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Basic Steps (basic + step)
Selected AbstractsReview article: Basic steps in adapting response surface methodology as mathematical modelling for bioprocess optimisation in the food systemsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2010Titus U. Nwabueze Summary Techniques involving choosing process combinations for optimisation without due consideration for relevant experimental designs is scientifically unreliable and irreproducible. Mathematical modelling, of which response surface methodology (RSM) is one, provides a precise map leading to successful optimisation. This paper identified key process variables, building the model and searching the solution through multivariate regression analysis, interpretation of resulting polynomial equations and response surface/contour plots as basic steps in adapting the central composite design to achieve process optimisation. It also gave information on appropriate RSM software packages and choice of order in RSM model and data economy in reducing the factorial experiments from large number parameter combinations to a far less number without losing any information including quadratic and interaction (if present) effects. It is expected that this paper will afford many food scientists and researchers the opportunity for adapting RSM as a mathematical model for achieving bioprocess optimisation in food systems. [source] The revisit of QoS routing based on non-linear Lagrange relaxationINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 1 2007Gang Feng Abstract The development of efficient quality of service (QoS) routing algorithms in a high-speed networking or the next generation IP networking environment is a very important and at the same time very difficult task due to the need to provide divergent services with multiple QoS requirements. Recently, a heuristic algorithm H_MCOP, which is based on a non-linear Lagrange relaxation (NLR) technique, has been proposed to resolve the contradiction between the time complexity and the quality of solution. Even though H_MCOP has demonstrated outstanding capability of finding feasible solutions to the multi-path constrained (MCP) problem, it has not exploited the full capability that an NLR-based technique could offer. In this paper, we propose a new NLR-based heuristic called NLR_MCP, in which the search process is interpreted from a probability's perspective. Simulation results indicate that NLR_MCP can achieve a higher probability of finding feasible solutions than H_MCOP. We also verify that the performance improvement of a MCP heuristic has a tremendous impact on the performance of a higher level heuristic that uses a MCP heuristic as the basic step. Copyright © 2006 John Wiley & Sons, Ltd. [source] Cleavage of the iron-methionine bond in c-type cytochromes: Crystal structure of oxidized and reduced cytochrome c2 from Rhodopseudomonas palustris and its ammonia complexPROTEIN SCIENCE, Issue 1 2002Silvano Geremia Abstract The three-dimensional structures of the native cytochrome c2 from Rhodopseudomonas palustris and of its ammonia complex have been obtained at pH 4.4 and pH 8.5, respectively. The structure of the native form has been refined in the oxidized state at 1.70 Å and in the reduced state at 1.95 Å resolution. These are the first high-resolution crystal structures in both oxidation states of a cytochrome c2 with relatively high redox potential (+350 mV). The differences between the two oxidation states of the native form, including the position of internal water molecules, are small. The unusual six-residue insertion Gly82-Ala87, which precedes the heme binding Met93, forms an isolated 310 -helix secondary structural element not previously observed in other c-type cytochromes. Furthermore, this cytochrome shows an external methionine residue involved in a strained folding near the exposed edge of the heme. The structural comparison of the present cytochrome c2 with other c-type cytochromes has revealed that the presence of such a residue, with torsion angles , and , of approximately ,140 and ,130°, respectively, is a typical feature of this family of proteins. The refined crystal structure of the ammonia complex, obtained at 1.15 Å resolution, shows that the sulphur atom of the Met93 axial ligand does not coordinate the heme iron atom, but is replaced by an exogenous ammonia molecule. This is the only example so far reported of an X-ray structure with the heme iron coordinated by an ammonia molecule. The detachment of Met93 is accompanied by a very localized change in backbone conformation, involving mainly the residues Lys92, Met93, and Thr94. Previous studies under typical denaturing conditions, including high-pH values and the presence of exogenous ligands, have shown that the detachment of the Met axial ligand is a basic step in the folding/unfolding process of c-type cytochromes. The ammonia adduct represents a structural model for this important step of the unfolding pathway. Factors proposed to be important for the methionine dissociation are the strength of the H-bond between the Met93 and Tyr66 residues that stabilizes the native form, and the presence in this bacterial cytochrome c2 of the rare six-residue insertion in the helix 310 conformation that increases Met loop flexibility. [source] Testing association between disease and multiple SNPs in a candidate geneGENETIC EPIDEMIOLOGY, Issue 5 2007W. James Gauderman Abstract Current technology allows investigators to obtain genotypes at multiple single nucleotide polymorphism (SNPs) within a candidate locus. Many approaches have been developed for using such data in a test of association with disease, ranging from genotype-based to haplotype-based tests. We develop a new approach that involves two basic steps. In the first step, we use principal components (PCs) analysis to compute combinations of SNPs that capture the underlying correlation structure within the locus. The second step uses the PCs directly in a test of disease association. The PC approach captures linkage-disequilibrium information within a candidate region, but does not require the difficult computing implicit in a haplotype analysis. We demonstrate by simulation that the PC approach is typically as or more powerful than both genotype- and haplotype-based approaches. We also analyze association between respiratory symptoms in children and four SNPs in the Glutathione-S-Transferase P1 locus, based on data from the Children's Health Study. We observe stronger evidence of an association using the PC approach (p = 0.044) than using either a genotype-based (p = 0.13) or haplotype-based (p = 0.052) approach. Genet. Epidemiol. 2007. © 2007 Wiley-Liss, Inc. [source] Review article: Basic steps in adapting response surface methodology as mathematical modelling for bioprocess optimisation in the food systemsINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 9 2010Titus U. Nwabueze Summary Techniques involving choosing process combinations for optimisation without due consideration for relevant experimental designs is scientifically unreliable and irreproducible. Mathematical modelling, of which response surface methodology (RSM) is one, provides a precise map leading to successful optimisation. This paper identified key process variables, building the model and searching the solution through multivariate regression analysis, interpretation of resulting polynomial equations and response surface/contour plots as basic steps in adapting the central composite design to achieve process optimisation. It also gave information on appropriate RSM software packages and choice of order in RSM model and data economy in reducing the factorial experiments from large number parameter combinations to a far less number without losing any information including quadratic and interaction (if present) effects. It is expected that this paper will afford many food scientists and researchers the opportunity for adapting RSM as a mathematical model for achieving bioprocess optimisation in food systems. [source] Best starting point to comprehensive process safety educationPROCESS SAFETY PROGRESS, Issue 3 2007Milos Ferjencik Abstract Instruction in process safety began at the Faculty of Chemical Technology, University of Pardubice, in the nineties. In 1994, a course named the Safety Engineering was formed. We aimed to equip our students with a theory that would orientate them in safety problems during their professional lives. Similar to analogous courses at other universities, the Safety Engineering course tends to follow basic steps of the quantitative risk analysis (QRA). An accident analysis and two basic notions,a system and a hazard,were selected as starting points of the course. But after a few years of experience we felt that the Safety Engineering course did not represent exactly what the majority of our students needed. Although the concept of risk analysis represents a fundamental part of any process safety theory, there is another concept that seems to be essential for professionals involved in the process industry,safety management. We started to recognize that an introduction into comprehensive process safety education should be divided into two stages. The safety management and the risk analysis should represent focal points of the first and the second stages, respectively. Two stage arrangement of the process safety course seems to suit needs of our students better than the previous scheme. After the idea of division of the process safety course had arisen, a new starting point for the comprehensive safety education had to be found. An old approach of Kletz's on "learning from accidents" showed itself to be suitable to fulfill this role most naturally. © 2007 American Institute of Chemical Engineers Process Saf Prog 26:195,202, 2007 [source] A rational approach to heavy-atom derivative screeningACTA CRYSTALLOGRAPHICA SECTION D, Issue 4 2010M. Gordon Joyce Despite the development in recent times of a range of techniques for phasing macromolecules, the conventional heavy-atom derivatization method still plays a significant role in protein structure determination. However, this method has become less popular in modern high-throughput oriented crystallography, mostly owing to its trial-and-error nature, which often results in lengthy empirical searches requiring large numbers of well diffracting crystals. In addition, the phasing power of heavy-atom derivatives is often compromised by lack of isomorphism or even loss of diffraction. In order to overcome the difficulties associated with the `classical' heavy-atom derivatization procedure, an attempt has been made to develop a rational crystal-free heavy-atom derivative-screening method and a quick-soak derivatization procedure which allows heavy-atom compound identification. The method includes three basic steps: (i) the selection of likely reactive compounds for a given protein and specific crystallization conditions based on pre-defined heavy-atom compound reactivity profiles, (ii) screening of the chosen heavy-atom compounds for their ability to form protein adducts using mass spectrometry and (iii) derivatization of crystals with selected heavy-metal compounds using the quick-soak method to maximize diffraction quality and minimize non-isomorphism. Overall, this system streamlines the process of heavy-atom compound identification and minimizes the problem of non-isomorphism in phasing. [source] Von der Werfthalle des CargoLifter zum Tropical Island Resort: Klima- und Energiekonzept für den weltweit größten überdachten tropischen FreizeitparkBAUPHYSIK, Issue 6 2004Heinrich Post Dr.-Ing. Für die Umplanung der ehemaligen CargoLifter-Halle zum "Tropical Island Resort" werden die wesentlichen Schritte des Climaengineering im Rahmen der Vorplanung beschrieben. Zunächst werden die Klimakonzepte für den winterlichen- und sommerlichen Betriebsfall vorgestellt, die sich nach der Analyse von Baukörper, Nutzungsanforderungen und Außenklima und der Optimierung der technischen Anlagenparameter im Rahmen von komplexen, dynamischen Gebäude- und Raumströmungssimulationen ergaben. Abschließend wird das Energiekonzept des Tropical Island Resort beschrieben. From CargoLifter hangar to Tropical Island Resort ndash; climate and energy design for the world's largest covered tropical amusement park. For the redesign of the former hangar of CargoLifter into "Tropical Island Resort" the basic steps of climate engineering during preliminary planning stage are specified. First of all the indoor climate concepts for winter and summer conditions are presented, resulting from complex, dynamical building and airfluid simulations regarding building analysis, usage demands, outdoor climate and optimization of technical equipment. Finaly energie strategy of Tropical Island Resort is characterized. [source] Non-linear instructional design model: eternal, synergistic design and developmentBRITISH JOURNAL OF EDUCATIONAL TECHNOLOGY, Issue 4 2004Caroline Crawford Instructional design is at the heart of each educational endeavour. This process revolves around the steps through which the thoughtful productions of superior products are created. The ADDIE generic instructional design model emphasises five basic steps within the instructional design process: analyse, design, develop, implement and evaluate. The simplistic nature of the ADDIE model, including the ease of application and possibilities towards the cyclical features of the process, enable a more holistic overview of the instructional design process. The Eternal, Synergistic Design Model emphasises the non-linear nature of the instructional design process. The continuous design and development focuses upon the core evaluation of the product, wherein the Pareto principle emphasises the feedback related to the 20% of difficulties while maintaining an eye upon the 80% neutral and positive aspects of the product. [source] | |||||||||||||