Monte Carlo Forest Search: UNSAT Solver Synthesis via Reinforcement learning

We introduce Monte Carlo Forest Search (MCFS), an offline algorithm for automatically synthesizing strong tree-search solvers for proving \emph{unsatisfiability} on given distributions, leveraging ideas from the Monte Carlo Tree Search (MCTS) algorithm that led to breakthroughs in AlphaGo. The crucial difference between proving unsatisfiability and existing applications of MCTS, is that policies produce trees rather than paths. Rather than finding a good path (solution) within a tree, the search problem becomes searching for a small proof tree within a forest of candidate proof trees. We introduce two key ideas to adapt to this setting. First, we estimate tree size with paths, via the unbiased approximation from Knuth (1975). Second, we query a strong solver at a user-defined depth rather than learning a policy across the whole tree, in order to focus our policy search on early decisions, which offer the greatest potential for reducing tree size. We then present MCFS-SAT, an implementation of MCFS for learning branching policies for solving the Boolean satisfiability (SAT) problem that required many modifications from AlphaGo. We matched or improved performance over a strong baseline on two well-known SAT distributions (\texttt{sgen}, \texttt{random}). Notably, we improved running time by 9\% on \texttt{sgen} over the \texttt{kcnfs} solver and even further over the strongest UNSAT solver from the 2021 SAT competition

A Phase 3 Trial of 2 Years of Androgen Suppression and Radiation Therapy With or Without Adjuvant Chemotherapy for High-Risk Prostate Cancer: Final Results of Radiation Therapy Oncology Group Phase 3 Randomized Trial NRG Oncology RTOG 9902.

PURPOSE: Long-term (LT) androgen suppression (AS) with radiation therapy (RT) is a standard treatment of high-risk, localized prostate cancer (PCa). Radiation Therapy Oncology Group 9902 was a randomized trial testing the hypothesis that adjuvant combination chemotherapy (CT) with paclitaxel, estramustine, and oral etoposide plus LT AS plus RT would improve overall survival (OS). METHODS AND MATERIALS: Patients with high-risk PCa (prostate-specific antigen 20-100 ng/mL and Gleason score [GS] ≥ 7 or clinical stage ≥ T2 and GS ≥ 8) were randomized to RT and AS (AS + RT) alone or with adjuvant CT (AS + RT + CT). CT was given as four 21-day cycles, delivered beginning 28 days after 70.2 Gy of RT. AS was given as luteinizing hormone-releasing hormone for 24 months, beginning 2 months before RT plus an oral antiandrogen for 4 months before and during RT. The study was designed based on a 6% improvement in OS from 79% to 85% at 5 years, with 90% power and a 2-sided alpha of 0.05. RESULTS: A total of 397 patients (380 eligible) were randomized. The patients had high-risk PCa, 68% with GS 8 to 10 and 34% T3 to T4 tumors, and median prostate-specific antigen of 22.6 ng/mL. The median follow-up period was 9.2 years. The trial closed early because of excess thromboembolic toxicity in the CT arm. The 10-year results for all randomized patients revealed no significant difference between the AS + RT and AS + RT + CT arms in OS (65% vs 63%; P=.81), biochemical failure (58% vs 54%; P=.82), local progression (11% vs 7%; P=.09), distant metastases (16% vs 14%; P=.42), or disease-free survival (22% vs 26%; P=.61). CONCLUSIONS: NRG Oncology RTOG 9902 showed no significant differences in OS, biochemical failure, local progression, distant metastases, or disease-free survival with the addition of adjuvant CT to LT AS + RT. The trial results provide valuable data regarding the natural history of high-risk PCa treated with LT AS + RT and have implications for the feasibility of clinical trial accrual and tolerability using CT for PCa

DIPOLE MOMENTS OF THE LOWEST π∗←π∗\pi^{*}\leftarrow\pi^{*} STATES OF THE ISOELECTRONIC SERIES PHENYLACETYLENE, PHENYLISOCYANIDE, BENZONITRILE

Author Institution: Department of Chemistry, University of IllinoisStark effects have been obsrved in the rotational fine structure of the lowest singlet $\pi^{*}\leftarrow\pi$ transitions in the molecules phenylacetylene, benzonitrile, phenylisocyanide (2787 \AA, 2738 \AA, 2723 \AA. respectively). From these observations the change in dipole moment on excitation can be determined. It is found that the order of increasing change is phenylacetylene, phenylisocyanide, benzonitrile. This is also the order of increasing change in the mean bond lengths parallel to the symmetry axis. Since the molecules form an isoelectronic series, correlations can be made with various resonance models for the electronic structure of the excited state

American College of Radiology (ACR) and American Society for Radiation Oncology (ASTRO) Practice Guideline for the Performance of Stereotactic Radiosurgery (SRS)

American College of Radiology and American Society for Radiation Oncology Practice Guideline for the Performance of Stereotactic Radiosurgery (SRS). SRS is a safe and efficacious treatment option of a variety of benign and malignant disorders involving intracranial structures and selected extracranial lesions. SRS involves a high dose of ionizing radiation with a high degree of precision and spatial accuracy. A quality SRS program requires a multidisciplinary team involved in the patient management. Organization, appropriate staffing, and careful adherence to detail and to established SRS standards is important to ensure operational efficiency and to improve the likelihood of procedural success. A collaborative effort of the American College of Radiology and American Society for Therapeutic Radiation Oncology has produced a practice guideline for SRS. The guideline defines the qualifications and responsibilities of all the involved personnel, including the radiation oncologist, neurosurgeon, and qualified medical physicist. Quality assurance is essential for safe and accurate delivery of treatment with SRS. Quality assurance issues for the treatment unit, stereotactic accessories, medical imaging, and treatment-planning system are presented and discussed. Adherence to these practice guidelines can be part of ensuring quality and patient safety in a successful SRS program