Study of the (p,Pi) Reaction in the Two-Nucleon Model

This work was supported by the National Science Foundation Grants NSF PHY 78-22774 A03, NSF PHY 81-14339, and by Indiana Universit

A Multistage Stochastic Programming Approach to the Dynamic and Stochastic VRPTW - Extended version

We consider a dynamic vehicle routing problem with time windows and stochastic customers (DS-VRPTW), such that customers may request for services as vehicles have already started their tours. To solve this problem, the goal is to provide a decision rule for choosing, at each time step, the next action to perform in light of known requests and probabilistic knowledge on requests likelihood. We introduce a new decision rule, called Global Stochastic Assessment (GSA) rule for the DS-VRPTW, and we compare it with existing decision rules, such as MSA. In particular, we show that GSA fully integrates nonanticipativity constraints so that it leads to better decisions in our stochastic context. We describe a new heuristic approach for efficiently approximating our GSA rule. We introduce a new waiting strategy. Experiments on dynamic and stochastic benchmarks, which include instances of different degrees of dynamism, show that not only our approach is competitive with state-of-the-art methods, but also enables to compute meaningful offline solutions to fully dynamic problems where absolutely no a priori customer request is provided.Comment: Extended version of the same-name study submitted for publication in conference CPAIOR201

Dependence of the Martian radiation environment on atmospheric depth: Modeling and measurement

The energetic particle environment on the Martian surface is influenced by solar and heliospheric modulation and changes in the local atmospheric pressure (or column depth). The Radiation Assessment Detector (RAD) on board the Mars Science Laboratory rover Curiosity on the surface of Mars has been measuring this effect for over four Earth years (about two Martian years). The anticorrelation between the recorded surface Galactic Cosmic Ray-induced dose rates and pressure changes has been investigated by Rafkin et al. (2014) and the long-term solar modulation has also been empirically analyzed and modeled by Guo et al. (2015). This paper employs the newly updated HZETRN2015 code to model the Martian atmospheric shielding effect on the accumulated dose rates and the change of this effect under different solar modulation and atmospheric conditions. The modeled results are compared with the most up-to-date (from 14 August 2012 to 29 June 2016) observations of the RAD instrument on the surface of Mars. Both model and measurements agree reasonably well and show the atmospheric shielding effect under weak solar modulation conditions and the decline of this effect as solar modulation becomes stronger. This result is important for better risk estimations of future human explorations to Mars under different heliospheric and Martian atmospheric conditions

Identification and Energy Measurements of Light Particles with a CsI(Tl)-Photodiode Combination

This research was sponsored by the National Science Foundation Grant NSF PHY-931478

Association Between Supratotal Glioblastoma Resection and Patient Survival: A Systematic Review and Meta-Analysis

- BACKGROUND: Gross total resection (GTR) of the contrast enhancing (CE) area will improve the survival of patients with glioblastoma (GBM). However, GBM can infiltrate into the brain parenchyma, beyond the CE margins. It remains unclear whether resection beyond the CE area (supratotal resection [SPTR]) can improve survival without causing additional neurological deficits. The aim of the present meta-analysis was to study the association between SPTR and overall survival of patients of GBM. - METHODS: Embase, PubMed, and other literature databases were searched for eligible studies until August 2018. Studies involving patients with GBM that had compared SPTR with GTR were included in the present study. The main outcome was overall survival, presented as hazard ratios (HRs) with 95% confidence intervals (CIs) and median overall survival differences with the 95% CIs. - RESULTS: The meta-analysis, which included 6 studies and 1168 unique patients with GBM, showed that compared with GTR, SPTR of GBM resulted in a 53% lower risk of mortality at any time during follow-up (HR, 0.47; 95% CI, 0.31e 0.72; P [ 0.0005). The median overall survival of the SPTR group was 6.4 months (95% CI, 3.2e9.7) longer than the GTR group (P [ 0.0001). Reports on postoperative deficits were limited, and the quality of evidence was moderate to very low. - CONCLUSIONS: Compared with GTR, SPTR of GBM resulted in a lower risk of mortality and longer median overall survival. However, the quality of evidence of the available studies was poor. Therefore, it remains unclear whether SPTR is safe and actually improves the survival of patients with GBM. Future prospective trials and a standardized definition of SPTR are needed

Measurements of Forbush decreases at Mars: both by MSL on ground and by MAVEN in orbit

The Radiation Assessment Detector (RAD), on board Mars Science Laboratory's (MSL) Curiosity rover, has been measuring ground level particle fluxes along with the radiation dose rate at the surface of Mars since August 2012. Similar to neutron monitors at Earth, RAD sees many Forbush decreases (FDs) in the galactic cosmic ray (GCR) induced surface fluxes and dose rates. These FDs are associated with coronal mass ejections (CMEs) and/or stream/corotating interaction regions (SIRs/CIRs). Orbiting above the Martian atmosphere, the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft has also been monitoring space weather conditions at Mars since September 2014. The penetrating particle flux channels in the Solar Energetic Particle (SEP) instrument onboard MAVEN can also be employed to detect FDs. For the first time, we study the statistics and properties of a list of FDs observed in-situ at Mars, seen both on the surface by MSL/RAD and in orbit detected by the MAVEN/SEP instrument. Such a list of FDs can be used for studying interplanetary CME (ICME) propagation and SIR evolution through the inner heliosphere. The magnitudes of different FDs can be well-fitted by a power-law distribution. The systematic difference between the magnitudes of the FDs within and outside the Martian atmosphere may be mostly attributed to the energy-dependent modulation of the GCR particles by both the pass-by ICMEs/SIRs and the Martian atmosphere