TY - JOUR A1 - Vernesi, C. A1 - Pecchioli, E. A1 - Tiedemann, Ralph A1 - Randi, E. A1 - Bertorelle, G. T1 - The genetic structure of natural and reintroduced roe deer (Capreolus capreolus) populations in the Alps and central Italy, with reference to the mitochondrial DNA phylogeography of Europe Y1 - 2002 SN - 0962-1083 ER - TY - JOUR A1 - Tiedemann, Ralph A1 - Paulus, Kirsten B. A1 - Scheer, M. A1 - Von Kistowski, K. G. A1 - Skirnisson, K. A1 - Bloch, D. A1 - Dam, M. T1 - Mitochondrial DNA and microsatellite variation in the eider duck (Somateria mollissima) indicate stepwise postglacial colonization of Europe and limited current long-distance dispersal N2 - To unravel the postglacial colonization history and the current intercolony dispersal in the common eider, Somateria mollissima, we analysed genetic variation at a part of the mitochondrial control region and five unlinked autosomal microsatellite loci in 175 eiders from 11 breeding colonies, covering the entire European distribution range of this species. As a result of extreme female philopatry, mitochondrial DNA differentiation is substantial both among local colonies and among distant geographical regions. Our study further corroborates the previous hypothesis of a single Pleistocene refugium for European eiders. A nested clade analysis on mitochondrial haplotypes suggests that (i) the Baltic Sea eider population is genetically closest to a presumably ancestral population and that (ii) the postglacial recolonization progressed in a stepwise fashion via the North Sea region and the Faroe Islands to Iceland. Current long-distance dispersal is limited. Differentiation among colonies is much less pronounced at microsatellite loci. The geographical pattern of this nuclear genetic variation is to a large extent explained by isolation by distance. As female dispersal is very limited, the geographical pattern of nuclear variation is probably explained by male-mediated gene flow among breeding colonies. Our study provides genetic evidence for the assumed prominent postglacial colonization route shaping the present terrestrial fauna of the North Atlantic islands Iceland and the Faroes. It suggests that this colonization had been a stepwise process originating in continental Europe. It is the first molecular study on eider duck populations covering their entire European distribution range Y1 - 2004 SN - 0962-1083 ER - TY - JOUR A1 - Ravaoarimanana, I. B. A1 - Tiedemann, Ralph A1 - Montagnon, D. A1 - Rumpler, Y. T1 - Molecular and cytogenetic evidence for cryptic speciation within a rare endemic Malagasy lemur, the Northern Sportive Lemur (Lepilemur septentrionalis) N2 - Evolutionary relationships of different populations of the threatened malagasy lemur Lepilemur septentrimialis were assessed by sequence analysis of mitochondrial DNA (D-loop region and partial Cyt b gene). One hundred and fifty nine samples were collected from five main different localities in the northern part of Madagascar. We applied the phylogenetic species concept based on fixed diagnostic differences to determine the status of different geographical populations. No nucleotide site diagnoses Ankarana from Andrafiamena or Analamera. However, numerous fixed differences separate Sahafary from all other populations. These results were corroborated by phylogenetic trees. As previous cytogenetic studies, our molecular data suggest that two cryptic species of Lepilemur occur in the extreme north of Madagascar. This speciation is probably caused by chromosomal rearrangements in at least one of the evolutionary lineages. Our study comprises another striking example of how molecular genetic assay can detect phylogenetic discontinuities that are not reflected in traditional morphologically based taxonomies. Our study indicates that the Sahafary population is a hitherto undescribed endangered endemic species which urgently needs conservation efforts. (C) 2003 Elsevier Inc. All rights reserved Y1 - 2004 SN - 1055-7903 ER - TY - JOUR A1 - Milinkovitch, M. C. A1 - Monteyne, D. A1 - Gibbs, J. P. A1 - Fritts, T. H. A1 - Tapia, W. A1 - Snell, H. L. A1 - Tiedemann, Ralph A1 - Caccone, Adalgisa A1 - Powell, J. R. T1 - Genetic analysis of a successful repatriation programme : giant Galapagos tortoises N2 - As natural populations of endangered species dwindle to precarious levels, remaining members are sometimes brought into captivity, allowed to breed and their offspring returned to the natural habitat. One goal of such repatriation programmes is to retain as much of the genetic variation of the species as possible. A taxon of giant GalApagos tortoises on the island of Espahola has been the subject of a captive breeding-repatriation programme for 33 years. Core breeders, consisting of 12 females and three males, have produced more than 1200 offspring that have been released on Espanola where in situ reproduction has recently been observed. Using microsatellite DNA markers, we have determined the maternity and paternity of 132 repatriated offspring. Contributions of the breeders are highly skewed. This has led to a further loss of genetic variation that is detrimental to the long-term survival of the population. Modifications to the breeding programme could alleviate this problem Y1 - 2004 SN - 0962-8452 ER - TY - JOUR A1 - Grobler, J. P. A1 - Hartl, G. B. A1 - Grobler, N. A1 - Kotze, A. A1 - Botha, K. A1 - Tiedemann, Ralph T1 - The genetic status of an isolated black wildebeest (Connochaetes gnou) population from the Abe Bailey Nature Reserve, South Africa : Microsatellite data on a putative past hybridization with blue wildebeest (C-taurinus) N2 - The present study aimed at assessing genetic purity of black wildebeest (Connochoetes gnou) at Abe Bailey Nature Reserve, Gauteng Province, South Africa, using a multitocus microsatellite approach. Five loci were studied in black and blue (C. taurinus) wildebeest, the latter being a closely related species and known to produce hybrids with the morphologically very similar black wildebeest. In fact, the entire national black wildebeest population of South Africa potentially contains a significant proportion of introgressed blue wildebeest genes. In our case, eight out of 39 alleles were unique to black and 22 to blue wildebeest, with nine alleles shared between pure populations of the two species in Line with their taxonomic proximity. A possible Limited past introgression of blue wildebeest genes into the Abe Bailey population, corresponding to documents on population history, was only supported by the presence of a single allele otherwise exclusively found in samples of four pure blue but not in samples of two pure black wildebeest control populations. However, an assignment test and coefficients of population divergence did not support an extended introgression of C. taurinus alleles into the C. gnou population under study. Average heterozygosity at Abe Bailey proved to be intermediate between black and blue wildebeest, the tatter species generally harbouring more genetic variation than the former owing to larger population sizes and the absence of population bottlenecks in historical times. The implications of our data are discussed with reference to the persistence of introgressed genes and the conservation of pure black wildebeest gene pools Y1 - 2005 SN - 1616-5047 ER - TY - JOUR A1 - Tiedemann, Ralph A1 - Moll, K. A1 - Paulus, Kirsten B. A1 - Schlupp, Ingo T1 - New microsatellite loci confirm hybrid origin, parthenogenetic inheritance, and mitotic gene conversion in the gynogenetic Amazon molly (Poecilia formosa) N2 - We describe the first microsatellite loci for the gynogenetic Amazon molly, Poecilia formosa, an all-female species arisen through hybridization of the bisexual species Poecilia mexicana and Poecilia latipinna. The loci showed one to six alleles and an expected heterozygosity between zero and 0.75. As expected with parthenogenetic inheritance, most loci were either constantly homozygous (five loci) or constantly heterozygous (eight loci). For six loci, both heterozygotes and homozygotes occurred. This and the fact that some loci only showed alleles of one of the ancestral species could indicate genome homogenization through mitotic gene conversion. Our new loci conformed to the hybrid origin of Amazon molly and are also applicable to both ancestral bisexual species Y1 - 2005 SN - 1471-8278 ER - TY - JOUR A1 - Feulner, Philine g. d. A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Eighteen microsatellite loci for endemic African weakly electric fish (Campylomormyrus, Mormyridae) and their cross species applicability among related taxa N2 - We describe isolation and characterization of the first microsatellite loci specifically developed for African weakly electric fish (Mormyridae), for the genus Campylomormyrus. Seventeen of our 18 loci are polymorphic within the Campylomormyrus numenius species complex. The polymorphic loci showed four to 15 alleles per locus, an expected heterozygosity between 0.46 and 0.94, and an observed heterozygosity between 0.31 and 1.00. Most primers also yield reproducible results in several other mormyrid species. These loci comprise a set of molecular markers for various applications, from moderately polymorphic loci suitable for population studies to highly polymorphic loci for pedigree analysis in mormyrids Y1 - 2005 ER - TY - GEN A1 - Neye, Gundula A1 - Wallschläger, Hans-Dieter A1 - Tiedemann, Ralph T1 - Song dialect boundaries in the Yellowhammer: Do they restrict gene flow? T2 - Journal of ornithology Y1 - 2006 SN - 0021-8375 VL - 147 IS - Supplement 1 SP - 219 EP - 219 PB - Blackwell CY - New York ER - TY - GEN A1 - Tiedemann, Ralph A1 - Pfautsch, Simone T1 - MHC evolution in ducks and allies T2 - Journal of ornithology Y1 - 2006 SN - 0021-8375 VL - 147 IS - Supplement 1 SP - 48 EP - 48 PB - Blackwell CY - New York ER - TY - JOUR A1 - Stuckas, H A1 - Tiedemann, Ralph T1 - Eight new microsatellite loci for the critically endangered fire-bellied toad Bombina bombina and their cross- species applicability among anurans N2 - We describe eight new microsatellite loci for the critically endangered fire-bellied toad, Bombina bombina. Seven of them are polymorphic with two to seven alleles per locus, an expected heterozygosity between 0.41 and 0.8, and an observed heterozygosity between 0.27 and 0.7. The yield of new loci was relatively low, presumably due to mildly repetitive sequence motifs in microsatellite flanking regions. As typical for anurans, cross-species amplification was limited (here, to congeners Bombina orientalis and Bombina variegata). Combining these new loci with those already available provides a reasonable number of loci for population studies and pedigree analysis in Bombina Y1 - 2006 UR - http://onlinelibrary.wiley.com/doi/10.1111/j.1471-8286.2005.01171.x/pdf U6 - https://doi.org/10.1111/j.1471-8286.2005.01171.x ER - TY - JOUR A1 - Wronski, Torsten A1 - Tiedemann, Ralph A1 - Apio, Ann A1 - Plath, Martin T1 - Cover, food, competitors and individual densities within bushbuck Tragelaphus scriptus female clan home ranges N2 - We examined factors predicting female densities within the common home ranges of related females ("clans") in bushbuck Tragelaphus scriptus Pallas, 1776. In this species, each female forms an individual home range, but the home ranges of matrilineal clan members strongly overlap. We found female densities to increase in areas with high canopy cover. Moreover, individual home range sizes tended to decrease with increasing cover. Food plant availability and intruder pressure by two heterospecific competitors did not significantly affect female densities. Apparently, canopy cover is the major limited resource in this species. A possible explanation is that both adult bushbuck and - even more markedly - fawns hide from predators in dense vegetation, in particular in thicket clumps and coalescences. The study shows an effect of habitat properties (eg sufficient canopy cover) on a within-population level in bushbuck, where female densities differ even among proximate clan areas Y1 - 2006 ER - TY - JOUR A1 - Feulner, Philine G. D. A1 - Kirschbaum, Frank A1 - Schugardt, Christian A1 - Ketmaier, Valerio A1 - Tiedemann, Ralph T1 - Electrophysiological and molecular genetic evidence for sympatrically occuring cryptic species in African weakly electric fishes (Teleostei : Mormyridae : Campylomormyrus) N2 - For two sympatric species of African weakly electric fish, Campylomormyrus tamandua and Campylomormyrus numenius, we monitored ontogenetic differentiation in electric organ discharge (EOD) and established a molecular phylogeny, based on 2222 bp from cytochrome b, the S7 ribosomal protein gene, and four flanking regions of unlinked microsatellite loci. In C tamandua, there is one common EOD type, regardless of age and sex, whereas in C numenius we were able to identify three different male adult EOD waveform types, which emerged from a single common EOD observed in juveniles. Two of these EOD types formed well supported clades in our phylogenetic analysis. In an independent line of evidence, we were able to affirm the classification into three groups by microsatellite data. The correct assignment and the high pairwise FST values support our hypothesis that these groups are reproductively isolated. We propose that in C numenius there are cryptic species, hidden behind similar and, at least as juveniles, identical morphs. Y1 - 2006 UR - http://www.sciencedirect.com/science/journal/10557903 U6 - https://doi.org/10.1016/j.ympev.2005.09.008 SN - 1055-7903 ER - TY - JOUR A1 - Gessner, Jörn A1 - Arndt, Gerd-Michael A1 - Tiedemann, Ralph A1 - Bartel, Ryszard A1 - Kirschbaum, Frank T1 - Remediation measures for the Baltic sturgeon: status review and perspectives JF - Journal of applied ichthyology N2 - More than one century ago, sturgeons were prevalent species in the fish communities of all major German rivers both in the North and the Baltic seas drainages. Since then, the populations declined rapidly due to river damming, overfishing and pollution. The last sturgeon catches in the Baltic drainage system occurred during the late 1960ies. Only a few individual captures have been reported during the last 30 years with the most recent records in the Lake Ladoga ( Russia), where the last confirmed catch was recorded in 1984, and a single individual caught off Estonia in 1996. Today, sturgeons are considered missing or extinct in German waters. First attempts for remediation of the species were undertaken in the mid 1990ies. Subsequently, phylogenetic and population genetic analyses of the species were carried out using mtDNA, microsatellites, and nuclear markers ( SNPs). These genetic analyses using recent and historic material have proven the existence of two different species in the Baltic Sea in what was previously considered to represent the European Atlantic sturgeon only. In the Baltic Sea, the American Atlantic sturgeon ( A. oxyrinchus) succeeded to colonize this brackish water system during the Middle Ages. In the North Sea, the European Atlantic sturgeon ( A. sturio) is considered to be the endemic species. These results led to the separation of the remediation activities in the North Sea and the Baltic Sea tributaries. Further studies on the mechanism that lead to the extinction of A. sturio in Germany and the subsequent succession of the A. oxyrinchus mtDNA haplotype are currently been carried out. Broodstock development using the northernmost populations of A. oxyrinchus is currently under way. As a further prerequisite to re-introduce this species into the Baltic, the evaluation of the status of critical habitats for the early life stages of the American Atlantic sturgeon in the River Odra has been performed in collaboration with the Institute for Inland Fisheries of Poland. Alternative fisheries techniques, based on the data of by-catch of exotic sturgeons in the fishery, are presently developed in close cooperation with the fishery to reduce fisheries related mortality in juvenile sturgeons upon release. Monitoring of habitat utilization and migration characteristics of juvenile fish upon experimental release will have to be carried out shortly, using acoustic telemetry, with the aim to follow the fate of the released fish and to determine the best time-size-release-window for future release programmes. Y1 - 2007 U6 - https://doi.org/10.1111/j.1439-0426.2007.00925.x SN - 0175-8659 VL - 22 IS - S1 SP - 23 EP - 31 PB - Wiley-Blackwell CY - Oxford ER - TY - JOUR A1 - Plath, Martin A1 - Kromuszczynski, Katja A1 - Tiedemann, Ralph T1 - Audience effect alters male but not female mating preferences N2 - Males often face strong mating competition by neighboring males in their social environment. A recent study by Plath et al. (Anim Behav 75:21-29, 2008a) has demonstrated that the visual presence of a male competitor (i.e., an audience male) affects the expression of male mating preferences in a poeciliid fish (Poecilia mexicana) with a weaker expression of mating preferences when an audience male observed the focal male. This may be a tactic to reduce sperm competition, since surrounding males likely share intrinsic preferences for female traits or copy mate choice decisions. Here, we examined the hypothesis that a same-sex audience would affect female mate preferences less than male mating preferences. Our hypothesis was based on the assumptions that (1) competition for mates in a fashion that would be comparable in strength to sperm competition or overt male-male aggression is absent among Poecilia females, and (2) P. mexicana females typically form female-biased shoals, such that almost any female mate choice in nature occurs in front of a female audience. Poecilia females (P. mexicana, surface and cave form, and the closely related gynogenetic Poecilia formosa) were given a choice between a large and a small male, and the tests were repeated while a conspecific, a heterospecific, or no audience female (control) was presented. Females spent more time in the neutral zone and, thus, less time near the males during the second part of a trial when an audience was presented, but-consistent with predictions-females showed only slightly weaker expression of mate preferences during the second part of the tests. This decline was not specific to the treatment involving an audience and was significantly weaker than the effect seen in the male sex. Y1 - 2009 UR - http://www.springerlink.com/content/100464 U6 - https://doi.org/10.1007/s00265-008-0672-7 SN - 0340-5443 ER - TY - JOUR A1 - Bleidorn, Christoph A1 - Hill, Natascha A1 - Erséus, Christer A1 - Tiedemann, Ralph T1 - On the role of character loss in orbiniid phylogeny (Annelida) : molecules vs. morphology N2 - Orbiniid phylogeny is matter of debate and incongruence between hypothesis based on molecules and morphology has been repeatedly reported. Moreover, the phylogenetic position of the "oligochaetoid polychaetes" of the taxon Questa varies between morphological and molecular cladistic analyses. Here, we present a nearly complete mitochondrial genome of Questa ersei. The mitochondrial gene order is roughly identical to known orbiniid taxa. Several translocations of tRNAs are unique to Orbiniidae and Questa when compared to other annelid mitochondrial genomes. Additionally, we assembled sequence data of six genes (18S, 16S, cox1, cox3, nad1, nad4) for a representative orbiniid taxon sampling and analysed all data in concatenation using Maximum Likelihood and Bayesian inference. For comparison with morphology we compiled a morphological data matrix for all taxa included in our molecular analyses. Our results strongly support a close relationship of Questa with orbiniids (sequence data, gene order, an 18 bp indel, morphology), and a position nested within orbiniids is recovered in our sequence based analyses. We demonstrate remarkable incongruence of most included morphological characters with the recovered best ML tree and suppose that repeated independent character loss might be an explanation. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/10557903 U6 - https://doi.org/10.1016/j.ympev.2009.03.022 SN - 1055-7903 ER - TY - JOUR A1 - Bleidorn, Christoph A1 - Lanterbecq, Deborah A1 - Eeckhaut, Igor A1 - Tiedemann, Ralph T1 - A PCR survey of Hox genes in the myzostomid Myzostoma cirriferum N2 - Using degenerate primers, we were able to identify seven Hox genes for the myzostomid Myzostoma cirriferum. The recovered fragments belong to anterior class (Mci_lab, Mci_pb), central class (Mci_Dfd, Mci_Lox5, Mci_Antp, Mci_Lox4), and posterior class (Mci_Post2) paralog groups. Orthology assignment was verified by phylogenetic analyses and presence of diagnostic regions in the homeodomain as well as flanking regions. The presence of Lox5, Lox4, and Post2 supports the inclusion of Myzostomida within Lophotrochozoa. We found signature residues within flanking regions of Lox5, which are also found in annelids, but not in Platyhelminthes. As such the available Hox genes data of myzostomids support an annelid relationship. Y1 - 2009 UR - http://www.springerlink.com/content/100526 U6 - https://doi.org/10.1007/s00427-009-0282-z SN - 0949-944X ER - TY - JOUR A1 - Sharma, Reeta A1 - Stuckas, Heiko A1 - Bhaskar, Ranjana A1 - Rajput, Sandeep A1 - Khan, Imran A1 - Goyal, Surendra Prakash A1 - Tiedemann, Ralph T1 - mtDNA indicates profound population structure in Indian tiger (Panthera tigris tigris) N2 - We analyzed mtDNA polymorphisms (parts of control region, ND5, ND2, Cytb, 12S, together 902 bp) in 59 scat and 18 tissue samples from 13 Indian populations of the critically endangered Indian tiger (Panthera tigris tigris), along with zoo animals as reference. Northern tiger populations exhibit two unique haplotypes suggesting genetic isolation. Western populations from Sariska (extinct in 2004) and Ranthambore are genetically similar, such that Ranthambore could serve as a source for reintroduction in Sariska. Zoo populations maintain mitochondrial lineages that are rare or absent in the wild. Y1 - 2009 UR - http://www.springerlink.com/content/105709 U6 - https://doi.org/10.1007/s10592-008-9568-3 SN - 1566-0621 ER - TY - JOUR A1 - Stuckas, Heiko A1 - Stoof, Kathleen A1 - Quesada, Humberto A1 - Tiedemann, Ralph T1 - Evolutionary implications of discordant clines across the Baltic Mytilus hybrid zone (Mytilus edulis and Mytilus trossulus) N2 - It is well established that reproductive isolation often arises from genome incompatibilities and that genes encoding reproductive traits are less prone to introgression. Hybrid zones of Mytilus trossulus and Mytilus edulis provide an intriguing model to assess reproductive isolation. Although gene flow is restricted in North America, introgression is pervasive in the Baltic. This study aimed at analyzing the shape of multilocus clines across the Baltic contact zone between M. edulis and M. trossulus to infer mechanisms of restriction to gene flow. We use maximum likelihood methods to construct the best fitting individual clines for five markers located on biparentally inherited autosomes and paternally and maternally inherited mitochondrial DNA (mtDNA). Strong cline shape differences among markers suggest that reproductive isolation arising from genome-wide incompatibilities is weak, and that these discrepancies possibly result from genetic drift, hybrid zone movement or marker-specific selection. However, the finding of a common cline center for M7 lysin (involved in fertilization) and paternally transmitted mtDNA (causing nuclear-mitochondrial incompatibilities in hybrids) suggest that these loci may play a role in incomplete reproductive isolation. Y1 - 2009 UR - http://www.nature.com/hdy/archive/index.html U6 - https://doi.org/10.1038/Hdy.2009.37 SN - 0018-067X ER - TY - JOUR A1 - Feulner, Philine G. D. A1 - Plath, Martin A1 - Engelmann, Jacob A1 - Kirschbaum, Frank A1 - Tiedemann, Ralph T1 - Electrifying love : electric fish use species-specific discharge for mate recognition N2 - Mate choice is mediated by a range of sensory cues, and assortative mating based on these cues can drive reproductive isolation among diverging populations. A specific feature of mormyrid fish, the electric organ discharge (EOD), is used for electrolocation and intraspecific communication. We hypothesized that the EOD also facilitates assortative mating and ultimately promotes prezygotic reproductive isolation in African weakly electric fishes. Our behavioural experiments using live males as well as EOD playback demonstrated that female mate recognition is influenced by EOD signals and that females are attracted to EOD characteristics of conspecific males. The dual function of the EOD for both foraging and social communication (including mate recognition leading to assortative mating) underlines the importance of electric signal differentiation for the divergence of African weakly electric fishes. Thus, the EOD provides an intriguing mechanism promoting trophic divergence and reproductive isolation between two closely related Campylomormyrus species occurring in sympatry in the lower Congo rapids. Y1 - 2009 UR - http://www.journals.royalsoc.ac.uk/link.asp?id=110824 U6 - https://doi.org/10.1098/rsbl.2008.0566 SN - 1744-9561 ER - TY - GEN A1 - Bleidorn, Christoph A1 - Podsiadlowski, Lars A1 - Zhong, Min A1 - Eeckhaut, Igor A1 - Hartmann, Stefanie A1 - Halanych, Kenneth M. A1 - Tiedemann, Ralph T1 - On the phylogenetic position of Myzostomida : can 77 genes get it wrong? N2 - Background: Phylogenomic analyses recently became popular to address questions about deep metazoan phylogeny. Ribosomal proteins (RP) dominate many of these analyses or are, in some cases, the only genes included. Despite initial hopes, hylogenomic analyses including tens to hundreds of genes still fail to robustly place many bilaterian taxa. Results: Using the phylogenetic position of myzostomids as an example, we show that phylogenies derived from RP genes and mitochondrial genes produce incongruent results. Whereas the former support a position within a clade of platyzoan taxa, mitochondrial data recovers an annelid affinity, which is strongly supported by the gene order data and is congruent with morphology. Using hypothesis testing, our RP data significantly rejects the annelids affinity, whereas a platyzoan relationship is significantly rejected by the mitochondrial data. Conclusion: We conclude (i) that reliance of a set of markers belonging to a single class of macromolecular complexes might bias the analysis, and (ii) that concatenation of all available data might introduce conflicting signal into phylogenetic analyses. We therefore strongly recommend testing for data incongruence in phylogenomic analyses. Furthermore, judging all available data, we consider the annelid affinity hypothesis more plausible than a possible platyzoan affinity for myzostomids, and suspect long branch attraction is influencing the RP data. However, this hypothesis needs further confirmation by future analyses. T3 - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - paper 123 KW - Cirriferum myzostomida KW - Mitochondrial genomes KW - Transfer-rna KW - Data sets KW - Sequence Y1 - 2009 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-44893 ER -