54,636 research outputs found
Heterospecific Hymenoptera found inside the nests of Bombus impatiens (Hymenoptera: Apidae).
The nests of social Hymenoptera are particularly attractive to species engaging in resource robbing due to their concentration of resources. Here, the identity of heterospecific intruders in Bombus impatiens nests are described, with a particular focus on intrusion by invasive species – Vespula germanica and Anthidium oblongatum. While V. germanica is well known as a resource robber, this is the first time Anthidium spp. have been documented entering the nest of a social heterospecific. Of 16 Bombus impatiens colonies placed in a field in Lansing, MI, eight had heterospecific intruders, including Apis mellifera, A. oblongatum, and V. germanica. Motivations behind entering a foreign nest are discussed
Two-dimensional graphics tools for a transputer based display board
A package of 2-D graphics routines has been developed in an effort to standardize and simplify the user interface for a transputer based graphics display board. The routines available take advantage of the graphic board's capabilities while also presenting an intuitive approach for generating drawings. The routines allow a user to perform graphics rendering in a 2-D real-coordinate space without regard to the actual screen coordinates. Multiple windows, which can be placed arbitrarily on the screen as well as the ability to use double-buffering techniques for smooth animations are also supported. The routines are designed to be run on a transputer other than the graphics display board. The window and screen parameters are maintained locally. The conversion to device coordinates is also performed locally. The only data sent to the display board are control and device coordinate display commands. The routines available include: rotation translation, and scaling commands; absolute and relative point and line commands; circle, rectangle and polygon commands; and window and viewpoint definition commands
Multiprocessor graphics computation and display using transputers
A package of two-dimensional graphics routines was developed to run on a transputer-based parallel processing system. These routines were designed to enable applications programmers to easily generate and display results from the transputer network in a graphic format. The graphics procedures were designed for the lowest possible network communication overhead for increased performance. The routines were designed for ease of use and to present an intuitive approach to generating graphics on the transputer parallel processing system
Evolution of concentration in the United Kingdom cement industry: Structure, conduct, and performance. Evolution of concentration and competition series No. 20, November 1978
Water and the Biology of Prions and Plaques
This is an attempt to account for the insolubility and/or aggregation of prions and plaques in terms of a model of water consisting of an equilibrium between high 
density and low density microdomains. Hydrophobic molecules, including proteins, 
accumulate selectively into stable populations, enriched in high density water, at 
charged sites on biopolymers. In enriched high density water, proteins are probably 
partially unfolded and may precipitate out when released. All extracellular matrices 
contain such charged polymers. Prions, which have been shown to accumulate in soils 
and clays containing silicates and aluminates also probably accumulate in 
extracellular matrices. 
 
Release of proteins follows hydrolysis of the charged groups by highly reactive high 
density water. This is normally a slow process but is greatly accelerated by urea. 
Plaques may form with age and disease because of accumulation of urea and, perhaps, 
glucose in the blood. This favours precipitation of proteins emerging from matrices, 
rather than refolding and solution. Dialysis should, therefore, interfere with plaque 
formation and impede the development of some age-related diseases
On Perturbations of Unitary Minimal Models by Boundary Condition Changing Operators
In this note we consider boundary perturbations in the A-Series unitary
minimal models by phi_{r,r+2} fields on superpositions of boundaries. In
particular, we consider perturbations by boundary condition changing operators.
Within conformal perturbation theory we explicitly map out the space of
perturbative renormalisation group flows for the example phi_{1,3} and find
that this sheds light on more general phi_{r,r+2} perturbations. Finally, we
find a simple diagrammatic representation for the space of flows from a single
Cardy boundary condition.Comment: 27 pages, 10 figure
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