Genotype–phenotype mapping implications for genetic programming representation: Commentary on “On the mapping of genotype to phenotype in evolutionary algorithms” by Peter A. Whigham,Grant Dick,and James Maclaurin

Here we comment on the article “On the mapping of genotype to phenotype in evolutionary algorithms,” by Peter A. Whigham, Grant Dick, and James Maclaurin. The article reasons about analogies from molecular biology to evolutionary algorithms and discusses conditions for biological adaptations in the context of grammatical evolution, which provide a useful perspective to GP practitioners. However, the connection of the listed implications for GP is not sufficiently convincing for the reader . Therefore this commentary will (1) examine the proposed principles one by one, challenging the authors to provide more supporting evidence where felt that this was needed, and (2) propose a methodical way to GP practitioners to apply these principles when designing GP representations.     

Exploring Plasmonic Resonances Toward “Large-Scale” Flexible Optical Sensors with Deformation Stability

The next generation of sensors requires a simple yet compact lab on chip-based precise optical detection mechanism where data interpretation can be achieved with minimum effort. Hereby, cost-efficient strategies of manufacturing both propagating surface plasmon polariton (SPP) and localized surface plasmon resonance (LSPR) sensors on flexible platforms are explored via mechanical instabilities and oblique-angled metal evaporation. Centimeter scaled dielectric grating structures produced by plasma oxidation of pre-stressed polydimethylsiloxane film have comprised the substrates, thus imparting inherent flexibility. Subsequently, both continuous and discontinuous 1D-metallic lattices are obtained via vapor deposition of gold at different angles. The optical isotropy (gold surface-grating) and anisotropy (gold edge-grating) are distinctly observed as a difference between forward and backward diffraction efficiencies, backed by analytical correlation to the observed orders. Supported with electromagnetic modeling, the SPP and LSPR excitations are experimentally characterized under reflectance and transmittance measurements, along with a demonstration of their sensing capabilities. The LSPR supported flexible sensor provides superiority in terms of sensitivity, which is investigated under mechanical deformations to exhibit consistency of the resonant wavelength. Such consistency is strategically unraveled via “finite element method” based approaches, thus providing a new paradigm of cost-efficient, large-scaled flexible sensors.     

Emergence in genetic programming

Banzhaf explores the concept of emergence and how and where it happens in genetic programming [1]. Here we consider the question: what shall we do with it? We argue that given our ultimate goal to produce genetic programming systems that solve new and difficult problems, we should take advantage of emergence to get closer to this goal.     

Electrochemical hydrogen storage performance of Mg–Ti–Zr–Ni alloys

Mg_1.5Ti_0.5−xZr_xNi (x = 0, 0.1, 0.2, 0.3, 0.4), Mg_1.5Ti_0.3Zr_0.1Pd_0.1Ni and Mg_1.5Ti_0.3Zr_0.1Co_0.1Ni alloys were synthesized by mechanical alloying and their electrochemical hydrogen storage characteristics were investigated. X-ray diffraction studies showed that all the replacement elements (Ti, Zr, Pd and Co) perfectly dissolved in the amorphous phase and Zr facilitated the amorphization of the alloys. When the Zr/Ti ratio was kept at 1/4 (Mg_1.5Ti_0.4Zr_0.1Ni alloy), the initial discharge capacity of the alloy increased slightly at all the ball milling durations. The further increase in the Zr/Ti ratio resulted in reduction in the initial discharge capacity of the alloys. The presence of Zr in the Ti-including Mg-based alloys improved the cyclic stability of the alloys. This action of Zr was attributed to the less stable and more porous characteristics of the barrier hydroxide layer in the presence of Zr due to the selective dissolution of the disseminated Zr-oxides throughout the hydroxide layer on the alloy surface. Unlike Co, the addition of Pd into the Mg–Ti–Zr–Ni type alloy improved the alloy performance significantly. The positive contribution of Pd was assumed to arise from the facilitated hydrogen diffusion on the electrode surface in the presence of Pd. As the Zr/Ti atomic ratio increased, the charge transfer resistance of the alloy decreased at all the depths of discharges. Co and Pd were observed to increase the charge transfer resistance of the Mg–Ti–Zr–Ni alloys slightly.     

Concerns with Passive Anaerobic Bioreactors for Selenium Removal from Coal Slurry Liquid Wastes

Mine Water and the Environment - Passive anaerobic bioreactors (PABs) are flow-through trenches filled with plant substrates that serve as energy and carbon sources for bacteria that carry out...     

Enhancement of the mechanical properties of EN52CrMoV4 spring steel by deep cryogenic treatment

The effect of the deep cryogenic treatment on the micro-structure and mechanical properties (tensile strength, toughness, residual stress and fatigue strength) of the medium carbon spring steel, which is subjected to different heat treatment steps, is investigated. Deep cryogenic treatment causes spring steel to keep compressive residual stress more efficiently due to an increase in the density of the crystalline defects, retardation in the stress relief after the phase transformations and nano-cluster carbide formations. If deep cryogenic treatment is applied before the tempering then the homogeneously distributed fine carbides form after the tempering and the grains remain relatively fine. The microstructure with homogeneously distributed fine carbides and fine grains cause spring steels to have simultaneously enhanced tensile strength, ductility and fatigue strength. If deep cryogenic treatment is applied after the conventional heat treatment (quenching+tempering), however, the coarse carbides form in the micro-structure and the improvement in the mechanical properties of the spring steel is limited.     

Effect of additives on nickel-phosphorus deposition obtained by electroless plating: Characterization and corrosion resistance in 3%(mass) sodium chloride medium

Nichel-phosphorus (Ni-P) coatings are deposited on mild steel by using an electroless plating process. The effect of three calix[4]arene derivatives, namely tetra methyl ester-P-tertbutyl calix[4]arene (Calix1), tetra acid-P-tert-butyl calix[4]arene (Calix2) and tetra methyl P-tert-butyl-thicalix[4]arene ester (Calix3) on the deposition rate, the deposit composition, and the morphological surface was investigated and the study of growth mechanisms has delivered useful information about the surface properties of deposit. It is found that these additives modify the deposition rate and the nickel crystallization process. In fact, the Calix1 and Calix3 act as an accelerator, while Calix2 acts as an inhibitor for the nickel electroless. Furthermore, it is shown that the chemical bath is more stable with calix[4]arene derivatives addition and the obtained deposits are compact and adherent. It is observed also that the nickel content increases with additives. On the other hand, the X-ray diffraction showed that the orientation peaks are intensified at {1 1 1} in the presence of Calix2, confirming obtained results of EDAX spectrum. The cyclic voltammetry revealed that the tested additives strongly influence the cathodic process and slightly affect the hypophosphite oxidation. Finally, it is found that these compounds improve the anticorrosion efficiency of Ni-P coating on the mild steel substrate in 3% (mass) NaCl, where its polarization resistance increases with Calix2 and Calix3 addition.     

Synthesis of Antiviral Perfluoroalkyl Derivatives of Teicoplanin and Vancomycin

The limited scope of antiviral drugs and increasing problem of antiviral drug resistance represent a global health threat. Glycopeptide antibiotics and their lipophilic derivatives have emerged as relevant inhibitors of diverse viruses. Herein, we describe a new strategy for the synthesis of dual hydrophobic and lipophobic derivatives of glycopeptides to produce selective antiviral agents without membrane-disrupting activity. Perfluorobutyl and perfluorooctyl moieties were attached through linkers of different length to azido derivatives of vancomycin aglycone and teicoplanin pseudoaglycone, and the new derivatives were evaluated against a diverse panel of viruses. The teicoplanin derivatives displayed strong anti-influenza virus activity at nontoxic concentrations. Some of the perfluoroalkylated glycopeptides were also active against a few other viruses such as herpes simplex virus or coronavirus. These data encourage further exploration of glycopeptide analogues for broad antiviral application.     

Pourquoi adoptez-vous des comportements écologiques? Validation en langue fran?aise de l'échelle de motivation vis-à-vis les comportements écologiques.

This article presents the French-Canadian validation of the Motivation Towards the Environment Scale (MTES), along with information regarding its psychometric properties. Ss were 338 17–51 yr olds. The "Echelle de Motivation vis-a-vis les Comportements Ecologiques" (EMCE) is based on Self-determination Theory. It consists of 6 subscales measuring intrinsic motivation (IM), four forms of extrinsic motivation (EM by external, introjected, identified, and integrated regulation), and amotivation. In Study 1, results of a confirmatory factor analysis (using LISREL VII) supported the factorial structure of the scale. In addition, the construct validity of the EMCE was supported by a series of correlational analyses among the 6 subscales, as well as between these subscales and several variables relevant to the environment. Finally, results of Study 2 reveal that the EMCE subscales displayed satisfactory internal consistency, as well as high temporal stability. The results compared quite favourably to those of the English-Canadian version. Directions concerning the future use of the EMCE in environmental research are proposed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Effect of concentration gradient on the anodic behavior of tungsten

Potentiodynamic and potentiostatic polarization experiments, the electrochemical impedance spectroscopy, the rotating disk electrode technique, and surface pH measurements were used to study the effect of tungstate ions on the anodic behavior of tungsten (W). Deliberately added tungstate ions, which are also tungsten dissolution products, were found to decrease the anodic currents at around the point of zero charge, increase the anodic currents in the neutral to weakly basic range and have no effect on the anodic currents in the strongly basic conditions. This variable effect was attributed to the competition between the stabilization of the tungsten oxide due to higher concentration of the dissolution products next to the metal surface and the stabilization of the local pH as a result of the enhanced polymerization reactions of the tungstate species. The surface pH measurements showed that the polymerization reactions kept the W surface pH higher (i.e. closer to the bulk pH) in the absence of a pH buffer in the neutral and weakly basic solutions. The tungstate ion was considered as a potentially useful additive in W chemical mechanical polishing (CMP) slurries, since this ion could increase the stability of the oxide phase to be removed by polishing and serve as a pH buffering agent.