Reward Poisoning in Reinforcement Learning: Attacks Against Unknown Learners in Unknown Environments

We study black-box reward poisoning attacks against reinforcement learning (RL), in which an adversary aims to manipulate the rewards to mislead a sequence of RL agents with unknown algorithms to learn a nefarious policy in an environment unknown to the adversary a priori. That is, our attack makes minimum assumptions on the prior knowledge of the adversary: it has no initial knowledge of the environment or the learner, and neither does it observe the learner's internal mechanism except for its performed actions. We design a novel black-box attack, U2, that can provably achieve a near-matching performance to the state-of-the-art white-box attack, demonstrating the feasibility of reward poisoning even in the most challenging black-box setting

The Role of Relaxation Training to Pregnant Mothers on Health Index of Infants

ABSTRACT: Introduction & Objective: Investigations have shown that the emotional stress during the pregnancy period could have sustainable effects on the embryo. Different factors such as family members, spouse, supporting friends could relive these effects, but coping skills especially relaxation could be more effective on stress. This study was conducted to investigate the effect of relaxation training to pregnant mothers on health index such as Apgar index, weight, height, and cowlick grade in infants. Materials & Methods: This is a clinical trail in which 100 pregnant women who referred to health center of Yasuj (2006-2008) were selected using simple sampling method and assigned randomly to case and control groups. The relaxation was taught to the case group whereas nothing was taught to control groups. At the time of delivery the above mentioned indices were assessed. The gathered data was analyzed using SPSS software. Results: The results showed a significant difference between two groups in weight, height, cephalic index, and colic grade (with better situation in case group). There was no significant difference between two groups in Apgar scores. Conclusion: Considering the results of this study, it seems that teaching of relaxation to pregnant women could be effective in health index of children especially in the time of delivery. Therefore attention should be paid to different methods for reducing the stress in this group of mothers. Keywords: relaxation, pregnant women, infants, Apgar score

An overview of neuro-oncology research and practice in Iran, three years with the NOSC initiative

Research and practice of neuro-oncology compiles clinical neuroscience expertise from neurosurgery, radiation oncology, neuroradiology, medical oncology, neuropathology and related disciplines to optimize planning and therapy in central nervous system malignancies. Such an interdisciplinary context prompted health-care providers from all related disciplines to establish the Neuro-Oncology Scientific Club (NOSC) in Iran and let it flourish since 3 years ago. With the advent of advanced technologies and through continued share of experience, NOSC members have tried to provide more integrated diagnoses and therapeutic care to brain tumor patients across the country. NOSC activities revolve around some key tenets including dissemination of education and updates, facilitation of institutional collaborations; data registry and patients� awareness. By virtue of recent insights on molecular characterization of brain tumors such as codeletion of chromosomes 1p and 19q in anaplastic gliomas and O6-methylguanine-DNA methyltransferase (MGMT) promoter methylation in glioblastoma, a range of translational research is being followed within NOSC. The most recent NOSC meeting which was held in Tehran, recapitulated main advances and dealt with the current debates on functional neurosurgery, biological markers and neuroimaging, risk prediction models in high grade gliomas and clinical issues in pediatric neuro-oncology. This article gives an overview of current hotspots in neuro-oncology research and practice which are pursued within NOSC. © 2015, Int J Clin Exp Med. All rights reserved