Dark septate endophytes and arbuscular mycorrhizal fungi (Paris‐morphotype) affect the stable isotope composition of 'classically' non-mycorrhizal plants

The vast majority of terrestrial plants exchange nutrients with fungal partners forming different mycorrhizal types. The minority of plants considered as non-mycorrhizal, however, are not necessarily free of any fungi, but are frequently colonized by elusive fungal endophytes, such as dark septate endophytes (DSE) or fine root endophytes (FRE). While a functional role of FRE in improvement of nutrient gain was recently elucidated, the function of DSE is still in discussion and was here addressed for 36 plant species belonging to the families Equisetaceae, Cypereaceae and Caryophyllaceae. Molecular and microscopic staining approaches were conducted to verify the presence of DSE in the investigated species. Stable isotope natural abundances of the elements carbon, nitrogen, hydrogen and oxygen and total nitrogen concentrations were analyzed for the respective species of the target plant families and accompanying mycorrhizal and non-mycorrhizal (Brassicaceae) plant species. Staining approaches confirmed the presence of DSE in all investigated species within the families Equisetaceae, Cyperaceae and Caryophyllaceae. A co-colonization with Paris-type arbuscular mycorrhiza (AM) was occasionally found by staining and molecular approaches in species of the Equisetaceae. Species of the Equisetaceae, Cyperaceae and Caryophyllaceae were significantly 15N-enriched in comparison to accompanying plants. In addition, a significant 13C and 2H enrichment and increased total nitrogen concentrations were found for representatives of the Equisetaceae. The 15N-enrichment found here for representatives of Equisetaceae, Cyperaceae and Caryophyllaceae provides evidence for a functional role of the ubiquitous DSE fungi. DSE fungi obviously provide access to 15N-enriched soil organic compounds probably in exchange for organic carbon compounds from plant photosynthesis. As indicated by additional 13C- and 2H-enrichments, representatives of the Equisetaceae apparently gain simultaneously organic carbon compounds from their AM fungi of the Paris-morphotype. Thus, species of the Equisetaceae have to be considered as partially, or in case of the achlorophyllous fertile Equisetum arvense, as fully mycoheterotrophic at least in some stages of their life cycle. So far mostly underappreciated fungi classified as DSE are suggested to occupy an ecologically relevant role similar to mycorrhizae and the occurrence of simultaneous functions of DSE and AM fungi in Equisetaceae is proposed

State preparation of a fluxonium qubit with feedback from a custom FPGA-based platform

We developed a versatile integrated control and readout instrument for experiments with superconducting quantum bits (qubits), based on a field-programmable gate array (FPGA) platform. Using this platform, we perform measurement-based, closed-loop feedback operations with $428 \, \mathrm{ns}$ platform latency. The feedback capability is instrumental in realizing active reset initialization of the qubit into the ground state in a time much shorter than its energy relaxation time $T_1$. We show experimental results demonstrating reset of a fluxonium qubit with $99.4\,\%$ fidelity, using a readout-and-drive pulse sequence approximately $1.5 \, \mathrm{\mu s}$ long. Compared to passive ground state initialization through thermalization, with the time constant given by $T_1 = ~ 80 \, \mathrm{\mu s}$, the use of the FPGA-based platform allows us to improve both the fidelity and the time of the qubit initialization by an order of magnitude.Comment: 3 pages, 2 figures. The following article has been submitted to the AIP Conference Proceedings of the Fifth International Conference on Quantum Technologies (ICQT-2019

Quantum non-demolition dispersive readout of a superconducting artificial atom using large photon numbers

Reading out the state of superconducting artificial atoms typically relies on dispersive coupling to a readout resonator. For a given system noise temperature, increasing the circulating photon number $\bar{n}$ in the resonator enables a shorter measurement time and is therefore expected to reduce readout errors caused by spontaneous atom transitions. However, increasing $\bar{n}$ is generally observed to also increase these transition rates. Here we present a fluxonium artificial atom in which we measure an overall flat dependence of the transition rates between its first two states as a function of $\bar{n}$, up to $\bar{n}\approx200$. Despite the fact that we observe the expected decrease of the dispersive shift with increasing readout power, the signal-to-noise ratio continuously improves with increasing $\bar{n}$. Even without the use of a parametric amplifier, at $\bar{n}=74$, we measure fidelities of 99% and 93% for feedback-assisted ground and excited state preparation, respectively.Comment: typos corrected, added figure at p.10 (section IV of the Supplemental Material), added reference

Quantum Nondemolition Dispersive Readout of a Superconducting Artificial Atom Using Large Photon Numbers

Reading out the state of superconducting artificial atoms typically relies on dispersive coupling to a readout resonator. For a given system noise temperature, increasing the circulating photon number $\overline{n}$ in the resonator enables a shorter measurement time and is therefore expected to reduce readout errors caused by spontaneous atom transitions. However, increasing $\overline{n}$ is generally observed to also monotonously increase these transition rates. Here we present a fluxonium artificial atom in which, despite the fact that the measured transition rates show nonmonotonous fluctuations within a factor of 6, for photon numbers up to $\overline{n}$≈200, the signal-to-noise ratio continuously improves with increasing $\overline{n}$. Even without the use of a parametric amplifier, at $\overline{n}$=74, we achieve fidelities of 99% and 93% for feedback-assisted ground and excited state preparations, respectively. At higher $\overline{n}$, leakage outside the qubit computational space can no longer be neglected and it limits the fidelity of quantum state preparation

Scientific Railway Signalling Symposium 2023 - Einfach Fahren! – Digitale Transformation im Spannungsfeld Automatisierung, europäische Standardisierung und schneller Rollout

Im Rahmen des Programms „Digitale Schiene Deutschland“ wird aktuell an der digitalen Transformation der Infrastruktur gearbeitet. Ziel ist es unter anderem, eine höhere Kapazität sowie optimale Auslastung des Schienennetzes zu erreichen, ohne im größeren Umfang zusätzliche Gleise zu verlegen. Für dieses Ziel bedarf es eines harmonisierten und reibungslosen Zusammenspiels zukunftsweisender Technologien im Bereich der Leit- und Sicherungstechnik, die zunächst umfassend erforscht und anschließend im Feld eingesetzt werden müssen. Mit dieser spannenden Thematik beschäftigte sich das Scientific Railway Signalling Symposium (SRSS) 2023 am 14. Juni, welches vom Institut für Bahnsysteme und Bahntechnik der TU Darmstadt zusammen mit der DB Netz AG sowie erstmals dem Fachgebiet Bahnbetrieb und Infrastruktur am Institut für Land- und Seeverkehr der TU Berlin organisiert wurde. Ca. 100 Fachexpert:innen aus Forschung und Praxis verfolgten die unterschiedlichen Vorträge unter dem Tagungstitel „Einfach Fahren! – Digitale Transformation im Spannungsfeld Automatisierung, europäische Standardisierung und schneller Rollout“ und brachten ihre Expertise in Diskussionsrunden ein. Zu Beginn der Tagung stellte Volker Hentschel von der DB Netz AG in seiner Keynote das volle Potenzial des digitalen Bahnsystems vor. Dabei gab er einen Überblick über die Innovationen, deren Umsetzung in den kommenden Jahren im Rahmen der Digitalen Schiene zu erwarten sind. Daran anschließend diskutierten die Kleingruppen, welche Innovationen der digitalen LST schnell zu Verbesserungen im Feld führen können. Bevor Markus Montigel, RAILvelation GmbH, zum Abschluss des Tages durch einen interaktiven Vortrag das Motto des Tages „Einfach fahren“ noch einmal aus etwas Distanz reflektierte, boten zahlreiche Beiträge detaillierte Einblicke zu unterschiedlichen LST-bezogenen Themen aus Wissenschaft und Praxis. Aufgrund der gestiegenen Anzahl der Vorträge im Vergleich zu den Vorjahren wurde die Tagung im Nachmittagsblock erstmals in parallele Sessions aufgeteilt. In dieser Publikation sind diejenigen Beiträge enthalten, die erfolgreich den Review-Prozess durchlaufen haben. Eine wesentliche Innovation ist das Automatisierte Fahren, dessen Sicherheit vor Einführung geprüft und sichergestellt werden muss. Marco Kinas et al. beschreiben daher in ihrem Beitrag Aspekte des im Rahmen des ATO-RISK-Projekts verfolgten Ansatzes, so z.B. den Einsatz von Regelwerken als Risikoakzeptanzprinzip gemäß der CSM-Verordnung und die Analyse menschlicher Faktoren im Vergleich zum derzeitigen bemannten Betrieb. Neben der funktionalen Sicherheit spielt auch die Sicherheit vor Angriffen eine wichtige Rolle. Simon Unger et al. erläutern daher in ihrem Beitrag das Zusammenspiel zwischen Safety und Security und arbeiten insbesondere die Relevanz von Security in Safety-kritischen Systemen anhand des RaSTA-Protokolls heraus. Im Gegensatz zu Safety handelt es sich bei Security um einen dynamischen Aspekt, denn die Bedrohungslage durch Angreifer kann sich stetig wandeln. Matthias Drodt von der DB Netz AG und Frank Weber vom Eisenbahn-Bundesamt beschreiben in ihrem Beitrag daher Lösungsansätze zur Zulassung der sehr dynamischen IT-Security in Eisenbahnsystemen. Für eine schnelle Zulassung und einen schnellen Rollout ist auch eine Beschleunigung des Entwicklungs- und Sicherheitsnachweisprozesses notwendig. Frederic Reiter et al. beschreiben in ihrem Paper eine vollständig virtualisierte Evaluierungsumgebung für digitale Stellwerke, die die Komplexität reduziert und Tests für Ausführung von Funktionen vor der Integration mit physischen Komponenten ermöglicht. Gunnar Smith von Prover Technology aus Stockholm stellt in seinem Beitrag die Methoden vor, die zur Reduzierung des Aufwandes in der Entwicklungsphase der LST-Systeme und dadurch auch zum schnellen Rollout beitragen werden. Julian Lucas von der TU Darmstadt und Markus Rothkehl von der DB Netz beschreiben ein Konzept für ein modulares Nachweisverfahren für verschiedene Komponenten der digitalen Sicherungstechnik. Auch im Falle eines beschleunigten Rollouts wird jedoch eine längere Übergangsphase zur digitalen LST erforderlich sein, in der es mehrere Migrationsschritte geben wird. In seinem Beitrag erläutert Melvin Zinngrebe von SBB AG zwei Strategien, die von der SBB AG zur Bewältigung der Migrationsherausforderungen angewendet werden. Eine davon ist die Lebensverlängerung der ersten Generation elektronischer Stellwerke, um Investitionen in eine Übergangstechnologie vor der Führerstandssignalisierung (FSS)-Migration zu vermeiden. Die andere Strategie ist eine Nachrüstung mit FSS. Zuverlässige Infrastrukturdaten sind eine unerlässliche Voraussetzung für die erfolgreiche Durchführung der digitalen Transformation. Benedikt Wenzel et al. haben in ihrem Beitrag die Auswirkungen auf die Qualität von Infrastrukturdaten und geeignete Strategien zur Bewältigung der Herausforderungen, die mit der Erstellung und Pflege zuverlässiger Infrastrukturdaten verbunden sind, herausgearbeitet. Um Pünktlichkeit und den reibungslosen Zugverkehr sicherstellen zu können, ist die Gewährleistung der Verfügbarkeit von LST-Systemen ein wichtiges Thema. In ihrem Paper beleuchten Simon Hofer und Martin Müller von team Technology Management GmbH verschiedene Strategien, um die Anforderungen an die hohe Verfügbarkeit beim Zugsicherungssystem ETCS gewährleisten zu können. Die Potenziale für Kapazitätssteigerungen und Leistungsverbesserungen, die durch Digitale Stellwerke, ETCS und andere Technologien erzielt werden können, sind in Deutschland nach wie vor enorm. Peter Reinhart von der DB Netz AG fasst in seinem Paper den bisherigen Erkenntnisstand hierzu anhand des Digitalen Knoten Stuttgart zusammen. Die breite Themenvielfalt der in diesem Tagungsband enthaltenen Artikel zeigt, wie dynamisch das Umfeld in unserer Branche derzeit ist und wie viele spannende Innovationen wir in den nächsten Jahren erwarten dürfen

COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≤ 18 years: 69, 48, 23; 85%), older adults (≥ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

Overlap and Specificity in the Substrate Spectra of Human Monoamine Transporters and Organic Cation Transporters 1, 2, and 3

Human monoamine transporters (MATs) are cation transporters critically involved in neuronal signal transmission. While inhibitors of MATs have been intensively studied, their substrate spectra have received far less attention. Polyspecific organic cation transporters (OCTs), predominantly known for their role in hepatic and renal drug elimination, are also expressed in the central nervous system and might modulate monoaminergic signaling. Using HEK293 cells overexpressing MATs or OCTs, we compared uptake of 48 compounds, mainly phenethylamine and tryptamine derivatives including matched molecular pairs, across noradrenaline, dopamine and serotonin transporters and OCTs (1, 2, and 3). Generally, MATs showed surprisingly high transport activities for numerous analogs of neurotransmitters, but their substrate spectra were limited by molar mass. Human OCT2 showed the broadest substrate spectrum, and also the highest overlap with MATs substrates. Comparative kinetic analyses revealed that the radiotracer meta-iodobenzylguanidine had the most balanced uptake across all six transporters. Matched molecular pair analyses comparing MAT and OCT uptake using the same methodology could provide a better understanding of structural determinants for high cell uptake by MATs or OCTs. The data may result in a better understanding of pharmacokinetics and toxicokinetics of small molecular organic cations and, possibly, in the development of more specific radiotracers for MATs

Stereoselectivity in the Membrane Transport of Phenylethylamine Derivatives by Human Monoamine Transporters and Organic Cation Transporters 1, 2, and 3

Stereoselectivity is well known and very pronounced in drug metabolism and receptor binding. However, much less is known about stereoselectivity in drug membrane transport. Here, we characterized the stereoselective cell uptake of chiral phenylethylamine derivatives by human monoamine transporters (NET, DAT, and SERT) and organic cation transporters (OCT1, OCT2, and OCT3). Stereoselectivity differed extensively between closely related transporters. High-affinity monoamine transporters (MATs) showed up to 2.4-fold stereoselective uptake of norepinephrine and epinephrine as well as of numerous analogs. While NET and DAT preferentially transported (S)-norepinephrine, SERT preferred the (R)-enantiomer. In contrast, NET and DAT showed higher transport for (R)-epinephrine and SERT for (S)-epinephrine. Generally, MAT stereoselectivity was lower than expected from their high affinity to several catecholamines and from the high stereoselectivity of some inhibitors used as antidepressants. Additionally, the OCTs differed strongly in their stereoselectivity. While OCT1 showed almost no stereoselective uptake, OCT2 was characterized by a roughly 2-fold preference for most (R)-enantiomers of the phenylethylamines. In contrast, OCT3 transported norphenylephrine and phenylephrine with 3.9-fold and 3.3-fold preference for their (R)-enantiomers, respectively, while the para-hydroxylated octopamine and synephrine showed no stereoselective OCT3 transport. Altogether, our data demonstrate that stereoselectivity is highly transporter-to-substrate specific and highly diverse even between homologous transporters