Distributions of electron waiting times in quantum-coherent conductors

The distribution of electron waiting times is useful to characterize quantum transport in mesoscopic structures. Here we consider a generic quantum-coherent conductor consisting of a mesoscopic scatterer in a two-terminal setup. We extend earlier results for single-channel conductors to setups with several (possibly spin-degenerate) conduction channels and we discuss the effect of a finite electronic temperature. We present detailed investigations of the electron waiting times in a quantum point contact as well as in two mesoscopic interferometers with energy-dependent transmissions: a Fabry-P\'erot interferometer and a Mach-Zehnder interferometer. We show that the waiting time distributions allow us to determine characteristic features of the scatterers, for instance the number of resonant levels in the Fabry-P\'erot interferometer that contribute to the electronic transport.Comment: 13 pages, 11 figure

Permission-Based Separation Logic for Multithreaded Java Programs

This paper motivates and presents a program logic for reasoning about multithreaded Java-like programs with concurrency primitives such as dynamic thread creation, thread joining and reentrant object monitors. The logic is based on concurrent separation logic. It is the first detailed adaptation of concurrent separation logic to a multithreaded Java-like language. The program logic associates a unique static access permission with each heap location, ensuring exclusive write accesses and ruling out data races. Concurrent reads are supported through fractional permissions. Permissions can be transferred between threads upon thread starting, thread joining, initial monitor entrancies and final monitor exits.\ud This paper presents the basic principles to reason about thread creation and thread joining. It finishes with an outlook how this logic will evolve into a full-fledged verification technique for Java (and possibly other multithreaded languages)

Permission-Based Separation Logic for Multithreaded Java Programs

This paper presents a program logic for reasoning about multithreaded Java-like programs with dynamic thread creation, thread joining and reentrant object monitors. The logic is based on concurrent separation logic. It is the first detailed adaptation of concurrent separation logic to a multithreaded Java-like language. The program logic associates a unique static access permission with each heap location, ensuring exclusive write accesses and ruling out data races. Concurrent reads are supported through fractional permissions. Permissions can be transferred between threads upon thread starting, thread joining, initial monitor entrancies and final monitor exits. In order to distinguish between initial monitor entrancies and monitor reentrancies, auxiliary variables keep track of multisets of currently held monitors. Data abstraction and behavioral subtyping are facilitated through abstract predicates, which are also used to represent monitor invariants, preconditions for thread starting and postconditions for thread joining. Value-parametrized types allow to conveniently capture common strong global invariants, like static object ownership relations. The program logic is presented for a model language with Java-like classes and interfaces, the soundness of the program logic is proven, and a number of illustrative examples are presented

Surface Modification of Membranes for Fouling Reduction

Despite great effort that has been made to reduce and understand fouling, this phenomenon is still a major problem in membrane applications. Numerous methods, both from a chemical and engineering point of view, have been introduced to overcome this problem. In this contribution, we report on the modification of membranes with polyelectrolytes and polyelectrolyte multilayers utilizing two of the mentioned strategies. The effect of surface modification on the fouling behavior as well as on the critical flux will be discussed on two examples, microfiltration membranes and RO membranes

A consistent BGK model with velocity-dependent collision frequency for gas mixtures

We derive a multi-species BGK model with velocity-dependent collision frequency for a non-reactive, multi-component gas mixture. The model is derived by minimizing a weighted entropy under the constraint that the number of particles of each species, total momentum, and total energy are conserved. We prove that this minimization problem admits a unique solution for very general collision frequencies. Moreover, we prove that the model satisfies an H-Theorem and characterize the form of equilibrium

Electron Waiting Times in Mesoscopic Conductors

Electron transport in mesoscopic conductors has traditionally involved investigations of the mean current and the fluctuations of the current. A complementary view on charge transport is provided by the distribution of waiting times between charge carriers, but a proper theoretical framework for coherent electronic systems has so far been lacking. Here we develop a quantum theory of electron waiting times in mesoscopic conductors expressed by a compact determinant formula. We illustrate our methodology by calculating the waiting time distribution for a quantum point contact and find a cross-over from Wigner-Dyson statistics at full transmission to Poisson statistics close to pinch-off. Even when the low-frequency transport is noiseless, the electrons are not equally spaced in time due to their inherent wave nature. We discuss the implications for renewal theory in mesoscopic systems and point out several analogies with energy level statistics and random matrix theory.Comment: 4+ pages, 3 figure

Mass cannibalism in the Linear Pottery Culture at Herxheim (Palatinate, Germany)

The Early Neolithic central place at Herxheim is defined by a perimeter of elongated pits containing fragments of human bone, together with pottery imported from areas several hundred kilometres distant. This article offers a context for the centre, advancing strong evidence that the site was dedicated to ritual activities in which cannibalism played an important par

Real-Life Study for the Diagnosis of House Dust Mite Allergy - The Value of Recombinant Allergen-Based IgE Serology

Background: Dermatophagoides pteronyssinus is one of the most important perennial allergen sources worldwide. Molecular diagnostics using the commercially available major allergens (Der p 1 and Der p 2) in combination with Der p 10 do not detect house dust mite (HDM) sensitization in a number of cases when used alone. The objective was to evaluate the IgE reactivity profiles of these patients using an experimental immunoassay biochip. Methods: Sera of HDM-allergic patients (positive skin prick test, CAP class 1 for allergen extract, and positive intranasal provocation) were tested for IgE antibodies against Der p 1, Der p 2, and Der p 10 by ImmunoCAP fluorescence enzyme immunoassay. Negatively tested sera were examined by an experimental chip containing 13 microarrayed HDM allergens. Results: Of 97 patients tested, 16 showed negative results to Der p 1, Der p 2, and Der p 10. MeDALL chip evaluation revealed 5 patients mono-sensitized to Der p 23, and 11 patients were negative for all HDM MeDALL chip components. Seven sera were available for further testing, and 3 of them showed IgE reactivity to dot-blotted nDer p 1, and 2 reacted with high-molecular weight components (>100 kDa) in nitrocellulose-blotted HDM extract when tested with 1251-labeled anti-IgE in a RAST-based assay. The HDM extract-specific IgE levels of the 11 patients were <3.9 kU/I. Conclusions: Recombinant allergen-based IgE serology is of great value when conventional IgE diagnostics fails. Der p 23 is an important HDM allergen, especially when major allergens are negative. Therefore, it would be desirable to have Der p 23 commercially available. Further research concerning the prevalence and clinical significance of different HDM allergens is needed. (C) 2016 S. Karger AG, Base

The Janthinobacterium sp. HH01 genome encodes a homologue of the V. cholerae CqsA and L. pneumophila LqsA autoinducer synthases

Janthinobacteria commonly form biofilms on eukaryotic hosts and are known to synthesize antibacterial and antifungal compounds. Janthinobacterium sp. HH01 was recently isolated from an aquatic environment and its genome sequence was established. The genome consists of a single chromosome and reveals a size of 7.10 Mb, being the largest janthinobacterial genome so far known. Approximately 80% of the 5,980 coding sequences (CDSs) present in the HH01 genome could be assigned putative functions. The genome encodes a wealth of secretory functions and several large clusters for polyketide biosynthesis. HH01 also encodes a remarkable number of proteins involved in resistance to drugs or heavy metals. Interestingly, the genome of HH01 apparently lacks the N-acylhomoserine lactone (AHL)-dependent signaling system and the AI-2-dependent quorum sensing regulatory circuit. Instead it encodes a homologue of the Legionella- and Vibrio-like autoinducer (lqsA/cqsA) synthase gene which we designated jqsA. The jqsA gene is linked to a cognate sensor kinase (jqsS) which is flanked by the response regulator jqsR. Here we show that a jqsA deletion has strong impact on the violacein biosynthesis in Janthinobacterium sp. HH01 and that a jqsA deletion mutant can be functionally complemented with the V. cholerae cqsA and the L. pneumophila lqsA genes

Response of Common and Rare Beetle Species to Tree Species and Vertical Stratification in a Floodplain Forest

Vertical stratification and host tree species are factors with a high influence on the structure of communities of xylobiont beetles. However, little is known about how this influence varies between common and rare species. Based on estimated species richness, we compared alpha and beta diversity patterns of common and rare species in the canopy of the Leipzig floodplain forest to assess their response to vertical stratification and tree species. We used two measures of rarity: threat level in red lists and abundance based on octaves. The understory displayed a significantly higher number of common species than the canopy strata. Conversely, the canopy strata harbored a higher number of rare species. Turnover was always dominant over richness differences in beta diversity partitions. Using Raup–Crick null models and non-metric multidimensional scaling, we found that the vertical strata accounted for 19% of the overall beta diversity of common species and for 15% of the overall beta diversity of rare species. The tree species accounted for 7% of the overall beta diversity of the common species and 3% of the beta diversity of the rare species. Our results indicate that studies carried out in the understory alone do not allow drawing conclusions regarding the biodiversity in the canopy strata, and thus regarding the overall community structure of xylobiont beetles in the canopy.This study is kindly supported by the German Centre for Integrative Biodiversity Research (iDiv) Halle-Jena-Leipzig, funded by the German Research Foundation (FZT 118). The Article processing charges were funded by the Open Science Office of the Leipzig University Library.info:eu-repo/semantics/publishedVersio