Towards the observation of phase locked Bloch oscillations in arrays of small Josephson junctions

We have designed an experiment and performed extensive simulations and preliminary measurements to identify a set of realistic circuit parameters that should allow the observation of constant-current steps at I=2ef in short arrays of small Josephson junctions under external AC drive of frequency f. Observation of these steps demonstrating phase lock of the Bloch oscillations with the external drive requires a high-impedance environment for the array, which is provided by on-chip resistors close to the junctions. We show that the width and shape of the steps crucially depend on the shape of the drive and the electron temperature in the resistors

Market Dependency as Boundary for Solidarity

Der Beitrag untersucht Grenzlinien der Solidarität. Er betrachtet, wie in Krisensituationen Unterstützungsbedarfe für jene soziale Gruppen verhandelt werden, die in etablierten Solidaritätsdiskursen in eine Deutungslücke fallen. Untersuchungsgegenstand bildet die öffentliche Verhandlung von Solidarität mit Soloselbstständigen zu Beginn der Coronapandemie. Gestützt auf Auswertungen von 21 qualitativen Interviews und ein Textkorpus mit 2428 Zeitungsartikeln zeichnen wir den Diskurs um Soforthilfe nach. Mittels einer Kombination aus strukturierender Inhaltsanalyse und Textmining zeigen wir auf, dass die Deutungsfigur der Marktabhängigkeit von Soloselbstständigen in dieser Krisenzeit dazu dient, die Hilfsbedürftigkeit der Gruppe zu identifizieren (soziale Grenzziehung), aber auch die Ausgestaltung der Hilfe kontrovers zu diskutieren (substanzielle Grenzziehung). Wir zeigen, wie sich Solidaritätsnormen im Diskursverlauf konfigurieren und dabei Marktabhängigkeit als relevante Grenze für Solidarität freigeben, diese aber nur zeitlich begrenzt wirksam bleibt.This article asks how boundaries of solidarity are constructed. From a sociological perspective, solo self-employed workers, who are both employees and entrepreneurs, fall into a collective interpretation gap in the discourse on solidarity. However, this changes at the beginning of the Covid-19 pandemic. Drawing on the analyses of 21 qualitative interviews and a text corpus of 2428 newspaper articles, we trace the public discourse on “Soforthilfe.” Using a combination of structuring content analysis and text mining, we show that the market dependency of the solo self-employed serves to identify the group’s need for financial support (social boundary), but also to controversially discuss the design of this support (substantive boundary). We show how norms of solidarity are configured throughout the discourse, releasing market dependence as a relevant boundary for solidarity – at least temporarily

A type III complement factor D deficiency: Structural insights for inhibition of the alternative pathway.

Abstract Background: Complement factor D (FD) is the rate-limiting enzyme of the alternative complement pathway. Previous reports of FD deficiency featured absent plasma FD (type I deficiency) and susceptibility to meningococcal infection. A new FD mutant, which is non-functional but fully expressed, was identified in a patient with invasive meningococcal disease. Objectives: We sought to investigate the molecular features of this novel FD mutant. Methods: We performed complement haemolytic assays, western blot analysis of serum FD and Sanger sequencing of the CFD gene. Recombinant mutant FD was assessed by in vitro catalytic assays, circular dichroism, thermal shift assays, esterolytic assays and surface plasmon resonance. Molecular dynamics simulation was used to visualise the structural changes in mutant FD. Results: A homozygous single-nucleotide variation of the CFD gene in the patient and their sibling resulted in an arginine to proline (R176P) substitution in FD. While R176P FD was stable and fully expressed in blood, it had minimal catalytic activity. Mutation R176P caused key FD-C3bB binding exosite loop 156-162 to lose its binding-competent conformation and stabilised the inactive conformation of FD. Consequently, R176P FD was unable to bind its natural substrate, C3bB. Neither patient nor sibling demonstrated the glucose homeostasis impairment that occurs in FD-null mice. Conclusions: Here, we report the first genetically confirmed functional, or type III, deficiency of an activating complement serine protease. This novel mechanism of FD inhibition can inform further development of alternative pathway inhibitors to treat common inflammatory diseases such as age-related macular degeneration

The multiple faces of self-assembled lipidic systems

Lipids, the building blocks of cells, common to every living organisms, have the propensity to self-assemble into well-defined structures over short and long-range spatial scales. The driving forces have their roots mainly in the hydrophobic effect and electrostatic interactions. Membranes in lamellar phase are ubiquitous in cellular compartments and can phase-separate upon mixing lipids in different liquid-crystalline states. Hexagonal phases and especially cubic phases can be synthesized and observed in vivo as well. Membrane often closes up into a vesicle whose shape is determined by the interplay of curvature, area difference elasticity and line tension energies, and can adopt the form of a sphere, a tube, a prolate, a starfish and many more. Complexes made of lipids and polyelectrolytes or inorganic materials exhibit a rich diversity of structural morphologies due to additional interactions which become increasingly hard to track without the aid of suitable computer models. From the plasma membrane of archaebacteria to gene delivery, self-assembled lipidic systems have left their mark in cell biology and nanobiotechnology; however, the underlying physics is yet to be fully unraveled

The search campaign to identify and Image the Philae Lander on the surface of comet 67P/Churyumov-Gerasimenko

On the 12th of November 2014, the Rosetta Philae Lander descended to make the first soft touchdown on the surface of a comet – comet 67P/Churyumov- Gerasimenko. That soft touchdown did occur but due to the failure in the firing of its two harpoons, Philae bounced and travelled across the comet making contact with the surface twice more before finally landing in a shaded rocky location somewhere on the southern hemisphere of the comet. The search campaign, led by ESA, involved multiple teams across Europe with a wide range of techniques used in support of it. This search campaign would continue through 2015 where a prime candidate on the surface was identified and on into 2016 to end on the 2nd of September 2016 when a definitive and conclusive image was taken of the lander on the surface of the comet, confirming the prime candidate to indeed be Philae

Composition of Reactive System Components

This paper will present the case for using a formal component-based specification technique for reactive systems, such as the Object Calculus of Fiadeiro and Maibaum. The Object Calculus provides a modular, highly declarative and abstract specification language, suitable for refinement using model-based design notations such as B or VDM. In the Object Calculus, pre/post style specifications of the effect of actions can be given, together with temporal logic specifications of expected histories of behaviour of the system. Keywords: Temporal logic, Reactive systems, Program specification, Object Calculus, Specification languages. Workshop Goals: Investigate application of formal specification in component-based systems, particularly reactive systems. 1 Background Temporal logic is an established technique for the specification of reactive systems: it has the advantage of being declarative and supporting reasoning, and it is sufficiently expressive for many practical cases. The..