Decoherence Patterns of Topological Qubits from Majorana Modes

We investigate the decoherence patterns of topological qubits in contact with the environment by a novel way of deriving the open system dynamics other than the Feynman-Vernon. Each topological qubit is made of two Majorana modes of a 1D Kitaev's chain. These two Majorana modes interact with the environment in an incoherent way which yields peculiar decoherence patterns of the topological qubit. More specifically, we consider the open system dynamics of the topological qubits which are weakly coupled to the fermionic/bosonic Ohmic-like environments. We find atypical patterns of quantum decoherence. In contrast to the cases of non-topological qubits for which they always decohere completely in all Ohmic-like environments, the topological qubits decohere completely in the Ohmic and sub-Ohmic environments but not in the super-Ohmic ones. Moreover, we find that the fermion parities of the topological qubits though cannot prevent the qubit states from decoherence in the sub-Ohmic environments, can prevent from thermalization turning into Gibbs state. We also study the cases in which each Majorana mode can couple to different Ohmic-like environments and the time dependence of concurrence for two topological qubits.Comment: 20 pages, 10 figures; v2 ref updated to match NJP versio

Fuzzy rule based multiwavelet ECG signal denoising

Since different multiwavelets, pre- and post-filters have different impulse responses and frequency responses, different multiwavelets, pre- and post-filters should be selected and applied at different noise levels for signal denoising if signals are corrupted by additive white Gaussian noises. In this paper, some fuzzy rules are formulated for integrating different multiwavelets, pre- and post-filters together so that expert knowledge on employing different multiwavelets, pre- and post-filters at different noise levels on denoising performances is exploited. When an ECG signal is received, the noise level is first estimated. Then, based on the estimated noise level and our proposed fuzzy rules, different multiwavelets, pre- and post-filters are integrated together. A hard thresholding is applied on the multiwavelet coefficients. According to extensive numerical computer simulations, our proposed fuzzy rule based multiwavelet denoising algorithm outperforms traditional multiwavelet denoising algorithms by 30%

A Multiple-Precision Study on the Modified Collocation Trefftz Method

Recently, Liu (CMES 21(2007), 53) developed the modified collocation Trefftz method (MCTM) by setting a characteristic length slightly larger than the maximum radius of the computational domain. In this study, we find that the range of admissible characteristic length can be significantly enlarged if the LU decomposition is applied for solving the resulted dense unsymmetric matrix. Furthermore, we discover a range formula for admissible characteristic length, in which the number of the T-complete functions, the shape of the computation domain, and the exponent bits of the involved floating-point arithmetic have been taken into consideration. In order to validate the prescribed formula for different exponent bits, the multiple precision floating-point reliable (MPFR) library is used. In addition, we find that the MCTM is a numerical method of exponential convergence. In other words, increasing the numbers of the T-complete functions can reduce the logarithmic error proportionally till the precision limit, which can be set up for the MPFR library. Numerical experiments are carried out to demonstrate that the proposed MCTM with the LU decomposition can solve the Laplace equation stably and accurately, even for a Cauchy problem. A multiple-precision comparison between the MCTM and the method of fundamental solution is also preformed

Rapid detection of BRCA1/2 recurrent mutations in Chinese breast and ovarian cancer patients with multiplex SNaPshot genotyping panels.

BRCA1/2 mutations are significant risk factors for hereditary breast and ovarian cancer (HBOC), its mutation frequency in HBOC of Chinese ethnicity is around 9%, in which nearly half are recurrent mutations. In Hong Kong and China, genetic testing and counseling are not as common as in the West. To reduce the barrier of testing, a multiplex SNaPshot genotyping panel that targeted 25 Chinese BRCA1/2 mutation hotspots was developed, and its feasibility was evaluated in a local cohort of 441 breast and 155 ovarian cancer patients. For those who tested negative, they were then subjected to full-gene testing with next-generation sequencing (NGS). BRCA mutation prevalence in this cohort was 8.05% and the yield of the recurrent panel was 3.52%, identifying over 40% of the mutation carriers. Moreover, from 79 Chinese breast cancer cases recruited overseas, 2 recurrent mutations and one novel BRCA2 mutation were detected by the panel and NGS respectively. The developed genotyping panel showed to be an easy-to-perform and more affordable testing tool that can provide important contributions to improve the healthcare of Chinese women with cancer as well as family members that harbor high risk mutations for HBOC

The use of corticosteroids in patients with COPD or asthma does not decrease lung squamous cell carcinoma

BACKGROUND: Asthma and COPD (chronic obstructive pulmonary disease) lead to persistent airway inflammation and are associated with lung cancer. The objective of the study was to assess the relationship between inhaled (ICS) and oral corticosteroid (OCS) use, and risk of lung squamous cell carcinoma (SqCC). METHODS: This study was a nested case–control study. Patients with newly diagnosed asthma or COPD between 2003 and 2010 were identified from the National Health Insurance Database. Cases were defined as patients diagnosed with SqCC after enrollment. For each case, four control individuals who were randomly matched for sex and age and date diagnosis of asthma or COPD were selected. RESULTS: From the 1,672,455 eligible participants, 793 patients with SqCC were matched with 3,172 controls. The odds ratios (ORs) of SqCC in men who received high and low-dose ICS were 2.18 (95 %CI, 1.56–3.04) and 1.77 (1.22–2.57), respectively. Similarly, the ORs were 1.46 (95 %CI, 1.16–1.84) and 1.55 (95 %CI, 1.22–1.98) for men who were placed on low and high dose OCS. However, there was no significant association between cumulative ICS and/or OCS and risk of SqCC in women. Recent dose increase in corticosteriod was significantly associated with risk of SqCC. Specifically, among men, the ORs for SqCC were 8.08 (95 %CI, 3.22–20.30) for high-dose ICS + OCS, 4.49 (95 % CI, 2.05–9.85) for high-dose ICS, and 3.54 (95 % CI, 2.50–5.01) for high-dose OCS treatments, respectively. The OR for SqCC in women who received high-dose OCS was 6.72 (95 %CI, 2.69–16.81). CONCLUSION: Corticosteroid use did not decrease SqCC in patients with asthma or COPD. Recent dose increase in corticosteroids was associated with SqCC

Assessing the carcinogenic potential of low-dose exposures to chemical mixtures in the environment: the challenge ahead.

Lifestyle factors are responsible for a considerable portion of cancer incidence worldwide, but credible estimates from the World Health Organization and the International Agency for Research on Cancer (IARC) suggest that the fraction of cancers attributable to toxic environmental exposures is between 7% and 19%. To explore the hypothesis that low-dose exposures to mixtures of chemicals in the environment may be combining to contribute to environmental carcinogenesis, we reviewed 11 hallmark phenotypes of cancer, multiple priority target sites for disruption in each area and prototypical chemical disruptors for all targets, this included dose-response characterizations, evidence of low-dose effects and cross-hallmark effects for all targets and chemicals. In total, 85 examples of chemicals were reviewed for actions on key pathways/mechanisms related to carcinogenesis. Only 15% (13/85) were found to have evidence of a dose-response threshold, whereas 59% (50/85) exerted low-dose effects. No dose-response information was found for the remaining 26% (22/85). Our analysis suggests that the cumulative effects of individual (non-carcinogenic) chemicals acting on different pathways, and a variety of related systems, organs, tissues and cells could plausibly conspire to produce carcinogenic synergies. Additional basic research on carcinogenesis and research focused on low-dose effects of chemical mixtures needs to be rigorously pursued before the merits of this hypothesis can be further advanced. However, the structure of the World Health Organization International Programme on Chemical Safety 'Mode of Action' framework should be revisited as it has inherent weaknesses that are not fully aligned with our current understanding of cancer biology

Changes in cup inclination impact impingement-free hip motion after canine total hip replacement.

ObjectiveTo evaluate the effects of changes in prosthetic cup inclination on impingement-free hip abduction, adduction, and internal and external rotation after simulated total hip replacement in dogs.MethodsFor 6 dogs, CT scans of the hip region were used to prepare 3-D surface models of cementless total hip replacement. For each dog, 15 models with cup inclination ranging from -35° to 35° in 5° increments were prepared using computer-aided design software. For each implant position, impingement-free hip motion in abduction, adduction, and internal and external rotation was evaluated using a custom-built computer program for hip flexion/extension angles ranging from 50° to 160° in 5° increments.ResultsA total of 7,920 computer simulations were conducted. Increased cup inclination led to decreased impingement-free abduction in hip extension and increased abduction in hip flexion. Decreased cup inclination led to decreased abduction at all hip angles. Maximal inclination led to increased external rotation in full hip extension, and maximal declination led to increased internal rotation and adduction in full hip flexion.ConclusionsDuring total hip replacement, changes in cup inclination influence hip abduction and, to a lesser extent, internal rotation and adduction in flexion and external rotation in extension. The assessment of intraoperative impingement should include abduction, extension combined with external rotation, and flexion combined with adduction and internal rotation.Clinical relevanceThe inclination of a truncated cup influences impingement-free abduction. Inclination should be controlled during cup insertion to keep the prosthetic neck in the central portion of the cup truncation during abduction

Fuzzy multiwavelet denoising on an ECG signal

Since different multiwavelets, pre- and post-filters have different impulse and frequency responses characteristics, different multiwavelets, pre- and post-filters should be selected, integrated and applied at different noise levels if a signal is corrupted by an additive white Gaussian noise (AWGN). In this letter, some fuzzy rules on selecting and integrating different multiwavelets, pre- and post-filters together are proposed. These fuzzy rules are setup based on the training results of the denoising performances of applying different multiwavelets, pre- and post-filters at different noise levels. When a new electrocardiogram (ECG) signal is applied, the appropriate multiwavelets, pre- and post-filters are selected and integrated based on fuzzy rules and the noise level of the signal. A hard thresholding is applied on the multiwavelet coefficients. According to an extensive simulation, we found that our proposed fuzzy rule-based multiwavelet denoising algorithm achieves 30% improvement compared to the traditional multiwavelet denoising algorithms

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal