Laboratory and Field Study of the Attraction of Male Pea Midges, Contarinia pisi, to Synthetic Sex Pheromone Components

Behavioral activity of the recently identified sex pheromone components of the pea midge, Contarinia pisi, (2S,11S)-diacetoxytridecane, (2S,12S)-diacetoxytridecane, and 2-acetoxytridecane, was tested in wind tunnel and field-trapping experiments. In the wind tunnel, the attractancy of the three-component blend in a 7 : 10 : 0.1 ratio (following the above order, mimicking the ratios found in gland extract) did not differ significantly from female gland extract, whereas a mixture of the two major components (7 : 10) only attracted 2% of the males to the source. In the field, traps baited with the three-component blend caught by far the largest number of males. Traps baited with the two major components only caught slightly more than the blank traps, and catches in traps baited with 2-acetoxytridecane alone did not differ from catches in the blank traps. Traps baited with the racemate of all three components did not catch more than the blank traps, indicating that some of the enantiomers are inhibitory.     

Improving yield and shape in a crushing plant

There is increasing demand to optimise yield and increase capacity of crushing plants. Research in this area has resulted in the development of numerous optimisation tools, and resent research has shown that the economic aspects of production have great influence on the optimisation results. The profitability of a product is influenced by several parameters, and control of all these parameters is necessary to use some sort of optimisation software.In this paper, we present a case study of a typical crushing plant, with the goal of reducing the number of crusher while keeping the plant capacity and quality. By reducing the number of crusher the plant will need less maintenance which will decrease the operating costs. The article presents a method to combine crushing plant simulation and optimisation with quality and economic considerations in order to successfully study alternative configurations of the plant.     

InP-based optically pumped VECSEL operating CW at 1550 nm

We present a vertical external-cavity surface-emitting laser operating at 1550 nm. The laser comprises an InGaAsP-based gain element, with a resonant periodic gain structure on top of a distributed Bragg reflector, and a high reflectivity spherical mirror as the external reflector. Optical pumping is achieved using a 1250-nm fiber Raman laser. A maximum continuous output power of 70 mW was obtained under multitransverse mode operation at 233 K. Under single-mode operation, we obtained a maximum power of 60 mW with a beam quality factor M/sup 2/ less than 1.1.     

Full characterization of a high-power semiconductor disk laser beam with simultaneous capture of optimally sized focus and farfield

We report on a beam characterization method that is based on the simultaneous measurement of the focus field and the farfield, thus avoiding problems with beam fluctuations during the measurement. By using reflections from both sides of a planoconvex lens, the method implements two branches of an optical system working simultaneously. Also, by letting the planoconvex lens be antireflection treated, and by allowing for both of the reflected fields to fill large and approximately equal areas on a camera detector array, the method significantly lowers the intensity onto the detector array, thus minimizing the need for additional disturbing attenuation filters to avoid camera saturation. In the numerical retrieval of the phase distribution, based on the measured intensity distributions of the focus and farfield, iterative propagation between the two branches is performed. The phase retrieval uses the two-step algorithm for the numerical field propagation conveniently providing an arbitrary choice of sampling distance in each plane.     

Catalytic oxidation of sulphite in diluted aqueous solutions

The rate of reaction of dissolved oxygen and sulphite ions in diluted aqueous solutions, which has industrial importance in abatement of air pollution by sulphur dioxide, was investigated in homogeneous and in heterogeneous systems. Cobaltous sulphate was used as a catalyst.The rate of sulphite oxidation was found to be zero order with respect to oxygen and three-halves order with respect to sulphite. The influence of the catalyst concentration was found to follow a square root dependence. The reaction rate constant increased with pH. The heterogeneous conditions resulted in a reaction rate that was about one order of magnitude lower than that under homogeneous conditions. This difference indicates an induction period of the sulphite oxidation.     

Teleradiology by two different concepts. Technical note

Two different teleradiology concepts are described. Their advantages, disadvantages and costs are discussed.     

Brain monoamine output alterations after a single venlafaxine challenge in experimental hepatic encephalopathy

Venlafaxine (VEN) pharmacokinetics and effects on the brain monoamine output were investigated in the context of experimental hepatic encephalopathy (HE). Systemic VEN (10 mg/kg; subcutaneous) was administered to chronic portacaval shunted (PCS) and sham-operated rats. Their neocortical extracellular levels of 5-HT, 5-HIAA, NA, and DA were then assessed using microdialysis. Serum, brain extracellular, and brain tissue levels of racemic VEN and its main metabolites were also investigated. In a dose-equipotent manner, the VEN challenge increased the 5-HT levels in PCS rats compared with VEN-treated controls, whereas the 5-HIAA levels decreased similarly with time after the challenge in PCS and controls. Brain extracellular NA levels increased similarly in PCS and controls after VEN, but DA increased predominantly in controls. A similar single dose challenge resulted in clearly higher VEN levels in serum, brain extracellular fluid, and brain tissue in the PCS rats compared with controls. However, the VEN brain tissue/serum ratios were in the same order of magnitude for the two groups. Of the main VEN metabolites, only O-desmethylvenlafaxine (ODV) could be detected in pharmacologically significant amounts. The ODV concentration was also elevated in all three investigated biomatrices of the PCS rats versus control rats. The authors concluded that a typical novel brain monoamine-acting drug, such as VEN, exhibits both pharmacokinetic and pharmacodynamic alterations in experimental HE. Accordingly, the results of this study suggest that this frequently used type of drug should be further studied for its potential combined kinetic/dynamic actions in compromised patients with liver impairment.