41 research outputs found

    I=2 Pion scattering length with improved actions on anisotropic lattices

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    ππ\pi\pi scattering length in the I=2 channel is calculated within quenched approximation using improved gauge and improved Wilson fermion actions on anisotropic lattices. The results are extrapolated towards the chiral, infinite volume and continuum limit. This result improves our previous result on the scattering length. In the chiral, infinite volume and continuum limit, we obtain a0(2)mπ=0.0467(45)a^{(2)}_0m_\pi=-0.0467(45), which is consistent with the result from Chiral Perturbation Theory, the experiment and results from other lattice calculations.Comment: 7 pages, 2 figures, typeset wit elsart.cl

    A Scientometric Analysis of Worldwide Intercropping Research Based on Web of Science Database between 1992 and 2020

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    Intercropping has been practiced worldwide in both traditional and sustainable agriculture to feed the growing population. This study aims to analyze the research status and evolution of intercropping, to identify the influential authors, research centers, and articles, and to reveal the main research topics between 1992 and 2020 based on the Web of Science Core Collection database. The results show that the volume of publications in this field has increased rapidly over the past three decades. The analysis identifies the top three authors (i.e., Meine Van Noordwijk, Wenyu Yang, and Teja Tscharntke), top three contributing organizations (i.e., the World Agroforestry Center (ICRAF), the Chinese Academy of Science, and the INRA), and three most productive countries (i.e., the USA, India, and China). Co-occurrence analysis demonstrates that studies on intercropping can be divided into four clusters as centered by keywords of intercropping/maize, biodiversity/conservation, agroforestry, and carbon, respectively. Lal 2004 is the most influential study with the greatest number of citations and Agroforestry Systems is the most utilized journal. Perspectives on future studies were also given. This study helps researchers to clarify the current research status in the field of intercropping and put forward its future research

    Design of a Mechatronics Model of Urinary Bladder and Realization and Evaluation of Its Prototype

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    Annually, there are many bladder cancer patients undergoing radical cystectomy (RC) with urinary diversion worldwide. Until 2019, intestinal cystoplasty is still the gold standard for bladder replacement, but this therapy is always associated with severe complications. An ideal bladder substitute without using intestinal tissue remains a challenge today. In this work, an artificial mechatronics bladder (AMB) as a brand new bladder replacement approach is developed. We studied the main physiological function characteristics of a natural urinary bladder from teaching books and relevant papers. According to these characteristics, we completed an overall design of AMB and made a prototype in lab. The prototype successfully realized the functions of a natural bladder in vitro. It can expand to store urine in real time when urine is flowing into it. It can send a urination alarm when it is fully filled and can void urine automatically after receiving remote control signals. According to relevant papers and our test experience, if the prototype could be smaller and lighter and manufactured with good biocompatibility materials such as PTFE, we think it is possible for AMB to be implanted in an animal’s body, and we deduce AMB could realize the functions of a natural urinary bladder in vivo. After thorough validation from animal testing, we hope AMB can be a good clinical option for bladder removal patients in the future

    Evaluation of Soil Water Availability (SWA) Based on Hydrological Modelling in Arid and Semi-Arid Areas: A Case Study in Handan City, China

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    To evaluate the spatial and temporal soil water availability (SWA) and improve the soil water use efficiency in agriculture, this study established a new index system for SWA evaluation considering the soil storage capacity, the temporal and spatial matching degree between soil water supply and crop water demand, and the soil water transformation and utilization efficiency. To quantitatively calculate the indexes, a self-developed hydrological model (MODCYCLE) was introduced and applied in Handan City. The results show that MODCYCLE performed well in simulating the soil hydrological processes. A comparison of the observed soil moisture data and the simulated values revealed relative errors below 10% and correlation coefficients all above 0.7. According to the evaluation results, the SWA for different typical years was very unevenly distributed in Handan City. The average SWA in a normal year is 0.71, which is higher than that in dry years at 0.62 and in wet years at 0.65. Regarding different regions, the average SWA was generally much higher in the eastern plain area than that in the western mountainous area. Generally, there is a great potential for improving SWA and further the sustainable development of soil water resource, particularly for dryland farming in similar areas

    Elongated Small Object Detection from Remote Sensing Images Using Hierarchical Scale-Sensitive Networks

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    The detection of elongated objects, such as ships, from satellite images has very important application prospects in marine transportation, shipping management, and many other scenarios. At present, the research of general object detection using neural networks has made significant progress. However, in the context of ship detection from remote sensing images, due to the elongated shape of ship structure and the wide variety of ship size, the detection accuracy is often unsatisfactory. In particular, the detection accuracy of small-scale ships is much lower than that of the large-scale ones. To this end, in this paper, we propose a hierarchical scale sensitive CenterNet (HSSCenterNet) for ship detection from remote sensing images. HSSCenterNet adopts a multi-task learning strategy. First, it presents a dual-direction vector to represent the posture or direction of the tilted bounding box, and employs a two-layer network to predict the dual direction vector, which improves the detection block of CenterNet, and cultivates the ability of detecting targets with tilted posture. Second, it divides the full-scale detection task into three parallel sub-tasks for large-scale, medium-scale, and small-scale ship detection, respectively, and obtains the final results with non-maximum suppression. Experimental results show that, HSSCenterNet achieves a significant improved performance in detecting small-scale ship targets while maintaining a high performance at medium and large scales

    Long-Term Prediction of Sea Surface Temperature by Temporal Embedding Transformer With Attention Distilling and Partial Stacked Connection

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    Sea surface temperature (SST) is one of the most important parameters in the global ocean–atmosphere system, and its long-term changes will have a significant impact on global climate and ecosystems. Accurate prediction of SST, therefore, especially the improvement of long-term predictive skills is of great significance for fishery farming, marine ecological protection, and planning of maritime activities. Since the effective and precise description of the long-range dependence between input and output requires higher model prediction ability, it is an extremely challenging task to achieve accurate long-term prediction of SST. Inspired by the successful application of the transformer and its variants in natural language processing similar to time-series prediction, we introduce it to the SST prediction in the China Sea. The model Transformer with temporal embedding, attention Distilling, and Stacked connection in Part (TransDtSt-Part) is developed by embedding the temporal information in the classic transformer, combining attention distillation and partial stacked connection, and performing generative decoding. High-resolution satellite-derived data from the National Oceanic and Atmospheric Administration is utilized, and long-term SST predictions with day granularity are achieved under univariate and multivariate patterns. With root mean square error and mean absolute error as metrics, the TransDtSt-Part outperforms all competitive baselines in five oceans (i.e., subareas of Bohai, Yellow Sea, East China Sea, Taiwan Strait, and South China Sea) and six prediction horizons (i.e., 30, 60, 90, 180, 270, and 360 days). Experimental results demonstrate that the performance of the innovative model is encouraging and promising for the long-term prediction of SST

    Regulation of telomerase towards tumor therapy

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    Abstract Cancer is an aging-related disease, while aging plays an important role in the development process of tumor, thus the two are inextricably associated. Telomere attrition is one of the recognized hallmark events of senescence. Hence, targeting telomerase which could extends telomere sequences to treat tumors is widely favored. Cancer cells rely on high activity of telomerase to maintain a strong proliferative potential. By inhibiting the expression or protein function of telomerase, the growth of cancer cells can be significantly suppressed. In addition, the human immune system itself has a defense system against malignant tumors. However, excessive cell division results in dramatic shortening on telomeres and decline in the function of immune organs that facilitates cancer cell evasion. It has been shown that increasing telomerase activity or telomere length of these immune cells can attenuate senescence, improve cellular viability, and enhance the immunosuppressive microenvironment of tumor. In this paper, we review the telomerase-targeting progress using different anti-tumor strategies from the perspectives of cancer cells and immune cells, respectively, as well as tracking the preclinical and clinical studies of some representative drugs for the prevention or treatment of tumors

    Ceruloplasmin/Hephaestin Knockout Mice Model Morphologic and Molecular Features of AMD

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    PURPOSE: Iron is an essential element in human metabolism but also is a potent generator of oxidative damage with levels that increase with age. Several studies suggest that iron accumulation may be a factor in age-related macular degeneration (AMD). In prior studies, both iron overload and features of AMD were identified in mice deficient in the ferroxidase ceruloplasmin (Cp) and its homologue hephaestin (Heph) (double knockout, DKO). In this study, the location and timing of iron accumulation, the rate and reproducibility of retinal degeneration, and the roles of oxidative stress and complement activation were determined. METHODS: Morphologic analysis and histochemical iron detection by Perls' staining was performed on retina sections from DKO and control mice. Immunofluorescence and immunohistochemistry were performed with antibodies detecting activated complement factor C3, transferrin receptor, L-ferritin, and macrophages. Tissue iron levels were measured by atomic absorption spectrophotometry. Isoprostane F2α-VI, a specific marker of oxidative stress, was quantified in the tissue by gas chromatography/mass spectrometry. RESULTS: DKOs exhibited highly reproducible age-dependent iron overload, which plateaued at 6 months of age, with subsequent progressive retinal degeneration continuing to at least 12 months. The degeneration shared some features of AMD, including RPE hypertrophy and hyperplasia, photoreceptor degeneration, subretinal neovascularization, RPE lipofuscin accumulation, oxidative stress, and complement activation. CONCLUSIONS: DKOs have age-dependent iron accumulation followed by retinal degeneration modeling some of the morphologic and molecular features of AMD. Therefore, these mice are a good platform on which to test therapeutic agents for AMD, such as antioxidants, iron chelators, and antiangiogenic agents
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