Risk-sensitive reinforcement learning (RL) aims to optimize policies that balance the expected reward and risk. In this paper, we present a novel risk-sensitive RL framework that employs an Iterated Conditional Value-at-Risk (CVaR) objective under both linear and general function approximations, enriched by human feedback. These new formulations provide a principled way to guarantee safety in each decision making step throughout the control process. Moreover, integrating human feedback into risk-sensitive RL framework bridges the gap between algorithmic decision-making and human participation, allowing us to also guarantee safety for human-in-the-loop systems. We propose provably sample-efficient algorithms for this Iterated CVaR RL and provide rigorous theoretical analysis. Furthermore, we establish a matching lower bound to corroborate the optimality of our algorithms in a linear context.
Fibrous dysplasia (FD) is an uncommon benign fibro-osseous lesion of the bone, characterized by the replacement of normal cancellous bone with fibroblastic tissue that contains irregularly shaped metaplastic woven bone1. This disease has different forms: monostotic (MFD), polyostotic (PFD), or variable with cutaneous and endocrine abnormalities (McCune-Albright syndrome)2. MFD most commonly affects the ribs, femur, tibia, jaws, calvarium, and humerus3,4. Spine involvement in MFD is exceedingly rare, particularly in the lumbar spine. To our knowledge, there have been only fifteen cases of lumbar MFD previously described in the literature4-18. We present a rare case of MFD of the fourth lumbar vertebra and review the relevant literature.
The patient was informed that data concerning the case would be submitted for publication, and she provided consent.
A thirty-seven-year-old woman presented with right-sided low back pain of five years’ duration. One month before admission, she developed bilateral leg pain and numbness, which was more prominent on the right side. The pain became worse at night and forced her to be confined to bed. No history of trauma was reported. The family history was unremarkable. Conservative treatment, including the use of nonsteroidal anti-inflammatory drugs and bracing, failed.
Physical examination revealed tenderness over the right paravertebral area of L4. The spinal range of motion was impaired. The straight leg raise test was positive at 40° on the right side and 50° on the left side. Sensation to pinprick was diminished between the L4 and L5 dermatomes on both sides, but especially on the right side. There were motor deficits. No endocrinological dysfunction or skin pigmentation was present. Deep tendon reflexes were symmetrical. Laboratory investigation, including total blood-cell count, hormone levels, erythrocyte sedimentation rate, C-reactive protein level, cancer marker (alpha-fetoprotein [AFP], CA10, carcinoembroyonic antigen …
We report the observation of colossal positive magnetoresistance (MR) in single crystalline, high mobility TaAs2 semimetal. The excellent fit of MR by a single quadratic function of the magnetic field B over a wide temperature range (T = 2–300 K) suggests the semiclassical nature of the MR. The measurements of Hall effect and Shubnikov-de Haas oscillations, as well as band structure calculations, suggest that the giant MR originates from the nearly perfectly compensated electrons and holes in TaAs2. The quadratic MR can even exceed 1 200 000% at B = 9 T and T = 2 K, which is one of the largest values among those of all known semi-metallic compounds, including the very recently discovered WTe2 and NbSb2. The giant positive magnetoresistance in TaAs2 not only has a fundamentally different origin from the negative colossal MR observed in magnetic systems but also provides a nice complemental system that will be beneficial for applications in magnetoelectronic devices.
We report an optical spectroscopy study of a single-crystal sample of PrSb, one of the monoantimonide $R\mathrm{Sb}$ compounds, which show interesting properties, such as topological nontrivial surface states and extremely large magnetoresistance. The plasma frequency is revealed at about $4300\phantom{\rule{0.28em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$, suggesting a low carrier density. In addition, we found two quasilinear components with variable slopes in the real part of the optical conductivity ${\ensuremath{\sigma}}_{1}(\ensuremath{\omega})$. In combination with theoretical calculations which reveal a band inversion, our results may provide optical spectroscopic evidence of a topological nontrivial property in PrSb.
Objective: The multiple evaluation method of radar map was used to evaluate the literature quality of systematic evaluation /meta analysis of moxibustion therapy for functional constipation, providing clear and reliable evidence for the majority of users. Methods: The retrieval strategy was developed and perfected, and the quality of literature was evaluated from six aspects: publication time, design type, AMSTAR score, PRISMA score, heterogeneity and publication bias.Results: Finally, 5 literature that met the established requirements were included, and the publication years were concentrated from 2018 to 2021. Randomized controlled trials accounted for a large proportion of design types, AMSTAR scores ranged from 12 to 23, PRISMA scores ranged from 21 to 40, and the average rank score of 5 literature was 3.43. Among them, the literature quality of xuan Yichen and Wu Xinyu was relatively good, with balanced and stable scores in all dimensions, while the treatment of the rest was poor (mainly manifested in: the literature retrieval strategy was not comprehensive enough; The existence of heterogeneity was not satisfactorily explained and discussed; Lack of reporting on research funding and funding sources; Lack of literature search and screening flow chart reports in study selection; The characteristics of the literature are not fully reported). Most literature have low homogeneity and publication bias.Conclusion: Systematic evaluation/Meta Analysis of moxibustion therapy for functional constipation the quality of literature needs to be further improved, especially the quality of methodology and reportage. The radar chart shows the data in a concise, intuitive and clear way, which is worthy of wide application in various specialties of traditional Chinese medicine.
We investigated the magnetoresistive behavior of an ideal Dirac semimetal---high-quality single crystals of ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$ with a Fermi level very close to the Dirac point. A large linear magnetoresistance (LMR), up to 3100% in a magnetic field of 14 T, was observed at a temperature of $T=2\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. The detailed field and temperature dependencies reveal that the LMR occurs only when the Zeeman energy surpasses the thermal energy. Our result hints that the field-induced relative shifting of the two Weyl-Fermi surfaces in each Dirac cone in momentum space is likely responsible for the LMR behavior.
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