The distribution of species range size: a stochastic process

The major role played by environmental factors in determining the geographical range sizes of species raises the possibility of describing their long-term dynamics in relatively simple terms, a goal which has hitherto proved elusive. Here we develop a stochastic differential equation to describe the dynamics of the range size of an individual species based on the relationship between abundance and range size, derive a limiting stationary probability model to quantify the stochastic nature of the range size for that species at steady state, and then generalize this model to the species-range size distribution for an assemblage. The model fits well to several empirical datasets of the geographical range sizes of species in taxonomic assemblages, and provides the simplest explanation of species-range size distributions to date

Enroller: an experiment in aggregating resources

This chapter describes a collaborative project between e-scientists and humanists working to create an online repository of linguistic data sets and tools. Corpora, dictionaries, and a thesaurus are brought together to enable a new method of research. It combines our most advanced knowledge in both computing and linguistic research techniques

Solenoid valve design has one moving part

Solenoid valve structure has only one moving part, a ball and spring assembly. This eliminates wear caused by sliding motion contact between stationary and moving parts or between moving parts

Thrust bearing

A gas lubricated thrust bearing is described which employs relatively rigid inwardly cantilevered spokes carrying a relatively resilient annular member or annulus. This annulus acts as a beam on which are mounted bearing pads. The resilience of the beam mount causes the pads to accept the load and, with proper design, responds to a rotating thrust-transmitting collar by creating a gas film between the pads and the thrust collar. The bearing may be arranged for load equalization thereby avoiding the necessity of gimbal mounts or the like for the bearing. It may also be arranged to respond to rotation in one or both directions

High speed hybrid bearing comprising a fluid bearing and a rolling bearing convected in series

A description is given of an antifriction bearing and a process by which its fatigue life may be extended. The method involves a rotating shaft supported by a fluid bearing and a rolling element bearing coupled in series. Each bearing turns at a fraction of the rotational speed of the shaft. The fluid bearing is preferably conical, thereby providing thrust and radial load support in a single bearing structure

Soft, thermally conductive material

Silicon rubber filled with high percentage of silver-plated copper microspheres provides soft, thermally conductive seat for thermal switch. Material also could be used in thin sheet form to prevent corrosion between dissimilar metals while maintaining good thermal communication. It could be used as thermal gasketing

Labor Unions and Coalitions in Buffalo

Labor unions have evolved tremendously since their inception in 1866 in the United States. Today, some unions in the Buffalo region are responding to free market fundamentalism with the development of multiple coalition partners. Coalitions are composed of unions and like-minded activist organizations. This creative response to a long-term economic crisis has created a high road social infrastructure. Unions have moved beyond their traditional roles of collective bargaining and representation to a more community-oriented mission of improving the quality of local jobs