1,964 research outputs found
Optimal Quantization in Energy-Constrained Sensor Networks under Imperfect Transmission
This paper addresses the optimization of quantization at local sensors under strict energy constraint and imperfect transmission to improve the reconstruction performance at the fusion center in the wireless sensor networks (WSNs). We present optimized quantization scheme including the optimal quantization bit rate and the optimal transmission power allocation among quantization bits for BPSK signal and binary orthogonal signal with envelope detection, respectively. The optimization of the quantization is formulated as a convex problem and the optimal solution is derived analytically in both cases. Simulation results demonstrate the effectiveness of our proposed quantization schemes
Phenomenology of a Low-Energy Neutrino Factory and Related Experiments
The discovery of neutrino oscillations is one of the most important in the recent history of particle physics, being the first evidence of physics beyond the Standard Model. We describe the theoretical framework of the neutrino oscillation model, motivate the necessity for a new generation of neutrino oscillation experiments and study the phenomenological factors which influence the design of these experiments.
We perform the first detailed study of a European super-beam setup using the CERN to Pyhasalmi baseline of 2285 km, analysing the physics reach of this setup with a 100 kiloton liquid argon detector and comparing its performance to that of a 50 kiloton liquid scintillator detector and a 440 kiloton water Cerenkov detector. The liquid argon and liquid scintillator detectors are found to perform best, providing sensitivity to theta_{13}, delta and the mass hierarchy for sin^{2}2theta_{13} > 10^{-2}.
A potential successor to super-beam experiments is a neutrino factory. We study a low-energy neutrino factory, a setup which has so far not been analysed in any detail, performing optimisation studies and an analysis of its sensitivity to oscillation parameters and non-standard matter interactions. We show that for sin^{2}2theta_{13} > 4x10^{-3}, a low-energy neutrino factory using a 20 kiloton totally active scintillating detector has 100% CP coverage for hierarchy sensitivity and theta_{13} discovery, and has greater sensitivity to CP violation than the high-energy neutrino factory. We consider the novel concept of including the `platinum channels' in addition to the `golden channels', showing that this is a powerful way of resolving the degeneracies between the oscillation and non-standard parameters. This enhances the sensitivity, such that the low-energy neutrino factory can put upper bounds \gtrsim10^{-2} on the non-standard interaction parameters epsilon_{e\mu} and epsilon_{e\tau}
On the improvement of the low energy neutrino factory
The low energy neutrino factory has been proposed as a very sensitive setup
for future searches for CP violation and matter effects. Here we study how its
performance is affected when the experimental specifications of the setup are
varied. Most notably, we have considered the addition of the 'platinum' nu_{mu}
-> nu_{e} channel. We find that, whilst theoretically the extra channel
provides very useful complementary information and helps to lift degeneracies,
its practical usefulness is lost when considering realistic background levels.
Conversely, an increase in statistics in the 'golden' nu_{e} -> nu_{mu} channel
and, to some extent, an improvement in the energy resolution, lead to an
important increase in the performance of the facility, given the rich energy
dependence of the 'golden' channel at these energies. We show that a low energy
neutrino factory with a baseline of 1300 km, muon energy of 4.5 GeV, and either
a 20 kton totally active scintillating detector or 100 kton liquid argon
detector, can have outstanding sensitivity to the neutrino oscillation
parameters theta13, delta and the mass hierarchy. For our estimated exposure of
2.8 x 10^{23} kton x decays per muon polarity, the low energy neutrino factory
has sensitivity to theta13 and delta for sin^{2}(2theta13) > 10^{-4} and to the
mass hierarchy for sin^{2}(2theta13) > 10^{-3}.Comment: 13 pages, 8 eps figures. Version published in PRD - experimental
section with preliminary results removed, abstract and conclusions re-written
accordingly, title changed, author list amended
An incremental approach to unravel the neutrino mass hierarchy and CP violation with a long-baseline Superbeam for large
Recent data from long-baseline neutrino oscillation experiments have provided
new information on \theta_{13}, hinting that 0.01\lesssim sin^2 2\theta_{13}
\lesssim 0.1 at 2 sigma C.L. Confirmation of this result with high significance
will have a crucial impact on the optimization of the future long-baseline
oscillation experiments designed to probe the neutrino mass ordering and
leptonic CP violation. In this context, we expound in detail the physics reach
of an experimental setup where neutrinos produced in a conventional wide-band
beam facility at CERN are observed in a proposed Giant Liquid Argon detector at
the Pyh\"asalmi mine, at a distance of 2290 km. This particular setup would
have unprecedented sensitivity to the mass ordering and CP violation in the
light of large \theta_{13}. With a 10 to 20 kt `pilot' detector and just a few
years of neutrino beam running, the mass hierarchy could be determined,
irrespective of the true values of \delta_{CP} and the mass hierarchy, at 3
sigma (5 sigma) C.L. if sin^2 2\theta_{13}(true) = 0.05 (0.1). With the same
exposure, we start to have 3 sigma sensitivity to CP violation if sin^2
2\theta_{13}(true) > 0.05, in particular testing maximally CP-violating
scenarios at a high C.L. After optimizing the neutrino and anti-neutrino
running fractions, we study the performance of the setup as a function of the
exposure, identifying three milestones to have roughly 30%, 50% and 70%
coverage in \delta_{CP}(true) for 3 sigma CP violation discovery. For
comparison, we also study the CERN to Slanic baseline of 1540 km. This work
demonstrates that an incremental program, staged in terms of the exposure, can
achieve the desired physics goals within a realistically feasible timescale,
and produce significant new results at each stage.Comment: 30 pages, 32 pdf figures, 6 table
Constraint-Based Heuristic On-line Test Generation from Non-deterministic I/O EFSMs
We are investigating on-line model-based test generation from
non-deterministic output-observable Input/Output Extended Finite State Machine
(I/O EFSM) models of Systems Under Test (SUTs). We propose a novel
constraint-based heuristic approach (Heuristic Reactive Planning Tester (xRPT))
for on-line conformance testing non-deterministic SUTs. An indicative feature
of xRPT is the capability of making reasonable decisions for achieving the test
goals in the on-line testing process by using the results of off-line bounded
static reachability analysis based on the SUT model and test goal
specification. We present xRPT in detail and make performance comparison with
other existing search strategies and approaches on examples with varying
complexity.Comment: In Proceedings MBT 2012, arXiv:1202.582
Novel frataxin isoforms may contribute to the pathological mechanism of friedreich ataxia
This is an open-access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.Friedreich ataxia (FRDA) is an inherited neurodegenerative disease caused by frataxin (FXN) deficiency. The nervous system and heart are the most severely affected tissues. However, highly mitochondria-dependent tissues, such as kidney and liver, are not obviously affected, although the abundance of FXN is normally high in these tissues. In this study we have revealed two novel FXN isoforms (II and III), which are specifically expressed in affected cerebellum and heart tissues, respectively, and are functional in vitro and in vivo. Increasing the abundance of the heart-specific isoform III significantly increased the mitochondrial aconitase activity, while over-expression of the cerebellum-specific isoform II protected against oxidative damage of Fe-S cluster-containing aconitase. Further, we observed that the protein level of isoform III decreased in FRDA patient heart, while the mRNA level of isoform II decreased more in FRDA patient cerebellum compared to total FXN mRNA. Our novel findings are highly relevant to understanding the mechanism of tissue-specific pathology in FRDA.This work was supported by the intramural program of the National Institute of Child Health and Human Development, National Institutes of Health, and in part by Friedreich ataxia research association; by the National Nature Science Foundation of China (NSFC) (No. 31071085), by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry, and by State Key Laboratory of Pharmaceutical Biotechnology (No. ZZYJ-SN-201006). Zvonimir Marelja was supported by a grant from the Studienstiftung des Deutschen Volkes and by Deutscher Akademischer Austauschdienst scholarship. Additional support was obtained from the Deutsche Forschungsgemeinschaft Grant SL1171/5-3
Monoclonal Antibodies Capable of Binding SARS-CoV-2 Spike Protein Receptor Binding Motif Specifically Prevent GM-CSF Induction.
A severe acute respiratory syndrome (SARS)-like coronavirus (SARS-CoV-2) has recently caused a pandemic COVID-19 disease that infected more than 25.6 million and killed 852,000 people worldwide. Like the SARS-CoV, SARS-CoV-2 also employs a receptor-binding motif (RBM) of its envelope spike protein for binding the host angiotensin-converting enzyme 2 (ACE2) to gain viral entry. Currently, extensive efforts are being made to produce vaccines against a surface fragment of a SARS-CoV-2, such as the spike protein, in order to boost protective antibody responses. It was previously unknown how spike protein-targeting antibodies would affect innate inflammatory responses to SARS-CoV-2 infections. Here we generated a highly purified recombinant protein corresponding to the RBM of SARS-CoV-2, and used it to screen for cross-reactive monoclonal antibodies (mAbs). We found two RBM-binding mAbs that competitively inhibited its interaction with human ACE2, and specifically blocked the RBM-induced GM-CSF secretion in both human monocyte and murine macrophage cultures. Our findings have suggested a possible strategy to prevent SARS-CoV-2-elicited cytokine storm , and provided a potentially useful criteria for future assessment of innate immune-modulating properties of various SARS-CoV-2 vaccines. One Sentence Summary: RBM-binding Antibodies Inhibit GM-CSF Induction
- …