1,175 research outputs found

    The Cold War\u27s Last Battlefield: Reagan, the Soviets and Central America

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    Central America was the final place where U.S. and Soviet proxy forces faced off against one another in armed conflict. In The Cold War\u27s Last Battlefield, Edward A. Lynch blends his own first-hand experiences as a member of the Reagan Central America policy team with interviews of policy makers and exhaustive study of primary source materials, including once-secret government documents, in order to recount these largely forgotten events and how they fit within Reagan\u27s broader foreign policy goals. Lynch\u27s compelling narrative reveals a president who was willing to risk both influence and image to aggressively confront Soviet expansion in the region. He also demonstrates how the internal debates between competing sides of the Reagan administration were really an argument about the basic thrust of U.S. foreign policy, and that they anticipated, to a remarkable degree, policy discussions following the September 11, 2001 terror attacks. --Back coverhttps://digitalcommons.hollins.edu/facbooks/1079/thumbnail.jp

    Formal and Doctrinal Differences Between Government and Private Contracts

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    Justice Holmes admonishes us that men must turn square corners when they deal with the Government. This Square Corner Doctrine finds application in the extensive and expanding area of government contracting. This note surveys briefly some ways in which a contract between the United States Government and a private businessman or corporation may be at variance with a contract between private parties based upon common law principles

    Whose Rights Are They, Anyway?

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    The authors discuss sovereignty and the history behind a nation’s prerogative to intercede in the affairs of other nations to protect human rights

    An Attempt to Reproduce the Schwarz‐Hora Effect

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    Several attempts were made to observe the modulation of an electron beam by a laser (the Schwarz‐Hora effect). These were not successful and possible reasons are reported

    DATA MANAGEMENT SYSTEMS FOR MICRO-COMPUTERS: A SURVEY

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    Information Systems Working Papers Serie

    Leveraging OpenStack and Ceph for a Controlled-Access Data Cloud

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    While traditional HPC has and continues to satisfy most workflows, a new generation of researchers has emerged looking for sophisticated, scalable, on-demand, and self-service control of compute infrastructure in a cloud-like environment. Many also seek safe harbors to operate on or store sensitive and/or controlled-access data in a high capacity environment. To cater to these modern users, the Minnesota Supercomputing Institute designed and deployed Stratus, a locally-hosted cloud environment powered by the OpenStack platform, and backed by Ceph storage. The subscription-based service complements existing HPC systems by satisfying the following unmet needs of our users: a) on-demand availability of compute resources, b) long-running jobs (i.e., >30> 30 days), c) container-based computing with Docker, and d) adequate security controls to comply with controlled-access data requirements. This document provides an in-depth look at the design of Stratus with respect to security and compliance with the NIH's controlled-access data policy. Emphasis is placed on lessons learned while integrating OpenStack and Ceph features into a so-called "walled garden", and how those technologies influenced the security design. Many features of Stratus, including tiered secure storage with the introduction of a controlled-access data "cache", fault-tolerant live-migrations, and fully integrated two-factor authentication, depend on recent OpenStack and Ceph features.Comment: 7 pages, 5 figures, PEARC '18: Practice and Experience in Advanced Research Computing, July 22--26, 2018, Pittsburgh, PA, US

    2-(1H-1,3-Benzodiazol-2-ylsulfan­yl)-1-(4-chloro­phen­yl)ethanone

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    The mol­ecule in the structure of the title compound, C15H11ClN2OS, displays two planar residues [r.m.s. deviation = 0.014 Å for the benzimidazole residue, and the ketone group is co-planar with the benzene ring to which it is attached forming a O—C—C—C torsion angle of −173.18 (14) °] linked at the S atom. The overall shape is based on a twisted V, the dihedral angle formed between the two planes being 82.4 (2) °. The amine-H atom is bifurcated, forming N—H⋯O and N—H⋯S hydrogen bonds leading to dimeric aggregates. These are linked into a supra­molecular chain along the c axis via C—H⋯π hydrogen bonds. Chains form layers in the ab plane being connected along the c axis via weak π–π inter­actions [3.9578 (8) Å] formed between centrosymmetrically related chloro-substituted benzene rings

    Static single-arm force generation with kinematic constraints

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    Abstract This study investigates natural single-arm interac-tion with kinematic constraints. Smooth, frictionless, kinematic constraints reduce the degrees-of-freedom of motion at the hand, but add force freedoms. These force freedoms allow the hand to push and pull against the constraints with no effect on the task. Understanding how subjects take advantage of kinematic constraints will be useful in designing constraint surfaces for assisted manipulation. This paper reports the results of an experiment studying how subjects make use of the presence of a kinematic constraint in a static planar single-arm task. Subjects are asked to hold a handle that is free to slide on a linear rail, and to apply a force tangent to the rail to resist a pulling force. Thus the goal of the task is to hold the handle stationary. Subjects are also free to apply any force normal to the rail, as these forces have no effect on the task. This freedom does not exist without a kinematic constraint. We nd that subjects make use of the force freedom by applying signicant forces against the constraint in a consistent and constraint-conguration-dependent fashion. We show that the constraint forces can be predicted by a convex, scale-invariant objective function on the hand force space. The level curves of this objective function can be found directly from the experimental data without any biomechanical modeling. I

    An 11-Year Global Gridded Aerosol Optical Thickness Reanalysis (v1.0) for Atmospheric and Climate Sciences

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    While stand alone satellite and model aerosol products see wide utilization, there is a significant need in numerous atmospheric and climate applications for a fused product on a regular grid. Aerosol data assimilation is an operational reality at numerous centers, and like meteorological reanalyses, aerosol reanalyses will see significant use in the near future. Here we present a standardized 2003–2013 global 1 × 1 ◦ and 6-hourly modal aerosol optical thickness (AOT) reanalysis product. This data set can be applied to basic and applied Earth system science studies of significant aerosol events, aerosol impacts on numerical weather prediction, and electro-optical propagation and sensor performance, among other uses. This paper describes the science of how to develop and score an aerosol reanalysis product. This reanalysis utilizes a modified Navy Aerosol Analysis and Prediction System (NAAPS) at its core and assimilates quality controlled retrievals of AOT from the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua and the Multi-angle Imaging SpectroRadiometer (MISR) on Terra. The aerosol source functions, including dust and smoke, were regionally tuned to obtain the best match between the model fine- and coarse-mode AOTs and the Aerosol Robotic Network (AERONET) AOTs. Other model processes, including deposition, were tuned to minimize the AOT difference between the model and satellite AOT. Aerosol wet deposition in the tropics is driven with satellite-retrieved precipitation, rather than the model field. The final reanalyzed fine- and coarse-mode AOT at 550 nm is shown to have good agreement with AERONET observations, with global mean root mean square error around 0.1 for both fine- and coarse-mode AOTs. This paper includes a discussion of issues particular to aerosol reanalyses that make them distinct from standard meteorological reanalyses, considerations for extending such a reanalysis outside of the NASA A-Train era, and examples of how the aerosol reanalysis can be applied or fused with other model or remote sensing products. Finally, the reanalysis is evaluated in comparison with other available studies of aerosol trends, and the implications of this comparison are discussed

    Caudate nucleus volume mediates the link between cardiorespiratory fitness and cognitive flexibility in older adults

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    The basal ganglia play a central role in regulating the response selection abilities that are critical formental flexibility. In neocortical areas, higher cardiorespiratory fitness levels are associated with increased gray matter volume, and these volumetric differences mediate enhanced cognitive performance in a variety of tasks. Here we examine whether cardiorespiratory fitness correlates with the volume of the subcortical nuclei that make up the basal ganglia and whether this relationship predicts cognitive flexibility in older adults. Structural MRI was used to determine the volume of the basal ganglia nuclei in a group of older, neurologically healthy individuals (mean age 66 years, N = 179).Measures of cardiorespiratory fitness (VO2max), cognitive flexibility (task switching), and attentional control (flanker task) were also collected. Higher fitness levels were correlated with higher accuracy rates in the Task Switching paradigm. In addition, the volume of the caudate nucleus, putamen, and globus pallidus positively correlated with Task Switching accuracy.Nested regression modeling revealed that caudate nucleus volume was a significantmediator of the relationship between cardiorespiratory fitness, and task switching performance. These findings indicate that higher cardiorespiratory fitness predicts better cognitive flexibility in older adults through greater grey matter volume in the dorsal striatum
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