Thermal and Mechanical Design and Simulation for the first high precision Quantum Optics Experiment on a Sounding Rocket

The MAIUS-1 payload is a high precision quantum optics experiment about to fly on a VSB-30 sounding rocket with the scientific objective to demonstrate the feasibility of creating the first Bose-Einstein condensates and performing atom interferometry in Space. To achieve these goals the experiment is using various sensitive instruments imposing strong requirements on the thermal and mechanical design. In the introduction this thesis gives a short overview and characterization of available microgravity platforms in Europe. Moreover a detailed characterization of the environment aboard the VSB-30 sounding rocket is presented based on flight data from former MASER and TEXUS missions. In the main chapters the mechanical and thermal design of the MAIUS-1 scientific payload is described in detail. This includes various technical solutions as for example a low-cost vibration isolation, a sealing for RADAX hull segments of pressurized payloads or umbilicals to provide water cooling until lift-off. In addition the test methods and results for the different payload components is presented. The design and test of the ultra-high vacuum system with a nominal pressure of 1E-10 hPa is described in a dedicated chapter. This includes theoretical background on outgassing of technical surfaces and calculation of the conductance of a vacuum system. Different pumping and sealing techniques are introduced. Furthermore the results of intensive testing of Conflat (CF) and Indium sealings under vibrational and static loads are presented as well as test results for the entire pumping system. The thermal control system of the MAIUS-1 scientific payload has been designed using multiple MATLAB codes in combination with ANSYS to estimate the heat flux into the rocket hull by aerodynamic heating during ascent as well as the heat transfer from the heated rocket hull to the system housing walls by natural convection. These codes and their theoretical background are presented herein as well. The thesis closes with recommendations and possible improvements for future space-born quantum optics experiments

A general approach for discriminative de-novo motif discovery from highthroughput data

De novo motif discovery has been an important challenge of bioinformatics for the past two decades. Since the emergence of high-throughput techniques like ChIP-seq, ChIP-exo and protein-binding microarrays (PBMs), the focus of de novo motif discovery has shifted to runtime and accuracy on large data sets. For this purpose, specialized algorithms have been designed for discovering motifs in ChIP-seq or PBM data. However, none of the existing approaches work perfectly for all three high-throughput techniques. In this article, we propose Dimont, a general approach for fast and accurate de novo motif discovery from high-throughput data. We demonstrate that Dimont yields a higher number of correct motifs from ChIP-seq data than any of the specialized approaches and achieves a higher accuracy for predicting PBM intensities from probe sequence than any of the approaches specifically designed for that purpose. Dimont also reports the expected motifs for several ChIP-exo data sets. Investigating differences between in vitro and in vivo binding, we find that for most transcription factors, the motifs discovered by Dimont are in good accordance between techniques, but we also find notable exceptions. We also observe that modeling intra-motif dependencies may increase accuracy, which indicates that more complex motif models are a worthwhile field of research

MotifAdjuster: a tool for computational reassessment of transcription factor binding site annotations

MotifAdjuster helps to detect errors in binding site annotations

Unveiling Permafrost Transformations: Investigating Organic Carbon Characteristics and Dynamics in Alaskan Lowland Landscapes

Lowland permafrost landscapes are experiencing dramatic changes as the climate in the Arctic has been warming almost four times the rate of the global average in the past four decades. On the Alaskan North Slope, extensive thermokarst processes are steering the dynamics of lakes and drained lake basins (DLBs). With progressing climate change, re-aggradation of permafrost in DLBs becomes potentially impeded. Additionally, along the Beaufort Sea coast, thaw-induced destabilization is causing substantial erosion, exposing previously frozen terrestrial deposits to the marine environment. The consequences for the biogeochemical system, which holds significant amounts of organic carbon, remain understudied. Therefore, we aim to investigate the carbon pool characteristics in thermokarst terrain close to Utqiaġvik. Sediment cores were sampled in 2022 and include two thermokarst lakes, one DLB and one undisturbed upland core. While West Twin Lake has freshwater conditions, East Twin Lake exhibits brackish water. The up to 2 m long sediment cores are investigated with a multidisciplinary approach. Bio- and hydrochemical analyses offer a detailed understanding of the current carbon pool properties. Additionally, n-alkane biomarker analyses, accompanied by carbon isotopy and the C/N ratio, serve as proxies to characterize the degradation state of organic carbon and its changes post permafrost thaw. Initial findings on carbon quantity and quality are presented, along with preliminary results from a 12-month-long incubation experiment. In this experiment, carbon dioxide and methane production rates are measured at ten depths along the sediment cores. The outcomes of this study contribute to a more comprehensive understanding of organic carbon degradation and its implications for the future carbon pool at a landform-specific level

Large Herbivores and Their Interaction with Arctic Soil Carbon Storage

Permafrost degradation and organic matter decomposition in the terrestrial Arctic are strongly depending on soil temperatures. A factor that affects these temperatures is grazing and snow trampling by large herbivorous animals, as well as animal-induced changes in vegetation cover. We analysed samples taken from adjacent areas with different grazing intensities, both in a permafrost environment (Siberia) and seasonally frozen ground (norther Finland) for TOC, C/N ratio, d13C, bulk density and radiocarbon age. While in permafrost there was a strong increase in soil carbon storage with high grazing intensity, this effect is not visible in seasonally frozen ground. However, in both areas we observed massive changes in vegetation composition and structure, following the grazing gradient. We conclude that seasonally frozen ground allows for more intensive carbon relocation and mixing, which outweighs the effects animals have in the permafrost region but state that on permafrost, animals might efficiently be utilized to stabilise permafrost temperatures and reduce organic material decomposition

Distribution of mineral constituents in Yedoma permafrost: implications for Yedoma formation

Ice-rich permafrost deposits such as Yedoma are highly sensitive to thaw and given that they contain up to one third of the organic carbon content of the Northern circumpolar permafrost region, their degradation is considered to be a potential climate tipping point on Earth. Accurately predicting the impact of climate warming on the fate of organic carbon in Yedoma requires better constraints on the mineral element reserve in these deposits. This study provides evidence for the homogeneity of chemical composition and mineralogy of Yedoma deposits with depth. This suggests that upon deep thaw through thermokarst or thermo-erosion a high reserve in mineral nutrients is likely to be exposed also from deeper deposits