153 research outputs found
Configurable indexing and ranking for XML information retrieval
Indexing and ranking are two key factors for efficient and effective XML information retrieval. Inappropriate indexing may result in false negatives and false positives, and improper ranking may lead to low precisions. In this paper, we propose a configurable XML information retrieval system, in which users can configure appropriate index types for XML tags and text contents. Based on users ’ index configurations, the system transforms XML structures into a compact tree representation, Ctree, and indexes XML text contents. To support XML ranking, we propose the concepts of “weighted term frequency ” and “inverted element frequency, ” where the weight of a term depends on its frequency and location within an XML element as well as its popularity among similar elements in an XML dataset. We evaluate the effectiveness of our system through extensive experiments on the INEX 03 dataset and 30 content and structure (CAS) topics. The experimental results reveal that our system has significantly high precision at low recall regions and achieves the highest average precision (0.3309) as compared with 38 official INEX 03 submissions using the strict evaluation metric
AI Chain on Large Language Model for Unsupervised Control Flow Graph Generation for Statically-Typed Partial Code
Control Flow Graphs (CFGs) are essential for visualizing, understanding and
analyzing program behavior. For statically-typed programming language like
Java, developers obtain CFGs by using bytecode-based methods for compilable
code and Abstract Syntax Tree (AST)-based methods for partially uncompilable
code. However, explicit syntax errors during AST construction and implicit
semantic errors caused by bad coding practices can lead to behavioral loss and
deviation of CFGs.To address the issue, we propose a novel approach that
leverages the error-tolerant and understanding ability of pre-trained Large
Language Models (LLMs) to generate CFGs. Our approach involves a Chain of
Thought (CoT) with four steps: structure hierarchy extraction, nested code
block extraction, CFG generation of nested code blocks, and fusion of all
nested code blocks' CFGs. To address the limitations of the original CoT's
single-prompt approach (i.e., completing all steps in a single generative
pass), which can result in an ``epic'' prompt with hard-to-control behavior and
error accumulation, we break down the CoT into an AI chain with explicit
sub-steps. Each sub-step corresponds to a separate AI-unit, with an effective
prompt assigned to each unit for interacting with LLMs to accomplish a specific
purpose.Our experiments confirmed that our method outperforms existing CFG
tools in terms of node and edge coverage, especially for incomplete or
erroneous code. We also conducted an ablation experiment and confirmed the
effectiveness of AI chain design principles: Hierarchical Task Breakdown, Unit
Composition, and Mix of AI Units and Non-AI Units.Our work opens up new
possibilities for building foundational software engineering tools based on
LLMs, as opposed to traditional program analysis methods
Inhibitory Effect of Curcumol on Jak2-STAT Signal Pathway Molecules of Fibroblast-Like Synoviocytes in Patients with Rheumatoid Arthritis
Hyperplasia of synovial membrane in rheumatoid arthritis (RA) is a critical pathological foundation for inducing articular injury. The janus kinase and signal transducer and activator of transcription (Jak-STAT) pathway plays a critical role in synovial membrane proliferation induced by platelet-derived growth factor (PDGF). To explore the anti-cell proliferation mechanism of curcumol, a pure monomer extracted from Chinese medical plant zedoary rhizome, the changes of Jak2-STAT1/3 signal pathway-related molecules in synoviocytes were observed in vitro. In this study, the fibroblast-like synoviocytes (FLS) in patients with RA were collected and cultured. The following parameters were measured: cell proliferation (WST-1 assay), cell cycles (fluorescence-activated cell sorting, FACS), STAT1 and STAT3 activities (electrophoretic mobility shift assay, EMSA), and the protein expressions of phosphorylated Jak2, STAT1, and STAT3 (Western blot). It was shown that curcumol could inhibit the RA-FLS proliferation and DNA synthesis induced by PDGF-BB in a dose-dependent manner in vitro. The transcription factors activities of STAT1 and STAT3 were obviously elevated after PDGF-BB stimulation (P < 0.05). Super-shift experiments identified the STAT1 or STAT3 proteins in the complex. Furthermore, the different concentration curcumol could downregulate the DNA binding activities of STAT1 and STAT3 (P < 0.05) and inhibit the phosphorylation of Jak2 while it had no effect on the protein expressions of STAT1 and STAT3. Positive correlations were found between changes of cell proliferation and DNA-binding activities of STAT1 and STAT3, respectively (P < 0.01). In conclusion, curcumol might suppress the FLS proliferation and DNA synthesis induced by PDGF-BB through attenuating Jak2 phosphorylation, downregulating STAT1 and STAT3 DNA-binding activities, which could provide theoretical foundation for clinical treatment of RA
Dimensionality-confined superconductivity within SrNbO3-SrTiO3 heterostructures
Interfaces between transition-metal oxides are able to host two-dimensional
electron gases (2DEGs) and exhibit exotic quantum phenomena. Here we report the
observation of superconductivity below 230 mK for the heterostructure composed
of SrNbO3 (SNO) and SrTiO3 (STO). Different from some other counterparts with
two insulators, the metallic SNO provides a novel mechanism to form a quasi
2DEG by charge transfer from bulk towards interface under strain. The
superconductivity, residing within the strained SNO layer near the interface,
is contributed by an electron system with record-low carrier density. Notably,
although embedded in a normal metallic layer with a carrier density 4 to 5
orders higher, the electron system is still uniquely well-protected to retain
high mobility and lies deep in extreme quantum regime
Leaf size of woody dicots predicts ecosystem primary productivity
A key challenge in ecology is to understand the relationships between organismal traits and ecosystem processes. Here, with a novel dataset of leaf length and width for 10 480 woody dicots in China and 2374 in North America, we show that the variation in community mean leaf size is highly correlated with the variation in climate and ecosystem primary productivity, independent of plant life form. These relationships likely reflect how natural selection modifies leaf size across varying climates in conjunction with how climate influences canopy total leaf area. We find that the leaf size–primary productivity functions based on the Chinese dataset can predict productivity in North America and vice-versa. In addition to advancing understanding of the relationship between a climate-driven trait and ecosystem functioning, our findings suggest that leaf size can also be a promising tool in palaeoecology for scaling from fossil leaves to palaeo-primary productivity of woody ecosystems
Syntropic spin alignment at the interface between ferromagnetic and superconducting nitrides
The magnetic correlations at the superconductor/ferromagnet (S/F) interfaces
play a crucial role in realizing dissipation-less spin-based logic and memory
technologies, such as triplet-supercurrent spin-valves and "{\pi}" Josephson
junctions. Here we report the coexistence of an induced large magnetic moment
and a crypto ferromagnetic state at high-quality nitride S/F interfaces. Using
polarized neutron reflectometry and d. c. SQUID measurements, we quantitatively
determined the magnetization profile of S/F bilayer and confirmed the induced
magnetic moment in the adjacent superconductor only exists below TC.
Interestingly, the direction of the induced moment in the superconductors was
unexpectedly parallel to that in the ferromagnet, which contrasts with earlier
findings in S/F heterostructures based on metals or oxides. The
first-principles calculations verify the observed unusual interfacial spin
texture is caused by the Heisenberg direct exchange coupling through d orbital
overlapping and severe charge transfer across the interfaces. Our work
establishes an incisive experimental probe for understanding the magnetic
proximity behavior at S/F interfaces and provides a prototype epitaxial
building block for superconducting spintronics.Comment: 21 pages, 5 figures, supplementary file with 14 figure
Enhancement of Low-field Magnetoresistance in Self-Assembled Epitaxial La0.67Ca0.33MnO3:NiO and La0.67Ca0.33MnO3:Co3O4 Composite Films via Polymer-Assisted Deposition
Polymer-assisted deposition method has been used to fabricate self-assembled epitaxial La(0.67)Ca(0.33)MnO(3):NiO and La(0.67)Ca(0.33)MnO(3):Co(3)O(4) films on LaAlO(3) substrates. Compared to pulsed-laser deposition method, polymer-assisted deposition provides a simpler and lower-cost approach to self-assembled composite films with enhanced low-field magnetoresistance effect. After the addition of NiO or Co(3)O(4), triangular NiO and tetrahedral Co(3)O(4) nanoparticles remain on the surface of La(0.67)Ca(0.33)MnO(3) films. This results in a dramatic increase in resistivity of the films from 0.0061 Ω•cm to 0.59 Ω•cm and 1.07 Ω•cm, and a decrease in metal-insulator transition temperature from 270 K to 180 K and 172 K by the addition of 10%-NiO and 10%-Co(3)O(4), respectively. Accordingly, the maximum absolute magnetoresistance value is improved from −44.6% to −59.1% and −52.7% by the addition of 10%-NiO and 10%-Co(3)O(4), respectively. The enhanced low-field magnetoresistance property is ascribed to the introduced insulating phase at the grain boundaries. The magnetism is found to be more suppressed for the La(0.67)Ca(0.33)MnO(3):Co(3)O(4) composite films than the La(0.67)Ca(0.33)MnO(3):NiO films, which can be attributed to the antiferromagnetic properties of the Co(3)O(4) phase. The solution-processed composite films show enhanced low-field magnetoresistance effect which are crucial in practical applications. We expect our polymer-assisted deposited films paving the pathway in the field of hole-doped perovskites with their intrinsic colossal magnetoresistance
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