10,437 research outputs found
The Core, Periphery, and Beyond: Stock Market Comovements among EU and Non-EU Countries
We thank conference participants at the 2016 Financial Management Association and our discussant Fernando Moreira, and two anonymous referees for immensely helpful comments. We also thank Andrew Patton and James P. LeSage for sharing their MATLAB codes for computing quantile dependence. The authors of this paper are responsible for any errors or omissions. The Securities and Exchange Commission, as a matter of policy, disclaims responsibility for any private publication or statement by any of its employees. The views expressed herein are those of the authors and do not necessarily reflect the views of the Commission or the authors\u27 colleagues on the staff of the Commission
A Parallel Tree code for large Nbody simulation: dynamic load balance and data distribution on CRAY T3D system
N-body algorithms for long-range unscreened interactions like gravity belong
to a class of highly irregular problems whose optimal solution is a challenging
task for present-day massively parallel computers. In this paper we describe a
strategy for optimal memory and work distribution which we have applied to our
parallel implementation of the Barnes & Hut (1986) recursive tree scheme on a
Cray T3D using the CRAFT programming environment. We have performed a series of
tests to find an " optimal data distribution " in the T3D memory, and to
identify a strategy for the " Dynamic Load Balance " in order to obtain good
performances when running large simulations (more than 10 million particles).
The results of tests show that the step duration depends on two main factors:
the data locality and the T3D network contention. Increasing data locality we
are able to minimize the step duration if the closest bodies (direct
interaction) tend to be located in the same PE local memory (contiguous block
subdivison, high granularity), whereas the tree properties have a fine grain
distribution. In a very large simulation, due to network contention, an
unbalanced load arises. To remedy this we have devised an automatic work
redistribution mechanism which provided a good Dynamic Load Balance at the
price of an insignificant overhead.Comment: 16 pages with 11 figures included, (Latex, elsart.style). Accepted by
Computer Physics Communication
Object knowledge modulates colour appearance
We investigated the memory colour effect for colour diagnostic artificial objects. Since knowledge about these objects and their colours has been learned in everyday life, these stimuli allow the investigation of the influence of acquired object knowledge on colour appearance. These investigations are relevant for questions about how object and colour information in high-level vision interact as well as for research about the influence of learning and experience on perception in general. In order to identify suitable artificial objects, we developed a reaction time paradigm that measures (subjective) colour diagnosticity. In the main experiment, participants adjusted sixteen such objects to their typical colour as well as to grey. If the achromatic object appears in its typical colour, then participants should adjust it to the opponent colour in order to subjectively perceive it as grey. We found that knowledge about the typical colour influences the colour appearance of artificial objects. This effect was particularly strong along the daylight axis
Gallium arsenide 55Fe X-ray-photovoltaic battery
The effects of temperature on the key parameters of a prototype GaAs 55Fe radioisotope X-ray microbattery were studied over the temperature range -20 °C to 70 °C. A p-i-n GaAs structure was used to collect the photons from a 254 Bq 55Fe radioisotope X-ray source. Experimental results showed that the open circuit voltage and the short circuit current decreased with increased temperature. The maximum output power and the conversion efficiency of the device decreased at higher temperatures. For the reported microbattery, the highest maximum output power (1 pW, corresponding to 0.4 ΌW/Ci) was observed at -20 °C. A conversion efficiency of 9% was measured at -20 °C
Vedolizumab: an α4ÎČ7 integrin antagonist for ulcerative colitis and Crohnâs disease
Ulcerative colitis (UC) and Crohnâs disease (CD) are chronic, relapsing inflammatory bowel diseases associated with significant morbidity. Conventional therapies for these diseases include corticosteroids, aminosalicylates, immunomodulators, and monoclonal antibodies. Over the years tumor necrosis factor (TNF)-α antagonists alone or in combination with other therapies have emerged as the cornerstone of treatment for induction and maintenance of remission of moderate to severe UC and CD. Unfortunately, some patients with moderate to severe UC and CD are unable to attain or maintain remission with TNF-α antagonist treatment. Vedolizumab, a humanized monoclonal antibody, is the first integrin receptor antagonist approved that selectively antagonizes α4ÎČ7 gastrointestinal integrin receptors. US Food and Drug Administration approval is for treatment of patients with moderate to severe active UC and CD who have inadequate response with, lost response to, or are intolerant to a TNF-α antagonist or an immunomodulator; or have inadequate response with, are intolerant to, or demonstrate dependence on corticosteroids. When administered according to approved dosing in patients with moderate to severe CD and UC, vedolizumab induces clinical response rates up to 31.4% and 47.1% at week 6, and clinical remission rates up to 39% and 41.8% at week 52, respectively. Serious adverse events reported with vedolizumab include serious infections, malignancies, and anaphylaxis. Since vedolizumab is gastrointestinal selective, to date, it has not shown evidence of causing progressive multifocal leukoencephalopathy; however, postmarketing studies monitoring for this adverse effect are ongoing. Further assessment of vedolizumab earlier in the course of these diseases and in combination with other therapies is warranted
To The Sun / words by David W. Guion
Cover: part of a series titled Five Imaginary Early Louisiana Songs of Slavery; Publisher: G. Schirmer Inc. (New York)https://egrove.olemiss.edu/sharris_d/1104/thumbnail.jp
Three Negro Poems / music by Jacques Wolfe; words by Clement Woodbury
Cover: abstract drawing of African American faces; Publisher: G. Schirmer Inc. (New York)https://egrove.olemiss.edu/sharris_d/1095/thumbnail.jp
A Banjo Song / music by Sidney Homer; words by Howard Weeden
Cover: from a series called Bandanna Ballads; Publisher: G. Schirmer Inc. (New York)https://egrove.olemiss.edu/sharris_c/1008/thumbnail.jp
Trees / music by Oscar Rasbach; words by Joyce Kilmer
Cover: drawing of trees; Publisher: G. Schirmer Inc. (New York)https://egrove.olemiss.edu/sharris_d/1044/thumbnail.jp
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