of gene targeting in ES cells allows the role oncogenes in development to be tested directly. Two recent studies have examined the phenotype of N‐myc mutant mice generated by gene targeting(1,2). In both reports, the (...) class='Hi'>mutation is an embryonic lethal at 11.5 days of gestation confirming a critical role for this proto‐oncogene in development and the inability of other members of the myc family to substitute functionally for N‐myc. Although the phenotypes are similar in general outline, the two reports differ in the specifics of the morphological and histological abnormalities identified. The disparity may result from the mutation created, the genetic background of the mutant mice or the criteria used to determine abnormalities. Assuredly, there is valuable information to be gained about N‐myc function from these mutant mice. However, these reports make it clear that morphological and histological abnormalities in N‐myc mutant mice serve as a starting point rather than as an endpoint. The challenge now is to link the defect at the cellular level to the abnormalities at the physiological level. (shrink)

In this article, I argue that concern with the public sphere and the necessary conditions for a genuine democracy can be seen as a central theme of Jurgen Habermas's work that deserves respect and critical scrutiny in the contemporary moment, when throughout the world liberal democracies are in crisis. My study intends to point to the continuing importance of Habermas' problematic of the public sphere and its relevance for debates over democratic politics and social and cultural life in the (...) present age, in an era in which the Occupy Movements, Black Lives Matter, #MeToo, the Trump Resistance Movement, and Ukraine and Palestine Solidarity groups use social media to struggle against multiple forms of oppression. At stake is delineating a concept of the public sphere which facilitates maximum public participation and debate over the key issues of the contemporary era and which consequently promotes the cause of radical democracy and social transformation. (shrink)

The article examines the collaborations between the pensionnaires of the Villa Medici in Rome and the members of the French School of Athens, shedding light on the complex relationships between architecture, art, and archeology. The second half of the 19th century was a period during which the exchanges and collaborations between archaeologists, artists, and architects acquired a reinvented role and a dominant place. Within such a context, Athens was the place par excellence, where the encounter between these three disciplines took (...) place. The main objective of the article is to render explicit how the revelations of archeology, actively disseminated by the members of the French School of Athens—the “Athéniens”—had an important impact on the approach of certain pensionnaires of the Villa Medici in Rome. Particular emphasis is placed on certain pensionnaires, who decided to devote their envois to ancient monuments of Greece. In parallel, the article intends to shed light on the methods that helped the pensionnaires-architects of the Villa Medici in Rome appropriate archaeological discoveries concerning Greek antiquities. The article takes, as a starting point, the following hypothesis: to better understand the figure of the architect-archaeologist, of whom Jacques Ignace Hittorff is an emblematic example, it is pivotal to bear in mind that before the second half of the 19th century neither the figure of Hellenic archeology nor the figure of the architect had yet acquired their autonomy. Taking into account that Johann Joachim Winckelmann, in the middle of the 18th century, forged an ideal Greek model, which was criticized during the second half of the 19th century, the article also sheds light on the fact that the revelations of archaeologists have called into question the Winckelmannian image of Greece. Another aspect that is explored in the article is Jacques Ignace Hittorff’s studies concerning the polychromy of ancient Greek monuments, paying special attention to his Restitution du temple d’Empédocle à Sélinonte ou l’Architecture polychrome chez les Grecs. The article also explores how the shifts of the status of philhellenism are related to the mutations of the meaning of travel to Greece. In parallel, it investigates the impact of Greek independence on the ideals of beauty and nature in arts, as well as how Greek independence is related to the intensification of the interest in the excavations of Greek antiquities. (shrink)

La notion d’expérimentation, initialement réservée au domaine des sciences expérimentales, est employée aujourd’hui pour qualifier de multiples pratiques sociopolitiques : gouvernementales, activistes ou artistiques. Cette extension des usages du terme manifeste l’influence de l’imaginaire des pratiques de recherche expérimentale sur les conceptions contemporaines du politique. Elle accompagne des mutations du parler et de l’agir politiques qu’il importe de mieux caractériser, au confluent de la raison scientifique et technique et des transformations de l’espace public.Experimentation, which initially concerned only the experimental sciences (...) field, is a term now used to describe a great many forms of socio-political practice, for example among governments, activists or artists. This extension of the term’s usage illustrates the influence of imagination in experimental research on contemporary conceptions of politics. It is supporting changes in the patterns of political speech and action that need to be better characterised, as they are occurring at the point where scientific and technical reason meets the transformation of the public sphere. (shrink)

El siguiente artículo toma como punto de partida al concepto de industria cultural desde sus principales exponentes, para exponer sus usos actuales. Este nació como concepto filosófico como parte de la obra de los autores representantes de la llamada Escuela de Frankfurt, Theodor Adorno y Max Horkheimer, con valiosos aportes de Walter Benjamin. En la actualidad ha mutado su definición, siendo utilizado de manera instrumentalpor parte del Estado y organismos internacionales, para definir al grupo de sectores de producción cultural y (...) simbólica de acuerdo a sus parámetros económicos. En este sentido, desde aquél concepto de industria cultural de los años cuarenta podremos ver que hay un recorrido en el cual se van transformando las posturas acerca de lo que el arte y la cultura posibilitan. La función social del arte va escondiéndose detrás de su inmersión cada vez más visible dentro de la producción mercantil, si bien en los últimos años la cultura aparece como motor de desarrollo económico e identitario. Esta transición será ilustrada con el caso argentino, dando cuenta de los cambios en el sector. The following article takes as its starting point the concept of Culture Industry from its leading exponents, and exposes its current uses. The Culture Industry began like a philosophical concept, as part of the work of the Frankfurt School authors, Theodor Adorno and Max Horkheimer, with contributions of Walter Benjamin. Nowadays, this concept definition has mutated, being used instrumentally by the state and international organizations, to define the cultural and symbolic production according to economic parameters. In this sense, paying attention to that idea of Culture Industry, we can see that there is a path in which the possibilities of meanings of art and culture are changing. The social function of art is subordinating behind the commodity production, although in recent years the culture appears as an engine of economic development and identity. This transition will be illustrated accounting for changes in the sector in the case of Argentina. (shrink)

Italian priest, essayist, and intellectual of the twentieth century, Ernesto Balducci identified the crucial turning points of the new millennium by advancing original perspectives capable of opening unusual future scenarios. Sensitive to emergences of society (pollution, wars, ecological collapse), he retraces the causes in the more general ?crisis of modernity,? proposing a new paideia and a new model of thought. He theorizes the construction of a novel planetary horizon that presupposes not only the building of new organizational structures, but also (...) the achieving of an authentic ?anthropological mutation? capable of inverting the course of history. While the old ethics were anthropocentric, founded on the supremacy of humankind over the world and nature, the new ethics is planetary, meaning that humankind must no longer be used as the parameter, but instead, the global horizon over which the effects of his or her actions extend. (shrink)

Cet article questionne l’étendue, la variété, la complexité, parfois la paradoxalité des effets de l’infiltration du virtuel dans les aires intersubjectives du couple et de la famille hypermodernes globalisés. L’approche retenue croise approche psychanalytique du lien et de la psychologie interculturelle et s’appuie sur la clinique et les recherches de l’auteure en contexte tunisien socialement et culturellement mutant. Sur la base de deux vignettes illustratives du phénomène du « bovarysme virtuel », elle met en évidence deux points concernant cet espace (...) du possible et du potentiel. D’une part, il contribue à exacerber les quiproquos entre des subcultures de genre sur fond de paysage sociétal bien engagé sur les voies de l’individualisme et de la dépatriarcalisation ; d’autre part, il contribue à simuler et stimuler le processus d’interculturation, potentielle voie de relance de subjectivités et liens en crise. (shrink)

This chapter offers a critique of intelligent design arguments against evolution and a philosophical discussion of the nature of science, drawing several lessons for the teaching of evolution and for science education in general. I discuss why Behe’s irreducible complexity argument fails, and why his portrayal of organismal systems as machines is detrimental to biology education and any under-standing of how organismal evolution is possible. The idea that the evolution of complex organismal features is too unlikely to have occurred by (...) random mutation and selection (as recently promoted by Dembski) is very widespread, but it is easy to show students why such small probability arguments are fallacious. While intelligent design proponents have claimed that the exclusion of supernatural causes mandated by scientific methods is dogmatically presupposed by science, scientists have an empirical justification for using such methods. This justification is instructive for my discussion of how to demarcate science from pseudoscience. I argue that there is no universal account of the nature of science, but that the criteria used to judge an intellectual approach vary across historical periods and have to be specific to the scientific domain. Moreover, intellectual approaches have to be construed as practices based on institutional factors and values, and to be evaluated in terms of the activities of their practitioners. Science educators should not just teach scientific facts, but present science as a practice and make students reflect on the nature of science, as this gives them a better appreciation of the ways in which intelligent design falls short of actual science. (shrink)

A first year graduate student, Ann Dee Margulies, changed my research career in 1962 by challenging me to direct her in the isolation of recombination‐deficient mutants of Escherichia coli K‐12. She succeeded in isolating two mutants, which conjugated with donor strains and received the donor DNA, but could not recombine that DNA with their own chromosomes. Ann Dee showed that both mutants were much more sensitive to UV radiation than was the wild type. Furthermore, she showed that one of these (...) mutants carried a single mutation affecting both recombination and resistance. This work, published in 1965, was the first demonstration of the recA gene of E. coli. Subsequent work led to the discovery of many more recombination genes, the phenomenon of post replication‐recombination repair, the invention of the SOS hypothesis and the discovery of genes encoding proteins with similar primary structure and function in all major groups of organisms. This article honors the memory of Ann Dee. (shrink)

This corrigendum concerns [, § ] on ordered difference existentially closed valued fields where we overlooked the problem of immediate extensions.

A totally ordered group G is essentially periodic if for every definable non-trivial convex subgroup H of G every definable subset of G is equal to a finite union of cosets of subgroups of G on some interval containing an end segment of H; it is coset-minimal if all definable subsets are equal to a finite union of cosets, intersected with intervals. We study definable sets and functions in such groups, and relate them to the quasi-o-minimal groups introduced in Belegradek (...) et al. . Main results: An essentially periodic group G is abelian; if G is discrete, then definable functions in one variable are ultimately piecewise linear. A group such that every model elementarily equivalent to it is coset-minimal is quasi-o-minimal , and its definable functions in one variable are piecewise linear. (shrink)

It is known today that Hegel's philosophy was at the center of the development of pragmatism. In particular, the relation of Dewey's philosophy to Hegel's has recently been studied with great attention1. Many studies have revealed that the German philosopher had a fundamental influence on the young John Dewey, particularly with regard to his theory of culture, for his logic, as well as for his psychology. These new readings propose a profoundly original view of Dewey and explain why he thought (...) of his philosophy as a "permanent Hegelian deposit".Our work aims to... (shrink)

Given a simple non-trivial finite-dimensional Lie algebra L, fields $K_i$ and Chevalley groups $L(K_i)$ , we first prove that $\Pi_{\mathcal{U}} L(K_i)$ is isomorphic to $L(\Pi_{\mathcal{U}}K_i)$ . Then we consider the case of Chevalley groups of twisted type ${}^n\!L$ . We obtain a result analogous to the previous one. Given perfect fields $K_i$ having the property that any element is either a square or the opposite of a square and Chevalley groups ${}^n\!L(K_i)$ , then $\pu{}^n\!L(K_i)$ is isomorphic to ${}^n\!L(\pu K_i)$ . (...) We apply our results to prove the decidability of the set of sentences true in almost all finite groups of the form L(K) where K is a finite field and L a fixed untwisted Chevalley type. (shrink)

Le présent article examine la façon dont John Dewey a entrepris de poser le problème de la valuation et de ses conséquences au sein de sa théorie de l’éducation. Plus spécifiquement, nous voudrions montrer que son effort pour repenser l’articulation des moyens et des fins du processus de valuation contribue à repenser l’enquête morale. Celle-ci, si elle fait alors l’objet d’une pédagogie qui met au centre l’expérience vécue du sujet, nous oblige à concevoir à nouveaux frais les valeurs que nous (...) accordons aux connaissances apprises. Notre analyse entend démontrer que : 1) de même que dans le domaine éthique, rien n’a de valeur en soi pour le sujet agissant. Mais que 2) la valuation de tout acte est déterminée en situation, alors, 3) dans le domaine de la pédagogie, aucune connaissance n’a de valeur en soi pour l’élève. 4) Ainsi la première tâche de l’enseignant.e est de former l’élève à des processus de valuation efficaces. Cela dans le but que celui-ci puisse à son tour, clairement, déterminer pour lui-même les connaissances qui auront de la valeur. Si notre hypothèse est juste alors cette tâche devient à la fois un point de départ important de la pédagogie pragmatiste et un impératif incontournable de l’éthique enseignante. -/- The present article examines how Dewey addressed the problem of value, as well as the consequences that this solution had for his educational theory. More specifically, I aim to show that Dewey’s effort to rethink means and ends within the process of valuation contributes to a recasting of moral inquiry. If moral inquiry becomes part of a pedagogy that focuses upon the lived experience of the subject, this compels us to rethink the value we attribute to acquired knowledge. My analysis will demonstrate 1) that even within the ethical domain, nothing has value in itself for the acting subject, but that 2) the value of all acts must be determined within specific situations, and therefore 3) within the domain of pedagogy, no knowledge has value in and of itself for the student. 4) Thus the first task of the teacher is to teach students how to evaluate questions of value, which will push them to determine for themselves what knowledge has value. If my hypothesis is correct, this task becomes simultaneously an important starting place for pragmatist pedagogy and a cornerstone of a new ethic of teaching. (shrink)

Given a model-complete theory of topological fields, we considered its generic differential expansions and under a certain hypothesis of largeness, we axiomatised the class of existentially closed ones. Here we show that a density result for definable types over definably closed subsets in such differential topological fields. Then we show two transfer results, one on the VC-density and the other one, on the combinatorial property NTP2.

Studies on Neurospora chromosome segment duplications (Dps) performed since the publication of Perkins's comprehensive review in 1997 form the focus of this article. We present a brief summary of Perkins's seminal work on chromosome rearrangements, specifically, the identification of insertional and quasiterminal translocations that can segregate Dp progeny when crossed with normal sequence strains (i.e., T × N). We describe the genome defense process called meiotic silencing by unpaired DNA that renders Dp‐heterozygous crosses (i.e., Dp × N) barren, which provides (...) a basis for identifying Dps, and discuss whether other processes also might contribute to the barren phenotype of Dp × N and Dp × Dp crosses. We then turn to studies suggesting that large Dps (i.e., >300 kbp) can allow smaller gene‐sized duplications to escape another genome defense process called repeat‐induced point mutation (RIP), possibly by titration of the RIP machinery. Finally, we assess whether in natural populations dominant RIP suppressor Dps provide an “RIP‐free” niche for evolution of new genes following the duplication of existing genes. (shrink)

We describe classes of existentially closed ordered difference fields and rings. We show an Ax-Kochen type result for a class of valued ordered difference fields.

We consider the reduct to the module language of certain theories of fields with a non surjective endomorphism. We show in some cases the existence of a model companion. We apply our results for axiomatizing the reduct to the theory of modules of non principal ultraproducts of separably closed fields of fixed but non zero imperfection degree.

With this proposal, we wish to revisit the Idea of the University in the perspective of the democratic project of the American philosopher and pragmatist John Dewey. Our hypothesis consists in the thesis that the deweyen project confronts the problem of the social distribution of knowledge, in the aim of giving us the means to transform the latter. In this way, if we consider that the university is part of this distribution through its student learning function, then our purpose is (...) to demonstrate that this learning is currently guided by an individual intelligence paradigm harms that the development of collective intelligence. For John Dewey, the latter is one of the central means of his democratic project which would reconcile the Idea of a University with real University institutions. Therefore, according to him, if universities want to contribute to the democratic project, we must adopt a new pedagogical orientation promoting individual and collective intelligence. (shrink)

"Philosophy for Children: a Way to Reconcile Disciplinary Teaching and School Life? Drawing mainly on John Dewey's writings, this contribution aims to extend the dualism of a traditional conception of education at the epistemological, pedagogical and organizational levels. This conception was already criticised by this author at the beginning of the 20th century and still remains widely present today among the school community. Through this approach, we demonstrate that the dualist approach is as many obstacles to be removed in the (...) process both to improve and rebuild a better education. The hypothesis defended here consists to demonstrate how philosophy for children, strengthened by its pragmatist heritage, can challenge these dualisms and thereby jeopardize the traditional conception of education. Keywords: John Dewey, philosophy of education, co-curriculum, school life, philosophy for children ". (shrink)

We show that if G is a group of finite Morley rank, then the verbal subgroup is of finite width, where w is a concise word. As a byproduct, we show that if G is any abelian-by-finite group, then Gn= is definable.

Le féminisme est un mouvement théorique et politique pluriel et en perpétuelle évolution. Aussi ce travail se situe dans les champs de la philosophie de l’éducation et plus particulièrement au sein des débats entre plusieurs courants philosophiques se réclamant du féminisme. Il cherche à évaluer l’intérêt de deux de ces approches philosophiques au regard de la construction d’une pédagogie féministe. Se trouve ainsi comparées l’approche de la théorie critique (proche du marxisme matérialiste et de l’école de Francfort) et l’approche pragmatiste (...) (issue des travaux de Jane Addams et John Dewey) par rapport au problème du “consciousness-raising” en pédagogie. Ce dernier présente en effet des difficultés à l’approche critique qui seront exposées dans la première partie de l’argumentation. L’hypothèse de notre travail est que le pragmatisme peut apporter des outils théoriques répondant à ses difficultés et venant ainsi compléter ceux de la théorie critique au profit de la pédagogie féministe. Ainsi la deuxième partie de notre argumentation se concentre sur l’intérêt épistémique de ces outils pédagogiques que propose le pragmatisme. Ces derniers sont rendus possibles par la valorisation épistémique de la perplexité et de l’empathie, et nous verrons en quoi ils permettent d’augmenter l’efficacité du “consciousness-raising” lors des pratiques pédagogiques quotidiennes. (shrink)

The reception of Dewey's work has suffered, in terms of his political philosophy, from a certain mistrust. First, in the field of education, Dewey's refusal to grant "ultimate" or "high" status to certain values, even those of the French Republic, has made him a mistrusted figure.1 Apart from the pedagogues of Education Nouvelle, which defied the then dominant "Cartesian tradition of the dualistic philosophy of reason" in France, Dewey was little studied before the 1960s. In 2013, Kambouchner perceived an opposition (...) between Dewey and Durkheim;2 however, the French reception of The Public and Its Problems in 1927 also suffered from suspicion and skepticism.3 To begin, there was suspicion with regard to this... (shrink)

In Dellunde et al. 997–1015), we determined the complete theory Te of modules of separably closed fields of characteristic p and imperfection degree e, eω{∞}. Here, for 0≠eω, we describe the closed set of the Ziegler spectrum corresponding to Te. Further, we establish a correspondence between certain submodules and n-types and we investigate several notions of dimensions and their relationships with the Lascar rank. Finally, we show that Te has uniform p.p. elimination of imaginaries and deduce uniform weak elimination of (...) imaginaries. (shrink)

We revisit Kolchin's results on definability of differential Galois groups of strongly normal extensions, in the case where the field of constants is not necessarily algebraically closed. In certain classes of differential topological fields, which encompasses ordered or p‐valued differential fields, we find a partial Galois correspondence and we show one cannot expect more in general. In the class of ordered differential fields, using elimination of imaginaries in, we establish a relative Galois correspondence for relatively definable subgroups of the group (...) of differential order automorphisms. (shrink)

Summary In this paper we examine the reaction of the Leiden low-temperature laboratory of Heike Kamerlingh Onnes to new ideas in quantum theory. Especially the contributions of Albert Einstein (1906) and Peter Debye (1912) to the theory of specific heat, and the concept of zero-point energy formulated by Max Planck in 1911, gave a boost to solid state research to test these theories. In the case of specific heat measurements, Kamerlingh Onnes's laboratory faced stiff competition from Walter Nernst's Institute (...) of Physical Chemistry in Berlin. In fact, Berlin got the better of it because Leiden lacked focus. After the liquefaction of helium in 1908, Kamerlingh Onnes transformed his laboratory into an international facility for low temperature research, and for this reason it was impossible to make headway with the specific heat measurements. In the case of zero-point energy, Leiden developed a magnetic research programme to test the concept. Initially the balance of evidence seemed to be tipping in favour of zero-point energy. After 1914, however, Leiden would desert the theory in fovour, of a concept from calssical physics. A curious move that illustrates Kamerlingh Onnes's discomfort with the new quantum theory. (shrink)

We consider separably closed fields of characteristic $p > 0$ and fixed imperfection degree as modules over a skew polynomial ring. We axiomatize the corresponding theory and we show that it is complete and that it admits quantifier elimination in the usual module language augmented with additive functions which are the analog of the $p$-component functions.

We consider first-order theories of topological fields admitting a model-completion and their expansion to differential fields . We give a criterion under which the expansion still admits a model-completion which we axiomatize. It generalizes previous results due to M. Singer for ordered differential fields and of C. Michaux for valued differential fields. As a corollary, we show a transfer result for the NIP property. We also give a geometrical axiomatization of that model-completion. Then, for certain differential valued fields, we extend (...) the positive answer of Hilbert’s seventeenth problem and we prove an Ax–Kochen–Ershov theorem. Similarly, we consider first-order theories of topological fields admitting a model-companion and their expansion to differential fields, and under a similar criterion as before, we show that the expansion still admits a model-companion. This last result can be compared with those of M. Tressl: on one hand we are only dealing with a single derivation whereas he is dealing with several, on the other hand we are not restricting ourselves to definable expansions of the ring language, taking advantage of our topological context. We apply our results to fields endowed with several valuations. (shrink)

We consider valued fields with a distinguished isometry or contractive derivation as valued modules over the Ore ring of difference operators. Under certain assumptions on the residue field, we prove quantifier elimination first in the pure module language, then in that language augmented with a chain of additive subgroups, and finally in a two-sorted language with a valuation map. We apply quantifier elimination to prove that these structures do not have the independence property.