Tracing the relation between black holes and dark haloes

We present new velocity dispersion measurements for a set of 12 spiral galaxies and use them to derive a more accurate V_c - sigma relation which holds for a wide morphological range of galaxies. Combined with the M_BH - sigma relation, this relation can be used as a tool to estimate supermassive black hole (SMBH) masses by means of the asymptotic circular velocity. Together with the Tully-Fisher relation, it serves as a constraint for galaxy formation and evolution models.Comment: 2 pages, 2 figures, to appear in Proc. IAU Symp. 220, "Dark Matter in Galaxies" eds. S. Ryder, D.J. Pisano, M. Walker, & K. Freeman (San Francisco: ASP

Completely analytical families of anisotropic gamma-models

We present new analytical distribution functions for anisotropic spherical galaxies. They have the density profiles of the gamma-models, which allow a wide range of central density slopes, and are widely used to fit elliptical galaxies and the bulges of spiral galaxies. Most of our models belong to two two-parameter families. One of these parameters is the slope gamma of the central density cusp. The other allows a wide range of varying radial and tangential anisotropies, at either small or large radii. We give analytical formulas for their distribution functions, velocity dispersions, and the manner in which energy and transverse velocity are distributed between orbits. We also give some of their observable properties, including line-of-sight velocity profiles which have been computed numerically. Our models can be used to provide a useful tool for creating initial conditions for N-body and Monte Carlo simulations.Comment: 21 pages, 15 figures, accepted for publication in MNRA

Dynamical models linking BH masses and DM content

We investigate the relation between the dark matter distribution of galaxies and their central supermassive black holes which is suggested by the v_c-sigma relation. Since early-type galaxies appear to have larger black holes than late-type ones, we look for an equivalent pattern in the dark matter distribution as a function of Hubble type. To achieve our goal we use a state-of-the-art modelling code that allows a variety of geometries to be fitted to a combination of radio and optical observations of galaxies with different morphology.Comment: 2 pages, 2 figures, contributed paper to Proceedings of the Conference "Growing Black Holes" held in Garching, Germany, June 21-25, 2004, edited by A. Merloni, S. Nayakshin and R. Sunyaev, Springer-Verlag series of "ESO Astrophysics Symposia

FCC046: a candidate gaseous polar ring dwarf elliptical galaxy in the Fornax Cluster

FCC046 is a Fornax Cluster dwarf elliptical galaxy. Optical observations have shown that this galaxy, besides an old and metal-poor stellar population, also contains a very young centrally concentrated population and is actively forming stars, albeit at a very low level. Here, we report on 21cm observations of FCC046 with the Australia Telescope Compact Array (ATCA) which we conducted in the course of a small survey of Fornax Cluster early-type dwarf galaxies. We have discovered a ~10^7 Mo HI cloud surrounding FCC046. We show that the presence of this significant gas reservoir offers a concise explanation for this galaxy's optical morphological and kinematical properties. Surprisingly, the HI gas, as evidenced by its morphology and its rotational motion around the galaxy's optical major axis, is kinematically decoupled from the galaxy's stellar body. This is the first time such a ring of gaseous material in minor-axis rotation is discovered around a dwarf galaxy.Comment: 5 pages, 4 figures, published in Astrophysical Journal Letter

Grotesken uit de Italiaanse renaissance. Onderzoek en restauratie van de muur- en gewelfschilderingen(1537) van de Onze-Lieve-Vrouw-Lofkapel in de Antwerpse kathedraal (prov. Antwerpen)

De conservatie en restauratie van de schilderingen (1537) van de Onze-Lieve-Vrouw-Lofkapel vormden de aanleiding tot verder onderzoek naar de context van hun ontstaan en geschiedenis, de filosofie en deontologie van de huidige restauratiebehandeling vooral met betrekking tot de re-integratie van lacunes, de gebruikte materialen en technieken van de oude schildering, de iconografie en de herkomst van de motieven, de identificatie van de heraldische voorstellingen en last but not least de persoon van de schilder

Les Mollusques perforants

In search of a better protection against predators, molluscs have developped various ways of adaptation and evolution to bury themselves in different substrates. The most striking exemples are found among the bivalvia

Antimicrobial stewardship programs in a hospital setting : development of quality indicators and implementation of interventions

Health care is challenged by the emergence of antibiotic resistance and the slow pipeline of new antibiotics, especially against Gram negative multi-resistant bacteria. The most important cause of emergence and spread of antimicrobial resistance has been a massive overuse of antibiotics worldwide across all ecosystems over the past decades, including humans, animals, aquaculture, and agriculture. Antimicrobial resistance may lead to more difficult to treat infections and may hence be associated with increased patient mortality, longer hospital stays, and increased healthcare costs. Up to 30% of antimicrobial regimens in hospitals are considered inappropriate. An effective approach to improving antimicrobial use in hospitals is an organised antimicrobial stewardship program. In this thesis we tried to develop and validate quality indicators in order to monitor antimicrobial stewardship programs in a hospital setting. Furthermore we evaluated key components of an antimicrobial stewardship program to optimize antimicrobial prescribing. With a multidisciplinary panel from four European countries we developed 57 structure indicators from which ten indicators were identified as a minimal set of key indicators. A validation survey in eleven European hospitals showed a significant heterogeneity with regard to their scoring for structural components of effective antibiotic stewardship. We concluded that potential structure indicators examined in this study, with focus on the top-ten indicators, could be used for regular assessment of the extent and strength of hospital antimicrobial stewardship programs. The feasibility and clinical relevance of measuring a process indicator for appropriate iv use of highly bioavailable antimicrobial drugs, allowing early IV to oral switch, was evaluated revealing a substantial heterogeneity of the performance gap. Absence of an iv-to-po switch programme was associated with more inappropriate prescribing. The results of this study indicated that the iv-to-po quality indicator is widely applicable and could be a tool to evaluate compliance with iv-to-po switch guidelines. Optimizing antibiotic dosing regimens is a core activity within an antimicrobial stewardship program. Extended and continuous infusions with betalactam antibiotics have been suggested as a means of pharmacokinetic and pharmacodynamic optimisation of antimicrobial therapy. A survey was undertaken to investigate the recommendations on extended and continuous infusions of ceftazidime, cefepime, piperacillin–tazobactam, meropenem and vancomycin by the local antibiotic management teams (AMTs) in Belgian acute hospitals. This survey showed that extended and continuous infusions are widely implemented in Belgian hospitals but revealed significant variation in the recommended dosing regimens. Two interventional studies were performed to optimize antimicrobial prescribing. These focused on appropriate timing of the initiation of an antimicrobial treatment for presumed infections in the emergency ward and on parenteral to oral conversion of fluoroquinolone antibiotics. We showed that the implementation of merely persuasive interventions such as hospital-wide publication of guidelines in the local drug letter and educational interactive sessions towards nurses and physicians only resulted in limited improvement. However, a pro-active intervention by a clinical pharmacist to stimulate parenteral to oral conversion resulted in a significant reduction of the duration of the intravenous treatment, as well as in treatment cost. Finally we assessed the functioning of a multidisciplinary infectious diseases team (MIT), which is an example of educational outreach intervention. The MIT formulated a daily average of 5 interventions for non-critically ill adult patients in a teaching hospital. Following bedside assessment by junior staff, diagnostic and therapeutic recommendations were communicated by phone and by notes towards prescribers in the electronic patient file resulting in high acceptance rates, in particular for therapeutic recommendations. In general this thesis provides indicators to the AMT’s to evaluate their antimicrobial stewardship activities. Proactive interventions on an individual patient level are needed to optimize antimicrobial prescribing

Automated UML-based ontology generation in OSLO²

In 2015, Flanders Information started the OSLO2 project, aimed at easing the exchange of data and increasing the interoperability of Belgian government services. RDF ontologies were developed to break apart the government data silos and stimulate data reuse. However, ontology design still encounters a number of difficulties. Since domain experts are generally unfamiliar with RDF, a design process is needed that allows these experts to efficiently contribute to intermediate ontology prototypes. We designed the OSLO2 ontologies using UML, a modeling language well known within the government, as a single source specification. From this source, the ontology and other relevant documents are generated. This paper describes the conversion tooling and the pragmatic approaches that were taken into account in its design. While this tooling is somewhat focused on the design principles used in the OSLO2 project, it can serve as the basis for a generic conversion tool. All source code and documentation are available online