1,242 research outputs found
Quantum Generative Modeling of Sequential Data with Trainable Token Embedding
Generative models are a class of machine learning models that aim to learn
the underlying probability distribution of data. Unlike discriminative models,
generative models focus on capturing the data's inherent structure, allowing
them to generate new samples that resemble the original data. To fully exploit
the potential of modeling probability distributions using quantum physics, a
quantum-inspired generative model known as the Born machines have shown great
advancements in learning classical and quantum data over matrix product
state(MPS) framework. The Born machines support tractable log-likelihood,
autoregressive and mask sampling, and have shown outstanding performance in
various unsupervised learning tasks. However, much of the current research has
been centered on improving the expressive power of MPS, predominantly embedding
each token directly by a corresponding tensor index. In this study, we
generalize the embedding method into trainable quantum measurement operators
that can be simultaneously honed with MPS. Our study indicated that combined
with trainable embedding, Born machines can exhibit better performance and
learn deeper correlations from the dataset.Comment: 5 pages, 4 figure
In-plane torsional stiffness in a macro-panel element for practical finite element modelling
Finite element (FE) analysis produces results, which, in most cases, gain in accuracy, as the size of the FE mesh is reduced. However, this is not necessarily the case when beam and shell element connections induce in-plane torsional effects in the shell. In such situations, shell elements either do not allow for an in-plane torsional stiffness, or, when present, the in-plane torsional stiffness is incorrectly affected by the sizes of the elements. To overcome this problem, we propose a macro- panel element that has fewer degrees of freedom, includes a new model for in-plane torsional stiffness, and produces results with sufficient accuracy to meet engineering requirements. The panel element is based on the principle of sub-structuring, i.e., the panel is meshed internally by smaller shell elements. As shown in the paper, the proposed panel element can be quite large, yet, it can give accurate analysis results. This work helps to overcome a common dilemma in practical use of finite element analysis, where finite element theory requires element sizes to be sufficiently small, but practical considerations suggest the use of large-size elements that simplify the modelling process and reduce excesses in generated results. A model built using macro-panel elements is equivalent to the model built using smaller shell elements, with the normal and shear stresses in the former being the same as the stresses in the finely meshed shell element model, We identify a number of performance benefits that become available as a consequence of modelling the shell elements at a higher level of abstraction
The effect of 17β-estradiol-DNA adducts on the replication of exon # 5 of the human suppressor gene p53
AbstractUsing a PCR technique, exon # 5 of the human tumor suppressor gene p53 was amplified and ligated into the pCRII vector and transformed into Escherichia coli INVαF’ competent cells. The cloned exon # 5 was 184 bp long. Evidence is presented to show that after dimethyldioxirane epoxidation, 17β-estradiol was able to form 17β-estradiol-DNA adducts and to strongly inhibit the replication of the cloned exon # 5 producing smaller sizes of DNA fragments and introducing errors of incorporation at the 3′-end of the terminating DNAs. The errors occurred mainly at the clusters of the complementary ‘G’ and ‘A’ bases on the template strand DNA, presumably, the major sites where the 17β-estradiol-DNA adducts were formed
Superconductivity from Doping Symmetric Mass Generation Insulators: Application to LaNiO under Pressure
We investigate the bilayer nickelates as a platform to realize the symmetric
mass generation (SMG) insulator, a featureless Mott insulator that arises due
to the Lieb-Schultz-Mattis (LSM) anomaly cancellation in bilayer spin-1/2
lattice systems. Through a single-orbital bilayer square lattice model
involving intralayer hopping and interlayer superexchange interaction ,
we demonstrate the emergence of high-temperature superconductivity (SC) upon
doping the SMG insulator. The SC phase features -wave interlayer
spin-singlet pairing and exhibits a crossover between the BCS and BEC limits by
tuning the ratio. We estimate the SC transition temperature from
both the weak and strong coupling limits at the mean-field level. Our findings
offer insights into the experimentally observed decrease in with pressure
and the strange metal behavior above . Additionally, we propose that both
Ni and orbitals can exhibit superconductivity in
LaNiO under pressure, but their should vary in opposite ways
under doping. This characteristic difference suggests a potential experimental
pathway to identify which electronic orbital plays the principal role in the
formation of superconductivity in this system.Comment: 11 pages, 5 figures, 2 table
Production of Gadolinium-loaded Liquid Scintillator for the Daya Bay Reactor Neutrino Experiment
We report on the production and characterization of liquid scintillators for
the detection of electron antineutrinos by the Daya Bay Reactor Neutrino
Experiment. One hundred eighty-five tons of gadolinium-loaded (0.1% by mass)
liquid scintillator (Gd-LS) and two hundred tons of unloaded liquid
scintillator (LS) were successfully produced from a linear-alkylbenzene (LAB)
solvent in six months. The scintillator properties, the production and
purification systems, and the quality assurance and control (QA/QC) procedures
are described.Comment: 15 pages, 11 figures. Submitted to Nuclear Instruments and Methods in
Physics Research Section
Ceratophysella species from mushrooms in China (Collembola, Hypogastruridae)
Four species of the genus Ceratophysella living on mushrooms are reported from China, including a new species, Ceratophysella skarzynskii Weiner & Sun, sp. n., which is described from alpine mushrooms. The new species belongs to the Ceratophysella group of species with a dorsal chaetotaxy of type B and differs from the other species in a combination of characters. Ceratophysella skarzynskii sp. n. is distinguished by its small body size (maximum length 1.09 mm), number of peg-like s-chaetae (30–32) in the ventral sensory file, the trilobed apical vesicle of antennal segment IV, five modified chaetae on dens, and serrated dorsal chaetae. A key to the Chinese species of the genus has been provided
The effect of depression symptoms and social support on black-white differences in health-related quality of life in early pregnancy: the health status in pregnancy (HIP) study
Abstract Background Lower physical and social functioning in pregnancy has been linked to an increased risk of preterm delivery and low birth weight infants, butt few studies have examined racial differences in pregnant women’s perception of their functioning. Even fewer studies have elucidated the demographic and clinical factors contributing to racial differences in functioning. Our objective was to determine whether there are racial differences in health-related quality of life (HRQoL) in early pregnancy; and if so, to identify the contributions of socio-demographic characteristics, depression symptoms, social support and clinical factors to these differences. Methods Cross-sectional study of 175 women in early pregnancy attending prenatal clinics in urban setting. In multivariate analysis, we assessed the independent relation of black race (compared to white) to HRQoL scores from the eight domains of the Medical Outcomes (SF-36) Survey: Physical Functioning, Role-Physical, Bodily Pain, Vitality, General Health, Social Functioning, Role-Emotional, and Mental Health. We compared socio-demographic and clinical factors and depression symptoms between black and white women and assessed the relative importance of these factors in explaining racial differences in physical and social functioning. Results Black women comprised 59% of the sample; white women comprised 41%. Before adjustment, black women had scores that were 14 points lower in Physical Function and Bodily Pain, 8 points lower in General Health, 4 points lower in Vitality and 7 points lower in Social Functioning. After adjustment for depression symptoms, social support and clinical factors, black women still had HRQoL scores that were 4 to 10 points lower than white women, but the differences were no longer statistically significant. Level of social support and payment source accounted for most of the variation in Physical Functioning, Bodily Pain and General Health. Social support accounted for most of the differences in Vitality and Social Functioning. Conclusions Payment source and social support accounted for much of the racial differences in physical and social function scores. Efforts to reduce racial differences might focus on improving social support networks and Socio-economic barriers
Level of physical activity among middle-aged and older Chinese people: evidence from the China health and retirement longitudinal study
Background: With data from different regions accumulated, physical inactivity (PI) was found to be pandemic worldwide. Using China Health and Retirement Longitudinal Study (CHARLS), a nationwide longitudinal survey data, we aimed to delineate the prevalence, incidence and risk factors of physical inactivity (PI) among Chinese people aged 45 years and older. Methods: The CHARLS covered nearly all provinces, autonomous regions, municipalities of mainland China. With data from CHARLS, three cross-sectional analyses and a cohort analysis were conducted. In cross-sectional studies, we used surveys at 2011, 2013 and 2015 to examine the prevalence and its trend of PI. Multivariate generalized linear model was conducted in survey at 2011 to examine the risk factors for prevalent PI. Multiple imputation of missing values was used and results before and after imputation were compared. In cohort analysis, we identified people free of PI at 2011 and followed them up until 2015 to estimate the incidence of PI. Generalized estimating equation was used to examine the risk factors associated with incidence PI. In all analyses, PI was defined as insufficient physical activity according to the International Physical Activity Questionnaire (IPAQ) criterion. Results: 6650, 5946 and 9389 participants were eligible for cross-sectional analyses, and 4525 participants were included for cohort analysis. The weighted prevalence of PI was 22.25% (95% CI: 20.63–23.95%) in 2011, 20.64% (95% CI: 19.22–22.14%) in 2013 and 19.31% (95% CI: 18.28–20.38%) in 2015. In multivariate analysis, PI was associated with older age, higher education, overweight, obesity and difficulties in daily living, and was negatively associated with working and higher level of expenditure. No material change was detected in results after multiple imputation. In cohort analysis, older age, abundant public facilities, difficulties in daily living were identified as risk factors of incidence PI, while urban areas, college and above education, and working were protective factors. Conclusions: PI is pandemic in 45 years and older people in China. People with older age, difficulties in daily living and people who are not working are at higher risk. More efforts should be paid in estimating and promoting leisure-time physical activities
Quiet New Particle Formation in the Atmosphere
Atmospheric new particle formation (NPF) has been observed to take place in practice all around the world. In continental locations, typically about 10-40% of the days are so-called NPF event days characterized by a clear particle formation and growth that continue for several hours, occurring mostly during daytime. The other days are either non-event days, or days for which it is difficult to decide whether NPF had occurred or not. Using measurement data from several locations (Hyytiala, Jarvselja, and near-city background and city center of Budapest), we were able to show that NPF tends to occur also on the days traditionally characterized as non-event days. One explanation is the instrument sensitivity towards low number concentrations in the sub-10 nm range, which usually limits our capability to detect such NPF events. We found that during such days, particle formation rates at 6 nm were about 2-20% of those observed during the traditional NPF event days. Growth rates of the newly formed particles were very similar between the traditional NPF event and non-event days. This previously overlooked phenomenon, termed as quiet NPF, contributes significantly to the production of secondary particles in the atmosphere.Peer reviewe
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