Recent trends in three-dimensional (3D) display technologies are very interesting in that both old-fashioned and up-to-date technologies are being actively investigated together. The release of the first commercially successful 3D display product raised new research topics in stereoscopic display. Autostereoscopic display renders a ray field of a 3D image, whereas holography replicates a wave field of it. Many investigations have been conducted on the next candidates for commercial products to resolve existing limitations. Up-to-date see-through 3D display is a concept close to the ultimate goal of presenting seamless virtual images. Although it is still far from practical use, many efforts have been made to resolve issues such as occlusion problems.

Background: The Akt/PKB family of kinases is frequently activated in human cancers, including oral squamous cell carcinoma (OSCC). Akt-induced epithelial-to-mesenchymal transition (EMT) involves downregulation of E-cadherin, which appears to result from upregulation of the transcription repressor Snail. Recently, it was proposed that carcinoma cells, especially in metastatic sites, could acquire the mesenchymal-to-epithelial reverting transition (MErT) in order to adapt the microenvironments and re-expression of E-cadherin be a critical indicator of MErT. However, the precise mechanism and biologic or clinical importance of the MErT in cancers have been little known. This study aimed to investigate whether Akt inhibition would restore the expression of E-cadherin and β-catenin, reduce that of Vimentin, and induce the MErT in OSCC cells with low or negative expression of E-cadherin. We also investigate whether inhibition of Akt activity would affect the E-cadherin repressors and signaling molecules like NF-κB, ERK, and p38.

It is not yet clear what triggers the activity of active galactic nuclei (AGNs), but galaxy merging has been suspected to be one of the main mechanisms fuelling the activity. Using deep optical images taken at various ground-based telescopes, we investigate the fraction of galaxy mergers in 39 luminous AGNs (M R -22.6 mag) at z ≤ 0.3 (a median redshift of 0.155), of which the host galaxies are generally considered as early-type galaxies. Through visual inspection of the images, we find that 17 of 39 AGN host galaxies (43.6%) show the evidence for current or past mergers like tidal tails, shells, and disturbed morphology. In order to see if this fraction is abnormally high, we also examined the merging fraction of normal early-type galaxies in the Sloan Digital Sky Survey (SDSS) Strip 82 data (a median redshift of 0.04), of which the surface-brightness limit is comparable to our imaging data. To correct for the effects related to the redshift difference of the two samples, we performed an image simulation by putting a bright point source as an artificial AGN in the images of SDSS early-type galaxies and placing them onto the redshifts of AGNs. The merging fraction in this realistic sample of simulated AGNs is only ∼ 5 − 15% (1/4 to 1/8 of that of real AGNs). Our result strongly suggests that luminous AGN activity is associated with galaxy merging.

Digital holographic microscopy (DHM) is a potent tool to perform three-dimensional imaging and tracking. We present a review of the state-of-the-art of DHM for three-dimensional profiling and tracking with emphasis on DHM techniques, reconstruction criteria for three-dimensional profiling and tracking, and their applications in various branches of science, including biomedical microscopy, particle imaging velocimetry, micrometrology, and holographic tomography, to name but a few. First, several representative DHM configurations are summarized and brief descriptions of DHM processes are given. Then we describe and compare the reconstruction criteria to obtain three-dimensional profiles and four-dimensional trajectories of objects. Details of the simulated and experimental evidences of DHM techniques and related reconstruction algorithms on particles, biological cells, fibers, etc., with different shapes, sizes, and conditions are also provided. The review concludes with a summary of techniques and applications of three-dimensional imaging and four-dimensional tracking by DHM.

Recent studies suggest that faint active galactic nuclei may be responsible for the reionization of the universe. Confirmation of this scenario requires spectroscopic identification of faint quasars (M 1450 > −24 mag) at z 6, but only a very small number of such quasars have been spectroscopically identified so far. Here, we report the discovery of a faint quasar IMS J220417.92+011144.8 at z ∼ 6 in a 12.5 deg 2 region of the SA22 field of the Infrared Medium-deep Survey (IMS). The spectrum of the quasar shows a sharp break at ∼ 8443Å, with emission lines redshifted to z = 5.944 ± 0.002 and rest-frame ultraviolet continuum magnitude M 1450 = −23.59 ± 0.10 AB mag. The discovery of IMS J220417.92+011144.8 is consistent with the expected number of quasars at z ∼ 6 estimated from quasar luminosity functions based on previous observations of spectroscopically identified lowluminosity quasars . This suggests that the number of M 1450 ∼ −23 mag quasars at z ∼ 6 may not be high enough to fully account for the reionization of the universe. In addition, our study demonstrates that faint quasars in the early universe can be identified effectively with a moderately wide and deep near-infrared survey such as the IMS.