Because collective cognition emerges from local signaling among group members, deciphering communication systems is crucial to understanding the underlying mechanisms. Alarm signals are widespread in the social insects and can elicit a variety of behavioral responses to danger, but the functional plasticity of these signals has not been well studied. Here we report an alarm pheromone in the ant...

We describe procedures for measuring cortisol in plasma and serum by isotope dilution and mass spectrometry. A method that incorporated solvent extraction, derivatization, and gas chromatography/high-resolution mass spectrometry provided data of good precision; interassay CVs were generally 3 to 4% for the concentration range of 100-650 nmol/L. Replacing solvent extraction with extraction on a ...

Bud exudates from 9 poplars showing a range o f resistance to bacterial canker and poplar rust were analyzed by gas chromatography-mass spectrometry and the components o f the bud exudate identified. Those compounds previously reported in the literature to have notable antimicrobial activity were listed and the quantities present in the bud exudates o f the speci­ mens analyzed were compared. N...

Food safety has a direct impact on human health and as such is a growing concern worldwide. Presence of harmful pesticide residue in food is a serious cause for concern among consumers so it is important to monitor levels of pesticides in foods. The aim of this study was simultaneous determination of concentrations of 58 pesticides in 40 wheat flour samples collected from Tehran market in Janua...

The production of peptaibols by a marine-related Trichoderma longibrachiatum strain was studied using electrospray ionisation multiple-stage ion trap mass spectrometry (ESI-MSn-IT) and gas chromatography/electron impact mass spectrometry (GC/EI-MS). Two major groups of peptaibols were identified, those with long sequences (20 amino acids) and others with short sequences (11 amino acids). This p...

The results of gas chromatography/mass spectrometry (MS), with Ion Signature Technology, Inc. (North Smithfield, RI) quantitative deconvolution software, are discussed for pesticides identified both as target compounds by using retention and MS data and as unknowns by using only mass spectra. Target compound analysis of 32 pesticides, surrogates, and an internal standard added to lemon oil over...

An environmentally friendly and sensitive method for determination of blockers and agonists was described in this paper. The method is based on a homemade sol-gel solid-phase microextraction (SPME) coating with simultaneous on-fiber derivatization and subsequent gas chromatography mass spectrometry (GC/MS) analysis. The influences of the main factors on the type and thickness of the homemade fi...

We characterized three Japanese firefly species (Luciola lateralis, Luciola cruciata, and Lucidina biplagiata) and three North American firefly species (Lucidota atra, Photuris lucicrescens, and Photuris cinctipennis) based on their surface hydrocarbons. The analysis of firefly extracts by gas chromatography-mass spectrometry (GC-MS) revealed clear differences in the chromatographic profiles an...

To date, only differential extraction-based approaches have been able to determine the presence of covalently bound contaminants such as the reduced forms of trinitrotoluene (TNT) in field soils. Here, we employed thermal elution, pyrolysis, and gas chromatography/mass spectrometry (GC/MS) to distinguish between covalently bound and non-covalently bound reduced forms of TNT in soil. Model soil ...

Two fatalities resulting from suicidal ingestion of flecainide are described. The decedents, ages 33 and 15, were otherwise healthy; both took their mothers' medications. In one case, from electrocardiographic data, there was found a high-grade conduction block with idioventricular rhythm. Blood and tissue samples from autopsy were analyzed for flecainide by gas chromatography/nitrogen-phosphor...