Occurrence and movement of total and tylosin-resistant enterococci, erm genes and tylosin in tile-drained agricultural fields receiving swine manure application

The use of tylosin at subtherapeutic levels by the swine industry provides selective pressure for the development of antibiotic resistance in gastrointestinal bacteria. The land application of swine manure to drained agricultural fields might introduce elevated levels of total and tylosin-resistant enterococci, erm genes and tylosin. The goal of this study was to develop an understanding of the occurrence and transport of total and tylosin-resistant enterococci, erm genes and tylosin in tile-drained chisel plow and no-till agricultural fields that have received multi-year application of liquid swine manure through injection over two growing seasons. Resistance to tylosin in manure, soil and water samples was investigated at the field scale level using phenotypic based (membrane filtration) and genotypic based (qPCR) methods and compared with samples from control plots treated with urea and ammonium nitrate (UAN). Tylosin was quantified using LC-MS/MS. Plots in a corn-soybean rotation were identified for sampling from 2010-2012. Soil samples were collected from each manure plot, from both the direct area of injection and from the area between the manure bands and from control plots. Each one-acre plot is drained separately and tile water samples were collected directly from the discharge tile line weekly while the tiles were flowing. The results of this study suggest that tylosin usage has increased the short-term occurrence of total and tylosin-resistant enterococci, erm genes, and tylosin in soils, but has had minimal effect on tile drainage water quality under dryer than average condition

EFFECTS OF SEDIMENTS ON BMPS FOR HIGHWAY RUNOFF CONTROL

Numerous studies conducted on highway stormwater runoff and its control with Best Management Practices (BMPs) indicate that sediment is the major pollutant that affects performance and longevity of BMPs. Currently, there are several knowledge gaps related to the effects of sediments on highway BMPs: a) how much sediment will be generated by a construction site by a section of highway with its surrounding watershed under different conditions; b) how sediment is intercepted by different BMPs with or without pretreatment sections; and c) what are the effects of these sediments on BMPs’ hydraulic behavior, longevity, and pollutants removal or release. The objectives of this study are to: 1) develop models to predict both surface runoff and sediment yield from highway systems under different conditions; and 2) evaluate how to incorporate models into design and management of BMPs for highway runoff control. RUSLE2 was used to estimate sediment yield for different settings (e.g., construction sites, different highway sections) under different environmental (e.g., soils, vegetation, slopes) and weather conditions (e.g., different rain events). Several highway sites across the state were selected to model runoff and sediment delivery under various construction scenarios. Several BMP designs were modeled at each of the highway sites to assess how the sediments would affect longevity of the BMP. Results indicate that BMPs reduce pollutants within channels. The data also points to BMPs on stabilized sites having higher efficiencies and longer lifespans. The developed models will assist in the planning, design and management of structural BMPs for highway runoff control. Advisor: John Stansbur

Use of UHPC piles in integral abutment bridges

In order to make the Ultra High Performance Concrete (UHPC) pile, developed in Phase I of the UHPC Pile Project at Iowa State University (ISU), a viable option in practice, laboratory testing, field testing and installation of a production pile in the field were undertaken during Phase II of this project. A detailed understanding of the section behavior and lateral loading behavior was determined and compared to that of a steal HP 10 x 57 pile through lateral load analyses of a UHPC pile section. The analysis found that UHPC piles were suitable for integral abutments of bridges. To make the field installation of UHPC piles possible, the overall performance of a common pile-to-abutment connection was verified in the laboratory by defining the UHPC pile-to-abutment connection, which is similar to the currently used connection for steel HP 10 x 57 piles. Both piles performances were verified by testing their connection when subjected to weak-axis bending. The test piles met performance criteria during the laboratory displacements of 0.28 and 0.42 inches which correspond to 1.0 and 1.55 inches in the field. Next, the field testing began to ensure that the production pile would achieve the desired behavior and capacities required by integral abutment bridges. A vertical load test on a 46-ft UHPC test pile was completed one week after being driven into the ground at the same site where the UHPC production pile was implemented into a 223-ft long integral bridge with a 24¢ª skew. Before failure, the test pile resisted 1.5 times the predicted capacity based on the Iowa Bluebook method of design for concrete piles, verifying appropriateness of reducing the UHPC production pile by 16% in length compared to the specified length of 65-ft for the HP 10 x 57 piles on the integral bridge. Additionally, a lateral load test was conducted between the second test pile with a newly designed splice detail and the vertical load test pile, which confirmed the adequacy of the splice detail and the lateral load resistance of the pile. The 46-ft test pile was also tested during the lateral load test. The results of the laboratory and field studies indicated that the UHPC pile in the field is a viable option

Evolutionary Strategies Combined With Novel Binary Hill Climbing Used for Online Walking Pattern Generation in Two Legged Robot

Evolutionary algorithms (EA) has often been proposed as a method for designing system

ROCE/WACC og meravkastning : anerkjenner og belønner aksjemarkedet verdiskapning riktig?

Formålet med denne masterutredningen har vært å undersøke om markedet priser verdiskapning riktig og dermed om markedet er effisient. Tilnærmingen til verdiskapning er gjort ved å se på ROCE/WACC. Problemstillingen for oppgaven er: ”Gir selskaper med historisk høy ROCE/WACC en bedre avkastning enn selskaper med historisk lav ROCE/WACC?” I følge teorien om markedseffisiens skal det ikke være noe forskjell i avkastning mellom porteføljer bestående av høy og lav ROCE/WACC. Selskaper med høy ROCE/WACC skal være relativt høyere priset. Data som analysen er bygget på er innhentet fra FactSet og gjelder for tidsperioden 1993 til 2012. Datasettet inkluderer aksjer notert på MSCI World, ekskludert finanssektoren og inneholder regnskapsdata fra årsrapporter og aksjepriser på årlig basis. I utredningen ser vi på forskjellen i avkastning porteføljer med høy ROCE/WACC har i forhold til de med lav. Vi ser globalt over hele perioden og i delperioder. I tillegg ser vi nærmere på regioner og sektorer, samt kontrollerer for kjente risikofaktorer for å undersøke hva som kan ligge bak faktoren. Vi finner at selskaper med høy ROCE/WACC har en tendens til å prestere bedre enn selskaper med lav ROCE/WACC når vi justerer for markedsrisiko, men resultatene er ikke signifikante for alle tidsperioder, regioner og sektorer. Dersom tendensen kommer fra en risikopremie burde den gjelde generelt, noe som ikke er tilfelle i tidsperioden vi undersøker. Vi mener derfor det er mulig at markedet ikke er fullstendig effisient, og dermed undervurderer markedsmakten selskaper kan ha og hvor lenge de kan ha den. I de sektorene vi oppdager effekten mest, består vinnerporteføljene av veletablerte store selskaper som kan ha store fordeler bestående av høye inngangsbarrierer, merkevare, stordriftsfordeler, få konkurrenter o.l., samtidig som de viser god evne til verdiskapning

An Investigation of Load and Resistance Factor Design of Drilled Shafts Using Historical Field Test Data

To achieve engineered designs with consistent levels of reliability, the Federal Highway Administration (FHWA) mandated that all new bridges initiated after October 1, 2007, including those founded upon drilled shafts, be designed according to the Load and Resistance Factor Design (LRFD) approach. As the first step in developing efficient regional LRFD procedures for drilled shafts, the Drilled SHAft Foundation Testing (DSHAFT) database was formulated. DSHAFT was aimed at assimilating high quality, historical drilled shaft test data from Iowa and the surrounding states, and it presently contains data from 41 drilled shaft load tests, 38 of which are O-cell load tests, along with subsurface information and structural details. Following an introduction to DSHAFT, several challenges associated with subsurface investigations, measurement of geomaterial properties, and test methods employed in current practice for drilled shaft capacity estimations are discussed. An improved procedure is then proposed featuring three different cases for establishing the equivalent top load-displacement response of drilled shafts. Using the proposed procedure and LRFD framework, it is shown that robust, more efficient regional LRFD resistance factors can be established for drilled shafts with a target displacement limit

Genetic Learning Algorithms Combined With Novel Binary Hill Climbing Used for Online Walking-Pattern Generation in Legged Robots

According to Darwin every species on this planet have developed froma small group of simple molecules into all the modern species living among us today. The reason why some species survive and others don’t is what Darwin called Natural Selection, which means that every individual have to fight for its existence. Those who are best fit will survive. This has brought life to the well known saying: "Survival of the Fittest". The best fit will have the best chance to reproduce, to pass its well fitted, surviving qualities on to their offspring. And the offspring of two well-equipped parents will have a high probability of adaptation, and so the circle of life goes on... A set of evolutionary search methods have been extracted from the Darwinian theories of evolution. These have been evolving in computer environments for several decades and have been passing through different areas of computer science, from theoretical tuning problems, algorithm developing, clustering, chip design, and several real world applications have been the foci the last years. In this thesis Genetic Algorithms and Evolvable Hardware is used for evolving gaits in a walking biped robot controller. The focus is fast learning in a real-time environment. An incremental approach combining a genetic algorithm with hill climbing is proposed. This combination interacts in an efficient way to generate precise walking patterns in less than 15 generations. Our proposal is compared to various versions of Genetic Algorithms and stochastic search, and finally tested on a pneumatic biped walking robot

Gender gaps in online social connectivity, promotion and relocation reports on LinkedIn

Online professional social networking platforms provide opportunities to expand networks strategically for job opportunities and career advancement. A large body of research shows that women’s offline networks are less advantageous than men’s. How online platforms such as LinkedIn may reflect or reproduce gendered networking behaviours, or how online social connectivity may affect outcomes differentially by gender is not well understood. This paper analyses aggregate, anonymised data from almost 10 million LinkedIn users in the UK and US information technology (IT) sector collected from the site’s advertising platform to explore how being connected to Big Tech companies (‘social connectivity’) varies by gender, and how gender, age, seniority and social connectivity shape the propensity to report job promotions or relocations. Consistent with previous studies, we find there are fewer women compared to men on LinkedIn in IT. Furthermore, female users are less likely to be connected to Big Tech companies than men. However, when we further analyse recent promotion or relocation reports, we find women are more likely than men to have reported a recent promotion at work, suggesting high-achieving women may be self-selecting onto LinkedIn. Even among this positively selected group, though, we find men are more likely to report a recent relocation. Social connectivity emerges as a significant predictor of promotion and relocation reports, with an interaction effect between gender and social connectivity indicating the payoffs to social connectivity for promotion and relocation reports are larger for women. This suggests that online networking has the potential for larger impacts for women, who experience greater disadvantage in traditional networking contexts, and calls for further research to understand differential impacts of online networking for socially disadvantaged groups