Development of Competency Indexes to Assess Nursing Postgraduate's Tutor

The aim of this study was to develop competency indexes assessing nursingpostgraduate's tutor in China. Based on Iceberg competency theory, a Delphisurvey was carried out. 30 nursing experts in 16 provinces of China wereinvited to rate the importance of indexes and give some comments on thecontent. There were 22 experts taking part in two rounds Delphi study. AKendall's W test also demonstrated experts were well coordinated. Duringthe first round, overall mean scores were high, except for 1 tertiary index.We also added and moved some indexes building on the experts'suggestions. After two rounds, we developed competency indexesappropriate to assess tutots' competencies, consisting of 5 preliminaryindexes, 13 secondary indexes and 68 tertiary indexes. The competencyindexes were validated and scientific, it can be used to assess tutors in China

Vegetation patches increase wind-blown litter accumulation in a semi-arid steppe of northern China

Litter decomposition is an important source of soil organic matter and nutrients; however, few studies have explored how vegetation patches affect wind-driven litter mobility and accumulation. In this study, we aimed to test the following hypotheses: (1) vegetation patches can reduce litter removal and facilitate litter accumulation, (2) litter mobility results in the heterogeneous redistribution of carbon and nutrients over the land surface, and (3) litter removal rates differ among different litter types (e.g., leaf and stem). Four vegetation patch types and six litter types were used to investigate the impacts of vegetation patches on litter mobility and accumulation. The results show that compared with almost bare ground patches, patches with vegetation cover had significantly higher litter accumulation, with the shrub patch type having the highest accumulation amount. The rate of litter removal due to wind was highest for the almost bare surface type (P4) and lowest for the shrub patch (P1) and Stipa grandis community (P2) types. There were significant differences in the removal rate among the different litter types. These findings indicate that wind-based litter redistribution among bare, S. grandis -dominated, and shrub-dominated patches is at least partially responsible for increasing the spatial heterogeneity of resources on a landscape scale

Simultaneous Metal-Insulator and Antiferromagnetic Transitions in Orthorhombic Perovskite Iridate Sr0.94Ir0.78O2.68 Single Crystals

The orthorhombic perovskite SrIrO3 is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose a novel insulating state. We report results of our investigation of bulk single-crystal Sr0.94Ir0.78O2.68 or Ir-deficient, orthorhombic perovskite SrIrO3. It retains the same crystal structure as stoichiometric SrIrO3 but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear-temperature dependence up to 800 K but the strong electronic anisotropy renders an insulating behavior in the out-of-plane resistivity. The Hall resistivity undergoes an abrupt sign change and grows below 40 K, which along with the Sommerfeld constant of 20 mJ/mole K2 suggests a multiband effect. All results including our first-principles calculations underscore a delicacy of the metallic state in SrIrO3 that is in close proximity to an AFM insulating state. The contrasting ground states in isostructural Sr0.94Ir0.78O2.68 and SrIrO3 illustrate a critical role of even slight lattice distortions in rebalancing the ground state in the iridates. Finally, the observed simultaneous AFM and MI transitions reveal a direct correlation between the magnetic transition and formation of a charge gap in the iridate, which is conspicuously absent in Sr2IrO4.Comment: 5 figure

Anisotropic nonlinear elasticity in a spherical bead pack: influence of the fabric anisotropy

Stress-strain measurements and ultrasound propagation experiments in glass bead packs have been simultaneously conducted to characterize the stress-induced anisotropy under uniaxial loading. These measurements, realized respectively with finite and incremental deformations of the granular assembly, are analyzed within the framework of the effective medium theory based on the Hertz-Mindlin contact theory. Our work shows that both compressional and shear wave velocities and consequently the incremental elastic moduli agree fairly well with the effective medium model by Johnson et al. [J. Appl. Mech. 65, 380 (1998)], but the anisotropic stress ratio resulting from finite deformation does not at all. As indicated by numerical simulations, the discrepancy may arise from the fact that the model doesn't properly allow the grains to relax from the affine motion approximation. Here we find that the interaction nature at the grain contact could also play a crucial role for the relevant prediction by the model; indeed, such discrepancy can be significantly reduced if the frictional resistance between grains is removed. Another main experimental finding is the influence of the inherent anisotropy of granular packs, realized by different protocols of the sample preparation. Our results reveal that compressional waves are more sensitive to the stress-induced anisotropy, whereas the shear waves are more sensitive to the fabric anisotropy, not being accounted in analytical effective medium models.Comment: 9 pages, 8 figure

A newly synthetic chromium complex – chromium(phenylalanine)3 improves insulin responsiveness and reduces whole body glucose tolerance

AbstractLow-molecular-weight organic chromium complexes such as chromium picolinate are often used as dietary supplements to improve insulin sensitivity and to correct dyslipidemia. However, toxicity associated with such chromium compounds has compromised their therapeutic value. The aim of this study was to evaluate the impact of a newly synthesized complex of chromium with phenylalanine, Cr(pa)3 on insulin-signaling and glucose tolerance. Cr(pa)3 was synthesized by chelating chromium(III) with d-phenylalanine ligand in aqueous solution. In mouse 3T3-adipocytes, Cr(pa)3 augmented insulin-stimulated glucose-uptake as assessed by a radioactive-glucose uptake assay. At the molecular level, Cr(pa)3 enhanced insulin-stimulated phosphorylation of Akt in a time- and concentration-dependent manner without altering the phosphorylation of insulin receptor. Oral treatment with Cr(pa)3 (150μg/kg/d, for six weeks) in ob/ob(+/+) obese mice significantly alleviated glucose tolerance compared with untreated obese mice. Unlike chromium picolinate, Cr(pa)3 does not cleave DNA under physiological reducing conditions. Collectively, these data suggest that Cr(pa)3 may represent a novel, less-toxic chromium supplement with potential therapeutic value to improve insulin sensitivity and glycemic control in type II diabetes

Finite-time trajectory tracking control for rigid 3-DOF manipulators with disturbances

This paper addresses the robust finite time trajectory tracking control problem for a rigid three-degrees-of-freedo

Simultaneous Metal-Insulator and Antiferromagnetic Transitions in Orthorhombic Perovskite Iridate Sr\u3csub\u3e0.94\u3c/sub\u3eIr\u3csub\u3e0.78\u3c/sub\u3eO\u3csub\u3e2.68\u3c/sub\u3e Single Crystals

The orthorhombic perovskite SrIrO3 is a semimetal, an intriguing exception in iridates where the strong spin-orbit interaction coupled with electron correlations tends to impose an insulating state. We report results of our investigation of bulk single-crystal Sr0.94Ir0.78O2.68 or Ir-deficient, orthorhombic perovskite SrIrO3. It retains the same crystal structure as stoichiometric SrIrO3 but exhibits a sharp, simultaneous antiferromagnetic (AFM) and metal-insulator (MI) transition occurring in the basal-plane resistivity at 185 K. Above it, the basal-plane resistivity features an extended regime of almost linear temperature dependence up to 800 K but the strong electronic anisotropy renders an insulating behavior in the out-of-plane resistivity. The Hall resistivity undergoes an abrupt sign change and grows below 40 K, which along with the Sommerfeld constant of 20mJ/molK2 suggests a multiband effect. All results including our first-principles calculations underscore a delicacy of the paramagnetic, metallic state in SrIrO3 that is in close proximity to an AFM insulating state. The contrasting ground states in isostructural Sr0.94Ir0.78O2.68 and SrIrO3 illustrate a critical role of lattice distortions and Ir deficiency in rebalancing the ground state in the iridates. Finally, the concurrent AFM and MI transitions reveal a direct correlation between the magnetic transition and formation of an activation gap in the iridate, which is conspicuously absent in Sr2IrO4

Optimal scheduling of microgrid with distributed power based on water cycle algorithm

Microgrid, taking advantage of distributed power generation technology, plays an important role in maximizing the utilization of renewable energy. Based on the problems of the energy crisis, environmental contamination and the high operating cost of the microgrid, the microgrid model can effectively ease energy pressure.We can dispatch the output of each part in the microgrid to obtain the optimal economy. Since many traditional optimization algorithms have limitations of local optimization, multiple iterations, and slow convergence speed, this paper proposes a method that applies the Water Cycle Algorithm (WCA) to optimize the dispatch of the microgrid to minimize the operating cost. The mathematical model of each distributed power is established. The interactive power between the microgrid and large grid is also considered. The lowest generation cost considering environmental benefits is taken as the objective function. Water cycle algorithm is implemented to obtain the optimal solution under various constraints. Some optimization algorithms such as Genetic Algorithm (GA), Interior Search Algorithm (ISA), and Differential Search Algorithm (DSA) were used for results evaluation. By comparing the results obtained from four different algorithms, a case study shows the WCA possesses the advancements of better convergence performance, faster calculation and higher precision compared to the other algorithms. The results demonstrate that the WCA applied to determine the optimal scheduling of the microgrid can achieve a better result than some other algorithms with an acceptable accuracy and efficiency

Udwadia-Kalaba Approach for Three Link Manipulator Dynamics With Motion Constraints

Aiming to dynamic modeling of a three-link manipulator subjected to motion constraints, a novel explicit approach to the dynamical equations based on Udwadia-Kalaba (UK) theory is established. The motion constraints on the three-link manipulator can be regarded as external constraints of the system. However, it is not easy to obtain explicit equations for the dynamic modeling of constrained systems. For a multibody system subjecting to motion constraints, it is common to introduce Lagrange multipliers, but obtaining an explicit dynamical equation using traditional Lagrange multipliers is difficult. In order to obtain such equations more simply, motion constraints are handled using the UK equation. Compared with the Lagrange method, the UK approach can simplify the analysis and solution of a constrained system, without the need to introduce additional auxiliary variables to solve the Lagrange equation. Based on a more real-life nominal system (whose parameters are known) model considering the uncertain environment, this paper develops a nonlinear controller that satisfies the required trajectory. This controller allows the nonlinear nominal system to track the desired trajectory exactly without linearizations or approximations. These continuous controllers compensate extra force to eliminate the errors caused by uncertainties. The controllers are based on a generalization of sliding surfaces. Error bounds on tracking caused by uncertainties are analytically obtained. The numerical results show the simplicity and efficacy of the proposed methodology, and the reliability of the error bounds