Until the discovery of catalytic RNA, the notion that all enzymes are proteins had seemed incontrovertible. Now the existence of RNA enzymes has been confirmed in a variety of contexts. What is known about the chemistry of RNA‐catalyzed reactions is reviewed below, with particular attention to the self‐splicing rRNA intron of Tetrahymena thermophila and the processing of pre‐tRNA molecules by RNase P.

We study a new variant of the dissipative particle dynamics (DPD) model that includes the possibility of dynamically forming and breaking strong bonds. The emergent reaction kinetics may then interact with self-assembly processes. We observe that self-assembled amphiphilic aggregations such as micelles have a catalytic effect on chemical reaction networks, changing both equilibrium concentrations and reaction frequencies. These simulation results are in accordance with experimental results on the so-called “concentration effect”.

Antibodies have now been shown to catalyze a variety of chemical transformations, including hydrolytic, concerted, and bimolecular reactions. The inherent chirality of the antibody binding pocket has been exploited to exert precise stereochemical control over their catalyzed reactions. The mechanisms by which antibodies catalyze reactions are not expected to differ in any general way from those of natural enzymes. Antibodies use their binding energy to stabilize species of higher free energy which appear along the reaction coordinate or effect general acid/base (...) catalysis. The advent of catalytic antibodies promises new catalysts that extend the range of catalysis by proteins to chemical transformations that were not required during the evolution of enzymes. (shrink)

It is proposed in this paper that enzymes, by virtue of a number of correctly positioned sites of interaction with substrates, can force the compression of hydrogen bonds, increasing the probability of proton transfer by quantum mechanical tunneling. By such a catalytic mechanism a rate enhancement of many orders of magnitude may be obtained with a very low energy input requirement. The mechanism would, however, require a highly structured catalyst.Pertinent aspects of hydrogen bond theory and of tunneling theory are briefly (...) reviewed. (shrink)

The last two words of the title for this essay are taken from a paper by R. S. Lillie, and the first phrase is also taken by implication from the same source. The study of chemical phenomena in life has progressed far enough so that underlying chemical causes, involved in Professor Lillie's picture of Biological Causation, may in part be discussed in general terms, and apart from the mass of detail known about the agents and processes involved. Moreover, this mass (...) of detail is now great enough so that even though we are far from having a complete or even a comprehensive picture of these causes at least some of the fundamental principles involved in the chemical aspects of biological causation are clearly revealed. (shrink)

The article is dedicated to the history of developing highly effective catalysts in the leading scientific institutions of Ukraine and explores the prerequisites for developing theories in physical chemistry, in particular those related to kinetics and catalysis. It highlights the significance of scientific discoveries at the turn of the 19th and 20th century and their application by native scientists to advance theoretical development in the field of chemistry. Special attention is paid to the works of Lev Pisarzhevskii, focusing on his (...) advancements in electronic chemistry and, in particular, the electronic theory of catalysis. The article also outlines current challenges in creating highly efficient catalysts for the chemical and light industry, emphasizing the importance of such indicators of catalysts as activity and selectivity. Drawing on historical, scientific and patent data, the study investigates the process of creating a highly efficient catalyst for obtaining acrylic acid from acrolein. This catalyst holds a great ractical importance for the production of various polymers in industrial conditions. It is shown that, as a result of research conducted by native scientists of the Institute of Physical Chemistry of the Academy of Sciences of the Ukrainian SSR and the Chemistry Department of Kyiv State University, the catalyst K-2-5 was developed. The catalyst has good indicators for the industrial production of acrylic acid from acrolein. The authors also highlight works studying the properties of the obtained catalyst, specifically its porous structure, which is an important factor in catalytic processes. They extensively focus on the kinetic indicators of catalytic reactions that occur when using this catalyst. The article also emphasizes the relevance of these developments for advancing research in catalysis and chemical industrial production. (shrink)

Contemporary neo-liberal society is ruled by the market. Davies, Chen and Lentin and Titley show that its objectification and categorization founds a competitive notion of agency that disables subjective construction of self and intersubjective understanding of the world. As the market's rules and norms are set by white patriarchy, its competitive paradigm structurally disadvantages others. Art too is objectified and categorized by neo-liberal institutions, equally embedded in white patriarchal market structures and severely limiting democratic public access to a diverse artistic (...) field, argue hooks, Mercer and Piper. Yet, Piper's artwork shows, art holds emancipatory potential. Defined as transforming experience, its ambiguity provides a structure for constituting agentic subjectivity and intersubjective signification processes, defying objective/objectifying market workings. Photography's specific qualities allow Piper to democratize access to the paradigm she proposes. Her artistic choices may thus found the potential to publicly construct a notion of aesthetic agency as resistance to the neo-liberal market. (shrink)

Free radicals are generally perceived as highly reactive species which are harmful to biological systems. There are, however, a number of enzymes that use carbon‐based radicals to catalyse a variety of important and unusual reactions. The most prominent example is ribonucleotide reductase, an enzyme which is crucial for the synthesis of DNA. In general, radicals are used to remove hydrogen from unreactive positions in the substrate, and in this way the substrate is activated to undergo chemical transformations that would otherwise (...) be difficult to achieve. Several different mechanisms have evolved which allow enzymes to generate and maintain radicals in increasingly aerobic enviroments. An unexpected finding is the existance of stable protein‐based radicals, residing on a variety of amino‐acid side chains, which serve to link the radical‐generating and catalytic sites and to store the radical between turnovers. (shrink)

While nanosciences and nanotechnologies appear as new concepts developed at the end of the twentieth century, we show that metallic nanoparticles have already been used since ancient times, in particular as colorant in the glass and ceramic industries. Moreover, a lot of natural nanomaterials are also present in the mineral, vegetal and animal worlds. Nevertheless, the breakthrough of nanotechnology has been permitted in the past few decades by the advent of apparatus allowing the manipulation and observation of the nanoworld. Indeed, (...) nowadays, nanomaterials and nanoparticles are used for many applications in our daily life, such as in the fields of electronics, catalysis, optics, biology, and medicine. This article presents an overview about nanotechnologies, with applications from ancient times till the present. (shrink)

This paper calls attention to a philosophical presupposition, coined here the continuity thesis which underlies and unites the different, often conflicting, hypotheses in the origin of life field. This presupposition, a necessary condition for any scientific investigation of the origin of life problem, has two components. First, it contends that there is no unbridgeable gap between inorganic matter and life. Second, it regards the emergence of life as a highly probable process. Examining several current origin-of-life theories. I indicate the implicit (...) or explicit role played by the continuity thesis in each of them. In addition, I identify the rivals of the thesis within the scientific community — the almost miracle camp. Though adopting the anti-vitalistic aspect of the continuity thesis, this camp regards the emergence of life as involving highly improbable events. Since it seems that the chemistry of the prebiotic stages and of molecular self-organization processes rules out the possibility that life is the result of a happy accident, I claim that the almost miracle view implies in fact, a creationist position. (shrink)

During the past two decades, philosophers of biology have increasingly turned their attention to mechanisms of biological phenomena. Through analyses of mechanistic proposals advanced by biologists, the goal of these philosophers is to understand what a mechanism is and how mechanisms explain. These analyses have generally focused on mechanistic proposals for phenomenon that occur at the cellular or sub-cellular level, such as synapse firing, protein synthesis, or metabolic pathway operation. Little is said about the mechanisms of the macromolecular reactions that (...) underpin these phenomena. These reactions comprise a diverse family of reaction types, and include protein folding, macromolecular complex formation, receptor-ligand interactions, and enzyme catalysis. In this paper, I develop an account of mechanism that focuses exclusively on macromolecular reactions. I begin by reviewing how mechanism is understood in enzymology, and how mechanistic concepts of enzymology apply to macromolecular reactions in general. We will see that the mechanism of a macromolecular reaction is most accurately described as a progression of reaction intermediates, where the evolution of intermediates, from one to the next, is characterized by an energetic coupling between chemistry and protein dynamics. I then make the case that this description necessitates a grounding in a process ontology. To describe the mechanism by which a macromolecular reaction occurs is to describe a process. (shrink)

The concept of “life” certainly is of some use to distinguish birds and beavers from water and stones. This pragmatic usefulness has led to its construal as a categorical predicate that can sift out living entities from non-living ones depending on their possessing specific properties—reproduction, metabolism, evolvability etc. In this paper, we argue against this binary construal of life. Using text-mining methods across over 30,000 scientific articles, we defend instead a degrees-of-life view and show how these methods can contribute to (...) experimental philosophy of science and concept explication. We apply topic-modeling algorithms to identify which specific properties are attributed to a target set of entities (bacteria, archaea, viruses, prions, plasmids, phages and the molecule of adenine). Eight major clusters of properties were identified together with their relative relevance for each target entity (two that relate to metabolism and catalysis, one to genetics, one to evolvability, one to structure, and—rather unexpectedly—three that concern interactions with the environment broadly construed). While aligning with intuitions—for instance about viruses being less alive than bacteria—these quantitative results also reveal differential degrees of performance that have so far remained elusive or overlooked. Taken together, these analyses provide a conceptual “lifeness space” that makes it possible to move away from a categorical construal of life by empirically assessing the relative lifeness of more-or-less alive entities. (shrink)

We hypothesize that life began not with the first self‐reproducing molecule or metabolic network, but as a prebiotic ecology of co‐evolving populations of macromolecular aggregates (composomes). Each composome species had a particular molecular composition resulting from molecular complementarity among environmentally available prebiotic compounds. Natural selection acted on composomal species that varied in properties and functions such as stability, catalysis, fission, fusion and selective accumulation of molecules from solution. Fission permitted molecular replication based on composition rather than linear structure, while fusion (...) created composomal variability. Catalytic functions provided additional chemical novelty resulting eventually in autocatalytic and mutually catalytic networks within composomal species. Composomal autocatalysis and interdependence allowed the Darwinian co‐evolution of content and control (metabolism). The existence of chemical interfaces within complex composomes created linear templates upon which self‐reproducing molecules (such as RNA) could be synthesized, permitting the evolution of informational replication by molecular templating. Mathematical and experimental tests are proposed. BioEssays 28: 399–412, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

Contemporary philosophy of art generally assumes that aesthetic experience is constituted by a certain ontological-phenomenological structure: the apprehension by a subject of an object. This article explores an underexamined critique of this philosophical model found within the black intellectual and artistic tradition. I will specifically focus on the version of this critique proposed by the similarly underexamined black philosophers Adrian Piper and Fred Moten. This critique, which I dub the subjectivizing concern, takes issue with the notion of ontological distance that (...) I argue defines the subject-object model. I define ontological distance as the removal and alienation of the subject’s fundamental sense of self from that of so-called objects. The subjectivizing concern holds that this distance is not value neutral. Rather, the subject-object model is considered to be directly entwined with projects and practices of aesthetic and extraesthetic racism and antiblackness. After offering Piper’s own model of aesthetic experience—which she dubs catalysis—as an alternative, I propose three possible ways in which the subject-object model can be conceived as tied to antiblack racism. (shrink)

This paper describes a tentative model for how discrete memories transform into an interconnected conceptual network, or worldview, wherein relationships between memories are forged by way of abstractions. The model draws on Kauffman’s theory of how an information-evolving system could emerge through the formation and closure of an autocatalytic network. Here, the information units are not catalytic molecules, but memories and abstractions, and the process that connects them is not catalysis but reminding events (i.e. one memory evokes another). The result (...) is a worldview that both structures, and is structured by, self-triggered streams of thought. (shrink)

The title is his own. Herbert Feigl, the provocateur and the soul (if we may put it so) of modesty, wrote to me some years ago, "I'm more of a catalyst than producer of new and original ideas all my life... ", but then he com pleted the self-appraisal: "... with just a few exceptions perhaps". We need not argue for the creative nature of catalysis, but will simply remark that there are 'new and original ideas' in the twenty-four papers (...) selected for this volume, in the extraordinary aperrus of the 25-year-old Feigl in his Vienna dissertation of 1927 on Zufall und Gesetz, in the creative critique and articulation in his classical monograph of 1958 on The 'Mental' and the 'Physical'; and the reader will want to turn to some of the seventy other titles in our Feigl bibliography appended. Professor Feigl has been a model philosophical worker: above all else, honest, self-aware, open-minded and open-hearted; keenly, devotedly, and even arduously the student of the sciences, he has been a logician and an empiricist. Early on, he brought the Vienna Circle to America, and much later he helped to bring it back to Central Europe. The story of the logical empiricist movement, and of Herbert Feigl's part in it, has often been told, importantly by Feigl himself in four papers we have included here. (shrink)

Despite their seemingly endless diversity, proteins adopt a limited number of structural forms. It has been estimated that 80% of proteins will be found to adopt one of only about 400 folds, most of which are already known. These folds are largely formed by a limited ‘vocabulary’ of recurring supersecondary structure elements, often by repetition of the same element and, increasingly, elements similar in both structure and sequence are discovered. This suggests that modern proteins evolved by fusion and recombination from (...) a more ancient peptide world and that many of the core folds observed today may contain homologous building blocks. The peptides forming these building blocks would not in themselves have had the ability to fold, but would have emerged as cofactors supporting RNA‐based replication and catalysis (the ‘RNA world’). Their association into larger structures and eventual fusion into polypeptide chains would have allowed them to become independent of their RNA scaffold, leading to the evolution of a novel type of macromolecule: the folded protein. BioEssays 25:837–846, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

Insights play a role in every field that can be called knowledge, but are of particular interest to the philosophy of religion and special divine action. Although these acts of understanding cannot be generated at will, a second person can vastly accelerate understanding by a first person. In this paper, I argue that this catalysis of insight is best attained in a situation of ‘second- person relatedness’, involving epistemic humility and shared awareness of shared focus. I also argue that this (...) approach provides an appropriate interpretation of Aquinas’s account of God’s gift of understanding. On this basis, it is specifically the context of second-person relatedness to God, as ‘I’ to ‘you’, that is expected to have the most far-reaching impact on understanding of the world. I illustrate the conclusions by means of the story of The Snow Queen, by Hans Christian Andersen, drawing also some practical implications for insights in daily life. (shrink)

Enzymes are protein catalysts of extraordinary efficiency, capable of bringing about rate enhancements of their biochemical reactions that can approach factors of 1020. Theories of enzyme catalysis, which seek to explain the means by which enzymes effect catalytic transformation of the substrate molecules on which they work, have evolved over the past century from the “lock-and-key” model proposed by Emil Fischer in 1894 to models that explicitly rely on transition state theory to the most recent theories that strive to provide (...) accounts that stress the essential role of protein dynamics. In this paper, I attempt to construct a metaphysical framework within which these new models of enzyme catalysis can be developed. This framework is constructed from key doctrines of process thought, which gives ontologic priority to becoming over being, as well as tenets of a process philosophy of chemistry, which stresses environmentally responsive molecular transformation. Enzyme catalysis can now be seen not as enzyme acting on its substrate, but rather as enzyme and substrate entering into a relation which allows them to traverse the reaction coordinate as an ontologic unity. (shrink)

Modern science has undoubtedly become one the principal engines of economic growth, even though the epistemological status of scientific knowledge has been continuously contested. Leaving the philosophical problem of knowledge aside, this paper examines how scientific discovery contributes to the production of wealth. The analysis focuses on a recent achievement at the crossroads of chemistry, immunology and biotechnology: antibody catalysis. For this purpose, we develop a model of entrepreneurial work to explain how the discovery of natural products and processes generates (...) new economic opportunities. The proposed model is based on the assumption that scientists believe that the natural environment is a repository of 'natural capital'. Natural capital includes goods that are not made by humans but can be used to produce other goods and services. The belief in natural capital induces scientists to search for and identify a natural property that, in the specific cultural context of their work, is recognized as a valuable resource. The selection of such a property forms the initial phase of the discovery process. Certain research methods are then deployed to create novel empirical conditions within which the selected property is transformed into a specific good. The discovery of natural capital thus comprises a historically accountable entrepreneurial endeavour. (shrink)

BackgroundThe effect of orgasm on the development and shaping of partner preferences may involve a catalysis of the neurochemical mechanisms of bonding. Therefore, understanding such process is relevant for neuroscience and psychology.MethodsA systematic review was carried out using the terms Orgasm, Sexual Reward, Partner Preference, Pair Bonding, Brain, Learning, Sex, Copulation.ResultsIn humans, concentrations of arousing neurotransmitters and potential bonding neurotransmitters increase during orgasm in the cerebrospinal fluid and the bloodstream. Similarly, studies in animals indicate that those neurotransmitters and others modulate (...) the appetitive and consummatory phases of sexual behavior and reward. This suggests a link between the experience of orgasm/sexual reward and the neurochemical mechanisms of pair bonding. Orgasm/reward functions as an unconditioned stimulus. Some areas in the nervous system function as UCS-dete... (shrink)

Only those whose work and interests have led them to notice it, will have realised, in all probability, the remarkable extent to which the term organization has gained currency, or acquired new and special emphasis, throughout the entire range of scientific and sociological literature during the last ten or twenty years.In biology and bio-chemistry organization has been discussed or used as a technical term, mostly since 1930 by at least thirty well-known authors; amongst the more prominent are Huxley, Wilson, Woodger, (...) Cannon, Waddington, McDougall, Needham, Block, Hopkins and Sherrington. Under this magic term some authors refer to the physico-chemical nature of the cell or cytoplasm, and usually with special reference to selective or directive catalysis; others to the general constitution or structure of the organism and almost indistinguishable from general morphology and physiology; others to embryological development as such ; others more especially to “relations” between cells, organs and structural parts, often in an abstract sense; others refer more particularly to a hypothetical integrating and/or co-ordinating factor : a few refer to re-constitution from dissociated cells as observed in experiments with Sponges and Hydroids. (shrink)

One observes regulation at every biological level. Organisms, cells, and biochemical processes operate efficiently, normally wasting neither material nor energy, and adjusting their functions to external influences. Nature evidently has evolved mechanisms specifically dedicated to regulation at many levels. What is the molecular basis of this control?In the 1950s these molecular control mechanisms began to be explored seriously. The discoveries of feedback inhibition of enzyme activity were important because they gave an initial example of how regulation is achieved at the (...) molecular level. We showed that certain enzymes are composed of two parts, one for catalysis and another distinct part present only to regulate this catalysis. Catalytic activity can be either stimulated or inhibited when a small molecule in the environment combines with the enzyme's regulatory site. In particular, a final product of a metabolic pathway generates a feedback loop which automatically limits its own excessive production, by combining with the regulatory site of an early enzyme in that pathway. Later studies showed that catalytic and regulatory structures of some enzymes could be separated physically.The discovery of regulatory sites and their interaction with molecules unrelated to their substrates was the basis for the generalized allosteric concept. This concept extends the regulatory site idea to a wide variety of processes such as control of gene expression, hormone action, and cellular growth. (shrink)

1 Before we begin -- 2 The case for technological imperfections -- 3 Cookery and technological spices -- 4 A short log of technology from wood -- 5 Reader beware -- 6 Key features of chemistry and solids -- 7 Examples of new glass technologies -- 8 Optical fibre communication -- 9 Beauty from imperfections -- 10 Valuable imperfections in crystal lattices -- 11 Impurities and the growth of semiconductors -- 12 Small anomalies and long-range consequences -- 13 Photonics in (...) the twenty-first century -- 14 Chemistry and catalysis -- 15 Imperfections in music -- 16 Evolution achieved through imperfections -- 17 Hints for a successful scientific career -- 18 Science in the realm of opinion -- 19 Improving our future lives -- 20 The greatest challenges that we face. (shrink)

Nanotechnology has from its very beginning been surrounded with an aura of novelty. For instance, on the 28 introductory pages of the report that prepared the US National Nanotechnology Initiative (NNI), Nanotechnology Research Directions (NSTC/IWGN 1999), we read 73 times the term “new”, 15 times “novel”, 7 times “innovation”, and 21 times “revolution”. The authors concede that one should distinguish between different nanotechnologies, because “Many existing technologies do already depend on nanoscale processes. Photography and catalysis are two examples of ‘old’ (...) nanotechnologies” (ibid, p. xxvi). One might conclude here that, if all the existing nanotechnologies are “old” nanotechnologies, “new” nanotechnologies do not yet exists but are only promises of the future. However, without further explanation and distinction between presence and future, they suggest that most nanotechnologies are or will be new. Furthermore, they claim that nanotechnology (in singular) is a generator of further new technologies, since “Nanotechnology will give birth to new fields that at present are only visions of leading researchers” (ibid., p. xviii). Whenever science managers speak of nanotechnology (in singular), sophisticated distinctions seem to give way to plain claims about the present and future novelty of nanotechnology. As the NNI director Mihail Roco wrote in a 2001 report, “A revolution is occurring in science and technology […] Nanotechnology will fundamentally transform science, technology, and society. In 10 to 20 years, a significant proportion of industrial production, healthcare practice, and environmental management will be changed by the new technology.” (Roco & Bainbridge, pp. 1, 19) When they put on their hats as science managers, scientists rarely reject but mostly support such novelty claim, as did for instance the chemists George Whitesides and Paul Alivisatos in the earlier report: “Nanostructures are the entry into a new realm in physical and biological science.” (NSTC/IWGN 1999, p.. (shrink)

It is often claimed there is information in some biological entity or process, most especially in genes. Genetic “information” refers to distinct notions, either of concrete properties of molecular bonds and catalysis, in which case it is little more than a periphrasis for correlation and causal relations between physical biological objects (molecules), or of abstract properties, in which case it is mind-dependent. When information plays a causal role, nothing is added to the account by calling it “information”. In short, if (...) genetic information is concrete, it is causality. If it is abstract, it is in the head. (shrink)

Thymidylate synthase plays a central role in the biosynthesis of thymidylate, an essential precursor for DNA biosynthesis. In addition to its role in catalysis and cellular metabolism, it is now appreciated that thymidylate synthase functons as an RNA binding protein. Specifically, thymidylate synthase binds with high affinity to its own mRNA, resulting in translational repression. An extensive series of experiments has been performed to elucidate the molecular elements underlying the interaction between thymidylate synthase and its own mRNA. In addition to (...) characterization of the underlying cis‐ and trans‐acting elements, recent studies have shown that thymidylate synthase has the capacity to bind specifically to other cellular RNA species. While the biological significance of these other RNA/thymidylate synthase interactions remains to be defined, this work suggests a potential role for TS in coordinately regulating several critical aspects of cellular metabolism. (shrink)

One popular recombinant DNA tool is the EcoRI endonuclease, which cleaves DNA at GAATTC sites and serves as a paradigm for sequence specific DNA‐enzyme interactions. The recently revised X‐ray crystal structure of an EcoRI‐DNA complex reveals EcoRI employs novel DNA recognition motifs, a four α‐helix bundle and two extended chains, which project into the major groove to contact substrate purines and pyrimidines. Interestingly, pyrimidine contacts had been predicted based on genetic and biochemical studies. Current work focuses on the EcoRI active (...) site structure, enzyme and substrate conformational changes during catalysis, and host‐restriction system interactions. (shrink)

Eos or the Wider Aspects of Cosmogony J H Jeans Originally published in 1928 "A fascinating summary of his tremendous conclusions…" Times Literary Supplement "No book in the series surpasses Eos in brilliance and profundity…" Is this universe permanent or transitory? If transitory, is it near its end or just beginning? Is life common or rare? Where does life stand in relation t the stupendous mass of inert matter? These and other issues are lucidly dealt with in this book. 80pp, (...) 6 b&w plates Hermes, or the Future of Chemistry T W Jones Originally published in 1928. "A complete and readable survey of chemical developments, making special reference to bio-chemistry, synthetic fuels, and catalysis." Manchester Guardian "Tells us…with brilliant clarity, what chemistry and its achievements are likely to be in the future." Morning Post Chemistry as the means of human emancipation is the subject of this book. Today chemistry is one off the master factors of our existence; tomorrow, the author argues, it will dominate every phase of life, winning for man the goal of all endeavour: economic freedom, and may also effect a startling change in man himself. 82pp. Sybilla or the Future of Prophecy C A Mace Originally published in 1927 "An entertaining and instructive pamphlet." Morning Post An examination of the possibilities of scientific forecasting. 90pp Archimedes or the Future of Physics L L Whyte Originally published in 1928. "This book will be an inspiration. The writer is a clear and fearless thinker." Discovery When this volume was written, physics, biology and psychology were, in the author’s view, converging towards a scientific synthesis of unprecedented importance whose influence on thought and social custom would be profound. This book interprets those events. 88pp. (shrink)

Proponemos que ciertos “detalles” (la catálisis, según Barthes) revelan la presencia del poder disciplinario en la esfera del relato moderno. Iniciamos el análisis a partir de algunas unidades descriptivas del Purén Indómito, a las que consideramos antecedentes directos de esa revelación, y concluimos con la novela Martín Rivas y el cuento El matadero. El texto colonial da cuenta detallada de la vida cotidiana en el reino de Chile, cuenta que expresa las estrategias del poder de soberanía, mientras que en los (...) relatos modernos relevará la presencia del poder disciplinario. Así, la presencia de detalles dramáticos en el Purén obedece a lograr la intervención jurídica-moral del monarca en el reino. En cambio, a partir del realismo esos detalles muestran el actuar de los cuerpos a someter y disciplinar, tal y como ocurre en Martín Rivas y El matadero. La estrategia narrativa será entonces sacar a la luz los detalles de las costumbres retrógradas, bárbaras, sucias, de la sociedad latinoamericana para disciplinarlas, limpiarlas y conseguir, así, naciones modernas y productivas. Our proposition is that certain “details” (catalysis, according to Barthes) reveal the presence of disciplinary power in the sphere of modern fiction. Our analysis starts with some of the descriptive units of Purén Indómito, which we consider to be a direct precedent for this revelation, and we conclude with the novella, Martín Rivas, and the short story, El matadero. The text dating from the colonial period gives a detailed account of daily life in the kingdom of Chile, describing the strategies of the sovereign power, while the modern stories highlight the presence of disciplinary power. Thus, the purpose of the dramatic details recounted in Purén is to ensure the legal-moral intervention of the monarch in the kingdom. In realist works, on the other hand, these details show the actions of organisations to subject and discipline the people, just as it occurs in Martín Rivas and El matadero. In this case, the narrative strategy is to exhibit the details of the foul, barbarous, reactionary customs of Latin American societies in order to discipline and purify them, and thus transform them into modern, productive nations. (shrink)

Ostwald (born September 2, 1853, Riga, Latvia, Russia; died April 4, 1932, at his private estate near Leipzig, Germany) almost single-handedly established physical chemistry as an acknowledged academic discipline. In 1909, he was awarded the Nobel Prize in chemistry for his work on catalysis, chemical equilibria, and reaction velocities. Ostwald was graduated in chemistry at the University of Dorpat (now Tartu, Estonia) and appointed professor of chemistry in Riga in 1881, before he moved from Russia to Germany on the chair (...) in physical chemistry at the University of Leipzig in 1887. For about twenty years he made Leipzig an international center of physical chemistry: by establishing an instruction and research laboratory that attracted virtually the whole next generation of physical chemists; by editing the first journal of the field (Zeitschrift für physikalische Chemie); and by writing numerous textbooks. In 1906, he retired from university and devoted the rest of his life to various topics, including the history and philosophy of science, color theory, painting, the writing of textbooks and popular books about science, the international organization of science, and the formation of an artificial language for the international exchange of ideas. Since his master degree thesis in 1876, Ostwald followed the general approach of applying physical measurement and mathematical reasoning to chemical issues. One of his major research topics was the chemical affinity of acids and bases. To that end, he studied the point of equilibrium in reactions systems where two acids in aqueous solution compete with each other for reaction with one base and vice versa. Because chemical analysis would have changed the equilibria, he skillfully adapted the measurement of physical properties to that problem, such as volume, refractive index, and electrical conductivity. From his extensive data he derived for each acid and base a characteristic affinity coefficient independent of the particular acid-base reactions. To understand the different chemical affinities, Ostwald drew on a new, but then hardly accepted and not yet fully developed, theory advanced by Svante Arrhenius. According to this theory of electrolytic dissociation, electrolytes like acids, bases, and salts dissociate in solution into oppositely charged ions to a certain degree, such that at infinite solution dissociation is complete.. (shrink)

Bacteria use trans‐translation to rescue stalled ribosomes and target incomplete proteins for proteolysis. Despite similarities between tRNAs and transfer‐messenger RNA (tmRNA), the key molecule for trans‐translation, new structural and biochemical data show important differences between translation and trans‐translation at most steps of the pathways. tmRNA and its binding partner, SmpB, bind in the A site of the ribosome but do not trigger the same movements of nucleotides in the rRNA that are required for codon recognition by tRNA. tmRNA‐SmpB moves from (...) the A site to the P site of the ribosome without subunit rotation to generate hybrid states, and moves from the P site to a site outside the ribosome instead of to the E site. During catalysis, transpeptidation to tmRNA appears to require the ribosomal protein bL27, which is dispensable for translation, suggesting that this protein may be conserved in bacteria due to trans‐translation. These differences provide insights into the fundamental nature of trans‐translation, and provide targets for new antibiotics that may have decrease cross‐reactivity with eukaryotic ribosomes. (shrink)

was a detailed analysis of the methodology of biological investigation. The dissertation examined case studies involving enzymes, proteins, catalysis and other matters apparently far removed from his later work on Mexican and Chicano thought. However, Haddox’s existential engagement with basic philosophical questions is evident throughout this work.

The Earth agglomerates and heats. Convection cells within the planetary interior expedite the cooling process. Volcanoes evolve steam, carbon dioxide, sulfur dioxide and pyrophosphate. An acidulous Hadean ocean condenses from the carbon dioxide atmosphere. Dusts and stratospheric sulfurous smogs absorb a proportion of the Sun’s rays. The cooled ocean leaks into the stressed crust and also convects. High temperature acid springs, coupled to magmatic plumes and spreading centers, emit iron, manganese, zinc, cobalt and nickel ions to the ocean. Away from (...) the spreading centers cooler alkaline spring waters emanate from the ocean floor. These bear hydrogen, formate, ammonia, hydrosulfide and minor methane thiol. The thermal potential begins to be dissipated but the chemical potential is dammed. The exhaling alkaline solutions are frustrated in their further attempt to mix thoroughly with their oceanic source by the spontaneous precipitation of biomorphic barriers of colloidal iron compounds and other minerals. It is here we surmise that organic molecules are synthesized, filtered, concentrated and adsorbed, while acetate and methane—separate products of the precursor to the reductive acetyl-coenzyme-A pathway—are exhaled as waste. Reactions in mineral compartments produce acetate, amino acids, and the components of nucleosides. Short peptides, condensed from the simple amino acids, sequester ‘ready-made’ iron sulfide clusters to form protoferredoxins, and also bind phosphates. Nucleotides are assembled from amino acids, simple phosphates carbon dioxide and ribose phosphate upon nanocrystalline mineral surfaces. The side chains of particular amino acids register to fitting nucleotide triplet clefts. Keyed in, the amino acids are polymerized, through acid–base catalysis, to alpha chains. Peptides, the tenuous outer-most filaments of the nanocrysts, continually peel away from bound RNA. The polymers are concentrated at cooler regions of the mineral compartments through thermophoresis. RNA is reproduced through a convective polymerase chain reaction operating between 40 and 100°C. The coded peptides produce true ferredoxins, the ubiquitous proteins with the longest evolutionary pedigree. They take over the role of catalyst and electron transfer agent from the iron sulfides. Other iron–nickel sulfide clusters, sequestered now by cysteine residues as CO-dehydrogenase and acetyl-coenzyme-A synthase, promote further chemosynthesis and support the hatchery—the electrochemical reactor—from which they sprang. Reactions and interactions fall into step as further pathways are negotiated. This hydrothermal circuitry offers a continuous supply of material and chemical energy, as well as electricity and proticity at a potential appropriate for the onset of life in the dark, a rapidly emerging kinetic structure born to persist, evolve and generate entropy while the sun shines. (shrink)

Life is supported by a myriad of chemical reactions. To describe the overall process we have formulated entropy for an open system undergoing chemical reactions. The entropy formula allows us to recognize various ways for the system to move towards more probable states. These correspond to the basic processes of life i.e. proliferation, differentiation, expansion, energy intake, adaptation and maturation. We propose that the rate of entropy production by various mechanisms is the fitness criterion of natural selection. The quest for (...) more probable states results in organization of matter in functional hierarchies. (shrink)

The purpose of this paper is to show an application of variety engineering in the social realm. It focuses on reducing environmental complexity by catalysing self-organizing processes. This catalysis is based on the use of Sen and Nussbaum’s capabilities approach. By doing this an organization may improve the quality of the relations with their clients by transforming environmental agents into new suppliers. This approach opens a new dimension of social responsibility for organizations. A particular case is presented in which a (...) regional university in Colombia faces the challenge of attending low-income students coming from small municipalities. They designed a strategy to offer low-cost housing and a daily balanced meal without using the university's own resources. Instead, they managed to involve some agents of the community by developing their capabilities. This kind of variety engineering shows the possibility of new forms of social responsibility in universities by incorporating the capabilities approach into their managerial practices. This is something that is currently under study in other universities. (shrink)

The problem of the possible occurrence of silicon porphyrins in the living organisms has been put forward in the context of the hypothesis of siliceous life forms and the study of the molecular evolution of porphyrin systems. Some properties of the tetrapyrrole complexes of silicon as well as essential data and theories from domains of silicon biochemistry and paleobiochemistry have been reviewed.This has been a basis for doing some extrapolations and showing connections with bioelectronics, whereas some possible functions of hypothetical (...) Si-porphyrins in biostructures, e.g. catalytic ones, have been shown. In the bioplasma concept, a possible use of Si-tetrapyrrole complexes as a model useful in the study of the plasma mechanism of enzymatic catalysis has been proposed, and a role of silicon analogues of chlorophyll-like compounds in primordial photosynthesis has been suggested. (shrink)

Pyridoxal 5′‐phosphate, the vitamin B6 derivative, acts as the coenzyme of many enzymes involved in amino acid metabolism. Exceptionally, this compound was found covalently bound to glycogen phosphorylase, the key enzyme in the regulation of glycogen metabolism. Although it is essential for the function of phosphorylase, its direct role has remained an enigma. We have recently found that the glucose moiety of pyridoxal (5′)diphospho (1)‐α‐D‐glucose, a conjugate of pyridoxal 5′‐phosphate and glucose 1‐phosphate through a pyrophosphate linkage, is transferred to the (...) nonreducing end of glycogen, forming a new α‐1,4‐glucosidic linkage. This finding emphasizes the importance of the direct phosphate‐phosphate interaction between the coenzyme and the substrate in the phosphorylase catalytic reaction. We have proposed a catalytic mechanism for phosphorylase in which the phosphate group of pyridoxal 5′‐phosphate acts as an electrophile to the phosphate group of glucose 1‐phosphate. This appears to represent the first instance of the direct involvement of a phosphate group in catalysis by enzymes. (shrink)

In many Western science systems, funding structures increasingly stimulate academic research to contribute to practical applications, but at the same time the rise of bibliometric performance assessments have strengthened the pressure on academics to conduct excellent basic research that can be published in scholarly literature. We analyze the interplay between these two developments in a set of three case studies of fields of chemistry in the Netherlands. First, we describe how the conditions under which academic chemists work have changed since (...) 1975. Second, we investigate whether practical applications have become a source of credibility for individual researchers. Indeed, this turns out to be the case in catalysis, where connecting with industrial applications helps in many steps of the credibility cycle. Practical applications yield much less credibility in environmental chemistry, where application-oriented research agendas help to acquire funding, but not to publish prestigious papers or to earn peer recognition. In biochemistry practical applications hardly help in gaining credibility, as this field is still strongly oriented at fundamental questions. The differences between the fields can be explained by the presence or absence of powerful upstream end-users, who can afford to invest in academic research with promising long term benefits. (shrink)

This is the second of a series of essays on the development and reception of Wilhelm Ostwald’s energetics. The first essay described the chemical origins of Ostwald’s interest in the energy concept and his motivations for seeking a comprehensive science of energy. The present essay and the next discuss his various attempts, beginning in 1891 and extending over almost 3 years, to develop a consistent and coherent energetic theory. A final essay will consider reactions to this work and Ostwald’s replies, (...) and will also seek to evaluate his program of research. Ostwald’s project – to reconstruct physics and chemistry “as a pure energetics” – is worth attending to for several reasons: first, because Ostwald did ground-breaking work in chemistry (he was awarded a Nobel Prize in 1909 for his studies in catalysis and rates of reaction); second, because an important school of physical chemistry formed around him at Leipzig, a school that promoted his ideas; and, finally, because he was a prominent and vigorous participant in debates at the end of the nineteenth century concerning the proper course of physical theory. (shrink)

This is the third of a series of essays on the development and reception of Wilhelm Ostwald’s energetics. The first essay described the chemical origins of Ostwald’s interest in the energy concept and his motivations for seeking a comprehensive science of energy. The second essay and the present one discuss his various attempts, beginning in 1891 and extending over almost 3 years, to develop a consistent and coherent energetic theory. A final essay will consider reactions to this work and Ostwald’s (...) replies, and will also seek to evaluate his program of research. Ostwald’s project—to reconstruct physics and chemistry “as a pure energetics”—is worth attending to for several reasons: first, because Ostwald did ground-breaking work in chemistry (he was awarded a Nobel Prize in 1909 for his studies in catalysis and rates of reaction); second, because an important school of physical chemistry formed around him at Leipzig, a school that promoted his ideas; and, finally, because he was a prominent and vigorous participant in debates at the end of the nineteenth century concerning the proper course of physical theory. (shrink)

In 2000, a simple, foundational thermodynamic paradox was proposed: a sealed blackbody cavity contains a diatomic gas and a radiometer whose apposing vane surfaces dissociate and recombine the gas to different degrees (A $_{2} \rightleftharpoons $ 2A). As a result of differing desorption rates for A and A $_{2}$ , there arise between the vane faces permanent pressure and temperature differences, either of which can be harnessed to perform work, in apparent conflict with the second law of thermodynamics. Here we (...) report on the first experimental realization of this paradox, involving the dissociation of low-pressure hydrogen gas on high-temperature refractory metals (tungsten and rhenium) under blackbody cavity conditions. The results, corroborated by other laboratory studies and supported by theory, confirm the paradoxical temperature difference and point to physics beyond the traditional understanding of the second law. (shrink)