The Relationship Between Teachers’ Perception Toward Principal’s Leadership Behavior and School Climate Among Nursery & Kindergarten Sections in An International School of Thailand

This study was conducted mainly to determine if there was significant relationship between teachers’ perception towards principal’s leadership behavior and school climate among Nursery & Kindergarten sections in an International school of Thailand in academic year 2016 – 2017. Questionnaires composed of Leader Behavior Description and the Organization Climate Description items were given to 53 of full-time teachers in this study. The study found that teachers in Nursery & Kindergarten sections were perceived their principal as task behavior leader, and the school climate were positive. Moreover, there was a significant relationship between teachers’ perception towards principal’s leadership behavior and school climate among Nursery & Kindergarten sections in an International school of Thailand

Temperature dependence of circular DNA topological states

Circular double stranded DNA has different topological states which are defined by their linking numbers. Equilibrium distribution of linking numbers can be obtained by closing a linear DNA into a circle by ligase. Using Monte Carlo simulation, we predict the temperature dependence of the linking number distribution of small circular DNAs. Our predictions are based on flexible defect excitations resulted from local melting or unstacking of DNA base pairs. We found that the reduced bending rigidity alone can lead to measurable changes of the variance of linking number distribution of short circular DNAs. If the defect is accompanied by local unwinding, the effect becomes much more prominent. The predictions can be easily investigated in experiments, providing a new method to study the micromechanics of sharply bent DNAs and the thermal stability of specific DNA sequences. Furthermore, the predictions are directly applicable to the studies of binding of DNA distorting proteins that can locally reduce DNA rigidity, form DNA kinks, or introduce local unwinding.Comment: 15 pages in preprint format, 4 figure

Large deformation of spherical vesicle studied by perturbation theory and Surface evolver

With tangent angle perturbation approach the axial symmetry deformation of a spherical vesicle in large under the pressure changes is studied by the elasticity theory of Helfrich spontaneous curvature model.Three main results in axial symmetry shape: biconcave shape, peanut shape, and one type of myelin are obtained. These axial symmetry morphology deformations are in agreement with those observed in lipsome experiments by dark-field light microscopy [Hotani, J. Mol. Biol. 178, (1984) 113] and in the red blood cell with two thin filaments (myelin) observed in living state (see, Bessis, Living Blood Cells and Their Ultrastructure, Springer-Verlag, 1973). Furthermore, the biconcave shape and peanut shape can be simulated with the help of a powerful software, Surface Evolver [Brakke, Exp. Math. 1, 141 (1992) 141], in which the spontaneous curvature can be easy taken into account.Comment: 16 pages, 6 EPS figures and 2 PS figure

Instability and Periodic Deformation in Bilayer Membranes Induced by Freezing

The instability and periodic deformation of bilayer membranes during freezing processes are studied as a function of the difference of the shape energy between the high and the low temperature membrane states. It is shown that there exists a threshold stability condition, bellow which a planar configuration will be deformed. Among the deformed shapes, the periodic curved square textures are shown being one kind of the solutions of the associated shape equation. In consistency with recent expe rimental observations, the optimal ratio of period and amplitude for such a texture is found to be approximately equal to (2)^{1/2}\pi.Comment: 8 pages in Latex form, 1 Postscript figure. To be appear in Mod. Phys. Lett. B. 199

Bis{μ-2-[(2-oxidobenzyl­idene)amino­meth­yl]phenolato-κ3 O,N,O′}bis­[(pyridine-κN)zinc(II)]

In the title centrosymmetric zinc(II) complex, [Zn2(C4H13NO2)2(C6H5N)2], each ZnII atom is coordinated by two 2-[(2-oxidobenzyl­idene)amino­meth­yl]phenolate (L) ligands and one pyridine (py) mol­ecule in a distorted trigonal-bipyramidal geometry. Each L ligand behaves as a tridentate ligand and provides a phenolate oxygen bridge which links the two ZnII atoms. The ZnL(py) units are linked by π–π inter­actions between adjacent pyridine mol­ecules, with a centroid–centroid distance of 3.724 Å, resulting in a two-dimensional structure

Malaria incidence from 2005–2013 and its associations with meteorological factors in Guangdong, China

Background: The temporal variation of malaria incidence has been linked to meteorological factors in many studies, but key factors observed and corresponding effect estimates were not consistent. Furthermore, the potential effect modification by individual characteristics is not well documented. This study intends to examine the delayed effects of meteorological factors and the sub-population's susceptibility in Guangdong, China. Methods: The Granger causality Wald test and Spearman correlation analysis were employed to select climatic variables influencing malaria. The distributed lag non-linear model (DLNM) was used to estimate the non-linear and delayed effects of weekly temperature, duration of sunshine, and precipitation on the weekly number of malaria cases after controlling for other confounders. Stratified analyses were conducted to identify the sub-population's susceptibility to meteorological effects by malaria type, gender, and age group. Results: An incidence rate of 1.1 cases per 1,000,000 people was detected in Guangdong from 2005-2013. High temperature was associated with an observed increase in malaria incidence, with the effect lasting for four weeks and a maximum relative risk (RR) of 1.57 (95% confidence interval (CI): 1.06-2.33) by comparing 30°C to the median temperature. The effect of sunshine duration peaked at lag five and the maximum RR was 1.36 (95% CI: 1.08-1.72) by comparing 24 hours/week to 0 hours/week. A J-shaped relationship was found between malaria incidence and precipitation with a threshold of 150 mm/week. Over the threshold, precipitation increased malaria incidence after four weeks with the effect lasting for 15 weeks, and the maximum RR of 1.55 (95% CI: 1.18-2.03) occurring at lag eight by comparing 225 mm/week to 0 mm/week. Plasmodium falciparum was more sensitive to temperature and precipitation than Plasmodium vivax. Females had a higher susceptibility to the effects of sunshine and precipitation, and children and the elderly were more sensitive to the change of temperature, sunshine duration, and precipitation. Conclusion: Temperature, duration of sunshine and precipitation played important roles in malaria incidence with effects delayed and varied across lags. Climatic effects were distinct among sub-groups. This study provided helpful information for predicting malaria incidence and developing the future warning system.School of Nursin

Enhanced Hygrothermal Stability of In-Situ-Grown MAPbBr₃ Nanocrystals in Polymer with Suppressed Desorption of Ligands

Currently, the intrinsic instability of organic-inorganic hybrid perovskite nanocrystals (PNCs) at high temperature and high humidity still stands as a big barrier to hinder their potential applications in optoelectronic devices. Herein, we report the controllable in-situ-grown PNCs in polyvinylidene fluoride (PVDF) polymer with profoundly enhanced hygrothermal stability. It is found that the introduced tetradecylphosphonic acid (TDPA) ligand enables significantly improved binding to the surface of PNCs via a strong covalently coordinated P-O-Pb bond, as evidenced by density functional theory calculations and X-ray photoelectron spectroscopy analyses. Accordingly, such enhanced binding could not only make efficient passivation of the surface defects of PNCs but also enable the remarkably suppressed desorption of the ligand from the PNCs under high-temperature environments. Consequently, the photoluminescence quantum yield (PL QY) of the as-fabricated MAPbBr3-PNCs@PVDF film exhibits almost no decay after exposure to air at 333 K over 1800 h. Once the temperatures are increased from 293 to 353 K, their PL intensity can be kept as 88.6% of the initial value, much higher than that without the TDPA ligand (i.e., 42.4%). Moreover, their PL QY can be maintained above 50% over 1560 h (65 days) under harsh working conditions of 333 K and 90% humidity. As a proof of concept, the as-assembled white light-emitting diodes display a large color gamut of 125% National Television System Committee standard, suggesting their promising applications in backlight devices.</p

Numerical observation of non-axisymmetric vesicles in fluid membranes

By means of Surface Evolver (Exp. Math,1,141 1992), a software package of brute-force energy minimization over a triangulated surface developed by the geometry center of University of Minnesota, we have numerically searched the non-axisymmetric shapes under the Helfrich spontaneous curvature (SC) energy model. We show for the first time there are abundant mechanically stable non-axisymmetric vesicles in SC model, including regular ones with intrinsic geometric symmetry and complex irregular ones. We report in this paper several interesting shapes including a corniculate shape with six corns, a quadri-concave shape, a shape resembling sickle cells, and a shape resembling acanthocytes. As far as we know, these shapes have not been theoretically obtained by any curvature model before. In addition, the role of the spontaneous curvature in the formation of irregular crenated vesicles has been studied. The results shows a positive spontaneous curvature may be a necessary condition to keep an irregular crenated shape being mechanically stable.Comment: RevTex, 14 pages. A hard copy of 8 figures is available on reques