The Return of \u3ci\u3eHexagenia\u3c/i\u3e (Ephemeroptera: Ephemeridae) to the Lower Fox River, Wisconsin

Burrowing mayflies (Hexagenia bilineata) were collected in 1991 in the vicinity of the DePere dam on the Fox River, Brown County, Wisconsin. Because Hexagenia mayflies are indicators of good water quality, their emergence from the Fox River is evidence of improvement in conditions at the sediment-water interface

Secondary Predation on the Horsehair Worm \u3ci\u3eGordius Robustus\u3c/i\u3e (Nematomorpha: Gordiida)

The gut contents of a brown trout (Salmo trutta) included horsehair worms (Gordius robustus, Nematomorpha: Gordiida) emerging from a camel cricket (Ceuthophilus sp., Orthoptera: Gryllacrididae). This provides more evidence of secondary ingestion than most previous reports of predation on horsehair worms, but it also illustrates the difficulty of distinguishing in practice between direct and secondary predation

\u3ci\u3eMantis Religiosa\u3c/i\u3e (Mantodea: Mantidae) in Door County, Wisconsin

The European mantid (Mantis religiosa) has been observed at several sites spanning a distance of approximately 50 km in northern Door County, Wisconsin. A reliable sighting of an unidentified praying mantid on Chambers Island in Green Bay suggests the possibility that the species occurs there as well. Lake-induced moderation of the Door County climate may have resulted in conditions especially conducive for the establishment of European mantids

\u3ci\u3eHexagenia Bilineata\u3c/i\u3e (Ephemeroptera: Ephemeridae) Persists at Low Levels of Abundance in the Lower Fox River, Wisconsin

After burrowing mayflies (Hexagenia bilineata) were first noted in the vicinity of the DePere Dam on the Fox River in 1991, adults have been observed in small numbers each summer since then. It is possible that the Fox River population has remained at low levels because of an Allee effect. In addition, it is possible that the population is still limited by poor environmental quality, presumably in the upper layer of sediment inhabited by the larvae. Two other relatively sensitive species associated with benthic habitat, the sea lamprey (Petromyzon marinus) and the lake sturgeon (Acipenser fulvescens), have been observed in the Fox River in recent years. Collectively these species provide an indication of improved environmental conditions, but it is not yet clear that any of the three have established populations capable of successfully reproducing in the lower Fox River on a consistent basis

Spectroscopic Observations of New Oort Cloud Comet 2006 VZ13 and Four Other Comets

Spectral data are presented for comets 2006 VZ13 (LINEAR), 2006 K4 (NEAT), 2006 OF2 (Broughton), 2P/Encke, and 93P/Lovas I, obtained with the Cerro-Tololo Inter-American Observatory 1.5-m telescope in August 2007. Comet 2006 VZ13 is a new Oort cloud comet and shows strong lines of CN (3880 angstroms), the Swan band sequence for C_2 (4740, 5160, and 5630 angstroms), C_3 (4056 angstroms), and other faint species. Lines are also identified in the spectra of the other comets. Flux measurements of the CN, C_2 (Delta v = +1,0), and C_3 lines are recorded for each comet and production rates and ratios are derived. When considering the comets as a group, there is a correlation of C_2 and C_3 production with CN, but there is no conclusive evidence that the production rate ratios depend on heliocentric distance. The continuum is also measured, and the dust production and dust-to-gas ratios are calculated. There is a general trend, for the group of comets, between the dust-to-gas ratio and heliocentric distance, but it does not depend on dynamical age or class. Comet 2006 VZ13 is determined to be in the carbon-depleted (or Tempel 1 type) class.Comment: 8 pages, 6 figures, 6 tables; Accepted by MNRA

Distribution of the Water Scorpion \u3ci\u3eNepa Apiculata\u3c/i\u3e (Hemiptera: Nepidae) in Wisconsin

The water scorpion Nepa apiculata Uhler was considered rare in Wiscon- sin by Hilsenhoff (1984), who collected only 11 individuals during a 25-year period. All of his collections were from overwintering sites, especially debris in streams, during early spring or autumn (Hilsenhoff, pers. comm.). He concluded that the species was restricted to southern Wisconsin. Recent collections indicate that N. apiculata is more widely distributed. These records, summarized below, are documented with specimens in the University of Wisconsin-Madison insect collection

The Assassin Bug \u3ci\u3eZelus Luridus\u3c/i\u3e (Heteroptera: Reduviidae) in Michigan\u27s Upper Peninsula

(excerpt) On 17 July 1992, an assassin bug (Zelus luridus Stal) was flushed from the stomach of a smallmouth bass (Micropterus dolomieu) collected in West Long Lake of the University of Notre Dame Environmental Research Center, Gogebic County, Michigan

Effect of hole geometry and Electric-Discharge Machining (EDM) on airflow rates through small diameter holes in turbine blade material

The effects of two design parameters, electrode diameter and hole angle, and two machine parameters, electrode current and current-on time, on air flow rates through small-diameter (0.257 to 0.462 mm) electric-discharge-machined holes were measured. The holes were machined individually in rows of 14 each through 1.6 mm thick IN-100 strips. The data showed linear increase in air flow rate with increases in electrode cross sectional area and current-on time and little change with changes in hole angle and electrode current. The average flow-rate deviation (from the mean flow rate for a given row) decreased linearly with electrode diameter and increased with hole angle. Burn time and finished hole diameter were also measured

Strain-induced ferroelectricity in simple rocksalt binary oxides

The alkaline earth binary oxides adopt a simple rocksalt structure and form an important family of compounds because of their large presence in the earth's mantle and their potential use in microelectronic devices. In comparison to the class of multifunctional ferroelectric perovskite oxides, however, their practical applications remain limited and the emergence of ferroelectricity and related functional properties in simple binary oxides seems so unlikely that it was never previously considered. Here, we show using first-principles density functional calculations that ferroelectricity can be easily induced in simple alkaline earth binary oxides such as barium oxide (BaO) using appropriate epitaxial strains. Going beyond the fundamental discovery, we show that the functional properties (polarization, dielectric constant and piezoelectric response) of such strained binary oxides are comparable in magnitude to those of typical ferroelectric perovskite oxides, so making them of direct interest for applications. Finally, we show that magnetic binary oxides such as EuO, with the same rocksalt structure, behave similarly to the alkaline earth oxides, suggesting a route to new multiferroics combining ferroelectric and magnetic properties