The space of bounded variation with infinite-dimensional codomain

We study functions of bounded variation with values in a Banach or in a metric space. We provide several equivalent notions of variations and provide the notion of a time derivative in this abstract setting. We study four distinct topologies on the space of bounded variations and provide some insight into the structure of these topologies. In particular, we study the meaning of convergence, duality and regularity for these topologies and provide some useful compactness criteria, also related to the classical Aubin-Lions theorem. We finally provide some useful applications to stochastic processes

Mangelnde Datenverfügbarkeit als Hemmnis für passgenaue Optimierung der Proteinversorgung von Monogastriern

Die Beratung zur Optimierung der Proteinversorgung von Schweinen und Geflügel benötigt umfassende betriebliche Daten. In einer Studie mit 56 ökologisch wirtschaftenden Betrieben ergab sich für viele Betriebe Verbesserungspotential hinsichtlich der bedarfsgerechten Fütterung und effizienten Nutzung von Nährstoffen. Die heterogenen Betriebsbedingungen lassen keine verallgemeinerten Empfehlungen zu sondern erfordern betriebsspezifische Strategien auf der Grundlage belastbarer Daten, um mögliche Synergieeffekte und Potentiale einer verbesserten Wertschöpfung erschließen zu können. Folglich sind Mängel in der Dokumentation und Datenaufzeichnung ein erhebliches Hemmnis in der Entwicklung betriebsspezifischer Optimierungsstrategien

Transformation Plasmonics

This review article provides the state of the art in the emerging topic of transformation plasmonics, with applications thought in cloaking.International audienceSurface plasmons polaritons (SPPs) at metal/dielectric interfaces have raised lots of expectations in the on-going quest towards scaling down optical devices. SPP optics offers a powerful and flexible platform for real two-dimensional integrated optics, capable of supporting both light and electrons. Yet, a full exploitation of the features of SPPs is conditioned by an accurate control of their flow. Most efforts have so far focused on the extrapolation of concepts borrowed from guided optics. This strategy has already led to many important breakthroughs but a fully deterministic control of SPP modes remains a challenge. Recently, the field of optics was stimulated by a novel paradigm, transformation optics, which offers the capability to control light flow in any desired fashion. While it has already significantly contributed to the design of metamaterials with unprecedented optical properties, its versatility offers new opportunities towards a fully deterministic control of SPPs and the design of a new class of plasmonic functionalities. Here, we review recent progress in the application of transformation optics to SPPs. We first briefly describe the theoretical formalism of transformation plasmonics, focusing on its specificities over its three-dimensional optical counterpart. Numerical simulations are then used to illustrate its capability to tame SPP flows at a metal interface patterned with a dielectric load. Finally, we review recent experimental implementations leading to unique SPP functionalities at optical frequencies

Static Disorder in Excitation Energies of the Fenna-Matthews-Olson Protein: Structure-Based Theory Meets Experiment

Inhomogeneous broadening of optical lines of the Fenna-Matthews-Olson (FMO) light-harvesting protein is investigated by combining a Monte Carlo sampling of low-energy conformational substates of the protein with a quantum chemical/electrostatic calculation of local transition energies (site energies) of the pigments. The good agreement between the optical spectra calculated for the inhomogeneous ensemble and the experimental data demonstrates that electrostatics is the dominant contributor to static disorder in site energies. Rotamers of polar amino acid side chains are found to cause bimodal distribution functions of site energy shifts, which can be probed by hole burning and single-molecule spectroscopy. When summing over the large number of contributions, the resulting distribution functions of the site energies become Gaussians, and the correlations in site energy fluctuations at different sites practically average to zero. These results demonstrate that static disorder in the FMO protein is in the realm of the central limit theorem of statistics. © 2020 American Chemical Society

A Predictive Model for the Pd-Catalyzed Site-Selective Oxidation of Diols

A predictive model, shaped as a set of rules, is presented that predicts site-selectivity in the mono-oxidation of diols by palladium-neocuproine catalysis. For this, the factors that govern this site-selectivity within diols and between different diols have been studied both experimentally and with computation. It is shown that an electronegative substituent antiperiplanar to the C-H bond retards hydride abstraction, resulting in a lower reactivity. This explains the selective oxidation of axial hydroxy groups in vicinal cis-diols. Furthermore, DFT calculations and competition experiments show how the reaction rate of different diols is determined by their configuration and conformational freedom. The model has been validated by the oxidation of several complex natural products, including two steroids. From a synthesis perspective, the model predicts whether a natural product comprising multiple hydroxy groups is a suitable substrate for site-selective palladium-catalyzed oxidation.</p

Enhancing Four-Wave-Mixing Processes by Nanowire Arrays Coupled to a Gold Film

We consider the process of four-wave mixing in an array of gold nanowires strongly coupled to a gold film. Using full-wave simulations, we perform a quantitative comparison of the four-wave mixing efficiency associated with the thin film geometry with and without the nanowire arrays. When the nanowire array is present, both the delocalized surface plasmon of the film as well as the localized surface plasmon resonances of the nanowires contribute to the local field enhancement, yielding an overall FWM efficiency enhancement of up to four orders-of-magnitude over a wide range of excitation angles. The film-coupled nanowire array is easily amenable to nanofabrication, and could find application as an ultra-compact component for integrated photonic and quantum optic systems.Comment: 5 pages, 4 figure

Near-field examination of perovskite-based superlenses and superlens-enhanced probe-object coupling

A planar slab of negative index material works as a superlens with sub-diffraction-limited imaging resolution, since propagating waves are focused and, moreover, evanescent waves are reconstructed in the image plane. Here, we demonstrate a superlens for electric evanescent fields with low losses using perovskites in the mid-infrared regime. The combination of near-field microscopy with a tunable free-electron laser allows us to address precisely the polariton modes, which are critical for super-resolution imaging. We spectrally study the lateral and vertical distributions of evanescent waves around the image plane of such a lens, and achieve imaging resolution of wavelength/14 at the superlensing wavelength. Interestingly, at certain distances between the probe and sample surface, we observe a maximum of these evanescent fields. Comparisons with numerical simulations indicate that this maximum originates from an enhanced coupling between probe and object, which might be applicable for multifunctional circuits, infrared spectroscopy, and thermal sensors.Comment: 20 pages, 6 figures, published as open access article in Nature Communications (see http://www.nature.com/ncomms/

Neue Kennwerte für die Wasserbindung in Böden - Ergebnisse der Abstimmung zwischen dem Personenkreis Wasserhaushaltstabellen der Ad-hoc-AG Boden und dem DWA

Mit den vorliegenden Diagrammen und Tabellen liegen bundesweit abgestimmte Grundlagen für die Einschätzung des Wasser- und Lufthaushaltes von Böden vor. Die Werteschwankungen von Wasserge-halten in verschiedenen Porenbereichen des Bodens können über die graphische Datenauswertung auf der Basis des Korn-größendiagramms schlüssig abgebildet werden. Gegenüber der bodenkundlichen Kartieranleitung (Ad-hoc-AG Boden 2005) liegen folgende Änderungen bzw. Erweiterungen vor: - Schätzrahmen mit Werten für 5 Trockenrohdichten - Schätzrahmen mit Angaben für pF 2,5 - Schätzrahmen mit Angaben für die Frühjahrsfeuchte - Diagramme auf der Basis des Korngrößendreiecks - Erweiterung der Tabelle mit Zuschlägen in Abhängigkeit von der Humusstufe und Bodenart für pF 2,5 Schätzrahmen und Diagramme bieten ein aufeinander abgestimmtes Gesamtpaket für die feldbodenkundliche Arbeit

The bioenergetic role of dioxygen and the terminal oxidase(s) in cyanobacteria

AbstractOwing to the release of 13 largely or totally sequenced cyanobacterial genomes (see http://www.kazusa.or.jp/cyano and www.jgi.doe.gov/), it is now possible to critically assess and compare the most neglected aspect of cyanobacterial physiology, i.e., cyanobacterial respiration, also on the grounds of pure molecular biology (gene sequences). While there is little doubt that cyanobacteria (blue-green algae) do form the largest, most diversified and in both evolutionary and ecological respects most significant group of (micro)organisms on our earth, and that what renders our blue planet earth to what it is, viz. the O2-containing atmosphere, dates back to the oxygenic photosynthetic activity of primordial cyanobacteria about 3.2×109 years ago, there is still an amazing lack of knowledge on the second half of bioenergetic oxygen metabolism in cyanobacteria, on (aerobic) respiration. Thus, the purpose of this review is threefold: (1) to point out the unprecedented role of the cyanobacteria for maintaining the delicate steady state of our terrestrial biosphere and atmosphere through a major contribution to the poising of oxygenic photosynthesis against aerobic respiration (“the global biological oxygen cycle”); (2) to briefly highlight the membrane-bound electron-transport assemblies of respiration and photosynthesis in the unique two-membrane system of cyanobacteria (comprising cytoplasmic membrane and intracytoplasmic or thylakoid membranes, without obvious anastomoses between them); and (3) to critically compare the (deduced) amino acid sequences of the multitude of hypothetical terminal oxidases in the nine fully sequenced cyanobacterial species plus four additional species where at least the terminal oxidases were sequenced. These will then be compared with sequences of other proton-pumping haem–copper oxidases, with special emphasis on possible mechanisms of electron and proton transfer