1,787 research outputs found
The Causality Relationship between Hnx Index and Stock Trading Volume in Hanoi Stock Exchange
This paper examines the casual relations between the market return and trading volume for the Ha Noi Stock Exchange during the period from May 3th , 2013 to March 2rd, 2016. This paper uses Granger test and the results showed that the change of the volume of transactions that affect the change of HNX-Index. On the basis of this conclusion, we shall determine the degree of influence of the change in trading volume with HNX-Index by means of regression analysis
Self-Focusing Dynamics of Coupled Optical Beams
We theoretically and experimentally investigate the mutual collapse dynamics
of two spatially separated optical beams in a Kerr medium. Depending on the
initial power, beam separation, and the relative phase, we observe repulsion or
attraction, which in the latter case reveals a sharp transition to a single
collapsing beam. This transition to fusion of the beams is accompanied by an
increase in the collapse distance, indicating the effect of the nonlinear
coupling on the individual collapse dynamics. Our results shed light on the
basic nonlinear interaction between self-focused beams and provide a mechanism
to control the collapse dynamics of such beams.Comment: 5 pages, 4 figure
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Draft Genome Sequences of Four Saccharibacter sp. Strains Isolated from Native Bees.
The genus Saccharibacter is currently understudied, with only one described species, Saccharibacter floricola, isolated from a flower. In an effort to better understand the microbes that come in contact with native bee pollinators, we isolated and sequenced four additional strains of Saccharibacter from native bees in the genera Melissodes and Anthophora These genomes range in size from 2,104,494 to 2,316,791 bp (mean, 2,246,664 bp) and contain between 1,860 and 2,167 (mean, 2,060) protein-coding genes
Learned Non-Rigid Object Motion is a View-Invariant Cue to Recognizing Novel Objects
There is evidence that observers use learned object motion to recognize objects. For instance, studies have shown that reversing the learned direction in which a rigid object rotated in depth impaired recognition accuracy. This motion reversal can be achieved by playing animation sequences of moving objects in reverse frame order. In the current study, we used this sequence-reversal manipulation to investigate whether observers encode the motion of dynamic objects in visual memory, and whether such dynamic representations are encoded in a way that is dependent on the viewing conditions. Participants first learned dynamic novel objects, presented as animation sequences. Following learning, they were then tested on their ability to recognize these learned objects when their animation sequence was shown in the same sequence order as during learning or in the reverse sequence order. In Experiment 1, we found that non-rigid motion contributed to recognition performance; that is, sequence-reversal decreased sensitivity across different tasks. In subsequent experiments, we tested the recognition of non-rigidly deforming (Experiment 2) and rigidly rotating (Experiment 3) objects across novel viewpoints. Recognition performance was affected by viewpoint changes for both experiments. Learned non-rigid motion continued to contribute to recognition performance and this benefit was the same across all viewpoint changes. By comparison, learned rigid motion did not contribute to recognition performance. These results suggest that non-rigid motion provides a source of information for recognizing dynamic objects, which is not affected by changes to viewpoint
Anthracimycin activity against contemporary methicillin-resistant Staphylococcus aureus.
Anthracimycin is a recently discovered novel marine-derived compound with activity against Bacillus anthracis. We tested anthracimycin against an expanded panel of Staphylococcus aureus strains in vitro and in vivo. All strains of S. aureus tested, including methicillin-susceptible, methicillin-resistant (MRSA) and vancomycin-resistant strains of S. aureus, were susceptible to anthracimycin at MIC values of â©œ0.25âmgâl(-1). Although its postantibiotic effects were minimal, anthracimycin exhibited potent and rapid bactericidal activity, with a >4-log kill of USA300 MRSA within 3âh at five times its MIC. At concentrations significantly below the MIC, anthracimycin slowed MRSA growth and potentiated the bactericidal activity of the human cathelicidin, LL-37. The bactericidal activity of anthracimycin was somewhat mitigated in the presence of 20% human serum, and the compound was minimally toxic to human cells, with an IC50 (inhibitory concentration 50)=70âmgâl(-1) against human carcinoma cells. At concentrations near the MIC, anthracimycin inhibited S. aureus nucleic acid synthesis as determined by optimized macromolecular synthesis methodology, with inhibition of DNA and RNA synthesis occurring in the absence of DNA intercalation. Anthracimycin at a single dose of 1 or 10âmgâkg(-1) was able to protect mice from MRSA-induced mortality in a murine peritonitis model of infection. Anthracimycin provides an interesting new scaffold for future development of a novel MRSA antibiotic
Low mass T Tauri and young brown dwarf candidates in the Chamaeleon II dark cloud found by DENIS
We define a sample designed to select low-mass T Tauri stars and young brown
dwarfs using DENIS data in the Chamaeleon II molecular cloud. We use a star
count method to construct an extinction map of the Chamaeleon II cloud. We
select our low-mass T Tauri star and young brown dwarf candidates by their
strong infrared colour excess in the I-J/J-K_s colour-colour dereddened
diagram. We retain only objects with colours I-J>2, and spatially distributed
in groups around the cloud cores. This provides a sample of 70 stars of which 4
are previously known T Tauri stars. We have carefully checked the reliability
of all these objects by visual inspection on the DENIS images. Thanks to the
association of the optical I-band to the infra-red J and K_s bands in DENIS, we
can apply this selection method to all star formation regions observed in the
southern hemisphere. We also identify six DENIS sources with X-ray sources
detected by ROSAT. Assuming that they are reliable low-mass candidates and
using the evolutionary models for low-mass stars, we estimate the age of these
sources between 1 Myr and < 10 Myr.Comment: 7 Pages, including 3 PostScript figures. Accepted for publication in
Astronomy & Astrophysic
Microdosing and other phase 0 clinical trials: facilitating translation in Drug Development
Increasing costs of drug development and ethical concernsabout the risks of exposing humans and animals to novelchemical entities favor limited exposure clinical trials suchas microdosing and other phase 0 trials. An increasing bodyof research supports the validity of extrapolation from thelimited drug exposure of phase 0 approaches to the full,therapeutic exposure. An increasing number of applicationsand design options demonstrate the versatility and exibilitythese approaches offer to drug developers
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