A visual exploration workflow as enabler for the exploitation of Linked Open Data

Abstract. Semantically annotating and interlinking Open Data results in Linked Open Data which concisely and unambiguously describes a knowledge domain. However, the uptake of the Linked Data depends on its usefulness to non-Semantic Web experts. Failing to support data consumers to understand the added-value of Linked Data and possible exploitation opportunities could inhibit its diffusion. In this paper, we propose an interactive visual workflow for discovering and ex-ploring Linked Open Data. We implemented the workflow considering academic library metadata and carried out a qualitative evaluation. We assessed the work-flow’s potential impact on data consumers which bridges the offer: published Linked Open Data; and the demand as requests for: (i) higher quality data; and (ii) more applications that re-use data. More than 70 % of the 34 test users agreed that the workflow fulfills its goal: it facilitates non-Semantic Web experts to un-derstand the potential of Linked Open Data.

Rabi oscillations in a quantum dot-cavity system coupled to a non-zero temperature phonon bath

We study a quantum dot strongly coupled to a single high-finesse optical microcavity mode. We use a rotating wave approximation method, commonly used in ion-laser interactions, tegether with the Lamb-Dicke approximation to obtain an analytic solution of this problem. The decay of Rabi oscillations because of the electron-phonon coupling are studied at arbitrary temperature and analytical expressions for the collapse and revival times are presented. Analyses without the rotating wave approximation are presented by means of investigating the energy spectrum.Comment: 7 pages, 5 figures; Revised versio

Stroke placement in women’s professional tennis: What’s after the serve?

The aim of the present study was to investigate the placement of the return, and the 3rd and 4th strokes in professional women’s tennis, the possible differences related to the level of play and to derive practical recommendations from the results. In total this study contains an examination of 2562 returns, 2065 3rd strokes and 1606 4th strokes from 28 players in 19 professional women’s tennis matches (WTA & ITF 2018-2020 season). All strokes were classified using a specific court division method taking outcome (i.e., in, out, net) and placements into account for statistical analyses. Results show that returns are mainly placed into the court’s middle zones whereas 3rd strokes are placed more into offensive zone groups with 4th strokes similarly placed but more scattered. No correlation was found between the placement of the return and the 3rd stroke. Correlations were found between the placement of 4th stroke and the return, between the 4th and the 3rd stroke as well as between WTA and ITF players regarding all three strokes (return, 3rd stroke, 4th stroke). Present findings may be of interest to female tennis players and their coaches aiming to improve practice patterns in training and competitive performance in matches

Luminescence of GaAs nanowires consisting of wurtzite and zincblende segments

GaAs nanowires (NWs) grown by molecular-beam epitaxy may contain segments of both the zincblende (ZB) and wurtzite (WZ) phases. Depending on the growth conditions, we find that optical emission of such NWs occurs either predominantly above or below the band gap energy of ZB GaAs [E(g,ZB)]. This result is consistent with the assumption that the band gap energy of wurtzite GaAs [E(g,WZ)] is larger than E(g,ZB) and that GaAs NWs with alternating ZB and WZ segments along the wire axis establish a type II band alignment, where electrons captured within the ZB segments recombine with holes of the neighboring WZ segments. Thus, the corresponding transition energy depends on the degree of confinement of the electrons, and transition energies exceeding E(g,ZB) are possible for very thin ZB segments. At low temperatures, the incorporation of carbon acceptors plays a major role in determining the spectral profile as these can effectively bind holes in the ZB segments. From cathodoluminescence measurements of single GaAs NWs performed at room temperature, we deduce a lower bound of 55 meV for the difference E(g,WZ)-E(g,ZB).Comment: 8 pages, 10 figure

Quantum state engineering in hybrid open quantum systems

We investigate a possibility to generate nonclassical states in light-matter coupled noisy quantum systems, namely, the anisotropic Rabi and Dicke models. In these hybrid quantum systems, a competing influence of coherent internal dynamics and environment-induced dissipation drives the system into nonequilibrium steady states (NESSs). Explicitly, for the anisotropic Rabi model, the steady state is given by an incoherent mixture of two states of opposite parities, but as each parity state displays light-matter entanglement, we also find that the full state is entangled. Furthermore, as a natural extension of the anisotropic Rabi model to an infinite spin subsystem, we next explored the NESS of the anisotropic Dicke model. The NESS of this linearized Dicke model is also an inseparable state of light and matter. With an aim to enrich the dynamics beyond the sustainable entanglement found for the NESS of these hybrid quantum systems, we also propose to combine an all-optical feedback strategy for quantum state protection and for establishing quantum control in these systems. Our present work further elucidates the relevance of such hybrid open quantum systems for potential applications in quantum architectures

Modeling of cotunneling in quantum dot systems

Transport through nanosystems is treated within the second order von Neumann approach. This approach bridges the gap between rate equations which neglect level broadening and cotunneling, and the transmission formalism, which is essentially based on the single-particle picture thereby treating many-particle interactions on an approximate level. Here we provide an alternative presentation of the method in order to clarify the underlying structure. Furthermore we apply it to the problem of cotunneling. It is shown that both elastic and inelastic cotunneling can be described quantitatively, while the transmission approach with a mean-field treatment of the interaction provides an artificial bistability.Comment: 7 pages, 3 Figures included, final version with journal informatio

Radio Emission from Ultra-Cool Dwarfs

The 2001 discovery of radio emission from ultra-cool dwarfs (UCDs), the very low-mass stars and brown dwarfs with spectral types of ~M7 and later, revealed that these objects can generate and dissipate powerful magnetic fields. Radio observations provide unparalleled insight into UCD magnetism: detections extend to brown dwarfs with temperatures <1000 K, where no other observational probes are effective. The data reveal that UCDs can generate strong (kG) fields, sometimes with a stable dipolar structure; that they can produce and retain nonthermal plasmas with electron acceleration extending to MeV energies; and that they can drive auroral current systems resulting in significant atmospheric energy deposition and powerful, coherent radio bursts. Still to be understood are the underlying dynamo processes, the precise means by which particles are accelerated around these objects, the observed diversity of magnetic phenomenologies, and how all of these factors change as the mass of the central object approaches that of Jupiter. The answers to these questions are doubly important because UCDs are both potential exoplanet hosts, as in the TRAPPIST-1 system, and analogues of extrasolar giant planets themselves.Comment: 19 pages; submitted chapter to the Handbook of Exoplanets, eds. Hans J. Deeg and Juan Antonio Belmonte (Springer-Verlag

Staphylococcus aureus Induces Eosinophil Cell Death Mediated by α-hemolysin

Staphylococcus aureus, a major human pathogen, exacerbates allergic disorders, including atopic dermatitis, nasal polyps and asthma, which are characterized by tissue eosinophilia. Eosinophils, via their destructive granule contents, can cause significant tissue damage, resulting in inflammation and further recruitment of inflammatory cells. We hypothesised that the relationship between S. aureus and eosinophils may contribute to disease pathology. We found that supernatants from S. aureus (SH1000 strain) cultures cause rapid and profound eosinophil necrosis, resulting in dramatic cell loss within 2 hours. This is in marked contrast to neutrophil granulocytes where no significant cell death was observed (at equivalent dilutions). Supernatants prepared from a strain deficient in the accessory gene regulator (agr) that produces reduced levels of many important virulence factors, including the abundantly produced α-hemolysin (Hla), failed to induce eosinophil death. The role of Hla in mediating eosinophil death was investigated using both an Hla deficient SH1000-modified strain, which did not induce eosinophil death, and purified Hla, which induced concentration-dependent eosinophil death via both apoptosis and necrosis. We conclude that S. aureus Hla induces aberrant eosinophil cell death in vitro and that this may increase tissue injury in allergic disease

THE RIGHT TO THE CITY AND DATA PROTECTION: COMPLEMENTARY FOR DEVELOPING CITIZEN-CENTRIC DIGITAL CITIES?

In digital cities, urban space integrates physical and digital worlds. Information and communication technologies, often controlled by private companies, become ubiquitous, not least to capture and process (personal) data. While private governance can reconfigure public values and relations between public institutions and citizens, the question arises who decides what cities become, whose interests they serve. This paper presents ongoing research about the Right to the City (Lefebvre, 1968) and the right to personal data protection, guided by a social constructivist perspective and the methodological framework of actor-network-theory. As part of a four-year research track, we conducted an empirical cross-case analysis of urban data processing projects affected by the GDPR. The aim was to answer the question of how ‘users’ of cities can be represented meaningfully in processes that shape cities by means of those two rights. To do so, we interviewed people directly involved in Belgian ‘smart’ city projects. The main results of this research show that the two rights can be complementary in fostering agency and protecting citizen interests in technologically enhanced, citizen-centric cities. Data protection impacts smart city developments, but true agency of citizens as in the Right to the City remains limited. We will discuss why especially interdisciplinary research is required to further understanding in this complex, cross-domain environment and to lower barriers to citizen inclusion in practice