Emergency Department overcrowding is an important healthcare issue garnering significant public and regulatory scrutiny in Canada and around the world. Many approaches to alleviate excessive waiting ...times and lengths of stay have been considered and implemented to various degrees. In theory, a more optimal emergency department patient flow may be assisted via balancing patient loads between emergency departments within the region - in essence spreading patients more evenly throughout this system. This investigation uses available data for one regional health authority, and utilizes simulation to explore a process control strategy built on `crowdinforming', aimed to balance patient loads between six Emergency Departments within a mid-sized Canadian city. The preliminary model uses patient arrival rates as an indicator of `busyness' and as the basis for crowdinforming. Intuitively expected metrics such as the number of patients waiting, the average length of stay, and time waiting to be seen were not found to be meaningful metrics of emergency department `busyness' with this particular data set for the purpose of a process control strategy.
Mon.Not.Roy.Astron.Soc. 361 (2005) 460-468 We have used a Fourier Transform Spectrometer on the James Clerk Maxwell
Telescope to study the submillimetre continuum emission from dust in three hot
...molecular cores (HMC). The spectral index beta of the dust emission for these
sources has been determined solely within the 30 GHz wide 350 GHz (850 micron)
passband to an accuracy comparable to those determined through multi-wavelength
observations. We find an average beta = 1.6, in agreement with spectral indices
determined from previous submillimetre observations of these sources and with
those determined for HMC in general. The largest single source of uncertainty
in these results is the variability of the atmosphere at 350 GHz, and with
better sky subtraction techniques we show that the dust spectral index can
clearly be determined within one passband to high accuracy with a submillimetre
FTS. Using an imaging FTS on SCUBA-2, the next generation wide-field
submillimetre camera currently under development to replace SCUBA at the JCMT
in 2006, we calculate that at 350 GHz it will be possible to determine beta to
+/- 0.1 for sources as faint as 400 mJy/beam and to +/- 0.3 for sources as
faint as 140 mJy/beam.
Context. Ammonia and its deuterated isotopologues probe physical conditions in dense molecular cloud cores. The time-dependence of deuterium fractionation and the relative abundances of different ...nuclear spin modifications are supposed to provide a means of determining the evolutionary stages of these objects. Aims. We aim to test the current understanding of spin-state chemistry of deuterated species by determining the abundances and spin ratios of NH2D, NHD2 and ND3 in a quiescent, dense cloud. Methods. Spectral lines of NH3, NH2D, NHD2, ND3 and N2D+ were observed towards a dense, starless core in Ophiuchus with the APEX, GBT and IRAM 30-m telescopes. The observations were interpreted using a gas-grain chemistry model combined with radiative transfer calculations. The chemistry model distinguishes between the different nuclear spin states of light hydrogen molecules, ammonia and their deuterated forms. Different desorption schemes can be considered. Results. High deuterium fractionation ratios with NH2D = NH3 similar to 0 : 4, NHD2 = NH2D similar to 0 : 2 and ND3 = NHD2 similar to 0 : 06 are found in the core. The observed ortho/para ratios of NH2D and NHD2 are close to the corresponding nuclear spin statistical weights. The chemistry model can approximately reproduce the observed abundances, but consistently predicts too low ortho/para-NH2D, and too large ortho/para-NHD2 ratios. The longevity of N2H+ and NH3 in dense gas, which is prerequisite to their strong deuteration, can be attributed to the chemical inertia of N-2 on grain surfaces. Conclusions. The discrepancies between the chemistry model and the observations are likely to be caused by the fact that the model assumes complete scrambling in principal gas-phase deuteration reactions of ammonia, which means that all the nuclei are mixed in reactive collisions. If, instead, these reactions occur through proton hop/hydrogen abstraction processes, statistical spin ratios are to be expected. The present results suggest that while the deuteration of ammonia changes with physical conditions and time, the nuclear spin ratios of ammonia isotopologues do not probe the evolutionary stage of a cloud.
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