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The thesis is about ideological change of political parties and the way parties gather information, learn by updating their beliefs and ultimately make "rational choices". Analyzing 1451 policy moves of 137 parties in 22 OECD-countries from 1950 to 2013 it is a story about rational learning, about emulating other parties abroad and chasing public opinion. Yet, the "internal life" of a party conditions the effects when activists have some influence over the formation of party policy. As volunteers facing a scarcity of time and resources, members of the party on the ground have a different information horizon, and may arrive at the opposite decision where to move than party elites which (can) rest their decision on a broader set of information resources. In some parties the party on the ground thus constitutes an "internal wall of resistance" to the strategy party elites would choose, if they were free from constraints.
The present doctoral dissertation comprises new studies on the fossil vertebrate assemblage recovered from the late Early Jurassic marine “Green Series” clay deposits of Grimmen and Dobbertin in north-eastern Germany that contribute to fill the gap of knowledge regarding its faunal composition and its relevance for understanding Early Jurassic vertebrate life. The investigations led to the recognition of wide range of vertebrate taxa, including basal gravisaurian sauropods, secondarily marine reptiles, a diverse fauna of leptolepid fishes, and a new genus and species of pycnodontiform fishes. In addition, a taxonomic revision of the Early Jurassic saurichthyid fish Saurorhynchus was performed, leading to the identification of two new, previously unnamed species. The results provide new insights into the taxonomic, systematic, and ecological diversity of Early Jurassic vertebrates, and hence add significant new data to our knowledge on Lower Jurassic vertebrate palaeobiodiversity patterns.
Numerous signalling pathways orchestrate the development, the functions, and the survival of cells, mostly in response to external stimuli. An overwhelming amount of data supports the concept of specific, spatio-temporal redox signalling pathways that affect the redox state of protein cysteinyl side chains and thus the biological function of these proteins. Glutaredoxins (Grxs) and thioredoxins (Trxs) catalyse reversible thiol-disulphide exchange reactions. The cytosolic Grx2 isoform Grx2c is essential for brain development and axonal outgrowth. A reversible dithiol-disulphide switch of CRMP2 has been identified as one of the major targets regulated by Grx2c. This CRMP2 redox switch is toggled in neuronal differentiation. Reduction of CRMP2 thiols induces profound conformational changes, modifying interactions and downstream elements of this redox switch. In [article I] and [manuscript V], we identified the Cys504 of CRMP2 to be the redox regulated residue. We used various in vitro assays with recombinant protein and molecular dynamics simulations to characterise the conformational change. The changes involve the solvent accessible surface area of at least one known phosphorylation site at the C-terminus of the protein. In [article III], we analysed the function of Grx2 and Trx1 in a model for perinatal asphyxia. Trx family proteins exhibit a very complex, cell-type and tissue specific expression pattern following hypoxia/ischemia and reoxygenation, especially Trx1 and Grx2. The results imply the clinical relevance for both proteins in perinatal asphyxia as well as many other neurological disorders. In agreement with the results presented in [articleI], Grx2 may be required for the re-establishment of neuronal integrity and connectivity. Cell shape, all forms of intracellular transport, and cell movement depend on the cytoskeleton, particularly on the fine tuned complex regulation of the dynamic re-arrangement of actin filaments and microtubules. In [article IV], we discuss the redox regulation of this dynamic cytoskeletal remodelling. Taking recent discoveries into account, we focus on redox signalling mechanisms, e.g. reversible thiol and methionyl switches. These switches are specifically controlled by enzymes such as Trx1 and Grx2c, for instance, and not the result of random modification by unspecific oxidants. Methionyl sulphoxidation of actin can be reversed by methionyl sulphoxide reductase (MsrA), promoting actin polymerisation. Human cells express two different Msr enzymes (MsrA and MsrB), that can reduce S- and R-methionyl sulphoxide, respectively. In the gram-positive Streptococcus pneumoniae, on the other hand, both Msr genes and thus enzymes were fused during evolution. In [article II], we characterised the surface-exposed thioredoxin family lipoproteins Etrx1 and 2 and regulators of this Msr (SpMsrAB). A loss of function of both Etrx proteins or SpMsrAB dramatically reduced pneumococcal virulence, enhanced the bacterial uptake by macrophages, and accelerated pneumococcal killing by H2O2 or free methionine sulphoxide. Identification and characterisation of components of this redox regulated system may contribute to the design of new antimicrobials. In [manuscript VI], we investigated the effects of Grx2c expression on cell morphology, migration, and invasion behaviour of cancer cells. Grx2c expressing cancer cells developed dramatic changes in phenotype, including alterations in cytoskeletal dynamics and significantly increased motility and invasiveness. We used quantitative proteomics and phopshoproteomic approaches to characterise the underlying mechanisms. Proteins and pathways regulating cytoskeletal dynamics, cell adhesion, and receptor-mediated signal transduction were detected to be specifically altered. We started a clinical pilot study with patients suffering from clear cell renal cell carcinoma (ccRCC). Grx2c was expressed with significantly higher frequency in ccRCC compared to healthy kidney tissue, associated with a strong trend for locally more advanced tumour stages and a clear tendency for a decreased cancer-specific survival, compared to patients without detectable Grx2c. These results were supported by data from "The Cancer Genome Atlas". In synopsis, the results presented and discussed in these articles and manuscripts, support the concept of specific redox signalling in different models and model organisms. They also demonstrate the importance of the specific redox control of signalling pathways that, in the case of errors or misinterpretations, contribute to pathophysiological alterations. The regulation of the CRMP2 redox switch by Grx2c, for instance, is physiologically essential for brain development, but might lead to cancer progression, if "switched on" in adult tissue. Identification of further interaction partners as well as the development of compounds modulating this redox switch and CRMP2s conformations, will be part of our future research.
Deflected by the barrier function of topographical structures such as high mountain ranges, open water bodies or desert, migrating birds concentrate at certain points or corridors referred to as ‘bottlenecks’. An area like this was discovered at Mount Besh Barmag (Azerbaijan) in autumn 2007, but the data gathered during a four-week survey was insufficient to do more than hint at the existence of a major bird migration bottleneck. Therefore, a comprehensive bird migration study was conducted to analyse the magnitude of this potential bottleneck site. The study covers the periods from August to mid-November 2011 and from March to the end of May 2012 and includes daily counts at three observation points focusing on three different migrant types: passerine, waterbirds and soaring birds. In addition, a sound recorder with an omnidirectional microphone collected bird migration calls by both day and night. In total, 278 bird species were observed in an estimated passage of 1,239,369–1,514,267 diurnally migrating individuals in autumn 2011 and 646,733–817,183 individuals in spring 2012. Fifteen species passed through the study area in numbers exceeding 1% of their world populations and 34 species in more than 1% of their flyway populations in at least one of the observation periods. 84% of the observed migrating birds in autumn 2011 and 95% of them in spring 2012 passed through at heights below 50 m above ground exposing them imminently to the danger of collision with obstacles. In the analysis of nocturnal sound recordings, 119 bird species were identified of which 106 were expected to occur as migrants, and calculated estimates revealed the occurrence of 108,986 calls in autumn 2011 and 33,348 calls in spring 2012. The volume of diurnal bird migration emerging from the data with respect to species number and number of individuals is certainly a strong indication of the existence of a major bird migration bottleneck at Besh Barmag. On account of methodological constraints, the high number of night flight calls can only hint at a nocturnal bird migration bottleneck and confirmatory research aided by visual methods (radar, thermal imaging) is necessary to back up the acoustic results. The Besh Barmag bottleneck offers a great opportunity to establish a standardised long-term monitoring programme to investigate avian population dynamics in the vast and little known Eurasian landmass. Acoustic-based monitoring might be a cost-effective method, but it is limited to a few vocally prolific species only. The aim should rather be the establishment of a bird observatory as already successfully installed in a number of European bird migration bottlenecks.
Transfusion-related acute lung injury (TRALI) is an adverse transfusion reaction and the major cause of transfusion-related mortality. The syndrome occurs within six hours after transfusion and is characterized by acute respiratory distress and the occurrence of a non-cardiogenic, bilateral lung edema. TRALI is almost entirely induced by leukocyte-reactive substances which are present in the blood product and get transferred to the recipient during transfusion. The majority of cases (~80%) is caused by leukocyte-reactive immunoglobulins and is accordingly classified as immune-mediated TRALI. The responsible antibodies are generated via alloimmunization and are directed against human leukocyte antigens of class I and II or human neutrophil alloantigens (HNA). Within the HNA class, HNA-3a antibodies have an exceptional clinical relevance as they are most frequently involved in severe and fatal TRALI cases. The high mortality was associated with their characteristic ability to induce a strong neutrophil aggregation response. The described clinical relevance of HNA-3a antibody-mediated TRALI motivates the screening for new strategies for preventive or acute pharmacologic intervention. Knowledge of the molecular pathomechanisms is a crucial prerequisite and thus, respective investigations are required. In order to achieve this goal, HNA-3a antibody-induced cytotoxicity and aggregation were assessed on the molecular level by usage of flow cytometry, the granulocyte agglutination test and by phosphoproteome analysis. The current study provides insight into molecular processes during HNA-3a antibody-induced neutrophil responses and is the first to assess neutrophils using global, gel-free phosphoproteome analyses. Accordingly, it is the first to provide neutrophil phosphoproteome data in the context of TRALI. Gel-free phosphoproteome analyses of primary neutrophils required the highly selective and sensitive phosphopeptide enrichment from stable and sufficiently large protein extracts. However, an appropriate workflow did not exist and was hence developed by sequential protocol optimization steps. The developed workflow was finally proven suitable for comparative gel-free phosphoproteomics when detecting the formyl-methionyl-leucyl-phenylalanine-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2) signaling in a proof-of-principle experiment. The following single parameter analyses were conducted to investigate neutrophils for their responses to HNA-3a antibodies in absence and presence of proinflammatory priming conditions. Results revealed that the direct stimulation of neutrophils with HNA-3a antibodies will likely not cause the induction of cytotoxic effector functions. In contrast, neutrophils react predominantly by aggregation, a process which is potentially mediated by integrins and causes a secondary, subthreshold activation of solely ERK2. Accordingly, only the neutrophil aggregation response could also be enhanced by an appropriate priming. Taken together, the single parameter analyses proved neutrophil aggregation as the main pathomechanism in HNA-3a antibody-mediated TRALI and thus, the underlying signaling pathways were investigated by global, gel-free phosphoproteomics. The following phosphoproteome analyses indicated the induction of a biphasic signaling during 30 minutes of HNA-3a antibody treatment and signaling pathways of Rho family GTPases could be associated with the first and the second phase. Additionally, the involvement of ERK signaling was indicated in the second phase and this result corroborated thus the data of the previous single parameter analyses. The comprehensive analysis of the identified signaling pathways revealed Rho, Rac and Cdc42 as central regulators and the specific inhibition of Rho in the following validating experiments led very intriguingly to a significant enhancement of HNA-3a antibody-mediated neutrophil aggregation. Hence, this result indicated a potential inhibitory effect of HNA-3a antibodies on Rho activity. Therefore, Rho inhibition was suggested to occur in parallel to an adhesion-inducing signaling pathway and might hence be involved in the stabilization of neutrophil aggregates in HNA-3a antibody-induced TRALI. The results from this doctoral thesis contributed to the generation of a new pathogenesis model for HNA-3a antibody-mediated TRALI. In this model, neutrophils respond to direct HNA-3a antibody exposure predominantly by homotypic aggregation. These potentially very stable and primed aggregates accumulate in the lung and are susceptible to parallel, proinflammatory stimulation. Subsequently, this cascade leads to full neutrophil activation and finally to TRALI induction.
Introduction: Antiseptics are used for the prophylaxis of infections of acute wounds and for the treatment of critically colonized chronic wounds as well as localized infections of acute and chronic wounds. If an antiseptic with too much tissue toxicity and/or too little efficacy is used, the wound healing can be delayed.
Objective: The aim was to compare the irritation potency of frequently used wound antiseptics by using the hen's egg test on the chorioallantoic membrane (HET-CAM). Additionally, the influence of antiphlogistic active additives which might increase the tolerability was examined. To allow a more extensive comparison, antiseptics classified as obsolete such as hydrogen peroxide, creams on PVP- iodine base, silver sulfadiazine, chlorhexidine and nitrofural as well as the non-antiseptic wound treatment agents dexpanthenol and hemoglobin spray were also examined.
Method: The HET-CAM was used as a semi-in-vivo method to test the tolerability of wound antiseptics to tissues by observing the reactions that occur in the blood vessels of the highly vascularized CAM such as hemorrhage, lysis and coagulation. The irritation score (IS) was calculated and differentiated in 4 ranges according to Spielmann (1991).
Results: The vascular injuries of the CAM were considered as an indirect indicator of the tolerability. It is accepted that agents with no or low irritation potential on the CAM are to be preferred in the clinical practice if they are clinically effective.
Severe CAM reaction was observed after short-term application of octenidine based wound gel (active ingredient octenidine 0.05%) (IS: 10.3) and chlorhexidine digluconate 0.5% solution (IS: 9.5). Moderate reaction was observed for the combination of octenidine 0.05% in aqueous solution with panthenol 1.34% and allantoin 0.2% (IS: 8.7), hydrogen peroxide 1.5% in aqueous solution (IS: 6.1) and hydrogen peroxide 0.5% solution (IS: 5.5). Slight reaction was observed for hydrogen peroxide 1.5% solution in combination with sodium thiocyanate 0.698% (IS: 2.6), sodium thiocyanate 0.698% solution (IS: 2.1) and Dermacyn® (active ingredient NaOCl/HOCl each 0.004) (IS: 1.2). Polihexanide 0.04% in Ringer solution (IS: 0.9), Polihexanide 0.05% in Lipofundin, Granulox® (active agent hemoglobin 10%) (IS: 0) and dexpanthenol 5% solution (IS: 0) showed no reaction. In the long-term observation (24 hours after application), Dermacyn® showed the best results (59% of irritation remained alive after 24 hours). The addition of dexpanthenol and allantoin reduced the irritability only slightly, whereas the decrease of IS of hydrogen peroxide by addition of sodium thiocyanate was almost significant (p 0.0596).
Conclusion: It is suggested that agents with no or low irritation potential on the CAM are to be preferred in the clinical practice if they are clinically effective. It is suggested that further in vivo and in vitro studies are to be undertaken with these agents.
Solely regarding local tolerability, polihexanide and hypochlorite are the antiseptic agents of choice of the tested preparations. The wound oxygenizer hemoglobin spray is tolerated without irritation as well as the negative control 0.9% NaCl solution. Because of their other disadvantages in conjunction with their irritability, the outdated cream formulations on basis of silver sulfadiazine, PVP- iodine, chlorhexidine and nitrofural cannot be recommended for wound antisepsis.
The thyroid gland is of crucial importance in human metabolism. Its main secretion products, L-thyroxine (T4) and 3,3’,5-triiodo-L-thyronine (T3), are essential for proper development of multiple tissues and organs as well as for their functioning in the adult organism. The secretion of thyroid hormones (TH) is stimulated by thyrotropin (TSH) released from the pituitary gland. This tight connection between both hormones is of crucial importance for the clinical diagnosis of thyroid dysfunction. During the last two decades the concept of TH action developed to increased complexity. However, most of the recent advances in the field of TH research are based either on cell culture, tissue or animal models or stem from studies investigating specific hypotheses in humans. Thus, experimental approaches for the comprehensive, hypothesis-free characterization of metabolic effects of classical and non-classical TH in human are urgently needed. This holds true in particular for the TH derivative 3,5-diiodothyronine (3,5-T2). It was described to alleviate the typical detrimental metabolic consequences of a high-fat diet and even reversed hepatic steatosis. To replicate these experimental findings from rodents in humans, comprehensive data from the population-based Study of Health in Pomerania (SHIP) was analyzed in the present work. Based on a euthyroid, diabetes-free SHIP-subsample (N=761), non-linear associations between the serum concentrations of 3,5-T2 and glucose as well as TSH were detected. In contrast, no significant 3,5-T2 associations with several anthropometric markers or blood lipid parameters were observed, partially questioning the transferability of the beneficial metabolic 3,5-T2 effects reported for pharmacological intervention studies on rodents to humans. Recent advances in technological development now allow for the use of high-throughput spectrometric platforms to characterize the small molecule content (metabolome) of blood and urine samples. The detected metabolome constituents can be associated with any relevant parameters of interest, thereby extending the scope of classical association studies. Therefore, in the second part of the present thesis, the metabolic fingerprints of FT4, TSH as well as the ratio log(TSH)/FT4 as markers of thyroid function were profiled. Strong differences between the metabolic fingerprints of FT4 and TSH were observed, partially alleviated by the log(TSH)/FT4 ratio. These findings not only emphasize the high diagnostic value of the combined evaluation of TSH and FT4 in the assessment of thyroid function but additionally argue for a holistic approach in the diagnosis of thyroid function. More moderate endogenous effects of 3,5-T2 were evaluated by comparing its urinary metabolic fingerprint with that of the classical TH. A number of associations became apparent, indicating a function of endogenous 3,5-T2 in intermediary metabolism. Besides partially confirming associations with respect to the presented findings in animal studies, the strongest 3,5-T2-association was observed with trigonelline, a metabolite described earlier to exhibit similar beneficial effects as 3,5-T2 on glucose metabolism when used as a pharmacological agent in animal studies. An association towards hippurate indicated a partial overlap with the metabolic profile of TSH and hence consolidated results from the first two projects in the sense of a thyromimetic role of 3,5-T2 in the feedback regulation of TH. The diagnosis of thyroid disorders based on the classical markers TSH and FT4 suffers from restricted sensitivity in the subclinical range as both parameters have broad reference ranges in the general population. Therefore, in an approach to detect novel peripheral biomarkers of thyroid function, sixteen healthy young men were challenged with 250 µg of levothyroxine (L-T4) over a period of eight weeks in the fourth project presented here as part of this thesis. Monitoring of the volunteers over a period of sixteen weeks allowed delineation of the metabolic shifts first towards thyrotoxicosis and later in the context of the restoration of euthyroidism. The use of mass spectrometry for the comprehensive characterization of the metabolite as well as the protein content of samples taken at the different time points revealed profound molecular alterations, despite the lack of any clinical symptoms in the volunteers. Molecular signatures of thyrotoxicosis indicated increased energy expenditure, pronounced defense against systemic oxidative stress, a general drop in apolipoproteins, as well as increased abundances of proteins related to the coagulation cascade and the complement system. Good and robust classification of the thyroid state independent of TSH and FT4 was achieved using random forest analysis with a subset of fifteen metabolites and proteins, indicating new options in the individualized diagnosis of thyroid disorders.
Certain basal Teleostei from the Early Jurassic of Mecklenburg-Western Pomerania (Germany) and the Late Jurassic of the Franconian Alb (Bavaria, Germany), the Swabian Alb (Baden-Württemberg, Germany) and the western Jura-Mountains (Ain, France) are described. The present doctoral dissertation includes four studies, dealing with representatives of “Pholidophoriformes”, Leptolepidae and Orthogonikleithridae. These studies include anatomical descriptions of new taxa and reviews of poorly known fishes. Furthermore, the stratigraphic and palaeobiogeographical distributions of the examined taxa are discussed.
Costs of reproduction. A demographical approach to examine life-history trade-offs ─ Abstract. Resource-allocation trade-offs are fundamental constraints of life-history evolution. In particular the trade-offs between reproduction and longevity and between present and future reproduction are expected to form reproductive patterns. Unfortunately, exploring such trade-offs in natural populations is complicated and may not be possible. In face of several limitations, zoo data appear to be useful to better understand the reproductive biology of endangered, rare or cryptic species. In the first step, it was sought after with a data-mining, comparative multi-species approach for broad patterns of correlations between lifespan and variables in bird-eating spiders (Theraphosidae). The subfamily Eumenophoriinae on average lived longest, followed by the Theraphosinae, Ornithoctinae, Grammostolinae, Selenocosmiinae, Ischnocolinae and finally the Avicularinae. Species inhabiting tropical, more humid and/or low-altitude environments lived longer, suggesting that more predictable environments favour the evolution of longer lifespans. Furthermore, large range size, low abundance, sub-terrestrial life-style, and aggressive behaviour were all linked with longer lifespans. An argument for resource allocation trade-offs was found as larger spiderling and prosoma size were negatively related to longevity. In the second step, a demographical approach has been applied for two old-world deer species (Vietnamese sika deer Cervus nippon pseudaxis, Mesopotamian fallow deer Dama dama mesopotamica). In both species, births peaked right before the onset of the rainy season in natural environments. Females reached high reproductive output earlier in life and had (in one species only) higher survival rates than males. Offspring number covaried positively rather than negatively with longevity. In females, the length of the reproductive phase correlated positively with longevity, birth rate within the entire lifespan, and offspring number, while it was negatively correlated to the birth rate during the reproductive phase (in one species). The length of the post-reproductive phase was positively related to longevity and negatively to birth rate during the entire lifespan. In the third section, life-histories of Asiatic (Equus hemionus ssp.) and African wild asses (Equus africanus ssp.) have been anlaysed in a comparative way with another demographical long-term approach. All taxa showed even in captivity peak birth rates during the periods of highest food availability in their natural environments. Sex-specific survival rates with females living longer than males were evident in Kulan and Onager but not in Kiang and Somali wild ass, pointing towards different life-history strategies even among closely related taxa. Females achieved their highest reproductive output earlier than males, which is typical for polygynous mating systems. Offspring number and longevity were rather positively correlated than negatively. Taken together evidence for reproductive trade-offs was weak, though the length of the reproductive period was negatively related to birth rates within the reproductive period. Birth intervals increased with female age, probably reflecting detrimental effects of senescence.
The aims of this study were to quantify the key mineralization processes and the resulting nutrient release potentials of different sediment types, their ranges of extent and dependency on varying environmental conditions such as seasonal variations or shifts in oxygen availability. Benthic phosphate fluxes and flux potentials were of particular interest as P is an essential nutrient for algal growth in marine systems and phosphate is often limiting primary production, hence strongly promotes the production of new biomass. A major P source in marine environments are mineralization products of early diagenetic processes.
To gain insight into the pathways of organic matter mineralization and subsequent secondary reactions, key reactants in the solid and the dissolved phase were considered in typical sediments of the Baltic Sea and the Black Sea. Seven study sites in the German Baltic Sea region, representative of the major depositional environments, including coarse and fine grained sediments, both rich or poor in organic carbon, were intensively studied. The investigations were conducted on a seasonal basis during ten ship-based expeditions between July 2013 and March 2016, covering spring- and autumn algal blooms, stagnation periods with bottom water hypoxia and winter dormancy. Hypoxic conditions frequently developed in the bottom waters of the Bay of Mecklenburg, Stoltera and the Arkona Basin sites, shallower stations like the Tromper Wiek, the Oder Bank and the Darss Sill were usually not affected by hypoxia. Increased nutrient concentrations in the bottom waters coincided with oxygen depletion. High salinity dynamics were observed in the bottom waters above the studied sediments, which were due to frequent salt water inflows from the North Sea. Bottom water temperature variability was seasonally conditioned.
The studied sands showed 2-3 orders of magnitude higher permeability values and about one order of magnitude lower organic matter contents compared to the studied muds. Occasionally, strongly increased organic matter contents were observed in the sands, likely induced by downward mixing of plankton bloom derived particles. The organic matter was found to be essentially supplied by marine phytoplankton, indicated by its elemental composition and isotopic signature.
Additionally, an adapted approach of the Keeling plot method was made to characterize the source material of organic matter mineralization. In marine environments, dissolved inorganic carbon concentrations often increase with depth together with an isotopic carbon signature shift to lighter values due to organic matter mineralization. The Keeling plot method was commonly used to determine the isotopic signature of carbon sources for ecosystem respiration. Conventionally, the influence of respiratory depletion of 13CO2 on the isotopic composition of the atmosphere was studied in terrestrial and limnic biogeochemistry. The same approach was applied on organic matter mineralization in sediments and the water column during this study. Mixing of bottom water derived background DIC and DIC released into the environment during organic carbon decomposition was assumed. In a modification of previous approaches, where changes in concentration and δ13C of DIC were followed over time, vertical profiles were analyzed in this study, which represent time-dependent variations superimposed by transport processes . DI13C gradients in the water column of the Black Sea and pore water profiles in the Black Sea and the Baltic Sea were used to estimate the 13C signature of the mineralized organic carbon via Keeling plot analysis. The Black Sea water column revealed a δ13C signature of the organic matter source close to the signature of typical particulate organic matter in the ocean and previously reported values for the Black Sea euphotic zone. In the pore waters of Black Sea sediments (from short and long sediment cores), Keeling plot analysis clearly demonstrates that the released DIC at depth can be derived from different sources. An isotopically very light carbon source (< –60 ‰) was associated with anaerobic oxidation of methane in the Black Sea. Marine organic matter was the principal source for DIC in the deeps of Baltic Sea basins, while the calculated carbon source isotopic signature in sediments of sand flats and bays was shifted to heavier δ13C signatures compared to marine organic matter. These shifts were attributed to potential dissolution of sedimentary carbonates or organic inputs of terrestrial C4 vascular plants like maize and other agricultural plants. The carbon source isotopic composition calculated via Keeling plot analysis correlated well with directly measured δ13C signatures of surface sediments POM.
Organic matter mineralization activity in the southern Baltic Sea sediments was studied via gross sulfate reduction rate analysis and total oxygen uptake measurements in sands and muds. Oxygen penetration depths were less than 4 mm in both, muddy and sandy sediments. Oxygen uptake rates were similar in muds (10.2 mmol m–2 d–1) and sands (10.7 mmol m–2 d–1), while significantly higher rates were measured in the coastal near sites of the Bay of Mecklenburg (about 12 mmol m–2 d–1) than in the deeper Arkona Basin (about 9 mmol m–2 d–1). Substantial sulfate reduction was measured in the muddy (about 4 mmol m–2 d–1) and the sandy (about 1 mmol m–2 d–1) study sites. Highest sulfate reduction rates (4.4 – 5 mmol m–2 d–1) were detected in the muds of the Bay of Mecklenburg during summer, about twice as high as in the Arkona Basin muds. Increased mineralization activity of the coastal near muds of the Bay of Mecklenburg is attributed to enhanced input of fresh organic matter during algal blooms.
About twofold higher oxygen consumption and sulfate reduction rates were measured in summer compared to winter in sandy and muddy sediments.
The studied sites were usually characterized by a typical biogeochemical zonation with oxic, suboxic and sulfidic zones. The concentration profiles in the muds reflected sulfate reduction and secondary redox-reactions, liberating dissolved carbon, nitrogen, phosphorus and hydrogen sulfide into the interstitial waters. Orders of magnitude lower concentrations were detected in the sands, while their top centimeters were mostly irrigated and mineralization products only accumulated below.
A several centimeter thick suboxic zone was sustained by active downward transport of oxidized material in the southern Baltic Sea coastal sediments, presumably mainly through bioturbation. Especially sulfur and iron species were involved in the secondary reactions between the metabolites of early diagenetic processes occurring in the suboxic zone. Partly high temporal variability was observed in the form of vertical migration of the sulfidic zone and a corresponding expansion and shrinking of the suboxic zone. The Arkona Basin site showed the most stable geochemical zonation over time, while the Luebeck Bight site and especially the Mecklenburg Bight site showed striking dynamics. The consequent redox-regime shifts within the surface sediments might promote mineralization of organic matter as higher sulfate reduction rates and higher total oxygen uptake were measured in these more dynamic muds. The vertical shifts of the redox-gradients can largely be explained by temporal and spatial variability of bioturbation activity, but also anthropogenic activities may play a role. Bottom trawling, may be the dominant mixing process at the Mecklenburg Bight site.
In the sands, less reactive iron and manganese contents were available compared to the studied muds, which may be due to frequent irrigation of the top centimeters leading to a loss of pore water reservoirs like dissolved Fe and Mn.
Another mixing process, storm induced sediment resuspension, was suggested to be important for the sediments in the study area. A severe sediment resuspension event at the silty Tromper Wiek site was indicated by steep gradients in pore water concentration and particulate mater content profiles in the top ∼ 5 cm sediments. Carrying out non steady state modeling (Bo Liu, IOW), the successive re-development of the pore water profiles towards a steady-state was simulated and the time span necessary to establish measured pore water profiles after the sediment disturbance event was approximated. In the predicted time span, daily average wind speeds reached an annual high of the category ‘gale’ which was probably sufficient to resuspend and irrigate the surface silt-type sediments.
This study showed that sediment mixing processes have a strong influence on early diagenetic reactions, solute release potentials and actual fluxes from the sediments. Also the sediment mixing via bottom trawl fishing can be regarded as an event-like disturbance. The newly developed approach of non-steady-state modeling of pore water sets (Bo Liu; IOW) can help to answer the question, how long it takes to reach a steady-state after a sediment disturbance event.
The concentration profiles in interstitial waters were used to calculate net transformation rates via the transport-reaction models REC and PROFILE. The calculations revealed net release of H4SiO4 and PO4 within the top 20 cm of the studied muds, while net DIC and NH+4 consumption and sulfate production was clearly evident within the top ∼ 5 cm. Intensive reoxidation of sulfide that was produced via sulfate reduction was also indicated by large deviations between the modeled net sulfate transformation rates and experimentally derived gross sulfate reduction rates. These surface near transformations were probably associated with microbial chemosynthesis.
The studied sands of the southern Baltic Sea were usually characterized by very low pore water gradients, probably due to their frequent irrigation. Accordingly, calculated transformation rates were one to two orders of magnitude lower in the studied sands compared to the muds of the southern Baltic Sea. However, during a situation with a stratified water column, substantial pore water reservoirs with the typical concentration trends were present in the sandy Darss Sill sediments. Integrated production rates of PO4, Mn2+ and H4SiO4 derived from these concentration profiles were in the same order of magnitude as in the muddy Arkona Basin.
Intensive pore water irrigation is also capable to transport fresh organic matter into the sediment as was occasionally indicated by strongly increased surface near TOC in the sands. Considerable gross sulfate reduction rates and total oxygen uptake rates were measured in the sandy Oder Bank sediments, where pore water concentration profiles rather suggested absence of diagenetic processes. The studied sands were, hence, not unreactive substrates but usually rather unable to preserve the mineralization products.
This reflects the often limited significance of pore water evaluations in irrigated sandy sites but also the high mineralization potentials of coastal sands. Early diagenetic processes and the impact of intense benthic-pelagic exchange in such shallow marine environments is still poorly understood, as they were rarely investigated in the past and are methodologically more difficult to investigate.
The Baltic Sea deeps Gotland Deep and Landsort Deep were mainly controlled by sulfate reduction and shallow anaerobic oxidation of methane. Calculated rates of net sulfate reduction and net sulfide production were equivalent, indicating a lack of sulfide re-oxidation reactions. Phosphate liberation rates were low in the surface sediments, but strong linear concentration gradients indicated liberation at depth.
The euxinic Black Sea sediments were purely controlled by sulfate reduction via anaerobic oxidation of methane at the sulfate-methane transition zone in sediment depths of up to several meters. Subsequent diffusive concentration gradients clearly dominated pore water profiles in the surface sediments.
Benthic solute reservoirs of the top 10 cm pore waters were generally higher in the muds than in the sands of the southern Baltic Sea. The smaller reservoirs in the sands were cause by intensive exchange between pore water and bottom water in these permeable sediments. The three studied muddy sites of the southern Baltic Sea showed great dissimilarities with respect to their pore water compositions. Large observed pools of dissolved Fe2+ and PO4 clearly point to reduction of reactive Fe and release of adsorbed P pools. Multi-dimensional scaling analysis showed that seasonal variability played only a minor role for the observed variability of the benthic solute reservoirs. Principal component analysis revealed that the studied sediments can be characterized by essentially two factors based on their pore water reservoirs of the top 10 cm: 1) their mineralization and accumulation efficiency and 2) their secondary reactions in the suboxic zone, reflecting fundamental differences in their sedimentation conditions and mixing processes. While the sands were similar to each other due to their overall low reservoirs, sands, silts and muds mainly differed in their mineralization and accumulation efficiency. Large variability was also observed within the studied muds regarding their predominating redox metabolites. Highest dissimilarities were evident between the neighboring sites Mecklenburg Bight (mostly suboxic) and Luebeck Bight (mostly sulfidic). Therefore, the biogeochemical state in the studied sediments were shown to be mainly controlled by their sediment type and the transport of reactive iron into the sediments. The supply of organic matter to the sea floor controlled the overall mineralization activity, while the sediment permeability determined the accumulation efficiency of the sediment. Mixing of surface sediments together with the complex relation of oxygen, sulfur, iron and phosphorus in the solid and aqueous phase is controlling benthic nutrient fixation/liberation reactions. Salinity variability showed no noticeable effects on early diagenetic processes. During four sampling occasions in the Arkona Basin, bottom water salinity showed strong variability which was also effecting pore water concentration profiles in more than 15 cm depth. However, concentration profiles of typical organic matter mineralization products remained remarkably stable. Also gross sulfate reduction rates seemed to be unaffected by the variable pore water sulfate concentrations.
Nutrient fluxes across the sediment-water interface were obtained by the interpretation of vertical pore water concentration profiles via different models (diffusive fluxes) and via incubation of intact sediment cores (total fluxes). Benthic diffusive fluxes represent potential release of solutes into the water column. They were often strongly associated with the benthic reservoirs, thus fluxes were highest in the muds, considerably lower in the organic-poorer silts, and generally close to zero in the sands. The dissimilarities between diffusive fluxes in the different sediments were mainly controlled by the sediment type. Highest variability was observed within the muds, controlled by their different diagenetic pathways due to different sediment mixing intensities.
In the muddy sediments, diffusive PO4 fluxes were much higher than mineralization of organic matter with the common element ratios of marine organic matter can provide, indicating active recycling of phosphorus within the muds due to recurring adsorption and re-release on reactive iron oxyhydroxide phases. Especially in the strongly mixed Mecklenburg Bight sediments, pore water dissolved PO4 was primarily controlled by the release of adsorbed P. Actual PO4 release into the bottom waters (determined via core incubation experiments) was only measured under extended bottom water oxygen deficiency conditions. The same applied to the redox-sensitive solutes Fe2+, Mn2+ and sulfide.
For the less redox-sensitive solutes, diffusion usually accounted only for a fraction of the total interfacial flux. The proportion of advective to diffusive transport was estimated with different methods. Bioturbation induced sediment mixing was quantified by comparing the diffusive H4SiO4 fluxes derived from pore water modeling with the total fluxes derived from the core incubations. The studied muds showed infauna induced advection proportions of about 35 – 100 %. Only when infauna was absent, diffusion became the dominant transport process across the sediment-water interface. In the studied sands, advection was the dominating transport process, since their generally low surface near reservoirs lead to diffusive fluxes close to zero. However, it remains unclear whether bioturbation or hydrodynamic irrigation are responsible for that. An attempt was made to estimate the effect of hydrodynamic irrigation for a range of reasonable bottom water velocities from the sediment bedform geometry after Neumann et al. (2017). However, resulting potential hydrodynamic irrigation was found to be rather low compared to reported values from the literature and may significantly underestimate actual irrigation of the sandy sediments.
In a new non steady-state multi-element diagenetic modeling approach (Bo Liu, IOW), vertical δ13C pore water profiles were used to estimate the significance of advective transport processes. Mixing processes at the sediment-water interface were expressed as multiple of pure diffusion (ε). By adjusting this mixing coefficient as boundary condition for best fits of predicted to measured pore water profiles, the degree of these mixing processes was estimated. In the Arkona Basin surface sediments, this approach revealed best fits assuming a mixing depth of 3.5 cm with a tenfold higher total mixing degree based on diffusional transport. The calculated mixing depths and intensities were similar to bioturbation depths and rates obtained via traditional methods (Morys, 2016). The novel modeling approach is a promising method to evaluate surface sediment mixing processes.
Increased mineralization activity during productive seasons lead to increased oxygen consumption and therefore frequent bottom water hypoxia. The effects of hypoxic bottom water conditions on the early diagenetic processes in the sediments were studied via prolonged core incubation experiments. Shifts to bottom water oxygen deficiency had various consequences for benthic reservoirs and fluxes. The oxygen consumption decreased during hypoxic incubation phases. Decreased bioturbation activity diminished advective transport so that total fluxes of redox-insensitive solutes (e.g. H4SiO4) were decreased. Reactive iron and manganese oxides act as barrier (“iron curtain”) in the suboxic zone, preventing redox-sensitive solutes from their release into the water column. After a shift to bottom water hypoxia, these reactive oxides are re-dissolved and liberated into the water column. Prolonged incubation experiments suggested that the Mn-oxide reservoirs were depleted first before the Fe-oxides with the adsorptively bound phosphate were liberated.
The release of nutrients (especially phosphorus), dissolved inorganic carbon, and redox- sensitive compounds (e.g. hydrogen sulfide) strongly varied in the different studied environments, covering coastal-near oxic, temporary hypoxic and euxinic conditions.
In environments, where advection through hydrodynamic irrigation or bioturbation do not occur, like in anoxic or euxinic systems, surface-near pore water gradients reflect total solute interfacial fluxes. They depend on the supply of organic matter to the sea floor, the mineralization rates in the sediments and the composition of the overlying bottom water. In the Black Sea, much of the organic matter mineralization was performed already in the water column and not in the sediments, leading to a decreasing export of organic matter to the sediment and increasing concentrations of mineralization products in the bottom water with increasing water depth. Accordingly, benthic fluxes across the sediment-water interface of the deep Black Sea sites were the lowest of the entire study, essentially reflecting the low mineralization rates of AOM in deeper layers. Highest fluxes in the Black Sea were observed at the continental slope at intermediate water depths, but were still lower than in the Baltic Sea deeps.
In contrast, highest DIC fluxes were detected in the oxygen depleted Baltic Sea deeps Gotland Deep and Landsort Deep. These basins are shallow enough that reactive organic matter reaches the sea floor, where it is mineralized via sulfate reduction close to the sediment surface. Strong concentration gradients and therefore high diffusive interfacial fluxes across the sediment-water interface were evident. As bioturbation was absent, these diffusive fluxes were representative for total interfacial fluxes unlike in sediments with additional advective flux components.
In more complex environments, like coastal oxic sediments, inhabited by macrofauna, overflowed by currents and affected by resuspension events, the sediment surface represents an interface between turbulent and calm conditions, high and low concentrations and/or different redox-states. Such gradients are the basis for intensive exchange processes. The surface sediments in the coastal sites of the southern Baltic Sea were characterized by active organic matter mineralization via sulfate reduction and mixing induced secondary reactions taking place in the suboxic zone. This included the removal of dissolved sulfide due to iron oxide reduction with simultaneous liberation of PO4 into the interstitial waters. High surface near P reservoirs existed due to internal P cycling within the sediments, which was in turn driven by continuous re-oxidation of the reduced iron by downwards transported oxygen. These reservoirs were only actually released into the water column during bottom water oxygen deficiency situations, when the iron re-oxidation was inhibited.
This also applies for sediments of the Gulf of Finland and the deeper Baltic Sea basins Bornholm Basin and Gdanks basin, where temporary hypoxic conditions are responsible for recurrent benthic phosphate release.
The widespread occurring phosphate adsorption on sedimentary solid iron phases is a much debated ecosystem service of marine sediments. As discussed in this work, the sedimentary P liberation rates and pools of readily bio-available dissolved phosphate can be substantial in Baltic Sea muddy sediments. Actual phosphate fluxes across the sediment-water interface, though, are relatively small because phosphate is scavenged by adsorption on iron oxyhydroxides that are usually an integral part of coastal marine sediments if overlain by oxic bottom waters. Although muddy sediments often show only an oxic layer of only few millimeters thickness, adsorption capacities of iron oxyhydroxides are large enough to substantially retain P from being liberated into the water column. Falling under reducing conditions, iron oxyhydroxides are re-dissolved, liberating high amounts of PO4 into the surrounding waters. While permanently oxic sediments will preserve adsorbed P, permanently anoxic sediments steadily release mineralized P into the water column. However, sedimentary environments of oscillating redox conditions are predestined for high, burst-like benthic P fluxes. Especially in a quasi isolated environment like the Baltic Sea, with high nutrient inputs but only few sinks, these internal recycling processes promote eutrophication in the long-term. Further expanding hypoxia and anoxia in the Baltic Sea with a subsequent loss of benthic fauna and altered nutrient dynamics in the surface sediments may be the consequence.
Streptococcus pneumoniae (pneumococci), a human pathobiont, express and expose several proteinaceous colonization and virulence factors on its surface to facilitate on the one hand colonization of the upper respiratory tract and on the other hand pathogenesis in the host. In this study the interaction of two of such factors referred to as pneumococcal virulence factor A (PavA) and pneumococcal virulence factor B (PavB) and acting as microbial surface components recognizing adhesive matrix molecules (MSCRAMMs), was delineated with the two host matricellular proteins fibronectin (Fn) and vitronectin (Vn). Despite similarity in nomenclature, PavA and PavB represent two diverse pneumococcal proteins with respect to their structure and association with the pneumococcal surface. PavA is a non-classical surface protein (NCSP) with an ambiguous mode of secretion and anchorage while PavB is a characteristic MSCRAMM, anchored via sortase A to pneumococcal peptidoglycan. PavB has a signature of repetitive modules termed as streptococcal surface repeats (SSURE). Pneumococci preferentially interact with immobilized human Fn. In vitro cell culture adherence assays demonstrated that cell bound Fn facilitates the adherence of pneumococci to the host cells and this particular interaction is indifferent to host cell type and is species non-specific. Flow cytometry and immunoblot analyses further indicated the ability of pneumococci to interact with the soluble form of Fn in a dose-dependent but species non-specific manner. The molecular interaction of PavA and PavB (via its SSURE domains) with Fn was delineated further in detail via several direct protein-protein interaction approaches. Ligand overlay assays, surface plasmon resonance studies and SPOT peptide arrays demonstrated that PavA and PavB target at least 13 out of the 15 type III fibronectin domains located in the C-terminal part of Fn. Strikingly, both pneumococcal fibronectin-binding proteins (FnBPs) recognize similar peptides in targeted type III repeats. Structural comparisons revealed that the targeted type III epitopes cluster on the inner strands of both β-sheets forming the fibronectin domains. Importantly, synthetic peptides of FnIII1, FnIII5 or FnIII15 bind directly to FnBPs PavA and PavB, respectively. Thus, analysis of interaction of pneumococcal FnBPs PavA and PavB revealed a probable conserved and/or common pattern of molecular interaction with human Fn. In addition to Fn, pneumococcal PavB interacts with other host matricellular proteins such as human plasminogen (Plg) and human thrombospondin-1 (hTSP-1). Pneumococcal proteins such as PspC and PspC-like Hic have earlier been demonstrated to interact with hTSP-1 as well as human Vn, thereby depicting a redundant function as MSCRAMMs. In this study the role of PavB as a pneumococcal vitronectin binding protein (VnBP) was assessed. Flow cytometric analysis suggested PavB as VnBP, because strains deficient for PavB exhibited a significantly decreased ability to acquire vitronectin compared to wild-type pneumococci. When using a double knockout, deficient in expression of PavB and the VnBP PspC, the pneumococcal interaction with vitronectin was completely abolished. The direct protein-protein interaction assays such as far western ligand overlay, ELISA, and surface plasmon resonance indicated the interaction of SSURE domains with both soluble and immobilized Vn. However, the binding activity depends on the number of SSURE domains with five SSURE showing the highest binding activity to Vn. The interaction of PavB with Vn was charge dependent and heparin sensitive as analyzed by ELISA. The importance of the heparin binding domains of Vn in this interaction was further analyzed via direct protein-protein interaction approaches. Binding studies (far western ligand overlay, ELISA, and surface plasmon resonance) with truncated recombinant Vn fragments indicated that PavB targets the C-terminal heparin-binding domain (HBD3) of vitronectin, a characteristic shared with PspC, hence, suggesting a conserved molecular interaction of pneumococci with Vn. In addition to its function as an MSCRAMM, PavB has the capability to interact directly with host epithelial cells via an unknown cellular receptor. Thus, this study aimed to identify cellular receptor(s) for PavB. In vitro cell culture adherence and invasion assays confirmed that pneumococcal PavB is involved in promoting pneumococcal adherence to respiratory epithelial cells without employing any molecular bridge. The direct interaction between PavB and host epithelial cells was further confirmed via direct binding assays when using Cy5-labeled PavB and flow cytometric analysis. Strikingly, exogenously added human vitronectin competitively inhibited binding of PavB to respiratory epithelial cells. This observation led us to hypothesize that the major vitronectin receptor αvβ3 integrin acts as a potential receptor for PavB. This hypothesis was supported by functional blocking assays with monoclonal antibodies recognizing specific integrin subunits. The results revealed reduced binding of PavB in the presence of bound antibodies recognizing αv integrin indicating that PavB employs αvβ3 integrin as its direct receptor on eukaryotic cells. This was further confirmed via a direct binding assay of PavB to mouse embryonic fibroblasts (MEFs) where cells lacking αvβ3 demonstrated a marked decrease in binding to PavB. Although functional blocking assay and direct binding assay with MEFs supported the role of αvβ3 integrin as a direct adhesin for PavB, RNA interference of αv integrin in epithelial cells did not impair the binding of PavB in αv-knocked down cells in comparison to non-transfected cells. Finally, surface plasmon resonance (SPR) analysis indicated the direct interaction between pneumococcal PavB and recombinant αvβ3 integrin. In this study we report for the first time the interaction of a Gram-positive extracellular pathogen, namely Streptococcus pneumoniae, with one of the host ICAMs, namely the αvβ3 integrin. In conclusion, the present study analysed some of the aspects of molecular interaction of pneumococcal MSCRAMMs PavA and PavB with hFn and hVn. The hot spots of interaction on C-terminal FnIII repeats were delineated for PavA and PavB. HBD3 was revealed to be pivotal for PavB-Vn interaction. In addition the redundant role of pneumococcal PavB as an MSCRAMM was demonstrated. Furthermore this study successfully identifies a direct receptor for pneumococcal PavB, namely αvβ3 integrin. The mechanism and biological rationale of this newly identified interaction is a matter of debate and awaits further scientific analyses.
Forests are and have been of major importance to cover a variety of societal needs. Today the demands on forests are ever increasing with sequestering carbon and balancing the climate, to name only a few. To cover those requirements forests need vital, productive, and sustainable. A difficult concept as such as the understanding of a healthy forest varies greatly. Nevertheless, forests still have to produce a sufficient amount of yield while threatened by changing climate conditions. These are predicted to bring extended and more intense drought periods as well as a higher frequency of storms and the promotion of secondary disturbances like insects calamities to also rise. In this complex situation of high and versatile demand the focus is on the allocation of the “right” forest. Forest management is requested to balance the needs of humans against those of wildlife against those of the trees themselves. To gain the respective knowledge on species responses and provenance growth, now and in the future research gaps need to be closed. All factors influencing tree growth and therefore ultimately yield need to be understood and special focus needs to be on the interactions within the forest ecosystem. One of the parameters in understanding aggregated tree growth is the dynamic of growth. This can be visualised by dendroecological methods, providing a picture of growth within the individual years. Growth dynamics are dependent on multiple factors, some, like soil being preconditioning and other like climate causing short-term responses. In this thesis I focus on the influence of climate on annual tree growth using a new approach of daily climate data to calculate climate-growth correlations. This method has the advantage of representing tree processes better than the former approach of using monthly means. Furthermore the program enables the user to feed climate scenarios and therefore estimate future growth. To gather information on species as well as provenance differences to provide advice to foresters I used different trials in Britain and Germany. On the British site different oak species were planted while the German sites are stocked with various spruce provenances. For the latter we additionally used stable carbon isotope analysis to calculate intrinsic water use efficiency. The climate-growth correlations revealed differences between the oak species with a generally higher linkage to precipitation than temperature. While the differences are clear, the question of thresholds and the role of extreme events became apparent in this work. VII Abstract Assessing the impact of extreme events using dendrometer data revealed little differences in the response to short term events of the three investigated species, oak, beech, and pine. We were able to pick up stimulus-response-relationships and as a novel result no species-specific responses were found when focusing on such a small time frame. The provenance trials offered the opportunity to investigate the potential of the use of daily climate data more closely. The two contrasting sites planted with six spruce provenances each gave an insight on the adaptive potential of provenances as well as an indication on the response times. Depending on the proceeding environmental and the local climate conditions decisions have to be made on the species or provenance selection. This thesis provides a method as well as insight on the behaviour of the important European species beech, oak, pine, and spruce. It, however, highlights the limitations such methods have for large scale estimates. While general trends on the response to specific soil factors can be used, the climatic responses, be it thresholds or climate-growth correlations can only be seen within the ecological context of their sampling region.
The establishment and management of protected areas has become a universally accepted way to conserve biodiversity and the wide range of goods and services they offer. Sustainable management of forest resources requires good decision-making from a range of different stakeholders. This dissertation develops a model based on spatial data and expert judgments to assess the vulnerability of the most threatened species of fauna and flora in a selected protected area. Based on the study objectives, the availability of data and technology, the study concludes vulnerability as composed of multidimensional losses, which can be measured as a function of the three components: exposure, sensitivity and adaptive capacity. In order to measure vulnerability, the research applies the Analytic Hierarchy Process (AHP), a well-known multi-criteria decision making approach, using the open access Super Decisions software in a spatial database context with the help of Geographic Information Systems (GIS).
In this work, the discovery, expression and characterization of new eukaryotic Baeyer-Villiger monooxygenases (BVMOs) from yeasts has been shown. A rational design of one of these enzymes led to the identification of key residues to alter the sulfoxidation activity of this group of enzymes. Additionally, in another rational design approach, the cofactor specificity of the BVMO cyclohexanone monooxygenase from Acinetobacter calcoaceticus could be substantially altered to accept the much cheaper and therefore industrially more relevant cofactor NADH.
The dissertation describes an Indigenous dream framework that underscores the significance of dreams as a mirror of trauma and a way that leads back to Indigenous knowledges. Significant differences of Western and Indigenous epistemology are exemplified by juxtaposing Western and Indigenous dream discourses. The selected prose fiction allows for a dream categorization that emphasizes the significance and meaning of dreams as a metaphorical as well as narrative device.
Nightmares/Anxiety dreams are often the result of the devastating effects of colonization and especially Residential School. Nightmares in the texts are often exact replicas of the abuse suffered in the boarding schools. They are discussed in the context of Robert Arthur Alexie’s novel Porcupines and China Dolls (2001/2009) represents dreams and traumatic nightmares and deals with the fictional Blue People First Nation. The community’s collective intergenerational trauma of Residential School experience keeps them stuck in dysfunctional dynamics dominated by suicides, sexual and physical abuse, drug and sex addictions.
Telling dreams, categorized as “instructing dreams,” and “announcing dreams,” teach the dreamer what will happen in the future. They are discussed in the context of Richard Van Camp’s short stories “On the Wings of this Prayer” and “The Fleshing” (Godless but Loyal to Heaven, 2012), which represent the category of the ecological nightmare as well as of telling dreams. Ecological nightmares display environmentally destructive effects of capitalist globalization that have come to “infect” the world. The Windigo figure in the stories serves as a manifestation of resource and in particular petro-capitalism and Western society’s constant need to subjugate nature. Ecological dreams hence call for ecological vigilance and establish Indigenous knowledges as a source of resurgence and restoration.
Existential dreams function as decolonizing tools that facilitate liberation. The thesis provides a literary analysis of Richard Wagamese’ novel Ragged Company (2008) and Cherie Dimaline’s short story “room 414” (Red Rooms, 2007) where homelessness is postulated as the manifestation of individual and tribal/communal disjointedness and isolation. Through existential dreaming, the urban lives of most of the characters dwelling in the shadows and margins of society are existentially transformed and healing seems possible. Paternalistic colonial mindsets continue to patronize Indigenous knowledges (as unreliable and unscientific) until Western “discoveries” prove what has been known for decades.
The thesis underscores dreams as an essential part of Indigenous Knowledges, i.e. as knowledge sources. Surmounting Western dream perceptions and instead valorizing Indigenous knowledges, the characters in the texts discussed in my thesis, unremittingly follow their dreams’ instruction and eventually achieve reconciliation and healing. In the fictional texts discussed, nightmares represent homelessness, trauma, stagnation, and a disconnection to one’s (Native) background, whereas dreams represent continuity through the restoration of identity, finding home, and a sense of belonging. The notion of a dream reality and a waking reality influencing and informing each other relies on sharing dreams with the community, eventually leading to an enactment of the dream or vision. Dreaming and identity are significantly linked and foster processes of intellectual self-determination. The characters’ inability to externalize their internal wishes, desires, and needs results in further denial and consequential bitterness that feed into the spiral of alcohol and drug abuse as well as metaphorical and literal homelessness. The dreams’ semantic field strongly alludes to ceremonial traditions and provides the prospect of a rooted Indigeneity. At the turning points in the lives of the characters, when dreams and visions start to appear, they are lost in translation. The characters’ own illiteracy towards Native epistemology and spirituality has them trapped in the inability to read and act on their dream messages. Strong (often female) Indigenous presences that go hand in hand with the appearance of dreams provide the protagonists with guidance and lead the way back to the “Old Ways.” Through dreaming, the spiral of colonialism is disrupted and replaced by the circle of reconciliation and relationality.
Encephalitides induced by lyssa-, borna- and astroviruses: molecular detection and characterization
(2017)
Encephalitis is a severe inflammatory disease of the brain which often has a fatal outcome or can lead to subsequent damages. In around two-thirds of all human encephalitis cases, the causative agent is, despite improved diagnostics, unknown today. Aim of this work was the development, improvement and validation of diagnostic methods, improvement of sampling strategies and the development of optimized systems for characterization of three viruses causing viral encephalitis. The main burden of RABV lies in developing countries, were standard diagnostic tools are often not realizable. Therefore, simple and rapid diagnostic tests for the use under resource limited settings, so called point-of-care tests (POCT), are favorable. Commercially available lateral flow device (LFD) based immunodiagnostic tests were analyzed and failed in terms of sensitivity compared to the standard FAT and RT-qPCR (Paper I). Therefore, molecular RABV alternative targeting genome tests were developed and combined with rapid nucleic acid extraction methods. The new HighSpeed RT-qPCR and RPA assays together with magnetic bead based automated or manual extraction methods delivered a specificity between 100% and 97.2% and a limit of detection of 10 or 1,000 genome copies per reaction, respectively and seem suitable as novel POCT (Paper II). Recently, a novel zoonotic VSBV-1, responsible for fatal encephalitis of three squirrel breeders, was detected. For further investigations of this new virus, methods for an in-vivo sampling approach of squirrels were established. They were useful to identify animals harboring this dangerous virus, and new sequence data could be obtained from the VSBV-1 positive animals. Until now, 3.5% of all investigated squirrels were VSBV-1 RNA positive and two subfamilies (Sciurinae and Callosciurinae) are affected. The pathogen occurs not only in Germany, but also squirrel holdings and zoological gardens in the Netherlands and Croatia were tested positive, indicating a serious human health threat of this virus (Paper III and IV). With the help of a metagenomic approach, astroviruses were detected to be associated to encephalitis in cattle and sheep. These viruses were detected in a cow in Germany (Paper V), and in brain samples from two sheep in the United Kingdom (Paper VI). In both cases, the sequences generated by high-throughput-sequencing (HTS) were confirmed by specific RT-qPCRs, which could be used for subsequent screening approaches. Together, methods for the detection of three different encephalitis viruses were developed, validated and applied for different sample material.
Estimating effects of craniofacial morphology on gingival recession and clinical attachment loss
(2017)
Objectives: Currently, evidence for the association between face morphology, attachment loss and
recession is lacking. Face type can be described by the ratio of facial width and facial length. We
hypothesize, that the facial type might be related to gingival recession (REC) and clinical attachment
loss (CAL) and that a broad face is associated with less recession and attachment loss than a long
face.
Materials and methods: Data from the 10 year follow-up of the Study of Health in Pomerania
(SHIP-2; 2008-2012; 2333 participants) were used. Periodontitis was assessed by probing depth (PD)
and clinical attachment loss (CAL). Generalized regression models were used to assess associations
between specific landmark distances extracted from magnetic resonance images (MRI) head scans
and clinically assessed gingival recession adjusting(REC) or clinical attachment loss(CAL) adjusting
for relevant confounders.
Results: Maximum cranial width was negatively associated with mean REC and mean CAL
(p<0.05). Also, higher mean REC and higher mean CAL correlate positively with long face
(B=0.361 with 95% CI), upper anterior facial height.
Conclusion: According to the results of the present study, gingival recession and clinical attachment
loss were associated with higher Prosopic face and facial length indices results.
Quang Xuong is considered as one of the most developed districts in Thanh Hoa Province in terms of agricultural. The major purpose of this research is to find good places to suggest for annual crops production in the case study. Therefore, the assessment of land potential productivity, land suitability, and land cover/land use change in different periods is essential for making strategies of sustainable agricultural development as this will help land-users and land managers to discover the potential and limitations of the current existing land conditions to make appropriate policies and plans for future land use. Its results will provide basic information to make reasonable decisions for investments and rational reclamations of cultivated land before and after each crop season in order to meet the objectives of sustainable development in terms of economic efficiency, social acceptability, and environmental protection. The research site is located at latitudes 19 degree 34 minute N - 19 degree 47 minuteN and at longitudes 105 degree 46 minute E - 105 degree 53 minute E. The total area is about 227km2; in which 128km2 is in use for agricultural activities. Based on soil classification methods by FAO-UNESCO (1988), the agricultural land is classified into six main soil groups, including Arenosols, Salic Fluvisols, Fluvisols, Gleysols, Acrisols, and Leptosols, 12 soil units and 18 sub-units. The largest area belongs to the Fluvisols group with 9358.29ha and the smallest area is identified as the Leptosol group with 219.33ha. Most of the soil in this district has low to moderate nutrition, but in general, they are still suitable for agricultural production. There are 42 land units defined in the land mapping, which can be different from each other by one or more land characteristics. The land mapping unit is created from the overlay of all thematic maps of soil chemicals, soil physical characteristics, and relative topography together by application of GIS techniques. It presents land characteristics and properties in this case study and will be used in comparasion with a particular crop requirement for growth in land suitability evaluation process. A certain land unit may be suitable for one or more types of different land use. It is also classified as highly suitable for a specific land utilization type, but less suitable or unsuitable for other crops. For example, in this study, land unit 26 is determined as highly suitable (S1) for growing paddy rice and maize, but it falls into moderately suitability (S2) for groundnut crop by using parametric (square root) method used in this thesis. Depending on the kind of crops need to be evaluated and its requirement for development compared with each land unit characteristics, land-users will determine the best suitable place for crop production. Identification of land use change in different periods of time has become a central key to monitoring of land resources. It is relatively important for effective land management to protect the land resources, especially the land used for agricultural production from overuse and environmental changes. The sprawl of inhabitant areas, development of rural infrastructures, and industrialization are responsible for serious losses of agricultural land. In this study, remote sensing techniques were applied to studying the trends of land cover change in the abovementioned district in a period of about 24 years from 1989 to 2013. ArcGIS software was adopted to develop the land cover and the change of land use maps from 1989 to 2013. Two satellite images with moderate resolution were collected from USGS Earth Explorer website, Landsat5 TM for 1989 and Landsat8 OLI & TIRS for 2013. After image geo-processing, the images were classified into six land cover categories by applying supervised classification method (Maximum Likelihood). The six main obtained land cover types were built-up areas, agricultural land, forest land, water surface area, salty land, and unused land. The overall accuracies of land cover maps for 1989 and 2013 were 94.08% and 92.91%, respectively. The results of change detection analysis indicate that the cultivated, water surface and unused lands decreased by 22%, 17%, and 91%, respectively. In other side, the built-up and salty land increased by 78%, 58%, respectively and forest land increased from 52.69ha in 1989 to 395.76ha in 2013. The assessment of land potential productivity for agricultural production and land suitability for selected annual crops was based on FAO guidelines for land evaluation (FAO, 1976, 1985, and 1993) which were adopted and slightly modified for compatibility with Vietnamese conditions. All related data were stored, analyzed, mapped and presented in ArcGIS software. Weighted Linear Combination Method developed by Hopkins (1977) and GIS techniques were used to analyze and determine the land potential for agricultural use in the study area. The results show that 5.26%, 83.10%, 10.06%, and 1.57% of the investigated areas were assessed as high potential, moderate potential, low potential and very low potential for growing crops. Regarding land suitability evaluation, the simple limitation, parametric (square root), and AHP methods were used to evaluate the suitability levels for selected crops, including paddy rice, sweet potato, groundnut, maize, potato, sesame, soybean, and green pepper. The obtained results indicate that each applied method provides different results of land suitability level for a specific crop in certain land units compared to the other two methods, and OM, soil pH, soil texture, and relative topography were found out as the main limitation factors which affected land suitability level. The study also suggests that three different methods as abovementioned can be expanded and applied in other places with the appropriate factors used for land suitability evaluation according to particular area conditions.
The virosphere comprises all known and unknown viruses in our ecosystems. Advanced sequencing technologies in combination with metagenomic analysis have become a key tool for exploring this global diversity of viruses. However, discovery of novel viruses and comparative analyses are often based on small sequence fragments or lack biological context, which restricts a proper classification. In this study advanced genomic methods were used that included comprehensive knowledge of viral genomes along with supporting biological metadata in order to identify and classify viruses at different levels of genetic relationships. In a first example, the genetic background of vaccine-induced rabies cases was revealed by analyzing and comparing the genetic diversity of viral populations. Furthermore, the fundament for a taxonomic reclassification of orthopoxviruses was established on basis of a wide scale genomic analysis. In addition, novel neurotropic mamastroviruses from sheep and cattle were classified as members of a single species that provided evidence of interspecies transmission. Finally, two putative novel species of alphaherpesviruses and orthopoxviruses were identified. These examples are based on field cases that provide substantial corresponding clinical metadata and information of host-pathogen interactions. The analyses, therefore, puts taxonomic classification into biological and epidemiological context, rather than addressing generic phylogenetic relationships. Furthermore, the presented work demonstrates that a universal approach for virus classification is neither feasible nor reasonable as analyses must be adjusted the nature of the addressed virus. All results with impact on the current taxonomic classification will be or are already reported to the International Committee on Taxonomy of Viruses. In conclusion, this thesis contributed to the classification concepts of viruses and expanded the knowledge of virosphere diversity.
Staphylococcus aureus (S. aureus) is the leading cause of serious diseases in human both from hospital and community associated infections. Some clinical manifestations of S. aureus infections are infective endocarditis (IE), osteoarticular infections, skin and soft tissue, pleuropulmonary, and device-related infections. In Germany, S. aureus is the second most common cause of hospital-acquired (HA) infections. About 16.7% of these nosocomial infections are caused by HA-MRSA clinical isolates. It has been a huge threat for the clinicians/scientists to control the emergence of such infections caused by S. aureus. S. aureus exhibits increasing virulence and resistance to various antibiotics, complicating prevention and treatment of infections. Eventually, active and passive vaccines might be the alternative strategy to deal with S. aureus related diseases. An effective S. aureus vaccine would provide great potential security and many societal benefits. However, so far vaccine trials have failed often due to limited number of available antigen candidates (monovalent/single antigen) in the clinical trials. Efforts to develop not only S. aureus vaccine but also prognosis or diagnosis tools are challenging tasks. That was the motivation point for the current thesis to identify potential antigen candidates for the aid of vaccine development using immunoproteomics approaches. From the earlier studies, passive immunisation with CP5, CP8, PNAG, ClfA, SdrG, alpha-hemolysin and active immunisation with IsdB, SEB, ClfA, CP5, CP8 were examined during preclinical trials and found to be the best examples for potential vaccine candidates. The antibody responses against S. aureus infections are heterogenous, still it is possible to identify the antibody signatures to a number of corresponding S. aureus antigens, whose abundance and presence could correlate to the disease state and may predict treatment outcome. To support this hypothesis, goals were set to develop and validate serological assay by indirect detection using suspension array technology (SAT). During the study, an antigen library of 140 recombinant S. aureus antigens was generated. Further serological assay were developed and validated to monitor the insights of antibody mediated humoral responses during S. aureus infection from various episodes of S. aureus infection. As an outcome, potential immunogenic antigen candidates were identified which may be used as candidates in active/passive vaccination and to stratify the patient. In total, three studies were carried out using serum and plasma samples from S. aureus nasal colonised healthy individuals (carriers and non-carriers) and bacteraemia patients (control, complicated and uncomplicated sepsis). Bead-based assays were performed and subsequent statistical analyses were done to identify immunogenic antigens that might discriminate between the different clinical status and outcome. Screening of healthy individuals (study-1) have shown significantly higher IgG responses against 14 antigens in S. aureus nasal carriers compared to non-carriers. Furthermore, the clonal complex 30 group of healthy carriers has shown significantly higher IgG responses against toxic shock syndrome toxin-1 (Tsst1) in comparison to non-clonal complex 30 healthy carriers. Study-2 have shown extensively higher IgG responses against 67 antigens in control samples compared to sepsis patients. 50% of the antigens eliciting different immune responses belonged to the extracellular components of S. aureus. The IgG responses against MSCRAMM proteins such as FnbA, FnbB, Efb-1 have been shown to be significantly higher in complicated sepsis. Study-3 have shown notably higher IgG responses against 8 antigens (Plc, SspB, IsaA, SEM, GlpQ, HlgC, SACOL0444, SACOL0985) at baseline in uncomplicated sepsis patients compared to patients subsequently developing complicated sepsis. In summary, the group of immunogenic antigens that have been identified in these studies using immunoproteomics approach could be a starting point for the development of S. aureus vaccines. Moreover, the suspension array technology approach facilitated the identification of new S. aureus antigen candidates in addition to earlier reports. The current results of this study support the hypothesis that it is possible to identify a serological response to potential S. aureus antigens that correlate to progression of S. aureus infections.