Towards Practical Capture of High-Fidelity Relightable Avatars

In this paper, we propose a novel framework, Tracking-free Relightable Avatar (TRAvatar), for capturing and reconstructing high-fidelity 3D avatars. Compared to previous methods, TRAvatar works in a more practical and efficient setting. Specifically, TRAvatar is trained with dynamic image sequences captured in a Light Stage under varying lighting conditions, enabling realistic relighting and real-time animation for avatars in diverse scenes. Additionally, TRAvatar allows for tracking-free avatar capture and obviates the need for accurate surface tracking under varying illumination conditions. Our contributions are two-fold: First, we propose a novel network architecture that explicitly builds on and ensures the satisfaction of the linear nature of lighting. Trained on simple group light captures, TRAvatar can predict the appearance in real-time with a single forward pass, achieving high-quality relighting effects under illuminations of arbitrary environment maps. Second, we jointly optimize the facial geometry and relightable appearance from scratch based on image sequences, where the tracking is implicitly learned. This tracking-free approach brings robustness for establishing temporal correspondences between frames under different lighting conditions. Extensive qualitative and quantitative experiments demonstrate that our framework achieves superior performance for photorealistic avatar animation and relighting.Comment: Accepted to SIGGRAPH Asia 2023 (Conference); Project page: https://travatar-paper.github.io

FgPex3, a Peroxisome Biogenesis Factor, Is Involved in Regulating Vegetative Growth, Conidiation, Sexual Development, and Virulence in Fusarium graminearum

Peroxisomes are involved in a wide range of important cellular functions. Here, the role of the peroxisomal membrane protein PEX3 in the plant-pathogen and mycotoxin producer Fusarium graminearum was studied using knock-out and complemented strains. To fluorescently label peroxisomes’ punctate structures, GFP and RFP fusions with the PTS1 and PTS2 localization signal were transformed into the wild type PH- 1 and 1FgPex3 knock-out strains. The GFP and RFP transformants in the 1FgPex3 background showed a diffuse fluorescence pattern across the cytoplasm suggesting the absence of mature peroxisomes. The 1FgPex3 strain showed a minor, non-significant reduction in growth on various sugar carbon sources. In contrast, deletion of FgPex3 affected fatty acid b-oxidation in F. graminearum and significantly reduced the utilization of fatty acids. Furthermore, the 1FgPex3 mutant was sensitive to osmotic stressorsas well as to cell wall-damaging agents. Reactive oxygen species (ROS) levels in the mutant had increased significantly, which may be linked to the reduced longevity of cultured strains. The mutant also showed reduced production of conidiospores, while sexual reproduction was completely impaired. The pathogenicity of 1FgPex3, especially during the process of systemic infection, was strongly reduced on both tomato and on wheat, while to production of deoxynivalenol (DON), an important factor for virulence, appeared to be unaffected

Population Analysis of the Fusarium graminearum Species Complex from Wheat in China Show a Shift to More Aggressive Isolates

A large number of Fusarium isolates was collected from blighted wheat spikes originating from 175 sampling sites, covering 15 provinces in China. Species and trichothecene chemotype determination by multilocus genotyping (MLGT) indicated that F. graminearum s. str. with the 15-acetyl deoxynivalenol (15ADON) chemotype and F. asiaticum with either the nivalenol (NIV) or the 3-acetyl deoxynivalenol (3ADON) chemotype were the dominant causal agents. Bayesian model-based clustering with allele data obtained with 12 variable number of tandem repeats (VNTR) markers, detected three genetic clusters that also show distinct chemotypes. High levels of population genetic differentiation and low levels of effective number of migrants were observed between these three clusters. Additional genotypic analyses revealed that F. graminearum s. str. and F. asiaticum are sympatric. In addition, composition analysis of these clusters indicated a biased gene flow from 3ADON to NIV producers in F. asiaticum. In phenotypic analyses, F. asiaticum that produce 3ADON revealed significant advantages over F. asiaticum that produce NIV in pathogenicity, growth rate, fecundity, conidial length, trichothecene accumulation and resistance to benzimidazole. These results suggest that natural selection drives the spread of a more vigorous, more toxigenic pathogen population which also shows higher levels of fungicide resistance

Differentiable deformation graph-based neural non-rigid registration

The traditional pipeline for non-rigid registration is to iteratively update the correspondence and alignment such that the transformed source surface aligns well with the target surface. Among the pipeline, the correspondence construction and iterative manner are key to the results, while existing strategies might result in local optima. In this paper, we adopt the widely used deformation graph-based representation, while replacing some key modules with neural learning-based strategies. Specifically, we design a neural network to predict the correspondence and its reliability confidence rather than the strategies like nearest neighbor search and pair rejection. Besides, we adopt the GRU-based recurrent network for iterative refinement, which is more robust than the traditional strategy. The model is trained in a self-supervised manner and thus can be used for arbitrary datasets without ground-truth. Extensive experiments demonstrate that our proposed method outperforms the state-of-the-art methods by a large margin

Interfacial Structure and Transformation of Guanine-Rich Oligonucleotides on Solid Supported Lipid Bilayer Investigated by Sum Frequency Generation Vibrational Spectroscopy

Lipid membrane-anchored guanine-rich oligonucleotides with non-Watson–Crick structures can perform structure transformation in a controllable and reversible manner upon the external stimuli. Elucidating the mechanisms of their interaction and transformation is the key to understand medical applicability and functioning feasibility of these oligonucleotides. In this study, the molecular structure and interfacial transformation kinetics of guanine-rich oligonucleotides at model cell membrane were investigated by sum frequency generation vibrational spectroscopy (SFG-VS) in real time and <i>in situ</i>. The conformations of oligonucleotides are obtained by analyzing the SFG spectra in the “fingerprint” region. The results indicate that the electrostatic interaction and hydrophobic interaction are both important to the interfacial adsorption and transformation of oligonucleotides. The tilt angles of oligonucleotides with different conformations were also calculated. Molecular insights into interfacial oligonucleotides will help researchers to control the oligonucleotide–lipid membrane interactions in a desired manner and improve the reproductivity, stability, and reversibility of oligonucleotide-based applications

On conjugate product of complex polynomials

Some concepts, such as divisibility, coprimeness, in the framework of ordinary polynomial product are extended to the framework of conjugate product. Euclidean algorithm for obtaining greatest common divisors in the framework of conjugate product is also established. Some criteria for coprimeness are established