1,741 research outputs found
Oviposition deterrents for Aedes aegypti in extracts of Lemna minor
Dual choice bioassays demonstrated that water and methanolic extracts of <i>Lemna minor</i> L., in aqueous solution, deterred oviposition by <i>Aedes aegypti</i> L. The methanolic extracts were active at concentrations of 1000 and 10,000 PPM but were inactive at 1, 10, and 100 PPM. Pentane extracts and L. minor culture water showed no activity. None of the extracts bioassayed were biologically active against <i>Culex pipiens</i> L. Experiments in which physical contact with the extracts was prevented, provide evidence that a volatile chemical emanating from the extract is responsible for the deterrency
The Penn State ORSER system for processing and analyzing ERTS and other MSS data
The author has identified the following significant results. The office for Remote Sensing of Earth Resources (ORSER) of the Space Science and Engineering Laboratory at the Pennsylvania State University has developed an extensive operational system for processing and analyzing ERTS-1 and similar multispectral data. The ORSER system was developed for use by a wide variety of researchers working in remote sensing. Both photointerpretive techniques and automatic computer processing methods have been developed and used, separately and in a combined approach. A remote Job Entry system permits use of an IBM 370/168 computer from any compatible remote terminal, including equipment tied in by long distance telephone connections. An elementary cost analysis has been prepared for the processing of ERTS data
Detection of Minimal Supersymmetric Model Higgs Bosons in \gam\gam Collisions: Influence of SUSY Decay Modes
We demonstrate that supersymmetric decay modes of the neutral Higgs bosons of
the MSSM could well make their detection extremely difficult when produced
singly in \gam\gam collisions at a back-scattered laser beam facility.Comment: 12 pages, requires phyzzx.tex and tables.tex, full postscript file
including embedded tables available via anonymous ftp at ucdhep.ucdavis.edu
as [anonymous.gunion]gamgamsusy.ps, preprint UCD-94-3
Settlement Predictions in Residual Soils by Dilatometer, Pressuremeter and One-Dimensional Compression Tests: Comparison with Measured Field Response
A case study investigating settlement predictions based on data from one dimensional compression, pressuremeter (PMT) and dilatometer (DMT) tests is presented. A relationship is established between PMT and DMT evaluated moduli and the standard penetration N values. These relationships are utilized in the settlement computations. The predictions obtained by each method are compared to the actual measured settlement. The column location at which settlement observations were made was instrumented with strain gages to measure the actual applied loads. A comparison between actual and design loads is made. Settlement predictions using PMT were performed utilizing two different existing approaches. A distinction is made between the rheological factors, both termed α, used in each of the methods
ERTS and aircraft multispectral scanner digital data users manual
There are no author-identified significant results in this report
Oviposition deterrents for Aedes aegypti in extracts of Lemna minor
Dual choice bioassays demonstrated that water and methanolic extracts of Lemna minor L., in aqueous solution, deterred oviposition by Aedes aegypti L. The methanolic extracts were active at concentrations of 1000 and 10,000 PPM but were inactive at 1, 10, and 100 PPM. Pentane extracts and L. minor culture water showed no activity. None of the extracts bioassayed were biologically active against Culex pipiens L. Experiments in which physical contact with the extracts was prevented, provide evidence that a volatile chemical emanating from the extract is responsible for the deterrency
Pre-emergence insecticide applications for control of the mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Scolytidae)
An experiment was set up near Princeton, British Columbia, to investigate the efficacy of carbaryl (Sevin SL) and chlorpyrifos and (Dursban 4E) at 1% and 2% a.i. in water, to prevent the successful emergence of mountain pine beetles, Dendroctonus ponderosae Hopkins, from infested lodgepole pines, Pinus contorta var. latifolia Engelmann. All treatments were effective in killing the emerging beetles outright. Mortality ranged from 83.3% for 1% Sevin to 94.9% for 2% Dursban, compared with 6.1% mortality of beetles emerging from water-treated control trees. Living emergent beetles from all treatments suffered >50 and >90% mortality after 1 and 5 days, respectively, compared with 5 and 10 days, respectively, for beetles from control treatments
Hylemya antiqua (Meigen): Longevity and oviposition in the laboratory?
In laboratory cultures, some female Hylemya antiqua (Meigen) were still alive and ovipositing after 66 days, whereas males usually survived no longer than 50 days. The average lifespan of 12 individually-reared, reproducing females was 48 days. Oviposition began no earlier than 8 days, and on the average, 10.5 days after the females emerged. Heavy oviposition by most females was cyclic, occurring every other day. The mean fecundity/female in 3 cultures was 259.2, 114.5 and 218.4, respectively, but for individually-reared females, it was 491.5. Variations in diet and environment probably lead to poor or inconsistent correlation of laboratory data on longevity and fecundity with actual events in the field. However, these data provide precise guidelines for utilization of H. antiqua in laboratory experiments
Observations on Eriocampa ovata L. (Hymenoptera: Tenthredinidae) infesting red alder in southwestern British Columbia
As in Quebec, Eriocampa ovata L. in British Columbia is bivoltine, parthenogenetic and overwinters as a prepupa. Unlike E. ovata in Quebec, the first instar larvae emerge on the lower side of the leaf, and pass through 6 or 7 rather than 5 or 6 larval instars. Defoliation characteristically leaves only the midrib and main secondary veins. In limited areas, small trees may be completely defoliated
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