38 research outputs found
Super Vust theorem and Schur-Sergeev duality for principal finite -superalgebras
In this paper, we first formulate a super version of Vust theorem associated
with a regular nilpotent element . As an application of
this theorem, we then obtain the Schur-Sergeev duality for principal finite
-superalgebras which is partially a super version of Brundan-Kleshchev's
higher level Schur-Weyl duality.Comment: 35 pages, comments are welcom
DSMNet: Deep High-precision 3D Surface Modeling from Sparse Point Cloud Frames
Existing point cloud modeling datasets primarily express the modeling
precision by pose or trajectory precision rather than the point cloud modeling
effect itself. Under this demand, we first independently construct a set of
LiDAR system with an optical stage, and then we build a HPMB dataset based on
the constructed LiDAR system, a High-Precision, Multi-Beam, real-world dataset.
Second, we propose an modeling evaluation method based on HPMB for object-level
modeling to overcome this limitation. In addition, the existing point cloud
modeling methods tend to generate continuous skeletons of the global
environment, hence lacking attention to the shape of complex objects. To tackle
this challenge, we propose a novel learning-based joint framework, DSMNet, for
high-precision 3D surface modeling from sparse point cloud frames. DSMNet
comprises density-aware Point Cloud Registration (PCR) and geometry-aware Point
Cloud Sampling (PCS) to effectively learn the implicit structure feature of
sparse point clouds. Extensive experiments demonstrate that DSMNet outperforms
the state-of-the-art methods in PCS and PCR on Multi-View Partial Point Cloud
(MVP) database. Furthermore, the experiments on the open source KITTI and our
proposed HPMB datasets show that DSMNet can be generalized as a post-processing
of Simultaneous Localization And Mapping (SLAM), thereby improving modeling
precision in environments with sparse point clouds.Comment: To be published in IEEE Geoscience and Remote Sensing Letters (GRSL
Efficient Deep Reinforcement Learning via Adaptive Policy Transfer
Transfer Learning (TL) has shown great potential to accelerate Reinforcement
Learning (RL) by leveraging prior knowledge from past learned policies of
relevant tasks. Existing transfer approaches either explicitly computes the
similarity between tasks or select appropriate source policies to provide
guided explorations for the target task. However, how to directly optimize the
target policy by alternatively utilizing knowledge from appropriate source
policies without explicitly measuring the similarity is currently missing. In
this paper, we propose a novel Policy Transfer Framework (PTF) to accelerate RL
by taking advantage of this idea. Our framework learns when and which source
policy is the best to reuse for the target policy and when to terminate it by
modeling multi-policy transfer as the option learning problem. PTF can be
easily combined with existing deep RL approaches. Experimental results show it
significantly accelerates the learning process and surpasses state-of-the-art
policy transfer methods in terms of learning efficiency and final performance
in both discrete and continuous action spaces.Comment: Accepted by IJCAI'202
Solitary fibrous tumor of the adrenal gland: a case report and review of the literature
Solitary fibrous tumor (SFT) is a rare mesenchymal tumor, probably of fibroblastic origin, mainly in the extremities and pleura. Primary SFT of the adrenal gland is clinically more rare. Here, we report the case of a 47-year-old woman who detected a left adrenal mass on physical examination, without any symptoms, and no laboratory abnormalities. A computed tomography (CT) examination of the adrenal gland suggested a round-like soft tissue density shadow in the left adrenal area. An unenhanced scan showed uneven density of the mass, with a scattered circular-like cystic low-density shadow inside, and an enhanced scan showed obvious uneven enhancement. We considered it to be adrenal pheochromocytoma. Ultimately, the patient was treated with laparoscopic left adrenalectomy. A pathological examination suggested an adrenal SFT. We reviewed previous case reports of adrenal SFTs and summarized the clinical characteristics of adrenal SFT combined with the relevant literature. For adrenal tumors with uneven low-density shadow and uneven CT enhancement features, we should consider the differential diagnosis of adrenal SFT
Overall survival and cancer-specific survival were improved in local treatment of metastatic prostate cancer
BackgroundFor metastatic prostate cancer (mPCa), radical prostatectomy (RP) and radiation therapy (RT) may improve overall survival (OS) and cancer-specific survival (CSS). Compared with RT, RP shows significant advantages in improving patient outcomes. External beam radiation therapy (EBRT) even slightly elevates CSM with no statistical difference in OS compared with no local treatment (NLT).ObjectiveTo evaluate OS and CSS after local treatment (LT) (including RP and RT) versus NLT in mPCa.Design, setting, and participantsWithin the Surveillance, Epidemiology and End Results (SEER) database (2000-2018), 20098 patients with metastatic prostate cancer were selected in this study, of which 19433 patients had no local treatment, 377 patients with radical prostate treatment, and 288 patients with RT.Outcome measurements and statistical analysisMultivariable competing risks regression analysis after propensity score matching (PSM) was used to calculate CSM. Multivariable Cox regression analysis was used to identify the risk factors. Kaplan-Meier methods were used to calculate OS.Results and limitationsA total of 20098 patients were included: NLT (n = 19433), RP (n=377) and RT (n=288). In a competing risk regression analysis after PSM (ratio 1:1), RP resulted in a significantly lower CSM (hazard ratio [HR] 0.36, 95% confidence interval [CI] 0.29-0.45) than NLT, while RT showed a slightly lower CSM (HR 0.77, 95% CI 0.63-0.95). In a competing risk regression analysis after PSM (ratio 1:1), RP led to a lower CSM (HR 0.56, 95% CI 0.41-0.76) versus RT. As for all-cause mortality (ACM), RP (HR 0.37, 95% CI 0.31-0.45) and RT (HR 0.66, 95% CI 0.56-0.79). also showed a downward trend. In terms of OS, RP and RT significantly improved the survival probability compared with NLT, with the effect of RP being more pronounced. Obviously, older age, Gleason scores ≥8, AJCC T3-T4 stage, AJCC N1, AJCC M1b-M1c were all associated with higher CSM (P <0.05). The same results held true for ACM. The limitation of this article is that it is not possible to assess the effect of differences in systemic therapy on CSM in mPCa patients and clinical trials are needed to verify the results.ConclusionsFor patients with mPCa, both RP and RT are beneficial to patients, and the efficacy of RP is better than RT from the perspective of CSM and ACM. Older age, higher gleason scores and the more advanced AJCC TNM stage all put patients at higher risk of dying.Patient summaryA large population-based cancer database showed that in addition to first-line therapy (hormonal treatment), RP and radiotherapy can also benefit patients with mPCa
Multi-Scale Research on the Mechanisms of Soil Arching Development and Degradation in Granular Materials with Different Relative Density
Soil arching is significantly influenced by relative density, while its mechanisms have barely been analyzed. A series of DEM numerical simulations of the classical trapdoor test were carried out to investigate the multi-scale mechanisms of arching development and degradation in granular materials with different relative density. For analysis, the granular assembly was divided into three zones according to the particle vertical displacement normalized by the trapdoor displacement δ. The results show that before the maximum arching state (corresponding to the minimum arching ratio), contact forces between particles in a specific zone (where the vertical displacement of particles is larger than 0.1δ but less than 0.9δ) increase rapidly and robust arched force chains with large particle contact forces are generated. The variation in contact forces and force chains becomes more obvious as the sample porosity decreases. As a result, soil arching generated in a denser particle assembly is stronger, and the minimum value of the arching ratio is increased with the sample porosity. After the maximum arching state, the force chains in this zone are degenerated gradually, leading to a decrease in particle contact forces in microscale and an increase in the arching ratio in macroscale. The recovery of the arching ratio after the minimum value is also more significant in simulations with a larger relative density, as the degeneration of contact force chains is more obvious in denser samples. These results indicate the importance of contact force chain stabilities in specific zones for improving soil arching in engineering practice
Leveraging Machine Learning and Geo-Tagged Citizen Science Data to Disentangle the Factors of Avian Mortality Events at the Species Level
Abrupt environmental changes can affect the population structures of living species and cause habitat loss and fragmentations in the ecosystem. During August–October 2020, remarkably high mortality events of avian species were reported across the western and central United States, likely resulting from winter storms and wildfires. However, the differences of mortality events among various species responding to the abrupt environmental changes remain poorly understood. In this study, we focused on three species, Wilson’s Warbler, Barn Owl, and Common Murre, with the highest mortality events that had been recorded by citizen scientists. We leveraged the citizen science data and multiple remotely sensed earth observations and employed the ensemble random forest models to disentangle the species responses to winter storm and wildfire. We found that the mortality events of Wilson’s Warbler were primarily impacted by early winter storms, with more deaths identified in areas with a higher average daily snow cover. The Barn Owl’s mortalities were more identified in places with severe wildfire-induced air pollution. Both winter storms and wildfire had relatively mild effects on the mortality of Common Murre, which might be more related to anomalously warm water. Our findings highlight the species-specific responses to environmental changes, which can provide significant insights into the resilience of ecosystems to environmental change and avian conservations. Additionally, the study emphasized the efficiency and effectiveness of monitoring large-scale abrupt environmental changes and conservation using remotely sensed and citizen science data
Advances in the research of nanodrug delivery system for targeted treatment of liver fibrosis
Liver fibrosis is one of the major threats to human health. At present, anti-liver fibrosis drugs exist some problems,such as, lack of targeting, limited treatment effect and more or less toxic side effects. In order to improve the efficacy of targeted therapy for liver fibrosis, the development of a large number of nanocarriers and strategies of targeted therapy for liver fibrosis have been widely studied. In this paper, the research progress of nano-delivery vectors targeting cells related to the process of liver fibrosis in recent years was reviewed in terms of targeting vectors and the types of modified ligands, providing a new strategy for targeted cell therapy and theoretical reference for the realization of high efficient targeted therapy of liver fibrosis