206 research outputs found
Research Report on the Effect of Network Teaching Mode of Art Courses under the Concept of Ideological and Political Education
Since the National Conference on ideological and political work in Colleges and Universities, the Party Committee of Beijing United University has closely focused on the fundamental problem of “what kind of person to train, how to train and for whom to train”, and regards the course of ideological and political thinking as the fundamental measure to carry out the fundamental task of building up people by virtue. In 2020, in the event of the new epidemic situation, the school actively implemented the work plan of “stopping classes and not stopping learning” in Beijing, and opened the historic revolution of the whole school network teaching in education and teaching.In recent years, Beijing Union University in the “curriculum ideological and political” construction is constantly open up. In order to promote teaching practice and teaching research, the school teacher teaching development center set up the first teaching promoters of Beijing United University in 2019. The project team was set up by the school teaching promoters to study the effect of the online teaching mode of art courses under the concept of ideological and political education
Localization, phases and transitions in the three-dimensional extended Lieb lattices
We study the localization properties and the Anderson transition in the 3D Lieb lattice L3(1) and its extensions L3(n) in the presence of disorder. We compute the positions of the flat bands, the disorder-broadened density of states and the energy-disorder phase diagrams for up n = 4. Via finite-size scaling, we obtain the critical properties such as critical disorders and energies as well as the universal localization lengths exponent ν. We find that the critical disorder Wc decreases from ∼ 16.5 for the cubic lattice, to ∼ 8.6 for L3(1), ∼ 5.9 for L3(2) and ∼ 4.8 for L3(3). Nevertheless, the value of the critical exponent ν for all Lieb lattices studied here and across various disorder and energy transitions agrees within error bars with the generally accepted universal value ν = 1.590 (1.579, 1.602)
Bipartite Graph Pre-training for Unsupervised Extractive Summarization with Graph Convolutional Auto-Encoders
Pre-trained sentence representations are crucial for identifying significant
sentences in unsupervised document extractive summarization. However, the
traditional two-step paradigm of pre-training and sentence-ranking, creates a
gap due to differing optimization objectives. To address this issue, we argue
that utilizing pre-trained embeddings derived from a process specifically
designed to optimize cohensive and distinctive sentence representations helps
rank significant sentences. To do so, we propose a novel graph pre-training
auto-encoder to obtain sentence embeddings by explicitly modelling
intra-sentential distinctive features and inter-sentential cohesive features
through sentence-word bipartite graphs. These pre-trained sentence
representations are then utilized in a graph-based ranking algorithm for
unsupervised summarization. Our method produces predominant performance for
unsupervised summarization frameworks by providing summary-worthy sentence
representations. It surpasses heavy BERT- or RoBERTa-based sentence
representations in downstream tasks.Comment: Accepted by the 2023 Conference on Empirical Methods in Natural
Language Processing (EMNLP 2023
Disorder effects in the two-dimensional Lieb lattice and its extensions
We study the localization properties of the two-dimensional Lieb lattice and its extensions in the presence of disorder using transfer matrix method and finite-size scaling. We find that all states in the Lieb lattice and its extensions are localized for W≥1. Clear differences in the localization properties between disordered flat band and disordered dispersive bands are identified. Our results complement previous experimental studies of clean photonic Lieb lattices and provide information about their stability with respect to disorder
Direct conversion of astrocytes into neuronal cells by drug cocktail
Direct conversion of astrocytes into neuronal cells by
drug cocktail
Cell Research advance online publication 2 October 2015; doi:10.1038/cr.2015.120
Dear Editor,
Neurological disorder is one of the greatest threats
to public health according to the World Health Organization.
Because neurons have little or no regenerative
capacity, conventional therapies for neurological disorders
yielded poor outcomes. While the introduction of
exogenous neural stem cells or neurons holds promise,
many challenges still need to be tackled, including cell
resource, delivery strategy, cell integration and cell
maturation. Reprogramming of fibroblasts into induced
pluripotent stem cells or directly into desirable neuronal
cells by transcription factors (TFs) or small molecules
can solve some problems, but other issues remain to be
addressed, including safety, conversion efficiency and
epigenetic memory [1, 2].
Astrocytes are considered to be the ideal starting
candidate cell type for generating new neurons, due to
their proximity in lineage distance to neurons and ability
to proliferate after brain damage. Many studies have
already revealed that astrocytes of the central nervous
system can be reprogrammed into induced neuronal cells
by virus-mediated overexpression of specific TFs in vitro
and in vivo [3-6]. However, application of this virus-mediated
direct conversion is still limited due to concerns
on clinical safety. We have previously reported direct
conversion of somatic cells into neural progenitor cells
(NPCs) in vitro by cocktail of small molecules under hypoxia
[7]. Here we set out to explore whether astrocytes
can be induced into neuronal cells by the chemical cocktail
in vitro
New Superhard Carbon Phases Between Graphite and Diamond
Two new carbon allotropes (H-carbon and S-carbon) are proposed, as possible
candidates for the intermediate superhard phases between graphite and diamond
obtained in the process of cold compressing graphite, based on the results of
first-principles calculations. Both H-carbon and S-carbon are more stable than
previously proposed M-carbon and W-carbon and their bulk modulus are comparable
to that of diamond. H-carbon is an indirect-band-gap semiconductor with a gap
of 4.459 eV and S-carbon is a direct-band-gap semiconductor with a gap of 4.343
eV. The transition pressure from cold compressing graphite is 10.08 GPa and
5.93 Gpa for H-carbon and S-carbon, respectively, which is in consistent with
the recent experimental report.Comment: 5pages,4figures,submitted to Phys.Rev.Lett on 18Jan12, transfer to
Phys.Rev.B on 25Mar12; Solid State Communications(2012),
http://dx.doi.org/10.1016/j.ssc.2012.05.02
Low alpha-defensin gene copy number increases the risk for IgA nephropathy and renal dysfunction
IgA nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. Although a major source of genetic variation, copy number variations (CNVs) and their involvement in disease development have not been well studied. Here, we performed association analysis of the DEFA1A3 CNV locus in two independent IgAN cohorts of Southern Chinese Han (total1189 cases and 1187 controls). We discovered three independent copy number associations within the locus: DEFA1A3 (P=3.99×10-9, OR=0.88), DEFA3 (P=6.55×10-5, OR=0.82) and a noncoding deletion variant (211bp) (P=3.50×10-16, OR=0.75) (OR per copy, fixed-effects meta-analysis). While showing strong association with increased risk for IgAN (P=9.56×10-20), low total copy numbers of the three variants also showed significant association with renal dysfunction in patients with IgAN (P=0.03, HR=3.69, after controlling for the effects of known prognostic factors) as well as high serum IgA1 (P=0.02) and a high proportion of galactose-deficient IgA1 (P=0.03). For replication, we confirmed the associations of DEFA1A3 (P=4.42×10-4, OR=0.82) and DEFA3 copy numbers (P=4.30×10-3, OR=0.74) with IgAN in a Caucasian cohort (531 cases and 198 controls) and found the 211bp variant to be much rarer in Caucasians. Interestingly, we also observed an association of the 211bp copy number with membranous nephropathy (P=1.11×10-7, OR=0.74 in 493 Chinese cases and 500 matched controls), but not with diabetic kidney disease (in 806 Chinese cases and 786 matched controls). By explaining 4.96% of disease risk and influencing the renal dysfunction in IgAN, the DEFA1A3 CNV locus is a potential candidate for therapeutic target and prognostic marker development
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