95 research outputs found
\u27In So Many Ways Do the Planets Bear Witness\u27: The Impact of Copernicanism on Judicial Astrology at the English Court, 1543-1660
The traditional historiography of science from the late-nineteenth through the mid-twentieth centuries has broadly claimed that the Copernican revolution in astronomy irrevocably damaged the practice of judicial astrology. However, evidence to the contrary suggests that judicial astrology not only continued but actually expanded during the sixteenth and early seventeenth centuries. During this time period, judicial astrologers accomplished this by appropriating contemporary science and mathematics. Copernicus\u27s De revolutionibus, in particular, provided better mathematics for determining the positions of the planets than the prevailing Ptolemaic system and reformist astrologers interested in making astrology a precise, mathematical science embraced this new astronomy. This study evaluates the impact that Copernicus\u27s heliocentric theory of the cosmos had on the practice of judicial astrology, particularly within the English court patronage system between the publication of Copernicus\u27s De revolutionibus in 1543 and the Restoration of the monarchy and founding of the Royal Society in 1660. In England, while noble patrons defined the value of science in terms of its practical utility, many English judicial astrologers successfully argued for scientific legitimacy based on their ability to precisely predict planetary locations. Contrary to their European counterparts on the Continent, English patrons typically required tangible, practical results to justify their support of client-scientists. The heliocentric theory received a largely positive reaction in England, and many astrologers readily employed its mathematics to make more precise predictions of planetary locations, which would presumably lead to better prognostications of human events. As long as scientists and patrons defined science in these exclusively mathematical terms, astrology could comfortably exist within these scientific boundaries. However, throughout the mid-sixteenth century, multiple processes occurred that changed astrology from a science into a popular belief in England. Patrons began to lose interest in astrology and thus financed fewer astrologers, and with the instability of the Civil War, fewer patrons were in positions of power to provide this sort of support. Furthermore, as astrology enjoyed increased popularity among the lower and merchant classes of England through almanac and pamphlet publications, scientists saw it in their best professional interest to consciously distance themselves from astrology and redefine and re-categorize it beyond the reasonable margins of proper scientific practice. In short, while astrology declined as a scientific activity during the latter half of the seventeenth century, it found success as a popular activity beyond the confines of conventional science
âRusticall chymistryâ: Alchemy, Saltpeter Projects, and Experimental Fertilizers in Seventeenth-century English Agriculture
Municipal CorporationsâSpecial AssessmentsâLocal Improvement Districts.â Heavens v. King County Rural Library Dist.
Trade RegulationâPrice DiscriminationâMeaning of Like Grade and Quality Under Section 2(a) of the Robinson-Patman Act.âBorden Co. v. FTC
Sapiens Dominabitur Astris: A Diachronic Survey of a Ubiquitous Astrological Phrase
From the late thirteenth through late seventeenth centuries, a single three-word Latin phraseâsapiens dominabitur astris, or âthe wise man will be master of the starsââproliferated in astrological, theological, philosophical, and literary texts. It became a convenient marker denoting orthodox positions on free will and defining the boundaries of the scientifically and morally legitimate practice of astrology. By combining the methodology of a diachronic historical survey with a microhistorical focus on evolving phraseology, this study argues that closely examining the use of this phrase reveals how debates about the meanings of wisdom, free will, determinism, and the interpretation of stellar influence on human events changed radically across four centuries of Western European cultural and intellectual history. The first half of this article charts the scholastic response to theological criticisms of astrology and the reconciliation of Aristotelian-Ptolemaic cosmology with Catholic theology, paying special attention to its implications for astrology as viewed through scholarly uses of the phrase. The second half of the article shows how the phrase developed a multitude of idiosyncratic meanings in the sixteenth and seventeenth centuries, fracturing its late medieval scholastic unity, as new forms of philosophical, socio-political, religious, and scientific critiques upended astrological beliefs and practices. Ultimately, this paper argues that examining the theory and praxis of astrology through the changing phraseological meanings of âsapiens dominabitur astrisâ allows historians and cultural anthropologists to better discern the dialectical (as opposed to binary) relationships between free will and determinism in the West
âĂlan vital ⊠and how to fake it: Morton Feldman and Merle Marsicanoâs Vernacular Metaphysics.â
Scholars have explored the relationship between US experimentalism and vitalist philosophy largely through John Cageâs reception of Henri Bergson. Recent scholarship has shown the importance of vitalism to the wider New York School. Evidence from Feldmanâs archive suggests he too absorbed Bergsonian philosophy. Feldman signalled this when he wrote of âHenri Bergsonâs Ă©lan vital ⊠and how to fake itâ in his unpublished lectures, New York Style. He borrows vitalist vocabulary for piece titles (Extensions and Durations) and, in an early sketchbook, describes his open-form Intermission 6 as âan outline of becomingâ. These interests are also apparent in his collaborations. His nearly-lost dance piece Figure of Memory, written for choreographer Merle Marsicano, is Feldmanâs only other open form piece (along with Intermission 6). Marsicano employed similar vitalist language to Feldman and applied it to her dance. Feldmanâs collaboration with Marsicano signals a shared vernacular metaphysics mingling Bergsonism, self-abnegation, and aesthetic form
Visualizing helicases unwinding DNA at the single molecule level
DNA helicases are motor proteins that catalyze the unwinding of double-stranded DNA into single-stranded DNA using the free energy from ATP hydrolysis. Single molecule approaches enable us to address detailed mechanistic questions about how such enzymes move processively along DNA. Here, an optical method has been developed to follow the unwinding of multiple DNA molecules simultaneously in real time. This was achieved by measuring the accumulation of fluorescent single-stranded DNA-binding protein on the single-stranded DNA product of the helicase, using total internal reflection fluorescence microscopy. By immobilizing either the DNA or helicase, localized increase in fluorescence provides information about the rate of unwinding and the processivity of individual enzymes. In addition, it reveals details of the unwinding process, such as pauses and bursts of activity. The generic and versatile nature of the assay makes it applicable to a variety of DNA helicases and DNA templates. The method is an important addition to the single-molecule toolbox available for studying DNA processing enzymes
Single-molecule experiments in biological physics: methods and applications
I review single-molecule experiments (SME) in biological physics. Recent
technological developments have provided the tools to design and build
scientific instruments of high enough sensitivity and precision to manipulate
and visualize individual molecules and measure microscopic forces. Using SME it
is possible to: manipulate molecules one at a time and measure distributions
describing molecular properties; characterize the kinetics of biomolecular
reactions and; detect molecular intermediates. SME provide the additional
information about thermodynamics and kinetics of biomolecular processes. This
complements information obtained in traditional bulk assays. In SME it is also
possible to measure small energies and detect large Brownian deviations in
biomolecular reactions, thereby offering new methods and systems to scrutinize
the basic foundations of statistical mechanics. This review is written at a
very introductory level emphasizing the importance of SME to scientists
interested in knowing the common playground of ideas and the interdisciplinary
topics accessible by these techniques. The review discusses SME from an
experimental perspective, first exposing the most common experimental
methodologies and later presenting various molecular systems where such
techniques have been applied. I briefly discuss experimental techniques such as
atomic-force microscopy (AFM), laser optical tweezers (LOT), magnetic tweezers
(MT), biomembrane force probe (BFP) and single-molecule fluorescence (SMF). I
then present several applications of SME to the study of nucleic acids (DNA,
RNA and DNA condensation), proteins (protein-protein interactions, protein
folding and molecular motors). Finally, I discuss applications of SME to the
study of the nonequilibrium thermodynamics of small systems and the
experimental verification of fluctuation theorems. I conclude with a discussion
of open questions and future perspectives.Comment: Latex, 60 pages, 12 figures, Topical Review for J. Phys. C (Cond.
Matt
DNA mechanics as a tool to probe helicase and translocase activity
Helicases and translocases are proteins that use the energy derived from ATP hydrolysis to move along or pump nucleic acid substrates. Single molecule manipulation has proved to be a powerful tool to investigate the mechanochemistry of these motors. Here we first describe the basic mechanical properties of DNA unraveled by single molecule manipulation techniques. Then we demonstrate how the knowledge of these properties has been used to design single molecule assays to address the enzymatic mechanisms of different translocases. We report on four single molecule manipulation systems addressing the mechanism of different helicases using specifically designed DNA substrates: UvrD enzyme activity detection on a stretched nicked DNA molecule, HCV NS3 helicase unwinding of a RNA hairpin under tension, the observation of RecBCD helicase/nuclease forward and backward motion, and T7 gp4 helicase mediated opening of a synthetic DNA replication fork. We then discuss experiments on two dsDNA translocases: the RuvAB motor studied on its natural substrate, the Holliday junction, and the chromosome-segregation motor FtsK, showing its unusual coupling to DNA supercoiling
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