1,492 research outputs found
Mediation effect of students’ perception of accounting on the relationship between game-based learning and learning approaches
This study explores the mediation effect of students’ perceptions toward accounting to enhance their adoption of the deep learning approach. We adopt game-based learning (GBL) using a self-developed LEGO® simulation game as the active learning material. Participants of this study comprised undergraduate students majoring in accounting from a northern university in Italy. This study contributes to the literature by providing several new insights. First, we present statistical evidence of a mediation effect of students’ perceptions toward accounting on their learning approach, although the course offers a short-time activity. Second, we did not confirm the significance of students’ strong image of conformity in accounting as a mediator in the relationship between GBL and a surface approach to learning. We interpret that students hold more favorable images of conformity to accounting than before taking the GBL course, possibly fostering them to engage with deep approach processes while adopting appropriate facilitation of active learning
The International Linear Collider beam dumps
The ILC beam dumps are a key part of the accelerator design. At Snowmass
2005, the current status of the beam dump designs were reviewed, and the
options for the overall dump layout considered. This paper describes the
available dump options for the baseline and the alternatives and considers
issues for the dumps that require resolution.Comment: Prepared for 2005 International Linear Collider Physics and Detector
Workshop and 2nd ILC Accelerator Workshop, Snowmass, Colorado, 14-27 Aug 200
Estimating Dust Temperature and Far-IR Luminosity of High-Redshift Galaxies using ALMA Single-Band Continuum Observations
We present a method that derives the dust temperatures and infrared (IR)
luminosities of high-redshift galaxies assuming radiation equilibrium in a
simple dust and stellar distribution geometry. Using public data from the
Atacama Large Millimeter/submillimeter Array (ALMA) archive, we studied dust
temperatures assuming a clumpy interstellar medium (ISM) model for
high-redshift galaxies, then tested the consistency of our results with those
obtained using other methods. We find that a dust distribution model assuming a
clumpiness of may accurately represent
the ISM of high-redshift star-forming galaxies. By assuming a value of
, our method enables the derivation of dust temperatures and IR
luminosities of high-redshift galaxies from dust continuum fluxes and emission
sizes obtained from single-band ALMA observations. to demonstrate the method
proposed herein, we determined the dust temperature () of a star-forming galaxy, MACS0416-Y1.
Because the method only requires a single-band dust observation to derive a
dust temperature, it is more easily accessible than multi-band observations or
high-redshift emission line searches and can be applied to large samples of
galaxies in future studies using high resolution interferometers such as ALMA.Comment: Accepted for publication in MNRAS, 8 pages, 3 figures, For our public
python scripts, see https://github.com/yfudamoto/FIS22sed.gi
Structure and magnetism of self-organized Ge(1-x)Mn(x) nano-columns
We report on the structural and magnetic properties of thin Ge(1-x)Mn(x)films
grown by molecular beam epitaxy (MBE) on Ge(001) substrates at temperatures
(Tg) ranging from 80deg C to 200deg C, with average Mn contents between 1 % and
11 %. Their crystalline structure, morphology and composition have been
investigated by transmission electron microscopy (TEM), electron energy loss
spectroscopy and x-ray diffraction. In the whole range of growth temperatures
and Mn concentrations, we observed the formation of manganese rich
nanostructures embedded in a nearly pure germanium matrix. Growth temperature
mostly determines the structural properties of Mn-rich nanostructures. For low
growth temperatures (below 120deg C), we evidenced a two-dimensional spinodal
decomposition resulting in the formation of vertical one-dimensional
nanostructures (nanocolumns). Moreover we show in this paper the influence of
growth parameters (Tg and Mn content) on this decomposition i.e. on nanocolumns
size and density. For temperatures higher than 180deg C, we observed the
formation of Ge3Mn5 clusters. For intermediate growth temperatures nanocolumns
and nanoclusters coexist. Combining high resolution TEM and superconducting
quantum interference device magnetometry, we could evidence at least four
different magnetic phases in Ge(1-x)Mn(x) films: (i) paramagnetic diluted Mn
atoms in the germanium matrix, (ii) superparamagnetic and ferromagnetic low-Tc
nanocolumns (120 K 400 K) and
(iv) Ge3Mn5 clusters.Comment: 10 pages 2 colonnes revTex formatte
Spin-glass-like behavior of Ge:Mn
We present a detailed study of the magnetic properties of
low-temperature-molecular-beam-epitaxy grown Ge:Mn dilute magnetic
semiconductor films. We find strong indications for a frozen state of
Ge_{1-x}Mn_{x}, with freezing temperatures of T_f=12K and T_f=15K for samples
with x=0.04 and x=0.2, respectively, determined from the difference between
field-cooled and zero-field-cooled magnetization. For Ge_{0.96}Mn_{0.04}, ac
susceptibility measurements show a peak around T_f, with the peak position T'_f
shifting as a function of the driving frequency f by Delta T_f' / [T_f' Delta
log f] ~ 0.06, whereas for sample Ge_{0.8}Mn_{0.2} a more complicated behavior
is observed. Furthermore, both samples exhibit relaxation effects of the
magnetization after switching the magnitude of the external magnetic field
below T_f which are in qualitative agreement with the field- and
zero-field-cooled magnetization measurements. These findings consistently show
that Ge:Mn exhibits a frozen magnetic state at low temperatures and that it is
not a conventional ferromagnet.Comment: Revised version contains extended interpretation of experimental dat
A small oxazine compound as an anti-tumor agent: A novel pyranoside mimetic that binds to VEGF, HB-EGF, and TNF-α
A novel pyranoside mimetic compound, DMBO (2-(2,6-difluorophenyl)-5-(4-methoxyphenyl)-1-oxa-3-azaspiro5.5undecane), was designed and synthesized. The sugar mimicking behavior of DMBO was addressed by its ability to bind several growth factors/cytokines such as vascular endothelial growth factor (VEGF), heparin-binding epidermal growth factor-like growth factor (HB-EGF), and tumor necrosis factor (TNF)-α as demonstrated by the recently developed surface plasmon resonance assay. DMBO exhibited strong anti-proliferation activity in vitro against tumor cells including a highly metastatic murine osteosarcoma cell line LM8G7 that secretes VEGF as well as two human ovarian cell lines, OVSAHO and SKOV-3, which secrete TNF-α and HB-EGF respectively. Furthermore, DMBO inhibited the metastatic activity to the mouse liver of LM8G7 cells injected from a lateral tail vein, and affected the heparan-degrading activity of LM8G7 cells. Here, we report that DMBO acts as a human heparanase inhibitor in vitro possibly as a substrate mimetic. DMBO also inhibited the migration and invasion of LM8G7 cells and angiogenic events such as endothelial cell proliferation, migration and capillary tube-like formation in vitro. More prominently, the administration of DMBO with heparin resulted in synergistic anti-tumor effects in mouse model. of. osteosarcoma. These preclinical data shows the potential anti-cancer effects of DMBO. © 2010 Elsevier Ireland Ltd
High Temperature Ferromagnetism in GaAs-based Heterostructures with Mn Delta Doping
We show that suitably-designed magnetic semiconductor heterostructures
consisting of Mn delta-doped GaAs and p-type AlGaAs layers, in which the
locally high concentration of magnetic moments of Mn atoms are controllably
overlapped with the 2-dimensional hole gas wavefunction, realized remarkably
high ferromagnetic transition temperatures (TC). Significant reduction of
compensative Mn interstitials by varying the growth sequence of the structures
followed by low temperature annealing led to high TC up to 250 K. The
heterostructure with high TC exhibited peculiar anomalous Hall effect behavior,
whose sign depends on temperature.Comment: 18 pages, 4 figure
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