2,363 research outputs found
Validation of the Organizational Culture Assessment Instrument: An Application of the Korean Version
The purpose of this study was to examine the psychometric properties of the Korean version of the Organizational Culture Assessment Instrument (OCAI) based on the Competing Values Framework (CVF). More specially, cultural equivalence between the Korean version and the original English version of the OCAI was evaluated using 39 bilingual Koreans. Next, a field test was conducted to examine scale reliability and construct validity of the Korean version of the OCAI using 133 organizational members from the Korean Professional Baseball League (KPBL). The findings indicate that the Korean version was successfully translated, items maintained the same meaning of the original OCAI items, and yielded acceptable psychometric properties making it applicable to Korean sport organizations
Spontaneous generation and active manipulation of real-space optical vortex
Optical vortices host the orbital nature of photons, which offers an extra
degree of freedom in photonic applications. Unlike vortices in other physical
entities, optical vortices require structural singularities, which restrict
their abilities in terms of dynamic and interactive characteristics. In this
study, we present the spontaneous generation and external magnetic
field-induced manipulation of an optical vortex and antivortex. A
gradient-thickness optical cavity (GTOC) consisting of an Al/SiO2/Ni/SiO2
multilayer structure realised the distinct transition between the trivial and
non-trivial topological phases, depending on the magneto-optic effects of the
Ni layer. In the non-trivial topological phase, the mathematical singularities
generating the optical vortex and antivortex pair in the reflected light
existed in the generalised parameter space of the thicknesses of the top and
bottom SiO2 layers, which is bijective to the real space of the GTOC. Coupled
with the magnetisation, the optical vortex and antivortex in the GTOC
experienced an effective spin-orbit interaction and showed topology-dependent
dynamics under external magnetic fields. We expect that field-induced
engineering of optical vortices will pave the way for the study of topological
photonic interactions and their applications.Comment: 22 pages, 4 figure
Optical spectroscopic investigation on the coupling of electronic and magnetic structure in multiferroic hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films
We investigated the effects of temperature and magnetic field on the
electronic structure of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films
using optical spectroscopy. As the magnetic ordering of the system was
disturbed, a systematic change in the electronic structure was commonly
identified in this series. The optical absorption peak near 1.7 eV showed an
unexpectedly large shift of more than 150 meV from 300 K to 15 K, accompanied
by an anomaly of the shift at the Neel temperature. The magnetic field
dependent measurement clearly revealed a sizable shift of the corresponding
peak when a high magnetic field was applied. Our findings indicated strong
coupling between the magnetic ordering and the electronic structure in the
multiferroic hexagonal RMnO3 compounds.Comment: 16 pages including 4 figure
Southern Hemisphere mid- and high-latitudinal AOD, CO, NO2, and HCHO: spatiotemporal patterns revealed by satellite observations
To assess air pollution emitted in Southern Hemisphere mid-latitudes and transported to Antarctica, we investigate the climatological mean and temporal trends in aerosol optical depth (AOD), carbon monoxide (CO), nitrogen dioxide (NO2), and formaldehyde (HCHO) columns using satellite observations. Generally, all these measurements exhibit sharp peaks over and near the three nearby inhabited continents: South America, Africa, and Australia. This pattern indicates the large emission effect of anthropogenic activities and biomass burning processes. High AOD is also found over the Southern Atlantic Ocean, probably because of the sea salt production driven by strong winds. Since the pristine Antarctic atmosphere can be polluted by transport of air pollutants from the mid-latitudes, we analyze the 10-day back trajectories that arrive at Antarctic ground stations in consideration of the spatial distribution of mid-latitudinal AOD, CO, NO2, and HCHO. We find that the influence of mid-latitudinal emission differs across Antarctic regions: western Antarctic regions show relatively more back trajectories from the mid-latitudes, while the eastern Antarctic regions do not show large intrusions of mid-latitudinal air masses. Finally, we estimate the long-term trends in AOD, CO, NO2, and HCHO during the past decade (2005-2016). While CO shows a significant negative trend, the others show overall positive trends. Seasonal and regional differences in trends are also discussed
Changes of the growth plate in children: 3-dimensional magnetic resonance imaging analysis
Purpose This pilot study assessed changes in the growth plate and growth rates in children during a 6-month period. Methods The study included 31 healthy children (17 boys, 14 girls) under evaluation for growth retardation. Height, weight, bone age, insulin like growth factor-1 (IGF-1), and insulin like growth factor binding protein 3 (IGF-BP3) were measured at baseline and after 6 months. In addition, the diameter, thickness, and volume of the femoral and tibial growth plates were measured using magnetic resonance imaging. Results The mean bone age in boys and girls was 11.7 and 10.7 years, respectively. In boys, height (z score) (-0.2 vs. 0.0), weight (z score) (0.8 vs. 1.1), body mass index (BMI) (z score) (1.27 vs. 1.5), IGF-1 (ng/mL) (343.6 vs. 501.8), and IGF-BP3 (ng/mL) (5,088.5 vs. 5,620.0) were significantly higher after 6 months. In girls, height (z score) (-1.0 vs. -0.7), weight (z score) (-0.5 vs. 0.1), BMI (z score) (-0.02 vs. 0.3), IGF-1 (ng/mL) (329.3 vs. 524.6), and IGF-BP3 (ng/mL) (4,644.4 vs. 5,593.6) were also significantly higher after 6 months. In both sexes, the mean diameter and volume of the femoral and tibial growth plates were significantly increased 6 months later. Conclusion No significant correlation was found between changes in the growth plate and clinical parameters in children with growth retardation in this study, other than correlations of change in femoral diameter with weight and BMI. A larger, long-term study is needed to precisely evaluate the correlation between change in the growth plate and growth
Congenital Heart Disease (Atrioventricular Septal Defect) in the Mouse with Trisomy 16
Failure of fusion between the superior and inferior cushions has
usually been assumed to be the main morphogenetic event in producing hearts
with deficient atrioventricular septation (atrioventricular septal, or endocardial cushion
defects). Morphological studies on human autopsy specimens, however, showed
that another consistent finding is the marked disproportion between the dimensions
of the inlet and outlet of the left ventricle, which, until now, has no known
developmental basis.
We have studied the early formation of the hearts with atrioventricular septal
defects, using a mouse model with trisomy 16. Animals were studied between the
10th and 19th days of gestation by stereomicroscopic examination, scanning electronmlcroscopy
and the in-vitro incorporation of thymidine.
The first detectable morphological abnormality of the heart in the trisomic
mouse was observed on the 11th day, being a persistence of an infolding at the
inferior atrioventricular junction. This infolding was present in both trisomic and
eusomic animals on the 10th day. This morphology could be explained by a differential
growth of the myocardium at the inferior atrioventricular junction, which
was found to be a distinct zone with low incorporation of thymidine. On the 11th
day, the inferior atrioventricular cushion was bigger in the trisomic hearts. The
abnormalities of the cushions observed on the 12th day or later were deemed to
be consequences of these primary defects.
Sectioning of the heart from the left lateral aspect convincingly showed morphological
changes of the superior and inferior cushion or bridging leaflets in this
animal model. Abnormal endocardial cushions and abnormality in the proliferation
index of the myocardium at the inferior atrioventricular junction play more significant
roles in the formation of the hearts with deficient atrioventricular septation,
than the abnormalities found in the atrioventricular cushions
Breakdown of the interlayer coherence in twisted bilayer graphene
Coherent motion of the electrons in the Bloch states is one of the
fundamental concepts of the charge conduction in solid state physics. In
layered materials, however, such a condition often breaks down for the
interlayer conduction, when the interlayer coupling is significantly reduced by
e.g. large interlayer separation. We report that complete suppression of
coherent conduction is realized even in an atomic length scale of layer
separation in twisted bilayer graphene. The interlayer resistivity of twisted
bilayer graphene is much higher than the c-axis resistivity of Bernal-stacked
graphite, and exhibits strong dependence on temperature as well as on external
electric fields. These results suggest that the graphene layers are
significantly decoupled by rotation and incoherent conduction is a main
transport channel between the layers of twisted bilayer graphene.Comment: 5 pages, 3 figure
Electronic structures of hexagonal RMnO3 (R = Gd, Tb, Dy, and Ho) thin films
We investigated the electronic structure of multiferroic hexagonal RMnO3 (R =
Gd, Tb, Dy, and Ho) thin films using both optical spectroscopy and
first-principles calculations. Using artificially stabilized hexagonal RMnO3,
we extended the optical spectroscopic studies on the hexagonal multiferroic
manganite system. We observed two optical transitions located near 1.7 eV and
2.3 eV, in addition to the predominant absorption above 5 eV. With the help of
first-principles calculations, we attribute the low-lying optical absorption
peaks to inter-site transitions from the oxygen states hybridized strongly with
different Mn orbital symmetries to the Mn 3d3z2-r2 state. As the ionic radius
of the rare earth ion increased, the lowest peak showed a systematic increase
in its peak position. We explained this systematic change in terms of a
flattening of the MnO5 triangular bipyramid
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