Algorithms and Applications for non-coding RNAs in Aging

Gene expression is a complex molecular process governing fate and function of most eukaryotic cells. The fundamental mechanism, namely that genetic material of a cell is compactly stored on chromosomal DNA and at times being transcribed into messenger-RNA to facilitate on-demand protein biosynthesis, is widely known. However, the interplay of biochemical regulatory pathways underlying an individual’s disease phenotype development remains incompletely understood. Intriguingly, the ∼ 20.000 protein-coding genes only account for 2% of the human genome, triggering profound questions on the purpose of remaining segments. In recent years it became apparent that non-coding RNAs essentially tune the observed gene expression circuits. In particular the small non-coding RNAs such as microRNAs, turned out to be regulatory players by switching on and off protein translation of target messenger-RNAs. Several thousand mammalian microRNAs have been discovered so far but little is known about their impact on the transcriptome, which likely depends on contextual variables like cell type identity, cellular and tissue environment or phase of activation. Previous efforts demonstrated that gene expression programs in human and mouse undergo gradual changes along the life trajectory with amplification at higher ages. In parallel, age-related diseases are currently accumulating in our globally aging population, posing a serious challenge to our society and healthcare systems. Neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease show steadily rising incidence rates with several million people already affected. Both are caused by pathological protein accumulation in selectively vulnerable neurons and brain regions. Notably, these neurological disorders do not appear all of a sudden in an individual but are believed to originate after long asymptomatic phases of subtle aberrant changes on the cellular level, turning early diagnosis into an intricate affair. Yet, no single comprehensive model to explain aging associated changes in gene expression exists and certainly any such model must take into account the role of microRNAs and other important non-coding RNAs. With the advent of ultra-high-throughput sequencing techniques and unprecedented computational power, the screening of microRNAs and their targets from human biofluids and tissues became not only affordable but scalable. To deal with the increasing complexity of molecular studies, novel bioinformatics-driven approaches are needed to generate reproducible and comprehensive conclusions from large-scale data sets. Here, the role of small non-coding RNAs in governing gene expression changes observed in complex age-related diseases is explored with the aid of new methods and databases as well as several thousand RNA profiling samples. This cumulative doctoral thesis comprises eight peer-reviewed publications. Basic research covers a comprehensive review on most target prediction tools and a novel experimental and computational workflow for microRNA-target pathway identification. In addition, with miRPathDB 2.0 the so-far largest database on enriched microRNA pathways for human and mouse is presented. Moreover, the new versatile web tool miEAA 2.0 allows rapid annotation of statistically enriched molecular properties and functions for large lists of microRNAs from ten species. The lessons learned from web-based tool development were condensed in an invited summary and survey article on scientific web server availability along with best practices for developers. The here presented toolkit was used in three applied research studies to investigate the association between microRNAs and their target pathways in the context of aging as well as the to date largest Parkinson’s disease biomarker discovery framework. Circulating microRNAs obtained low-invasively from whole-blood samples bear diagnostic and prognostic value in Alzheimer’s and Parkinson’s disease patients, which was discovered using machine learning models. Furthermore, selected microRNA families were found to systematically target entire signaling pathways as to effectively silence gene expression. Indeed, these pathways are affected in prevalent neurodegenerative disorders. Taken together, the published candidate signatures and validated targets are pivotal for subsequent experimental perturbation in microRNA or gene knockout studies. In future efforts, large-scale single-cell studies will be required to further dissect disease and cell-type specificity of aging disease biomarker candidates and their long-term effect on gene expression, possibly indicating early neuropathological hallmarks.Genexpression ist ein komplexer molekularer Prozess, der das Überleben und die Funktion der meisten eukaryotischen Zellen entscheidend beeinflusst. Der zugrunde liegende Mechanismus, nämlich, dass das genetische Material einer Zelle kompakt in chromosomaler DNA vorliegt und je nach Bedarf in messenger-RNA zur Proteinbiosynthese genutzt wird, ist weitgehend bekannt. Allerdings ist das Zusammenspiel der regulatorischen Pfade im Hintergrund der phenotypischen Veränderungen von erkrankten Individuen nur wenig verstanden. Interessanterweise machen die fast 20.000 protein-kodierenden Gene nur in etwa 2% des menschlichen Erbgutes aus. In den letzten Jahren hat man festgestellt, dass nicht-kodierende RNAs eine essentielle Rolle bei der Einstellung der beobachteten Genexpressionsschaltkreise spielen. Insbesondere kleine nicht-kodierende RNAs wie microRNAs, stellten sich als zuvor unterschätzte regulatorische Einheiten heraus, die die Translation von Ziel-messenger-RNA in Proteine an und ausschalten. Mehrere tausend microRNAs wurden bisher bei Säugetieren entdeckt, trotzdem ist immer noch wenig über ihren Einfluss auf das Transkriptom bekannt, ein Zusammenhang der wahrscheinlich vom Kontext wie Zelltypidentität, dem zelluären Umfeld sowie dem umgebenden Gewebe, und den Aktivierungsphasen abhängt. Frühere Forschungsarbeiten haben bereits gezeigt, dass das Genexpressionsprogramm im Menschen und in der Maus sukzessiven Änderungen im Laufe des Lebens unterworfen ist, welche sich im höheren Alter verstärken. Zur gleichen Zeit akkumulieren Fälle von altersbedingten Krankheiten in unserer immer älter werdenden, globalen Population, was ernstzunehmende Herausforderungen für unsere Gesellschaft sowie unser Gesundheitssystem mit sich bringt. Neurodegenerative Krankheiten wie Morbus Alzheimer und Morbus Parkinson zeigen eine kontinuierlich ansteigende Inzidenz, wobei bereits mehrere millionen Menschen weltweit betroffen sind. Besonders für diese Krankheiten ist, dass sie bei einem Menschen nicht spontan oder plötzlich entstehen, sondern vermutlich nach langer Zeit der asymptomatischen Phase aufgrund schleichender, abnormaler Veränderungen auf zellulärer Ebene entstehen, was eine frühe Diagnose überaus schwierig gestaltet. Bisher existiert noch kein verständliches Modell das die altersassoziierten Veränderungen der Genexpression erklären kann, wobei jedes darauf ausgerichtete Modell mit Bestimmtheit die Rolle der microRNAs und anderen wichtigen nicht-kodierenden RNAs zwangsläufig in Betracht ziehen muss. Mit dem Aufkommen der Sequenzierung im Ultrahochdurchsatzverfahren und der unübertroffenen Leistung moderner Computersysteme, wurde die Untersuchung von microRNAs und ihren Zielgenen anhand von Proben menschlicher Flüssigkeiten und Geweben nicht nur möglich gemacht, sondern kann entsprechend hochskaliert werden. Um mit der zunehmenden Komplexität molekularer Studien Schritt zu halten, braucht es neue Ansätze der Bioinformatik um reproduzierbare und nachvollziehbare Schlüsse aus großen Datensätzen gewinnen zu können. Im Rahmen dieser Arbeit wurden kleine nicht-kodierende RNAs hinsichtlich ihrer Rolle der Genregulation in komplexen altersbedingten Krankheiten anhand neuer Methoden und Datenbanken sowie mehreren tausend Proben der RNA-Sequenzierung untersucht. Diese kumulative Dissertationsarbeit umfasst acht von unabhängigen Experten begutachtete (peer-reviewed), wissenschaftliche Publikationen. Die Grundlagenforschung enthält einen umfassenden Übersichtsartikel zu fast allen Methoden der Vorhersage von microRNA Zielgenen sowie ein neuartiges Protokoll bestehend aus Labormethoden und computergestützen Berechnungen zur Identifikation von durch microRNAs regulierte Genpfade. Zusätzlich wird mit miRPathDB 2.0 die bisher größte Datenbank zu signifikant angereicherten microRNA Zielpfaden präsentiert. Des Weiteren, bietet die neue und vielseitige, web-basierte Software miEAA 2.0 die Möglichkeit der rasanten Annotation statistisch angereicherter, molekularer Eigenschaften sowie bekannter Funktionen einer gegebenen Liste an microRNAs von zehn Spezies. Die durch web-basierte Softwareentwicklung zuvor angelernten Fähigkeiten sowie daraus resultierende Empfehlungen für nachfolgende Entwickler wurden kurz und bündig in einem eingeladenen Übersichtsartikel zum Thema Verfügbarkeit wissenschaftlicher Software im Internet veröffentlicht. Die hier präsentierten Werkzeuge wurden gezielt in drei Studien zur angewandten Forschung genutzt um die Assoziation zwischen microRNAs und ihren Zielpfaden im Kontext der allgemeinen Altersforschung sowie im Rahmen der bisher größten Studie zur Entdeckung von Biomarkern der Parkinson Krankheit zu untersuchen. Im Blutkreislauf zirkulierende microRNAs, die anhand von Vollblutproben extrahiert wurden, zeigen diagnostisches und prognostisches Potential bei Alzheimer und Parkinson Patienten, was mit Methoden des maschinellen Lernens entdeckt werden konnte. Überdies konnte herausgefunden werden, dass bestimmte microRNA Familien systematisch Signalwege blockieren können, um die Genexpression herunterzufahren. Tatsächlich sind diese Pfade auch in neurodegenerativen Krankheiten betroffen. Insgesamt sind die hier publizierten Signaturen von Kandidaten-microRNAs und einiger validierter Zielgene herausragend dazu geeignet in weiteren Studien anhand von gezielter Ausschaltung im Labor genauer untersucht zu werden. In zukünftigen Forschungsprojekten sollten groß angelegte Untersuchungen vieler einzelner Zellen im Vordergrund stehen, um zu verstehen wie spezifisch für Krankheit oder Zelltyp die hier genannten Biomarker-Kandidaten für altersbedingte Krankheiten sind. Auch wird es wichtig sein die Langzeiteffekte von dysregulierten microRNAs auf die Genexpression zu verstehen, die möglicherweise frühzeitig neuropathologische Kennzeichen widerspiegeln

Strategies for an adaptive control system to improve power grid resilience with smart buildings

Low-voltage distribution grids face new challenges through the expansion of decentralized, renewable energy generation and the electrification of the heat and mobility sectors. We present a multi-agent system consisting of the energy management systems of smart buildings, a central grid controller, and the local controller of a transformer. It can coordinate the provision of ancillary services for the local grid in a centralized way, coordinated by the central controller, and in a decentralized way, where each building makes independent control decisions based on locally measurable data. The presented system and the different control strategies provide the foundation for a fully adaptive grid control system we plan to implement in the future, which does not only provide resilience against electricity outages but also against communication failures by appropriate switching of strategies. The decentralized strategy, meant to be used during communication failures, could also be used exclusively if communication infrastructure is generally unavailable. The strategies are evaluated in a simulated scenario designed to represent the most extreme load conditions that might occur in low-voltage grids in the future. In the tested scenario, they can substantially reduce voltage range deviations, transformer temperatures, and line congestions

On the lifetime of bioinformatics web services

Web services are used through all disciplines in life sciences and the online landscape is growing by hundreds of novel servers annually. However, availability varies, and maintenance practices are largely inconsistent. We screened the availability of 2396 web tools published during the past 10 years. All servers were accessed over 133 days and 318 668 index files were stored in a local database. The number of accessible tools almost linearly increases in time with highest availability for 2019 and 2020 (∼90%) and lowest for tools published in 2010 (∼50%). In a 133-day test frame, 31% of tools were always working, 48.4% occasionally and 20.6% never. Consecutive downtimes were typically below 5 days with a median of 1 day, and unevenly distributed over the weekdays. A rescue experiment on 47 tools that were published from 2019 onwards but never accessible showed that 51.1% of the tools could be restored in due time. We found a positive association between the number of citations and the probability of a web server being reachable. We then determined common challenges and formulated categorical recommendations for researchers planning to develop web-based resources. As implication of our study, we propose to develop a repository for automatic API testing and sustainability indexing

A multiparameter Stochastic Sewing lemma and the regularity of local times associated to Gaussian sheets

We establish a multiparameter extension of the stochastic sewing lemma. This allows us to derive novel regularity estimates on the local time of locally non-deterministic Gaussian fields. These estimates are sufficiently strong to derive regularization by noise results for SDEs in the plain. In this context, we make the interesting and rather surprising observation that regularization effects profiting from each parameter of the underlying stochastic field in an additive fashion usually appear to be due to boundary terms of the driving stochastic field

The Science of Startups: The Impact of Founder Personalities on Company Success

Startup companies solve many of today's most complex and challenging scientific, technical and social problems, such as the decarbonisation of the economy, air pollution, and the development of novel life-saving vaccines. Startups are a vital source of social, scientific and economic innovation, yet the most innovative are also the least likely to survive. The probability of success of startups has been shown to relate to several firm-level factors such as industry, location and the economy of the day. Still, attention has increasingly considered internal factors relating to the firm's founding team, including their previous experiences and failures, their centrality in a global network of other founders and investors as well as the team's size. The effects of founders' personalities on the success of new ventures are mainly unknown. Here we show that founder personality traits are a significant feature of a firm's ultimate success. We draw upon detailed data about the success of a large-scale global sample of startups. We found that the Big 5 personality traits of startup founders across 30 dimensions significantly differed from that of the population at large. Key personality facets that distinguish successful entrepreneurs include a preference for variety, novelty and starting new things (openness to adventure), like being the centre of attention (lower levels of modesty) and being exuberant (higher activity levels). However, we do not find one "Founder-type" personality; instead, six different personality types appear, with startups founded by a "Hipster, Hacker and Hustler" being twice as likely to succeed. Our results also demonstrate the benefits of larger, personality-diverse teams in startups, which has the potential to be extended through further research into other team settings within business, government and research

HumiR: Web Services, Tools and Databases for Exploring Human microRNA Data

For many research aspects on small non-coding RNAs, especially microRNAs, computational tools and databases are developed. This includes quantification of miRNAs, piRNAs, tRNAs and tRNA fragments, circRNAs and others. Furthermore, the prediction of new miRNAs, isomiRs, arm switch events, target and target pathway prediction and miRNA pathway enrichment are common tasks. Additionally, databases and resources containing expression profiles, e.g., from different tissues, organs or cell types, are generated. This information in turn leads to improved miRNA repositories. While most of the respective tools are implemented in a species-independent manner, we focused on tools for human small non-coding RNAs. This includes four aspects: (1) miRNA analysis tools (2) databases on miRNAs and variations thereof (3) databases on expression profiles (4) miRNA helper tools facilitating frequent tasks such as naming conversion or reporter assay design. Although dependencies between the tools exist and several tools are jointly used in studies, the interoperability is limited. We present HumiR, a joint web presence for our tools. HumiR facilitates an entry in the world of miRNA research, supports the selection of the right tool for a research task and represents the very first step towards a fully integrated knowledge-base for human small non-coding RNA research. We demonstrate the utility of HumiR by performing a very comprehensive analysis of Alzheimer’s miRNAs

Preventing Civic Space Restrictions: an Exploratory Study of Successful Resistance Against NGO Laws

In many countries around the world, civil society organizations are facing increasing restrictions that constrain their autonomy, capacity and/or freedom of action. While the general phenomenon of shrinking civic space and the adoption of legal restrictions in particular have become more widespread since the early 2000s, there are also cases in which governmental attempts to adopt restrictive NGO laws have been frustrated, aborted or, at least, significantly mitigated as a consequence of domestic and/or international resistance. This PRIF Report takes a look at four such cases (Azerbaijan, Kenya, Kyrgyzstan and Zambia) and identifies conditions and dynamics that help understand successful resistance against legal civic space restrictions

Aviator: a web service for monitoring the availability of web services

With Aviator, we present a web service and repository that facilitates surveillance of online tools. Aviator consists of a user-friendly website and two modules, a literature-mining based general and a manually curated module. The general module currently checks 9417 websites twice a day with respect to their availability and stores many features (frontend and backend response time, required RAM and size of the web page, security certificates, analytic tools and trackers embedded in the webpage and others) in a data warehouse. Aviator is also equipped with an analysis functionality, for example authors can check and evaluate the availability of their own tools or those of their peers. Likewise, users can check the availability of a certain tool they intend to use in research or teaching to avoid including unstable tools. The curated section of Aviator offers additional services. We provide API snippets for common programming languages (Perl, PHP, Python, JavaScript) as well as an OpenAPI documentation for embedding in the backend of own web services for an automatic test of their function. We query the respective APIs twice a day and send automated notifications in case of an unexpected result. Naturally, the same analysis functionality as for the literature-based module is available for the curated section. Aviator can freely be used at https://www.ccb.uni-saarland.de/aviator

Research Output and International Cooperation Among Countries During the COVID-19 Pandemic: Scientometric Analysis

Background: The COVID-19 pandemic, caused by the novel coronavirus SARS-CoV-2, has instigated immediate and massive worldwide research efforts. Rapid publication of research data may be desirable but also carries the risk of quality loss. Objective: This analysis aimed to correlate the severity of the COVID-19 outbreak with its related scientific output per country. Methods: All articles related to the COVID-19 pandemic were retrieved from Web of Science and analyzed using the web application SciPE (science performance evaluation), allowing for large data scientometric analyses of the global geographical distribution of scientific output. Results: A total of 7185 publications, including 2592 articles, 2091 editorial materials, 2528 early access papers, 1479 letters, 633 reviews, and other contributions were extracted. The top 3 countries involved in COVID-19 research were the United States, China, and Italy. The confirmed COVID-19 cases or deaths per region correlated with scientific research output. The United States was most active in terms of collaborative efforts, sharing a significant amount of manuscript authorships with the United Kingdom, China, and Italy. The United States was China’s most frequent collaborative partner, followed by the United Kingdom. Conclusions: The COVID-19 research landscape is rapidly developing and is driven by countries with a generally strong prepandemic research output but is also significantly affected by countries with a high prevalence of COVID-19 cases. Our findings indicate that the United States is leading international collaborative efforts