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1

Digitale Medien

Phylogenetic position of Dictyostelium inferred from multiple protein data sets (1995)

Kuma, Kei-ichi ; Nikoh, Naruo ; Iwabe, Naoyuki ; [weitere]

Springer

Journal of molecular evolution 41 (1995), S. 238-246

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ISSN: 1432-1432

Schlagwort(e): Cellular slime molds ; Animals ; Fungi ; Plantae ; Maximum-likelihood method ; Evolution

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Abstract The phylogenetic position of Dictyostelium inferred from 18S rRNA data contradicts that from protein data. Protein trees always show the close affinity of Dictyostelium with animals, fungi, and plants, whereas in 18S rRNA trees the branching of Dictyostelium is placed at a position before the massive radiation of protist groups including the divergence of the three kingdoms. To settle this controversial issue and to determine the correct position of Dictyostelium, we inferred the phylogenetic relationship among Dictyostelium and the three kingdoms Animalia, Fungi, and Plantae by a maximum-likelihood method using 19 different protein data sets. It was shown at the significance level of 1 SE that the branching of Dictyostelium antedates the divergence of Animalia and Fungi, and Plantae is an outgroup of the Animalia-Fungi-Dictyostelium clade.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF00170678

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2

Digitale Medien

Evolutionary relationships of eukaryotic kingdoms (1996)

Kumar, Sudhir ; Rzhetsky, Andrey

Springer

Journal of molecular evolution 42 (1996), S. 183-193

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ISSN: 1432-1432

Schlagwort(e): Small-subunit ribosomal RNA ; Phylogeny ; Animals ; Fungi ; Plants ; Alveolates ; Heterokonts ; Stramenopiles

Quelle: Springer Online Journal Archives 1860-2000

Thema: Biologie

Notizen: Abstract The evolutionary relationships of four eukaryotic kingdoms—Animalia, Plantae, Fungi, and Protista—remain unclear. In particular, statistical support for the closeness of animals to fungi rather than to plants is lacking, and a preferred branching order of these and other eukaryotic lineages is still controversial even though molecular sequences from diverse eukaryotic taxa have been analyzed. We report a statistical analysis of 214 sequences of nuclear small-subunit ribosomal RNA (srRNA) gene undertaken to clarify these evolutionary relationships. We have considered the variability of substitution rates and the nonindependence of nucleotide substitution across sites in the srRNA gene in testing alternative hypotheses regarding the branching patterns of eukaryote phylogeny. We find that the rates of evolution among sites in the srRNA sequences vary substantially and are approximately gamma distributed with size and shape parameter equal to 0.76. Our results suggest that (1) the animals and true fungi are indeed closer to each other than to any other “crown” group in the eukaryote tree, (2) red algae are the closest relatives of animals, true fungi, and green plants, and (3) the heterokonts and alveolates probably evolved prior to the divergence of red algae and animal-fungus-green-plant lineages. Furthermore, our analyses indicate that the branching order of the eukaryotic lineages that diverged prior to the evolution of alveolates may be generally difficult to resolve with the srRNA sequence data.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF02198844

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3

Digitale Medien

Atoms to astronomy: Computer graphics at the Jet Propulsion Laboratory (1986)

Holzman, Robert E.

Springer

The visual computer 2 (1986), S. 159-163

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ISSN: 1432-2315

Schlagwort(e): Education ; Animation ; Computer graphics ; Physics ; Solar system

Quelle: Springer Online Journal Archives 1860-2000

Thema: Informatik

Notizen: Abstract Within the Jet Propulsion Laboratory in Pasadena, California, state of the art computer graphics animation is done in the Computer Graphics Laboratory. The topics of the animations cover many scientific disciplines. Specific features of the system developed there, both hardware and software, are discussed. The prime mover of the effort is Dr. James F. Blinn of Pasadena; his role and experiences are elaborated. Their current largest project is The Mechanical Universe; the system is used for its production.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01900326

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4

Digitale Medien

Segmentation and tracking of piglets in images (1995)

McFarlane, N. J. B. ; Schofield, C. P.

Springer

Machine vision and applications 8 (1995), S. 187-193

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ISSN: 1432-1769

Schlagwort(e): Tracking ; Segmentation ; Pigs ; Animals ; Computer vision

Quelle: Springer Online Journal Archives 1860-2000

Thema: Informatik

Notizen: Abstract An algorithm was developed for the segmentation and tracking of piglets and tested on a 200-image sequence of 10 piglets moving on a straw background. The image-capture rate was 1 image/140 ms. The segmentation method was a combination of image differencing with respect to a median background and a Laplacian operator. The features tracked were blob edges in the segmented image. During tracking, the piglets were modelled as ellipses initialised on the blobs. Each piglet was tracked by searching for blob edges in an elliptical window about the piglet's position, which was predicted from its previous two positions.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1007/BF01215814

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5

Digitale Medien

Animal Consciousness and Ethics in Asia and the Pacific (1997)

Macer, Darryl

Springer

Journal of agricultural and environmental ethics 10 (1997), S. 249-267

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ISSN: 1573-322X

Schlagwort(e): Animals ; Asia ; consciousness ; Australia ; Hong Kong ; India ; Israel ; Japan ; New Zealand ; The Philippines ; Russia ; Singapore ; Thailand

Quelle: Springer Online Journal Archives 1860-2000

Thema: Energietechnik , Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft , Philosophie

Notizen: Abstract The interactions between humans, animals and the environment have shaped human values and ethics, not only the genes that we are made of. The animal rights movement challenges human beings to reconsider interactions between humans and other animals, and maybe connected to the environmental movement that begs us to recognize the fact that there are symbiotic relationships between humans and all other organisms. The first part of this paper looks at types of bioethics, the implications of autonomy and the value of being alive. Then the level of consciousness of these relationships are explored in survey results from Asia and the Pacific, especially in the 1993 International Bioethics Survey conducted in Australia, Hong Kong, India, Israel, Japan, New Zealand, The Philippines, Russia, Singapore and Thailand. Very few mentioned animal consciousness in the survey, but there were more biocentric comments in Australia and Japan; and more comments with the idea of harmony including humans in Thailand. Comparisons between questions and surveys will also be made, in an attempt to describe what people imagine animal consciousness to be, and whether this relates to human ethics of the relationships.

Materialart: Digitale Medien

URL: http://dx.doi.org/10.1023/A:1007774409131

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6

Digitale Medien

Dual-mode free volume model for diffusion of gas molecules in glassy polymers (1997)

Barbari, T. A.

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 1737-1746

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ISSN: 0887-6266

Schlagwort(e): free volume ; dual mode ; diffusion ; glassy polymer ; Physics ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: The development of a new model for the diffusion of gas molecules in glassy polymers is presented which utilizes concepts from free volume theory and relies on a dual-mode interpretation of sorptive dilation in glassy polymers. Three assumptions are made in the development of the model. First, the free volume available for molecular transport processes is taken as constant below the glass transition temperature. Second, two populations of gas molecules are assumed to exist - one which contributes to the maintenance of an iso-free volume state upon sorptive dilation and one which does not contribute owing to sorption into regions of unrelaxed volume. Third, the former population is assumed to be mobile while the latter is not. The resulting model predicts, at constant temperature, a diffusion coefficient that is independent of solute volume fraction. This is in contrast to the widely used dual-mode sorption model with partial immobilization for gas transport in glassy polymers which leads to a diffusion coefficient that is dependent on solute mole fraction through the molar gas concentration. The new model is used to interpret gas transport data from permeation experiments for carbon dioxide, methane, and ethylene in three polycarbonates. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1737-1746, 1997

Zusätzliches Material: 9 Ill.

Materialart: Digitale Medien

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7

Digitale Medien

Surface modification strategies for multicomponent polymer systems, Part I: Use of diblock copolymers as surface modifiers of rutile (1997)

Wang, Weidong ; Schreiber, Henry P. ; Yu, Yisong ; [weitere]

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 1793-1805

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ISSN: 0887-6266

Schlagwort(e): rutile ; surface modification ; diblock copolymer ; inverse gas chromatography ; Physics ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: Various functional diblock copolymers have been used as surface modifiers for rutile pigment in an effort to condition the solid for eventual use in multicomponent polymer systems. Coated surfaces were analyzed by inverse gas chromatography at infinite and finite dilution of the vapor phase, and by XPS. At high coverages (about 10% by weight of the pigment), the diblocks were randomly oriented at the air interface, effectively masking the surface of the rutile. At low diblock concentrations acid/base interactions dominated the orientation of the adsorbed molecule at the rutile interface, thereby also affecting the orientational states at the air interface. In this condition, the performance of the pigment in specified host polymer systems may be expected to vary with the selection of the diblock copolymer modifier. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1793-1805, 1997

Zusätzliches Material: 5 Ill.

Materialart: Digitale Medien

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8

Digitale Medien

The phase morphology and crystal growth habits of DNA fractions. Optical microscopy and light scattering (1997)

Monar, Kenneth ; Phillips, Paul J.

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 1843-1854

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ISSN: 0887-6266

Schlagwort(e): crystallization ; DNA ; fractionation ; gel-electrophoresis ; morphology ; phase transition ; SALLS ; sonication ; Physics ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: Polydisperse DNA of reasonable molecular weights was prepared from a mammalian source via sonication and fractionation. A method for characterizing the molecular weight using gel electrophoresis is described. Quiescent crystallization was studied in thin films of one of the fractions induced by rapidly changing the hydration state isothermally. We report the occurrence of the semicrystalline nature of DNA. The crystal growth occurring via aggregates is best described as sheaves and spherulites from DNA gels in the relative humidity range (RH) corresponding to A-DNA. These habits exhibit primary nucleation and secondary growth, which closely resemble those of melt-crystallized, synthetic macromolecules and, in a follow-up report, will be shown to be lamellar in nature. Small, needle-like crystals are observed for B-DNA hydration levels, and are unstable at lower hydration levels. A transformation from needle to lamellar crystals can occur, even when the primary nucleation of lamellar forms is otherwise absent at that hydration level, through a cylindrical phase exhibiting selective reflection of colored bands. The hydration level plays, in part, the role of the supercooling in this system and the long-known hysteresis in the formation and dissolution of the A-DNA (crystals) can now be viewed in light of those factors known to operate in semicrystalline systems. A morphological phase diagram is developed and is in accord with the known physical evidence. Because this preparation and these morphological observations are without precedence, substantial detail into methodology is included for this first article in the series. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1843-1854, 1997

Zusätzliches Material: 10 Ill.

Materialart: Digitale Medien

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9

Digitale Medien

The first 85% kraft lignin-based thermoplasticsPaper No. 22,538 of the Scientific Journal Series of the Minnesota Agricultural Experiment Station, funded through Minnesota Agricultural Experiment Station Project No. 43-68, supported by Hatch Funds. (1997)

Li, Yan ; Mlynár, Juraj ; Sarkanen, Simo

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 1899-1910

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ISSN: 0887-6266

Schlagwort(e): kraft lignin ; thermoplastics ; polymer association ; poly(vinyl acetate) ; Physics ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: Interest in the development of lignin-containing polymeric materials has been upheld more or less continuously for the past 20 years. Tendencies toward high moduli and poorly defined thermal transitions have been regarded as imposing inevitable limitations upon the use of lignin derivatives for such purposes. Incorporation of more than 25-40% (w/w) lignin had usually resulted in materials that were brittle and weak. For the first time, however, from homogeneous blends containing 85% (w/w) underivatized industrial kraft lignin with poly(vinyl acetate) and two plasticizers, a series of thermoplastics has been fabricated with promising mechanical properties. The tensile behavior of these new polymeric materials depends directly upon the degree of association between the intrinsic kraft lignin components. In extending to values about 25 MPa and 1.5 GPa, respectively, the tensile strengths and Young's moduli vary linearly with the effective M̄w for the kraft lignin species, under conditions where the proportions of the individual molecular components, both associated and discrete, do not change. Moreover, melt-flow index measurements indicate that these polymeric materials are amenable to thermal processing by extrusion molding. Thus a significant step has been taken toward developing a new generation of thermoplastics that are lignin-based in a very fundamental way. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1899-1910, 1997

Zusätzliches Material: 5 Ill.

Materialart: Digitale Medien

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10

Digitale Medien

Viscoelasticity and self-diffusion in melts of entangled linear polymers (1997)

Gell, Carol B. ; Graessley, William W. ; Fetters, Lewis J.

Bognor Regis [u.a.] : Wiley-Blackwell

Journal of Polymer Science Part B: Polymer Physics 35 (1997), S. 1933-1942

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ISSN: 0887-6266

Schlagwort(e): self-diffusion ; viscosity ; polymer melt ; entanglement ; Physics ; Polymer and Materials Science

Quelle: Wiley InterScience Backfile Collection 1832-2000

Thema: Chemie und Pharmazie , Physik

Notizen: Dynamic properties in the melt state for two saturated hydrocarbon polymers, poly(ethylene-alt-propylene) (PEP) and head-to-head polypropylene (HHPP), were investigated by viscoelastic and diffusion measurements. Several nearly monodisperse linear samples of each species were used. Zero-shear viscosity η0 and self-diffusion coefficient D varied with temperature in accord with the WLF equation, and they also varied with molecular weight M in a manner that was consistent with the behavior of other species. The product η0D was of particular interest because extensive previous results for two other species, polystyrene and polyethylene, had led Pearson et al. to suggest that η0D/(η0D)Rouse is a universal function of the number of entanglements per molecule M/Me. With values for the Rouse model product for each species calculated from chain dimensions, and entanglement molecular weight from the plateau modulus, we show that the data for PEP and HHPP also support the Pearson universal form. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1933-1942, 1997

Zusätzliches Material: 6 Ill.

Materialart: Digitale Medien

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