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  • Author: N. W. Davies x
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The rapid development of the Internet as a major communication tool between scientists has led to the need for a co-ordinated IUPAC presence. Many diverse groups have already initiated distribution of IUPAC related material via their Web sites. These guidelines will provide the structure on which the official IUPAC Internet site maintained through the Secretariat will be based. Rules governing the interaction between this central site and various sites operated by other IUPAC bodies are published here as well as guidelines for the operation of sites maintained by other bodies which contain IUPAC related information. The need for special care when making provisional recommendations widely available on the Internet will be emphasized.

INTRODUCTION

WWW.IUPAC.ORG

INTERNET HOMEPAGE DESIGN - SOME DO'S AND DON'TS

RECOMMENDATION TO USE CHEMICAL MULTIPURPOSE INTERNET MAIL EXTENSIONS ON IUPAC INTERNET WEBSITES

CHEMICAL MARKUP LANGUAGE

GLOSSARY

Summary

This is the first report of post-harvest wood staining in blackwood (Acacia melanoxylon R. Br). In Tasmanian sawmills, an orange-brown stain commonly occurs upon cutting fresh blackwood. An investigation of the causal mechanism of stain development was completed using fresh flitches and stockpiled logs. Some fungi and bacteria were isolated from stained and unstained blackwood, but no species was consistently present in stained wood alone. Wood pH did not vary between stained and unstained wood, but there was some evidence of alterations in phenol composition. Blackwood extracts were analysed by HPLC and a minor phenolic compound was detected that was consistently found in stained samples and rarely in unstained. UV spectra indicated that this compound may be a quinone, but mass spectrometry data was inconclusive. Experiments with blackwood extracts showed that addition of oxygen (by means of H2O2 treatment) increased absorbance in the “brown” wavelengths characteristic of stain. This supports the assumption that the stain is an oxidative chemical stain, as it develops quite rapidly from cut surfaces.

Summary

Identification of plant hybrids produced from closely related species can be difficult using morphological characteristics alone, particularly when identifying young seedlings. In this study, we compared the performance of three calibration models developed to discriminate between seedlings of Eucalyptus globulus, E. nitens and their first-generation hybrid using either foliar oil chemistry or near-infrared reflectance spectral data from fresh, whole leaves. Both oil and near-infrared reflectance spectroscopy (NIRS) models were developed using partial least-squares discriminant analysis and showed high classification accuracy, all correctly classifying more than 91% of samples in cross-validation. Additionally, we developed a larger, “global” and independently validated NIRS model specifically to discriminate between E. globulus and F1 hybrid seedlings of different ages. This model correctly classified 98.1% of samples in cross-validation and 95.1% of samples from an independent test set. These results show that NIRS analysis of fresh, whole leaves can be used as a rapid and accurate alternative to chemical analysis for the purpose of hybrid identification.