Lappuse 1 no 136 rezultātiem
A new time-integrated thermal desorption technique has been developed that can be used with selected ion flow tube mass spectrometry, TI-TD/SIFT-MS, for off-line quantitative analyses of VOCs accumulated onto sorbents. Using a slow desorption temperature ramp, the absolute amounts of desorbed
The turpentine fraction of conifer oleoresin is a complex mixture of monoterpene olefins and plays important roles in defense and in the mediation of chemical communication between conifer hosts and insect predators. The stereochemistry of the turpentine monoterpenes is critical in these
Volatiles collected on Poropak Q from fusiform rust galls (Cronartium quercuum F. sp.fusiforme) of loblolly pine for 3 hr were better ovi-position stimulants forDioryctria amatella (Hulst) females than extracts of 8-hr collections. GLC analysis of these extracts showed no major differences in
Emissions of Biogenic Volatile Organic Compounds (BVOCs) observed during 2007 from an experimental Pinus taeda plantation in Central North Carolina are compared with model estimates from the Model of Emissions of Gases and Aerosols from Nature (MEGAN) version 2.1. Relaxed eddy accumulation (REA)
Resin obtained from Pinus radiata and five monoterpene components of resin (limonene, α-pinene, β-pinene, camphene, and myrcene) were tested to determine their effects on mycelial growth and germination and survival of spores of Fusarium circinatum, the cause of pitch canker in pine, and F.
There is a growing awareness of vegetation's role as a source of potentially reactive hydrocarbons that may serve as photochemical oxidant precursors. This study assessed the influence of light and temperature, independently, on monoterpene emissions from slash pine (Pinus elliottii Engelm.). Plants
Bioassays were conducted with first-stage larvae and newly emerged females of the southern pine coneworm,Dioryctria amatella (Hulst), to detect feeding and ovipositional preferences for different host-plant materials collected between April and August. Correlations between measures of insect
Monoterpenoid compounds extracted from wood of Scots pine, Pinus sylvestris L, synergized the attraction of the old-house borer, Hylotrupes bajulus (L), to the male pheromone (3R)-3-hydroxy-2-hexanone ((3R)-ketol) + 1-butanol. Glasshouse experiments using ground traps baited with extracts derived
Monoterpenes emitted to air from two Swedish kraft (sulphate) pulp-mills were determined by sampling on the Tenax adsorbent followed by laboratory analysis using thermal desorption combined with high-resolution gas chromatography. The composition of the terpenes was found to be similar in the
Glass capillary columns with liquid phases of different polarities were prepared and tested. Of the nine liquid phases used (Apiezon L, SE-30, OV-101, Ucon 50 LB 550X, Emulphor ON-870, Carbowax 20M, FFAP, SP-1000 and Silar 10C) FFAP was the most suitable for the separation of monoterpene
In order to develop a valuable method for accurate screening of biogenic emissions from undisturbed living plants or for plant-insect interactions, solid-phase microextraction (SPME) has been combined with dynamic branch enclosure cuvettes and enantioselective GC/MS. The study was conducted at
Conifers respond to herbivore attack with defensive chemicals, which are toxic to both insects and their associated microorganisms. Microorganisms associated with insects have been widely reported to metabolize toxic chemicals, which may help both microorganisms and host insects overcome host
Antioxidants from several nutrients, e.g. vitamin E, beta-carotene, or flavonoids, inhibit the oxidative modification of low-density lipoproteins. This protective effect could possibly retard atherogenesis and in consequence avoid coronary heart diseases. Some studies have shown a positive effect of
The secondary compounds of pines (Pinus) can strongly affect the physiology, ecology and behaviors of the bark beetles (Coleoptera: Curculionidae, Scolytinae) that feed on sub-cortical tissues of hosts. Jack pine (Pinus banksiana) has a wide natural distribution range in North America (Canada and
The mountain pine beetle (Dendroctonus ponderosae, MPB) has killed millions of lodgepole pine (Pinus contorta) trees in Western Canada, and recent range expansion has resulted in attack of jack pine (Pinus banksiana) in Alberta. Establishment of MPB in the Boreal forest will require use of jack pine