11615 research outputs found
Sort by
On Ideals Related to Compact Tree Forcings and Their Covering Numbers
Get PDFWe investigate the ideals on the space of the reals that are associated with the classical forcing notions of Sacks and Silver and the closely related Mycielski ideals. We prove that (with one exception) no non-trivial inclusion between any pair of ideals is provable in ZFC. Continuing the work of Jörg Brendle and Otmar Spinas, we show that except for two pairs of distinct ideals (I,J), cov(I) < \cov(J)$ is always consistent, unless this contradicts a trivial ZFC-inequality
Essays on Empirical Finance: Out-of-sample Methods and Applications
Get PDFFinancial research faces a replication crisis as many empirical studies of long-short investment strategies (originally developed in the U.S. equity market) cannot be replicated or are susceptible to p-hacking, data snooping, HARKing (i.e. hypothesising after the results are known) and are therefore sample specific. This is a highly debated topic, given the large degrees of freedom researchers have in defining an investment strategy and the number of strategies that have been published in recent years. This cumulative thesis approaches this discussion in some ways. How likely is it that one set of rules will fit all empirical questions? The problem is exacerbated when international data are used for replication. Thus, how likely is it that a set of rules defined for the U.S. will apply to all international stock markets? The major part of this dissertation focuses on international scientific replications using similar (but not same) data and applications of the existing U.S. results. The results show that the straightforward application of a long-short strategy originally developed in the U.S. can be highly misleading and that for any long-short strategy, one needs to reconsider what an appropriate test in international markets might look like from a theoretical and pragmatic perspective. This is an interesting contrast to the current trend towards large comparative studies of sometimes hundreds of anomalies, in which the theoretical and conceptual specificities of individual strategies are lost. One major reason that long-short strategies cannot simply be applied from the U.S. to international equity markets is because these markets are much smaller than the U.S.. Adjustments are therefore inevitable
Southern Ocean evidence for recurring West Antarctic Ice Sheet destabilization during Marine Isotope Stage 11
Get PDFMillennial-scale deoxygenation of Antarctic Bottom Water (AABW) in the Atlantic Southern Ocean during past interglacials was linked to West Antarctic Ice Sheet (WAIS) melt-driven suppression of dense water formation along the Antarctic margin. However, the circum-Antarctic extent of these 'AABW stagnation events' and drivers of WAIS retreat remain unclear. Here, we identify recurring bottom water O2 minima in the central Pacific Southern Ocean during Marine Isotope Stage (MIS) 11 (424-374 ka ago) that are synchronous with their Atlantic Southern Ocean counterparts. As they (partially) align with Circumpolar Deep Water (CDW) warming above present-day levels and/or a reorganization of deep-ocean circulation, we postulate recurring and synchronized Pacific-Atlantic AABW perturbation events during MIS11 through WAIS retreat and enhanced exposure to ocean heat (i.e., CDW) from below. This indicates a significant contribution of WAIS meltwater to sea-level high-stands during MIS11 and, by analogy, to sea-level rise due to ocean warming in the future
Low Transmission Rate of Hepatitis E Virus by Transfusion of Hepatitis E Virus RNA-Positive Blood Products
Get PDFIntroduction: Hepatitis E virus (HEV) can cause transfusion-transmitted (TT) infections. Therefore, in many countries, blood donor screening for HEV RNA has been established. The amount of infectious HEV RNA concentration in blood donations and screening strategy (pool size, single-sample testing) are still debated. Methods: Blood donations, taken before the universal blood donor screening for HEV RNA, were investigated retrospectively for HEV RNA. Recipients of an HEV RNA-positive blood product were traced by look-back procedure. Archive samples of these recipients were investigated for TT-HEV infection by HEV RNA and anti-HEV IgG testing. HEV RNA concentration in the donor and in the transfused blood product was determined. Results: In 85/75,905 donations (0.1%), HEV RNA was detectable. A total of 28 recipients of 139 blood products from these donations could be further investigated. In 2/28 (7.1%) recipients, a possible TT-HEV infection occurred, but sequence analysis between donor and recipient could not be performed. HEV RNA concentration could be determined in 23 blood products and ranged from 10.9 IU/mL to 116,400 IU/mL donor plasma and absolute 120 IU–8,748,000 IU in the final blood product. In the cases of possible TT-HEV infection, HEV RNA concentration was 62,880 IU/mL donor plasma, according to 691,680–943,200 in the red blood cell concentrate and 593 IU/mL donor plasma, according to 8,302–11,267 IU in the pooled platelet concentrate. Conclusion: Only a minority of HEV RNA-positive blood products caused a TT-HEV infection. With the limitation of the low number of investigated cases, even in blood products, which were contaminated with extremely high HEV RNA concentrations, there was no evidence for TT-HEV infection. Blood donor screening for HEV RNA by pooled samples should be favored over single-sample testing
Effects of a Gel Containing the Defined Microalgae Extract Spiralin® on the Skin Microbiome and Clinical Activity in Atopic Dermatitis: A Double-Blind, Intraindividual Vehicle-Controlled Proof-Of-Concept Study
Get PDFIntroduction Changes in the skin microbiome in atopic dermatitis (AD) include a reduced bacterial diversity and increased abundance of Staphylococcus aureus. Topical antibiotics and antiseptics may decrease bacterial pathogens but lack positive effects on microbiome diversity.[...] The Shannon index reflecting α-diversity and the abundance of S. aureus were calculated from the analysis of 16s rRNA gene libraries with untreated non-lesional skin serving as control. Clinical activity was determined by the Target Lesion Severity Score (TLSS) and lesion size. Results Positive effects of the active gel on the microbiome after 4 weeks of treatment were indicated by a significant increase of the Shannon index in areas treated with verum (mean increase 16.7%; p < 0.01 vs. baseline), but not in areas treated with vehicle. This increase in verum-treated lesions was more pronounced in lesions with an at least 50% (26.3%) or an at least 75% reduction of the TLSS (33.3%). There was also a stronger decrease of the abundance of S. aureus in lesions treated with active gel compared to those treated with vehicle (25.5% vs. 9.4%), but significance was not met. There were several trends, indicating clinical effects of the active gel. For example, vehicle-treated areas showed no reduction in area size (77.8 cm2 at week 4 compared to 77.0 cm2 at baseline), while verum-treated lesion area decreased on average by 6.9 cm2. Active and vehicle gel were well tolerated, and very few local side effects were noted. Conclusion These preliminary results indicate a positive effect of a gel-containing Spiralin® on the skin microbiome in patients with active AD lesions combined with reductions in clinical disease activity, supporting further investigations of the active gel alone or in combination with anti-inflammatory treatments in larger AD studies
Impact of primary production and net ecosystem metabolism on carbon and nutrient cycling at the land-sea interface
Get PDFEstuaries are typically net heterotrophic systems and a source of CO2 to the atmosphere, while continental shelves are net CO2 sinks. Yet, primary production and net ecosystem metabolism (NEM) are variable, and this has implications for nutrient and carbon processing along the land-sea interface. To resolve this variability, high-frequency dissolved oxygen and ancillary biogeochemical data from a research station (FerryBox) located at the outflow of a temperate estuary into a shelf sea, were used to quantify the gross primary production (GPP) and NEM at the land-sea interface. In early and mid-spring in the outer Elbe Estuary (Germany), we find that low GPP rates (155 ± 46 mg C m-2 d-1 in April 2020 and 74 ± 24 mg C m-2 d-1 in March to April 2021) were light limited, as a function of elevated turbidity (31 ± 9 NTU and 35 ± 7 NTU) and solar irradiance. When turbidity decreased in late spring (May), we observed elevated GPP rates, and highest GPP rates in summer (June-August), with seasonal averages of 613 ± 89 mg C m-2 d-1 in 2020 and 558 ± 77 mg C m-2 d-1 in 2021. Primary production in the outer Elbe Estuary waters was not nutrient-limited, since concentrations all year-round exceeded the expected limiting levels of 5 µM Si, 0.5 µM PO43- and 2 µM NO3-. [...] December to August, was likely driven by the concurrent and significant seasonal uptake of inorganic carbon by primary producers in the upper estuary and upstream regions. This highlights the heterogeneity of inorganic carbon patterns along the land-sea continuum and the continuity of biogeochemical processing in the upstream regions of a temperate estuary to sea
Depuration kinetics of trinitrotoluene (TNT) and its metabolites in exposed blue mussels (Mytilus edulis L.)
Get PDFExplosives released by dumped warfare material pose a threat to the marine environment and can enter the marine food web. 2,4,6-Trinitrotoluene (TNT) is one of the most used explosives in munitions and is, therefore, of special interest. To test the uptake, depuration, and potential biotransformation of TNT, common blue mussels (Mytilus edulis) from the German North Sea were exposed to different TNT concentrations in two laboratory experiments (first experiment, 48-h exposure to TNT concentrations of 0, 0.625, 1.25, and 2.5 mg/L; second experiment, 24-h exposure to 0 and 5 mg/L deuterated TNT) followed by recovery phases in clean artificial seawater (first experiment, 60-h recovery; second experiment, 12-h recovery). Water samples and mussel soft bodies were analyzed for TNT and its metabolites 2-amino-4,6-dinitrotoluene (2-ADNT), 4-amino-2,6-dinitrotoluene (4-ADNT), and 2,4-diamino-6-nitrotoluene (2,4-DANT) using Gas Chromatography – Tandem Mass Spectrometry (GC-MS/MS) techniques. The results showed a continuous uptake of dissolved TNT during exposure and a rapid depuration during the recovery phase, independent of the original TNT exposure concentrations. Furthermore, evidence for the biotransformation of TNT is shown by the presence of labelled ADNTs both in mussel soft bodies analyzed within the recovery phase and in water sampled during the recovery phase. Overall, 57% to 76% of the measured concentration was biotransformed within the first 4 h after the exposure
Navigation and real-time sensor fusion for automated observation and data assimilation
Get PDFThis thesis deals with the navigation of autonomous underwater vehicles (AUVs) based on real-time sensor measurements using automatic control methods. The use of AUVs for data collection has enormous potential to reduce costs and improve data quality. AUVs are cheaper to operate than towed or remotely operated systems, especially since the vessel can perform other measurements during this time. In science, AUVs are typically used to acquire data by navigating along so-called lawnmower patterns but the use of AUVs on completely pre-programmed trajectories is suboptimal. Since the spatial boundaries of the phenomenon to be observed cannot be precisely determined a priori, (near) real-time adaptation of the navigation is essential to achieve high data quality comparable to that of towed or remotely operated systems. In this thesis, three application examples of varying complexity are considered, namely the detection and tracking of a boundary layer (thermocline), the localization of a source using the example of a hydrothermal vent, and the estimation of the concentration of a sediment plume as it occurs in deep-sea mining. In the first two application examples an approach based on extremum seeking control (ESC) is used. This is an optimization method that does not require an explicit model, which can be particularly advantageous in the marine context. In the third use case, Bayesian optimization (BO) is used to estimate the concentration of a sediment plume. This optimization method is used to solve difficult-to-evaluate functions, also known as blackbox functions
A Nutritional Evaluation of Plant-Based Meat and Sausage Analogues
Get PDFPlant-based meat and sausage analogues (PBMAs) are gaining popularity due to growing concerns about the health, environmental, and ethical impacts of animal-based foods. In the present study, we compared the nutritional quality of 298 PBMAs to 294 animal-based reference products available on the German retail market in 2024 across nine subcategories. PBMAs generally contained less total fat, saturated fat, and protein, but more fibre, carbohydrates, and sugar compared to meat products. Notably, most meat analogues exhibited higher salt contents. Nutri-Scores of PBMAs were significantly favourable in six subcategories. Among PBMAs, approximately 60% demonstrated good protein quality, while only 12% were fortified with key micronutrients, including vitamin B12 or iron. Most PBMAs contained one or more additives and flavourings. These findings suggest that while PBMAs often offer favourable nutritional profiles, reformulation and clearer nutritional guidance could help to further support the emergence of healthier plant-based options
Non-Coding RNAs (microRNAs, lncRNAs, circRNAs) in Adenomyosis: A Systematic Review of Mechanistic and Translational Evidence
Get PDFAdenomyosis (AM) is a hormonally responsive uterine disorder defined by ectopic endometrial tissue within the myometrium, causing pain, abnormal bleeding, and subfertility. Non-coding RNAs (ncRNAs)-including microRNAs (miRNAs), long non-coding RNAs (lncRNAs), and circular RNAs (circRNAs)-are post-transcriptional regulators implicated also in uterine remodeling. We systematically reviewed original studies evaluating ncRNAs in AM using human samples, in vitro and animal models, or bioinformatic approaches. Data sources included PubMed and Google Scholar (inception up to 10 August 2025). Forty-one studies were included and synthesized across mechanistic, diagnostic, and translational domains. miRNAs (n = 31) were the most studied subclass, followed by lncRNAs (n = 10) and circRNAs (n = 5). Recurrent miRNAs such as miR-10b and miR-30c-5p (downregulated, inhibitory) and miR-145 (upregulated, promotive) regulate epithelial invasion, epithelial-mesenchymal transition, and cytoskeletal remodeling via PI3K-AKT/MAPK and Talin1 signaling. The let-7a/LIN28B axis governed estrogen-sensitive proliferation in the junctional zone, while miR-21 exhibited compartment-specific roles in decidualization and ectopic cell survival. Extracellular-vesicle (EV)-bornemiRNAs (e.g., miR-92a-3p, miR-25-3p, miR-4669) contributed to immune polarization and show early diagnostic potential. lncRNAs and circRNAs acted via chromatin modifiers and ceRNA networks. Most findings remain at the discovery stage. Convergent dysregulation was observed in key signaling pathways, including JAK-STAT, Wnt/β-catenin, and Hippo-YAP. ncRNAs regulate critical axes of invasion, proliferation, immune modulation, and hormonal response in AM. Targets with preliminary causal support-miR-10b/ZEB1, let-7a/LIN28B, and miR-145/Talin1-warrant further validation. Circulating miRNAs-especially in EVs-offer promise for non-invasive diagnosis