First Report of the Neoephemeridae (Ephemeroptera) in Wisconsin

The mayfly family Neoephemeridae was discovered in Wisconsin for the first time and is represented by the species Neoephemera bicolor. Nymphs were collected from three sites in two rivers in northern Wisconsin. Adults were reared from nymphs. Some physical and chemical characteristics of the sample locations are discussed

Pilot interministerial operation for remote sensing

Advantages and disadvantages of traditional methods of obtaining required information for land and resources management and the possibilities of remote sensing are discussed. The services available, organization and objectives of the pilot operation are presented. Emphasis is placed on multidisciplinary dialog among designers, builders, operators, interpreters and users in all phases. The principles, operation and practical applications of remote sensing systems and processing systems under the pilot operation are presented

New data and the hard pomeron

New structure-function data are in excellent agreement with the existence of a hard pomeron, with intercept about 1.4. It gives a very economical description of the data. Having fixed 2 parameters from the data for the real-photon cross section $\sigma^{\gamma p}$, we need just 5 further parameters to fit the data for $F_2(x,Q^2)$ with $x\leq 0.001$. The available data range from $Q^2=0.045$ to 35 GeV$^2$. With guesses consistent with dimensional counting for the $x$ dependences of our three separate terms, the fit extends well to larger $x$ and to $Q^2=5000$ GeV$^2$. With no additional parameters, it gives a good description of data for the charm structure function $F_2^c(x,Q^2)$ from $Q^2=0$ to 130 GeV$^2$. The two pomerons also give a good description of both the $W$ and the $t$ dependence of $\gamma p\to J/\psi p$.Comment: 11 pages, plain tex, with 10 figures embedded using epsf. (Spurious figure removed.

Synthesis and antibacterial activities of enamine derivatives of dehydroacetic acid

Dehydroacetic acid is a common pyrone derivative used commercially as an antibacterial and antifungal agent. Based on the synthesis of dehydroacetic acid (1) from N-hydroxysuccinimdyl acetoacetate, a novel series of enamine-based derivatives were synthesised in order to improve the antibacterial activity of dehydroacetic acid. The antibacterial activities of the synthesised analogues were evaluated against Escherichia coli and Staphylococcus aureus. Derivative 4d (N-Ph) was identified as the most potent inhibitor of S. aureus growth. Overall, derivative 4b (N-Me) showed the best broad-spectrum activity with five-fold greater minimum inhibitory concentration and 11-fold greater minimum biocidal concentration against E. coli when compared to dehydroacetic acid, in addition to improved antibacterial activity against S. aureus

Fatty acid supplementation reverses the small colony variant phenotype in triclosan-adapted staphylococcus aureus: Genetic, proteomic and phenotypic analyses

Staphylococcus aureus can develop a small colony variant (SCV) phenotype in response to sub-lethal exposure to the biocide triclosan. In the current study, whole genome sequencing was performed and changes in virulence were investigated in five Staphylococcus aureus strains following repeated exposure to triclosan. Following exposure, 4/5 formed SCV and exhibited point mutations in the triclosan target gene fabI with 2/4 SCVs showing mutations in both fabI and fabD. The SCV phenotype was in all cases immediately reversed by nutritional supplementation with fatty acids or by repeated growth in the absence of triclosan, although fabI mutations persisted in 3/4 reverted SCVs. Virulence, determined using keratinocyte invasion and Galleria mellonella pathogenicity assays was significantly (p < 0.05) attenuated in 3/4 SCVs and in the non-SCV triclosan-adapted bacterium. Proteomic analysis revealed elevated FabI in 2/3 SCV and down-regulation in a protein associated with virulence in 1/3 SCV. In summary, attenuated keratinocyte invasion and larval virulence in triclosan-induced SCVs was associated with decreases in growth rate and virulence factor expression. Mutation occurred in fabI, which encodes the main triclosan target in all SCVs and the phenotype was reversed by fatty acid supplementation, demonstrating an association between fatty acid metabolism and triclosan-induced SCV

Mentoring Undergraduate Research in Mathematical Modeling

In writing about undergraduate research in mathematical modeling, I draw on my 31 years as a mathematics professor at the University of Nebraska–Lincoln, where I mentored students in honors’ theses, REU groups, and research done in a classroom setting, as well as my prior experience. I share my views on the differences between research at the undergraduate and professional levels, offer advice for undergraduate mentoring, provide suggestions for a variety of ways that students can disseminate their research, offer some thoughts on mathematical modeling and how to explain it to undergraduates, and discuss the challenges involved in broadening research participation to include early career students and mid-tier students and how to deliver a research experience in a classroom setting. While different situations pose different challenges, different problems require different approaches, and different experiences lead to different conclusions, it is my hope that my experiences will be of broad value to a wide audience

Using asymptotics for efficient stability determination in epidemiological models

Analytical stability calculation is done to prove stability properties for systems with parameters that do not have explicit values. For systems with three components, the usual method of finding the characteristic polynomial as the determinant of J-lambda I and applying the Routh-Hurwitz conditions is reasonably efficient. For larger systems of four to six components, the method is impractical, as the calculations become too messy. In epidemiological models, there is often a very small parameter that appears as the ratio of a disease-based time scale to a demographic time scale; this allows efficient use of asymptotic approximation to simplify the calculations at little cost. Here we describe the tools and an example of efficient stability analysis, followed by a set of guidelines that are generally useful in applying the method.Comment: 15 pages, 2 figure