193 research outputs found
Weakly-supervised 3D Pose Transfer with Keypoints
The main challenges of 3D pose transfer are: 1) Lack of paired training data
with different characters performing the same pose; 2) Disentangling pose and
shape information from the target mesh; 3) Difficulty in applying to meshes
with different topologies. We thus propose a novel weakly-supervised
keypoint-based framework to overcome these difficulties. Specifically, we use a
topology-agnostic keypoint detector with inverse kinematics to compute
transformations between the source and target meshes. Our method only requires
supervision on the keypoints, can be applied to meshes with different
topologies and is shape-invariant for the target which allows extraction of
pose-only information from the target meshes without transferring shape
information. We further design a cycle reconstruction to perform
self-supervised pose transfer without the need for ground truth deformed mesh
with the same pose and shape as the target and source, respectively. We
evaluate our approach on benchmark human and animal datasets, where we achieve
superior performance compared to the state-of-the-art unsupervised approaches
and even comparable performance with the fully supervised approaches. We test
on the more challenging Mixamo dataset to verify our approach's ability in
handling meshes with different topologies and complex clothes. Cross-dataset
evaluation further shows the strong generalization ability of our approach.Comment: Accepted to ICCV 2023, Project page:
https://jinnan-chen.github.io/ws3dpt
Development and Characterization of Supercooled Polyethylene Naphthalate
The utilization of undercooled or supercooled polymers presents a promising approach for the creation of single-polymer composites (SPCs), applicable not only to compaction processing but also to extrusion, injection molding, and 3D printing techniques. This study focuses on the development and characterization of supercooled polyethylene naphthalate (PEN) through differential scanning calorimetry (DSC) and rheological measurements. By employing predetermined conditions, a supercooling degree of 50 ˚C for PEN was achieved. The impact of maximum heating temperature, cooling rate, and shear rate on the supercooling degree was examined, revealing that higher supercooling degrees of PEN can be attained by increasing these factors. Additionally, the flow behavior of supercooled polymer melts at various temperatures was analyzed. The supercooling state of PEN exhibited remarkable stability for a minimum duration of half an hour at temperatures exceeding 250 ˚C
A late Changhsingian (latest Permian) deep-water brachiopod fauna from Guizhou, South China
A deep-water brachiopod fauna (20 species in 19 genera) is described from the Late Permian Shaiwa Group of Ziyun, Guizhou, South China. New species include Pygmochonetes? shaiwaensis and Martinia ziyunensis. This fauna is associated with deep-water assemblages of pelagic radiolarians, foraminifers, bivalves and ammonoids. The brachiopod faunal correlations and age constraints of the associated fossil groups suggest that the Shaiwa fauna is late Changhsingian (latest Permian) in age. The Shaiwa fauna superficially resembles the coeval deep-water assemblage from Guangxi, South China; both are characterized by a mixture of deep-water brachiopods and shallow-water elements
Redetermination at 113 K of 2,2-tetramethylene-1,2-dihydroquinazolin-4(3H)-one
The title compound {systematic name: spiro[cyclopentane-1,2′(1′H)-quinazolin]-4′(3′H)-one]}, C12H14N2O, has been reported previously [Klemm, Weakley, Gilbertson & Song (1998 ▶). J. Heterocycl Chem. 35, 1269–1273]. Its structure has been redetermined at 113 K with greater precision for all data. The molecule is built up from two fused six-membered rings and one five-membered ring linked through a spiro C atom. The pyrimidine ring has an envelope conformation and the cyclopentane ring adopts a distorted boat form. There are intermolecular N—H⋯O hydrogen bonds, which form a two-dimensional sheet parallel to the (001) plane
2-Methyl-2-phenyl-1,2-dihydroquinazolin-4(3H)-one
In the molecule of the title compound, C15H14N2O, the six-membered 1,3-diaza ring assumes an envelope conformation. The two benzene ring planes are almost perpendicular to each other, making a dihedral angle of 85.53 (5)°. Supramolecular aggregation is mainly effected by N—H⋯O hydrogen bonding
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Gut stem cell aging is driven by mTORC1 via a p38 MAPK-p53 pathway.
Nutrients are absorbed solely by the intestinal villi. Aging of this organ causes malabsorption and associated illnesses, yet its aging mechanisms remain unclear. Here, we show that aging-caused intestinal villus structural and functional decline is regulated by mTORC1, a sensor of nutrients and growth factors, which is highly activated in intestinal stem and progenitor cells in geriatric mice. These aging phenotypes are recapitulated in intestinal stem cell-specific Tsc1 knockout mice. Mechanistically, mTORC1 activation increases protein synthesis of MKK6 and augments activation of the p38 MAPK-p53 pathway, leading to decreases in the number and activity of intestinal stem cells as well as villus size and density. Targeting p38 MAPK or p53 prevents or rescues ISC and villus aging and nutrient absorption defects. These findings reveal that mTORC1 drives aging by augmenting a prominent stress response pathway in gut stem cells and identify p38 MAPK as an anti-aging target downstream of mTORC1
Whole-genome microRNA sequencing analysis in patients with pulmonary hypertension
Pulmonary hypertension (PH) is a pathological disorder with multiple clinical manifestations that lead to cardiovascular and respiratory diseases in most patients. Recent studies have revealed that microRNAs (miRNAs) play important roles as upstream signaling molecules in several diseases, including PH. However, miRNAs that can be used as diagnostic or prognostic biomarkers for PH have not been identified. Thus, in this study, peripheral blood samples obtained from patients with PH and healthy individuals were subjected to genome-wide miRNA sequencing and transcriptome analysis. We screened 136 differentially expressed miRNAs in patients with PH and verified that four differentially expressed miRNAs, namely, hsa-miR-1304-3p, hsa-miR-490-3p, hsa-miR-11400, and hsa-miR-31-5p, could be used as clinical diagnostic biomarkers for pulmonary arterial hypertension. Our findings provide a basis for further in-depth investigations of the specific mechanisms of miRNAs in PH
Boosting freshwater fish conservation with high-resolution distribution mapping across a large territory
The lack of high-resolution distribution maps for freshwater species across large extents fundamentally challenges biodiversity conservation worldwide. We devised a simple framework to delineate the distributions of freshwater fishes in a high-resolution drainage map based on stacked species distribution models and expert information. We applied this framework to the entire Chinese freshwater fish fauna (>1600 species) to examine high-resolution biodiversity patterns and reveal potential conflicts between freshwater biodiversity and anthropogenic disturbances. The correlations between spatial patterns of biodiversity facets (species richness, endemicity, and phylogenetic diversity) were all significant (r = 0.43–0.98, p < 0.001). Areas with high values of different biodiversity facets overlapped with anthropogenic disturbances. Existing protected areas (PAs), covering 22% of China's territory, protected 25–29% of fish habitats, 16–23% of species, and 30–31% of priority conservation areas. Moreover, 6–21% of the species were completely unprotected. These results suggest the need for extending the network of PAs to ensure the conservation of China's freshwater fishes and the goods and services they provide. Specifically, middle to low reaches of large rivers and their associated lakes from northeast to southwest China hosted the most diverse species assemblages and thus should be the target of future expansions of the network of PAs. More generally, our framework, which can be used to draw high-resolution freshwater biodiversity maps combining species occurrence data and expert knowledge on species distribution, provides an efficient way to design PAs regardless of the ecosystem, taxonomic group, or region considered.Strategic Priority Research Program of Chinese Academy of Sciences XDB31000000Second Tibetan PlateauScientific Expedition Program 2019QZKK0304, 2019QZKK05010102National Key Research and Devel-opment Program of China 2021YFC3200300103National Natural Science Foundation of China 32070436, 4207744
Two-step synthesis of fatty acid ethyl ester from soybean oil catalyzed by Yarrowia lipolytica lipase
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