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Microbial hydrogen oxidation potential in seasonally hypoxic Baltic Sea sediments
Get PDFThe majority of the organic matter (OM) degradation on the seafloor occurs in coastal regions. Since oxygen (O2) becomes quickly depleted in the top sediments, most of the OM decomposition is driven by microbial sulfate reduction (SR) and fermentation, the latter generating molecular hydrogen (H2). If the H2 is not consumed by hydrogenotrophic microorganisms and accumulates in the sedimentary porewaters, OM degradation is hindered. Despite the importance of H2 scavenging microorganisms for OM mineralization, the knowledge on H2 oxidizers and their constraints in coastal marine sediments is still quite limited. Here we investigated the role of H2 oxidizers in top (2 to 5 cm, suboxic-sulfidic) and bottom (18 to 22 cm, sulfidic) coastal sediments from a location exposed to seasonal hypoxia in the SW Baltic Sea. We used sediments from April, May and August, representative of different seasons. We spiked respective sediment slurries with H2 and incubated them for up to 4 weeks under O2-free conditions. [...] Sediments exposed to near anoxic bottom water conditions favored a microbial starter community exhibiting the highest H2 oxidation potential. Most of the observed H2 oxidation potential appeared associated with hydrogenotrophic sulfate reducers. The putative involvement of massively enriched ANME in H2 cycling in May 18 to 22 cm sediment horizons is conspicuous. While the differences in the observed H2 oxidation potentials in the studied sediment slurries are likely related to the (season-depending) overall redox state of the sediments and interstitial waters, the influence of microbial interconnections could not be fully resolved and evaluated, demonstrating the need for further consumption- and community-based studies
Charting a course for marine sustainability: legal and policy coordination in developing countries amidst trade and shipping turbulence
Get PDFIntroduction: Trade fluctuations and maritime sanctions have a range of potential adverse impacts on the maritime sector, including port congestion, operational restrictions, fuel supply disruptions and others, leading to increased fuel consumption and higher pollutant emissions, and even a greater risk of marine pollution incidents, further challenging marine sustainability. Developing countries, especially Least Developed Countries (LDCs), Landlocked Developing Countries (LLDCs), and Small Island Developing States (SIDS), are particularly vulnerable to such trade and shipping turbulence. This study aims to explore how developing countries can leverage multilateral legal frameworks to advance marine environmental protection in response to the challenges [...] Results: The analysis concludes that achieving marine sustainability requires embedding equity safeguards into IMO and WTO processes, strengthening regional cooperation frameworks, and enhancing national legal capacities. In terms of concrete measures, developing countries need to actively participate in international rule-making processes and advocate for technological and financial support to mitigate these adverse impacts, thereby chart a course for marine sustainability. Discussion: The global maritime system is undergoing a profound transformation that presents both risks and opportunities for vulnerable developing countries, including LLDCs, LDCs, and SIDS. To navigate this new landscape, these nations require robust legal and policy coordination to mitigate trade risks and promote sustainable shipping. However, a severe scarcity of locally driven, policy-relevant research perpetuates their vulnerability in global governance. The international community must therefore move beyond token inclusion and deliberately invest in building domestic research capacity for these vulnerable states, thereby amplifying their voices
Test-Retest Reliability and Inter-Scanner Reproducibility of Improved Spinal Diffusion Tensor Imaging
Get PDFBackground/Objectives: Spinal diffusion tensor imaging (sDTI) remains a challenging method for the selective evaluation of key anatomical structures, like pyramidal tracts (PTs) and dorsal columns (DCs), and for reliably quantifying diffusion metrics such as fractional anisotropy (FA), radial diffusivity (RD), mean diffusivity (MD), and axial diffusivity (AD). This prospective, single-center study aimed to assess the reproducibility, robustness, and reliability of an optimized axial sDTI protocol, specifically intended for long fiber tracts. Methods: We developed an optimized Stejskal-Tanner sequence for high-resolution, axial sDTI of the cervical spinal cord at 3.0 T. Using advanced standardized evaluation and post-processing methods, we estimated DTI values for PTs, DCs, and AHs at the level of the second cervical vertebra. [...]. Results: The optimized sDTI protocol demonstrated high consistency for FA between test-retest sessions and across scanners. For the Skyra, the DC region showed the highest reliability (average ICC = 0.858) followed by the PT region (average ICC = 0.789). On the Prisma, the PT region reached an average ICC of 0.854, with the DC region at 0.758. Pooled inter-scanner data indicated good-to-excellent agreement, particularly in the PT region (average ICC = 0.860). FA CVs remained low (<10%) across all regions and scanners. RD showed good-to-excellent ICC values for PTs and DCs (average ICC for Skyra 0.642 and 0.769 and 0.926 and 0.830 for Prisma, respectively) but showed a higher CV between 14.6 and 19.4% for these two scanners. Conclusions: Improved sDTI offers highly reproducible FA measurements for all metrics with scanner independence, supporting its potential as a robust tool for detecting and monitoring spinal cord pathologies
The Remineralizing and Desensitizing Potential of Hydroxyapatite in Dentistry: A Narrative Review of Recent Clinical Evidence
Get PDFAlthough caries is declining in industrialized countries, early childhood caries and molar-incisor hypomineralization (MIH) remain clinically relevant. To meet the demand for effective and well-tolerated preventive strategies, hydroxyapatite (HAp) has gained attention as a biocompatible, fluoride-free agent. A structured narrative review was conducted to evaluate recent clinical evidence on the use of HAp. A PubMed search identified clinical trials from the past five years that investigated HAp-based products. Studies were included if they reported clinical outcomes related to remineralization, caries prevention, or desensitization. Fifteen clinical studies met the inclusion criteria. HAp seems to be a safe and effective alternative to flouride, especially for children or individuals at risk of overexposure. While both agents show similar efficacy in caries prevention, HAp may offer additional advantages in managing hypersensitivity and MIH. Compared to other remineralizing agents, such as calcium sodium phosphosilicate, HAp demonstrated comparable efficacy. Combination therapies show the most promising results. Future research should explore synergies of active ingredients and include standardized long-term studies to substantiate the clinical relevance of HAp
Empowering Future HR Professionals: A Design-Based Research Approach to Project-Based Learning in Work and Organizational Psychology
Get PDFThis study reports on a Design-Based Research (DBR) project that implemented Project-Based Learning (PjBL) in an undergraduate psychology course on Human Resource Development (HRD). The purpose was to move beyond lecture-based instruction and explore how open pedagogy can create authentic, student-centered learning experiences that bridge theory and practice. Over two course iterations (n = 31), students co-designed, implemented, and evaluated HRD interventions for their peers, supported by peer and instructor feedback and complemented by a co-created open-book exam. Quantitative pre- and post-tests revealed significant improvements in students’ knowledge of HRD methods, learning theories, and application competencies, as well as enhanced confidence in their professional qualifications. Students valued the openness of the design, its practical orientation, and the error-friendly learning environment, though challenges emerged regarding workload, communication, and intrinsic motivation. Educators reported a transformation of their role from knowledge transmitter to facilitator and co-learner, while also identifying opportunities to use AI for generating authentic case tasks. The findings suggest that PjBL, combined with open pedagogy, fosters self-directed learning, transparency, and collaboration, thereby contributing to cultural change in higher education toward openness, participation, and innovation
The Retinoid Tamibarotene Aggravates Skin Inflammation in a Model of Bullous Pemphigoid-like Epidermolysis Bullosa Acquisita
Get PDFTamibarotene (AM80) is an agonist of retinoic acid receptor alpha. It is licensed in Japan for the treatment of acute promyelocytic leukemia. Results from preclinical models suggest that tamibarotene might also be effective in the treatment of diverse autoimmune diseases. The effect of tamibarotene on autoimmune diseases of the skin, however, has not been explored. We therefore examined the effect of tamibarotene on disease in the antibody-transfer mouse model of bullous pemphigoid (BP)-like epidermolysis bullosa acquisita (EBA), a prototypical example for pemphigoid diseases. Pemphigoid diseases are a group of autoimmune blistering skin diseases driven by autoantibodies and the recruitment and activity of granulocytes in the dermis. In sharp contrast to its effect in models of other autoimmune diseases, tamibarotene aggravated EBA pronouncedly. At the peak of disease, skin inflammation in tamibarotene-treated mice involved, on average, 1.6-fold more of the total body surface compared to vehicle-treated mice. Tamibarotene markedly reduced the recruitment of regulatory T cells (Tregs) into the dermis. This blunted the counterregulatory mechanisms that normally curb skin inflammation in this model. The effect aligns with previous reports describing tamibarotene-mediated downregulation of skin-homing receptors on Tregs. In addition, tamibarotene prolonged the responsiveness of aging neutrophils to immune complexes in vitro, providing another mechanism that may exacerbate EBA. Collectively, our results suggest that tamibarotene may elicit detrimental effects in patients with EBA by abolishing the recruitment of Tregs into skin. This warrants great caution when using tamibarotene in patients with EBA and possibly other pemphigoid diseases
Governance of the Implementation of Education for Sustainable Development (ESD) in Schools—Perceptions of Key Stakeholders in Education
Get PDFEducation for Sustainable Development (ESD) plays a pivotal role in facilitating a sustainable transformation. A prerequisite for the successful implementation of ESD is the coordinated cooperation of stakeholders from different levels of the education system. The present study explores the perceptions of key stakeholders in education in Germany concerning (a) the conceptual framework of ESD, (b) the present status of ESD implementation, and (c) the ideal governance of ESD implementation. An exploratory, qualitative approach was selected as the study design. A total of eleven interviews were conducted with stakeholders representing various levels of the German education system, including representatives from ministries, state institutes, associations, and school practice. The findings indicate that the stakeholders have a shared understanding of ESD, with varying degrees of elaboration and areas of emphasis. All acknowledge the advancement in the implementation of ESD, concurrently recognizing the necessity for substantial enhancement. This study’s main contributions are a better understanding of stakeholders’ perceptions on ESD implementation and an ideal governance model that allocates specified responsibilities across all relevant system levels and actors. A combined bottom-up and top-down approach is proposed as essential in the pursuit of fostering sustainability within and through education, encompassing professionalism, profoundness, and persistence
Plasmastruktur und -dynamik in Zweifrequenz-Entladungen: Ein multidiagnostischer Ansatz vom Plasmavolumen bis zur Randschicht
Get PDFThis dissertation examines the structure and dynamics of low-pressure dual-frequency capacitively coupled plasmas (2f-CCPs) and elucidates the role of the Electrical Asymmetry Effect (EAE). By adjusting the relative phase between two applied RF frequencies, ion energy and ion flux can be tuned largely independently of reactor geometry. The aim is to experimentally determine how this phase control shapes plasma behaviour from the quasi-neutral bulk to the sheath. A multi-diagnostic approach was employed. A custom-built Langmuir probe provided access to electron density, electron temperature, and plasma potential in the bulk. These measurements reveal a pronounced asymmetric dependence of all parameters on the excitation phase, originating from phase-dependent electron heating and resulting ionization dynamics. Complementary optical emission photometry enabled a non-invasive determination of the time-averaged sheath width and exhibited similar trends. A central element of this work is the use of optical tweezers. A single microparticle, stably trapped by counter-propagating laser beams, served as a highly sensitive, non-invasive force probe in the boundary regions. At high laser power, the strong electric field force in the sheath was quantified, whereas at reduced power the enhanced trap sensitivity allowed the first direct measurement of the much weaker ion drag force in the presheath. The resulting force profiles reconstruct the classical discharge structure: a nearly force-free bulk, a presheath shaped by ion drag, and a sheath dominated by the electric field. Across all diagnostics, the measured quantities display a clear asymmetric dependence on the excitation phase. These findings demonstrate how the EAE couples global driving conditions to local plasma behaviour and establish optically trapped microparticles as a powerful diagnostic tool for boundary regions that remain inaccessible to conventional techniques
Sport, Behinderung und Inklusion: Die Special Olympics World Games 2023 als Inklusionsmotor
No full textDiese Arbeit untersucht den Einfluss der Special Olympics World Games 2023 in Berlin auf die Einstellungen von Menschen ohne Behinderungen gegenüber Menschen mit Behinderungen sowie deren Tendenzen zu inklusivem Verhalten im Sport. Zu diesem Zweck wurde ein auf der Theorie des geplanten Verhaltens (TgV) basierender Fragebogen entworfen und validiert. Mit diesem Fragebogen wurden in einer Quer- und Längsschnittuntersuchung Lehrkräfte und ehrenamtlich Tätige in Sportvereinen mittels online-Fragebogen befragt. Während für die beiden Dimensionen Einstellungen und Subjektive Norm aus der TgV keine Veränderung festgestellt werden konnte, deuten die Ergebnisse darauf hin, dass sich die Wahrgenommene Verhaltenskontrolle zumindest kurzfristig zum Positiven verändert hat
Characterization of Phospholipase D3’s Activity, Structure, and Regulation in Lysosomal Metabolism and Disease
Get PDFThe phospholipase D3, along with the closely related phospholipase D4, has recently been described as lysosomal 5’-exonuclease specifically degrading single-stranded nucleic acids. Not only does their deficiency lead to a severe deregulation of the innate immune system and to a massive autoinflammatory phenotype, but variants in the PLD3 gene have been linked to the development of late-onset Alzheimer’s Disease by genome-wide association studies. These studies however have been disputed among different authors using different data sets to confirm or refute the association. To clarify this association, as well as to refine its role in the innate immune system, more data on PLD3’s cellular and molecular function is necessary. This thesis therefor aimed to provide methods and cellular data for the further characterization of PLD3’s function. Using a stable mammalian expression system, the soluble domain of PLD3 was produced with high purity. With an adaptation concerning the cell lines used for expression, this protocol was also applicable to produce high amounts of PLD3 with a homogenous glycosylation pattern that could be used in a collaboration project to resolve the crystal structure of PLD3 binding a single-stranded oligonucleotide. Furthermore, the recombinant enzyme was used to develop a fluorescence-based assay for the specific determination of PLD3’s 5’-exonuclease activity, which also proved to be applicable for whole cell lysates. This enabled the functional characterization of sequence variations and mutations, including those linked to the development of neurodegenerative diseases. Another focus of this thesis was to provide insights into PLD3’s regulation inside the cell. This included a more thorough description of PLD3’s proteolytic processing inside the lysosome and contributed to the discovery of homodimerization being crucial for its correct folding and trafficking