364 research outputs found
Análisis de los manuales de alemán en las universidades chinas: Contenido medioambiental y perspectivas ecológicas
German is offered to students as one of the leading foreign languages in Chinese universities, and German language textbooks are an important resource to influence these students’ environmental awareness. Taking transitivity as a theoretical framework, the present research was conducted to explore the transitivity features and ecological view of the environmental content in German language textbooks used in Chinese universities. The results show that transitivity patterns were significantly unbalanced in the environmental content, and an eco-beneficial view dominated to actively encourage students to protect nature. However, the political and cultural values underlying humanity’s destruction of the natural environment were not much touched upon. Corresponding suggestions are made for textbook compilers and classroom teachers.
FUNDING INFORMATION. This research was supported by a Grant from the Foreign Language Education and Teaching Reform of Lanzhou Jiaotong University (JGZ202337). We would like to express our thanks to the anonymous reviewers and the editors for their constructive suggestions on this research.El alemán es una lengua extranjera clave que estudian los universitarios chinos, y los manuales de alemán se han convertido en un importante recurso que influye en la conciencia medioambiental de estos alumnos. Este estudio utiliza la transitividad como marco teĂłrico para explorar las caracterĂsticas de transitividad y las perspectivas ecolĂłgicas del contenido medioambiental de los manuales de alemán de las universidades chinas. Los resultados muestran que el uso del modelo de transitividad para los contenidos medioambientales es muy desigual; predominan las perspectivas ecolĂłgicamente beneficiosas para animar a los alumnos a proteger la naturaleza. Sin embargo, no se abordan suficientemente los valores polĂticos y culturales que subyacen a la destrucciĂłn de la naturaleza por los seres humanos. Este documento ofrece sugerencias al respecto para los autores de manuales y los profesores de la asignatura
A Survey on the Higher Education “Three Spirits” Construction in Sichuan Province, PRC
Under the guidance of “the Scientific Outlook on Development”, the Sichuan universities and colleges have rethought the present lazy and separate situation of the “Three Spirits”. Based on analyzing the relationship of the “Three Spirits”, they have taken such measures as constructing learning group and cultivating educational tradition etc, and established the mechanism of “educational guidance” and “cultural edification” to promote the virtuous change of the “Three Spirits”construction, it thus has important practical value
Giant uterine artery pseudoaneurysm after a missed miscarriage termination in a cesarean scar pregnancy
BACKGROUND: Uterine artery pseudoaneurysms are dangerous and can lead to severe hemorrhage. We report an uncommon cause of a giant pseudoaneurysm in a missed miscarriage in a woman with a cesarean scar pregnancy. CASE PRESENTATION: The patient was a 25-year-old Chinese woman with a missed miscarriage in a cesarean scar pregnancy. Curettage was performed under ultrasound monitoring. A uterine artery pseudoaneurysm measuring 71 × 44 × 39 mm was detected the next day by Doppler ultrasonography. While waiting for admittance to an advanced institution to undergo embolization treatment, the pseudoaneurysm ruptured spontaneously. The subsequent severe hemorrhage necessitated hysterectomy. CONCLUSION: A delay in diagnosis of uterine artery pseudoaneurysms may result from a long period between the curettage and follow-up examination. Ultrasound and Doppler ultrasonography should be performed repeatedly at short intervals to rule out them, especially in cesarean scar pregnancies. For a giant uterine artery pseudoaneurysm, interventional embolization might be the first treatment choice. If time allows, intra-operative ligation of the feeding vessels should be attempted before any decision to perform a hysterectomy is made. However, hysterectomy remains a possibility when severe bleeding occurs
Three-dimensionality of the bulk electronic structure in WTe2
We use temperature- and field-dependent resistivity measurements
[Shubnikov--de Haas (SdH) quantum oscillations] and ultrahigh resolution,
tunable, vacuum ultraviolet (VUV) laser-based angle-resolved photoemission
spectroscopy (ARPES) to study the three-dimensionality (3D) of the bulk
electronic structure in WTe2, a type-II Weyl semimetal. The bulk Fermi surface
(FS) consists of two pairs of electron pockets and two pairs of hole pockets
along the X-Gamma-X direction as detected by using an incident photon energy of
6.7 eV, which is consistent with the previously reported data. However, if
using an incident photon energy of 6.36 eV, another pair of tiny electron
pockets is detected on both sides of the Gamma point, which is in agreement
with the small quantum oscillation frequency peak observed in the
magnetoresistance. Therefore, the bulk, 3D FS consists of three pairs of
electron pockets and two pairs of hole pockets in total. With the ability of
fine tuning the incident photon energy, we demonstrate the strong
three-dimensionality of the bulk electronic structure in WTe2. The combination
of resistivity and ARPES measurements reveal the complete, and consistent,
picture of the bulk electronic structure of this material.Comment: 6 pages, 3 figure
Observation of Fermi Arcs in Type-II Weyl Semimetal Candidate WTe2
We use ultrahigh resolution, tunable, vacuum ultraviolet laser angle-resolved
photoemission spectroscopy (ARPES) to study the electronic properties of
WTe, a material that was predicted to be a type-II Weyl semimetal. The Weyl
fermion states in WTe2 were proposed to emerge at the crossing points of
electron and hole pockets; and Fermi arcs connecting electron and hole pockets
would be visible in the spectral function on (001) surface. Here we report the
observation of such Fermi arcs in WTe2 confirming the theoretical predictions.
This provides strong evidence for type-II Weyl semimetallic states in WTe2.Comment: 5 pages, 4 figure
Electronic structure of RSb (R = Y, Ce, Gd, Dy, Ho, Tm, Lu) studied by angle-resolved photoemission spectroscopy
We use high resolution angle-resolved photoemission spectroscopy (ARPES) and
electronic structure calculations to study the electronic properties of
rare-earth monoantimonides RSb (R = Y, Ce, Gd, Dy, Ho, Tm, Lu). The
experimentally measured Fermi surface (FS) of RSb consists of at least two
concentric hole pockets at the point and two intersecting electron
pockets at the point. These data agree relatively well with the electronic
structure calculations. Detailed photon energy dependence measurements using
both synchrotron and laser ARPES systems indicate that there is at least one
Fermi surface sheet with strong three-dimensionality centered at the
point. Due to the "lanthanide contraction", the unit cell of different
rare-earth monoantimonides shrinks when changing rare-earth ion from CeSb to
LuSb. This results in the differences in the chemical potentials in these
compounds, which is demonstrated by both ARPES measurements and electronic
structure calculations. Interestingly, in CeSb, the intersecting electron
pockets at the point seem to be touching the valence bands, forming a
four-fold degenerate Dirac-like feature. On the other hand, the remaining
rare-earth monoantimonides show significant gaps between the upper and lower
bands at the point. Furthermore, similar to the previously reported results
of LaBi, a Dirac-like structure was observed at the point in YSb,
CeSb, and GdSb, compounds showing relatively high magnetoresistance. This
Dirac-like structure may contribute to the unusually large magnetoresistance in
these compounds.Comment: 8 figure
Using molecular dynamics simulations as an aid in the prediction of domain swapping of computationally designed protein variants
In standard implementations of computational protein design, a positive-design approach is used to predict sequences that will be stable on a given backbone structure. Possible competing states are typically not considered, primarily because appropriate structural models are not available. One potential competing state, the domain-swapped dimer, is especially compelling because it is often nearly identical to its monomeric counterpart, differing by just a few mutations in a hinge region. Molecular dynamics (MD) simulations provide a computational method to sample different conformational states of a structure. Here, we tested whether MD simulations could be used as a post-design screening tool to identify sequence mutations leading to domain-swapped dimers. We hypothesized that a successful computationally-designed sequence would have backbone structure and dynamics characteristics similar to that of the input structure, and that in contrast, domain-swapped dimers would exhibit increased backbone flexibility and/or altered structure in the hinge-loop region to accommodate the large conformational change required for domain swapping. While attempting to engineer a homodimer from a 51 amino acid fragment of the monomeric protein engrailed homeodomain (ENH), we had instead generated a domain-swapped dimer (ENH_DsD). MD simulations on these proteins showed increased MD simulation derived B factors in the hinge loop of the ENH_DsD domain-swapped dimer relative to monomeric ENH. Two point mutants of ENH_DsD designed to recover the monomeric fold were then tested with an MD simulation protocol. The MD simulations suggested that one of these mutants would adopt the target monomeric structure, which was subsequently confirmed by X-ray crystallography
Computational Design of the β-Sheet Surface of a Red Fluorescent Protein Allows Control of Protein Oligomerization
Computational design has been used with mixed success for the design of protein surfaces, with directed evolution heretofore providing better practical solutions than explicit design. Directed evolution, however, requires a tractable high-throughput screen because the random nature of mutation does not enrich for desired traits. Here we demonstrate the successful design of the β-sheet surface of a red fluorescent protein (RFP), enabling control over its oligomerization. To isolate the problem of surface design, we created a hybrid RFP from DsRed and mCherry with a stabilized protein core that allows for monomerization without loss of fluorescence. We designed an explicit library for which 93 of 96 (97%) of the protein variants are soluble, stably fluorescent, and monomeric. RFPs are heavily used in biology, but are natively tetrameric, and creating RFP monomers has proven extremely difficult. We show that surface design and core engineering are separate problems in RFP development and that the next generation of RFP markers will depend on improved methods for core design
R-Net: A Deep Network for Multi-oriented Vehicle Detection in Aerial Images and Videos
Vehicle detection is a significant and challenging task in aerial remote
sensing applications. Most existing methods detect vehicles with regular
rectangle boxes and fail to offer the orientation of vehicles. However, the
orientation information is crucial for several practical applications, such as
the trajectory and motion estimation of vehicles. In this paper, we propose a
novel deep network, called rotatable region-based residual network (R-Net),
to detect multi-oriented vehicles in aerial images and videos. More specially,
R-Net is utilized to generate rotatable rectangular target boxes in a half
coordinate system. First, we use a rotatable region proposal network (R-RPN) to
generate rotatable region of interests (R-RoIs) from feature maps produced by a
deep convolutional neural network. Here, a proposed batch averaging rotatable
anchor (BAR anchor) strategy is applied to initialize the shape of vehicle
candidates. Next, we propose a rotatable detection network (R-DN) for the final
classification and regression of the R-RoIs. In R-DN, a novel rotatable
position sensitive pooling (R-PS pooling) is designed to keep the position and
orientation information simultaneously while downsampling the feature maps of
R-RoIs. In our model, R-RPN and R-DN can be trained jointly. We test our
network on two open vehicle detection image datasets, namely DLR 3K Munich
Dataset and VEDAI Dataset, demonstrating the high precision and robustness of
our method. In addition, further experiments on aerial videos show the good
generalization capability of the proposed method and its potential for vehicle
tracking in aerial videos. The demo video is available at
https://youtu.be/xCYD-tYudN0
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