Variability in streamflow and electrical conductivity in temporary headwater streams on Zürichberg

The understanding of streamflow generation in temporary headwater streams is greatly restricted. Our limited knowledge can be partly attributed to insufficient data on streamflow in these types of streams, as well as complexities arising from a variety of influencing factors and variations among headwater catchments. Their impact on the water quantity and quality of the downstream river network reinforces the urgent need for further research in this field, especially in light of expected developments under climate and land use changes. To achieve sustainable management of these ecosystems, a more in-depth understanding of their functioning is essential. This thesis presents the results of manual surveys conducted on discharge and streamwater electric conductivity (EC) in the headwater catchment on Zürichberg. The study analyzed the spatiotemporal patterns of absolute values and variability in streamflow and water chemistry of temporal streams. It also examined the correlation between these measurements and various catchment characteristics such as elevation, slope, and geology. Additionally, the study investigated the potential to predict flow cessation or the duration of dry streambed conditions based on the coefficient of variation in discharge and EC values. The measured data exhibited complex spatiotemporal patterns for both discharge and EC. Different sites and streams display patterns influenced by varying factors such as topography, springs, and geology. The entire study area displays intensified influence of deeper groundwater at lower elevations and in steeper catchments. The presence of Molasse only moderately correlates with the variability in EC, indicating a weak trend of more stable water sources in Molasse areas. The negative correlation between the mean EC, a proxy for water age, and discharge variability renders a balancing effect of deeper groundwater on streamflow. In contrast, younger streamflow displays a trend towards greater discharge variability. However, the data on variability cannot predict the probability of a stream segment drying up during low-flow conditions towards the end of summer. Further research is needed to fully understand how the complex features of headwater catchments affect the generation of streamflow in temporary headwater streams and to be able to implement sustainable management practices and predict the impact of global change

Bryophytes from the Cape Verde Islands

Almost 450 specimens of bryophytes, so far the largest collection of bryophytes ever made on the Cape Verde Islands, were collected in 1995 by the second author on the major islands of the archipelago. Twenty seven species (3 hepatics, 24 mosses) are reported as new to the Cape Verde Islands: Lejeunea ulicina (Tayl.) Gottsche et al., Riccia cavernosa Hoffm. emend. Raddi, Targionia hypophylla L., Barbula cf. consanguinea (Thwait. & Mitt.) Jaeg., Barbula unguiculata Hedw., Brachymenium exile (Dozy & Molk.) Bosch. & Lac., Bryoerythrophyllum ferruginascens (Stirt.) Giac., Bryoerythrophyllum inaequalifolium (Tayl.) Zander, Bryum cellulare Hook., Chenia leptophylla (C. Müll.) Zander, Desmatodon bogosicus C. Müll., Didymodon australasiae (Hook. & Grev.) Zander, Didymodon maschalogena (Ren. & Card.) Broth. (Didymodon michiganensis [Steere] K. Saito), Didymodon vinealis (Brid.) Zander var. flaccidus (B.S.G.) Zander, Eurhynchium meridionale (B.S.G.) De Not., Eurhynchium speciosum (Brid.) Jur., Fissidens sciophyllus Mitt., F. bogosicus C. Müll., F. flaccidus Mitt., F. helictocaulos C. Müll., Gymnostomiella cf. vernicosa (Hook.) Fleisch., Gymnostomum calcareum Nees & Hornsch., Hyophila involuta (Hook.) Jaeg., Orthotrichum diaphanum Brid., Tortula cuneifolia (With.) Turn., Tortula laevipila (Brid.) Schwaegr. and Weissia microstoma (Hedw.) C. Müll. The doubtful record of Marchantia paleacea Bertol. could be confirmed. Numerous species are recorded as new to single islands. Tortula pierrotii Biz. described from Tanzania has proved to be synyomous with Bryoerythrophyllum inaequalifolium. Didymodon maschalogena (Ren. & Card.) Broth. is an older name for Didymodon michiganensis (Steere) K. Saito. A study of types of species described as endemic to the Cape Verde Islands revealed that Barbula bolleana (C. Müll.) Broth. is an earlier name for Hydrogonium bolleanum (C. Müll.) Jaeg., Barbula elliottii Broth., Barbula kivuensis Leroy & P. de la Varde and Barbula madagassa Ren. & Card. are synonymous with the latter, Hyophila crenulata C. Müll. ex Dus. var. brevifolia Bizot is synonymous with Hyophila involuta (Hook.), Barbula sulcata Geh. is synonymous with B. convoluta Hedw. and Tortula subcaroliniana Bizot is synonymous with Tortula amphidiacea (C. Müll.) Broth. In addition to the so far unpublished results of recent collections, a complete survey of the bryophyte flora of the Cape Verde Islands is given. A hundred and sixty two species (2 species of hornworts, 36 species of hepatics and 124 species of mosses) are so far known from this archipelago

FGF8 Acts as a Right Determinant during Establishment of the Left-Right Axis in the Rabbit

AbstractBackground: FGF8 has been implicated in the transfer of left-right (L-R) asymmetry from the embryonic midline (node) to the lateral plate mesoderm (LPM). Surprisingly, opposite roles have been described in chick and mouse. In mouse, FGF8 is required for the left-asymmetric expression of nodal, lefty2, and Pitx2. In chick, FGF8 represses nodal and Pitx2 on the right side. This discrepancy could reflect evolutionary differences between birds and mammals. Alternatively, the right-asymmetric expression of fgf8, which is not found in mouse, at the chick node may be a prerequisite of right-sided function. Finally, chick (blastodisc) and mouse (egg cylinder) differ with respect to the topology of the early gastrula/neurula embryo.Results: The rabbit blastodisc was investigated as an additional mammalian L-R model system. While nodal, lefty, and Pitx2 showed asymmetric expression in the left LPM, fgf8 and all other midline marker genes were symmetrically expressed at the node like in mouse. Left-sided application of FGF8 repressed the endogenous transcription of nodal as well as ectopic expression induced by the parallel administration of BMP4. Right-sided inhibition of FGF8 signaling induced bilateral marker gene expression, demonstrating that, in rabbit, FGF8 acts as a right determinant like in chick.Conclusions: These findings suggest that the anatomy of the early embryo (blastodisc versus egg cylinder) rather than taxonomical differences or asymmetry in expression constitutes an important determinant of FGF8 function in L-R axis formation. The rabbit may provide a useful model for early human embryogenesis, as human embryos develop via a blastodisc as well

Der Einfluß von Melatonin auf das Wachstum humaner Haarfollikel unter In-vitro-Bedingungen

In der vorliegenden Arbeit wurde erstmals das Wachstum menschlicher Haar-follikel unter Einwirkung von Melatonin in vitro untersucht. Dabei zeigte sich unter niedrigeren Konzentrationen ( 30 µmol ) ein besseres Wachstum im Vergleich zum Basiskulturmedium Williams E Medium. Im Kulturmedium mit Melatoninantagonist 4-PDOT war im gesamten Untersuchungszeitraum ein signifikant schlechteres Wachstum im Vergleich zu Melatonin 30 µmol und Williams E Medium zu beobachten. Eine direkte Melatoninwirkung am Haarfollikel ist somit zu vermuten. Mit Ki-67-Antikörper wurde die Proliferationszellfraktion in Follikeln aus verschiedenen Kulturmedien dargestellt. Signifikante Unterschiede waren hierbei nicht aufzuzeigen

Unterhaltung in der Wüste

Soziales Handeln und Kommunikation sind die zentralen Elemente, durch die sich eine Gesellschaft konstituiert und verortet. Diese Studie zielt auf eine detaillierte Analyse der sozialen Gesichtspunkte der verbalen Interaktion am Beispiel der Imuhaê-NomadInnen in der Algerischen Sahara ab. Die forschungsleitende Fragestellung dabei lautet: Wie reflektiert sich Soziabilität im interaktionalen Gebrauch von semiotischen Ressourcen? Ziel dieser Untersuchung ist es, die komplexen sozialen Zusammenhänge der interaktionalen Kommunikation bei den Imuhaê zu analysieren. Dabei dient als Grundstein der Forschung der von Hymes (1971[1962]) entwickelte Ansatz der Ethnographie des Sprechens. Das Hauptaugenmerk dieser Arbeit liegt auf der semiotischen Gemeinschaft von Sprechen, Raum, Zeit, Gender, Alter, Hierarchie, sozialen Werten und Normen in einer nomadischen Gesellschaft. Bei dieser Arbeit handelt es sich um eine empirische Studie, die auf teilnehmender Beobachtung in der Feldforschung basiert. Die qualitative Methode der Anthropologie erlaubt Einblick in die soziokulturellen Komponenten der Unterhaltung. Durch das Sprechen eröffnet sich die unsichtbare Dimension des sozialen Handelns. Der Fokus der Untersuchung liegt nicht auf der Bevölkerung insgesamt, sondern auf der individuellen Persönlichkeit. Mit Hilfe der Darstellung einer Person in ihrem Umfeld und im Zusammenhang mit einer kommunikativen Komponente wird versucht, dem „native point of view“ entgegen zu kommen. Zunächst wird in dieser Studie das ethnographische Feld um die Imuhaê aufgespannt. In einem Überblick präsentiere ich das nomadische Gefüge im geographischen Kontext. Danach entfaltet sich der komplexe linguistische Raum mit seiner enormen Sprachenvielfalt. Im Anschluss erfolgt die Aufarbeitung der persönlichen Erfahrungen in der Feldforschung, in der die permanente Selbstreflexion erforderlich ist. Den Abschluss des ersten einführenden Teils dieser Studie bildet ein kurzer theoretischer Einstieg in die linguistische Nomadologie und in die Ethnographie des Sprechens. Der empirische zweite Teil ist das Kernstück – die Nomadographie des Sprechens. Die Unterhaltungen in der Wüste werden anhand von personalisierten linguistischen Portraits veranschaulicht. Durch die Darstellung des sozialen, räumlichen und zeitlichen Schauplatzes wird zunächst eine Kontextualisierung der verbalen Kommunikation versucht. Die Exposition des Alltagsgesprächs bis hin zu komplexen Sprechgenres zeigen die verbale Virtuosität der NomadInnen. In dem Zusammenhang wird unter anderem auf die Geheimsprachen, die Rätsel, die Poesie, die Sprichwörter und die Geschichten der Imuhar eingegangen. Im letzten Teil werden die vielschichtigen Zusammenhänge von Soziabilität und Sprachgebrauch analysiert. Soziale Werte und Normen beeinflussen die Wahl der Worte und formen sprachliche Interaktionsnormen. Durch die analytische Betrachtung der Bedeutung des Sprechens werden die Sprechmuster der NomadInnen nachvollziehbar. Dafür werden die Bedingungen des adäquaten Kommunikationsverhaltens fokussiert und es wird versucht, die Kommunikations-gewohnheiten der Gemeinschaft darzustellen. Die Situationen, der Gebrauch, das Muster und die Funktion des Sprechens zeigen den engen Konnex von verbaler Interaktion und Soziabilität. Was bedeutet das Sprechen für NomadInnen? Im letzten Kapitel kristallisiert sich das Sprechkonzept der Imuhaê heraus und die Interpretationsmuster des Sprechens der NomadInnen werden deutlich. Das Wissen über die Art und Weise des Sprechens (ways of speaking) eröffnet den Zugang zu einer Gesellschaft. Der Sprachgebrauch wird als sozialer Prozess interpretiert. Diese Untersuchung analysiert das Sprechverhalten in der Unterhaltung der Imuhaê mit einem holistischen Ansatz. Welche semiotischen Muster sind in welchem Kontext verfügbar und wie, wann und wo werden diese verwendet? Haben Sahara-NomadInnen eine spezifische Auffassung, was Sprechen bedeutet, und woraus setzt sich adäquates Sprechen in der Gesellschaft der nomadischen Imuhaê zusammen? Thema dieser Studie ist die kommunikative Funktion der Sprache bei der Konstitution von sozialem Leben in der Wüste.Social acting and communication are the central elements, which constitute a society. This study focuses on a detailed analysis of social aspects of verbal interaction among the Imuhar nomads (“Tuareg”) in the Algerian desert. The central question in my research is: How is sociability reflected in its interactional use of semiotic resources? The aim of this study is to analyse the complex social components of interactional communication in the Imuhar society. The approach to an ethnography of speaking as developed by Hymes (1971[1962]) gives the basis of this research. The focal point of this work is to be found in the semiotic congruence between speaking, space, time, gender, age, hierarchy, values, and norms in a nomadic society. This empiric study is based on participant observation in fieldwork. The qualitative method in anthropology allows an insight into the social and cultural components in verbal interaction. Speaking opens the invisible dimension of social acting. The focus of the investigation is not on the population as such, but aims on the individual personality. Introducing a person in a situation of speaking and in a context of communicative components shall try to find the “native point of view”. In the first part of this study the ethnographic field of the Imuhar is presented. Then, the complex linguistic space is described with its enormous variety of language, followed by a concise theoretical introduction in the Linguistic Anthropology and the ethnography of speaking. The second, the empiric, is the main part – the nomadography of speaking. The conversations in the desert are illustrated by the way of personalised linguistic portraits. Presenting the social, spatial and timely situation tries to contextualise the verbal communication. Exposing the everyday talk up to the complex genres of speaking shows the verbal virtuosity of the nomads. In the final part the multi-layered connections of sociability and the use of speech are analysed. Social values and norms have an influence to chose words and form norms of interaction. By the analytic viewing of the meaning of speaking the patterns of speech of the nomads can be followed. Consequently the conditions of adequate behaviour of communication are focussed to try to illustrate the habits of communications of the community. The situation, the use, the pattern and the function of speaking show the close correlation of verbal interaction and sociability. What means speaking to the nomads? In the last chapter the concept of speaking crystallises and the patterns of interpretation of speaking among nomads gets clear. The knowledge on the ways of speaking opens an access to this society. The use of speech is interpreted as a social process. Which semiotic patterns are available in which context and how, when and where are they used? As for this the various speech genres like the secret languages, the riddles, the proverbs and the tales among Imuhar are investigated. Do nomads in the desert have a specific conception, what speaking means and what adequate speaking implies in the society of the Imuhar? The theme of the study is the communicative function of language while constituting social life in the desert

Products released from structurally different dextrans by bacterial and fungal dextranases

Dextran hydrolysis by dextranases is applied in the sugar industry and the medical sector, but it also has a high potential for use in structural analysis of dextrans. However, dextranases are produced by several organisms and thus differ in their properties. The aim of this study was to comparatively investigate the product patterns obtained from the incubation of linear as well as O3- and O4-branched dextrans with different dextranases. For this purpose, genes encoding for dextranases from Bacteroides thetaiotaomicron and Streptococcus salivarius were cloned and heterologously expressed in Escherichia coli. The two recombinant enzymes as well as two commercial dextranases from Chaetomium sp. and Penicillium sp. were subsequently used to hydrolyze structurally different dextrans. The hydrolysis products were investigated in detail by HPAEC-PAD. For dextranases from Chaetomium sp., Penicillium sp., and Bacteroides thetaiotaomicron, isomaltose was the end product of the hydrolysis from linear dextrans, whereas Penicillium sp. dextranase led to isomaltose and isomaltotetraose. In addition, the latter enzyme also catalyzed a disproportionation reaction when incubated with isomaltotriose. For O3- and O4-branched dextrans, the fungal dextranases yielded significantly different oligosaccharide patterns than the bacterial enzymes. Overall, the product patterns can be adjusted by choosing the correct enzyme as well as a defined enzyme activity

A Machine Learning-Based Raman Spectroscopic Assay for the Identification of Burkholderia mallei and Related Species

Burkholderia (B.) mallei, the causative agent of glanders, and B. pseudomallei, the causative agent of melioidosis in humans and animals, are genetically closely related. The high infectious potential of both organisms, their serological cross-reactivity, and similar clinical symptoms in human and animals make the differentiation from each other and other Burkholderia species challenging. The increased resistance against many antibiotics implies the need for fast and robust identification methods. The use of Raman microspectroscopy in microbial diagnostic has the potential for rapid and reliable identification. Single bacterial cells are directly probed and a broad range of phenotypic information is recorded, which is subsequently analyzed by machine learning methods. Burkholderia were handled under biosafety level 1 (BSL 1) conditions after heat inactivation. The clusters of the spectral phenotypes and the diagnostic relevance of the Burkholderia spp. were considered for an advanced hierarchical machine learning approach. The strain panel for training involved 12 B. mallei, 13 B. pseudomallei and 11 other Burkholderia spp. type strains. The combination of top- and sub-level classifier identified the mallei-complex with high sensitivities (>95%). The reliable identification of unknown B. mallei and B. pseudomallei strains highlighted the robustness of the machine learning-based Raman spectroscopic assay