Use of entomopathogenic bacterium Pseudomonas putida (Enterobacteriaceae) and it secretions against the Greater Wax Moth Galleria mellonella pupae

The bacterium from Pseudomonas putida from Steinernema abbasi and its metabolic secretions caused the mortality of the Galleria mellonella pupae. Experiments were conducted in sand and filter paper on time exposure, temperature, moisture, dose and time of penetration of bacterium in pupae and tested stored or dried toxic metabolites using G. mellonella pupae as a test target organism. Death of pupae was probably due to the toxic metabolites. Pseudomonas putida cells were recovered from the haemocoele when bacterial cells were applied to the G. mellonella pupae indicating that bacterial cells can enter the haemocoele in the absence of nematode vector. Penetration of bacterium was found rapidly after application on G. mellonella pupae. Pseudomonas putida or its toxic secretions can be used as a microbial control for insect control. The experimental results indicate that there is possibility of using P. putida and its toxic secretions as a biopesticide and can contribute in the development of new microbial and biological control against insect pests.

Influence of temperature on the production and infectivity of entomopathogenic nematodes against larvae and pupae of vine weevil, Otiorhynchus sulcatus, (Coleoptera: Curculionidae)

Susceptibility of late instar vine weevil Otiorhynchus sulcatus larvae and pupae to four species entomopathogenic nematodes were tested. Bioassays on production and infectivity to larvae and pupae were compared for two steinernematids and two heterorhabditis such as Steinernema carpocapsae, S. feltiae, Heterorhabditis indica and H. bacteriophora. Nematodes production of all species was determined by the number infective juveniles (IJs) established in vine weevil larvae and pupae O. sulcatus using sand and filter paper bioassay. S. feltiae produced the maximum number in larvae and pupae at 20°C as compared to other nematodes but production of H. indica, was better at 25°C in larvae and pupae followed by H. bacteriophora, S. carpocapsae and Infectivity test of larvae and pupae was also done in sand media. Infective juveniles recovered from larvae and pupae when infected with S. feltiae produced maximum infective juveniles at 20°C temperatures than all other isolates. H. bacteriophora produced higher number of IJs in larvae and pupae than all other nematode isolates at 25°C. This paper indicates the application of nematodes with the knowledge of insect pest biology represents a possible new strategy for O. sulcatus larvae and pupae.

Pathogenicity of the bacterium Pseudomonas putida from the entomopathogenic nematode Steinernema abbasi and its secretion against Galleria mellonella larvae

The Entomopathogenic bacterium Pseudomonas putida from Steinernema abbasi and its metabolic secretions were lethal to the Galleria mellonella larvae. Different laboratory experiments on time interval, substrate, moisture, temperature, dose, penetration of cells, stored and dried metabolites were conducted in sand and filter paper bioassays. It was concluded that death was probably due to the toxic metabolites. This bacterium and its metabolites were found very effective at 30 degree C. Penetration of bacterium was rapid after application on G. mellonella larvae. P. putida cells were recovered from the haemocoele when suspensions containing bacterial cells were applied to the G. mellonella indicating that bacterial symbionts do have a free-living existence and can enter the haemocoele in the absence of nematode vector. Stored metabolite and dried metabolites were found persistent for long time. This bacterium or its toxic secretions can be used for insect control that can be important component of integrated pest management against different insect pests. P. putida and its secretions are suggested as the most appropriate suspension to apply against insect pest control program in tropical ecological regions.

Pathogenicity of the bacterium Xenorhabdus nematophila isolated from the entomopathogenic nematode Steinernema carpocapsae and its secretions against Galleria mellonella larvae

The entomopathogenic bacterium, Xenorhabdus nematophila was isolated from the hemolymph of Galleria mellonella infected with Steinernema carpocapsae. The bacterial cells and its metabolic secretions have been found lethal to the Galleria larvae. Toxic secretion in broth caused 95% mortality within 4 d of application whereas the bacterial cells caused 93% mortality after 6 d. When filter and sand substrates were compared, the later one was observed as appropriate. Similarly, bacterial cells and secretion in broth were more effective at 14% moisture and 25 °C temperature treatments. Maximum insect mortality (100%) was observed when bacterial concentration of 4×106 cells/ml was used. Similarly, maximum bacterial cells in broth (95%) were penetrated into the insect body within 2 h of their application. However, when stored bacterial toxic secretion was applied to the insects its efficacy declined. On the other hand, when the same toxic secretion was dried and then dissolved either in broth or water was proved to be effective. The present study showed that the bacterium, X. nematophila or its toxic secretion can be used as an important component of integrated pest management against Galleria.

Molecular evidence from ascidians for the evolutionary origin of vertebrate cranial sensory placodes

Cranial sensory placodes are specialised areas of the head ectoderm of vertebrate embryos that contribute to the formation of the cranial sense organs and associated ganglia. Placodes are often considered a vertebrate innovation, and their evolution has been hypothesised as one key adaptation underlying the evolution of active predation by primitive vertebrates. Here, we review recent molecular evidence pertinent to understanding the evolutionary origin of placodes. The development of vertebrate placodes is regulated by numerous genes, including members of the Pax, Six, Eya, Fox, Phox, Neurogenin and Pou gene families. In the sea squirt Ciona intestinalis (a basal chordate and close relative of the vertebrates), orthologues of these genes are deployed in the development of the oral and atrial siphons, structures used for filter feeding by the sessile adult. Our interpretation of these findings is that vertebrate placodes and sea squirt siphon primordia have evolved from the same patches of specialised ectoderm present in the common ancestor of the chordates.

Growth, yield and development of strawberry cv. 'Elsanta' under novel photoselective film clad greenhouses

Film greenhouse claddings are typically used to protect horticultural crops from low temperature and high rainfall conditions. However, a range of novel plastic films have been developed which filter specific radiation wavelengths with the aim of providing the grower with greater control of crop growth and development. A replicated experiment was conducted in 8 small experimental greenhouses, covered with different photoselective films characterised by a range of red/far-red ratios and PAR transmissions to study their effects on the growth, yield and quality of the strawberry cv. 'Elsanta'. Marketable yield per plant was 51% greater under the film with the highest light transmission (control) compared with the lower light transmission films. Similarly, unmarketable fruit number and average non-marketable individual fruit weight per plant was lowest under films with higher light transmissions and higher under lower light transmission films. Cropping duration was longer under films with high R/FR. Also plants under high R/FR were more compact (due to shorter petiole lengths) compared to plants grown under low R/FR. The results are discussed in relation to the increased use of photoselective films in protected horticulture and the need for higher quality fruit and vegetables.

Formation of organic acids from the gas-phase ozonolysis of terpinolene

Gas-phase ozonolysis of terpinolene was studied in static chamber experiments using gas chromatography coupled to mass spectrometric and flame ionisation detection to separate and detect products. Two isomers of C-7-diacids and three isomers of C-7-aldehydic acids were identified in the condensed phase after derivatisation. Possible mechanisms of formation of these acids were investigated using different OH radical scavengers and relative humidities, and were compared to those reported earlier for the ozonolysis of beta-pinene. In addition, branching ratios for some of the individual reaction steps, e. g. the branching ratio between the two hydroperoxide channels of the C-7-CI, were deduced from the quantitative product yield data. Branching ratios for POZ decomposition and the stabilisation/decomposition of the C-7-CI were also obtained from measurements of the C-7 primary carbonyl product.

An on-line algorithm of uncertain time delay estimation in a continuous system

In this paper, we present an on-line estimation algorithm for an uncertain time delay in a continuous system based on the observational input-output data, subject to observational noise. The first order Pade approximation is used to approximate the time delay. At each time step, the algorithm combines the well known Kalman filter algorithm and the recursive instrumental variable least squares (RIVLS) algorithm in cascade form. The instrumental variable least squares algorithm is used in order to achieve the consistency of the delay parameter estimate, since an error-in-the-variable model is involved. An illustrative example is utilized to demonstrate the efficacy of the proposed approach.

Towards the automatic reconstruction of dendritic trees using particle filters

The 3D reconstruction of a Golgi-stained dendritic tree from a serial stack of images captured with a transmitted light bright-field microscope is investigated. Modifications to the bootstrap filter are discussed such that the tree structure may be estimated recursively as a series of connected segments. The tracking performance of the bootstrap particle filter is compared against Differential Evolution, an evolutionary global optimisation method, both in terms of robustness and accuracy. It is found that the particle filtering approach is significantly more robust and accurate for the data considered.

Investigation of cadmium alternatives in thin-film coatings - art. no. 62860C

The health risks associated with the inhalation or ingestion of cadmium are well documented([1,2]). During the past 18 years, EU legislation has steadily been introduced to restrict its use, leaving a requirement for the development of replacement materials. This paper looks at possible alternatives to various cadmium II-VI dielectric compounds used in the deposition of optical thin-films for various opto-electronic devices. Application areas of particular interest are for infrared multilayer interference filter fabrication and solar cell industries, where cadmium-based coatings currently find widespread use. The results of single and multilayer designs comprising CdTe, CdS, CdSe and PbTe deposited onto group IV and II-VI materials as interference filters for the mid-IR region are presented. Thin films of SnN, SnO2, SnS and SnSe are fabricated by plasma assisted CVD, reactive RF sputtering and thermal evaporation. Examination of these films using FTIR spectroscopy, SEM, EDX analysis and optical characterisation methods provide details of material dispersion, absorption, composition, refractive index, energy band gap and layer thicknesses. The optimisation of deposition parameters in order to synthesise coatings with similar optical and semiconductor properties as those containing cadmium has been investigated. Results of environmental, durability and stability trials are also presented.

Integrating the Utkin observer with the unscented Kalman filter

This paper describes the integration of an Utkin observer with the unscented Kalman filter, investigates the performance of the combined observer, termed the unscented Utkin observer, and compares it with an unscented Kalman filter. Simulation tests are performed using a model of a single link robot arm with a revolute elastic joint rotating in a vertical plane. The results indicate that the unscented Utkin observer outperforms the unscented Kalman filter.

A Mobile Agent Based Spam Filter System

A new distributed spam filter system based on mobile agent is proposed in this paper. We introduce the application of mobile agent technology to the spam filter system. The system architecture, the work process, the pivotal technology of the distributed spam filter system based on mobile agent, and the Naive Bayesian filter method are described in detail. The experiment results indicate that the system can prevent spam emails effectively.

Optimal discrimination and classification of THz spectra in the wavelet domain

In rapid scan Fourier transform spectrometry, we show that the noise in the wavelet coefficients resulting from the filter bank decomposition of the complex insertion loss function is linearly related to the noise power in the sample interferogram by a noise amplification factor. By maximizing an objective function composed of the power of the wavelet coefficients divided by the noise amplification factor, optimal feature extraction in the wavelet domain is performed. The performance of a classifier based on the output of a filter bank is shown to be considerably better than that of an Euclidean distance classifier in the original spectral domain. An optimization procedure results in a further improvement of the wavelet classifier. The procedure is suitable for enhancing the contrast or classifying spectra acquired by either continuous wave or THz transient spectrometers as well as for increasing the dynamic range of THz imaging systems. (C) 2003 Optical Society of America.

A novel approach to the detection of synchronisation in EEG based on empirical mode decomposition

Transient neural assemblies mediated by synchrony in particular frequency ranges are thought to underlie cognition. We propose a new approach to their detection, using empirical mode decomposition (EMD), a data-driven approach removing the need for arbitrary bandpass filter cut-offs. Phase locking is sought between modes. We explore the features of EMD, including making a quantitative assessment of its ability to preserve phase content of signals, and proceed to develop a statistical framework with which to assess synchrony episodes. Furthermore, we propose a new approach to ensure signal decomposition using EMD. We adapt the Hilbert spectrum to a time-frequency representation of phase locking and are able to locate synchrony successfully in time and frequency between synthetic signals reminiscent of EEG. We compare our approach, which we call EMD phase locking analysis (EMDPL) with existing methods and show it to offer improved time-frequency localisation of synchrony.

Detection of neural correlates of self-paced motor activity using empirical mode decomposition phase locking analysis

Transient episodes of synchronisation of neuronal activity in particular frequency ranges are thought to underlie cognition. Empirical mode decomposition phase locking (EMDPL) analysis is a method for determining the frequency and timing of phase synchrony that is adaptive to intrinsic oscillations within data, alleviating the need for arbitrary bandpass filter cut-off selection. It is extended here to address the choice of reference electrode and removal of spurious synchrony resulting from volume conduction. Spline Laplacian transformation and independent component analysis (ICA) are performed as pre-processing steps, and preservation of phase synchrony between synthetic signals. combined using a simple forward model, is demonstrated. The method is contrasted with use of bandpass filtering following the same preprocessing steps, and filter cut-offs are shown to influence synchrony detection markedly. Furthermore, an approach to the assessment of multiple EEG trials using the method is introduced, and the assessment of statistical significance of phase locking episodes is extended to render it adaptive to local phase synchrony levels. EMDPL is validated in the analysis of real EEG data, during finger tapping. The time course of event-related (de)synchronisation (ERD/ERS) is shown to differ from that of longer range phase locking episodes, implying different roles for these different types of synchronisation. It is suggested that the increase in phase locking which occurs just prior to movement, coinciding with a reduction in power (or ERD) may result from selection of the neural assembly relevant to the particular movement. (C) 2009 Elsevier B.V. All rights reserved.