Effectiveness of Various CCR Unit Closure Strategies

Power utilities are increasingly challenged by regulatory agencies to implement remediation strategies that are able to anticipate long-term changes to groundwater quality in response to closure activities. However, unanticipated changes to site geochemistry during closure can have unforeseen impacts leading to groundwater impairments caused by leaching of coal combustion residual (CCR) constituents. In some cases, the cessation of recharge flux may even further inhibit the natural rehabilitation of a site by further shifting it from the pre-existing conditions. Here we present an evaluation of multiple closure scenarios where 3-D reactive geochemical modeling was used to evaluate constituent flux and concentration downgradient of the unit undergoing closure. Modeling identified that there was no measurable difference in time to achieve compliance at downgradient monitoring wells when comparing 90% to 100% ash removal. Additionally, modeling identified the current regulator-approved closure approach of 90% closure-by-removal with the addition of a cap on the CCR unit results in an equal if not better reduction in flux and improvement in groundwater quality than 100% closure-by-removal. Thus, the current regulator-approved strategy is the most appropriate for achieving groundwater compliance

Quantifying innovation in surgery

Objectives: The objectives of this study were to assess the applicability of patents and publications as metrics of surgical technology and innovation; evaluate the historical relationship between patents and publications; develop a methodology that can be used to determine the rate of innovation growth in any given health care technology. Background: The study of health care innovation represents an emerging academic field, yet it is limited by a lack of valid scientific methods for quantitative analysis. This article explores and cross-validates 2 innovation metrics using surgical technology as an exemplar. Methods: Electronic patenting databases and the MEDLINE database were searched between 1980 and 2010 for “surgeon” OR “surgical” OR “surgery.” Resulting patent codes were grouped into technology clusters. Growth curves were plotted for these technology clusters to establish the rate and characteristics of growth. Results: The initial search retrieved 52,046 patents and 1,801,075 publications. The top performing technology cluster of the last 30 years was minimally invasive surgery. Robotic surgery, surgical staplers, and image guidance were the most emergent technology clusters. When examining the growth curves for these clusters they were found to follow an S-shaped pattern of growth, with the emergent technologies lying on the exponential phases of their respective growth curves. In addition, publication and patent counts were closely correlated in areas of technology expansion. Conclusions: This article demonstrates the utility of publically available patent and publication data to quantify innovations within surgical technology and proposes a novel methodology for assessing and forecasting areas of technological innovation

Next-Generation High-Resolution Methods for Site Characterization

Next-Generation High-Resolution Methods for Site Characterization Authors Dr. PJ Nolan - United States - WSP USA Mr. Cole Mayer - United States - WSP USA Ms. Dawn Prell - United States - WSP USA Dr. Rens Verburg - United States - WSP USA Abstract The requirements from regulatory agencies and other stakeholders to provide more robust site characterization when entering remedial action or developing alternative source demonstrations (ASDs) at Coal Combustion Product (CCP) sites have increased in recent years. In many cases, the current mainstream site characterization methods used for these efforts fail to meet those requirements. Here, we demonstrate that next-generation high-resolution methods commonly used in the mining industry and academic research are valuable tools for site characterization at CCP sites. X-Ray Adsorption Spectroscopy (XAS), utilizing a synchrotron, was applied to determine elemental valence state and speciation/mineral phase association, conclusively proving the provenance and natural occurrence of multiple CCP constituents at a site. Another method, Tescan Integrated Mineral Analysis (TIMA) coupled to Laser-Ablation Inductively Coupled Mass Spectrometry (LA-ICPMS), maps a geological thin section before targeted laser ablation determines the elements associated with specific mineral phases. Using this method, we demonstrated the natural presence of elevated lithium within the structure of specific clay minerals, which is not possible using traditional analytical methods. Thus, the advantage of adopting high-resolution, next-generation methods for use in the CCP industry is clear. These methods enable power utilities to have greater clarity moving into remedial action and provide the site characterization information necessary to meet the increasing stakeholder expectations

Liver-specific activation of AMPK prevents steatosis on a high fructose diet

AMP-activated protein kinase (AMPK) plays a key role in integrating metabolic pathways in response to energy demand. We identified a mutation in the γ1 subunit (γ1D316A) that leads to activation of AMPK. We generated mice with this mutation to study the effect of chronic liver-specific activation of AMPK in vivo. Primary hepatocytes isolated from these mice have reduced gluconeogenesis and fatty acid synthesis, but there is no effect on fatty acid oxidation compared to cells from wild-type mice. Liver-specific activation of AMPK decreases lipogenesis in vivo and completely protects against hepatic steatosis when mice are fed a high-fructose diet. Our findings demonstrate that liver-specific activation of AMPK is sufficient to protect against hepatic triglyceride accumulation, a hallmark of non-alcoholic fatty liver disease (NAFLD). These results emphasize the clinical relevance of activating AMPK in the liver to combat NAFLD and potentially other associated complications (e.g., cirrhosis and hepatocellular carcinoma)

Escape rate and Hausdorff measure for entire functions

The escaping set of an entire function is the set of points that tend to infinity under iteration. We consider subsets of the escaping set defined in terms of escape rates and obtain upper and lower bounds for the Hausdorff measure of these sets with respect to certain gauge functions.Comment: 24 pages; some errors corrected, proof of Theorem 2 shortene

Electronic stress tensor analysis of hydrogenated palladium clusters

We study the chemical bonds of small palladium clusters Pd_n (n=2-9) saturated by hydrogen atoms using electronic stress tensor. Our calculation includes bond orders which are recently proposed based on the stress tensor. It is shown that our bond orders can classify the different types of chemical bonds in those clusters. In particular, we discuss Pd-H bonds associated with the H atoms with high coordination numbers and the difference of H-H bonds in the different Pd clusters from viewpoint of the electronic stress tensor. The notion of "pseudo-spindle structure" is proposed as the region between two atoms where the largest eigenvalue of the electronic stress tensor is negative and corresponding eigenvectors forming a pattern which connects them.Comment: 22 pages, 13 figures, published online, Theoretical Chemistry Account

A Close Nuclear Black Hole Pair in the Spiral Galaxy NGC 3393

The current picture of galaxy evolution advocates co-evolution of galaxies and their nuclear massive black holes (MBHs), through accretion and merging. Quasar pairs (6,000-300,000 light-years separation) exemplify the first stages of this gravitational interaction. The final stages, through binary MBHs and final collapse with gravitational wave emission, are consistent with the sub-light-year separation MBHs inferred from optical spectra and light-variability of two quasars. The double active nuclei of few nearby galaxies with disrupted morphology and intense star formation (e.g., NGC 6240 and Mkn 463; ~2,400 and ~12,000 light-years separation respectively) demonstrate the importance of major mergers of equal mass spirals in this evolution, leading to an elliptical galaxy, as in the case of the double radio nucleus (~15 light-years separation) elliptical 0402+379. Minor mergers of galaxies with a smaller companion should be a more common occurrence, evolving into spiral galaxies with active MBH pairs, but have hitherto not been seen. Here we report the presence of two active MBHs, separated by ~430 light-years, in the Seyfert galaxy NGC 3393. The regular spiral morphology and predominantly old circum-nuclear stellar population of this galaxy, and the closeness of the MBHs embedded in the bulge, suggest the result of minor merger evolution.Comment: Preprint (not final) version of a paper to appear in Natur

High-order chromatin architecture determines the landscape of chromosomal alterations in cancer

The rapid growth of cancer genome structural information provides an opportunity for a better understanding of the mutational mechanisms of genomic alterations in cancer and the forces of selection that act upon them. Here we test the evidence for two major forces, spatial chromosome structure and purifying (or negative) selection, that shape the landscape of somatic copy-number alterations (SCNAs) in cancer1. Using a maximum likelihood framework we compare SCNA maps and three-dimensional genome architecture as determined by genome-wide chromosome conformation capture (HiC) and described by the proposed fractal-globule (FG) model2. This analysis provides evidence that the distribution of chromosomal alterations in cancer is spatially related to three-dimensional genomic architecture and additionally suggests that purifying selection as well as positive selection shapes the landscape of SCNAs during somatic evolution of cancer cells