228 research outputs found
CCNS Response to LANL\u27s Letter of January 29, 2007 - Information Concerning Radionuclides in Water Supply Wells
Response by Concerned Citizens for Nuclear Safety (CCNS) to the January 29, 2007 letter from Andrew Phelps, Associate Director of Environmental Programs at Los Alamos National Laboratory (LANL) about reported detections of radionuclides in the Los Alamos County and the City of Santa Fe drinking water wells.
There are a number of supplemental files that accompany this document. They are:
January 29, 2007 Letter from LANL to CCNS - Information Concerning Radionuclides in Water Supply WellsAttachment 1: Predicted Plume Migration for Sources Releases at the Water Table Below Mortandad Canyon
Attachment 2: Data Gaps Prevent Accurate Calculation of Containment Travel Times by Computer Models
Attachment 3: DOE/LANL has Used Improper Fluid-Assisted Drilling Methods that Mask Detection of Groundwater Contamination for the Installation of the LANL Characterization Wells that are Planned to be Used as Monitoring Wells
Flyer: Downstream from Los Alamos? Your Drinking Water is at Risk (English)
Flyer: Downstream from Los Alamos? Your Drinking Water is at Risk (Spanish)
This research was completed money allocated during Round 5 of the Citizens’ Monitoring and Technical Assessment Fund (MTA Fund). Clark University was named conservator of these works.
If you have any questions or concerns please contact us at [email protected]://commons.clarku.edu/ccns/1002/thumbnail.jp
Geologic studies to identify the source for high levels of radium and barium in Illinois ground-water supplies: a preliminary report
Analyses of water from municipal wells in Illinois by the Illinois Environmental Protection Agency showed that more than 300 wells exceeded the upper limit, 3 picocuries/liter (U.S. Public Health Service, 1962), for gross alpha radiation in drinking water. More than 30 wells exceeded the upper limit, 1 milligram/liter (U.S. Public Health Service, 1962), for barium in drinking water. High levels of radiation in ground water were more extensive in areal distribution than the high levels of barium. All of the affected wells were finished in bedrock, primarily in rocks of the Cambrian and Ordovician Systems of northern Illinois. The geologic settings in which the high levels of radiation and barium were documented indicated that the problem was not restricted to Illinois.The source of the radiation in ground water was thought to be the natural occurrence of the radioactive elements.uranium-238 and thorium-232 in the aquifer rocks. Analyses of a limited number of rock samples indicated that uranium and thorium concentrations were highest in fine-grained sediments in the aquifer systems; the highest concentration was in shales that confine the aquifer.The occurrence of natural radioisotopes in ground water was thought to be complex, involving source rocks, ground water chemistry, and the hydraulic stress placed on the aquifer.Chemical analyses of rock samples indicated that high concentrations of barium were widespread in rocks of the Cambrian and Ordovician Systems. The concentration of barium in ground water was controlled by solubility equilibria reactions with sulfate ion. A map showing sulfate ion concentration in the Cambrian-Ordovician Aquifer could be used to delimit regions where barium might occur at concentrations exceeding 1 milligram/liter.U.S. Department of the InteriorU.S. Geological Surve
Massive pericardial hematoma simulating constrictive pericarditis: a complication of radiofrequency catheter ablation
AbstractJ Thorac Cardiovasc Surg 1998;115:726-
Isotopic and geologic studies to identify the sources of sulfate in groundwater containing high barium concentrations
"Final report, project no. A-100-I11.""November 1981"--P. 1 of cover.Bibliography: p. 36-39."UILU-WRC-81-0165"--P. 1 of cover
Stroke Severity Predicted by Aortic Atheroma Detected by Ultra-Fast and Cardiac-Gated Chest Tomography†
Background and Purpose: The presence of aortic atherosclerosis is an independent risk factor for secondary stroke. The present study was designed to have an initial exploration of the correlation between the load and extent of aortic atheroma (AA) and initial stroke severity or clinical outcome 3 months after stroke. Methods: Cardiac-gated chest tomography (CGCT) was used to detect and measure AA in patients with acute ischemic stroke as shown by our group in prior prospective studies and this is part four sub-exploratory study of the same cohort. The National Institute of Health Stroke Scale (NIHSS) was used to assess the initial stroke severity, and the modified Rankin Scale (mRS) was used to assess 3-month outcome. Results: Thirty-two patients underwent CGCT for evaluation of AA, and 21 were found to have AA. AA was more prevalent in patient with NIHSS >6 (14/17 versus 7/15, p-value 0.03). Applying the multiple logistic regression and propensity score adjustment (using the propensity of having AA given the baseline features as covariates) showed a non-significant trend that AA is three times more likely to be associated with NIHSS >6 (p = 0.08, OR 3.08, 95% CI 0.94–13.52). There was no evidence of association of AA with 3-month functional outcome (mRS): 11/14 (78.6%) mRS >1 had AA, and 10/18 (55.5%) of those with mRS ≤1 had AA (p = 0.27). Conclusion: In our current study with limited sample number and exploratory nature, the presence of AA on CGCT with acute ischemic stroke patients may be associated with worse neurological deficit at presentation. There was no evidence of association with 3-month functional outcome using the mRS
Evaluation of left ventricular ejection fraction using through-time radial GRAPPA
BACKGROUND: The determination of left ventricular ejection fraction using cardiovascular magnetic resonance (CMR) requires a steady cardiac rhythm for electrocardiogram (ECG) gating and multiple breathholds to minimize respiratory motion artifacts, which often leads to scan times of several minutes. The need for gating and breathholding can be eliminated by employing real-time CMR methods such as through-time radial GRAPPA. The aim of this study is to compare left ventricular cardiac functional parameters obtained using current gold-standard breathhold ECG-gated functional scans with non-gated free-breathing real-time imaging using radial GRAPPA, and to determine whether scan time or the occurrence of artifacts are reduced when using this real-time approach. METHODS: 63 patients were scanned on a 1.5T CMR scanner using both the standard cardiac functional examination with gating and breathholding and the real-time method. Total scan durations were noted. Through-time radial GRAPPA was employed to reconstruct images from the highly accelerated real-time data. The blood volume in the left ventricle was assessed to determine the end systolic volume (ESV), end diastolic volume (EDV), and ejection fraction (EF) for both methods, and images were rated for the presence of artifacts and quality of specific image features by two cardiac readers. Linear regression analysis, Bland-Altman plots and two-sided t-tests were performed to compare the quantitative parameters. A two-sample t-test was performed to compare the scan durations, and a two-sample test of proportion was used to analyze the presence of artifacts. For the reviewers´ ratings the Wilcoxon test for the equality of the scores’ distributions was employed. RESULTS: The differences in EF, EDV, and ESV between the gold-standard and real-time methods were not statistically significant (p-values of 0.77, 0.82, and 0.97, respectively). Additionally, the scan time was significantly shorter for the real-time data collection (p<0.001) and fewer artifacts were reported in the real-time images (p<0.01). In the qualitative image analysis, reviewers marginally preferred the standard images although some features including cardiac motion were equivalently rated. CONCLUSION: Real-time functional CMR with through-time radial GRAPPA performed without ECG-gating under free-breathing can be considered as an alternative to gold-standard breathhold cine imaging for the evaluation of ejection fraction in patients
Ultra-low dose contrast CT pulmonary angiography in oncology patients using a high-pitch helical dual-source technology
PURPOSEWe aimed to determine if the image quality and vascular enhancement are preserved in computed tomography pulmonary angiography (CTPA) studies performed with ultra-low contrast and optimized radiation dose using high-pitch helical mode of a second generation dual source scanner.METHODSWe retrospectively evaluated oncology patients who had CTPA on a 128-slice dual-source scanner, with a high-pitch helical mode (3.0), following injection of 30 mL of Ioversal at 4 mL/s with body mass index (BMI) dependent tube potential (80–120 kVp) and current (130–150 mAs). Attenuation, noise, and signal-to-noise ratio (SNR) were measured in multiple pulmonary arteries. Three independent readers graded the images on a 5-point Likert scale for central vascular enhancement (CVE), peripheral vascular enhancement (PVE), and overall quality.RESULTSThere were 50 males and 101 females in our study. BMI ranged from 13 to 38 kg/m2 (22.8±4.4 kg/m2). Pulmonary embolism was present in 29 patients (18.9%). Contrast enhancement and SNR were excellent in all the pulmonary arteries (395.3±131.1 and 18.3±5.7, respectively). Image quality was considered excellent by all the readers, with average reader scores near the highest possible score of 5.0 (CVE, 4.83±0.48; PVE, 4.68±0.65; noise/quality, 4.78±0.47). The average radiation dose length product (DLP) was 161±60 mGy.cm.CONCLUSIONUsing a helical high-pitch acquisition technique, CTPA images of excellent diagnostic quality, including visualization of peripheral segmental/sub-segmental branches can be obtained using an ultra-low dose of iodinated contrast and low radiation dose
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