Blended learning combines online digital resources with traditional classroom activities and enables students to attain higher learning performance through well-defined interactive strategies ...involving online and traditional learning activities. Learning analytics is a conceptual framework and as a part of our Precision education used to analyze and predict students' performance and provide timely interventions based on student learning profiles. This study applied learning analytics and educational big data approaches for the early prediction of students' final academic performance in a blended Calculus course. Real data with 21 variables were collected from the proposed course, consisting of video-viewing behaviors, out-of-class practice behaviors, homework and quiz scores, and after-school tutoring. This study applied principal component regression to predict students' final academic performance. The experimental results show that students' final academic performance could be predicted when only one-third of the semester had elapsed. In addition, we identified seven critical factors that affect students' academic performance, consisting of four online factors and three traditional factors. The results showed that the blended data set combining online and traditional critical factors had the highest predictive performance.
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Due to the poor self-regeneration of brain tissue, stem cell transplantation therapy is purported to enable the replacement of lost neurons after traumatic brain injury (TBI). The ...main challenge of brain regeneration is whether the transplanted cells can survive and carry out neuronal functions in the lesion area. The brain is a complex neuronal network consisting of various types of cells that significantly influence on each other, and the survival of the implanted stem cells in brain is critically influenced by the surrounding cells. Although stem cell-based therapy is developing rapidly, most previous studies just focus on apply single type of stem cells as cell source. Here, we found that co-culturing human umbilical cord mesenchymal stem cells (hUC-MSCs) directly with the activated astrocytes benefited to the proliferation and neuron differentiation of hUC-MSCs in vitro. In this study, hUC-MSCs and the activated astrocytes were seeded in RADA16-BDNF peptide scaffold (R-B-SPH scaffold), a specifical self-assembling peptide hydrogel, in which the environment promoted the differentiation of typical neuron-like cells with neurites extending in three-dimensional directions. Moreover, the results showed co-culture of hUC-MSCs and activated astrocytes promoted more BDNF secretion which may benefit to both neural differentiation of ectogenic hUC-MSCs and endogenic neurogenesis. In order to promote migration of the transplanted hUC-MSCs to the host brain, the hUC-MSCs were forced with CXC chemokine receptor 4 (CXCR4). We found that the moderate-sized lesion cavity, but not the large cavity caused by TBI was repaired via the transplantation of hUC-MSCsCXCR4 and activated astrocytes embedded in R-B-SPH scaffolds. The functional neural repair for TBI demonstrated in this study is mainly due to the transplantation system of double cells, hUC-MSCs and activated astrocytes. We believe that this novel cell transplantation system offers a promising treatment option for cell replacement therapy for TBI.
In this reach, we specifically linked RGIDKRHWNSQ, a functional peptide derived from BDNF, to the C-terminal of RADARADARADARADA (RADA16) to structure a functional self-assembling peptide hydrogel scaffold, RADA16-BDNF (R-B-SPH scaffold) for the better transplantation of the double cell unit. Also, the novel scaffold was used as cell-carrier for transplantation double cell unit (hUC-MSCs/astrocyte) for treating traumatic brain injury. The results of this study showing that R-B-SPH scaffold was pliancy and flexibility to fit the brain lesion cavity and promotes the outgrowth of axons and dendrites of the neurons derived from hUC-MSCs in vitro and in vivo, indicating the 3D R-B-SPH scaffold provided a suitable microenvironment for hUC-MSC survival, proliferation and differentiation. Also, our results showing the double-cells transplantation system (hUC-MSCs/astrocyte) may be a novel cell-based therapeutic strategy for neuroregeneration after TBI with potential value for clinical application.
Background
Increased left atrium diameter (LAD) is associated with an elevated risk of cardiovascular diseases. The relationship between nutrition status and left atrial enlargement (LAE) is still ...unclear. The present study aimed to investigate the association of famine exposure in early life with LAE in adulthood.
Methods
Participants were divided into non‐exposed, fetal, early, middle and late childhood exposed groups according to birth data. LAE was defined when LAD was ≥3.9 cm in women and ≥4.1 cm in men, or ≥2.3 cm m−2 by a sex‐independent cut‐off normalised for body surface area. Multivariate logistic regression was performed to calculate the odds ratio (OR) and confidence interval (CI) between famine exposure and LAE.
Results
In total, 2522 905 male, mean (SD) age 59.1 (3.65) years subjects were enrolled, including 392 (15.5%) LAE subjects. The prevalence of LAE in non‐exposed, fetal, early, middle and late childhood exposed groups was 55 (10.8%), 38 (11.2%), 88 (18.1%), 102 (16.7%) and 109 (19.0%), respectively. Compared to the non‐exposed group, the ORs for LAE were in fetal (OR = 0.956, 95% CI = 0.605–1.500, P = 0.847), late (OR = 1.748, 95% CI = 1.208–2.555, P = 0.003), middle (OR = 1.647, 95% CI = 1.140–2.403, P = 0.008) and early (OR = 1.630, 95% CI = 1.116–2.399, P = 0.012) childhood exposed groups after adjusting potential cofounders. When stratified by gender, smoking, body mass index, hypertension and diabetes, we found that the effect of famine exposure on LAE was only modified by diabetes (Pinteraction = 0.007).
Conclusions
Famine exposure during childhood stage might increase the risk of LAE in adults, and this effect interacts with diabetes.
Famine exposure during childhood stage might increase the risk of left atrial enlargement in adults, and this effect interacts with diabetes.
We experimentally realize a universal set of single-bit and two-bit geometric quantum gates by adiabatically controlling solid-state spins in a diamond defect. Compared with the nonadiabatic ...approach, the adiabatic scheme for geometric quantum computation offers a unique advantage of inherent robustness to parameter variations, which is explicitly demonstrated in our experiment by showing that the single-bit gates remain unchanged when the driving field amplitude varies by a factor of 2 or the detuning fluctuates in a range comparable to the inverse of the gate time. The reported adiabatic control technique and its convenient implementation offer a paradigm for achieving quantum computation through robust geometric quantum gates, which is important for quantum information systems with parameter-fluctuation noise such as those from the inhomogeneous coupling or the spectral diffusion.
We present improved germanium-based constraints on sub-GeV dark matter via dark matter-electron (χ-e) scattering using the 205.4 kg·day dataset from the CDEX-10 experiment. Using a novel calculation ...technique, we attain predicted χ-e scattering spectra observable in high-purity germanium detectors. In the heavy mediator scenario, our results achieve 3 orders of magnitude of improvement for m_{χ} larger than 80 MeV/c^{2} compared to previous germanium-based χ-e results. We also present the most stringent χ-e cross-section limit to date among experiments using solid-state detectors for m_{χ} larger than 90 MeV/c^{2} with heavy mediators and m_{χ} larger than 100 MeV/c^{2} with electric dipole coupling. The result proves the feasibility and demonstrates the vast potential of a new χ-e detection method with high-purity germanium detectors in ultralow radioactive background.
Because cerebral morphological abnormalities in major depressive disorder (MDD) may be modulated by antidepressant treatment, inclusion of medicated patients may have biased previous meta-analyses of ...voxel-based morphometry (VBM) studies. A meta-analysis of VBM studies on medication-free MDD patients should be able to distinguish the morphological features of the disease itself from those of treatment.
A systematic search was conducted for the relevant studies. Effect-size signed differential mapping was applied to analyse the grey matter differences between all medication-free MDD patients and healthy controls. Meta-regression was used to explore the effects of demographics and clinical characteristics.
A total of 14 datasets comprising 400 medication-free MDD patients and 424 healthy controls met the inclusion criteria. The pooled meta-analysis and subgroup meta-analyses showed robustly reduced grey matter in prefrontal and limbic regions in MDD. Increased right thalamus volume was only seen in first-episode medication-naive patients, and increased grey matter in the bilateral anterior cingulate cortex only in medication wash-out patients. In meta-regression analyses the percentage of female patients in each study was negatively correlated with reduced grey matter in the right hippocampus.
By excluding interference from medication effects, the present study identified grey matter reduction in the prefrontal-limbic network in MDD. The subgroup meta-analysis results suggest that an increased right thalamus volume might be a trait directly related to MDD, while an increased anterior cingulate cortex volume might be an effect of medication. The meta-regression results perhaps reveal the structural underpinning of the sex differences in epidemiological and clinical aspects of MDD.
The long noncoding RNA TINCR shows aberrant expression in human squamous carcinomas. However, its expression and function in gastric cancer remain unclear. We report that TINCR is strongly ...upregulated in human gastric carcinoma (GC), where it was found to contribute to oncogenesis and cancer progression. We also revealed that TINCR overexpression is induced by nuclear transcription factor SP1. Silencing TINCR expression inhibited cell proliferation, colony formation, tumorigenicity and apoptosis promotion, whereas TINCR overexpression promoted cell growth, as documented in the SGC7901 and BGC823 cell lines. Mechanistic analyses indicated that TINCR could bind to STAU1 (staufen1) protein, and influence KLF2 mRNA stability and expression, then KLF2 regulated cyclin-dependent kinase genes CDKN1A/P21 and CDKN2B/P15 transcription and expression, thereby affecting the proliferation and apoptosis of GC cells. Together, our findings suggest that TINCR contributes to the oncogenic potential of GC and may constitute a potential therapeutic target in this disease.
Black carbon (BC) aerosol at high altitudes of the Qinghai–Tibetan Plateau has potential effects on the regional climate and hydrological cycle. An intensive measurement campaign was conducted at ...Qinghai Lake (~ 3200 m above sea level) at the edge of the northeastern Qinghai–Tibetan Plateau during winter using a ground-based single particle soot photometer (SP2) and a photoacoustic extinctiometer (PAX). The average concentration of refractory BC (rBC) and number fraction of coated rBC were found to be 160 ± 190 ng m−3 and 59 % for the entire campaign, respectively. Significant enhancements of rBC loadings and number fraction of coated rBC were observed during a pollution episode, with an average value of 390 ng m−3 and 65 %, respectively. The mass size distribution of rBC particles showed log-normal distribution, with a peak diameter of ~ 187 nm regardless of the pollution level. Five-day backward trajectory analysis suggests that the air masses from north India contributed to the increased rBC loadings during the campaign. The potential source contribution function (PSCF) model combined with the fire counts map further proves that biomass burning from north India is an important potential source influencing the northeastern Qinghai–Tibetan Plateau during the pollution episode. The rBC mass absorption cross section (MACrBC) at λ = 532 nm was slightly larger in clean days (14.9 m2 g−1) than during the pollution episode (9.3 m2 g−1), likely due to the effects of brown carbon and the uncertainty of the MACrBC calculation. The MACrBC was positively correlated with number fraction of coated rBC during the pollution episode with an increasing rate of 0.18 (m2 g−1) %−1. The number fraction of coated rBC particles showed positive correlation with light absorption, suggesting that the increase of coated rBC particles will enhance the light absorption. Compared to rBC mass concentration, rBC mixing sate is more important in determining absorption during the pollution episode, estimated from the same percentage-wise increment of either rBC mass concentration or the number fraction of coated rBC. The estimated BC direct radiative forcing was +0.93 W m−2 for the pollution episode, which is 2 times larger than that in clean days. Our study provides insight into the potential climatic impacts of rBC aerosol transported to the Qinghai–Tibetan Plateau from south Asian regions, and is also useful for future modeling studies.
As a major component of the LAMOST Galactic surveys, the LAMOST Spectroscopic Survey of the Galactic Anticentre (LSS-GAC) aims to survey a significant volume of the Galactic thin/thick discs and halo ...for a contiguous sky area of over 3400 deg2 centred on the Galactic anticentre (|b| ≤ 30°, 150 ≤ l ≤ 210°), and obtain λλ3700–9000 low-resolution (R ∼ 1800) spectra for a statistically complete sample of ∼3 M stars of all colours down to a limiting magnitude of r ∼ 17.8 mag (to 18.5 mag for limited fields). Together with Gaia, the LSS-GAC will yield a unique data set to advance our understanding of the structure and assemblage history of the Galaxy, in particular its disc(s). In addition to the main survey, the LSS-GAC will also target hundreds of thousands objects in the vicinity fields of M 31 and M 33 and survey a significant fraction (over a million) of randomly selected very bright stars (r ≤ 14 mag) in the Northern hemisphere. During the Pilot and the first year Regular Surveys of LAMOST, a total of 1042 586 750 867 spectra of a signal-to-noise ratio S/N(7450 Å) ≥ 10 S/N(4650 Å) ≥ 10 have been collected. In this paper, we present a detailed description of the target selection algorithm, survey design, observations and the first data release of value-added catalogues (including radial velocities, effective temperatures, surface gravities, metallicities, values of interstellar extinction, distances, proper motions and orbital parameters) of the LSS-GAC.
ABSTRACT
High time resolution and accuracy are of critical importance in the studies of timing analysis and time delay localization of gamma-ray bursts (GRBs), soft gamma-ray repeaters (SGRs) and ...pulsars. The Gravitational wave high-energy Electromagnetic Counterpart All-sky Monitor (GECAM) consisting of two micro-satellites, GECAM-A and GECAM-B, launched on 2020 December 10, is aimed at monitoring and locating X-ray and GRBs all over the sky. To achieve its scientific goals, GECAM is designed to have the highest time resolution (0.1 $\mu {\rm s}$) among all GRB detectors ever flown. Here, we make a comprehensive time calibration campaign including both on-ground and on-orbit tests to derive not only the relative time accuracy of GECAM satellites and detectors, but also the absolute time accuracy of GECAM-B. Using the on-ground calibration with a $\rm ^{22}Na$ radioactive source, we find that the relative time accuracy between GECAM-A and GECAM-B is about 0.15 $\mu {\rm s}$ (1σ). To measure the relative time accuracy between all detectors of a single GECAM satellite, cosmic-ray events detected on orbit are utilized since they could produce many secondary particles simultaneously record by multiple detectors. We find that the relative time accuracy among all detectors onboard GECAM-B is about 0.12 $\mu {\rm s}$ (1σ). Finally, we use the novel Li-CCF method to perform the absolute time calibration with Crab pulsar and SGR J1935+2154, both of which were jointly observed by GECAM-B and Fermi/GBM, and obtain that the time difference between GECAM-B and Fermi/GBM is 3.06 ± 6.04 $\mu {\rm s}$ (1σ).
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