Notes on the Life Histories of \u3ci\u3eAcrosternum Hilare\u3c/i\u3e and \u3ci\u3eCosmopepla Bimaculata\u3c/i\u3e (Heteroptera: Pentatomidae) in Southern Illinois

The life histories of Acrosternum hilare and Cosmopepla bimaculata were studied in southern Illinois from May 1972 to September 1974 and from September 1992 to June 1995. Both species were bivoltine, overwintered as adults, and became active in early spring. The subsequent generations were characterized by marked overlapping of the nymphal instars. No active adults were found after early November

Resurvey of the Pentatomoidea (Heteroptera) of the La Rue-Pine Hills Research Natural Area in Union County, Illinois

A resurvey of the Pentatomoidea of the La Rue-Pine Hills Research Natural Area was conducted from September 1992 to June 1995 and the results compared with those of an earlier survey by McPherson and Mohlenbrock (1976). Sampling during the resurvey was limited to the 17 collecting sites of the earlier survey, thus permitting comparisons of the flora and fauna in the two studies. Notes were taken on the times of occurrence of adult and immature stages and on the food plants. Of the 49 pentatomoid species and subspecies included in the original survey, 36 were collected during the resurvey. Of the 13 not collected, 12 were rare and one, Holcostethus limbolarius (Stål), was relatively common during the original survey. Two additional species, Galgupha ovalis Hussey and Corimelaena obscura McPherson and Sailer, were added to the list, the latter because it was described as new subsequent to the original survey. The most noticeable change in the vegetation that accounted for differences in pentatomoid diversity and abundance was the marked reduction in abundance of common mullein, Verbascum thapsus L. The resurvey showed that 11 of the 17 sites had changed in character and plant composition, seven because of woody invasion and four because of the influence of exotic and invasive species; the remaining six had changed little. Exotic plant species have become an increasingly prominent component of the vegetative communities

Multiple curved descending approaches and the air traffic control problem

A terminal area air traffic control simulation was designed to study ways of accommodating increased air traffic density. The concepts that were investigated assumed the availability of the microwave landing system and data link and included: (1) multiple curved descending final approaches; (2) parallel runways certified for independent and simultaneous operation under IFR conditions; (3) closer spacing between successive aircraft; and (4) a distributed management system between the air and ground. Three groups each consisting of three pilots and two air traffic controllers flew a combined total of 350 approaches. Piloted simulators were supplied with computer generated traffic situation displays and flight instruments. The controllers were supplied with a terminal area map and digital status information. Pilots and controllers also reported that the distributed management procedure was somewhat more safe and orderly than the centralized management procedure. Flying precision increased as the amount of turn required to intersect the outer mark decreased. Pilots reported that they preferred the alternative of multiple curved descending approaches with wider spacing between aircraft to closer spacing on single, straight in finals while controllers preferred the latter option. Both pilots and controllers felt that parallel runways are an acceptable way to accommodate increased traffic density safely and expeditiously

Resurvey of the Pentatomoidea (Heteroptera) of the La Rue-Pine Hills Research Natural Area in Union County, Illinois

A resurvey of the Pentatomoidea of the La Rue-Pine Hills Research Natural Area was conducted from September 1992 to June 1995 and the results compared with those of an earlier survey by McPherson and Mohlenbrock (1976). Sampling during the resurvey was limited to the 17 collecting sites of the earlier survey, thus permitting comparisons of the flora and fauna in the two studies. Notes were taken on the times of occurrence of adult and immature stages and on the food plants. Of the 49 pentatomoid species and subspecies included in the original survey, 36 were collected during the resurvey. Of the 13 not collected, 12 were rare and one, Holcostethus limbolarius (Stål), was relatively common during the original survey. Two additional species, Galgupha ovalis Hussey and Corimelaena obscura McPherson and Sailer, were added to the list, the latter because it was described as new subsequent to the original survey. The most noticeable change in the vegetation that accounted for differences in pentatomoid diversity and abundance was the marked reduction in abundance of common mullein, Verbascum thapsus L. The resurvey showed that 11 of the 17 sites had changed in character and plant composition, seven because of woody invasion and four because of the influence of exotic and invasive species; the remaining six had changed little. Exotic plant species have become an increasingly prominent component of the vegetative communities

Race/ethnicity and gender differences in drug use and abuse among college students

This study examines race/ethnicity and gender differences in drug use and abuse for substances other than alcohol among undergraduate college students. A probability-based sample of 4,580 undergraduate students at a Midwestern research university completed a cross-sectional Web-based questionnaire that included demographic information and several substance use measures. Male students were generally more likely to report drug use and abuse than female students. Hispanic and White students were more likely to report drug use and abuse than Asian and African American students prior to coming to college and during college. The findings of the present study reveal several important racial/ethnic differences in drug use and abuse that need to be considered when developing collegiate drug prevention and intervention efforts.https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2377408/https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2377408/Accepted manuscrip

Light scattering and phase behavior of Lysozyme-PEG mixtures

Measurements of liquid-liquid phase transition temperatures (cloud points) of mixtures of a protein (lysozyme) and a polymer, poly(ethylene glycol) (PEG) show that the addition of low molecular weight PEG stabilizes the mixture whereas high molecular weight PEG was destabilizing. We demonstrate that this behavior is inconsistent with an entropic depletion interaction between lysozyme and PEG and suggest that an energetic attraction between lysozyme and PEG is responsible. In order to independently characterize the lysozyme/PEG interactions, light scattering experiments on the same mixtures were performed to measure second and third virial coefficients. These measurements indicate that PEG induces repulsion between lysozyme molecules, contrary to the depletion prediction. Furthermore, it is shown that third virial terms must be included in the mixture's free energy in order to qualitatively capture our cloud point and light scattering data. The light scattering results were consistent with the cloud point measurements and indicate that attractions do exist between lysozyme and PEG.Comment: 5 pages, 2 figures, 1 tabl

Columnar and lamellar phases in attractive colloidal systems

In colloidal suspensions, the competition between attractive and repulsive interactions gives rise to a rich and complex phenomenology. Here, we study the equilibrium phase diagram of a model system using a DLVO interaction potential by means of molecular dynamics simulations and a thermodynamical approach. As a result, we find tubular and lamellar phases at low volume fraction. Such phases, extremely relevant for designing new materials, may be not easily observed in the experiments because of the long relaxation times and the presence of defects.Comment: 5 pages, 5 figure

Visualisation and optimisation of shielding gas coverage during gas metal arc welding

The density gradients and flow characteristics of the gas shield during gas metal arc welding (GMAW) of DH36, higher strength ‘construction steel’ were visualised using schlieren imaging. A systematic study was undertaken to determine the effect of shielding gas flow rate, as well as changes in the nozzle stand-off and angle, on the weld quality. The schlieren images were used to validate 2D and 3D magnetohydrodynamic (MHD) finite element models of the interaction between the Ar shielding gas, the arc and the ambient atmosphere. Weld porosity levels were determined through x-ray radiography. Sufficient shielding gas coverage was provided at a minimum of 9 l/min pure Ar, irrespective of relatively large increases in the nozzle stand-off and angle. Using 80% Ar/20% CO2 shielding gas, and 86% Ar/12% CO2/2% O2 shielding gas with flux cored arc welding (FCAW-G), achieved good quality welds down to 5 l/min. The introduction of 12 l/min in production welding has been implemented with no compromise in the weld quality and further reductions are feasible

Spillway Rock Scour Analysis - Composite of Physical & Numerical Modelling, Paradise Dam, Australia

A number of problems and solutions of rock scour downstream of spillways have been evaluated using a composite approach, based on the gathering of detailed data from a physical model and utilising those data in a sequence of calibration and application of numerical modelling of the scour. Our paper will describe the application of the Computational Scour Model (CSM - Bollaert, 2002 and subsequent) as the numerical procedure that makes the composite approach a proven methodology for such problems. The paper will focus on a case study application of the procedure based on the experiences of flooding and scour at the Paradise Dam, Queensland, Australia. Flooding in 2013 caused substantial scour downstream of the primary spillway. The occurrence led to a series of studies for the evaluation of the geology, and the evident hydraulics behaviour using a well-instrumented physical model to capture pressure and velocity transients, all as part of a process to determine the scour mechanism, and to determine the response of the spillway and areas downstream to future floods of larger magnitude. Utilising the transient data from approximately 60 pressure transducers, ADV measurements for transient velocities, together with the detailed geologic assessment, the comprehensive scour modelling procedures developed by Bollaert were applied for calibration of the numerical model and its application for possible discharge scenarios. The paper will discuss the design and construction of the physical model and instrumentation as a key part of securing adequate data for the composite procedure, and go on to illustrate the outcomes of the CSM procedures