Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

As NASA is looking to explore further into deep space, multifunctional materials are a necessity for decreasing complexity and mass. One area where multifunctional materials could be extremely beneficial is in the micrometeoroid orbital debris (MMOD) shield. A typical MMOD shield on the International Space Station (ISS) is a stuffed whipple shield consisting of multiple layers. One of those layers is the thermal blanket, or multi-layer insulation (MLI). By increasing the MMOD effectiveness of MLI blankets, while still preserving their thermal capabilities, could allow for a less massive MMOD shield. Thus, a study was conducted to evaluate concept MLI blankets for MMOD shields. In conjunction, these MLI blankets and the subsequent MMOD shields were also evaluated for their radiation shielding effectiveness towards protecting crew. These concepts were evaluated against the ISS MLI blankets and the ISS MMOD shield, which acted as the baseline. These radiation shielding assessments were performed using the high charge and energy transport software (HZETRN). This software is based on a one-dimensional formula of the Boltzmann transport equation with a straight-ahead approximation. Each configuration was evaluated against the following environments to provide a diverse view of radiation shielding effectiveness in most space environments within the heliosphere: August 1972 solar particle event, October 1989 solar particle event, 1982 galactic cosmic ray environment (during solar maximum), 1987 galactic cosmic ray environment (during solar minimum), and a low earth orbit environment in 1970 that corresponded to an altitude of 400 km and inclination of 51.6 . Both the absorbed dose and the dose equivalent were analyzed, but the focus of the discussion was on the dose equivalent since the data is most concerned with radiation shielding of the crew. The following paper outlines the evaluations performed and discusses the results and conclusions of this evaluation for radiation shielding effectiveness. Future work will focus on optimizing the radiation shielding properties for the MMOD shield. Submissio

Advanced Multifunctional MMOD Shield: Radiation Shielding Assessment

As NASA is looking to explore further into deep space, multifunctional materials are a necessity for decreasing complexity and mass. One area where multifunctional materials could be extremely beneficial is in the micrometeoroid orbital debris (MMOD) shield. A typical MMOD shield on the International Space Station (ISS) is a stuffed whipple shield consisting of multiple layers. One of those layers is the thermal blanket, or multi-layer insulation (MLI). Increasing the MMOD effectiveness of MLI blankets, while still preserving their thermal capabilities, could allow for a less massive MMOD shield. Thus, a study was conducted to evaluate a concept MLI blanket for an MMOD shield. In conjunction, this MLI blanket and the subsequent MMOD shield was also evaluated for its radiation shielding effectiveness towards protecting crew. The overall MMOD shielding system using the concept MLI blanket proved to only have a marginal increase in the radiation mitigating properties. Therefore, subsequent analysis was performed on various conceptual MMOD shields to determine the combination of materials that may prove superior for radiation mitigating purposes. The following paper outlines the evaluations performed and discusses the results and conclusions of this evaluation for radiation shielding effectiveness

Host support of Ty3 retrotransposition in Saccharomyces cerevisiae

Ty3 is a Saccharomyces cereviae LTR retrotransposon. The structure of Ty3 is similar to that of a simple retrovirus. It is 5.4 kb in length and encodes overlapping GAG3 and POL3 reading frames flanked by 340 bp long terminal repeats. Expression of Ty3 results in production of Gag3 and Gag3-Pol3 polyproteins which assemble together with genomic RNA into in association with P-body proteins. VLPs are also associated with these clusters. The nucleo-capsid domain of Ty3 Gag3 is required in trans for recruitment of Ty3 RNA into P bodies. The untranslated regions of Ty3 RNA are sufficient in cis for recruitment of RNA to P bodies, but the GAG3-POL3 coding domain of the RNA can also confer association with P body proteins. In contrast, only the untranslated sequences confer packaging of a mini-Ty3 transcript. Upon assembly, Gag3 is processed into capsid, spacer, and nucleocapsid. Gag3-Pol3 is processed into those proteins and protease, junction, reverse transcriptase, and integrase. We propose that P-body proteins promote Ty3 VLP assembly and a mass spectrometry approach is being taken to further define the components of these dynamic complexes. However, in spite of genetic evidence that P-body proteins play a positive role in Ty3 production, these intracellular foci may also act as host traps to down-regulate transposition. Ty3-P body clusters become perinuclear over time and are physically associated with nuclear pores. A specific class of FG nucleoporins are required for Ty3 nuclear entry

Polygenic Risk Score Prediction for Endometriosis

Endometriosis is a major health care challenge because many young women with endometriosis go undetected for an extended period, which may lead to pain sensitization. Clinical tools to better identify candidates for laparoscopy-guided diagnosis are urgently needed. Since endometriosis has a strong genetic component, there is a growing interest in using genetics as part of the clinical risk assessment. The aim of this work was to investigate the discriminative ability of a polygenic risk score (PRS) for endometriosis using three different cohorts: surgically confirmed cases from the Western Danish endometriosis referral Center (249 cases, 348 controls), cases identified from the Danish Twin Registry (DTR) based on ICD-10 codes from the National Patient Registry (140 cases, 316 controls), and replication analysis in the UK Biobank (2,967 cases, 256,222 controls). Patients with adenomyosis from the DTR (25 cases) and from the UK Biobank (1,883 cases) were included for comparison. The PRS was derived from 14 genetic variants identified in a published genome-wide association study with more than 17,000 cases. The PRS was associated with endometriosis in surgically confirmed cases [odds ratio (OR) = 1.59, p = 2.57× 10(−7)] and in cases from the DTR biobank (OR = 1.50, p = 0.0001). Combining the two Danish cohorts, each standard deviation increase in PRS was associated with endometriosis (OR = 1.57, p = 2.5× 10(−11)), as well as the major subtypes of endometriosis; ovarian (OR = 1.72, p = 6.7× 10(−5)), infiltrating (OR = 1.66, p = 2.7× 10(−9)), and peritoneal (OR = 1.51, p = 2.6 × 10(−3)). These findings were replicated in the UK Biobank with a much larger sample size (OR = 1.28, p < 2.2× 10(−16)). The PRS was not associated with adenomyosis, suggesting that adenomyosis is not driven by the same genetic risk variants as endometriosis. Our results suggest that a PRS captures an increased risk of all types of endometriosis rather than an increased risk for endometriosis in specific locations. Although the discriminative accuracy is not yet sufficient as a stand-alone clinical utility, our data demonstrate that genetics risk variants in form of a simple PRS may add significant new discriminatory value. We suggest that an endometriosis PRS in combination with classical clinical risk factors and symptoms could be an important step in developing an urgently needed endometriosis risk stratification tool