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Background Estimates of radiation risks following prolonged exposures at low doses and low-dose rates are uncertain. Medical radiation workers are a major component of the Million Person Study (MPS) of low-dose health effects. Annual personal dose equivalents, HP(10), for individual workers are available to facilitate dose-response analyses for lung cancer, leukemia, ischemic heart disease (IHD) and other causes of death. Materials and methods The Landauer, Inc. dosimetry database identified 109,019 medical and associated radiation workers first monitored 1965-1994. Vital status and cause of death were determined through 2016. Mean absorbed doses to red bone marrow (RBM), lung, heart, and other organs were estimated by adjusting the recorded HP(10) for each worker by scaling factors, accounting for exposure geometry, energy of the incident photon radiation, sex of the worker and whether an apron was worn. There were 4 exposure scenarios: general radiology characterized by low-energy x-ray exposure with no lead apron use, interventional radiologists/cardiologists who wore aprons, nuclear medicine personnel and radiation oncologists exposed to high-energy photon radiation, and other workers. Standardized mortality ratio (SMR) analyses were performed. Cox proportional hazards models were used to estimate organ-specific radiation risks. Results Overall, 11,433 deaths occurred (SMR 0.60; 95%CI 0.59,0.61), 126 from leukemia other than chronic lymphocytic leukemia (CLL), 850 from lung cancer, and 1,654 from IHD. The mean duration of monitoring was 23.7 y. The excess relative rate (ERR) per 100 mGy was estimated as 0.10 (95% CI -0.34, 0.54) for leukemia other than CLL, 0.15 (0.02, 0.27) for lung cancer, and -0.10 (-0.27, 0.06) for IHD. The ERR for lung cancer was 0.16 (0.01, 0.32) among the 55,218 male workers and 0.09 (-0.19, 0.36) among the 53,801 female workers; a difference that was not statistically significant (p value =0.062). Conclusions Medical radiation workers were at increased risk for lung cancer that was higher among men than women, although this difference was not statistically significant. In contrast, the study of Japanese atomic bomb survivors exposed briefly to radiation in 1945 found females to be nearly 3 times the radiation risk of lung cancer compared with males on a relative scale. For medical workers, there no statistically significant radiation-associations with leukemia excluding CLL, IHD or other specific causes of death. Combining these data with other cohorts within the MPS, such as nuclear power plant workers and industrial radiographers, will enable more precise estimates of radiation risks at relatively low cumulative doses.

Background The aim of the Million Person Study (MPS) of Low Dose Health Effects is to examine the level of radiation risk for chronic exposures received gradually over time and not acutely as was the case for the Japanese atomic bomb survivors. Nuclear power plant (NPP) workers comprise nearly 15 percent of the MPS. Leukemia, selected cancers, Parkinson's disease, ischemic heart disease (IHD) and other causes of death are evaluated. Methods and material The U.S. Nuclear Regulatory Commission's Radiation Exposure Information and Reporting System (REIRS) and the Landauer, Inc. dosimetry databases identified 135,193 NPP workers first monitored 1957-1984. Annual personal dose equivalents [Hp(10)] were available for each worker. Radiation records from all places of employment were sought. Vital status was determined through 2011. Mean absorbed doses to red bone marrow (RBM), esophagus, lung, colon, brain and heart were estimated by adjusting the recorded Hp(10) for each worker by scaling factors, accounting for exposure geometry and energy of the incident gamma radiation. Standardized mortality ratios (SMR) were calculated. Radiation risks were estimated using Cox proportional hazards models. Results Nearly 50% of workers were employed for more than 20 years. The mean duration of follow-up was 30.2 y. Overall, 29,076 total deaths occurred, 296 from leukemia other than chronic lymphocytic leukemia (CLL), 3,382 from lung cancer, 140 from Parkinson's disease and 5,410 from IHD. The mean dose to RBM was 37.9 mGy (maximum 1.0 Gy; percent >100 mGy was 9.2%), 43.2 mGy to lung, 43.7 mGy to colon, 33.2 mGy to brain, and 43.9 mGy to heart. The SMRs (95% CI) were 1.06 (0.94;1.19) for leukemia other than CLL, 1.10 (1.07;1.14) for lung cancer, 0.90 (0.76;1.06) for Parkinson's disease, and 0.80 (0.78; 0.82) for IHD. The excess relative risk (ERR) per 100 mGy for leukemia other than CLL was 0.15 (90% CI 0.001; 0.31). For all solid cancers the ERR per 100 mGy (95% CI) was 0.01 (-0.03; 0.05), for lung cancer -0.04 (-0.11; 0.02), for Parkinson's disease 0.24 (-0.02; 0.50), and for IHD -0.01 (-0.06; 0.04). Conclusion Prolonged exposure to radiation increased the risk of leukemia other than CLL among NPP workers. There was little evidence for a radiation-association for all solid cancers, lung cancer or ischemic heart disease. Increased precision will be forthcoming as the different cohorts within the MPS are combined, such as industrial radiographers and medical radiation workers who were assembled and evaluated in like manner.

Background Epidemiologic studies of radiation-exposed populations form the basis for human safety standards. They also help shape public health policy and evidence-based health practices by identifying and quantifying health risks of exposure in defined populations. For more than a century, epidemiologists have studied the consequences of radiation exposures, yet the health effects of low levels delivered at a low-dose rate remain equivocal. Materials and methods The Million Person Study (MPS) of U.S. Radiation Workers and Veterans was designed to examine health effects following chronic exposures in contrast with brief exposures as experienced by the Japanese atomic bomb survivors. Radiation associations for rare cancers, intakes of radionuclides, and differences between men and women are being evaluated, as well as noncancers such as cardiovascular disease and conditions such as dementia and cognitive function. The first international symposium, held November 6, 2020, provided a broad overview of the MPS. Representatives from four U.S. government agencies addressed the importance of this research for their respective missions: U.S. Department of Energy (DOE), the Centers for Disease Control and Prevention (CDC), the U.S. Department of Defense (DOD), and the National Aeronautical Space Agency (NASA). The major components of the MPS were discussed and recent findings summarized. The importance of radiation dosimetry, an essential feature of each MPS investigation, was emphasized. Results The seven components of the MPS are DOE workers, nuclear weapons test participants, nuclear power plant workers, industrial radiographers, medical radiation workers, nuclear submariners, other U.S. Navy personnel, and radium dial painters. The MPS cohorts include tens of thousands of workers with elevated intakes of alpha particle emitters for which organ-specific doses are determined. Findings to date for chronic radiation exposure suggest that leukemia risk is lower than after acute exposure; lung cancer risk is much lower and there is little difference in risks between men and women; an increase in ischemic heart disease is yet to be seen; esophageal cancer is frequently elevated but not myelodysplastic syndrome; and Parkinson's disease may be associated with radiation exposure. Conclusions The MPS has provided provocative insights into the possible range of health effects following low-level chronic radiation exposure. When the 34 MPS cohorts are completed and combined, a powerful evaluation of radiation-effects will be possible. This final article in the MPS special issue summarizes the findings to date and the possibilities for the future. A National Center for Radiation Epidemiology and Biology is envisioned.

The Athabasca River Basin in Alberta, Canada, is of international significance, and understanding water supply is critically important to the sustainability of the region. In the upper Athabasca Ri...

The development of hydrological models that produce practically useful and physically defensible results is an ongoing challenge in hydrology. This challenge is further compounded in large, spatial...

Lakes and reservoirs have critical impacts on hydrological, biogeochemical, and ecological processes, and they should be an essential component of regional-scale hydrological and eco-hydrological m...

The goal of this study was twofold: firstly, to investigate vocational accounting students’ attitudes towards sustainable development; secondly, to explore the influence of students’ professional s...

Purpose Scientific Committee 6-9 was established by the National Council on Radiation Protection and Measurements (NCRP), charged to provide guidance in the derivation of organ doses and their uncertainty, and produced a report, NCRP Report No. 178, Deriving Organ Doses and their Uncertainty for Epidemiologic Studies with a focus on the Million Person Study of Low-Dose Radiation Health Effects (MPS). This review summarizes the conclusions and recommendations of NCRP Report No. 178, with a concentration on and overview of the dosimetry and uncertainty approaches for the cohorts in the MPS, along with guidelines regarding the essential approaches used to estimate organ doses and their uncertainties (from external and internal sources) within the framework of an epidemiologic study. Conclusions The success of the MPS is tied to the validity of the dose reconstruction approaches to provide realistic estimates of organ-specific radiation absorbed doses that are as accurate and precise as possible and to properly evaluate their accompanying uncertainties. The dosimetry aspects for the MPS are challenging in that they address diverse exposure scenarios for diverse occupational groups being studied over a period of up to 70 y. Specific dosimetric reconstruction issues differ among the varied exposed populations that are considered: atomic veterans, U.S. Department of Energy workers exposed to both penetrating radiation and intakes of radionuclides, nuclear power plant workers, medical radiation workers, and industrial radiographers. While a major source of radiation exposure to the study population comes from external gamma- or x-ray sources, for some of the study groups, there is also a meaningful component of radionuclide intakes that requires internal radiation dosimetry assessments.

The advent of new technology presents new opportunities for forwarding thinking law enforcement administrators and new legal challenges for the courts. One such new technology is portable mass spec...

Contemporary societies around the world face a number of what have been termed ‘wicked problems’ (Churchman, 1967; Rittel & Webber, 1973). These issues include but are not restricted to health ineq...

Multiple sets of growth rate data for small fatigue cracks in seven different aircraft gas turbine engine rotor materials, including both titanium alloys and nickel-based superalloys, have been collected and are critically compared against corresponding large-crack data. The database includes a wide range of microstructures as well as multiple stress ratios and temperatures. The ability of the simple El Haddad small-crack model and its length parameter a0 to correlate the small-crack and large-crack data by adjusting the small-crack driving force is critically evaluated. Different methods of estimating a0, including the traditional calculation from large-crack threshold and endurance limit properties, as well as a new approach based on empirical scaling from microstructural dimensions, are explored and compared. Strengths and limitations of the simple El Haddad approach for engineering applications are discussed, as well as the practical significance of small-crack effects for life prediction.

In Indonesia, where stroke is the leading cause of death, we designed and tested a brief intervention to increase physician-patient conversations about stroke prevention in community health centers. The pilot study used a quasi-experimental design involving repeated cross-sectional data collection over 15 weeks to compare pre- and during-intervention differences within four centers. We conducted exit interviews with 675 patients immediately following their medical appointments to assess whether physicians discussed stroke risks and provided recommendations to modify their risk behaviors. From pre-intervention to during intervention, patients reported more frequent physician recommendations to modify their stroke risk behaviors. We also conducted interviews with eight providers (physicians and nurses) after the intervention to get their feedback on its implementation. This study demonstrated that a brief intervention to motivate physician-patient conversations about stroke prevention may improve these conversations in community health centers. While interventions to reduce risk hold considerable promise for reducing stroke burden, barriers to physician-patient conversations identified through this study need to be addressed.

An efficient heterogeneous method for the synthesis of diarylacetic acids was developed utilizing silica sulfuric acid as a catalyst. The reaction is highly efficient with a small amount of catalyst for the combination of a variety of electron-neutral to electron-rich arenes with glyoxylic acid. The reaction can also be utilized to synthesize unsymmetric derivatives from activated mandelic acids in good to excellent yields.

We use bank retail interest rates as price examples in a study of the determinants of price durations. The extraordinary richness of the data allows us to address some major open issues from the price rigidity literature, such as the functional form of the hazard of changing a price, the effect of firm and market characteristics on the duration of prices, and asymmetry in the speed of adjustments to positive and negative cost shocks. We find that the probability of a bank changing its retail rate initially (that is, in roughly the first six months of a spell) increases with time. The most important determinants of the duration of retail interest rates are the cumulated change in the money market interest rates and the policy rate since the last retail rate change. Among bank and market characteristics, the size of the bank, its market share in a given local market, and its geographical scope significantly modify retail rate durations. Retail rates adjust asymmetrically to positive and negative wholesale interest rate changes; the asymmetry of the adjustment is reinforced in part by the bank’s market share. This suggests that monopolistic distortions play a vital role in explaining asymmetric price adjustments.

We empirically examine whether a major government intervention in the small firm credit market yields significantly better results in markets that are less financially developed. The government int...

We developed laboratory exercises using zebrafish (Danio rerio) and nematodes (Caenorhabditis elegans) for a sophomore-level Integrative Biology Laboratory course. Students examined live wildtype zebrafish at different stages of development and noted shifts occurring in response to fgf8a deficiency. Students were introduced to development in other fish species to demonstrate how variation in developmental systems affects phenotype. Finally, students cultured glp-1(bn18ts) C. elegans mutants under different conditions to illustrate how the environment and genetics act concurrently to modulate development. Undergraduate students responded positively to both the fish and C. elegans laboratory modules. These novel laboratory exercises are intended to promote an integrative view of biology and to help prepare undergraduate students for independent research with faculty.

This paper presents the results of a judicial impact study of the 2009 Supreme Court decision in Arizona v. Gant, which modified the rules police have to follow when conducting vehicle searches incident to arrest. Following up on an earlier study, this research draws on principal-agent theory to consider the differences between the responses of US courts of appeals panels to Gant with decisions of state supreme courts and attempts to understand why defendants win on Gant issues 44% of the time in state supreme courts, compared with 15% of the time in the US courts of appeals. A detailed content analysis of the opinions in 102 appellate courts decisions in which Gant could have potentially served as a controlling precedent revealed an interesting set of differences between state and federal courts. Federal judges were more likely than state supreme court justices to actively seek alternative rationales that allowed them to avoid the exclusionary rule.

Previous observational and quasi-experimental studies in sub-Saharan Africa have suggested the effectiveness of youth-targeted HIV prevention interventions using sport as an educational tool. No studies have yet assessed the effect of similar programs in the Caribbean. A quasi-experimental trial was conducted to assess the effectiveness of a sports-based intervention in six migrant settlements in the Puerto Plata Province of the Dominican Republic. A total of 397 structured interviews were conducted with 140 adolescents prior to, immediately following, and four months following 10-hour interventions using the Grassroot Soccer curriculum. Interview responses were coded, aggregated into composite scores, and analyzed using logistic regression, adjusting for baseline differences as well as age, sex, community, and descent. At post-intervention, significant differences were observed between groups in HIV-related knowledge (adjOR = 13.02, 95% CI = 8.26, 20.52), reported attitudes (adjOR = 12.01, 95% CI = 7.61, 18.94), and reported communication (adjOR = 3.13, 95% CI = 1.91, 5.12). These differences remained significant at four-month follow-up, though declines in post-intervention knowledge were observed in the Intervention group while gains in knowledge and reported attitudes were observed in the Control group. Results suggest that this sports-based intervention could play a valuable role in HIV prevention efforts in the Caribbean, particularly those targeting early adolescents. Further evaluation of sports-based interventions should include indicators assessing behavioral and biological outcomes, longer-term follow-up, a larger sample, randomization of study participants, and strenuous efforts to minimize loss-to-follow-up.

The guaranteed lending programs of the Small Business Administration (SBA) are large and growing rapidly. The SBA's fiscal year 2009 Performance Budget calls for $28 billion in guaranteed loans for...

Modernization in developing regions affects local diets and nutrition. Using qualitative rapid appraisal methods, we examined the effect of dietary delocalization on food preferences and procurement sources and dietary diversity in rural Tibet. The diets of Tibetans are being both positively and negatively influenced as the region modernizes. For example, greenhouses and chicken rearing represent local adaptations which could improve micronutrient consumption. At the same time, the recent introduction of calorie-rich, nutrient-poor commoditized foods could insult nutrition but are increasingly popular among children. Multimodal public health interventions can minimize harmful and maximize beneficial effects of the nutrition transition in Tibet.

Variation in attitudes and preferences among communities has been cited as a primary consideration for the development of grizzly bear management plans in North America. We undertook a study in 2004 to determine if there were differences among two rural populations and an urban population on the issue of grizzly bear management in Alberta, Canada. Results from a mail survey showed that there was a greater diversity of views and potential for conflict between the two rural groups than between the rural groups and the urban group. We used a cognitive hierarchy of knowledge, attitudes, and normative beliefs as a theoretical foundation and analyzed the effects of social influences (including residency) and demographics. A structural equation analysis showed that being an off-road vehicle user had a greater influence on acceptance of access restrictions than residency or cognitive and demographic factors.

Increasingly, policymakers look to the small business sector as a potential engine of economic growth. Policies to promote small businesses include tax relief, direct subsidies, and indirect subsid...

An emerging trend in the state‐of‐the‐art instream flow assessment applications is the use of three‐dimensional channel topography coupled with two‐dimensional hydrodynamic models. These components are most often integrated with biological response functions for depth, velocity, and substrate to simulate physical habitat for target species and life stages. These approaches typically involve the simple extension of the one‐dimensional conceptual habitat models represented by the Physical Habitat Simulation System (PHABSIM) developed by the U.S. Fish and Wildlife Service (Stalnaker, 1995). However, as demonstrated in this paper, the physical habitat based template represented by high‐resolution channel topography and two‐dimensional hydrodynamic model outputs can extend these simple conceptual models of habitat to incorporate additional behavior‐based decision rules. The approach demonstrated in this paper evaluates the spatial suitability of physical habitat for chinook fry based on the incorporat...

This article discusses the problem of school violence and the fear about school safety that have been reinforced by extensive news media coverage of the recent series of school shooting incidents. Vari- ous factors associated with school violence are addressed, including sociocultural influences on adolescents that pose a challenge to counsel- ors and therapists working with this clientele. In order to reduce violence and aggression in schools and to ease concerns about safety, steps must be taken not only by schools but also by parents and communities. Fami- lies can play an important protective role in minimizing at-risk behavior by young people. In fact, many of the most effective youth violence in- terventions include family components. Several of these programs are described as well as a number of collaborative approaches that demon- strate the potential synergy of school counselors and family therapists working together. With the addition of more courses in family dynamics Patricia E. Hudson is affiliated with the Division of Human Services and Counsel

In the mid 1990s, the New South Wales government introduced management measures to increase the size of the population of the eastern rock (spiny) lobster, Jasus verreauxi. A fully orthogonal sampling design was begun in July 1995 to test, amongst others, the hypothesis that the relative abundance of recruits (stages of peuruli to early juveniles combined) to the eastern rock lobster population will change over space and time. In the design for the full sampling strategy were the factors of Year (eight levels) and Location (four levels). Three replicate collectors at each of three sites at each location were sampled during the first quarter of each lunar month between August and January between 1995–96 and 2002–03 (inclusive). Recruits occurred on collectors between September and January each year. Results of the two‐factor ANOVA showed a significant interaction between Year and Location, meaning that differences in mean relative abundance of recruits between years will depend upon the location. ...

Ecophys.Fish is a deterministic STELLA® model for simulating rates of fish growth in environmental regimes that have simultaneous temporal variation in food, oxygen, temperature, pH, and salinity. The purpose of this article is to introduce Ecophys.Fish to those who might want to use it as a framework or starting point for applications of their own. We believe our model, although focused in autecology, will prove useful at organizational levels both below and above the individual fish. Ecophys.Fish is a quantitatively explicit interpretation of concepts originally formalized by F.E.J. Fry, almost 60 years ago. Fry's “physiological classification of environment” and his concept of “metabolic scope for activity” were coupled with conventional bioenergetics to provide the model's theoretical basis. The model's inputs are initial size of fish, and time series of temperature, pH, dissolved-oxygen concentration (DO), salinity, and food availability and its energy content. Outputs are food consumption, oxygen co...

Synopsis A new specimen of Palaeoburmesebuthus grimaldii Lourenco, 2002, recently described from Cretaceous (Albian) Burmite, is reported. This is more complete than the holotype consisting of five scattered, unequal parts: a complete metasoma with an attached partial mesosoma bearing a visible stigma, a right pedipalp chela and three leg fragments. Comparisons to extinct and extant lineages of scorpions are made, although the partially observable trichobothrial pattern of the pedipalp chela precludes definitive family placement. The relative position of the fragments and the severe damage they have suffered imply that it was dismembered by a predator and provides the oldest evidence of scorpions being preyed upon by other animals.

(2003). Natural Resources Damages Assessments and Claims in the Great Lakes Basin. Soil and Sediment Contamination: An International Journal: Vol. 12, No. 2, pp. 253-304.

This research applied the construct equivalence approach for deriving and empirically validating analog measures based on data not originally designed to measure the theoretical constructs of inter...

Most state-of-the-art applications of habitat modelling rely on three-dimensional channel topography and two-dimensional hydrodynamic models that have centered on the simple extension of one-dimensional physical habitat-based concepts (i.e., extension of the Physical Habitat Modelling System - PHABSIM). However, as demonstrated in this paper, these approaches can be extended to more realistically incorporate both the physical habitat-based metrics of streamflow and behavioural decision rules that can incorporate fish community structure and dynamics. This approach evaluates the spatial suitability of physical habitat-based on the incorporation of behavioural rule sets, such as the association with escape cover type and distance, exclusion zones associated with predators or linear dominance hierarchies, and lag-time dependence of macroinvertebrate re-colonization of habitats associated with varial zones induced by peaking/load following operations of hydropower facilities. In the paper we lay the foundatio...

SiC and Si3N4 materials were tested under various turbine engine combustion environments, chosen to represent either conventional fuel-lean or fuel-rich mixtures proposed for high speed aircraft. Representative CVD, sintered, and composite materials were evaluated in both furnace and high pressure burner rig exposure. While protective SiO2 scales form in all cases, evidence is presented to support paralinear growth kinetics, i.e. parabolic growth moderated simultaneously by linear volatilization. The volatility rate is dependent on temperature, moisture content, system pressure, and gas velocity. The burner tests were used to map SiO2 volatility (and SiC recession) over a range of temperature, pressure, and velocity. The functional dependency of material recession (volatility) that emerged followed the form: exp(-Q/RT) * Px * vy. These empirical relations were compared to rates predicted from the thermodynamics of volatile SiO and SiOxHv reaction products and a kinetic model of diffusion through a moving ...

(1998). US policy and the Kosovo crisis. The International Spectator: Vol. 33, No. 4, pp. 23-39.

Vegetation on point bars must be adapted to changing hydrological and geomorphological conditions. Detailed population data are gathered for 106 1 m2 quadrats on two point bars on the Cedar River, Iowa, in the year following a major establishment event when a brief steady river stage coincided with the dispersal period for common riparian pioneer species (Salix interior, S. nigra, Populus deltoides) during a drought year. Significant differences were found in the location of seedlings and different forms of sprouts on a gradient of elevation. Most seedlings, mostly Salix interior, established in a very narrow range that produced a band along the edge of the river. While density in this band is in part related to sediment texture, it is clear that the densities found (e.g., > 500 m-2) must result from dispersal by water to the strand line. [Key words: establishment, point bar, riparian, Salix, seedling.]

Observations are critical to determining which geologic processes are active in developing geologic products or topographic landforms. Frequently, accepted geologic models of processes limit consideration of additional processes that may be involved. For example, the wide acceptance of the detrital model for the formation of gold nuggets has limited consideration of how chemical processes, in the surface environment, can contribute to gold-nugget growth. Observations document that: 1) some gold nuggets are larger than gold masses in the lode source; 2) gold-rich rims form on gold nuggets; 3) gold fineness increases with transport distance; 4) gold is transported in aqueous solution in the surface environment. These observations require that chemical transport of gold be recognized as an important process in some surface environments and raises the possibility of gold-nugget growth by precipitation of gold from aqueous solutions onto existing gold concentrations to produce gold nuggets. Accurate observatio...