31325 research outputs found
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Effect of anemone presence on blue mussel Mytilus edulis predation by the sea star Asterias rubens
No full textThe effect of anemone attachment on the predation of the blue mussel
Mytilus edulis by the common sea star Asterias rubens was tested. These organisms are found in abundance around the island of Sylt, where their interactions shape community structures. Overall, a preference for mussels without anemones over anemone-equipped mussels and preference for mussels covered with other epibionts over epibiont-free mussels were observed. This indicates that A. rubens do not simply avoid anemone-equipped mussels due to physical hindrance but rather that the avoidance behaviour is specific to anemones, possibly due to their ability to deploy cnidocytes for defence.Peer Reviewe
Arbeitsfähigkeit nach ambulanter Psychotherapie
No full textZusammenfassung: Theoretischer Hintergrund: Psychische Störungen sind mit langen Krankheitsausfällen und hohen betrieblichen und gesellschaftlichen Kosten verbunden. Psychotherapeutische Behandlungen können die Arbeitsfähigkeit verbessern und zu einer Reduktion von Arbeitsunfähigkeitstagen führen. Methode: Im Rahmen des KODAP-Projektes (Koordination der Datenerhebung und -auswertung an Forschungs-, Lehr- und Ausbildungsambulanzen für psychologische Psychotherapie) wurden Daten von Patient_innen mit psychischen Störungen ( N = 2823) erhoben und der prädiktive Wert von Patient_innen- und Behandlungsmerkmalen auf den Arbeitsfähigkeitsstatus (arbeitsfähig vs. arbeitsunfähig) nach ambulanter Psychotherapie untersucht. Ergebnisse: Mehr als die Hälfte der zu Therapiebeginn arbeitsunfähigen Patient_innen waren zum Therapieende weiterhin arbeitsunfähig. Das Vorliegen von Arbeitsfähigkeit zum Therapiebeginn, keine Vorbehandlungen und ein höherer Bildungsgrad erhöhten die Wahrscheinlichkeit am Ende der Psychotherapie arbeitsfähig zu sein. Die Reduktion der selbstberichteten Depressivität unterscheidet sich in Abhängigkeit von der Veränderung des Arbeitsfähigkeitsstatus. Schlussfolgerung: Die Aufrechterhaltung und Wiederherstellung der Arbeitsfähigkeit sollte stärker in die Psychotherapieforschung einbezogen werden.Abstract: Background: Mental disorders are associated with long sick leave periods and high costs. Psychotherapeutic treatments have proved to improve work ability and lead to a reduction in sick leave days. Methods: The KODAP Project (Coordinating Research at the Outpatient Clinics for Psychotherapy in Germany) collected data from individuals with mental disorders ( N = 2823) and examined the predictive value of patient and treatment characteristics on work ability status following psychotherapy. Results: More than half of the patients who could not work at the beginning of therapy remained unable to work thereafter. Initial work ability, no pretreatments, and a higher education level increased the likelihood of being able to work. The reduction in self-reported depression differs depending on the change in work ability status. Conclusions: The maintenance and restoration of work ability should be more strongly integrated into psychotherapy research.Peer Reviewe
Modification of aggregation-prone regions of Arabidopsis glutamyl-tRNA reductase leads to increased stability while maintaining enzyme activity
No full textThe aggregation-prone region (APR) is a hydrophobic polypeptide motif that promotes protein aggregation, most commonly in the unfolded or misfolded state. It has been described that chaperones can shield the APRs of proteins, thereby preventing aggregate formation during de novo protein synthesis and stress response. Glutamyl-tRNA reductase (GluTR) is a key enzyme in tetrapyrrole biosynthesis (TBS) which catalyzes the rate-limiting step of 5-aminolevulinic acid synthesis. The GluTR sequence contains two APRs located at the N-terminus, which are suggested to be associated with the dysregulation of protein homeostasis during folding and refolding processes or under stress conditions. It remains open if these APRs directly contribute to GluTR aggregation in vivo , and how their removal or the modification might impact the aggregation and stability. In this study, we altered and removed the GluTR-APRs to investigate their effects on the stability and enzymatic activity of GluTR. Deletion of the APRs has been shown to be highly disruptive to the structure of GluTR, and a substitution mutation of V→P in each APR has also lowered the GluTR stability and activity. In contrast, the mutation V→T resulted in a modest reduction (18–30%) in GluTR aggregation in vitro , which was associated with a 27% improvement in GluTR stability in vivo relative to the wild-type enzyme. These results indicate that a point mutation in APR can improve GluTR stability without significantly affecting enzyme activity, thus imposing a potential direction for bioengineering of GluTR to improve productivity of the TBS pathway in plants.Peer Reviewe
Synthesis and synchrotron characterisation of Zr-based catalysts for various applications
No full textIn der vorliegenden Arbeit werden Katalysatoren auf der Basis von ZrF4 hergestellt und mit Synchrotronstrahlung umfassend charakterisiert. Zirkoniumchlorofluorid (ZCF) katalysiert einen außergewöhnlichen HF-Transfer bei Raumtemperatur, bei dem auf eine C–F-Bindungsaktivierung von Fluorpentan eine anschließende Hydrofluorierung eines Alkins folgt. ZCF wurde hinsichtlich seiner Materialeigenschaften untersucht und die lokale Umgebung um die Zr-Zentren mit EXAFS aufgeklärt. Zusätzlich wurde eine Monte-Carlo-Typ Modellierung unter Verwendung von Röntgen- und Neutronen-Totalstreuungsdatensätzen durchgeführt, um ein „Big-Box“-Modell des Materials zu erhalten. Dabei wurden die Metallchlorofluoride untersucht und Parallelen zwischen drei bekannten Chlorofluorid-Materialien gezogen. Ein amorphes ZrF4, das unter milden Bedingungen in Dehydrofluorierungs- und Friedel-Crafts-Reaktionen katalytisch aktiv ist, wurde durch eine fluorolytische Sol-Gel-Synthese erhalten. Auch hier wurden die Metallzentren mit EXAFS in ihrer lokalen Umgebung aufgeklärt. Es wurde festgestellt, dass luftstabile Verbindungen als Zr-Quelle verwendet werden können. Der Syntheseweg konnte erweitert werden, um ZrF4 als Träger für einen Hochentropie-Elektrokatalysator zu verwenden. Der Katalysator erreichte eine signifikante Leistung bei der Sauerstoffproduktion mit einer Stromdichte von 100 mA cm-2 bei einem externen Potential von 1,60 V gegenüber der SHE. Damit werden Katalysatoren wie IrO2 übertroffen. EXAFS- und PDF-Analysen wurden verwendet, um die Integrität des ZrF4-Trägers und der Metallfluorid-Einheiten zu bestätigen. Schließlich wurde die Valence-to-Core-Röntgenemissionsspektroskopie (VtC-XES) von Zr-Verbindungen etabliert. Hier liefert die Studie einen neuen Beitrag zum Verständnis der 4d-Metall-VtC-XES. Insbesondere wurde eine Unterscheidung von Sauerstoff- und Fluorliganden mit Hilfe von Röntgenstrahlung diskutiert und erfolgreich an den zuvor besprochenen Materialien demonstriert.In this study, ZrF4-based catalysts are prepared and thoroughly characterised using synchrotron radiation. Zirconium chlorofluoride (ZCF) performs an exceptional HF transfer where a C–F- bond activation of fluoropentane is followed by a subsequent hydrofluorination of an alkyne. ZCF was investigated in its material properties and elucidated in its local environment about the Zr centres using EXAFS. Moreover, empirical potential structure refinement modelling was performed using X-ray and neutron total scattering datasets to obtain a big box model of the material. Here, the metal chlorofluorides were investigated and parallels between three main representatives were drawn. Furthermore, a ZrF4 which is catalytically active in dehydrofluorination and Friedel-Crafts reactions at mild conditions, was obtained from a fluorolytic sol-gel synthesis. Again, the metal centres were elucidated in their local environment using EXAFS. Importantly, it was established that air-stable compounds like Zr(acac)4 can be used as Zr-source. The synthetic route was then extended to use ZrF4 as a support for a high-entropy electrocatalyst consisting of a fluorinated mixture of Mn, Fe, Ni, Co and Zn. The catalyst achieved significant performance in oxygen evolution reaction reaching a current density of 100 mA cm-2 at an external potential of 1.60 V vs RHE, thus outperforming benchmark catalysts such as IrO2. EXAFS and PDF analysis were used to confirm the integrity of the ZrF4 support and the metal fluoride entities. Finally, Valence-to-Core X-ray emission spectroscopy (VtC-XES) of Zr-compounds was established. The study presents a new piece to the 4d metal VtC-XES understanding. Specifically, the study focussed on the differentiation between oxygen and fluorine atoms using X-rays. The gained knowledge was directly successfully applied and demonstrated onto the previously discussed materials
Proceedings in Marine Biology - Volume 4, Number 2, 2025
No full textThis volume deals exlusively with the results of the research field trip of the Humboldt-Universität zu Berlin to the AWI - Wattenmeerstation Sylt (Germany) from 22.09. - 05.08.2024Peer Reviewe
Early harmonies, enduring echoes—how early life experiences and personality traits shape music performance anxiety
No full textMusic performance anxiety (MPA) is a deeply personal and often debilitating experience, causing talented musicians to dread the very stages upon which they showcase their art. An increasing number of studies have addressed this anxiety phenomenon, however, definitions vary and the underlying causes remain unclear. According to the DSM-5, MPA is categorized as a specific subtype of social anxiety disorder, with a shared understanding that its development is shaped by predisposing vulnerabilities as well as external stressors and circumstances. This mini-review provides an overview of relevant literature on the multi-dimensional causes of MPA, with a particular focus on early life experiences and personality traits. It aims to address three key challenges in the field by emphasizing the importance of an enhanced investigation of formative life events, recognizing the (potentially) mediating effects of personalities, and highlighting the necessity to explore protective factors. Investigating early life experiences and personality traits in the context of MPA can deepen our understanding of its origin and development, offering valuable perspectives to tailor interventions, prevent the escalation of anxiety, and foster supportive environments conducive to the well-being and professional growth of musicians.Peer Reviewe
Sex-specific trunk movement coordination in participants with low-back pain and asymptomatic controls
No full textThe article processing charge was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) – 491192747 and the Open Access Publication Fund of Humboldt-Universität zu Berlin.Background: Trunk posture and lumbo-pelvic coordination can influence spinal loading and are commonly used as clinical measures in the diagnosis and management of low-back pain and injury risk. However, sex and pain specific characteristics have rarely been investigated in a large cohort of both healthy individuals and low-back pain patients. It has also been suggested that the motor control of trunk stability and trunk movement variability is altered in individuals with low-back pain, with possible implications for pain progression. Nonetheless, clear links to low-back pain are currently lacking.
Objective: To investigate trunk posture, lumbo-pelvic coordination, trunk dynamic stability and trunk movement variability in an adequately large cohort of individuals with low-back pain and asymptomatic controls and to explore specific effects of sex, pain intensity and pain chronicity.
Methods: We measured lumbo-pelvic kinematics during trunk flexion and trunk dynamic stability and movement variability during a cyclic pointing task in 306 adults (156 females) aged between 18 and 64 years, reporting either no low-back pain or pain in the lumbar area of the trunk. Participants were grouped based on their characteristic pain intensity as asymptomatic (ASY, N = 53), low to medium pain (LMP, N = 185) or medium to high pain (MHP, N = 68). Participants with low-back pain that persisted for 12 weeks or longer were categorized as chronic (N = 104). Data were analyzed using linear mixed models in the style of a two way anova.
Results: Female participants showed a higher range of motion in both the trunk and pelvis during trunk flexion, as well as an increased lumbar lordosis in standing attributed to a higher pelvic angle that persisted throughout the entire trunk flexion movement, resulting in a longer duration of lumbar lordosis. The intensity and chronicity of the pain had a negligible effect on trunk posture and the lumbo-pelvic coordination. Pain chronicity had an effect on trunk dynamic stability (i.e., increased trunk instability), while no effects of sex and pain intensity were detected in trunk dynamic stability and movement variability.
Conclusions: Low-back pain intensity and chronicity was not associated with lumbo-pelvic posture and kinematics, indicating that lumbo-pelvic posture and kinematics during a trunk flexion movement have limited practicality in the clinical diagnosis and management of low-back pain. On the other hand, the increased local instability of the trunk during the cyclic coordination task studied indicates control errors in the regulation of trunk movement in participants with chronic low-back pain and could be considered a useful diagnostic tool in chronic low-back pain.Peer Reviewe
Who (Really) Wins with Basic Income: Personality and Values as Predictors of Happiness Trajectories
No full textUniversal Basic Income (UBI) might cause different effects in happiness depending on a person’s individual characteristics. In an online panel study of 573 basic income recipients in Germany, we examined whether personality traits (NEOAC) and certain personal values (self-direction, stimulation, hedonism, power, achievement, universalism, benevolence) predicted trajectories in happiness. Latent Growth Curve Analysis revealed that overall, most individuals experienced similar changes in happiness over time. For personality traits as predictors, higher neuroticism and openness to new experience were linked to growth in well-being. Additionally for personal values, significant growth in life satisfaction appeared to be associated with lower hedonism at the beginning of the study, and growth in well-being was related to higher levels of self-direction. In fact, none of the subgroups suffered in happiness. We conclude with implications and some important directions for further research regarding the effect of basic income on happiness.Open Access funding enabled and organized by Projekt DEAL.Ernst-Abbe-Hochschule Jena (3327)Peer Reviewe
Silicon diffusion and n-type doping in AIN
No full textIn dieser Dissertation wird das Diffusionsverhalten von Silizium (Si) in AlN und epitaktischem AlN, das auf Saphirsubstraten gewachsen ist, grundlegend untersucht. Wir scheiden amorphes Si1-xNx durch reaktives Sputtern auf AlN ab, das als Si-Quelle dient. Unsere Untersuchung umfasst thermisches Glühen bei Temperaturen zwischen 1500 und 1700°C für 1-4 Stunden. Wir untersuchen die strukturellen und kompositorischen Veränderungen, die durch das Hochtemperaturglühen hervorgerufen werden, und analysieren die komplexen Diffusionsmechanismen von Si in AlN. Die Erforschung grundlegender Diffusionsparameter wird durch eine Analyse der Si-Diffusion in AlN-Kristallen mit geringer Versetzungsdichte möglich. Unsere Diffusionsexperimente zeigen ausgeprägte konvexe, kastenförmige Diffusionsprofile mit konzentrationsabhängigen Diffusionskoeffizienten. Durch die Integration der experimentellen Ergebnisse mit bestehenden theoretischen Berechnungen stellen wir fest, dass die Si-Diffusion in AlN durch einfach negativ geladene Dotierstoff-Leerstellenpaare vermittelt wird. Der intrinsische Diffusionskoeffizient weist ein temperaturabhängiges Verhalten mit einer Aktivierungsenthalpie von 10.34eV auf. Im zweiten Teil dieser Arbeit konzentrieren wir uns auf die Untersuchung der Auswirkungen der Diffusion von Si- und Sauerstoffverunreinigungen in epitaktischen AlN-Schichten, die auf Saphirsubstraten gewachsen sind. Unsere Untersuchung zeigt die Bildung von Polaritätsinversionen in AlN als Folge von Hochtemperaturglühen. Dabei finden wir, dass Si- und O-Verunreinigungen entscheidend für deren Bildung sind. Unser Modell geht davon aus, dass erhöhte Konzentrationen von Verunreinigungs-Leerstellen-Clustern in der AlN-Struktur die Stabilität des Kristallgitters beeinträchtigen, was zu den beobachteten Polaritätsumkehrungen nach dem Glühen führt. Die wesentliche Annahme für den beobachteten Mechanismus ist, dass Si-Donatoren die Ausscheidung von O fördern und die Polaritätsumkehrungen ermöglichen.In this dissertation, we conduct an in-depth investigation on the diffusion behavior of silicon (Si) in both bulk AlN and epitaxial AlN grown on sapphire substrates. We introduce Si into AlN using reactive sputtering to deposit amorphous Si1-xNx onto AlN, which serves as the Si source. Our investigation includes thermal annealing conducted at temperatures between 1500 and 1700°C, with durations from 1 to 4 h. We study the structural and compositional changes induced by the high-temperature annealing, unraveling the intricate diffusion mechanisms of Si in AlN. The exploration of fundamental diffusion parameters becomes feasible through the analysis of Si diffusion in low dislocation density bulk AlN crystals. Our diffusion experiments reveal distinctive convex box-like diffusion profiles, characterized by a concentration-dependent diffusion coefficient. By integrating experimental results with existing theoretical calculations, we find that Si diffusion in AlN is mediated by singly negatively charged dopant-vacancy pairs. The intrinsic diffusion coefficient exhibits a temperature-dependent behavior with an activation enthalpy of 10.34 eV. In the second part of this work, we shift our focus to investigating the impact of Si and oxygen (O) impurity diffusion in epitaxial AlN layers grown on sapphire substrates. Our investigation reveals the formation of polarity inversions in AlN resulting from high-temperature annealing. The presence of both Si and O impurities is crucial for the formation and stabilization of these polarity inversions. Our model proposes that increased concentrations of impurity-vacancy clusters within the AlN structure exerts an influence on the stability of the crystal lattice, culminating in the observed polarity inversions after annealing. Si impurities are hypothesized to play a crucial role in promoting O precipitation and enabling the polarity inversions
DeepGreen—A Data Hub for the Distribution of Scholarly Articles From Publishers to Open Access Repositories in Germany
No full textThe article processing charge was funded by the Open Access Publication Fund of Humboldt-Universität zu Berlin.DeepGreen is an automated delivery service for open access articles. Originally conceived to take advantage of the so-called open access component—a secondary publication right in Alliance and National licences in Germany to promote green open access—it aims to streamline open access processes by automating the distribution of full-text articles and metadata from publishers to repositories. The service, developed by a consortium and funded by the German Research Foundation (DFG) in its initial phase, has successfully established itself as a national service, facilitating open access content distribution and contributing to Germany's open access infrastructure. As of December 2024, DeepGreen distributes articles from 14 publishers to 84 institutional repositories and 6 subject-specific repositories. This article describes the role of the DeepGreen service in Germany, its collaboration with publishers and the potential of automated processes for storing articles in open access repositories, which, as publicly owned institutional infrastructures, ensure sustainable access and provide secure, redundant storage.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659Einstein Center Digital FuturePeer Reviewe