Drumlins des Drenthe-Stadiums am Nordostrand der Westfälischen Bucht

Am Rande der Westfälischen Bucht liegen bei Versmold und Gütersloh zwei Drumlinfelder. Die zusammen über 60 Rücken, die aus Sand und Geschiebelehm bestehen, wurden durch einen Gletscher des Inlandeises geformt, der aus der Westfälischen Bucht gegen die Randhöhen des Teutoburger Waldes vordrang. Es handelt sich um die Erstbeschreibung von Drumlins im Altmoränengebiet Nordwestdeutschlands.At the border of the Westphalian lowland-bay you can find two drumlin-areas northeast of Versmold and Gütersloh respectively. There are all together more than sixty ridges consisting of sand and moralne, and formed by a glacier of the inland ice coming from the Westphalian lowland-bay and proceeding towards the bordering chain of the Teutoburger Wald hills. This is the first time that drumlins are described in the Saalian old moraines of Northwest Germany

Grobgeschiebestatistik als Hilfsmittel bei der Kartierung eiszeitlicher Halte

Zu den Zielen der Eiszeitforschung gehört das Erfassen der Stillstandslagen des nordischen Inlandeises. Im Tiefland haben sich dabei Morphologie und Leitgeschiebestatistik bewährt. In mittelgebirgigen Landschaften setzen erosive Abtragung der Moränen und fluviatile Umlagerung von Geschieben der Anwendung dieser Methoden oft enge Grenzen. Hier bietet sich als zusätzliche Methode die Grobgeschiebestatistik an. Danach lassen sich glaziale Halte auch aus der Ansammlung von fluviatil nicht transportablen groben nordischen Blöcken in schmalen Streifen im Gelände ablesen. Der Beitrag befaßt sich weiterhin mit den kritischen Einschränkungen des Aussagewertes der Methode, vor allem in Relation zu den herkömmlichen Verfahren. Einige Hinweise sollen der praktischen Arbeit mit der Grobgeschiebestatistik im Gelände dienen.researc

Eine saaleeiszeitliche Mittelmoräne zwischen Teutoburger Wald und Wiehengebirge

In der Arbeit wird erstmals für den nordwestdeutschen Raum eine saaleeiszeitliche Mittelmoräne beschrieben. Ihre Bildung ist eine Folge des Einflusses des Reliefs, besonders der Pässe des Wiehengebirges, auf das von Norden in die Herforder Liasmulde vordringende Inlandeis.researc

Velocity Tails for Inelastic Maxwell Models

We study the velocity distribution function for inelastic Maxwell models, characterized by a Boltzmann equation with constant collision rate, independent of the energy of the colliding particles. By means of a nonlinear analysis of the Boltzmann equation, we find that the velocity distribution function decays algebraically for large velocities, with exponents that are analytically calculated.Comment: 4 pages, 2 figure

Bath generated work extraction and inversion-free gain in two-level systems

The spin-boson model, often used in NMR and ESR physics, quantum optics and spintronics, is considered in a solvable limit to model a spin one-half particle interacting with a bosonic thermal bath. By applying external pulses to a non-equilibrium initial state of the spin, work can be extracted from the thermalized bath. It occurs on the timescale \T_2 inherent to transversal (`quantum') fluctuations. The work (partly) arises from heat given off by the surrounding bath, while the spin entropy remains constant during a pulse. This presents a violation of the Clausius inequality and the Thomson formulation of the second law (cycles cost work) for the two-level system. Starting from a fully disordered state, coherence can be induced by employing the bath. Due to this, a gain from a positive-temperature (inversion-free) two-level system is shown to be possible.Comment: 4 pages revte

Social Preferences and the Efficiency of Bilateral Exchange

Under what conditions do social preferences, such as altruism or a concern for fair outcomes, generate efficient trade? I analyze theoretically a simple bilateral exchange game: Each player sequentially takes an action that reduces his own material payoff but increases the other player’s. Each player’s preferences may depend on both his/her own material payoff and the other player’s. I identify necessary conditions and sufficient conditions on the players’ preferences for the outcome of their interaction to be Pareto efficient. The results have implications for interpreting the rotten kid theorem, gift exchange in the laboratory, and gift exchange in the field

Towards automatic pulmonary nodule management in lung cancer screening with deep learning

The introduction of lung cancer screening programs will produce an unprecedented amount of chest CT scans in the near future, which radiologists will have to read in order to decide on a patient follow-up strategy. According to the current guidelines, the workup of screen-detected nodules strongly relies on nodule size and nodule type. In this paper, we present a deep learning system based on multi-stream multi-scale convolutional networks, which automatically classifies all nodule types relevant for nodule workup. The system processes raw CT data containing a nodule without the need for any additional information such as nodule segmentation or nodule size and learns a representation of 3D data by analyzing an arbitrary number of 2D views of a given nodule. The deep learning system was trained with data from the Italian MILD screening trial and validated on an independent set of data from the Danish DLCST screening trial. We analyze the advantage of processing nodules at multiple scales with a multi-stream convolutional network architecture, and we show that the proposed deep learning system achieves performance at classifying nodule type that surpasses the one of classical machine learning approaches and is within the inter-observer variability among four experienced human observers.Comment: Published on Scientific Report

Spin Motion in Electron Transmission through Ultrathin Ferromagnetic Films Accessed by Photoelectron Spectroscopy

Ab initio and model calculations demonstrate that the spin motion of electrons transmitted through ferromagnetic films can be analyzed in detail by means of angle- and spin-resolved core-level photoelectron spectroscopy. The spin motion appears as precession of the photoelectron spin polarization around and as relaxation towards the magnetization direction. In a systematic study for ultrathin Fe films on Pd(001) we elucidate its dependence on the Fe film thickness and on the Fe electronic structure. In addition to elastic and inelastic scattering, the effect of band gaps on the spin motion is addressed in particular.Comment: 4 pages, 5 figure

Work extraction in the spin-boson model

We show that work can be extracted from a two-level system (spin) coupled to a bosonic thermal bath. This is possible due to different initial temperatures of the spin and the bath, both positive (no spin population inversion) and is realized by means of a suitable sequence of sharp pulses applied to the spin. The extracted work can be of the order of the response energy of the bath, therefore much larger than the energy of the spin. Moreover, the efficiency of extraction can be very close to its maximum, given by the Carnot bound, at the same time the overall amount of the extracted work is maximal. Therefore, we get a finite power at efficiency close to the Carnot bound. The effect comes from the backreaction of the spin on the bath, and it survives for a strongly disordered (inhomogeneously broadened) ensemble of spins. It is connected with generation of coherences during the work-extraction process, and we derived it in an exactly solvable model. All the necessary general thermodynamical relations are derived from the first principles of quantum mechanics and connections are made with processes of lasing without inversion and with quantum heat engines.Comment: 30 pages, 6 figure

Analysis of host responses to Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa.

BACKGROUND: Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. METHODS: We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. RESULTS: There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST(-) and TST(+) contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST(+) contacts (LTBI) compared to TB and TST(-) contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. CONCLUSIONS: Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy trials