A low-voltage retarding-field Mott polarimeter for photocathode characterization

Nuclear physics experiments at Thomas Jefferson National Accelerator Facility's CEBAF rely on high polarization electron beams. We describe a recently commissioned system for prequalifying and studying photocathodes for CEBAF with a load-locked, low-voltage polarized electron source coupled to a compact retarding-field Mott polarimeter. The polarimeter uses simplified electrode structures and operates from 5 to 30 kV. The effective Sherman function for this device has been calibrated by comparison with the CEBAF 5 MeV Mott polarimeter. For elastic scattering from a thick gold target at 20 keV, the effective Sherman function is 0.201(5). Its maximum efficiency at 20 keV, defined as the detected count rate divided by the incident particle current, is 5.4(2) x 10-4, yielding a figure-of-merit, or analyzing power squared times efficiency, of 1.0(1) x 10-5. The operating parameters of this new polarimeter design are compared to previously published data for other compact Mott polarimeters of the retarding-field type.Comment: 9 figure

The clinical cell-cycle risk (CCR) score is associated with metastasis after radiation therapy and provides guidance on when to forgo combined androgen deprivation therapy with dose-escalated radiation

PURPOSE: The clinical cell-cycle risk (CCR) score, which combines the University of California, San Francisco\u27s Cancer of the Prostate Risk Assessment (CAPRA) and the cell cycle progression (CCP) molecular score, has been validated to be prognostic of disease progression for men with prostate cancer. This study evaluated the ability of the CCR score to prognosticate the risk of metastasis in men receiving dose-escalated radiation therapy (RT) with or without androgen deprivation therapy (ADT). METHODS AND MATERIALS: This retrospective, multi-institutional cohort study included men with localized National Comprehensive Cancer Network (NCCN) intermediate-, high-, and very high-risk prostate cancer (N = 741). Patients were treated with dose-escalated RT with or without ADT. The primary outcome was time to metastasis. RESULTS: The CCR score prognosticated metastasis with a hazard ratio (HR) per unit score of 2.22 (95% confidence interval [CI], 1.71-2.89; P \u3c .001). The CCR score better prognosticated metastasis than NCCN risk group (CCR, P \u3c .001; NCCN, P = .46), CAPRA score (CCR, P = .002; CAPRA, P = .59), or CCP score (CCR, P \u3c .001; CCP, P = .59) alone. In bivariable analyses, CCR score remained highly prognostic when accounting for ADT versus no ADT (HR, 2.18; 95% CI, 1.61-2.96; P \u3c .001), ADT duration as a continuous variable (HR, 2.11; 95% CI, 1.59-2.79; P \u3c .001), or ADT given at or below the recommended duration for each NCCN risk group (HR, 2.19; 95% CI, 1.69-2.86; P \u3c .001). Men with CCR scores below or above the multimodality threshold (CCR score, 2.112) had a 10-year risk of metastasis of 3.7% and 21.24%, respectively. Men with below-threshold scores receiving RT alone had a 10-year risk of metastasis of 3.7%, and for men receiving RT plus ADT, the 10-year risk of metastasis was also 3.7%. CONCLUSIONS: The CCR score accurately and precisely prognosticates metastasis and adds clinically actionable information relative to guideline-recommended therapies based on NCCN risk in men undergoing dose-escalated RT with or without ADT. For men with scores below the multimodality threshold, adding ADT may not significantly reduce their 10-year risk of metastasis

Angular Momentum Partitioning and Hexacontatetrapole Moments in Impulsively Excited Argon Ions

We have studied polarized electron collisions with Ar in which the target is simultaneously ionized and excited to form Ar+(3p4(1D)4p) states. We measured the integrated Stokes parameters of the subsequent fluorescence emitted by the 2F7/2, 2F5/2, 2D5/2, and 2P3/2 states along the direction of electron polarization. The Rubin-Bederson hypothesis is shown to hold for the L and S multipoles of these states. The electric quadrupole and hexadecapole of the 1D core are derived. By recoupling these moments with the electric quadrupole moment of the 4p electron, we calculate higher moments of the total ionic orbital angular momentum, including its hexacontatetrapole (64-pole) moment

Angular momentum partitioning and the subshell multipole moments in impulsively excited argon ions

We have investigated collisions between transversely polarized electrons and Ar, in which the Ar is simultaneously ionized and excited to the Ar+*[3p4(+D)4p] states. The Stokes parameters of the fluorescence emitted in the following transitions was measured: (+D)4s 2D/2−(1D)4p 2F7/2 (461.0 nm), (1D)4s 2D5/2 −(1D)4p 2F5/2 (463.7 nm), (1P)3d 2D5/2−(1D)4p 2D5/2 (448.2 nm), and (1D)4s 2D3/2−(1D)4p 2P3/2 (423.7 nm). We develop the angular momentum algebra necessary to extract from these data, starting from the overall atomic J multipoles, the partitioning of orbital angular momentum into the 1D core electric quadrupole and hexadecapole moments, and the outer 4p electric quadrupole moment. The magnetic dipole of the outer electron is also determined. This procedure requires the assumption of good LS coupling for these states, which is justified. We recouple these individual core- and outer-electron moments to calculate the initial electric quadrupoles, hexadecapoles, and hexacontatetrapoles of the initial excited-state manifold. The detailed time structure of the electron-atom collision is considered, as well as the time evolution of the excited ionic state. The Rubin-Bederson hypothesis is thus shown to hold for the initial ionic L and S terms. The consequences of the breakdown of LS coupling are considered. From the circular polarization data, estimates of the relative importance of direct and exchange excitation cross section are made. We discuss experimental issues related to background contributions, Hanle depolarization of the fluorescence signal, and cascade contributions. Nonlinearity of the equations relating the Stokes parameters to the subshell multipole moments complicates the data analysis. Details of the Monte Carlo terrain-search algorithm used to extract multipole data is discussed, and the implications of correlation between the various subshell multipole moments is analyzed. The physical significance of the higher-order multipole moments is discussed, and graphical representations of the effects of these multipoles on the excited ionic charge clouds is presented

Lessons learned from Hurricane Maria in Puerto Rico: Practical measures to mitigate the impact of a catastrophic natural disaster on radiation oncology patients

PURPOSE: Although the wind, rain, and flooding of Hurricane Maria in Puerto Rico abated shortly after its landfall on September 20, 2017, the disruption of the electrical, communications, transportation, and medical infrastructure of the island was unprecedented in scope and caused lasting harm for many months afterward. A compilation of recommendations from radiation oncologists who were in Puerto Rico during the disaster, and from a panel of American Society for Radiation Oncology (ASTRO) cancer experts was created. METHODS AND MATERIALS: Radiation oncologists throughout Puerto Rico collaborated and improvised to continue treating patients in the immediate aftermath of the storm and as routine clinical operations were restored gradually. Empirical lessons from the experience of radiation therapy administration in this profoundly altered context of limited resources, impaired communication, and inadequate transportation were organized into a recommended template, applicable to any radiation oncology practice. ASTRO disease-site experts provided evidence-guidelines for mitigating the impact of a 2- to 3-week interruption in radiation therapy. RESULTS: Practical measures to mitigate the medical impact of a disaster are summarized within the framework of Prepare, Communicate, Operate, Compensate. Specific measures include the development of an emergency operations plan tailored to specific circumstances, prospective coordination with other radiation oncology clinics before a disaster, ongoing communications with emergency management organizations, and routine practice of alternate methods to disseminate information among providers and patients. CONCLUSIONS: These recommendations serve as a starting point to assist any radiation oncology practice in becoming more resiliently prepared for a local or regional disruption from any cause. Disease-site experts provide evidence-based guidelines on how to mitigate the impact of a 2- to 3-week interruption in radiation therapy for lung, head and neck, uterine cervix, breast, and prostate cancers through altered fractionation or dose escalation

Scoring Aave Accounts for Creditworthiness

Scoring the creditworthiness of accounts that interact with decentralized financial (DeFi) protocols remains an important yet unsolved problem. In this paper, we propose a credit scoring system for those accounts that have interacted with the Aave v2 liquidity protocol. The key component of this system is a tree-based binary classifier that predicts "position delinquency." To the community, we provide our method, results, and the (abridged) dataset on which this system is built

Guía de orientación en la práctica profesional de la valoración reglamentaria de la situación de dependencia en personas con enfermedad de alzheimer y otras demencias

La presente guía tiene el objetivo de ser un instrumento útil en la práctica profesional de la valoración oficial de la situación de dependencia en personas con enfermedad de Alzheimer y otras demencias, y servir de apoyo a la formación de los profesionales de los órganos de valoración. Con esta finalidad se ha realizado una revisión de las condiciones de salud de este colectivo que pueden dar lugar a situación de dependencia, en aplicación del Baremo de Valoración de la Dependencia (BVD), aprobado por Real Decreto 174/2011, de 11 de febrero