the pea aphid, acyrthosiphon pisum (harris) is one of the most important pests of pea throughout the world.host stage preference under choice and no-choice tests and age-specific functional response of praon volucre (haliday) parasitizing a. pisum were investigated. the experiments were carried out under laboratory conditions at 25 ± 1 °c, 60 ± 5% rh and a photoperiod of 14: 10 h (l: d). functi...

The approaches and interpretations of a class of 6th graders and a class of 8th graders in a U.S. middle school asked to engage in tasks that involved using observations to describe and classify samples is the subject of this paper. Overall 8th graders were better able to perform the tasks, suggesting a developmental advantage aspect. However, the descriptions of the rock and mineral samples re...

Janine M Preble1,2 & Charles Stephen Foster*,1,2,3 Massachusetts Eye Research & Surgery Institution, 5 Cambridge Center, 8th Floor, Cambridge, MA 02142, USA Ocular Immunology & Uveitis Foundation, 5 Cambridge Center, 8th Floor, Cambridge, MA 02142, USA Harvard Medical School, 25 Shattuck Street, Boston, MA 02115, USA *Author for correspondence: Tel.: +1 617 621 6377 Fax: +1 617 494 1430 sfoster...

The connection between local structure and the grain size distribution in nanophase palladium is studied by XAFS and x-ray diffraction (XRD). We show that there is a reduced average coordination number in all samples; this reduction is compatible with a size effect, cmtradicting previous XAFS measurements. Both a f i t shell analysis and a full analysis up to the 8th coordination shell, includi...