A computational intelligence method for traversing dynamically constructed networks of knowledge

A core goal for autonomous systems such as proposed here is automated collaboration in order to perform tasks or share information. The system is always distributed by default and frequently on a large-scale. It can be argued that robustness and economy demand the deployment of a tested autonomic supporting infrastructure whenever possible. A knowledge network is a generic structure that organises distributed knowledge of any format into a system that will allow it to be retrieved efficiently. The rationale of the knowledge network is to act as a middle layer that connects to a multitude of sources, organises them based on various concepts and finally provides well-structured, pre-organised knowledge to individual services and applications. To use the knowledge network we need a querying mechanism to be able to retrieve information. The knowledge network will organise itself in an autonomous manner and it is possible to use the querying mechanism also as part of the knowledge organization mechanism, to autonomously create temporary views that reflect the use of the system. This paper is an attempt to investigate the peculiarities of node behaviour in traversing such a knowledge network. We investigate a variety of methods of traversing a knowledge network.     

Electrokinetic remediation of plutonium-contaminated nuclear site wastes: results from a pilot-scale on-site trial

This paper examines the field-scale application of a novel low-energy electrokinetic technique for the remediation of plutonium-contaminated nuclear site soils, using soil wastes from the Atomic Weapons Establishment (AWE) Aldermaston site, Berkshire, UK as a test medium. Soils and sediments with varying composition, contaminated with Pu through historical site operations, were electrokinetically treated at laboratory-scale with and without various soil pre-conditioning agents. Results from these bench-scale trials were used to inform a larger on-site remediation trial, using an adapted containment pack with battery power supply. 2.4 m(3) (ca. 4t onnes) of Pu-contaminated soil was treated for 60 days at a power consumption of 33 kWh/m(3), and then destructively sampled. Radiochemical data indicate mobilisation of Pu in the treated soil, and migration (probably as a negatively charged Pu-citrate complex) towards the anodic compartment of the treatment cell. Soil in the cathodic zone of the treatment unit was remediated to a level below free-release disposal thresholds (1.7 Bq/g, or <0.4 Bq/g above background activities). The data show the potential of this method as a low-cost, on-site tool for remediation of radioactively contaminated soils and wastes which can be operated remotely on working sites, with minimal disruption to site infrastructure or operations.     

High-throughput screening of drug-lipid membrane interactions via counter-propagating second harmonic generation imaging

Here we report the use of counter-propagating second harmonic generation (SHG) to image the interactions between the local anesthetic tetracaine and a multicomponent planar supported lipid bilayer array in a label-free manner. The lipid bilayer arrays, prepared using a 3D continuous flow microspotter, allow the effects of lipid phase and cholesterol content on tetracaine binding to be examined simultaneously. SHG images show that tetracaine has a higher binding affinity to liquid-crystalline phase lipids than to solid-gel phase lipids. The presence of 28 mol % cholesterol decreased the binding affinity of tetracaine to bilayers composed of the mixed chain lipid, 1-steroyl-2-oleoyl-sn-glycero-3-phophocholine (SOPC), and the saturated lipids 1,2-dimyristoyl-sn-glycero-3-phophocholine (DMPC) and 1,2-dipamitoyl-sn-glycero-3-phophocholine (DPPC) while having no effect on diunsaturated 1,2-dioleoyl-sn-glycero-3-phophocholine (DOPC). The maximum surface excess of tetracaine increases with the degree of unsaturation of the phospholipids and decreases with cholesterol in the lipid bilayers. The paper demonstrates that SHG imaging is a sensitive technique that can directly image and quantitatively measure the association of a drug to a multicomponent lipid bilayer array, providing a high-throughput means to assess drug-membrane interactions.     

Detection and quantification of adulteration of durum wheat flour by flour from common wheat using reverse phase HPLC

When common wheat (Triticum aestivum L) gliadins were separated by RP-HPLC, a major doublet peak eluted at 47.20 and 47.94 min. This peak was consistently found to be absent in Durum wheat (Triticum durum Desf) gliadins separated under identical conditions. In Durum wheat gliadins a characteristic small peak eluted at 48.30 min followed at 50.47, 510.37, 52.80 min by larger peaks. The peak area ratio of the peaks eluting at 50.47 and 51.37 min was found to be 2.18 (±0.14). This ratio was found to decrease proportionally on contamination of Durum wheat flour with flour from some common wheat varieties. This ratio alone was not enough to detect and quantify adulteration by all varieties of common wheat. An alternative method was found whereby the peak emerging between 47 and 49 min in the Durum wheat gliadin elution profile was expressed as a ratio of the total protein applied. This ratio was shown to increase when Durum wheat flour was adulterated with flour from common wheat thus enabling quantitative estimation of the level of adulteration. A third method of detecting adulteration of Durum wheat flour is also proposed in which the peak emerging between 47 and 49 min is collected and the protein separated by PAGE. The presence of more than one band of γ/β-gliadins is indicative of adulteration.     

Photodegradation of Famotidine by Integrated Photocatalytic Adsorbent (IPCA) and Kinetic Study

Abstract  

Integrated photocatalytic adsorbents (IPCAs) comprised of nanocrystalline titanium dioxide (TiO₂) and activated carbon (AC) were prepared using an ultrasonic impregnation technique. The IPCAs were characterised by scanning electron microscopy (SEM) and Fourier-transform infrared (FT-IR) spectroscopy and were employed as catalysts for the photodegradation of famotidine-an active pharmaceutical ingredient-in aqueous solutions using illumination from a 125 W medium pressure mercury lamp. The degradation kinetics were found to follow a pseudo-first-order rate law and varying TiO₂ loadings induced different increases in the apparent first-order rate constant of the process. The kinetic behaviour can be described in terms of a modified Langmuir–Hinshelwood (LH) model. The IPCA prepared using a 10% TiO₂ to AC loading exhibited the highest rate constant with a K _C and k _r of 0.0172 L/mg and 0.237 mg/L/min, respectively. The LH model fits the experimental data and elucidates the effect of the TiO₂ content of the IPCA on the degradation rate. The use of calcination (heat treatment) in IPCA preparation and its effect on photocatalytic and adsorption performance were also investigated. The present work demonstrates that the combination of TiO₂ and AC results in a promising material for application in the degradation of organic pollutants.     

Deterministic parallel backtrack search

The backtrack search problem involves visiting all the nodes of an arbitrary binary tree given a pointer to its root subject to the constraint that the children of a node are revealed only after their parent is visited. We present a fast, deterministic backtrack search algorithm for a p-processor COMMON CRCW-PRAM, which visits any n-node tree of height h in time O((n/p+h)(logloglogp)²). This upper bound compares favourably with a natural Ω(n/p+h) lower bound for this problem. Our approach embodies novel, efficient techniques for dynamically assigning tree-nodes to processors to ensure that the work is shared equitably among them.     

Relational being.

Reviews the book, Relational being: Beyond self and community by Kenneth J. Gergen (see record 2009-10534-000). In this book, Gergen develops and elaborates a theoretical framework for shifting the unit of analysis in psychology and other social sciences away from the individual toward relationships. The core arguments of the book revolve around claims that individuals (“bounded entities”) are social constructs that should be understood not as natural and self-evident phenomena but rather as emergent from relationships. By corollary, many of the properties traditionally associated with individuals (e.g., thoughts, feelings, beliefs) are argued to be better understood as relational accomplishments; that is, as arising from the larger context of the social fabric from which individuals are seen to be emergent. Significantly, Gergen also asserts that traditional individualist assumptions have negative impacts on our social world. He focuses on a number of specific domains to illustrate how a relational approach would lead to a more constructive, harmonious, and better existence. I found much value in the practical aspects of Gergen’s exposition of relational being, while feeling uncomfortable with the epistemological and ontological foundations provided in the book. The root of this ambiguity seems to lie in Gergen’s own contradictory stance, which oscillates between offering a relational approach as “just another perspective” (i.e., no more or less true than any other) and implying the moral and epistemic superiority of relational over individualist approaches. Although the former position seems to me sensible and appropriate, the latter (which dominates in the book) constitutes an unnecessary universalism that seems to run counter to the pluralistic spirit that is evident in parts of the book. Gergen’s own words, "Let us replace the Hobbesian dystopia of 'all against all,' with a vision of 'all with all'" (p. 403) for me sums up both the strengths and weaknesses of the book—the insights offered by the application of a relational perspective to specific practical contexts are a truly valuable contribution; but suggesting that this perspective is a panacea and needs to replace all individualistic accounts is counterproductive. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Symposium review: Genomic investigations of flavor formation by dairy microbiota

Flavor is one of the most important attributes of any fermented dairy product. Dairy consumers are known to be willing to experiment with different flavors; thus, many companies producing fermented dairy products have looked at culture manipulation as a tool for flavor diversification. The development of flavor is a complex process, originating from a combination of microbiological, biochemical, and technological aspects. A key driver of flavor is the enzymatic activities of the deliberately inoculated starter cultures, in addition to the environmental or “nonstarter” microbiota. The contribution of microbial metabolism to flavor development in fermented dairy products has been exploited for thousands of years, but the availability of the whole genome sequences of the bacteria and yeasts involved in the fermentation process and the possibilities now offered by next-generation sequencing and downstream “omics” technologies is stimulating a more knowledge-based approach to the selection of desirable cultures for flavor development. By linking genomic traits to phenotypic outputs, it is now possible to mine the metabolic diversity of starter cultures, analyze the metabolic routes to flavor compound formation, identify those strains with flavor-forming potential, and select them for possible commercial application. This approach also allows for the identification of species and strains not previously considered as potential flavor-formers, the blending of strains with complementary metabolic pathways, and the potential improvement of key technological characteristics in existing strains, strains that are at the core of the dairy industry. An in-depth knowledge of the metabolic pathways of individual strains and their interactions in mixed culture fermentations can allow starter blends to be custom-made to suit industry needs. Applying this knowledge to starter culture research programs is enabling research and development scientists to develop superior starters, expand flavor profiles, and potentially develop new products for future market expansion.