Modest-2: A Summary

This is a summary paper of MODEST-2, a workshop held at the Astronomical Institute ``Anton Pannekoek'' in Amsterdam, 16-17 December 2002. MODEST is a loose collaboration of people interested in MOdelling DEnse STellar systems, particularly those interested in modelling these systems using all the available physics (stellar dynamics, stellar evolution, hydrodynamics and the interplay between the three) by defining interfaces between different codes. In this paper, we summarize 1) the main advances in this endeavour since MODEST-1; 2) the main science goals which can be and should be addressed by these types of simulations; and 3) the most pressing theoretical and modelling advances that we identified.Comment: Accepted by New Astronom

Myxome des Herzens:Ergebnisse chirurgischer Therapie

In der Thorax-, Herz- und Gefäßchirurgie der Universitätsklinik Münster wurden 52 Frauen und 26 Männer mit kardialem Myxom zwischen 1989 und 2005 operativ versorgt und die Ergebnisse retrospektiv analysiert. Das mittlere Alter betrug zum Operationszeitpunkt 56 Jahre. Es fanden sich konstitutionelle, klappenvitienähnliche und embolisch bedingte Symptome. Die Resektion linksatrialer Myxome erfolgte über eine Inzision der rechten oberen Pulmonalvene und das interatriale Septum wurde quer inzidiert. Die mittlere OP-Dauer betrug 2½ h. Postoperativ traten Rhythmusstörungen auf, die medikamentös oder durch Schrittmacherimplantation therapiert wurden. Ein Patient verstarb direkt postoperativ (30-Tage Follow-up). Im Langzeitverlauf starben von 10 Patienten 9 an nichtkardialen Erkrankungen. Nur zwei Patienten hatten ein Rezidiv. Die Resektion kardialer Myxome ist die Therapie der Wahl, wobei eine lebenslange Nachsorge aufgrund der noch nach Jahren bestehenden Rezidivmöglichkeit erfolgen sollte

On the Mass of Dense Star Clusters in Starburst Galaxies from Spectro-Photometry

The mass of unresolved young star clusters derived from spectro-photometric data may well be off by a factor of 2 or more once the migration of massive stars driven by mass segregation is accounted for. We quantify this effect for a large set of cluster parameters, including variations in the stellar IMF, the intrinsic cluster mass, and mean mass density. Gas-dynamical models coupled with the Cambridge stellar evolution tracks allow us to derive a scheme to recover the real cluster mass given measured half-light radius, one-dimensional velocity dispersion and age. We monitor the evolution with time of the ratio of real to apparent mass through the parameter eta. When we compute eta for rich star clusters, we find non-monotonic evolution in time when the IMF stretches beyond a critical cutoff mass of 25.5 solar mass. We also monitor the rise of color gradients between the inner and outer volume of clusters: we find trends in time of the stellar IMF power indices overlapping well with those derived for the LMC cluster NGC 1818 at an age of 30 Myr. We argue that the core region of massive Antennae clusters should have suffered from much segregation despite their low ages. We apply these results to a cluster mass function, and find that the peak of the mass distribution would appear to observers shifted to lower masses by as much as 0.2 dex. The star formation rate (SFR) derived for the cluster population is then underestimated by from 20 to 50 per cent.Comment: 20 pages, 16 figures, accepted for publication in MNRA

The M/L ratio of massive young clusters

We point out a strong time-evolution of the mass-to-light conversion factor \eta commonly used to estimate masses of dense star clusters from observed cluster radii and stellar velocity dispersions. We use a gas-dynamical model coupled with the Cambridge stellar evolution tracks to compute line-of-sight velocity dispersions and half-light radii weighted by the luminosity. Stars at birth are assumed to follow the Salpeter mass function in the range [0.15--17 M_\sun]. We find that $\eta$, and hence the estimated cluster mass, increases by factors as large as 3 over time-scales of 20 million years. Increasing the upper mass limit to 50 M_\sun leads to a sharp rise of similar amplitude but in as little as 10 million years. Fitting truncated isothermal (Michie-King) models to the projected light profile leads to over-estimates of the concentration par ameter c of $\delta c\approx 0.3$ compared to the same functional fit applied to the proj ected mass density.Comment: Draft version of an ApJ lette

Factors influencing life satisfaction in acute myeloid leukemia survivors following allogeneic stem cell transplantation: a cross-sectional study

Background: Allogeneic stem cell transplantation (alloSCT) is the preferred option of postremission therapy for high-risk patients suffering from acute myeloid leukemia (AML). Therefore, monitoring life satisfaction (LS) of long-term survivors following alloSCT is becoming increasingly important for oncologists. The aim of the study was to evaluate individual survivor priority of various general and health-related domains of life and their satisfaction with these domains. Furthermore, we investigated the impact of general and health-related LS on resilience, anxiety, depression and quality of life in AML survivors following alloSCT. Methods: Forty-one AML survivors (median age at time of assessment = 49.0 years) who had undergone alloSCT (median time since transplantation = 3.1 years) were enrolled in the study. Psychosocial parameters were assessed using the following instruments: FLZM (Questions on Life Satisfaction), EORTC QLQ-C30, HADS (Hospital Anxiety and Depression Scale) and the RS-25 (Resilience Scale-25 items). Correlation analyses were computed to reveal the associations between the different questionnaires. Results: Independence from help or care, well-regulated living conditions and financial security contributed positively to LS, whereas being off work due to health-reasons and dissatisfaction with physical aspects were negatively associated to the subjective feelings of overall satisfaction. Moreover, a high quality of life was strongly positively correlated with LS (Spearman’s rho general LS: 0.643 and health-related LS: 0.726, both p < 0.001). A high degree of resilience was also strongly positively correlated with better LS (general LS: 0.700, health-related LS: 0.675, both p < 0.001). Symptoms of anxiety and depression were associated with an impaired general LS (anxiety: −0.674, depression: −0.698, both p < 0.001). Conclusions: Our results indicate that LS should be considered an important key contributor to the survivors’ well-being following alloSCT. Thus, identifying protective psychological and physical factors that relieve stressors is of high importance in order to support long-term AML survivors with their special needs.<br

Avalanche photodiodes for the CMS electromagnetic calorimeter

Avalanche photodiodes(APD's) will be used as photodetectors in the CMS barrel electromagnetic crystal calorimeter for high precision energy measurements in a hostile radiation environment. Significant progress has been made in the characteristics of these devices being expressly developed for CMS. Parameters of the final structure APD's together with demonstrations of radiation hardness and plans for quality assurance/control during the production phase are presented

Dynamical Processes in Globular Clusters

Globular clusters are among the most congested stellar systems in the Universe. Internal dynamical evolution drives them toward states of high central density, while simultaneously concentrating the most massive stars and binary systems in their cores. As a result, these clusters are expected to be sites of frequent close encounters and physical collisions between stars and binaries, making them efficient factories for the production of interesting and observable astrophysical exotica. I describe some elements of the competition among stellar dynamics, stellar evolution, and other processes that control globular cluster dynamics, with particular emphasis on pathways that may lead to the formation of blue stragglers.Comment: Chapter 10, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G. Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe