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  • Electron microscopy  (383)
  • taxonomy  (81)
  • Springer  (464)
  • MDPI Publishing
  • 2000-2004  (72)
  • 1975-1979  (392)
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  • Springer  (464)
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  • 1
    Digitale Medien
    Digitale Medien
    Biogeography, geographic variation and habitat preference in the Amazilia Hummingbird,Amazilia amazilia Lesson (Aves: Trochilidae), with notes on the status ofAmazilia alticola Gould (2000)
    Springer
    Journal of ornithology 141 (2000), S. 93-101 
    Details
    ISSN: 1439-0361
    Schlagwort(e): Biogeography ; geographic variation ; taxonomy ; Amazilia ; Trochilidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Die vorliegende Studie stellt die Ergebnisse von Untersuchungen zur Biogeographie, geographischen Variation, Habitatwahl und Taxonomie der Lesson-Amazilie (Amazilia amazilia) vor. Das Taxon umfaßt gegenwärtig fünf Unterarten, die von W-Ecuador bis SW-Peru verbreitet sind und überwiegend submontane Lebensräume besiedeln. Die Ventralfärbung unterliegt klinaler Variation; weiße Gefiederanteile nehmen von nördlichen zu südlichen Populationen ab, rotbraune Partien dagegen zu. Eigenständige morphologisch-morphometrische Kennzeichen sowie Unterschiede in den Habitatpräferenzen und in der Gesangsstruktur rechtfertigen es, die bisherige UnterartA. a. alticola als Paraspezies (A. alticola, Loja-Amazilie) anzuerkennen. Der Vulgärname weist auf den rezenten Verbreitungsschwerpunkt in den südecuadorianischen Anden hin. Aufgrund der engen Verwandtschaft bildenA. amazilia undA. alticola sowie die in Kolumbien endemische ArtA. castaneiventris eine Superspezies.
    Notizen: Summary This paper reviews the biogeography, geographic variation, and habitat characteristics of the Amazilia Hummingbird (Amazilia amazilia). Based on morphological features, habitat preferences, and bioacoustics, I propose that the currently recognized subspeciesA. a. alticola should be regarded as a species distinct fromA. amazilia. Synapomorphic characters found in both taxa indicate membership of the same superspecies, together with the Colombian speciesA. castaneiventris. Considering the distributional focus ofA. alticola in the Andes of southern Ecuador, the English species name Loja Hummingbird is suggested.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01651776
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  • 2
    Digitale Medien
    Digitale Medien
    Calls of the Jungle Crow (Corvus macrorhynchos s.l.) as a taxonomic character (2000)
    Springer
    Journal of ornithology 141 (2000), S. 275-284 
    Details
    ISSN: 1439-0361
    Schlagwort(e): East Asia ; taxonomy ; species delimitation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Beschreibung / Inhaltsverzeichnis: Zusammenfassung Über die Gliederung der ostasiatischen Dickschnabelkrähen (Corvus macrorhynchos s.l.) in Biospezies besteht bisher keine einhellige Meinung. In dem großen Verbreitungsgebiet zwischen Indien, Japan und Timor werden gegenwärtig eine, zwei oder drei Arten anerkannt. Hier versuchen wir, in akustischen Merkmalen artanzeigende Merkmale zu finden. Eine Diskriminanzanalyse der Rufstruktur (76 Parameter) trennt dreiCorvus-Taxa (levaillantii undjaponensis aus der ‘macrorhynchos-Gruppe’,splendens) von der Südabdachung des Himalaya (Nepal, Kashmir) vollständig voneinander. BeiC. japonensis bleiben die trennenden Merkmale über große geographische Gebiete konstant. Die akustischen Unterschiede werden als taxonomisch relevant angesehen; sie zeigen Artgrenzen an. Folglich werden die Dickschnabelkrähen aus den Tief- und Hochlagen Nepals (Kontaktzone um 2 000 m) zwei Biospezies zugeordnet (C. japonensis undC. levaillantii), in Übereinstimmung mit morphologischen, ökologischen und parasitologischen Daten. Taxonomische Extrapolation der Befunde auf die Systematik anderer ‘macrorhynchos’-Populationen erscheint über die Rufstruktur (bis zum Fernen Osten Rußlands) und über Federling-Parasiten (Mallophaga) auf große Teile SO-Asiens möglich, bedarf aber für die stimmlichen Merkmale noch weiterer Klärung. Wahrscheinlich müssen immacrorhynchos-Komplex mindestens drei biologische Arten anerkannt werden (C. japonensis, C. levaillantii, C. macrorhynchos s. str.).
    Notizen: Summary A discriminant analysis of the call structure completely separates threeCorvus taxa (levaillantii andjaponensis of the ‘macrorhynchos group’,splendens) inhabiting the southern slopes of the Himalayas (Nepal, Kashmir). The acoustic differences are considered taxonomically relevant, indicating species boundaries. Therefore the Jungle Crows of lower and upper Nepal (contact zone at around 2,000 m) are assigned to two biospecies (C. japonensis andC. levaillantii), as is consistent with morphological, ecological and parasitological data. It appears possible to extrapolate the findings regarding call structure to the systematics of other ‘macrorhynchos’ populations as distant as the Russian Far East, and those regarding mallophagan parasites to large areas of SE Asia; regarding the vocal characteristics, however, further clarification is needed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02462237
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  • 3
    Digitale Medien
    Digitale Medien
    Questioning species realities (2000)
    Springer
    Conservation genetics 1 (2000), S. 67-76 
    Details
    ISSN: 1572-9737
    Schlagwort(e): mitochondrial DNA ; phylogeny ; phylogeography ; speciation ; species concepts ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1010133721121
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  • 4
    Digitale Medien
    Digitale Medien
    Building on Bedrock: William Steel Creighton and the Reformation of Ant Systematics, 1925–1970 (2000)
    Springer
    Journal of the history of biology 33 (2000), S. 27-70 
    Details
    ISSN: 1573-0387
    Schlagwort(e): ants ; E. O. Wilson ; Ernst Mayr ; systematics ; Systematics and the Origin of Species ; taxonomy ; William L. Brown ; William Morton Wheeler ; William Steel Creighton
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Geschichte
    Notizen: Abstract Ideas about the natural world are intertwined with the personalities, practices, and the workplaces of scientists. The relationships between these categories are explored in the life of the taxonomist William Steel Creighton. Creighton studied taxonomy under William Morton Wheeler at Harvard University. He took the rules he learned from Wheeler out of the museum and into the field. In testing the rules against a new situation, Creighton found them wanting. He sought a new set of taxonomic principles, one he eventually found in Ernst Mayr's Systematics and the Origin of Species. Mayr's ideas tied together a number of themes running through Creighton's life: the need for a revised taxonomy, the emphasis on fieldwork, and the search for a new power center for ant taxonomy after Wheeler died. Creighton's adoption of Mayr's ideas as part of his professional identity also had very real implications for his career path: field studies required long and intensive studies, and Creighton would always be a slow worker. His method of taxonomy contrasted sharply not only with Wheeler's but also with two of his younger colleagues, William L. Brown and E. O. Wilson, who took over Wheeler's spot at Harvard in 1950. The disputes between these men over ant taxonomy involved, in addition to questions of technical interest, questions about where and how best to do taxonomy and who could speak withthe most authority. Creighton's story reveals how these questions are interrelated. The story also reveals the importance of Mayr's book for changes occurring in taxonomy in the middle of the twentieth century.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004712911037
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  • 5
    Digitale Medien
    Digitale Medien
    Defect structure of the low temperature α-cristobalite phase and the cristobalite ⇆ tridymite transformation in (Si-Ge)O2 (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 386-397 
    Details
    ISSN: 1432-2021
    Schlagwort(e): Key words Cristobalite ; Tridymite ; Phase transformation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Abstract Using minimum exposure techniques, it is feasible to perform high resolution electron microscopy on the α-cristobalite phase of (Si0.9 Ge0.1)O2, which is extremely radiation sensitive. Such images reveal atomic scale information of twins and tridymite-like stacking faults on (1 1 1)β planes, as well as of domain boundaries resulting from the β→α transition. Polytype structures are formed in certain cases. Morphological features suggest that the phase transformation cristobalite → tridymite proceeds by means of a zonal dislocation mediated synchro-shear process on (1 1 1)β planes; the geometry of this process is analyzed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002699900082
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  • 6
    Digitale Medien
    Digitale Medien
    The need for a shared database infrastructure: combining X-ray crystallography and electron microscopy (2000)
    Springer
    European biophysics journal 29 (2000), S. 457-462 
    Details
    ISSN: 1432-1017
    Schlagwort(e): Key words X-ray crystallography ; Electron microscopy ; Biological databases
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Physik
    Notizen: Abstract Advances in structural biology are opening greater opportunities for understanding biological structures from the cellular to the atomic level. Particularly promising are the links that can be established between the information provided by electron microscopy and the atomic structures derived from X-ray crystallography and nuclear magnetic resonance spectroscopy. Combining such different kinds of structural data can result in novel biological information on the interaction of biomolecules in large supramolecular assemblies. As a consequence, the need to develop new databases in the field of structural biology that allow for an integrated access to data from all the experimental techniques is becoming critical. Pilot studies performed in recent years have already established a solid background as far as the basic information that an integrated macromolecular structure database should contain, as well as the basic principles for integration. These efforts started in the context of the BioImage project, and resulted in a first complete database prototype that provided a versatile platform for the linking of atomic models or X-ray diffraction data with electron microscopy information. Analysis of the requirements needed to combine data at different levels of resolution have resulted in sets of specifications that make possible the integration of all these different types in the context of a web environment. The case of a structural study linking electron microscopy and X-ray data, which is already contained within the BioImage data base and in the Protein Data Bank, is used here to illustrate the current approach, while a general discussion highlights the urgent need for integrated databases.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002490000089
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  • 7
    Digitale Medien
    Digitale Medien
    Evidence for stable grain boundary melt films in experimentally deformed olivine-orthopyroxene rocks (2000)
    Springer
    Physics and chemistry of minerals 27 (2000), S. 480-494 
    Details
    ISSN: 1432-2021
    Schlagwort(e): Key words Olivine ; Grain boundary ; Partial melt ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie , Geologie und Paläontologie , Physik
    Notizen: Abstract The microstructure of olivine-olivine grain boundaries has been studied in experimentally deformed (1200–1227 °C, 300 MPa) partially molten olivine and olivine-orthopyroxene rocks. In-situ melting produced ∼1 vol% melt in all samples studied. Grain boundary analyses were carried out using a number of transmission electron microscopy techniques. The grain boundary chemistry in undeformed olivine-orthopyroxene starting material showed evidence for the presence of an intergranular phase along some, but not all, of the olivine-olivine boundaries. In the deformed samples, ultrathin Si-rich, Al- and Ca-bearing amorphous films have been observed along all investigated olivine-olivine grain boundaries. The chemistry of the grain boundaries, which is considered to be indicative for the presence of a thin film, was measured with energy-dispersive X-ray spectroscopy (EDX) and energy-filtering imaging. The amorphous nature of the films was confirmed with diffuse dark field imaging, Fresnel fringe imaging, and high-resolution electron microscopy. The films range in thickness from 0.6 to 3.0 nm, and EDX analyses show that the presence of Al and Ca is restricted to this ultrathin film along the grain boundaries. Because thin melt films have been observed in all the samples, they are thought to be stable features of the melt microstructure in deformed partially molten rocks. The transition from the occasional presence of films in the undeformed starting material to the general occurrence of the films in deformed materials suggests that deformation promotes the formation and distribution of the films. Alternatively, hot-pressing may be too short for films to develop along all grain boundaries. A difference in creep strength between the studied samples could not be attributed to grain boundary melt films, as these have been found in all deformed samples. However, a weakening effect of grain boundary melt films on olivine rheology could not be ruled out due to the lack of confirmed melt-film free experiments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s002690000090
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  • 8
    Digitale Medien
    Digitale Medien
    Two new species and one new variety of Agaricales from central Honshu, Japan (2000)
    Springer
    Mycoscience 41 (2000), S. 15-23 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Agaricales ; Clitocybe trogioides var.odorifera ; Gerronema nemorale ; Psathyrella cineraria ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two new species and one new variety of Agaricales are described and illustrated from central Honshu, Japan:Clitocybe trogioides var.odorifera var. nov. (subgenusCystoclitus sectionCystoclitus), forming white, infundibuliform basidiomata, was collected from leaf litter in theQuercus-Pasania forests;Gerronema nemorale sp. nov. (sectionXanthophylla), forming small, olivaceous, omphalinoid basidiomata, was found on dead fallen twigs in theQuercus-Pasania forests;Psathyrella cineraria sp. nov. (subgenusMycophylla sectionArgillosporae), forming basidiomata covered by detersile, dark grey, fibrillose-squamulose veil, was found on decayed wood ofQuercus myrsinaefolia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464381
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  • 9
    Digitale Medien
    Digitale Medien
    Diaporthe kyushuensis sp. nov., the teleomorph of the causal fungus of grapevine swelling arm in Japan, and its anamorphPhomopsis vitimegaspora (2000)
    Springer
    Mycoscience 41 (2000), S. 111-114 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Diaporthe kyushuensis ; grapevine swelling arm ; Phomopsis vitimegaspora ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Diaporthe kyushuensis sp. nov. is described and named as the teleomorph of causal fungus of grapevine swelling arm. The anamorph of the fungus isPhomopsis vitimegaspora.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464318
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  • 10
    Digitale Medien
    Digitale Medien
    Cronartium orientale, sp. nov., segregation of the pine gall rust in eastern Asia fromCronartium quercuum (2000)
    Springer
    Mycoscience 41 (2000), S. 115-122 
    Details
    ISSN: 1618-2545
    Schlagwort(e): distribution ; Pinus ; Quercus ; taxonomy ; Uredinales
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The Asian pine gall rust, which has hitherto been assigned toCronartium quercuum distributed in North America, is described asC. orientale, sp. nov. The spermogonial and aecial states occur on hard pines, and the uredinial and telial states occur on various oaks.Cronartium orientale has globose, almost hyaline basidiospores in contrast to the ellipsoid, yellow-orange ones of North AmericanC. quercuum s.l. Characteristics of the new rust species in morphology, DNA analysis, and host alternation are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464319
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  • 11
    Digitale Medien
    Digitale Medien
    A newLeptographium species associated withTomicus piniperda in south-western China (2000)
    Springer
    Mycoscience 41 (2000), S. 573-578 
    Details
    ISSN: 1618-2545
    Schlagwort(e): China ; Leptographium ; morphology ; taxonomy ; Tomicus piniperda
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Tomicus species (Coleoptera: Scolytidae) are serious pests of pines with a wide distribution in Europe, Asia and America. In Yunnan, south-western China,T. piniperda has destroyed more than 0.5 million ha ofPinus yunnanensis in the past 15 years. A blue stain fungus belonging to the genusLeptographium is associated with both the shoot-feeding and trunk-attacking stages of the beetle's life cycle. The fungus is morphologically similar to the anamorph ofOphiostoma crassivaginatum and toL. pyrinum, which are both characterised by short robust conidiophores and hyphae covered by a granular layer. Both these species have been isolated from conifers and are associated with insects. After comparing the fungus fromT. piniperda with similarLeptographium species, using light and scanning electron microscopy, we concluded that it represents a new taxon, which is described here asL. yunnanense sp. nov.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02460923
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  • 12
    Digitale Medien
    Digitale Medien
    Species, Demes, and the Omega Taxonomy: Gilmour and The NewSystematics (2000)
    Springer
    Biology and philosophy 15 (2000), S. 349-388 
    Details
    ISSN: 1572-8404
    Schlagwort(e): cline ; definition ; deme ; evolutionary synthesis ; experimental taxonomy ; J. Heslop-Harrison ; J.S. Huxley ; J.S.L. Gilmour ; nominalism ; systematics ; Systematics Association ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Philosophie
    Notizen: Abstract The word ``deme'' was coined by the botanists J.S.L. Gilmour and J.W.Gregor in 1939, following the pattern of J.S. Huxley's ``cline''. Its purposewas not only to rationalize the plethora of terms describing chromosomaland genetic variation, but also to reduce hostility between traditionaltaxonomists and researchers on evolution, who sometimes scorned eachother's understanding of species. A multi-layered system of compoundterms based on deme was published by Gilmour and J. Heslop-Harrison in1954 but not widely used. Deme was adopted with a modified meaning byzoologists leading the evolutionary synthesis – Huxley, Simpson, Wright,and Mayr. Connections are shown between Gilmour's ideas around definingthe deme, his role in founding the Systematics Association, and his chapter``Taxonomy and Philosophy'' in the book The New Systematics. Thishistorical episode raises questions about the role of carefully-definedwords in scientific practice.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006774217770
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  • 13
    Digitale Medien
    Digitale Medien
    A new variety ofCortinarius elatior from Japan (2000)
    Springer
    Mycoscience 41 (2000), S. 87-89 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Cortinarius elatior var.albipes ; Cortinarius Sect.Defibulati ; new variety ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cortinarius elatior var.albipes var. nov., found in the deciduous forest is described and illustrated. It is distinguished from the type variety by having a white stipe and longer spores. The differences betweenCortinarius elatior var.albipes and similar taxa are briefly discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464390
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  • 14
    Digitale Medien
    Digitale Medien
    Ceratostomella hyalocoronata, a new pyrenomycete from a stream in southern China (2000)
    Springer
    Mycoscience 41 (2000), S. 167-169 
    Details
    ISSN: 1618-2545
    Schlagwort(e): East Asia ; freshwater fungi ; taxonomy ; tropical mycology ; Xylariales
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ceratostomella hyalocoronata is described and illustrated as a new species from old decaying wood immersed in a stream in Guangdong Province, southern China. It is compared toC. hyalostoma, a temperate terrestrial species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02464327
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  • 15
    Digitale Medien
    Digitale Medien
    Three new marine ascomycetes from driftwood in Australia sand dunes (2000)
    Springer
    Mycoscience 41 (2000), S. 379-388 
    Details
    ISSN: 1618-2545
    Schlagwort(e): arenicolous ; marine fungi ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Caryospora australiensis sp. nov.,Platystomum scabridisporum sp. nov. andSavoryella melanospora sp. nov. are described from driftwood collected from a sand dune at Rye, on the Mornington Peninsula Nature Park, Victoria, Australia. These species are compared with other taxa in these and related genera.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02463951
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  • 16
    Digitale Medien
    Digitale Medien
    Two underscribed heterobasidiomycetes from Ontario (2000)
    Springer
    Mycoscience 41 (2000), S. 371-377 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Platygloea ; Platygloeales ; Sigmogloea ; taxonomy ; Tremellales
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Specimens of two heterobasidiomycetous species, collected in Ontario and studied respectively by H. S. Jackson and R. F. Cain, are described as new; they arePlatygloea jacksonii andSigmogloea tremelloidea. P. jacksonii is characterized by small basidia and basidiospores and by sympodially developing conidia.Sigmogloea tremelloidea is an anomalous taxon with cylindric, mostly transversely septate (“auricularioid”) basidia, but some features suggest a possible relationship to the Tremellales.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02463950
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  • 17
    Digitale Medien
    Digitale Medien
    Cortinarius purpurascens var.largusoides andCortinarius herpeticus var.fageticola new to Japan (2000)
    Springer
    Mycoscience 41 (2000), S. 407-410 
    Details
    ISSN: 1618-2545
    Schlagwort(e): Cortinarius purpurascens var.largusoides ; Cortinarius herpeticus var.fageticola ; Cortinarius Sect.Scauri ; mycoflora ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two species ofCortinarius Sect.Scauri collected in forests ofQuercus serrata andQ. mongolica var.grosseserrata, Q. serrata andFagus crenata, orQ. mongolica var.grosseserrata andF. crenata in Niigata prefecture were identified asCortinarius purpurascens var.largusoides andC. herpeticus var.fageticola, new to Japan. Macro- and microscopical descriptions of each species are given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02463956
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  • 18
    Digitale Medien
    Digitale Medien
    Biocompatibility of MPC: in vivo evaluation for clinical application (2000)
    Springer
    Journal of artificial organs 3 (2000), S. 39-46 
    Details
    ISSN: 1619-0904
    Schlagwort(e): Poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC) ; In vivo biocompatibility ; Artificial endocrine pancreas ; Electron microscopy ; Glucose sensor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin , Technik allgemein
    Notizen: Abstract Biocompatibility is important to assure a mild body reaction to an implanted device and its long-term stability and functionality. In diabetes research, subcutaneously implanted glucose monitoring systems need biocompatible surfaces for long-term application. The biocompatibility of poly(2-methacryloyloxyethyl phosphorylcholine-co-n-butyl methacrylate) (MPC), a material similar to the phospholipid layer of a cell membrane, was compared in vivo with the biocompatibility of polyurethane (PU), polyvinyl alcohol (PVA), and cuprophane (CUP). Needle-type glucose sensors and hollow-fiber probes used for microdialysis were coated with these four different biomaterials and implanted subcutaneously in 18 rats and 7 healthy volunteers. At set intervals, the implants and, in the case of the rats, also the surrounding tissue were removed and characterized by light and electron microscopy. MPC-coated sensors and hollow-fiber probes showed smooth and thin deposits in flat layers, whereas the surface deposits on PU- and PVA-coated sensors and those on CUP hollow-fiber probes appeared as rough, irregular, and dense attachments of aggregated cells and protein. This study confirmed results from earlier in vitro tests by showing the biocompatibility and reliability of MPC. Even though the amount of protein and cells attached to the MPC surface was not as low as expected from in vitro experiments, the biocompatibility and long-term stability of the implanted devices were superior to those of PU, PVA, and CUP.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02479925
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  • 19
    Digitale Medien
    Digitale Medien
    Intraspecific Variation in the Vocalizations and Hand Pad Morphology of Southern Lesser Bush Babies (Galago moholi): A Comparison with G. senegalensis (2000)
    Springer
    International journal of primatology 21 (2000), S. 537-555 
    Details
    ISSN: 1573-8604
    Schlagwort(e): galago ; taxonomy ; vocalization ; morphology ; zoogeography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Previous studies have shown the taxonomic value of vocal repertoires and hand (volar) pad characteristics in the classification of cryptic nocturnal primates such as bush babies. However, no study included quantitative comparisons within the geographical range of any one species. We investigated levels of intraspecific variation in calls and hand pad characteristics of the southern lesser bush baby (Galago moholi), using the northern lesser bush baby (Galago senegalensis) for interspecific comparisons. Examination of calls recorded from different regions along a transect of 1500 km across southern Africa revealed low levels of intraspecific variation in Galago moholi, whereas comparisons with homologous call-types in G. senegalensis revealed them to be significantly different. Volar pad measurements across the ranges of both species also showed low levels of intraspecific variation and relatively high interspecific variation. These findings demonstrate that vocal and volar pad characteristics can be used as consistent measures of difference between species that look almost identical. These methods provide a practical means of distinguishing between cryptic species, whether in the field, in captivity, or, in the case of volar pads, of preserved specimens.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005400205038
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  • 20
    Digitale Medien
    Digitale Medien
    Taxonomic Revision of Mouse Lemurs (Microcebus) in the Western Portions of Madagascar (2000)
    Springer
    International journal of primatology 21 (2000), S. 963-1019 
    Details
    ISSN: 1573-8604
    Schlagwort(e): mouse lemurs ; Microcebus ; taxonomy ; revision ; new species
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Microcebus (mouse lemurs) are the smallest extant primates. Until recently, they were considered to comprise two different species: Microcebus murinus, confined largely to dry forests on the western portion of Madagascar, and M. rufus, occurring in humid forest formations of eastern Madagascar. Specimens and recent field observations document rufous individuals in the west. However, the current taxonomy is entangled due to a lack of comparative material to quantify intrapopulation and intraspecific morphological variation. On the basis of recently collected specimens of Microcebus from 12 localities in portions of western Madagascar, from Ankarana in the north to Beza Mahafaly in the south, we present a revision using external, cranial, and dental characters. We recognize seven species of Microcebus from western Madagascar. We name and describe 3 spp., resurrect a previously synonymized species, and amend diagnoses for Microcebus murinus (J. F. Miller, 1777), M. myoxinus Peters, 1852, and M. ravelobensis Zimmermann et al., 1998.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005511129475
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  • 21
    Digitale Medien
    Digitale Medien
    Phylogenetic Relationships of Spider Monkeys (Ateles) Based on Mitochondrial DNA Variation (2000)
    Springer
    International journal of primatology 21 (2000), S. 381-420 
    Details
    ISSN: 1573-8604
    Schlagwort(e): phylogenetics ; taxonomy ; systematic ; Ateles ; Cebidae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Our goal was to determine phylogenetic relationships among geographically and taxonomically distinct haplotypes of spider monkeys (Ateles) based on DNA sequence variation for the mitochondrial DNA control region and cytochrome c oxidase subunit II gene. We obtained samples from most previously recognized subspecies of Ateles, ranging from Central America throughout the Amazon Basin, to determine phylogenetic relationships among racially recognized groups. Comparison of DNA sequences using both parsimony analysis and genetic distance analysis produced phylogenetic relationships that were very similar for each genetic region. We analyzed the phylograms produced, along with associated bootstrap support, confidence probabilities, and genetic distances between taxonomic groups, to identify four monophyletic species of Ateles: Ateles paniscus, composed of haplotypes from the northeastern Amazon Basin; A. belzebuth in the southern Amazon Basin; A. hybridus, located primarily along the Magdalena River valley of Colombia; and A. geoffroyi, which includes two former species: A. geoffroyi and A. fusciceps. This arrangement is contradictory to long-held taxonomies of Ateles based on pelage variation and is similar to a recent analysis based on craniodental variation. Results of this investigation suggest patterns of gene flow, evolutionary relationships, and speciation patterns that are more plausible than previous pelage-based taxonomies, which required seemingly impossible patterns of gene flow. Conservation efforts aimed at protecting Ateles, one of the Neotropics most endangered genera, will also benefit from the findings presented in this paper.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005435718241
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  • 22
    Digitale Medien
    Digitale Medien
    Use of Vocal Fingerprinting for Specific Discrimination of Gray (Microcebus murinus) and Rufous Mouse Lemurs (Microcebus rufus) (2000)
    Springer
    International journal of primatology 21 (2000), S. 837-852 
    Details
    ISSN: 1573-8604
    Schlagwort(e): vocalization ; sexual advertisement ; predator advertisement ; taxonomy ; evolution ; mouse lemur ; primate ; Madagascar
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Advertisement calls are often important noninvasive tools for discriminating cryptic species and for assessing specific diversity and speciation patterns in nature. We investigated the contribution of these calls to uncover specific diversity in nocturnal Malagasy lemurs. We compared sexual advertisement and predator advertisement calls of two mouse lemur species, western gray and eastern rufous mouse lemurs (Microcebus murinus and M. rufus, respectively) living in two contrasting habitats (dry deciduous vs. rain forest), and analyzed them statistically. Both species emitted several highly variable whistle calls in the context of predator-avoidance. Intrapopulation variation was high and overlapped interspecific variation. Sexual advertisement calls, given in the mating context, displayed a totally distinct, species-specific acoustic structure. Whereas gray mouse lemurs produced rapidly multifrequency modulated, long trill calls, rufous mouse lemurs gave slowly frequency-modulated short chirp calls. Our results suggest specific status for gray and rufous mouse lemurs and indicate the importance of predation and social needs in shaping vocal communication.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1005594625841
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  • 23
    Digitale Medien
    Digitale Medien
    Epicuticular wax morphology and the taxonomy ofRosa (sectionCaninae, subsectionRubiginosae) (2000)
    Springer
    Plant systematics and evolution 221 (2000), S. 107-112 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Rosaceae ; Rosa ; Caninae ; epicuticular waxes ; taxonomy ; hybridism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Classification within the genusRosa is problematic due to ± continuous variation of morphological characters. The dogroses, (Rosa, sectionCaninae) are classified only by their unique meiotic system not by directly visible characters. The intrasectional structure remains insufficient, as the characters (glands, hairs and prickles) are known to exhibit great morphological divergence affected by both genetic plasticity and environmental influences. Taxonomy of dogroses follows a highly artificial system which allows us to identify morphospecies, which are not necessarily evolutionary species. However, SEM-studies in theCaninae revealed that all taxa of the subsectionRubiginosae are characterised by a granule type of epicuticular waxes, whereas members from the other subsections (with three exceptions) form triangular rodlets. Comparison with specimens grown under the same conditions confirmed these findings on natural populations and additionally revealed that following artificial hybridism, offspring develop the maternal type of wax structure due to the matroclinal inheritance in this section.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01086384
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  • 24
    Digitale Medien
    Digitale Medien
    Software dependent phenetic relationships of non-nodulating African species ofAcacia (2000)
    Springer
    Plant systematics and evolution 220 (2000), S. 139-146 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Acacia ; classification ; Leguminosae ; morphology ; phenetics ; RAPD ; software ; taxonomy ; UPGMA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The phenetic analysis of non-nodulatingAcacia species by Harrier et al. (1997) was repeated to illustrate how different computer programs may generate alternative UPGMA trees for the very same data, even in the absence of data input order effects (ties). For example, all Harrier et al.'s UPGMA dendrograms produced by software from the Scottish Agricultural Statistics Service differed from those obtained by the packages NTSYS and MVSP87. Particularly, the positions ofA. albida, A. rovumae, andA. pentagona, as well as the relationships betweenDiacanthae andTriacanthae were affected by this phenomenon. Hence, whenever clustering techniques are used, care should be taken to consider possible software-dependent caveats and artefacts. Nevertheless, all programs provided clusterings that largely coincided with the subgeneric and sectional groupings proposed by Vassal (1972) although the positions of some species varied depending on whether morphological or molecular data were considered (e.g.A. albida andA. rovumae).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985042
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  • 25
    Digitale Medien
    Digitale Medien
    Secretory cavities and pellucid dots in leaflets ofLonchocarpus (Leguminosae, Papilionoideae, Millettieae) (2000)
    Springer
    Plant systematics and evolution 221 (2000), S. 61-68 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Leguminosae ; Papilionoideae ; Lonchocarpus ; leaflets ; secretory cavities ; false secretory cavities ; pellucid dots ; glands ; anatomy ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The occurrence of leaflet secretory cavities in 23 Brazilian species ofLonchocarpus was surveyed anatomically and compared with data from external morphology (presence of pellucid dots) to evaluate their taxonomic significance. This study revealed three cases: presence of secretory cavities associated with pellucid dots, pellucid dots corresponding to false secretory cavities, and absence of pellucid dots and secretory cavities. These results indicate that in this genus the “glandular pellucid dots” cited in morphological descriptions do not always correspond to secretory cavities, and that their nature must always be confirmed by histological sections. Secretory cavities have systematic significance at subgeneric taxonomic level for the genusLonchocarpus.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01086380
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  • 26
    Digitale Medien
    Digitale Medien
    New chromosome counts inStreptocarpus (Gesneriaceae) from Madagascar and the Comoro Islands and their taxonomic significance (2000)
    Springer
    Plant systematics and evolution 224 (2000), S. 173-182 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Gesneriaceae ; Streptocarpus ; Chromosome numbers ; growth patterns ; taxonomy ; Africa ; Comoro Islands ; Madagascar
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This study records the chromosome numbers of 10 species ofStreptocarpus; nine of the counts are new. With the exception ofS. buchananii of mainland Africa, all the results are for plants endemic to Madagascar and the Comoro Islands. While there is a strong correlation between basic number and growth form in the two subgenera of the genus on the African mainland (x = 15 among caulescent species in subgenusStreptocarpella; x = 16 among acaulescent species in subgenusStreptocarpus), the situation appears more complex among Madagascan and Comoro Island species. One notable example of deviation from this correlation is shown byS. papangae, a shrubby caulescent species, with 2n = 32 (x = 16). Polyploidy in the genus appears to be absent on mainland Africa, but is present in Madagascar and the Comoro Islands, ranging from tetraploidy to octoploidy. Evolutionary implications of the cytological observations are considered.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00986341
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  • 27
    Digitale Medien
    Digitale Medien
    Inter- and intraspecific genetic variation inHippophae (Elaeagnaceae) investigated by RAPD markers (2000)
    Springer
    Plant systematics and evolution 225 (2000), S. 85-101 
    Details
    ISSN: 1615-6110
    Schlagwort(e): Elaeagnaceae ; Hippophae ; sea buckthorn ; Systematics ; taxonomy ; genetic variation ; RAPD
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Genetic diversity has been investigated by the application of molecular markers in, for the first time, all the taxa recognised in recent treatises of the genusHippophae. RAPD (random amplified polymorphic DNA) analyses were conducted with 9 decamer primers, which together yielded 219 polymorphic markers. We found 16 fixed RAPD markers, i.e. markers that either occurred in all plants of a population or were absent from all plants. Several of these markers were useful for analysis of interspecific relationships, whereas others can be considered as taxon-specific markers. Clustering of taxa and populations in our neighbour-joining based dendrogram was in good agreement with some recently suggested taxonomic treatises ofHippophae. Amount and distribution of genetic variability varied considerably between species. Partitioning of molecular variance withinH. rhamnoides supported earlier findings that a considerable part of the total variance resides among subspecies (59.6%) Within-population variability also differed considerably. Percentage polymorphic RAPD loci and Lynch and Milligan within-population gene diversity estimates showed relatively high values for some species close to the geographic centre of origin in Central Asia, e.g.H. tibetana and the putatively hybridogenousH. goniocarpa. Spatial autocorrelation analyses performed on 12 populations ofH. rhamnoides revealed positive autocorrelation of allele frequencies when geographic distances ranged from 0 to 700 km, and no or negative autocorrelation at higher distances. At distances between 700 and 1900 km, we observed deviations from the expected values with strongly negative autocorrelation of allele frequencies. A corresponding relationship between geographic and genetic distances could not be found when the analysis instead was based on one population from each of 8 species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00985460
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  • 28
    Digitale Medien
    Digitale Medien
    Effects of photic and thermal stress on distal and proximal rhabdomeres in the crayfish eye: why are the visual membranes of the 8th retinula cell more resilient than the others? (2000)
    Springer
    Protoplasma 210 (2000), S. 156-163 
    Details
    ISSN: 1615-6102
    Schlagwort(e): Electron microscopy ; Photoreceptor ; Visual membrane ; Photic radiation damage ; Retina ; Crustacea
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Visual membranes of the crayfish eye either belong to the small, distally placed rhabdomere of retinula cell R8 or are part of the much more voluminous proximal rhabdom, made up of rhabdomeres belonging to cells R1–R7. Under various conditions of environmental stress (e.g., prolonged darkness, elevated temperature, bright light with and without a concomitant rise in temperature, flickering lights) the visual membranes of R8 prove far more resistant to structural damage than those of R1–R7. Membrane damage is known to occur when dormant lipoxygenases become activated, for example through heat. Since R8 is the only type of visual cell in the crayfish retina that does not contain grains of screening pigment, the view that screening-pigment granules could “aggravate” or even “trigger” membrane damage in times of stress is strengthened. Functionally, R8's strong resistance to physical damage when exposed to flickering lights points to a role of the distal rhabdom in the movement detection system of the crayfish eye.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF01276855
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  • 29
    Digitale Medien
    Digitale Medien
    Bdelloid rotifers from Korea (2000)
    Springer
    Hydrobiologia 439 (2000), S. 91-101 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Rotifera ; Bdelloidea ; Korea ; taxonomy ; biogeography
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Twenty-five samples from 18 terrestrial and/or freshwater habitats in the eastern part of Korea yielded 38 new records of bdelloid rotifers, 22 of which are new to the Asian fauna. Among these Korean new records, Dissotrocha aculeata reversa Berzins and Habrotrocha plana Milne were recorded outside their type localities for the first time, and Macrotrachela bullata (Murray) was reported only from two countries after its description. Bradyscela granulosa de Koning, Habrotrocha gracilis gracilis Montet, Macrotrachela latior Donner, Philodina duplicalcar (de Koning) and P. rugosa coriacea Bryce are recorded outside Europe for the first time. The taxonomy and distribution of these rare species are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004181414535
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  • 30
    Digitale Medien
    Digitale Medien
    Interpopulation differentiation within C. kolensis and C. strenuus strenuus (Crustacea: Copepoda): evidence from cytogenetic methods (2000)
    Springer
    Hydrobiologia 417 (2000), S. 37-42 
    Details
    ISSN: 1573-5117
    Schlagwort(e): taxonomy ; cytogenetic methods ; Cyclops kolensis ; Cyclops strenuus strenuus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Comparisons of behavior of chromosomes and characteristics of eliminated chromatin during anaphase of chromatin diminution divisions were made of Russian and German populations of Cyclops kolensis and Cyclops strenuus strenuus. Differences in cytogenetic features included timing and amount of eliminated chromatin. Differences were also marked in duration of chromatin diminution, as well as timing and location of eliminated DNA between Russian and German populations of C. strenuus strenuus. In contrast to the German population of C. strenuus, the Russian population of C. strenuus strenuus did not exhibit gonomery.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003819809155
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  • 31
    Digitale Medien
    Digitale Medien
    Key to the identification of the genera of bdelloid rotifers (2000)
    Springer
    Hydrobiologia 418 (2000), S. 73-80 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Rotifera ; Bdelloidea ; pictorial key ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We propose a simple, user-friendly key joined to a pictorial key to the bdelloid genera, in the attempt to make bdelloid identification more accessible to non-bdelloid-specialists. The key is mostly based on illustrations rather than on descriptions, and is accompanied by an introduction of the main features readily observable in active bdelloids.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003840216827
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  • 32
    Digitale Medien
    Digitale Medien
    The morphology of the upper lip of Cypridoidea ostracods: taxonomic and phylogenetic significance (2000)
    Springer
    Hydrobiologia 418 (2000), S. 169-184 
    Details
    ISSN: 1573-5117
    Schlagwort(e): ostracods ; upper lip ; taxonomy ; phylogeny
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract This paper represents the first study of the morphology of the upper lip (labrum) and hypostome of ostracods using scanning electron microscopy (S.E.M.). There is considerable variation in the upper lip morphology of the 23 species of Cypridoidea (Podocopina) ostracods used in this study. The detail of the upper lip morphology of each species is very distinctive, so that species determination can be made on this feature alone, but it is not useful in diagnosing genera or subfamilies. The hypostome is not readily studied due to the large amounts of dense pseudochaetae (small, setae-like projections) protruding from it and hence is considered not to be a useful taxonomic feature. Several features of the upper lip and mouth region are documented for the first time. Comparisons of the general morphology of the upper lips of Recent ostracods with the upper lip of the fossil ostracod Pattersoncypris micropapillosa Bate, 1972, indicate that there has been very conservative evolution in these features since the Cretaceous.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003934528762
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  • 33
    Digitale Medien
    Digitale Medien
    Ryocalanus spinifrons, a new species of Ryocalanidae (Copepoda: Calanoida), from the southwestern part of Sagami Bay, Japan (2000)
    Springer
    Hydrobiologia 432 (2000), S. 127-131 
    Details
    ISSN: 1573-5117
    Schlagwort(e): new species ; Ryocalanoid copepod ; taxonomy ; benthopelagic ; Sagami Bay
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new Ryocalanoid copepod, Ryocalanus spinifrons, collected by the MTD net system at a depth of 1400 m from the southwestern part of Sagami Bay, Japan, is described. The new species is morphologically very close to R. infelix Tanaka, 1956 (female unknown) from the Izu region of Sagami Bay. It is distinguished from other species by the presence of 12 long spinules on the ventral inner side of the fifth pedigerous somite, nine setae on the coxal epipodite of the maxillule and nine large robust spinules on the coxal segment of the fourth leg. The row of five robust spines on the paragnath distinguishes R. spinifrons.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004090724831
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  • 34
    Digitale Medien
    Digitale Medien
    Taxonomic analysis of species characters for copepodid instars 4 and 5 of the subfamily Eucyclopinae of European Russia (2000)
    Springer
    Hydrobiologia 417 (2000), S. 57-79 
    Details
    ISSN: 1573-5117
    Schlagwort(e): copepodid instars ; Eucyclopinae ; taxonomy ; morphological characters
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Morphological characters useful for taxonomic identification of older copepodid instars of the subfamily Eucyclopinae were studied among 14 species of Eucyclops, Macrocyclops, Ectocyclops, Paracyclops and Tropocyclops known from European Russia. For taxonomic analysis, the following elements of copepodid morphology were chosen: armament and proportion of furcal rami; morphology of swimming legs and reduced 5th and 6th legs; antennule segmentation; and relative body length of copepodid instars in comparison with the female length. Changes in morphology of major copepodid instars of the subfamily Eucyclopinae during ontogenetic development are traced and noticeable differences among five genera and 14 species are described. These differences among major copepodid stages may be important for both taxonomic and ecological analysis. For taxonomy, they provide information on development of sexes and species during maturation. For ecology they allow identification of the specimens at 4–5 copepodid instars in diapause. A key to major copepodid instars of the species from the subfamily Eucyclopinae which are known from limnetic habitats of the European part of Russia is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003878616907
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  • 35
    Digitale Medien
    Digitale Medien
    Components of morphological variation in Baikalian endemial cyclopid Acanthocyclops signifer complex from different localities (2000)
    Springer
    Hydrobiologia 417 (2000), S. 25-35 
    Details
    ISSN: 1573-5117
    Schlagwort(e): morphological variation ; fluctuating asymmetry ; taxonomy ; Copepoda ; Cyclopidae ; Acanthocyclops signifer ; Lake Baikal
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Use of traditional methods for morphological studies only permits the analysis of a small part of the information embodied in morphological structures. Besides comparing populations using the mean values of characters which allows one to estimate their morphological similarity, analysis of variation among individuals within a population can be informative. Variation among individuals consists of factorial and stochastic components. The factorial component is an upper estimate of genetic heterogeneity and thus permits one to evaluate the population's adaptability. The stochastic component (estimated by fluctuating asymmetry, i.e. random deviations from perfect bilateral symmetry), being a measure of developmental stability, is an indicator of a population's fitness. Assessment of measurement error is necessary for assessment of the true value of the stochastic component and for selection of the most informative characters. Such analysis allows one to extract additional information from morphological data in comparison with methods traditionally used on copepods. This approach was applied to an analysis of morphological variation in the study of the Baikalian endemic cyclopoid Acanthocyclops signifer (Mazepova) from three different isolated localities. Characters typically used in studies of taxonomy of this group are considered here. Measurement error was rather high (more than 50% of the stochastic component), which can be explained by technical difficulties of measuring the characters. All populations differ in the mean values of the characters. This shows the taxonomic heterogeneity of this group and reveals the necessity of its taxonomic revision. Populations also differ in the level of stochastic and factorial components of the total variance. The data are interpreted from the point of view of taxonomy and the possible evolution of the group.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003866215089
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  • 36
    Digitale Medien
    Digitale Medien
    Nitocrellopsis texana n. sp. from central TX (U.S.A.) and N. ahaggarensis n. sp. from the central Algerian Sahara (Copepoda, Harpacticoida) (2000)
    Springer
    Hydrobiologia 418 (2000), S. 81-97 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Harpacticoida ; new species ; redescription ; taxonomy ; troglobitics ; trans-Atlantic distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Nitocrellopsis texana n. sp. found in samples collected by SCUBA divers in Honey Creek Cave (Texas, U.S.A.) is described. This species is the first representative of this stygobitic taxon from a Northern American locality. The original description of N. ioneli (Dumont & Decraemer, 1975) is amended and the closely related N. ahaggarensis n. sp. is described from a well near Tamanghasset in the Ahaggar mountains in Algeria. The monophyly of Nitocrellopsis is discussed and its present day distribution is analyzed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003892200897
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  • 37
    Digitale Medien
    Digitale Medien
    The dinoflagellate genus Prorocentrum along the coasts of the Mexican Pacific (2000)
    Springer
    Hydrobiologia 418 (2000), S. 111-121 
    Details
    ISSN: 1573-5117
    Schlagwort(e): dinoflagellates ; Prorocentrum ; morphology ; taxonomy ; Mexican Pacific ; red tides
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We surveyed the dinoflagellate genus Prorocentrum Ehrenberg in Mexican Pacific waters, where it is rather common and sometimes causes red tides in coastal areas or shrimp farms. Material collected from Baja California and the Gulf of California was analyzed. Thirteen species were identified, all of them planktonic (although P. mexicanum is also epiphytic). All species are described by light microscopy, and most are also described by scanning electron microscopy; comments on morphology, taxonomy and distribution are made. Red tides were caused by P. dentatum, P. minimum and P. triestinum. Prorocentrum mexicanum and P. minimum were suspected of being toxic. Four species, previously reported in the Gulf of California, were not found. A total of 18 species, including the new records P. dactylum and P. lebourae have been to date reported from the Mexican Pacific.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003806719515
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  • 38
    Digitale Medien
    Digitale Medien
    Eucyclops dumonti sp.nov. from Central Mongolia (2000)
    Springer
    Hydrobiologia 441 (2000), S. 63-71 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Mongolia ; Eucyclops dumonti ; taxonomy ; zooplankton ; spring fauna
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Eucyclops dumonti sp.nov. is described from a shallow spring-fed lake in Central Mongolia. Data on its morphological variability are given, a comparison with the type population of Eucyclops serrulatus (Fischer, 1853) from St. Petersburg area is made, and its position relative to some closely related congeners is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017592005551
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  • 39
    Digitale Medien
    Digitale Medien
    Redescription of Diaphanosoma dubium Manuilova, 1964 (Branchiopoda: Ctenopoda: Sididae), and description of a new, related species (2000)
    Springer
    Hydrobiologia 441 (2000), S. 73-92 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Diaphanosoma dubium ; D. pseudodubium sp.nov. ; morphology ; taxonomy ; geographical distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The poorly known D. dubium Manuilova is redescribed on extensive material from more than 80 populations from the Russian Far East, Central Asia, Mongolia, China, Japan, Vietnam, the Philippines, Thailand, Malaysia, Bangladesh, India and Sri Lanka. Its morphological variability and geographical distribution are analysed and supplemented by notes on biology. The conspecificity of morphologically different distant populations is discussed. In the northern part of its range, D. dubium was long confused with D. brachyurum or D. leuchtenbergianum, and in the south with D. modigliani. It seems that the recent appearance of D. dubium in fish ponds of Uzbekistan and Kazakhstan was an introduction, together with Far Eastern fish. D. pseudodubium sp.nov., close to but markedly different, is described from two lakes in the lower Amur river system. D. dubium, D. pseudodubium, D. tropicum and D. modigliani s. str. form a group of related species, widely distributed in Eastern and Southern Asia.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017574921558
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  • 40
    Digitale Medien
    Digitale Medien
    Molecular genetic analyses of species boundaries in the sea (2000)
    Springer
    Hydrobiologia 420 (2000), S. 73-90 
    Details
    ISSN: 1573-5117
    Schlagwort(e): sibling species ; taxonomy ; DNA ; electrophoresis ; allozymes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The tools of molecular genetics have enormous potential for clarifying the nature and age of species boundaries in marine organisms. Below I summarize the genetic implications of various species concepts, and review the results of recent molecular genetic analyses of species boundaries in marine microbes, plants, invertebrates and vertebrates. Excessive lumping, rather than excessive splitting, characterizes the current systematic situation in many groups. Morphologically similar species are often quite distinct genetically, suggesting that conservative systematic traditions or morphological stasis may be involved. Some reproductively isolated taxa exhibit only small levels of genetic differentiation, however. In these cases, large population sizes, slow rates of molecular evolution, and relatively recent origins may contribute to the difficulty in finding fixed genetic markers associated with barriers to gene exchange. The extent to which hybridization blurs species boundaries of marine organisms remains a subject of real disagreement in some groups (e.g. corals). The ages of recently diverged species are largely unknown; many appear to be older than 3 million years, but snails and fishes provide several examples of more recent divergences. Increasingly sophisticated genetic analyses make it easier to distinguish allopatric taxa, but criteria for recognition at the species level are highly inconsistent across studies. Future molecular genetic analyses should help to resolve many of these issues, particularly if coupled with other biological and paleontological approaches.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003933603879
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  • 41
    Digitale Medien
    Digitale Medien
    A new Ceratium species (Dinophyceae) from Lake Doïrani, Macedonia, Greece (2000)
    Springer
    Hydrobiologia 424 (2000), S. 101-108 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Ceratium ; freshwater ; ecology ; morphology ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new taxon of Ceratium is described from Lake Doïrani, Greece. It is proposed as a new species and named Ceratium monoceras. It differs morphologically from known species of Ceratium by having only one horn, the apical horn. Accordingly, the vegetative cells form cysts that have only one spine. Details of its ecology and occurence are given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003957129071
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  • 42
    Digitale Medien
    Digitale Medien
    Nematodes from the Strait of Magellan and the Beagle Channel (Chile): the genera Cervonema and Laimella (Comesomatidae: Nematoda) (2000)
    Springer
    Hydrobiologia 427 (2000), S. 27-49 
    Details
    ISSN: 1573-5117
    Schlagwort(e): taxonomy ; marine nematodes ; Cervonema ; Laimella ; the Strait of Magellan ; Chile
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Five species of Cervonema and four species of Laimella are described from the Strait of Magellan and the Beagle Channel, Chile, six species of which are new to science. Cervonema chilensisn. sp. and Cervonema hermanin. sp. are separated from other known species of Cervonema by a short cervical region (less than one head diameter from the front end to the anterior border of the amphids). Cervonema chilensisn. sp. is characterised by a tail length of 5 anal diameters with posterior half filiform; Cervonema hermani n. sp. is characterised by a tail length of 6–9 anal diameter and posterior part (75%) cylindrical. Cervonema shiaen. sp. is characterised by the cephalic seta 4 μm long, amphids 9–10 μm in diameter; spicules 16 μm long and 0.8–0.9 abd; tail 4.7–5.4 anal diameter and 50% posterior part filiform; 4–5 minute precloacal supplements. Laimella subterminatan. sp. is characterised by the subterminal position of the buccal cavity which separates it from the other species of the genus. Laimella annaen. sp. is characterised by the head diameter 9–11 μm, cephalic setae and external labial setae 9 + 5 μm long, respectively, amphids 7 μm in diameter; spicules 28–30 μm long; tail 14–17 anal diameter and posterior part (75%) filiform; 5 precloacal supplements. Laimella sandraen. sp. is very close to Laimella annaen.sp. in having similar cephalic sensilla, amphids and spicules. Laimella sandraen. sp., however, can be separated from L.annaen. sp. by the shape of head and the structure of sperm cells, the total body length and the cylindrical part of tail. Cervonema papillatum Jensen, 1988, C. tenuicauda (Stekhoven, 1950) and L. longicauda Cobb, 1920 are found in this area as well. The key of all known species of Cervonemaand Laimellais presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003943021901
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  • 43
    Digitale Medien
    Digitale Medien
    Description of a new Nipergasilus species (Family: Ergasilidae) from the gills of grey mullet (2000)
    Springer
    Hydrobiologia 428 (2000), S. 61-66 
    Details
    ISSN: 1573-5117
    Schlagwort(e): parasitic Copepoda ; taxonomy ; new species ; grey mullet
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A new Nipergasilus species is described from the gills of the grey mullet Valamugil cunnesius from several localities in India and Pakistan. The new species is closely related to Nipergasilus bora (Yamaguti, 1939) which is also recorded here on three species of grey mullet. The genus Nipergasilus is redefined in order to accommodate the second species.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003931713959
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  • 44
    Digitale Medien
    Digitale Medien
    New species of Rhynchelmis (Clitellata, Lumbriculidae), with observations on the Nearctic species (2000)
    Springer
    Hydrobiologia 428 (2000), S. 1-59 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Clitellata ; Oligochaeta ; Lumbriculidae ; Rhynchelmis ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The Nearctic species of Rhynchelmis (Lumbriculidae) are distinguished from the Palearctic group Rhynchelmis s. str. by longitudinal muscle bands that do not curl inwards. Six new species from western North America support the existence of two major groupings within the Nearctic fauna. Species in Group 1 are distinguished from other Rhynchelmis by large penial bulbs and multiple spermathecal diverticula. Within Group 1, Rhynchelmis yakimorum n. sp., Rhynchelmis monsserratus n. sp., Rhynchelmis gustafsoni n. sp. and Rhynchelmis utahensis n. sp. differ from the related Rhynchelmis (=Sutroa) rostrata in having short penes and spermathecae with 2 short, lobed diverticula. R. monsserratus is distinguished by a single, median spermatheca, R. gustafsoni has closely appressed, median spermathecae and atria, and R. utahensis differs in structural details of spermathecae and male pores. Rhynchelmis gilensis n. sp. has a single, median spermatheca with unbranched diverticula and distinctive nephridia. Redescription of material from the type localities of both Sutroa alpestris and R. rostrata supports their combination. Group 2, corresponding in part to Rhynchelmoides, is distinguished from Group 1 mostly by characters that are inconsistent or appear plesiomorphic. Within Group 2, Rhynchelmis saxosa n. sp. closely resembles Rhynchelmis alaskana, except for the absence of lateral blood vessels in posterior segments and distribution of prostates. Rhynchelmis elrodi and Rhynchelmis glandula consistently differ in presence of ventral glands and have different distributions, so their supposed synonymy is rejected.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003919312142
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  • 45
    Digitale Medien
    Digitale Medien
    New species of Metepsilonema (Nemata, Epsilonematidae) from the Channel and the Mediterranean Sea with a polytomous key for the identification of species of the genus (2000)
    Springer
    Hydrobiologia 429 (2000), S. 25-47 
    Details
    ISSN: 1573-5117
    Schlagwort(e): marine nematodes ; Epsilonematidae ; Metepsilonema ; taxonomy ; key to species
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Four new species of Metepsilonema are described from sublittoral stations from the Channel and are mainly characterized: M. volutum sp.nov. by the large body size for the genus up to 460 μm, 118–121 well overlapping annuli and wide multispiral amphids; M. amphidoxum sp.nov. by 127–133 shortly overlapping annuli and sexual dimorphism in amphid size; M. comptum sp.nov. by 133–140 non-overlapping annuli, anteriormost annuli provided with a wide lumen and borders ornamented with ridges and M. corrugatum sp.nov. by 108–111 overlapping annuli provided with ridges). Additional information is provided for M. callosum together with a discussion on intraspecific variability. A new species of Metepsilonema spec. based on females only, is described but remain unnamed. M. comptum sp.nov. and M. corrugatum sp.nov. are also occurring in the Mediterranean Sea. A polytomous key to species level is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003975425673
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  • 46
    Digitale Medien
    Digitale Medien
    The freeliving nematode genus Parodontophora Timm 1963 (Nematoda: Axonolaimidae) is not exclusively marine: Parodontophora limnophila sp. nov. from freshwater in China (2000)
    Springer
    Hydrobiologia 431 (2000), S. 205-210 
    Details
    ISSN: 1573-5117
    Schlagwort(e): China ; freshwater ; Nematoda ; new species ; Parodontophora ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Parodontophora limnophila sp. nov. is described from Poyang Lake, the largest freshwater lake of China. It is characterized by having an amphid with its posterior end close to the base of the stoma, relatively short cephalic setae, opisthocephalic setae arranged as two subdorsal groups of three longitudinally arranged setae and two single subventral setae, excretory pore at the level of the anterior part of the stoma and renette gland 34–47% of the oesophageal length. To date, the new species is the only Parodontophora species found in freshwater habitats.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004052531906
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  • 47
    Digitale Medien
    Digitale Medien
    Morariopsis dumonti n.sp. (Crustacea: Copepoda: Harpacticoida) – a new species from an unsaturated karstic zone in Slovenia (2000)
    Springer
    Hydrobiologia 436 (2000), S. 73-80 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Harpacticoida ; ground water ; interstitial ; taxonomy ; Slovenia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Morariopsishas a disjunct distribution. It has been found in south-eastern Europe and in the Baikal region in Russia. In Europe two species are known, both from the Dinaric region. They have been found in three caves only, but always in puddles filled with percolating water. This indicates that they inhabit an unsaturated karstic environment. A third species, Morariopsis dumontin.sp has now been found, in the same type of habitat, on several dates, in a small cave in central Slovenia. Males were recorded for the first time in this genus. The new species is related to Morariospsis kieferiPetkovski, 1959 from Dalmatia. The main differences are in the ornamentation of the furca and of the abdominal segments. P5 and particularly endopodite of P4 in males suggest a close relation between Morariaand Morariopsis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026585820968
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  • 48
    Digitale Medien
    Digitale Medien
    Parastenocaris andreji n. sp. (Crustacea; Copepoda) – the first record of the genus in Slovenia (SE Europe) (2000)
    Springer
    Hydrobiologia 437 (2000), S. 235-239 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Harpacticoida ; ground water ; interstitial ; taxonomy ; Slovenia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Parastenocaris andreji n. sp. was found in ground water in a northwestern part of Slovenia (southern part of Central Europe). Two adult females of the new species were filtered out of 20 000 l of water during examination of an aquifer for water supply. The bore well was 10 m deep. The aquifer is fed by rainwater and probably only occasionally from a nearby alpine river Sava. The new species differs markedly from other known species of the genus by shape and armature of furcal rami, very long and slim maxillae and some characters on endopodites P2–P5. The closest related species are probably Parastenocaris nolliKiefer, 1938 with subspecies P. nolli alpinaKiefer, 1960, P. gertrudae Kiefer, 1968 and P. austriacaKiefer, 1976.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026513917821
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  • 49
    Digitale Medien
    Digitale Medien
    Thermotolerant fungi erroneously reported in applied research work as possessing thermophilic attributes (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 869-880 
    Details
    ISSN: 1573-0972
    Schlagwort(e): Biotechnology ; ecology ; fungi ; nomenclature ; synopsis ; taxonomy ; thermophilic ; thermotolerant
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract In applied research work dealing with heat-tolerant fungi, currently classified into two groups: namely thermotolerants and thermophiles, information on levels of thermotolerance is generally scant. Cited binomials are often referred to as representatives of thermophilic taxa. The present contribution attempts to specify proper heat-tolerance levels of species cited in biotechnological papers of academic and applied research types published in the last four decades. This assessment integrates relevant available information concerning well defined thermotolerant taxa. Distinction between both groups of heat-tolerant fungi is a mean to optimize investigations of temperature-dependent physiological processes. The nomenclatural status of the binomials retrieved was also re-appraised following the International Code of Botanical Nomenclature. Articles of the code govern the legal validity of fungal names. The goal is to deter `ghost names' that have no status of any kind. Their use in the literature is not only a source of confusion but also hinders the preparation of sound reviews and reference documents. The intention was also to detect names which do not fulfill all criteria for a valid legal publication. Their status could then be validated if the taxonomic position of the fungus justifies this procedure. The taxonomic status of these thermotolerants was also re-examined following present-day knowledge of their respective genera. Integration of warranted taxonomic decisions in the literature of applied research is crucial. These decisions consider the status of a fungus as a valid species (proposed synonymies) or the nature of its generic affinities (name change). Strict application of these decisions severly reduces levels of heterogeneity regarding names used for the same organism. It also clarifies its generic affinities with other thermotolerant fungi. The present note is not an exhaustive assessment on the nomenclatural and taxonomic positions of known thermotolerant fungi, an ecological group for which a global document remains to be produced. It only deals with those taxa most commonly cited in the literature examined. Over 130 fungi are here considered. The group manifests a diversity of taxonomic characters since it includes members of the following systematic groupings: Oomycetes, Zygomycetes, Ascomycetes, anamorphic fungi and Holobasidiomycetes. Few new taxonomic synonyms and invalid binomials are introduced in the present contribution. The former concern the following taxa: Gilmaniella thermophila, Mucor thermoaerospora, Sporotrichum lignicola and Zalerion thermophylii. Three binomials proved to have no taxonomic status of any sort: Acremonium cellulophilum, Nodulisporium microsporum and N. thermoroseum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008979123304
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  • 50
    Digitale Medien
    Digitale Medien
    Young children's partitioning strategies (2000)
    Springer
    Educational studies in mathematics 43 (2000), S. 191-221 
    Details
    ISSN: 1573-0816
    Schlagwort(e): analog objects ; children's informal knowledge ; conceptual mapping ; fair shares ; partitive quotient fraction construct ; partitioning tasks ; partitioning strategies ; quantification ; taxonomy ; teaching interventions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Mathematik
    Notizen: Abstract Taxonomies for classifying children's partitioning strategies have generally focused on the contexts in which the strategies occur and whether the strategies generate fair shares. Therefore, the overall aim of this study was to increase our knowledge about young children's partitioning strategies by setting out not only to identify new partitioning strategies but also to develop a taxonomy for classifying young children's partitioning strategies in terms of their ability to facilitate the abstraction of the partitive quotient fraction construct from the concrete activity of partitioning objects and/or sets of objects. Clinical interviews were conducted with twelve purposely-selected Year Three students. Each student was presented with a unique set of realistic partitioning tasks. The paper concludes with a taxonomy for: (i) qualitatively evaluating a child's progress towards the abstraction of the partitive quotient fraction construct, and (ii) planning and implementing teaching interventions commensurate with the child's level of progress towards the abstraction of the partitive quotient fraction construct. This taxonomy provides researchers and teachers with means of better utilising children's informal partitioning strategies as the foundation upon which to further develop their understandings of the partitive quotient fraction construct.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1017513716026
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  • 51
    Digitale Medien
    Digitale Medien
    Pichia sporocuriosa sp. nov., a new yeast isolated from rambutan (2000)
    Springer
    Antonie van Leeuwenhoek 77 (2000), S. 37-42 
    Details
    ISSN: 1572-9699
    Schlagwort(e): new yeast species ; Pichia sporocuriosa ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A strain of a hitherto undescribed yeast species with a unique ascospore morphology was isolated from rambutan (Nephelium lappaceum). A description of the new species, Pichia sporocuriosa, is given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002095523955
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  • 52
    Digitale Medien
    Digitale Medien
    Phylogenetic analysis of Bacillus subtilis and related taxa based on partial gyrA gene sequences (2000)
    Springer
    Antonie van Leeuwenhoek 78 (2000), S. 123-127 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Bacillus subtilis ; gyrA ; phylogeny ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Partial gyrA sequences were determined for twelve strains belonging to Bacillus amyloliquefaciens, B. atrophaeus, B. licheniformis, B. mojavensis,B. subtilis subsp. subtilis, B. subtilissubsp. spizizenii and B. vallismortis. The average nucleotide and translated amino acid similarities for the seven type strains were 83.7 and 95.1%, respectively, whereas the corresponding value for the 16S rRNA sequences was 99.1%. All of the type strains were sharply separated; the closest relationship was found between B. atrophaeus and B. mojavensis which shared a nucleotide similarity of 95.8%. Phylogenetic trees were inferred from gyrA nucleotide sequences using the neighbor-joining, Fitch–Margoliash and maximum parsimony algorithms. The test strains were divided into four groups, which generally reflected results previously reported in restriction digest and DNA-DNA hybridization studies. It is concluded from the comparative sequence analysis that the gyrA sequences provide a firm framework for the rapid and accurate classification and identification of Bacillus subtilis and related taxa.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1026555830014
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  • 53
    Digitale Medien
    Digitale Medien
    Re-examination of some species of the genus Geotrichum Link: Fr (2000)
    Springer
    Antonie van Leeuwenhoek 77 (2000), S. 71-81 
    Details
    ISSN: 1572-9699
    Schlagwort(e): DNA heterogeneity ; genome comparison ; Geotrichum ; taxonomy ; yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The nutritional physiology and the growth rate of thirty-four strains representing species of Geotrichum without known teleomorph states were examined. From twenty-seven strains the mol% G+C were calculated from the DNA melting curves. The first derivatives of the melting curves of seven strains, including the type strain of Geotrichum clavatum, demonstrated the presence of two peaks, 12% away from each other; the remaining strains showed only a single broad peak. DNA homology values among strains of the former group were high, indicating their conspecificity. The strains of the latter group could be subdivided into six DNA homology groups, four of which could be identified with recognized species and two may represent novel taxa. A combined key of Geotrichum and its teleomorph states Galactomyces and Dipodascus is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002030518989
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  • 54
    Digitale Medien
    Digitale Medien
    Species of the genus Psoroptes (Acari: Psoroptidae): A taxonomic consideration (2000)
    Springer
    Experimental and applied acarology 24 (2000), S. 213-225 
    Details
    ISSN: 1572-9702
    Schlagwort(e): Psoroptes ; taxonomy ; species differentiation ; phenotype ; genotype
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The biosystematic status of mite species belonging to the genus Psoroptes Gervais, 1841 is difficult to determine by phenotypic methods and has been subject to taxonomic revisions and ongoing debate. At present, the existence of five species, P. cuniculi (Delafond, 1859), P. ovis (Hering, 1838), P. equi (Hering, 1838), P. cervinus Ward, 1915 and P. natalensis Hirst, 1919, is generally accepted. This classification is based mainly on the host species, the localization of the mites on their hosts and morphological characters of male mites. However, a critical review of the literature indicates that the features used to discriminate between the five species are not unequivocal: (a) the localization of mite populations on host animals is not completely strict, (b) the lengths of the outer opisthosomal setae of male mites, which are the main morphological features used for species discrimination, overlap between the five postulated species, and (c) host specificity cannot be deduced from results of transfer experiments. Rather, conspecificity of the members of the genus Psoroptes has to be presumed which is supported by molecular genetic analyses. On these grounds and on rules of priority P. cervinus Ward, 1915, P. cuniculi (Delafond, 1859), P. natalensis Hirst, 1919 and P. ovis (Hering, 1838) are seen as synonyms of P. equi (Hering, 1838).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1006443722815
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  • 55
    Digitale Medien
    Digitale Medien
    Emendation of the basidiomycetous yeast genus Kondoa and the description of Kondoa aeria sp. nov (2000)
    Springer
    Antonie van Leeuwenhoek 77 (2000), S. 293-302 
    Details
    ISSN: 1572-9699
    Schlagwort(e): Basidiomycetous yeasts ; Kondoa aeria sp. nov. ; ribosomal DNA sequencing ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Kondoa Y. Yamada, Nakagawa & Banno was erected to accommodate a single taxon, K. malvinella (Fell & Hunter) Y. Yamada, Nakagawa & Banno, which was transferred from the teliospore-forming genus Rhodosporidium Banno based on pronounced differences in the 5S and 26S ribosomal RNA (rRNA) nucleotide sequences to R. toruloides Banno. In contrast with the original description, reinvestigation of K. malvinella revealed the formation of transversely septate (auricularioid) basidia that did not arise on teliospores, but formed directly on the dikaryotic mycelium. The four-celled basidia developed sterigmata on which forcibly discharged asymmetric basidiospores (ballistospores) were produced. Additionally, a new taxon emerged from the study of recent isolates, for which the name K. aeria sp. nov. is proposed. This new species produced two-celled auricularioid basidia on hyphae with incomplete clamp connections. Ballistospores arose on the basidia at the tip of sterigmata and, after ejection, germinated by budding. These observations led us to present an emended diagnosis for the genus Kondoa. Analysis of the sequence data from the D1/D2 region of the 26S rRNA gene showed a very close resemblance between K. aeria and K. malvinella in a cluster that also contained several Bensingtonia species. Taxa in this cluster share specific physiological traits and produce characteristic pinkish-cream to mauve colonies; in contrast, formation of ballistoconidia is only observed in the Bensingtonia species. Sequence data supported placement of K. malvinella and K. aeria in the `Agaricostilbum clade' of the Urediniomycetes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1002453628455
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  • 56
    Digitale Medien
    Digitale Medien
    An information retrieval system for VIR's herbarium, St. Petersburg, Russia, as a tool for cultivated plant research (2000)
    Springer
    Genetic resources and crop evolution 47 (2000), S. 147-152 
    Details
    ISSN: 1573-5109
    Schlagwort(e): cultivated plants ; databases ; herbarium ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The herbarium collection of the N.I. Vavilov Institute of Plant Industry (WIR) contains specimens of cultivated plants, their wild relatives and weedy plants and provides ample opportunities for research. It is a unique special herbarium collection and one of those rare collections having a card index (catalog). For the catalog to be functional, it should reflect the current changes in the taxa names. Only a computerized card file may meet this requirement. The creation of a database for VIR's herbarium was launched in 1995. VIR is carrying out a range of work necessary for providing a wider access to its herbarium and related information for the international scientific community.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008762024513
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  • 57
    Digitale Medien
    Digitale Medien
    Population diversity of the Vicia sativa agg. (Fabaceae) in the flora of the former USSR deduced from RAPD and seed protein analyses (2000)
    Springer
    Genetic resources and crop evolution 47 (2000), S. 171-183 
    Details
    ISSN: 1573-5109
    Schlagwort(e): evolution ; genetic resources ; RAPDs ; seed protein electrophoresis ; taxonomy ; Vicia
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
    Notizen: Abstract The genetic diversity of 58 wild and weedy populations representing taxa within the V. sativa aggregate from the former USSR, 4 cultivars of V. sativa, 2 accessions of V. cordata and 3 accessions of V. macrocarpa from Mediterranean countries were analysed using randomly amplified DNA fragments (RAPDs) and seed protein electrophoresis (SDS-PAGE). Interspecific variation between taxa in the V. sativa aggregate could readily be detected using both techniques. RAPDs and seed protein patterns were found to be an effective means of identifying accessions that cannot be identified clearly by morphological criteria alone. RAPD and seed protein analysis revealed a clear relationship between observed genetic variation of populations and their geographical distribution. Populations from each region had their own gene pools. Geographical variation was detected in V. segetalis. The degree of genetic divergence between local populations was usually related to proximity. In several locations where wild and weedy populations of different V. sativa agg. taxa grow sympatrically, intermediate forms could be detected at the DNA and protein levels. Both RAPD and seed protein analysis support the view that the V. sativa aggregate consists of 8 taxa warranting recognition at the species level. Several species in this aggregate are evolving intra-specific groups which can readily be detected at the molecular level.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008756420011
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  • 58
    Digitale Medien
    Digitale Medien
    The contributions of Ulrich K. Einsle to the taxonomy of the copepoda (2000)
    Springer
    Hydrobiologia 417 (2000), S. 1-10 
    Details
    ISSN: 1573-5117
    Schlagwort(e): taxonomy ; copepods ; Einsle ; chromatin diminution ; enzyme electrophoresis ; Cyclops
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003806912364
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  • 59
    Digitale Medien
    Digitale Medien
    Three species of Tobrilidae (Nematoda: Enoplida) from Li River at Guiling, China (2000)
    Springer
    Hydrobiologia 421 (2000), S. 77-90 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Tobrilidae ; new record ; Nematoda ; taxonomy ; China
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Eutobrilus annetteae Joubert & Heyns, 1979 with its male reported for the first time, Semitobrilus pellucidus (Bastian, 1865) Tsalolichin, 1983, and Epitobrilus allophysis(Steiner, 1919) Tsalolichin, 1996 are described from the Li River at Guiling, China. The male of Eutobrilus annetteae is characterized by lots of crystalloids inside body, almost straight spicules about one anal body diameter long and seven equally sized supplements. Semitobrilus pellucidus from Guiling shows large variation in body width, position of amphids, form of buccal cavity, distance between denticles, direction of vagina, arrangement of oocytes, and shape of eggs. It is different from other populations in its shorter cephalic setae, less than 60% of head width, in its shorter tail and smaller c′ value. In males, there are 6–9 supplements, reduced and irregulary spaced. Epitobrilus allophysisis characterized by its labial setae longer than 50% of head width, small, posteriorly located ovoid amphid, single egg occupying whole space of uterus and blunt tail tip.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003981807711
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  • 60
    Digitale Medien
    Digitale Medien
    Subgeneric differentiation within Kurzia (Crustacea: Anomopoda: Chydoridae) and a new species from Central America (2000)
    Springer
    Hydrobiologia 421 (2000), S. 165-178 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Kurzia ; Crustacea ; Anomopoda ; Chydoridae ; taxonomy ; distribution ; Cladocera
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The genus Kurzia is divided into two subgenera: Kurzia s. str. and Rostrokurzia n. subg. Subgenus Kurzia includes Kurzia (K.) latissima Kurz, 1874, with a palearctic -, Kurzia (K.) polyspina n. sp. with a neotropic - , and Kurzia (K.) cf. media (Birge, 1879) with a nearctic distribution. Rostrokurzia includes Kurzia (R.) longirostris Daday, 1898 (pantropical distribution), and Kurzia (R.) brevilabris Rajapaksa & Fernando, 1986, from subtropical and tropical Asia. Kurzia latissima Kurz, 1874, from Central Europe is redescribed in detail.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003919712255
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  • 61
    Digitale Medien
    Digitale Medien
    New and little known Nematodes (Monhysteroida, Nematoda) from the Strait of Magellan and the Beagle Channel (Chile) (2000)
    Springer
    Hydrobiologia 429 (2000), S. 9-23 
    Details
    ISSN: 1573-5117
    Schlagwort(e): taxonomy ; marine nematodes ; Sabatieria ; Metacomesoma ; Paramonhystera ; Siphonolaimus ; the Strait of Magellan ; Chile
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Six species of Monhysteroida are described from the Strait of Magellan and the Beagle Channel, Chile. Three species of which, Sabatieria heipi n. sp., Paramonhystera geraerti n. sp. and Siphonolaimus smetti n. sp., are new to science. Sabatieria heipi n. sp. is characterised by a body length of 1529–1934 μm, cuticle punctuations with lateral differentiation; cephalic setae 5 μm long, amphids spiral with 4.0–4.2 turns, 10–11 μm in diameter; spicules 76 μm (2.1 anal body diameter), with a 6 μm projection in the ventral distal extremity, 11 minute precloacal supplements; tail 3.7–4.7 anal body diameter (abd) long with enlarged tip. Paramonhystera geraerti n. sp. is characterised by a body size of 705–767 μm; head diameter 12 μm, the cephalic setae 6 μm; amphids circular, 9–10 μm in diameter; spicules slender 108–116 μm (5.6 abd) long, 5 precloacal supplements; and tail 4.0–5.2 abd. Siphonolaimus smetti n. sp. is characterised by the long spear (40–45 μm), head diameter 11–12 μm, amphids circular, 12–13 μm in diameter or 50–57% of corresponding body diameter; the spicules 55 μm and 1.5 abd; tail conical, 2.8 abd (males) and 4.0 abd (females) long. Three other species, i.e. Metacomesoma cyatholaimoides Wieser, 1954, Paramonhystera biforma Wieser, 1956 and P. megacephala (Steiner, 1916) are redescribed. A key of all known species of Paramonhystera is proposed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1003995005971
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  • 62
    Digitale Medien
    Digitale Medien
    Two new species of Mesocyclops from southern China and notes on the genus Mesocyclops in China (2000)
    Springer
    Hydrobiologia 429 (2000), S. 115-131 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Mesocyclops mariae n.sp. ; Mesocyclops shenzhenensis n. sp. ; Guangxi ; Guangdong ; China ; taxonomy ; distribution
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two new Mesocyclops species, M. mariae n. sp. and M. shenzhenensisn. sp., are described from southern China, the former species from Guangxi province, the latter from Guangdong province. Both species have setules on the medial margin of the caudal rami. Compared with each other, there are some conspicuous differences, such as the spinule pattern of the antenna basipodite, the structure of receptaculum seminis, the armature of coxopodite and basipodite of P4 and the armature of the caudal rami. The paper also compares the two new species with their supposedly closest relatives, M. pseudospinosus Dussart & Fernando, 1988, M. leuckarti(Claus, 1857) and M. pehpeiensisHu, 1943. In addition, other species of Mesocyclops in China are discussed and a key to 10 Chinese species of Mesocyclops is provided.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004028731322
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  • 63
    Digitale Medien
    Digitale Medien
    A review on the occurrence and taxonomy of heterotrophic protists in extreme acidic environments of pH values ≤ 3 (2000)
    Springer
    Hydrobiologia 433 (2000), S. 153-156 
    Details
    ISSN: 1573-5117
    Schlagwort(e): acid ; taxonomy ; protists ; ciliate ; flagellate
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The occurrence and some important taxonomic problems of heterotrophic protists from extremely acidic (pH ≤3) environments are briefly discussed. Almost all information on the occurrence of heterotrophic protists from extremely acidic environments is restricted to acid mine drainage (AMD) or streams influenced by AMD. Most of the information is provided for ciliates. Very little information is available on the occurrence of flagellates, rhizopods and heliozoa in this environment. Within the ciliates Urotricha, Vorticella and Oxytricha dominate in acidic mining lakes. Actinophrys sp. is the most important heliozoan in these environments. There are many taxonomic problems which are not solved so far. Live observations and taxonomic methods adapted to the extreme chemical matrix are necessary for correct identification.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004039309694
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  • 64
    Digitale Medien
    Digitale Medien
    Taxonomic re-evaluation of Aphanizomenon flos-aquae NH-5 based on morphology and 16S rRNA gene sequences (2000)
    Springer
    Hydrobiologia 438 (2000), S. 99-105 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Aphanizomenon ; Cyanobacteria ; 16S rRNA ; morphology ; sequences ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The taxonomy of Aphanizomenon flos-aquae strain NH-5, a producer of cyanotoxins, was re-evaluated by comparison with six other Aphanizomenon strains using morphological characteristics and 16S rRNA gene sequences. Strain NH-5 was concluded to be improperly identified as Aph. flos-aquae based upon (1) lack of bundle formation in the trichomes, (2) location of akinetes next to heterocytes, (3) lower similarities (less than 97.5%) in the 16S rRNA gene sequences relative to Aph. flos-aquae strains, and (4) comparison within a phylogenetic tree constructed from 16S rRNA gene sequences. The Aphanizomenon strains investigated in this study are classified to four morphological groups as described by the classical taxonomy of Komárek & Kovácik (1989). This classification was supported from the phylogenetic results of 16S rRNA gene sequences. This study also discusses the generic boundaries between Aphanizomenon and Anabaena.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004166029866
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  • 65
    Digitale Medien
    Digitale Medien
    Morphological variation of four planktic nostocalean cyanophytes – members of the genus Aphanizomenon or Anabaena? (2000)
    Springer
    Hydrobiologia 438 (2000), S. 107-116 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Cyanophyta/Cyanobacteria ; Aphanizomenon ; Anabaena ; taxonomy ; morphology of trichomes ; heterocytes and akinetes ; Slovakia ; Austria
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Morphological variation of trichomes, heterocytes and akinetes in four species classified into the nostocalean genera Aphanizomenon Morren ex Bornet et Flahault or Anabaena Bory (Cyanophyta/Cyanobacteria) was studied from natural samples by LM and illustrated by drawings and micrographs. All investigated species, Aphanizomenon gracile (Lemmerm.) Lemmerm., A. aphanizomenoides (Forti) Komárek et Horecká, Anabaena bergii Ostenfeld, A. minderi Huber-Pestalozzi, occur in the plankton as solitary trichomes, similar to many representatives of the genus Anabaena. Main generic diagnostic characters of Aphanizomenon and Anabaena are discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004118213936
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  • 66
    Digitale Medien
    Digitale Medien
    Taxonomic studies of planktic species of Anabaena based on morphological characteristics in cultured strains (2000)
    Springer
    Hydrobiologia 438 (2000), S. 117-138 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Anabaena ; cyanobacteria ; identification ; morphology ; planktic ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Fifty (50) strains of planktic species of Anabaena (cyanobacteria), including collections from Japan and China and from different culture collections, were induced to form akinetes at low temperature (15 °C). Their morphologies were then observed and described. Fourty seven strains successfully formed akinetes and these were classified into 20 species comprising seven with straight trichomes and 13 with coiled trichomes. Three strains, which did not form akinetes, were separated into two taxonomic groups, but could not be identified to any described species. In addition, a key to the planktic species of Anabaena described in the study is presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004170230774
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  • 67
    Digitale Medien
    Digitale Medien
    The taxonomic position of Cyanidium, Cyanidioschyzon and Galdieria: an update (2000)
    Springer
    Hydrobiologia 433 (2000), S. 137-143 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Cyanidium caldarium ; Cyanidioschyzon merolae ; Galdieria sulphuraria ; taxonomy ; acidophily
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ecophysiological, cytomorphological, biochemical and molecular data presently available for the acidophilic red algal species Cyanidium caldarium, Cyanidioschyzon merolae and Galdieria sulphuraria are summarised. The taxonomic position of the three genera is discussed and emendements to the generic diagnosis are presented.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004031123806
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  • 68
    Digitale Medien
    Digitale Medien
    Molecular variation in Galdieria sulphuraria (Galdieri) Merola and its bearing on taxonomy (2000)
    Springer
    Hydrobiologia 433 (2000), S. 145-151 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Cyanidium caldarium ; Cyanidioschyzon merolae ; Galdieria sulphuraria ; rbcL ; taxonomy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cyanidium caldarium, Cyanidioschyzon merolae and Galdieria sulphuraria are three unicellular algae characteristic, of acid thermal environments. Recently, on the basis of morphological characters, three new species of Galdieria (G. partita, G. daedala, G. maxima ) isolated from acid-thermal springs in Russia have been instituted. A selected region of rbcL and the sequence of the intergenic spacer between the rbcL and rbcS have been amplified and sequenced from different Galdieria species and strains, in order to define molecular relationship among these interesting algae. The obtained cladogram shows that Cyanidium caldarium and Cyanidioschyzon merolae form a sister group which, in turn, is in a sister group relationship with Galdieria. This last genus is divided in two clades, one of which includes G. sulphuraria accessions from Naples (Italy), California, and Yellowstone and the other one includes G. sulphuraria accessions from Java (Indonesia) and from the Russian species. These results support the status of the genus Galdieria and suggest that G. daedala, G. maxima and G. partita are three very similar strains of G. sulphuraria; the rbcL variation within Galdieria accessions has a pattern which is broadly connected to the geographial distribution. The data obtained from the intergenic rbcL-rbcS spacer partly confirm those from the rbcL analysis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004035224715
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  • 69
    Digitale Medien
    Digitale Medien
    Karualona n.gen. (Anomopoda: Chydoridae), with a description of two new species, and a key to all known species (2000)
    Springer
    Hydrobiologia 435 (2000), S. 61-82 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Chydoridae ; Anomopoda ; taxonomy ; Karualona ; trunk limbs
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The species group of Alona karua is raised to generic rank and named Karualona. The genus is defined on the basis of a number of characters of the body and its appendages. Tentative new microcharacters are introduced, related to the type and length of selected setae of P1, P2, P3 and P4. Two new species are described, one from the island of Socotra and one from Mexico. A key to the five currently recognized species is given.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004006521874
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  • 70
    Digitale Medien
    Digitale Medien
    Several new and known species from the families Coninckiidae and Comesomatidae (Nematoda) in the White Sea (2000)
    Springer
    Hydrobiologia 435 (2000), S. 43-59 
    Details
    ISSN: 1573-5117
    Schlagwort(e): Nematoda ; Coninckiidae ; Comesomatidae ; White Sea ; taxonomy ; descriptions
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Ten new and known species of the genera Coninckia, Cervonema, Laimella and Sabatieria are described from the White Sea. Coninckia macroseta sp. n. resembles C. seta Wieser et Hopper, 1967 (Florida coast of U.S.A.) in shape of the amphid and other characters, but differs from the latter by greater body length (2399 μm versus 1300–1400 μm) and by the a-index (83 versus and a 57–58). Cervonema proximamphidum sp. n. differs from all other species of Cervonema by the shape of posterior widening of the pharynx (except for C. allometricum Wieser, 1954 whose original description is too brief). The pharynx of the new species forms posteriorly a conical widening with vague radial striation, whereas the pharynx of other Cervonema species presents posteriorly an oval or elongate thickening with wavy contour and distinct muscular transversal striation. The other diagnostic characters of Cervonema proximamphidum sp. n. are close position of the amphid to the anterior end (distance from the anterior end to the amphid 6–7.5 μm), longer outer labial and cephalic setae (5–5.5 μm), relatively longer and slender body (respectively, 1423–1563 μm and a=30.9–41.1). Specimens Cervonema minutus Muthumbi, Soetaert et Vincx, 1997 largely agree with the original description of Muthumbi et al. (1997) based on the nematodes sampled in the Indian Ocean deep sea; only cephalic setae length (2.7–3.5 versus 2 μm) differ. The White Sea specimens Laimella filipjevi coincide well with the description of Jensen (1979) made on nematodes from the western Baltic Sea, except slight difference in body length (1564–1837 μm versus 1086–1152 μm). Sabatieria kolaensis (Ssaweljev, 1912) is redescribed and restored as valid species. Sabatieria kolaensis was assigned by Platt (1985) to the list of dubious species because of very brief original description lacking some important details. Sabatieria kolaensis belongs to the S. praedatrix species group and is characterized by the greatest number of preanal supplements (31–40). Sabatieria lawsi Platt, 1983 was previously known from the only Antarctic Peninsula shelf; the single White Sea male specimen corresponds well to the original diagnosis of Platt (1983). Sabatieria lawsi is considered to be very close or near identical to S. praedatrix de Man, 1907. The species Sabatieria longispinosa Lorenzen, 1972, S. ornata (Ditlevsen, 1918), S. pulchra (G. Schneider, 1906) and S. strigosa Lorenzen, 1972 are also described and discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1004070919109
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  • 71
    Digitale Medien
    Digitale Medien
    Middle pleistocene humans from africa (2000)
    Springer
    Human evolution 15 (2000), S. 63-74 
    Details
    ISSN: 1824-310X
    Schlagwort(e): comparative anatomy ; taxonomy ; species ; Homo erectus ; Homo heidelbergensis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Patterns of human evolution in the Middle Pleistocene remain poorly understood. There is general consensus that by the onset of this time period, populations ofHomo erectus were dispersed from Africa into Eurasia, including the Far East. In the western part of this range (perhaps in Africa),Homo erectus then produced a daughter lineage exhibiting more advanced characters of the face, braincase and cranial base. How this new species should be defined is currently debated. In my view, fossils from sites such as Bodo and Broken Hill in Africa may be lumped with material from earlier Middle Pleistocene localities in Europe. Such a taxon is appropriately namedHomo heidelbergensis. Whether the hypodigm should be extended to include fossils from China is another question. In any case, this group of hominids is plausibly ancestral to both the specialized Neanderthals of Europe and more modern humans of the later Middle Pleistocene.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02436235
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  • 72
    Digitale Medien
    Digitale Medien
    Thermophilic fungi and applied research: a synopsis of name changes and synonymies (2000)
    Springer
    World journal of microbiology and biotechnology 16 (2000), S. 881-888 
    Details
    ISSN: 1573-0972
    Schlagwort(e): Biotechnology ; ecology ; fungi ; nomenclature ; status ; synopsis ; taxonomy ; thermophile
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract The present synopsis reports on taxonomic decisions and name changes introduced in the last decades for a number of thermophilic fungi. Taxa dealt with are those most commonly cited in the literature of fundamental and applied work or concern species having complex taxonomic histories. The definition of a thermophile follows the classificatory scheme elaborated by Cooney & Emerson in 1964. The synopsis provides the latest legal valid names for several thermophiles. Binomials of accepted synonymies are also reported with arguments in favour of these taxonomic decisions. The material of this contribution is a synthetic simplified account of two previous reviews on the taxonomy of thermophilic fungi. The present document aims: (1) to suppress the use of ghost binomials having no status of any kind; (2) to favour the continuous use of the latest legal valid name of a taxon to avoid cases of redundancies by citing binomials of known synonyms. Homogeneity in cited names is a fundamental prerequisite for comparative studies. The synopsis is thus a sound tool for future critical reviews of ecological and of biotechnological interests. The status of over a hundred names are here reviewed. Two additional new synonyms are proposed; these concern Mucor miehei var. minor and Sporotrichum cellulophilum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1023/A:1008970306466
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  • 73
    Digitale Medien
    Digitale Medien
    Time-related changes in the ultrastructure of osteoclasts after injection of parathyroid hormone in young rats (1979)
    Springer
    Calcified tissue international 27 (1979), S. 129-135 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Parathyroid hormone ; Osteoclasts ; Electron microscopy ; Morphometry ; Metaphysis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The effects of parathyroid hormone (PTH) on the size of the osteoclasts, nuclei, ruffled borders, and clear zones in long bones of thyroparathyroidectomized (TPTX) rats were quantitated as a function of time. These data were compared with the number of osteoclasts in the bone and with plasma calcium levels. A significant increase in the average size of the ruffled borders was demonstrated 30 min after injection of 50 U of purified bovine PTH, and of the clear zones 30–90 min after PTH. This was followed at 90 min by an increase in the average size of the cells. The sizes of ruffled borders and clear zones dropped sharply to control levels after 6 h, whereas the size of the cells remained elevated up to 12 h and returned to control values at 24 h. Plasma calcium levels were increased, but not significantly, between 30 min and 6 h. An increase in the number of osteoclasts was significant after 12 h. Removal of the parathyroid glands did not diminish the normal activity of osteoclasts. In animals with intact glands injection of 50 U of PTH did not cause a significant change in cell size or resorbing apparatus. It is concluded that PTH acts to rapidly stimulate the bone resorptive activity of osteoclasts and to cause a delayed increase in their number.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02441175
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  • 74
    Digitale Medien
    Digitale Medien
    Orientation of apatite in single osteon samples as studied by pole figures (1979)
    Springer
    Calcified tissue international 29 (1979), S. 101-105 
    Details
    ISSN: 1432-0827
    Schlagwort(e): Osteon ; X-ray diffraction ; Pole figures ; Electron microscopy ; Calcification
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin , Physik
    Notizen: Summary The X-ray diffraction method based on pole figures has been applied to single osteon samples in order to obtain information about the texture of the inorganic bone fraction and the way it changes during calcification. The osteon samples were cylindrically shaped, with axes corresponding to those of the haversian canals. Selection was carried out according to the degree of calcification and the orientation of collagen bundles and inorganic particles. Osteons at both the initial and final stages of calcification were chosen. Arrangements of fiber bundles and inorganic particles in successive lamellae characteristic of three types of osteons were selected: longitudinal, alternate, and transversal. The results indicate that in all three types of osteons, the long axis of the sample is apparently the only direction of orientation because the transversally oriented crystallites give an isotropic diffuse scattering as would be expected if all the inorganic particles were irregularly oriented around the osteon axis. The number of longitudinally oriented crystallites increases progressively from transversally oriented osteons to alternately and longitudinally oriented ones. The crystallite orientation in an axial direction increases in fully calcified osteons. This last result is in agreement with the electron microscopic finding that the long needle-shaped crystallites covering much more than a major collagen period and measuring 40–45 Å in width increase in number as calcification proceeds.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF02408064
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  • 75
    Digitale Medien
    Digitale Medien
    Acetobacter bacteriophage A-1 (1979)
    Springer
    Archives of microbiology 121 (1979), S. 193-197 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Acetobacter suboxydans ; Bacteriophage A-1 ; Restriction ; Modification ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A bacteriophage ofAcetobacter suboxydans was isolated and found to correspond to type A phage according to Bradley's classification. The phage contains double stranded DNA. The length of the latency period and burst size could not be precisely determined because of apparent non-synchronous release of phage from single infective cycles. The host range was determined using 24 strains ofAcetobacter andGluconobacter species. Evidence for a probable occurence of host determined restriction and modification was obtained withAcetobacter suboxydans strain ATCC 621. The phage is designated A-1 and it is the first one to be reported forAcetobacter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00689986
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  • 76
    Digitale Medien
    Digitale Medien
    Bdellovibrio-like parasite of cyanobacteria symbiotic in marine sponges (1979)
    Springer
    Archives of microbiology 123 (1979), S. 101-103 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Bdellovibrio ; Cyanobacteria ; Marine sponges ; Symbiosis ; Infection ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A bdellovibrio-like bacterium was observed infecting unicellular symbiotic cyanobacteria in two coral reef sponges, Neofibularia irata and Jaspis stellifera. The infecting bacterium, which was located between the cell wall and the cytoplasmic membrane of the cyanobacteria, was similar in size and appearance to previously described bdellovibrios. This observation is believed to extend the host range of the bdellovibrios.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00403507
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  • 77
    Digitale Medien
    Digitale Medien
    Electron microscopic study on the quaternary structure of the isolated particulate alcohol-acetaldehyde dehydrogenase complex and on its identity with the polygonal bodies of Clostridium kluyveri (1979)
    Springer
    Archives of microbiology 120 (1979), S. 255-262 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Alcohol dehydrogenase ; Acetaldehyde dehydrogenase ; Clostridium kluyveri ; Electron microscopy ; Polygonal bodies ; Enzyme complex
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The alcohol-acetaldehyde dehydrogenase complex of Clostridium kluyveri has been separated from contaminating β-hydroxybutyryl-CoA dehydrogenase by repeated precipitation with manganese and ammonium sulfate. Mn++ was required for maximum alcohol dehydrogenase activity. The molecular weight of the enzyme complex was 194,000 as determined by sucrose density gradient centrifugation. The enzyme complex has been shown to contain two types of subunits with molecular weights of 55,000±2,600 and 42,000±1,200, respectively which are arranged in “H”-shaped particles. In solutions with an ionic strength above 25 mM the enzyme complex precipitated in the form of lumps as has been shown with specific ferritin-conjugated antibodies. These lumps are assumed to be aggregated polygonal bodies present in C. kluyveri.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00423073
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  • 78
    Digitale Medien
    Digitale Medien
    R-Bodies in newly isolated free-living hydrogen-oxidizing bacteria (1979)
    Springer
    Archives of microbiology 121 (1979), S. 9-15 
    Details
    ISSN: 1432-072X
    Schlagwort(e): R-Bodies ; Kappa particles ; Free-living hydrogen bacteria ; Induction ; Electron microscopy ; Chemical composition ; Defective prophages ; Plasmids
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract R-Bodies have been found in a recently isolated pseudomonas-like free-living hydrogen oxidizing bacterium. Their isolation, fine structure and chemical composition are described and compared with the R-bodies from the kappa particles (Caedobacter), obligate endosymbionts of Paramecium aurelia. The 2K 1 R-bodies exhibited essential characteristics of the kappa R-bodies; however, their size and some other structural aspects proved that they represent a new type of R-bodies. The presence of phage tail-like particles in cells induced with Mitomycin C is in favour of the hypothesis that the R-bodies might be coded by defective prophages, or by extrachromosomal elements.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00409199
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  • 79
    Digitale Medien
    Digitale Medien
    The cell cycle of Bacillus subtilis as studied by electron microscopy (1979)
    Springer
    Archives of microbiology 123 (1979), S. 173-181 
    Details
    ISSN: 1432-072X
    Schlagwort(e): Bacillus subtilis ; Cell cycle ; DNA replication ; Cell division ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Bacillus subtilis strain Marburg was grown exponentially with a doubling time of 65 min. To follow the time course of various cell cycle events, cells were collected by agar filtration and were then classified according to length. The DNA replication cycle was determined by a quantitative analysis of radioautograms of tritiated thymidine pulse labeled cells. The DNA replication period was found to be 45 min. This period is preceded and followed by periods without DNA synthesis of about 10 min. The morphology and segregation of nucleoplasmic bodies was studied in thin sections. B. subtilis contains two sets of genomes. DNA replication and DNA segregation seem to go hand in hand and DNA segregation is completed shortly after termination of DNA replication. Cell division and cell separation were investigated in whole mount preparations (agar filtration) and in thin sections. Cell division starts about 20 min after cell birth; cell separation starts at about 45 min and before completion of the septum.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00446817
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  • 80
    Digitale Medien
    Digitale Medien
    Distribution and fine structure of the lymphatic system in the human testis (1979)
    Springer
    Cell & tissue research 200 (1979), S. 15-27 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lymph vessels ; Testis ; Man ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of lymph vessels in the human testis was investigated using ink injection methods, and light and electron microscopy. Lymph capillaries occur in the septula testis but are absent in the intertubular tissue. They consist of endothelial cells provided with an incomplete basal lamina and anchoring filaments of the adjacent connective tissue. Frequently, the endothelial cells are separated by gaps measuring up to 2μm. The lymph capillaries of the septula testis are connected to lymph vessels in the rete testis and tunica albuginea. These vessels have occasional smooth muscle cells and valves. At the posterior margin of the testis, the network of lymph vessels merges into collecting ducts, which together with vessels derived from the rete testis are drained by the lymphatic system in the spermatic cord.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236883
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  • 81
    Digitale Medien
    Digitale Medien
    The tanycyte of the rat median eminence (1979)
    Springer
    Cell & tissue research 200 (1979), S. 329-334 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Median eminence ; Axon terminals ; Tanycytes ; Electron microscopy ; Rat
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The present ultrastructural study proves the existence of nerve terminals closely apposed to the plasmalemmata of tanycytes in the rat median eminence. Several of these “axo-tanycytic” endings display remarkable accumulations of agranular endoplasmic reticulum in the form of pleomorphic vesicles which are closely apposed on either side of the plasma membrane of each cell compartment. Some of these vesicular profiles give the impression of structural continuity across both membrane systems. This phenomenon is discussed in the context of being a potential substratum for communication between both cell compartments.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236425
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  • 82
    Digitale Medien
    Digitale Medien
    Are there specialized junctions in the pars maculata of the distal tubule? (1979)
    Springer
    Cell & tissue research 200 (1979), S. 337-344 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Glomerulo-tubular feedback ; Tight junctions ; Macula densa ; Distal tubule ; Electron microscopy ; Freeze fracture ; Horseradish peroxidase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the present study the tight junctions at the macula densa were compared to those of the adjacent straight and convoluted segments of the distal tubule using freeze fracturing and thin sectioning techniques. Only insignificant differences were found in the number of strands and the apico-basal depth of the tight junctions in the three distal tubular segments of rat, dog and tree shrew. In experiments with horseradish peroxidase on mice and tree shrews, the tracer did not penetrate the apical junctions in any of the distal tubular segments. Our findings do not support the concept of considerably higher permeability of the tight junctions at the macula densa, as previously reported. Gap junctions were never observed in the distal nephron. The present results suggest that the glomerulo-tubular feedback is more likely to be mediated by transcellular resorption of solutes than by passive diffusion through a leaky paracellular shunt pathway.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234846
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  • 83
    Digitale Medien
    Digitale Medien
    Ultrastructural morphometry of blastogenesis I: Transformation of small lymphocytes stimulated in vivo with dinitrochlorobenzene (1979)
    Springer
    Cell & tissue research 200 (1979), S. 495-509 
    Details
    ISSN: 1432-0878
    Schlagwort(e): T-lymphocytes ; Blast cells ; Lymph node ; Electron microscopy ; Stereology
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Changes in the volumes and surfaces of subcellular compartments of unstimulated small lymphocytes and immunoblasts in mouse axillary lymph nodes have been established using stereological techniques. Blast transformation was induced in vivo with dinitrochlorobenzene (DNCB). Cell samples were obtained by random sampling regimes applied at light and electron microscopic levels. From electron micrographs the volume densities of euchromatin, heterochromatin, nucleoli, mitochondria, Golgi apparatus and rough endoplasmic reticulum were determined. Cell surface/volume ratios were also computed. By estimating mean nuclear volumes using light microscopy, it was possible to calculate absolute compartmental volumes and to evaluate the plasma membrane surface areas of average cells. Transformation in this model was characterized by a considerable cellular hypertrophy and a substantial increase in plasmalemma surface. Hypertrophy was the consequence of increases in the volumes of all measured intracellular compartments, notably euchromatin and “residual cytoplasm” (including ground cytoplasm and free ribosomes). These changes are discussed in the context of the altered metabolic status of cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234859
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  • 84
    Digitale Medien
    Digitale Medien
    Demonstration of acid phosphatase activity induced by 20-hydroxyecdysone in the fat body of Calliphora (1979)
    Springer
    Cell & tissue research 200 (1979), S. 435-442 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Fat body ; Calliphora ; Electron microscopy ; Cytochemistry ; Ecdysterone
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In the larval fat body of Calliphora erythrocephala, protein accumulation and autophagic activity occur prior to the onset of puparium formation. The involvement of the lysosomal system in the degradation of sequestered protein and cell organelles can be demonstrated by the electron microscopical cytochemical localization of the lysosomal marker enzyme acid phosphatase in so-called protein granules. These granules contain not only newly synthetized or absorbed protein but also remnants of cell organelles such as mitochondria and endoplasmic reticulum. Ligation of the larvae behind the brain-ring gland complex prevents the appearance of these acid phosphatase positive granules. They can be induced in ligated larvae by the injection of 20 hydroxyecdysone into the abdomen. These findings are briefly discussed in relation to the role of moulting hormones in normal development, especially with regard to the induction of autophagic activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234854
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  • 85
    Digitale Medien
    Digitale Medien
    An electron microscopic study of lipid absorption in the pyloric caeca of rainbow trout (Salmo gairdnerii) fed wax ester — rich zooplankton (1979)
    Springer
    Cell & tissue research 200 (1979), S. 475-486 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lipid absorption ; Pyloric caeca ; Electron microscopy ; Feeding experiment ; Rainbow trout
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Rainbow trout were killed 4 and 18 h after being fed wax ester-rich marine Zooplankton and the absorptive epithelium of the pyloric caeca examined by electron microscopy. Numerous osmiophilic drops were seen in the lamina propria underlying the epithelium of fish killed at both times, but these drops were only abundant within columnar epithelial cells of fish killed 4 h after feeding. Pinocytotic profiles were not common at the luminal plasma membranes, nor were osmiophilic droplets seen in the terminal web area between the luminal plasma membrane and the extensive smooth endoplasmic reticulum. Numerous osmiophilic droplets, 30–100 nm in diameter, were present in the cisternae of the smooth endoplasmic reticulum with up to five separate droplets per individual cisterna. Columnar epithelial cells also contained up to 100 large osmiophilic drops (“conglomerates”) which tended to be concentrated in the supranuclear (Golgi) regions. The conglomerates were 250–1200 nm in diameter and were themselves made up of smaller droplets 30–400 nm in diameter. Conglomerates were present both within intracellular membranes and free in the cytoplasm. Osmiophilic droplets in the intercellular spaces and lamina propria were similar in size to individual droplets within conglomerates. We conclude that triacylglycerols are elaborated in the smooth endoplasmic reticulum, transferred to and processed in the Golgi region and finally discharged serosally as chylomicron-like particles of not greater than 400 nm diameter.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234857
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  • 86
    Digitale Medien
    Digitale Medien
    Formation of sarcomeres in the embryonic heart of the lobster (1979)
    Springer
    Cell & tissue research 198 (1979), S. 477-486 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Embryonic heart ; Myogenesis ; Sarcomere ; Crustacea (Homarus americanus) ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Cardiomyoblasts in the myocardium of embryonic lobsters at 3–4 weeks and 6 months of development were examined with the transmission electron microscope in order to describe the events in the formation of sarcomeres in a neurogenic cardiac system. Thick and thin myofilaments appear first in the cell periphery near the sarcolemma. They align in parallel in a sequential fashion to form consecutive sarcomeric units. Well-defined A and I bands appear before any semblance of a Z line is present. The initial sarcomere is anchored to the sarcolemma by the insertion of thin myofilaments into a region of electron dense material associated intimately with the sarcolemma. Myofibrils grow outward in several planes away from the electron-dense regions of membrane that serve as focal points for myofibril formation.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234192
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  • 87
    Digitale Medien
    Digitale Medien
    The effect of L-DOPA on the ultrastructure of the adenohypophysis of the Chinese quail, Excalfactoria chinensis (1979)
    Springer
    Cell & tissue research 198 (1979), S. 521-526 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adenohypophysis ; Electron microscopy ; L-DOPA ; Lysosomes ; Chinese quail, Excalfactoria chinensis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Intraperitoneally injected L-DOPA was found to stimulate strongly the lysosomal system of all of the cell types of the adenohypophysis. We suggest that this amine may play a role in the regulation of the secretory activity of the gland by mediating the lysosomal activity, this role being of variable importance according to the fluctuations in hormonal activity. Ultrastructural changes occur in some cell types following injection of L-DOPA. The question as to whether these changes are induced directly by L-DOPA or via the monoaminergic system of the hypothalamus and its hypophysiotropic hormones is discussed.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234195
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  • 88
    Digitale Medien
    Digitale Medien
    Electron microscopic study of the giant cells in the olfactory bulb of labyrinth fish (Belontiidae, Perciformes) (1979)
    Springer
    Cell & tissue research 199 (1979), S. 509-517 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Olfactory bulb ; Giant cells ; Neurosecretion ; Electron microscopy ; Labyrinth fish
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The giant cells in the olfactory bulb of labyrinth fish, most likely belonging to the nervus terminalis, show ultrastructural features of active synthesis of secretory material. Dense core vesicles (70–100 nm in diameter), found in the perikaryon as well as in the axon, are the possible storage sites of the secretory substance. Its chemical nature is unknown. In some of these vesicles acid phosphatase is demonstrable. Large membrane-bound bodies (up to 2000 nm in diameter), either containing an electron dense matrix or debris of cytoplasmic organelles, are also acid phosphatase-positive, suggesting their lysosomal nature. Some other ultrastructural characteristics of these cells are also described.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236086
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  • 89
    Digitale Medien
    Digitale Medien
    Ultrastructural responses of pancreatic β cells to metabolic alkalosis (1979)
    Springer
    Cell & tissue research 201 (1979), S. 159-163 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Insulin secretion ; Acid-base changes ; Electron microscopy ; Pancreas perfusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The ultrastructural changes in pancreatic β cells were studied following glucose-induced insulin secretion in vitro, at two different extracellular pH (7.4 and 7.8). The pancreata perfused at pH 7.4 exhibited a biphasic insulin response to glucose challenge together with signs of increased emiocytotic activity and numerous microtubules in the β cells. Conversely, the pancreata perfused at pH 7.8 showed a significant decrease in insulin secretion, and their β cells revealed scarce emiocytotic images and a marked increase of intracellular granulolysis. These results represent the ultrastructural correlate of the reduced insulin secretion produced by metabolic alkalosis in the perfused rat pancreas.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238055
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  • 90
    Digitale Medien
    Digitale Medien
    Fine structure of the rabbit adrenal cortex and the effects of short-term ACTH administration (1979)
    Springer
    Cell & tissue research 201 (1979), S. 165-179 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Adrenal cortex ; Steroid release ; Rabbit ; Electron microscopy ; Morphometry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The fine structure of the rabbit adrenal cortex was investigated. The parenchymal cells display the ultrastructural features of steroid-producing cells, and also contain numerous electron-dense bodies frequently located near intercellular canaliculi, which open into the subendothelial space. Short-term ACTH-administration induced a noticeable decrease in the volume of the lipid compartment in the cells of all three cortical zones and a significant increase in the volume of dense bodies in the cells of zona fasciculata and zona reticularis. The hypothesis that these dense bodies are secretory granules is discussed in the light of biochemical evidence showing that ACTH increases the concentration of both corticosterone and cortisol in the decapsulated-enucleated adrenal homogenate and does not affect the activity of two lysosome-marker enzymes (i.e., acid phosphatase and β-glucuronidase).
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00235055
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  • 91
    Digitale Medien
    Digitale Medien
    Spatial distribution of excitatory innervation on a muscle fiber of the lobster (Homarus americanus) (1979)
    Springer
    Cell & tissue research 199 (1979), S. 171-175 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Crustaceans ; Neuromuscular synapse ; Multiterminal innervation ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The distribution of nerve terminals from a single excitatory motor axon has been followed along a fiber from the proximal accessory flexor muscle of the lobster by thin serial sectioning at periodic intervals. The excitatory motor axon provides small axonal branches (diameter 5–12 μm) of varying lengths that travel along the surface of the muscle fiber. Each of these branches gives rise to discrete synaptic terminals which are not uniformly distributed. Individual terminals vary in length from 10–60 μm and the majority possess neuromuscular synapses. The greatest distance between synapses is slightly over 1 mm which is well within the length constant (2.6 mm) of this muscle fiber. Thus the spatial distribution of synapses is such as to ensure adequate depolarization along the entire length of the muscle fiber.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237737
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    Digitale Medien
    Digitale Medien
    Marginal bundles of axoplasmic microtubules at nodes of Ranvier within muscle (1979)
    Springer
    Cell & tissue research 199 (1979), S. 281-288 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Annular microtubules ; Nodes of Ranvier ; Nerve ; Axon ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Using a special albumin technique, nodes of Ranvier have been examined within frog skeletal muscle, sciatic nerve and rat and frog cerebrum. Initial segments have been examined in cerebrum of frog and rat. Microtubules usually run longitudinally through these regions, but within the bare area of the intramuscular node of Ranvier, annular or helical bundles of microtubules run in a marginal band at right angles to the more centrally placed longitudinal microtubules. These nodal bare areas show a pronounced convexity and it is suggested that the annular microtubules serve to maintain this convexity during muscle contraction.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00236139
    Standort Signatur Erwartet Verfügbarkeit
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  • 93
    Digitale Medien
    Digitale Medien
    A new morphological aspect of the brush cells of the mouse gallbladder epithelium (1979)
    Springer
    Cell & tissue research 201 (1979), S. 37-44 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Brush cell ; Receptor ; Lateral microvilli ; Gallbladder ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The brush cells of the gallbladder epithelium of the mouse have microvilli not only at their luminal border but also on their lateral surface, from the level of the nucleus to the junctional complex. The lateral microvilli radiate from the brush cell in all directions, contain a core of filaments, and penetrate up to 3 μm into the adjacent cells. The microvilli in these locations display small desmosomes at their base.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238045
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Fine structure of the monkey epididymis: A correlated thin-section and freeze-cleave study (1979)
    Springer
    Cell & tissue research 201 (1979), S. 451-458 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Epididymis ; Freeze-fracture ; Electron microscopy ; Male reproduction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The epithelium of the monkey epididymis was studied by means of freeze-fracture techniques and conventional electron microscopy. For the study of transepithelial permeability lanthanum hydroxide was used as an intercellular tracer. The epididymal epithelium consists mainly of tall columnar cells. The long stereocilia at the apical surface, similarly to microvilli, exhibit after freeze-fracture, two distinct faces: the E face, concave and with fewer membrane-associated particles, and the complementary convex P face. In the lumen unusual groups of smooth-surfaced vacuoles are present. A tight junctional network, which shows some permeability to the lanthanum tracer, is located at the apical end of the cells. Supranuclear cross-fractures clearly show the well developed Golgi cisternae and numerous vacuole profiles. The highly infolded, centrally located nucleus exhibits, after freeze-fracture, an even distribution of nuclear pores. In the perinuclear region the rough endoplasmic reticulum, which also presents pores, displays a sheet-like organization. The basal cytoplasm is filled by numerous globular profiles of membrane-bounded granules. Freeze-cleave exposes large cytoplasmic areas where the types and amount of organelles indicate an intense metabolic activity.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237003
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    A study of TSH-synthesis of spontaneously hypertensive rats by electron microscopic morphometry and autoradiography (1979)
    Springer
    Cell & tissue research 201 (1979), S. 467-477 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Anterior pituitary ; Hormone synthesis ; Morphometry ; Autoradiography ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary In order to compare the functional state of the anterior pituitary of spontaneously hypertensive rats (SHR) with that of normotensive Wistar Kyoto rats (WKR), the anterior pituitary was examined by morphometry and autoradiography at the level of electron microscopy. The relative number and the relative volume of thyrotrophs in the anterior pituitary were significantly greater in SHR compared with age-matched WKR at 0, 7, 30–33 days, and 10 months of age, while the relative number of somatotrophs in SHR was significantly smaller at 1 and 10 months of age. Electron microscope autoradiographic analysis of uptake of 3H-lysine by thyrotrophs of both strains at the age of approximately one month showed that 3H-lysine was incorporated into protein and transported finally to secretory granules which migrated to near the cell membrane to be discharged. Silver grains were significantly more numerous over the thyrotrophs of SHR than over those of WKR at 30 min, 1 h, and 4h after the injection of 3H-lysine. The present study has ascertained morphologically that a congenital hypersynthesis of TSH by the anterior pituitary occurs in SHR.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237005
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Digitale Medien
    Digitale Medien
    An ultrastructural study of macrophage-mediated resorption of calcified tissue (1979)
    Springer
    Cell & tissue research 202 (1979), S. 125-132 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Macrophage ; Osteoclast ; Bone resorption ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Ultrastructural observations on macrophage-mediated resorption of calcified tissue of killed fetal long bones are described and correlated with increased 45Ca release into the medium. Macrophages disrupt calcified tissue extracellularly and appear to engulf large fragments of mineralized matrix. Ruffled borders, which are common features of osteoclasts at sites of resorption of bone, do not develop in macrophages. However, clear zones are seen in macrophages as well as osteoclasts. These findings provide additional evidence for non-osteoclast-mediated resorption of calcified tissue.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00239225
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Activation of human T-lymphocytes (1979)
    Springer
    Cell & tissue research 201 (1979), S. 101-127 
    Details
    ISSN: 1432-0878
    Schlagwort(e): T-lymphocytes ; Cell activation ; Stereology ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Stereological data of phytohaemagglutinin (PHA)-activated human T-lymphocytes were recorded at intervals (12 to 72 h) together with biochemical (isotope-uptake, lymphotoxin-release) and morphological measurements. About 98 % of the cells were activated 12 h after PHA-stimulation. The activation phase lasted less than 48 h, i.e., cells entering the activation phase within 12 h were at their activation maximum by 48 h. The activated cell increased in size. The nuclear/cytoplasmic-ratio decreased. Most of the cytoplasmic organelles developed in phase with the increase of cytoplasmic volume. After 48 h, mitotic figures were frequently seen. Due to the increasing number of secondary, activated daughter cells, parameters of most cytoplasmic components declined between 48 and 72 h. Structural changes in the nucleus preceded the 3H-leucine uptake, which had not reached its maximum after 72 h of incubation. The 3H-leucine uptake started as early as 12 h after culture initiation, and its increase was proportional to the increasing polyribosome density. No maximum uptake was reached up to 72 h, but the development of structural components related to this uptake was at its maximum at the end of the activation phase (48 h). The formation of bound ribosomes occurred subsequent to the enlargement of the surface of the rough endoplasmic reticulum. Initial polysome formation occurred at the expense of existing free ribosomes.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00238051
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Fine structure of isolated fibrils from the cuticle of Lumbricus sp. (1979)
    Springer
    Cell & tissue research 201 (1979), S. 459-466 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Electron microscopy ; Collagen ; Cuticle ; Lumbricus
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary A method has been developed to isolate and purify cuticular fibrils of Lumbricus. Polarizing microscopy confirms the collagenous nature of the isolated fibrils. Study in the electron microscope of isolated fibrils, negatively or positively stained, shows that they are cylindrical, unbranching and without periodic structure. Enzymatic treatment of cuticles with alpha-amylase and trypsin results in a more or less complete dissociation of the fibrils which appear clearly to be made up of helically wound bundles of filaments (30–40 Å). The structure of the cuticular fibrils is discussed in relation to biochemical and biophysical data and compared to the ultrastructural organization of other periodically cross-banded fibrils.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00237004
    Standort Signatur Erwartet Verfügbarkeit
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  • 99
    Digitale Medien
    Digitale Medien
    A study of cells present in peripheral lymph of pigs with special reference to a type of cell resembling the langerhans cell (1979)
    Springer
    Cell & tissue research 202 (1979), S. 407-430 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Lymph (pig) ; Langerhans cells ; Phase contrast microscopy ; Histochemistry ; Electron microscopy
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary Large mononuclear cells with long, actively moving cytoplasmic veils were observed in lymph coming from the skin. The enzyme histochemistry and ultrastructure of these cells suggested that they are related to epidermal Langerhans cells and interdigitating cells in the lymph node. It has been reported that Langerhans cells and interdigitating cells play a role in contact hypersensitivity by taking up antigen and presenting it to thymus-dependent lymphocytes, and it is likely that the veiled cells in the lymph are also involved. After skin-painting with 1-fluoro-2,4-dinitrobenzene (DNFB), the veiled cells in lymph coming from the site of painting became more active and were observed contacting other cells present in the lymph; many large cellular aggregates were found. Since neutrophilic leucocytes and mononuclear phagocytes were the predominating cell types in this lymph, there was no evidence for a massive recruitment of immunocompetent lymphocytes at the site of painting. Neonatally thymectomized pigs do not develop allergic reactivity to DNFB. It is of interest that the number of veiled cells and their ability to form large cellular aggregates was not affected in these animals. Therefore, it is unlikely that the defect in responsiveness can be attributed to a failure in the function of veiled cells.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00220434
    Standort Signatur Erwartet Verfügbarkeit
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  • 100
    Digitale Medien
    Digitale Medien
    On the problem of counting and sizing mitochondria: A general reappraisal based on ultrastructural studies of mammalian lymphocytes (1979)
    Springer
    Cell & tissue research 204 (1979), S. 297-303 
    Details
    ISSN: 1432-0878
    Schlagwort(e): Mitochondria ; Electron microscopy ; Stereology ; Number and volume ; Lymphocytes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The authors ask the question whether the parameters “number” and “volume” are suitable for the morphometric analysis of mitochondria. In several types of cell, irregularity of mitochondrial shape makes it technically difficult, if not impossible, to obtain reliable stereological estimates of mean organelle volume or number per unit volume. Of more fundamental concern is whether number of mitochondria per cell is of any real value as a structural correlate of respiratory potential and hence as a measure of cell function. Alternative parameters might serve better for this purpose. Though the problem is illustrated by reference to quantitative studies of lymphocytes, it is also pertinent to the investigation of many other cell types.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00234641
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