The Male Abdominal Glands of <Emphasis Type="Italic">Leucophaea maderae</Emphasis>: Chemical Identification of the Volatile Secretion and Sex Pheromone Function

In Leucophaea maderae, male calling behavior involves the release of a sex pheromone from the abdominal sternal glands. An extract of sternal glands attracted conspecific females over a distance. The compounds present were identified as hydroxy-3-butan-2-one, (2R, 3R)-butanediol, senecioic acid, and (E)-2-octenoic acid. The same components are also present in male tergal glands. The identified compounds were tested on their own and in mixtures. Their biological function is discussed.     

Pesticide residues survey in citrus fruits

The use of pesticides is widespread in citrus fruits production for pre- and post-harvest protection and many chemical substances may be applied in order to control undesirable moulds or insects. A survey was carried out to evaluate levels of pesticide residues in citrus fruits. Two multiresidue analytical methods were used to screen samples for more than 200 different fungicides, insecticides and acaricides. A total of 240 samples of citrus fruits including lemon, orange, mandarin, grapefruit, lime, pomelo and kumquat were taken in various markets in the Geneva area during the year 2003. Ninety-five percent of the 164 samples issued from classical agriculture contained pesticides and 38 different compounds have been identified. This high percentage of positive samples was mainly due to the presence of two post-harvest fungicides, imazalil and thiabendazole, detected in 70% and 36% of samples respectively. Only three samples exceeded the Swiss maximum residue limits (MRLs). Fifty-three samples sold with the written indication “without post-harvest treatment” were also controlled. Among theses samples, three exceeded the Swiss MRLs for penconazole or chlorpyrifos and 18 (34%) did not respect the written indication since we found large amounts of post-harvest fungicides. Finally, 23 samples coming from certified organic production were analysed. Among theses samples, three contained small amounts of pesticides and the others were pesticides free.     

Phospholipid Distribution and Phospholipid Fatty Acids of the Tropical Tunicates <Emphasis Type="Italic">Eudistoma</Emphasis> sp. and <Emphasis Type="Italic">Leptoclinides uniorbis</Emphasis>

Two tunicates, Eudistoma sp. and Leptoclinides uniorbis, collected from the tropical waters off Djibouti were investigated for lipids and phospholipid (PL) fatty acids. PL accounted for 38.2% of the total lipids in Eudistoma sp. and for 30.2% in L. uniorbis. PL classes were quantified by normal-phase high-performance liquid chromatography using an evaporative light-scattering detector and revealed essential differences. Eudistoma sp. contained mainly phosphatidylcholine (PC, 70.3% of total PL) and lysophosphatidylcholine (LPC, 11.9%) and was devoid of phosphatidylserine (PS), whereas the major PL of L. uniorbis was PS (59.1%) followed by PC (22.5%) and LPC (8.8%). Gas chromatography–mass spectrometry analyses of fatty acid (FA) derivatives revealed 38 FA in Eudistoma sp., and 35 FA in L. uniorbis, ranged from C₁₂ to C₂₄ chain lengths. Polyunsaturated FA accounted for 25.9% in Eudistoma sp. and for 32.3% in L. uniorbis. Interestingly, L. uniorbis contained a high percentage (16.7%) of the 20:5n-3 acid (8.9% in Eudistoma sp.) and the 18:4n-3 acid (4.1%). Significant levels of the 20:4n-6 acid were observed in both organisms (7.8 and 6.0% respectively). Eudistoma sp. contained the rare 20:3n-7 acid (2.3%) only recorded to date in hydrothermal vent animals. The cyclopropane dihydrosterculic acid was identified in both tunicates (0.7 and 0.5% respectively). These latter FA, together with some unusual branched saturated and monounsaturated FA, revealed the occurrence of associated bacteria in the tunicates. Another noticeable feature was a series of eight C₁₆ to C₁₈ aldehyde dimethylacetals revealing the presence of plasmalogens at 5.0% in Eudistoma sp. and 14.2% in L. uniorbis. The results of this study were compared with those previously published for other tunicates regarding mainly PL content and FA composition.     

Effect of a Drying Pretreatment on Morphology of Porous Poly(Ether-Imide) Membrane Prepared Using Vapor-Induced Phase Separation

Symmetric porous membranes were prepared from concentrated poly(ether-imide) (PEI) solutions using vapor-induced phase separation (VIPS) coupled with a drying pretreatment. Moderately concentrated solutions of PEI in N-methylpyrrolidinone (NMP) (14–16 wt%) were first cast on glass plates and the solvent was then allowed to evaporate under a dry air flow up to the desired concentration (16–38 wt%) before forming the membrane structure by VIPS. The polymer concentration profiles (confocal Raman microscopy) and model predictions were in good agreement to show that the evaporation stage did not induce a polymer gradient concentration with PEI/NMP systems. These results were confirmed by examination of the final membrane morphology (SEM).     

UCC日产万吨熟料水泥生产线燃料处理及燃烧系统特点

0引言法国皮拉德EGCI股份公司(PILLARD EGCI)成立于1919年,是专业从事锅炉、回转窑及分解炉燃烧设备的专业公司。在世界范围内,皮拉德公司提供的水泥及其它矿物处理行业的回转窑及分解炉燃     

Effect of oxide additives and particle size on stabilization of treated commercial zirconia

Commercial zirconia was milled and sedimented to separate finer and coarser particles. Then additives such as CaO and Y₂O₃ were added in proportions of 7 and 13 mol.% each. Wet mixing of these powders was done in the ball mill. These mixtures were then compacted through uniaxial compaction using 150 MPa of pressure to make pellets of 8 mm diameter and 3 mm height approximately. The compacts were sintered at 1700 °C under argon atmosphere during 1 h. Densification calculations revealed densities of more than 80% in all samples. Scanning electron microscopy (SEM) showed that closed porosity was present. X-ray diffraction (XRD) results confirmed the presence of cubic phase with quantities higher in samples of finer powder and 13 mol.% additive.     

Diagnosis Method Using ΔIDDQ Probabilistic Signatures: Theory and Results

This paper presents a diagnostic method based on differential I_DDQprobabilistic signatures, inspired by telecommunications systems. The method and its unique features are described. Then, results from an IC monitor containing controllable faults show the capability of the method to diagnose actual activated faults, despite a strong experimental current standard variation. These results validate previous simulation procedures, which are applied to quantify effects not covered by the monitor experiment, that is, the effect of the load of a bridged node and the effect of the bridge resistance value. These experimental and simulation results reveal the robustness of the proposed diagnosis method, that has identified and located every single fault considered so far.     

《可持续发展设计指南》选载(之十一)如何选择可持续性发展水资源和室内环境技术

一、中国的缺水问题在中国的很多地区,可用水量的日益减少是当前最大的社会、经济和政治问题。以人均可用量2500m3的标准相比较,中国大陆的淡水供应只达到2000m3,属于世界     

Development of a quadruplex-real-time-PCR for screening food for genetically modified organisms

With the ever increasing number of genetically modified plants authorized worldwide, including in the European Union, high throughput detection methods need to be developed. In this paper, a quadruplex-real-time-PCR method is described which allows rapid and simultaneous screening of food for the presence of target DNA sequences from the cauliflower mosaic virus 35S promoter, the NOS terminator from Agrobacterium tumefaciens, the soya reference lectin gene and the maize reference alcool dehydrogenase gene (adh). Three of the four primers and probe combinations have already been published elsewhere, whereas primers and probe for NOS terminator-PCR were developed in-house. Validation data show sensitivities down to five copies for 35S promoter and NOS terminator PCR, even when target sequences of the competing PCRs are in large excess. Thorough adjustment of primer and probe concentrations allowed high individual PCR efficiencies with negligible physical cross-talk between the four detection channels. This method provides a basis for a rapid screening of food for the most frequently used regulatory elements present in GM crops authorized for food in the European Union. In addition it provides information about the presence of species which are possibly genetically modified.