International Migration, Integration and Social Cohesion online publications
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(Mal-) adaptive synchronization in the human brain:Signatures of neural oscillations in psychiatric and normative populations
Get PDFNeural oscillations are a fundamental mechanism to orchestrate precise temporal coordination in the brain and slightly different patterns in neural oscillations may have far-reaching consequences for cognitive functioning. The goal of this thesis is to elucidate the neuronal oscillatory mechanisms that reflect cognitive processing. I investigated the cognitive mechanism of attention in normative groups as well as in people with psychiatric disorders namely, post-traumatic stress disorder and autism spectrum disorder. I aim to shed light on attentional resource allocation in various cognitive paradigms as well as neural mechanisms at rest. For the final chapter, I had the unique opportunity to investigate neural power and connectivity in patients with obsessive-compulsive disorder while they received deep brain stimulation treatment
Pan-Africanism:A legacy of slavery
Get PDFPan-Africanism has been studied as an ideology, an epistemology, a theory; and also, as a social movement. However, it has insufficiently been studied as an institutionalized phenomenon and as a producer of knowledge. Most work has been conducted on the emergence of Pan-Africanism in the African diaspora in the mid-to-late 19th century. Yet, far less has been written about Pan-Africanism as an epistemology, that is as a set of ideas and ideologies.In this dissertation, it is argued that Pan Africanism is part of an Africana intellectual tradition. Both Pan-Africanism, as a series of epistemologies – and the Africana intellectual tradition - emerged directly from history and experience. It is therefore argued that epistemic Pan-African knowledge production uses history and experience as its reference. That is, it does not construct its intellectualisms from reading the enlightenment writers, such as is commonly practiced within the European intellectual tradition.Throughout its history, Pan-Africanism saw numerous unreasonable responses from predominantly (former) colonizing powers to reasonable arguments voiced in Pan-African congress petitions and speeches. This happened against the background of a changing world order. Whereas Pan-Africanism started in a situation dominated by the necessity to engage, it moved to a situation in which it increasingly was able to confront (former) colonial and imperial powers. As the circumstances of world politics changed, so did the epicenter of Pan Africanism, and in this dissertation, the author highlights how Pan-Africanism moved its epicenter from the Diaspora to Africa, where it was transformed and institutionalized
Gear shifting in Archaca and Eukarya
Get PDFThis thesis investigates the different levels of coupling in Archaea and Eukarya using a systems biology approach that integrates modelling, experiments, and theory. Specifically, chapter 2 summarizes the bidirectional coupling between cellular metabolism and the cell cycle machinery in budding yeast, which involves complex metabolic and biosynthetic reactions necessary for building new cells. Chapter 3 focuses on investigating the effect of the Cyclin B/Cdk1 complex on some yeast metabolic enzymes using in vitro phosphorylation assays, finding that Fba1 and Pgk may be phosphorylated by Cdk1. Additionally, this study examines the possible effect of Sic1 on the activities of three important metabolic enzymes, finding that Sic1 may have a slight negative effect on Hxk2 activity. The thesis also describes a minimal computer model of the cell cycle that predicts timely mitotic cyclin Clb2 expression and validates the model through chromatin immunoprecipitation experiments. The last two chapters focus on understanding the phenomenon of gear shifting in the hyperthermophilic archaeon Saccharolobus solfataricus. Chapter 5 describes gear shifting both at the substrate-level phosphorylation around glyceraldehyde-3 phosphate dehydrogenase, or at the membrane-linked oxidative phosphorylation with the involvement of alternative terminal oxidases. Specifically, with application of kinetic models, chapter 6 shows that the ATP/ADP ratio could well be the force driving the shifting of the organisms from the high-gear GAPDH plus PGK route to the low-gear GAPN. Overall, the study contributes to a better understanding of the coupling between metabolic and cell cycle machinery and the phenomenon of gear shifting in extremophilic organisms
From self to others:Neural and social perspectives on cue-triggered decision-making
No full textPredictable, reward-related cues in the environment play a crucial role in guiding behavior and shaping decision-making. Through a series of experiments, this dissertation investigates the role of the motor cortex in cue-triggered decision-making and examines whether the influence of environmental cues on behavior can be transmitted through observation or vicarious reward.Chapter 1 reviews key theories and findings on environmental cues, the Pavlovian-to-Instrumental Transfer (PIT) paradigm, mirror neuron systems, vicarious transfer and reward, and the use of transcranial magnetic stimulation (TMS) and motor-evoked potentials (MEPs).Chapter 2 employs an extended PIT task combined with single-pulse TMS to examine motor cortex activation during cue-triggered decision-making. Results confirm the behavioral influence of cues but indicate that the motor cortex is not directly involved in this process.Chapter 3 summarizes EEG findings from the PIT task and proposes methodological refinements for MEP collection to more accurately capture cue-related motor activity.Chapter 4 implements these refinements, recording MEPs closer to cue onset, replicating earlier behavioral effects, and finding no evidence of direct motor cortex involvement.Chapter 5 introduces a vicarious PIT paradigm, demonstrating that cue-driven behavioral influences can extend to observers through mere observation.Chapter 6 shows that PIT effects persist for rewards delivered to others, remaining insensitive to outcome devaluation but potentially modulated by reward intensity.Chapter 7 synthesizes these findings, highlighting the limited role of the motor cortex in cue-triggered decision-making and the potential for environmental cues to shape behavior socially and vicariously. Limitations and future research directions are also discussed.<br/
Precision in the storm:Host response dysregulation as a guide for prognosis and targeted therapies in pneumonia and sepsis
No full textThe overall objective of this thesis is to advance the field of immunomodulation in sepsis, pneumonia, and COVID-19 by aiding in the transition from clinical severity-based approaches to host response-based precision medicine using advanced (machine-learning) statistics and multi-omics. To address this, the thesis is organized into three key parts, each examining critical challenges identified in the introduction. Part I exemplifies the potential benefits of focusing on host response dysregulation and how to facilitate such a paradigm shift. Part II evaluates the impact of an increasingly relevant global factor: ageing populations and its potential implications for the effectiveness of immunomodulatory therapies. Finally, Part III investigates host response alterations underpinning adverse outcomes at multiple stages of disease progression: in pneumonia and COVID-19 before and during established sepsis. By employing multi-omics, including (cellular) transcriptomics and (cellular and plasma) proteomics, this chapter seeks to uncover actionable pathways that drive clinical deterioration and mortality and proposes novel research and therapeutic opportunities for early and potentially life-saving interventions
Writing the Muslim life in Russia, 1880s-1920s:Islamic education and the formation of the autobiographical genre
Get PDFThis dissertation examines autobiographies (Turkic: tärjemä-i hälem) of Russian Muslims written from the 1880s to the 1920s. The authors, representing different generations and political views, from reformists and secularists to conservatives and isolationists, shared a common cultural and social background: all were men of letters educated in madrasas with similar curricula and social norms. And their student experiences are key themes in most autobiographies. The emphasis on education was not only based on personal stories. I argue that autobiography became a prominent way for educated Muslim men to discuss and express both individual and collective Muslim identities during the late 19th and early 20th centuries. Education emerged as a crucial theme in public discourse, allowing those involved to assert leadership roles by highlighting their educational roles. Broadly, the focus on education as shaping individual and community life was heavily influenced by development and progress discourses, introduced through Ottoman and Russian translations and European intermediaries. Just as an educated person can improve their circumstances through effort, entire communities and nations can achieve a notable position globally if they value education and are led by virtuous, dedicated individuals. This work explores how these Muslim figures narrated their paths toward Muslim leadership.<br/
Novel assessment techniques to diagnose syndesmotic instability
Get PDFIf not treated or missed, syndesmotic instability may lead to osteoarthritic changes over time and impact patient quality of life and function. Syndesmotic instability should be treated surgically with either a static or dynamic treatment strategy. This thesis aims to improve existing diagnostic assessment techniques of the syndesmosis and to develop new ones in three parts, including I. arthroscopic assessment for diagnosing syndesmotic instability, II. new methods for diagnosing syndesmotic instability using portable ultrasound and weightbearing computed tomography (CT), III. methods to assess radiographic and patient functional outcomes after treatment. The key takeaways from this thesis are:1. The 2.0 mm threshold value of arthroscopic distal tibiofibular diastasis may lead to overtreatment of coronal syndesmotic instability. 2. Dynamic ultrasound allows one to evaluate sagittal translation of the distal tibiofibular joint effectively and reliably. 3. In biomechanical research portable ultrasound performed like arthroscopy when diagnosing syndesmotic instability in the sagittal plane. 4. In biomechanical research portable ultrasound could reliably detect tibiofibular clear space opening after external rotation stress. 5. (portable) Ultrasound is readily available, non-invasive, low-cost, affording contralateral comparison, and therefore a technique worth investigating further.6. Weightbearing CT scan is a very promising technique for diagnosing syndesmotic instability.7. Syndesmotic area seems the best and most reliable 2D parameter to detect instability or (mal)reduction of the syndesmosis.8. Screw and tightrope reduction techniques do not restore syndesmotic area as compared to the intact contralateral ankle. 9. We found no difference in clinical outcomes between screw and tightrope reduction techniques
Novel fluorophores for advancing super-resolution and correlative microscopy
Get PDFOptical and electronmicroscopy are fundamental imaging techniques in life and material sciences.However, conventional optical microscopy is constrained by the diffractionlimit (~200 nm), preventing visualization of fine subcellular structures.Single-molecule localization microscopy (SMLM) overcomes this limitation byexploiting photoswitchable fluorophores to achieve nanometre-scale resolution.Further expanding SMLM applications and enabling super-resolution correlativelight and electron microscopy (SR-CLEM) require intrinsically blinking andchemically stable fluorophores.This thesis reportsthe development of two classes of such fluorophores—nanographenes and rylenes—anddemonstrates their utility in advanced imaging. Hydrophilic and functionalizednanographenes were synthesized and exhibit environment-independent blinkingunder diverse conditions, enabling SMLM imaging of amyloid fibrils in air,lysosomal dynamics in live cells, and nascent peptide translation in neurons.These studies revealed heterogeneous local translation along axonal branches.To extend SMLM intothe near-infrared (NIR) region, intrinsically blinking rylene derivatives weredeveloped, offering reduced phototoxicity for live-cell SMLM imaging. Theirexceptional chemical stability allowed successful application in SR-CLEM,retaining robust blinking behavior after osmium tetroxide fixation and Epon resinembedding. Both single- and dual-color SR-CLEM were achieved, and theOsO₄-induced quenching mechanism, involving energy/electron transfer and aninner filter effect, was elucidated, providing valuable guidance for the futuredesign of SR-CLEM-compatible fluorophores.Overall, this researchestablishes nanographenes and rylenes as robust, intrinsically blinkingfluorophores for SMLM and SR-CLEM. The mechanistic insights and moleculardesigns presented here advance the development of fluorophores and expand thefrontiers of super-resolution microscopy in the life sciences.</p
KRAB-ZNFs: controllers of transposable element activity and safeguards of genome integrity
Get PDFTransposable elements (TEs) are mobile DNA sequences that can move within genomes, shaping genomic diversity and evolution. However, their movement can cause DNA breaks and structural rearrangements, leading to genomic instability. As a defense mechanism, KRAB zinc finger proteins (KRAB-ZNFs) evolved as key repressors of TEs, binding specific TE sequences to silence them through epigenetic mechanisms. This dynamic interplay between TEs and KRAB-ZNFs has fueled an evolutionary arms race, promoting rapid diversification of both elements. Consequently, TE and KRAB-ZNF interactions have profoundly influenced genome architecture, regulatory networks, and species-specific traits across vertebrates. This thesis explores the versatility of KRAB-ZNF functions in the human genome, suggesting roles that extend beyond their established involvement in TE transposition repression. While previous research has primarily focused on KRAB-ZNFs as regulators of gene expression as an alternative model, this work broadens the scope to investigate additional roles, including the KRAB-ZNF mediated control of TEs involved in stem cell pluripotency and protecting our genome from excessive meiotic recombination. The findings presented here aim to inform and inspire further research into KRAB-ZNFs’ diverse contributions to gene expression network innovation, genome stability and human genome evolution
Mechanistic insights into energy transfer in highly doped upconversion nanoparticles
No full textHighly doped upconversion nanoparticles (UCNPs) feature complex energy transfer dynamics that enable strong luminescence but also introduce significant challenges such as cross-relaxation and concentration quenching. This thesis presents a comprehensive investigation into the underlying mechanisms of energy transfer in highly doped UCNPs and explores strategies to enhance their upconversion luminescence (UCL). Cryogenic temperature conditions are employed to effectively suppress non-radiative losses in Er³⁺-rich systems, leading to pronounced luminescence enhancement. Additionally, modulation of cross-relaxation channels enables finely tuned temperature-dependent emission, allowing these materials to function as highly sensitive luminescent thermometers. To further improve excitation efficiency and mitigate photothermal effects, Er-rich systems are integrated with Nd³⁺ sensitization, enabling effective 808 nm excitation and enhanced UCL output compared to conventional 980 nm systems. Beyond mechanistic studies, the practical versatility of highly doped UCNPs is demonstrated in two light-driven systems: near-infrared-triggered photoclick reactions and optically powered rotary molecular motors. Together, these results provide deep mechanistic insights into lanthanide-doped nanomaterials and establish a versatile platform for next-generation UCNPs with enhanced performance in photochemistry, biomedical imaging, optical sensing, and nanoscale photonic applications