Viruses as living processes

John Dupre University of Exeter Egenis Byrne House, St German's Road Exeter EX4 4PJ UK Guttinger University of Exeter Egenis Byrne House, St German's Road Exeter EX4 4PJ United KingdomThe view that life is composed of distinct entities with well-defined boundaries has been undermined in recent years by the realisation of the near omnipresence of symbiosis. What had seemed to be intrinsically stable entities have turned out to be systems stabilised only by the interactions between a complex set of underlying processes (Dupré, 2012). This has not only presented severe problems for our traditional understanding of biological individuality but has also led some to claim that we need to switch to a process ontology to be able adequately to understand biological systems. A large group of biological entities, however, has been excluded from these discussions, namely viruses. Viruses are usually portrayed as stable and distinct individuals that do not fit the more integrated and collaborative picture of nature implied by symbiosis. In this paper we will contest this view. We will first discuss recent findings in virology that show that viruses can be ‘nice’ and collaborate with their hosts, meaning that they form part of integrated biological systems and processes. We further offer various reasons why viruses should be seen as processes rather than things, or substances. Based on these two claims we will argue that, far from serving as a counterexample to it, viruses actually enable a deeper understanding of the fundamentally interconnected and collaborative nature of nature. We conclude with some reflections on the debate as to whether viruses should be seen as living, and argue that there are good reasons for an affirmative answer to this question

Obstructions to a general characterization of graph correspondences

For a countable discrete space V, every nondegenerate separable C*-correspondence over c_0(V) is isomorphic to one coming from a directed graph with vertex set V. In this paper we demonstrate why the analogous characterizations fail to hold for higher-rank graphs (where one considers product systems of C*-correspondences) and for topological graphs (where V is locally compact Hausdorff), and we discuss the obstructions that arise.Comment: major revision; stated some results in greater generalit

Ubiquitin and endocytic internalization in yeast and animal cells.

Endocytosis is involved in a wide variety of cellular processes, and the internalization step of endocytosis has been extensively studied in both lower and higher eukaryotic cells. Studies in mammalian cells have described several endocytic pathways, with the main emphasis on clathrin-dependent endocytosis. Genetic studies in yeast have underlined the critical role of actin and actin-binding proteins, lipid modification, and the ubiquitin conjugation system. The combined results of studies of endocytosis in higher and lower eukaryotic cells reveal an interesting interplay in the two systems, including a crucial role for ubiquitin-associated events. The ubiquitylation of yeast cell-surface proteins clearly acts as a signal triggering their internalization. Mammalian cells display variations on the common theme of ubiquitin-linked endocytosis, according to the cell-surface protein considered. Many plasma membrane channels, transporters and receptors undergo cell-surface ubiquitylation, required for the internalization or later endocytic steps of some cell-surface proteins, whereas for others, internalization involves interaction with the ubiquitin conjugation system or with ancillary proteins, which are themselves ubiquitylated. Epsins and Eps15 (or Eps15 homologs), are commonly involved in the process of endocytosis in all eukaryotes, their critical role in this process stemming from their capacity to bind ubiquitin, and to undergo ubiquitylation

Las tecnologias visuales en movimiento

En su estudio fundacional, Las técnicas del observador (1990), Jonathan Crary postula que una historia de la visión o de la percepción “depende mucho más que de una simple enumeración de cambios o desplazamientos de las prácticas representacionales […]. La visión y sus efectos son siempre inseparables de las posibilidades de un sujeto observador, que es a la vez un producto histórico y el lugar de ciertas prácticas, técnicas, instituciones, y procedimientos de subjetivación”. Así, en las décadas de 1810 y 1820, Crary sitúa una ruptura del régimen escópico entre un modelo de visión geométrico y un modelo fisiológico. Este artículo defiende que un abordaje metodológico enfocado en la materialidad de las tecnologías visuales revela que en la modernidad temprana (es decir, antes del siglo XIX) la observación dependía de un involucramiento y un entrecruzamiento corpóreo, más que de una división estricta entre sujeto y objeto. La palabra clave en tal aproxi-mación es movilidad, que actúa sobre tres niveles: 1) la movilidad y la animación de las imágenes; 2) la materialidad móvil de los instrumentos, y 3) la movilidad en términos de la portabilidad de las tecnologías visuales a lo largo de diferentes sitios y continentes

Demodulation of Spatial Carrier Images: Performance Analysis of Several Algorithms Using a Single Image

http://link.springer.com/article/10.1007%2Fs11340-013-9741-6#Optical full-field techniques have a great importance in modern experimental mechanics. Even if they are reasonably spread among the university laboratories, their diffusion in industrial companies remains very narrow for several reasons, especially a lack of metrological performance assessment. A full-field measurement can be characterized by its resolution, bias, measuring range, and by a specific quantity, the spatial resolution. The present paper proposes an original procedure to estimate in one single step the resolution, bias and spatial resolution for a given operator (decoding algorithms such as image correlation, low-pass filters, derivation tools ...). This procedure is based on the construction of a particular multi-frequential field, and a Bode diagram representation of the results. This analysis is applied to various phase demodulating algorithms suited to estimate in-plane displacements.GDR CNRS 2519 “Mesures de Champs et Identification en Mécanique des Solide

К вопросу инвестиций в угольные шахты

Визначено доцільність інвестицій у вугільне виробництво України. Розглянуто шляхи підвищення інвестиційної привабливості вугільних шахт України, а також формування відповідного інвестиційного клімату у державі. Ключові слова: економіка, інвестиції, інновації, собівартість, прибуток, вугледобувні підприємства.Определена целесообразность инвестиций в угольное производство Украины. Рассмотрены пути повышения инвестиционной привлекательности угольных шахт Украины, а также формирования соответствующего инвестиционного климата в стране. Ключевые слова: экономика, инвестиции, инновации, себестоимость, прибыль, угледобывающие предприятия.Determine the feasibility of investment in coal production in Ukraine. Ways of improvement of investment attractiveness of Ukraine’s coal mines, as well as the formation of the investment climate in the country. Key words: economy, investment, innovations, prime cost, profit, coal producing plants