96 research outputs found
Development of a simulated lung fluid leaching method to assess the release of potentially toxic elements from volcanic ash
Freshly erupted volcanic ash contains a range of soluble elements, some of which can generate harmful effects in living cells and are considered potentially toxic elements (PTEs). This work investigates the leaching dynamics of ash-associated PTEs in order to optimize a method for volcanic ash respiratory hazard assessment. Using three pristine (unaffected by precipitation) ash samples, we quantify the release of PTEs (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, V, Zn) and major cations typical of ash leachates (Mg, Na, Ca, K) in multiple simulated lung fluid (SLF) preparations and under varying experimental parameters (contact time and solid to liquid ratio). Data are compared to a standard water leach (WL) to ascertain whether the WL can be used as a simple proxy for SLF leaching. The main findings are: PTE concentrations reach steady-state dissolution by 24 h, and a relatively short contact time (10 min) approximates maximum dissolution; PTE dissolution is comparatively stable at low solid to liquid ratios (1:100 to 1:1000); inclusion of commonly used macromolecules has element-specific effects, and addition of a lung surfactant has little impact on extraction efficiency. These observations indicate that a WL can be used to approximate lung bioaccessible PTEs in an eruption response situation. This is a useful step towards standardizing in vitro methods to determine the soluble-element hazard from inhaled ash
History and Applications of Dust Devil Studies
Studies of dust devils, and their impact on society, are reviewed. Dust devils have been noted since antiquity, and have been documented in many countries, as well as on the planet Mars. As time-variable vortex entities, they have become a cultural motif. Three major stimuli of dust devil research are identified, nuclear testing, terrestrial climate studies, and perhaps most significantly, Mars research. Dust devils present an occasional safety hazard to light structures and have caused several deaths
A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)
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Population ecology of the sea lamprey (Petromyzon marinus) as an invasive species in the Laurentian Great Lakes and an imperiled species in Europe
The sea lamprey Petromyzon marinus (Linnaeus) is both an invasive non-native species in the Laurentian Great Lakes of North America and an imperiled species in much of its native range in North America and Europe. To compare and contrast how understanding of population ecology is useful for control programs in the Great Lakes and restoration programs in Europe, we review current understanding of the population ecology of the sea lamprey in its native and introduced range. Some attributes of sea lamprey population ecology are particularly useful for both control programs in the Great Lakes and restoration programs in the native range. First, traps within fish ladders are beneficial for removing sea lampreys in Great Lakes streams and passing sea lampreys in the native range. Second, attractants and repellants are suitable for luring sea lampreys into traps for control in the Great Lakes and guiding sea lamprey passage for conservation in the native range. Third, assessment methods used for targeting sea lamprey control in the Great Lakes are useful for targeting habitat protection in the native range. Last, assessment methods used to quantify numbers of all life stages of sea lampreys would be appropriate for measuring success of control in the Great Lakes and success of conservation in the native range
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SAS4A validation and analysis of in-pile TUCOP experiments
This paper presents the results of SAS4A analysis for PFR/TREAT experiment L07, a simulated TUCOP accident. This is one of a series of TUCOP tests with different channel conditions at pin failure time and different power burst shapes. While other TUCOP tests such as L6 and L7 have been analyzed with earlier versions of the SAS code, the L07 analysis is the first to use the release version of SAS4A without special modifications, using recommended values of the input variables whenever possible. The PRIMAR-4 thermal-hydraulic model is used to compute the loop characteristics during the test
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SAS validation and analysis of in-pile TUCOP experiments
The validation of the SAS4A accident analysis code centers on its capability to calculate the wide range of tests performed in the TREAT (Transient Reactor Test Facility) in-pile experiments program. This paper presents the SAS4A analysis of a simulated TUCOP (Transient-Under-Cooled-Over-Power) experiment using seven full-length PFR mixed oxide fuel pins in a flowing sodium loop. Calculations agree well with measured thermal-hydraulic, pin failure time and post-failure fuel motion data. The extent of the agreement confirms the validity of the models used in the SAS4A code to describe TUCOP accidents
Helping Beginning Supervisors Reduce Barriers to Licensure: Ethical Roadblocks in Supervision
Ethical and competent supervision are critical to successful entry into the profession for counselors in training and newly licensed counselors. New supervisors should be mindful of the mistakes even well-intentioned supervisors can make that jeopardize the licensure process, or worse, the well-being of clients. Lack of attention to substantial supervision paperwork requirements can cost supervisees long delays in licensure, and call into question a supervisor’s reputation as a competent and ethical professional. The purpose of this article is to help inform beginning supervisors on how to use ethical guidelines to avoid some of the most common supervision pitfalls, including multiple relationships, the use of technology in supervision, documentation requirements, and gatekeeping responsibilities
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