233 research outputs found
{μ-N,N,N′,N′-TetraÂkis[(diphenylÂphosphanÂyl)methÂyl]benzene-1,4-diamine}ÂbisÂ[(2,2′-bipyridÂyl)copper(I)] bisÂ(tetraÂfluoridoborate)
In the title compound, [Cu2(C10H8N2)2(C58H52N2P4)](BF4)2, the dinuclear cation lies on an inversion centre. The CuI atom is coordinated by two N atoms from a 2,2′-bipyridine ligand and two P atoms from an N,N,N′,N′-tetraÂkisÂ[(diphenylÂphosÂphanÂyl)methÂyl]benzene-1,4-diamine ligand in a distorted tetraÂhedral geometry. In the crystal, interÂmolecular C—H⋯F hydrogen bonds link the ions into layers parallel to [01]. π–π interÂactions [centroid–centroid distance = 3.668 (4) Å] are also observed. One F atom of the anion is disordered over two orientations with a refined occupancy ratio of 0.675 (13):0.325 (13)
Effective crowd anomaly detection through spatio-temporal texture analysis
Abnormal crowd behaviors in high density situations can pose great danger to public safety. Despite the extensive installation of closed-circuit television (CCTV) cameras, it is still difficult to achieve real-time alerts and automated responses from current systems. Two major breakthroughs have been reported in this research. Firstly, a spatial-temporal texture extraction algorithm is developed. This algorithm is able to effectively extract video textures with abundant crowd motion details. It is through adopting Gabor-filtered textures with the highest information entropy values. Secondly, a novel scheme for defining crowd motion patterns (signatures) is devised to identify abnormal behaviors in the crowd by employing an enhanced gray level co-occurrence matrix model. In the experiments, various classic classifiers are utilized to benchmark the performance of the proposed method. The results obtained exhibit detection and accuracy rates which are, overall, superior to other techniques
Quark masses and low energy constants in the continuum from the tadpole improved clover ensembles
We present the light-flavor quark masses and low energy constants using the
2+1 flavor full-QCD ensembles with stout smeared clover fermion action and
Symanzik gauge actions. Both the fermion and gauge actions are tadpole improved
self-consistently. The simulations are performed on 11 ensembles at 3 lattice
spacings fm, 4 spatial sizes fm, 7 pion
masses MeV, and several values of the strange quark mass.
The quark mass is defined through the partially conserved axial current (PCAC)
relation and renormalized to 2 GeV through the
intermediate regularization independent momentum subtraction (RI/MOM) scheme.
The systematic uncertainty of using the symmetric momentum subtraction (SMOM)
scheme is also included. Eventually, we predict MeV,
MeV, and MeV with the systematic
uncertainties from lattice spacing determination, continuum extrapolation and
renormalization constant included. We also obtain the chiral condensate
MeV and the pion decay constant MeV in the chiral limit, and the next-to-leading order low energy
constants and .Comment: Version accepted by PRD. 7 pages, 4 figures, with more details in the
appendi
TMRT observations of 26 pulsars at 8.6 GHz
Integrated pulse profiles at 8.6~GHz obtained with the Shanghai Tian Ma Radio
Telescope (TMRT) are presented for a sample of 26 pulsars. Mean flux densities
and pulse width parameters of these pulsars are estimated. For eleven pulsars
these are the first high-frequency observations and for a further four, our
observations have a better signal-to-noise ratio than previous observations.
For one (PSR J0742-2822) the 8.6~GHz profiles differs from previously observed
profiles. A comparison of 19 profiles with those at other frequencies shows
that in nine cases the separation between the outmost leading and trailing
components decreases with frequency, roughly in agreement with
radius-to-frequency mapping, whereas in the other ten the separation is nearly
constant. Different spectral indices of profile components lead to the
variation of integrated pulse profile shapes with frequency. In seven pulsars
with multi-component profiles, the spectral indices of the central components
are steeper than those of the outer components. For the 12 pulsars with
multi-component profiles in the high-frequency sample, we estimate the core
width using gaussian fitting and discuss the width-period relationship.Comment: 33 pages, 49 figures, 5 Tables; accepted by Ap
Enterovirus 71 viral capsid protein linear epitopes: Identification and characterization
Background: To characterize the human humoral immune response against enterovirus 71 (EV71) infection and map human epitopes on the viral capsid proteins. Methods: A series of 256 peptides spanning the capsid proteins (VP1, VP2, VP3) of BJ08 strain (genomic C4) were synthesized. An indirect enzyme-linked immunosorbent assay (ELISA) was carried out to detect anti-EV71 IgM and IgG in sera of infected children in acute or recovery phase. The partially overlapped peptides contained 12 amino acids and were coated in the plate as antigen (0.1 μg/μl). Sera from rabbits immunized with inactivated BJ08 virus were also used to screen the peptide panel. Results: A total of 10 human anti-EV71 IgM epitopes (vp1-14 in VP1; vp2-6, 21, 40 and 50 in VP2 and vp3-10, 12, 15, 24 and 75 in VP3) were identified in acute phase sera. In contrast, only one anti-EV71 IgG epitope in VP1 (vp1-15) was identified in sera of recovery stage. Four rabbit anti-EV71 IgG epitopes (vp1-14, 31, 54 and 71) were identified and mapped to VP1. Conclusion: These data suggested that human IgM epitopes were mainly mapped to VP2 and VP3 with multiepitope responses occurred at acute infection, while the only IgG epitope located on protein VP1 was activated in recovery phase sera. The dynamic changes of humoral immune response at different stages of infection may have public health significance in evaluation of EV71 vaccine immunogenicity and the clinical application of diagnostic reagents
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