Refine
Year of publication
- 2018 (113) (remove)
Document Type
- Doctoral Thesis (113) (remove)
Language
- English (113) (remove)
Has Fulltext
- yes (113)
Is part of the Bibliography
- no (113)
Keywords
- vascular endothelial cells (2)
- ABCE1 (1)
- Afghanistan (1)
- Allosteric inhibition (1)
- Aurora kinase (1)
- Autism Spectrum Disorder (1)
- Bertolt Brecht (1)
- Biological citizenship (1)
- Bourdieu, Pierre (1)
- Brownian motion (1)
Institute
- Biowissenschaften (24)
- Biochemie, Chemie und Pharmazie (22)
- Informatik und Mathematik (17)
- Physik (17)
- Medizin (7)
- Gesellschaftswissenschaften (4)
- Rechtswissenschaft (3)
- Sprach- und Kulturwissenschaften (3)
- Biochemie und Chemie (2)
- Geowissenschaften (2)
The individual parameter
(2018)
The present thesis tackles the unification of two-dimensional semantic systems, which are designed to deal with context-dependency of a certain kind i.e. indexicality, with dynamic theories of meaning, designed to capture facts about anaphoricity and the distribution of definite and indefinite articles. The need for a more principled look at this unification is twofold. Firstly, there is an overlap of these two families of theories in terms of empirical data, namely third person personal pronouns, as well as definite descriptions. Both kinds of expressions have anaphoric as well as non-anaphoric usages, whereas some of the latter ones can be captured in terms of indexicality. But, on the other hand, no language, especially not German and English, the main sources of data in this thesis, seems to distinguish these two usages formally, i.e. by employing different expressions. Hence the need for a unified framework in which this sort of ambiguity can be treated. Secondly, the theoretical state is dissatisfactory in the sense that the families of theories take very disparate forms that are not easy to relate conceptually.
The overlap in empirical area of application strongly suggests that this dichotomy is an artifact of the way these theories traditionally are developed and justified. This thesis seeks to overcome this state of the field. It proceeds as follows.
The first chapter discusses the way in which theories indexicality are designed. After taking a closer look some hallmarks of these theories such as the notions of index- and context-dependency themselves, double indexing, etc., it develops a notion of index dependency that makes use of a more complex individual parameter than the one that is usually assumed in the literature. Apart from agents and addressees, the two standard components of indices that represent contexts, additional objects are assumed. This leads to a variant of the semantics of deictically used third person expression that is called ‘indexical theory of demonstratives’, which is then investigated further.
The second chapter discusses the classics of dynamic semantics: DRT, DPL, and FCS. It arrives at the common core of all of these theories that consists in the assumption of a novel sort of variable namely active variables as opposed to free and bound ones that are intended to model the behavior of (in)definite descriptions and pronouns. The projection behavior of these variables or discourse referents is described either in (discourse-)syntactic or semantic terms. The chapter also arrives at a new formulation of the uniqueness condition that is thought to be part of the semantics of definite descriptions and sketches an account of transparent negation.
The third chapter then combines the insights of the previous ones by developing the notion of representation that connects the entities of evaluation of the first chapter i.e. indices with those of the second namely sets of assignments, a.k.a. files. The formal language that emerged in the second chapter is endowed with two kinds of variables for situations to allow for double indexing within a dynamic setting. A novel interpretation mechanism for the so designed language is proposed, which is shown to capture not only those aspects that are known to exist in two-dimensional frameworks, but also certain other index-index interactions that are described in yet another body of literature.
The final chapter discusses potential flaws of the theory and sketches an account of allegedly bound indexicals that is compatible with Kaplan’s infamous ban on monsters.
NADH:ubiquinone oxidoreductase (Complex Ⅰ) is the first and largest enzyme in the respiratory chain. It catalyzes the transfer of two electrons from NADH to ubiquinone via a series of enzyme-bound redox centers - Flavin mononucleotide (FMN) and iron-sulfur (Fe-S) clusters – and couples the exergonic reaction with the endergonic translocation of four protons across the membranes. Bacteria contain the minimal form of complex I, which is composed of 14 conserved core subunits with a molecular mass of around 550 kDa. Complex Ⅰ has an L-shaped structure which can be subdivided into two major parts (arms). The hydrophilic arm protruding into the bacterial cytosol (or mitochondrial matrix) harbors the binding site for the substrate NADH, the two- to one-electron switch FMN and all one-electron transferring Fe-S clusters and therefore considered as the catalytic unit. The membrane arm consists of the membranespanning subunits and conducts the proton pumping process. The Quinone binding site is located at the interface of both arms. ...
Due to the resurrection of data-hungry models (such as deep convolutional neural nets), there is an increasing demand for large-scale labeled datasets and benchmarks in the computer vision fields (CV). However, collecting real data across diverse scene contexts along with high-quality annotations is often expensive and time-consuming, especially for detailed pixel-level label prediction tasks such as semantic segmentation, etc. To address the scarcity of real-world training sets, recent works have proposed the use of computer graphics (CG) generated data to train and/or characterize performance of modern CV systems. CG based virtual worlds provide easy access to ground truth annotations and control over scene states. Most of these works utilized training data simulated from video games and pre-designed virtual environments and demonstrated promising results. However, little effort has been devoted to the systematic generation of massive quantities of sufficiently complex synthetic scenes for training scene understanding algorithms. In this work, we develop a full pipeline for simulating large-scale datasets along with per-pixel ground truth information. Our simulation pipeline constitutes of mainly two components: (a) a stochastic scene generative model that automatically synthesizes traffic scene layouts by using marked point processes coupled with 3D CAD objects and factor potentials, (b) an annotated-image rendering tool that renders the sampled 3D scene as RGB image with a chosen rendering method along with pixel-level annotations such as semantic labels, depth, surface normals etc. This pipeline is capable of automatically generating and rendering a potentially infinite variety of outdoor traffic scenes that can be used to train convolutional neural nets (CNN).
However, several recent works, including our own initial experiments demonstrated that the CV models that are trained naively on simulated data lack generalization capabilities to real-world scenes. This opens up several fundamental questions about what is it lacking in simulated data compared to real data and how to use it effectively. Furthermore, there has been a long debate since 1980’s on the usefulness of CG generated data for tuning CV systems. Primarily, the impact of modeling errors and computational rendering approximations, due to various choices in the rendering pipeline, on trained CV systems generalization performance is still not clear. In this thesis, we take a case study in the context of traffic scenarios to empirically analyze the performance degradations when CV systems trained with virtual data are transferred to real data. We first explore system performance tradeoffs due to the choice of the rendering engine (e.g., Lambertian shader (LS), ray-tracing (RT), and Monte-Carlo path tracing (MCPT)) and their parameters. A CNN architecture, DeepLab, that performs semantic segmentation, is chosen as the CV system being evaluated. In our case study, involving traffic scenes, a CNN trained with CG data samples generated with photorealistic rendering methods (such as RT or MCPT), shows already a reasonably good performance on real-world testing data from CityScapes benchmark. Use of samples from an elementary rendering method, i.e., LS, degraded the performance of CNN by nearly 20%. This result conveys that training data must be photorealistic enough for better generalizability of the trained CNN models. Furthermore, the use of physics-based MCPT rendering improved the performance by 6% but at the cost of more than three times the rendering time. This MCPT generated dataset when augmented with just 10% of real-world training data from CityScapes dataset, the performance levels achieved are comparable to that of training CNN with the complete CityScapes dataset.
The next aspect we study in the thesis involves the impact of choice of parameter settings of scene generation model on the generalization performance of CNN models trained with the generated data. Towards this end, we first propose an algorithm to estimate our scene generation model parameters given an unlabeled real world dataset from the target domain. This unsupervised tuning approach utilizes the concept of generative adversarial training, which aims at adapting the generative model by measuring the discrepancy between generated and real data in terms of their separability in the space of a deep discriminatively-trained classifier. Our method involves an iterative estimation of the posterior density of prior distributions for the generative graphical model used in the simulation. Initially, we assume uniform distributions as priors over parameters of a scene described by our generative graphical model. As iterations proceed the uniform prior distributions are updated sequentially to distributions for the simulation model parameters that leads to simulated data with statistics that are closer to the distributions of the unlabeled target data.
...
Universities typically offer video-based courses and internships to prepare prospective teachers for classroom management. Empirical studies have shown the effectiveness of analyzing video clips in programs for teacher training. However, no empirical studies have explored the relationship between the teaching experience of prospective teachers and the effectivity of video-based courses on classroom management. The research question was: How can classroom management competency be effectively conveyed in video-based courses regarding the differences in practical experiences of prospective teachers. Theory on cognitive load and situated learning suggests that prospective teachers with teaching experience could benefit more from a situated instructional strategy, whereas prospective teachers without this experience benefit more from a cognitive instructional strategy.
The sample consisted of a total of 87 prospective teachers belonging to a first cohort that had participated in an internship and a second cohort that had not yet participated. Participants of both cohorts were randomly assigned to a course following one of the two instructional strategies. A video test was designed to assess classroom management competence. Additionally, measurements of prospective teachers’ attentiveness and their self-efficacy at the start of the internship were included.
The study showed a significant main effect between pretest and posttest. However, neither a significant difference in the effectiveness between the two instructional strategies nor between the two cohorts was found (first order). Also, the effectiveness of the instructional strategy was not influenced by the availability of teaching experience (second order). Scores on the video test were not significantly related to prospective teachers’ attentiveness. The prospective teachers that participated in the course before participation in the internship rated their own classroom management significantly lower than the prospective teachers that participated in the course after participating in their internship.
These results firstly indicate that there was no significant difference in cognitive load between the groups, implying that both instructional strategies are suitable for the conveying of classroom management competence within universities. Secondly, the current study has found no evidence that the trait of attentiveness influences prospective teachers’ performance within video tests. Thirdly, these results give reason to believe that the valid assessment of self-efficacy on classroom management depends on the degree of familiarity with the topic, for example, through previous dealings within video-based courses. The limited reliability of the new video test should be taken into account when interpreting the results of the current study.
Identification and characterization of hypoxia-regulated long non-coding RNAs in endothelial cells
(2018)
RNA deep sequencing of the human transcriptome revealed that almost ~84 % of the genome are transcribed, however, only 2 % of all transcripts encode for proteins. All remaining transcripts are referred to as non-coding RNAs and can be divided into small non-coding RNAs (<200 nt) and long non-coding RNAs (lncRNAs; >200 nt). Studies throughout the last decade suggest a broad functional spectrum for lncRNAs. Regarding the cardiovascular field, several studies could show that lncRNAs are implicated in various aspects of endothelial cell biology. The response to hypoxia and the regulation of angiogenesis are key events in the context of several diseases. Therefore, the aim of this study was to determine the influence of hypoxia on lncRNA expression in human umbilical vein endothelial cells and furthermore, to characterize the lncRNA function on a molecular level. ...
The genetic mutation of the coagulation factor VIII (fVIII) results in a defective or missing protein, leading to a malfunctioning blood coagulation. The resulting disease is called hemophilia A. Depending on the severity of the mutation, affected patients experience an increased risk of pathologic bleeding after minor trauma or even sudden bleeding events. Substitution therapies with extrinsic fVIII exist using plasmatic or recombinant fVIII products. Due to an insufficient immune tolerance towards substituted fVIII, about 30 % of patients develop allogenic neutralizing antibodies (inhibitors) against substituted fVIII products. The gold standard of treating inhibitors is the immune tolerance induction (ITI), where patients are given frequent, high doses of fVIII to induce an immune tolerance. ITI therapy fails in about 30 % of patients. Mechanisms of action of ITI are part of research, as insufficient knowledge about mechanisms and prognostic factors complicate treatment. For example, the development of anti-idiotypic antibodies, which occur naturally as a regulatory mechanism of the immune system, are being studied. Such anti-idiotypes have been detected in immunoglobuline preparations and in patients after successful ITI.
Inhibitors interfere with fVIII function in coagulation by binding functional epitopes within fVIII domains. Inhibitors against the A2 and C2 domain are predominantly found, however also the C1 domain has been shown to be highly immunogenic in some patients. The polyclonality of inhibitors aggravates the understanding and treatment of these. The present project therefore focusses on the selection of synthetic anti-idiotypic antibodies to target inhibitors in patients. The phage display method was applied to, for one, isolate anti-idiotypic single chain variable fragments (scFvs) specific against human polyclonal anti-fVIII antibodies and second against two C1 domain-specific inhibitory monoclonal antibodies (mAbs).
In the first project, anti-fVIII antibodies were purified from human plasma to serve as target molecules. A previous project showed that using full plasma as a target did not yield anti-idiotypic antibodies from phage display. For the purification, protein A chromatography and fVIII coupled Affi Gel® chromatography were applied. The isolated antibodies were next used as targets for the selection of anti-idiotypic scFvs. Analysis revealed that none of the selected phages solely bound the anti-fVIII antibody target. Consequently, the test protocol was modified, which resulted in a reduction of unspecific binders. Yet, no target-specific binders were isolated from phage pools. Reason for this may have been the high diversity of the polyclonal antibody target and the limited diversity of the phage libraries.
The aim of the second project, was the selection and characterization of scFvs, that target the paratopes of C1 domain-specific mAbs GMA8011 and LE2E9. From a therapeutic viewpoint, the preparation of an anti-idiotypic antibody pool, tailored to each patient’s inhibitor population, could help neutralize inhibitors in patients. Ultimately, one GMA8011-specific scFv-carrying phage clone (H2C1) and two specifics to LE2E9 (H3G7, H3F10) were isolated. In further experiments, only the GMA8011-specific scFv showed competitive behavior in presence of fVIII, pointing towards an anti-idiotypic binding to the inhibitor paratope. The LE2E9-specific scFvs did not prevent binding of the inhibitor to fVIII. Hence, no anti-idiotypic behavior could be determined. For further characterization, selected scFvs were genetically fused to Fc antibody fragments and recombinantly produced. In this antibody format, all three scFvs showed concentration dependent binding to the target and the isotype control. The binding specificity to the target, observed in phage context, could not be reproduced. Competition experiments with fVIII confirmed that none of the scFvs bound the paratope of their target inhibitor.
The selection of anti-idiotypic scFvs from phage display libraries proves to be effortful. Polyclonal anti-fVIII antibodies purified from hemophilic plasma appear to be unsuitable as a target for phage display, likely due to the high diversity of the target molecules. Furthermore, the preparation of an individualized anti-idiotypic pools for patients by selecting scFvs against single inhibitory mAbs proves to be difficult. The selection of scFvs against anti-C1 inhibitors GMA8011 and LE2E9 produced three promising scFv-carrying phages. However, analysis could not detect anti-idiotypic behavior. Further research with inhibitors, monoclonal and polyclonal, and anti-idiotypic antibodies should be performed to bring better insight into the highly complex paratope-epitope interaction.
The study focuses on the introduction of a health education curriculum in Cyprus’ public schools. The curriculum’s implementation is looked at as a project of modernization and is examined ethnographically in two primary schools in the Republic of Cyprus over a period of three years. Utilizing theories and methods from Science and Technology Studies and Global Ethnography, the study examines the entanglements of Science with Culture and of Tradition with Modernity as experts, teachers, parents and children encounter the new health education curriculum. Health education is compared to a project of biological citizenship and the curriculum is seen as an actant attempting to form a personal obligation towards health by promoting “common sense” knowledge and privileging “modern” individuals.
Enhanced aridification of Central Asia driven by the combined effects of orogenic surface uplift, Paratethys retreat, changes in atmospheric moisture transport and global cooling is one of the most prominent Cenozoic climate change events of the Northern Hemisphere. Deciphering regional long-term patterns of Central Asian hydrology is, therefore, a key element in understanding the role of Northern Hemisphere mid-latitude drying in the global hydrological system. Pedogenic carbonates record information of the paleoecosystem, the paleogeography, hydrology, tectonic and climatic conditions as well as the sedimentary regime during the time in which they formed. The calcrete-bearing paleosols in continental sedimentary basins yield the possibility for understanding these processes, mechanisms and controlling factors. This study characterizes long-term paleoenvironmental conditions between the late Oligocene and early Miocene in SE Kazakhstan based on stable isotopes, elemental geochemistry and laser ablation U-Pb geochronology from alluvial, fluvial and pedogenic deposits. The main topics addressed in this thesis are paleosol and calcrete formation processes in the light of geochemistry, tectonic and climatic influences on both, as well as the paleoenvironmental and hydrological conditions which led to these processes.
The sedimentological succession of the 14 km-long Kendyrlisai Valley in the Ili Basin, SE Kazakhstan in Central Asia, yields exceptional well-developed paleosols which provide an insight into the relationship between tectonics and sedimentation as well as soil formation processes. The valley accommodates more than 600 m of siliciclastic sediments deposited in a fluvial to alluvial environment in the lower part which grade into lacustrine to fluvial deposition with minor gypsum accumulation in the upper part. The yet undated sediments of Kendyrlisai Valley are compared with a biostratigraphically dated and well described succession in an adjacent location. The correlation of the two successions revealed a proximal-distal relation with the Kendyrlisai Valley succession represents the basin margin position with coarse alluvial-fluvial sediments. The calcrete nodules in Kendyrlisai Valley paleosols give the opportunity of U-Pb dating with LA-ICP-MS which uses the variation in both U and Pb to directly date the calcite. The U-Pb dating revealed a late Oligocene-early Miocene age for the investigated section. The analysis of facies and geochemistry of the paleosol profiles in Kendyrlisai Valley gives insight into calcretization stages, pedogenic processes and landscape stability. Kendyrlisai Valley paleosols show a low to moderate weathering intensity with the highest weathering intensity between 0.5 and 0.8 m depth in the paleosol profile. The comparison between acid leachable and non-acid leachable fraction indicate an incorporation of Ca and Ba in incipient calcrete calcite, whereas clay minerals adsorb Mg and Sr. During the evolution from early to more mature calcrete stages, i.e. calcrete nodules, Ba is lost by dissolution and subsequently adsorbed on clay minerals. The nodules consist almost exclusively of pure calcium carbonate with rare substitution of Ca by Mg indicating a constant supply of Ca by weathering and solution during calcrete formation. The occurrence of Mg-bearing clay minerals indicates high evaporative conditions with alkaline waters (pH >9).
Sampled calcrete nodule cross sections reveal more than one weathering and calcrete formation phase with a higher supply of Ca, Mg and Fe during early phases. The organic and inorganic carbon isotope composition of the calcrete nodules reflects C3 metabolism under occasionally moisture stress, resulting in higher δ13C values and lower respiration rates. This study also presents calculated atmospheric pCO2 values from the calcrete nodules with the equation from Cerling et al. (1999). The average calculated CO2 concentration for Kendyrlisai Valley paleosols is 313 ± 110 ppmv. The comparison with data from other studies during the late Oligocene–early Miocene reveal lower values for Kendyrlisai Valley paleosols, which may stem from an underestimation of the plant-respired CO2.
The knowledge of the variability within the paleosols and calcrete nodules enables a reliable paleoclimatic interpretation for the Kendyrlisai Valley and beyond the Ili Basin. Sedimentary facies and geochemical weathering indices suggest an increased surface and groundwater discharge fed by orographically-enhanced precipitation in the Tien Shan hinterland. In contrast, pedogenic stable isotope data and elevated rates of Mg fixation in clay minerals mirror enhanced rates of evaporation in the vadose zone due to protracted aridification. This study posits that pronounced surface uplift of the Tien Shan Mountains during the Oligocene–Miocene transition promoted regionally increased orographic precipitation and the development of fluvial discharge systems.
The comparison with other studies in adjacent basins creates a precipitation pattern for Central Asia during the late Oligocene to early Miocene. The westerlies supplied Central Asia with atmospheric moisture from the West, possibly from the Eastern Paratethys. The uplifting Tien Shan Mountain ranges captured this moisture on their luv-side, resulting in a pronounced orographic rainfall in the adjacent Ili and Issyk Kul Basins. The Tarim Basin and the Valley of Lakes experienced drier conditions due to the rain shadow effect on the lee-side of the Tien Shan and Altai Mountains. In course of this findings, the thesis highlights the crucial role the Tien Shan Mountains play and had been playing in former times as an orographic barrier for the distribution of atmospheric moisture across Central Asia.
Aim: Long noncoding RNAs (lncRNAs) belong to the interface of epigenetics and exhibit diverse functions. Their features depend on their sequence, genomic location and tertiary structure. The aim was to identify novel lncRNAs and characterise their physiological functions and mechanisms in endothelial cells. Three different approaches were performed:
The hypothesis that pseudogene-annotated lncRNA NONHSAT073641 regulates the expression of their parental gene platelet activating factor acetylhydrolase 1b regulatory subunit 1 (PAFAH1B1) was examined.
The physiological functions and in vivo relevance of most lncRNAs are still unknown, therefore a part of this work aimed to identify lncRNAs in response to a pathophysiological stimulus (high amplitude stretch) in endothelial cells.
The long intergenic noncoding RNA antisense to S1PR1 (LISPR1) gene, is located within the promotor of sphingosine-1-phosphate receptor 1 (S1PR1) and shares a part of the promotor region. This study examined additionally the hypothesis that LISPR1 controls the S1PR1 expression in endothelial cells.
Methods: The angiogenic functions of NONHSAT073641 and LISPR1 were examined with spheroid-outgrowth and scratch wound assays. Furthermore, stretch experiments were performed in order to identify differently expressed lncRNAs in human umbilical vein endothelial cells (HUVECs). In addition, the in vivo relevance of both lncRNAs was examined in samples from pulmonary arterial hypertension patients. Knockdown (e.g. LNA GapmeRs), knockout (CRISPR/ Cas9) and overexpression experiments (e.g. CRISPR activation) were performed to analyse target genes. The molecular mechanism of LISPR1 was investigated with RNA and Chromatin immunoprecipitation.
Results: NONHSAT073641 and PAFAH1B1 exhibited angiogenic function in endothelial cells. It could be observed that NONHSAT073641 is not regulating the expression of PAFAH1B1. The pro-angiogenic feature of PAFAH1B1 might be attributed to the target gene matrix Gla protein (MGP). NONHSAT073641 and PAFAH1B1 were significantly induced in CTEPH samples and might be important in the development of this disease. It could be speculated that NONHSAT073641 is regulating the expression of the cell-cycle regulator BCL2L11 as has been investigated in mice.
LISPR1 is a cis-acting lncRNA which maintains S1PR1 gene transcription by intercepting the transcriptional repressor ZNF354C and enabling Polymerase II (PolII) to bind. ZNF354C regulates S1PR1 expression in HUVECs. However, the role of ZNF354C in pulmonary arterial hypertension (PAH) is unknown. LISPR1 and S1P1 receptor were both significantly depleted in COPD samples. It can be assumed that due to higher S1P production, the signalling is attenuated through reduction of the lncRNA LIPSR1 and thus the receptor S1P1.
The stretch experiments present a possible in vitro model in order to mimic the condition of endothelial cells during high blood pressure, such as in PAH. Referring to published data, it could be confirmed that stretching of endothelial cells alters the gene expression, which is on the other hand linked to cardiovascular disease. In cardiovascular disease mechanical stretch altered genes, which are participating in the vascular remodelling process. The role of differently expressed lncRNAs (TGFβ2-AS1, CTD-2033D15.2, INHBA-AS1, RP11-393I2.4, TAPT1-AS1, TPM1-AS1, CFLAR-AS1 and HIF1α-AS2) upon mechanical stretch is yet not clarified.
Conclusion: NONHSAT073641 and LISPR1 are important for the endothelial angiogenic function. Both lncRNAs were deregulated in PAH samples. The pathophysiological stimulus had an impact on the expression of different lncRNAs (e.g. TGFβ2-AS1) and pathways (e.g. TGF-β) in endothelial cells.
Metabolic engineering can serve to convert microorganisms to
microbial cell factories with the goal of producing various chemicals. Commonly used strategies to modify metabolic pathways include deletions and overexpression of genes, as well as the introduction of heterologous genes or genes which have been optimized for the host organism or for a reaction of interest. Aside from these classic metabolic engineering strategies, researchers have also implemented pathway compartmentalization strategies, which mimic nature’s strategies of colocalizing enzymes for pathway optimization.
In this thesis, classic metabolic engineering strategies were combined with pathway compartmentalization strategies. For pathway compartmentalization, mitochondria and peroxisomes were harnessed, and additionally a new strategy to create artificial subcellular organelles was evaluated. In the latter approach, the so-called Zera peptide was fused to the enzymes of interest. Zera consists of the first 113 amino acids of the plant storage protein γ-Zein (Zea mays). Natively, plant storage proteins accumulate in endoplasmic reticulum (ER)-derived vesicles in plant seeds and serve as an amino acid source for the germinating plant. In this thesis, it was shown that Zera also induces the formation of artificial, ER-derived vesicles in Saccharomyces cerevisiae. Furthermore, it was shown that Zera fusion enzymes remained active, albeit with sometimes reduced activity.
In line with the goal of compartmentalizing pathways in these artificial, Zera-induced vesicles, a new tool was developed to determine the pH in the ER of S. cerevisiae and in the ER-derived vesicles. pHluorin, a pH-sensitive green fluorescent protein (GFP) variant, is commonly used to analyze the cytosolic pH or the pH of subcellular organelles. In this thesis, it was shown that pHluorin has very low fluorescence intensity and pH sensitivity in the ER and in Zera-induced ER-derived vesicles. Therefore, a superfolder variant of pHluorin was developed which allows reliable pH measurements in these compartments and can be used to analyze whether the organellar or vesicular pH suits a pathway of interest....