The activating receptors 2B4 and NTB-A, but not CRACC are subject to ligand-induced down-regulation on human natural killer cells

Activation of natural killer cells can be mediated by different receptors. Stimulation of the receptors 2B4, NTB-A and CRACC, members of the SLAM-related receptor family, induces cytotoxicity and cytokine production. The surface expression of 2B4 and other activating natural killer cell receptors is down-modulated after receptor engagement, which results in a weaker response to consecutive stimulation. We tested whether this regulatory mechanism applies to all SLAM-related receptors expressed by primary human natural killer cells. After co-culture with target cells expressing the respective ligands different effects on receptor surface expression were observed. While 2B4 ex-pression was strongly reduced, NTB-A showed less prominent down-modulation and the expression level of CRACC remained unchanged. The expression levels of the receptor-proximal signaling molecules SAP, EAT-2 and FynT did not change after receptor engagement. Co-culture with target cells expressing the ligands for NTB-A or CRACC had no impact on subsequent NTB-A or CRACC-mediated NK cell activation

Deploying and Evaluating Pufferfish Privacy for Smart Meter Data (Technical Report)

Information hiding ensures privacy by transforming personalized data so that certain sensitive information cannot be inferred any more. One state-of-the-art information-hiding approach is the Pufferfish framework. It lets the users specify their privacy requirements as so-called discriminative pairs of secrets, and it perturbs data so that an adversary does not learn about the probability distribution of such pairs. However, deploying the framework on complex data such as time series requires application specific work. This includes a general definition of the representation of secrets in the data. Another issue is that the tradeoff between Pufferfish privacy and utility of the data is largely unexplored in quantitative terms. In this study, we quantify this tradeoff for smart meter data. Such data contains fine-grained time series of power-consumption data from private households. Disseminating such data in an uncontrolled way puts privacy at risk. We investigate how time series of energy consumption data must be transformed to facilitate specifying secrets that Pufferfish can use. We ensure the generality of our study by looking at different information-extraction approaches, such as re-identification and non-intrusive-appliance-load monitoring, in combination with a comprehensive set of secrets. Additionally, we provide quantitative utility results for a real-world application, the so-called local energy market

Ecology of the chelid turtles Platemys platycephala, Mesoclemmys gibba and Mesoclemmys nasuta in French Guyana

Obwohl Französisch Guyana ein relative kleines, in Größe mit Österreich vergleichbares, Land ist, zeigt es eine beeindruckende Diversität an Schildkröten: 14 Arten der Ordnung Testudines kommen auf einer Fläche von 86.504 km² vor. Von diesen 14 Arten gehören viele zu wissenschaftlich unterrepräsentierten Familien wie auch die cheliden Schildkröten Mesoclemmys gibba, Mesoclemmys nastua und Platemys platycephala. Diese drei Arten werden regelmäßig in der Reserve Naturelle de Nouragues, einem Schutzgebiet in Französisch Guyana, angetroffen. In dieser Arbeit wird eine zusammenfassende Übersicht von Aspekten der Ökologie dieser drei cheliden Arten gegeben. Jede Art wird detailliert anhand von Vergleichen mit Museumsexemplaren beschrieben. Aufzeichnungen über die Verbreitung in Französisch Guyana wurden in Verbreitungskarten dargestellt. Daten über Habitat und Aktivität, Ernährung und Fortpflanzung aus dem natürlichen Verbreitungsgebiet mit besonderem Fokus auf Französisch Guyana, aquiriert aus der zugänglichen wissenschaftlichen Literatur werden besprochen und verglichen. Wegen des Mangels an Daten zu bestimmten Aspekten der Life-History wie Inkubationsdauer, Paarung und Ernährung wurde auch Liebhaberliteratur mit Daten aus der Haltung einbezogen, allerdings in separaten Kapiteln. Aufzeichnungen über Funde von Mesoclemmys gibba sind hauptsächlich über die küstennahen Gebiete von Französisch Guyana verteilt, aufgrund ihrer pan-amazonischen Verbreitung ist es aber wahrscheinlich, dass die Art auch in den südlichen Teilen des Landes vorkommt. Es handelt sich um eine scheue Spezies, die in ihren Anforderungen an das Habitat nicht besonders beschränkt ist, solange es ein wenig Wasser und typische Futterelemente wie Amphibienlarven, Insekten und Würmer gibt. Algen und Pflanzensamen wurden auch als von wild lebenden Tieren aufgenommene Nahrung berichtet. Mesoclemmys gibba scheint sehr anpassungsfähig an variierende Habitatbedingungen zu sein und es wird auch über Ästivation unter für die Schildkröten ungünstigen Bedingungen berichtet. Unter natürlichen Bedingungen ist kein Paarungsverhalten beschrieben und es gibt nur wenige Daten über Reproduktion in der Natur. Typischerweise werden zwei bis vier Eier in flache Gruben abgelegt und mit Blättern bedeckt. In Französisch Guyana werden die Eier während der Trockenzeit gelegt und Schlüpflinge erscheinen fünf bis sechs Monate später zu Beginn der Regenzeit. Mehrere Berichte über die Haltung und Zucht von M. nasuta in menschlicher Obhut sind vorhanden, die sie als ruhige Art beschreiben, welche sich leicht an die Terrarienhaltung anpasst. Mesoclemmys nasuta ist eine endemische Art für den Guyanaschild und wird seit 1987 als eigenständig von der nah verwandten Art M. raniceps angesehen. Daher muss beim Lesen der älteren Literatur Vorsicht geboten sein, um nicht Daten von Guyana-Populationen mit denen von außerhalb Französisch Guyanas zu vermischen. Die Art kann in kleinen Waldbächen und Tümpeln im gesamten Land angetroffen werden, aber wegen ihrer versteckten Lebensweise sind Beobachtungen selten. M. nasuta scheint eng and Wasserkörper einer gewissen Größe gebunden zu sein, denn es gibt keine Berichte von über Land wandernden oder ästivierenden Tieren. Kotanalysen von frisch gefangenen Tieren zeigten, dass Krabben, Käfer und Teile von Früchten, Pflanzen und Samen als Nahrungsquelle genutzt werden. Daten über Paarung und Fortpflanzung in der Natur sowie in der Haltung sind nicht vorhanden. Wie auch M. gibba ist auch Platemys platycephala eine Art mit einer weitreichenden Verbreitung über das gesamte amazonische Südamerika. Sie ist von mehreren über Französisch Guyana verteilten Lokalitäten bekannt, scheint aber Wälder mit geschlossenem Kronendach und temporäre Tümpel zu bevorzugen. Beobachtungen an wildlebenden Exemplaren werden oftmals gemacht, während sie nach Nahrung suchen, was hauptsächlich in kleinen Wasserkörpern passiert. Zum Ruhen suchen sich die Tiere umgefallene Baumstämme aus oder graben sich in Blätter an der Wurzel eines Baumes ein. Niederschlag scheint eine bedeutende Rolle im Leben von P. platycephala zu spielen und es wird vermutet, dass die Art während der Trockenzeit ästiviert. Keine direkten Beobachtungen der Nahrungsaufnahme sind derzeit in der Literatur vorhanden, aber Magenspülungen und Beobachtungen an Exemplaren in menschlicher Obhut weisen darauf hin, dass sie sich von Kaulquappen, Amphibieneiern, kleinen Insekten und Würmern ernähren. Ein Paarungsverhalten ist in der Natur und in menschlicher Obhut beschrieben. Weibchen legen nur ein einzelnes Ei pro Gelege ab, aber mehrere Gelege pro Saison sind möglich. Die Inkubationszeit in der Natur ist unbekannt, aber in der Haltung erscheinen Schlüpflinge nach ungefähr 180 Tagen.Although French Guyana is a relatively small country, comparable in size to Austria, its turtle diversity is impressive: 14 species of the order Testudines occur over an area of 86.504 km². Of these 14 species, many belong to scientifically underrepresented families such as the chelid turtles Mesoclemmys gibba, Mesoclemmys nasuta and Platemys platycephala. These three species are regularly recorded in the Reserve Naturelle de Nouragues, a forest reserve in French Guyana. In this thesis, a comprehensive review of aspects of the ecology of these three chelid species is given. Every species is described in detail by comparing museum specimens. Distribution records in French Guyana are compiled for composition of distribution maps. Data on habitat and activity, feeding and reproduction from their native range with special focus on French Guyana, acquired from available scientific literature are reviewed and compared. Because of lack of data of certain aspects of life history like incubation period, mating and feeding, also hobbyist literature with data from captive husbandry is incorporated in separate chapters. Records of Mesoclemmys gibba are dispersed mainly along the coast of French Guyana, but because of its pan-amazonian distribution it is likely that the species also occurs in the southern parts of the country. It is a shy species that doesn’t seem to be constricted to any specific habitat as long as there is some fresh water and typical food items such as amphibian larvae, insects and worms. Algae and plant seeds are also reported to be ingested by free-ranging specimens. M. gibba seems to be very adaptable to varying habitat conditions and is also reported to aestivate if necessary. Mating behaviour is not described under natural conditions and data on natural reproduction are scarce. Typically, two to four eggs are laid in shallow cavities and covered with leaves. In French Guyana, eggs are deposited during the dry season and hatchlings emerge five to six months later at the start of the rainy season. Several reports of keeping and breeding M. gibba under captive conditions are available which describe it as a gentle species which adapts easily. Mesoclemmys nasuta is an endemic species of the Guyana Shield and is considered a separate species of the closely related species M. raniceps since 1987. Therefore older literature has to be read carefully to avoid mixing up data from guyanian populations with populations from outside of French Guyana. The species is found in small forest streams and ponds all over the country, but because of its hidden lifestyle, observations are rare. M. nasuta seems to be closely bound to water bodies of a certain size, because there are no records of specimens migrating over land or reports on aestivating specimens. Fecal analyses of freshly caught specimens showed that crabs, beetles and parts of fruits, plants and seeds are used as food sources. Data on mating and reproduction are absent from the field and from captivity. Like M. gibba, Platemys platycephala is a species with a wide-ranging distribution all over amazonian South America. It is known from several locations spread over French Guyana, but seems to prefer forests with closed canopy and temporary ponds. Observations on specimens in the field are often made when they are foraging for food, which is mostly done in small waterbodies. For resting, specimens will chose fallen trees or bury themselves under leaves at the roots of trees. Rainfall seems to play an important role in the life of P. platycephala and the species is suspected to aestivate during the dry season. No direct observations on feeding are currently reported, but stomach flushings and observations on captive specimens indicate that they feed on tadpoles, amphibian eggs, small insects and worms. Mating behaviour is described under natural and captive conditions. Females will lay only one single egg per clutch, but multiple clutches per season are possible. Incubation time in the field is unknown, but in captivity hatchlings emerge after approximately 180 days

Pattern-sensitive Time-series Anonymization and its Application to Energy-Consumption Data

Time series anonymization is an important problem. One prominent example of time series are energy consumption records, which might reveal details of the daily routine of a household. Existing privacy approaches for time series, e.g., from the field of trajectory anonymization, assume that every single value of a time series contains sensitive information and reduce the data quality very much. In contrast, we consider time series where it is combinations of tuples that represent personal information. We propose (n; l; k)-anonymity, geared to anonymization of time-series data with minimal information loss, assuming that an adversary may learn a few data points. We propose several heuristics to obtain (n; l; k)-anonymity, and we evaluate our approach both with synthetic and real data. Our experiments confirm that it is sufficient to modify time series only moderately in order to fulfill meaningful privacy requirements

Two-photon interference from remote deterministic quantum dot microlenses

This article may be downloaded for personal use only. Any other use requires prior permission of the author and AIP Publishing. This article appeared in Appl. Phys. Lett. 110, 011104 (2017) and may be found at https://doi.org/10.1063/1.4973504.We report on two-photon interference (TPI) experiments using remote deterministic single-photon sources. Employing 3D in-situ electron-beam lithography, we fabricate quantum-light sources at specific target wavelengths by integrating pre-selected semiconductor quantum dots within monolithic microlenses. The individual single-photon sources show TPI visibilities of 49% and 22%, respectively, under pulsed p-shell excitation at 80 MHz. For the mutual TPI of the remote sources, we observe an uncorrected visibility of 29%, in quantitative agreement with the pure dephasing of the individual sources. Due to its efficient photon extraction within a broad spectral range (>20 nm), our microlens-based approach is predestinated for future entanglement swapping experiments utilizing entangled photon pairs emitted by distant biexciton-exciton radiative cascades.DFG, 43659573, SFB 787: Halbleiter - Nanophotonik: Materialien, Modelle, BauelementeEC/FP7/615613/EU/External Quantum Control of Photonic Semiconductor Nanostructures/EXQUISIT

Clinical trial updates and hotline sessions presented at the European Society of Cardiology Congress 2008

This article summarizes the results of a number of clinical trials in the field of cardiovascular medicine which were presented during the Hotline and Clinical Trial Update Sessions at the annual meeting of the European Society of Cardiology, held in Munich, Germany, from 30th August to 3rd September 2008. The data were presented by leading experts in the field with relevant positions in the trials. It is important to note that unpublished reports should be considered as preliminary data, as the analysis may change in the final publications. The comprehensive summaries have been generated from the oral presentation and the webcasts of the European Society of Cardiology and should provide the readers with the most comprehensive information on diagnostic and therapeutic developments in cardiovascular medicine

MAPPING THE SURROUNDINGS AS A REQUIREMENT FOR AUTONOMOUS DRIVING

Motivated by the hype around driverless cars and the challenges of the sensor integration and data processing, this paper presents a model for using a XBox One Microsoft Kinect stereo camera as sensor for mapping the surroundings. Today, the recognition of the environment of the car is mostly done by a mix of sensors like LiDAR, RADAR and cameras. In the case of the outdoor delivery challenge Robotour 2016 with model cars in scale 1:5, it is our goal to solve the task with one camera only. To this end, a three-stage approach was developed. The test results show that our approach can detect and locate objects at a range of up to eight meters in order to incorporate them as barriers in the navigation process

Overcoming Bias: Equivariant Filter Design for Biased Attitude Estimation with Online Calibration

Stochastic filters for on-line state estimation are a core technology for autonomous systems. The performance of such filters is one of the key limiting factors to a system's capability. Both asymptotic behavior (e.g.,~for regular operation) and transient response (e.g.,~for fast initialization and reset) of such filters are of crucial importance in guaranteeing robust operation of autonomous systems. This paper introduces a new generic formulation for a gyroscope aided attitude estimator using N direction measurements including both body-frame and reference-frame direction type measurements. The approach is based on an integrated state formulation that incorporates navigation, extrinsic calibration for all direction sensors, and gyroscope bias states in a single equivariant geometric structure. This newly proposed symmetry allows modular addition of different direction measurements and their extrinsic calibration while maintaining the ability to include bias states in the same symmetry. The subsequently proposed filter-based estimator using this symmetry noticeably improves the transient response, and the asymptotic bias and extrinsic calibration estimation compared to state-of-the-art approaches. The estimator is verified in statistically representative simulations and is tested in real-world experiments.Comment: to be published in Robotics and Automation Letter

Deploying and Evaluating Pufferfish Privacy for Smart Meter Data (Technical Report \u2715)

Information hiding ensures privacy by transforming personalized data so that certain sensitive information cannot be inferred any more. One state-of-the-art information-hiding approach is the Pufferfish framework. It lets the users specify their privacy requirements as so-called discriminative pairs of secrets, and it perturbs data so that an adversary does not learn about the probability distribution of such pairs. However, deploying the framework on complex data such as time series requires application specific work. This includes a general definition of the representation of secrets in the data. Another issue is that the tradeoff between Pufferfish privacy and utility of the data is largely unexplored in quantitative terms. In this study, we quantify this tradeoff for smart meter data. Such data contains fine-grained time series of power-consumption data from private households. Disseminating such data in an uncontrolled way puts privacy at risk. We investigate how time series of energy consumption data must be transformed to facilitate specifying secrets that Pufferfish can use. We ensure the generality of our study by looking at different information-extraction approaches, such as re-identification and non-intrusive-appliance-load monitoring, in combination with a comprehensive set of secrets. Additionally, we provide quantitative utility results for a real-world application, the so-called local energy market