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Separate Steps (separate + step)
Selected AbstractsClustering: An Essential Step from Diverging to ConvergingCREATIVITY AND INNOVATION MANAGEMENT, Issue 1 2007Marc Tassoul Within the context of new product development processes and the Creative Problem Solving (CPS) process, the authors have come to the view that clustering is to be seen as a separate step in the process of diverging and converging. Clustering is generally presented as part of the converging stages, and as such categorized as a selection technique, which in the authors' view does not do justice to this activity. It is about expanding knowledge, about connecting ideas, and connecting ideas to problem statements, functionalities, and values and consequences. It is about building a shared understanding, in other words about ,making sense', an essential creative activity in the development of concepts and, although different from a more freewheeling divergent phase, can be as creative and maybe even more so. Four kinds of clusterings are distinguished: object clustering, morphological clustering, functional clustering and gestalt clustering. Object clustering is mainly aimed at categorizing ideas into an overviewable set of groups of ideas. No special connections are being made, other then looking for similarities. Morphological clustering is used to split up a problem into subproblems after which the ideas generated are considered as subsolutions which can then be combined into concepts. Functional clustering is interesting when different approaches can be chosen to answer some question. It permits a more strategic choice to be made. Gestalt clustering is a more synthesis like approach, often with a more metaphoric and artistic stance. Collage is a good example of such clustering. General guidelines for clustering are: use a bottom-up process of emergence; postpone early rationalisations and verbalisations; start grouping ideas on the basis of feeling and intuition; and use metaphoric names to identify clusters. [source] Impaired removal of DNA interstrand cross-link in Nijmegen breakage syndrome and Fanconi anemia, but not in BRCA-defective groupCANCER SCIENCE, Issue 11 2008Ken Tsuchida Human diseases characterized by a high sensitivity to DNA interstrand cross-links (ICL) and predisposition to malignance include Nijmegen breakage syndrome (NBS) and Fanconi anemia (FA), which is further classified to three groups: (1) FA core-complex group; (2) FA-ID complex group; and (3) breast cancer (BRCA)-defective group. The relationships between these four groups and the basic defect in ICL repair remain unclear. To study the details of ICL repair in NBS and FA, a highly sensitive PPB (psoralen,polyethylene oxide,biotin) dot blot assay was developed to provide sensitive quantitative measurements of ICL during the removal process. Studies utilizing this assay demonstrated a decreased rate of ICL removal in cells belonging to the FA core-complex group (e.g. groups A and G) and FA-ID complex group (group D2), while ICL removal was restored to normal levels after these cells were complemented with wt-FANCA, wt-FANCG and wt-FANCD2. Conversely, FA-D1 cells with a defective BRCA2 protein displayed normal ICL removal, although they were compromised with respect to recombination. This normal ICL removal rate in recombination-deficient cells was confirmed by using XRCC3-defective Chinese hamster cells, which are similarly compromised with respect to recombination and are sensitive to mitomycin C. The present study also showed that cells from patients with Nijmegen breakage syndrome were defective in ICL removal, while they were impaired in the recombination. These results indicate an obvious defect of FA and NBS in the ICL repair process, except in the BRCA-defective group, and a separate step of recombination-mediated repair pathway between the BRCA group and NBS. (Cancer Sci 2008; 99: 2238,2243) [source] Quick assessment of cytotoxins effect on Daphnia magna using in vivo fluorescence microscopyENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 6 2010Vera V. Teplova Abstract A novel approach to contaminant toxicity screening is proposed. The use of fluorescent microscopy with fluorescent dyes allows for assessing intoxication of Daphnia magna tissues, at various stages of exposure, to contaminants present in water. As shown, D. magna may not only be used as a test species in toxicity tests based on its lethality, but due to its translucency and application of fluorescent probes, separate steps of its intoxication and dying can be visualized. Using a variety of fluorescent probes, the present study also contributes to a better understanding of the toxicity mechanisms. Environ. Toxicol. Chem. 2010;29:1345,1348. © 2010 SETAC [source] A Versatile Solvent-Free "One-Pot" Route to Polymer Nanocomposites and the in situ Formation of Calcium Phosphate/Layered Silicate Hybrid NanoparticlesADVANCED FUNCTIONAL MATERIALS, Issue 11 2010Hans Weickmann Abstract Poly(methyl methacrylate) (PMMA), polystyrene (PS), and polyurethane (PU) nanocomposites containing well-dispersed calcium phosphate/layered silicate hybrid nanoparticles were prepared in a versatile solvent-free "one-pot" process without requiring separate steps, such as organophilic modification, purification, drying, dispersing, and compounding, typical for many conventional organoclay nanocomposites. In this "one-pot" process, alkyl ammonium phosphates were added as swelling agents to a suspension of calcium/layered silicate in styrene, methyl methacrylate, or polyols prior to polymerization. Alkyl ammonium phosphates were prepared in situ by reacting phosphoric acid with an equivalent amount of alkyl amines such as stearyl amine (SA) or the corresponding ester- and methacrylate-functionalized tertiary alkyl amines, obtained via Michael Addition of SA with methyl acrylate or ethylene 2-methacryloxyethyl acrylate. Upon contact with the calcium bentonite suspension, the cation exchange of Ca2+ in the silicate interlayers for alkyl ammonium cations rendered the bentonite organophilic and enabled effective swelling in the monomer accompanied by intercalation and in situ precipitation of calcium phosphates. According to energy dispersive X-ray analysis, the calcium phosphate precipitated exclusively onto the surfaces of the bentonite nanoplatelets, thus forming easy-to-disperse calcium phosphate/layered silicate hybrid nanoparticles. Incorporation of 5,15,wt% of such hybrid nanoparticles into PMMA, PS, and PU afforded improved stiffness/toughness balances of the polymer nanocomposites. Functionalized alkyl ammonium phosphate addition enabled polymer attachment to the nanoparticle surfaces. Transmission electron microscopy (TEM) analyses of PU and PU-foam nanocomposites, prepared by dispersing hybrid nanoparticles in the polyols prior to isocyanate cure, revealed the formation of fully exfoliated hybrid nanoparticles. [source] Retrospective selection bias (or the benefit of hindsight)GEOPHYSICAL JOURNAL INTERNATIONAL, Issue 2 2001Francesco Mulargia SUMMARY The complexity of geophysical systems makes modelling them a formidable task, and in many cases research studies are still in the phenomenological stage. In earthquake physics, long timescales and the lack of any natural laboratory restrict research to retrospective analysis of data. Such ,fishing expedition' approaches lead to optimal selection of data, albeit not always consciously. This introduces significant biases, which are capable of falsely representing simple statistical fluctuations as significant anomalies requiring fundamental explanations. This paper identifies three different strategies for discriminating real issues from artefacts generated retrospectively. The first attempts to identify ab initio each optimal choice and account for it. Unfortunately, a satisfactory solution can only be achieved in particular cases. The second strategy acknowledges this difficulty as well as the unavoidable existence of bias, and classifies all ,anomalous' observations as artefacts unless their retrospective probability of occurrence is exceedingly low (for instance, beyond six standard deviations). However, such a strategy is also likely to reject some scientifically important anomalies. The third strategy relies on two separate steps with learning and validation performed on effectively independent sets of data. This approach appears to be preferable in the case of small samples, such as are frequently encountered in geophysics, but the requirement for forward validation implies long waiting times before credible conclusions can be reached. A practical application to pattern recognition, which is the prototype of retrospective ,fishing expeditions', is presented, illustrating that valid conclusions are hard to find. [source] Repertoire selection by pre-B-cell receptors and B-cell receptors, and genetic control of B-cell development from immature to mature B cellsIMMUNOLOGICAL REVIEWS, Issue 1 2000Fritz Melchers Summary: During B-cell development the surrogate light (SL) chain is selectively expressed in progenitor and precursor B cells during the developmental stages of DH to JH and VH to DH JH rearrangements. Approximately half of all H chains produced by these rearrangements cannot pair with SL chains and cannot form a pre-B-cell receptor (pre-BCR). A spectrum of affinities between VpreB and individual VH domains generates preB cells with pre-BCR of different fitness which, in turn, determines the extent of the pre-B II-cell proliferation and the fidelity of allelic exclusion of the H chain locus. Once pre-BCR is expressed, SL chain expression is turned off. As pre-B II cells proliferate, SL is diluted out, thus limiting pre-BCR formation. As a consequence, pre-B II cells stop proliferating, become small and resting and begin to rearrange the L chain loci. Multiple rearrangements of the k L chain alleles are often detected in wild-type small pre-B II cells. Around 20% of the H chain-expressing small pre-B II cells also express L chains but do not display the Ig on the surface. Hence, it is likely that not all L chains originally generated in resting pre-B II cells can pair with the H chain previously present in that cell. The best fitting ones are selected preferentially to generate sIg+ B cells. Furthermore, the transition of immature B cells from the bone marrow to spleen and their development to mature cells appear as two separate steps controlled by different genes. [source] Numerical simulation of the microscale impregnation in commingled thermoplastic composite yarnsADVANCES IN POLYMER TECHNOLOGY, Issue 2 2010R. Gennaro Abstract The impregnation of a glass woven fabric with an amorphous polyethylene terephthalate copolymer (PET- g) matrix was investigated using a finite element (FE) model for interbundle and intrabundle flow of the matrix. Micrographs of samples obtained by film stacking of PET- g to impregnate the glass fabric have confirmed the occurrence of interbundle and intrabundle flow, taking place as separate steps. On the basis of this evidence, two different mechanisms for the fiber impregnation were postulated. The first flow process is associated with a macroscale interbundle impregnation, whereas the second is associated with microscale intrabundle impregnation. Two different FE models were developed to simulate the microscopic and macroscopic flow of the matrix, considering a large number of different random fiber arrangements. Both models could account for the non-Newtonian rheological behavior of the thermoplastic matrix. The microscale impregnation of fibers was simulated by using randomly spaced and nonoverlapping unidirectional filaments. The effect of the number of filaments and the number of random distributions necessary to achieve an adequate accuracy of the method was assessed. The results obtained from the simulation showed that at low pressures, the polymer melt exhibits Newtonian behavior, which makes it possible to predict the tow permeability by the Darcy law. A more difficult situation arises at high pressures because of the non-Newtonian behavior of the melt. This requires the introduction of a value for the permeability that is also dependent on the rheological properties of the melt. The same non-Newtonian behavior of the matrix was observed for macroscale impregnation of bundles. © 2010 Wiley Periodicals, Inc. Adv Polym Techn 29:122,130, 2010; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20179 [source] Stabilities of Trityl-Protected Substrates: The Wide Mechanistic Spectrum of Trityl Ester HydrolysesCHEMISTRY - A EUROPEAN JOURNAL, Issue 25 2010Markus Horn Abstract Ionization rates of para -substituted triphenylmethyl (trityl) acetates, benzoates, and para -nitrobenzoates have been determined in aqueous acetonitrile and aqueous acetone at 25,°C. Conventional and stopped-flow techniques have been used to evaluate rate constants ranging from 1.38×10,5 to 2.15×102,s,1 by conductimetry and photospectrometry methods. The varying stabilities of the differently substituted tritylium ions account for a gradual change of reaction mechanism. Poorly stabilized carbocations are generated slowly by the ionization of their covalent precursors and trapped fast by water. Better stabilized carbocations are generated more rapidly and accumulate, so that ionization and trapping by water can be observed as separate steps in a single experiment. Finally, highly stabilized tritylium ions do not react with water, and only the rates of their formation could be measured. The ionization rate constants correlate linearly with Winstein's ionizing powers Y; the low slopes (0.17 Organic Intercalation Material: Reversible Change in Interlayer Distances by Guest Release and Insertion in Sandwich-Type Inclusion Crystals of Cholic AcidCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2005Kazunori Nakano Dr. Abstract Cholic acid (CA) forms inclusion crystals that have a sandwich-type lamellar structure constructed by the alternative stacking of host bilayers and guest layers. Five disubstituted benzenes, o -toluidine, m -fluoroaniline, o -chlorotoluene, o -bromotoluene, and indene, are accommodated in the two-dimensional void space between the host bilayers at 1:2 host,guest stoichiometries. Thermal gravimetric analysis of the inclusion crystals revealed that all the guest molecules, except o -toluidine, are released in two separate steps, indicating the formation of intermediate crystals after the first guest release. Adequate heat treatment of the four inclusion crystals induces release of half or three quarters of the guest molecules. X-ray diffraction patterns of the intermediate crystals revealed that the crystals have a bilayer structure the same as those of the common CA inclusion crystals. They have one-dimensional cavities, in which the guest molecules are included at a 1:1 or 2:1 host,guest stoichiometry. These facts indicate that the host bilayers move 1.6,4.5 Å perpendicular to the layer direction by desorption of the guest molecules. Furthermore, a reverse structural change is also achieved by absorption of the guest molecules to regenerate the starting sandwich-type inclusion crystals. This reversible change in the host bilayer by the guest sorption and desorption is a novel example of organic intercalation materials. [source] DIPKIP: A CONNECTIONIST KNOWLEDGE MANAGEMENT SYSTEM TO IDENTIFY KNOWLEDGE DEFICITS IN PRACTICAL CASESCOMPUTATIONAL INTELLIGENCE, Issue 1 2010Álvaro Herrero This study presents a novel, multidisciplinary research project entitled DIPKIP (data acquisition, intelligent processing, knowledge identification and proposal), which is a Knowledge Management (KM) system that profiles the KM status of a company. Qualitative data is fed into the system that allows it not only to assess the KM situation in the company in a straightforward and intuitive manner, but also to propose corrective actions to improve that situation. DIPKIP is based on four separate steps. An initial "Data Acquisition" step, in which key data is captured, is followed by an "Intelligent Processing" step, using neural projection architectures. Subsequently, the "Knowledge Identification" step catalogues the company into three categories, which define a set of possible theoretical strategic knowledge situations: knowledge deficit, partial knowledge deficit, and no knowledge deficit. Finally, a "Proposal" step is performed, in which the "knowledge processes",creation/acquisition, transference/distribution, and putting into practice/updating,are appraised to arrive at a coherent recommendation. The knowledge updating process (increasing the knowledge held and removing obsolete knowledge) is in itself a novel contribution. DIPKIP may be applied as a decision support system, which, under the supervision of a KM expert, can provide useful and practical proposals to senior management for the improvement of KM, leading to flexibility, cost savings, and greater competitiveness. The research also analyses the future for powerful neural projection models in the emerging field of KM by reviewing a variety of robust unsupervised projection architectures, all of which are used to visualize the intrinsic structure of high-dimensional data sets. The main projection architecture in this research, known as Cooperative Maximum-Likelihood Hebbian Learning (CMLHL), manages to capture a degree of KM topological ordering based on the application of cooperative lateral connections. The results of two real-life case studies in very different industrial sectors corroborated the relevance and viability of the DIPKIP system and the concepts upon which it is founded. [source]
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