999 research outputs found
Content-Based Instruction (CBI) for the Social Future: A Recommendation for Critical Content-Based Language Instruction (CCBI)
In this article, we seek to reconceptualize content-based instruction (CBI) curricula and practices from a critical perspective. Further, we propose developing criticality as an essential component of CBI, advocating for an approach we call critical content-based instruction (CCBI). While the importance of CBI has long been recognized, previous discussions predominantly focused on its effectiveness for language learning (and content learning to a lesser degree), and overlooked its fundamental linkage and relevance to broader educational missions. In order to fully maximize the potential of CBI and envision language education as integral to the advancement of society, we argue that a critical approach to CBI should be considered. First, we lay out how CBI came to be and how it has been treated in language pedagogy. We believe CBI is indeed a suitable forum for introducing and implementing a critical perspective because of its original contribution of broadening language education to meet societal needs. Second, we provide an overview of recent discourse surrounding world language education. Based on these reviews, we lastly and most importantly delineate directions for CCBI by presenting examples and possible challenges
Inconsistency in the Standard of CareâToward Evidence-Based Management of Exertional Heat Stroke
Tokyo 2020 Summer Olympics are projected to experience environmental heat stress that surpasses the environmental conditions observed in the Atlanta (1996), Athens (2004), Beijing (2008), and Rio (2016) Summer Olympics. This raises particular concerns for athletes who will likely to be exposed to extreme heat during the competitions. Therefore, in mass-participation event during warm season, it is vital for the hosting organization to build preparedness and resilience against heat, including appropriate treatment, and management strategies for exertional heat stroke (EHS). However, despite the existing literature regarding the evidence-based management of EHS, rectal thermometry and whole-body cold-water immersion are not readily accepted by medical professionals outside of the sports, and military medicine professionals. Current Japanese medical standard is no exception in falling behind on evidence-based management of EHS. Therefore, the first aim of this paper is to elucidate the inconsistency between the standard of care provided in Japan for EHS and what has been accepted as the gold standard by the scientific literature. The second aim of this paper is to provide optimal EHS management strategies that should be implemented at the Tokyo 2020 Summer Olympics from organizational level to maximize the safety of athletes and to improve organizational resilience to heat. The risk of extreme heat is often neglected until a catastrophic incidence occurs. It is vital for the Japanese medical leadership and athletic communities to re-examine the current EHS management strategies and implement evidence-based countermeasure for EHS to expand the application of scientific knowledge
Cold CO Gas in Protoplanetary Disks
In a disk around DM Tau, previous observation of 13CO (J=2-1 and 1-0
transitions) derived the 13CO gas temperature of \sim 13-20K, which is lower
than the sublimation temperature of CO (20 K). We argue that the existence of
such cold CO can be explained by a vertical mixing of disk material. As the gas
is transported from a warm layer to a cold layer, CO is depleted onto dust
grains with a timescale of \sim 10^3 yr. Because of the steep temperature
gradient in the vertical direction, an observable amount of CO is still in the
gas phase when the fluid parcel reaches the layer of \sim 13 K. Apparent
temperature of CO decreases as the maximum grain size increases from
micron-size to mm-size.Comment: 11 pages, 2 figures, accepted to ApJ
Molecular Evolution in Collapsing Prestellar Cores III: Contraction of A Bonnor-Ebert Sphere
The gravitational collapse of a spherical cloud core is investigated by
numerical calculations. The initial conditions of the core lie close to the
critical Bonnor-Ebert sphere with a central density of \sim 10^4 cm^{-3} in one
model (alpha=1.1), while gravity overwhelms pressure in the other (alpha=4.0),
where alpha is the internal gravity-to-pressure ratio. The alpha=1.1 model
shows reasonable agreement with the observed velocity field in prestellar
cores. Molecular distributions in cores are calculated by solving a chemical
reaction network that includes both gas-phase and grain-surface reactions. When
the central density of the core reaches 10^5 cm^{-3}, carbon-bearing species
are significantly depleted in the central region of the alpha=1.1 model, while
the depletion is only marginal in the other model. The two different approaches
encompass the observed variations of molecular distributions in different
prestellar cores, suggesting that molecular distributions can be probes of
contraction or accumulation time scales of cores. The central enhancement of
the NH3/N2H+ ratio, which is observed in some prestellar cores, can be
reproduced under certain conditions by adopting recently measured branching
fractions for N2H+ recombination. Various molecular species, such as CH3OH and
CO2, are produced by grain-surface reactions. The ice composition depends
sensitively on the assumed temperature. Multi-deuterated species are included
in our most recent gas-grain chemical network. The deuterated isotopomers of
H3+ are useful as probes of the central regions of evolved cores, in which
gas-phase species with heavy elements are strongly depleted. At 10 K, our model
can reproduce the observed abundance ratio of ND3/NH3, but underestimates the
isotopic ratios of deuterated to normal methanol.Comment: 38 pages, 9 figure
Multi-component optical solitary waves
We discuss several novel types of multi-component (temporal and spatial)
envelope solitary waves that appear in fiber and waveguide nonlinear optics. In
particular, we describe multi-channel solitary waves in bit-parallel-wavelength
fiber transmission systems for high performance computer networks, multi-colour
parametric spatial solitary waves due to cascaded nonlinearities of quadratic
materials, and quasiperiodic envelope solitons due to quasi-phase-matching in
Fibonacci optical superlattices.Comment: 12 pages, 11 figures; To be published in: Proceedings of the Dynamics
Days Asia-Pacific: First International Conference on Nonlinear Science
(Hong-Kong, 13-16 July, 1999), Editor: Bambi Hu (Elsevier Publishers, 2000
Quasiperiodic Envelope Solitons
We analyse nonlinear wave propagation and cascaded self-focusing due to
second-harmonic generation in Fibbonacci optical superlattices and introduce a
novel concept of nonlinear physics, the quasiperiodic soliton, which describes
spatially localized self-trapping of a quasiperiodic wave. We point out a link
between the quasiperiodic soliton and partially incoherent spatial solitary
waves recently generated experimentally.Comment: Submitted to PRL. 4 pages with 5 figure
Molecular Evolution in Collapsing Prestellar Cores
We have investigated the evolution and distribution of molecules in
collapsing prestellar cores via numerical chemical models, adopting the
Larson-Penston solution and its delayed analogues to study collapse. Molecular
abundances and distributions in a collapsing core are determined by the balance
among the dynamical, chemical and adsorption time scales. When the central
density n_H of a prestellar core with the Larson-Penston flow rises to 3 10^6
cm^{-3}, the CCS and CO column densities are calculated to show central holes
of radius 7000 AU and 4000 AU, respectively, while the column density of N2H+
is centrally peaked. These predictions are consistent with observations of
L1544. If the dynamical time scale of the core is larger than that of the
Larson-Penston solution owing to magnetic fields, rotation, or turbulence, the
column densities of CO and CCS are smaller, and their holes are larger than in
the Larson-Penston core with the same central gas density. On the other hand,
N2H+ and NH3 are more abundant in the more slowly collapsing core. Therefore,
molecular distributions can probe the collapse time scale of prestellar cores.
Deuterium fractionation has also been studied via numerical calculations. The
deuterium fraction in molecules increases as a core evolves and molecular
depletion onto grains proceeds. When the central density of the core is n_H=3
10^6 cm^{-3}, the ratio DCO+/HCO+ at the center is in the range 0.06-0.27,
depending on the collapse time scale and adsorption energy; this range is in
reasonable agreement with the observed value in L1544.Comment: 21 pages, 17 figure
Biological Differences Between Ovarian Cancer-associated Fibroblasts and Contralateral Normal Ovary-derived Mesenchymal Stem Cells
Background/Aim: The aim of this study was to clarify the biological differences between ovarian cancerassociated fibroblasts (OCa-CAFs) and normal ovary-derived mesenchymal stem cells (NO-MSCs). Materials and Methods: Surgically resected ovarian cancer and contralateral normal ovarian tissue samples were cut into small pieces for culture as âexplantsâ. The number of outgrown cells, their proliferative kinetics, and expression levels of cell surface markers of CAFs, as well as three miRNAs in OCa-CAFs and NO-MSCs were compared directly. Differentially expressed genes between both groups were also investigated. Results: Comparable numbers of outgrown cells were harvested from both groups. Significantly higher expression of α-smooth muscle actin and miR-142 was found in OCa-CAFs, which decreased significantly during ex vivo cell expansion. A total of 21 differentially expressed genes were identified between both groups. Conclusion: OCa-CAFs showed different biological properties in direct comparison with NO-MSCs, which might play major roles in the pathogenesis of ovarian cancer
Evolution of Molecular Abundance in Protoplanetary Disks
We investigate the evolution of molecular abundance in quiescent
protoplanetary disks which are presumed to be around weak-line T Tauri stars.
In the region of surface density less than g cm (distance from
the star AU in the minimum- mass solar nebula), cosmic rays are
barely attenuated even in the midplane of the disk and produce chemically
active ions such as He and H. Through reactions with these ions CO
and N are finally transformed into CO, NH, and HCN. In the region
where the temperature is low enough for these products to freeze onto grains,
considerable amount of carbon and nitrogen is locked up in the ice mantle and
is depleted from the gas phase in a time scale yr.
Oxidized (CO) ice and reduced (NH and hydrocarbon) ice naturally
coexist in this part of the disk. The molecular abundance both in the gas phase
and in ice mantle varies significantly with the distance from the central star.Comment: 7 pages latex file (using aas2pp4.sty), 3 figures (ps file), to
appear in the Astrophysical Journal Letter
A ferromagnetic EuâPt surface compound grown below hexagonal boron nitride
One of the fundamental applications for monolayer-thick 2D materials is their use as protective layers of metal surfaces and in situ intercalated reactive materials in ambient conditions. Here we investigate the structural, electronic, and magnetic properties, as well as the chemical stability in air of a very reactive metal, Europium, after intercalation between a hexagonal boron nitride (hBN) layer and a Pt substrate. We demonstrate that Eu intercalation leads to a hBN-covered ferromagnetic EuPt2 surface alloy with divalent Eu2+ atoms at the interface. We expose the system to ambient conditions and find a partial conservation of the di-valent signal and hence the EuâPt interface. The use of a curved Pt substrate allows us to explore the changes in the Eu valence state and the ambient pressure protection at different substrate planes. The interfacial EuPt2 surface alloy formation remains the same, but the resistance of the protecting hBN layer to ambient conditions is reduced, likely due to a rougher surface and a more discontinuous hBN coating
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