For Pre-Trained Vision Models in Motor Control, Not All Policy Learning Methods are Created Equal

In recent years, increasing attention has been directed to leveraging pre-trained vision models for motor control. While existing works mainly emphasize the importance of this pre-training phase, the arguably equally important role played by downstream policy learning during control-specific fine-tuning is often neglected. It thus remains unclear if pre-trained vision models are consistent in their effectiveness under different control policies. To bridge this gap in understanding, we conduct a comprehensive study on 14 pre-trained vision models using 3 distinct classes of policy learning methods, including reinforcement learning (RL), imitation learning through behavior cloning (BC), and imitation learning with a visual reward function (VRF). Our study yields a series of intriguing results, including the discovery that the effectiveness of pre-training is highly dependent on the choice of the downstream policy learning algorithm. We show that conventionally accepted evaluation based on RL methods is highly variable and therefore unreliable, and further advocate for using more robust methods like VRF and BC. To facilitate more universal evaluations of pre-trained models and their policy learning methods in the future, we also release a benchmark of 21 tasks across 3 different environments alongside our work

EFFECT OF HARVESTING QUOTA AND PROTECTION ZONE IN A REACTION-DIFFUSION MODEL ARISING FROM FISHERY MANAGEMENT

A reaction-diffusion logistic population model with spatially nonhomogeneous harvesting is considered. It is shown that when the intrinsic growth rate is larger than the principal eigenvalue of the protection zone, then the population is always sustainable; while in the opposite case, there exists a maximum allowable catch to avoid the population extinction. The existence of steady state solutions is also studied for both cases. The existence of an optimal harvesting pattern is also shown, and theoretical results are complemented by some numerical simulations for one-dimensional domains

Computed Web Learning Software Design with a Medical Psychological Perspective: Depression as an Example and Economic Analysis

We have tried to use computer technology in teaching and designing the necessary knowledge points for the diagnosis, treatment, and prevention of depression. We have also used computer platforms to elucidate this model as an economics product and carry out the necessary investigation and study of the market prospects, and we have proposed innovative points in solving the problem based on basic knowledge in medical psychology, and we have reported the results in conjunction with the results of the study

On-Line Monitoring and Fault Diagnosis of Box Transformer Substation Based on VPRS-RBFNN

Box transformer substation (BTS) is an important power distribution environment. To ensure the safe and stable operation of the power distribution system, it is critical to monitor the BTS operation and diagnose its faults in a reliable manner. In the Internet of Things (IoT) environment, this paper aims to develop a real-time and accurate online strategy for BTS monitoring and fault diagnosis. The framework of our strategy was constructed based on the IoT technique, including a sensing layer, a network layer and an application layer. On this basis, a BTS fault diagnosis method was established with variable precision rough set (VPRS) as the pre-network and the radial basis function neural network (RBFNN) as the back-fed network. The VPRS and the RBFNN were selected, because the BTS faults have many characteristic parameters, with complex nonlinear relationship with fault modes. Finally, a prototype of our strategy was developed and applied to the fault diagnosis of an actual BTS. The results fully demonstrate the effectiveness and feasibility of our strategy

Plasma kallikrein structure reveals apple domain disc rotated conformation compared to factor XI

BackgroundPlasma prekallikrein (PK) and factor XI (FXI) are apple domain‐containing serine proteases that when activated to PKa and FXIa cleave substrates kininogen, factor XII, and factor IX, respectively, directing plasma coagulation, bradykinin release, inflammation, and thrombosis pathways.ObjectiveTo investigate the three‐dimensional structure of full‐length PKa and perform a comparison with FXI.MethodsA series of recombinant full‐length PKa and FXI constructs and variants were developed and the crystal structures determined.Results and conclusionsA 1.3 Å structure of full‐length PKa reveals the protease domain positioned above a disc‐shaped assemblage of four apple domains in an active conformation. A comparison with the homologous FXI structure reveals the intramolecular disulfide and structural differences in the apple 4 domain that prevents dimer formation in PK as opposed to FXI. Two latchlike loops (LL1 and LL2) extend from the PKa protease domain to form interactions with the apple 1 and apple 3 domains, respectively. A major unexpected difference in the PKa structure compared to FXI is the 180° disc rotation of the apple domains relative to the protease domain. This results in a switched configuration of the latch loops such that LL2 interacts and buries portions of the apple 3 domain in the FXI zymogen whereas in PKa LL2 interacts with the apple 1 domain. Hydrogen‐deuterium exchange mass spectrometry on plasma purified human PK and PKa determined that regions of the apple 3 domain have increased surface exposure in PKa compared to the zymogen PK, suggesting conformational change upon activation

Surface-Modified Phthalocyanine-Based Two-Dimensional Conjugated Metal–Organic Framework Films for Polarity-Selective Chemiresistive Sensing

Surface-modification of phthalocyanine-based two-dimensional conjugated metal-organic framework (2D c-MOF) films by grafting aliphatic alkyl chains is developed for achieving high-performance polarity-selective chemiresistive sensing toward humidity and polar alcohols. 2D conjugated metal–organic frameworks (2D c-MOFs) are emerging as electroactive materials for chemiresistive sensors, but selective sensing with fast response/recovery is a challenge. Phthalocyanine-based Ni2[MPc(NH)8] 2D c-MOF films are presented as active layers for polarity-selective chemiresisitors toward water and volatile organic compounds (VOCs). Surface-hydrophobic modification by grafting aliphatic alkyl chains on 2D c-MOF films decreases diffused analytes into the MOF backbone, resulting in a considerably accelerated recovery progress (from ca. 50 to ca. 10 s) during humidity sensing. Toward VOCs, the sensors deliver a polarity-selective response among alcohols but no signal for low-polarity aprotic hydrocarbons. The octadecyltrimethoxysilane-modified Ni2[MPc(NH)8] based sensor displays high-performance methanol sensing with fast response (36 s)/recovery (13 s) and a detection limit as low as 10 ppm, surpassing reported room-temperature chemiresistors

Operative choice for subtrochanteric femoral fracture in school-aged children: Triple elastic stable intramedullary nail versus locking plate

BackgroundThe management strategy of subtrochanteric fractures remains controversial, and triple elastic stable intramedullary nail (ESIN) has not been reported for pediatric subtrochanteric fractures. This study aimed to compare the clinical effects of treating school-aged children with subtrochanteric fractures with triple ESINs versus locking plates.MethodsWe conducted a retrospective review of pediatric patients with subtrochanteric femoral fracture receiving either triple ESINs (TE) or locking plates (LPs) between January 2010 and January 2018. Sixteen patients in each group with matched age, sex, and fracture characteristics were included in the study. The preoperative data, including baseline information of the patients, fracture pattern, and types of surgical procedure, were collected from the hospital database. Patients were followed-up at the outpatient clinic in the 3rd month, 6th month, 12th month, and annually afterward. Hardware removal was performed at 9 – 18 months after the primary surgery.ResultsIn all, 16 patients (8.4 ± 1.5-year-old, 7 boys, 9 girls) in the TE group and 16 patients (8.4 ± 1.4-year-old, 7 boys, 9 girls) in the LP group were included. There was significantly less operative time, reduced estimated blood loss, and shortened hospital stay for the TE as compared with the LP (P < 0.001). However, higher fluoroscopy frequency was observed in the TE group than in the LP group (P < 0.001). The time to union was faster in the TE group than in the LP group (P = 0.031). However, the angulation was higher in the TE group (3.2 ± 0.6) than the LP group (1.8 ± 0.5), and the incidence of implant prominence was higher in the TE group (7/16, 43.8%) than the LP group (1/16, 6.3%).ConclusionCompared with the locking plates, triple ESINs demonstrated significantly less operative time, reduced estimated blood loss, and shortened hospital stay. Besides, both TE and LP groups produced satisfactory outcomes in school-aged children with subtrochanteric fractures. Therefore, TE remains a feasible choice for subtrochanteric fractures in school-aged children

Surface-Modified Phthalocyanine-Based Two-Dimensional Conjugated Metal–Organic Framework Films for Polarity-Selective Chemiresistive Sensing

This corrigendum corrects an omission from the Acknowledgement section. The research leading to the results published in this manuscript was also supported by the project CALIPSOplus under Grant Agreement 730872 from the EU Framework Programme for Research and Innovation HORIZON 2020