Precise radial velocities of giant stars. XI. Two brown dwarfs in 6:1 mean motion resonance around the K giant star ν\nu Ophiuchi

We present radial-velocity (RV) measurements for the K giant $\nu$ Oph (= HIP88048, HD163917, HR6698), which reveal two brown dwarf companions with a period ratio close to 6:1. For our orbital analysis we use 150 precise RV measurements taken at Lick Observatory between 2000 and 2011, and we combine them with RV data for this star available in the literature. Using a stellar mass of $M = 2.7\,M_\odot$ for $\nu$ Oph and applying a self-consistent N-body model we estimate the minimum dynamical companion masses to be $m_1\sin i \approx 22.2\,M_{\mathrm{Jup}}$ and $m_2\sin i \approx 24.7\,M_{\mathrm{Jup}}$, with orbital periods $P_1 \approx 530$ d and $P_2 \approx 3185$ d. We study a large set of potential orbital configurations for this system, employing a bootstrap analysis and a systematic $\chi_{\nu}^2$ grid-search coupled with our dynamical fitting model, and we examine their long-term stability. We find that the system is indeed locked in a 6:1 mean motion resonance (MMR), with $\Delta \omega$ and all six resonance angles $\theta_{1}, \ldots, \theta_{6}$ librating around 0$^\circ$. We also test a large set of coplanar inclined configurations, and we find that the system will remain in a stable resonance for most of these configurations. The $\nu$ Oph system is important for probing planetary formation and evolution scenarios. It seems very likely that the two brown dwarf companions of $\nu$ Oph formed like planets in a circumstellar disk around the star and have been trapped in a MMR by smooth migration capture.Comment: 17 pages, 9 figures. New version with corrected number in title. No other change

Demografischer Wandel und demografisches Altern im Ruhrgebiet

Demografische Entwicklungen haben insbesondere kleinräumige Effekte. Hierauf haben sich die Kommunen, aber auch die wirtschaftlich Handelnden einzustellen. Diese Einsicht nimmt der Beitrag zum Anlass, um am Beispiel des Ruhrgebiets die zu erwartenden demografischen und sozialstrukturellen Veränderungen darzustellen und die Konsequenzen für den Arbeitsmarkt und die Wirtschaft herauszuarbeiten. Besonders betont werden dabei die Chancen und Potenziale des demografischen Wandels. Dargestellt wird dies insbesondere anhand eines inzwischen abgeschlossenen Forschungsprojekts, welches sich zum Ziel gesetzt hat, gemeinsam mit den Wirtschaftsakteuren vor Ort neue demografiesensible Geschäftsfelder im Bereich Wellness/Gesundheit, Informationstechnologie, Finanzdienstleistungen und vor allem Wohnen zu erschließen.Demographic developments have in particular small-scale effects. On that the municipalities and the economic actors have to adjust their actions. This insight takes the contribution to the cause, in order to represent by the example of the Ruhr Region the demographic and social structural changes which can be expected and to work the consequences out for the job market and the economy. Especially the chances and potentials of the demographic change are in the spotlight. This focus founds it empirically basis on a finished research project, which had the aim, to discover together with local economic actors new demography-sensitive business fields within the range wellness/health, information technology, financial services and first of all habitation

Analyzing the Impact of Process Change Operations on Time-Aware Processes

The proper handling of temporal constraints is crucial in many application domains. Contemporary process-aware information systems, however, still lack a sophisticated support of time-aware processes. As a particular challenge, by nature, (most) time-aware processes need to be quite flexible as time can neither be slowed down nor stopped. Hence it must be possible to dynamically adapt a time-aware process instance in order to cope with unforeseen events. In turn, when applying dynamic changes to a time-aware process it crucial that the resulting process instance is again sound as well as temporally consistent; i.e., it must still be possible to complete the process instance without violating any of its temporal constraints. This paper extends existing process change operations, which ensure soundness of the resulting process instance, by additionally considering temporal constraints. Furthermore, it provides pre- and post-conditions that ensure that the resulting process instance is again temporally consistent. Finally, we analyze the impact a change has on the overall temporal properties of a process instance and---based on the results---provide means to significantly reduce the complexity of the required time calculations. The latter is crucial to ensure scalability of the approach. The approach has been prototypically implemented in the AristaFlow BPM Suite

The Zugspitze radiative closure experiment for quantifying water vapor absorption over the terrestrial and solar infrared - Part 3: Quantification of the mid- and near-infrared water vapor continuum in the 2500 to 7800cm-1 spectral range under atmospheric conditions

We present a first quantification of the near-infrared (NIR) water vapor continuum absorption from an atmospheric radiative closure experiment carried out at the Zugspitze (47.42° N, 10.98° E; 2964 m a.s.l.). Continuum quantification is achieved via radiative closure using radiometrically calibrated solar Fourier transform infrared (FTIR) absorption spectra covering the 2500 to 7800 cm−1 spectral range. The dry atmospheric conditions at the Zugspitze site (IWV 1.4 to 3.3 mm) enable continuum quantification even within water vapor absorption bands, while upper limits for continuum absorption can be provided in the centers of window regions. Throughout 75 % of the 2500 to 7800 cm−1 spectral range, the Zugspitze results agree within our estimated uncertainty with the widely used MT_CKD 2.5.2 model (Mlawer et al., 2012). In the wings of water vapor absorption bands, our measurements indicate about 2–5 times stronger continuum absorption than MT_CKD, namely in the 2800 to 3000 cm−1 and 4100 to 4200 cm−1 spectral ranges. The measurements are consistent with the laboratory measurements of Mondelain et al. (2015), which rely on cavity ring-down spectroscopy (CDRS), and the calorimetric–interferometric measurements of Bicknell et al. (2006). Compared to the recent FTIR laboratory studies of Ptashnik et al. (2012, 2013), our measurements are consistent within the estimated errors throughout most of the spectral range. However, in the wings of water vapor absorption bands our measurements indicate typically 2–3 times weaker continuum absorption under atmospheric conditions, namely in the 3200 to 3400, 4050 to 4200, and 6950 to 7050 cm−1 spectral regions

Dealing with Changes of Time-Aware Processes

The proper handling of temporal process constraints is crucial in many application domains. Contemporary process-aware information systems (PAIS), however, lack a sophisticated support of time-aware processes. As a particular challenge, the execution of time-aware processes needs to be flexible as time can neither be slowed down nor stopped. Hence, it should be possible to dynamically adapt time-aware process instances to cope with unforeseen events. In turn, when applying such dynamic changes, it must be re-ensured that the resulting process instances are temporally consistent; i.e., they still can be completed without violating any of their temporal constraints. This paper presents the ATAPIS framework which extends well established process change operations with temporal constraints. In particular, it provides pre- and post-conditions for these operations that guarantee for the temporal consistency of the changed process instances. Furthermore, we analyze the effects a change has on the temporal properties of a process instance. In this context, we provide a means to significantly reduce the complexity when applying multiple change operations. Respective optimizations will be crucial to properly support the temporal perspective in adaptive PAIS

What are the Problem Makers: Discovering the Most Frequently Changed Activities in Adaptive Processes

Recently, a new generation of adaptive Process-Aware Information System (PAIS) has emerged, which enables dynamic service changes (i.e., changes of instances derived from a composite service and process respectively). This, in turn, results in a large number of process variants derived from the same process model, but differing in their structure due to the applied changes. Since such process variants are expensive to maintain, the process model should evolve accordingly. It is therefore our goal to discover those activities that have been more often involved in process (instance) adaptations than others, such that we can focus on them when re-designing the process model. This paper provides two approaches to rank activities based on their involvement in process adaptations and process configurations respectively. The first approach allows to precisely rank the activities, but it is very expensive to perform since the algorithm is at $\mathcal{NP}$ level. We therefore provide as alternative approach an approximation ranking algorithm which computes in polynomial time. The performance of the approximation algorithm is evaluated and compared through a comprehensive simulation of 3600 process models. By applying statistical significance tests, we can also identify several factors which influence the performance of the approximation ranking algorithm

Enabling Time-Aware Process Support with the ATAPIS Toolset

The proper handling of temporal constraints is crucial for business processes in many application domains. Contemporary process-aware information systems (PAIS), however, lack a sophisticated support of time-aware processes. First of all, at design time it should be possible to specify the temporal constraints of a business process. In turn, this should be accompanied by checking the respective time-aware process schema for inconsistencies that may emerge due to hidden interdependencies among the temporal constraints. The latter is crucial to enable a robust and error-free execution of the time-aware process schema. At run time, corresponding process instances need to be monitored for violations of their temporal constraints. This demo paper presents the ATAPIS Toolset for modeling and enacting time-aware processes. The toolset is based on AristaFlow BPM Suite---an industrial-strength process management system. The ATAPIS Toolset enables process engineers to correctly specify and implement time-aware processes. Further, time-aware process instances can be efficiently executed, whilst monitoring their temporal constraints. Altogether, the ATAPIS Toolset covers the temporal perspective of processes at design as well as run time in a comprehensive way

Emergence of the mitochondrial reticulum from fission and fusion dynamics

Mitochondria form a dynamic tubular reticulum within eukaryotic cells. Currently, quantitative understanding of its morphological characteristics is largely absent, despite major progress in deciphering the molecular fission and fusion machineries shaping its structure. Here we address the principles of formation and the large-scale organization of the cell-wide network of mitochondria. On the basis of experimentally determined structural features we establish the tip-to-tip and tip-to-side fission and fusion events as dominant reactions in the motility of this organelle. Subsequently, we introduce a graph-based model of the chondriome able to encompass its inherent variability in a single framework. Using both mean-field deterministic and explicit stochastic mathematical methods we establish a relationship between the chondriome structural network characteristics and underlying kinetic rate parameters. The computational analysis indicates that mitochondrial networks exhibit a percolation threshold. Intrinsic morphological instability of the mitochondrial reticulum resulting from its vicinity to the percolation transition is proposed as a novel mechanism that can be utilized by cells for optimizing their functional competence via dynamic remodeling of the chondriome. The detailed size distribution of the network components predicted by the dynamic graph representation introduces a relationship between chondriome characteristics and cell function. It forms a basis for understanding the architecture of mitochondria as a cell-wide but inhomogeneous organelle. Analysis of the reticulum adaptive configuration offers a direct clarification for its impact on numerous physiological processes strongly dependent on mitochondrial dynamics and organization, such as efficiency of cellular metabolism, tissue differentiation and aging

"Gestresste" Mitochondrien werden isoliert : ein Protein schlägt die Brücke zwischen Qualitätskontrolle und Dynamik

Mitochondrien sind die Kraftwerke unserer Zellen. In ihnen findet die Zellatmung statt, die unseren Körper mit lebenswichtiger Energie versorgt. Zusätzlich teilen sich die Zellorganellen und verschmelzen wieder miteinander im Minutentakt. Was aber passiert, wenn Teile dieses dynamischen Geflechts Defekte aufweisen? Die Antwort dazu könnte ein Protein sein, das auf zwei verschiedene Weisen in die Mitochondrien-Membranen eingebaut wird. Liegt keine kurze Form des Proteins vor, ist das ein Hinweis dafür, dass die Organellen defekt sind. Die Mitochondrien verbrennen die mit der Nahrung zugeführten Kohlenhydrate und Fette unter Verbrauch von Sauerstoff zu Kohlendioxid und Wasser. Bei diesem Vorgang, der Zellatmung, wird über eine Reihe von Proteinkomplexen ein elektrochemisches Potenzial aufgebaut, das zur Produktion des Energieträgers ATP (Adenosintriphosphat) genutzt wird. ATP kann aus den Mitochondrien abtransportiert werden und steht somit als eine Art Treibstoff für alle Stoffwechselprozesse zur Verfügung. Die Arbeit der Mitochondrien ist der Hauptgrund für unseren täglichen Sauerstoffbedarf. Außerdem tragen die Nano-Kraftwerke der Zelle dazu bei, unsere Körpertemperatur auf 37 °C aufrechtzuerhalten. Aufgrund dieser zentralen Funktionen ist es nicht verwunderlich, dass eine Reihe von Krankheiten beim Menschen durch den Funktionsverlust von Mitochondrien verursacht oder beeinflusst wird. Das sind in erster Linie neurologische oder muskuläre Erkrankungen, aber auch Diabetes, Fettleibigkeit, verschiedene Formen von Krebs und Alterungsprozesse. Folglich ist es von immenser Bedeutung zu verstehen, wie Mitochondrien funktionieren, wie sie ihre Funktionalität aufrechterhalten und gegebenenfalls repariert oder entsorgt werden können. Dem können wir am Wissenschaftsstandort Frankfurt hervorragend nachgehen, da sich einige international ausgewiesene Forschungsgruppen in den Fachbereichen Medizin, Biologie, Chemie und am Max-Planck-Institut für Biophysik mit verschiedenen Aspekten der mitochondrialen Biologie befassen. In zahlreichen interdisziplinären Kooperationen wird so versucht, dieses komplexe System besser zu verstehen