Comparison of Integrated Radiation Transport Models with TEPC Measurements for the Average Quality Factors in Spaceflights

The purpose of this work is to test our theoretical model for the interpretation of radiation data measured in space. During the space missions astronauts are exposed to the complex field of radiation type and kinetic energies from galactic cosmic rays (GCR), trapped protons, and sometimes solar particle events (SPEs). The tissue equivalent proportional counter (TEPC) is a simple time-dependent approach for radiation monitoring for astronauts on board the International Space Station. Another and a newer approach to Microdosimetry is the use of silicon-on-insulator (SOI) technology launched on the MidSTAR-1 mission in low Earth orbit (LEO). In the radiation protection practice, the average quality factor of a radiation field is defined as a function of linear energy transfer (LET), Q(sub ave)(LET). However, TEPC measures the average quality factor as a function of the lineal energy y, Q(sub ave)(y), defined as the average energy deposition in a volume divided by the average chord length of the volume. Lineal energy, y, deviates from LET due to energy straggling, delta-ray escape or entry, and nuclear fragments produced in the detector volume. Monte Carlo track structure simulation was employed to obtain the response of a TEPC irradiated with charged particle for an equivalent site diameter of 1 micron of wall-less counter. The calculated data of the energy absorption in the wall-less counter were compiled for various y values for several ion types at various discrete projectile energy levels. For the simulation of TEPC response from the mixed radiation environments inside a spacecraft, such as, Space Shuttle and International Space Station, the complete microdosimetric TEPC response, f( y, E, Z), were calculated with the Monte Carlo theoretical results by using the first order Lagrangian interpolation for a monovariate function at a given y value (y = 0.1 keV/micron 5000 keV/micron) at any projectile energy level (E = 0.01 MeV/u to 50,000 MeV/u) of each specific radiation type (Z = 1 to 28). Because the anomalous response has been observed at large event sizes in the experiment due to the escape of energy out of sensitive volume by delta-rays and the entry of delta-rays from the high-density wall into the low-density gas-volume cavity, Monte Carlo simulation was also made for the response of a walled-TEPC with wall thickness 2 mm and density 1 g/cm(exp 3). The radius of cavity was set to 6.35 mm and a gas density 7.874 x 10(exp -5) g/cm(exp 3). The response of the walled- and the wall-less counters were compared. The average quality factor Q(sub ave)(y) for trapped protons on STS-89 demonstrated the good agreement between the model calculations and flight TEPC data as shown. Using an integrated space radiation model (this includes the transport codes HZETRN and BRYNTRN, the quantum nuclear interaction model QMSFRG) and the resultant response distribution functions of walled-TEPC from Monte-Carlo track simulations, we compared model calculations with walled-TEPC measurements from NASA missions in LEO and made predictions for the lunar and the Mars missions. The Q(sub ave)(y) values for the trapped or the solar protons ranged from 1.9-2.5. This over-estimates the Qave(LET) values which ranged from 1.4-1.6. Both quantities increase with shield thickness due to nuclear fragmentation. The Q(sub ave)(LET) for the complete GCR spectra was found to be 3.5-4.5, while flight TEPCs measured 2.9-3.4 for Q(sub ave)(y). The GCR values are decreasing with the shield thickness. Our analysis for a proper interpretation of data supports the use of TEPCs for monitoring space radiation environment

No Pain, No Gain, No Compensation: Expoliting Professional Athletes through Substandard Medical Care Administered by Team Physician

This note discusses the role of the team physician and the unique conflicts he or she faces when providing medical care to athletes. In particular, the note describes the pressure team doctors experience from team management, the coaching staff, and the players themselves. Next, the note discusses the types of claims professional athletes have brought against their doctors and team employers and how the terms of collective bargaining agreements (CBA) and workers\u27 compensation laws create obstacles to their recovery. The note will explore the need for a specialized legal standard within the practice of sports medicine and identify the disincentive for sports physicians to act professionally in the absence of a heightened standard of care. The final section of the note offers solutions to address the conflicts team physicians face. Recommendations include establishing a more definite and predictable legal standard of care for application to sports medicine practitioners, creating an alternative application of state workers\u27 compensation laws to the professional sports workplace, and amending the CBAs currently governing major professional sports

Aesthetics and the Police Power

Under the Ohio Constitution municipalities have the authority to exercise all powers of local self-government. This authority is exercised through police power which is sufficient to support the enactment and enforcement of a wide variety of regulations which serve the public welfare. The police power, then, is the means whereby there is delegated by the state to the municipality effective power to promote and protect the general welfare. The purpose of any enforceable ordinance established under the police power must be directly related to the general welfare of the community wherein it operates

Interpretation of TEPC Measurements in Space Flights for Radiation Monitoring

For the proper interpretation of radiation data measured in space, the results of integrated radiation transport models were compared with the tissue equivalent proportional counter (TEPC) measurements. TEPC is a simple, time-dependent approach to radiation monitoring for astronauts on board the International Space Station. Another and a newer approach to microdosimetry is the use of silicon-on-insulator (SOI) technology launched on the MidSTAR-1 mission in low Earth orbit (LEO). In the radiation protection practice, the average quality factor of a radiation field is defined as a function of linear energy transfer (LET), Qave(LET). However, TEPC measures the average quality factor as a function of the lineal energy y, Qave(y), defined as the average energy deposition in a volume divided by the average chord length of the volume. The deviation of y from LET is caused by energy straggling, delta-ray escape or entry, and nuclear fragments produced in the detector volume. The response distribution functions of the wall-less and walled TEPCs were calculated from Monte-Carlo track simulations. Using an integrated space radiation model (which includes the transport codes HZETRN and BRYNTRN, and the quantum nuclear interaction model QMSFRG) and the resultant response distribution functions from Monte-Carlo track simulations, we compared model calculations with the walled-TEPC measurements from NASA missions in LEO and made predictions for the lunar and the Mars missions. Good agreement was found for Qave(y) between the model and measured spectra from past NASA missions. The Qave(y) values for the trapped or the solar protons ranged from 1.9-2.5. This over-estimates the Qave(LET) values which ranged from 1.4-1.6. Both quantities increase with shield thickness due to nuclear fragmentation. The Qave(LET) for the complete GCR spectra was found to be 3.5-4.5, while flight TEPCs measured 2.9-3.4 for Qave(y). The GCR values are decreasing with the shield thickness. Our analysis of the measurements of TEPCs can be used for a proper interpretation of observed data of monitoring the space radiation environment

Tumor Response to Radiotherapy is Dependent on Genotype-Associated Mechanisms in vitro and in vivo

Background: We have previously shown that in vitro radiosensitivity of human tumor cells segregate non-randomly into a limited number of groups. Each group associates with a specific genotype. However we have also shown that abrogation of a single gene (p21) in a human tumor cell unexpectedly sensitized xenograft tumors comprised of these cells to radiotherapy while not affecting in vitro cellular radiosensitivity. Therefore in vitro assays alone cannot predict tumor response to radiotherapy. In the current work, we measure in vitro radiosensitivity and in vivo response of their xenograft tumors in a series of human tumor lines that represent the range of radiosensitivity observed in human tumor cells. We also measure response of their xenograft tumors to different radiotherapy protocols. We reduce these data into a simple analytical structure that defines the relationship between tumor response and total dose based on two coefficients that are specific to tumor cell genotype, fraction size and total dose. Methods: We assayed in vitro survival patterns in eight tumor cell lines that vary in cellular radiosensitivity and genotype. We also measured response of their xenograft tumors to four radiotherapy protocols: 8 × 2 Gy; 2 × 5Gy, 1 × 7.5 Gy and 1 × 15 Gy. We analyze these data to derive coefficients that describe both in vitro and in vivo responses. Results: Response of xenografts comprised of human tumor cells to different radiotherapy protocols can be reduced to only two coefficients that represent 1) total cells killed as measured in vitro 2) additional response in vivo not predicted by cell killing. These coefficients segregate with specific genotypes including those most frequently observed in human tumors in the clinic. Coefficients that describe in vitro and in vivo mechanisms can predict tumor response to any radiation protocol based on tumor cell genotype, fraction-size and total dose. Conclusions: We establish an analytical structure that predicts tumor response to radiotherapy based on coefficients that represent in vitro and in vivo responses. Both coefficients are dependent on tumor cell genotype and fraction-size. We identify a novel previously unreported mechanism that sensitizes tumors in vivo; this sensitization varies with tumor cell genotype and fraction size

Is the Message Getting Through?

When referring to gaining proper medical care in Japan, the Council of ocal　Authorities for International Relations (CLAIR, 2018) website mentioned　that foreign residents often need to overcome three additional metaphorical walls when compared to most Japanese residents: a language barrier, an organizational one, and a psychological barrier. However, these three alls/obstacles exist in other aspects of daily life and emergency situations for foreign residents as well. In an effort to lower these walls local international associations, municipal governments, NPOs, and other volunteer organizations provide services, workshops, classes, and information (For example, Nagoya International Center ＆ Aichi Medical Interpreting System). This research is an analysis of the current state of information access in languages beyond Japanese by international centers, branches, municipality websites, and other resources centers focusing on supporting foreign residents and/or those with limited Japanese proficiency within Aichi Prefecture. I based this on the following research questions: (1) What kind of information is made most and least available and to what extent? (2) How easily can the information be found from the home pages? (3) How accurate, up-to-date, and comprehensible is the available information? Data was collected by checking each website and listing what information was available, what was missing for the nonJapanese language versions, and what sites used incomprehensible language or translation software to a point that the information became misleading. I then conclude with recommendations of language and essential information such websites should prioritize on providing and model websites that could be used as a basis of improving the quality of information presented on other locales’ websites. Key words : Electronic Communication, Cultural Studies, Governance, Second Language Studies, Social Issues, Immigration Studie

Foreign Resident Voices on Information Access

AbstractThe purpose of this study was to investigate the current level of accessibility to public information and public services intended to facilitate foreign residents with limited-Japanese proficiency. This paper provides a summary and comparative analysis of the initial findings of survey of 90 websites and the responses of 38 English-speaking foreign residents’ online questionnaire. The analysis focused on the of multilingual availability and quality of international centers and local municipalities information meant for foreign residents compared to where the respondents’ reported how they obtain information for daily life, public support services, their level of trust of the information, and how they would prefer to access this information