Cation mono- and co-doped anatase TiO2_2 nanotubes: An {\em ab initio} investigation of electronic and optical properties

The structural, electronic, and optical properties of metal (Si, Ge, Sn, and Pb) mono- and co-doped anatase TiO$_{2}$ nanotubes are investigated, in order to elucidate their potential for photocatalytic applications. It is found that Si doped TiO$_{2}$ nanotubes are more stable than those doped with Ge, Sn, or Pb. All dopants lower the band gap, except the (Ge, Sn) co-doped structure, the decrease depending on the concentration and the type of dopant. Correspondingly, a redshift in the optical properties for all kinds of dopings is obtained. Even though a Pb mono- and co-doped TiO$_{2}$ nanotube has the lowest band gap, these systems are not suitable for water splitting, due to the location of the conduction band edges, in contrast to Si, Ge, and Sn mono-doped TiO$_{2}$ nanotubes. On the other hand, co-doping of TiO$_{2}$ does not improve its photocatalytic properties. Our findings are consistent with recent experiments which show an enhancement of light absorption for Si and Sn doped TiO$_{2}$ nanotubes.Comment: revised and updated, 23 pages (preprint style), 7 figures, 5 table

Visualizing Convolutional Networks for MRI-based Diagnosis of Alzheimer's Disease

Visualizing and interpreting convolutional neural networks (CNNs) is an important task to increase trust in automatic medical decision making systems. In this study, we train a 3D CNN to detect Alzheimer's disease based on structural MRI scans of the brain. Then, we apply four different gradient-based and occlusion-based visualization methods that explain the network's classification decisions by highlighting relevant areas in the input image. We compare the methods qualitatively and quantitatively. We find that all four methods focus on brain regions known to be involved in Alzheimer's disease, such as inferior and middle temporal gyrus. While the occlusion-based methods focus more on specific regions, the gradient-based methods pick up distributed relevance patterns. Additionally, we find that the distribution of relevance varies across patients, with some having a stronger focus on the temporal lobe, whereas for others more cortical areas are relevant. In summary, we show that applying different visualization methods is important to understand the decisions of a CNN, a step that is crucial to increase clinical impact and trust in computer-based decision support systems.Comment: MLCN 201

Application of SRAP in the genetic diversity of Tricholoma matsutake in northeastern China

Tricholoma matsutake is an ectomycorrhizal (ECM) fungus that produces economically important mushrooms. The study firstly applied SRAP technique into genetic diversity of T. matsutake. A total of 129 strains from 13 geographical locations in northeastern China, were amplified by using selected 12 primer pairs. The polymorphic band number amplified by each primer pair ranged from 7 to 13. In total 154 bands were observed, of which 118 were polymorphic (76.62%). Abundant genetic variation was detected within individual populations. Dongning maintained a higher genetic diversity while Hunchun was lower. The analyses found a significant positive correlation between genetic distance and geographical distance and no correlation between genetic distance and altitudinal differences among populations. Based on the UPGMA cluster diagram, the 13 populations may be divided with the genetic distance of 0.035 into three groups.Key words: Genetic diversity, Tricholoma matsutake, fungi, sequence related amplified polymorphism (SRAP)

Developing Interpreting Competence Scales in China

Tertiary-level interpreter training and education have developed rapidly in China, and more than 500 undergraduate and postgraduate degree programs have been launched over the past decade. Despite the rapid development, there has been no standardized framework allowing for the reliable and valid measurement of interpreting competence in China. Against this background, the China Standards of English (CSE), which are the Chinese counterpart to the Common European Framework of Reference (CEFR), were unveiled in 2018 after four years of government-funded research and validation. One vital component of the CSE is the descriptor-referenced interpreting competence scales. This article provides a systematic account of the design, development, and validation of the interpreting competence scales in China. Within the CSE, the construct of interpreting competence was defined according to an interactionist approach. It encompasses not only cognitive abilities, interpreting strategies, and subject matter knowledge, but also considers performance in typical communicative settings. Based on the construct definition, a corpus of relevant descriptors was built from three main sources, including: a) interpreting training syllabuses, curricular frameworks, rating scales, and professional codes of conduct; b) previous literature on interpreting performance assessment, competence development, and interpreter training and education; c) exemplar-generation data on assessing interpreting competence and typical interpreting activities, which were collected from interpreting professionals, trainers, and trainees. The corpus contains 9,208 descriptors of interpreting competence. A mixed-method survey was then conducted to analyze, scale, and validate the descriptors among 30,682 students, 5,787 teachers, and 139 interpreting professionals from 28 provinces, municipalities, and regions in China. The finalized set included 369 descriptors that reference interpreting competence. The CSE-Interpreting Competence Scales with theoretically and empirically based descriptors represent a major effort in research on interpreting competence and its assessment, and they have significant potential to be applied widely in interpreting training, research, and assessment

On determination of the geometric cosmological constant from the OPERA experiment of superluminal neutrinos

The recent OPERA experiment of superluminal neutrinos has deep consequences in cosmology. In cosmology a fundamental constant is the cosmological constant. From observations one can estimate the effective cosmological constant $\Lambda_{eff}$ which is the sum of the quantum zero point energy $\Lambda_{dark energy}$ and the geometric cosmological constant $\Lambda$. The OPERA experiment can be applied to determine the geometric cosmological constant $\Lambda$. It is the first time to distinguish the contributions of $\Lambda$ and $\Lambda_{dark energy}$ from each other by experiment. The determination is based on an explanation of the OPERA experiment in the framework of Special Relativity with de Sitter space-time symmetry.Comment: 7 pages, no figure

Pressure Effect on the superconducting properties of LaO_{1-x}F_{x}FeAs(x=0.11) superconductor

Diamagnetic susceptibility measurements under high hydrostatic pressure (up to 1.03 GPa) were carried out on the newly discovered Fe-based superconductor LaO_{1-x}F_{x}FeAs(x=0.11). The transition temperature T_c, defined as the point at the maximum slope of superconducting transition, was enhanced almost linearly by hydrostatic pressure, yielding a dT_c/dP of about 1.2 K/GPa. Differential diamagnetic susceptibility curves indicate that the underlying superconducting state is complicated. It is suggested that pressure plays an important role on pushing low T_c superconducting phase toward the main (optimal) superconducting phase.Comment: 7 pages, 4 figure