Equivalence between various versions of the self-dual action of the Ashtekar formalism

Different aspects of the self-dual (anti-self-dual) action of the Ashtekar canonical formalism are discussed. In particular, we study the equivalences and differences between the various versions of such an action. Our analysis may be useful for the development of an Ashtekar formalism in eight dimensions.Comment: 10 pages, Latex, minor correction

Nonlinear resonant behavior of the dispersive readout scheme for a superconducting flux qubit

A nonlinear resonant circuit comprising a SQUID magnetometer and a parallel capacitor is studied as a readout scheme for a persistent-current (PC) qubit. The flux state of the qubit is detected as a change in the Josephson inductance of the SQUID magnetometer, which in turn mediates a shift in the resonance frequency of the readout circuit. The nonlinearity and resulting hysteresis in the resonant behavior are characterized as a function of the power of both the input drive and the associated resonance peak response. Numerical simulations based on a phenomenological circuit model are presented which display the features of the observed nonlinearity.Comment: 9 pages, 9 figure

The 2+1 Kepler Problem and Its Quantization

We study a system of two pointlike particles coupled to three dimensional Einstein gravity. The reduced phase space can be considered as a deformed version of the phase space of two special-relativistic point particles in the centre of mass frame. When the system is quantized, we find some possibly general effects of quantum gravity, such as a minimal distances and a foaminess of the spacetime at the order of the Planck length. We also obtain a quantization of geometry, which restricts the possible asymptotic geometries of the universe.Comment: 59 pages, LaTeX2e, 9 eps figure

AUTOMATIC IN-SITU SELF-CALIBRATION OF A PANORAMIC TLS FROM A SINGLE STATION USING 2D KEYPOINTS

Terrestrial laser scanner (TLS) measurements are unavoidably affected by systematic influences due to internal misalignments. The magnitude of the resulting errors can exceed the magnitude of random errors significantly deteriorating the quality of the obtained point clouds. Hence, the task of calibrating TLSs is important for applications with high demands regarding accuracy. In recent years, multiple in-situ self-calibration approaches were derived allowing the successful estimation of up-to-date calibration parameters. These approaches rely either on using manually placed targets or on using man-made geometric objects found in surroundings. Herein, we widen the existing toolbox with an alternative approach for panoramic TLSs, for the cases where such prerequisites cannot be met. We build upon the existing target-based two-face calibration method by substituting targets with precisely localized 2D keypoints, i.e. local features, detected in panoramic intensity images using the Förstner operator. To overcome the detriment of the perspective change on the feature localization accuracy, we estimate the majority of the relevant calibration parameters from a single station. The approach is verified on real data obtained with the Leica ScanStation P20. The obtained results were tested against the affirmed target-based two-face self-calibration. Analysis proved that the estimated calibration parameters are directly comparable both in the terms of parameter precision and correlation. In the end, we employ an effective evaluation procedure for testing the impact of the calibration results on the point cloud quality

Report of the Horse Mackerel Exchange and Workshop 2006

Following a recommendation from PGCCDBS, a workshop on age calibration of horse mackerel was carried out. The workshop was preceded by an exchange. The objectives were: to improve the quality of horse mackerel readings by international calibration. In particular, attempt to resolve the observed differences between countries. Estimate the accuracy and precision of the age readings before and after the intercalibration. Take into account differences between areas and methods. Training of new horse mackerel readers

Developing SOEPsurvey and SOEPservice: The (Near) Future of the German Socio-Economic Panel Study (SOEP)

Das Sozio-oekonomische Panel (SOEP) ist als multidisziplinäres Haushaltspanel, das Informationen zu allen Personen, die in einem Panel-Haushalt leben, erhebt und damit alle Altersjahrgänge abdeckt, nach 25 Jahren Laufzeit auch zu einer Kohorten- Studie geworden. Der zunehmende Erfolg der Forschungsinfrastruktur-Einrichtung SOEP speist sich in erster Linie daraus, dass die Analysekraft von Längsschnittstudien mit jedem weiteren Erhebungsjahr zunimmt. Hinzu kommen im Falle des SOEP seit Beginn an eine lange Reihe von Innovationen bei der Erhebung, Datenaufbereitung und Nutzer-Service. Deswegen gilt es zu überlegen, wie die wissenschaftliche Power des SOEP weiter gestärkt werden kann. Nicht zuletzt auch, da es für neue, spezialisierte Panel-Studien (wie das Nationale Bildungspanel oder das DFG-geförderte Familienpanel PAIRFAM) eine Referenz und ggf. Verankerung der Hochrechnung darstellt. Zudem kann das SOEP künftig eine größere Rolle als ,,Kontroll-Stichprobe" für Interventions-Studien spielen; etwa im Bereich der Kindheitsentwicklung. Auf diese neuen Rollen muss es vorbereitet sein. Die im SOEP in den letzten Jahren realisierten Erhebungsinnovationen wie z. B. die Inkorporation psychologischer Konzepte, physische Gesundheitsmessungen (Greifkraft), die Messung kognitiver Fähigkeiten und die Erprobung von Verhaltens- Experimenten werden in anderen Panel-Studien aufgegriffen und auf eine größere Stichprobenbasis gestellt. Im UK wird mit ,,Understanding Society" ein Haushaltspanel mit 40.000 Haushalten begonnen; in den Niederlanden wird mit MESS ein Haushaltspanel von über 5.000 Haushalten für innovative Messmethoden zur Verfügung gestellt. Die Erhebungsinhalte des SOEP werden von den Forschungs- und Politikberatungs-Communities unverändert stark nachgefragt. In UK hat ein für ,,Understanding Society" breit angelegter Konsultationsprozess keine grundsätzlich neuen Befragungsinhalte zu Tage gefördert, die das SOEP nicht bereits enthält oder die für das SOEP ohnehin im Gespräch sind. Wichtiger als die ,,Entdeckung" völlig neuer Erhebungsinhalte ist das thematische wie zeitliche ,,Zuschneiden" der Details von Befragungsinhalten auf (zugespitzte) neue (theoretische) Fragestellungen und dabei gleichzeitig bewährte sowie viel genutzte zentrale Befragungsinhalte und deren Befragungsrhythmen beizubehalten. Das ,,Maßschneidern" von Erhebungsinhalten wird in den nächsten Jahren die eigentliche Herausforderung für Infrastruktur- Erhebungen wie die PSID, ,,Understanding Society" und das SOEP sein. Bei den Erhebungsinhalten sollten die ,,Ränder" des Lebenslaufs eine größere Rolle spielen, da diese von Haushalts-Panels besonders gut erfasst werden können. Diese Verbesserungen der Erhebungen beziehen sich einerseits auf die fötale Phase von in das SOEP hineingeborenen Kindern und die (frühe) Kindheit, andererseits auf die letzte Lebensphase und das Sterben. In der Mitte des Lebenslaufs werden verbesserte Fragen zum Einkommen, Sparen und Vermögen sowie auch psychologische Konstrukte eine zentrale Rolle spielen, außerdem gezielte Fragen (event triggered questionnaires) in Verbindung mit zentralen Lebensereignissen wie z. B. Eheschließung, Scheidung, Eintritt in und Austritt aus Arbeitslosigkeit. Es wird die Etablierung einer SOEP-"Innovations-Stichprobe" vorbereitet, um theoriegeleitete Forschungsfragen gezielter unterstützen zu können. Dazu wird es auch notwendig sein, neue Messkonzepte zu erproben (z. B. die Erhebung von Biomarkern, qualitative Erhebungen, aber auch Experimente und gezielte Interventionsstudien). Um die Power von Längsschnittdaten von Anfang an für die Innovations-Stichprobe ausnutzen zu können, ist geplant, zwei kleinere Teilstichproben des SOEP, die seit 1998 bzw. 2006 laufen (Subsamples E und H), in die Innovationsstichprobe zu überführen. Um die statistische Power langlaufender Längsschnittdaten entscheidend zu verbessern, schätzen wir eine Mindestfallzahl von etwa 500 Personen pro Geburtsund Alterskohorte für ausreichend ein. Um dieses Ziel zu erreichen, muss die Fallzahl des SOEP-Standard-Samples erhöht werden. Als ,,Nebeneffekt" werden dadurch wesentlich bessere Analysen für relativ kleine Gruppen in der Bevölkerung möglich; etwa für allein Erziehende oder bestimme Immigrantengruppen. Außerdem verbessern sich als weiterer ,,Nebeneffekt" auch regionale Analysemöglichkeiten, z. B. für die meisten Bundesländer und in großen Bundesländern bis hin zu Regierungsbezirken (oder ähnlich abgegrenzten regionalen Einheiten). In letzter Zeit wird immer deutlicher, welche große Bedeutung das SOEP als ,,Referenz-Datensatz" für spezialisierte und vom SOEP völlig unabhängige Erhebungen hat (neben Beobachtungsstudien, wie etwa Zwillings-Studien, auch Labor- und Interventions-Studien). Zur Unterstützung dieser Funktion ist eine neue Art von Service, der in Deutschland bislang nicht vorgehalten wird, notwendig (Beratung von Spezial-Erhebungen; ggf. Datenaufbereitung von längsschnittlichen Spezial-Erhebungen), der auch in ein Datenservicezentrum eingebracht werden könnte. After 25 years as a multidisciplinary household panel containing information on all individuals residing in panel households and thus covering all age cohorts, the German Socio-Economic Panel (SOEP) has become a true cohort study as well. The increasing success of the SOEP research infrastructure comes above all from the increasing analytical power that longitudinal studies attain with each successive survey year. In the case of SOEP, a long series of innovations in surveying, data preparation, and user service have also played a major role. For this reason, it is important to consider how the scientific capacity of SOEP can be further enhanced-- not least of all since the SOEP can form a key point of reference (or "anchor") for new, specialized panel studies (such as the National Educational Panel and the family panel PAIRFAM, funded by the German Research Foundation). Furthermore SOEP can become a kind of "control sample" for intervention studies, for example, in the field of child development. The SOEP survey and its governance structures must be prepared for these new tasks. The numerous innovations introduced into SOEP in recent years--questions dealing with psychological concepts, physical health measures (grip strength), measures of cognitive capabilities, and behavioral experiments--have been incorporated into other panel studies as well, and thus provided with a larger sample base. In the UK, the "Understanding Society" household panel study was launched with 40,000 households; in the Netherlands, the MESS household panel study of over 5,000 households offered a new basis for testing innovative measurement methods. The results of the SOEP survey are in continuing high demand in the research and policy advisory community. From our point of view, the large-scale consultation process conducted to define the content of the UK survey "Understanding Society" failed to identify any fundamentally new survey content that the SOEP either did not already contain or that was not already being discussed for the SOEP. More important than "discovering" entirely new survey areas is "tailoring" the details of existing survey content to address new, more specific (theoretical) questions, and thus maintaining proven and widely used elements of survey content. The "tailoring" of survey content will be the real challenge facing infrastructure surveys like PSID, "Understanding Society," and the SOEP in the coming years. In the future, the "margins" of the life course should play a stronger role in survey content, since household panels are able to provide outstanding data of these life phases. The SOEP, and other household panel surveys, can be improved, on the one hand, by including the fetal phase of life and early childhood for children born into the panel, and on the other, by including late life and death. In the middle of the life course, improved questions on income, savings, and wealth as well as psychological constructs will play a central role, as will specific questions (in "eventtriggered" questionnaires) on central life occurrences such as marriage, divorce, and entry into and exit from unemployment. Current plans for SOEP foresee the addition of an "Innovation Sample" that will make it possible to better address theory-based research questions required for testing new measurement concepts (e.g., the surveying of biomarkers, qualitative surveys, but also experiments and targeted intervention studies). In order to exploit the power of longitudinal data from the outset, we plan to incorporate two smaller SOEP subsamples that have been running since 1998 and 2006 (Subsamples E and H, respectively) into the Innovation Sample. In order to decisively improve the statistical power of long-term longitudinal data, we believe that a minimum case number of about 500 persons per birth and age cohort is required. In order to reach this goal, the case number in the SOEP standard samples needs to be increased. A positive side-effect of this enlargement would be a significantly improved potential for analyses of relatively small groups within the population: for example, lone parents or specific immigrant groups. Another positive side-effect would be an improved potential for regional analyses: for example, for the majority of federal states. In recent times, the importance of SOEP as a "reference dataset" for specialized surveys which are independent from SOEP (observational studies such as twin studies, and laboratory and intervention studies) has become strikingly evident. To enhance this important function, new types of service are needed (advice on special surveys, possibly also data preparation for special surveys), which could become part of a Data Service Center.Household Panels, German Socio-Economic Panel Study, SOEP

Gott Time Machines, BTZ Black Hole Formation, and Choptuik Scaling

We study the formation of BTZ black holes by the collision of point particles. It is shown that the Gott time machine, originally constructed for the case of vanishing cosmological constant, provides a precise mechanism for black hole formation. As a result, one obtains an exact analytic understanding of the Choptuik scaling.Comment: 6 pages, Late

Optimizing individual benefits of pulmonary rehabilitation including a multifaceted dietary intervention – A single-arm feasibility study

IntroductionFew studies have examined the effectiveness of nutrition interventions in municipal COPD rehabilitation programs. The objectives of this study were to examine the feasibility of implementation in practice (primary) and the feasibility of study methods and potential effectiveness (secondary) of a multidisciplinary dietary intervention offered to patients who start municipal rehabilitations program.MethodsThis study was a single arm intervention study with a pre-post design. Participant were recruited from five different municipal rehabilitation centers and received three individualized dietary counselling's. The primary outcome was retention, compliance to the intervention and complement of data collection. Secondary outcomes included changes in dietary intake, body composition and physical function. Analysis of the primary and secondary outcomes was primarily based on descriptive statistics.ResultsIn total, 111 (77%) of 145 eligible patients from five different municipalities consented to participate. Of them 99 (89%) completed. Before the intervention 67 (63%) of the participants had 75% or more of their requirement of energy covered, and 48 (45%) had 75% or more of their protein requirements covered. At the end of the intervention, 76 (77%) of the participants had 75% or more coverage of energy requirements and 80 (83%) had 75% or more coverage of their protein requirements. In general, the level of completeness was high.ConclusionWe found recruitment to be feasible, a high rate of retention, a high compliance to the intervention and high completeness of the data collection