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  • 1
    Electronic Resource
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    Springer
    Journal of ornithology 139 (1998), S. 121-129 
    ISSN: 1439-0361
    Keywords: fossil birds ; Hassiavis laticauda n. gen. n. sp. ; Archaeotrogonidae Mourer-Chauviré 1980 ; feather preservation ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Description / Table of Contents: Zusammenfassung Ein Vogel aus dem Mittel-Eozän der Grube Messel (Hessen, Deutschland) wird als neue Gattung und Art der Archaeotrogonidae Mourer-Chauviré 1980 beschrieben (incertae sedis). Die Exemplare aus Messel wären die ersten artikulierten Skelette dieser Familie.Hassiavis laticauda n. gen. n. sp. unterscheidet sich vor allem im Bau des Coracoids von der GattungArchaeotrogon Milne-Edwards 1892. Besonders bemerkenswert ist die ausgezeichnete Erhaltung der Flügel- und Schwanzbefiederung einiger Exemplare. Einige Schwanzfedern des Holotypus zeigen eine Querbänderung, welche möglicherweise auf die ursprüngliche Pigmentierung dieser Federn zurückzuführen ist. Die phylogenetische Stellung der Archaeotrogonidae wird diskutiert. Zur Zeit sind keine Synapomorphien bekannt, welche diese Familie mit einer der bestehenden Ordnungen verbinden.
    Notes: Summary A bird from the Middle Eocene of the Grube Messel (Hessen, Deutschland) is described as a new genus and species of the Archaeotrogonidae Mourer-Chauviré 1980 (incertae sedis). The specimens from Messel would be the first articulated skeletons of this family.Hassiavis laticauda n. gen. n. sp. is distinguished from the genusArchaeotrogon Milne-Edwards 1892 in the morphology of the coracoid. The excellent preservation of the wing feathers and those of the tail in several of the specimens is exceptional. Some tail feathers of the holotype are barred, which might be traced back to the original pigmentation of these feathers. The phylogenetic position of the Archaeotrogonidae is discussed. At present no synapomorphies are known, which could set up a closer relationship between this family and one of the existing orders.
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  • 2
    ISSN: 1570-7458
    Keywords: Diptera ; Calliphoridae ; Muscidae ; Oestridae ; blowfly ; odour ; dimethyl trisulphide ; attraction ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A field test with synthetic dimethyl trisulphide as attractant in flight traps was carried out in Finnmark, northern Norway, in July 1992 and 1994. The reindeer oestrids Hypoderma (=Oedemagena) tarandi (L.) and Cephenemyia trompe (Modeer) (Diptera: Oestridae), previously shown to react positively to dimethyl trisulphide on the olfactory receptor level, were only caught in small numbers, with no significant differences between baited and unbaited traps. In both years, however, the baited traps caught significantly more individuals of Calliphoridae and Hydrotaea anxia (Zetterstedt) (Diptera: Muscidae) than unbaited control traps. In 1992, Protophormia terraenovae (Robineau-Desvoidy) (Diptera: Calliphoridae) and H. anxia were the predominant species (78.5% and 20.5%, respectively). In 1994, H. anxia was the most prevalent species (73.6%). Seven species of Calliphoridae were caught, with P. terraenovae, Calliphora vomitoria (L.), C. uralensis (Villeneuve) and C. loewi (Enderlain) as the most numerous ones. Dimethyl trisulphide is probably a decomposition product from bacterial activity and may be one of the major cues for calliphorid host finding. The significance of the reaction for oestrids on the receptor level, but evidently not on a behavioural level, remains unclear.
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  • 3
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    Entomologia experimentalis et applicata 80 (1996), S. 320-324 
    ISSN: 1570-7458
    Keywords: multitrophic interactions ; phylogeny ; evolution ; fitness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 4
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    Entomologia experimentalis et applicata 80 (1996), S. 315-319 
    ISSN: 1570-7458
    Keywords: phylogeny ; host shift ; climate ; abiotic thermal constraints ; leaf quality ; phenology ; larval growth ; oviposition preference ; Lepidoptera
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
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  • 5
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    Entomologia experimentalis et applicata 80 (1996), S. 297-305 
    ISSN: 1570-7458
    Keywords: mandibulate folivores ; constraints ; diet breadth ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic studies are increasing our understanding of the evolution of associations between phytophagous insects and their host plants. Sequential evolution, i.e. the shift of insect herbivores onto pre-existing plant species, appears to be much more common than coevolution, where reciprocal selection between interacting insects and plants is thought to induce chemical diversification and resistance in plants and food specialization in insects. Extreme host specificity is common in phytophagous insects and future studies are likely to reveal even more specialization. Hypotheses that assume that food specialists have selective advantages over generalists do not seem to provide a general explanation for the ubiquity of specialist insect herbivores. Specialists are probably committed to remain so, because they have little evolutionary opportunity to reverse the process due to genetically determined constraints on the evolution of their physiology or nervous system. The same constraints might result in phylogenetic conservatism, i.e. the frequent association of related insect herbivores with related plants. Current phylogenetic evidence, however, indicates that there is no intrinsic direction to the evolution of specialization. Historical aspects of insect-host plant associations will be illustrated with the small ermine moth genus Yponomeuta. Small ermine moths show an ancestral host association with the family Celastraceae. The genus seems to be committed to specialization per se rather than to a particular group of plants. Whatever host shift they have made in their evolutionary past (onto Rosaceae, Crassulaceae, and Salicaceae), they remain monophagous. The oligophagous Y. padellus is the only exception. This species might comprise a mosaic of genetically divergent host-associated populations.
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  • 6
    ISSN: 1572-8854
    Keywords: X-ray structure ; iridium complexes ; pyridylphosphine ligands
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The structure of the title tetranuclear cluster, C59H42N3O8P3Ir4, was determined by X-ray analysis. It crystallizes in the monoclinic space groupC2/c. The unit cell parameters are:a =47.277(6),b=10.519(3),c=23.025(4) Å, β=105.77(1)°. The iridium atoms form a nearly regular tetrahedron. Between Ir4 and N336 atoms exists a relatively strong bond, thus one of the phosphine ligands is bridging one coordinatingvia P and N atoms.
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  • 7
    ISSN: 1572-8854
    Keywords: X-ray structure ; pyramidalized sp2 carbon ; facial differentiation ; stereoselectivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The X-ray crystal structure of the title compound is reported. Crystal data: T = 100 K, monoclinic, P21/n, a = 8.2990(17), b = 13.2300(26), c = 12.0350(24) Å, β = 93.676(30)°, V = 1318.7 (5) Å3, and R = 0.0368. The methylene carbon atoms in the cyclohexadiene ring are disordered over two positions above and below the ring plane. The chlorine substituted endocyclic double bond deviates from planarity with an angle of 8.10(13)° toward the endo-face. The facially differentiated 1,3-cyclohexadiene moiety is only slightly pyramidalized, deviating 1.75(20)° also toward the endo-face of the tricyclic system.
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  • 8
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    Journal of chemical crystallography 29 (1999), S. 115-119 
    ISSN: 1572-8854
    Keywords: Aminosulphines ; thionicotinamide S-oxide ; thiobenzamid ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Thiobenzamide and thionicotnamide S-oxide were prepared as intermediates in the dimerization of corresponding thioamides to 1,2,4-thiadiazoles and the X-ray crystal structure of thionicotinamide S-oxide water solvate was determined. Crystals belong to orthorhombic Pbca space group with a = 14.129(3), b = 7.299(2), c = 15.277(3)Å, and Z = 8. The geometry of the molecule accords well with that found in similar compounds; an intramolecular N–H···O hydrogen bond is present, while the packing is mainly determined by the hydrogen bond system involving the water molecule and the side-chain of the organic molecule. The contacts between pyridine moieties, stacked along the [010] axis, complete the packing.
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  • 9
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    Journal of chemical crystallography 29 (1999), S. 667-670 
    ISSN: 1572-8854
    Keywords: 6′-butoxy-2,6-diamino-3,3′-azo-dipyridine ; X-ray structure ; hydrogen bonds
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Chemical preparation, X-ray single crystal, and calorimetric studies of C14H18N6O · H2O are described. The compound crystallizes in the triclinic space group, P $${\bar 1}$$ with unit cell dimensions: a = 6.2640(3), b = 10.9840(4), c = 12.2220(3) Å, α = 105.03(2), β = 96.96(2), γ = 101.6(2)°, V = 712.10(5) Å3, and Z = 2. The 6′-butoxy-2,6-diamino-3,3′-azo-dipyridine monohydrate structure is built up from organic layers parallel to the (120) plane linked via O—H···N bond.
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  • 10
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    Journal of chemical crystallography 29 (1999), S. 653-657 
    ISSN: 1572-8854
    Keywords: picoline derivative ; X-ray structure ; nonlinear optic
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Because of their strongly delocalized π electronic systems, polymeric and non-polymeric aromatic compounds show high nonlinear optical properties. The present work deals with the synthesis and structural characterization (including X-ray single crystal studies) of new picoline derivatives, 5-ethyl-2-(4-nitro-styryl)-pyridine, space group P $${\bar 1}$$ a = 6.9505(7), b = 7.418(1), c = 13.877(2) Å, α = 105.14(1), β = 93.88(1), γ = 105.89(1)°, and 5-ethyl-2-(4-nitro-7-ol-styryl)-pyridine, space group Pcab, a = 8.628(2), b = 10.405(2), and c = 31.604(5) Å.
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  • 11
    ISSN: 1572-8854
    Keywords: vinilic sulfides ; thioacetylenes ; tosylates ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The reaction between 1-phenylsulphenyl-2-phenylethyne and p-toluenesulfonic acid in methylene chloride gives (Z)-1-(phenylsulphenyl)-2-phenylethenyl p-toluenesulfonate (1) in good yields. This reaction is both a regio- and a stereospecific cis addition, confirmed by X-ray crystal structure analysis of the title compound. 1 crystallizes in the monoclinic space group P21/n with the lattice parameters a = 10.556(3), b = 9.730(3), c = 19.687(3) Å, β = 105.05(2)°, V = 1952.7(8) Å3, and Z = 4. The results of elemental analysis, IR and NMR spectroscopy are included.
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  • 12
    ISSN: 1572-8854
    Keywords: 4-iminecinnoline analogs of quinolones ; X-ray structure ; intramolecular hydrogen bond ; packing
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Crystal structures of hydrochlorides of 7-chloro- and 7-methyl-4-iminecinnoline analogs of antibacterial quinolones have been determined by X-ray diffraction methods. The cell parameters for the 7-chloro (1) analog in the space group P21/c are a = 9.061(1), b = 19.062(1), c = 7.310(1)Å, β = 104.92(1)°, Z = 4, and D calc = 1.569 g/cm3 and for the 7-methyl (2) analog in the space group P $${\bar 1}$$ are a = 7.277(5), b = 9.080(5), c = 10.058(5) Å, α = 106.10(1), β = 102.38(1), γ = 90.18(1)°, Z = 2, and D calc = 1.429 g/cm3. Despite geometrical equivalency of methyl and chlorine and some resemblance of their packings, the crystal structures are not isostructural. Each compound forms a strong intramolecular hydrogen bond between protonated 4-imine (a donor) and 3-carboxylic (an acceptor) groups. Compounds with a similar bond, but with reversed functionality and orientation of the 3-carboxylic group, form common quinolones, being mostly 4-oxoquinoline-3-carboxylic acids. The difference should exclude chemical affinity of 4-imine analogs to the guanine base of a bacterial DNA in DNA-gyrase complex, as proposed by Shen et al. 2 for 4-oxoquinoline-3-carboxylic acids showing antibacterial activity. Also the free acidic function of a carboxyl group may significantly lower permeability of 4-imine-3-carboxylic analogs of quinolones. Surprisingly, they have demonstrated antibacterial activity comparable with that of nalidixic acid.
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  • 13
    ISSN: 1572-8854
    Keywords: ruthenium cluster ; bis(diphenylphosphino)methane ; hydride ; chloride ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The reaction of [Ru3(CO)10(μ-dppm)] 1 with PPhCl2 in refluxing CHCl3 results in the isolation of [(μ-H)Ru3(CO)8(μ-Cl)(μ-dppm)] 3 in 10% yield. Compound 3, which has been structurally characterized by crystallographic methods, is also formed from the reaction of 1 with H2 in refluxing CCl4. The compound crystallizes in the monoclinic space group P21/c with a = 16.814(2), b = 18.7590(12), c = 11.486(2) Å, β = 97.745(11)°, V = 3589.8(8) Å3, and Z = 4. The hydride and chloride ligands bridge the same edge of the triruthenium cluster as the dppm ligand.
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  • 14
    ISSN: 1572-8854
    Keywords: heterobimetallic ; dodecanuclear ; Mo-Ag-S cage cluster ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The crystal structure of the title compound, [Et4N]2[(Mo2Ag2S2O2edt2)3(μ6-S)]·3H2O (edt=SC2H4S−), has been investigated by X-ray diffraction techniques, the crystal is tetragonal, space group P4l2l2, with a = b = 13.4801(4), c = 37.7381(14) Å, V = 6857.5(4) Å3 andZ = 4. The anion of the title compound can be viewed as a cage consisting of three [Mo2S2O2(S2C2H4)2]2−/2 Ag+ fragments, with an S2− at the cage center bonding to six Ag atoms. The cage has two big windows each composed of a puckered Ag3S6C6 15-membered ring.
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  • 15
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    Journal of chemical crystallography 30 (2000), S. 773-776 
    ISSN: 1572-8854
    Keywords: X-ray structure ; triosmium cluster ; decacarbonyl ; quinoline
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Decacarbonyl-μ-hydrido-μ-1,8-η2-quinoline-triosmium crystallizes in the triclinic space group P $$\bar 1$$ with a = 7.8551(6), b = 9.1283(8), c = 16.7915(8) Å, α = 74.788(2), β = 88.086(2), γ = 66.392(3)°, V = 1062.22(13)° Å3, T = 150 K, and Z = 2. The molecule consists of an Os3 triangle with the hydride and the heterocyclic ligand bridging the same Os—Os edge. The heterocyclic ligand is coordinated through the C(8) carbon and nitrogen atoms in a new μ-1,8-η2-bonding mode. The Os—Os distances lie in the close range 2.8837(4)–2.9034(4) Å with an average value of 2.892(7) Å.
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  • 16
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    Journal of chemical crystallography 25 (1995), S. 743-745 
    ISSN: 1572-8854
    Keywords: Lithium binder ; X-ray structure ; 1,3-bis(8-quinolyloxy)propane
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The X-ray crystal structure of 1,3-bis(8-quinolyloxy)propane, monoclinic, space group C2/c(No. 15),a=25.367(4);b=4.923(5) andc=14.418(4)Å; β=111.18(2)o;Z=4 has been determined by direct methods. A final least squares refinement based on 812 observed reflections (I〉2δ(I)) gave finalR values ofR f=0.043 andR w=0.034.
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  • 17
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    Journal of chemical crystallography 26 (1996), S. 47-51 
    ISSN: 1572-8854
    Keywords: X-ray structure ; N-salicylideneamine ; Schiff base ; tautomeric equilibrium ; keto-enamine tautomer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound crystallizes in the orthorhombic space group P212121, withZ=4,a=6.068(1)Å,b=10.922(1)Å, andc=21.713(2)Å. The compound is the chiral ligand of a copper complex used as an enantioselective catalyst. It crystallizes from methanol in the keto-enamine form, though the enol-imine isomer predominates in the solution. Most N-salicylideneamines studied by X-ray are enol-imines. The two tautomeric forms may interchange through anintramolecular hydrogen bond and the distances between non-H atoms in the resulting cyclic −O−H...N=C−C=C- or −C=O...H−N−C=C- fragment may be misleading, so that H atom position is the crucial factor for determination of the proper tautomeric form.
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  • 18
    ISSN: 1572-8854
    Keywords: X-ray structure ; unsaturated monosaccharides
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Methyl 6-(N-benzenesulfonylamino)-N,O-isopropylidene-2,3,6,8-tetradeoxy-α-d-erythrooct-2-enopyranos-4-uloside, C18H23N1O6S1, (3) crystallizes in the orthorhombic space groupP212121. The unit cell parameters are:a=7.839(2),b=10.111(2),c=24.217(5) Å. The dihydropyranone ring adopts a deformed sofa conformation with the O5 atom deviating 0.586(2) Å from the least-squares plane and the β-face of the carbonyl group shielded by the terminal (C8) methyl group. 1,1-O,O-Ethylidene-3,4-dideoxy-d,l-hex-3-enoz-2-ulopyranos-5-ulose, C8H10O5, (6) crystallizes in the monoclinic space groupP21/n. The unit cell parameters are:a=6.310(1),b=18.656(3),c=7.604(1) Å, β=106.01(1)°. The dihydropyranone ring adopts a deformed sofa conformation with O6 atom deviating 0.482(1) Å from the leastsquares plane and the hydroxy and dioxolanyl substituents are in pseudoaxial and pseudoequatorial positions, respectively. The average planes of six-membered and five-membered rings are approximately coplanar.
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  • 19
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    Journal of chemical crystallography 26 (1996), S. 301-303 
    ISSN: 1572-8854
    Keywords: 2,6-Lutidine complex ; palladium(II) ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The X-ray structure oftrans-(2,6-lutidine)2PdCl2 has been determined. Golden orange crystals of the complex crystallize in the triclinic space group $$P\bar 1$$ , with cell dimensionsa=7.6950(8),b=7.9705(10),c=8.0485(8)Å, α=116.967(9), β=113.343(8), and γ=93.836(9)°;V=385.18(7)Å3 andZ=2. 1336 unique reflections withI net〉3σ (I) on refinement afforded values ofR=0.018 andR w=0.023.
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  • 20
    ISSN: 1572-8854
    Keywords: Melaminium dinitramide and melaminium nitrate ; melaminium salts ; dinitramide salt ; hydrogen bonding ; X-ray structure ; energetic materials
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Two energetic salts of the melaminium cation have been prepared and structurally characterized from room temperature X-ray single crystal diffraction data. Melaminium dinitramide (I), triclinic, P1¯, a = 6.6861(11), b = 6.9638(16), c = 10.447(2) Å , α = 99.07(3), β = 98.30(3), γ = 108.50(3)°, V = 445.6(2) Å3, and Z = 2. Melaminium nitrate (II), monoclinic, P21/c, a = 3.5789(7), b = 20.466(4), c = 10.060(2) Å, β = 94.01(2)°, V = 735.0(3) Å3, and Z = 4. The crystal structures of both salts show distinct monoprotonated melaminium cations and dinitramide- or nitrate anions, respectively. Efficient packing in the solid state is achieved by extensive hydrogen bonding between two-dimensional zigzag ribbons of the melaminium cations and the respective anions resulting in high densities of the solid state structures of 1.74 (I) and 1.71 g/cm3 (II).
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  • 21
    ISSN: 1572-8854
    Keywords: X-ray structure ; dtc ; cadmium complex
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The cadmium complex of bis(dipropyldithiocarbamate), [Cd2(n-Pr2dtc)4] (dtc = dithiocarbamate) was crystallized from ethylether. It crystallizes in the monoclinic system, space group P 2I/c, with lattice parameters, a = 8.2532(1), b = 19.4519(1), c = 13.4163(2) Å, β = 99.243(1)°, and Z = 4. The X-ray single-crystal structure of [Cd2(n-Pr2dtc)4] reveals that the complex is binuclear in the solid state and the Cd atom has a distorted square-pyramidal coordination environment and four equatorial donors are the two bidentate chelate sulfur atoms from two dtc ligands, of which the sulfur atom from the bridging dtc ligand occupies the apical position of the symmetry-related Cd atom in the dimer structure.
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  • 22
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    Journal of chemical crystallography 30 (2000), S. 233-236 
    ISSN: 1572-8854
    Keywords: Mixed-metal clusters ; phosphido-bridged clusters ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Treatment of Fe2(CO)6(μ2-PPhH)2 with BuLi (2 equiv.), followed by the addition of PtCl2 (dppe), affords the phosphido-bridged cluster Fe2(CO)6(μ3-PPh)2Pt(dppe). The Fe2Pt cluster was isolated and characterized in solution by IR and 31P NMR spectroscopy, and the molecular structure of Fe2(CO)6(μ3-PPh)2Pt(dppe) determined by X-ray diffraction analysis. Fe2(CO)6(μ3-PPh)2Pt(dppe) crystallizes in the orthorhombic space group Pbca, a = 17.539(3) Å, b = 21.490(2) Å, c = 22.959(3) Å, V = 8653.5(18) Å3, Z = 8, dcalc = 1.670 g cm−3; R = 0.0644, Rw = 0.0389 for 5040 observed reflections with I 〉 3σ(I).
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  • 23
    ISSN: 1572-8854
    Keywords: 1-Chloro-1,2-benziodoxolin-3(1H)-one·tetra-n-butylammonium chloride ; 1-chlorobenziodoxolinone-chloride ; γ3-iodane ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The title compound,6, a novel 1∶1 complex of 1-chloro-1,2-benziodoxolin-3(1H)-one (5) andtetra-n-butylammonium chloride, was prepared from tetra-n-butylammoniumo-iodoxybenzoate (7) and acetyl chloride. A single crystal of6 was subjected to X-ray analysis: triclinic, space group $$P\bar 1;$$ a=10.239(2),b=11.518(2),c=11.523(3)Å; α=73.20(2); β=87.85(2), γ=87.72(2)°; R1=0.0326. The most notable structural feature of crystalline6 is the existence of a “secondary” bond [I· ·Cl(2), 2.943(1)Å] between the chloride ion and the iodine atom of the chlorobenziodoxolinone moiety. Further coordination at iodine includes three primary bonds: I−C [2.115(4) Å], I−O [2.145(3) Å], I−Cl(1) [2.454(1) Å]. The entire 1-chlorobenziodoxolinone-chloride sub-structure is planar and exhibits iodine-centered bond angles of 78.8(1)° [C−I−O], 92.0(1)° [C−I−Cl(1)], 97.6(1)° [Cl(2)−I−O] and 91.6(1)° [Cl(2)−I−Cl(1)]. The unit cell of6 contains two loosely packed formula units. The chlorobenziodoxolinone-chloride sub-structures occupy a common plane and exhibit a centrosymmetric relationship, while the tetra-n-butylammonium ions are situated one above and one below the plane. Bonding at the iodine atom in6 is more consistent with a 10-I-3 species electrostatically associated with the chloride ion than a 12-I-4 species such as the tetrachloroiodate ion.
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  • 24
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    Journal of chemical crystallography 26 (1996), S. 835-840 
    ISSN: 1572-8854
    Keywords: X-ray structure ; organotungsten complex ; half-sandwich ; heavy metal
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The crystal structures of [(η5-C5H4COOH)W(CO)3R] (R=Me, I) have been determined. They crystallize in two different monoclinic space groups. R=Me isP21/c,a=10.4833(6),b=8.0144(7),c=13.0731(6) Å, β=93.147(4)°, andD(calc)=2.374 g-cm−3 forZ=4. R=I isP21/n,a=7.814(2),b=13.075(4),c=11.097(4) Å, β=91.75(2)°, andD(calc)=2.953 g-cm−3 forZ=4. Both possess a “four-legged piano stool” geometry. The methyl ligand in the R=Me complex is disordered between two positions insyn oranti relative to the substituted carbon of the cyclopentadienyl ligand. The iodo ligand in the R=I complex is, however, exclusively insyn-position.
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  • 25
    ISSN: 1572-8854
    Keywords: host–guest complexes ; antimony trifluoride ; azacrown ethers ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Synthesis and single-crystal X-ray structures are recorded for three adducts of SbF3 with different azacrown ethers. [SbF3·H2O·L1], 1, (L1 = 12,13-benz-1,10-di(azamethyl)-4,7-dioxacyclotetradecane-1,14-dione), triclinic, $$P\bar 1$$ , a = 11.234(2), b = 11.691(2), c = 8.869(2) Å, α = 94.66(3), β = 113.12(3), γ = 67.82(3)°, Z = 2. [SbF3Cl·H2O·(HL2)], 2, (L2 = monoaza-18-crown-6), orthorhombic, P212121, a = 8.763(2), b = 13.003(3), a = 16.836(3) Å, Z = 4. [(SbF3)2Cl2·(H2L3)], 3, (L3 = 1,10-diaza-18-crown-6), triclinic, $$P\bar 1$$ , a = 8.284(2), b = 9.016(2), c = 9.134(2) Å, α = 82.92(3), β = 65.24(3), γ = 63.38(3)°, Z = 1. All three structures include SbF3 neutral molecules in the pyramidal mode and the antimony second coordination sphere is completed up to six in different fashions. In 1 the dimeric (SbF3)2 adducts are made up due to the involvement of the symmetry-related fluorine atom in coordination. The distorted octahedron is then completed by water molecule and carbonyl oxygen of L1. The neutral molecules are joined by coordination and hydrogen bonds in the infinite ribbons. 2 and 3 are both comprised of neutral and charged species also bounded via coordination and hydrogen bonds. L2 and L3 in the complexes adopt the form of single and double-charged cations, respectively. The inorganic backbone unites the neutral SbF3 molecules and chloride anions in the alternative mode. The sixth coordination site in the antimony polyhedron is completed by the water molecule in 2 and the ethereal oxygen atom in 3. Alignment of the inorganic entities within the structures of 2 and 3 is strikingly similar. Hydrogen bonding patterns are discussed.
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  • 26
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    Journal of chemical crystallography 29 (1999), S. 383-389 
    ISSN: 1572-8854
    Keywords: chiral auxiliary ; π-stacking ; asymmetric synthesis ; X-ray structure ; chromium complexes
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract (—)-8-Phenylmenthol was prepared and converted to the corresponding tricarbonyl (η6-arene) chromium(0) complex. Derivitization as the acrylate ester (1) and subsequent X-ray analysis revealed a 1:1 mix of s-cis and s-trans acrylate in the unit cell, and geometric proximity to support a through-space π stacking interaction in the case of the s-trans isomer. The dihedral angle between the best planes through the chromium-bound aryl ring and the acrylate group is 19.9° for the s-trans isomer and 34.4° for the s-cis isomer. Crystal data for (1): C22H26O5Cr, monoclinic, P21 (No. 4), a = 10.269(1), b = 10.482(1), c = 19.787(2), β = 95.85(1), Z = 4, and D calc = 1.32 g cm−3.
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  • 27
    ISSN: 1572-8854
    Keywords: X-ray structure ; pentacoordinated copper(II) ; square-pyramid ; acetonitrile coordination
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The syntheses and structures of two square-pyramidal acetonitrile coordinated copper(II) complexes, [Cu(HbhsNO2)(CH3CN)2]ClO4 (1) and [Cu(HahsNO2)(CH3CN)(ClO4)] (2), are described. The mononegative ligands are obtained by deprotonation of the phenolic-OH of N-(benzoyl)-N′-(5-nitrosalicylidene)hydrazine (H2bhsNO2) and of N-(anisoyl)-N′-(5-nitrosalicylidene)hydrazine (H2ahsNO2). Crystal data for 1: monoclinic, P21/c (#14), a = 9.7245(14), b = 20.23(4), c = 11.042(3) Å, β = 91.86(2)°, V = 2171.0(7) Å3, and Z = 4 and for 2: triclinic, P1¯ (#2), a = 9.7710(19), b = 9.9687(15), c = 11.062(5) Å, α = 73.10(3), β = 88.77(3), γ = 88.379(14)°, V = 1030.4(5) Å3, and Z = 2. In each complex the planar ligand binds the metal ion via phenolate-O, imine-N, and amide-O. The nitrogen of an acetonitrile molecule satisfies the fourth site of the square-plane containing the metal ion. In 1 the axial coordination is provided by the nitrogen of a second acetonitrile molecule, whereas in 2 one of the oxygen atoms of the perchlorate occupies the fifth axial site. The axial acetonitrile molecule of 1 is bound to the metal center in a bent mode. The other noticeable difference between the two structures is in the geometry at the metal center. A large displacement (0.23 Å) of the metal ion from the ONON basal plane towards the axial coordinating atom is observed in 1. On the other hand, there is no displacement of the metal center from the same ONON basal plane in 2. The EPR and electronic spectral features in acetonitrile solutions are consistent with the solid state structures.
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  • 28
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    Journal of chemical crystallography 30 (2000), S. 411-414 
    ISSN: 1572-8854
    Keywords: L-arginine fluoride ; second harmonic generator ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract L-arginine fluoride is a promising compound that exhibits nonlinear optical properties. It efficiently converts two single photons of the same polarization and frequency ω to one photon of frequency 2ω (type I phase matching). C6H15N4O2 +F− is monoclinic, space group P21, a = 5.4475(4) Å, b = 8.5133(6) Å, c = 10.2195(7) Å, β = 93.475(6)°. The cation has a zwitterionic form, protonated at both the guanidyl and amino groups. The arginine Cγ atom is in a trans position to the carboxyl group. A complex three-dimensional hydrogen bond network links the anions and cations together.
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  • 29
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    Journal of chemical crystallography 30 (2000), S. 731-735 
    ISSN: 1572-8854
    Keywords: phosphine selenide ; Au(I) ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The X-ray structure determination of the complex, [(cyclohexyl)3PSe-AuBr], revealed a triclinic space group P-1, with a = 9.7654(7), b = 10.9441(9), c = 11.2064(9) Å, α = 117.076(6)°, β = 99.076(6)° γ = 95.417(6)°, V = 1034.07(14) Å3 and Z = 2. The Au(I) atom in this complex has a linear coordination with Se1 atom at 2.3776(9) Å on one side and Br1 at 2.3843(9) Å at the trans position making the Se1-Au1-Br1 angle of 177.97(4)°. The P1 atom in the phosphine has tetrahedral geometry. All three cyclohexyl groups are in their usual boat conformation. The phosphorus atom of the triphenylphosphine is approximately perpendicular to the Se1—Au1—Br1 linkage with P1—Se1—Au1 angle of 99.19(6)°. The Δδ in the 31P NMR of the free ligands and their corresponding L—Se—Au—Br (L—Se = trialkyl/arylphosphine selenides) complexes, and the changes in the P—Se bond frequencies in the FTIR upon complexation, are indicative of the bonding of the ligand to Au(I) through selenium. There is a strong corelation between the chemical shifts of the 31P NMR and the C—P—C angle in the phosphines.
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  • 30
    ISSN: 1572-8854
    Keywords: 1-(4-Nitrobenzyl)pyridinium ; bis(maleonitriledithiolato)nickelate(II) complex ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The structure of [NO2Py]2[Ni(mnt)2], as determined by x-ray single crystal analysis, consists of two 1-(4-nitrobenzyl)pyridinium cations and one [Ni(mnt)2]2− anion. The crystallographic data for the complex:monoclinic P21/n, a = 9.913(2) Å, b = 11.968(2) Å, c = 14.566(3) Å, β = 100.36(3)°, V = 1699.9(6) Å3, Z = 2. The [Ni(mnt)2]2− anion has a crystallographically imposed center of symmetry and exhibits a relatively planar structure. The cation, [NO2Py]+, adopts a conformation where both the aromatic rings are twisted to the C11-C10-N3 reference plane. The anions (A) and the cations (C) consist of alternating layers (i.e., of type ···C1A1C2A2C1A1C2···) along the c axis of the crystallographic unit cell.
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  • 31
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    Journal of chemical crystallography 30 (2000), S. 321-328 
    ISSN: 1572-8854
    Keywords: Rhodium ; copper ; hydride ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The binuclear compound [(triphos)RhH(μ-H)2Cu(diphos*)]+ with triphos = CH3C(CH2PPh2)3 and diphos* = o-C6H4(CH2P(C6H11)2)2 has been prepared and characterized. It crystallizes as [CF3SO3] salt in the monoclinic P21/c space group with Z = 4, a = 13.802(4)Å, b = 19.462(4)Å, c = 26.604(5)Å, β = 99.8(3)°, and V = 7041(3)Å3. The structure of the complex consists of two metal fragments with hydride ligands bridging the Rh-Cu contact. The hydride ligands were not located by X-rays but, from the arrangement of the heavy atoms and by methods of potential energy, the most probable positions of two hydride ligands bridging the Rh-Cu interaction and one that remains terminal on the rhodium atom, were obtained.
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  • 32
    ISSN: 1572-8854
    Keywords: Manganese ; pyridine-2-thiolate ; bis(diphenylphosphino)propane ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract The dimeric complex [Mn2(μ-pyS)2(CO)6] (1) reacted with 2 molar equivalents of Ph2P(CH2)3PPh2 (dppp) and Ph2P(CH2)2PPh2 (dppe) to give the respective monomeric chelate complexes [Mn(η2-pyS)(η2-dppp)(CO)2] (2) and [Mn(η2-pyS)(η2-dppe)(CO)2] (3). In contrast, with 2 molar equivalents of Ph2P(CH2)5PPh2 (dpppe), 1 gave the highly insoluble polymeric complex [Mn(η2-pyS)(μ-dpppe)(CO)2]n (4). An X-ray structure determination shows that 2 crystallizes in the monoclinic space group P21/n with a = 10.721(2) Å, b = 19.712(5) Å, c = 14.846(4) Å, β = 109.06(2)°, V = 2965.5(14) Å3, and Z = 4. The complex has a distorted octahedral geometry with the dppp ligand, one CO group and the N atom of the chelating pyS ligand occupying equatorial sites, and one CO group and the S atom of the pyS ligand lying in the axial positions.
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  • 33
    ISSN: 1420-9055
    Keywords: Alpine lakes ; hydrochemistry ; acidification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract During a four-year study (1988–1991), 413 lakes in the Central Alps (Italy, Switzerland and Austria) were investigated to quantify their acidification. The ionic content of the lakes was generally low: 68% of them had alkalinity values of less than 200 µeq 1−1 and were regarded as sensitive to acidification. Moreover, 36% of the lakes showed alkalinity values of less than 50 µeq 1−1. Redundancy Analysis was used to relate the hydrochemistry of 187 lakes to their catchment characteristics. Calcite weathering was the main factor influencing lake chemistry. The same analysis, applied to a subset of 101 lakes lying in watersheds exclusively composed of silicic rocks, showed that lake chemistry was influenced by silicate weathering and nitrogen uptake. These processes were found to be mainly related to lake altitude and the fraction of the watershed not covered by vegetation, i.e. controlled by temperature. The importance of these relations to explain the pH shift produced by climatic variation is also discussed.
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  • 34
    ISSN: 1432-1432
    Keywords: Two classes of aminoacyl-tRNA synthetases ; Sequence comparisons ; Homology ; X-ray structure ; Structure-function relationships ; Origin of aminoacyl-tRNA synthetases ; Two ancestral molecules ; Genetic code
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Previous sequence analyses have suggested the existence of two distinct classes of aminoacyl-tRNA synthetase. The partition was established on the basis of exclusive sets of sequence motifs (Eriani et al. [1990] Nature 347:203–306). X-ray studies have now well defined the structural basis of the two classes: the class I enzymes share with dehydrogenases and kinases the classic nucleotide binding fold called the Rossmann fold, whereas the class II enzymes possess a different fold, not found elsewhere, built around a six-stranded antiparallel β-sheet. The two classes of synthetases catalyze the same global reaction that is the attachment of an amino acid to the tRNA, but differ as to where on the terminal adenosine of the tRNA the amino acid is placed: class I enzymes act on the 2′ hydroxyl whereas the class II enzymes prefer the 3′ hydroxyl group. The three-dimensional structure of aspartyl-tRNA synthetase from yeast, a typical class II enzyme, is described here, in relation to its function. The crucial role of the sequence motifs in substrate binding and enzyme structure is high-lighted. Overall these results underline the existence of an intimate evolutionary link between the aminoacyl-tRNA synthetases, despite their actual structural diversity.
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  • 35
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    Journal of molecular evolution 42 (1996), S. 648-657 
    ISSN: 1432-1432
    Keywords: Major histocompatibility complex (Mhc) ; HumanMhc (HLA) ; DRB genes ; Gene duplication ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The major histocompatibility complex (Mhc) consists of class I and class II genes. In the humanMhc (HLA) class II genes, nineDRB loci have been identified. To elucidate the origin of these duplicated loci and allelic divergences at the most polymorphicDRBI locus, introns 4 and 5 as well as the 3′ untranslated region (altogether approximately 1,000 base pairs) of sevenHLA-DRB loci, threeHLA-DRBI alleles, and nine nonhuman primateDRB genes were examined. It is shown that there were two major diversification events inHLA-DRB genes, each involving gene duplications and allelic divergences. Approximately 50 million years (my) ago,DRBI *04 and an ancestor of theDRB1 *03 cluster (DRBI *03, DRBI*15, andDRB3) diverged from each other andDRB5, DRB7, DRB8, and an ancestor of theDRB2 cluster (DRB2, DRB4, andDRB6) arose by gene duplication. Later, about 25 my ago,DRBI *15 diverged fromDRBI*03, andDRB3 was duplicated fromDRBI *03. Then, some 20 my ago, the lineage leading to theDRB2 cluster produced two new loci,DRB4 andDRB6. TheDRBI *03 andDRBI *04 allelic lineages are extraordinarily old and have persisted longer than some duplicated genes. The orthologous relationships ofDRB genes between human and Old World monkeys are apparent, but those between Catarrhini and New World monkeys are equivocal because of a rather rapid expansion and contraction of primateDRB genes by duplication and deletion.
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  • 36
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    Conservation genetics 1 (2000), S. 67-76 
    ISSN: 1572-9737
    Keywords: mitochondrial DNA ; phylogeny ; phylogeography ; speciation ; species concepts ; taxonomy
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    Topics: Biology
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  • 37
    ISSN: 1573-0832
    Keywords: Epidermophyton floccosum ; Trichophyton spp. ; Microsporum spp. ; mitochondrial DNA ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Eleven strains of Epidermophyton floccosum were compared with 5 Microsporum and 5 Trichophyton species with respect to the restriction fragment length polymorphism (RFLP) of the mitochondrial DNA to reveal their phylogenetic relationships. The phylogeny of 11 species showed that the three dermatophyte genera could not be separated from each other and could be considered to be congeneric. This result is not inconsistent with the results from ribosomal RNA sequences.
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  • 38
    ISSN: 1573-0832
    Keywords: China ; epidemiology ; mitochodrial DNA ; phylogeny ; restriction fragment length polymorphism (RFLP) ; Sporothrix schenckii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mitochondrial DNA (mtDNA) types based on restriction fragment length polymorphism (RFLP)patterns with HaeIII were investigated in clinical isolates of Sporothrix schenckii in China. In addition to 23 mtDNA types (Types 1–23) so far reported, a new mtDNA type (Type 24) was found in this study. Type 24 was divided into two subtypes, Subtype 24A and 24B based on RFLP with EcoRV. Sixty-seven isolates in China consisted of 58 isolates of Type 4, 5 of Type 6, 1 of Type 5, 1 of Type 20 and 2 of Type 24. Based on the phylogeny of the mtDNA types (Types 1–24) constructed by estimating sequence divergences of mtDNA, mtDNA types clustered into two groups: Group A (Types 1–3, Type 11, Types 14–19 and Types 22–23) and Group B (Types 4–10, Types 12–13,Types 20–21 and Type 24). These results suggest that mostS. schenckii isolates in China belong to Group B.
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  • 39
    ISSN: 1573-0832
    Keywords: chitin synthase gene 1 ; dermatophyte ; Epidermophyton floccosum ; Microsporum ; phylogeny ; Trichophyton
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The Nucleotide sequence of the chitin synthase1 (CHS1) gene of Epidermophyton floccosum, an anthrophophilic dermatophyte which is the type species of the genus Epidermophyton was analyzed to determine its phylogenetic relation to eight other dermatophyte species belonging to the genera Microsporum and Trichophyton, which were sequenced in our previous studies. A genomic DNA fragment about 620 bp in length of the CHS1 genewas amplified from E. floccosum by polymerasechain reaction (PCR) and was sequenced. The CHS1 nucleotide sequence showed more than 85% similarity with sequences derived from the other dermatophytes. Phylogenetic analyses of the sequences from E. floccosum revealed that the genus Epidermophyton may be genetically distinct from Microsporum and Trichophyton.
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  • 40
    ISSN: 1573-0832
    Keywords: black-dot ringworm ; chitin synthase gene ; phylogeny ; Trichophyton rubrum ; T. tonsurans ; T. violaceum
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract A clinical isolate from a black-dot ringworm lesion of a 28-year-old female Japanese was investigated by morphological and biochemical analyses as well as molecular analyses. The isolate grew well onthiamine enriched agar and did not produce violetpigment, macroconidia or microconidia on Sabouraud's dextrose agar. Approximately 620-bp genomic DNA fragments of the CHS1 gene were amplified from Trichophyton mentagrophytes, T. rubrum, T. tonsurans and T. violaceum by polymerase chain reaction (PCR) and sequenced. The chitin synthase 1 (CHS1) nucleotide sequences of the clinical isolate showed more than 97% similarity to that of T. violaceum and less than 96% similarity to that of T. mentagrophytes, T. rubrum and T. tonsurans. The phylogenetic analysis of their sequences revealed that the clinical isolate was genetically close to T. violaceum and distinct from T. mentagrophytes, T. rubrum and T. tonsurans. Therefore, the isolate was confirmed as T. violaceum by mycological examination and molecular analyses.
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  • 41
    ISSN: 1573-0832
    Keywords: Candida ; identification ; PCR ; phylogeny ; RAPD
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Fast and reliable identification of different species of the genus Candida is important to define adequate therapeutic decisions, because the different species have highly variable susceptibilities to antifungal drugs; azoles and amphothericin B. Accurate statistical records on case history and epidemiological studies also depend on effective identification. To address this problem we established a RAPD method that enabled direct identification of five very common species of Candida. Initially, reference band patterns were established for C. albicans, C. tropicalis, C. parapsilosis, C. glabrata and C. krusei. One of the primers, M2, showed remarkably conserved intra-specific patterns of approximately 10 bands each, ranging in size from 2.0 to 0.1 kb. These patterns were significantly different and species-specific. Few bands were conserved between different species of Candida, which was assumed to be consistent with their phylogenetic relatedness. In addition, band patterns were constant and reproducible and DNA isolated from single colonies yielded sufficient DNA for identification. The reference band patterns were then used, in blind experiments, to identify species of Candida in 50 randomly chosen samples, including clinical isolates and ATCC strains. RAPD results were 100% consistent with results obtained by conventional diagnostic methods and were achieved in one day instead of several days taken by conventional methods. Because ideal identification methods should be consistent with phylogeny and taxonomy we tested whether RAPD could be used to calculate genetic distances. Comparison of RAPD phylogenetic trees with 18S rRNA trees showed significant differences in tree topologies which indicated that RAPD data could not accurately measure the relative distances between different species. Also, computer simulations of RAPD random patterns were used to test whether the observed degree of RAPD band pattern similarities could occur at random. These simulations suggested that the level of inter-specific band pattern similarities observed in our data could be obtained at random, while intra-specific pattern similarities could not. RAPD would be helpful to discriminate between isolates but not to quantitate the differences. We suggest that the inaccurate estimate of genetic distances from RAPD is a general limitation of the technique and not a specific problem of our identification method. Because of the repetitive character of the target sequences, genetic distances calculated from RAPD could be affected by paralogy, namely, recombination and duplication events not parallel with speciation events.
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  • 42
    ISSN: 1573-0832
    Keywords: epidemiology ; mitochondrial DNA ; phylogeny ; restriction fragment length polymorphism (RFLP) ; Sporothrix schenckii
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract Mitochondrial DNA (mtDNA) types based on restriction fragment length polymorphism (RFLP) patterns with HaeIII were investigated in clinical isolates of Sporothrix schenckii in North and South America. In addition to 14 mtDNA types (Types 1–14) so far reported, six new mtDNA types, Types 15–20 were found in this study. Type 3 was divided into two subtypes, Subtype 3A and Subtype 3B based on RFLP with Msp1. Type 14 was also divided into three subtypes, Subtype 14A, Subtype 14B and Subtype 14C based on RFLP with Hha1. Nineteen isolates in the United States consisted of 1 isolate of Type 1, 12 of Type 2, 2 of Type 4, 3 of Type 14 (1 of Subtype 14B and 2 of Subtype 14C) and 1 of Type 15. Twenty nine isolates in Venezuela consisted of 13 of Type 3 (Subtype 3B), 6 of Type 4, 1 of Type 18, 3 of Type 19 and 6 of Type 20. Thirteen isolates in Argentina consisted of 2 of Type 3 (Subtype 3A), 4 of Type 4, 4 of Type 16 and 3 of Type 17. One isolate in Brazil was Type 3 (Subtype 3A). Based on the phylogeny of 20 mtDNA types (Types 1–20) constructed by estimating sequence divergences of mtDNA, mtDNA types were clustered into two groups: Group A (Types 1–3, Type 11 and Types 14–19) and Group B (Types 4–10, Types 12–13 and Type 20). These results suggest that S. schenckiiisolates in North and South America mainly belong to Group A.
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  • 43
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    Journal of the history of biology 32 (1999), S. 321-341 
    ISSN: 1573-0387
    Keywords: molecular biology ; molecular evolution ; natural history ; phylogeny ; systematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , History
    Notes: Abstract Biologists and historians often present natural history and molecular biology as distinct, perhaps conflicting, fields in biological research. Such accounts, although supported by abundant evidence, overlook important areas of overlap between these areas. Focusing upon examples drawn particularly from systematics and molecular evolution, I argue that naturalists and molecular biologists often share questions, methods, and forms of explanation. Acknowledging these interdisciplinary efforts provides a more balanced account of the development of biology during the post-World War II era.
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  • 44
    ISSN: 1572-9699
    Keywords: phylogeny ; prosthecobacter ; taxonomy ; Verrucomicrobia ; Verrucomicrobiae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Four strains of nonmotile, prosthecate bacteria were isolated in the 1970s and assigned to the genus Prosthecobacter. These strains were compared genotypically by DNA/DNA reassociation and 16S rDNA based phylogenetic analyses. Genotypic comparisons were complemented with phenotypic characterizations. Together, these studies clearly indicate each Prosthecobacter strain represents a novel species of bacteria. We propose three new species of Prosthecobacter, P. dejongeii strain FC1, P. vanneervenii strain FC2, and P. debontii strain FC3; P. fusiformis is reserved for the type strain of the genus, strain FC4. Additionally, we propose the genera Prosthecobacter and Verrucomicrobium, currently members of the order Verrucomicrobiales, to comprise a novel higher order taxonomic group, the division Verrucomicrobia div. nov. and the class Verrumicrobiae class nov. Many novel members of the Verrucomicrobia, as revealed by molecular ecology studies, await isolation and description.
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  • 45
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    Experimental and applied acarology 23 (1999), S. 437-454 
    ISSN: 1572-9702
    Keywords: feather mites ; morphological adaptations ; phylogeny ; coevolution ; co-speciation ; birds ; ectoparasites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Feather mites are highly specialized plumage and skin ectoparasites that are variously adapted for inhabiting certain microhabitats on a bird's body. Different feather mite taxa of higher (familial) rank adapted to the same microhabitats display similar main morphological adaptations even if they are rather distantly related to one another. Hypotheses on the evolution of general adaptations in morphology of feather mites during colonization and establishment in different microhabitats are presented. According to recent data, feather mites are a paraphyletic group consisting of three superfamilies: Analgoidea, Pterolichoidea and Freyanoidea. We present our view on the general feather mite phylogeny course at the familial rank for the Analgoidea by means of cladistic analysis. Co-speciation of parasites with their hosts is postulated as a main factor driving feather mite evolution. Examples are given of non-coevolutionary events, for example recolonization from one host species onto another, extinction and multiple speciation.
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  • 46
    ISSN: 1572-9818
    Keywords: CFLP ; Cleavase I ; Phaseolus ; phylogeny ; ptDNA intergenic regions
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The CFLP methodology was applied for Cleavase I site detection within ptDNA intergenic regions (atpB-rbcL and rps14-psaB) at both interspecific and intraspecific levels in the genus Phaseolus. Optimal Cleavase I reaction temperature was 55 °C and the semi-dry electrophoretic transfer was more efficient than the original capillary one. Cleavase reactions yield a high number of fragments as compared to PCR-RFLP and allowed differentiation within and between landraces and wild forms of the Lima bean (Phaseolus lunatus L.) originating from Andean and Mesoamerican regions of Latin America. From sequencing data and using stemloop program (GCG, Madison), congruent numbers of hairpins/fragments were identified within the sequences, highlighting the robustness of the Cleavase I. Our results pointed out the ubiquity of short conserved motifs amongst a geographically localized group of species. In the vicinity of these motifs, synapomorphic-like substitutions were frequently observed. A phylogenetic tree based on these sequences is congruent with the CFLP pattern as well as with the widely accepted phylogeny of the genus. The usefulness of this new tool as alternative and/or complementary to PCR-RFLP technology on ptDNA is suggested and discussed.
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  • 47
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    Mangroves and salt marshes 3 (1999), S. 105-115 
    ISSN: 1572-977X
    Keywords: dissolved Mn ; hydrochemistry ; particulate Mn ; sediments ; Sepetiba Bay ; tidal variation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract This study investigated the behavior of soluble and particulate manganese, during tidal cycles in a mangrove tidal creek and adjacent mud flats in SE Brazil. We identify the major processes affecting manganese transport to mangroves. The results showed that manganese variability occurs both seasonally, and over the tidal cycle, in response to changing redox potentials. Tidal water flooding mud flats are enriched in manganese, originating from upward migration of reduced species and further adsorption onto suspended particles under oxic conditions. During the tidal cycle, particulate manganese concentrations are higher during flood periods, whilst dissolved concentrations are higher during ebb periods. Although quantitatively different, this pattern occurs both in winter and summer. The dynamics of manganese characterized in this study suggest that this metal may play a significant role as a conveyor of trace metals to mangrove ecosystems, as suggested by earlier studies.
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  • 48
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    Insectes sociaux 43 (1996), S. 375-389 
    ISSN: 1420-9098
    Keywords: Nasutitermitinae ; Subulitermes ; Coatitermes ; Velocitermes ; evolution ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The developmental pathways of the neuter castes were studied in three species of Nasutitermitinae from central Panama. The humivorousSubulitermes denisae andCoatitermes clevelandi display several primitive traits: absence of sex dimorphism, representation of both sexes among workers and soldiers, and occurrence of successive worker instars. The litter-dwellingVelocitermes barrocoloradensis has a more complex caste system: female larvae are larger than males and give rise to the large workers, which constitute the bulk of the work force; male larvae proceed to soldiers through a small worker or a special larval instar. The resulting soldier caste is polymorphic. These results support previously formulated hypotheses regarding a link between humivorous diet and reduced polymorphism on the one hand, and between forest-floor foraging and large continuous size variation among soldiers on the other. Whereas the caste systems ofSubulitermes andCoatitermes probably represent a primitive condition,Velocitermes shares derived traits withNasutitermes and the other fully nasute genera previously studied. I therefore hypothesize that ancestors with these advanced features may have spread from the neotropics and be at the origin of most nasute genera, including humivorous taxa, present in other regions.
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  • 49
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    Cellular and molecular life sciences 52 (1996), S. 522-530 
    ISSN: 1420-9071
    Keywords: Seed chalcids ; Megastigmus ; hymenoptera ; isozymes ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract The degree of genetic variability and the taxonomic status of adults of 14 seed chalcid species of the genusMegastigmus was analyzed using electrophoresis on horizontal starch gel. Variability of chalcid populations with host tree was observed in 21 host species. A total of 13 enzyme loci were considered. Seven of the loci were found to be polymorphic. The electrophoretic data strongly supported the adaptation of each chalcid species to a limited number of congeneric hosts, and confirmed the morphologically-based taxonomy of the genus. The resulting dendrogram separated the chalcid species into three distinct groups, infesting 1) Pinaceae spp., 2) Cupressaceae spp., and 3) Angiosperm spp., respectively. The highest level of overall genetic similarity was observed among the chalcid populations infesting conifers of the generaPseudotsuga andAbies. The genetic identity values observed among populations infesting 5 differentAbies species tended to reflect the occurrence of conspecific populations rather than that of distinct chalcid species. Genetic identity was similarly important among the chalcid species infesting seeds of Cupressaceae. By contrast, a large genetic distance was observed between two seed chalcids attacking a same host,Rosa montana.
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  • 50
    ISSN: 1423-0445
    Keywords: sex pheromone ; synergist ; antagonist ; mate recognition ; reproductive isolation ; chemotaxonomoy ; phylogeny ; evolution ; Lepidoptera ; Tortricidae
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The geometric isomers (E,E)-, (E,Z)-, (Z,E)-, and (Z,Z)-8,10-dodecadien-1-yl acetate were identified as sex pheromone components or sex attractants in the tribes Eucosmini and Grapholitini of the tortricid subfamily Olethreutinae. Species belonging to the more ancestral Tortricinae were not attracted. Each one isomer was behaviourally active in males ofCydia andGrapholita (Grapholitini), either as main pheromone compound, attraction synergist or attraction inhibitor. Their reciprocal attractive/antagonistic activity in a number of species enables specific communication with these four compounds.Pammene, as well as otherGrapholita andCydia responded to the monoenic 8- or 10-dodecen-1-yl acetates. Of the tribes Olethreutini and Eucosmini,Hedya, Epiblema, Eucosma, andNotocelia trimaculana were also attracted to 8,10-dodecadien-1-yl acetates, but several otherNotocelia to 10,12-tetradecadien-1-yl acetates. The female sex pheromones ofC. fagiglandana, C. pyrivora, C. splendana, Epiblema foenella andNotocelia roborana were identified. (E,E)- and (E,Z)-8,10-dodecadien-1-yl acetate are producedvia a commonE9 desaturation pathway inC. splendana. CallingC. nigricana andC. fagiglandana females are attracted to wingfanning males.
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  • 51
    ISSN: 1423-0445
    Keywords: postpharyngeal gland ; phylogeny ; hydrocarbons ; chemotaxonomy ; Hymenoptera ; Cataglyphis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary A comparative morphological and chemical study of six endemic species ofCataglyphis from the Iberian Peninsula:C. ibericus, C. rosenhaueri, C. hispanicus, C. humeya, C. velox andC. floricola and the Moroccan speciesC. bombycinus is described. The morphological study relied primarily on genitalia characteristics, whereas the chemical study concentrated on the postpharyngeal gland constituents. Cladograms based on the morphological and chemical data were performed using Ward's method. The dendrogram based on morphological features revealed that the IberianCataglyphis can be classified into three species groupsalbicans, altisquamis andemmae. The same pattern occurred when the dimethylalkanes constituents of the postpharyngeal gland were utilised as character states, with a slight displacement of species within thealtisquamis group. However, when the complete hydrocarbon blend was utilised major discrepancies in the dendrograms occurred.Cataglyphis velox proved to be very similar toC. bombycinus, whereasC. floricola clustered with the other two species of thealtisquamis group. Based on the geographical distribution and paleontological data (Tinaut 1993) it is assumed thatC. floricola recently invaded the Iberian Peninsula. Based on the chemical findings we postulate that chemical character displacement occurred inC. floricola as a result of its sympatry withC. velox after the former colonized the Iberian Peninsula. We further discuss the possible reason for the different dendrograms obtained when only the dimethylalkanes are considered and its implication for the communicative role of the postpharyngeal gland secretion in these ants.
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  • 52
    ISSN: 1432-1327
    Keywords: Key words Ceruloplasmin ; Copper oxidase ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The X-ray structure of human serum ceruloplasmin has been solved at a resolution of 3.1 Å. The structure reveals that the molecule is comprised of six plastocyanin-type domains arranged in a triangular array. There are six copper atoms; three form a trinuclear cluster sited at the interface of domains 1 and 6, and there are three mononuclear sites in domains 2, 4 and 6. Each of the mononuclear coppers is coordinated to a cysteine and two histidine residues, and those in domains 4 and 6 also coordinate to a methionine residue; in domain 2, the methionine is replaced by a leucine residue which may form van der Waals type contacts with the copper. The trinuclear centre and the mononuclear copper in domain 6 form a cluster essentially the same as that found in ascorbate oxidase, strongly suggesting an oxidase role for ceruloplasmin in the plasma.
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  • 53
    ISSN: 1432-072X
    Keywords: Key wordsThiobacillus taxonomy ; Thiobacillus ; aquaesulis ; Thiobacillus halophilus ; 16S rRNA ; phylogeny ; 16S rDNA sequences ; Proteobacteria
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Total base sequences of the 16S rRNA genes of Thiobacillus halophilus and Thiobacillus aquaesulis show that these bacteria fall into the gamma- and beta-subdivisions, respectively of the Proteobacteria. The closest relative of T. halophilus is Thiobacillus hydrothermalis (with 98.7% similarity), and the closest relative of T. aquaesulis is Thiobacillus thioparus (93.2% similarity). Physiological properties and mol% G+C content of their DNA serve to confirm that these four organisms are all distinct species. It is reiterated that the species currently assigned to the genus Thiobacillus are clearly so diverse that they need reclassification into several genera. The type species, T. thioparus, is unequivocally placed in the beta-subdivision of the Proteobacteria, thus requiring that the use of the genus name Thiobacillus be restricted to the chemolithoautotrophic species falling into that group. T. aquaesulis and T. thioparus may thus be regarded as true species of Thiobacillus. The relatively large number of obligately chemolithoautotrophic Thiobacillus species falling in the gamma-subdivision of the Proteobacteria need further study in order to assess the case for reclassification into one or more new or different genera.
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  • 54
    ISSN: 1432-1327
    Keywords: Key words Superoxide dismutase ; Propionibacterium shermanii ; X-ray structure ; Metal specificity ; Cambialism
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The first structure of a cambialistic superoxide dismutase (SOD) from Propionibacterium shermanii exhibiting similar activity with iron and with manganese was solved at a resolution of 1.6 Å and 1.9 Å respectively. Surprisingly, no obvious differences between the two SODs were observable. The protein crystallises as a homo dimer in the asymmetric unit. Because of the crystallographic symmetry, it forms a tetramer. Structures of both the manganese and the ferric form were solved using molecular replacement techniques and multiple isomorphous replacement. The tertiary structure is similar to that of the other superoxide dismutases, the metal being fivefold coordinated by three histidines, one aspartate and one water molecule. The second shell of residues consists of hydrophobic amino acids, histidines and two water molecules, which are assumed to be involved in both the catalytic activity and structural stability of this superoxide dismutase. This shell may also be responsible for the cambialistic behaviour. This work shows that the reason for the metal specificity is not trivial, although minor alterations in the metal environment might be responsible for this behaviour.
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  • 55
    ISSN: 1432-1327
    Keywords: Key words Dimeric dihaem cytochrome ; Stacked haem arrangement ; MAD phasing ; X-ray structure ; Novel fold
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  Haem-containing proteins are directly involved in electron transfer as well as in enzymatic functions. The "split-Soret" cytochrome (SSC) was isolated from the sulfate- and nitrate-reducing bacterium Desulfovibrio desulfuricans ATCC 27774 and has no significant nitrate or nitrite reductase activity. The protein received its name due its unusual spectral properties. It is a dimer containing two identical subunits of 26.3 kDa, each with two haem-c groups. A preliminary model for the three-dimensional structure of this cytochrome was derived using the Multiple Wavelength Anomalous Dispersion (MAD) phasing method. This model shows that SSC is indeed a dimer containing four haems at one end of the molecule. In each monomer the two haems have their edges overlapped within van der Waals contacts with an iron-to-iron distance of 9 Å. The polypeptide chain of each monomer supplies the sixth axial ligand to the haems of the other monomer. This work shows that SSC constitutes a new class of cytochrome. The stacking of the two haems in the monomer within van der Waals distances of each other, and also the short (van der Waals) distances between the two monomers in the dimeric molecule are unprecedented in hemoproteins. This particular haem arrangement is an excellent model for the spectral study (undertaken several years ago) of haem-haem interaction using the aggregated haem undecapeptide derived from mammalian cytochrome c.
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  • 56
    ISSN: 1432-1327
    Keywords: Key words Prismane ; Hybrid cluster ; Desulfovibrio ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The three-dimensional structure of the native "putative prismane" protein from Desulfovibrio vulgaris (Hildenborough) has been solved by X-ray crystallography to a resolution of 1.72 Å. The molecule does not contain a [6Fe-6S] prismane cluster, but rather two 4Fe clusters some 12 Å apart and situated close to the interfaces formed by the three domains of the protein. Cluster 1 is a conventional [4Fe-4S] cubane bound, however, near the N-terminus by an unusual, sequential arrangement of four cysteine residues (Cys 3, 6, 15, 21). Cluster 2 is a novel 4Fe structure with two μ2-sulfido bridges, two μ2-oxo bridges, and a partially occupied, unidentified μ2 bridge X. The protein ligands of cluster 2 are widely scattered through the second half of the sequence and include three cysteine residues (Cys 312, 434, 459), one persulfido-cysteine (Cys 406), two glutamates (Glu 268, 494), and one histidine (His 244). With this unusual mixture of bridging and external type of ligands, cluster 2 is named the "hybrid" cluster, and its asymmetric, open structure suggests that it could be the site of a catalytic activity. X-ray absorption spectroscopy at the Fe K-edge is readily interpretable in terms of the crystallographic model when allowance is made for volume contraction at 10 K; no Fe··Fe distances beyond 3.1 Å could be identified. EPR, Mössbauer and MCD spectroscopy have been used to define the oxidation states and the magnetism of the clusters in relation to the crystallographic structure. Reduced cluster 1 is a [4Fe-4S]1+ cubane with S = 3/2; it is the first biological example of a "spin-admixed" iron-sulfur cluster. The hybrid cluster 2 has four oxidation states from (formally) all FeIII to three FeII plus one FeIII. The four iron ions are exchange coupled resulting in the system spins S = 0, 9/2, 0 (and 4), 1/2, respectively, for the four redox states. Resonance Raman spectroscopy suggests that the bridging ligand X which could not be identified unambiguously in the crystal structure is a solvent-exchangeable oxygen.
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  • 57
    ISSN: 1432-1327
    Keywords: Key words Recombinant horse apoferritin ; X-ray structure ; Stability ; Function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract  The X-ray structure of recombinant horse L-chain (rL) apoferritin, solved at 2.0 Å resolution with a final R factor of 17.9%, gives evidence that the residue at position 93 in the sequence is a proline and not a leucine, as found in earlier sequencing studies. The structure is isomorphous with other apoferritin structures, and we thus draw particular attention to those structural features which can be related to the stability and function of the protein. Analysis of hydrogen bonding and salt bridge interactions shows that dimers and tetramers are the most stable molecular entities within the protein shell: a result confirming earlier biophysical experiments. The stability of horse rL apoferritin to both dissociation into subunits at acidic pH values and to complete unfolding in guanidine chloride solutions is compared with that of other apoferritins. This emphasizes the role played by the salt bridge in the stability of this protein family. The horse rL apoferritin is significantly more resistant to denaturation than horse spleen ferritin, which in turn is more resistant than any human rH apoferritins, even those for which a salt bridge is restored. Finally, this structure determination not only establishes that a preformed pocket exists in L-chain apoferritin, at a site known to be able to bind porphyrin, but also underlines the particular function of a cluster of glutamic acids (E53, E56, E57 and E60) located at the entrance of this porphyrin-binding pocket.
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  • 58
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    Journal of industrial microbiology and biotechnology 15 (1995), S. 67-70 
    ISSN: 1476-5535
    Keywords: Megasphaera cerevisiae ; 16S rRNA ; DNA probe ; beer spoilage ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract The 16S ribosomal RNA gene from the beer-spoilage organism,Megasphaera cerevisiae was polymerase chain reaction (PCR)-amplified and sequenced. Analysis confirmed the phylogenetic position ofM. cerevisiae as a sister taxon ofMegasphaera elsdenii, within the obligately anaerobic, Gram-negative cocci. The sequence obtained should facilitate the development of DNA probes for early detection of this spoilage organism.
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  • 59
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    Journal of industrial microbiology and biotechnology 17 (1996), S. 159-169 
    ISSN: 1476-5535
    Keywords: molecular ecology ; 16S rDNA ; gene library ; oligonucleotide probes ; uncultured organisms ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Abstract Molecular 16S rDNA-based techniques were applied to a peat sample from northern Germany in order to investigate the bacterial diversity present and compare the clone sequences with those obtained from similar studies on other terrestrial samples. Genomic DNA was extracted from the peat matrix by a direct lysis procedure. 16S rRNA genes were amplified using PCR primers targeting conserved regions of bacterial 16S rDNA. 16S rDNA fragments were blunt end cloned into a plasmid vector and the resulting clone library of 262 sequences was screened by hybridization with different oligonucleotide probes and sequence analysis of randomly selected clones. The 16S rDNA insert of 76 clones was partially sequenced. Clones identified either by hybridization or by sequence analysis fell into three phyla. As judged by hybridization with a specific oligonucleotide probe, 42% of the clones represented members of the alpha subclass of Proteobacteria. Twenty-five of these clones were selected randomly for sequence analysis; none could be assigned to any of the known genera of this subclass. The second largest clone group comprises 15% of the clones and clusters aroundAcidimicrobium ferrooxidans andRubrobacter radiotolerans, both of which are remotely related to members of the order Actinomycetales. The third major clone cluster (10%) was moderately to remotely related to theAcidobacterium capsulatum phylum. Of the additional clones sequenced, a few could be assigned to other subclasses ofProteobacteria, theVerrucomicrobium phylum and the phylum of spirochetes. Comparison of the results presented here with those from other environments reveals a significant number of common clone clusters. As the vast majority of sequences retrieved from any of the marine and terrestrial samples investigated so far by molecular methods indicate the presence of novel bacterial species it can be assumed that a huge, as yet untapped biotechnological potential is present in the environment.
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  • 60
    ISSN: 1573-1561
    Keywords: Sex pheromone ; Idaea aversata ; Idaea straminata ; Idaea biselata ; (Z,Z)-9,11-tetradecadienyl acetate ; (Z,Z)-7,9-dodecadienyl acetate ; (Z,E)-7,9-dodecadienyl acetate ; Lepidoptera ; Geometridae ; electroantennography ; single cell recording ; biosynthesis ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Pheromone compounds so far identified from most geometrid moths consist of all-Z diene, triene, or tetraene hydrocarbons with chain lengths of C17 to C21, and their monoepoxide derivatives biosynthesized from linoleic and linolenic acids. The present study reports the occurrence of olefinic acetates as sex pheromones in three species of Geometridae. (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate found in female gland extracts ofIdaea aversata elicited significant responses from conspecific male antennae in gas chromatography with electroantennographic detection (GCEAD). In extracts ofI. straminata, (Z,Z)-7,9-dodecadienyl acetate, (E,Z)-7,9-dodecadienyl acetate, and (Z,Z)-7,9-dodecadienyl acetate were found, and the synthetic compounds elicited strong responses from conspecific male antennae. In the third species,I. biselata, only (Z,Z)-7,9-dodecadienyl acetate was found in the female extracts, and this compound elicited a strong EAD response from the conspecific male antenna. The identities of the pheromone components inI. aversata andI. straminata were further confirmed according to their characteristic ions after GC-MS analyses. Single sensillum recordings fromI. aversata showed two types of pheromone-detecting sensilla present on the male antenna. One type contained two receptor neurons, one of which was specifically tuned to (Z,Z)-9,11-tetradecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. A second type contained one neuron responding to (Z,Z)-7,9-dodecadienyl acetate. The two types were clearly different also with respect to external morphology, the former being considerably longer and having a larger base diameter. Also inI. straminata two physiological types of sensilla could be distinguished. One type contained two neurons, one of which responded to (Z,Z)-7,9-dodecadienyl acetate, the other to (Z,E)-9,11-tetradecadienyl acetate. The second type contained one neuron, responding to (Z,Z)-7,9-dodecadienyl acetate. No correlation between external morphology and physiological response of the investigated sensilla was observed inI. straminata. In field tests, a two-component blend containing (Z,Z)-9,11-tetradecadienyl acetate and (Z,Z)-7,9-dodecadienyl acetate in a ratio of 10:1 was attractive to males ofI. aversata. This two-component blend was also attractive to males ofI. straminata, but in a ratio of 1:1. High numbers of maleI. biselata were caught in traps baited with (Z,Z)-7,9-dodecadienyl acetate alone. The incorporation of deuterium labels into pheromone components after topical application of deuterium-labeled palmitic acid confirmed that the pheromone components ofI. aversata could be synthesized from this precursor, as has been previously observed for acetate pheromone components of many other moth species. Our results suggest that an evolutionary reversal back to the production of palmitic acid-derived pheromone components has occurred within the geometrid subfamily Sterrhinae.
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  • 61
    ISSN: 1573-4919
    Keywords: guanine nucleotide-binding proteins ; evolution ; phylogeny ; structure-function
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract ADP-ribosylation factors (ARFs) are ∼20-kDa guanine nucleotide-binding proteins that are allosteric activators of the NAD:arginine ADP-ribosyltransferase activity of cholera toxin and appear to play a role in intracellular vesicular trafficking. Although the physiological roles of these proteins have not been defined, it has been presumed that each has a specific intracellular function. To obtain genetic evidence that each ARF is under evolutionary pressure to maintain its structure, and presumably function, rat ARF cDNA clones were isolated and their nucleotide and deduced amino acid sequences were compared to those of other mammalian ARFs. Deduced amino acid sequences for rat ARFs 1, 2, 3, 5 and 6 were identical to those of the known cognate human and bovine ARFs; rat ARF4 was 96% identical to human ARF4. Nucleotide sequences of both the untranslated as well as the coding regions were highly conserved. These results indicate that the ARF proteins are, as a family, extraordinarily well conserved across mammalian species. The unusually high degree of conservation of the untranslated regions is consistent with these regions having important regulatory roles and that individual ARFs contain structurally unique elements required for specific functions.
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  • 62
    ISSN: 1573-4919
    Keywords: active site ; catalytic mechanism ; creatine kinase ; high-energy phosphate transport ; membrane binding ; metabolic channeling ; mitochondrial energetics ; octamer/dimer equilibrium ; X-ray structure
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Abstract Mitochondrial creatine kinase (Mi-CK) is a central enzyme in energy metabolism of tissues with high and fluctuating energy requirements. In this review, recent progress in the functional and structural characterization of Mi-CK is summarized with special emphasis on the solved X-ray structure of chicken Mib-CK octamer (Fritz-Wolf et al., Nature 381, 341-345, 1996). The new results are discussed in a historical context and related to the characteristics of CK isoforms as known from a large number of biophysical and biochemical studies. Finally, two hypothetical functional aspects of the Mi-CK structure are proposed: (i) putative membrane binding motifs at the top and bottom faces of the octamer and (ii) a possible functional role of the central 20 Å channel.
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  • 63
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    Biochemical genetics 33 (1995), S. 377-388 
    ISSN: 1573-4927
    Keywords: muntjacs ; mitochondrial DNA ; restriction maps ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Mitochondrial DNA restriction maps for 12 restriction enzymes of four species of muntjacs—Indian muntjac(M. muntjak), Gongshan muntjac(M. gongshanensis), black muntjac(M. crinifrons), and Chinese muntjac(M. reevesi)—were compared to estimate the phylogenetic relationships among them. Phylogenetic trees were constructed by both distance and parsimony methods. The two resulting trees share a similar topology, which indicates that the black muntjac and the Gongshan muntjac are closely related, followed by the Chinese muntjac; the Indian muntjac is the sister taxon to all the other muntjacs.
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  • 64
    ISSN: 1573-4927
    Keywords: firefly ; Luciolinae ; phylogeny ; communication system ; allozyme analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Japanese fireflies of the subfamily Luciolinae are biochemically analyzed using 13 allozymes, and the phylogenetic relationships obtained from this analysis are compared with their flash communication systems. As a result, the Japanese Luciolinae can be divided into three groups.Hotaria parvula andH. tsushimana together withLuciola yayeyamana andL. kuroiwae from the first group, and they use the same communication system.L. lateralis, Curtos okinawana, andC. costipennis make up the second group, and their communication systems are also the same.L. cruciata makes up the last one, and its communication system is different from the other fireflies of Luciolinae. Therefore, their taxonomical arrangement and communication systems are not congruent. However, the genetic similarity deduced by allozymic analysis of the members of the Japanese Luciolinae is highly consistent with their flash communication systems.
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  • 65
    ISSN: 1573-5028
    Keywords: Alga ; mitochondrial genome ; phylogeny ; Platymonas subcordiformis ; Prasinophyceae ; restriction ; gene map
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract the entire mitochondrial genome (mt genome) of the unicellular green alga Platymonas subcordiformis (synonym Tetraselmis subcordiformis; Prasinophyceae) was cloned and a physical map for the four restriction enzymes Hind III, Eco RI, Bgl II and Xba I was constructed. The mt genome of P. subcordiformis is a 42.8 kb circular molecule, coding for at least 23 genes. Hybridization and sequence analysis revealed the presence of a ca. 1.5 kb inverted repeat on the mt genome of P. subcordiformis. Phylogenetic analyses based on sequences of several coxI genes were carried out. Our data indicate that mitochondria from P. subcordiformis and from land plants form a natural, monophyletic group.
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  • 66
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    Plant molecular biology 29 (1995), S. 1127-1142 
    ISSN: 1573-5028
    Keywords: Plant photoreceptor ; gene structure ; introns ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The phytochrome photoreceptor in the green alga Mesotaenium caldariorum is encoded by a small family of highly related genes. DNA sequence analysis of two of the algal phytochrome genes indicates an atypical gene structure with numerous long introns. The two genes, termed mesphy1a and mesphy1b, encode polypeptides which differ by one amino acid in the region of overlap that was sequenced. RT-PCR studies have established the intron-exon junctions of both genes and show that both are expressed. RNA blot analysis indicates a single transcript of ca. 4.1 kb in length. The deduced amino acid sequence of the mesphy1b gene reveals that the photoreceptor consists of 1142 amino acids, with an overall structure similar to other phytochromes. Phylogenetic analyses indicate that the algal phytochrome falls into a distinct subfamily with other lower plant phytochromes. Profile analysis of an internal repeat found within the central hinge region of the phytochrome polypeptide indicates an evolutionary relatedness to the photoactive yellow protein from the purple bacterium Ectothiorhodospira halophila, to several bacterial sensor kinase family members, and to a family of eukaryotic regulatory proteins which includes the period clock (per) and single-minded (sim) gene products of Drosophila. Since mutations which alter phytochrome activity cluster within the region delimited by these direct repeats (P.H. Quail et al., Science 268 (1995): 675–680), this conserved motif may play an important role in the signal transducing function of these disparate protein families.
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  • 67
    ISSN: 1573-5028
    Keywords: Arabidopsis ; calcium ; calmodulin ; gene family ; kinase ; phylogeny
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    Notes: Abstract A family of calcium-responsive protein kinases is abundant in plant cell extracts but has not been identified in animals and fungi. These enzymes have a unique structure consisting of a protein kinase catalytic domain fused to carboxy-terminal autoregulatory and calmodulin-like domains. In this report, we present the amino acid sequences for eight new Arabidopsis cDNA clones encoding isoforms of this enzyme. Three isoforms were expressed as fusion proteins in Escherichia coli and exhibited calcium-stimulated protein kinase activity. We propose CPK as the gene designation for this family of enzymes and describe a phylogenetic analysis for all known isoforms.
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  • 68
    ISSN: 1573-4927
    Keywords: firefly ; Luciolinae ; phylogeny ; communication system ; allozyme analysis
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    Topics: Biology , Chemistry and Pharmacology
    Notes: Abstract Japanese fireflies of the subfamily Luciolinae are biochemically analyzed using 13 allozymes, and the phylogenetic relationships obtained from this analysis are compared with their flash communication systems. As a result, the Japanese Luciolinae can be divided into three groups.Hotaria parvula andH. tsushimana together withLuciola yayeyamana andL. kuroiwae from the first group, and they use the same communication system.L. lateralis, Curtos okinawana, andC. costipennis make up the second group, and their communication systems are also the same.L. cruciata makes up the last one, and its communication system is different from the other fireflies of Luciolinae. Therefore, their taxonomical arrangement and communication systems are not congruent. However, the genetic similarity deduced by allozymic analysis of the members of the Japanese Luciolinae is highly consistent with their flash communication systems.
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  • 69
    ISSN: 1573-5028
    Keywords: barley ; chloroplast ; ndhB gene ; phylogeny ; RNA editing
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    Notes: Abstract The ndhB-encoded transcript from barley chloroplasts deviates from the genomic ndhB sequence by nine C-to-U transitions, which is the maximum number of editing events for a chloroplast mRNA reported so far. Comparison with ndhB transcripts from other chloroplast species shows that six of the nine editing sites observed in barley are structurally and functionally conserved in maize, rice and tobacco. The remaining three sites, however, show divergent patterns of conservation even within the three members of the grass family. The conservation of two of these sites in tobacco but not in the closely related graminean species suggests that divergence of the ndhB editing sites is caused by the loss of preexisting editing sites rather than by gain of new sites.
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  • 70
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    Russian journal of marine biology 26 (2000), S. 432-438 
    ISSN: 1608-3377
    Keywords: Mutation ; phylogeny ; nuclear DNA ; mitochondrial DNA ; salmonid fishes ; divergence time
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    Topics: Biology
    Notes: Abstract Mutation rates of the mitochondrial and nuclear genomes of salmonid fishes were assessed on the basis of a phylogenetic study of 12 species representing four genera of the family Salmonidae. Analysis of the extent of divergence of the masu salmon Oncorhynchus masou and the Pacific trout Parasalmo suggests a high rate of mtDNA mutation in the masu salmon. However, the nuclear genome in this species has mutated relatively slowly. For the other 5 species of Pacific salmon, no discrepancy was found in the mutation rates of mitochondrial and nuclear DNA. Values of the absolute time of divergence of taxa, calculated for the two independently inherited parts of the salmonid genome, were approximately within the same range and coincided with those based on evolutionary hypotheses [1, 21].
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  • 71
    ISSN: 1618-2545
    Keywords: Erysiphaceae ; internal transcribed spacer ; phylogeny ; powdery mildew ; secondary structure
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    Topics: Biology
    Notes: Abstract The nucleotide sequences of the internal transcribed spacer (ITS) regions of the ribosomal DNA including the 5.8S rRNA gene and the 5′ end of the 28S rRNA gene have been determined for 19 species in 10 genera of the powdery mildew fungi in order to analyze their phylogenetic relationship. These fungi were divided into two large groups based on the nucleotide length of the ITS regions, and this grouping was in line with that based on the morphological characters of the anamorphic stage rather than the teleomorphic stage. Although the variable ITS sequences were often ambiguously aligned, conserved sites were also found. Thus, a neighbor-joining tree was constructed using the nucleotide sequence data of the conserved sites of the ITS regions, the 5.8S rRNA gene, and the 5′ end of the 28S rRNA gene. The phylogenetic tree displayed the presence of four groups in the powdery mildews, which were distinguished by their morphology and/or host ranges. In the ITS2 region, the presence of a common secondary structure having four hairpin domains was suggested, in spite of the highly variable nucleotide sequences of this region. The predicted secondary structure was supported by the compensatory mutations as well as compensatory conserved sequences and high G+C content in the predicted stem regions.
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  • 72
    ISSN: 1618-2545
    Keywords: Erysiphe ; internal transcribed spacer ; Microsphaera ; phylogeny ; powdery mildew
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    Notes: Abstract The genusMicrosphaera has been considered to be derived from sectionErysiphe of the genusErysiphe by a single event. Cleistothecial appendages are the most distinct difference between the two genera and have an important role for overwintering. To understand the phylogenetic relationship betweenErysiphe sectionErysiphe andMicrosphaera more precisely, phylogenetic trees were constructed using the nucleotide sequences of the rDNA ITS region from 11Erysiphe (sectionErysiphe) and 16Microsphaera taxa. The phylogenetic trees indicated the close relationship between the two genera. However, the generaErysiphe (sectionErysiphe) andMicrosphaera did not group into separate monophyletic lineages; instead, they formed several small clusters that were mixed together. This result suggests that the differentiations of the genera occurred two or more times independently. This also supports the idea that appendage morphology does not always accurately reflect the phylogeny of the powdery mildews because the morphology of appendages may evolve convergently under the selection pressure of their particular biotopes (host plants).
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  • 73
    ISSN: 1618-2545
    Keywords: Chromista ; internal transcribed spacer ; phylogeny ; Pythium ; 5.8S rDNA
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    Notes: Abstract The sequences of ITS regions in 30 species and two groups of the genusPythium were resolved. In the phylogenetic trees, the species were generally divided into two clusters, referred to here as the F and S groups. The species in the two groups correspond in terms of their sporangial morphology, with the F group being filamentous/lobulate and the S group being spherical. Genetic divergence within the F group was lower than that within the S group. Other morphological characteristics such as oogonial structure and sexual nature appeared to be unrelated to the groupings in these trees. An alignment analysis revealed common sequences to all the species and arrangements specific to each F or S group. It was found that the ITS region was a good target in designing species-specific primers for the identification and detection ofPythium species. In the tree based on 5.8S rDNA sequences, oomycetes are distantly related to other fungi but separated from algae in Chromista.
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  • 74
    ISSN: 1618-2545
    Keywords: phylogeny ; SSU rDNA ; Trichosporon
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    Notes: Abstract Small subunit ribosomal DNA sequences of all species of the basidiomycetous anamorphic yeast genusTrichosporon were determined, and phylogenetic trees were constructed by the neighbor-joining and maximum likelihood methods. The sequence data showed that, with the exception ofT. pullulans, the genus is monophyletic, although its members have two different major ubiquinones, Q9 and Q10. The genus can be divided phylogenetically into three major clusters. Species with Q10 as the major ubiquinone constitute a single cluster, while those with Q9 form two clusters.Trichosporon pullulans was phylogenetically distinct from other taxa of the genus. It is located in a cluster containingCystofilobasidium capitatum, Mrakía frigida, Xanthophyllomyces dendrorhous and three species ofUdeniomyces. This result sugests thatT. pullulans does not belong to the genusTrichosporon.
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  • 75
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    Plant systematics and evolution 200 (1996), S. 193-211 
    ISSN: 1615-6110
    Keywords: Leguminosae ; Stylosanthes ; Chloroplast DNA ; RFLPs ; phylogeny ; systematics
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    Topics: Biology
    Notes: Abstract A detailed analysis of chloroplast DNA restriction fragment length variation was undertaken to reconstruct the maternal phylogeny of 18 taxa from both sections of the papilionoid tropical forage legume genusStylosanthes. Data were analysed by means of the computer program PAUP, using an heuristic search with Wagner parsimony. The resulting cladogram dividedStylosanthes into four separate clades, which comprised: (i) theS. guianensis complex and related species (i.e.S. gracilis, S. grandifolia andS. montevidensis); (ii)S. hispida, tetraploidS. hamata s. l.,S. sympodialis, S. humilis, S. leiocarpa, S. angustifolia and certain accesions ofS. scabra; (iii)S. calcicola, S. viscosa, diploidS. hamata s. str., andS. fruticosa, plus accessions ofS. scabra, S. capitata and one accession ofS. grandifolia; and (iv)S. macrocephala and other accessions ofS. capitata not included within clade 3. Results are generally congruent with previously established interspecific relationships and, moreover, enabled identification of putative maternal progenitors for four tetraploid taxa:S. humilis was identified as a likely maternal parent of bothS. sympodialis andS. hamata s. l.,S. viscosa as a maternal parent ofS. scabra, andS. macrocephala as a maternal parent ofS. capitata.
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  • 76
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    Plant systematics and evolution 201 (1996), S. 93-116 
    ISSN: 1615-6110
    Keywords: Caryophyllaceae ; Silene sect.Sedoideae ; RAPD ; ITS sequences ; cladistics ; phylogeny
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    Notes: Abstract Hierarchical patterns inSilene sect.Sedoideae were investigated using random amplified polymorphic DNA (RAPD), nucleotide sequences of the internal transcribed spacer (ITS) regions of the 18S–28S nuclear ribosomal DNA, and discrete morphological characters. All data sets firmly supported the species recognized. The RAPD data offered the best resolution at the intraspecific level, supporting the current intraspecific classifications ofS. sedoides andS. integripetala. The ITS sequences and the morphological data gave poor resolution within species, and the three data sets disagreed about the relationships among species. The signal from the RAPD data was strongest and remained when the total data set was analysed. The three data sets all support an amphiploid origin ofS. aegaea, with the strongest evidence from the ITS sequences. Incongruences among data sets as well as merits and shortcomings of each are discussed. The robustness of the results can be evaluated using perturbations of data, i.e., bootstrap and jackknife of taxa and characters. These methods should not be taken as methods of statistical inference at the taxonomic level, because unbiased sampling appears impossible. RAPD data, however, come close to being suitable for statistical estimation of hierarchies at the genome level, but several methodological problems have to be solved.
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  • 77
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    Plant systematics and evolution 205 (1997), S. 125-146 
    ISSN: 1615-6110
    Keywords: Orchidaceae ; Orchidoideae ; Spiranthoideae ; Epidendroideae ; Pollen ; pollinia ; massulae ; phylogeny ; morphology
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    Topics: Biology
    Notes: Abstract The sectile state, in which pollinia are subdivided into units larger than tetrads, is one of several systematically important orchid pollinium characters. We recognize two types of sectile pollinia, based upon form and arrangement of massulae. One type is found primarily in members ofOrchidoideae-Spiranthoideae, while the other characterizes epidendroid genera. Additional characters that have systematic potential are massula dimorphism, caudicle composition, and degree of tetrad packing. Hollow sectile pollinia uniteArethusa andCalopogon; Stereosandra andEpipogium have dissimilar pollina, but other characters support a close relationship between them. The sectile condition is interpreted as resulting from a shift in the timing of cohesion of developing pollen cells.
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  • 78
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    Plant systematics and evolution 206 (1997), S. 133-159 
    ISSN: 1615-6110
    Keywords: Magnoliales ; Annonaceae ; Palynology ; phylogeny ; cladistics
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    Notes: Abstract Phylogenetic analyses based on morphology placeAnaxagorea and other taxa with granular monosulcate pollen, as in otherMagnoliales, at the base ofAnnonaceae. Taxa with columellar tetrads, granular tetrads, and inaperturate monads form a derived clade. To test the systematic importance of palynology, we analyzed the data set with pollen characters removed. The result was lower resolution and a different rooting of the family, betweenUvariopsis and other groups with columellar tetrads.Anaxagorea and other monosulcates are higher in the tree, implying that granular monosulcate pollen, laminar stamens, and irregular endosperm ruminations are reversals. This rooting is highly unparsimonious when pollen characters are included, and only weakly supported over theAnaxagorea rooting when pollen is excluded. Together with preliminary molecular analyses, these experiments confirm the special value of palynology in systematics ofAnnonaceae.
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  • 79
    ISSN: 1615-6110
    Keywords: Chenopodiaceae ; CO2-fixation types ; ecology ; phytogeography ; phylogeny ; evolution of arid flora ; Old World flora: Africa ; Asia ; Europe
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    Notes: Abstract Photosynthetic pathways are reported for 305 species ofChenopodiaceae from Africa, Asia and Europe. Ecological characteristics, phytogeography and life forms of all species are given, and their correlation with relevant CO2-fixation types are discussed. 205 species (67.2%) exhibit the C4-pathway and 100 species (32.8%) the C3-pathway of CO2-fixation. Most of the C4 species are of Irano-Turanian origin. The diversity of C4 species of the Irano-Turanian phytochoria, with very harsh winters, are interpreted by the active period of Chenopods in summer. There is a close relationship between some special morphotypes and respective photosynthetic type. Halophytes and xerophytes with articulated stems and stem succulents ofAnabasis-type are exclusively C4. Leaf succulent halophytes and xerohalophytes are predominantly C4. Hygrohalophytes with leaf or stem succulence are often C3. Probably many C4 Salsoleae have been evolved in the Afroasiatic arid zone after the climatic changes of the Miocene. Among them there is a high proportion of annuals that have a younger origin. There is some evidence that the present Chenopods of the subfamily “Salsoloideae” may have their ancient stock in NW Africa. We found close taxonomic relationships between photosynthetic pathways and infrageneric classification in genera with both types of C3 and C4, likeAtriplex andSuaeda.
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  • 80
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    Plant systematics and evolution 207 (1997), S. 173-203 
    ISSN: 1615-6110
    Keywords: Compositae ; Asteraceae ; Cardueae ; Carlininae ; Echinopeae ; Cladistics ; phylogeny
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    Topics: Biology
    Notes: Abstract A cladistic analysis of 45 genera ofCardueae for 75 characters is presented, taking into account characters of bracts, corolla, stamens, styles and cypselas. Forty-six binary characters completeBremer's (1994) work. Some of the characters considered byBremer are criticised. The traditionalCarlininae is a paraphyletic group, the ten genera studied sharing no common derived character. A new classification of theCardueae is proposed and the distribution of the tribe is presented. Several new combinations are proposed. The nomenclature ofCentaurea is discussed and the status of the genusSerratula is analysed.
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  • 81
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    Plant systematics and evolution 209 (1998), S. 93-122 
    ISSN: 1615-6110
    Keywords: Fabaceae ; Mirbelieae ; Daviesia ulicifolia ; Phenetics ; ordination ; phylogeny ; morphometric characters ; gap coding ; paraphyly ; species problem ; Flora of Australia
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    Notes: Abstract Daviesia ulicifolia is a widespread species that exhibits complex variation throughout its range. Using ordination and cluster analysis of morphometric characters we resolved ten terminal taxa for phylogenetic analysis. A data set including these and five closely related species was coded for a combination of morphometric and qualitative characters and analysed using parsimony. This revealed thatD. ulicifolia is paraphyletic by inclusion ofD. acicularis, D. arenaria andD. microcarpa. One terminal cluster is more similar to an outgroup species (D. arthropoda) than toD. ulicifolia and should be treated as a new species. Given recent theoretical and empirical studies showing paraphyly to be both expected and observed at species level, we propose that all existing species in this group continue to be recognised taxonomically. We suggest subdividingD. ulicifolia into several subspecies.
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  • 82
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    Plant systematics and evolution 195 (1995), S. 177-185 
    ISSN: 1615-6110
    Keywords: Magnoliidae ; Chloranthaceae ; Ascarina ; Chloranthus ; Hedyosmum ; Sarcandra ; Chromosome numbers ; karyomorphology ; phylogeny
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    Notes: Abstract Karyological observations on 7 species and 2 varieties of 4 genera belonging to theChloranthaceae demonstrate the presence of three basic chromosome numbers within the family, i.e., x = 8 (Hedyosmum), 13 (Ascarina) and 15 (Chloranthus, Sarcandra). The karyomorphology ofChloranthus andAscarina is similar, whereasSarcandra andHedyosmum display unique characteristics. Both karyological aspects, i.e., chromosome number and karyomorphology, demonstrate remarkable diversity ofChloranthaceae and complex relationships between its genera. A distant affinity betweenChloranthaceae andPiperales is suggested.
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  • 83
    ISSN: 1615-6110
    Keywords: Gentianaceae ; Gentianinae ; Centaurium ; nrDNA ; ITS ; PCR ; sequencing ; phylogeny ; molecular systematics
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    Topics: Biology
    Notes: Abstract The internal transcribed spacer (ITS) regions of 18S–25S nuclear ribosomal DNA from representatives of 23 species of the subtribeGentianinae and one outgroup species (Centaurium capitatum) were analyzed by polymerase chain reaction amplification and direct DNA sequencing. Within the taxa analyzed, the length of the ITS1 region varied from 221 to 233 bp, ITS2 from 226 to 234 bp. Of the aligned sequences of 497 positions, 151 sites involved gaps or nucleotide ambiguity, 133 were invariable and 213 showed divergence. In pairwise comparisons among the taxa of the subtribeGentianinae and the outgroup, sequence divergence ranged from 1.3% to 34.1% in ITS1, from 0 to 28.1% in ITS2 and from 0.6% to 27.5% in combined ITS1 and ITS2. Phylogenetic trees generated from ITS sequences were highly resolutive and principally concordant with morphological classifications for the major phylogenetic divisions in the subtribe. An ancient divergence leading to two evolutionary lines was suggested in the subtribe by both DNA sequence and morphological data. One line encompasses the generaGentiana, Crawfurdia andTripterospermum, morphologically characterized by their glands on the base of ovary and their plicate corolla, while the other line involves all other members of the subcribe surveyed, characterized by their epipetalous glands and simple corolla without plicae.Megacodon, with glands on the base of ovary but without plicae on its corolla, was revealed to be more related to the latter group than to the former.Comastoma, Gentianella andGentianopsis were shown to be well-defined monophyletic genera.Pterygocalyx showed much closer affinity toGentianopsis than to any other genus. Some conflictions were detected in the genusSwertia.
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    Plant systematics and evolution 198 (1995), S. 101-141 
    ISSN: 1615-6110
    Keywords: Lamiaceae ; Labiatae ; Verbenaceae ; Lamioideae ; Chloanthoideae ; Nepetoideae ; Pogostemonoideae ; Scutellarioideae ; Pericarp ; anatomy ; phylogeny ; classification
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    Notes: Abstract Pericarp structure was investigated in 158 species of the familiesLamiaceae andVerbenaceae. Data from 221 out of 262 genera ofLamiaceae s.l. and a few ofVerbenaceae s.str. were collected in a table. A cladistic analysis was performed on the basis of pericarp characters only. The abandonment of subfam.Pogostemonoideae as a taxonomic unit is considered. Examples of groups given additional support by similarities in pericarp characters are: (1) the gynobasic-styled labiates (subfamiliesPogostemonoideae, Lamioideae, Nepetoideae); (2) aLamioideae-Pogostemonoideae-group; (3)Nepetoideae; (4) aWestringia-Hemigenia-Hemiandra-Microcorys group (in subfam.Chloranthoideae); (5) aLepechinia-Chaunostoma-group (inNepetoideae); (6) aPrunella-Cleonia-group (inNepetoideae).
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    Plant systematics and evolution 199 (1996), S. 17-32 
    ISSN: 1615-6110
    Keywords: Apiaceae ; Umbelliferae ; Anthriscus ; Taxonomy ; phylogeny ; evolution ; ecological radiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Species boundaries and phylogenetic relationships of 17 taxa ofAnthriscus (Apiaceae), with special emphasis on the critical sect.Cacosciadium, were explored using morphological data with principal component analysis, phenetics, and phylogenetics. The analyses did not provide satisfactory resolution of taxa from sect.Cacosciadium and only four species were retained. The total number of species was reduced to nine. Sect.Cacosciadium is distinguished by only two synapomorphies while sects.Anthriscus andCaroides are better supported. Present geographic and ecological variation suggests that the radiation ofAnthriscus occurred through divergence of peripheral isolated populations adapting to different habitats: high montane meadows and screes, shady climax forests, and seasonally dry habitats at lower altitudes. The adaptive significance of particular morphological traits is discussed.
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    Plant systematics and evolution 199 (1996), S. 217-242 
    ISSN: 1615-6110
    Keywords: Asterales ; Campanulales ; Abrophyllaceae ; Alseuosmiaceae ; Argophyllaceae ; Brunoniaceae ; Donatiaceae ; Escalloniaceae ; Goodeniaceae ; Menyanthaceae ; Chloroplast DNA ; phylogeny ; rbcL
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    Notes: Abstract TherbcL gene of 25 taxa was sequenced and analyzed cladistically in order to define more precisely the orderAsterales s.l. and to reconstruct the phylogeny ofGoodeniaceae. The cladistic analyses show that theAsterales comprise the familiesAbrophyllaceae, Alseuosmiaceae, Argophyllaceae, Asteraceae, Calyceraceae, Campanulaceae s.l.,Donatiaceae, Goodeniaceae (includingBrunoniaceae),Menyanthaceae, Pentaphragmataceae, andStylidiaceae. Abrophyllaceae, Alseuosmiaceae, Brunoniaceae, andDonatiaceae have previously not been studied in this respect. Within theGoodeniaceae, four groups supported by therbcL data can be distinguished: the genusLechenaultia, theAnthotium-Dampiera-group, the genusBrunonia, and a group formed by the remaining genera, theScaevola-Goodenia-group.
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  • 87
    ISSN: 1615-6110
    Keywords: Valerianaceae ; Valerianeae ; Fedia ; Fruit polymorphism ; seed dispersal ; supergene ; genetic control ; phylogeny
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    Notes: Abstract The genusFedia consists of three species (F. cornucopiae, F. graciliflora andF. pallescens) of winter annual herbs, endemic to the western Mediterranean Basin. The deciduous terminal fruits of these taxa are polymorphic in the development of their pericarp and/or calyx, and each population is dimorphic or more rarely trimorphic. The three main fruit types are dispersed in several manners, and are specialized for either epizoochory or myrmecochory. On the basis of our experimental study of dimorphic and trimorphic populations ofF. pallescens subsp.pallescens, a genetic model is presented in order to explain the control of this intrapopulational polymorphism. It is postulated that two diallelic loci are tightly linked on the same chromosome in a functional supergene. One allele of each locus displays a dominance effect in the heterozygous state. Within the four possible homologous allelic segments, only two are present in the dimorphic populations, three in the trimorphic ones, and are otherwise associated in diverse combinations in the remaining taxa of the genus. Similar examples of fruit polymorphism are already documented in the tribeValerianeae, subtribeFediinae. The hypothesis is put forward that this fruit polymorphism is a synapomorphy for the subtribe.
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    Plant systematics and evolution 211 (1998), S. 93-102 
    ISSN: 1615-6110
    Keywords: Primulales ; Primulaceae ; Myrsinaceae ; Theophrastaceae ; DNA ; rbcL sequences ; phylogeny ; classification
    Source: Springer Online Journal Archives 1860-2000
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    Notes: Abstract A cladistic analysis of phylogenetic relationships in thePrimulales has been conducted, based on nucleotide sequence data from the chloroplast DNA generbcL. The analysis included 16 taxa representing all three families in the order, and also six genera from other orders, viz.Magnolia (Magnoliaceae),Caltha (Ranunculaceae),Geranium (Geraniaceae),Nicotiana (Solanaceae),Diospyros (Ebenaceae), andManilkara (Sapotaceae). Previous cladistic analyses of morphological data have indicated that theTheophrastaceae are monophyletic, and that theMyrsinaceae are paraphyletic if including the genusMaesa. The results of the present work corroborate this conclusion, but also indicate that thePrimulaceae are paraphyletic.Maesa is part of an unresolved clade that also include theTheophrastaceae and thePrimulaceae, and theMyrsinaceae s. str. The latter is part of a monophyletic group also comprising thePrimulaceae-Lysimachiinae andCyclamen. It is concluded that dramatic changes in family circumscriptions are needed in order for taxonomy to reflect strictly monophyletic groups in thePrimulales.
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    Plant systematics and evolution 211 (1998), S. 201-216 
    ISSN: 1615-6110
    Keywords: Fabaceae ; Stylosanthes ; RAPDs ; phylogeny ; systematics ; taxon identification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Random amplified polymorphic DNA (RAPD) was assessed for its suitability as a tool to be used in the identification of taxa from the genusStylosanthes (Fabaceae, Papilionoideae, Aeschynomeneae). Five random primers were used to ‘fingerprint’ accessions from seven species in the genus, and generated RAPD profiles that were species-specific. Data were used to examine evolutionary relationships between taxa, employing both clustering and ordination techniques, and the results were compared with those from a previous cladistic analysis of chloroplast DNA (cpDNA) restriction fragments. Both multivariate approaches indicated relationships that were generally similar to those obtained by RFLP analysis of cpDNA. However, while cluster analysis grouped together all accessions within species, ordination placed certain accessions ofS. humilis, S. macrocephala andS. capitata into separate groups. Experiments to test the assumed homology of comigrating RAPDs estimated 85.7% homology for accessions within species, and 53.8% homology for accessions between species. The value of RAPD data in systematics is discussed.
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  • 90
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    Plant systematics and evolution 212 (1998), S. 215-246 
    ISSN: 1615-6110
    Keywords: Rubiaceae ; Exostema ; Morphology ; ITS sequences ; cladistics ; phylogeny ; diversity ; Caribbean biogeography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The neotropical genusExostema comprises 25 species of trees and shrubs, ranging in distribution from Bolivia to Mexico and throughout the West Indies, with most species endemic to the Greater Antilles. Infrageneric relationships and species-level patterns of evolution were investigated in phylogenetic analyses using morphological, molecular, and combined data sets. All data sets resolved three main species groups which correspond to the three sections recognized byMcDowell (1996). However, the analyses of ITS sequence data placed the two South American species basal to the three main clades. Otherwise, the morphological and molecular data are highly compatible, and produce a more robust yet consistent phylogeny in the combined data analysis. Morphological evolution inExostema involves many specializations for xeric habitats, reflecting repeated ecological shifts from moist forest to exposed, seasonally dry environments during the diversification of the genus. Both moth and bee pollination syndromes are found inExostema, and shifts in pollination ecology appear pivotal to the differentiation of the three sections. Biogeographically,Exostema likely originated in South America and migrated via Central America to the Greater Antilles, where the morphological diversification and speciation are most extensive.
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  • 91
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    Plant systematics and evolution 213 (1998), S. 1-19 
    ISSN: 1615-6110
    Keywords: Ranunculaceae ; Ranunculus ; Chloroplast DNA ; phylogeny ; restriction site maps
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A chloroplast DNA restriction site map forRanunculus sceleratus (Ranunculaceae) was constructed using 14 restriction endonucleases. The total size of the chloroplast genome is 152.4kb. No inversions were detected relative to the tobacco chloroplast DNA. Cladistic analyses of chloroplast DNA restriction site polymorphism were employed in order to elucidate the phylogeny among 76 species of the genusRanunculus in a wide sense and one species ofTrautvetteria. A total of 341 informative restriction site changes were detected. Parsimony jackknifing, bootstrapping and decay analysis were undertaken in order to evaluate the amount of support for the monophyletic groups. The results suggest that the analysed species ofRanunculus are divisible into two main clades. Only few of the traditional sections and subgenera ofRanunculus are monophyletic. The genusTrautvetteria is nested within a clade comprising, e.g.Ranunculus cymbalaria, R. andersonii, R. lapponicus andR. ficaria. SubgenusBatrachium lies within a larger clade containing, e.g.R. sceleratus andR. hyperboreus. Contractions of the inverted repeat due to parallel deletions of 200–300 bp close to the JSB have occurred in many clades and the phylogenetic distribution of this size reduction was mapped among the species.
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  • 92
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    Keywords: Barbeyaceae ; Dirachmaceae ; Elaeagnaceae ; Rhamnaceae ; Rosaceae ; Ulmaceae ; Urticales ; Barbeya ; Dirachma ; Actinorhizal symbiosis ; plastid DNA ; monotypic plant families ; phylogeny ; rbcL ; rosids ; trnL-F ; Africa ; Arabia ; Socotra ; Somalia
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Barbeya is a monotypic genus in the Horn of Africa and adjacent parts of Arabia. It is usually treated as the familyBarbeyaceae and regarded as an aberrant member ofUrticales. Dirachma, with one species on Socotra and one in Somalia, is usually treated as the familyDirachmaceae, inGeraniales, but a position inMalvales has also been suggested. Analyses of molecular data, from bothrbcL andtrnL-F, indicate thatBarbeya andDirachma are closely related inter se as well as toRhamnaceae andElaeagnaceae. In an analysis based on morphologyBarbeya groups withElaeagnaceae, andDirachma withRhamnaceae andUlmaceae. In a combined molecular and morphological analysisBarbeya is the sister group ofElaeagnaceae andDirachma is the sister group of the wholeBarbeya-Elaeagnaceae-Rhamnaceae clade. However, the support for these arrangements is weak and, rather than mergingBarbeyaceae withDirachmaceae as suggested by the molecular analysis or withElaeagnaceae as suggested by the morphological and combined analyses, it seems best to retain bothBarbeyaceae andDirachmaceae in their present circumscriptions, but in both cases in completely new positions in the angiosperm system. The results are compatible with a new circumscription ofRhamnales comprisingRhamnaceae, Elaeagnaceae, Dirachmaceae andBarbeyaceae.
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  • 93
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    Plant systematics and evolution 215 (1999), S. 37-47 
    ISSN: 1615-6110
    Keywords: Ranunculaceae ; Aconitum ; Delphinium ; Helleborus ; Nigella ; Seed oil ; fatty acids ; phylogeny ; evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Many members ofRanunculaceae contain unusual fatty acids in their seed oils. This leads to rather typical genus-specific fatty acid patterns or “fingerprints” in these seed oils. The members of theDelphinioideae and/orHelleboroideae, however, do not contain highly unusual fatty acids. Nevertheless, their seed oil fatty acid fingerprints are also fairly typical and genus-specific, and the patterns found are rather consistent throughout several species of one genus. It was found that species ofAconitum do not contain fatty acids with 20 carbon atoms.Delphinium, Consolida, Helleborus, Nigella and others do contain C20 fatty acids. In allHelleborus species, for example, there was a consistent C20 fatty acid pattern of 20:0≪20:1≫20:2〉20:3. Species ofNigella andGaridella contain high levels,Helleborus low levels, of 20:2n-6 in their seed oils.Delphinium andAconitum both contain low levels of 18:3n-3, whereasHelleborus spp. consistently show high levels of this fatty acid. The genus-specific fatty acid patterns found are discussed, and a correlation with the subfamily and tribe affiliation of the genera investigated here is attempted.
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  • 94
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    Plant systematics and evolution 215 (1999), S. 255-285 
    ISSN: 1615-6110
    Keywords: Brassiceae ; Isozyme number ; chromosome number ; phylogeny ; gene duplication
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Variation in isozyme number was used to assess the evolution of haploid chromosome numbers (n=6−75) and systematic relationships in the tribeBrassiceae, which is believed to be one of the few monophyletic tribes in theBrassicaceae. Ten enzyme systems were surveyed among 108 species in 35 genera of tribeBrassiceae and for 11 species from seven other tribes. The data indicated that taxa with n=7−13 and n=14−18 were similar in isozyme number, suggesting that genera with n=14−18 did not arise from polyploidy (i.e. entire duplication) of the n=7−13 genomes. These results suggest that aneuploidy and/or chromosome fusion/splitting have played a more significant role than polyploidy in the evolution of higher base chromosome numbers in the tribe. The detection of widespread isozyme duplication in the tribe is consistent with reports of extensive gene duplication in theBrassica crop species, and suggests that the common ancestor of the tribe already had undergone a polyploid event, i.e. complete genome duplication, prior to aneuploid divergence. Inheritance studies conducted onSinapis arvensis showed that segregation ratios at seven loci (Fbp-2,Gpi-2,Idh-2,Pgm-2,Pgm-2′,Tpi-1,Tpi-1′) conformed to those expected under Mendelian inheritance. Isozyme duplications were phylogenetically informative at various taxonomic levels in the tribe. In particular, duplications for cytosolic phosphoglucomutase (Pgm-2,Pgm-2′) and plastid triosephosphate isomerase (Tpi-1,Tpi-1′) were evident in 33 of the 35 genera examined, supporting the monophyletic status of theBrassiceae with the inclusion ofOrychophragmus and the exclusion of controversial membersCalepina andConringia.
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  • 95
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    Plant systematics and evolution 216 (1999), S. 197-205 
    ISSN: 1615-6110
    Keywords: Dipterocarpaceae ; Monotoideae ; Dipterocarpoideae ; Pakaraimoideae ; Pseudomonotes ; Monotes ; Marquesia ; rbcL ; phylogeny ; biosystematics
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract The placement of a recently discovered South American monotypic genus,Pseudomonotes tropenbosii, in subfam.Monotoideae (Dipterocarpaceae) extends the geographical range of the subfamily from Africa to the Neotropics. Although morphological and anatomical evidence suggest similarities betweenPseudomonotes andMonotes, the close alliance of these two genera was questionable due to their disjunct distribution and a lack of phylogenetic analysis. In the present study, we reconstructed the phylogeny ofPseudomonotes and other putatively related taxa usingrbcL sequence data. The analysis ofrbcL sequences of 20 taxa belonging to 15 genera and eight families recovered a single most parsimonious tree. The genusSarcolaena (Sarcolaenaceae) formed a clade sister to the monophyleticDipterocarpaceae clade.Monotes andPseudomonotes formed a strongly supported group, sister to the monophyletic clade withPakaraimaea and the remaining Asiatic dipterocarp species studied. The study strongly supports the placement ofPseudomonotes within subfam.Monotoideae of theDipterocarpaceae.
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  • 96
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    Plant systematics and evolution 216 (1999), S. 251-263 
    ISSN: 1615-6110
    Keywords: Ranunculaceae ; Cimicifugeae ; Actaea ; Cimicifuga ; Souliea ; Anemonopsis ; Biogeography ; morphology ; ecology ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Phylogenetic analyses of the genusActaea were performed using morphological, ecological and biogeographical characters. Using solely morphological characters, the relationships of the three identified species-groups remain uncertain. Close biogeographical examination and comparison of the areas with ecological peculiarities as well as climate data gave important insight into the phylogeny ofActaea and the whole tribe. Consequently, the obtained biogeographical data were used for phylogenetic reconstructions. Both, from the point of view of morphological and biogeographical data,A. pachypoda andA. asiatica are the most ancestral species. They grow on the east sides of the continents, mainly in broad-leaved forests. In West Eurasia the apomorphicA. spicata andA. acuminata occur under similar climatic and ecological conditions, but these species are adapted to another climate rhythm. The most advanced species (A. erythrocarpa, A. rubra) are to be found in the boreal forests where they are widely distributed. This biogeographical approach revealed that the evolution of the species led to a gradual widening and shifting of their ecological constitutions.
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  • 97
    ISSN: 1615-6110
    Keywords: Brachypodium ; Poaceae ; ndhF ; ITS ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A phylogenetic reconstruction of eight species of the genusBrachypodium P. Beauv. (Poaceae) has been obtained combining sequence data from the chloroplastndhF gene and the nuclear ITS, and using five representatives of tribes Triticeae (Secale), Poeae (Lolium), Meliceae (Melica, Glyceria) and Oryzeae (Oryza) as out-groups. Similar numbers of informative substitutions for the ingroup species were provided by both the 3′ region of the chloroplastndhF gene and the nuclear ITS region. The Mediterranean annualBrachypodium distachyon appears to be the basal lineage, followed by the divergence of the New World non-rhizomatousB. mexicanum, which antedates the separation of a core of six European and Eurosiberian rhizomatous perennials (Brachypodium arbuscula, B. retusum, B. rupestre, B. phoenicoides, B. pinnatum, andB. sylvaticum). The evolutionary reconstruction based on sequences of the chloroplast and the nuclear genomes is congruent with topologies obtained from analysis of RAPD data.
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  • 98
    ISSN: 1615-6110
    Keywords: Primulaceae ; Cyclamen ; phylogeny ; rDNA sequences ; ITS ; morphology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract A molecular phylogenetic study of the genusCyclamen L. (Primulaceae) has been undertaken, based on sequence data from the 5.8S gene in the ribosomal nuclear DNA and its flanking internal transcribed spacers ITS1 and ITS2. Sequence data from 15 species ofCyclamen and seven outgroup taxa selected from Primulaceae and Myrsinaceae were analyzed phylogenetically. A second analysis based on a combined morphological and molecular dataset was performed to evaluate earlier hypotheses of character evolution in the genus. The results indicate that four monophyletic subgroups may be recognized in the genus, viz.Cyclamen, Psilanthum Schwarz,Eucosme Schwarz andGyrophoebe Schwarz. Each of the four subgenera is diagnosed by distinct basic chromosome number, as well as by morphological and molecular characteristics.
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  • 99
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    Plant systematics and evolution 220 (2000), S. 161-183 
    ISSN: 1615-6110
    Keywords: Pteridophyta ; Hypolepidaceae ; Dennstaedtiaceae ; Pteridium ; Histiopteris ; Hypolepis ; Dennstaedtia ; Construction morphology ; leaf development ; phase differentiation in leaf development ; soral development ; sorus ; receptacle ; indusium ; basipetal marginal sorus ; phylogeny
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract In contrast to the generally favoured hypothesis that the marginal position of sporangia and sori is the primitive condition, Hagemann (e.g. 1984a) holds the view that the superficial position of reproductive organs is primitive. Marginal reproductive organs correlate with a distinct succession of a vegetative and a reproductive developmental phase in the sporophyll (“phase differentiation in leaf development”). Since phase differentiation means an increase in complexity, marginal reproductive organs are considered advanced. In order to examine the relations between submarginal and marginal sori in the light of Hagemann's hypothesis, various soral forms of ferns were analysed using the methodological framework of construction morphology sensu Weber (1958). The sorus is regarded as a reproductive region of the leaf surface that comprises not only the sporangia but also the receptacle as an essential component. The growth pattern of the receptacle, the developmental succession of the sporangia, and the formation of the indusia lead to the recognition of several sorus types. In the present paper the “basipetal marginal sorus” is presented and defined as the combination of (a) a ridge-, cushion-, or rod-shaped receptacle, (b) a basipetal sequence of sporangia initiation, and (c) the presence of a lower and an upper indusium or of a cup-shaped indusium. As the first examples of this type, the sori of selected Hypolepidaceae and Dennstaedtiaceae are treated in detail. Regarding the phylogenetic relationships of the present families, the following conclusions can be drawn: (1) Owing to the meristem fusion of the indusia the sorus ofDennstaedtia possesses a new quality as compared to that of the Hypolepidaceae. Therefore, the Hypolepidaceae and the Dennstaedtiaceae should not be combined in a single family, as suggested by some authors. (2) The marginal position of the sori, and, in addition, the highly complex soral construction of the Dennstaedtiaceae, are not in support of the primitiveness of the two families, as sometimes assumed. (3) A sorus construction as found inDennstaedtia glauca can be gradually derived from a less elaborate one, such as that found, e.g., inPteridium. The continuous increase in the perfection of the soral construction (Pteridium → Dennstaedtia) suggests a placement of the Dennstaedtiaceae after the Hypolepidaceae.
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  • 100
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    Keywords: Rutaceae ; Rutoideae ; Citroideae ; Dictyolomatoideae ; Spathelioideae ; Flindersioideae ; Flindersia ; Molecular systematics ; phylogeny ; chloroplast ; trnL-trnF spacer ; ITS-1
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract DNA sequencing has been used to construct two molecular phylogenies at the intrafamily and intrageneric level within the Rutaceae. Analysis oftrnL-trnF sequence data for five Rutaceae subfamilies has shown that there is no molecular support for the current subfamily classifications within the Rutaceae. The Dictyolomatoideae and Spathelioideae belong to a clade separate from the clades containing the remaining Rutaceae subfamilies. Rutoideae and Citroideae do not form discrete clades which suggests a reassessment of the subfamily classification is necessary, particularly asRuta falls within the majority Citroideae clade. Flindersioideae forms a clade within the Rutaceae and does not form a separate family or form a clade with Meliaceae. Sequencing of 17Flindersia species produces a similar phylogeny to that proposed by other authors using morphological methods with two exceptions. The molecular phylogeny indicatesF. amboinensis is associated withF. fournieri andF. laevicarpa and, in addition,F. oppositifolia andF. pimenteliana were found to be genetically identical.
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