Identification of Novel Methane-, Ethane-, and Propane-Oxidizing Bacteria at Marine Hydrocarbon Seeps by Stable Isotope Probing

Marine hydrocarbon seeps supply oil and gas to microorganisms in sediments and overlying water. We used stable isotope probing (SIP) to identify aerobic bacteria oxidizing gaseous hydrocarbons in surface sediment from the Coal Oil Point seep field located offshore of Santa Barbara, California. After incubating sediment with ^(13)C-labeled methane, ethane, or propane, we confirmed the incorporation of ^(13)C into fatty acids and DNA. Terminal restriction fragment length polymorphism (T-RFLP) analysis and sequencing of the 16S rRNA and particulate methane monooxygenase (pmoA) genes in ^(13)C-DNA revealed groups of microbes not previously thought to contribute to methane, ethane, or propane oxidation. First, ^(13)C methane was primarily assimilated by Gammaproteobacteria species from the family Methylococcaceae, Gammaproteobacteria related to Methylophaga, and Betaproteobacteria from the family Methylophilaceae. Species of the latter two genera have not been previously shown to oxidize methane and may have been cross-feeding on methanol, but species of both genera were heavily labeled after just 3 days. pmoA sequences were affiliated with species of Methylococcaceae, but most were not closely related to cultured methanotrophs. Second, ^(13)C ethane was consumed by members of a novel group of Methylococcaceae. Growth with ethane as the major carbon source has not previously been observed in members of the Methylococcaceae; a highly divergent pmoA-like gene detected in the ^(13)C-labeled DNA may encode an ethane monooxygenase. Third, ^(13)C propane was consumed by members of a group of unclassified Gammaproteobacteria species not previously linked to propane oxidation. This study identifies several bacterial lineages as participants in the oxidation of gaseous hydrocarbons in marine seeps and supports the idea of an alternate function for some pmoA-like genes

Feasibility of Simulation to Teach High-Alert Medication Safety

High-alert medications (HAMs) pose a significant risk to patient safety. Nurses are in a unique position to identify and prevent HAM errors before they occur. There is insufficient research on the most effective ways to improve safety when nurses are caring for patients receiving high-alert medications. Simulation-based learning (SBL) has been recommended as a strategy to help decrease HAM errors, but evidence specific to simulation and HAM safety is extremely limited. This dissertation begins the process of addressing this need. Three manuscripts are included in this dissertation. The first manuscript is an integrative review of literature on the use of SBL to improve safe performance of medication administration and decrease medication errors by nurses and nursing students. In the second manuscript, the perspectives of practicing registered nurses on factors that support or interfere with safe administration of HAMs were evaluated through a qualitative descriptive study. Finally, findings from the qualitative descriptive study informed the development of two HAM simulation scenarios. The simulations were evaluated within a feasibility study on the use of a SBL on HAM safety with nursing students. Findings of this dissertation provide the groundwork for future interventional research into the effect of SBL on HAM safety outcomes

The necessity of Darwin

© 2009 Stanley K. Sessions and Herbert C. Macgregor. This document is licensed to the public under the Creative Commons Attribution 3.0 License (http://creativecommons.org/licenses/by/3.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.February 12th, 2009 was Charles Darwin’s 200th birthday, and November 2009 represents the 150th anniversary of the publication of his transformative book, The Origin of Species. It seems a good time to look back and assess Darwin’s legacy within the perspective of current knowledge of genetics, cytogenetics, and molecular biology in general. Although a comprehensive understanding of evolution would no doubt have emerged eventually, it is difficult to imagine how anyone could have matched Darwin’s prodigious and sustained efforts, as well as his talent for explaining things in simple terms

Hopanoids Play a Role in Membrane Integrity and pH Homeostasis in Rhodopseudomonas palustris TIE-1

Sedimentary hopanes are pentacyclic triterpenoids that serve as biomarker proxies for bacteria and certain bacterial metabolisms, such as oxygenic photosynthesis and aerobic methanotrophy. Their parent molecules, the bacteriohopanepolyols (BHPs), have been hypothesized to be the bacterial equivalent of sterols. However, the actual function of BHPs in bacterial cells is poorly understood. Here, we report the physiological study of a mutant in Rhodopseudomonas palustris TIE-1 that is unable to produce any hopanoids. The deletion of the gene encoding the squalene-hopene cyclase protein (Shc), which cyclizes squalene to the basic hopene structure, resulted in a strain that no longer produced any polycyclic triterpenoids. This strain was able to grow chemoheterotrophically, photoheterotrophically, and photoautotrophically, demonstrating that hopanoids are not required for growth under normal conditions. A severe growth defect, as well as significant morphological damage, was observed when cells were grown under acidic and alkaline conditions. Although minimal changes in shc transcript expression were observed under certain conditions of pH shock, the total amount of hopanoid production was unaffected; however, the abundance of methylated hopanoids significantly increased. This suggests that hopanoids may play an indirect role in pH homeostasis, with certain hopanoid derivatives being of particular importance

MANAGEMENT STRATEGY, INVESTMENT IN IT, AND PRODUCTIVITY

Previous literature on IT and productivity does not take into account different organizational goals and different management strategies for achieving these goals. But productivity and ROI relationships can easily differ as organizational goals and management strategies differ. Therefore, we argue, it is no longer appropriate to ask, "Does IT lead to productivity enhancement." or "Is the ROI on IT investments large or small or nonexistent? The better question is under what conditions of organizational climate and management choice does IT enhanced productivity result. To illustrate the powerful effect of organizational goals and management strategy on IT-productivity relationships, we examine the twenty year history of two of the largest IT users in the world: the Internal Revenue Service and the Social Security Administration. And we find that these two very similar agencies experienced very different results from massive investments in IT despite sharing a similar production function. There is nothing in micro economics however to explain the different strategies pursed by these managers. Instead we must turn to political and sociological models of organizations to understand the social construction of productivity results.Information Systems Working Papers Serie

What Explains the Incidence of the Use of a Common Sediment Control on Lots with Houses Under Construction?

To analyze compliance with one aspect of the regulation of stormwater discharge, we estimate a random-utility model of the probability that a builder uses a silt fence to control sediments on a lot with a house under construction in an urbanizing county of South Carolina. The probability increases if the builder is responsible to the subdivision’s developer or if a homeowners association exists. The probability also increases as the cost to install a silt fence decreases or the number of houses under construction per built house in a subdivision increases. The results can help county officials target inspection to improve compliance.compliance with regulation, erosion and sediment control, filter fabric, management of stormwater runoff, random-utility model, silt fence, storm water pollution prevention plan, Agribusiness, Community/Rural/Urban Development, Demand and Price Analysis, Environmental Economics and Policy, Industrial Organization, Land Economics/Use, Q01, Q24, Q53, Q58,

Using A Digital Planetarium For Teaching Seasons To Undergraduates

Computer-generated simulations and visualizations in digital planetariums have the potential to bridge the comprehension gap in astronomy education. Concepts involving three-dimensional spatial relationships can be difficult for the layperson to understand, since much of the traditional teaching materials used in astronomy education remain two-dimensional in nature. We study the student performance after viewing visualizations in an immersive theater and in non-immersive classrooms for the topic of seasons in an introductory undergraduate astronomy course. Using weekly multiple-choice quizzes to gauge student learning, comparison of curriculum tests taken immediately after instruction and pre-instruction quizzes show a significant difference in the results of students who viewed visualizations in the planetarium versus their counterparts who viewed non-immersive content in their classrooms, and those in the control group that saw no visualizations whatsoever. These results suggest that the immersive visuals help by freeing up cognitive resources that can be devoted to learning, while visualizations shown in the classroom may be an intrinsically inferior experience for students

Rapid Surface Lowering of Benito Glacier, Northern Patagonian Icefield

The Patagonian Icefields, which straddle the Andes below 46?S, are one of the most sensitive ice masses to climate change. However, recent mass loss from the icefields, along with its spatial and temporal variability, is not well constrained. Here we determine surface elevation changes of Benito Glacier, a 163 km2 outlet glacier draining the western flank of the North Patagonian Icefield, using a combination of field and satellite-derived elevation data acquired between 1973 and 2017. Our results demonstrate that, just below the equilibrium line, the glacier dramatically thinned by 139 m in the past 44 years, equivalent to a mean rate of 3.2 ? 0.2 m a-1. However, surface lowering was temporally variable, characterized by a hiatus between 2000 and 2013, and a subsequent increase up to 7.7 ? 3.0 m a-1 between 2013 and 2017. Analysis of Benito Glacier?s flow regime throughout the period indicates that the observed surface lowering was caused by negative surface mass balance, rather than dynamic thinning. The high rate of surface lowering observed over the past half a decade highlights the extreme sensitivity of mid-latitude glaciers to recent atmospheric forcingpublishersversionPeer reviewe