Anti-feedant activity of the polyacetylene,phenylheptatriyne (PHT), from the Asteraceae toEuxoa messoria (Lepidoptera: Noctuidae)

Summary Phenylheptatriyne (PHT), a polyacetylene from various species of Asteraceae reduced feeding and weight gain of larvae of the polyphagous insectEuxoa messoria when incorporated into an artificial diet at concentrations of 10–300 ppm. These results suggest a role as insect antifeedants for the widely distributed polyacetylenes of the Asteraceae.Acknowledgment. This work was supported by NSERC and Agriculture Canada (E.M.R.) We thank Dr R. J. Byers (Agriculture Canada) for eggs ofEuxoa. To whom reprint requests should be addressed.     

Effect of lead microparticles introduced into the respiratory system of the sensitivity of mice to Pasteurella multocida infection via aerosol]

Lead microparticles, resulting from the pyrolysis of organic lead used as an anti-knock agent in gasoline, were introduced into the lungs of Mice, during a short single exposure. When 6 microgram of lead were retained in the lungs (mean value per Mouse), the phagocytic ability of the pulmonary alveolar macrophages harvested 6 and 18 hrs. later, was significantly reduced. It was observed, in the same conditions, that the resistance of Mice to experimental infection by aerosolized Pasteurella multocida, was significantly reduced. When 3 microgram of lead were retained in the lungs, there was no significant difference between control and intoxicated Mice.     

Procaine, a local anesthetic, interacting with the cell membrane and inhibiting the processing of exported protein precursors in Escherichia coli]

In E. coli cells grown in the presence of procaine (0.55% w/v), precursor forms of alkaline phosphatase and of glutamine binding protein accumulate besides mature forms synthesized prior to procaine addition. An experimental technique, of general application, for isolation and purification of mature and precursor forms obtained under these conditions, is described.     

2,4-dinitro-(pyrimidine-2-yl) thiophenol, a new drug with antimitotic properties]

A new thiopyrimidine derivative has been synthesized. It can inhibit cell multiplication in Chick embryo fibroblasts, in Mouse Ehrlich ascites tumor cells and in Rat hepatoma cells (line Rueber) cultivated in vitro.     

The correlations of ions density with geomagnetic activity and solar dynamic pressure in cusp region

A statistical study of the properties of ions (O , He and H ) measured by the Cluster-II in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made dur-ing the summer and fall of 2001-2003. The main results are that: (1) O ion density responds in a sig-nificant way to geomagnetic index Kp, and He ion density is not correlated with geomagnetic index Kp, both of them have a significant positive correlation with solar wind dynamic pressure; (2) H ion density is also observed to increase with solar wind dynamic pressure, and not correlated with geomagnetic index Kp.     

The excitation of solar-like oscillations in a δSct star by efficient envelope convection

Delta Scuti (δSct) stars are opacity-driven pulsators with masses of 1.5-2.5 M⊙, their pulsations resulting from the varying ionization of helium. In less massive stars such as the Sun, convection transports mass and energy through the outer 30 per cent of the star and excites a rich spectrum of resonant acoustic modes. Based on the solar example, with no firm theoretical basis, models predict that the convective envelope in δSct stars extends only about 1 per cent of the radius, but with sufficient energy to excite solar-like oscillations. This was not observed before the Kepler mission, so the presence of a convective envelope in the models has been questioned. Here we report the detection of solar-like oscillations in the δSct star HD187547, implying that surface convection operates efficiently in stars about twice as massive as the Sun, as the ad hoc models predicted.