Behavioral and Sublethal Effects of Structurally Related Lower Terpenes onMyzus persicae

The sesquiterpenes farnesol, caryophyllene oxide, and 2,10-bisaboladien-1-one (patent #9602748) and the monoterpenes citronellol and geraniol were tested for settling inhibition and chronic effects on the aphidMyzus persicae by means of an improved leaf-disk assay. Of these compounds, geraniol, famesol, and the natural bisabolene significantly inhibit settling in choice tests. Furthermore, application of the bisabolene to intactCapsicum annuum leaves did not cause phytotoxicity, but did affect the insects' probing behavior by decreasing the probing activity and the number of intracellular punctures. Both compounds significantly decreased offspring production. Of the compounds tested, the natural product bisabolene could be a promising lead for future development of aphid control agents.     

Macroporous silicon for high-capacitance devices using metal electrodes

In this paper, high-capacity energy storage devices based on macroporous silicon are demonstrated. Small footprint devices with large specific capacitances up to 100 nF/mm², and an absolute capacitance above 15 μF, have been successfully fabricated using standard microelectronics and MEMS techniques. The fabricated devices are suitable for high-density system integration. The use of 3-D silicon structures allows achieving a large surface to volume ratio. The macroporous silicon structures are fabricated by electrochemical etching of silicon. This technique allows creating large structures of tubes with either straight or modulated radial profiles in depth. Furthermore, a very large aspect ratio is possible with this fabrication method. Macroporous silicon grown this way permits well-controlled structure definition with excellent repeatability and surface quality. Additionally, structure geometry can be accurately controlled to meet designer specifications. Macroporous silicon is used as one of the electrodes over which a silicon dioxide insulating layer is grown. Several insulator thicknesses have been tested. The second capacitor electrode is a solid nickel filling of the pores prepared by electroplating in a low-temperature industry standard process. The use of high-conductivity materials allows reaching small equivalent series resistance near 1 Ω. Thanks to these improvements, the presented devices are capable of operating up to 10 kHz.

PACS

84.32.Tt; 81.15.Pq; 81.05.Rm     

Alternative configuration for an optical ring resonator angular rate sensor by using a standard laser diode

In this work, we present an alternative approach to angular velocity optical sensing based on two-ring resonators. This configuration admits the use of a standard laser diode source (0.1 nm, 10,000 MHz, FWHM) reaching higher sensitivities when narrow spectral laser sources (1 MHz, FWHM) are used. We compare this configuration with the standard single-ring resonator angular rate sensor (SRARS), which must use a narrow laser at input. Finally, we conclude that the sensitivity of this new approach can also be enhanced by coupling high-power broadband laser sources in a large range (from 1°/h to 10,000°/h), reaching performance similar to that of a standard SRARS configuration.     

Primary endobronchial non-hodgkins lymphoma: description of a case and review of the literature]

Photosensitive epilepsy is relatively rare. However, a large proportion of individuals with epilepsy perceive that they are at an increased risk of a seizure whilst exposed to specific photic material. The difference between perceived and real risk may be due to inadequate education and misinformation. One half of the participants in the present survey could not recall being informed of the result of the 'gold standard' test for photosensitivity--intermittent photic stimulation during an electroencephalogram. Furthermore, approximately one-third of our sample were apparently given inaccurate and overcautious advice about their everyday exposure to photic material. Better information and advice is crucial to improve this situation in the future. The majority of people with epilepsy (>95%) who are not photosensitive can pursue activities that involve flickering or patterned light, encompassing educational, employment and leisure opportunities, without undue concern.     

Density and electrical conductivity of molten NaCl-KCl-AlCl3 mixtures

The density and specific electrical conductivity were investigated for molten ternary NaCl-KCl-AlCl₃ mixtures of interest to new industrial processes for electrolytic aluminium deposition. A method for the calculation of density and electrical conductivity of molten ternary mixtures on the basis of experimentally determined values for the binary systems NaCl-AlCl₃, NaCl-KCl and KCl-AlCl₃ has been proposed. The difference between the experimental and calculated density and electrical conductivity values of the ternary system was less than ± 1.5% for the density and ± 5% for the electrical conductivity, respectively.     

Binding of an arm repeat protein to the kinase domain of the S-locus receptor kinase

Screening of a yeast two-hybrid library for proteins that interact with the kinase domain of an S-locus receptor kinase (SRK) resulted in the isolation of a plant protein called ARC1 (Arm Repeat Containing). This interaction was mediated by the C-terminal region of ARC1 in which five arm repeat units were identified. Using the yeast two-hybrid system and in vitro binding assays, ARC1 was found to interact specifically with the kinase domains from SRK-910 and SRK-A14 but failed to interact with kinase domains from two different Arabidopsis receptor-like kinases. In addition, treatment with a protein phosphatase or the use of a kinase-inactive mutant reduced or abolished the binding of ARC1 to the SRK-910 kinase domain, indicating that the interaction was phosphorylation dependent. Lastly, RNA blot analysis revealed that the expression of ARC1 is restricted to the stigma, the site of the self-incompatibility response.     

Megalanthine,a Bioactive Sesquiterpenoid from <Emphasis Type="Italic">Heliotropium megalanthum</Emphasis>, its Degradation Products and their Bioactivities

The new bioactive sesquiterpenoid (3R,6E)-2,6,10-trimethyl-3-(3-p-hydroxyphenylpropanoyloxy)-dodeca-6,11-diene-2,10-diol, named megalanthine, was isolated from the resinous exudates of Heliotropium megalanthum. The degradation products of this compound were identified. Several plant-defensive properties (insecticidal, antifungal, and phytotoxic) were evaluated after obtaining positive results in a preliminary etiolated wheat coleoptile bioassay. This bioassay showed the need to have both the phenolic and sesquiterpene moieties of the natural product present to achieve a biological effect. This result was confirmed in phytotoxicity bioassays. Megalanthine was ruled out as a significant plant–plant defense agent because of its lack of stability. The positive results recorded in the antifungal and antifeedant tests suggest, however, that this chemical is relevant in several ecological interactions involving H. megalanthum.     

Giant electric-field-induced strains in lead-free ceramics for actuator applications – status and perspective

In response to the current environmental regulations against the use of lead in daily electronic devices, a number of investigations have been performed worldwide in search for alternative piezoelectric ceramics that can replace the market-dominating lead-based ones, representatively Pb(Zr _x Ti_1-x )O₃ (PZT)-based solid solutions. Selected systems of potential importance such as chemically modified and/or crystallographically textured (K, Na)NbO₃ and (Bi_1/2Na_1/2)TiO₃-based solid solutions have been developed. Nevertheless, only few achievements have so far been introduced to the marketplace. A recent discovery has greatly extended our tool box for material design by furnishing (Bi_1/2Na_1/2)TiO₃-based ceramics with a reversible phase transition between an ergodic relaxor state and a ferroelectric with the application of electric field. This paired the piezoelectric effect with a strain-generating phase transition and extended opportunities for actuator applications in a completely new manner. In this contribution, we will present the status and perspectives of this new class of actuator ceramics, aiming at covering a wide spectrum of topics, i.e., from fundamentals to practice.