Students’ Perception of Using Digital Badges in Blended Learning Classrooms

A digital badge system with a leaderboard ranking was implemented in an 18-week course offered by a Chinese mainland university during the 2018 Spring Semester. Fifty-four junior college students participated in this study, and the learning activities were based on a combination of online and offline methods using the Moodle system. The purpose of the study was to explore these college students’ perception of digital badges in blended learning classrooms as well as their perception of digital badges in general. Q methodology was used in a single case study of the students’ subjective experience of digital badges, and thirty-six Q-statements were selected after a comprehensive reflection of their views of digital badges. The participants were asked to sort the statements to model their opinion in a modified rank-order procedure. Twenty-two valid sorts were entered for the analysis, and three factors were identified to represent groups of participants with similar views. The results are discussed based on the views of students at a local university in mainland China and the way their demographic characteristics related to their perception of digital badges

Forward-looking Imaging via Doppler Estimates of Sum-difference Measurements in Scanning Monopulse Radar

Monopulse technique is used in scanning radar systems to improve image quality in the forward-looking area. However, monopulse measurements fail to resolve multiple targets in the same resolution cell because of angular glint which often results to image blurring. In response to this, we propose a monopulse forward-looking imaging method utilizing Doppler estimates of sum-difference measurements. First, target multiplicity is resolved by exploiting the different Doppler shifts caused by the relative motion between the platform and the targets at different directions. High azimuthal angle measurement accuracy of the Doppler estimates is then obtained using the Sum-Difference Amplitude-Comparison (SDAC) monopulse technique. Subsequently, the intensity of the sum channel estimates is projected onto the image plane according to the range and angle measurements. To further improve the precision of angle measurements, a Chirp-Z Transform (CZT)-based algorithm is proposed for the reconstruction of the Doppler estimates of the sum-difference channels. Simulation results demonstrate the capability of the proposed methods in resolving multiple targets at high squint angles in a large scanning field. Real data experiments show significant improvement of image profiles using the CZT-based algorithm compared to that of the conventional monopulse imaging method

TBCK Influences Cell Proliferation, Cell Size and mTOR Signaling Pathway

<div><p>Mammalian target of rapamycin (mTOR) is a central regulator for both cell proliferation and cell growth; however, little is known about the regulation of mTOR expression at the transcriptional level. Here, we provide evidences that a conserved human protein TBCK (TBC1 domain containing kinase) is involved in the regulation of mTOR signaling pathway. Depletion of TBCK significantly inhibits cell proliferation, reduces cell size, and disrupts the organization of actin, but not microtubule. Knockdown of TBCK induces a significant decrease in the protein levels of components of mTOR complex (mTORC), and suppresses the activity of mTOR signaling, but not MAPK or PDK1/Akt pathway. Further results show that TBCK influences the expression of mTORC components at the transcriptional level. Thus, these data suggest that TBCK may play an important role in cell proliferation, cell growth and actin organization possibly by modulating mTOR pathway.</p></div

Modification and Compensation of the Line-of-Sight Motion Error for Multirotor UAV SAR

The multirotor Unmanned Aerial Vehicle (UAV) has the advantages of small size, light weight, and low cost. However, imaging signal processing is complicated due to the extremely unstable flight path. Real-time adjustment of pulse repetition frequency based on inertial navigation data can compensate for the along-track displacement error in advance, but the residual error cannot be ignored for highly squinted high-band Synthetic Aperture Radar (SAR). Therefore, the residual along-track displacement error is extracted based on the difference between the measured displacement value and the ideal one, and then the Line-of-Sight (LOS) motion error of the squint imaging geometry is modified. The traditional first-order and second-order LOS error compensation factors are improved, and the tolerance of the amplitude and frequency of the sinusoidal displacement error of a multirotor UAV is analyzed based on paired echo theory. Simulation and flight experiments verify that the proposed method can reduce the LOS motion error by an order of magnitude in large squint imaging and significantly improve the imaging performance of the squinted SAR of a multirotor UAV

Characterization of TBCK.

<p>(<b>A</b>) Schematic comparison of TBCK homologs in <i>H. sapiens</i>, <i>M. musculus</i>, <i>D. rerio</i>, <i>D. melanogaster</i>, and <i>C. elegans</i>. Red, green and blue bars indicate possible kinase domain, TBC domain and rhodanese homology domain, respectively. (<b>B</b>) Expression of TBCK in mammalian cell lines. Total lysates from the indicated cells were resolved by SDS-PAGE and subjected to Western analysis. (<b>C</b>) Subcellular localization of TBCK. HEK293 cells grown on cover slides were immunostained with the antibodies as shown. DNA was visualized by DAPI. Bar, 10 μm.</p

Depletion of TBCK represses the mRNA level of mTOR complexes components.

<p>Total RNAs from HEK293 cells infected with the indicated lentivirus were analyzed by quantitative RT-PCR with the targeted genes as shown. Error bars indicate SE (** <i>P</i><0.01).</p

Depletion of TBCK influences mTOR signaling pathway.

<p>HEK293 cells were infected with the indicated lentivirus and subjected to Western blotting (<b>A</b>) and immunofluorescence analysis (<b>B</b>–<b>C</b>) with the antibodies as shown. GFP-positive signals indicate the cells infected by lentivirus. DNA was visualized by DAPI. Bar, 10 µm.</p

Depletion of TBCK inhibits cell proliferation.

<p>HEK293 cells infected with the lentiviruses targeting to the various regions of TBCK mRNA (TBCK-RNAi-1 or 2) were subjected to Western blotting (<b>A</b>), cell counts (<b>B</b>), fluorescence microscopy (<b>C</b>) and MTT analyses (<b>D</b>). Bar, 200 µm. Lentivirus-infected cells were GFP-positive. Data are shown as the mean of three independent experiments ± SE (* <i>P</i><0.05, ** <i>P</i><0.01).</p

TBCK depletion reduces cell size.

<p>HEK293 cells were infected with the indicated lentivirus and subjected to fluorescence microscopy (A–B) and FACS analysis (C–D). (<b>A</b>–<b>B</b>) GFP-positive signals indicate the cells infected by lentivirus. Bar, 20 µm. The area measurements of infected cells were quantified by Image-Pro Plus 6.0 software. Data are shown as the mean of three independent experiments ± SE (** <i>P</i><0.01, n>200). (<b>C</b>–<b>D</b>) Representative histogram of flow cytometry shows the size distribution (FSC-H) of GFP positive cells that were stained with propidium iodide. The mean of three independent experiments ± SE is shown (* <i>P</i><0.05, n>100,000).</p

TBCK plays a role in actin organization.

<p>HEK293 cells infected with the indicated lentivirus were subjected to immunofluorescence staining with phalloidin-TRITC (<b>A</b>) or anti-α-tubulin antibody (<b>C</b>). Lentivirus-infected cells were GFP-positive. DNA was visualized by DAPI. Bar, 10 µm. Single panel image of phalloidin-TRITC signal (<b>B</b>) or α-tubulin (<b>D</b>) is showed in rainbow palettes.</p