Biogeochemistry of the shelf sediments of south eastern Arabian sea: Effect on benthic bacterial heterotrophs

The composition and variability of heterotrophic bacteria along the shelf sediments of south west coast of India and its relationship with the sediment biogeochemistry was investigated. The bacterial abundance ranged from 1.12 x 103 – 1.88 x 106 CFU g-1 dry wt. of sediment. The population showed significant positive correlation with silt (r = 0.529, p< 0.05), organic carbon (OC) (r = 0.679, p< 0.05), total nitrogen (TN) (r = 0.638, p< 0.05), total protein (TPRT) (r = 0.615, p< 0.05) and total carbohydrate (TCHO) (r = 0.675, p< 0.05) and significant negative correlation with sand (r = -0.488, p< 0.05). Community was mainly composed of Bacillus, Alteromonas, Vibrio, Coryneforms, Micrococcus, Planococcus, Staphylococcus, Moraxella, Alcaligenes, Enterobacteriaceae, Pseudomonas, Acinetobacter, Flavobacterium and Aeromonas. BIOENV analysis explained the best possible environmental parameters i.e., carbohydrate, total nitrogen, temperature, pH and sand at 50m depth and organic matter, BPC, protein, lipid and temperature at 200m depth controlling the distribution pattern of heterotrophic bacterial population in shelf sediments. The Principal Component Analysis (PCA) of the environmental variables showed that the first and second principal component accounted for 65% and 30.6% of the data variance respectively. Canonical Correspondence Analysis (CCA) revealed a strong correspondence between bacterial distribution and environmental variables in the study area. Moreover, non-metric MDS (Multidimensional Scaling) analysis demarcated the northern and southern latitudes of the study area based on the bioavailable organic matter

Marine bacterial prodigiosin as dye for rubber latex, polymethyl methacrylate sheets and paper

Prodigiosin is known for its immunomodulatory, antibacterial, antimycotic, antimalarial, algicidal and anticancer activities. Here, we reported the evaluation of prodigiosin pigment as a dyeing agent in rubber latex, paper and polymethyl methacrylate (PMMA) so that it can be considered as an alternative to synthetic pigments. Maximum color shade was obtained in rubber sheet prepared with 0.5 parts per hundred gram of rubber (phr) pigment and PMMA sheet incorporated with 0.08 μg pigment. Results indicate scope for utilization of prodigiosin as dye for PMMA and rubber and also prodigiosin dyed paper as a pH indicator. Further, being a natural and water insoluble pigment, it is ecofriendly

State-of-the-Art: Transformation Invariant Descriptors

As the popularity of digital videos increases, a large number illegal videos are being generated and getting published. Video copies are generated by performing various sorts of transformations on the original video data. For effectively identifying such illegal videos, the image features that are invariant to various transformations must be extracted for performing similarity matching. An image feature can be its local feature or global feature. Among them, local features are powerful and have been applied in a wide variety of computer vision aplications .This paper focuses on various recently proposed local detectors and descriptors that are invariant to a number of image transformations.

Unusual surface and edge morphologies, sp2 to sp3 hybridized transformation and electronic damage after Ar+ ion irradiation of few-layer graphene surfaces

Roughness and defects induced on few-layer graphene (FLG) irradiated by Ar+ ions at different energies were investigated using X-ray photoemission spectroscopy (XPS) and atomic force microscopy techniques. The results provide direct experimental evidence of ripple formation, sp2 to sp3 hybridized carbon transformation, electronic damage, Ar+ implantation, unusual defects and edge reconstructions in FLG, which depend on the irradiation energy. In addition, shadowing effects similar to those found in oblique-angle growth of thin films were seen. Reliable quantification of the transition from the sp2-bonding to sp3-hybridized state as a result of Ar+ ion irradiation is achieved from the deconvolution of the XPS C (1s) peak. Although the ion irradiation effect is demonstrated through the shape of the derivative of the Auger transition C KVV spectra, we show that the D parameter values obtained from these spectra which are normally used in the literature fail to account for the sp2 to sp3 hybridization transition. In contrast to what is known, it is revealed that using ion irradiation at large FLG sample tilt angles can lead to edge reconstructions. Furthermore, FLG irradiation by low energy of 0.25 keV can be a plausible way of peeling graphene layers without the need of Joule heating reported previously

Development and Validation of Bacterial Consortia for Bioremediation of Detritus in Aquaculture Systems

Cochin University Of Science And Technology

Differential induction, isolation, physicochemical and molecular characterization of temperate phages of environmental Vibrio cholerae as evidence of phage mediated Horizontal Gene Transfer

The resurgence of the enteric pathogen Vibrio cholerae, the causative organism of epidemic cholera, remains a major health problem in many developing countries like India. The southern Indian state of Kerala is endemic to cholera. The outbreaks of cholera follow a seasonal pattern in regions of endemicity. Marine aquaculture settings and mangrove environments of Kerala serve as reservoirs for V. cholerae. The non-O1/non-O139 environmental isolates of V. cholerae with incomplete ‘virulence casette’ are to be dealt with caution as they constitute a major reservoir of diverse virulence genes in the marine environment and play a crucial role in pathogenicity and horizontal gene transfer. The genes coding cholera toxin are borne on, and can be infectiously transmitted by CTXΦ, a filamentous lysogenic vibriophages. Temperate phages can provide crucial virulence and fitness factors affecting cell metabolism, bacterial adhesion, colonization, immunity, antibiotic resistance and serum resistance. The present study was an attempt to screen the marine environments like aquafarms and mangroves of coastal areas of Alappuzha and Cochin, Kerala for the presence of lysogenic V. cholerae, to study their pathogenicity and also gene transfer potential. Phenotypic and molecular methods were used for identification of isolates as V. cholerae. The thirty one isolates which were Gram negative, oxidase positive, fermentative, with or without gas production on MOF media and which showed yellow coloured colonies on TCBS (Thiosulfate Citrate Bile salt Sucrose) agar were segregated as vibrios. Twenty two environmental V. cholerae strains of both O1 and non- O1/non-O139 serogroups on induction with mitomycin C showed the presence of lysogenic phages. They produced characteristic turbid plaques in double agar overlay assay using the indicator strain V. cholerae El Tor MAK 757. PCR based molecular typing with primers targeting specific conserved sequences in the bacterial genome, demonstrated genetic diversity among these lysogen containing non-O1 V. cholerae . Polymerase chain reaction was also employed as a rapid screening method to verify the presence of 9 virulence genes namely, ctxA, ctxB, ace, hlyA, toxR, zot,tcpA, ninT and nanH, using gene specific primers. The presence of tcpA gene in ALPVC3 was alarming, as it indicates the possibility of an epidemic by accepting the cholera. Differential induction studies used ΦALPVC3, ΦALPVC11, ΦALPVC12 and ΦEKM14, underlining the possibility of prophage induction in natural ecosystems, due to abiotic factors like antibiotics, pollutants, temperature and UV. The efficiency of induction of prophages varied considerably in response to the different induction agents. The growth curve of lysogenic V. cholerae used in the study drastically varied in the presence of strong prophage inducers like antibiotics and UV. Bacterial cell lysis was directly proportional to increase in phage number due to induction. Morphological characterization of vibriophages by Transmission Electron Microscopy revealed hexagonal heads for all the four phages. Vibriophage ΦALPVC3 exhibited isometric and contractile tails characteristic of family Myoviridae, while phages ΦALPVC11 and ΦALPVC12 demonstrated the typical hexagonal head and non-contractile tail of family Siphoviridae. ΦEKM14, the podophage was distinguished by short non-contractile tail and icosahedral head. This work demonstrated that environmental parameters can influence the viability and cell adsorption rates of V. cholerae phages. Adsorption studies showed 100% adsorption of ΦALPVC3 ΦALPVC11, ΦALPVC12 and ΦEKM14 after 25, 30, 40 and 35 minutes respectively. Exposure to high temperatures ranging from 50ºC to 100ºC drastically reduced phage viability. The optimum concentration of NaCl required for survival of vibriophages except ΦEKM14 was 0.5 M and that for ΦEKM14 was 1M NaCl. Survival of phage particles was maximum at pH 7-8. V. cholerae is assumed to have existed long before their human host and so the pathogenic clones may have evolved from aquatic forms which later colonized the human intestine by progressive acquisition of genes. This is supported by the fact that the vast majority of V. cholerae strains are still part of the natural aquatic environment. CTXΦ has played a critical role in the evolution of the pathogenicity of V. cholerae as it can transmit the ctxAB gene. The unusual transformation of V. cholerae strains associated with epidemics and the emergence of V. cholera O139 demonstrates the evolutionary success of the organism in attaining greater fitness. Genetic changes in pathogenic V. cholerae constitute a natural process for developing immunity within an endemically infected population. The alternative hosts and lysogenic environmental V. cholerae strains may potentially act as cofactors in promoting cholera phage ‘‘blooms’’ within aquatic environments, thereby influencing transmission of phage sensitive, pathogenic V. cholerae strains by aquatic vehicles. Differential induction of the phages is a clear indication of the impact of environmental pollution and global changes on phage induction. The development of molecular biology techniques offered an accessible gateway for investigating the molecular events leading to genetic diversity in the marine environment. Using nucleic acids as targets, the methods of fingerprinting like ERIC PCR and BOX PCR, revealed that the marine environment harbours potentially pathogenic group of bacteria with genetic diversity. The distribution of virulence associated genes in the environmental isolates of V. cholerae provides tangible material for further investigation. Nucleotide and protein sequence analysis alongwith protein structure prediction aids in better understanding of the variation inalleles of same gene in different ecological niche and its impact on the protein structure for attaining greater fitness of pathogens. The evidences of the co-evolution of virulence genes in toxigenic V. cholerae O1 from different lineages of environmental non-O1 strains is alarming. Transduction studies would indicate that the phenomenon of acquisition of these virulence genes by lateral gene transfer, although rare, is not quite uncommon amongst non-O1/non-O139 V. cholerae and it has a key role in diversification. All these considerations justify the need for an integrated approach towards the development of an effective surveillance system to monitor evolution of V. cholerae strains with epidemic potential. Results presented in this study, if considered together with the mechanism proposed as above, would strongly suggest that the bacteriophage also intervenes as a variable in shaping the cholera bacterium, which cannot be ignored and hinting at imminent future epidemics.

Sono, Photo and Sonophoto Catalytic Removal of Chemical and Bacterial Pollutants from Wastewater

The term ‘water pollution’ broadly refers to the contamination of water and water bodies (e.g. lakes, rivers, oceans, groundwater etc). Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove the harmful contaminants. This affects not only the plants and organisms living in these bodies of water but also the entire natural biological communities and the biodiversity.Advanced Oxidation Processes (AOPs) have been tested as environment-friendly techniques for the treatment of contaminated water, in view of their ability to convert pollutants into harmless end products. These techniques refer to a set of treatment procedures designed to remove organic or inorganic contaminants in wastewater by oxidation. The contaminants are oxidized by different reagents such as air, oxygen, ozone, and hydrogen peroxide which are introduced in precise, preprogrammed dosages, sequences and combinations under appropriate conditions. The procedure when combined with light in presence of catalyst is known as photocatalysis. When ultrasound (US) is used as the energy source, the process is referred as sonication. Sonication in presence of catalyst is referred as sonocatalysis. Of late, combination of light and sound as energy sources has been tested for the decontamination of wastewater in the presence of suitable catalyst. In this case, the process is referred as sonophotocatalysis. These AOPs are specially advantageous in pollution control and waste water treatment because unlike many other technologies, they do not just transfer the pollutant from one phase to another but completely degrade them into innocuous substances such as CO2 and H2O.

Wirkung von Ernterückständen transgener Pflanzen auf die mikrobielle C- und N-Transformation in landwirtschaftlich genutzten Böden am Beispiel von Bt-Mais

In der vorliegenden Arbeit ging es um die Erarbeitung, Anwendung und Beurteilung von quantitativen Analysenverfahren / Methoden für ein Monitoring von durch Bt-Mais verursachbaren Umwelteffekten im Boden. Die Ausgangsthese besagte, dass sich transgene Maisstreu beim mikrobiellen Abbau anders verhält als konventionelle. Bezugnehmend auf die These wurden zwei Freilandversuche (Freilandmikrokosmenmethode nach Raubuch 1997 über 2 Jahre, Quantifizierung des Maisstreuabbaus mit Hilfe kleiner Bodensäulen über 1 Jahr) und zwei Inkubationsversuche im Labor (INK bei drei verschiedenen Temperaturen über 49 Tage und INK mit verschiedenen landwirtschaftlich genutzten Böden über 49 Tage mit jeweils kontinuierlicher Respirationsratenermittlung nach Isermeyer 1952) sowie Inhaltsstoffbestimmungen der Maisstreu durchgeführt. Für alle Untersuchungen wurde Streu der vier Maissorten Novelis (transgen, Monsanto 810), Nobilis (Isolinie von Novelis), Valmont (transgen, Bt 176, Fa. Syngenta) und Prelude (Isolinie von Valmont) eingesetzt. Nach Beendigung der Laborversuche sowie des Freilandversuches nach der Freilandmikrokosmenmethode wurden mikrobielle Messgrößen wie Adenylategehalt, Ergosterolgehalt, Cmik- und Nmik-Gehalt am Boden-Streu-Gemisch bestimmt. Der Einsatz der Isotopentechnik (Bestimmung von 13C/12C an gemahlenem Boden-Streu-Gemisch bzw. gefriergetrocknetem K2SO4 als Extrakt aus dem Boden-Streu-Gemisch) ermöglichte eine genaue Quantifizierung der abgebauten Maisstreu und brachte dadurch Aufschluss über das Abbauverhalten verschiedener Maissorten. Bezüglich der Ermittlung der mikrobiellen Messgrößen ergab sich für die transgene Sorte Novelis* stets eine durchschnittlich geringere pilzliche Biomasse. Langfristig ergaben sich bei der Kohlenstoff- und Stickstoffdynamik keine Trends hinsichtlich transgener bzw. konventioneller Maisstreu. Sowohl im Freilandversuch nach der Mikrokosmenmethode als auch in den Inkubationsversuchen trat das Phänomen der kurzzeitigen Respirationsratenerhöhung der Mikroorganismen nach Zugabe der transgenen Maissorten auf, welches nicht bei Zugabe der konventionellen Maisstreu auszumachen war. ______________________________

Cereal/legume rotation effects on rhizosphere bacterial community structure in West African soils

The increased use of cereal/legume crop rotation has been advocated as a strategy to increase cereal yields of subsistence farmers in West Africa, and is believed to promote changes in the rhizosphere that enhance early plant growth. In this study we investigated the microbial diversity of the rhizoplane from seedlings grown in two soils previously planted to cereal or legume from experimental plots in Gaya, Niger, and Kaboli, Togo. Soils from these legume rotation and continuous cereal plots were placed into containers and sown in a growth chamber with maize (Zea mays L.), millet (Pennisetum glaucum L.), sorghum (Sorghum bicolor L. Moench.), cowpea (Vigna unguiculata L.) or groundnut (Arachis hypogaea L.). At 7 and 14 days after sowing, 16S rDNA profiles of the eubacterial and ammoniaoxidizing communities from the rhizoplane and bulk soil were generated using denaturing gradient gel electrophoresis (DGGE). Community profiles were subjected to peak fitting analyses to quantify the DNA band position and intensities, after which these data were compared using correspondence and principal components analysis. The data showed that cropping system had a highly significant effect on community structure (p <0.005), irrespective of plant species or sampling time. Continuous cereal-soil grown plants had highly similar rhizoplane communities across crop species and sites, whereas communities from the rotation soil showed greater variability and clustered with respect to plant species. Analyses of the ammonia-oxidizing communities provided no evidence of any effects of plant species or management history on ammonia oxidizers in soil from Kaboli, but there were large shifts with respect to this group of bacteria in soils from Gaya. The results of these analyses show that crop rotation can cause significant shifts in rhizosphere bacterial communities.

Bacterial ecology of ancient Saharan salt-enrichment ponds at Teguidda-n-Tessoumt

Little is known about the bacterial ecology of evaporative salt-mining sites (salterns) of which Teguidda-n-Tessoumt at the fringe of the West-African Saharan desert in Niger is a spectacular example with its many-centuries-old and very colorful evaporation ponds. During the different enrichment steps of the salt produced as a widely traded feed supplement for cattle, animal manure is added to the crude brine, which is then desiccated and repeatedly crystallized. This study describes the dominant Bacteria and Archaea communites in the brine from the evaporation ponds and the soil from the mine, which were determined by PCR-DGGE of 16S rDNA. Correspondence analysis of the DGGE-community fingerprints revealed a change in community structure of the brine samples during the sequential evaporation steps which was, however, unaffected by the brine's pH and electric conductivity (EC). The Archaea community was dominated by a phylogenetically diverse group of methanogens, while the Bacteria community was dominated by gamma proteobacteria. Microorganisms contained in the purified salt product have the potential to be broadly disseminated and are fed to livestock across the region. In this manner, the salt mines represent an intriguing example of long-term human activity that has contributed to the continual selection, cultivation, and dissemination of cosmopolitan microorganisms.

Synthesis of N-amino compounds and C2 symmetric N-amino compounds and transformation into aziridines using olefins

Aziridine, Stickstoffanaloga der Epoxide, können regio- und stereoselektive Ringöffnungsreaktionen eingehen, wodurch ihnen als „building blocks“ in der Organischen Synthese eine große Bedeutung zukommt. In dieser Arbeit wurden unterschiedliche N-Aminoverbindungen synthetisiert sowie die Anwendungsmöglichkeit dieser Hydrazinderivate als Stickstoffquellen in Aziridinierungen von Olefinen untersucht. In der vorliegenden Dissertation wurde eine neue Methode zur Darstellung von N-Aminosuccinimid entwickelt und die Einsatzmöglichkeit als Stickstoffquelle in Aziridinierungsreaktionen in einer Reihe von Umsetzungen mit funktionalisierten ebenso wie mit nicht-funktionalisierten Olefinen demonstriert. Die ableitbaren Aziridine wurden hierbei in Ausbeuten von bis zu 80 % erhalten. In der Aziridinierungsreaktion von N-Aminosuccinimid mit 4,7-Dihydro-2-isopropyl-1,3-dioxepin resultieren bicyclische Aziridinierungsprodukte, die als endo/exo-Isomere in einem 1:1-Verhältnis anfallen. Es ist in dieser Arbeit gelungen, die Isomere in guten Ausbeuten zu erhalten, sie säulenchromatographisch zu trennen und ihre Konfiguration im festen Zustand mittels Kristallstrukturanalyse eindeutig zu bestimmen. Enantiomerenangereicherte Olefine, wie z. B. in 2-Position alkylsubstituierte 5-Methyl-4H-1,3-dioxine mit Enantiomerenüberschüssen von 92% ee liefern in der Aziridinierung mit N-Aminosuccinimid und Iodosylbenzol ein 4-Methyl-1,3-oxazolidin-4-carbaldehydderivat in einer zweistufigen Reaktion- der Aziridinierung und einer Umlagerung- ein 4-Methyl-1,3-oxazolidin-4-carbaldehydderivat. Für die Diastereoselektivität des Aziridinierungsschrittes wurde 65 % de bestimmt. In einer neuen Synthese über zwei Stufen ausgehend von (+)-3,4-Dimethoxysuccinanhydrid konnte ein chiraler Stickstoffüberträger - (+)-N-Amino-3,4-dimethoxysuccinimid - in Ausbeuten bis zu 86 % synthetisiert. Die Umsetzung dieser optisch aktiven Stickstoffquelle mit einer Vielzahl prochiraler Alkene führt zu diastereomeren Aziridinen in Ausbeuten bis zu 65% und Diastereoselektivitäten von bis zu 66% de. Anhand ausgewählter Verbindungen konnten die Absolutkonfigurationen der Reaktionsprodukte mittels Kristallstrukturanalyse eindeutig geklärt werden.

Analyse selbsterregter Strömungsfelder im Verdichter-Leitrad durch Kopplung von Particle Image Velocimetry und Hitzdrahtanemometrie mittels Fast Fourier Transformation

Der Einsatz der Particle Image Velocimetry (PIV) zur Analyse selbsterregter Strömungsphänomene und das dafür notwendige Auswerteverfahren werden in dieser Arbeit beschrieben. Zur Untersuchung von solchen Mechanismen, die in Turbo-Verdichtern als Rotierende Instabilitäten in Erscheinung treten, wird auf Datensätze zurückgegriffen, die anhand experimenteller Untersuchungen an einem ringförmigen Verdichter-Leitrad gewonnen wurden. Die Rotierenden Instabilitäten sind zeitabhängige Strömungsphänomene, die bei hohen aerodynamischen Belastungen in Verdichtergittern auftreten können. Aufgrund der fehlenden Phaseninformation kann diese instationäre Strömung mit konventionellen PIV-Systemen nicht erfasst werden. Die Kármánsche Wirbelstraße und Rotierende Instabilitäten stellen beide selbsterregte Strömungsvorgänge dar. Die Ähnlichkeit wird genutzt um die Funktionalität des Verfahrens anhand der Kármánschen Wirbelstraße nachzuweisen. Der mittels PIV zu visualisierende Wirbeltransport erfordert ein besonderes Verfahren, da ein externes Signal zur Festlegung des Phasenwinkels dieser selbsterregten Strömung nicht zur Verfügung steht. Die Methodik basiert auf der Kopplung der PIV-Technik mit der Hitzdrahtanemometrie. Die gleichzeitige Messung mittels einer zeitlich hochaufgelösten Hitzdraht-Messung ermöglicht den Zeitpunkten der PIV-Bilder einen Phasenwinkel zuzuordnen. Hierzu wird das Hitzdrahtsignal mit einem FFT-Verfahren analysiert, um die PIV-Bilder entsprechend ihrer Phasenwinkel zu gruppieren. Dafür werden die aufgenommenen Bilder auf der Zeitachse der Hitzdrahtmessungen markiert. Eine systematische Analyse des Hitzdrahtsignals in der Umgebung der PIV-Messung liefert Daten zur Festlegung der Grundfrequenz und erlaubt es, der markierten PIV-Position einen Phasenwinkel zuzuordnen. Die sich aus den PIV-Bildern einer Klasse ergebenden Geschwindigkeitskomponenten werden anschließend gemittelt. Aus den resultierenden Bildern jeder Klasse ergibt sich das zweidimensionale zeitabhängige Geschwindigkeitsfeld, in dem die Wirbelwanderung der Kármánschen Wirbelstraße ersichtlich wird. In hierauf aufbauenden Untersuchungen werden Zeitsignale aus Messungen in einem Verdichterringgitter analysiert. Dabei zeigt sich, dass zusätzlich Filterfunktionen erforderlich sind. Im Ergebnis wird schließlich deutlich, dass die Übertragung der anhand der Kármánschen Wirbelstraße entwickelten Methode nur teilweise gelingt und weitere Forschungsarbeiten erforderlich sind.

Hegemony, Private Actors, and International Institutions: Transnational Corporations as the agents of transformation of the trade regime from GATT to the WTO

Diese Dissertation hat das Ziel, zum einen die Transformation des Handelssystems von der GATT zur Welthandelsorganisation (WTO) im Kontext einer veränderten Weltordnung und zum anderen die Rollen von transnationalen Unternehmen im Rahmen dieser Transformation zu untersuchen und zu verstehen. Die Arbeit wird theoretisch vom Neogramscianismus angeleitet, da die etablierten Ansätzen in den Internationalen Beziehungen und der International Politischen Ökonomie nur unzureichend die intersubjektive Natur von Regimen und nicht-staatlichen Akteuren darstellen. Für Anhänger des Neogramscianismus sind internationale Regime intersubjektive Einheiten, deren Zusammenspiel von Ideen und Machtkonfigurationen historische Strukturen prägen. Die Hegemonie ist ein Konzept, das soziale Einflüsse als Agenten historischen Wandels in international Regimen und der Weltordnung zusammenbindet. Mit dem Konzept der Hegemonie wird eine Machtsituation beschrieben, in der politische Macht in legitime Autorität übersetzt wird, indem die Zustimmung subalterner Akteure eingeholt wird. Hegemonie beinhaltet die konsensuellen Aspekte von Machtausübung in einer jeweiligen Weltordnung. Diese Dissertation argumentiert vor allem, dass die Transformation des Handelssystems als hegemonisch bezeichnet werden kann, da sie parallel mit der Transformation der Weltordnung von einer von den USA dominierten Nachkriegszeit zu einer neoliberalen Hegemonie stattfand. Mit der Transformation zur Welthandlungsorganisation wird der legale Rahmen des Handelssystems neu strukturiert und ihre normative Grundlagen neu definiert, wodurch der ethische Rahmen des Neoliberalismus reflektiert wird. Diese Änderungen werden in der neuartigen Anerkennung der legitimen Autorität des Marktes gegenüber Nationalstaaten und der Anerkennung von der Notwendigkeit von bindenden Disziplinen, die Regierungen übergeordnet sind, reflektiert. Diese Dissertation analysiert zwei Fälle, um die Rolle von transnationalen Unternehmen innerhalb diese Transformationsprozesses zu erklären. Dabei wird der Fokus vor allem auf die Aktivitäten und Fähigkeiten der Unternehmen gerichtet, die Ausrichtung des Handelsregimes zu bestimmen. Die erste Studie untersucht die Eingliederung von Dienstleistungen in das GATT Regime vor und während der Uruguay-Runde (1986 – 1994) und argumentiert, dass diese Eingliederung zu einer Neudefinierung von Liberalisierung und Normen der Nichtdiskriminierung führte. Die zweite Studie analysiert den gescheiterten Versuch, ausländische Direktinvestitionen noch bevor und während der 2001 begonnenen Doha Runde in die Welthandelsorganisation zu integrieren. Letztendlich wird in dieser Dissertation argumentiert, dass transnationale Unternehmen, die in den Vereinigten Staaten ansässig sind, hegemonische Agenten der Regimetransformation waren und eine wichtige Rolle dabei gespielt haben, Dienstleistungen in das GATT einzubinden. Und zwar gelang ihnen dies durch eine in den späten 1970er Jahren begonnenen Kampagne. Auf der einen Seite war die Kampagne darin erfolgreich, etablierte Denkstrukturen zu Handelsthemen systematisch im Sinne des Neoliberalismus zu verändern – und zwar sowohl hinsichtlich der normativen Inhalte als auch der intersubjektiven Bedeutungen des Regimes. Auf der anderen Seite deutet der Fall des Investitionsabkommens die Grenzen der hegemonischen Ideen, Institutionen, und Strömungen seit den frühen 90er Jahren an. Transnationale Unternehmen, die in Europa ansässig waren, sind mit ihren Bemühungen gescheitert, das Regime weiter zu transformieren und das Thema Investitionen in die legalen und normativen Rahmenbedingungen der WTO zu integrieren. Die Prioritäten und Strategien der transnationalen Unternehmen, die Agenda der WTO zu beeinflussen, waren beschränkt und wurden im Kontext einer angefochtenen neoliberalen Hegemonie geformt, die wiederum von dem Widerstand und anti-hegemonischen Kampagnen der Zivilgesellschaft beeinflusst wurden. Die Analyse in dieser Dissertation wurde durch eine qualitative Diskursanalyse von Sekundär- und Primärquellen durchgeführt: Regierungsvorschläge, Verhandlungstexte, Konferenzzusammenfassungen und Statements von Unternehmen.

Effects of transformation processes in 'jubraka' agroforestry systems of the Nuba Mountains, Sudan, on nutrient fluxes

Intensification processes in homegardens of the Nuba Mountains, Sudan, raise concerns about strongly positive carbon (C) and nutrient balances which are expected to lead to substantial element losses from these agroecosystems, in particular via soil gaseous emissions. Therefore, this thesis aimed at the quantification of C, nitrogen (N), phosphorus (P) and potassium (K) input and output fluxes with a special focus on soil gaseous losses, and the calculation of respective element balances. A further focus in this thesis was rainfall, a valuable resource for rain-fed agriculture in the Nuba Mountains. To minimize negative consequences of the high variability of rainfall, risk reducing mechanisms were developed by rain-fed farmers that may lose their efficacy in the course of climate change effects predicted for East Africa. Therefore, the second objective of this study was to examine possible changes in rainfall amounts during the last 60 years and to provide reliable risk and probability statements of rainfall-induced events of agricultural importance to rain-fed farmers in the Nuba Mountains. Soil gaseous emissions of C (in form of CO2) and N (in form of NH3 and N2O) of two traditional and two intensified homegardens were determined with a portable dynamic closed chamber system. For C gaseous emission rates reached their peak at the onset of the rainy season (2,325 g CO2-C ha-1 h-1 in an intensified garden type) and for N during the rainy season (16 g NH3-N ha-1 h-1 and 11.3 g N2O-N ha-1 h-1, in a traditional garden type). Data indicated cumulative annual emissions of 5,893 kg CO2-C ha-1, 37 kg NH3-N ha-1, and 16 kg N2O-N ha-1. For the assessment of the long-term productivity of the two types of homegardens and the identification of pathways of substantial element losses, a C and nutrient budget approach was used. In three traditional and three intensified homegardens observation plots were selected. The following variables were quantified on each plot between June and December in 2010: soil amendments, irrigation, biomass removal, symbiotic N2 fixation, C fixation by photosynthesis, atmospheric wet and dry deposition, leaching and soil gaseous emissions. Annual balances for C and nutrients amounted to -21 kg C ha-1, -70 kg N ha-1, 9 kg P ha-1 and -117 kg K ha-1 in intensified homegardens and to -1,722 kg C ha-1, -167 kg N ha-1, -9 kg P ha-1 and -74 kg K ha-1 in traditional homegardens. For the analysis of rainfall data, the INSTAT+ software allowed to aggregate long-term daily rainfall records from the Kadugli and Rashad weather stations into daily, monthly and annual intervals and to calculate rainfall-induced events of agricultural importance. Subsequently, these calculated values and events were checked for possible monotonic trends by Mann-Kendall tests. Over the period from 1970 to 2009, annual rainfall did not change significantly for either station. However, during this period an increase of low rainfall events coinciding with a decline in the number of medium daily rainfall events was observed in Rashad. Furthermore, the availability of daily rainfall data enabled frequency and conditional probability calculations that showed either no statistically significant changes or trends resulting only in minor changes of probabilities.