Sources of Chemical Signals which Enhance Multiparasitism Preference by a Cleptoparasitoid

The cleptoparasitoid Eupelmus vuilleti recognizes and prefers laying on hosts parasitized by Dinarmus basalis to unparasitized hosts. This recognition is based on the perception of a chemical substance deposited on the surface of the seed. Dufour’s gland secretion and cuticular hydrocarbons of D. basalis are attractive and may mediate the host discrimination. This activity is linked to a mixture of linear and methyl alkanes whose source is apparently the Dufour’s gland.     

Baker's yeast-mediated synthesis of endo-2-cineolylol, a starting compound for potential cosmetic odourants

Synopsis
Baker's yeast-mediated reduction of (+)-1,3,3-trimethyl-2-oxabicyclo[2,2,2]octan-6-one yields the corresponding 1,3,3-trimethyl-2-oxabicyclo[2,2,2]octan-6-ol as endo configuration in optically pure form. To study the reaction behaviour we have developed a RP-HPLC method. The synthesis and the olfactive character of some esters obtained from the endo -2-cineolylol are reported. A comparative odour evaluation between these esters and the corresponding compounds synthesized from the endo-exo alcohol mixture was performed.
Résumé
La réduction de (+)-1,3,3-triméthyl-2-oxabicyclo[2,2,2]octan-6-one par la lévure conduit au 1,3,3-triméthyl [2,2,2]octan-6-ol correspondant, de configuration endo avec une forme optique pure. On a développé une méthode RP-HPLC pour enregistrer le comportement de la réaction. La synthèse et le caractère olfactif des esters obtenus de cet alcool sont rapportés.. On a comparé l'évaluation de l'odeur de ces composés avec celle des composés correspondants, dérivés du mélange endo-eso des alcools.     

Relatively brief environmental enrichment aids recovery of learning capacity and alters brain measures after postweaning brain lesions in rats.

Two experiments showed that enriched postlesion experience aided in overcoming effects of simultaneous bilateral cerebral lesions made at 30 days of age in 64 male inbred Fischer rats (Exp I) and 60 male Berkeley S-sub-1 rats (Exp II). The lesions were directed to the occipital cortex, but in most cases there was also some impairment of the hippocampus. For 60 days after operations, half of the Ss lived in small individual cages and half lived in groups in large enriched-environment cages. They were then pretrained and tested on the standard 12 Hebb-Williams problems. Daily injections of methamphetamine (vs saline) during the period of differential experience in Exp I had no effect on the behavioral scores. Exp II included groups that received only 2 hrs/day of enriched experience, and they benefited as much as groups that remained in the enriched environment 24 hrs/day. Results demonstrate significant beneficial effects of environment when bilateral lesions were made at a later age and when the periods of enriched experience were shorter than have previously been tested. Two additional experiments with 112 Berkeley S-sub-1 rats revealed significant effects of both lesions and environment on weight and RNA/DNA of brain regions. (33 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental and theoretical radiation damage studies on crystalline silicon solar cells

An experimental facility was developed to asses in situ the degradation of crystalline silicon solar cells, fabricated by the Solar Energy Group of the National Atomic Energy Commission (CNEA), by measuring the current–voltage characteristic curve. The cells were irradiated with 10 MeV protons and fluences between 10⁸ and 10¹³ p/cm², using an external beam of the linear tandem accelerator TANDAR, at CAC-CNEA. Furthermore, theoretical simulations were performed to establish the relation between the variation of the electrical parameters and the degradation of the lifetime of minority carriers in the base. The damage constant for 10 MeV proton irradiated silicon solar cells of n⁺–p–p⁺ structure and 1 Ω cm base resistivity was determined. Finally, a proposal of a new model of radiation damage for silicon solar cells is discussed.     

Deposition rate and structural properties of microcrystalline glow discharge Si:H,Cl films

The deposition rate and the structural properties of Si:H, Cl films produced in SiCl₄H₂ glow discharges were studied as functions of the substrate temperature, the gas feed composition and the operating pressure. The experimental results were interpreted on the basis of a discharge equilibrium involving both deposition and etching of the film. A close relationship between the deposition rate and the crystallite size is shown.     

Discrimination of assertions and implications: A training procedure for adults and adolescents.

Research concerned with how implications in prose are processed has found that people often make inferences and subsequently remember them as asserted fact. This phenomenon is important for the understanding of human information processing and has important ramifications for applied areas such as courtroom testimony, consumer education, and advertising. A training procedure to teach the discrimination of implication from asserted fact was developed and tested with 32 undergraduates in Exp I and was revised and tested with 32 undergraduates and 64 7th and 9th graders in Exp II. It effectively reduced the number of inferences made but also reduced recognition of asserted fact. A marginal developmental trend of better discrimination with increasing age was found. Further modifications are suggested (e.g., extending the training over a series of sessions). (28 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Acoustic emission events from sodium vapour bubble collapsing: A stochastic model

The forward Kolmogorov equation method has been applied to a zero-dimensional model which describes the time distribution of acoustic emissions from sodium vapour bubble collapsing.Processes taken into account as components for outlining the upstated phenomenon are: energy generation, energy dissipation, bubble creation, acoustic emission and energy release from bubble collapsing.Processes involve affect or are induced by a population of particles (bubbles, acoustic pulses) and pseudoparticles (energetic units).A formulation is obtained for the expected values of some stochastic indicators, i.e. factorial moments and cumulants, autocorrelation function, waiting time distribution between contiguous events, of the time series consisting of acoustic emission pulses as detected by a suitable sensor.Preliminary but promising validation of the model and a sound prelude to an effective boiling regime diagnosing is obtained by processing data from the out-of-pile CFNa loop in Grenoble, France. Data are collected from a piezoelectric accelerometer located nearby the circuit.     

Wärmebehandlung von Stahl nach Kaltumformung

Zusammenhang zwischen Beanspruchungsbedingungen und Spannungsarmglühung nach Kaltumformung. Einfluß von Kaltumformgrad, Betriebstemperatur und Erzeugnisdicke auf das Sprödbruchverhalten. Merkmale zur Abgrenzung der Notwendigkeit des Spannungsarmglühens.     

Die Einflüsse der Schmelzenzusammensetzungen,der Temperaturgradienten an der Erstarrungsfront und der Erstarrungsgeschwindigkeit auf die Stabilität der ebenen Phasengrenze gerichtet erstarrender Legierungen

Erörterung der im Schrifttum aufgeführten Stabilitätskriterien für eine ebene Phasengrenze bei einer gerichteten Erstarrung von Metallschmelzen. Metallographische Untersuchung über den Einfluß der Erstarrungsgeschwindigkeit und des Temperaturgradienten in der Schmelze auf die Morphologie der Erstarrungsfront bei Kristallziehversuchen nach dem Czochralski-Verfahren und bei der Kristallisation von Schmelzen nach dem Bridgeman-Verfahren an Kupfer-Mangan-Nickel-Legierungen. Aussagen über die Stabilitätsbedingungen einer ebenen Phasengrenze bei Vorliegen kleiner und sehr großer Temperaturgradienten an der Erstarrungsfront.