A theoretical device, which incorporates the functions of clock, rod, nonrotating platform, and accelerometer, and whose operation depends on the properties of light rays and free particles, is defined. The device, which we call a metrosphere, is simple enough that it can be introduced at the starting point of relativity theory and versatile enough that it can serve as an aid in the development and conceptualization of the theory. Relative to an inertial frame, a moving metrosphere undergoes a Lorentz-Fitzgerald contraction (...) and the associated clock exhibits a Lorentz-Larmor rate retardation. From this fact and the assumption that there exists one inertial frame, it is possible to generate the kinematical results of special relativity. A metrosphere provides an observer with a local frame of reference, hence it is well adapted to the needs of general relativity, allows the equivalence principle to be introduced in a straightforward manner, and permits a smooth transition from special relativity to general relativity. (shrink)

Progressive supranuclear palsy is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP and 3,247 controls followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the (...) stage 1 SNPs that yielded P ≤ 10-3. We found significant previously unidentified signals associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component. © 2011 Nature America, Inc. All rights reserved. (shrink)

There is no indication of time dilation of clocks or of length contraction of rods in Marzke and Wheeler's clock or in Desloge's metrosphere.

Long before Jacques Derrida undertook a critique of phonocentrism as a form of ethnocentrism, a few teachers of deaf pupils rose to the challenge of working on a sign language independent of the structures of speech. For Derrida, this critique encompassed a reappraisal of Western limitations, while reflecting upon the boundaries and linearity of alphabetical versus ideographic writing. What I explore in this article is how the development of a pedagogy for deaf pupils went hand in hand with an examination (...) of language itself, including the dominance of alphabetical language, and led thinkers to question its role in the development of thought. The context of the development of a writing proper to sign language was one of the ferments in which this critique took shape, making writing practice the threshold of a critical investigation into the expressive qualities specific to sign language. My aim here is to sketch out the epistemological challenges and stakes of some of these conflicting approaches between the 1760s and the 1850s. This article analyzes some of the most radical linguistic conceptualizations about the potential of sign language to recreate the relationship between users and their language. I consider how teachers’ positionings led them to conceptualize sign language in distinct ways, ranging from a temporary, intermediary tool to an autonomous language with a writing of its own. After considering de Michel de l’Épée’s methodical signs and how far removed they are from the conception of a language of its own, as well as a discussion of them by deaf writer Pierre Desloges, I will investigate how Roch-Ambroise Bébian’s and Joseph Piroux’s conceptions of a writing specific to sign language led each of them to position it as a complete and independent language. (shrink)