Learning directed probabilistic logical models: ordering-search versus structure-search

We discuss how to learn non-recursive directed probabilistic logical models from relational data. This problem has been tackled before by upgrading the structure-search algorithm initially proposed for Bayesian networks. In this paper we show how to upgrade another algorithm for learning Bayesian networks, namely ordering-search. For Bayesian networks, ordering-search was found to work better than structure-search. It is non-obvious that these results carry over to the relational case, however, since there ordering-search needs to be implemented quite differently. Hence, we perform an experimental comparison of these upgraded algorithms on four relational domains. We conclude that also in the relational case ordering-search is competitive with structure-search in terms of quality of the learned models, while ordering-search is significantly faster.     

Response of Mythimna unipuncta Males to Components of the Sesamia nonagrioides Pheromone

Several sympatric lepidopteran species feed on maize plants, and the different components of their species-specific female sex pheromones may play a role in attracting conspecifics and/or deter heterospecific males. In this study, we analyzed the content of Mythimna unipuncta pheromone glands and tested the response of males to components of their own pheromone blend and that of Sesamia nonagrioides in the wind tunnel. Whole pheromone glands, and lures where (Z)-9-hexadecenyl acetate, Z)-11-hexadecen-1-ol or (Z)-9-hexadecenyl acetate + (Z)-11-hexadecen-1-ol were added to the major component, (Z)-11-hexadecenyl acetate, elicited significantly higher responses by M. unipuncta males than lures with main component alone, although the levels varied with concentration. In the field a rather different outcome was observed, as the addition of other compounds found in the female pheromone gland did not improve trap catch over lures with only (Z)-11-hexadecenyl acetate. The addition of (Z)-11-hexadecenal, a compound of the S. nonagrioides pheromone, to (Z)-11-hexadecenyl acetate significantly reduced attraction of M. unipuncta males both in the wind tunnel and in the field, as well as the number of sympatric clover cutworm, Discestra trifolii, under field conditions. The addition of (Z)-9-hexadecenyl acetate, a minor component of the M. unipuncta pheromone blend, reduced the number of S. nonagrioides captured in field traps that were baited with the S. nonagrioides lure. The significance of such inhibition in the reproductive isolation of sympatric species that attack maize is discussed.     

Coding repeat instability in the FLO11 gene of Saccharomyces yeasts

In Saccharomyces yeasts, the FLO11 gene encodes an adhesin involved in filamentation, invasive growth, flocculation and adherence to solid surfaces. In wild Saccharomyces flor yeasts, a particularly expanded FLO11 allele also confers to these yeasts the ability to float under stressing liquid environments. We report here that, under optimal laboratory conditions, the repeats domain of the FLO11 gene in these wild yeasts is extremely unstable. Changes in length in the FLO11 coding repeats domain affected Flo11p‐associated functions but, interestingly, some of these functions were affected more than others. Therefore, length variations in this single gene provide a combinatorial diversity, which may contribute to a very rapid adaptation to fluctuating environments. Functional analysis of contracted alleles indicated that buoyancy was not associated to FLO11 length. In contrast, this property depended on the different types of repetitive units found in this gene. Thus, not only variations in the number of intragenic repeats but also the abundance and/or distribution of the different repetitive units may have phenotypic and evolutionary implications. Copyright © 2009 John Wiley & Sons, Ltd.     

Theoretical considerations on the adsorption isotherm for ionic systems at electrode interphases

The Guggenheim model of the interphase has been used to study ionic adsorption at electrode interphases from constant ionic strength solutions. Starting with an experimental adsorption isotherm, we deduce the electric equation of state and this equation can help to know what kind of systems respond to the adsorption isotherm. Interphase electrochemical potentials are also obtianed and the stardard state guage is comented. Results can be transferred to understand some trends of ionic adsorption at varying ionic strength solutions.     

A unified interaction model for multiphase flows with the lattice Boltzmann method

The lattice Boltzmann method (LBM) has been increasingly adopted for modelling multiphase fluid simulations in engineering problems. Although relatively easy to implement, the ubiquitous Shan–Chen pseudopotential model suffers from limitations such as thermodynamic consistency and the formation of spurious currents. In the literature, the Zhang–Chen, Kupershtokh et al., the β-scheme, and the Yang–He alternative models seek to mitigate these effects. Here, through analytical manipulations, we call attention to a unified model from which these multiphase interaction forces can be recovered. Isothermal phase-transition simulations of single-component in stationary and oscillating droplet conditions, as well as spinodal decomposition calculations, validate the model numerically and reinforce that the multiphase forces are essentially equivalent. Parameters are selected based on the vapour densities at low temperatures in the Maxwell coexistence curve, where there is a narrow range of optimal values. We find that expressing the model parameters as functions of the reduced temperature further enhances the thermodynamic consistency without losing stability or increasing spurious velocities.     

Effectiveness of nitrogen incorporation to enhance the photoelectrochemical activity of nanostructured TiO2:NH3 versus H2-N2 annealing

Highly ordered TiO(2) nanohole layers were synthesized by anodic oxidation of titanium foils using ethylene glycol and ammonium fluoride as the electrolyte. The effectiveness of different methods, namely annealing at 500?°C in NH(3) and in H(2) diluted in N(2), to incorporate nitrogen into TiO(2) and thus extend its photoelectrochemical (PEC) activity to the visible range was studied. The intra-gap levels introduced by both processes were identified by means of XPS and PL measurements. Water splitting experiments demonstrated that annealing in H(2) improved the photocatalytic activity of pure TiO(2), while annealing in ammonia led to a decrease in the PEC performance.     

Transition from split streamlines to dip-coating during Langmuir–Blodgett film deposition

Mono-molecular films of arachidic acid were deposited on glass slides using the Langmuir–Blodgett (LB) technique. The liquid subphases were dilute solutions of ZnSO₄ at different pH. Glass slides were treated to create contact angles (θ) ranging from approximately 15° for clean glass slides, to contact angles greater than 120° for slides treated with ferric stearate. Intermediate contact angles were created by immersing slides in solutions of Sigmacote^® of varying concentration. Very small contact angles, θ≈0° were obtained with clean glass slides at high pH values. LB deposition data and transfer ratios (TR) were recorded for up-stroke and down-stroke operation. During upstroke, TR increase with decreasing contact angles reaching a maximum TR close to 100% when the receding contact angle is approximately 15–20°. This is typical of the split-ejection flow pattern found during up-stroke. For very small contact angles, i.e. less than 10°, TR suddenly become zero indicating a transition to a dip-coating flow pattern. During down-stroke operation, TR is zero or negative for small contact angles, reaching a maximum TR approximately 100% for contact angles larger than 120°.     

Performance assessment of intelligent distributed systems through software performance ontology engineering (SPOE)

In the computer science community there is a growing interest in the field of Ambient Intelligent Systems. This systems surround their human users with computing and networking technology unobtrusively embedded in their environment. This technology is aimed to provide the users with useful information and to take action to make the environment more convenient for them. As the number of users increases the resources that make Ambient Intelligence possible can be easily saturated making the system unstable and projecting an image of poor QoS to the users. The main goal of this paper is to provide the means for the Ambient Intelligent Systems to monitor themselves and take corrective action automatically if performance starts to drop. Our approach uses a Performance Ontology that structures the knowledge about Software Performance Engineering, and a reasoning engine that acts like an expert system with the Performance Ontology as its foundation. The case study at the end shows the applicability of the developed techniques.