Invariant manifolds and the geometry of front propagation in fluid flows

Recent theoretical and experimental work has demonstrated the existence of one-sided, invariant barriers to the propagation of reaction-diffusion fronts in quasi-two-dimensional periodically-driven fluid flows. These barriers were called burning invariant manifolds (BIMs). We provide a detailed theoretical analysis of BIMs, providing criteria for their existence, a classification of their stability, a formalization of their barrier property, and mechanisms by which the barriers can be circumvented. This analysis assumes the sharp front limit and negligible feedback of the front on the fluid velocity. A low-dimensional dynamical systems analysis provides the core of our results.Comment: 14 pages, 11 figures. To appear in Chaos Focus Issue: Chemo-Hydrodynamic Patterns and Instabilities (2012

An Unusual Hydrogen Migration/C−H Activation Reaction with Group 3 Metals

A novel hydrogen migration from the phenyl ring to the pyridine ring of an yttrium pyridyl complex supported by a 1,1′-ferrocene diamide ligand is reported. Density functional theory calculations were instrumental in probing the mechanism for this transformation

DIGESTIBILITY OF SELECTED FEED INGREDIENTS FOR TIGER GROUPER, Epinephelus fuscoguttatus

The apparent digestibility (AD) of eight feed ingredients are widely available in Indonesia was determined. In each of two 5x5 latin-square experimental, tiger grouper Epinephelus fuscoguttatus juveniles (100—150 g) were fed a reference diet and four test diets in accordance with the latin-square design. Test feed ingredients were substituted at rates of 40% for animal meals or 30% for plant meals. Chromic oxide was used as the digestibility marker. In determining the ingredient AD, the substitution ratio was calculated as the proportion of the nutrient (or energy) contributed by the test ingredient on an ‘as-is’ basis. Digestibility tanks were steeply slope 200 L cylindroconical tanks with a bottom outlet to facilitate faecal collection, which was carried out at 3-hourly intervals throughout the day. Each collection period took 5—7 days with a similar acclimatization time between diets. A combined ANOVA of the data for both experimental showed no difference (P>0.05) in the AD’s for each reference diets. Thus for comparative purpose, the derived AD’s of the test ingredients were analysed as a single ANOVA. The digestibility of animal meals was generally high(>59% for dry matter, >83% for protein, >65% for lipid, and >70 for gross energy) while that of plant meals was slow (<53% for dry matter, <53% for protein, <66% for lipid, and <46% for gross energy). This information will enable grow-out feeds for tiger grouper to be formulated on a least-cost digestible nutrient basis

Data assmilation tests using NISE10 Storm Surge Model

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Reaction of Group III Biheterocyclic Complexes

Group III alkyl complexes supported by a ferrocene diamide ligand (1,1′-fc(NSitBuMe_2)_2) have been found to be reactive toward aromatic N-heterocycles such as 1-methylimidazole and pyridines. These reactions were investigated experimentally and computationally. An initial C−H activation event is followed by a coupling reaction to form biheterocyclic complexes, in which one of the rings is dearomatized. In the case of 1-methylimidazole, the biheterocyclic compound could not be isolated and further led to an imidazole ring-opened product; in the case of pyridines, it transformed into an isomer with extended conjugation of double bonds. Mechanisms for both reactions are proposed on the basis of experimental and computational results. DFT calculations were also used to show that an energetically accessible pathway for the ring-opening of pyridines exists

An Innovative Approach for Community Engagement: Using an Audience Response System

Community-based participatory research methods allow for community engagement in the effort to reduce cancer health disparities. Community engagement involves health professionals becoming a part of the community in order to build trust, learn from the community and empower them to reduce disparities through their own initiatives and ideas. Audience Response Systems (ARS) are an innovative and engaging way to involve the community and obtain data for research purposes using keypads to report results via power point. The use of ARS within communities is very limited and serves to widen the disparity gap by not delivering new advances in medical knowledge and technology among all population groups. ARS was implemented at a community town hall event sponsored by a National Institute on Minority Health and Health Disparities Exploratory Center of Excellence, the Center for Equal Health. Participants appreciated being able to see how everyone else answered and felt included in the research process. ARS is beneficial because the community can answer truthfully and provides instant research results. Additionally, researchers can collect large amounts of data quickly, in a non-threatening way while tracking individual responses anonymously. Audience Response Systems proved to be an effective tool for successfully accomplishing community-based participatory research

Systematics of Multillidae (Hymenoptera) With Special Emphasis on Dasymutilla and Their Allies

Velvet ants are solitary wasps that have been virtually ignored in the past. Although over 4200 species have been described, fewer than 10 articles are published on these wasps each year. Their research potential is hindered by lack of phylogenetic and taxonomic data and lack of interest in the scientific community. In this dissertation, I sought to overcome the hindrances to mutillid research with a holistic systematic research model. By reconstructing phylogenies using molecular methods and correcting taxonomy based on the phylogenetic reconstructions, I was able to diminish the barriers to velvet ant research while concurrently presenting broadly interesting hypotheses. I applied this model to multiple hierarchical levels within the most widely studied velvet ant genus, Dasymutilla, and its allies. Molecular phylogenetic reconstructions, particularly those using the internal transcribed spacer units of ribosomal DNA (ITS1 and ITS2), were effective under Bayesian criteria. My results reveal the utility of velvet ants for studying biogeography and mimicry. I specifically determined that velvet ants dispersed between North and South America prior to the Great American Biotic Interchange and members of the genus Dasymutilla form the world’s largest known Müllerian mimicry complex. Taxonomic problems in Dasymutilla and their allies are addressed in the remaining sections of the dissertation. Overall, 35 species were treated taxonomically. Seven new sex associations were discovered, 22 species were recognized as synonyms, and nine new species were described. In each taxonomic treatment, hypotheses concerning biogeography, mimicry, and host selection were discussed briefly