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Same Approach (same + approach)
Selected AbstractsCAD-Based Photogrammetry for Reverse Engineering of Industrial InstallationsCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 4 2003Johan W. H. Tangelder For instance, in the case of a servicing plant, such a library contains descriptions of simple components such as straight pipes, elbows, and T-junctions. A new installation is constructed by selecting and connecting the appropriate components from the library. This article demonstrates that one can use the same approach for reverse engineering by photogrammetry. In our technique, the operator interprets images and selects the appropriate CAD component from a library. By aligning the edges of the component's wire frame to the visible edges in the images, we implicitly determine the position, orientation, and shape of the real component. For a fast object reconstruction the alignment process has been split in two parts. Initially, the operator approximately aligns a component to the images. In a second step a fitting algorithm is invoked for an automatic and precise alignment. Further improvement in the efficiency of the reconstruction is obtained by imposing geometric constraints on the CAD components of adjacent object parts. [source] Cervicomental "Turkey Gobbler": A New Source for Full-Thickness GraftsDERMATOLOGIC SURGERY, Issue 4 2002FIACS, Lawrence M. Field MD A LARGE NUMBER of sources for full-thickness grafts have been described. The concepts of adapting liposuction techniques from cosmetic surgery to reconstructive surgery, especially with flap reconstructions, have been well documented by this author and others in many forums over many years.1,7 However, obtaining the excess skin of the lower neck in those patients with "turkey gobbler" deformities utilizing liposuction aspiration and dissection techniques has not been previously documented. This same approach might at times be valuable in very obese necks with excessively redundant skin as well. [source] Analysis of chicken and turkey ovalbumins by microchip electrophoresis combined with exoglycosidase digestionELECTROPHORESIS, Issue 18 2003Xiuli Mao Abstract The polypeptide and carbohydrate patterns of two glycoproteins, chicken ovalbumin (CO) and turkey ovalbumin (TO), were analyzed by microchip electrophoresis (ME), following digestion with proteases and exoglycosidases. Glycopeptides derived from ovalbumin were obtained by digestion with Pronase, followed by dialysis, and then separated by ME. Using CO as model, the method was developed to deduce the structure of glycans from glycoproteins by comparing the electropherograms of glycopeptides with and without digestion of exolycosidases. Applying the same approach, the structure of oligosaccharides linked to TO was determined. TO was found to contain high-mannose type oligosaccharides and oligosaccharides with terminal N -acetylglucosamine residues. The complete primary analysis of CO and TO by ME described in this paper provides a basis for an analysis of glycoproteins with an integrated microfluidic chip. [source] Predatory hoverflies select their oviposition site according to aphid host plant and aphid speciesENTOMOLOGIA EXPERIMENTALIS ET APPLICATA, Issue 1 2007Raki Almohamad Abstract The hoverfly Episyrphus balteatus De Geer (Diptera: Syrphidae) is an abundant and efficient aphid-specific predator. Several aphidophagous parasitoids and predators are known to respond positively to aphid-infested plants. Semiochemicals from the latter association usually mediate predator/parasitoid foraging behavior toward sites appropriate for offspring fitness. In this study, we investigated the effect of aphid host plant and aphid species on foraging and oviposition behavior of E. balteatus. Behavioral observations were conducted using the Noldus Observer v. 5.0, which allows observed insect behavior to be subdivided into different stages. Additionally, the influence of aphid species and aphid host plant on offspring fitness was tested in a second set of experiments. Acyrthosiphon pisum Harris and Megoura viciae Buckton were equally attractive for E. balteatus whereas Aphis fabae Scopoli (all Homoptera: Aphididae) were less attractive. These results were correlated with (i) the number of eggs laid, which was significantly higher for the two first aphid species, and (ii) the fitness of hoverfly larvae, pupae, and adults. Two solanaceous plant species, Solanum nigrum L. and Solanum tuberosum L. (Solanaceae), which were infested with Myzus persicae Sulzer (Homoptera: Aphididae), were also compared using the same approach. Discrimination between these two M. persicae host plants was observed, with S. tuberosum being preferred as an oviposition site by the predatory hoverfly. Larval and adult fitness was correlated with the behavioral observations. Our results demonstrated the importance of the prey,host plant association on the choice of the oviposition site by an aphid predator, which is here shown to be related to offspring fitness. [source] Modeling the three-dimensional structure of H+ -ATPase of Neurospora crassaFEBS JOURNAL, Issue 21 2002Proposal for a proton pathway from the analysis of internal cavities Homology modeling in combination with transmembrane topology predictions are used to build the atomic model of Neurospora crassa plasma membrane H+ -ATPase, using as template the 2.6 Ć crystal structure of rabbit sarcoplasmic reticulum Ca2+ -ATPase [Toyoshima, C., Nakasako, M., Nomura, H. & Ogawa, H. (2000) Nature 405, 647,655]. Comparison of the two calcium-binding sites in the crystal structure of Ca2+ -ATPase with the equivalent region in the H+ -ATPase model shows that the latter is devoid of most of the negatively charged groups required to bind the cations, suggesting a different role for this region. Using the built model, a pathway for proton transport is then proposed from computed locations of internal polar cavities, large enough to contain at least one water molecule. As a control, the same approach is applied to the high-resolution crystal structure of halorhodopsin and the proton pump bacteriorhodopsin. This revealed a striking correspondence between the positions of internal polar cavities, those of crystallographic water molecules and, in the case of bacteriorhodopsin, the residues mediating proton translocation. In our H+ -ATPase model, most of these cavities are in contact with residues previously shown to affect coupling of proton translocation to ATP hydrolysis. A string of six polar cavities identified in the cytoplasmic domain, the most accurate part of the model, suggests a proton entry path starting close to the phosphorylation site. Strikingly, members of the haloacid dehalogenase superfamily, which are close structural homologs of this domain but do not share the same function, display only one polar cavity in the vicinity of the conserved catalytic Asp residue. [source] Uncertain inheritance and recognition as probabilistic default reasoningINTERNATIONAL JOURNAL OF INTELLIGENT SYSTEMS, Issue 6 2001T. H. Cao This paper proposes probabilistic default reasoning as a suitable approach to uncertain inheritance and recognition for fuzzy and uncertain object-oriented models. The uncertainty is due to the uncertain membership of an object to a class and/or the uncertain applicability of a property, i.e., an attribute or a method, to a class. First, we introduce a logic-based uncertain object-oriented model where uncertain membership and applicability are measured by support pairs, which are lower and upper bounds on probability. The probability for a property being applicable to a class is interpreted as the conditional probability of the property being applicable to an object given that the object is a member of the class. Each uncertainty applicable property is then a default probabilistic logic rule, which is defeasible. In order to reduce the computational complexity of general probabilistic default reasoning, we propose to use Jeffrey's rule for a weaker notion of consistency and for local inference, then apply them to uncertain inheritance of attributes and methods. Using the same approach but with inverse Jeffrey's rule, uncertain recognition as probabilistic default reasoning is also presented. © 2001 John Wiley & Sons, Inc. [source] Functional analysis of CBP/p300 in embryonic orofacial mesenchymal cellsJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 5 2006D.R. Warner Abstract CREB binding protein (CBP) and the close structural homolog, p300, are nuclear coactivators of multiple signaling pathways that play important roles in embryonic development and cellular homeostasis. TGF, regulates the proliferation rate of many cell types and has been demonstrated to inhibit the growth rate of mouse embryonic maxillary mesenchymal (MEMM) cells. The role of CBP and p300 in TGF,-mediated control of proliferation of MEMM cells was thus investigated using an in vitro gene knockdown approach. TGF, reporter assays demonstrated that p300 mRNA knockdown via targeted siRNAs led to a reduction in the response to TGF,, whereas knockdown of CBP by the same approach had an insignificant effect. In MEMM cell proliferation assays, siRNA-mediated knockdown of CBP and/or p300 had little impact upon TGF,-mediated growth inhibition; however, the basal rate of proliferation was increased. Inhibition of p300 activity via overexpression of a dominant-negative mutant (p300,C/H3) led to significant inhibition of TGF,-mediated activation of p3TP-lux. As with the siRNA knockdown approach, p300,C/H3 also increased the basal rate of cell proliferation of MEMM cells. CBP/p300 siRNA knockdown had a significant but incomplete inhibition of TGF,-induction of matrix metalloproteinase-9 (gelatinase B) expression. These data demonstrate that p300 is involved in Smad-mediated transcription of p3TP-lux, however, its role (and that of CBP) in biological processes such as the control of cell proliferation and extracellular matrix metabolism is more complex and may be mediated via mechanisms beyond coactivator recruitment. J. Cell. Biochem. 99: 1374,1379, 2006. © 2006 Wiley-Liss, Inc. [source] Non-parametric statistical methods for multivariate calibration model selection and comparison,JOURNAL OF CHEMOMETRICS, Issue 12 2003Edward V. Thomas Abstract Model selection is an important issue when constructing multivariate calibration models using methods based on latent variables (e.g. partial least squares regression and principal component regression). It is important to select an appropriate number of latent variables to build an accurate and precise calibration model. Inclusion of too few latent variables can result in a model that is inaccurate over the complete space of interest. Inclusion of too many latent variables can result in a model that produces noisy predictions through incorporation of low-order latent variables that have little or no predictive value. Commonly used metrics for selecting the number of latent variables are based on the predicted error sum of squares (PRESS) obtained via cross-validation. In this paper a new approach for selecting the number of latent variables is proposed. In this new approach the prediction errors of individual observations (obtained from cross-validation) are compared across models incorporating varying numbers of latent variables. Based on these comparisons, non-parametric statistical methods are used to select the simplest model (least number of latent variables) that provides prediction quality that is indistinguishable from that provided by more complex models. Unlike methods based on PRESS, this new approach is robust to the effects of anomalous observations. More generally, the same approach can be used to compare the performance of any models that are applied to the same data set where reference values are available. The proposed methodology is illustrated with an industrial example involving the prediction of gasoline octane numbers from near-infrared spectra. Published in 2004 by John Wiley & Sons, Ltd. [source] An accurate evaluation of the nonsymmetrical components of Green's functions for multilayered media in the near-field regionMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 4 2009Alaa K. AbdelmageedArticle first published online: 9 FEB 200 Abstract The discrete complex image method has proved to be one of the most efficient techniques to evaluate Green's functions for multilayered media, particularly in the near- and intermediate-field regions. Although the extraction of surface waves extends its validity to the far field, it suffers from erroneous results that contaminate the computation of the near field. To handle this problem for the nonsymmetrical components of Greens functions, we follow the same approach adopted by the author and others for the symmetrical components where a number of artificial poles are extracted for each physical surface-wave pole occurrence. This approach has proved its validity and yielded good results in all field regions. © 2009 Wiley Periodicals, Inc. Microwave Opt Technol Lett 51: 881,885, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.24201 [source] Photophysics of J-aggregate microcavitiesPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 6 2008P. Michetti Abstract We have developed a model in order to account for the photo-excitation dynamics of J-aggregate films and strongly coupled J-aggregate microcavities. The J-aggregates are described as a disordered Frenkel exciton system in which relaxation occurs due to the presence of a thermal bath of molecular vibrations. The link between the J-aggregate film and the microcavities is obtained introducing a model polariton wavefunction mixing cavity photon modes and J-aggregate superradiant excitons. With the same approach we have calculated both absorption and luminescence spectra for the J-aggregate film and the photoluminescence of strongly coupled organic microcavities. The model is able to explain the organic microcavities fast relaxation dynamics and polariton luminescence following non resonant pumping starting from the excitonic properties of the optically active layer. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] On the variational formulation of systems with non-holonomic constraintsANNALEN DER PHYSIK, Issue 9 2009D.H. Delphenich Abstract In a previous article by the author, it was shown that one could effectively give a variational formulation to non-conservative mechanical systems by starting with the first variation functional instead of an action functional. In this article, it is shown that this same approach will also allow one to give a variational formulation to systems with non-holonomic constraints. The key is to use an adapted anholonomic local frame field in the formulation, which then implies the replacement of ordinary derivatives with covariant ones. The method is then applied to the case of a vertical disc rolling without slipping or friction on a plane. [source] Synthesis of (1R,2R)- and (1S,2R)-1,2-Epoxy-3-hydroxypropylphosphonates as Analogues of FosfomycinARCHIV DER PHARMAZIE, Issue 9 2009Andrzej E. Wróblewski Abstract Cyclohexylammonium (1R,2R)-1,2-epoxy-3-hydroxypropylphosphonate was conveniently synthesized from dibenzyl (1S,2R)-2,3- O -cyclohexylidene-1,2,3-trihydroxypropylphosphonate by a reaction sequence including mesylation, hydrolysis of acetal, intramolecular Williamson reaction, and hydrogenation in the presence of cyclohexylamine. For dibenzyl (1S,2R)-2,3- O -cyclohexylidene-1,2,3-trihydroxypropylphosphonates the same approach was not successful, since prior the epoxide-ring closure tritylation of HO,C3 in dibenzyl (1R,2R)-2,3-dihydroxy-1-mesyloxypropylphosphonate was necessary and the hydrogenolysis of dibenzyl (1S,2R)-1,2-epoxy-3-trityloxypropylphosphonate yielded a complex reaction mixture. [source] Craniodental indicators of prey size preference in the FelidaeBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2009JULIE MEACHEN-SAMUELS In the present study, we used linear morphometrics of the crania, mandible and dentition to explore the association between craniodental shape and prey size among 35 species of living felids. To accomplish this, felids were divided into three prey-size groups: (1) large prey specialists; (2) small prey specialists; and (3) mixed prey feeders. From these linear measurements, large prey specialist felids can be distinguished from small and mixed prey feeders by their relatively robust canines and incisors and relatively wide muzzles. These cranial characters are advantageous when dispatching large prey, due to the stranglehold that cats employ during this activity. Robust canines resist the bending and torsional forces applied by struggling prey and a wider muzzle helps to stabilize grip and distribute bite forces more evenly during the killing bite. Small prey specialists had smaller canines, narrower muzzles and slightly longer jaws for a speed advantage when catching small, quick prey. Mixed prey feeders were intermediate between large and small prey specialists, indicating they are adapted to killing both sizes of prey. Given the success of this ecomorphological analysis of living felids that specialize on different prey sizes, we look forward to applying this same approach to extinct species. © 2009 The Linnean Society of London, Biological Journal of the Linnean Society, 2009, 96, 784,799. [source] Asymmetric Total Synthesis of Fredericamycin A: An Intramolecular Cycloaddition PathwayCHEMISTRY - A EUROPEAN JOURNAL, Issue 21 2005Shuji Akai Dr. Abstract The asymmetric total synthesis of the potent antitumor antibiotic fredericamycin A ((S)- 1) was achieved by the intramolecular [4+2] cycloaddition of the silylene-protected styrene derivative (S)- 7 followed by the aromatic Pummerer-type reaction of the sulfoxide (S)- 5. Although we had already succeeded in the total synthesis of racemic 1 by the same approach, synthesis of its asymmetric version was more complicated than we had expected due to the difficulties involved in constructing the quaternary carbon center and the tendency of this center to undergo facile racemization. Racemization of this center during the installation of the acetylene moiety on the dione (R)- 8 was the most serious aspect. Systematic studies of its DE-ring analogue (R)- 25 revealed that racemization of the quaternary carbon center proceeded by a retro-aldol,aldol reaction of the initial adduct, (1R)- 39,a -Li, and that the degree of racemization was dependent on the reaction temperature. The racemization process could be completely depressed by keeping the reaction temperature at ,78,°C. The construction of the stereogenic quaternary carbon center was achieved by the lipase-catalyzed desymmetrization of the prochiral 1,3-diol 9,a bearing the DEF-ring moiety. These studies enabled us to attain the asymmetric total synthesis of (S)- 1 while completely retaining the chiral integrity created by the enzymatic reactions. [source] | |||||||||||||||||||