31 research outputs found
Zur Bedeutung der Kundenzufriedenheit für im Schienenpersonennahverkehr tätige Unternehmen
No full textFür die SPNV-Unternehmen werden die bei ihren Kunden erzielten bzw. erzielbaren Fahrgelderlöse in Zukunft eine erheblich stärkere Bedeutung erhalten. Der demografische Wandel und die zunehmende Motorisierung werden darüber hinaus dazu führen, dass die Gruppe der Captives abnehmen wird. Damit wird der SPNV nach und nach erhebliche Anteile seiner größten und zugleich wichtigsten Kundengruppe auf lange Sicht verlieren. Zugleich wird die Zahl der wahlfreien Kunden weiter steigen; damit steigt die Gefahr für das SPNV-Unternehmen, dass sich diese Personen verstärkt gegen eine Nutzung des SPNV entscheiden, sofern dieser die an ihn gestellten Qualitätsansprüche nicht erfüllt. Um weiterhin am Markt bestehen und die geplanten Fahrgelderlöse generieren zu können, ist es daher für SPNV-Unternehmen von strategischer Bedeutung, die Qualitätsanforderungen der Fahrgäste zu kennen, diese dann selektiv zu erfüllen, um die sich hieraus ergebenden Erlöspotenziale abschöpfen zu können. Die Kundenzufriedenheit wird dabei immer mehr zum entschei-denden Faktor zur Generierung der geplanten Fahrgelderlöse. Gleichzeitig stehen die SPNV-Unternehmen der Herausforderung gegenüber, ihr Angebot wirtschaftlicher realisieren zu müssen. Im Grunde handelt es sich um ein Optimierungsproblem, bei dem in Abhängigkeit vom Verkehrsvertrag einerseits und den Einstellungen und dem Verhalten der Fahrgäste andererseits die wirtschaftlichste Investitionsstrategie gesucht wird.
Um das Optimierungsproblem lösen zu können, müssen Abhängigkeiten zwischen Maßnahmen, ihren wirtschaftlichen Dimensionen für das investierende Unternehmen, den Reaktionen der Fahrgäste sowie die Rahmenbedingungen eines Verkehrsvertrags bekannt sein. Die vorliegende Arbeit befasst sich mit dieser Fragestellung
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Lessons from a challenging system: accurate adsorption free energies at the amino acid/ZnO interface
No full textWe undertake steps to overcome four challenges that have hindered the understanding of ZnO/biomolecule interfaces at the atomic scale; parametrization of a classical force field, ZnO surface termination and amino acid protonation state in methanol, and convergence of enhanced- sampling molecular dynamics simulations. We predict adsorption free energies for histidine, serine, cysteine and tryptophan in remarkable agreement with experimental measurements obtained via a novel indicator-displacement assay. Adsorption is driven by direct surface/amino-acid interactions mediated by terminal hydroxyl groups and stabilized by strongly-structured methanol solvation shells
Cassava-associated Begomoviruses in India - Biodiversity, Tissue tropism and Function analysis
No full textGeminiviren befallen wichtige Nutzpflanzen und führen teilweise zu enormen Ernteverlusten. In den letzten Jahrzehnten stieg die Zahl von Virusinfektionen aufgrund der Ausbreitung des Übertragungsvektors (Bemisia tabaci, Genn.) und der schnellen Anpassung der Viren durch verschiedene molekulargenetische Mechanismen an. Untersuchungen über die Biodiversität von Cassava mosaic desease (CMD)-auslösenden Begomoviren in Indien sind bisher unvollständig.
Die Ergebnisse zeigen, dass neben dem schon bekannten Indian cassava mosaic virus (ICMV) auch das bisher nur in Sri Lanka nachgewiesene Sri Lankan cassava mosaic virus (SLCMV) in Indien weitverbreitet auftritt. Beide DNA Komponenten des bipartiten ICMV konnten isoliert und kloniert werden. Dieser Klon induzierte sowohl in experimentell verwendeten Nicotiana-Spezies als auch im natürlichen Wirt Maniok systemische und symptomatische Infektionen.
Um den Infektionsverlauf zu beobachten und die Funktion einzelner Offener Leserahmen (engl. open reading frame, ORF) zu bestimmen, wurden ICMV-Chimären erstellt, die anstelle des Kapsidprotein (engl. coat protein, CP) Gens das green fluorescence protein (GFP) Gen exprimierten. Damit konnte das Virus durch Fluoreszenzmikroskopie in vivo nachgewiesen und als phloemlimitiert bestimmt werden. Dieses Ergebnis konnte durch in situ Hybridisierungsstudien in systemisch infiziertem Maniok und Tabak bestätigt werden.
Die Funktion des ORF AV2 wurde mit Hilfe von GFP-Fusionsproteinen analysiert. Neben der Expression des Fusionsproteins im viralen Hintergrund wurde ein GFP-AV2-Fusionsprotein unter der Kontrolle des konstitutiven Cauliflower mosaic virus (CaMV) 35S Promotors erstellt. Fusionsproteine beider Konstrukte ergaben dieselbe zelluläre Verteilung. Mikroskopische Analysen zeigten eine mögliche Assoziation von AV2 mit Plasmodesmata und eine Funktion beim viralen Zell-zu-Zell Transport. Demnach kann AV2 die Funktion eines redundanten Transportproteins haben.This work investigated the growing ecological importance of geminiviruses in South India. Important crops are infected by geminiviruses, leading to enormous loss of yield. During the last decades infection rates of geminiviruses raised, either by the increased dissemination of the transfer vector for geminiviruses (Bemisia tabaci, Genn.) and the fast adaptation of viruses by mutation, recombination and pseudorecombination. Investigations on biodiversity of CMD-causing begomoviruses in India are incomplete so far. This gap should be closed by this work, investigating the diversity of cassava-associated begomoviruses in South India.
The results demonstrate, that beside the Indian cassava mosaic virus (ICMV), the Sri Lankan cassava mosaic virus (SLCMV), is widely distributed on the Indian subcontinent. ICMV DNA A and DNA B components were isolated and cloned. This clone induces CMD in experimentally used Nicotiana spec. as well as in the natural host cassava.
To monitor the progress of infection and to analyse the function of selected open reading frames (ORF), ICMV-chimeras were generated with the coat protein (CP) gene replaced by the green fluorescence protein (GFP) gene. Using these chimera, the virus could be determined as phloem-limited in affected plant tissues. The phloem-limitation was confirmed using in situ hybridisation in systemically infected tobacco and cassava plants.
The function of ORF AV2 was analysed using AV2-GFP fusion proteins. Two constructs were established. One expressing the fusion protein within the viral background, the other construct was driven by the constitutive 35S promoter of Cauliflower mosaic virus (CaMV), expressing the fusion protein in the absence of any other viral proteins. Fusion proteins, expressed form both constructs, were similarly distributed within plant cells. AV2 protein was probably associated with plasmodesmata and cell-to-cell movement. Therefore AV2 may function as a redundant movement protein
Moment dynamics of Zirconia particle formation for optimizing particle size distribution
No full textWe study the particle formation process of Zirconia ( ZrO 2 )-based material. With a model-based description of the particle formation process we aim for identifying the main growth mechanisms for different process parameters. After the introduction of a population balance based mathematical model, we derive the moment dynamics of the particle size distribution and compare the model to experimental data. From the fitted model we conclude that growth by molecular addition of Zr-tetramers or Zr-oligomers to growing particles as well as size-independent particle agglomeration takes place. For the purpose of depositing zirconia-based material (ZrbM) on a substrate, we determine the optimal process parameters such that the mineralization solution contains preferably a large number of nanoscaled particles leading to a fast and effective deposition on the substrate. Besides the deposition of homogeneous films, this also enables mineralization of nanostructured templates in a bioinspired mineralization process. The developed model is also transferable to other mineralization systems where particle growth occurs through addition of small molecular species or particle agglomeration. This offers the possibility for a fast determination of process parameters leading to an efficient film formation without carrying out extensive experimental investigations
Political trajectories in the painting of P. Wyndham Lewis
No full textThis thesis presents an analysis of the political dimension to the paintings of Percy Wyndham Lewis (1882-1957).Through an exegesis of the discreet and latent "voices" in Lewis's paintings the ideological parameters of his thought world are disclosed. These imperatives are examined for their display of political predispositions, for values and attitudes, which reveal a loading towards specific socio-cultural standards. In so far as these standards can be identified with historically relevant political programmes they become manifestos for political actions. Or, at the very least, they can be seen to exist as critical and prescriptive social insights. Importantly, the focus of this examination and interpretation remains the visual image and its related texts. A key aspect of both the methodology and argument within this thesis, insists that the visual image is the bearer of meaning in both its subject matter and technique. Values are communicated not only in reference to the thing displayed, but, in the manner of the display. Hence, an analysis of the intellectual and formal strategies employed by Lewis in his painting becomes a central concern of the thesis. Finally, the thesis rounds on the actual nature of Lewis's politics as revealed in his approach to art. While it is accepted that the mediation from the political to the painted throws up many and substantial barriers, the thesis insists that a political reading of Lewis's creative work is not only appropriate but necessary. In offering just such a reading the author hopes to transcend the boundaries between the disciplines of Art History and Sociology
Tissue and cell tropism of Indian cassava mosaic virus (ICMV) and its AV2 (precoat) gene product
No full textAbstractIn order to establish defined viruses for challenging plants in resistance breeding programmes, Indian cassava mosaic virus (ICMV; family Geminiviridae) DNA clones were modified to monitor viral spread in plants by replacing the coat protein gene with the green fluorescent protein (GFP) reporter gene. Comparative in situ hybridization experiments showed that ICMV was restricted to the phloem in cassava and tobacco. GFP-tagged virus spread similarly, resulting in homogeneous fluorescence within nuclei and cytoplasm of infected cells. To analyze viral intercellular transport in further detail, GFP was fused to AV2, a protein that has been implicated in viral movement. Expressed from replicating viruses or from plasmids, AV2:GFP became associated with the cell periphery in punctate spots, formed cytoplasmic as well as nuclear inclusion bodies, the latter as conspicuous paired globules. Upon particle bombardment of expression plasmids, AV2:GFP was transported into neighboring cells of epidermal tissues showing that the intercellular transport of the AV2 protein is not restricted to the phloem. The results are consistent with a redundant function of ICMV AV2 acting as a movement protein, presumably as an evolutionary relic of a monopartite geminivirus that may still increase virus fitness but is no longer necessary in a bipartite genome. The fusion of ICMV ORF AV2 to the GFP gene is the first example of a reporter construct that follows the whole track of viral DNA from inside the nucleus to the cell periphery and to the next cell
Representations of Jews and Jewishness in English painting, 1887-1914
No full textThis thesis concerns itself with pictorial representations of Jewish subjects in the period between the Anglo-Jewish Historical Exhibition on 1887 and the Twentieth Century Art Exhibition at the Whitechapel in 1914, on the eve of the First World War. It is organised in two parts. Its beginning and end, so the introductory first chapter
argues, can be glimpsed in Barraud's celebratory painting of Lord Lionel Rothschild being sworn into parliament (painted 1872,25 years after the event) and the alienated
Jewish subjects of the East End hauntingly captured by Mark Gertler in the years immediately preceding World War I.
The first part is devoted to the analysis of what the author identifies as an Anglo-Jewish artistic discourse. Its defining characteristics emerge, so the author argues, in the Anglo-Jewish Historical Exhibition held in honour of Queen Victoria's golden jubilee at the Albert Hall in 1887. These characteristics include a deliberate attempt to
visualise the Jewish community as a well-integrated part of middle / upper-class English society, sharing with the latter a past, a present and a future. This present and
future include also the civilising mission of empire. By contrast, the immigrant East End of London is emphatically not part of this discourse. After a detailed reading of
the Exhibition, two case studies are presented in this part of the thesis: the painters Solomon J. Solomon and John Singer Sargent, the former being an observant yet
acculturated London Jew and the latter being a non-Jewish American painter then resident in London. Their works discussed here span the end of the 19th and the
beginning of the 20th century. The chapter on Solomon J. Solomon is presented with a focus on a number of paintings that can be seen to thematise an Anglo-Jewish discourse. Among these are single and group portraits that show Jewish sitters as successful members of English society. Especially noteworthy are "mixed" groups that show Jewish and Gentile sitters together in a semi-neutral space of middle and upperclass sociability and civic ritual. Solomon's monumentally sized Allegory of the relationship between the Old and the New Testament, while offering an ostensibly harmonising vision, is perhaps Solomon's more daring and problematic work, since it re-inscribes the supersession of Judaism by Christianity.
The chapter on Sargent's portraits of Jewish sitters revisits the thesis that Sargent's images encode anti-Semitic stereotypes. The author proposes to read these paintings from the point of view of their contemporary reception. The documents adduced are interpreted to show that while some of Sargent's paintings did sometimes play to
deeply embedded anti-Semitic stereotypes among his critics, they were just as often openly admired as masterpieces of character depiction. Thus emerges a style of heightened characterisation that could stop short of caricature in some cases, but that could also capture qualities that the painter admired in sitters some of whom, such as the Wertheimers, he considered friends.
The second part of the thesis is titled An Offer of Integration. In parallel to the first part, it begins with a detailed reading of an exhibition, the Exhibition of Jewish Arts and Antiquities held at the Whitechapel Art Gallery in 1906. The author argues that this show, with its significant location now in the heart of the East End, represented an offer of integration towards the immigrant communities of the East End. At the same time, it could be seen as a response to the Aliens Act of 1905 which brought
immigration from Eastern Europe largely to an end. The author argues that the show constituted a part of an active programme of, as the author names it, Anglification: a
cultural and educational project aimed at transforming immigrants into Englishmen (and -women). In relation to this programme, the author places three chapters on three
modernist painters who painted scenes in the East End in the first and second decades of the 20th century: William Rothenstein, Alfred Wolmark and Mark Gertler. Rothenstein "discovered" the "aliens" of the East End in ca. 1905 and produced several paintings of religious subjects over the next two years, culminating in Carrying
the Law. The author posits that Rothenstein, an acculturated Jewish man of German-Jewish background from Bradford, painted scenes of Jewish prayer and study in a
broadly Rembrandtesque, late impressionist mode and sought to foreground their spiritual depth and nobility, rejecting the picturesque and anecdotal genre established in more conservative painters such as Pilichowski. Especially in Jews mourning in synagogue, almost all narrative detail (synagogue furniture, scrolls, books) have been
eliminated and the painting relies for it's a/effect entirely on the antique effect of the full-length prayershawls (typical of Eastern European Jews - Anglo-Jews preferred the scarf shaped small prayershawls) on the interiority of the praying men. The emphasis on interiority and spirituality, and the exploitation of the archaic black-and white aesthetic of the full-length prayershawl, was to set a precedent for a number of modernist painters engaging with Jewish subjects, such as Jacob Kramer. By contrast
with Rothenstein, so the author argues, Alfred Wolmark took a different position towards his "Jewish paintings". Again, this represents a relatively short phase in his oeuvre, preceding his colourist phase. In The Last Days of Rabbi Ben Ezra (1903), Wolmärk undertook to translate Robert Browning's well-known poem into the artistic idiom of a Rembrandtesque Eastern European Jewry.
As a conclusion, the epilogue revisits the 1956 Tercentenary Exhibition to trace how enduring the Anglo-Jewish discourse was
Peptide controlled shaping of biomineralized tin(II) oxide into flower-like particles
No full textThe size and morphology of metal oxide particles have a large impact on the physicochemical properties of these materials, e.g., the aspect ratio of particles affects their catalytic activity. Bioinspired synthesis routes give the opportunity to control precisely the structure and aspect ratio of the metal oxide particles by bioorganic molecules, such as peptides. This study focusses on the identification of tin(II) oxide (tin monoxide, SnO) binding peptides, and their effect on the synthesis of crystalline SnO microstructures. The phage display technique was used to identify the 7-mer peptide SnBP01 (LPPWKLK), which shows a high binding affinity towards crystalline SnO. It was found that the derivatives of the SnBP01 peptide, varying in peptide length and thus in their interaction, significantly affect the aspect ratio and the size dimension of mineralized SnO particles, resulting in flower-like morphology. Furthermore, the important role of the N-terminal leucine residue in the peptide for the strong organic-inorganic interaction was revealed by FTIR investigations. This bioinspired approach shows a facile procedure for the detailed investigation of peptide-to-metal oxide interactions, as well as an easy method for the controlled synthesis of tin(II) oxide particles with different morphologies
Influence of zinc on the calcium carbonate biomineralization of Halomonas halophila
No full textBackground: The salt tolerance of halophilic bacteria make them promising candidates for technical applications, like isolation of salt tolerant enzymes or remediation of contaminated saline soils and waters. Furthermore, some halophilic bacteria synthesize inorganic solids resulting in organic-inorganic hybrids. This process is known as biomineralization, which is induced and/or controlled by the organism. The adaption of the soft and eco-friendly reaction conditions of this formation process to technical syntheses of inorganic nano materials is desirable. In addition, environmental contaminations can be entrapped in biomineralization products which facilitate the subsequent removal from waste waters. The moderately halophilic bacteria Halomonas halophila mineralize calcium carbonate in the calcite polymorph. The biomineralization process was investigated in the presence of zinc ions as a toxic model contaminant. In particular, the time course of the mineralization process and the influence of zinc on the mineralized inorganic materials have been focused in this study. Results: H. halophila can adapt to zinc contaminated medium, maintaining the ability for biomineralization of calcium carbonate. Adapted cultures show only a low influence of zinc on the growth rate. In the time course of cultivation, zinc ions accumulated on the bacterial surface while the medium depleted in the zinc contamination. Intracellular zinc concentrations were below the detection limit, suggesting that zinc was mainly bound extracellular. Zinc ions influence the biomineralization process. In the presence of zinc, the polymorphs monohydrocalcite and vaterite were mineralized, instead of calcite which is synthesized in zinc-free medium.
Conclusions: We have demonstrated that the bacterial mineralization process can be influenced by zinc ions resulting in the modification of the synthesized calcium carbonate polymorph. In addition, the shape of the mineralized inorganic material is chancing through the presence of zinc ions. Furthermore, the moderately halophilic bacterium H. halophila can be applied for the decontamination of zinc from aqueous solutions
Macroscopic Properties of Biomimetic Ceramics Are Governed by the Molecular Recognition at the Bioorganic-Inorganic Interface
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