Host seeking parasitic nematodes use specific odors to assess host resources.

Entomopathogenic nematodes (EPNs) are insect parasites used as biological control agents. Free-living infective juveniles (IJs) of EPNs employ host-seeking behaviors to locate suitable hosts for infection. We found that EPNs can differentiate between naïve and infected hosts, and that host attractiveness changes over time in a species-specific manner. We used solid-phase microextraction and gas chromatography/mass spectrometry to identify volatile chemical cues that may relay information about a potential host's infection status and resource availability. Among the chemicals identified from the headspace of infected hosts, 3-Methyl-2-buten-1-ol (prenol) and 3-Hydroxy-2-butanone (AMC) were selected for further behavioral assays due to their temporal correlation with the behavioral changes of IJs towards the infected hosts. Both compounds were repulsive to IJs of Steinernema glaseri and S. riobrave in a dose-dependent manner when applied on an agar substrate. Furthermore, the repulsive effects of prenol were maintained when co-presented with the uninfected host odors, overriding attraction to uninfected hosts. Prenol was attractive to dauers of some free-living nematodes and insect larvae. These data suggest that host-associated chemical cues may have several implications in EPN biology, not only as signals for avoidance and dispersal of conspecifics, but also as attractants for new potential hosts

Genome Editing Method for the Anaerobic Magnetotactic Bacterium Desulfovibrio magneticus RS-1.

Magnetosomes are complex bacterial organelles that serve as model systems for studying bacterial cell biology, biomineralization, and global iron cycling. Magnetosome biogenesis is primarily studied in two closely related Alphaproteobacteria of the genus Magnetospirillum that form cubooctahedral-shaped magnetite crystals within a lipid membrane. However, chemically and structurally distinct magnetic particles have been found in physiologically and phylogenetically diverse bacteria. Due to a lack of molecular genetic tools, the mechanistic diversity of magnetosome formation remains poorly understood. Desulfovibrio magneticus RS-1 is an anaerobic sulfate-reducing deltaproteobacterium that forms bullet-shaped magnetite crystals. A recent forward genetic screen identified 10 genes in the conserved magnetosome gene island of D. magneticus that are essential for its magnetic phenotype. However, this screen likely missed mutants with defects in crystal size, shape, and arrangement. Reverse genetics to target the remaining putative magnetosome genes using standard genetic methods of suicide vector integration have not been feasible due to the low transconjugation efficiency. Here, we present a reverse genetic method for targeted mutagenesis in D. magneticus using a replicative plasmid. To test this method, we generated a mutant resistant to 5-fluorouracil by making a markerless deletion of the upp gene that encodes uracil phosphoribosyltransferase. We also used this method for targeted marker exchange mutagenesis by replacing kupM, a gene identified in our previous screen as a magnetosome formation factor, with a streptomycin resistance cassette. Overall, our results show that targeted mutagenesis using a replicative plasmid is effective in D. magneticus and may also be applied to other genetically recalcitrant bacteria.IMPORTANCE Magnetotactic bacteria (MTB) are a group of organisms that form intracellular nanometer-scale magnetic crystals though a complex process involving lipid and protein scaffolds. These magnetic crystals and their lipid membranes, termed magnetosomes, are model systems for studying bacterial cell biology and biomineralization and are potential platforms for biotechnological applications. Due to a lack of genetic tools and unculturable representatives, the mechanisms of magnetosome formation in phylogenetically deeply branching MTB remain unknown. These MTB contain elongated bullet-/tooth-shaped magnetite and greigite crystals that likely form in a manner distinct from that of the cubooctahedral-shaped magnetite crystals of the genetically tractable MTB within the Alphaproteobacteria Here, we present a method for genome editing in Desulfovibrio magneticus RS-1, a cultured representative of the deeply branching MTB of the class Deltaproteobacteria This marks a crucial step in developing D. magneticus as a model for studying diverse mechanisms of magnetic particle formation by MTB

Internal Control Strategies for Compliance with the Sarbanes-Oxley Act of 2002

Publicly traded corporations have dedicated time and money to adhering to the requirements of the Sarbanes-Oxley Act (SOX) of 2002; however, some companies face challenges in internal control compliance with SOX. Using the transformational leadership theory as the conceptual framework, the purpose of this multiple case study was to explore the strategies chief financial officers (CFOs) used to comply with corporate financial internal control policies. Data were collected using face-to-face, semistructured interviews with 3 CFOs of publicly traded manufacturing companies in Michigan and a review of documents. The selection criteria for participants included CFOs who have experience in SOX implementation and compliance in a manufacturing industry and who had successful strategies that they used to comply with corporate financial internal control policies. Transcript evaluation and member checking ensured the reliability of the data collected. Data were analyzed using qualitative data-analysis software and triangulation to interpret data collected from multiple sources. Four themes emerged from the study: (a) internal control process and financial reporting, (b) control process accountability, (c) compliance challenges, and (d) risk assessment. The findings could contribute to social change by providing internal-control best practices to help mitigate the elements of the fraud, confirm ethical behavior of employees, and impact positive growth and progress in communities

Becoming the Crossroads: Female Cultural Creators of the Mexican American Generation in the Texas Borderlands

This dissertation examines the cultural accomplishments of Mexican American women in 20th century Texas, looking at how women in the arts paved the way for a new Mexican American hybrid identity. I examine how Mexican American women in the borderlands, as Gloria Anzaldúa so aptly put it, “became the crossroads” in their bodies, minds and spirits. By examining the lives and work of the four women, Jovita González, Rosita Fernández, Alicia Dickerson Montemayor, and Consuelo “Chelo” González Amezcua, I have demonstrated that Mexican American women broke boundaries of their own culture and of Anglo Texas culture in order to create their art. In the process of becoming American, they flouted the conventional gender roles and paved the way for a generation of Chicana artists, musicians, and authors. My research was conducted in archives throughout Texas, by examining and analyzing letters, manuscripts, newspapers, recordings, films, TV and video clips, magazines, and art work. As artists of the borderlands, the women I researched participated in laying the groundwork for a hybrid Mexican American identity, developing Mexican American art that paved the way for the development of a distinctive Mexican American culture by the hybridization and use of common Mexican forms and references in their art, through which they reinforced and redefined Mexican American culture while telling stories that had not been told before

Devoted to the word : a formational approach to scripture

https://place.asburyseminary.edu/ecommonsatsdissertations/1773/thumbnail.jp

Terahertz single pixel imaging based on a Nipkow disk

We describe a terahertz single pixel imaging system based on a Nipkow disk. Nipkow disks have been used for fast scanning imaging systems since the first experimental television was invented in 1926. In our work, a Nipkow disk with 24 scanning lines was used to provide an axial resolution of 2 mm/pixel. We also show that by implementing a microscanning technique the axial resolution can be further improved to 0.5 mm/pixel. Imaging of several objects was demonstrated to show that this simple scanning system is promising for fast and/or real time terahertz imaging applications

Numerical and physical simulation of rapid microstructural evolution of gas atomised Ni superalloy powders

The rapid microstructural evolution of gas atomised Ni superalloy powder compacts over timescales of a few seconds was studied using a Gleeble 3500 thermomechanical simulator, finite element based numerical model and electron microscopy. The study found that the microstructural changes were governed by the characteristic temperatures of the alloy. At a temperature below the γ' solvus, the powders maintained dendritic structures. Above the γ' solvus temperature but in the solid-state, rapid grain spheroidisation and coarsening occurred, although the fine-scale microstructures were largely retained. Once the incipient melting temperature of the alloy was exceeded, microstructural change was rapid, and when the temperature was increased into the solid + liquid state, the powder compact partially melted and then re-solidified with no trace of the original structures, despite the fast timescales. The study reveals the relationship between short, severe thermal excursions and microstructural evolution in powder processed components, and gives guidance on the upper limit of temperature and time for powder-based processes if desirable fine-scale features of powders are to be preserved

Will Electric Cars Transform the U.S. Market

For the past forty years, United States Presidents have repeatedly called for a reduction in the country's dependence on fossil fuels in general and foreign oil specifically. Stronger efficiency standards and higher taxes on motor fuels are a step in this direction, but achieving even greater reductions in oil consumption will require changing the way Americans power their transportation system. Some officials advocate the electrification of the passenger vehicle fleet as a path to meeting this goal. The Obama administration has, for example, embraced a goal of having one million electric-powered vehicles on U.S. roads by 2015, while others proposed a medium-term goal where electric vehicles would consist of 20% of the passenger vehicle fleet by 2030—approximately 30 million electric vehicles. The technology itself is not in question—many of the global automobile companies are planning to sell plug-in hybrid electric vehicles (PHEVs) and/or battery electric vehicles (BEVs) by 2012. The key question is, will Americans buy them? The answer depends on four additional questions: 1. Is the cost of purchasing and operating an electric vehicle more or less expensive than the cost of a comparable conventional gasoline-powered vehicle? 2. Are the comparative costs likely to change over the next twenty years? 3. Do electric vehicles provide the same attributes as conventional cars, and if not, do the differences matter? 4. Will electric car owners be able to access the electricity needed to power their vehicles? This paper attempts to answer these four questions