Identification,Synthesis, and Behavioral Activity of 5,11-Dimethylpentacosane,A Novel Sex Pheromone Component of the Greater Wax Moth,Galleria Mellonella (L.)

The greater wax moth, Galleria mellonella (L.), is a serious and widespread pest of the honeybee, Apis mellifera L. In contrast to most moths, for which long-range mate finding is mediated by female-produced sex pheromones, G. mellonella males attract conspecific females over long distances by emitting large amounts of a characteristic scent in combination with bursts of ultrasonic calls. The male scent for this species was previously identified as a blend of nonanal and undecanal. When these compounds were bioassayed, characteristic short-range sexual behavior, including wing fanning, was triggered in conspecific females, but the aldehyde blend failed to elicit attraction over longer distances. We identified, via analysis and synthesis, a third male-specific compound, 5,11-dimethylpentacosane. We show that it acts as a behavioral synergist to the aldehydes. In wind tunnel experiments, very few female moths responded to the aldehyde blend or to 5,11-dimethylpentacosane tested separately, but consistently showed orientation and source contact when a combination of all three compounds was applied. The level of attraction to the three-component mixture was still lower than that to male extract, indicating that the composition of compounds in the synthetic blend is suboptimal, or that additional pheromone components of G. mellonella are yet to be identified. The identification of 5,11-dimethylpentacosane is an important step for the development of an efficient long-range attractant that will be integrated with other environmentally safe strategies to reduce damage to beehives caused by wax moths.     

Effect of the Degree of Phosphorylation on the Crystallinity of Native Potato Starch

X-ray diffraction technique, combined with digital image processing was used to compare the crystallinity of native starch from a number of potato varieties, differing in the degree of phosphorylation. The crystallinity was found to decrease linearily with an increased degree of phosphorylation. Based on earlier observations of the gelatinization enthalpies, it was assumed that the C-6 phosphates, which have an orientation out of the α-helices disturb the crystallization of the amylopectin during the starch synthesis. The C-3 phosphates, which are located in the interior parts of the α-helices, are not believed to interfere with the crystal structure.     

Catalytic effects of metals of the iron subgroup on the chlorination of titanium carbide to form nanostructural carbon

The effect of the reaction temperature and the metals of an iron subgroup on the thermo-chemical treatment of titanium carbide with a chlorine gas and their influence on the carbon structure obtained thereby was studied. Different analytical methods such as porosity measurements, X-ray diffraction spectrometry and a high-resolution electron microscopy revealed the catalytic behaviour of the above-mentioned metals, which appeared to support the formation of graphitised carbon at much lower temperatures compared to those needed for the ordinary thermo-chemical chlorination of titanium carbide.     

Influence of dietary partially hydrogenated vegetable and marine oils on membrane composition and function of liver microsomes and platelets in the rat

The aim of the present study was to investigate the influence of partially hydrogenated vegetable and marine oils on membrane composition and function of liver microsomes and platelets with particular reference to the metabolism of linoleic acid and the production of arachidonic acid metabolites. Four groups of male weanling rats were fed linoleic acid supplemented diets containing 20% (w/w) of partially hydrogenated low erucic acid rapeseed oil (HLRSO), partially hydrogenated herring oil (HHO), olive oil (OO) and trierucin + triolein (TE) for 10 weeks. An additional two groups were fed partially hydrogenated low erucic acid rapeseed oil and partially hydrogenated herring oil without linoleic acid supplementation (HLRSO- and HHO-, respectively). Substantial amounts oftrans fatty acids were incorporated into liver microsomes (12.6% in group HLRSO) and platelets (7.0% in group HLRSO-). This incorporation was not dependent on the dietary linoleic acid level. Hepatic microsomal Δ⁵-desaturase activity was significantly increased after HLRSO feeding compared to OO feeding. Δ⁶-Desaturase activity did not vary in the linoleic acid supplemented groups. Both Δ⁵- and Δ⁶-desaturase activities were significantly increased in groups without linoleic acid supplementation. Docosenoic acid was incorporated into platelet phospholipids in contrast to liver microsomes. In the platelet, docosenoic acid seemed to have a special preference for phosphatidylserine. Very small amounts were incorporated into platelet phosphatidylinositol. Feeding diets HLRSO, HHO and OO did not influence rat platelet cyclooxygenase or 12-lipoxygenase activity. Platelets from rats fed TE, however, produced significantly less 12-hydroxy-5,8,10,14-eicosatetraenoic acid (12-HETE) than platelets from rats fed OO. Feeding of HLRSO- and HHO- resulted in a significantly diminished production of the arachidonic acid metabolites 12-HETE, 12-hydroxy-5,8,10-heptadecatrienoic acid (HHT) and 6-keto-prostaglandin F_1α in stimulated platelets and aorta. Thus, high dietary levels oftrans isomers of monoenoic acids do not interfere with platelet cyclooxygenase or lipoxygenase activity provided sufficient amounts of linoleic acid are available.     

New developments at JET in diagnostics, real-time control, data acquisition and information retrieval with potential application to ITER

In magnetic confinement fusion, the operation of next generation devices will be significantly different compared to present day machines. The duration length of the discharges will require abandoning the traditional paradigm of processing and storing the data after the shot. In fact most information will have to be made available in real-time. The significant issues of machine protection will require more sophisticated and at the same time more robust feedback control schemes. Another very important issue emerged in the last years of JET operation, and which is expected to become more severe in ITER, is the large amount of data to be analysed, which cannot be handled in the most efficient way with traditional methods.In order to prepare for the operation of ITER, some tests are being performed at JET. The capacity of the real-time network has increased in the last years, and many more systems, mainly diagnostics have been connected to it in order to test their reliability and to assess the quality of the information they can provide for feedback control. To reduce the amount of data, a prototype of real-time adaptive data acquisition techniques is being implemented, to adjust the acquisition frequency to the time resolution of the phenomena to be analysed in the plasma. Lossless data compression techniques have been refined and various intelligent signal processing methods have already been implemented to allow an easier and more objective first screening of the data. To allow scientists from wide and diffuse communities to participate in the scientific and technical programme, various innovative tools for remote participation and experimentation are also being actively investigated.     

Survival factors regulating ovarian apoptosis -- dependence on follicle differentiation

Only a minute fraction of the ovarian follicles present in a fetal ovary will complete the path to ovulation. Most of the follicles will undergo atresia, a hormonally controlled apoptotic process. Apoptosis occurs at each stage of follicular development and there is a marked reduction in the number of follicles present at birth. Stage-dependent mechanisms of follicle survival can be postulated to achieve co-ordinated development, leading to ovulation of a small fraction of follicles. Indeed, hormone and growth factor regulation of follicular atresia is stage-specific. This short review considers the factors that promote survival of ovarian follicles throughout development, including endocrine, locally produced and intracellular mediators, as exemplified mainly by follicular development in rodents. In primordial follicles, oocyte apoptosis is considered to be the cause of subsequent follicle degeneration. In slow-growing preantral follicles, FSH is not a survival factor, but some locally produced growth factors are. Progression to the antral follicle stage is probably the most critical stage of follicle development in vivo, and FSH is a major survival factor at this stage. In addition, insulin-like growth factor I and interleukin 1beta are potent survival factors for cultured rat follicles at the antral stage. Preovulatory follicles express receptors for LH, and both of the gonadotrophins are survival factors at this stage. Relatively little is known about the period between the LH surge and ovulation; however, it has been suggested that at this stage progesterone acts as a survival factor.     

Oxidation behaviour of a Mo(Si,Al)2 based composite at 1500 °C

The oxidation of a Mo(Si,Al)₂ composite is investigated at 1500 °C in dry air using exposure times from 1 to 1000 h. Cross sections are examined with Scanning Electron Microscopy (SEM) and the phase composition is analyzed by X-ray diffraction (XRD). The material forms a continuous and protective alumina layer, the growth of the alumina layer following parabolic kinetics. Immediately below the scale Mo(Si,Al)₂ is replaced by a Mo₅(Si,Al)₃ layer due to the flux of aluminum to the scale. The Al concentration in the Mo(Si,Al)₂ phase in the underlying substrate decreases from 27% before exposure to 16–17% after 1000 h. The continuous alumina layer becomes covered by a top layer consisting of alumina grains embedded in a viscous melt with approximate composition 7 Na₂O–15 Al₂O₃–78 SiO₂. With time, sodium is volatilized from the melt and the top scale layer transforms to a mixture of alumina, mullite and silica melt.