578 research outputs found
Preliminary calculation of solar cosmic ray dose to the female breast in space mission
No regulatory dose limits are specifically assigned for the radiation exposure of female breasts during manned space flight. However, the relatively high radiosensitivity of the glandular tissue of the breasts and its potential exposure to solar flare protons on short- and long-term missions mandate a priori estimation of the associated risks. A model for estimating exposure within the breast is developed for use in future NASA missions. The female breast and torso geometry is represented by a simple interim model. A recently developed proton dose-buildup procedure is used for estimating doses. The model considers geomagnetic shielding, magnetic-storm conditions, spacecraft shielding, and body self-shielding. Inputs to the model include proton energy spectra, spacecraft orbital parameters, STS orbiter-shielding distribution at a given position, and a single parameter allowing for variation in breast size
Iterative approach to implicit student-generated mobile learning to promote visual literacy and peer mediated learning
This paper aims to report early findings of the second iteration of an implicit student-generated mobile learning project that promotes visual literacy and peer mediated learning. The first iteration was conducted with first year health science students at the University of Queensland, Australia, in 2013. We found that while the video assessment task may have aided learning for each student around their specific chosen topic, overall course learning outcomes did not improve. This was perhaps due to a failure of the peer mediated learning aspect of the learning activity. Furthermore, the labour intensive nature of the task may have attenuated overall performance in the course. Acting on these findings, we adjusted the visually based, peer-to-peer mobile learning activity accordingly. The revised assessment task was reintroduced in 2nd semester 2014, and early findings on the efficacy of the revised task on learning will be presented at the ascilite 2014 conference
Preliminary analysis of a radiobiological experiment for LifeSat
With the possibility of performing radiation life science experiments on a dedicated satellite (LifeSat) in space, a combined effort in radiation physics and radiation dosimetry, in addition to radiation biology, is clearly required to ensure that meaningful biological experiments can be performed. To better understand the relationship of these disciplines, some possible LifeSat missions are examined. As a trial biological system, tumorigenesis is considered in the Harderian gland of mice, a system of sufficient radiosensitivity for which relative biological effectiveness (RBE) is well defined by laboratory experiments
Analyses of risks associated with radiation exposure from past major solar particle events
Radiation exposures and cancer induction/mortality risks were investigated for several major solar particle events (SPE's). The SPE's included are: February 1956, November 1960, August 1972, October 1989, and the September, August, and October 1989 events combined. The three 1989 events were treated as one since all three could affect a single lunar or Mars mission. A baryon transport code was used to propagate particles through aluminum and tissue shield materials. A free space environment was utilized for all calculations. Results show the 30-day blood forming organs (BFO) limit of 25 rem was surpassed by all five events using 10 g/sq cm of shielding. The BFO limit is based on a depth dose of 5 cm of tissue, while a more detailed shield distribution of the BFO's was utilized. A comparison between the 5 cm depth dose and the dose found using the BFO shield distribution shows that the 5 cm depth value slightly higher than the BFO dose. The annual limit of 50 rem was exceeded by the August 1972, October 1989, and the three combined 1989 events with 5 g/sq cm of shielding. Cancer mortality risks ranged from 1.5 to 17 percent at 1 g/sq cm and 0.5 to 1.1 percent behind 10 g/sq cm of shielding for five events. These ranges correspond to those for a 45 year old male. It is shown that secondary particles comprise about 1/3 of the total risk at 10 g/sq cm of shielding. Utilizing a computerized Space Shuttle shielding model to represent a typical spacecraft configuration in free space at the August 1972 SPE, average crew doses exceeded the BFO dose limit
Radiation risk predictions for Space Station Freedom orbits
Risk assessment calculations are presented for the preliminary proposed solar minimum and solar maximum orbits for Space Station Freedom (SSF). Integral linear energy transfer (LET) fluence spectra are calculated for the trapped proton and GCR environments. Organ dose calculations are discussed using the computerized anatomical man model. The cellular track model of Katz is applied to calculate cell survival, transformation, and mutation rates for various aluminum shields. Comparisons between relative biological effectiveness (RBE) and quality factor (QF) values for SSF orbits are made
Drug delivery integrated circuit (ic) and system
Wireless and non-wireless drug delivery integrated circuits, systems, and methods of delivering therapeutic pharmaceutical compounds are provided. The system can include a control module, a wireless drug delivery integrated circuit, a first electrode and a second electrode that are both attached to the wireless drug delivery integrated circuit, an electroactive polymer, and a pharmaceutical compound. The electroactive polymer and the pharmaceutical compound can be formed as films on one of the electrodes and, when placed in a solution, a voltage potential can be applied across the electrodes causing the pharmaceutical compound to be released into the solution
Urinary proteomic profiling in severe obesity and obstructive sleep apnoea with CPAP treatment.
INTRODUCTION: Obstructive sleep apnoea (OSA) is common in obesity and is associated with cardiovascular and metabolic complications. Continuous positive airway pressure (CPAP) in OSA may lead to physiological changes reflected in the urinary proteome. The aim of this study was to characterise the urinary proteome in severely obese adult subjects with OSA who were receiving CPAP compared with severely obese subjects without OSA. METHODS: Severely obese subjects with and without OSA were recruited. Subjects with OSA were receiving CPAP. Body composition and blood pressure measurements were recorded. Urinary samples were analysed by Capillary Electrophoresis-Mass Spectrometry (CE-MS). RESULTS: Twenty-seven subjects with OSA-on-CPAP (age 49±7years, BMI 43±7 kg/m(2)) and 25 controls without OSA (age 52±9years, BMI 39±4 kg/m(2)) were studied. Age and BMI were not significantly different between groups. Mean CPAP use for OSA patients was 14.5±1.0 months. Metabolic syndrome was present in 14(52%) of those with OSA compared with 6(24%) of controls (p=0.039). A urinary proteome comprising 15 peptides was identified showing differential expression between the groups (p<0.01). Although correction for multiple testing did not reach significance, sequences were determined for 8 peptides demonstrating origins from collagens, fibrinogen beta chain and T-cadherin that may be associated with underlying cardiovascular disease mechanisms in OSA. CONCLUSIONS: The urinary proteome is compared in OSA with CPAP and without OSA in severe obesity. The effects of CPAP on OSA may lead to changes in the urinary peptides but further research work is needed to investigate the potential role for urinary proteomics in characterising urinary peptide profiles in OSA
Nuclear safety policy working group recommendations on nuclear propulsion safety for the space exploration initiative
An interagency Nuclear Safety Working Group (NSPWG) was chartered to recommend nuclear safety policy, requirements, and guidelines for the Space Exploration Initiative (SEI) nuclear propulsion program. These recommendations, which are contained in this report, should facilitate the implementation of mission planning and conceptual design studies. The NSPWG has recommended a top-level policy to provide the guiding principles for the development and implementation of the SEI nuclear propulsion safety program. In addition, the NSPWG has reviewed safety issues for nuclear propulsion and recommended top-level safety requirements and guidelines to address these issues. These recommendations should be useful for the development of the program's top-level requirements for safety functions (referred to as Safety Functional Requirements). The safety requirements and guidelines address the following topics: reactor start-up, inadvertent criticality, radiological release and exposure, disposal, entry, safeguards, risk/reliability, operational safety, ground testing, and other considerations
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Patient Willingness to Have Tests to Guide Antibiotic Use for Respiratory Tract Infections: From the WWAMI Region Practice and Research Network (WPRN).
INTRODUCTION: The majority of consultations for acute respiratory tract infections (RTIs) lead to prescriptions for antibiotics, which have limited clinical benefit. We explored patients' willingness to have blood tests as part of the diagnostic work-up for RTIs, and patient knowledge about antibiotics. METHODS: Patients at 6 family medicine clinics were surveyed. Regression modeling was used to determine independent predictors of willingness to have venous and point-of-care (POC) blood tests, and knowledge of the value of antibiotics for RTIs. RESULTS: Data were collected from 737 respondents (response rate 83.8%), of whom 65.7% were women, 60.1% were white, and 25.1% were current smokers; patients' mean age was 46.9 years. Sex (female), race (white), and a preference to avoid antibiotics were independent predictors of greater level of antibiotic knowledge. A total of 63.1% were willing to have a venous draw and 79% a POC blood test, to help guide antibiotic decision-making. Non-American Indian/Alaskan Native race, current smoking, and greater knowledge of antibiotics were independent predictors of willingness to have a POC test. CONCLUSION: A large majority of patients seemed willing to have POC tests to facilitate antibiotic prescribing decisions for RTIs. Poor knowledge about antibiotics suggests better education regarding antibiotic use might influence patient attitudes towards use of antibiotics for RTIs
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