OH-selected AGB and post-AGB stellar objects II.Blue versus red evolution off the AGB

Using objects found in a systematic survey of the galactic Plane in the 1612-MHz OH line, we discuss in detail two ``sequences'' of post-AGB evolution, a red and a blue. We argue that the red and the blue groups separate by initial mass at 4Msun, based on evolutionary-sequence turn-off colours, spectral energy distributions, outflow velocities and scaleheight. The higher-mass (blue) objects may have earlier AGB termination. The lower-mass (red) objects undergo very sudden reddening for IRAS colour R21\sim1.2; these sources must all undergo a very similar process at AGB termination. The transition colour corresponds to average initial masses of 1.7Msun. A combined IRAS-MSX colour proves a very sensitive tool to distinguish lower-mass, early post-AGB objects from sources still on the AGB and also to distinguish more evolved post-AGB objects from star-forming regions. The high-mass blue objects are the likely precursors of bipolar planetary nebulae, whereas the low-mass red objects will evolve into elliptical planetary nebulae.Comment: 12 pages, LaTex, 7 figures (1 colour), AJ (accepted

OH-selected AGB and post-AGB objects I.Infrared and maser properties

Using 766 compact objects from a survey of the galactic Plane in the 1612-MHz OH line, new light is cast on the infrared properties of evolved stars on the TP-AGB and beyond. The usual mid-infrared selection criteria, based on IRAS colours, largely fail to distinguish early post-AGB stages. A two-colour diagram from narrower-band MSX flux densities, with bimodal distributions, provides a better tool to do the latter. Four mutually consistent selection criteria for OH-masing red PPNe are given, as well as two for early post-AGB masers and one for all post--AGB masers, including the earliest ones. All these criteria miss a group of blue, high-outflow post-AGB sources with 60-mum excess; these will be discussed in detail in Paper II. The majority of post-AGB sources show regular double-peaked spectra in the OH 1612-MHz line, with fairly low outflow velocities, although the fractions of single peaks and irregular spectra may vary with age and mass. The OH flux density shows a fairly regular relation with the stellar flux and the envelope optical depth, with the maser efficiency increasing with IRAS colour R21. The OH flux density is linearly correlated with the 60-mum flux density.Comment: 16 pages, LaTex, 22 figures, AJ (accepted

Dissociation between medial frontal negativity and cardiac responses in the ultimatum game: Effects of offer size and fairness

In the present study, we examined the role of fairness and offer size on brain and cardiac responses in the ultimatum game (UG). Twenty healthy volunteers played the role of responder in a computerized version of the UG in which the fairness and size of the offers were systematically varied. Both fairness and size of the offer influenced the acceptance rates in a predictable way, leading to fewer accepted unfair and low offers. Only unfair high, but not unfair low offers were accompanied by a medial frontal negativity. An unexpected stronger cardiac deceleration to fairer offers was found, which was not affected by the size of the offers. Cardiac and electrocortical measures showed a different relation with performance, and both measures were correlated only modestly. This dissociation between cardiac responses and brain potentials is discussed in terms of a possible differential sensitivity to effects of stimulus probability and violation of the social rules

The Influence of BIA-ALCL on the Use of Textured Breast Implant and its Placement:A Survey of Dutch Plastic Surgeons

BACKGROUND: Breast implant-associated anaplastic large-cell lymphoma (BIA-ALCL) and its association with macrotextured breast implants may have induced plastic surgeons to change their breast augmentation and breast reconstruction practice.OBJECTIVES: The aim of this study was to survey Dutch plastic surgeons about the effects of BIA-ALCL on their choice of breast implant texture and placement technique.METHODS: An online questionnaire was distributed to all members of the Dutch Association of Plastic Surgeons. Descriptive data were presented as frequencies and percentages. Technique alterations were analyzed by the marginal homogeneity test for paired nominal data.RESULTS: A total of 63 plastic surgeons completed the questionnaire. The majority of respondents altered their use of textured implants due to BIA-ALCL concerns for both breast augmentation and reconstruction (75.4% and 69.8%, respectively; both being statistically significant, P &lt; .001). Microtextured and smooth/nanotextured breast implants are now most frequently used. BIA-ALCL did not influence the placement technique in breast augmentation and reconstruction (87.7% and 94.3%, respectively). Dual-plane breast implant placement is still the most favored technique for breast augmentation, and submuscular placement is still most favored for breast reconstruction.CONCLUSIONS: BIA-ALCL has had a significant impact on the use of macrotextured breast implants by Dutch plastic surgeons in both aesthetic and reconstructive breast surgery. Breast implant placement technique has not been affected.</p