2,715 research outputs found
Demonstration of the double Q^2-rescaling model
In this paper we have demonstrated the double Q^2-rescaling model (DQ^2RM) of
parton distribution functions of nucleon bounded in nucleus. With different
x-region of l-A deep inelastic scattering process we take different approach:
in high x-region (0.1\le x\le 0.7) we use the distorted QCD vacuum model which
resulted from topologically multi -connected domain vacuum structure of
nucleus; in low x-region (10^{-4}\le x\le10^{-3}) we adopt the Glauber
(Mueller) multi- scattering formula for gluon coherently rescattering in
nucleus. From these two approach we justified the rescaling parton distribution
functions in bound nucleon are in agreement well with those we got from DQ^2RM,
thus the validity for this phenomenologically model are demonstrated.Comment: 19 page, RevTex, 5 figures in postscrip
diffractive production in the direct photon process at HERA
We present a study of diffractive production in the direct
photon process at HERA based on the factorization theorem for lepton-induced
hard diffractive scattering and the factorization formalism of the
nonrelativistic QCD (NRQCD) for quarkonia production. Using the diffractive
gluon distribution function extracted from HERA data on diffractive deep
inelastic scattering and diffractive dijet photon production, we show that this
process can be studied at HERA with present integrated luminosity, and can give
valuable insights in the color-octet mechanism for heavy quarkonia production.Comment: Revtex, 21 pages, 7 EPS figure
An Iterative Path-Breaking Approach with Mutation and Restart Strategies for the MAX-SAT Problem
Although Path-Relinking is an effective local search method for many
combinatorial optimization problems, its application is not straightforward in
solving the MAX-SAT, an optimization variant of the satisfiability problem
(SAT) that has many real-world applications and has gained more and more
attention in academy and industry. Indeed, it was not used in any recent
competitive MAX-SAT algorithms in our knowledge. In this paper, we propose a
new local search algorithm called IPBMR for the MAX-SAT, that remedies the
drawbacks of the Path-Relinking method by using a careful combination of three
components: a new strategy named Path-Breaking to avoid unpromising regions of
the search space when generating trajectories between two elite solutions; a
weak and a strong mutation strategies, together with restarts, to diversify the
search; and stochastic path generating steps to avoid premature local optimum
solutions. We then present experimental results to show that IPBMR outperforms
two of the best state-of-the-art MAX-SAT solvers, and an empirical
investigation to identify and explain the effect of the three components in
IPBMR
NG2 cells response to axonal alteration in the spinal cord white matter in mice with genetic disruption of neurofilament light subunit expression
<p>Abstract</p> <p>Background</p> <p>Chondroitin sulphate proteoglycan (NG2) expressing cells, morphologically characterized by multi-branched processes and small cell bodies, are the 4<sup>th </sup>commonest cell population of non-neuronal cell type in the central nervous system (CNS). They can interact with nodes of Ranvier, receive synaptic input, generate action potential and respond to some pathological stimuli, but the function of the cells is still unclear. We assumed the NG2 cells may play an active role in neuropathogenesis and aimed to determine if NG2 cells could sense and response to the alterations in the axonal contents caused by disruption of neurofilament light subunit (NFL) expression.</p> <p>Results</p> <p>In the early neuropathological development stage, our study showed that the diameter of axons of upper motor neurons of NFL-/- mice decreased significantly while the thickness of their myelin sheath increased remarkably. Although there was an obvious morphological distortion in axons with occasionally partial demyelination, no obvious changes in expression of myelin proteins was detected. Parallel to these changes in the axons and their myelination, the processes of NG2 cells were disconnected from the nodes of Ranvier and extended further, suggesting that these cells in the spinal cord white matter could sense the alteration in axonal contents caused by disruption of NFL expression before astrocytic and microglial activation.</p> <p>Conclusion</p> <p>The structural configuration determined by the NFL gene may be important for maintenance of normal morphology of myelinated axons. The NG2 cells might serve as an early sensor for the delivery of information from impaired neurons to the local environment.</p
BatmanNet: Bi-branch Masked Graph Transformer Autoencoder for Molecular Representation
Although substantial efforts have been made using graph neural networks
(GNNs) for AI-driven drug discovery (AIDD), effective molecular representation
learning remains an open challenge, especially in the case of insufficient
labeled molecules. Recent studies suggest that big GNN models pre-trained by
self-supervised learning on unlabeled datasets enable better transfer
performance in downstream molecular property prediction tasks. However, they
often require large-scale datasets and considerable computational resources,
which is time-consuming, computationally expensive, and environmentally
unfriendly. To alleviate these limitations, we propose a novel pre-training
model for molecular representation learning, Bi-branch Masked Graph Transformer
Autoencoder (BatmanNet). BatmanNet features two tailored and complementary
graph autoencoders to reconstruct the missing nodes and edges from a masked
molecular graph. To our surprise, BatmanNet discovered that the highly masked
proportion (60%) of the atoms and bonds achieved the best performance. We
further propose an asymmetric graph-based encoder-decoder architecture for
either nodes and edges, where a transformer-based encoder only takes the
visible subset of nodes or edges, and a lightweight decoder reconstructs the
original molecule from the latent representation and mask tokens. With this
simple yet effective asymmetrical design, our BatmanNet can learn efficiently
even from a much smaller-scale unlabeled molecular dataset to capture the
underlying structural and semantic information, overcoming a major limitation
of current deep neural networks for molecular representation learning. For
instance, using only 250K unlabelled molecules as pre-training data, our
BatmanNet with 2.575M parameters achieves a 0.5% improvement on the average AUC
compared with the current state-of-the-art method with 100M parameters
pre-trained on 11M molecules.Comment: 11 pages, 3 figure
Impacts of residual aluminum from aluminate flocculant on the morphological and physiological characteristics of Vallisneria natans and Hydrilla verticillata
Aluminate is generally used as a flocculent in water and wastewater treatment processes, but the residual aluminum (Al) may have toxic effects on aquatic organisms when the concentration accumulates beyond a threshold level. The in situ and laboratory tests were conducted to evaluate the impact of residual Al on submerged macrophytes in West Lake, Hangzhou, China, which receives Al flocculant-purified water diverted from the Qiantang River. The responses of Vallisneria natans and Hydrilla verticillata were investigated based on their morphological and physiological parameters in pot culture and aquarium simulation experiments. In the pot culture experiments, the biomass, seedling number, plant height, stolon number, stolon length, and root weight were significantly higher at a site located 150 m from the inlet compared with those at a site located 15 m from the inlet (P < 0.05), thereby indicating that the residual Al significantly inhibited the morphological development of V. natans and H. verticillata. The variations in the chlorophyll-a, protein, and malondialdehyde contents of the two species in both the pot culture and aquarium simulation experiments also demonstrated that the two submerged macrophytes were stressed by residual Al. V. natans and H. verticillata accumulated 0.052-0.227 mg of Al per gram of plant biomass (fresh weight, mg/g FW) and 0.045-0.205 mg Al/g FW in the in situ experiments, respectively, where the amounts of Al were significantly higher in the plants in the treatment aquaria during the laboratory experiments than those in the controls. These results may have important implications for the restoration of submerged macrophytes and ecological risk assessments in Al-exposed lakes. It is recommended that the Al salt concentration used for the control of lake eutrophication should be reduced to an appropriate level.</p
Recurrent deletions of ULK4 in schizophrenia : a gene crucial for neuritogenesis and neuronal motility
Peer reviewedPublisher PD
Prevalence of non-alcoholic fatty liver disease and its relation to hypoadiponectinaemia in the middle-aged and elderly Chinese population
Introduction: Hypoadiponectinaemia is an important risk factor for non-alcoholic fatty liver disease (NAFLD). However, little is known about its role in the Chinese population. This study sought to assess the prevalence of NAFLD and its association with hypoadiponectinaemia in middle-aged and elderly Chinese. Material and methods: We conducted a population-based cross-sectional study in an urban Shanghai sample of 2201 participants age 50 years to 83 years (973 men, 1228 women). Hepatic ultrasonographic examination was performed for all participants. Serum adiponectin concentrations were measured by ELISA methods. Results: The prevalence of NAFLD was 19.8% (16.0% in men, 22.8% in women). Serum adiponectin levels were significantly higher in female than in male subjects (p < 0.001). Serum adiponectin levels were significantly lower in NAFLD subjects than those in control subjects (p < 0.001). The prevalence of NAFLD progressively increased with declining adiponectin levels (p(for) (trend) < 0.001). The participants in the lowest adiponectin quartile had a significantly increased risk for acquiring NAFLD (OR = 2.31, 95% CI 1.72-3.15) after adjustment for potential confounders. Conclusions: Population-based screening suggests that NAFLD is highly prevalent in middle-aged and elderly people in Shanghai, particularly among women. Serum adiponectin level is negatively associated with NAFLD independently of potential cofounders, indicating that hypoadiponectinaemia may contribute to the development of NAFLD
Geometry and optics calibration of WFCTA prototype telescopes using star light
The Large High Altitude Air Shower Observatory project is proposed to study
high energy gamma ray astronomy ( 40 GeV-1 PeV ) and cosmic ray physics ( 20
TeV-1 EeV ). The wide field of view Cherenkov telescope array, as a component
of the LHAASO project, will be used to study energy spectrum and compositions
of cosmic ray by measuring the total Cherenkov light generated by air showers
and shower maximum depth. Two prototype telescopes have been in operation since
2008. The pointing accuracy of each telescope is crucial to the direction
reconstruction of the primary particles. On the other hand the primary energy
reconstruction relies on the shape of the Cherenkov image on the camera and the
unrecorded photons due to the imperfect connections between photomultiplier
tubes. UV bright stars are used as point-like objects to calibrate the pointing
and to study the optical properties of the camera, the spot size and the
fractions of unrecorded photons in the insensitive areas of the camera.Comment: 5 pages, 6 figures, submitted to Chinese Physics
Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory
Photonic entanglement source and quantum memory are two basic building blocks
of linear-optical quantum computation and long-distance quantum communication.
In the past decades, intensive researches have been carried out, and remarkable
progress, particularly based on the spontaneous parametric down-converted
(SPDC) entanglement source and atomic ensembles, has been achieved. Currently,
an important task towards scalable quantum information processing (QIP) is to
efficiently write and read entanglement generated from a SPDC source into and
out of an atomic quantum memory. Here we report the first experimental
realization of a quantum interface by building a 5 MHz frequency-uncorrelated
SPDC source and reversibly mapping the generated entangled photons into and out
of a remote optically thick cold atomic memory using electromagnetically
induced transparency. The frequency correlation between the entangled photons
is almost fully eliminated with a suitable pump pulse. The storage of a
triggered single photon with arbitrary polarization is shown to reach an
average fidelity of 92% for 200 ns storage time. Moreover,
polarization-entangled photon pairs are prepared, and one of photons is stored
in the atomic memory while the other keeps flying. The CHSH Bell's inequality
is measured and violation is clearly observed for storage time up to 1
microsecond. This demonstrates the entanglement is stored and survives during
the storage. Our work establishes a crucial element to implement scalable
all-optical QIP, and thus presents a substantial progress in quantum
information science.Comment: 28 pages, 4 figures, 1 tabl
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