Vanishing of long time average p-enstrophy dissipation rate in the inviscid limit of the 2D damped Navier-Stokes equations

In 2007, Constantin and Ramos proved a result on the vanishing long time average enstrophy dissipation rate in the inviscid limit of the 2D damped Navier-Stokes equations. In this work, we prove a generalization of this for the p-enstrophy, sequences of distributions of initial data and sequences of strongly converging right-hand sides. We simplify their approach by working with invariant measures on the global attractors which can be characterized via bounded complete solution trajectories. Then, working on the level of trajectories allows us to directly employ some recent results on strong convergence of the vorticity in the inviscid limit

Kap-Centric control of nuclear pores based on promiscuous binding to FG nucleoporins

Nuclear pore complexes (NPCs) are remarkable molecular machines that perforate the nuclear envelope (NE) in eukaryotic cells and mediate the rapid bidirectional traffic of hundreds of proteins, ribonucleoproteins, and metabolites across the nuclear envelope. Their enormous structure is composed of multiple copies of 30 different proteins (Nups) that add up to 60 – 120 MDa of mass depending on the organism. Each NPC contains a 50 nm-diameter central channel through which only molecules smaller than ~40 kDa or ~5 nm in size can diffuse passively. The movement of larger molecules is impaired by a permeability barrier generated by ~200 partly intrinsically disordered phenylalanine-glycine (FG)-rich nucleoporins (FG Nups) that are tethered to the NPC transport channel surface. These FG Nups interact promiscuously with nuclear transport receptors (NTRs), such as karyopherins (Kaps; e.g. Kap-beta1) or NTF2, that mediate rapid trafficking of cargoes. Given that the number of FG repeats per FG Nup also varies from 5 to ~50, NTR-FG Nup binding involves highly multivalent interactions, which are generally known to impart a strong avidity that enhances stability and specificity. However, this is paradoxical in the context of the NPC, because the high submicromolar Kap-beta1-FG domain binding affinities predict slow off rates (given a diffusion-limited on rate) that contradict the rapid (~5 ms) in vivo dwell time. As this implies, Kap-FG binding ought to be sufficiently strong to ensure selectivity but also weak enough to promote fast translocation through the NPC. Nonetheless, an explanation as to how promiscuous binding of FG Nups to NTRs is balanced against the mechanistic control of the FG domain barrier is still lacking. The purpose of my work was to investigate FG Nup-NTR binding promiscuity and multivalency by measuring the interaction kinetics, binding affinity and in situ associated conformational changes in Nsp1p FG domains when binding NTF2 and Kap-beta1, both separately and together. Experimentally, this was achieved by using a novel surface plasmon resonance technique to correlate in situ mechanistic changes (molecular occupancy and conformational changes) with FG Nup-NTR binding. The obtained results show that surface-tethered Nsp1p FG domains form molecular brushes at physiological conditions. Kap-beta1 binding provokes brush extension while partitioning into a fast and slow kinetic phase, where the latter may form an integral part of the FG domain barrier. In contrast, NTF2 binding to pristine Nsp1p layers induced collapse, but not under competing interactions from Kap-beta1. Therefore, promiscuous binding of NTF2 to Kap-beta1-preloaded Nsp1p attenuates NTF2 towards higher off rates and more transient interactions. My work demonstrates that promiscuous binding of NTRs to FG Nups ought to influence nucleocytoplasmic transport. This depends on the concentration, size and binding strength of each NTR. Indeed, some form of hierarchy may exist between different NTRs such that their relative concentrations may impact NPC barrier function. This interpretation departs from the conventional view that the FG Nups alone form the NPC permeability barrier. Rather I conclude that concentrating NTRs in the NPC transport channel also contributes to generating crowding-based selective barrier function of the pore

Excited states of neutral donor bound excitons in GaN

We investigate the excited states of a neutral donor bound exciton (D0X) in bulk GaN by means of high-resolution, polychromatic photoluminescence excitation (PLE) spectroscopy. The optically most prominent donor in our sample is silicon accompanied by only a minor contribution of oxygen—the key for an unambiguous assignment of excited states. Consequently, we can observe a multitude of Si0X-related excitation channels with linewidths down to 200 μeV. Two groups of excitation channels are identified, belonging either to rotational-vibrational or electronic excited states of the hole in the Si0X complex. Such identification is achieved by modeling the excited states based on the equations of motion for a Kratzer potential, taking into account the particularly large anisotropy of effective hole masses in GaN. Furthermore, several ground- and excited states of the exciton-polaritons and the dominant bound exciton are observed in the photoluminescence (PL) and PLE spectra, facilitating an estimate of the associated complex binding energies. Our data clearly show that great care must be taken if only PL spectra of D0X centers in GaN are analyzed. Every PL feature we observe at higher emission energies with regard to the Si0X ground state corresponds to an excited state. Hence, any unambiguous peak identification renders PLE spectra highly valuable, as important spectral features are obscured in common PL spectra. Here, GaN represents a particular case among the wide-bandgap, wurtzite semiconductors, as comparably low localization energies for common D0X centers are usually paired with large emission linewidths and the prominent optical signature of exciton-polaritons, making the sole analysis of PL spectra a challenging task.EC/H2020/749565/EU/Heat Transport and its Effects on the Performance of Nanostructured, Photonic Materials/PhotoHeatEffectDFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, Bauelement

Global Production Linkages and Stock Market Comovement

Although real integration conceptually plays an important role for the comovement of international equity markets, documenting this link empirically has proven challenging. We construct a new dataset of theory-guided, relevant measures of bilateral trade in final and intermediate goods and services. With these measures, we provide evidence of a strong link between changes in international trade – in particular global value chains – and equity market comovement.These results suggest that supply chain disruptions and reshoring, for instance due to political tensions, war, and the COVID-19 crisis, might affect the interconnections between stock markets via rippling through the global production network

Virally mediated gene manipulation in the adult CNS

Understanding how the CNS functions poses one of the greatest challenges in modern life science and medicine. Studying the brain is especially challenging because of its complexity, the heterogeneity of its cellular composition, and the substantial changes it undergoes throughout its life-span. The complexity of adult brain neural networks results also from the diversity of properties and functions of neuronal cells, governed, inter alia, by temporally and spatially differential expression of proteins in mammalian brain cell populations. Hence, research into the biology of CNS activity and its implications to human and animal behavior must use novel scientific tools. One source of such tools is the field of molecular genetics—recently utilized more and more frequently in neuroscience research. Transgenic approaches in general, and gene targeting in rodents have become fundamental tools for elucidating gene function in the CNS. Although spectacular progress has been achieved over recent decades by using these approaches, it is important to note that they face a number of restrictions. One of the main challenges is presented by the temporal and spatial regulation of introduced genetic manipulations. Viral vectors provide an alternative approach to temporally regulated, localized delivery of genetic modifications into neurons. In this review we describe available technologies for gene transfer into the adult mammalian CNS that use both viral and non-viral tools. We discuss viral vectors frequently used in neuroscience, with emphasis on lentiviral vector (LV) systems. We consider adverse effects of LVs, and the use of LVs for temporally and spatially controllable manipulations. Especially, we highlight the significance of viral vector-mediated genetic manipulations in studying learning and memory processes, and how they may be effectively used to separate out the various phases of learning: acquisition, consolidation, retrieval, and maintenance

Panorama do Direito Internacional Privado atual e outros temas contemporâneos: Festschrift ao professor Jacob Dolinger

Divulgação dos SUMÁRIOS das obras recentemente incorporadas ao acervo da Biblioteca Ministro Oscar Saraiva do STJ. Em respeito à lei de Direitos Autorais, não disponibilizamos a obra na íntegra.Localização na estante: 341.9 P195

Strategien zur funktionsorientierten Qualitätsregelung in der Serienproduktion

Eine hohe Produktqualität ist in zunehmendem Maße eine zentrale Kundenanforderung und für produzierende Unternehmen ein entscheidender Faktor zur Behauptung der Führungsrolle im globalen Wettbewerb. In vielen Fällen steigt die Komplexität der Hochpräzisionsprodukte jedoch erheblich und die Anforderungen erreichen technologische Fertigungsgrenzen. Auftretende Fertigungsab-weichungen gefährden dabei die Erfüllung hoher Qualitätsanforderungen und damit die Sicherstellung der Funktionalität hergestellter Produkte. Eine Abhilfemaßnahme stellt der Ansatz zur Qualitätsregelung in der Produktion dar. Bisherige Ansätze der Qualitätsregelung basieren dabei auf der geometrischen Kompensation direkter Merkmalspaare. Besitzen Bauteile bzw. Teilbaugruppen eines Produktes mehrere funktionsrelevante Produktmerkmale, kommen bisherige Strategien der Qualitätsregelung jedoch an ihre Grenzen. Um das aufgezeigte Defizit zu beheben wird in der vorliegenden Arbeit eine Methode zur Planung und Bewertung der funktionsorientierten Qualitätsregelung vorgestellt. Die entwickelte Methode erlaubt das Erstellen Digitaler Zwillinge einzelner Produktausprägungen unter minimaler Gesamtunsicherheit, durch Modellierung und Kalibrierung. Quantitative, interpretierbare Funktionsmodelle der Digitalen Zwillinge können anhand statistischer Methoden abgeleitet werden. Sie ermöglichen die Echtzeit-nahe Funkti-onsprognose, unter minimaler Gesamtunsicherheit. Durch Integration dieser Funktionsmodelle in die Produktionssteuerung werden funktionsorientierte Strategiealternativen entwickelt und in ereignisorientierten Materialflusssimulationen analysiert. Die abschließende Auswahl geeigneter Strategiealternativen erfolgt anhand einer technischen und wirtschaftlichen Bewertung der Simulationsergebnisse. Die entwickelten Methoden des Planungsansatzes wird im industriellen Anwendungsfall der Serienproduktion zur Herstellung von Piezo-Injektoren exemplarisch demonstriert

On the Challenges of Reaching Pupils With Spacetech-Related Extracurricular Activities

Today\u27s rapid progress in space exploration leads to a high impact on our society. Especially young people are highly affected by this fascination. Despite this large pool of curious pupils, it remains challenging to find entry points into space and aeronautic-related careers for them. Often, these topics seem to be out of reach for most pupils. Educational programs like AstroPi (offered by ESA) or High School Aerospace Scholars (offered by NASA) target this issue. However, those projects never get into contact with actual outer space and remain mostly theoretical. The goal of the mission SpaceTeamSat1 and the CubeSat with the same name, is to provide an entry point to pupils, by giving them the opportunity to participate in a space mission. With SpaceTeamSat1, the TU Wien Space Team develops a 1U CubeSat platform from scratch and operates it in low earth orbit at an approximate altitude of 500 km. It shall allow pupils of secondary schools, aged between 15 and 19 to run their own code on a Raspberry Pi payload in space. The mentioned payload offers a variety of sensors and cameras, which allows the execution of a broad range of experiments. Participating pupils and teams formed from them will be supervised by their teachers on a regular basis. In order to teach common industry practices and maximize the chances of a successful mission, the TU Wien Space Team will offer additional guidance in the form of documentation, reviews, and get-togethers. The highlight of the mission will be a coding challenge, where teams of pupils will compete against each other over the most successful in-orbit experiment according to inventiveness, project management, and code quality. These tasks are divided into different levels, beginning at entry-level tasks, such as calculating the rotation rate or investigating the thermal behavior of the CubeSat. More advanced tasks may include taking pictures of the Earth or Moon. At the moment, SpaceTeamSat1 is in its prototyping phase and is planned to be launched in 2024. Complementary to that, a preliminary school outreach has begun, and a hand-selected group of secondary-level schools has been accepted to join as pilot participants. This allows for fine-tuning of the offered educational program and reveals drawbacks that can be targeted before the official start of the CubeSat mission. Additionally, the educational mission is evaluated and developed in cooperation with ESERO Austria. To our knowledge, the TU Wien Space Team is the only organization that offers such a mission so far. Since the know-how and technology that is produced in the course of the SpaceTeamSat1 mission is supposed to be open source, we are able to share insights on the difficulties that have been faced – or are expected – when proposing extracurricular activities to schools and pupils

Virtual In-line Inspection for Function Verification in Serial Production by means of Artificial Intelligence

In high-tech production, companies often deal with the manufacture of assemblies with quality requirements close to the technological limits of manufacturing processes. The article shows an approach of a virtual in-line inspection, predicting the products functionality. An artificial neural network (ANN) fed with product characteristics and process data as well as the resulting functional fulfillment of the product is trained for virtual function prognosis. Through the preventive identification of defective products before the final assembly step, components can be recovered and returned to serial production. By optimizing the parameters of the ANN, incorrect classifications are reduced and the practical applicability is ensured. The approach is demonstrated in an industrial application in the automotive industry