Mucoidy and cytotoxicity arise from two independent modifications of the phenotype of the bacterium Pseudomonas aeruginosa that contribute to the mortality and morbidity of cystic fibrosis. We show that, even though the transcriptional regulatory networks controlling both processes are quite different from a molecular or mechanistic point of view, they may be identical from a dynamic point of view: epigenesis may in both cases be the cause of the acquisition of these new phenotypes. This was highlighted by the identity of (...) formal graphs modelling these networks. A mathematical framework based on formal methods from computer science was defined and implemented with a software environment. It allows an easy and rigorous validation and certification of these models and of the experimental methods that can be proposed to falsify or validate the underlying hypothesis. (shrink)

This article examines a set of letters and observational reports that passed between Ludwig of Württemberg and Wilhelm of Hesse in response to the nova of 1572. Discussing the terminology used in this debate, it demonstrates that the terms “star” and “comet” were not unambiguous for sixteenth-century authors. A consideration of the relationship between accuracy of observation and the accuracy of the conclusions drawn from them, judged in the terms of twentieth-century astronomy, shows that those observers with the best instruments (...) did not always have the best understanding of what they had observed. Finally, the role played by theology in facilitating interpretations that did not accord with Aristotelian physics is highlighted. (shrink)

This volume is the latest in a series of books and articles stretching back more than three decades on a theme quite startling in its claims and implications: that terrestrial life did not originate on Earth but arrived in the form of cells or bacteria from outer space. The idea of “panspermia,” that the seeds of life are spread from planet to planet, dates to the 19th century with the ideas of Lord Kelvin. It was championed by the Swedish physicist, (...) chemist, and Nobelist Svante Arrhenius at the beginning of the 20th century. Once scientists recognized the difficulties of life surviving in the conditions of interplanetary and interstellar space, by the 1960s a neo-panspermia became popular: not life itself, but prebiotic chemicals were the new seeds of life, made more likely by the discovery of numerous complex organic molecules in meteorites, comets, and interstellar molecular clouds. But the difficulties of synthesizing anything more complicated than amino acids in the wake of the famous Miller-Urey experiment in 1953 kept alive the idea that life itself may be spread throughout the universe. At the center of this work is Chandra Wickramasinghe, a research student of the maverick astronomer Fred Hoyle. In 1962 Hoyle became interested in the origin and nature of interstellar dust, in particular as found in dense molecular clouds, and he and Wickramasinghe set to work on the problem. They became convinced that dust could not form inside molecular clouds, but must have originated in the atmospheres of cool stars, protoplanetary discs, or supernova ejecta, a theory now widely accepted. It was the next steps that became increasingly controversial: that the spectroscopic signature of dust was best explained by complex biomolecules such as cellulose; that biomolecules were assembled into still more complex forms inside comets; and that the living cells and bacteria generated there were responsible for the origin of life on Earth. And not only that: Hoyle and Wickramasinghe argued that the delivery of bacteria from space continues, affecting both the origin and the ongoing evolution of life, and may even be responsible for certain diseases on Earth. These theories were not only reported in reputable scientific journals such as Nature, but also in popular books including Lifecloud (1978), Diseases from Space (1979), and Evolution from Space (1981). Biologists were not impressed; Lynn Margulis, not known for the timidity of her own theories such as endosymbiosis, called the first book “wanton, amusing, promiscuous fiction.”. (shrink)

This paper examines the Hegelian moment of the for-another in its negative relation to the other moment of particularity: the for-itself. I identify the dissolving, fluidifying action of the for-another by examining figures within the Philosophy of Nature, particularly comets and moons, but also Hegel’s physics of light and sound. The dissolution of the lunar for-itself at the hands of the cometary for-another illustrates how the dynamic relation between the two moments of particularity participates in the presentation of essence, (...) within the Hegelian syllogism, i.e. as mediating between the universal and the singular. The dynamic action of cometary negativity occurs throughout the Philosophy of Nature and therefore should be pivotal to how the work is read. (shrink)

In a recent opinion piece, Denis Duboule has claimed that the increasing shift towards systems biology is driving evolutionary and developmental biology apart, and that a true reunification of these two disciplines within the framework of evolutionary developmental biology may easily take another 100 years. He identifies methodological, epistemological, and social differences as causes for this supposed separation. Our article provides a contrasting view. We argue that Duboule’s prediction is based on a one-sided understanding of systems biology as a science (...) that is only interested in functional, not evolutionary, aspects of biological processes. Instead, we propose a research program for an evolutionary systems biology, which is based on local exploration of the configuration space in evolving developmental systems. We call this approach—which is based on reverse engineering, simulation, and mathematical analysis—the natural history of configuration space. We discuss a number of illustrative examples that demonstrate the past success of local exploration, as opposed to global mapping, in different biological contexts. We argue that this pragmatic mode of inquiry can be extended and applied to the mathematical analysis of the developmental repertoire and evolutionary potential of evolving developmental mechanisms and that evolutionary systems biology so conceived provides a pragmatic epistemological framework for the EvoDevo synthesis. (shrink)

On the morning of April 23, 1971, a long line of Vietnam Veterans formed near the lower west terrace of the US Capitol building. Thousands of spectators and a contingent of journalists gathered around them. At 10 a.m., after an aged veteran in olive fatigues blew taps on a bugle, a 27-year-old former Marine sergeant named Jack Smith threw his combat medals over a crude chicken wire and wood fence that surrounded the Capitol. “We cast these [medals] away,” he announced, (...) “as symbols of shame, dishonor, and inhumanity” (p. 113). Observers estimated that between 600 and 3000 vets followed him,…. (shrink)

Gunn told me once that he had gone on a picnic on Primrose Hill with Ted and Sylvia. What was she like? She seemed a very good mother, Thom said, recalling the picnic basket she had prepared, adding that famous people never seemed to behave characteristically when he met them. Although neither Gunn nor Plath could have known it, they would come to have something deeply personal in common. Gunn's mother was a suicide who left her body for her children (...) (in her case, two teenage sons) to find in the morning. His poem about it is called “The Gas-Poker.”Readers may ask whether we do not already know enough about Sylvia and Ted. The bite mark on his cheek where she drew blood the night they met, the cup of warm milk set out for her toddlers to find with her body in the morning. This detail—the cup of warm milk cooled to frigid temperatures during a night that was one of the coldest on record locally—is, for me, the hardest to forgive. But Clark, drawing on a vast reservoir of evidence and anecdote amassed over years, is able to construct a more nuanced impression of Plath than we have had before. There are missteps, as when Clark complains of Plath's “popular, clichéd image as the Marilyn Monroe of the literati.” No one who has ever heard the breathy voice of Monroe singing “Happy Birthday, Mr. President” and compared it to the plummy, matronly, decidedly upper-class voice Plath cultivated for the BBC can believe that any such cliché exists. Plath mythologized her own life, but Clark succeeds in weaving a tight fabric of minutiae that permits the reader to see what Plath was doing at almost any hour of any particular day. In this steady neutral light, she becomes more fully human. (shrink)

In November 1664, a comet appeared in the European skies; by early March 1665, it had disappeared, but, at this very moment, another comet appeared, which stayed among the stars until mid-April. Observations of these two comets were made all over Europe, and even beyond. Although most secondary literature dedicated to these two comets has been focused on England and Italy, France was not to be outdone in terms of observations, small talk and publications. In this paper, I (...) would like to use the books that were published on these comets in France as a dispersive prism to understand the ongoing controversies about which principles should be accepted in natural philosophy in the mid-sixties. There were indeed several intellectual and institutional circumstances that gave a specific twist to the French debate: the sixties marked the beginning of the war between Jesuits and Cartesians that was to enflame learned France until the late nineties at least, they were also the period of gestation for the future Académie des sciences, and, finally, it is also during these years that French elites began to discredit systematically the practice of astrology as a popular superstition. My working hypothesis in this paper is that, in such circumstances, the two comets of 1664–1665 were an occasion for each camp to advocate publicly its positions about the proper principles for natural philosophy. By natural philosophical principles, I mean both ontological and epistemological principles. (shrink)

RésuméDans le présent article, on expose la théorie aristotélicienne des comètes, bien diffusée en Occident musulman par le biais des commentaires d'Ibn Rušd et d'Ibn Bāǧǧa, et abordée trois siècles plus tard dans un manuscrit inédit attribué au fameux mathématicien Ibn Ġāzī al-Miknāsī. Dans ce traité qui ne figure pas dans la liste connue de ses écrits, Ibn Ġāzī traite de l'astrologie des comètes suivant Ptolémée, et insére une critique attribuée à Iḫwān al-Ṣafā’, caractérisée par le rejet de l'idée des (...) comètes sidérales. On s'intéresse également aux classifications des comètes données par Ibn Ġāzī et un autre auteur peu connu ‘Alī al-Antākī. Ainsi, nous avons constaté que le contenu du De cometis du pseudo-Ptolémée est analogue au le texte d'Ibn Ġāzī, et pratiquement identique au texte d'al-Antākī. Par la suite, on analyse les observations de comètes réalisées du ixe jusqu’à la fin du xixe s. en Afrique du Nord et en Espagne musulmane, et consignées dans certains manuscrits d'astronomie et chroniques en langue arabe, mais qui n'ont jamais fait l'objet d’études approfondies. Les observations étudiées sont : les deux comètes X/975 P1 et X/998 D1 signalées par un auteur anonyme du xve s., l'observation de la comète X/1381 V1 rapportée par Ibn al- Qāḍī, le passage de la comète de Halley en 1456 rapporté par Muḥammad al-Zarkašī, la comète en C/1743 X1 observée par ‘Abd al-Razzāq ibn Ḥamadūš, et qui confirme sa structure en éventail, les deux observations de Ibn ‘Alī al-Šrīf al-Šalāṭī de la D/1770 L1, et surtout son témoignage concernant la C/1769 P1 où il a inséré une représentation graphique inédite en Occident musulman. (shrink)

Isaac Newton's closest approach to a system of the world in the critical period 1681–84 is provided in a set of untitled propositions concerning comets. They drastically revise his position maintained against Flamsteed in 1681 and may signal his adoption of a single comet solution for the appearances of 1680/1. Points of agreement and difference with the key pre-Principia texts of 1684–85 are analysed. He shows substantial control of the phenomena of tails which change very little in mechanical detail (...) throughout his subsequent work. An emerging theory of gravitation brings planets, their satellites, and comets under the same laws of motion, yet retains a celestial vortex and includes a singular proposition in lieu of the usual formulation of Keplers area law. The analysis raises questions on a number of issues of recent Newtonian scholarship ranging from his achievement following his correspondence with Robert Hooke in 1679 to his veneration of the wisdom of the ancients. (shrink)

The expressionpelle Libystidis ursae, which occurs atAen. 5.37 and 8.368, has caused a certain amount of puzzlement among scholars. This article will attempt to explain, through Virgil's allusions to Apollonius'Argonautica, the function ofLibystisas a pointer to the motif of the creation of a new homeland within a foreign territory, as is the case with Segesta and Rome. This idea is further developed by the two omens that forebode the foundations of Segesta and Rome, that is, the omen of Acestes' arrow (...) atAen. 5.522–8 and the weapon-omen atAen. 8.524–9, both of which are consistently associated with flames, comets, and lightning. These elements underline the symbolism of destruction, rebirth, and Jupiter's will that characterizes the foundations of Segesta and future Rome. (shrink)

ABSTRACT At first sight, the English astronomer John Bainbridge's treatise on the great comet of 1618 appears rather idiosyncratic. It regards the comet as a favourable omen and applies an astrological explanation that is completely metaphorical. At closer look, however, Bainbridge's interpretation appears well in line with the meaning commonly attributed to comets at the time. We should realize that an important function of the discourse on prodigious phenomena, such as comets, was to uphold and strengthen the confessional (...) social order. Moreover, the treatise was addressed to the King rather than to the common population. To understand the early modern interpretation of comets, the processes of confessionalization and de-confessionalization deserve more consideration. (shrink)

SummaryTwo paintings by Charles Piazzi Smyth have recently been given by the family to the National Maritime Museum, London. They are of the Great Comet 1843 I, and provide superb examples of the artistic skill of astronomers of that time and of one of the methods used to record astronomical subjects before the days of photography.

SummaryTwo paintings by Charles Piazzi Smyth have recently been given by the family to the National Maritime Museum, London. They are of the Great Comet 1843 I, and provide superb examples of the artistic skill of astronomers of that time and of one of the methods used to record astronomical subjects before the days of photography.

Don’t Look Up is a 2021 Netflix original film about two astronomers who discover a 9-kilometer “planet killer” comet on a collision course with Earth. The way humanity responds to this threat – which is less than ideal, given that the movie ends with humanity’s destruction – is supposed to be an allegory for how humanity is dealing with the real-world threat of climate change. Consequently, we argue, the movie is an argument that presents the viewer with a moral imperative: (...) Do all that you can to prevent climate change. But does the argument work? To answer this question, we look at criticism of the movie, decipher its messages, examine the aptness of its analogy, and use the philosophy of Plato, Kant, and Peter Singer to explain exactly what kind of argument the film is. In the end, we conclude that, while most (although not all) criticisms of the film fall flat – it doesn’t really matter. Given that the moral imperative presented by the movie is undeniable, the only appropriate response to the film is an unrelenting effort to fulfill our duty to stop climate change. (shrink)