94 research outputs found
Implementation of Steiner Point of Fuzzy Set
This paper deals with the implementation of Steiner point of fuzzy set. Some definitions and properties of Steiner point are investigated and extended to fuzzy set. This paper focuses on establishing efficient methods to compute Steiner point of fuzzy set. Two strategies of computing Steiner point of fuzzy set are proposed. One is called linear combination of Steiner points computed by a series of crisp α-cut sets of the fuzzy set. The other is an approximate method, which is trying to find the optimal α-cut set approaching the fuzzy set. Stability analysis of Steiner point of fuzzy set is also studied. Some experiments on image processing are given, in which the two methods are applied for implementing Steiner point of fuzzy image, and both strategies show their own advantages in computing Steiner point of fuzzy set
Evidence of Dark Contents in the Center of NGC 6517
Millisecond pulsars can serve as effective probes to investigate the presence
of Intermediate-mass Black Holes (IMBHs) within Galactic globular clusters
(GCs). Based on the standard structure models for GCs, we conduct simulations
to analyze the distributions of pulsar accelerations within the central region
of NGC 6517. By comparing the measured accelerations of pulsars obtained from
their period derivatives to the simulated distribution profiles, we
demonstrate that a central excess of dark mass is required to account for the
measured accelerations. Our analysis, which relies on existing pulsar timing
observations, is currently unable to differentiate between two possible
scenarios: an IMBH precisely situated at the core of the cluster with mass
, or a central concentration of stellar
mass dark remnants with a comparable total mass. However, with additional
acceleration measurements from a few more pulsars in the cluster, it will be
possible to differentiate the source of the nonluminous matter.Comment: 6 pages, 3 figures, 1 table. Accepted for publication in MNRA
Design and test of powerful air-assisted sprayer for high stalk crops
The canopies of high stalk crops, such as maize, intersect the rows at the later stages of growth, making conventional sprayers unable to enter the field for spraying. Air-assisted sprayers are often used to improve the deposition of droplets inside the canopy. In this study, the sprayer structure, the air-assisted system, and the spraying system were designed. The air-assisted conveyor system characteristics were numerically analyzed, and the wind-field distribution was tested. The wind-field distribution results showed that the near-ground wind speed exceeded 5 m s-1 in the sampling interval from 10 to 35 metres. The wind field covered a concentrated spatial area with a downward pressure trend, resulting in better drift resistance and penetration. Field tests for droplet distribution were conducted at three maize heights to verify the powerful air-assisted sprayer's technical performance and working quality. The test results showed that the droplet deposition and coverage decreased gradually along the range direction, and the top layer had the highest deposition and coverage across the canopy. The upper canopy of 0 to 12 metres range demonstrated a greater extent of coverage and deposition. The peak deposition area expanded from 9 to 33 metres in the lower canopy, with an average value of 3.77 μg cm-2. The droplet coverage within the 30 to 60 metres range only amounted to 15% to 18% of the total coverage
Differences in the Characteristics and Pathogenicity of Colletotrichum camelliae and C. fructicola Isolated From the Tea Plant [Camellia sinensis (L.) O. Kuntze]
Colletotrichum, the causative agent of anthracnose, is an important pathogen that invades the tea plant (Camellia sinensis). In this study, 38 isolates were obtained from the diseased leaves of tea plants collected in different areas of Zhejiang Province, China. A combination of multigene (ITS, ACT, GAPDH, TUB2, CAL, and GS) and morphology analyses showed that the 38 strains belonged to two different species, namely, C. camelliae (CC), and C. fructicola (CF). Pathogenicity tests revealed that CC was more invasive than CF. In vitro inoculation experiments demonstrated that CC formed acervuli at 72 hpi and developed appressoria on wound edges, but CF did not develop these structures. Under treatment with catechins and caffeine, the growth inhibition rates of CF were remarkably higher than those of CC, indicating that the nonpathogenic species CF was more vulnerable to catechins and caffeine. Growth condition testing indicated that CF grew at a wide temperature range of 15–35°C and that the optimum temperature for CC growth was 25°C. Growth of both CC and CF did not differ between acidic and weakly alkaline environments (pH 5–8), but the growth of CC was significantly reduced at pH values of 9 and 10. Furthermore, the PacC/RIM101 gene, which associated with pathogenicity, was identified from CC and CF genomes, and its expression was suppressed in the hyphae of both species under pH value of 5 and 10, and much lower expression level was detected in CC than that in CF at pH 6. These results indicated that temperature has more important effect than pH for the growth of two Colletotrichum species. In conclusion, the inhibition by secondary metabolite is an important reason why the pathogenicity by CC and CF are different to tea plant, although the environmental factors including pH and temperature effect the growth of two Colletotrichum species
Comprehensive Evaluation of Tea Cultivars Suitable for Matcha Production Using Multivariate Statistical Analysis
Matcha was prepared from 36 tea cultivars grown in the same tea garden according to the shading requirements for fresh leaves to be used for the production of matcha and its 11 quality indexes such as sensory quality, major physicochemical properties and chroma values were analyzed. In order to select tea cultivars suitable for the manufacturing of matcha, a comprehensive evaluation model of matcha quality was established by cluster analysis (CA), principal component analysis (PCA) and multiple linear regression analysis. The CA results showed that the 36 cultivars could be divided into three groups. Matcha from group I had the best quality with green color, fresh and mellow taste, and low phenol/ammonia ratio. Matcha from group II had high phenol/ammonia ratio and strong astringent taste. Matcha from Group III, consisting of etiolated and albino cultivars, had poor color and aroma quality. The PCA results showed that the cumulative contribution rate of the first five principal components was 88.152%. Comprehensive evaluation of matcha using the evaluation function constructed based on the first five principal components showed that the top 10 cultivars were Zhongcha 102, Taicha 12, Zhongcha 108, Fuding Dahao, Meizhan, Fuding Dabai, Fuyun 6, Zi Mudan, Maolv and Yingshuang. The model describing the relationship between sensory quality and physicochemical properties established by multiple linear regression analysis was as follows: y = 3.167|a*| + 46.850 (R2 = 0.710, P < 0.001). The scores of matcha cultivars evaluated by this model were highly consistent with the comprehensive evaluation results based on principal components, indicating that the a* value of dried tea could be used as a representative index to evaluate the quality of matcha. The results of this study can provide a reference for evaluating the suitability of tea cultivars for matcha manufacturing
Increased Formation of Follicular Antrum in Aquaporin-8-Deficient Mice Is Due to Defective Proliferation and Migration, and Not Steroidogenesis of Granulosa Cells
Aquaporin-8 (AQP8) is a water channel protein expressed exclusively in granulosa cells (GCs) in mouse ovary. Our previous studies of AQP8-deficient (AQP8-/-) mice demonstrated that AQP8 participates in folliculogenesis, including in the formation of follicles, ovulation, and atresia. However, its physiological function in formation of the antral follicle is still largely unknown. In the present study, we observed significantly increased numbers of antral follicles in AQP8-/- ovaries as well as significantly increased follicular antrum formation in in vitro 3D culture of AQP8-/- follicles. Functional detection of AQP8-/- GCs indicated that cell proliferation is impaired with FSH treatment, and wound healing and Transwell migration are also impaired with or without FSH treatment, compared with that in WT. However, the biosynthesis of estradiol and progesterone as well as the mRNA levels of key steroidogenic enzyme genes (CYP19A1 and StAR) in AQP8-/- GCs did not change, even with addition of FSH and/or testosterone. In order to estimate the influence of the impaired proliferation and migration on the density of GC mass, preantral follicles were injected with FITC-dextran, which distributes only in the intercellular space, and analyzed by confocal microscopy. The micrographs showed significantly higher transmission of fluorescence in AQP8-/- follicles, suggesting increased intercellular space of GCs. Based on this evidence, we concluded that AQP8 deficiency leads to increased formation of follicular antra in vivo and in vitro, and the mechanism may be associated with increased intercellular space of GCs, which may be caused by defective proliferation and migration of GCs. This study may offer new insight into the molecular mechanisms of the formation of follicular antrum
A repeating fast radio burst associated with a persistent radio source
The dispersive sweep of fast radio bursts (FRBs) has been used to probe the ionized baryon content of the intergalactic medium1, which is assumed to dominate the total extragalactic dispersion. Although the host-galaxy contributions to the dispersion measure appear to be small for most FRBs2, in at least one case there is evidence for an extreme magneto-ionic local environment3,4 and a compact persistent radio source5. Here we report the detection and localization of the repeating FRB 20190520B, which is co-located with a compact, persistent radio source and associated with a dwarf host galaxy of high specific-star-formation rate at a redshift of 0.241 ± 0.001. The estimated host-galaxy dispersion measure of approximately 903−111+72 parsecs per cubic centimetre, which is nearly an order of magnitude higher than the average of FRB host galaxies2,6, far exceeds the dispersion-measure contribution of the intergalactic medium. Caution is thus warranted in inferring redshifts for FRBs without accurate host-galaxy identifications
Compromised Mitochondrial Fatty Acid Synthesis in Transgenic Mice Results in Defective Protein Lipoylation and Energy Disequilibrium
A mouse model with compromised mitochondrial fatty acid synthesis has been engineered in order to assess the role of this pathway in mitochondrial function and overall health. Reduction in the expression of mitochondrial malonyl CoA-acyl carrier protein transacylase, a key enzyme in the pathway encoded by the nuclear Mcat gene, was achieved to varying extents in all examined tissues employing tamoxifen-inducible Cre-lox technology. Although affected mice consumed more food than control animals, they failed to gain weight, were less physically active, suffered from loss of white adipose tissue, reduced muscle strength, kyphosis, alopecia, hypothermia and shortened lifespan. The Mcat-deficient phenotype is attributed primarily to reduced synthesis, in several tissues, of the octanoyl precursors required for the posttranslational lipoylation of pyruvate and a-ketoglutarate dehydrogenase complexes, resulting in diminished capacity of the citric acid cycle and disruption of energy metabolism. The presence of an alternative lipoylation pathway that utilizes exogenous free lipoate appears restricted to liver and alone is insufficient for preservation of normal energy metabolism. Thus, de novo synthesis of precursors for the protein lipoylation pathway plays a vital role in maintenance of mitochondrial function and overall vigo
Sea surface temperature records of core ZY2 from the central mud area in the South Yellow Sea during last 6200 years and related effect of the Yellow Sea Warm Current
Research on the Intelligent Construction of the Rebar Project Based on BIM
Rebar engineering in the construction industry lacks effective technical means and has a high processing cost and high waste rate. Under the background of intelligent construction, the centralized processing mode of steel bars in prefabricated factories realizes the automatic processing of steel bars and improves the processing efficiency of steel bars. Using the C# programming language, combined with Revit secondary development technology, the automatic generation of the rebar model and the automatic export of rebar drawing are realized, which saves time for the designers to build the model. The calculation method of the cutting length of the steel bar is analyzed in this paper, which can be used as a reference for the subsequent optimization research of steel bar cutting. The assembly position information of the steel bar was introduced into an Excel table to help realize the automatic assembly of the steel bar cage and the intelligent construction of the steel bar. Combined with mixed reality technology, project personnel can interact with the reinforced BIM model through the mixed reality device Hololens2 to guide construction remotely
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