The Scent of a Partner: Ambrosia Beetles Are Attracted to Volatiles from Their Fungal Symbionts

Invasive fungus-growing ambrosia beetles are an emerging threat to forest ecosystems and fruit industries, but management tools are lacking. Here we explored the potential of beetle symbionts–ambrosia fungi–as a source of attractants. Our focus was the redbay ambrosia beetle, Xyleborus glabratus, and its symbiotic fungus, Raffaelea lauricola, which are devastating lauraceous hosts in the southeastern United States. We also tested three additional co-occurring beetle species and their symbionts. Each beetle species was consistently attracted to the odors of its symbiotic fungal species, occasionally also to symbionts of other species, but never to non-symbiotic Trichoderma. We further confirmed attraction to ethanol (positive control) in some species. Thus, ambrosia fungi produce volatiles attractive to their vector beetles, which may have potential as novel lures for ambrosia beetle management.     

APPLICATION OF CHROMATIC MONITORING AS A PLASMA DIAGNOSTIC TECHNIQUE

This paper describes the application of chromatic monitoring of both laboratory and industrial plasmas. The light emitted from the nitrogen plasma generated in the different plasma sources was measured with an imaging spectrograph. The emission spectra were reduced to data points representing the chromatic coordinates of these spectra. The data compression makes this method attractive for monitoring plasma parameter changes. The aim of this work was to test the possibility of application of chromatic monitoring for plasma processing.     

Effect of surface treatment upon the pull-out behaviour of aramid fibres from epoxy resins

A detailed study has been undertaken of the pull-out behaviour of aramid fibres with different surface characteristics from blocks of an epoxy resin matrix. The fibres employed had either no surface treatment (HM), a standard surface finish (HMF) or had been treated with a special epoxy-based adhesion-activating finish (HMA). The point-to-point variation of axial fibre strain along the fibres both inside and outside of the resin matrix has been determined from stress-induced Raman band shifts. This has enabled the distribution of interfacial shear stress along the fibre/matrix interface to be determined and, in combination with scanning electron microscope analysis of the specimens following pull-out testing, the failure mechanisms to be elucidated. It is found that pull out of the HM fibre takes place by a debond propagating along the fibre/matrix interface at a low level of interfacial shear stress. The HMF fibre showed better adhesion to the epoxy matrix with pull out occurring in a complex manner through both separation of the fibre skin and failure at the fibre/finish interface. No evidence of debonding was found for the HMA fibre and failure occurred by fracture of the fibre at the point where it entered the resin block.     

Linear Regression and Adaptive Appearance Models for Fast Simultaneous Modelling and Tracking

This work proposes an approach to tracking by regression that uses no hard-coded models and no offline learning stage. The Linear Predictor (LP) tracker has been shown to be highly computationally efficient, resulting in fast tracking. Regression tracking techniques tend to require offline learning to learn suitable regression functions. This work removes the need for offline learning and therefore increases the applicability of the technique. The online-LP tracker can simply be seeded with an initial target location, akin to the ubiquitous Lucas-Kanade algorithm that tracks by registering an image template via minimisation.     

A model for cell-surface-exposed carbohydrate moieties suitable for structural studies by NMR spectroscopy

In the present study a synthetic glycolipid system is presented that can be readily incorporated into phospholipid micelles and that allows the study of cell-surface-exposed carbohydrate units by high-resolution NMR techniques. Here, we present an efficient route for the synthesis of glycolipid compounds that contain mannose, mannobiose, or mannotriose coupled either directly to an alkyl chain or through a poly(ethylene glycol) linker. Furthermore, we have validated our model system by measuring the binding of cyanovirin N (CV-N), a cyanobacterial protein that binds with nanomolar affinity to the terminal arms of high-mannose structures of the HIV surface-envelope glycoprotein gp120, to glycolipids the carbohydrate portions of which comprise the corresponding high-mannose moieties. From the results of chemical-shift mapping with uniformly (15)N-labelled CV-N, we conclude that binding to the protein occurs at sites similar to those involved in binding the nonconjugated carbohydrates. We characterized the insertion of the glycolipids into dodecylphosphocholine (DPC) micelles by measuring translational diffusion, and we observed that the diffusion constants of the glycolipids were very similar to those of the DPC micelles themselves, but significantly deviated from those of the free glycolipids. We also present experimental proof that the glycolipids remain inserted in the micelles while binding to CV-N. Finally, by addition of a ligand that had a higher affinity to CV-N but which was not attached did not couple to a lipid anchor, CV-N could be released from the glycolipid and, hence, from the micelle-associated state.     

Combined exposure to cyanobacterial biomass, lead and the Newcastle virus enhances avian toxicity

Under environmental conditions, wild birds can be exposed to multiple stressors including natural toxins, anthropogenic pollutants and infectious agents at the same time.This experimental study was successful in testing the hypothesis that adverse effects of cyanotoxins, heavy metals and a non-pathogenic immunological challenge combine to enhance avian toxicity. Mortality occurred in combined exposures to naturally occurring cyanobacterial biomass and lead shots, lead shots and Newcastle vaccination as well as in single lead shot exposure. Mostly acute effects around day 10 were observed. On day 30 of exposure, there were no differences in the liver accumulation of lead in single and combined exposure groups. Interestingly, liver microcystin levels were elevated in birds co-exposed to cyanobacterial biomass together with lead or lead and the Newcastle virus. Significant differences in body weights between all Pb-exposed and Pb-non-exposed birds were found on days 10 and 20. Single exposure to cyanobacterial biomass resulted in hepatic vacuolar dystrophy, whereas co-exposure with lead led to more severe granular dystrophy. Haematological changes were associated with lead exposure, in particular. Biochemical analysis revealed a decrease in glucose and an increase in lactate dehydrogenase in single and combined cyanobacterial and lead exposures, which also showed a decreased antibody response to vaccination.The combined exposure of experimental birds to sub-lethal doses of individual stressors is ecologically realistic. It brings together new pieces of knowledge on avian health. In light of this study, investigators of wild bird die-offs should be circumspect when evaluating findings of low concentrations of contaminants that would not result in mortality on a separate basis. As such it has implications for wildlife biologists, veterinarians and conservationists of avian biodiversity.     

Magnetically Controllable Silver Nanocomposite with Multifunctional Phosphotriazine Matrix and High Antimicrobial Activity

A recently developed multi‐functional phosphotriazine‐based polymer is used as a matrix for embedding γ‐Fe₂O₃ nanoparticles as well as a suitable chemical template for surface modification with silver nanoparticles. For the primary magnetic modification, maghemite nanoparticles are surface modified with oleic acid in order to render them organophilic and to prevent the aggregation of the nanoparticles. This aggregation could occur as the polymer synthesis, based on reaction of phosphonitrilic chlorine and 1,4‐phenylenediamine, takes place in toluene. The surface active amine units of the polymer structure enable the reduction of silver cations to silver nanoparticles, which are well attached and finely dispersed on its surface. The developed nanocomposite represents one of the few magnetically controllable antibacterial agents based on silver nanoparticles. Magnetic measurements reveal the completely suppressed interactions among maghemite nanoparticles because of their perfect surface coating with an organic surfactant and fine dispersion inside the polymer matrix. This magnetic nanocomposite exhibits a high antibacterial and antifungal activity as proven by tests with nine bacterial strains and four candida (yeast genus) species. For the majority of the tested species, the minimum‐inhibition concentrations are below 100 mg L^?1, which is comparable to their equivalent minimum‐inhibition concentrations in colloidal silver systems.     

A 2D non-parabolic six-moments model

In order to describe carrier transport in inversion layers we have developed a two-dimensional non-parabolic macroscopic transport model up to the sixth order. To model the transport parameters with as few simplifying assumptions as possible, we apply an extraction technique from Subband Monte Carlo simulations followed by an interpolation within these Monte Carlo tables through the whole inversion layer. Important effects like surface-roughness scattering as well as quantization are inherently considered in the Subband Monte Carlo data, which are used to model higher-order mobilities as well as the macroscopic relaxation times as a function of the effective field and the carrier temperature. The parameters are compared with the results obtained from models using bulk Monte Carlo data, where neither surface roughness nor quantization are considered. The models are applied to a UTB SOI-MOSFET and their predictions are discussed for different gate lengths.     

Applying Petri Nets to Modeling of Many-Core Processor Self-Testing when Tests are Performed Randomly

Today’s many-core processors are manufactured in inherently unreliable technologies. Massively defective technologies used for production of many-core processors are the direct consequence of the feature size shrinkage in today’s CMOS (complementary metal-oxide-semiconductor) technology. Due to these reliability problems, fault-tolerance of many-core processors becomes one of the major challenges. To reduce the probability of failures of many-core processors various fault tolerance techniques can be applied. The most preferable and promising techniques are the ones that can be easily implemented and have minimal cost while providing high level of processor fault tolerance. One of the promising techniques for detection of faulty cores, and consequently, for performing the first step in providing many-core processor fault tolerance is mutual testing among processor cores. Mutual testing can be performed either in a random manner or according to a deterministic scheduling policy. In the paper we deal with random execution of mutual tests. Effectiveness of such testing can be evaluated through its modeling. In the paper, we have shown how Stochastic Petri Nets can be used for this purpose and have obtained some results that can be useful for developing and implementation of testing procedure in many-core processors.