Molecules in G1.6-0.025 - 'Hot' Chemistry in the Absence of Star Formation at the Periphery of the Galactic Center Region

We present molecular line mapping of the Giant Molecular Cloud G1.6-0.025, which is located at the high longitude end of the Central Molecular Zone of our Galaxy. We assess the degree of star formation activity in that region using several tracers and find very little. We made a large scale, medium (2') resolution map in the J = 2-1 transition of SiO for which we find clumpy emission over a ~0.8 x 0.3 degree-sized region stretching along the Galactic plane. Toward selected positions we also took spectra in the easy to excite J_k=2_k-1_k quartet of CH3OH and the CS 2-1 line. Throughout the cloud these \meth lines are, remarkably, several times stronger than, both, the CS and the SiO lines. The large widths of all the observed lines, similar to values generally found in the Galactic center, indicate a high degree of turbulence. Several high LSR velocity clumps that have 0-80 km/s higher velocities than the bulk of the molecular cloud appear at the same projected position as "normal" velocity material; this may indicate cloud-cloud collisions. Statistical equilibrium modeling of the CH3OH lines observed by us and others yield relatively high densities and moderate temperatures for a representative dual velocity position. We find 8 10^4 cm-3/30 K for material in the G1.6-0.025 cloud and a higher temperature (190 K), but a 50% lower density in a high velocity clump projected on the same location. Several scenarios are discussed in which shock chemistry might enhance the CH3OH and SiO abundances in G1.6-0.025 and elsewhere in the Central Molecular Zone.Comment: 51 pages incl. 9 figures and 6 Tables, ApJ (in press

Revisiting the capitalist road to communism: unconditional basic income and the post-labor world

The thesis of a capitalist road to communism (van der Veen and Van Parijs, 1986) asserts that Marx realm of freedom can be reached from within welfare capitalism, skipping socialism, by using a tax-financed unconditional basic income until it is close to disposable income per head, so that the very distinction between paid work and free time is cancelled as a result. We revisit and update this thesis for two reasons: the recent prospect of a post-labor society following the automation revolution in technology, and that welfare capitalism has become more inegalitarian and less hospitable to basic income. We use a simple economic model which incorporates an upward adjustment of basic income to labor-saving technical change and distinguishes between capital that complements labor and capital that is fully substitutable with labor. A baseline simulation of the model shows the economic feasibility of a capitalist transition to communism. Two versions of a scenario incorporating interplay between technical change and market socialist institutional reforms are set out which make the transition politically viable to some extent, depending on the social distribution of power over technology. The most promising version is one in which the productivity of labor and automation capital grow at similar rates. We show in which respects it approximates the ideal of communism. One finding is that communism does not require reaching the final stage of a post-labor society. We conclude with a reflection on the relevance of our present update for the more immediate future of unconditional basic income

The moderation of gender and generation in the effects of perceived destination image on tourist attitude and visit intention: A study of potential Chinese visitors to Australia

The overall purpose of this study is to examine the moderating roles of gender and generation in the effects of perceived destination image on tourist attitude and visit intention among Chinese potential tourists to Australia. Australia is one of the preferred destinations to Chinese tourists, and the China market emerges to be increasingly important to destination marketing organizations in Australia. Echoing the call for more gender studies in the tourism literature and also based on the generation theory, this study employed a cross-sectional questionnaire survey design and used structural equation modelling in its analysis. Survey data were collected through convenience sampling in the Chinese city Harbin at various public venues where urban residents can be found. The study identified Services and Tourism Provisions, Natural Environment and Quality of Life as three destination image dimensions perceived by Chinese urban residents towards Australia. Services and Tourism Provisions and Natural Environment both positively affected tourist attitude, which in turn levered up visit intention. The study found that the effect of Services and Tourism Provisions on attitude was stronger for men than for women, while the effect of Natural Environment on attitude was stronger for women than for men; for the post-1980s/1990s generation, the effect of Natural Environment on attitude was significantly stronger than that for the post-1960s/1970s generation. Implications for tourism marketers and managers are discussed

Is youth unemployment really the major worry? (AOM)

Youth unemployment is neither the only nor the basic problem of the European labour market. The comparative analysis of unemployment data demonstrates that the unemployment of older people is even more serious. The article proves that the weight of young people in total unemployment has as a tendency been declining in the “inner periphery” of the EU, among them in Central and Eastern European member states (CEECs). The trend is just the opposite in the developed or “core” countries of the Union where youngsters took a higher share in total unemployment in 2012 than 10-12 years ago. In Europe there are millions of young people beyond the active unemployed who do not want to work or think they cannot find a job that fulfils their expectations and refuse to take part in any kind of education or training (NEETs-“Not in Employment, Education or Training”). By estimating the rate of NEETs in the adult population the article claims that the NEETs-phenomenon is not the differentia specifica of the youth. At the end the article details two suggestions for the mitigation of the problem. It concludes that the joblessness in Europe is an old and tendencially worsening problem that cannot be solved by particular policies

In situ light dosimetry during photodynamic therapy of Barrett's esophagus with 5-aminolevulinic acid

Background and Objectives: Previous studies with PhotoDynamic Therapy (PDT) in bladder and bronchi have shown that due to scattering and reflection, the actually delivered fluence rate on the surface in a hollow organ can be significantly higher than expected. In this pilot study, we investigated the differences between the primary calculated and the actual measured fluence rate during PDT of Barrett's Esophagus (BE) using 23 independent clinical measurements in 15 patients. Study Design/Materials and Methods: A KTP-dye module laser at 630 nm was used as light source. Light delivery was performed using a cylindrical light diffuser inserted in the center of an inflatable transparent balloon with a length corresponding to the length of the Barrett's epithelium. The total light output power of the cylindrical diffuser was calibrated using an integrating sphere to deliver a primary fluence rate of 100 mW cm-2. Two fiber-optic pseudo sphere isotropic detectors were placed on the balloon and were used to measure fluence rate at the surface of the esophageal wall during PDT. Results and Conclusions: The actual fluence rate measured was 1.5-3.9 times higher than the primary fluence rate for 630 nm. In general, the fluence rate amplification factor decreased with increasing redness of the tissue and was less for shorter diffusers. Fluence rate variations in time were observed which coincided with patients coughing, movement, and esophageal spasms. These factors combined with inter patient variability of the fluence rate measured appears to justify the routine application of this technique in PDT of BE

The Galactic WN stars: Spectral analyses with line-blanketed model atmospheres versus stellar evolution models with and without rotation

CONTEXT: Very massive stars pass through the Wolf-Rayet (WR) stage before they finally explode. Details of their evolution have not yet been safely established, and their physics are not well understood. Their spectral analysis requires adequate model atmospheres, which have been developed step by step during the past decades and account in their recent version for line blanketing by the millions of lines from iron and iron-group elements. However, only very few WN stars have been re-analyzed by means of line-blanketed models yet. AIMS: The quantitative spectral analysis of a large sample of Galactic WN stars with the most advanced generation of model atmospheres should provide an empirical basis for various studies about the origin, evolution, and physics of the Wolf-Rayet stars and their powerful winds. METHODS: We analyze a large sample of Galactic WN stars by means of the Potsdam Wolf-Rayet (PoWR) model atmospheres, which account for iron line blanketing and clumping. The results are compared with a synthetic population, generated from the Geneva tracks for massive star evolution. RESULTS: We obtain a homogeneous set of stellar and atmospheric parameters for the Galactic WN stars, partly revising earlier results. CONCLUSIONS: Comparing the results of our spectral analyses of the Galactic WN stars with the predictions of the Geneva evolutionary calculations, we conclude that there is rough qualitative agreement. However, the quantitative discrepancies are still severe, and there is no preference for the tracks that account for the effects of rotation. It seems that the evolution of massive stars is still not satisfactorily understood.Comment: 19 pages, 11 figures, A&A, in press, additional Online-material on http://www.astro.physik.uni-potsdam.de/abstracts/galwn.htm

In Vivo Optical Measurements for Diagnostics and Monitoring of Treatment

The interaction of light with tissue and its use for medical purposes has been under investigation for centuries. Since the early nineteen sixties, the development of novel optical technology and advances in laser design/technology allowed a wide range of innovative applications in many fields of medicine. For the majority of light applications in medicine the distribution of light within tissue is of fundamental importance. The light distribution is determined by the optical properties of the tissue; scattering and absorption. This thesis focuses on two applications of light in medicine, photodynamic therapy (PDT) and optical diagnostics. For each application the effect of differences in and changes of tissue optical properties are investigated. The distribution of light within tissue is of vital importance in PDT and is strongly dependent on the in vivo optical properties. In vivo differences and variations in optical properties are also critically important for optical diagnostics. The hypothesis presented is that the underlying cause of the current limitations in clinical PDT and low sensitivity in optical diagnosis are due to the heterogeneous and dynamic nature of tissue optical properties. This thesis tests this hypothesis by investigating the spatial distribution, inter patient differences, and temporal behaviour of in vivo optical properties by means of in vivo light measurement