Optical simulation for illumination using GPGPU ray tracing

High-speed ray tracing for illumination optics using GPGPU was investigated. Optical simulation for illumination optics requires many rays tracing for precise simulation. Especially, optics for automotive LED lighting have small textures on the exit surface of the lens to diverge part of the light for satisfying specific illumination pattern which is required in the regulation. Many ray tracing requires much simulation times and it increases development cost. Recently, parallel computing using CPU and GPU has been used for accelerating computing speed and reported its merit in computer sciences. In this research, the ray tracing consists of two parts which are intersection searching and refraction calculation was done in parallel using CUDA, GPGPU API provided by NVIDIA. Interpolation calculations such as linear interpolation, Nagata triangular patch interpolation, and Nagata quadrilateral patch interpolation were used in intersection searching calculation. The results indicate that there is a possibility to accelerate ray tracing speed by using GPU. As a representative example, GPU ray tracing was about twice faster than the commercial software. In addition, error differences depend on the interpolation types for intersection calculation were observed. Moreover, the results indicate calculation error differences between single precision float calculation and double precision float calculation. In conclusion, even there are several issues such as errors from interpolation and calculation precision, accelerated ray tracing using GPU was achieved.This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at [email protected]

Scheduling for tandemly-connected sensor networks with heterogeneous link transmission rates

As a simplest sensor network topology, a tandemly-connected multi-hop wireless network model is studied, in which nodes are tandemly arranged and serially connected by unreliable lossy links. Each node generates a data packet in every one cycle period and forwards it bounded for either of two gateways at both ends of the network; the gateways can send the data to a server using a loss-free infrastructure. In such environments, packet losses often happen due to not only attenuation and fading but also interference among links, thus unscheduled packet forwarding schemes are inefficient and suffer from a low success ratio of packet delivery to the server. In our previous paper, we proposed a centralized scheduling to design a static time-slot allocation for redundant packet transmission based on the positions and packet loss rates of links to maintain a high success probability of delivering all sensor data. However, it only considered homogeneous links with the same transmission rate, and also it is not optimal in some topological conditions. Therefore, in this paper, we essentially enhanced it to adapt to heterogeneous links with different transmission rates and to topological conditions that are not covered by the previous scheme. Our scheme analytically derives an optimal static time-slot allocation and combines it with forward erasure correction (FEC) against packet losses based on inter-packet XOR coding. The results of synthetic simulation have shown the validity of the analytical optimization, the benefit of coding, and the issues hard to consider in analytical models as well.The 34th International Conference on Information Networking (ICOIN 2020), January 7-10, 2020, Barcelona, Spai

Impaired alignment of bone matrix microstructure associated with disorganized osteoblast arrangement in malignant melanoma metastasis

Malignant melanoma favors spreading to bone, resulting in a weakened bone with a high fracture risk. Here, we revealed the disorganized alignment of apatite crystals in the bone matrix associated with the homing of cancer cells by developing an artificially controlled ex vivo melanoma bone metastasis model. The ex vivo metastasis model reflects the progressive melanoma cell activation in vivo, resulting in decreased bone mineral density and expression of MMP1-positive cells. Moreover, less organized intercellular connections were observed in the neighboring osteoblasts in metastasized bone, indicating the abnormal and randomized organization of bone matrix secreted by disconnected osteoblasts. Our study revealed that the deteriorated microstructure associated with disorganized osteoblast arrangement was a determinant of malignant melanoma-related bone dysfunction.Matsugaki A., Kimura Y., Watanabe R., et al. Impaired alignment of bone matrix microstructure associated with disorganized osteoblast arrangement in malignant melanoma metastasis. Biomolecules, 11, 2, 1. https://doi.org/10.3390/biom11020131

In vivo FRET analyses reveal a role of ATP hydrolysis–associated conformational changes in human P-glycoprotein

P-glycoprotein (P-gp; also known as MDR1 or ABCB1) is an ATP-driven multidrug transporter that extrudes various hydrophobic toxic compounds to the extracellular space. P-gp consists of two transmembrane domains (TMDs) that form the substrate translocation pathway and two nucleotide-binding domains (NBDs) that bind and hydrolyze ATP. At least two P-gp states are required for transport. In the inward-facing (pre-drug transport) conformation, the two NBDs are separated, and the two TMDs are open to the intracellular side; in the outward-facing (post-drug transport) conformation, the NBDs are dimerized, and the TMDs are slightly open to the extracellular side. ATP binding and hydrolysis cause conformational changes between the inward-facing and the outward-facing conformations, and these changes help translocate substrates across the membrane. However, how ATP hydrolysis is coupled to these conformational changes remains unclear. In this study, we used a new FRET sensor that detects conformational changes in P-gp to investigate the role of ATP binding and hydrolysis during the conformational changes of human P-gp in living HEK293 cells. We show that ATP binding causes the conformational change to the outward-facing state and that ATP hydrolysis and subsequent release of γ-phosphate from both NBDs allow the outward-facing state to return to the original inward-facing state. The findings of our study underscore the utility of using FRET analysis in living cells to elucidate the function of membrane proteins such as multidrug transporters

Characterization of candidate intermediates in the Black Box of the ecdysone biosynthetic pathway in Drosophila melanogaster: Evaluation of molting activities on ecdysteroid-defective larvae

Early steps of the biosynthetic pathway of the insect steroid hormone ecdysone remains the “Black Box” wherein the characteristic ecdysteroid skeleton is built. 7-Dehydrocholesterol (7dC) is the precursor of uncharacterized intermediates in the Black Box. The oxidation step at C-3 has been hypothesized during conversion from 7dC to 3-oxo-2, 22, 25-trideoxyecdysone, yet 3-dehydroecdysone is undetectable in some insect species. Therefore, we first confirmed that the oxidation at C-3 occurs in the fruitfly, Drosophila melanogaster using deuterium-labeled cholesterol. We next investigated the molting activities of candidate intermediates, including oxidative products of 7dC, by feeding-rescue experiments for Drosophila larvae in which an expression level of a biosynthetic enzyme was knocked down by the RNAi technique. We found that the administration of cholesta-4, 7-dien-3-one (3-oxo-Δ4, 7C) could overcome the molting arrest of ecdysteroid-defective larvae in which the expression level of neverland was reduced. However, feeding 3-oxo-Δ4, 7C to larvae in which the expression levels of shroud and Cyp6t3 were reduced inhibited molting at the first instar stage, suggesting that this steroid could be converted into an ecdysteroid-antagonist in loss of function studies of these biosynthetic enzymes. Administration of the highly conjugated cholesta-4, 6, 8(14)-trien-3-one, oxidized from 3-oxo-Δ4, 7C, did not trigger molting of ecdysteroid-defective larvae. These results suggest that an oxidative product derived from 7dC is converted into ecdysteroids without the formation of this stable conjugated compound. We further found that the 14α-hydroxyl moiety of Δ4-steroids is required to overcome the molting arrest of larvae in loss of function studies of Neverland, Shroud, CYP6T3 or Spookier, suggesting that oxidation at C-14 is indispensable for conversion of these Δ4-steroids into ecdysteroids via 5β-reduction

Novel assay system for acidic Peptide:N-glycanase (aPNGase) activity in crude plant extract

Acidic peptide:N-glycanase (aPNGase) plays a pivotal role in plant glycoprotein turnover. For the construction of aPNGase-knockout or -overexpressing plants, a new method to detect the activity in crude plant extracts is required because endogenous peptidases present in the extract hamper enzyme assays using fluorescence-labeled N-glycopeptides as a substrate. In this study, we developed a new method for measuring aPNGase activity in crude extracts from plant material

Neurological Analysis Based on the Terminal End of the Spinal Cord and the Narrowest Level of Injured Spine in Thoracolumbar Spinal Injuries

This study aimed to clarify neurological differences among the epiconus, conus medullaris, and cauda equina syndromes. Eighty-seven patients who underwent surgery for acute thoracolumbar spinal injuries were assessed. We defined the epiconus as the region from the terminal end of the spinal cord to the proximal 1.0 to 2.25 vertebral bodies, the conus medullaris as the region proximal to < 1.0 vertebral bodies, and the cauda equina as the distal part of the nerve roots originating from the spinal cord. On the basis of the distance from the terminal end of the spinal cord to the narrowest level of the spinal canal, the narrowest levels were ordered as follows: the epiconus followed by the conus medullaris and cauda equina. The narrowest levels were the epiconus in 22 patients, conus medullaris in 37 patients, and cauda equina in 25 patients. On admission, significantly more patients had a narrowed epiconus of Frankel grades A-C than a narrowed cauda equina. At the final follow-up, there were no significant differences in neurological recovery among those with epiconus, conus medullaris, or cauda equina syndrome. Anatomically classifying the narrowest lesion is useful for clarifying the differences and similarities among these three syndromes