Dam Breach Analysis for Urbanizing Basins

Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.Development downstream of old and in many cases deficient, dams is responsible for a growing concern within communities that are transitioning from a rural to suburban environment. There are instances of permitted development being constructed in the shadow of a dam embankment without regard to the potential consequences from a dam failure. Loss of life is a real and sobering risk if a home is built in a potential dam breach zone. In Georgia, many of the dams in formerly rural areas do not fall under the regulatory oversight of the Georgia Safe Dams Program simply because they are smaller than the minimum size necessary by law to bring them into the Program. This does not diminish their potential for causing damage in the event of a breach. It is therefore imperative for development to account for the potential breach zone of even the smallest dams if they present a potential threat to downstream lives and structures. However, many breach zone delineation models are cumbersome and difficult to use, even for the most experienced modelers. It is therefore expensive to contract for that work, and as a result, modeling is often omitted. If a breach zone is delineated by a rough approximation, there is the potential to remove from development projects a substantial, and probably overestimated, portion of the usable land, thereby unnecessarily reducing the investment return for the developer. GIS and HEC-RAS offer a cost-effective and quick method to delineate a reasonable and effective potential dam breach zone. Through the use of a set of simple, but effective techniques, a breach zone can be defined for a reasonable cost that will protect lives and property, but not unduly impact the investment return potential for the development.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors

NlpC/P60 domain-containing proteins of Mycobacterium avium subspecies paratuberculosis that differentially bind and hydrolyze peptidoglycan

A subset of proteins containing NlpC/P60 domains are bacterial peptidoglycan hydrolases that cleave noncanonical peptide linkages and contribute to cell wall remodeling as well as cell separation during late stages of division. Some of these proteins have been shown to cleave peptidoglycan in Mycobacterium tuberculosis and play a role in Mycobacterium marinum virulence of zebra fish; however, there are still significant knowledge gaps concerning the molecular function of these proteins in Mycobacterium avium subspecies paratuberculosis (MAP). The MAP genome sequence encodes five NlpC/P60 domain-containing proteins. We describe atomic resolution crystal structures of two such MAP proteins, MAP_1272c and MAP_1204. These crystal structures, combined with functional assays to measure peptidoglycan cleavage activity, led to the observation that MAP_1272c does not have a functional catalytic core for peptidoglycan hydrolysis. Furthermore, the structure and sequence of MAP_1272c demonstrate that the catalytic residues normally required for hydrolysis are absent, and the protein does not bind peptidoglycan as efficiently as MAP_1204. While the NlpC/P60 catalytic triad is present in MAP_1204, changing the catalytic cysteine-155 residue to a serine significantly diminished catalytic activity, but did not affect binding to peptidoglycan. Collectively, these findings suggest a broader functional repertoire for NlpC/P60 domain-containing proteins than simply hydrolases

Extensive microbial and functional diversity within the chicken cecal microbiome

Chickens are major source of food and protein worldwide. Feed conversion and the health of chickens relies on the largely unexplored complex microbial community that inhabits the chicken gut, including the ceca. We have carried out deep microbial community profiling of the microbiota in twenty cecal samples via 16S rRNA gene sequences and an in-depth metagenomics analysis of a single cecal microbiota. We recovered 699 phylotypes, over half of which appear to represent previously unknown species. We obtained 648,251 environmental gene tags (EGTs), the majority of which represent new species. These were binned into over two-dozen draft genomes, which included Campylobacter jejuni and Helicobacter pullorum. We found numerous polysaccharide- and oligosaccharide-degrading enzymes encoding within the metagenome, some of which appeared to be part of polysaccharide utilization systems with genetic evidence for the co-ordination of polysaccharide degradation with sugar transport and utilization. The cecal metagenome encodes several fermentation pathways leading to the production of short-chain fatty acids, including some with novel features. We found a dozen uptake hydrogenases encoded in the metagenome and speculate that these provide major hydrogen sinks within this microbial community and might explain the high abundance of several genera within this microbiome, including Campylobacter, Helicobacter and Megamonas

Conserved Genes Act as Modifiers of Invertebrate SMN Loss of Function Defects

Spinal Muscular Atrophy (SMA) is caused by diminished function of the Survival of Motor Neuron (SMN) protein, but the molecular pathways critical for SMA pathology remain elusive. We have used genetic approaches in invertebrate models to identify conserved SMN loss of function modifier genes. Drosophila melanogaster and Caenorhabditis elegans each have a single gene encoding a protein orthologous to human SMN; diminished function of these invertebrate genes causes lethality and neuromuscular defects. To find genes that modulate SMN function defects across species, two approaches were used. First, a genome-wide RNAi screen for C. elegans SMN modifier genes was undertaken, yielding four genes. Second, we tested the conservation of modifier gene function across species; genes identified in one invertebrate model were tested for function in the other invertebrate model. Drosophila orthologs of two genes, which were identified originally in C. elegans, modified Drosophila SMN loss of function defects. C. elegans orthologs of twelve genes, which were originally identified in a previous Drosophila screen, modified C. elegans SMN loss of function defects. Bioinformatic analysis of the conserved, cross-species, modifier genes suggests that conserved cellular pathways, specifically endocytosis and mRNA regulation, act as critical genetic modifiers of SMN loss of function defects across species

A model for technology assessment and commercialization for innovative disruptive technologies

Disruptive technologies are scientific discoveries that break through the usual product technology capabilities and provide a basis for a new competitive paradigm as described by Anderson and Tushman [1990], Tushman and Rosenkopf [1992], and Bower and Christensen [1995]. Discontinuous innovations are products/processes/services that provide exponential improvements in the value received by the customer much in the same vein as Walsh [1996], Lynn, Morone and Paulson [1996], and Veryzer [1998]. For more on definitions of disruptive technologies and discontinuous innovations, see Walsh and Linton [1999] who provide a number of definitions for disruptive technologies and discontinuous innovations. Disruptive technologies and discontinuous innovations present a unique challenge and opportunity for R and D organizations seeking to build their commercialization efforts and to reinvent the corporation. These technologies do not have a proven path from scientific discovery to mass production and therefore require novel approaches. These critically important technologies are the wellspring of wealth creation and new competency generation but are not readily accepted by the corporate community. They are alternatively embraced and eschewed by the commercial community. They are finally accepted when the technology has already affected the industry or when the technological horse has already flown out of the hanger. Many firms, especially larger firms, seem reluctant to familiarize themselves with these technologies quickly. The trend seems to be that these firms prefer to react to a proven disruptive technology that has changed the product market paradigm. If true, then there is cause for concern. This paper will review the literature on disruptive technologies presenting a model of the progression from scientific idea to mass production for disruptive technologies contrasted to the more copious incremental technologies. The paper will then describe Sandia National Laboratories' involvement in one of the disruptive technology areas, namely micro-electromechanical systems (sometimes referred to as Microsystems or MEMS) and will survey a number of companies that have investigated Sandia's technological discoveries for potential use in an industrial capacity. The survey will focus on the movement of the research findings from the laboratory into the marketplace and all of the problem areas that disruptive technologies face in this arena. The paper will then state several hypotheses that will be tested. The data will be described with results and conclusions reported

Research needs for mining and industrial solid waste disposal

Report of a workshop held at Colorado State University, Fort Collins, Colorado, July 22 and 23, 1976.CER76-77JN13.Under the sponsorship of the National Science Foundation, through the initiative of the Embankment Dams and Slopes Committee of ASCE; NSF Grant No. ENG 76-09380