102,307 research outputs found

    The Velocity Distribution of the Nearest Interstellar Gas

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    The bulk flow velocity for the cluster of interstellar cloudlets within about 30 pc of the Sun is determined from optical and ultraviolet absorption line data, after omitting from the sample stars with circumstellar disks or variable emission lines and the active variable HR 1099. Ninety-six velocity components towards the remaining 60 stars yield a streaming velocity through the local standard of rest of -17.0+/-4.6 km/s, with an upstream direction of l=2.3 deg, b=-5.2 deg (using Hipparcos values for the solar apex motion). The velocity dispersion of the interstellar matter (ISM) within 30 pc is consistent with that of nearby diffuse clouds, but present statistics are inadequate to distinguish between a Gaussian or exponential distribution about the bulk flow velocity. The upstream direction of the bulk flow vector suggests an origin associated with the Loop I supernova remnant. Groupings of component velocities by region are seen, indicating regional departures from the bulk flow velocity or possibly separate clouds. The absorption components from the cloudlet feeding ISM into the solar system form one of the regional features. The nominal gradient between the velocities of upstream and downstream gas may be an artifact of the Sun's location near the edge of the local cloud complex. The Sun may emerge from the surrounding gas-patch within several thousand years.Comment: Typographical errors corrected; Five tables, seven figures; Astrophysical Journal, in pres

    Freedom of Information versus National Sovereignty: The Need for a New Global Forum for the Resolution of Transborder Date Flow Problems

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    This Note argues that the issues raised by transborder data flow restrictions must be dealt with on a global scale, not on a national basis. Part I of this Note discusses the international legal principles underlying the concept of freedom of information and the legal difficulties presented by the imposition of transborder data flow restrictions. Part II analyzes the perception among developing nations that sovereign rights are threatened by an unrestricted flow of information and discusses the measures developing nations are implementing to control this perceived threat. Part III analyzes several approaches suggested for dealing with the problems of transborder data flow restrictions and argues that a new international forum must be created to constructively address the legitimate concerns of the developing nations. This Note concludes that since the effective demise of Unesco, progress must be made toward creating a viable international forum to address the multilateral concerns over transborder data flow restrictions

    Incomplete Resolution of Deep Vein Thromboses during Rivaroxaban Therapy.

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    We present the case of a patient with a deep vein thrombosis (DVT) who failed rivaroxaban therapy. Our patient initially presented with left lower extremity edema, erythema, and pain. He was subsequently started on rivaroxaban therapy for a combined treatment period of 12 months, during and after which he persisted to have evidence of a DVT. The patient's prescribed drug regimen was changed from rivaroxaban to warfarin, which demonstrated a rapid resolution of the DVTs as determined by ultrasound assessment of our patient's lower extremity veins. Rivaroxaban, a factor Xa inhibitor, is a well-known oral anticoagulant that is used for a variety of indications and has become a mainstay in the treatment of deep vein thrombosis. With the introduction and emergence of this medication in the clinic, postmarketing reports of efficacy or lack thereof are important to review. In conclusion, we anticipate that it is likely that there are other patients with DVTs who may not respond to rivaroxaban and for whom alternative anticoagulation therapies should be explored

    124-Color Super-resolution Imaging by Engineering DNA-PAINT Blinking Kinetics

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    Optical super-resolution techniques reach unprecedented spatial resolution down to a few nanometers. However, efficient multiplexing strategies for the simultaneous detection of hundreds of molecular species are still elusive. Here, we introduce an entirely new approach to multiplexed super-resolution microscopy by designing the blinking behavior of targets with engineered binding frequency and duration in DNA-PAINT. We assay this kinetic barcoding approach in silico and in vitro using DNA origami structures, show the applicability for multiplexed RNA and protein detection in cells, and finally experimentally demonstrate 124-plex super-resolution imaging within minutes.We thank Martin Spitaler and the imaging facility of the MPI of Biochemistry for confocal imaging support

    Large transient states in quantum field theory

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    A study is made of the scattering of two large composite projectiles, such as heavy ions, which are initially prepared in a pure quantum state. It is shown that the quantum field theoretic evolution equation for this system, under certain conditions, goes over in form to the master equation of classical statistical mechanics. Thus, the statistical mechanical description of heavy ion collision is viewed as an implied outcome of the Correspondence Principle, which states that in the limit of large quantum number, quantum dynamics goes over to classical dynamics. This hypothesis is explored within the master equation transcription with particular focus on the quark-gluon formation scenario.Comment: 28 pages, In Press Nuclear Physics A 200
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