Identification of Volatile Potato Sesquiterpenoids and Their Olfactory Detection by the Two-spotted Stinkbug Perillus bioculatus

The predaceous stinkbug Perillus bioculatus is attracted towards volatiles emitted by damaged potato plants. Whereas mechanically damaged plants lost attractiveness 1 h after damage was inflicted, attraction was long-lasting when the plants were damaged by Colorado potato beetles Leptinotarsa decemlineata, a prey of P. bioculatus. A range of sesquiterpenoids was previously shown to be induced upon beetle damage. In order to evaluate the potential role of sesquiterpenoids in the attraction response, volatiles from damaged potato plants were collected and analyzed with GC-MS and GC-EAG. The antennae of P. bioculatus responded to -caryophyllene, -humulene, (E)--farnesene, (–)-germacrene D, and germacrene D-4-ol. Two sesquiterpenes that coeluted, -zingiberene and bicyclogermacrene, together also elicited olfactory responses of P. bioculatus, whereas the individual compounds did not. The response of P. bioculatus to a variety of sesquiterpenes at low dosages suggests a role for these compounds in prey detection of this stinkbug.     

The instability of health cognitions: Visceral states influence self-efficacy and related health beliefs.

Objective: To determine how visceral impulses, such as hunger and drug craving, influence health beliefs. Design: The authors assessed smokers' self-efficacy and intentions to quit while in a randomly assigned state of cigarette craving or noncraving (Study 1), and assessed dieters weight-loss beliefs while hungry or satiated (Study 2). Main outcome measures: Self-efficacy, smoking cessation, weight-loss goals. Results: The authors found, in both the context of smoking and weight-loss, that participants in a cold (e.g., satiated) state had different health beliefs than participants in a hot state (e.g., hungry). Specifically, in Study 1, the authors found that smokers who experienced cigarette craving had lower self-efficacy than did satiated smokers. Consequently, smokers who craved a cigarette had less intention to quit smoking in the future compared with satiated smokers. In Study 2, the authors found that hungry dieters had less self-efficacy than did satiated dieters. This difference led hungry dieters to form less ambitious future weight-loss goals and view prior weight-loss attempts with more satisfaction. Conclusion: These findings contribute to our understanding of the nature of health beliefs and reveal that health beliefs are more dynamic than previously assumed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determination of total volatile bases in fish: A collaborative study by the West European Fish Technologists' Association (WEFTA)

Summary Two series of collaborative tests were performed. Nine WEFTA laboratories participated in the first exercise, six in the second one. All laboratories applied a common method involving the precipitation of fish proteins by trichloroacetic acid followed by distillation of the extract after addition of sodium hydroxide (Codex method). They also carried out the TVB (total volatile bases) analyses by their own methods (home methods). Mackerel and cod were used. The results of both collaborative exercises showed important systematic errors between participating laboratories both with the codex and with the home methods. Better comparability was obtained when pure solutions of ammonia, di- and trimethyl-amine (the main components of TVB) were subjected to the same methods. On the other hand, the addition of TMA showed average recoveries of only 75% with significant variability among collaborators. The analytical methods should be further scrutinized and the effects of minor but possibly important variations should be investigated before proposing a reference TVB method.

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Bestimmung der gesamten flüchtigen Basen in Fisch: Ringversuchsergebnisse der Vereinigung der Westeuropäischen Fischtechnologen (WEFTA)

Zusammenfassung Es wurden zwei Serien von Ringversuchen durchgeführt. An der ersten nahmen neun, an der zweiten sechs WEFTA-Laboratorien teil. Alle Laboratorien wendeten eine gebräuchliche Methode an, die die Präcipitation des Fischproteins durch Trichloressigsäure mit nachfolgender Destillation des Extraktes nach Zugabe von Natriumhydroxid einschließt (Codex method). Außerdem führten die Teilnehmer die TVB-N-Bestimmungen (gesamte flüchtige Basen) mit ihren hauseigenen Methoden durch (home methods). Verwendet wurden Makrelen-und Kabeljauproben. Die Ergebnisse beider Ringversuche zeigen einen bedeutenden systematischen Fehler zwischen den teilnehmenden Laboratorien sowohl mit der Codex method als auch mit der home method. Wurden reine Lösungen von Ammoniak, Di- und Trimethylamin (die Hauptbestandteile von TVB) mit den gleichen Methoden untersucht, wurde eine bessere Vergleichbarkeit erzielt. Andererseits führte die Addition von Trimethylamin zu mittleren Wiederfindungsraten von nur 75% mit einer signifikanten Variabilität zwischen den Teilnehmern. Die analytischen Methoden sollten weiterhin genau untersucht werden und die Einflüsse von kleineren, möglicherweise aber wichtigen Abänderungen sollten erforscht werden, bevor eine einzelne TVB-N-Bestimmungsmethode als Referenzmethode vorgeschlagen wird.

     

Competing management approaches in large engineering projects: The Dutch RandstadRail project

The management of large engineering projects is often a combination of the focus on planning and control, and the ambition to be flexible given the complexity and uncertainties that characterises these kinds of projects. However, control and flexibility impose contradictory requirements upon the management of these projects. The literature on project management reflects this contradiction. Some authors underline that projects require firm planning and control, thus downplaying the role of flexibility. Others emphasise that projects require flexibility and responsiveness, thus moving away from rigid planning and control. In this contribution, we suggest that in practice project managers acknowledge the weakness of both extremes and therefore strive to combine the two. Moreover, we argue that project success is at risk when project managers do not succeed in meeting the requirements of control and flexibility. To be able to investigate how these competing requirements are dealt with in practice, a framework is developed. The usefulness of the framework is explored by applying the framework to the large engineering project Randstadrail—a light rail project in The Netherlands.     

On the Reliability of Sensitivity Test Methods for Submicrometer‐Sized RDX and HMX Particles

Submicrometer‐sized RDX and HMX crystals were produced by electrospray crystallization and submicrometer‐sized RDX crystals were produced by plasma‐assisted crystallization. Impact and friction sensitivity tests and ballistic impact chamber tests were performed to determine the product sensitivity. Rather than reflecting the quality of the particles, we found the sensitivity tests to be unreliable for submicrometer particles. The used impact test was not accurate enough, while in the friction and ballistic impact chamber tests the submicrometer‐sized crystals were distributed among the grooves of the porcelain plate or among the grains of the sandpaper used in these tests. These observations stress the need for revisiting the current standards used for determining the hazardous properties like friction and impact sensitivity of energetic materials in the case, where the sample consists of submicrometer‐sized crystals. Recommendations were suggested to develop new test methods that only use the interactions between the particles and therefore allow the application of sensitivity tests for submicrometer/nano‐sized energetic materials.     

Synthesis of Cyanoethyl Inulin,Aminopropyl Inulin and Carboxyethyl Inulin

Inulin was cyanoethylated by reaction with acrylonitrile in the presence of aqueous sodium hydroxide. Products with a degree of substution (ds) from 0.2 to 1.6 were prepared. The materials were analyzed using NMR spectroscopy and GPC analysis. The nitrile groups of cyanoethyl inulin were converted into amino groups by reduction with sodium borohydride in the presence of a transition metal chloride (CoCl₂.6H₂O). Furthermore, the nitrile groups were hydrolyzed towards carboxylates using hydrogen peroxide in alkaline medium. The polycarboxylate obtained by this means was shown to possess good calcium carbonate crystallization inhibition properties.     

An infrared analysis method to determine the aromatic carbon content of mineral lubricant base oils based on correlation with carbon-13 NMR aromaticities

A widely used method to determine base oil aromaticity was introduced by G. Brandes in 1956 and is based on a correlation between the infrared aromatic absorption band at 1610 cm⁻¹ and the aromaticity determined by the n-d-M method. Accurate and absolute aromaticities can be measured by carbon-13 NMR but, infortunately, this technique is not suitable for routine analysis. The aromaticities measured by NMR are almost invariably significantly lower than those obtained by Brandes' method. In this study, the areas of the infrared aromatic bands at 1610 and 815 cm⁻¹ of over 70 base oils with aromaticities ranging from 1–16% were correlated by multilinear regression with their carbon-13 NMR aromaticities. An equation to calculate the aromaticity from infrared absorptions was derived. These aromaticities show an excellent match with carbon-13 NMR data. This new infrared method can be applied as a fast and convenient base-oil quality control tool.