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Background: The characteristics of osteoporosis are decreased bone mass and destruction towards the microarchitecture of bone tissue, which raises the risk of fracture. Psychosocialstress and osteoporosis are linked by sympathetic nervous system, hypothalamic-pituitary-adrenal axis, and other endocrine factors. Psychosocial stress causes a series of effects on the organism, and this long-term depletion at the cellular level is considered to be mitochondrial allostatic load, including mitochondrial dysfunction and oxidative stress. Extracellular vesicles (EVs) are involved in the mitochondrial allostatic load process and may as biomarkers in this setting. As critical participants during cell-to-cell communications, EVs serve as transport vehicles for nucleic acid and proteins, alter the phenotypic and functional characteristics of their target cells, and promote cell-to-cell contact. And hence, they play a significant role in the diagnosis and therapy of many diseases, such as osteoporosis.
Aim: This narrative review attempts to outline the features of EVs, investigate their involvement in both psychosocial stress and osteoporosis, and analyze if EVs can be potential mediators between both.
Methods: The online database from PubMed, Google Scholar, and Science Direct were searched for keywords related to the main topic of this study, and the availability of all the selected studies was verified. Afterward, the findings from the articles were summarized and synthesized.
Results: Psychosocial stress affects bone remodeling through increased neurotransmitters such as glucocorticoids and catecholamines, as well as increased glucose metabolism. Furthermore, psychosocial stress leads to mitochondrial allostatic load, including oxidative stress, which may affect bone remodeling. In vitro and in vivo data suggest EVs might involve in the link between psychosocial stress and bone remodeling through the transfer of bioactive substances and thus be a potential mediator of psychosocial stress leading to osteoporosis.
Conclusions: According to the included studies, psychosocial stress affects bone remodeling, leading to osteoporosis. By summarizing the specific properties of EVs and the function of EVs in both psychosocial stress and osteoporosis, respectively, it has been demonstrated that EVs are possible mediators of both, and have the prospects to be useful in innovative research areas.
River flooding is a constant peril for societies, causing direct economic losses in the order of $100 billion worldwide each year. Under global change, the prolonged concentration of people and assets in floodplains is accompanied by an emerging intensification of flood extremes due to anthropogenic global warming, ultimately exacerbating flood risk in many regions of the world.
Flood adaptation plays a key role in the mitigation of impacts, but poor understanding of vulnerability and its dynamics limits the validity of predominant risk assessment methods and impedes effective adaptation strategies. Therefore, this thesis investigates new methods for flood risk assessment that embrace the complexity of flood vulnerability, using the understudied commercial sector as an application example.
Despite its importance for accurate risk evaluation, flood loss modeling has been based on univariable and deterministic stage-damage functions for a long time. However, such simplistic methods only insufficiently describe the large variation in damage processes, which initiated the development of multivariable and probabilistic loss estimation techniques. The first study of this thesis developed flood loss models for companies that are based on emerging statistical and machine learning approaches (i.e., random forest, Bayesian network, Bayesian regression). In a benchmarking experiment on basis of object-level loss survey data, the study showed that all proposed models reproduced the heterogeneity in damage processes and outperformed conventional stage-damage functions with respect to predictive accuracy. Another advantage of the novel methods is that they convey probabilistic information in predictions, which communicates the large remaining uncertainties transparently and, hence, supports well-informed risk assessment.
Flood risk assessment combines vulnerability assessment (e.g., loss estimation) with hazard and exposure analyses. Although all of the three risk drivers interact and change over time, such dependencies and dynamics are usually not explicitly included in flood risk models. Recently, systemic risk assessment that dissolves the isolated consideration of risk drivers has gained traction, but the move to holistic risk assessment comes with limited thoroughness in terms of loss estimation and data limitations. In the second study, I augmented a socio-hydrological system dynamics model for companies in Dresden, Germany, with the multivariable Bayesian regression loss model from the first study. The additional process-detail and calibration data improved the loss estimation in the systemic risk assessment framework and contributed to more accurate and reliable simulations. The model uses Bayesian inference to quantify uncertainty and learn the model parameters from a combination of prior knowledge and diverse data.
The third study demonstrates the potential of the socio-hydrological flood risk model for continuous, long-term risk assessment and management. Using hydroclimatic ad socioeconomic forcing data, I projected a wide range of possible risk trajectories until the end of the century, taking into account the adaptive behavior of companies. The study results underline the necessity of increased adaptation efforts to counteract the expected intensification of flood risk due to climate change. A sensitivity analysis of the effectiveness of different adaptation measures and strategies revealed that optimized adaptation has the potential to mitigate flood risk by up to 60%, particularly when combining structural and non-structural measures. Additionally, the application shows that systemic risk assessment is capable of capturing adverse long-term feedbacks in the human-flood system such as the levee effect.
Overall, this thesis advances the representation of vulnerability in flood risk modeling by offering modeling solutions that embrace the complexity of human-flood interactions and quantify uncertainties consistently using probabilistic modeling. The studies show how scarce information in data and previous experiments can be integrated in the inference process to provide model predictions and simulations that are reliable and rich in information. Finally, the focus on the flood vulnerability of companies provides new insights into the heterogeneous damage processes and distinct flood coping of this sector.
Childhood compared to adolescence and adulthood is characterized by high neuroplasticity represented by accelerated cognitive maturation and rapid cognitive developmental trajectories. Natural growth, biological maturation and permanent interaction with the physical and social environment fosters motor and cognitive development in children. Of note, the promotion of physical activity, physical fitness, and motor skill learning at an early age is mandatory first, as these aspects are essential for a healthy development and an efficient functioning in everyday life across the life span and second, physical activity behaviors and lifestyle habits tend to track from childhood into adulthood.
The main objective of the present thesis was to optimize and deepen the knowledge of motor and cognitive performance in young children and to develop an effective and age-appropriate exercise program feasible for the implementation in kindergarten and preschool settings. A systematic review with meta-analysis was conducted to examine the effectiveness of fundamental movement skill and exercise interventions in healthy preschool-aged children. Further, the relation between measures of physical fitness (i.e., static balance, muscle strength, power, and coordination) and attention as one domain of cognitive performance in preschool-aged children was analyzed. Subsequently, effects of a strength-dominated kindergarten-based exercise program on physical fitness components (i.e., static balance, muscle strength, power, and coordination) and cognitive performance (i.e., attention) compared to a usual kindergarten curriculum was examined.
The systematic review included trials focusing on healthy young children in kindergarten or preschool settings that applied fundamental movement skill-enhancing intervention programs of at least 4 weeks and further reported standardized motor skill outcome measures for the intervention and the control group. Children aged 4-6 years from three kindergartens participated in the cross-sectional and the longitudinal study. Product-orientated measures were conducted for the assessment of muscle strength (i.e., handgrip strength), muscle power (i.e., standing long jump), balance (i.e., timed single-leg stand), coordination (hopping on right/left leg), and attentional span (i.e., “Konzentrations-Handlungsverfahren für Vorschulkinder” [concentration-action procedure for preschoolers]).
With regards to the scientific literature, exercise and fundamental movement skill interventions are an effective method to promote overall proficiency in motor skills (i.e., object control and locomotor skills) in preschool children particularly when conducted by external experts with a duration of 4 weeks to 5 months. Moreover, significant medium associations were found between the composite score of physical fitness and attention as well as between coordination separately and attention in children aged 4-6 years. A 10-weeks strength-dominated exercise program implemented in kindergarten and preschool settings by educated and trained kindergarten teachers revealed significant improvements for the standing long jump test and the Konzentrations-Handlungsverfahren of intervention children compared to children of the control group.
The findings of the present thesis imply that fundamental movement skill and exercise interventions improve motor skills (i.e., locomotor and object control skills). Nonetheless, more high-quality research is needed. Additionally, physical fitness, particularly high performance in complex fitness components (i.e., coordination measured with the hopping on one leg test), tend to predict attention in preschool age. Furthermore, an exercise program including strength-dominated exercises, fundamental movement skills and elements of gymnastics has a beneficial effect on jumping performance with a concomitant trend toward improvements in attentional capacity in healthy preschool children. Finally, it is recommended to start early with the integration of muscular fitness (i.e., muscle strength, muscle power, muscular endurance) next to coordination, agility, balance, and fundamental movement skill exercises into regular physical activity curriculums in kindergarten settings.
The “HPI Future SOC Lab” is a cooperation of the Hasso Plattner Institute (HPI) and industry partners. Its mission is to enable and promote exchange and interaction between the research community and the industry partners.
The HPI Future SOC Lab provides researchers with free of charge access to a complete infrastructure of state of the art hard and software. This infrastructure includes components, which might be too expensive for an ordinary research environment, such as servers with up to 64 cores and 2 TB main memory. The offerings address researchers particularly from but not limited to the areas of computer science and business information systems. Main areas of research include cloud computing, parallelization, and In-Memory technologies.
This technical report presents results of research projects executed in 2018. Selected projects have presented their results on April 17th and November 14th 2017 at the Future SOC Lab Day events.
Biogeochemical analyses of lacustrine environments are well-established methods that allow exploring and understanding complex systems in the lake ecosystem. However, most were conducted in temperate lakes controlled by entirely different physical conditions than in tropical climates. The most important difference between the temperate and tropical lakes is lacking seasonal temperature fluctuations in the latter, which leads to a stable temperature gradient in the water column. Thus, the water column in tropical latitudes generally is void of perturbations that can be seen in their temperate counterparts. Permanent stratification in the water column provides optimal conditions for intact sedimentation. The geochemical processes in the water column and the weathering process in the distinct lithology in the catchment leads to the different biogeochemical characteristic in the sediment. Conducting a biogeochemical study in this lake sediment, especially in the Sediment Water Interface (SWI) helps reveal the sedimentation and diagenetic process records influenced by the internal or external loading. Lake Sentani, the study area, is one of the thousands of lakes in Indonesia and located in the Papua province. This tropical lake has a unique feature, as it consists of four interconnected sub-basins with different water depths. More importantly, its catchment is comprised of various different lithologies. Hence, its lithological characteristics are highly diverse, and range from mafic and ultramafic rocks to clastic sediment and carbonates. Each sub-basin receives a distinct sediment input. Equally important, besides the natural loading, Lake Sentani is also influenced by anthropogenic input. Previous studies have elaborated that there is an increase in population growth rate around the lake which has direct consequences on eutrophication. Considering these factors, the government of The Republic of Indonesia put Lake Sentani on the list of national priority lakes for restoration. This thesis aims to develop a fundamental understanding of Lake Sentani's sedimentary geochemistry and geomicrobiology with a special focus on the effects of different lithologies and anthropogenic pressures in the catchment area. We conducted geochemical and geomicrobiology research on Lake Sentani to meet this objective. We investigated geochemical characteristics in the water column, porewater, and sediment core of the four sub-basins. Additional to direct investigations of the lake itself, we also studied the sediments in the tributary rivers, of which some are ephemeral, as well as the river mouths, as connections between riverine and the lacustrine habitat. The thesis is composed of three main publications about Lake Sentani and supported by several publications that focus on other tropical lakes in Indonesia. The first main publication investigates the geochemical characterization of the water column, porewater, and surface sediment (upper 40-50 cm) from the center of the four sub-basins. It reveals that besides catchment lithology, the water column heavily influences the geochemical characteristics in the lake sediments and their porewater. The findings indicate that water column stratification has a strong influence on overall chemistry. The four sub-basins are very different with regard to their water column chemistry. Based on the physicochemical profiles, especially dissolved oxygen, one sub-basin is oxygenated, one intermediate i.e. just reaches oxygen depletion at the sediment-water interface, and two sub-basins are fully meromictic. However, all four sub-basins share the same surface water chemistry. The structure of the water column creates differences on the patterns of anions and cations in the porewater. Likewise, the distinct differences in geochemical composition between the sub-basins show that the lithology in the catchment affects the geochemical characteristic in the sediment. Overall, water column stratification and particularly bottom water oxygenation strongly influence the overall elemental composition of the sediment and porewater composition. The second publication reveals differences in surface sediment composition between habitats, influenced by lithological variations in the catchment area. The macro-element distribution shows that the geochemical characteristics between habitats are different. Furthermore, the geochemical composition also indicates a distinct distribution between the sub-basins. The geochemical composition of the eastern sub-basin suggests that lithogenic elements are more dominant than authigenic elements. This is also supported by sulfide speciation, particle distribution, and smear slide data. The third publication is a geomicrobiological study of the surface sediment. We compare the geochemical composition of the surface sediment and its microbiological composition and compare the different signals. Next Generation Sequencing (NGS) of the 16S rRNA gene was applied to determine the microbial community composition of the surface sediment from a great number of locations. We use a large number of sampling sites in all four sub-basins as well as in the rivers and river mouths to illustrate the links between the river, the river mouth, and the lake. Rigorous assessment of microbial communities across the diverse Lake Sentani habitats allowed us to study some of these links and report novel findings on microbial patterns in such ecosystems. The main result of the Principal Coordinates Analysis (PCoA) based on microbial community composition highlighted some commonalities but also differences between the microbial community analysis and the geochemical data. The microbial community in rivers, river mouths and sub-basins is strongly influenced by anthropogenic input from the catchment area. Generally, Bacteroidetes and Firmicutes could be an indicator for river sediments. The microbial community in the river is directly influenced by anthropogenic pressure and is markedly different from the lake sediment. Meanwhile, the microbial community in the lake sediment reflects the anoxic environment, which is prevalent across the lake in all sediments below a few mm burial depth. The lake sediments harbour abundant sulfate reducers and methanogens. The microbial communities in sediments from river mouths are influenced by both rivers and lake ecosystems. This study provides valuable information to understand the basic processes that control biogeochemical cycling in Lake Sentani. Our findings are critical for lake managers to accurately assess the uncertainties of the changing environmental conditions related to the anthropogenic pressure in the catchment area. Lake Sentani is a unique study site directly influenced by the different geology across the watershed and morphometry of the four studied basins. As a result of these factors, there are distinct geochemical differences between the habitats (river, river mouth, lake) and the four sub-basins. In addition to geochemistry, microbial community composition also shows differences between habitats, although there are no obvious differences between the four sub-basins. However, unlike sediment geochemistry, microbial community composition is impacted by human activities. Therefore, this thesis will provide crucial baseline data for future lake management.
In this thesis, we investigate language learning in the formalisation of Gold [Gol67]. Here, a learner, being successively presented all information of a target language, conjectures which language it believes to be shown. Once these hypotheses converge syntactically to a correct explanation of the target language, the learning is considered successful. Fittingly, this is termed explanatory learning. To model learning strategies, we impose restrictions on the hypotheses made, for example requiring the conjectures to follow a monotonic behaviour. This way, we can study the impact a certain restriction has on learning.
Recently, the literature shifted towards map charting. Here, various seemingly unrelated restrictions are contrasted, unveiling interesting relations between them. The results are then depicted in maps. For explanatory learning, the literature already provides maps of common restrictions for various forms of data presentation.
In the case of behaviourally correct learning, where the learners are required to converge semantically instead of syntactically, the same restrictions as in explanatory learning have been investigated. However, a similarly complete picture regarding their interaction has not been presented yet.
In this thesis, we transfer the map charting approach to behaviourally correct learning. In particular, we complete the partial results from the literature for many well-studied restrictions and provide full maps for behaviourally correct learning with different types of data presentation. We also study properties of learners assessed important in the literature. We are interested whether learners are consistent, that is, whether their conjectures include the data they are built on. While learners cannot be assumed consistent in explanatory learning, the opposite is the case in behaviourally correct learning. Even further, it is known that learners following different restrictions may be assumed consistent. We contribute to the literature by showing that this is the case for all studied restrictions.
We also investigate mathematically interesting properties of learners. In particular, we are interested in whether learning under a given restriction may be done with strongly Bc-locking learners. Such learners are of particular value as they allow to apply simulation arguments when, for example, comparing two learning paradigms to each other. The literature gives a rich ground on when learners may be assumed strongly Bc-locking, which we complete for all studied restrictions.
Diese Masterarbeit zielt darauf ab, exemplarisch an zoologischen Gärten für das politische Spannungsverhältnis zwischen Mensch und Tier zu sensibilisieren sowie die damit einhergehenden Aushandlungsprozesse auf individueller bzw. gesamtgesellschaftlicher Ebene didaktisch anschlussfähig zu machen. Nach einer kurzen begrifflichen Einführung der titelgebenden Termini werden in diesem Sinne vier verschiedene Ausdrucksformen ambivalenter Mensch-Tier-Beziehungen erörtert: die Entwicklungsgeschichte und Architektur sowie die Artenschutz- bzw. Bildungsleistungen der Zoos. Dabei wird der historisch vorbelastete Balanceakt zoologischer Gärten deutlich, in Gegenwart und Zukunft menschliche und tierliche Interessen glaubhaft in Einklang bringen zu müssen. Als Grundübel dieses Dilemmas wird wiederum der menschliche Anspruch identifiziert, Naturzustände vor dem Hintergrund eines fragwürdigen Legitimationsnarratives kulturell nachstellen zu wollen.
Außerdem entfaltet der Autor die These, dass der Zoo gerade durch die ihn prägenden Ambivalenzen gegenüber anderen Problembereichen der Mensch-Tier-Beziehungen an Kontroversität gewinnt und somit prädestiniert ist, um als politikdidaktische Reibungsfläche zeitgemäßer Mensch-Tier-Beziehungen zu fungieren. Dementsprechend werden abschließend Zugänge vorgeschlagen, um den Zoo als außerschulischen politischen Lernort vor dem Hintergrund vielfältiger Streitfragen erkunden und produktiv erörtern zu können.
Indem Schülerinnen und Schüler demnach die Wert- und Zweckrationalität der Zoos auf den Prüfstand stellen, werden sie dazu angeregt, sich selbst- und gesellschaftskritisch mit dem politischen Verhältnis zwischen Tieren und Menschen auseinanderzusetzen. Die dabei exemplarisch am Zoo gewonnenen Erkenntnisse und Überzeugungen lassen sich in Bezug auf die ebenso drängende wie polarisierende Tierfrage abstrahieren. Durch den somit geschaffenen Orientierungsrahmen werden die Lernenden nicht zuletzt in die Lage versetzt, ihre gereiften Vorstellungen von einem angemessenen Umgang mit (nichtmenschlichen) Tieren öffentlich zu vertreten.
Lithium-ion capacitors (LICs) are promising energy storage devices by asymmetrically combining anode with a high energy density close to lithium-ion batteries and cathode with a high power density and long-term stability close to supercapacitors. For the further improvement of LICs, the development of electrode materials with hierarchical porosity, nitrogen-rich lithiophilic sites, and good electrical conductivity is essential. Nitrogen-rich all-carbon composite hybrids are suitable for these conditions along with high stability and tunability, resulting in a breakthrough to achieve the high performance of LICs. In this thesis, two different all-carbon composites are suggested to unveil how the pore structure of lithiophilic composites influences the properties of LICs. Firstly, the composite with 0-dimensional zinc-templated carbon (ZTC) and hexaazatriphenylene-hexacarbonitrile (HAT) is examined how the pore structure is connected to Li-ion storage property as LIC electrode. As the pore structure of HAT/ZTC composite is easily tunable depending on the synthetic factor and ratio of each component, the results will allow deeper insights into Li-ion dynamics in different porosity, and low-cost synthesis by optimization of the HAT:ZTC ratio. Secondly, the composite with 1-dimensional nanoporous carbon fiber (ACF) and cost-effective melamine is proposed as a promising all-carbon hybrid for large-scale application. Since ACF has ultra-micropores, the numerical structure-property relationships will be calculated out not only from total pore volume but more specifically from ultra-micropore volume. From these results above, it would be possible to understand how hybrid all-carbon composites interact with lithium ions in nanoscale as well as how structural properties affect the energy storage performance. Based on this understanding derived from the simple materials modeling, it will provide a clue to design the practical hybrid materials for efficient electrodes in LICs.
Following the extinction of dinosaurs, the great adaptive radiation of mammals occurred, giving rise to an astonishing ecological and phenotypic diversity of mammalian species. Even closely related species often inhabit vastly different habitats, where they encounter diverse environmental challenges and are exposed to different evolutionary pressures. As a response, mammals evolved various adaptive phenotypes over time, such as morphological, physiological and behavioural ones. Mammalian genomes vary in their content and structure and this variation represents the molecular mechanism for the long-term evolution of phenotypic variation. However, understanding this molecular basis of adaptive phenotypic variation is usually not straightforward.
The recent development of sequencing technologies and bioinformatics tools has enabled a better insight into mammalian genomes. Through these advances, it was acknowledged that mammalian genomes differ more, both within and between species, as a consequence of structural variation compared to single-nucleotide differences. Structural variant types investigated in this thesis - such as deletion, duplication, inversion and insertion, represent a change in the structure of the genome, impacting the size, copy number, orientation and content of DNA sequences. Unlike short variants, structural variants can span multiple genes. They can alter gene dosage, and cause notable gene expression differences and subsequently phenotypic differences. Thus, they can lead to a more dramatic effect on the fitness (reproductive success) of individuals, local adaptation of populations and speciation.
In this thesis, I investigated and evaluated the potential functional effect of structural variations on the genomes of mustelid species. To detect the genomic regions associated with phenotypic variation I assembled the first reference genome of the tayra (Eira barbara) relying on linked-read sequencing technology to achieve a high level of genome completeness important for reliable structural variant discovery. I then set up a bioinformatics pipeline to conduct a comparative genomic analysis and explore variation between mustelid species living in different environments. I found numerous genes associated with species-specific phenotypes related to diet, body condition and reproduction among others, to be impacted by structural variants.
Furthermore, I investigated the effects of artificial selection on structural variants in mice selected for high fertility, increased body mass and high endurance. Through selective breeding of each mouse line, the desired phenotypes have spread within these populations, while maintaining structural variants specific to each line. In comparison to the control line, the litter size has doubled in the fertility lines, individuals in the high body mass lines have become considerably larger, and mice selected for treadmill performance covered substantially more distance. Structural variants were found in higher numbers in these trait-selected lines than in the control line when compared to the mouse reference genome. Moreover, we have found twice as many structural variants spanning protein-coding genes (specific to each line) in trait-selected lines. Several of these variants affect genes associated with selected phenotypic traits. These results imply that structural variation does indeed contribute to the evolution of the selected phenotypes and is heritable.
Finally, I suggest a set of critical metrics of genomic data that should be considered for a stringent structural variation analysis as comparative genomic studies strongly rely on the contiguity and completeness of genome assemblies. Because most of the available data used to represent reference genomes of mammalian species is generated using short-read sequencing technologies, we may have incomplete knowledge of genomic features. Therefore, a cautious structural variation analysis is required to minimize the effect of technical constraints.
The impact of structural variants on the adaptive evolution of mammalian genomes is slowly gaining more focus but it is still incorporated in only a small number of population studies. In my thesis, I advocate the inclusion of structural variants in studies of genomic diversity for a more comprehensive insight into genomic variation within and between species, and its effect on adaptive evolution.