Qube - A CubeSat for Quantum Key Distribution Experiments

In a world of global satellite communication networks, it is crucial to ensure the security of these data links. QUBE is a project that will develop and launch a CubeSat for the downlink of strongly attenuated light pulses, with encoded quantum information, which can be used for the exchange of encryption keys. This 3U Pico-Satellite will be built using the UNISEC-Europe standard, which has been proven to provide a robust framework for increased reliability for CubeSat missions. In addition to advanced reaction wheels for precision pointing, the satellite will be carrying the DLR-OSIRIS optical downlink system as well as dedicated payloads for testing components required for quantum key distribution. A miniaturized quantum random number generator (QRNG) will create a sequence of numbers, which can be used to set the quantum states of the light. The light pulses will then be downlinked to the optical ground station at DLR in Oberpfaffenhofen, Germany, which is equipped with the corresponding components for receiving the quantum states. Additionally, the random numbers will partially be made available via an RF downlink. This will allow evaluating the link loss as well as the noise and errors in the transmission of quantum signals. In QKD, due to the underlying quantum mechanics, any attempt of reading the quantum states will alter them, which makes interceptions easily detectable. The quantum communication experiments will evaluate whether secure communication links are possible even on a CubeSat scale. A major challenge for building the required CubeSat is the attitude determination and control system that will provide precise pointing. This work will outline detailed mission requirements as well as the chosen subsystems for tackling these challenges in order to deliver a successful mission

The TAMARIW Mission: A Pioneering CubeSat Rendezvous and Docking Experiment

TAMARIW consists of two 3U satellites that will be launched in a docked state as a single 6U. Each side houses identical components, which enable them to act independently, once seperated. The mission is planned for a 2025 launch

Musikalisch-improvisatorischer Ausdruck und Erkennen von Gefühlsqualitäten

Improvisationen als eine Form spontanen musikalischen Ausdrucks intrapsychischer Prozesse eröffnen wegen ihrer hohen Authentizität Zugänge zu sonst schwer erreichbaren Tiefendimensionen menschlichen Erlebens. Untersucht wurde die Frage, ob das gefühlsmäßige Erleben von Laien in Improvisationen auf dem Xylophon seinen komprimierten musikalischen Ausdruck findet und Zuhörern auf diese Weise erfassbar gemacht werden kann. Zu diesem Zweck wurde eine zweiteilige empirische Untersuchung durchgeführt: 20 Gymnasiast(inn)en improvisierten zu drei Grundgefühlen (Wut, Trauer, Freude) auf dem Xylophon; 74 Versuchspersonen hatten später die Improvisationen diesen Gefühlen richtig zuzuordnen. Dies gelang überzufällig häufig. Wesentliches Fazit dieser Untersuchung ist der Nachweis des intersubjektiv erkennbaren Ausdrucks des augenblicklichen Gefühlserlebens oder gefühlsbezogener Vorstellungen in Improvisationen Erwachsener ohne musikalische Professionalität. Dies ist von ausdruckspsychologischer Bedeutung, hat aber auch Implikationen für die klinisch-psychologische Diagnostik und Psychotherapie unter besonderer Berücksichtigung musiktherapeutischer Vorgehensweisen.Improvisations as a form of the spontaneous musical expression of intrapsychological processes offer accesses to otherwise difficultly reachable depth dimensions of human experience because of their high authenticity. It was investigated whether the emotional experience of laymen will be concisely put in improvisations on the xylophone and so made recordable for listeners. 20 grammar school pupils expressed three basis feelings (anger, sadness, joy) in improvisations on the xylophone; later 74 subjects had to assign correctly the improvisations to these feelings. They managed it outstandingly often. This study has proved the intersubjectively recognizable experience of feelings or images related to feelings in improvisations of adults without musical professionality. This is relevant to the psychology of expression and has also implications for the diagnostic in clinical psychology and psychotherapy especially considering procedures in music therapy

Lysine 63-Polyubiquitination Guards against Translesion Synthesis–Induced Mutations

Eukaryotic cells possess several mechanisms to protect the integrity of their DNA against damage. These include cell-cycle checkpoints, DNA-repair pathways, and also a distinct DNA damage–tolerance system that allows recovery of replication forks blocked at sites of DNA damage. In both humans and yeast, lesion bypass and restart of DNA synthesis can occur through an error-prone pathway activated following mono-ubiquitination of proliferating cell nuclear antigen (PCNA), a protein found at sites of replication, and recruitment of specialized translesion synthesis polymerases. In yeast, there is evidence for a second, error-free, pathway that requires modification of PCNA with non-proteolytic lysine 63-linked polyubiquitin (K63-polyUb) chains. Here we demonstrate that formation of K63-polyUb chains protects human cells against translesion synthesis–induced mutations by promoting recovery of blocked replication forks through an alternative error-free mechanism. Furthermore, we show that polyubiquitination of PCNA occurs in UV-irradiated human cells. Our findings indicate that K63-polyubiquitination guards against environmental carcinogenesis and contributes to genomic stability

Fundamentally secure data with the help of quantum key distribution on CubeSats

With the uprise of worldwide satellite communication networks, data security is a critical issue. This issue is being addressed in the QUBE project, which proposes a CubeSat for quantum cryptography experiments. The satellite and its subsystems are currently being developed and will be used for the downlink of individual photons, or strongly attenuated light pulses, containing encoded quantum information, which can then be employed for the exchange of encryption keys. The launch of the 3U Nanosatellite is planned for early 2020. It will be built using the UNISEC-Europe standard, which has demonstrated to be able to provide a robust structure for increased reliability in CubeSat missions. In addition to state-of-the-art reaction wheels for precision pointing, the satellite will be bringing the OSIRIS optical downlink system from DLR as well as two dedicated payloads for testing components required for quantum key distribution. A sequence of numbers will be created by a miniaturized quantum random number generator (QRNG), which will be used to set the quantum states of the light pulses. These pulses will then be downlinked to the optical ground station (OGS) at DLR in Oberpfaffenhofen, Germany. The ground station is also equipped with the corresponding components for receiving individual quantum states. In addition, the random numbers will be made available via an RF downlink. The photon states received by the optical ground station will then be compared to the previously generated numbers. Due to the underlying quantum mechanics, any attempt of reading the quantum states will alter them, which makes interceptions easily detectable. These quantum key distribution experiments will evaluate whether secure communication links are possible even on a CubeSat scale. A major challenge for building the proposed CubeSat is the attitude determination and control system that will provide precise pointing. This work will outline detailed mission requirements as well as the chosen subsystems for tackling these challenges in order to achieve a successful mission and prepare for future data security

QUBE – Quantum Key Distribution with CubeSat

QUBE (Quantum Key Distribution with CubeSat) is one out of three pilot projects in the frame of the national German initiative QUTEGA to promote quantum technologies. The project is funded by the German Federal Ministry of Education and Research (BMBF) with co-funding of industry as preparation for the European flagship on Quantum Technology. With the current development pace in quantum computation, it has been predicted that in less than two decades quantum computers will be able to break encryption codes deployed today, which are currently based on mathematical problems difficult to solve with classical computation. This shows the urgent need for quantum-safe encryption that is resistant to attacks of both, quantum and classical, computers. A long term solution for quantumsafe encryption is the use of a completely random, so-called One-Time-Pad generated with true Random Number Generation (RNG) and distributed via Quantum Key Distribution (QKD). The QKD in fiber networks is limited to approx. 100 km due to damping within the carrier medium. For longer distances so far only satellite based techniques are able to transmit the keys. As a pathfinder, QUBE plans perform an in-orbit demonstration of the core technologies on a CubeSat platform

QUBE – Towards Quantum Key Distribution with Small Satellites

Quantum Key Distribution (QKD) in space will be integral for future quan-tum networks. The space mission QUBE will test novel integrated optics components in a three-unit CubeSat demonstrating an economic route for global-scale QKD

Observation of Orbitally Excited B_s Mesons

We report the first observation of two narrow resonances consistent with states of orbitally excited (L=1) B_s mesons using 1 fb^{-1} of ppbar collisions at sqrt{s} = 1.96 TeV collected with the CDF II detector at the Fermilab Tevatron. We use two-body decays into K^- and B^+ mesons reconstructed as B^+ \to J/\psi K^+, J/\psi \to \mu^+ \mu^- or B^+ \to \bar{D}^0 \pi^+, \bar{D}^0 \to K^+ \pi^-. We deduce the masses of the two states to be m(B_{s1}) = 5829.4 +- 0.7 MeV/c^2 and m(B_{s2}^*) = 5839.7 +- 0.7 MeV/c^2.Comment: Version accepted and published by Phys. Rev. Let