177 research outputs found
Discrete Optimal Control Method Based on the Optimal Strategy of Fishing
Consideration was given to the discrete optimal control method for the optimal fishing strategy. Our method is new and efficient for discrete optimal control problem, which is different from the other optimal methods such as the traditional variational method, the Pontryagin principle of maximum, and the dynamic programming. The basic construction of the model is the traditional logistic function relating to the growth of fry. The discrete optimal control method for optimal fishing strategy was used to construct the optimal rate of each fishing strategy; the main focus of our work is on the rigorous mathematical analysis of the optimal control problem. The analysis allows one to obtain the optimal initial investment amount of the fry and the optimal size of the total catch. Furthermore, when the initial investment amount of the fry is below or above the optimal value and the intrinsic growth rate of fish R is too small, we derive that fishing operations should not be started in the last few years to make the overall fishing amount optimal. At last, several typical examples are given to illustrate the obtained results
THE EFFECT OF EMPLOYEE’S COMMITMENTS ON CUSTOMER’S LOYALTY BASED ON TRANSACTION COST
Few researchers, such as Hansen, Sandvick and Selnes (2003) and Jones, Taylor and Bansal (2008), have
mentioned about the effect of employee’s commitments and individual commitment on consumer’s
loyalty for products. This study aims to integrate the organizational commitment provided by Hansen,
Sandvik and Selnes (2003) with the affective commitment and the calculative commitment presented by
Jones et al. (2008) to explore the three types of commitments which affect customer’s loyalty to the
providers. Individual commitment, employee commitment, affective commitment and calculative
commitment are selected as research variables. The research attempts to understand the factors and
the effects of different commitments on consumer’s loyalty and consumer’s willing to continue
consumptions under the agent’s services from the different insurance companies. The 300 consumers
serviced by insurance agents are selected as research samples. The research method is applied
questionnaires analyzed by multiple Hierarchical Regression analysis. The research results show that
employee’s commitments and individual commitments positively influence the calculative commitment
and the affective commitment which affect consumer’s loyalty. Transaction cost does not have positive
effect on consumer’s loyalty
Serum microRNAs as biomarkers for the diagnosis of papillary thyroid carcinoma: a meta-analysis
Papillary thyroid carcinoma (PTC) is the most common form of thyroid cancer. Several studies have proposed serum microRNAs (miRNAs) as novel biomarkers for diagnosing PTC. In this study, we conducted a meta-analysis aiming to investigate the overall diagnostic accuracy of serum miRNAs in PTC detection. Three online databases including PubMed, EMBASE and Cochrane Library were searched up to 1 May 2021. We systematically reviewed studies evaluating the value of serum miRNAs in diagnosing PTC, and then summarized the area under receiver operating characteristics curve (AUROC), sensitivity, specificity, and diagnostic odds ratio to assess the accuracy of serum miRNAs for the discrimination between patients with PTC and patients with benign thyroid nodules and healthy controls. We included 32 studies from 6 articles. Overall, there were 463 PTC patients, 334 patients with benign thyroid nodules, and 104 healthy controls. The results showed that the summary sensitivity and specificity were 76% (95% confidence interval [CI]: 68%‒83%) and 86% (95% CI: 80%‒91%), respectively, and that the summary AUROC was 0.89 (95% CI: 0.86‒0.91), when serum miRNAs were used for discriminating between PTC patients and those with benign nodules. On the other hand, the summary sensitivity and specificity of serum miRNAs for discriminating between PTC patients and healthy controls were 82% (95% CI: 77%‒86%) and 84% (95% CI: 76%‒90%), respectively, and the summary AUROC was 0.89 (95% CI: 0.86‒0.92). We found that serum miRNAs have good diagnostic performance for the discrimination between patients with PTC and patients with benign nodules and healthy controls, and thus have considerable potential as novel minimally invasive tools for detecting PTC
Thermodynamic properties of higher-dimensional dS black holes in dRGT massive gravity
On the basis of the state parameter of de Sitter space-time satisfying the
first law of thermodynamics,we can derive some effective thermodynamic
quantities.When the temperature of the black hole horizon is equal to that of
the cosmological horizon, we think that the effective temperature of the
space-time should have the same value. Using this condition, we obtain a
differential equation of the entropy of the de Sitter black hole in the
higherdimensional de Rham, Gabadadze and Tolley (dRGT) massive gravity. Solving
the differential equation, we obtain the corrected entropy and effective
thermodynamic quantities of the de Sitter black hole. The results show that for
multiparameter black holes, the entropy satisfied differential equation is
invariable with different independent state parameters. Therefore, the entropy
of higher-dimensional dS black holes in dRGT massive gravity is only a function
of the position of the black hole horizon, and is independent of other state
parameters. It is consistent with the corresponding entropy of the black hole
horizon and the cosmological horizon. The thermodynamic quantities of
self-consistent de Sitter spacetime are given theoretically, and the equivalent
thermodynamic quantities have the second-order phase transformation similar to
AdS black hole, but unlike AdS black hole, the equivalent temperature of de
Sitter space-time has a maximum value. By satisfying the requirement of
thermodynamic equilibrium and stability of space-time, the conditions for the
existence of dS black holes in the universe are obtained.Comment: 11 pages, 6 figure
Biodiversity of wild alfalfa pollinators and their temporal foraging characters in Hexi Corridor, Northwest China
Seed production of alfalfa (Medicago sativa L.) is important in determining the effective distribution of new cultivars to farmers. However, little is known about the biodiversity and their community function of native wild pollinators of alfalfa in agronomic systems. We investigated the biodiversity of insects which visited alfalfa flowers and their temporal foraging characters in Hexi Corridor, China. A high biodiversity of insect visitors was discovered, 20 insect taxa in all, including 13 species of Hymenoptera, 3 species of Coleoptera, 3 species of Lepidoptera and 1 species of Diptera. Three native bee species, Andrena squamata, Anthophora melanognatha and Megachile abluta,were validated as the principal pollinators. They showed significant variations in tripping mode and their diurnal distribution patterns. Our results indicated that the native wild bees are diverse and they complement each other. This means they have developed a more complex system for the pollination of alfalfa than has been previously found out
2-Amino-4-(4-chlorophenyl)-6-ferrocenylpyridine-3-carbonitrile
In the molecule of the title compound, [Fe(C5H5)(C17H11ClN3)], the dihedral angles between the two five–membered rings and between the two six-membered rings are 3.28 (4) and 51.33 (4)°, respectively. In the crystal structure, intermolecular N—H⋯N hydrogen bonds link the molecules into centrosymmetric dimers
miRNA-378 reverses chemoresistance to cisplatin in lung adenocarcinoma cells by targeting secreted clusterin
Cisplatin resistance is a major obstacle in the treatment of NSCLC, and its mechanism has not been fully elucidated. The objectives of the study were to determine the role of miR-378 in the sensitivity of lung adenocarcinoma cells to cisplatin (cDDP) and its working mechanism. With TargetScan and luciferase assay, miR-378 was found to directly target sCLU. miR-378 and sCLU were regulated in A549/cDDP and Anip973/cDDP cells to investigate the effect of miR-378 on the sensitivity and apoptotic effects of cDDP. The effect of miR-378 upregulation on tumor growth was analyzed in a nude mouse xenograft model. The correlation between miR-378 and chemoresistance was tested in patient samples. We found that upregulation of miR-378 in A549/cDDP and Anip973/cDDP cells significantly down-regulated sCLU expression, and sensitized these cells to cDDP. miR-378 overexpression inhibited tumor growth and sCLU expression in a xenograft animal model. Analysis of human lung adenocarcinoma tissues revealed that the cDDP sensitive group expressed higher levels of miR-378 and lower levels of sCLU. miR-378 and sCLU were negatively correlated. To conclude, we identified sCLU as a novel miR-378 target, and we showed that targeting sCLU via miR-378 may help disable the chemoresistance against cisplatin in lung adenocarcinoma cells
Efficient gene editing in adult mouse livers via adenoviral delivery of CRISPR/Cas9
AbstractWe developed an adenovirus-based CRISPR/Cas9 system for gene editing in vivo. In the liver, we demonstrated that the system could reach the level of tissue-specific gene knockout, resulting in phenotypic changes. Given the wide spectrum of cell types susceptible to adenoviral infection, and the fact that adenoviral genome rarely integrates into its host cell genome, we believe the adenovirus-based CRISPR/Cas9 system will find applications in a variety of experimental settings
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