Random-coupled Neural Network

Improving the efficiency of current neural networks and modeling them in biological neural systems have become popular research directions in recent years. Pulse-coupled neural network (PCNN) is a well applicated model for imitating the computation characteristics of the human brain in computer vision and neural network fields. However, differences between the PCNN and biological neural systems remain: limited neural connection, high computational cost, and lack of stochastic property. In this study, random-coupled neural network (RCNN) is proposed. It overcomes these difficulties in PCNN's neuromorphic computing via a random inactivation process. This process randomly closes some neural connections in the RCNN model, realized by the random inactivation weight matrix of link input. This releases the computational burden of PCNN, making it affordable to achieve vast neural connections. Furthermore, the image and video processing mechanisms of RCNN are researched. It encodes constant stimuli as periodic spike trains and periodic stimuli as chaotic spike trains, the same as biological neural information encoding characteristics. Finally, the RCNN is applicated to image segmentation, fusion, and pulse shape discrimination subtasks. It is demonstrated to be robust, efficient, and highly anti-noised, with outstanding performance in all applications mentioned above

Impact of the high-level trigger for detecting long-lived particles at LHCb

Long-lived particles (LLPs) are very challenging to search for with current detectors and computing requirements due to their very displaced vertices. This study evaluates the ability of the trigger algorithms used in the Large Hadron Collider beauty (LHCb) experiment to detect long-lived particles and attempts to adapt them to enhance the sensitivity of this experiment to undiscovered long-lived particles. One of the challenges in the track reconstruction is to deal with the large amount of combinatorics of hits. A dedicated algorithm has been developed to cope with the large data output. When fully implemented, this algorithm would greatly increase the efficiency for any long-lived particle reconstruction in the forward region, for the Standard Model of particle physics and beyond

Observation of New Baryons in the Ξb- π+π- and Ξb0 π+π- Systems

The first observation and study of two new baryonic structures in the final state Ξb0π+π- and the confirmation of the Ξb(6100)- state in the Ξb-π+π- decay mode are reported using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1. In addition, the properties of the known Ξb∗0, Ξb′- and Ξb∗- resonances are measured with improved precision. The new decay mode of the Ξb0 baryon to the Ξc+ π- π+ π- final state is observed and exploited for the first time in these measurements

Test of lepton flavor universality using B0 →D∗-τ+ντ decays with hadronic τ channels

The branching fraction B(B0→D∗-τ+ντ) is measured relative to that of the normalization mode B0→D∗-π+π-π+ using hadronic τ+→π+π-π+(π0)ν¯τ decays in proton-proton collision data at a center-of-mass energy of 13 TeV collected by the LHCb experiment, corresponding to an integrated luminosity of 2 fb-1. The measured ratio is B(B0→D∗-τ+ντ)/B(B0→D∗-π+π-π+)=1.70±0.10-0.10+0.11, where the first uncertainty is statistical and the second is related to systematic effects. Using established branching fractions for the B0→D∗-π+π-π+ and B0→D∗-μ+νμ modes, the lepton universality test R(D∗-)B(B0→D∗-τ+ντ)/B(B0→D∗-μ+νμ) is calculated, R(D∗-)=0.247±0.015±0.015±0.012, where the third uncertainty is due to the uncertainties on the external branching fractions. This result is consistent with the Standard Model prediction and with previous measurements

Search for D∗(2007)0 → μ+μ− in B− → π−μ+μ− decays

The very rare D∗(2007)0→μ+μ- decay is searched for by analysing B-→π-μ+μ- decays. The analysis uses a sample of beauty mesons produced in proton–proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9 \,fb . The signal signature corresponds to simultaneous peaks in the μμ and πμμ invariant masses. No evidence for an excess of events over background is observed and an upper limit is set on the branching fraction of the decay at B(D∗(2007)0→μ+μ-)<2.6×10-8 at 90 % confidence level. This is the first limit on the branching fraction of D∗(2007)0→μ+μ- decays and the most stringent limit on D(2007) decays to leptonic final states. The analysis is the first search for a rare charm-meson decay exploiting production via beauty decays

Gender differential impact of bereavement on health outcomes: evidence from the China Health and Retirement Longitudinal Study, 2011–2015

Background: Bereavement is the experience of an individual following the death of a person of significance to the individual, most often referring to the spouse. Increased morbidity, health care utilization, and mortality are known to be associated with bereavement. Given China’s growing population of older adults, there is a critical need to assess the health consequences of bereavement. Method: We use data from the China Health and Retirement Longitudinal Study to examine the impact of bereavement on mental health and quality of life among a sample of mid- and older-aged adults. We use propensity score matching to construct a matching sample and difference-in-differences method to estimate the impact of bereavement on mental health and self-assessed health. Results: We find bereavement is associated with increased depression symptoms among women (1.542 point or 0.229 standard deviations of Center for Epidemiologic Studies Depression (CES-D) 10 score) but not consistently for men over time. No statistically significant effect of bereavement on self-assessed health is found. Conclusions: Our results show a harmful impact of bereavement on mental health among older women in China and point to the need for a comprehensive policy on survivor benefits in China, particularly for rural older women

Measurement of the mass difference and relative production rate of the ωb- and Ξb- baryons

The mass difference between the ωb- and Ξb- baryons is measured using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9 fb-1, and is found to be m(ωb-)-m(Ξb-)=248.54±0.51(stat)±0.38(syst) MeV/c2. The mass of the ωb- baryon is measured to be m(ωb-)=6045.9±0.5(stat)±0.6(syst) MeV/c2. This is the most precise determination of the ωb- mass to date. In addition, the production rate of ωb- baryons relative to that of Ξb- baryons is measured for the first time in pp collisions, using an LHCb dataset collected at a center-of-mass energy of 13 TeV and corresponding to an integrated luminosity of 6 fb-1. Reconstructing beauty baryons in the kinematic region 2<η<6 and pT<20 GeV/c with their decays to a J/ψ meson and a hyperon, the ratio fωb-fΞb-×B(ωb-→J/ψω-)B(Ξb-→J/ψΞ-)=0.120±0.008(stat)±0.008(syst), is obtained, where fωb- and fΞb- are the fragmentation fractions of b quarks into ωb- and Ξb- baryons, respectively, and B represents the branching fractions of their respective decays

Global emergence of a hypervirulent carbapenem-resistant <i>Escherichia coli </i>ST410 clone

Carbapenem-resistant Escherichia coli (CREC) ST410 has recently emerged as a major global health problem. Here, we report a shift in CREC prevalence in Chinese hospitals between 2017 and 2021 with ST410 becoming the most commonly isolated sequence type. Genomic analysis identifies a hypervirulent CREC ST410 clone, B5/H24RxC, which caused two separate outbreaks in a children's hospital. It may have emerged from the previously characterised B4/H24RxC in 2006 and has been isolated in ten other countries from 2015 to 2021. Compared with B4/H24RxC, B5/H24RxC lacks the blaOXA-181-bearing X3 plasmid, but carries a F-type plasmid containing blaNDM-5. Most of B5/H24RxC also carry a high pathogenicity island and a novel O-antigen gene cluster. We find that B5/H24RxC grew faster in vitro and is more virulent in vivo. The identification of this newly emerged but already globally disseminated hypervirulent CREC clone, highlights the ongoing evolution of ST410 towards increased resistance and virulence. </p

Targeting of the Human Coagulation Factor IX Gene at rDNA Locus of Human Embryonic Stem Cells

BACKGROUND: Genetic modification is a prerequisite to realizing the full potential of human embryonic stem cells (hESCs) in human genetic research and regenerative medicine. Unfortunately, the random integration methods that have been the primary techniques used keep creating problems, and the primary alternative method, gene targeting, has been effective in manipulating mouse embryonic stem cells (mESCs) but poorly in hESCs. METHODOLOGY/PRINCIPAL FINDINGS: Human ribosomal DNA (rDNA) repeats are clustered on the short arm of acrocentric chromosomes. They consist of approximately 400 copies of the 45S pre-RNA (rRNA) gene per haploid. In the present study, we targeted a physiological gene, human coagulation factor IX, into the rDNA locus of hESCs via homologous recombination. The relative gene targeting efficiency (>50%) and homologous recombination frequency (>10(-5)) were more than 10-fold higher than those of loci targeted in previous reports. Meanwhile, the targeted clones retained both a normal karyotype and the main characteristics of ES cells. The transgene was found to be stably and ectopically expressed in targeted hESCs. CONCLUSION/SIGNIFICANCE: This is the first targeting of a human physiological gene at a defined locus on the hESC genome. Our findings indicate that the rDNA locus may serve as an ideal harbor for transgenes in hESCs

The Power of Wings:How Do Air Connections Bring New Ideas in China

How does physical connectedness stimulate new ideas? This paper explores this question in the context of China, one of the largest countries and an innovation powerhouse of the world. Exploiting variation in air connectivity across time and space, we find that the introduction of non-stop air connections between cities boosts collaborative innovation, especially for long-distance city pairs. This improvement goes with reducing costs of face-to-face interactions, hence promoting knowledge flows. Further analysis shows that the disparity of within-city-pair innovative capability increases following direct air connections, and the effects on collaborative innovation are more pronounced in city pairs involving mega and smaller cities and enterprise innovators who are sensitive to travel costs