An Efficient Refocusing Scheme for Camera-Array Captured Light Field Video for Improved Visual Immersiveness

Light field video technology attempts to acquire human-like visual data, offering unprecedented immersiveness and a viable path for producing high-quality VR content. Refocusing that is one of the key properties of light field and a must for mixed reality applications has shown to work well for microlens based cameras, but as light field videos acquired by camera arrays have a low angular resolution, the refocused quality suffers. In this paper, we present an approach to improve the visual quality of refocused content captured by a camera array-based setup. Increasing the angular resolution using existing deep learning-based view synthesis method and refocusing the video using shift and sum refocusing algorithm produces over blurring of the in-focus region. Our enhancement method targets these blurry pixels and improves their quality by similarity detection and blending. Experimental results show that the proposed approach achieves better refocusing quality compared to traditional methods

A heterozygous moth genome provides insights into herbivory and detoxification

How an insect evolves to become a successful herbivore is of profound biological and practical importance. Herbivores are often adapted to feed on a specific group of evolutionarily and biochemically related host plants1, but the genetic and molecular bases for adaptation to plant defense compounds remain poorly understood2. We report the first whole-genome sequence of a basal lepidopteran species, Plutella xylostella, which contains 18,071 protein-coding and 1,412 unique genes with an expansion of gene families associated with perception and the detoxification of plant defense compounds. A recent expansion of retrotransposons near detoxification-related genes and a wider system used in the metabolism of plant defense compounds are shown to also be involved in the development of insecticide resistance. This work shows the genetic and molecular bases for the evolutionary success of this worldwide herbivore and offers wider insights into insect adaptation to plant feeding, as well as opening avenues for more sustainable pest management.Minsheng You … Simon W Baxter … et al

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Overexpression of Tamarix hispida ThTrx5 Confers Salt Tolerance to Arabidopsis by Activating Stress Response Signals

Salt stress inhibits normal plant growth and development by disrupting cellular water absorption and metabolism. Therefore, understanding plant salt tolerance mechanisms should provide a theoretical basis for developing salt-resistant varieties. Here, we cloned ThTrx5 from Tamarix hispida, a salt-resistant woody shrub, and generated ThTrx5-overexpressing transgenic Arabidopsis thaliana lines. Under NaCl stress, the germination rate of overexpressing ThTrx5 lines was significantly increased relative to that of the nontransgenic line; under salt stress, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and glutathione levels and root length and fresh weight values of transgenic ThTrx5 plants were significantly greater than corresponding values for wild-type plants. Moreover, with regard to the transcriptome, comparison of differential gene expression of transgenic versus nontransgenic lines at 0 h and 3 h of salt stress exposure revealed 500 and 194 differentially expressed genes (DEGs), respectively, that were mainly functionally linked to catalytic activity and binding process. Pull-down experiments showed that ThTrx bound 2-Cys peroxiredoxin BAS1-like protein that influences stress response-associated redox, hormone signal transduction, and transcription factor functions. Therefore, this work provides important insights into ThTrx5 mechanisms that promote salt tolerance in plants

Parallel Scheme for Multi-Layer Refinement Non-Uniform Grid Lattice Boltzmann Method Based on Load Balancing

The large-scale numerical simulation of complex flows has been an important research area in scientific and engineering computing. The lattice Boltzmann method (LBM) as a mesoscopic method for solving flow field problems has become a relatively new research direction in computational fluid dynamics. The multi-layer grid-refinement strategy deals with different-level of computing complexity through multi-scale grids, which can be used to solve the complex flow field of the non-uniform grid LBM without destroying the parallelism of the standard LBM. It also avoids the inefficiencies and waste of computational resources associated with standard LBMs using uniform and homogeneous Cartesian grids. This paper proposed a multi-layer grid-refinement strategy for LBM and implemented the corresponding parallel algorithm with load balancing. Taking a parallel scheme for two-dimensional non-uniform meshes as an example, this method presented the implementation details of the proposed parallel algorithm, including a partitioning scheme for evaluating the load in a one-dimensional direction and an interpolation scheme based on buffer optimization. Simply by expanding the necessary data transfer of distribution functions and macroscopic quantities for non-uniform grids in different parallel domains, our method could be used to conduct numerical simulations of the flow field problems with complex geometry and achieved good load-balancing results. Among them, the weak scalability performance could be as high as 88.90% in a 16-threaded environment, while the numerical simulation with a specific grid structure still had a parallel efficiency of 77.4% when the parallel domain was expanded to 16 threads

Three-Dimensional Graphene Hybrid SiO2 Hierarchical Dual-Network Aerogel with Low Thermal Conductivity and High Elasticity

We describe lightweight three-dimensional (3D) graphene hybrid SiO2 aerogels (GSAs) with hierarchically robust interconnected networks fabricated via an in situ deposition procedure after a hydrothermal assembling strategy with graphene oxide sheets. The nano-/micron-thick SiO2 coating conformably grew over porous graphene templates with two constituents (e.g., graphene and SiO2) and formed chemically bonded interfaces. In addition, it significantly refined the primary graphene pores by hundreds of microns into smaller porous patterns. Studies of its mechanical properties verified that the graphene interframework made the ceramic composites elastic, while SiO2 deposition enhanced the strength required it to resist deformation. The higher SiO2 contents resulted in lower elasticity but larger strength because of the apparent nanosize effect of SiO2 ceramic thickness; GSAs with a density of 82.3–250.3 mg/cm3 (corresponding to SiO2 sol with concentration ranging from 5 to 20 wt %) could reach a good balance of strength and elasticity. Benefiting from hierarchical micronetworks consisting of semiclosed or closed pores, GSAs offer excellent thermal-insulation performance, with thermal conductivity as low as 0.026 W/(m·K). GSAs offer improved fire-resistant capacity rather than that of pure carbon-based aerogels via the synergic protection of SiO2 ceramic accretion. This highlights the promising applications of GSAs as lightweight thermal-shielding candidates for industrial equipment, civil architectures, and defense transportation vehicles

980-nm external-cavity passively mode-locked laser with extremely narrow RF linewidth

This paper reports on the mode-locked operation of a 980-nm external-cavity passively mode-locked laser with extremely narrow RF linewidth. Optical pulses with 10-ps pulse duration were generated at a repetition rate of 955 MHz, with an average output power of 39.3 mW – which corresponds to a peak power of 4.1 W, generated directly from the oscillator. The RF spectrum displays a -3dB RF linewidth of only ~40 Hz, as well as a 60-dB dynamic contrast, revealing the exceptionally low-noise fundamental mode-locked operation of this laser. At a repetition rate of ~1 GHz, the highest peak power of 5.26 W was achieved, albeit with an increased -3dB RF linewidth of ~100 Hz. The two-section chip incorporated an active region with a dual InGaAs quantum well sandwiched by an asymmetrical waveguide, and was operated at room temperature. By taking advantage of the broad tunability of the repetition rate which externalcavity lasers can afford, we also investigated the limits of stable fundamental mode-locked operation at the lowest repetition rates (or maximum external cavity lengths). © (2013) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only