643 research outputs found
B\"{a}cklund transformations for high-order constrained flows of the AKNS hierarchy: canonicity and spectrality property
New infinite number of one- and two-point B\"{a}cklund transformations (BTs)
with explicit expressions are constructed for the high-order constrained flows
of the AKNS hierarchy. It is shown that these BTs are canonical transformations
including B\"{a}cklund parameter and a spectrality property holds with
respect to and the 'conjugated' variable for which the point
belongs to the spectral curve. Also the formulas of m-times
repeated Darboux transformations for the high-order constrained flows of the
AKNS hierarchy are presented.Comment: 21 pages, Latex, to be published in J. Phys.
The Specificity of Human Capital and Risk Management of the College Counselor from the Perspective of Internationalization
Shifting the concept of human resource to the concept of human capital is an inevitable tendency in developing human resource of college counselor. It is because the college counselor has its own specificity that it is hardly possible to avoid the risks of entry and exit which brings in completely. The paper listed the priority of psychological capital, human capital and social capital of the college counselor from the perspective of in-system in the order to attempt to discuss their inner logical relationship based on the basic theory of risk management. Key words: College counsellor; The specificity of human capital; Risk management; In-system Résumé: Déplacer le concept de ressources humaines pour le concept de capital humain est une tendance inévitable dans le développement des ressources humaines de conseiller du collège. C'est parce que le conseiller collège a sa propre spécificité qu'il n'est guère possible d'éviter les risques d'entrée et de sortie qui amène à fond. Le document énumère les priorités du capital psychologique, le capital humain et le capital social de la conseillère collège dans la perspective d'en-système dans l'ordre pour tenter de discuter de leur relation logique interne basé sur la théorie de base de gestion des risques. Mots clés: Université de conseiller; La spécificité du capital humain; La gestion des risques; Et du systèm
Role of vitamin D receptor gene Cdx2 and Apa1 polymorphisms in prostate cancer susceptibility: a meta-analysis
BACKGROUND: Vitamin D receptor (VDR) gene polymorphisms affect the risk of prostate cancer. However, studies investigating the relationship between VDR gene polymorphisms (Cdx2 and ApaI) and prostate cancer risk are equivocal. Therefore, we conducted a meta-analysis of all the studies to review the evidence available. METHODS: A comprehensive search of PubMed, EMBASE, and ISI Web of Science for studies published until September 2015 was conducted. Odds ratios (ORs) and 95 % confidence intervals (CIs) were analyzed to determine the association between VDR Cdx2 and ApaI polymorphisms, and prostate cancer risk. RESULTS: The meta-analysis included 10 studies involving 4979 cases and 4380 controls to analyze the VDR Cdx2 polymorphism. An additional 11 studies involving 2837 cases and 2884 controls were analyzed for the VDR ApaI polymorphism. Evidence failed to support the role of VDR Cdx2 and ApaI polymorphisms in prostate cancer. For Cdx2, the pooled OR was 1.11 (95 % CI = 0.93–1.33) for AA vs. GG genotypes, 0.97 (95 % CI = 0.88–1.06) for GA vs. AA genotypes, 0.99 (95 % CI = 0.91–1.08) for AA + GA vs. GG, and 1.12 (95 % CI = 0.95–1.31) for AA vs. GA + GG. No significant relationship was observed in any subgroup analysis based on ethnicity, controls, and Hardy–Weinberg equilibrium (HWE). ORs for the ApaI polymorphism were similar. CONCLUSIONS: VDR Cdx2 and ApaI polymorphisms are not associated with prostate cancer. Additional evidence is required to confirm this conclusion
Review: optical fiber sensors for civil engineering applications
Optical fiber sensor (OFS) technologies have developed rapidly over the last few decades, and various types of OFS have found practical applications in the field of civil engineering. In this paper, which is resulting from the work of the RILEM technical committee “Optical fiber sensors for civil engineering applications”, different kinds of sensing techniques, including change of light intensity, interferometry, fiber Bragg grating, adsorption measurement and distributed sensing, are briefly reviewed to introduce the basic sensing principles. Then, the applications of OFS in highway structures, building structures, geotechnical structures, pipelines as well as cables monitoring are described, with focus on sensor design, installation technique and sensor performance. It is believed that the State-of-the-Art review is helpful to engineers considering the use of OFS in their projects, and can facilitate the wider application of OFS technologies in construction industry
Research on flux of dry atmospheric falling dust and its characterization in a subtropical city, Guangzhou, South China
Guangzhou is the central city in the Pearl River Delta (PRD), China, and is one of the most polluted cities in the world. To characterize the ambient falling dust pollution, two typical sampling sites: urban (Wushan) and suburban (University Town) areas in Guangzhou city were chosen for falling dust collection over 1 year at time intervals of 1 or 2 months. The flux of dry deposition was calculated. In addition, mineral composition and morphology of atmospheric falling dust were studied by X-ray diffraction, scanning electron microscopy, and microscopic observation. The results revealed that the dust flux in Guangzhou city was 3.34–3.78 g/(m2 month) during the study period. The main minerals in the dust were quartz, illite, calcite, kaolinite, gypsum, plagioclase, dolomite, and amorphous matter. The morphological types included grained and flaky individual minerals, chain-like aggregates, spherical flying beads, and irregular aggregates, with the chain-like and spherical aggregates indicators of industrial ash. The major dusts were derived from industrial and construction activities. The gypsum present in the dust collected in winter season was not only derived from cement dust but may also have originated from the reaction of calcic material with sulfuric acids resulting from photooxidation of SOx and NOx, which confirmed serious air pollution due to SOx and NOx in Guangzhou. The abatement of fossil fuel combustion emissions and construction dust will have a significant beneficial effect on dust reduction
Design of a single-phase 6.5 MVA/25 kV superconducting traction transformer for the Chinese Fuxing high-speed train
Traction transformers are critical components of Chinese high-speed-trains. We are currently building a single–phase 6.5 MVA superconducting traction transformer which can achieve targets of less than 3 tons of transformer system weight, better than 99% efficiency, and 43% short-circuit impedance. The proposed transformer consists of four single-phase 25 kV/1.9 kV HTS windings, operating at 65 K, each of which drives a motor. The design incorporates Roebel cable in the LV windings to cope with large current and minimize AC loss. We present 2D FEM AC loss modelling results that identify the critical parameters that contribute to AC loss. We show that the combination of winding length ≥1 m, high performance Fujikura wires, and flux diverters arranged at the end of HV and LV windings, can restrain AC loss in the HTS windings to under 2 kW. We introduce an open-loop cooling system concept with sub-cooler integrated inside the transformer cryostat that can achieve total system weight under 3 tons assuming 2.5 kW total heat load and 8 h of continuous running time. A nominal efficiency of 99.5% can be achieved for this total heat load. The entire superconducting transformer system can be readily fit in the space allocated for conventional transformers in the Chinese Fuxing trains
APAview: A Web-Based Platform for Alternative Polyadenylation Analyses in Hematological Cancers
Background: Hematologic malignancies, such as acute promyelocytic leukemia (APL) and acute myeloid leukemia (AML), are cancers that start in blood-forming tissues and can affect the blood, bone marrow, and lymph nodes. They are often caused by genetic and molecular alterations such as mutations and gene expression changes. Alternative polyadenylation (APA) is a post-transcriptional process that regulates gene expression, and dysregulation of APA contributes to hematological malignancies. RNA-sequencing-based bioinformatic methods can identify APA sites and quantify APA usages as molecular indexes to study APA roles in disease development, diagnosis, and treatment. Unfortunately, APA data pre-processing, analysis, and visualization are time-consuming, inconsistent, and laborious. A comprehensive, user-friendly tool will greatly simplify processes for APA feature screening and mining.
Results: Here, we present APAview, a web-based platform to explore APA features in hematological cancers and perform APA statistical analysis. APAview server runs on Python3 with a Flask framework and a Jinja2 templating engine. For visualization, APAview client is built on Bootstrap and Plotly. Multimodal data, such as APA quantified by QAPA/DaPars, gene expression data, and clinical information, can be uploaded to APAview and analyzed interactively. Correlation, survival, and differential analyses among user-defined groups can be performed via the web interface. Using APAview, we explored APA features in two hematological cancers, APL and AML. APAview can also be applied to other diseases by uploading different experimental data
The Role of NMDA Receptors in Alzheimer’s Disease
In Alzheimer’s disease (AD), early synaptic dysfunction is associated with the increased oligomeric amyloid-beta peptide, which causes NMDAR-dependent synaptic depression and spine elimination. Memantine, low-affinity NMDAR channel blocker, has been used in the treatment of moderate to severe AD. However, clear evidence is still deficient in demonstrating the underlying mechanisms and a relationship between NMDARs dysfunction and AD. This review focuses on not only changes in expression of different NMDAR subunits, but also some unconventional modes of NMDAR action
FusDreamer: label-efficient remote sensing world model for multimodal data classification.
World models significantly enhance hierarchical understanding, improving data integration and learning efficiency. To explore the potential of the world model in the remote sensing (RS) field, this paper proposes a label-efficient remote sensing world model for multimodal data fusion (FusDreamer). The FusDreamer uses the world model as a unified representation container to abstract common and high-level knowledge, promoting interactions across different types of data, i.e., hyperspectral (HSI), light detection and ranging (LiDAR), and text data. Initially, a new latent diffusion fusion and multimodal generation paradigm (LaMG) is utilized for its exceptional information integration and detail retention capabilities. Subsequently, an open-world knowledge-guided consistency projection (OK-CP) module incorporates prompt representations for visually described objects and aligns language-visual features through contrastive learning. In this way, the domain gap can be bridged by fine-tuning the pre-trained world models with limited samples. Finally, an end-to-end multitask combinatorial optimization (MuCO) strategy can capture slight feature bias and constrain the diffusion process in a collaboratively learnable direction. Experiments conducted on four typical datasets indicate the effectiveness and advantages of the proposed FusDreamer
The triggering process of an X-class solar flare on a small quadrupolar active region
The occurrence of X-class solar flares and their potential impact on the
space weather often receive great attention than other flares. But predicting
when and where an X-class flare will occur is still a challenge. With the
multi-wavelength observation from the Solar Dynamics Observatory and FengYun-
3E satellite, we investigate the triggering of a GOES X1.0 flare occurring in
the NOAA active region (AR) 12887. Our results show that this unique X-class
flare is bred in a relatively small but complex quadrupolar AR. Before the
X-class flare, two filaments (F1 and F2) exist below a null-point topology of
the quadrupolar AR. Magnetic field extrapolation and observation reveal that F1
and F2 correspond to two magnetic flux ropes with the same chirality and their
adjacent feet rooted at nonconjugated opposite polarities, respectively.
Interestingly, these two polarities collide rapidly, accompanied by
photospheric magnetic flux emergence, cancellation and shear motion in the AR
center. Above this site, F1 and F2 subsequently intersect and merge to a longer
filament (F3) via a tether-cutting-like reconnection process. As a result, the
F3 rises and erupts, involving the large-scale arcades overlying filament and
the quadrupolar magnetic field above the AR, and eventually leads to the
eruption of the X-class flare with a quasi-X-shaped flare ribbon and a coronal
mass ejection. It suggests that the rapid collision of nonconjugated opposite
polarities provides a key condition for the triggering of this X-class flare,
and also provides a featured case for flare trigger mechanism and space weather
forecasting.Comment: 24 pages, 7 figures, accepted for publication in Ap
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