Anthropogenic radioactivity is being measured in near-real time by an international monitoring system designed to verify the
Comprehensive Nuclear Test Ban Treaty. Airborne radioactivity measurements are conducted in-situ by stations that are linked
to a central data processing and analysis facility. Aerosols are separated by high-volume air sampling with high-efficiency
particulate filters. Radio-xenon is separated from other gases through cryogenic methods. Gamma-spectrometry is performed
by high purity germanium detectors and the raw spectral data is immediately transmitted to the central facility via Internet,
satellite, or modem. These highly sensitive sensors, combined with the automated data processing at the central facility,
result in a system capable of measuring environmental radioactivity on the microbeequerel scale where the data is available
to scientists within minutes of the field measurement. During the past year, anthropogenic radioactivity has been measured
at approximately half of the stations in the current network. Sources of these measured radionuclides include nuclear power
plant emissions, Chernobyl resuspension, and isotope production facilities. The ability to thoroughly characterize site-specific
radionuclides, which contribute to the radioactivity of the ambient environment, will be necessary to reduce the number of
false positive events. This is especially true of anthropogenic radionuclides that could lead to ambiguous analysis.
A global radionuclide monitoring system is being engineered as part of a multi-technology verification system for the Comprehensive
Nuclear Test Ban Treaty. The system detects airborne radioactive aerosols and gases that can indicate nuclear weapons test
debris. The backbone of the system is a network of 80 remote detection stations that utilize high-volume air sampling and
high-resolution gamma spectrometry to provide in-situ assay and near-real time reporting. These stations are linked to the
International Data Centre, which is a central data processing hub where raw spectral data is automatically processed, analyzed,
and disseminated to the states parties. Measurements are categorized based on spectral content to determine which contain
anomalous anthropogenic radionuclides that require intensive radiochemical analysis at a certified laboratory. The resulting
system has the capability to measure microbecquerel concentrations of radionuclides and provide accessible data products within
minutes of field measurements. During the past year of international operations, the minimum detectable concentrations and
spectroscopy processing statistics were recorded as a function of geographical location and time. The results show that this
system is an effective tool for nuclear test monitoring, as well as other applications such as radiological emergency response,
public health monitoring, and scientific research.
A substantial number of people worldwide suffer from mental health problems during their lifetime. First-line treatments are not effective for everybody. Recent studies suggest that psychedelic drugs have high therapeutic potential for a variety of mental disorders.
This survey study aimed to assess the tendency of psychedelic users to self-medicate with psychedelics and to compare the effectiveness of self-administered psychedelics to treat their disorder and the treatment offered by a medical professional.
Methods and results
In total, 1,967 respondents consented were ≥18 years and completed the questionnaire. The mean (±SD) age was 25.9 (8.7); 79% were males, 20% females, and 1% classified themselves as “other.” Almost half of the respondents (46%) indicated to have suffered/to be suffering from a mental disorder, with 77% being diagnosed by a medical professional. In 99% of the diagnosed cases, the treatment was offered; 77% searched for treatments outside a medical professional’s recommendation with 81% who had used/were using psychedelics to treat/cure symptoms. Self-administered psychedelic treatment had a higher likelihood of being efficacious, with higher symptoms reduction and larger quality of life improvement compared to treatment offered by a medical professional.
Lifetime prevalence of psychopathologies in the current sample of psychedelic drug users seemed to be higher than in the general population. Self-medication with psychedelics was not highly frequent; although when it occurred, it was rated as significantly more effective as treatment offered by a medical professional. Current findings support research exploring the potential of psychedelics in the treatment of psychopathologies.
As part of the development support for the Comprehensive Nuclear-Test-Ban Treaty (CTBT), the Prototype International Data Center (PIDC) has been processing radionuclide data since 1995. Radionuclide data received from field stations includes gamma-ray spectra, meteorological data, and state of health (SOH) information. To date over 20 radionuclide monitoring stations have transmitted data to the PIDC. The radionuclide monitoring system collects both aerosol and gas samples. Gamma-ray spectral analysis is performed on the samples to determine if they contain anthropogenic radionuclides indicative of nuclear debris. A key radionuclide monitored by this system is 137Cs. Due to the half-life of 137Cs (30.17 y), amounts of this radionuclide releases are still present in the soil and atmosphere as a result of past nuclear tests and reactor releases. 137Cs from these sources are routinely detected in the prototype CTBT radionuclide monitoring system. Out of the multiple stations that contribute data to the PIDC, the highest 137Cs activity concentrations and largest range of concentrations are observed at the Kuwait City, Kuwait station. A special study was conducted to investigate the concentrations, trends, and origin of 137Cs in the Kuwait aerosol. This study combines over four years worth of aerosol data, meteorological data and soil sample analysis to explore this matter.
Authors:A. Rawson, V. Spate, C. Baskett, M. Mason, and L. Hillman
A chemical and radiochemical neutron activation analysis (CNAA/RNAA) method has been developed for the determination of three
calcium isotopes (48Ca,46Ca, and44Ca) in a single sample derived from urine. This method was developed in support of clinical research using a dual enriched
stable isotope methodology to study bone mineralization in premature infants, juvenile rheumatoid arthritics, and cystic fibrosis.
In these studies, one enriched isotope of calcium is administered orally, and one is administered intravenously. By making
determinations of three isotopes (two enriched, one unenriched) within the same sample, the perturbation from natural isotopic
ratios can be determined and used to calculate true absorption of calcium. In our method,48Ca is determined via the48Ca(n,γ)49Ca reaction and 3084 keV gamma-ray,46Ca via the46Ca(n,γ)47Ca reaction and 1296 keV gamma-ray, and44Ca via the44Ca(n,γ)45Ca reaction and 256 keV (max) beta-particle. A pair of chemical separation steps are employed to separate calcium from urine
as calcium oxalate with a yield in the range of 80–90%, and a radiochemical step is employed prior to the measurement of45Ca to remove interfering radionuclides.
Authors:S. Biegalski, G. Shipman, L. Mason, M. Pickering, and S. Altman
CREWS is a regional network of five high volume air samplers located around the Gulf of Mexico designed to detect extremely low level releases of airborne radioactivity from the nuclear power plants being constructed in Cuba. Four of the stations are currently operational. The CREWS stations use a high efficiency particulate filter to sample aerosols larger than about 10 nm. Aerosols are collected continuously for a week at a flow rate of 515 cubic meters per hour and then counted on a high purity germanium (HPGe) spectroscopy system. The first station began operation in October, 1998. This paper reports the concentration ranges and seasonal trends of the natural radionuclides 7Be and 210Pb detected by the CREWS system. Anthropogenic measurements are also provided and possible sources are discussed. Finally, the paper examines the average minimum detectable concentrations achieved by the systems and predicts the level of release that this system can detect from the Cuban reactors.
Authors:Jeremy L. Steinbacher, Yankai Lui, Brian P. Mason, William L. Olbricht, and D. Tyler McQuade
We present and validate simple mesofluidic devices for producing monodisperse droplets and materials. The significance of this work is a demonstration that simple and complex droplet formulations can be prepared uniformly using off-the-shelf small-diameter tubing, barbed tubing adapters, and needles. With these simple tools, multiple droplet-forming devices and a new particle concentrator were produced and validated. We demonstrate that the droplet-forming devices could produce low-dispersity particles from 25 to 1200 Km and that these results are similar to results from more complicated devices. Through a study of the fluid dynamics and a dimensional analysis of the data, we have correlated droplet size with two dimensionless groups, capillary number and viscosity ratio. The flowfocusing device is more sensitive to both parameters than the T-junction geometry. The modular character of our mesofluidic devices allowed us to rapidly assemble compound devices that use flow-focusing and T-junction devices in series to create complex droplet-in-microcapsule materials. This work demonstrates that flow chemistry does not require complicated tools, and an inexpensive tool-kit can allow anyone with interest to enter the field.
Authors:M. Mason, J. Morris, V. Spate, C. Baskett, T. Nichols, T. Horsman, L. Le Marchand, L. Kolonel, and S. Yukimoto
The measurement of dietary selenium intake in a free-living population using dietary recall techniques has been shown to be
spurious. Consequently, in our laboratory, we have focused on the development of biologic monitors such as blood, nails, hair
and urine. In this paper, we report on the neutron activation analysis of whole blood, plasma and nail specimens collected
from 285 Caucasian subjects, all permanent residents of Hawaii, participating in a malignant melanoma trial. Correlations
between monitors are presented and discussed in the context of selenium determinants and integration of selenium intake.
Authors:M. Mason, V. Spate, J. Morris, C. Baskett, T. Cheng, C. Reams, L. Le Marchand, B. Henderson, and L. Kolonel
There is currently great interest in iodine as a micro nutrient. Both high and low intakes have been associated with thyroid cancer incidence. Development of dietary iodine monitors is needed to supplement the use of dietary recall methods which have not been well validated for iodine. In this study, 30 pooled urine samples, from ethnic groups on various islands in the South Pacific, were analyzed for iodine using epithermal instrumental neutron activation analysis (EINAA).
Authors:M. Mason, J. Morris, B. Derenzy, V. Spate, L. Clarke, L. Hillman, L. Gawenis, T. Horsman, C. Baskett, T. Nichols, and J. Colbert
A genetically engineered “knockout gene” mouse model for human cystic fibrosis (CF) has been utilized to study bone mineralization.
In CF, the so-called cystic fibrosis transmembrane conductance regulator (CFTR) protein, a chloride ion channel, is either
absent or defective. To produce the animal model the murine CFTR gene has been inactivated producing CF symptoms in the homozygotic
progeny. CF results in abnormal intestinal absorption of minerals and nutrients which presumably results in substandard bone
mineralization. The objective of this study was to determine the feasibility of using whole-body thermal and fast neutron
activation analysis to determine mineral and trace-element differences between homozygote controls (+/+) and CF (−/−), murine
siblings. Gender-matched juvenile +/+ and −/− litter mates were lyophilized and placed in a BN capsule to reduce thermal-neutron
activation and irradiated for 10 seconds at φfast ≈ 1·1013 n·cm−2·s−1 using the MURR pneumatic-tube facility. Phosphorus was measured via the31P15(n,α)28Al13 reaction. After several days decay, the whole-body specimens were re-irradiated in the same facility, but without thermal-neutron
shielding, for 5 seconds and the gamma-ray spectrum was recorded at two different decay periods allowing measurement of77mSe,24Na,27Mg,38Cl,42K,49Ca,56Mn,66Cu and80Br from the corresponding radiative-capture reactions.