236 research outputs found
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Increasing TRUPACT-II wattage limits: two technical approaches
More than one-third of the drums in DOE`s TRU waste inventory cannot be presently shipped to WIPP in the TRUPACT-11 because they exceed the allowed limit of heat generation by virtue of radioactive decay. This limit was imposed to ensure that the amount of hydrogen generated by radiolysis does not achieve the lower explosive limit of hydrogen in air (5 percent v/v). Los Alamos is working to justify increasing these wattage limits: (1) by demonstrating that the phenomenon of matrix depletion greatly reduces the potential for hydrogen generation and (2) by investigating the use hydrogen getters to actively remove hydrogen from the headspace of the waste drums and/or the TRUPACT-11
Uniformity in the Wiener-Wintner theorem for nilsequences
We prove a uniform extension of the Wiener-Wintner theorem for nilsequences
due to Host and Kra and a nilsequence extension of the topological
Wiener-Wintner theorem due to Assani. Our argument is based on (vertical)
Fourier analysis and a Sobolev embedding theorem.Comment: v3: 18 p., proof that the cube construction produces compact
homogeneous spaces added, measurability issues in the proof of Theorem 1.5
addressed. We thank the anonymous referees for pointing out these gaps in v
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Patient Dependence and Longitudinal Changes in Costs of Care in Alzheimer's Disease
BACKGROUND/AIMS: To examine the incremental effect of patients' dependence on others, on cost of medical and nonmedical care, and on informal caregiving hours over time. METHODS: Data are obtained from 172 patients from the Predictors Study, a large, multicenter cohort of patients with probable Alzheimer disease (AD) followed annually for 4 years in 3 University-based AD centers in the USA. Enrollment required a modified Mini-Mental State Examination score >or=30. We examined the effects of patient dependence (measured by the Dependence Scale, DS) and function (measured by the Blessed Dementia Rating Scale, BDRS) on medical care cost, nonmedical care cost, and informal caregiving time using random effects regression models. RESULTS: A one-point increase in DS score was associated with a 5.7% increase in medical cost, a 10.5% increase in nonmedical cost, and a 4.1% increase in caregiving time. A one-point increase in BDRS score was associated with a 7.6% increase in medical cost, a 3.9% increase in nonmedical cost and an 8.7% increase in caregiving time. CONCLUSIONS: Both functional impairment and patient dependence were associated with higher costs of care and caregiving time. Measures of functional impairment and patient dependence provide unique and incremental information on the overall impact of AD on patients and their caregivers
Eurasian Arctic greening reveals teleconnections and the potential for novel ecosystems
Arctic warming has been linked to observed increases in tundra shrub cover and growth in recent decades on the basis of significant relationships between deciduous shrub growth/biomass and temperature. These vegetation trends have been linked to Arctic sea ice decline and thus to the sea ice/albedo feedback known as Arctic amplification. However, the interactions between climate, sea ice and tundra vegetation remain poorly understood. Here we reveal a 50- year growth response over a >100,000 km2 area to a rise in summer temperature for alder (Alnus) and willow (Salix), the most abundant shrub genera respectively at and north of the continental treeline. We demonstrate that whereas plant productivity is related to sea ice in late spring, the growing season peak responds to persistent synoptic-scale air masses over West Siberia associated with Fennoscandian weather systems through the Rossby wave train. Substrate is important for biomass accumulation, yet a strong correlation between growth and temperature encompasses all observed soil types. Vegetation is especially responsive to temperature in early summer. These results have significant implications for modelling present and future Low Arctic vegetation responses to climate change, and emphasize the potential for structurally novel ecosystems to emerge fromwithin the tundra zone.Vertaisarviointia edeltävä käsikirjoitu
Inter- and intraobserver reliability of the MTM-classification for proximal humeral fractures: A prospective study
<p>Abstract</p> <p>Background</p> <p>A precise modular topographic-morphological (MTM) classification for proximal humeral fractures may address current classification problems. The classification was developed to evaluate whether a very detailed classification exceeding the analysis of fractured parts may be a valuable tool.</p> <p>Methods</p> <p>Three observers classified plain radiographs of 22 fractures using both a simple version (fracture displacement, number of parts) and an extensive version (individual topographic fracture type and morphology) of the MTM classification. Kappa-statistics were used to determine reliability.</p> <p>Results</p> <p>An acceptable reliability was found for the simple version classifying fracture displacement and fractured main parts. Fair interobserver agreement was found for the extensive version with individual topographic fracture type and morphology.</p> <p>Conclusion</p> <p>Although the MTM-classification covers a wide spectrum of fracture types, our results indicate that the precise topographic and morphological description is not delivering reproducible results. Therefore, simplicity in fracture classification may be more useful than extensive approaches, which are not adequately reliable to address current classification problems.</p
Esophagectomy without mortality: What can surgeons do?
Introduction: Surgical resection remains the mainstay treatment for patients with localized esophageal cancer. It is, however, a complex procedure. Mortality rate used to be high, but in recent years, death rate has been reduced to below 5% in specialized centers. Methods: Outcome of esophagectomy can be improved by paying attention to (1) appropriate patient section, (2) choice of surgical techniques and their execution, and (3) optimizing perioperative care. A volume-outcome relationship is also evident. Surgeons can perform esophagectomy without mortality, but a multi-disciplinary team management is essential to achieve this goal. © 2009 The Society for Surgery of the Alimentary Tract.postprin
Assessment of the risk of cardiovascular complications in workers of the converter shop of the metallurgical plant
The purpose of the study is to determine the factors influencing the possible development of cardiovascular complications in workers of the converter shop of the metallurgical combine.Цель исследования – определить факторы, влияющие на возможное развитие сердечно-сосудистых осложнений у работников конвертерного цеха металлургического комбината
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