Status and Management of Pyrethroid Resistance in the Predatory Mite, \u3ci\u3eAmblyseius Fallacis\u3c/i\u3e (Acarina: Phytoseiidae)

Low levels of (5-15 fold) resistance to synthetic pyrethroid (SP) insecticides occur in unexposed apple orchard populations of the predatory mite, Amblyseius fallacis Garman. Permethrin resistance in one strain has been elevated 60--500 fold by selections in green- houses. Multiple resistances to DDT and azinphosmethyl are present and cross-resistance to SP-related compounds is generic at 10--250 fold. Permethrin resistance appears due to both hydrolytic esterase and knock down resistance mechanisms. Permethrin resistance appears to be polygenic and more recessive than dominant; it is unstable in the presence of high densities of susceptible immigrant types, but is reasonably stable in the presence of unselected, resistant immigrant types. Successful establishment of SP-resistant mites into SP-treated, commercial apple orchards was monitored using electrophoretic finger-printing techniques over a two year period. Aspects of management of resistance in A. fallacis to improve IPM are discussed

Radio frequency science considerations

Use of the 400 MHz telecommunications system to obtain scientific information, to provide backup information for the experiments flown, and to obtain measurements which aid in designing future probes is considered. Recommended objectives of such a program are summarized and include: measure 400 MHz amplitude to determine adsorption and perhaps scintillation (if data rate permits); measure noise strength near 400 MHz to reexamine 400 MHz choice and to observe thermal, cosmic, and local synchrotron noise trends; probe VSWR sensing to monitor integrity of system, icing, and possible plasma effects; after the probe is finished, have the bus radio occultation in the same region where the probe fell to evaluate the occultation

First Year Computer Science Projects at Coventry University:Activity-led integrative team projects with continuous assessment.

We describe the group projects undertaken by first year undergraduate Computer Science students at Coventry University. These are integrative course projects: designed to bring together the topics from the various modules students take, to apply them as a coherent whole. They follow an activity-led approach, with students given a loose brief and a lot of freedom in how to develop their project. We outline the new regulations at Coventry University which eases the use of such integrative projects. We then describe our continuous assessment approach: where students earn a weekly mark by demonstrating progress to a teacher as an open presentation to the class. It involves a degree of self and peer assessment and allows for an assessment of group work that is both fair, and seen to be fair. It builds attendance, self-study / continuous engagement habits, public speaking / presentation skills, and rewards group members for making meaningful individual contributions.Comment: 4 pages. Accepted for presentation at CEP2

Corotation of an intermittent solar wind source

The measured electron content of the solar wind in mid-1970 exhibited a region of relatively high electron density that reappeared at intervals of about 27.8 days. It is shown that the repeating event cannot be reconciled with the concept of a long-enduring steady flow, even though the recurrence period is close to the rotation period of the sun. This evidence of transients is inferred from the short duration of each appearance of the interval of higher density; each should last for roughly one corotation interval if it is caused by a steady stream. The radio path was approximately 0.8 AU long, and the corotation interval exceeded 3 days. Other aspects of the content data patterns support the view that such transient events are common in the solar wind. The mid-1970 repeating event is an unusually good example of the intermittent character of flow regions in the solar wind that fluctuate on a time scale of days but endure as identifiable regions for many months. A sputtering corotating source of thin solar plasma streams could explain this series of events; it could also be explained in terms of a stream that is steady in density and speed but undulating north-south so that it passes into and out of the 0.8 AU radio path in a matter of a day or less

Reduction and analysis of two sets of electron content measurements permitting the inference of electron density in the solar wind Final report

Reduction and analysis of electron content measurements permitting inference of electron density in solar win

The Correlation Function of Rich Clusters of Galaxies in CDM-like Models

We use ensembles of high-resolution CDM simulations to investigate the shape and amplitude of the two point correlation function of rich clusters. The standard scale-invariant CDM model with $\Omega=1$ provides a poor description of the clustering measured from the APM rich cluster redshift survey, which is better fitted by models with more power at large scales. The amplitudes of the rich cluster correlation functions measured from our models depend weakly on cluster richness. Analytic calculations of the clustering of peaks in a Gaussian density field overestimate the amplitude of the N-body cluster correlation functions, but reproduce qualitatively the weak trend with cluster richness. Our results suggest that the high amplitude measured for the correlation function of richness class $R \geq 2$ Abell clusters is either an artefact arising from incompleteness in the Abell catalogue, or an indication that the density perturbations in the early universe were very non-Gaussian.Comment: uuencoded compressed postscript ,MNRAS, in press, OUAST-93-1