4,000 research outputs found
Deterministic Transformations of Multipartite Entangled States with Tensor Rank 2
Transformations involving only local operations assisted with classical
communication are investigated for multipartite entangled pure states having
tensor rank 2. All necessary and sufficient conditions for the possibility of
deterministically converting truly multipartite, rank-2 states into each other
are given. Furthermore, a chain of local operations that successfully achieves
the transformation has been identified for all allowed transformations. The
identified chains have two nice features: (1) each party needs to carry out at
most one local operation and (2) all of these local operations are also
deterministic transformations by themselves. Finally, it is found that there
are disjoint classes of states, all of which can be identified by a single real
parameter, which remain invariant under deterministic transformations.Comment: 27 pages, 1 figure; added new references and improved the
presentatio
The Chinese New Middle Class and Green NGOs in South China: Vanguards of Guanxi (Connections)-Seeking, Laggards in Promoting Social Causes?
By examining the emerging Chinese new middle class as well as green non-governmental organisations, this study finds that while the emergence of the Chinese new middle class facilitates the growth of green NGOs, the Chinese new class is not activists or agitators working against the government. Based on in-depth interviews with leaders of green NGOs founded by the Chinese new middle class in Guangdong province, this research examines why green NGOs do not call for or advocate environmental protection It concludes that contrary to conventional wisdom, the Chinese new middle class is a vanguard of guanxi (connections)-seeking, but a laggard in promoting environmental protection and civil-society activism. Green NGOs are principally used as a tool to cultivate social capital in the form of guanxi in order to promote personal material interests
Hydrodynamic Description of Granular Convection
We present a hydrodynamic model that captures the essence of granular
dynamics in a vibrating bed. We carry out the linear stability analysis and
uncover the instability mechanism that leads to the appearance of the
convective rolls via a supercritical bifurcation of a bouncing solution. We
also explicitly determine the onset of convection as a function of control
parameters and confirm our picture by numerical simulations of the continuum
equations.Comment: 14 pages, RevTex 11pages + 3 pages figures (Type csh
Fluctuations of the number of participants and binary collisions in AA interactions at fixed centrality in the Glauber approach
In the framework of the classical Glauber approach, the analytical
expressions for the variance of the number of wounded nucleons and binary
collisions in AA interactions at a given centrality are presented. Along with
the optical approximation term, they contain additional contact terms arising
only in the case of nucleus-nucleus collisions. The magnitude of the additional
contributions, e.g., for PbPb collisions at SPS energies, is larger than the
contribution of the optical approximation at some values of the impact
parameter. The sum of the additional contributions is in good agreement with
the results of independent Monte Carlo simulations of this process. Due to
these additional terms, the variance of the total number of participants for
peripheral PbPb collisions and the variance of the number of collisions at all
values of the impact parameter exceed several multiples of the Poisson
variances. The correlator between the numbers of participants in colliding
nuclei at fixed centrality is also analytically calculated.Comment: updated version; as published by Phys. Rev.
Genetic study of congenital bile-duct dilatation identifies de novo and inherited variants in functionally related genes
Background:
Congenital dilatation of the bile-duct (CDD) is a rare, mostly sporadic, disorder that results in bile retention with severe associated complications. CDD affects mainly Asians. To our knowledge, no genetic study has ever been conducted.
Methods:
We aim to identify genetic risk factors by a “trio-based” exome-sequencing approach, whereby 31 CDD probands and their unaffected parents were exome-sequenced. Seven-hundred controls from the local population were used to detect gene-sets significantly enriched with rare variants in CDD patients.
Results:
Twenty-one predicted damaging de novo variants (DNVs; 4 protein truncating and 17 missense) were identified in several evolutionarily constrained genes (p < 0.01). Six genes carrying DNVs were associated with human developmental disorders involving epithelial, connective or bone morphologies (PXDN, RTEL1, ANKRD11, MAP2K1, CYLD, ACAN) and four linked with cholangio- and hepatocellular carcinomas (PIK3CA, TLN1 CYLD, MAP2K1). Importantly, CDD patients have an excess of DNVs in cancer-related genes (p < 0.025). Thirteen genes were recurrently mutated at different sites, forming compound heterozygotes or functionally related complexes within patients.
Conclusions:
Our data supports a strong genetic basis for CDD and show that CDD is not only genetically heterogeneous but also non-monogenic, requiring mutations in more than one genes for the disease to develop. The data is consistent with the rarity and sporadic presentation of CDD
Camera for QUasars in EArly uNiverse (CQUEAN)
We describe the overall characteristics and the performance of an optical CCD
camera system, Camera for QUasars in EArly uNiverse (CQUEAN), which is being
used at the 2.1 m Otto Struve Telescope of the McDonald Observatory since 2010
August. CQUEAN was developed for follow-up imaging observations of red sources
such as high redshift quasar candidates (z >= 5), Gamma Ray Bursts, brown
dwarfs, and young stellar objects. For efficient observations of the red
objects, CQUEAN has a science camera with a deep depletion CCD chip which
boasts a higher quantum efficiency at 0.7 - 1.1 um than conventional CCD chips.
The camera was developed in a short time scale (~ one year), and has been
working reliably. By employing an auto-guiding system and a focal reducer to
enhance the field of view on the classical Cassegrain focus, we achieve a
stable guiding in 20 minute exposures, an imaging quality with FWHM >= 0.6"
over the whole field (4.8' * 4.8'), and a limiting magnitude of z = 23.4 AB mag
at 5-sigma with one hour total integration time.Comment: Accepted for publication in PASP. 26 pages including 5 tables and 24
figure
Status and overview of development of the Silicon Pixel Detector for the PHENIX experiment at the BNL RHIC
We have developed a silicon pixel detector to enhance the physics
capabilities of the PHENIX experiment. This detector, consisting of two layers
of sensors, will be installed around the beam pipe at the collision point and
covers a pseudo-rapidity of | \eta | < 1.2 and an azimuth angle of | \phi | ~
2{\pi}. The detector uses 200 um thick silicon sensors and readout chips
developed for the ALICE experiment. In order to meet the PHENIX DAQ readout
requirements, it is necessary to read out 4 readout chips in parallel. The
physics goals of PHENIX require that radiation thickness of the detector be
minimized. To meet these criteria, the detector has been designed and
developed. In this paper, we report the current status of the development,
especially the development of the low-mass readout bus and the front-end
readout electronics.Comment: 9 pages, 8 figures and 1 table in DOCX (Word 2007); PIXEL 2008
workshop proceedings, will be published in the Proceedings Section of
JINST(Journal of Instrumentation
Color Reflection Invariance and Monopole Condensation in QCD
We review the quantum instability of the Savvidy-Nielsen-Olesen (SNO) vacuum
of the one-loop effective action of SU(2) QCD, and point out a critical defect
in the calculation of the functional determinant of the gluon loop in the SNO
effective action. We prove that the gauge invariance, in particular the color
reflection invariance, exclude the unstable tachyonic modes from the gluon loop
integral. This guarantees the stability of the magnetic condensation in QCD.Comment: 28 pages, 3 figures, JHEP styl
Unparticle Physics in Single Top Signals
We study the single production of top quarks in and
collisions in the context of unparticle physics through the Flavor Violating
(FV) unparticle vertices and compute the total cross sections for single top
production as functions of scale dimension d_{\U}. We find that among all,
LHC is the most promising facility to probe the unparticle physics via single
top quark production processes.Comment: 14 pages, 10 figure
Influences of dynamical disruptions on the evolution of pulsars in globular clusters
By comparing the physical properties of pulsars hosted by core-collapsed
(CCed) and non-core-collapsed (Non-CCed) globular clusters (GCs), we find that
pulsars in CCed GCs rotate significantly slower than their counterparts in
Non-CCed GCs. Additionally, radio luminosities at 1.4 GHz in CCed GCs are
higher. These findings are consistent with the scenario that dynamical
interactions in GCs can interrupt angular momentum transfer processes and
surface magnetic field decay during the recycling phase. Our results suggest
that such effects in CCed GCs are stronger due to more frequent disruptions of
compact binaries. This is further supported by the observation that both
estimated disruption rates and the fraction of isolated pulsars are
predominantly higher in CCed GCs.Comment: 9 pages, 8 figures, 3 tables, Accepted in MNRA
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