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A Monte-Carlo method for the generation of correlation and covariance matrices for independent and cumulative fission yields has been developed. The method uses a constrained Monte-Carlo resampling structure in order to vary evaluated fission yield libraries in a way that meets basic conservation principles. This results in the generation of correlation/covariance matrices with limited model bias and uncertainty; the matrices are primarily reflective of the evaluated fission yield uncertainties and correlations that arise from the evaluation process. This method has been applied to generate correlation and covariance matrices for all of the fissioning systems of the ENDF/B-VIII.0 and JEFF-3.3 evaluations, marking the first time such matrices have been generated for all of these systems. These covariance matrices have been published online for immediate public use. These correlation and covariance matrices can be used to improve uncertainty estimation in calculations of reactor antineutrino emission rates, decay heat problems, and nuclear forensics.

Theoretical models often differ significantly from measured data in their predictions of the magnitude of nuclear reactions that produce radionuclides for medical, research, and national security applications. In this paper, we compare a priori predictions from several state-of-the-art reaction modeling packages (CoH, EMPIRE, TALYS, and ALICE) to cross sections measured using the stacked-target activation method. The experiment was performed using the Lawrence Berkeley National Laboratory 88-Inch Cyclotron with beams of 25 and 55 MeV protons on a stack of iron, copper, and titanium foils. Thirty-four excitation functions were measured from 4–55 MeV, including the first measurement of the independent cross sections for natFe (p,x)49 , 51Cr , 51 , 52 m , 52 g , 56Mn , and 58 m , 58 gCo. All of the models, using default input parameters to assess their predictive capabilities, failed to reproduce the isomer-to-ground state ratio for reaction channels at compound and pre-compound energies, suggesting issues in modeling the deposition or distribution of angular momentum in these residual nuclei.

A stacked-target of natural lanthanum foils (99.9119% 139La) was irradiated using a 60 MeV proton beam at the LBNL 88-Inch Cyclotron. 139La(p,x) cross sections are reported between 35–60 MeV for nine product radionuclides. The primary motivation for this measurement was the need to quantify the production of 134Ce. As a positron-emitting analogue of the promising medical radionuclide 225Ac, 134Ce is desirable for in vivo applications of bio-distribution assays for this emerging radio-pharmaceutical. The results of this measurement were compared to the nuclear model codes TALYS, EMPIRE and ALICE (using default parameters), which showed significant deviation from the measured values.

The covariance committee of CSEWG (Cross Section Evaluation Working Group) established templates of expected measurement uncertainties for neutron-induced total, (n,γ), neutron-induced charged-particle, and (n,xn) reaction cross sections as well as prompt fission neutron spectra, average prompt and total fission neutron multiplicities, and fission yields. Templates provide a list of what uncertainty sources are expected for each measurement type and observable, and suggest typical ranges of these uncertainties and correlations based on a survey of experimental data, associated literature, and feedback from experimenters. Information needed to faithfully include the experimental data in the nuclear-data evaluation process is also provided. These templates could assist (a) experimenters and EXFOR compilers in delivering more complete uncertainties and measurement information relevant for evaluations of new experimental data, and (b) evaluators in achieving a more comprehensive uncertainty quantification for evaluation purposes. This effort might ultimately lead to more realistic evaluated covariances for nuclear-data applications. In this topical issue, we cover the templates coming out of this CSEWG effort–typically, one observable per paper. This paper here prefaces this topical issue by introducing the concept and mathematical framework of templates, discussing potential use cases, and giving an example of how they can be applied (estimating missing experimental uncertainties of 235U(n,f) average prompt fission neutron multiplicities), and their impact on nuclear-data evaluations.

Sensitivity studies of the i process have identified the region around 135I as a bottleneck for the neutron capture flow. Nuclear properties such as the Maxwellian-averaged cross section (MACS) are key to constrain the uncertainties in the final abundance patterns. With the Oslo method, we are able to indirectly measure such properties for the nuclei involved in this process. From the 124Sn(α, pγ)127Sb reaction data we extract the nuclear level density and γ-ray strength function for 127Sb. The level density at higher excitation energies is compatible with the constant-temperature model, while the γ-ray strength function presents features like an upbend and a pygmy-like structure below S n. From these two quantities we can calculate the MACS for the 126Sb(n, γ)127Sb reaction using the Hauser-Feshbach formalism, and constrain its uncerainties from the theoretical ones. Libraries such as JINA REACLIB, TENDL and BRUSLIB agree well with the experimental results, while ENDF/B-VIII.0 predicts a higher rate.

Sensitivity studies of the i process have identified the region around 135I as a bottleneck for the neutron capture flow. Nuclear properties such as the Maxwellian-averaged cross section (MACS) are key to constrain the uncertainties in the final abundance patterns. From the 124Sn(α, pγ)127Sb reaction we are able to indirectly measure the nuclear level density and γ-ray strength function for 127Sb using the Oslo method. From these two quantities we can calculate the MACS for the 126Sb(n, γ)127Sb reaction using the Hauser-Feshbach formalism, constrain its uncertainties and compare it to libraries such as JINA REACLIB, TENDL and BRUSLIB.

Purpose To determine whether low-dose computed tomography (LD-CT) affects the rate of early lung cancer detection in a high-risk population, how that rate compares with the rate given in the National Lung Screening Trial (NLST), whether using LD-CT provides a stage shift in lung cancer, and whether NLST results are reproducible. Methods Patient medical records from a Kentucky community hospital were retrospectively reviewed. Patients who were included had received LD-CT scans from January 2015 through December 2017, were aged 55 years to 79 years, had smoked for at least 30 pack-years or quit smoking in the past 15 years and were able to lie on their backs with their arms over their heads. Patients with any previous cancer were excluded. Retrospective chart review employed to collect data, and summarized quantitative data were used as measures of central tendency (ie, mean and mode). Results The study included 2924 patients, with 1483 men (50.7%) and 1441 women (49.3%). Sixty-six patients (42 men, 24 women) had lung cancer, all of whom smoked a maximum of 3.5 packs of cigarettes a day. Of the 66 patients, 7 patients (10.6%) died during the 3-year study timeframe. The study found an average of 2 cancer diagnoses per 100 LD-CT scans, whereas the NLST noted 1 diagnosis for every 320 scans. Mortality rate was associated with lung cancer in this high-risk population, calculated at 239 per 100 000 patients. Discussion Compared with NLST findings, this current study found that lung cancer is diagnosed in Kentucky residents at a higher rate, and that this group is at greater risk for developing smoking-related lung cancer. In addition, LD-CT is useful in early lung cancer detection for asymptomatic, high-risk populations and can improve quality of life, prolong life, and reduce overall health care costs. Conclusion Lung cancer is a public health care problem in the United States and specifically in Kentucky. This situation might improve if legislation prioritizes educating the medical community about the tools available for early detection of lung cancer, including LD-CT. [ABSTRACT FROM AUTHOR]

The article discusses the different types of ionizing radiation. Topics covered include the effect of radiation on biologic tissue, the basic principles of matter and energy, and the x-ray production process. Also presented is a list of radiation dose limits for radiation workers and the ways to limit exposure to radiation.

Iodinated contrast agents used in computed tomography (CT) examinations have the potential to cause adverse reactions in patients. The possibility of acute kidney injury should be of concern to radiologic technologists performing CT examinations. Although prevention is paramount, identifying and treating contrast-induced nephropathy, for example, as well as following appropriate guidelines regarding the handling and usage of contrast material, are crucial. This article discusses recent research in these areas. [ABSTRACT FROM AUTHOR]

Purpose To determine whether a relationship exists between the number of clinical sites available in radiography programs accredited by the Joint Review Committee on Education in Radiologic Technology and the job placement rates of graduates. Methods We performed a secondary analysis of data on job placement rates and the number of clinical sites available in 438 degree-granting radiography programs from January 2015 to March 2015. Results A weak, negative, nonsignificant correlation existed between the number of clinical sites and the job placement rate (Spearman's rho = -.113, n = 438, P = .018). The coefficient of determination was 1.28%. Discussion Research evaluating factors contributing to graduate employability is limited but indicates no need for radiography program administrators to adjust clinical site numbers solely on the basis of improving graduate employability. Conclusion The number of clinical sites available in a radiography program is not related to the job placement rate of its graduates. [ABSTRACT FROM AUTHOR]

The article discusses the need for radiologic technologists to keep ethical principles in mind when dealing with employers, coworkers and patients. Topics covered include the need for radiologic technologists to be respectful, truthful and to maintain trust and confidentiality. Also mentioned is how the use of social media sites increases the potential for ethical compromise.

The article discusses adverse effects of iodine-derived intravenous radiopaque contrast media (ROCM). Topics discussed include history of ROCM and its classification such as initiation of the use of sodium iodide as contrast media in 1920s, distribution and excretion of ROCM, reactions and adverse effects associated with ROCM, complication such as extravasation arising from radiographic contrast media, and use of epinephrine to treat contrast reactions in patients.

A study was conducted to revisit the perceptions of chief executive officers in US hospitals regarding the origin of leadership and how they felt about internally developed successors versus externally recruited successors. Furthermore, the study sought to develop understanding of how this group of executives utilizes the succession planning process, what factors impact successor identification, what positions are applicable for succession planning activities, and who is ultimately held responsible for leadership continuity within the hospital industry. The results of this 2012 study were compared with a previous study conducted in 2007 to determine if the perceptions had changed over time. [ABSTRACT FROM AUTHOR]

The article discusses the side effects of radiation therapy on the spinal cord. The author states that the two common areas treated with radiation that involves spinal cord irradiation are cancers of the lung, head and neck. In addition, in treating radiation-induced spinal cord injuries, staff members must be aware of the tolerance dose and factors that affect the likelihood of a spinal cord injury. Moreover, medical personnel must consider the total dose of the patient will receive and the fractionation of the total dose to decrease patient's chances of developing radiation myelitis.

PURPOSE Clinician job dissatisfaction and attrition are associated with increased healthcare costs, decreased patient satisfaction, reduced access to healthcare, and poor health quality and outcomes. As demand for healthcare exceeds the supply of physicians, particularly in cardiovascular medicine, the need for physician assistants (PAs) increases. As PAs assume more responsibility for meeting the cardiovascular needs of Americans, their job satisfaction will become increasingly important. Knowledge of job satisfaction among PAs practicing in cardiovascular medicine will be necessary to recruit and retain PAs. This study sought to assess overall job satisfaction and factors of job satisfaction among PAs practicing cardiovascular medicine in the United States. The findings can guide employers, healthcare administrators, and policy makers to optimize job satisfaction among PAs in cardiology. METHODS A quantitative descriptive study was conducted. The Misener Nurse Practitioner Job Satisfaction Scale (MNNPJS) was modified with permission to assess job satisfaction of PAs in cardiovascular medicine. The modified MNPJSS is a 45-item survey using a 6-point Likert scale with responses ranging from very satisfied to very dissatisfied. The survey measured overall job satisfaction, 45 factors of job satisfaction, and six composite factors of job satisfaction: intra-practice partnership/collegiality; challenge/autonomy; professional, social, and community interaction; professional growth; time; and benefits. Participants were recruited from the database of the Association of PAs in Cardiology. The A.T. Still University institutional review board approved the study. RESULTS Overall job satisfaction of PAs practicing in cardiology was high. Most (87.3%) PAs were satisfied or very satisfied. Just over 1% expressed overall job dissatisfaction. No correlation was found between overall job satisfaction and age, sex, race, years of experience, income, type of employer, practice setting, hours worked per week, the number of patients seen per week, or the number of on-call hours per week. PAs were most satisfied with job factors related to the composite factor challenge/autonomy and these factors had the greatest correlation with overall job satisfaction. Factors that had the strongest correlation with overall job satisfaction, by Spearman rho test, were sense of value for work done (r = 0.6), opportunity to expand scope of practice (r = 0.56), ability to expand skills/ procedures within scope of practice (r = 0.56), sense of accomplishment (r = 0.55), and supervising physician (r = 0.53). The level of autonomy was the factor of greatest satisfaction among respondents and correlated with overall satisfaction. CONCLUSIONS Job satisfaction among PAs in cardiology was high regardless of age, race, or sex. There was no difference in the level of satisfaction based on income, type of employer, practice setting, hours worked per week, the number of patients seen per week, or the number of on-call hours per week. Respondents were most satisfied with intrinsic factors of job satisfaction. Factors related to the composite factor of challenge/autonomy were associated with the greatest satisfaction and had the strongest correlation with overall job satisfaction. The level of autonomy was the factor of greatest satisfaction among respondents and correlated with overall satisfaction. This study provides insight into factors of job satisfaction among PAs. Findings may guide employers, healthcare administrators, and policy makers to increase PAs' autonomy and expand their scope of practice. The results can guide research about strategies to enhance intrinsic factors of job satisfaction to recruit and retain PAs. [ABSTRACT FROM AUTHOR]

Discusses the philosophy of French philosopher Maurice Merleau-Ponty. Views of Merleau-Ponty on science; Explanation of human action in terms of reasons; Connection of the philosophy Merleau-Ponty with ontology and metaphysics.