8,530 research outputs found
Well-formed Properties of Heterogeneous Quorum Systems
Byzantine quorum systems provide higher throughput than proofof-work and
incur modest energy consumption. Further, their modern incarnations incorporate
personalized and heterogeneous trust. Thus, they are emerging as an appealing
candidate for global financial infrastructure. However, since their quorums are
not uniform across processes anymore, the properties that they should maintain
to support abstractions such as reliable broadcast and consensus are not
well-understood. In this paper, we first see a general model of heterogeneous
quorum systems where each participant can declare its own quorums, and capture
their properties. It has been shown that the two properties quorum intersection
and availability are necessary. In this paper, we prove that they are not
sufficient. We then define the notion of quorum inclusion, and show that the
three conditions together are sufficient: we present reliable broadcast and
consensus protocols, and prove their correctness for quorum systems that
provide the three properties
Probing nuclear symmetry energy at high densities using pion, kaon, eta and photon productions in heavy-ion collisions
The high-density behavior of nuclear symmetry energy is among the most
uncertain properties of dense neutron-rich matter. Its accurate determination
has significant ramifications in understanding not only the reaction dynamics
of heavy-ion reactions especially those induced by radioactive beams but also
many interesting phenomena in astrophysics, such as the explosion mechanism of
supernova and the properties of neutron stars. The heavy-ion physics community
has devoted much effort during the last few years to constrain the high-density
symmetry using various probes. In particular, the pion-/pion+ ratio has been
most extensively studied both theoretically and experimentally. All models have
consistently predicted qualitatively that the pion-/pion+ ratio is a sensitive
probe of the high-density symmetry energy especially with beam energies near
the pion production threshold. However, the predicted values of the pion-/pion+
ratio are still quite model dependent mostly because of the complexity of
modeling pion production and reabsorption dynamics in heavy-ion collisions,
leading to currently still controversial conclusions regarding the high-density
behavior of nuclear symmetry energy from comparing various model calculations
with available experimental data. As more pion-/pion+ data become available and
a deeper understanding about the pion dynamics in heavy-ion reactions is
obtained, more penetrating probes, such as the kaon+/kaon0 ratio, eta meson and
high energy photons are also being investigated or planned at several
facilities. Here, we review some of our recent contributions to the community
effort of constraining the high-density behavior of nuclear symmetry energy in
heavy-ion collisions. In addition, the status of some worldwide experiments for
studying the high-density symmetry energy, including the HIRFL-CSR external
target experiment (CEE) are briefly introduced.Comment: 10 pages, 10 figures, Contribution to the Topical Issue on Nuclear
Symmetry Energy in EPJA Special Volum
Experimental realization of a broadband illusion optics device
We experimentally demonstrate the first metamaterial "illusion optics" device
- an "invisible gateway" by using a transmission-line medium. The device
contains an open channel that can block electromagnetic waves at a particular
frequency range. We also demonstrate that such a device can work in a broad
frequency range.Comment: 9 pages, 5 figure
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Neoadjuvant sipuleucel-T induces both Th1 activation and immune regulation in localized prostate cancer.
Sipuleucel-T is the only FDA-approved immunotherapy for metastatic castration-resistant prostate cancer. The mechanism by which this treatment improves survival is not fully understood. We have previously shown that this treatment can induce the recruitment of CD4 and CD8 T cells to the tumor microenvironment. In this study, we examined the functional state of these T cells through gene expression profiling. We found that the magnitude of T cell signatures correlated with the frequency of T cells as measured by immunohistochemistry. Sipuleucel-T treatment was associated with increased expression of Th1-associated genes, but not Th2-, Th17 - or Treg-associated genes. Post-treatment tumor tissues with high CD8+T cell infiltration was associated with high levels of CXCL10 expression. On in situ hybridization, CXCL10+ cells colocalized with CD8+T cells in post-treatment prostatectomy tumor tissue. Neoadjuvant sipuleucel-T was also associated with upregulation of immune inhibitory checkpoints, including CTLA4 and TIGIT, and downregulation of the immune activation marker, dipeptidylpeptidase, DPP4. Treatment-associated declines in serum PSA were correlated with induction of Th1 response. In contrast, rises in serum PSA while on treatment were associated with the induction of multiple immune checkpoints, including CTLA4, CEACAM6 and TIGIT. This could represent adaptive immune resistance mechanisms induced by treatment. Taken together, neoadjuvant sipuleucel-T can induce both a Th1 response and negative immune regulation in the prostate cancer microenvironment
Out-of-time-order correlator, many-body quantum chaos, light-like generators, and singular values
We study out-of-time-order correlators (OTOCs) of local operators in
spatial-temporal invariant or random quantum circuits using light-like
generators (LLG) -- many-body operators that exist in and act along the
light-like directions. We demonstrate that the OTOC can be approximated by the
leading singular value of the LLG, which, for the case of generic many-body
chaotic circuits, is increasingly accurate as the size of the LLG, ,
increases. We analytically show that the OTOC has a decay with a universal form
in the light-like direction near the causal light cone, as dictated by the
sub-leading eigenvalues of LLG, , and their degeneracies. Further, we
analytically derive and numerically verify that the sub-leading eigenvalues of
LLG of any size can be accessibly extracted from those of LLG of the smallest
size, i.e., . Using symmetries and recursive structures of
LLG, we propose two conjectures on the universal aspects of generic many-body
quantum chaotic circuits, one on the algebraic degeneracy of eigenvalues of
LLG, and another on the geometric degeneracy of the sub-leading eigenvalues of
LLG. As corollaries of the conjectures, we analytically derive the asymptotic
form of the leading singular state, which in turn allows us to postulate and
efficiently compute a product-state variational ansatz away from the asymptotic
limit. We numerically test the claims with four generic circuit models of
many-body quantum chaos, and contrast these statements against the cases of a
dual unitary system and an integrable system.Comment: 6 + 15 pages, 3 + 11 figures. Comments are welcome. Updated on
2023-10-1
A targeted gene panel that covers coding, non-coding and short tandem repeat regions improves the diagnosis of patients with neurodegenerative diseases
Genetic testing for neurodegenerative diseases (NDs) is highly challenging because of genetic heterogeneity and overlapping manifestations. Targeted-gene panels (TGPs), coupled with next-generation sequencing (NGS), can facilitate the profiling of a large repertoire of ND-related genes. Due to the technical limitations inherent in NGS and TGPs, short tandem repeat (STR) variations are often ignored. However, STR expansions are known to cause such NDs as Huntington\u27s disease and spinocerebellar ataxias type 3 (SCA3). Here, we studied the clinical utility of a custom-made TGP that targets 199 NDs and 311 ND-associated genes on 118 undiagnosed patients. At least one known or likely pathogenic variation was found in 54 patients; 27 patients demonstrated clinical profiles that matched the variants; and 16 patients whose original diagnosis were refined. A high concordance of variant calling were observed when comparing the results from TGP and whole-exome sequencing of four patients. Our in-house STR detection algorithm has reached a specificity of 0.88 and a sensitivity of 0.82 in our SCA3 cohort. This study also uncovered a trove of novel and recurrent variants that may enrich the repertoire of ND-related genetic markers. We propose that a combined comprehensive TGPs-bioinformatics pipeline can improve the clinical diagnosis of NDs
Circumstantial evidence for a soft nuclear symmetry energy at supra-saturation densities
Within an isospin- and momentum-dependent hadronic transport model it is
shown that the recent FOPI data on the ratio in central heavy-ion
collisions at SIS/GSI energies (Willy Reisdorf {\it et al.}, NPA {\bf 781}, 459
(2007)) provide circumstantial evidence suggesting a rather soft nuclear
symmetry energy \esym at compared to the
Akmal-Pandharipande-Ravenhall prediction. Some astrophysical implications and
the need for further experimental confirmations are discussed.Comment: Version to appear in Phys. Rev. Let
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