Mm/submm observations of symbiotic binary stars: implications for the mass loss and mass exchange

We discuss mm/submm spectra of a sample of symbiotic binary systems, and compare them with popular models proposed to account for their radio emission. We find that radio emission from quiescent S-type systems originates from a conical region of the red giant wind ionized by the hot companion (the STB model), whereas more complicated models involving winds from both components and their interaction are required to account for radio emission of active systems. We also find that the giant mass-loss rates derived from our observations are systematically higher than those for single cool giants. This result is in agreement with conclusions derived from IRAS observations and with requirements of models for the hot component.Comment: 7 pages, 8 figures. Paper presented at COSPAR 2000 "New results in FIR and Submm Astronomy", to be published in Advances in Space Researc

A search for symbiotic behaviour amongst OH/IR colour mimics

Recent maser surveys have shown that many potential OH/IR stars have no OH masers in their circumstellar envelopes, despite the modest requirements which should be implicitly met by IRAS colour-selected candidates. It has been suggested that these OH/IR colour mimics must have a degenerate companion which dissociates OH molecules and disrupts the masing action, ie. that they are related to symbiotic Miras. Coincidentally, there is a paucity of long-period symbiotic Miras and symbiotic OH/IR stars. Phenomonologically, those that are known seem to cluster in the zone where field Miras transform into OH/IR stars. If it could be proven that OH/IR colour mimics contain a degenerate star, that observable evidence of this star is hidden from view by CS dust whilst it slowly accretes from the wind of its Mira companion, then we have an excellent explanation for not only the existence of OH/IR colour mimics, but also for the low observed frequency of symbiotic OH/IR stars and the common occurrence of very slow novae in long-period symbiotic Miras. Here, we employ radio continuum radiation (which should escape unhindered from within the dust shells) as a simple probe of the postulated hot degenerate companions which would inevitably ionize a region of their surrounding gas. We compare the radio and infrared properties of the colour mimics with those of normal symbiotic Miras, using the strong correlation between radio and mid-IR emission in symbiotic stars. We show that if a hot companion exists then, unlike their symbiotic counterparts, they must produce radiation-bounded nebulae. Our observations provide no support for the above scenario for the lack of observed masers, but neither do they permit a rejection of this scenario.Comment: 6 pages; no figures attached; LaTeX (MN style); postscript figures via anonymous ftp in users/ers/mimic-figs on astro.caltech.edu; University of Toronto pre-print; ERSRJI

Consortium for materials development in space interaction with Space Station Freedom

The Consortium for Materials Development in Space (CMDS) is one of seventeen Centers for the Commercial Development of Space (CCDS) sponsored by the Office of Commercial Programs of NASA. The CMDS formed at the University of Alabama in Huntsville in the fall of 1985. The Consortium activities therefore will have progressed for over a decade by the time Space Station Freedom (SSF) begins operation. The topic to be addressed here is: what are the natural, mutually productive relationships between the CMDS and SSF? For management and planning purposes, the Consortium organizes its activities into a number of individual projects. Normally, each project has a team of personnel from industry, university, and often government organizations. This is true for both product-oriented materials projects and for infrastructure projects. For various projects Space Station offers specific mutually productive relationships. First, SSF can provide a site for commercial operations that have evolved as a natural stage in the life cycle of individual projects. Efficiency and associated cost control lead to another important option. With SSF in place, there is the possibility to leave major parts of processing equipment in SSF, and only bring materials to SSF to be processed and return to earth the treated materials. This saves the transportation costs of repeatedly carrying heavy equipment to orbit and back to the ground. Another generic feature of commercial viability can be the general need to accomplish large through-put or large scale operations. The size of SSF lends itself to such needs. Also in addition to processing equipment, some of the other infrastructure capabilities developed in CCDS projects may be applied on SSF to support product activities. The larger SSF program may derive mutual benefits from these infrastructure abilities

Discovery of hydroxyl and water masers in R Aquarii and H1-36 Arae

We present the first results from an all-sky maser-line survey of symbiotic Miras. Interferometric spectral-line observations of R Aqr and H1-36 Arae have revealed a 22-GHz water maser in the former and 1612-MHz hydroxyl and weak 22-GHz water maser emission from the latter. H1-36 has thus become the first known symbiotic OH/IR star. We have also detected weak OH line emission from the vicinity of R Aqr, but we note that there are small discrepencies between the OH- and H2O-line velocities and positions. These detections demonstrate unequivocally that dust can shield some circumstellar hydroxyl and water molecules from dissociation, even in systems which possess intense local sources of UV. Finally, we discuss some of the implications of these observations. The narrow profile of the water maser in R Aqr means that there may finally be an opportunity to determine the system's orbital parameters. We also point out that high resolution synthesis observations may trace the distribution of dust in H1-36 and R Aqr, possibly throwing light on the mass-loss process in symbiotic Miras and placing constraints on the amount of collimation experienced by UV radiation from their hot, compact companions.Comment: 7 pages; no figures attached; LaTex (MN style); postscript figures via anonymous ftp in /users/ers on astro.caltech.edu; University of Toronto pre-print; ERSRJI

Revised masses of dust and gas of SLUGS FIR bright galaxies based on a recent CO survey

Recent CO measurements of an essentially complete sub-sample of galaxies from the SCUBA Local Universe Survey (SLUGS) are used to examine their implications for dust and gas masses in this sample. Estimates of dust masses are affected by a contribution to the SCUBA brightness measurements by CO(3-2) emission, and molecular gas masses by the use of a modified value of the CO-to-H_2 conversion factor X. The average dust mass is reduced by 25-38 per cent, which has no bearing on earlier conclusions concering the shapes of the dust mass luminosity function derived from the SLUGS. The value of X found from the CO survey, when applied together with the reduction in dust masses, leads to lower estimates for the mean gas-to-dust mass ratios, where the gas includes both H_2 and HI. For the CO sample, the mean global ratio is reduced from approximately 430 to about 320-360, but is further reduced to values near 50 when applied to the nuclear regions relevant to the CO observations. We discuss these results and suggest that the differences between the nuclear and outer regions may simply reflect differences in metallicity or the existence of considerable amounts of unobserved cold dust in the outer regions of these galaxiies.Comment: 18 pages, 2 tables, 4 figures, accepted for publication in MNRA

Advance Care Planning Education for Older Adults

Advanced care planning guides health care professionals and surrogate decision-makers choices on end of life (EOL) care when individuals are no longer able to speak for themselves. Advanced care plans can benefit patients in their last six months of life by improving their quality of life and by reducing family members anxiety, depression, and stress when dealing with EOL treatment options. Aside from these benefits, poor communication and knowledge deficits often create barriers when medical staff, families or patients try to broach the subject of EOL care. Barriers can be overcome when health care professionals facilitate advanced care planning conversations in the right setting, with staff trusted by patients, and when medical decisions are not urgent. This scholarly project educated individuals older than 55 years of age. They were provided education on advanced directives, medical terminology, and how to initiate conversations about end of life wishes with family or friends. In one education session, two people attended. Of those two individuals, one had an advanced care plan, and the other individual did not have an advanced care plan. This education session encouraged the participants to update their existing advanced care plan routinely with changes and create one if they previously had not. This education session highlights the importance of educating individuals on the options they have towards EOL and what that can do to ensure their wishes are followed when they can no longer speak for themselves

Ritual Syntax

Frits Staal developed a theory of ritual in the late 1970s that is well-known to ritual studies scholars, though consistently misunderstood. Most attention has focused on Staal\u27s claim that rituals are meaningless, since this seems contrary to most theories of ritual, and to professed beliefs of ritual practitioners. I show that Staal\u27s treatment of meaning is more subtle than most readers allow, and I demonstrate that other theorists make similar claims, but my main focus is on another part of Staal\u27s theory: the claim that rituals have the same formal structure, or syntax, as natural languages. Staal adapts to ritual an approach originally developed for language by Noam Chomsky, to the effect that ritual structure is sufficiently complex that it can only be modeled by what is known as a Context Sensitive Language. Seen in this light, Staal\u27s theory is really a cognitive theory of ritual, in other words it is a theory of the mental qualities that are necessary for a person\u27s actions to count as ritual actions. My final chapter therefore considers this theory in the light of recent, cognitive approaches to religion, especially the work of Dan Sperber and Pascal Boyer. Most work in the cognitive science of religion relies on methods from cognitive psychology, and Staal\u27s theory is unique in presenting a computational model of ritual structure. It focuses our attention on the sequential ordering of the elementary actions that compose ritual sequences, and in the process it opens up a wide range of research programs for ethnologists and historians, as well as for ritual studies theorists. Staal\u27s theory is based on data from the Vedic ritual tradition, especially the fieldwork he pursued on a performance of the Agnicayana in South India; in the process of examining Staal\u27s theory, I consider a variety of topics relating to South Asian and Vedic ritual and grammatical theory, and I supplement this with a look at exempla from other ritual cultures. In addition to a thorough analysis and critique of Staal\u27s theory, I provide the foundation for what I call a “distributional” study of ritual structure