389 research outputs found
A Case Study of Mass Transport during the East-West Oscillation of the Asian Summer Monsoon Anticyclone
We use ERA-Interim reanalysis, MLS observations, and a trajectory model to examine the chemical transport and tracers distribution in the Upper Troposphere and Lower Stratosphere (UTLS) associated with an east-west oscillation case of the anticyclone in 2016. The results show that the spatial distribution of water vapor (H2O) was more consistent with the location of the anticyclone than carbon monoxide (CO) at 100āhPa, and an independent relative high concentration center was only found in H2O field. At 215āhPa, although the anticyclone center also migrated from the Tibetan Mode (TM) to the Iranian Mode (IM), the relative high concentration centers of both tracers were always colocated with regions where upward motion was strong in the UTLS. When the anticyclone migrated from the TM, air within the anticyclone over Tibetan Plateau may transport both westward and eastward but was always within the UTLS. The relative high concentration of tropospheric tracers within the anticyclone in the IM was from the east and transported by the westward propagation of the anticyclone rather than being lifted from surface directly. Air within the relative high geopotential height centers over Western Pacific was partly from the main anticyclone and partly from lower levels
Path Generation for Wheeled Robots Autonomous Navigation on Vegetated Terrain
Wheeled robot navigation has been widely used in urban environments, but
little research has been conducted on its navigation in wild vegetation.
External sensors (LiDAR, camera etc.) are often used to construct point cloud
map of the surrounding environment, however, the supporting rigid ground used
for travelling cannot be detected due to the occlusion of vegetation. This
often causes unsafe or not smooth path during planning process. To address the
drawback, we propose the PE-RRT* algorithm, which effectively combines a novel
support plane estimation method and sampling algorithm to generate real-time
feasible and safe path in vegetation environments. In order to accurately
estimate the support plane, we combine external perception and proprioception,
and use Multivariate Gaussian Processe Regression (MV-GPR) to estimate the
terrain at the sampling nodes. We build a physical experimental platform and
conduct experiments in different outdoor environments. Experimental results
show that our method has high safety, robustness and generalization
Towards Efficient Communications in Federated Learning: A Contemporary Survey
In the traditional distributed machine learning scenario, the user's private
data is transmitted between nodes and a central server, which results in great
potential privacy risks. In order to balance the issues of data privacy and
joint training of models, federated learning (FL) is proposed as a special
distributed machine learning with a privacy protection mechanism, which can
realize multi-party collaborative computing without revealing the original
data. However, in practice, FL faces many challenging communication problems.
This review aims to clarify the relationship between these communication
problems, and focus on systematically analyzing the research progress of FL
communication work from three perspectives: communication efficiency,
communication environment, and communication resource allocation. Firstly, we
sort out the current challenges existing in the communications of FL. Secondly,
we have compiled articles related to FL communications, and then describe the
development trend of the entire field guided by the logical relationship
between them. Finally, we point out the future research directions for
communications in FL
Enterovirus 71 induces degradation of TRIM38, a potential E3 ubiquitin ligase
<p>Abstract</p> <p>Background</p> <p>The tripartite motif (TRIM) proteins are a family of more than 70 members in human. However, only a few of them have been well studied. The TRIM proteins contain the conserved RING, B-box, coiled-coil, and SPRY domains, most of which are involved in protein ubiquitination. TRIM38 is a member of the TRIM protein family, which we studied in more detail here as its functions are largely unknown.</p> <p>Results</p> <p>Our study shows that, similar to other TRIM family members, TRIM38 is localized in the cytoplasm. TRIM38 increases ubiquitination of other cellular proteins and catalyzes self-ubiquitination. TRIM38 also promotes K63- and K48-linked ubiquitination of cellular proteins. An intact RING domain is important for the functions of TRIM38. In addition, enterovirus 71 infection induces TRIM38 degradation.</p> <p>Conclusions</p> <p>Our observations demonstrate that TRIM38 has E3 ubiquitin ligase activity and can be degraded during virus infection. These findings may provide insight into innate immune signaling pathways.</p
Self-Assembly of Mitochondria-Specific Peptide Amphiphiles Amplifying the Lung Cancer Cell Death through Targeting the VDAC1-Hexokinase-II Complex
International audienceMitochondria-targeting peptides represent an emergent approach for cancer inhibition. Here supramolecular assemblies of novel amphiphilic cell-penetrating peptides for targeting cancer cells mitochondria are reported. The employed strategy aims at amplifying the apoptotic stimuli by weakening the mitochondrial VDAC1 (voltage-dependent anion channel-1)-hexokinase-II (HK-II) interaction. Peptide engineering is performed with the N-terminus of the HK-II protein, which binds to VDAC1. First, a designed positively-charged segment (pKV) is anchored to the specific 15 aminoacid sequence (MIASHLLAYFFTELN) to yield a cell-penetrating peptide (pHK-pKV). Second, a lipid chain (Pal) is conjugated to the N-terminus of pHK-pKV in order to enhance the intracellular delivery of the HK-II scaffold. The self-assembly properties of these two synthetic peptides are investigated by synchrotron small-angle X-ray scattering (BioSAXS) and cryogenic transmission electron (cryo-TEM) imaging, which evidence the formation of nanoassemblies of ellipsoid-like shapes. Circular dichroism (CD) spectroscopy demonstrates the induction of partial Ī±-helical structures in the amphiphilic peptides. Confocal microscopy reveals the specific mitochondrial location of Pal-pHK-pKV assemblies in human non-small cell lung cancer (NSCLC) A549 cells. The cytotoxicity and apoptotic studies indicate the enhanced bioactivity of Pal-pHK-pKV self-assembled reservoirs, which cause massive A549 cell death with regard to pHK-pKV. Whereas the half maximum inhibitory concentration (IC 50) of the Pal-pHK-pKV peptide conjugates is 6.5 Ī¼M in the A549 cancer cell line, it is higher than 50 Ī¼M for healthy human mucosal epithelial cells such as the non-cancerous NCM460 cells. The results demonstrate the potential of self-assembled lipo-peptide (HK-II-derived) conjugates as a promising strategy in cancer therapy.
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