Butterflies (Lepidoptera) on Hill Prairies of Allamakee County, Iowa: A Comparison of the Late 1980s With 2013

In the late 1980s, several hundred butterflies were collected by John Nehnevaj from hill prairies and a fen in Allamakee County, Iowa. Nehnevaj’s collection included 69 species, 14 of which are currently listed in Iowa as species of greatest conservation need (SGCN). The goal of this study was to revisit sites surveyed in the 1980s and survey three additional sites to compare the species present in 2013 to the species found by Nehnevaj. A primary objective was to document the presence of rare prairie specialist butterflies (Lepidoptera), specifically the ottoe skipper (Hesperia ottoe W.H. Edwards; Hesperiidae), which was thought to be extirpated from Iowa. Twelve sites were surveyed 4 to 7 times between June and September 2013 using a meandering Pollard walk technique. A total of 2,860 butterflies representing 58 species were found; eight of these species were SGCN’s, including the hickory hairstreak (Satyrium caryaevorum McDunnough; Lycaenidae), and Leonard\u27s skipper (Hesperia leonardus Harris; Hesperiidae), species not collected in the 1980s, and the ottoe skipper and Baltimore checkerspot (Euphydryas phaeton Drury; Nymphalidae), both species also found by Nehnevaj. Species richness for the sites ranged from 14 to 33 species, with SGCNs found at 11 of the 12 sites. Significant landscape changes have occurred to hill prairies in Allamakee County over the past 25 years. Invasion by red cedar (Juniperus virginiana) has reduced hill prairie an average of 55.4% at these sites since the 1980s, but up to 100% on some of the sites surveyed by Nehnevaj. These changes in habitat may have contributed to the overall decrease in species richness. This study provides valuable information about the current status of butterflies present on northeastern Iowa hill prairies that can be used in directing future land management and conservation efforts

Pressure application technique for high-temperature composite fabrication

Technique utilizes characteristic of room-temperature vulcanizing rubber (RTV) which expands readily when heated. RTV expansion can exert uniform pressure on filament-reinforced polymer materials during curing. Technology accommodates high-temperature pressure application for P13-N polyimide composite consolidation during cure

Reliability-based failure analysis of brittle materials

The reliability of brittle materials under a generalized state of stress is analyzed using the Batdorf model. The model is modified to include the reduction in shear due to the effect of the compressive stress on the microscopic crack faces. The combined effect of both surface and volume flaws is included. Due to the nature of fracture of brittle materials under compressive loading, the component is modeled as a series system in order to establish bounds on the probability of failure. A computer program was written to determine the probability of failure employing data from a finite element analysis. The analysis showed that for tensile loading a single crack will be the cause of total failure but under compressive loading a series of microscopic cracks must join together to form a dominant crack

Reliability based analysis of contact problems

The Batdorf model is modified to include the reduction in shear due to the effect of compressive stresses on the crack face. This new formulation was used to obtain the probability of failure of ceramic components under contact stress conditions. The combined effect of the surface and volume flaws are included in the analysis. Due to the nature of the fracture of brittle materials under compressive loading, the component is modeled as a series system in order to establish bounds on the probability of failure

Explaining The Appearance and Success of Voter Referenda For Open-Space Conservation

This paper provides an empirical investigation of the factors that in?uence the appearance and success of voter referenda for policies designed to promote open-space conservation. We take advantage of a data set that includes detailed information on all such referenda that occurred in the United States between 1998 and 2003. Combining these data with information from the U.S. Census, we conduct a nationwide analysis along with focused analyses of referenda that occurred in New Jersey and Massachusetts. Among the questions that we consider are the following: What factors contribute to the appearance of an open- space referendum in a jurisdiction? How does an initiative's funding mechanism, such as a bond, property tax, sales tax, or income tax, affect the way citizens vote? How responsive are favorable votes to the costs of an open-space initiative? And how do socioeconomic characteristics affect demand for public provision of open space?

Seasonal variability in ichthyoplankton abundance and assemblage composition in the northern Gulf of Mexico off Alabama

Multiyear ichthyoplankton surveys used to monitor larval fish seasonality, abundance, and assemblage structure can provide early indicators of regional ecosystem changes. Numerous ichthyoplankton surveys have been conducted in the northern Gulf of Mexico, but few have had high levels of temporal resolution and sample replication. In this study, ichthyoplankton samples were collected monthly (October 2004–October 2006) at a single station off the coast of Alabama as part of a long-term biological survey. Four seasonal periods were identified from observed and historic water temperatures, including a relatively long (June–October) “summer” period (water temperature >26°C). Fish egg abundance, total larval abundance, and larval taxonomic diversity were significantly related to water temperature (but not salinity), with peaks in the spring, spring–summer, and summer periods, respectively. Larvae collected during the survey represented 58 different families, of which engraulids, sciaenids, carangids, and clupeids were the most prominent. The most abundant taxa collected were unidentified engraulids (50%), sand seatrout (Cynoscion arenarius, 7.5%), Atlantic bumper (Chloroscombrus chrysurus, 5.4%), Atlantic croaker (Micropogonias undulatus, 4.4%), Gulf menhaden (Brevoortia patronus, 3.8%), and unidentified gobiids (3.6%). Larval concentrations for dominant taxa were highly variable between years, but the timing of seasonal occurrence for these taxa was relatively consistent. Documented increases in sea surface temperature on the Alabama shelf may have various implications for larval fish dynamics, as indicated by the presence of tropical larval forms (e.g., fistularids, labrids, scarids, and acanthurids) in our ichthyoplankton collections and in recent juvenile surveys of Alabama and northern Gulf of Mexico seagrass habitats

Fluctuation spectra in the NASA Lewis bumpy-torus plasma

The electrostatic potential fluctuation spectrum in the NASA Lewis bumpy-torus plasma was studied with capacitive probes in the low pressure (high impedance) mode and in the high pressure (low impedance) mode. Under different operating conditions, the plasma exhibited electrostatic potential fluctuations (1) at a set of discrete frequencies, (2) at a continuum of frequencies, and (3) as incoherent high-frequency turbulence. The frequencies and azimuthal wave numbers were determined from digitally implemented autopower and cross-power spectra. The azimuthal dispersion characteristics of the unstable waves were examined by varying the electrode voltage, the polarity of the voltage, and the neutral background density at a constant magnetic field strength

A data acquisition and handling system for the measurement of radial plasma transport rates

A system which allows the transfer of experimental data from one or more transient recorders to a digital computer, the entry of calibration data and the entry of archival data is described. The overall approach is discussed and illustrated in detail

Inward transport of a toroidally confined plasma subject to strong radial electric fields

Digitally implemented spectral analysis techniques were used to investigate the frequency-dependent fluctuation-induced particle transport across a toroidal magnetic field. When the electric field pointed radially inward, the transport was inward and a significant enhancement of the plasma density and confinement time resulted