31325 research outputs found
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Verlängerung der Einrichtungsdauer von Studiengängen bzw. Studienfächern der Katholischen Theologie sowie der fachspezifischen Studien- und Prüfungsordnungen
No full textEditorial: Human movement coordination in healthy and pathological conditions: from neuromuscular and kinetic principles to muscle-tendon function
No full textPeer Reviewe
Design, Fabrication, and Application of Novel Photonic Quantum Devices for Communication and Sensing
No full textDer Alltagseinzug von Quantengeräten für Kommunikations- und Messanwendungen ist lediglich eine Frage der Zeit. Der Begriff »Quantengerät« beschreibt tragbare und robuste Maschinen, die auf Quanteneffekten beruhen und einem bestimmten Zweck dienen. Optische Quantengeräte bestehen aus kleineren photonischen Bausteinen. Die darin enthaltenen spinaktiven Festkörperfarbzentren besitzen vielversprechende Eigenschaften für die Realisierung von Quantenkommunikationsgeräten, wie lange Spinkohärenzzeiten, optische Steuerbarkeit und Auslesbarkeit von Spinzuständen. Magnetfeld- und temperaturabhängige Spinenergieniveaus sind hingegen für quantengestützte Messgeräte vorteilhaft. Das Hochskalieren von Quantennetzwerken zu einem weltweiten Quanteninternet erfordert die Serienproduktion von Quantenkommunikationsgeräten. Diese wiederum benötigen standardisierte Spin-Photon-Schnittstellen, die Photonverluste minimieren. Ungeachtet der möglichen Skalierbarkeit von Festkörperplattformen zeigen die enthaltenen Farbzentren ein individuell verschiedenes Verhalten. Jedoch sind aktuell weder skalierbare Methoden zur Lokalisierung und Klassifizierung von Farbzentren noch verlustarme Spin-Photon-Schnittstellen verfügbar. Als Lösungsansätze präsentiert diese Dissertation neue nanophotonische Bausteine, wie die »Sägefisch«- und »Dinosaurier«-Resonatoren, die die Manipulation der Licht-Materie-Wechselwirkung ermöglichen und zugleich hocheffiziente Spin-Photon-Schnittstellen darstellen. Ferner werden Methoden zur skalierbaren Untersuchung tausender Farbzentren sowie die flexible Software zur experimentellen Kontrolle »DynExp« eingeführt. Magnetfeldmessungen mit Farbzentren in Diamant beschränken sich zurzeit auf robuste, integrierte Einzelpixelmessgeräte oder auf bildgebende Verfahren mit fragilen Mikroskopaufbauten oder beweglichen Teilen. Im Gegensatz hierzu demonstriert diese Dissertation ein robustes und integriertes quantengestütztes Multipixelmessgerät zum Abbilden von Magnetfeldern.The entry of quantum devices for communication and sensing applications into daily life is only a matter of time. Here, the term ‘quantum device’ refers to mobile and robust machines that rely on quantum effects and serve a specific purpose. Optical quantum devices consist of smaller photonic building blocks that contain spin-active solid-state color centers. These color centers feature promising properties for the implementation of quantum communication devices, such as long spin coherence times and methods for optically controlling and reading out spin states. Moreover, magnetic field- and temperature-dependent spin state energy levels benefit quantum sensing devices. Scaling up quantum networks to a worldwide quantum internet requires the serial production of quantum communication devices. In turn, quantum communication devices depend on standardized spin-photon interfaces that minimize photon losses. Despite the possible scalability of solid-state platforms hosting color centers, individual color centers exhibit distinct characteristics. However, neither large-scale color center localization and classification techniques nor spin-photon interfaces with a near-unity efficiency are established to date. Addressing both issues, this thesis presents novel nanophotonic building blocks, like the ‘Sawfish’ and ‘Dinosaur’ photonic crystal cavities, that engineer light-matter interaction and provide highly efficient spin-photon interfaces. Furthermore, procedures for the large-scale analysis of thousands of color centers and the flexible experimental control software ‘DynExp’ are introduced. Magnetic field sensing with color centers in diamond is currently limited to robust, integrated single-pixel devices or to imaging methods that involve fragile microscope setups or moving components. In contrast, this thesis demonstrates a robust and integrated multi-pixel quantum sensing device for magnetic field imaging
What is in a name? Notes on the nomenclature of the Boophone disticha
No full textThis article examines the meaning of the scientific name of the bulbous plant Boophone disticha, along with its various common names in Afrikaans, English, and the Sotho-Tswana languages of southern Africa. The introduction addresses the question, “What is in a name?” The second section provides botanical information about the plant, including its species classification, growth patterns, dormancy, flowering characteristics, and geographical distribution. The discussion then shifts in the third section to the plant's taxonomy. Sub-section 3.1 reflects on the meaning of the scientific name, while sub-section 3.2 delves into the meanings of common or vernacular names in the aforementioned languages. In the fourth and concluding section, the author asserts that plant names convey essential information for the ethnographer; they not only offer extensive direct and indirect insights but also reflect the beliefs, values, and communication systems of specific cultural groups or societies
Steric Control in Low-Valent Mn Diamide Complexes: Contrasting Magnesium and Manganese in N2 and Benzene Activation
No full textReduction of MnII precursors with bulky diamide ligands provided access to a complex with the longest known Mn–Mn bond and to a rare example of N2 activation at high-spin MnI centers. While some instructive parallels can thus be drawn to observations made for Mg analogues, the accessibility of filled d orbitals in the respective MnI intermediates leads to a distinct behavior toward benzene that undergoes an oxidative addition.Air Force Office of Scientific Research 10.13039/100000181Australian Research Council 10.13039/501100000923Deutsche Forschungsgemeinschaft 10.13039/501100001659Einstein Stiftung Berlin 10.13039/501100006188Peer Reviewe
dVP_FAM—development and evaluation of a transsectoral digital care platform for individuals with familial cancer risks: study protocol for a multi-centre, cluster-randomised, mixed-methods study
No full textBackground: Individuals with a family history of cancer face an increased risk of developing breast and ovarian cancer. Up to 30% of the 70,000 annual breast cancer cases in Germany are associated with a familial cancer burden. Early identification of these risks is crucial as personalised measures can enable early detection or prevention of cancer. Primary care gynaecologists are uniquely suited to assess family histories and facilitate referrals to hereditary cancer centres. However, solutions on how to support early referral are still lacking. This study evaluates the impact of the digital care platform dVP_FAM as a potential remedy compared to standard care. The primary hypothesis is that the platform will increase the proportion of care-seeking women with a familial cancer risk who have not yet developed cancer. Secondary outcomes include improvements in care efficiency, patient empowerment, and health-related quality of life. Methods: The study is a multi-centre, cluster-randomised, mixed-method trial involving 44 gynaecological centres and 800 participants recruited through hereditary breast and ovarian cancer centres. All participants receive standard guideline-based care, while the intervention group also uses the dVP_FAM platform. The primary endpoint measures the proportion of participants with a familial cancer history who are cancer-free when seeking specialist counselling. Secondary outcomes are assessed using validated tools like the SF-12 and custom measures. Data collection employs a convergent mixed-methods approach, integrating quantitative and qualitative evidence. Discussion: The dVP_FAM platform represents an innovative approach to digitising cancer prevention in Germany, enhancing early detection and care coordination. If successful, dVP_FAM could serve as a scalable model for digital health innovations, improving efficiency and modernising the delivery of personalised care across health systems. Trial registration: German Clinical Trials Register, DRKS00030371 . Registered on 02 October 2023.Open Access funding enabled and organized by Projekt DEAL.Gemeinsame Bundesausschusshttp://dx.doi.org/10.13039/501100014840Charité - Universitätsmedizin Berlin (3093)Peer Reviewe
Proposal for a Bose–Einstein Condensate Based Test of Born's Rule Using Light–Pulse Atom Interferometry
No full textLight‐pulse atom interferometry with ultra‐cold quantum gases is proposed and numerically benchmarked as a platform to test the modulo‐square hypothesis of Born's rule. The interferometric protocol is based on a combination of double Bragg and single Raman diffraction to induce multipath interference in Bose–Einstein condensates (BECs) and block selected interferometer paths, respectively. In contrast to previous tests employing macroscopic material slits and blocking masks, optical diffraction lattices provide a high degree of control and avoid possible systematic errors like geometrical inaccuracies from manufacturing processes. In addition, sub‐recoil expansion rates of delta‐kick collimated BECs allow to prepare, distinguish and selectively address the external momentum states of the atoms. This further displays in close‐to‐unity diffraction fidelities favorable for both high‐contrast interferometry and high extinction of the blocking masks. In return, non‐linear phase shifts caused by repulsive atom‐atom interactions need to be taken into account, which we fully reflect in our numerical simulations of the multipath interferometer. Assuming that the modulo‐square rule holds, the impact of experimental uncertainties is examined in accordance with conventional BEC interferometer to provide an upper bound of 5.7×10−31.8×10−3on the statistical deviation of 1001000iterations for a hypothetical third‐order interference term.Deutsches Zentrum für Luft‐ und Raumfahrt 10.13039/501100002946Peer Reviewe
Allocation of Neural Resources for Visual Working Memory Storage
No full textDas Arbeitsgedächtnis ermöglicht es, Informationen vorübergehend zu speichern und zu verarbeiten, hat allerdings eine begrenzte Kapazität. In dieser Arbeit wird untersucht, wie Merkmale, Aufgabenkontext, und Verhaltensziele die Organisation der neuronalen Ressourcen des visuellen Arbeitsgedächtnisses beeinflussen können. In drei empirischen Studien haben wir untersucht, wie sich Merkmale von unterschiedlichen sensorischen Modalitäten und die zunehmende Anzahl an Merkmalen auf das Erinnerungsvermögen und die neuronalen Repräsentationen auswirken. Die Ergebnisse der Verhaltensstudie deuten darauf hin, dass Interferenzen auf der Ebene der spezifischen Merkmale auftreten, nicht nur auf der Ebene der sensorischen Modalität, und von den Erinnerungsstrategien dieser Merkmale beeinflusst werden. In zwei fMRT-Studien zeigen wir, dass der visuelle Kortex eine präzise Gedächtnisrepräsentation beizubehalten scheint, da sich die merkmalspezifische Information mit der Anzahl an zu erinnernden Merkmalen verringerte. Die parietalen Regionen enthielten weniger präzise Informationen für mehrere Merkmale, die möglicherweise auch von dem Aufgabenkontext moduliert werden. Auf der anderen Seite zeigte die frontale Region eine uneinheitliche Beteiligung an der Merkmalsspeicherung. Es könnte sein, dass diese Repräsentationen von Erwartungen über die kognitiven Anforderungen beeinflusst werden. Diese Arbeit bietet Einblicke in die neuronale Organisation der visuellen Arbeitsgedächtnisspeicherung und die Möglichkeiten und Grenzen der Dekodierung mehrerer Items aus neuronalen Aktivitätsmustern.Working memory allows us to store and manipulate information for short periods of time but is limited in its capacity. This thesis investigates how features, task structure, and behavioral goals influence the organization of neural resources for visual working memory storage. Across three empirical studies, we examined how different features and increasing set size impact behavioral recall and neural representations. First, our results suggest that interference occurs at the level of specific features, not only at the level of sensory modality, and may be influenced by the strategies used to memorize these features. In two fMRI studies, we show that the visual cortex maintained precise mnemonic representations, as item-specific information decreased with set size. The parietal cortex maintained less precise mnemonic information about multiple items as well, which are perhaps modulated by task context. On the other hand, the frontal region showed inconsistent involvement in memory maintenance, even under high load. It may be that other factors, such as expectations about the cognitive demand, influence item-specific information in this region. Overall, this thesis provides insights into the neural organization of visual working memory storage and the possibilities and limitations of decoding multiple items from neural activity patterns
