1,260 research outputs found

    Personal Jurisdiction Over Alien Corporate Parents and Affiliates in Antitrust Actions: A Plea for Perspicuity

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    The purpose of this Comment is to read the entrails of judicial conceptions which have been sacrificed for reasons of public policy. Antitrust law provides a fertile source of cases which consider these problems. Almost since the passage of the Sherman Act, alien corporations have been sued when acts committed abroad have adversely affected U.S. plaintiffs. The extraterritorial application of antitrust law is well established. In most antitrust cases against corporations, a single sixty-year-old statute governs venue and service of process. There is nevertheless little agreement on its meaning. After a brief review of the historical background, this Comment will consider present problems and trends in the case law. Misconceived corporate law and intricate federal jurisdiction questions have needlessly complicated the issues. International Shoe and state long-arm statutes provide straightforward solutions

    Phosphate bonding in refractories

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    Thesis (Sc.D.) Massachusetts Institute of Technology. Dept. of Metallurgy, 1950Bibliography: leaves 81-86.by Wm. David Kingery.Sc.D

    An uncharged amine in the transition state of the ribosornal peptidyl transfer reaction.

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    The ribosome has an active site comprised of RNA that catalyzes peptide bond formation. To understand how RNA promotes this reaction requires a detailed understanding of the chemical transition state. Here, we report the Bronsted coefficient of the a-amino nucleophile with a series of puromycin derivatives. Both 50S subunit- and 70S ribosome-catalyzed reactions displayed linear free-energy relationships with slopes close to zero under conditions where chemistry is rate limiting. These results indicate that, at the transition state, the nucleophile is neutral in the ribosome-catalyzed reaction, in contrast to the substantial positive charge reported for typical uncatalyzed aminolysis reactions. This suggests that the ribosomal transition state involves deprotonation to a degree commensurate with nitrogen-carbon bond formation. Such a transition state is significantly different from that of uncatalyzed aminolysis reactions in solution

    When the Sky Falls NASA's Response to Bright Bolide Events Over Continental USA

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    Being the only U.S. Government entity charged with monitoring the meteor environment, the Meteoroid Environment Office (MEO) has deployed a network of allsky and wide field meteor cameras, along with the appropriate software tools to quickly analyze data from these systems. However, the coverage of this network is still quite limited, forcing the incorporation of data from other cameras posted to the internet in analyzing many of the fireballs reported by the public and media. Information on these bright events often needs to be reported to NASA Headquarters by noon the following day; thus a procedure has been developed that determines the analysis process for a given fireball event based on the types and amount of data available. The differences between these analysis processes are shown by looking at four meteor events that the MEO responded to, all of which were large enough to produce meteorites

    Optical and Radar Measurements of the Meteor Speed Distribution

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    The observed meteor speed distribution provides information on the underlying orbital distribution of Earth-intersecting meteoroids. It also affects spacecraft risk assessments; faster meteors do greater damage to spacecraft surfaces. Although radar meteor networks have measured the meteor speed distribution numerous times, the shape of the de-biased speed distribution varies widely from study to study. Optical characterizations of the meteoroid speed distribution are fewer in number, and in some cases the original data is no longer available. Finally, the level of uncertainty in these speed distributions is rarely addressed. In this work, we present the optical meteor speed distribution extracted from the NASA and SOMN allsky networks [1, 2] and from the Canadian Automated Meteor Observatory (CAMO) [3]. We also revisit the radar meteor speed distribution observed by the Canadian Meteor Orbit Radar (CMOR) [4]. Together, these data span the range of meteoroid sizes that can pose a threat to spacecraft. In all cases, we present our bias corrections and incorporate the uncertainty in these corrections into uncertainties in our de-biased speed distribution. Finally, we compare the optical and radar meteor speed distributions and discuss the implications for meteoroid environment models

    Scara1 deficiency impairs clearance of soluble Amyloid-β by mononuclear phagocytes and accelerates Alzheimer’s-like disease progression

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    In Alzheimer’s disease soluble amyloid beta (sAβ) causes synaptic dysfunction and neuronal loss. Receptors involved in clearance of sAβ are not known. Here we use shRNA screening and identify the scavenger receptor Scara1 as a receptor for sAβ expressed on myeloid cells. To determine the role of Scara1 in clearance of sAβ in vivo, we cross Scara1 null mice with PS1-APP mice, a mouse model of Alzheimer’s disease and generate PS1-APP- Scara1-deficient mice. Scara1 deficiency markedly accelerates Aβ accumulation leading to increased mortality. In contrast, pharmacological upregulation of Scara1 expression on mononuclear phagocytes increases Aβ clearance. This approach is a potential treatment strategy for Alzheimer’s disease
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