The introduction of the image analysing computer (Quantimet 720) makes possible the rapid and accurate measurement of components in thin sections and extends the range of measurements possible. Two techniques for presenting material for analysis are outlined. Models are used to demonstrate the measurement of size, irregularity and orientation of components and their discrimination according to shape.
The ability of glandular hairs on the foliage of the wild potato species Solanum polyadenium andS. berthaultii to trap mite and insect pests is illustrated by scanning electron micrographs. Both potato species have hairs with four-lobed heads which release a sticky substance when ruptured. On S. polyadenium these hairs trapped aphids, Colorado beetle larvae and a leafhopper Javasella pellucida.S. berthaultiialso has hairs with a stickydroplet at their tips;these hairs trapped such small pests as spider mites, thrips and larval mealybugs. Adult whitefly were not trapped because a powdery wax from the whiteflies coated the hairs. I t is suggested that these glandular hairs could help protect potato crops by trapping many foliage pests, including disease vectors.
BackgroundDetailed local HIV-1 sequence data are essential for monitoring the HIV epidemic, for maintaining sensitive sequence-based diagnostics, and to aid in designing vaccines.ResultsReported here are full envelope sequences derived from 38 randomly selected HIV-1 infections identified at a Gambian clinic between 1991 and 2009. Special care was taken to generate sequences from circulating viral RNA as uncloned products, either by limiting dilution or single genome amplification polymerase chain reaction (PCR). Within these 38 isolates, eight were subtyped as A and 18 as CRF02_AG. A small number of subtype B, C, D viruses were identified. Surprising, however, was the identification of six isolates with subtype J-like envelopes, a subtype found normally in Central Africa and the Democratic Republic of the Congo (DRC), with gag p24 regions that clustered with subtype A sequences. Near full-length sequence from three of these isolates confirmed that these represent a novel circulating recombinant form of HIV-1, now named CRF49_cpx.ConclusionsThis study expands the HIV-1 sequence database from the Gambia and will provide important data for HIV diagnostics, patient care, and vaccine development.
An improved method for the sampling of splash droplets carrying fungal spores uses fixed photographic film. Droplets left clear, permanent traces within which spores were easily visible. The droplet spread factor was constant because the gelatine layer was uniform. A comparison of estimates of the numbers of splash droplets, spore‐carrying droplets and spores dispersed by a 5 mm drop falling onto a spore suspension (depth 0.5 mm) with those obtained by other workers demonstrated the reliability of this method. The accuracy was improved by semi‐automatic analysis of the spore‐carrying splash droplet traces with an image‐analysing computer.
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