Exciton-polaritons gas as a nonequilibrium coolant

Using angle-resolved Raman spectroscopy, we show that a resonantly excited ground-state exciton-polariton fluid behaves like a nonequilibrium coolant for its host solid-state semiconductor microcavity. With this optical technique, we obtain a detailed measurement of the thermal fluxes generated by the pumped polaritons. We thus find a maximum cooling power for a cryostat temperature of $50$K and below where optical cooling is usually suppressed, and we identify the participation of an ultrafast cooling mechanism. We also show that the nonequilibrium character of polaritons constitutes an unexpected resource: each scattering event can remove more heat from the solid than would be normally allowed using a thermal fluid with normal internal equilibration.Comment: 5 pages, 3 figures + supplemental materia

Wirkung und Verträglichkeit von Herbiziden in Solanum sisymbriifolium

Solanum sisymbriifolium, auch Litchitomate genannt, wurde im Rahmen des „Gemeinschaftsprojektes zur Erhaltung und Förderung eines zukunftsfähigen Frühkartoffelanbaues in Rheinland-Pfalz“ erfolgreich als Feindpflanze von Kartoffelzystennematoden (Globodera rostochiensis) im praktischen Anbau getestet. Das Wärme liebende Nachtschattengewächs zeichnet sich durch eine extrem langsame Jugendentwicklung und geringer Konkurrenzfähigkeit gegen Unkraut aus. Der erfolgreiche Anbau ist daher in hohem Maße abhängig von einer sicheren Unkrautbekämpfung. 2016 wurden Feldversuche (konventionell und logarithmisch) angelegt um das wirksame und verträgliche Mittelspektrum einzugrenzen. Im Herbizidparzellenversuch wurden alle Bodenherbizide mit einem Glyphosatmittel kombiniert, um größere Pflanzen noch sicher eliminieren zu können. Die Verträglichkeit war limitierender Faktor bei den Bodenwirkstoffen. Im Parzellenversuch verursachte Biathlon (Tritosulfuron) im Nachauflauf sehr ausgeprägte Wuchsdepressionen. Boxer (Prosulfocarb) war in voller Aufwandmenge und Novitron (Aclonifen+Clomazone) ab ¾ Feldaufwand ebenfalls kritisch in der Verträglichkeit. Als vergleichsweise gut verträglich erwiesen sich Centium (Clomazone) mit 0,25 l/ha, Bandur (Aclonifen) mit 1,0 l/ha, Novitron mit 0,9 kg/ha, Proman (Metobromuron) mit 1,0 kg/ha und die Spritzfolge Bandur/Cato (Aclonifen/Rimsulfuron) mit 1,0 l/0,01 g pro ha. Im logarithmischen Versuch wird ersichtlich, dass die Grenzaufwandmenge für Novitron bei etwa 1,0 kg/ha, für Bandur bei etwa 2,0 l/ha und für Proman bei ungefähr 1,0 kg/ha liegt. Sehr enge Grenzen sind gesteckt bei Sencor Liquid und Stomp Aqua, bei denen schon 0,1 l/ha mehr oder weniger über Totalausfall entscheiden. Die meisten Arten der vorhandenen Unkrautflora wurden von allen Herbiziden sicher erfasst. Eine Ausnahme bildete das Kreuzkraut, welches in verträglichem Rahmen nur von Centium erfasst wurde

Not All Data Are Created Equal: Lessons From Sampling Theory For Adaptive Machine Learning

In survey methodology, inverse probability weighted (Horvitz-Thompson) estimation has become an indispensable part of statistical inference. This is triggered by the need to deal with complex samples, that is, non-identically distributed data. The general idea is that weighting observations inversely to their probability of being included in the sample produces unbiased estimators with reduced variance. In this work, we argue that complex samples are subtly ubiquitous in two promising subfields of data science: Self-Training in Semi-Supervised Learning (SSL) and Bayesian Optimization (BO). Both methods rely on refitting learners to artificially enhanced training data. These enhancements are based on pre-defined criteria to select data points rendering some data more likely to be added than others. We experimentally analyze the distance from the so-produced complex samples to i.i.d. samples by Kullback-Leibler divergence and maximum mean discrepancy. What is more, we propose to handle such samples by inverse probability weighting. This requires estimation of inclusion probabilities. Unlike for some observational survey data, however, this is not a major issue since we excitingly have tons of explicit information on the inclusion mechanism. After all, we generate the data ourselves by means of the selection criteria. To make things more tangible, consider the case of BO first. It optimizes an unknown function by iteratively approximating it through a surrogate model, whose mean and standard error estimates are scalarized to a selection criterion. The arguments of this criterion's optima are evaluated and added to the training data. We propose to weight them by means of the surrogate model's standard errors at time of selection. For the case of deploying random forests as surrogate models, we refit them by weighted drawing in the bootstrap sampling step. Refitting may be done iteratively aiming at speeding up the optimization or after convergence aiming at providing applicants with a (global) interpretable surrogate model. Similarly, self-training in SSL selects instances from a set of unlabeled data, predicts its labels and adds these pseudo-labeled data to the training data. Instances are selected according to a confidence measure, e.g. the predictive variance. Regions in the feature space where the model is very confident are thus over-represented in the selected sample. We again explicitly exploit the selection criteria to define weights which we use for resampling-based refitting of the model. Somewhat counter-intuitively, the more confident the model is in the self-assigned labels, the lower their weights should be to counteract the selection bias. Preliminary results suggest this can increase generalization performance

Wrist-worn pervasive gaze interaction

This paper addresses gaze interaction for smart home control, conducted from a wrist-worn unit. First we asked ten people to enact the gaze movements they would propose for e.g. opening a door or adjusting the room temperature. On basis of their suggestions we built and tested different versions of a prototype applying off-screen stroke input. Command prompts were given to twenty participants by text or arrow displays. The success rate achieved by the end of their first encounter with the system was 46% in average; it took them 1.28 seconds to connect with the system and 1.29 seconds to make a correct selection. Their subjective evaluations were positive with regard to the speed of the interaction. We conclude that gaze gesture input seems feasible for fast and brief remote control of smart home technology provided that robustness of tracking is improved

TYK2 inhibition and its potential in the treatment of chronic inflammatory immune diseases

Immune-mediated chronic inflammatory diseases have emerged as a leading cause of morbidity and mortality in Western countries over the last decades. Although multiple putative factors have been suspected to be causally related to the diseases, their overarching etiology remains unknown. This review article summarizes the current state of scientific knowledge and understanding of the role of non-receptor tyrosine kinases, with a special focus on the Janus kinase TYK2 in autoimmune and immune mediated diseases as well as on the clinical properties of its inhibition. A panel of experts in the field discussed the scientific evidence and molecular rationale for TYK2 inhibition and its clinical application. Reviewing this meeting, we aim at providing an integrated overview of the clinical profile of TYK2 inhibition and its potential in targeted pharmacological therapy of chronic autoimmune and immune-mediated diseases, with a special focus on inflammatory diseases of the skin

Efficiency and timing performance of the MuPix7 high-voltage monolithic active pixel sensor

The MuPix7 is a prototype high voltage monolithic active pixel sensor with 103 times 80 um2 pixels thinned to 64 um and incorporating the complete read-out circuitry including a 1.25 Gbit/s differential data link. Using data taken at the DESY electron test beam, we demonstrate an efficiency of 99.3% and a time resolution of 14 ns. The efficiency and time resolution are studied with sub-pixel resolution and reproduced in simulations.Comment: 7 pages, 13 figures, submitted to Nucl.Instr.Meth.

Affective Aspects of Perceived Loss of Control and Potential Implications for Brain-Computer Interfaces

Most brain-computer interfaces (BCIs) focus on detecting single aspects of user states (e.g., motor imagery) in the electroencephalogram (EEG) in order to use these aspects as control input for external systems. This communication can be effective, but unaccounted mental processes can interfere with signals used for classification and thereby introduce changes in the signal properties which could potentially impede BCI classification performance. To improve BCI performance, we propose deploying an approach that potentially allows to describe different mental states that could influence BCI performance. To test this approach, we analyzed neural signatures of potential affective states in data collected in a paradigm where the complex user state of perceived loss of control (LOC) was induced. In this article, source localization methods were used to identify brain dynamics with source located outside but affecting the signal of interest originating from the primary motor areas, pointing to interfering processes in the brain during natural human-machine interaction. In particular, we found affective correlates which were related to perceived LOC. We conclude that additional context information about the ongoing user state might help to improve the applicability of BCIs to real-world scenarios

Structural control, evolution, and accumulation rates of massive sulfides in the TAG hydrothermal field

The Trans‐Atlantic Geotraverse (TAG) hydrothermal field on the Mid‐Atlantic Ridge is one of the best‐studied hydrothermal systems to date. However, high‐resolution bathymetric data obtained in 2016 by an autonomous underwater vehicle (AUV) reveal new information about the distribution of active and inactive hydrothermal deposits, and their relation to structural features. The discovery of previously undocumented inactive vent sites contributes to a better understanding of the accumulation rates and the resource potential of seafloor massive sulfide deposits at slow‐spreading ridges. The interpretation of ship‐based and high‐resolution AUV‐based data sets allowed for the determination of the main tectonic stress regimes that have a first‐order control on the location and distribution of past and present hydrothermal activity. The data reveal the importance of cross‐cutting lineament populations and temporal variations in the prevalent stress regime. A dozen sulfide mounds contribute to a substantial accumulation of hydrothermal material (~29 Mt). The accumulation rate of ~1,500 t/yr is comparable to those of other modern seafloor vent fields. However, our observations suggest that the TAG segment is different from many other slow‐spreading ridge segments in its tectonic complexity, which confines sulfide formation into a relatively small area and is responsible for the longevity of the hydrothermal system and substantial mineral accumulation. The inactive and weakly active mounds contain almost 10 times the amount of material as the active high‐temperature mound, providing an important indication of the global resource potential for inactive seafloor massive sulfide deposits