2,101 research outputs found
THE SHIFTING SANDS OF SPACE SECURITY: THE POLITICS AND LAW OF THE PEACEFUL USES OF OUTER SPACE
This article argues that the content of the legal term “peaceful purposes,”as used in international space law is changing. Peaceful Purposes as understood throughout the bulk of the Space Age has encompassed not only the UN Charter’s prohibitions on the use of force, but also a number of customary international law principles that enhanced it beyond mere non-aggression. Through an examination of state practice with regards to the military uses of outer space, this article concludes that the legal content of peaceful purposes is eroding towards an alignment with “non-aggressive” as understood in the law concerning the use of force. Specifically, this article argues that geopolitical and technological changes are encouraging states to pursue disruption in the space environment rather than stability, and this has been matched with state practice and rhetoric that exhibits that states are moving toward more offensive, rather than defensive, stances in the space environment
Reprogramming the world: Cyberspace and the geography of global order
We live in a world of “fake news”, data breaches, election hacking, and cyberwarfare in which 280 characters can change everything. Our analog past has been replaced with digital realities. The central claim of this book is that digital technologies are rewiring the way that society understands and thinks about global order as Cyberspace changes the content of international borders. The idea of a reprogrammed world, then, is one that does double duty. First, it performs a metaphorical function and maps the language of computer science and technology onto the system of global order. Throughout this book, the reader will find the use of these metaphors as a way to explain how digital technologies affect governance. Second, it describes a real and actual process that requires evaluation of the design of the international governance system. While international governance has never been a static process, the reprogramming being described herein is extraordinarily different from previous shifts in international governance. It is not the result of a war or of a contingent of sovereigns negotiating rules; it is a technologically driven process that redistributes power within that system and challenges the core concept of territorial sovereignty
Hydrophobic gating of mechanosensitive channel of large conductance evidenced by single-subunit resolution
Mechanosensitive (MS) ion channels are membrane proteins that detect and respond to membrane tension in all branches of life. In bacteria, MS channels prevent cells from lysing upon sudden hypoosmotic shock by opening and releasing solutes and water. Despite the importance of MS channels and ongoing efforts to explain their functioning, the molecular mechanism of MS channel gating remains elusive and controversial. Here we report a method that allows single-subunit resolution for manipulating and monitoring “mechanosensitive channel of large conductance” from Escherichia coli. We gradually changed the hydrophobicity of the pore constriction in this homopentameric protein by modifying a critical pore residue one subunit at a time. Our experimental results suggest that both channel opening and closing are initiated by the transmembrane 1 helix of a single subunit and that the participation of each of the five identical subunits in the structural transitions between the closed and open states is asymmetrical. Such a minimal change in the pore environment seems ideal for a fast and energy-efficient response to changes in the membrane tension.
Polar type density of states in non-unitary odd-parity superconducting states of gap with point nodes
It is shown that the density of states (DOS) proportional to the excitation
energy, the so-called polar like DOS, can arise in the odd-parity states with
the superconducting gap vanishing at points even if the spin-orbit interaction
for Cooper pairing is strong enough. Such gap stuructures are realized in the
non-unitary states, F_{1u}(1,i,0), F_{1u}(1,varepsilon,varepsilon^{2}), and
F_{2u}(1,i,0), classified by Volovik and Gorkov, Sov. Phys.-JETP Vol.61 (1985)
843. This is due to the fact that the gap vanishes in quadratic manner around
the point on the Fermi surface. It is also shown that the region of quadratic
energy dependence of DOS, in the state F_{2u}(1,varepsilon,varepsilon^{2}), is
restricted in very small energy region making it difficult to distinguish from
the polar-like DOS.Comment: 5 pages, 3 figures, submitted to J. Phys.: Condens. Matter Lette
S. aureus MscL Is a Pentamer In Vivo but of Variable Stoichiometries In Vitro: Implications for Detergent-Solubilized Membrane Proteins
Detergent-induced rearrangements of membrane-protein subunits explain why two MscL channel stoichiometries have been resolved by X-ray crystallography - but S. aureus MscL is truly a pentamer in vivo
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