51 research outputs found

    Efficient Space-Time Sampling with Pixel-wise Coded Exposure for High Speed Imaging

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    Cameras face a fundamental tradeoff between spatial and temporal resolution. Digital still cameras can capture images with high spatial resolution, but most high-speed video cameras have relatively low spatial resolution. It is hard to overcome this tradeoff without incurring a significant increase in hardware costs. In this paper, we propose techniques for sampling, representing and reconstructing the space-time volume in order to overcome this tradeoff. Our approach has two important distinctions compared to previous works: (1) we achieve sparse representation of videos by learning an over-complete dictionary on video patches, and (2) we adhere to practical hardware constraints on sampling schemes imposed by architectures of current image sensors, which means that our sampling function can be implemented on CMOS image sensors with modified control units in the future. We evaluate components of our approach - sampling function and sparse representation by comparing them to several existing approaches. We also implement a prototype imaging system with pixel-wise coded exposure control using a Liquid Crystal on Silicon (LCoS) device. System characteristics such as field of view, Modulation Transfer Function (MTF) are evaluated for our imaging system. Both simulations and experiments on a wide range of scenes show that our method can effectively reconstruct a video from a single coded image while maintaining high spatial resolution

    Multi-omics approaches reveal the molecular mechanisms underlying the interaction between Clonorchis sinensis and mouse liver

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    IntroductionClonorchiasis remains a serious global public health problem, causing various hepatobiliary diseases. However, there is still a lack of overall understanding regarding the molecular events triggered by Clonorchis sinensis (C. sinensis) in the liver.MethodsBALB/c mouse models infected with C. sinensis for 5, 10, 15, and 20 weeks were constructed. Liver pathology staining and observation were conducted to evaluate histopathology. The levels of biochemical enzymes, blood routine indices, and cytokines in the blood were determined. Furthermore, alterations in the transcriptome, proteome, and metabolome of mouse livers infected for 5 weeks were analyzed using multi-omics techniques.ResultsThe results of this study indicated that adult C. sinensis can cause hepatosplenomegaly and liver damage, with the most severe symptoms observed at 5 weeks post-infection. However, as the infection persisted, the Th2 immune response increased and symptoms were relieved. Multi-omics analysis of liver infected for 5 weeks identified 191, 402 and 232 differentially expressed genes (DEGs), proteins (DEPs) and metabolites (DEMs), respectively. Both DEGs and DEPs were significantly enriched in liver fibrosis-related pathways such as ECM-receptor interaction and cell adhesion molecules. Key molecules associated with liver fibrosis and inflammation (Cd34, Epcam, S100a6, Fhl2, Itgax, and Retnlg) were up-regulated at both the gene and protein levels. The top three metabolic pathways, namely purine metabolism, arachidonic acid metabolism, and ABC transporters, were associated with liver cirrhosis, fibrosis, and cholestasis, respectively. Furthermore, metabolites that can promote liver inflammation and fibrosis, such as LysoPC(P-16:0/0:0), 20-COOH-leukotriene E4, and 14,15-DiHETrE, were significantly up-regulated.ConclusionOur study revealed that the most severe symptoms in mice infected with C. sinensis occurred at 5 weeks post-infection. Moreover, multi-omics analysis uncovered predominant molecular events related to fibrosis changes in the liver. This study not only enhances our understanding of clonorchiasis progression but also provides valuable insights into the molecular-level interaction mechanism between C. sinensis and its host liver

    Non-volatile electric field-mediated magnetic anisotropy in CoZr/ PMN-PT structure

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    Introduction: Although electric field mediated the magnetic anisotropy in ferromagnetic/ferroelectric structure have an intense report, the angle between the magnetic uniaxial anisotropy and strain anisotropy influencing the rearrangement of the magnetic moment has not well investigated.Methods: Keithley 2410 direct current power supply was used to provide voltage through the Cu wires. Static magnetic properties of CoZr layer were measured through VSM (MicroSense EV9). Dynamic magnetic properties were obtained by FMR (JEOL JES-FA 300 spectrometer, power of 1-mW, X-band at 8.969 GHz).Results and Discussion: Electric field-mediated, room-temperature magnetic anisotropy of CoZr/Pb(Mg1/3Nb2/3)O3–PbTiO3 (PMN–PT) structures, in which easy axis of CoZr layer along either direction of [01-1] or [100] of PMN–PT, was investigated. Measured with vibrating sample magnetometer, for [01-1] easy-axis direction sample, when an electric field was applied, these directions of easy axis and hard axis remains unchanged. However, for [100] easy-axis direction sample, these directions of easy axis and hard axis were changed obviously with applying electric field, attributable to the competition between magnetic uniaxial anisotropy of CoZr layer and piezostrain anisotropy of PMN-PT substrate. Nevertheless, change of the resonance magnetic field with electric field–measured by ferromagnetic resonance–exhibited non-volatile behavior, which possibly indicates magnon-driven magnetoelectric coupling existing in CoZr/PMN–PT structures

    Schistosoma japonicum SjE16.7 Protein Promotes Tumor Development via the Receptor for Advanced Glycation End Products (RAGE).

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    Schistosome infection contributes to cancer development, but the mechanisms are still not well-understood. SjE16.7 is an EF-hand calcium-binding protein secreted from Schistosoma japonicum eggs. It is a neutrophil attractant and macrophage activator and, as such, plays an important role in the inflammatory granuloma response in schistosomiasis. Here, we show that SjE16.7 binds to host cells by interacting with receptors for advanced glycation end products (RAGE). This ligation leads to activation of the NF-κB signaling pathway, an increase in the generation of reactive oxygen species, and production of the pro-inflammatory cytokines IL-6 and TNF-α. Using a mouse model of colorectal cancer, we demonstrate that intraperitoneal injection of SjE16.7 promotes colorectal cancer progression along with systemic myeloid cell accumulation. Thus, our results identify a new helminth antigen contributing to tumor development in the mammalian host

    Bistability and Oscillations in Gene Regulation Mediated by Small Noncoding RNAs

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    The interplay of small noncoding RNAs (sRNAs), mRNAs, and proteins has been shown to play crucial roles in almost all cellular processes. As key post-transcriptional regulators of gene expression, the mechanisms and roles of sRNAs in various cellular processes still need to be fully understood. When participating in cellular processes, sRNAs mainly mediate mRNA degradation or translational repression. Here, we show how the dynamics of two minimal architectures is drastically affected by these two mechanisms. A comparison is also given to reveal the implication of the fundamental differences. This study may help us to analyze complex networks assembled by simple modules more easily. A better knowledge of the sRNA-mediated motifs is also of interest for bio-engineering and artificial control

    What is the Space of Spectral Sensitivity Functions for Digital Color Cameras?

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    Camera spectral sensitivity functions relate scene radiance with captured RGB triplets. They are important for many computer vision tasks that use color information, such as multispectral imaging, color rendering, and color constancy. In this paper, we aim to explore the space of spectral sensitivity functions for digital color cameras. After collecting a database of 28 cameras covering a variety of types, we find this space convex and two-dimensional. Based on this statistical model, we propose two methods to recover camera spectral sensitivities using regular reflective color targets (e.g., color checker) from a single image with and without knowing the illumination. We show the proposed model is more accurate and robust for estimating camera spectral sensitivities than other basis functions. We also show two applications for the recovery of camera spectral sensitivities — simulation of color rendering for cameras and computational color constancy. 1

    Interaction and Coupling Mechanism between Recessive Land Use Transition and Food Security: A Case Study of the Yellow River Basin in China

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    The Yellow River Basin (YRB) plays an important role in China’s socioeconomic development and ecological security. From the perspective of recessive land use transition (RLUT), exploring the watershed food security (FS) coordination mechanism is of strategic significance to territorial space optimization and high-quality development. To this end, a coordinated evaluation system was built for analyzing the coupling coordination degree (CCD), spatiotemporal evolution characteristics, and driving mechanism between RLUT and FS of 74 cities in the YRB from 2003 to 2018, using methods such as the coupling coordination degree model, spatial autocorrelation analysis, and the geo-detector model. The results are as follows: (1) Spatial imbalance of RLUT and FS in the YRB is significant. RLUT has significant differences between east and west, and FS has significant differences between north and south. (2) From 2003 to 2018, the CCD between RLUT and FS increased from 0.6028 to 0.6148, maintaining a steady upward trend, and the cold and hot characteristics of spatial agglomeration are significant. (3) The CCD between RLUT and FS depends on population density, average annual temperature, and average elevation. The driving effect of natural factors is higher than the socioeconomic factors on the total basin scale, but the opposite is true on the sub-basin scale. Clarifying the spatiotemporal pattern, characteristics, and mechanism of the coupling and the coordination of RLUT and FS can provide a scientific basis for territorial space planning

    Experimental Study on Tribological and Leakage Characteristics of a Rotating Spring-Energized Seal under High and Low Temperature

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    A spring-energized seal, whose PTFE plastic shell has excellent self-lubrication and a low temperature stability, is used widely in liquid fuel valves’ rotating end-face seals. However, in practical application, temperature has a larger effect on not only the physical and tribological properties of materials, but also on the leakage performance of spring-energized rings. Thus, a high and low temperature sealing test of the spring-energized seal that applies to an engine was carried out. In this paper, the leakage characteristics, friction torque and wear characteristics of a spring-energized ring under different temperatures were studied. The friction torque at high temperature was less than that at normal temperature, and a low temperature could effectively reduce the wear amount of PTFE material. In order to study the influence of temperature on PTFE filled with graphite, the friction and wear test of PTFE-2 was carried out. The results showed that the amount of wear of PTFE-2 was only 27.8% of that at the normal temperature but the friction coefficient was three times larger when the temperature was −45 °C
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