Chirality of synergistic sex pheromone components of the western hemlock looperLambdina fiscellaria lugubrosa (HULST) (Lepidoptera: Geometridae)

Bakers' yeast reduction of (2E)-3-(2-furanyl)-2-methyl-2-propenal yielded the synthetic intermediate, (2S)-3-(2-furanyl)-2-methylpropanol, of high chiral purity (>97% ee) for the synthesis of the enantiomers of 2,5-dimethylheptadecane and 7-methylheptadecane, two synergistic sex pheromone components of the western hemlock looper (WHL),Lambdina fiscellaria lugubrosa Hulst. In electrophysiological bioassays, (7S)- but not (7R)-7-methylheptadecane elicited strong antennal responses by male WHL antennae. In field trapping experiments, addition of (7S)- but not (7R)-7-methylheptadecane to (5R,11S)-5,11-dimethylheptadecane, the major sex pheromone component of WHL, increased attraction. Attraction to (5R,11S)-5,11-dimethylheptadecane in combination with (7S)-7-methyiheptadecane was further enhanced by the addition of (5S)- but not (5R)-2,5-dimethylheptadecane. Similarly, attraction to (5R,11S)-5,11-dimethylheptadecane combined with (5S)-2,5-dimethylheptadecane increased when 7S- but not (7R)-7-methylheptadecane was added as a third component. We conclude that (7S)-7-methylheptadecane and (5S)-2,5-dimethylheptadecane are the synergistic sex pheromone components of WHL. The synthetic methodology described is applicable to the synthesis of chiral methyl-branched pheromones in other orders of the Insecta, particularly Coleoptera, Diptera and Orthoptera.     

Electrical Conduction Behavior of La1+xSr1−xGa3O7–δ Melilite-Type Ceramics

Ceramics of the melilite-type compound La_{1+ x} Sr_{1− x} Ga₃O_7−δ were prepared by conventional ceramic processing. Samples prepared represented the entire homogeneity region of the phase (i.e., x =−0.15 to 0.60). Electrochemical characterization under variable temperature and atmospheric conditions in the vicinity of air entailed four-point direct-current conductivity measurements and electromotive force measurements. La_{1+ x} Sr_{1− x} Ga₃O_7−δ samples exhibited a p -type behavior with generally increased conductivity with increased substitution of lanthanum for strontium, which reached a saturation value of ∼10⁻¹ S·cm⁻¹ at 950°C.     

Calculation of the Detonation Velocities and Detonation Pressures of Dinitrobiuret (DNB) and Diaminotetrazolium Nitrate (HDAT‐NO3)

The enthalpies of combustion (Δ_combH) of dinitrobiuret (DNB) and diaminotetrazolium nitrate (HDAT‐NO₃) were determined experimentally using oxygen bomb calorimetry: Δ_combH(DNB)=5195±200 kJ kg⁻¹, Δ_combH(HDAT‐NO₃)=7900±300 kJ kg⁻¹. The standard enthalpies of formation (Δ_fH°) of DNB and HDAT‐NO₃ were obtained on the basis of quantum chemical computations at the electron‐correlated ab initio MP2 (second order Møller‐Plesset perturbation theory) level of theory using a correlation consistent double‐zeta basis set (cc‐pVTZ): Δ_fH°(DNB)=−353 kJ mol⁻¹, −1 829 kJ kg⁻¹; Δ_fH°(HDAT‐NO₃)=+254 kJ mol⁻¹, +1 558 kJ kg⁻¹. The detonation velocities (D) and detonation pressures (P) of DNB and HDAT‐NO₃ were calculated using the empirical equations by Kamlet and Jacobs: D(DNB)=8.66 mm μs⁻¹, P(DNB)=33.9 GPa, D(HDAT‐NO₃)=8.77 mm μs⁻¹, P(HDAT‐NO₃)=33.3 GPa.     

Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: methodologies for hierarchical composites

The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a 'parted' morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites.     

Identification of Sex Pheromone Components of Nettle Caterpillar, Setothosea asigna

Gas chromatographic–electroantennographic detection (GC-EAD) analyses of female nettle caterpillar, Setothosea asigna, pheromone gland extracts revealed seven antennally active compounds. Based on their retention indices on three fused silica columns (DB-5, DB-23, and DB-210), these compounds were hypothesized and, through comparative GC, GC-EAD and GC-mass spectrometry with authentic standards, confirmed to be Δ10-undecenal, dodecanal, (E)-9-dodecenal (E9–12:Ald), (Z)-9-dodecenal, (E)-9-dodecen-1-ol, (E)-9,11-dodecadienal (E9,11–12:Ald), and (E)-9,11-dodecadienol. E9–12:Ald and E9,11–12:Ald were most abundant in female S. asigna pheromone extracts. In field trapping experiments in Palembang, Indonesia, synthetic E9–12: Ald and E9,11–12:Ald at a 1:1 ratio, but not singly, attracted S. asigna males. Attractiveness of these two aldehydes could not be enhanced further through the addition of their corresponding alcohols and/or other aldehydic candidate pheromone components. Use of E9–12:Ald and E9,11–12:Ald for pheromone-based monitoring of S. asigna populations will require lure formulations that minimize pheromone degradation by ultraviolet radiation and atmospheric oxidation.     

Knowledge‐Based Conceptual Synthesis of Industrial‐Scale Downstream Processes for Biochemical Products

A generic, knowledge‐based guideline assisting downstream process synthesis for biochemical products is presented. It offers process designers a structured process design methodology supporting them in capturing potentially relevant information, which might be beyond their expertise. The guideline is based on heuristic knowledge which was collected, structured in a generic way, and clearly represented. The generation of alternative downstream routes as starting points for experiments, simulation, and cost calculation is hereby accelerated. The application of the guideline is demonstrated on the example of penicillin V downstream processing from fermentation broth.     

In the Nick of Time: Males of the Parasitoid Wasp <Emphasis Type="Italic">Pimpla disparis</Emphasis> Respond to Semiochemicals from Emerging Mates

Males of the parasitoid wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae) aggregate on parasitized gypsy moth, Lymantria dispar, host pupae when the emergence of a prospective mate is imminent or under way. We tested the hypotheses that the developing parasitoid (“DePa”) inside the host pupal case produces a pheromone that attracts and arrests mate-seeking males, and that the pheromone is most effective during the emergence of the parasitoid from the host. Results obtained in two-choice laboratory experiments, with 4–7-d-old virgin males, indicate that (1) DePa-derived semiochemicals arrest males, (2) the opening of a host pupal case strongly arrests males, and (3) the arrestment cue emanates from oral fluid secreted by both female and male parasitoids while they chew their way out of a host pupal case. This phenomenon implies that emerging females, which are haplodiploid and can reproduce without mating, do not engage in active pheromone signaling to attract males, and that mate-seeking males co-opt chemicals involved in eclosion as a mate-finding cue, taking a 50% chance that the prospective mate is a female.