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In this paper, an absorbing finite Markov chain model is developed to facilitate planning in a DBA Program in a Graduate School in Australia. The short- and long-term forecasting facilities offered by the model are used to determine the expected numbers in the DBA Program. The Markov model is also used to determine other critical attributes of the Program, such as expected success rate for candidates, expected first passage rimes prior to absorption per se and also prior to withdrawal and graduation specifically, all facilitating a status quo analysis. The absorbing state-specific first passage times are arrived at using a relatively simplified approach. This paper also illustrates how the model can be used to competitively benchmark these status quo attributes. The expected number of doctoral candidates in each 'state' within the Program (in both the short- and longterm contexts) can be used to estimate, among a range of important model attributes, the expected revenue stream and expected supervisor load in the DBA Program. From this information changes can be made to the Program where required. doi: 10.1057/palgrave.jors.2602639 Keywords: absorbing Markov chains; higher education; planning

This paper considers the difficulties associated with a production process that contains a sub-process that is not fully understood and for which data for many parameters are only able to be approximately obtained. The aluminium smelting industry epitomizes such a situation. Here, the critical sub-process that exemplifies these difficulties is the actual heart of the smelter, the electrolytic processing of alumina. This sub-process of aluminium production is at best 'fuzzy' and relies on the smelter operators to use their experience and tacit knowledge on a day-to-day basis, that is, the sub-process involves 'alchemy'. In this paper, this is referred to as the tacit knowledge problem. The impact of such sub-processes on production is significant and the development of a methodology that will lead to a reduced reliance on uncertain alchemy associated with them, highly beneficial. The role of Communities of Practice in finding a solution to the tacit knowledge problem is discussed together with its integration into a mixed-mode model for the determination of best practice production for the smelter. Keywords: Communities of Practice; mixed-mode modelling; knowledge management

In this paper, a simple heuristic is suggested that allows quick scheduling of small-to-medium-sized conferences by the programme chair/organizer. Owing to the nature of the problem that the heuristic was designed to solve, no annealing or combinatorial optimization techniques were required. Additionally, there is no explicit objective function associated with the problem only some simple constraints. The suggested heuristic aims to allocate all the conference papers to sessions over the conference duration taking into account presenter-based preferences (PBP) and some implicit attendee-based preferences. The conference programme chair (PC) may also insert preferences as to the positioning of papers and sessions. The heuristic also permits the PC to allocate appropriate rooms to sessions based on expectations regarding attendance. Owing to the simple nature of the heuristic, all that is required to facilitate its operation is a small programme created using a standard database package. The suggested heuristic, which effectively is a set of rules to be affected in a specific sequence, has been successfully used to schedule a Western Decision Sciences Institute (WDSI) annual conference. The conference spanned four days, had over three hundred participants, involved over 80 sessions with 200 papers and 50 special sessions. Journal of the Operational Research Society (2007) 58, 301-308. doi: 10.1057/palgrave.jors.2602144 Published online 11 January 2006 Keywords: conference scheduling; heuristics; practice of OR; timetabling

In this paper, a methodology for the ongoing diagnosis and facilitation (when required) of organizational change management programmes in an Australian University is described. The application of this methodology on an annual basis requires the assessment of research attitudes and behaviour, areas that have assumed considerable importance within universities around the world in the last decade. This increasing importance associated with research stems in part (a significant part) from the linkage of research quantum (output) of universities to their funding from government. The methodology developed in this paper embraces a wide range of OR-type techniques as well as a range of change management tools from human resources management. These two sets of techniques and tools work together as tools in their own right as well as providing the infrastructure to achieve the objectives. The developed methodology is an interesting blend of hard techniques and 'soft' approaches implemented through a soft heuristic, indeed this application is an example of mixed-mode modelling. The OR techniques (conventional in both their nature and application) are comprised of social judgement theory (for bench-marking research attitudes) and integer linear programming (for setting research targets). The results of the application of the developed methodology are discussed in terms of the effect on research quantum over a 5-year period. A similar methodology could be developed for a change process covering aspects of an organization other than research output in a number of countries. Keywords: Practice of OR; Performance measurement and management; mixed-mode modelling: change management

The relation between plasma brain natriuretic peptide (BNP) and the C-type natriuretic peptide (CNP) during the development of heart failure was investigated in sheep. Circulating levels of atrial natriuretic peptide (ANP), BNP and CNP were measured after acute and chronic ventricular pacing. Results showed an inverse relationship between pacing and arterial pressure, cardiac output, urine, sodium excretion and a positive relationship with left atrial pressure and plasma ANP, BNP and CNP.

Pathophysiological levels of atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) were co-infused into normal male subjects to determine if there are synergistic effects between ANP and BNP. Both peptides have similar physiological effects and are released into the plasma following myocardial infarction of congestive heart failure. The results show that co-infusion causes additive physiological effects, probably by causing the dissociation of pre-bound peptides from their clearance or biological receptors.

In normal and heart-failed sheep, angiotensin II (ANG II) is involved in the regulation of thirst and hemodynamics. In sheep the antagonist of the ANG II receptor, losartan, removes the drinking responses to heart failure, causes diuresis and anti-natriuresis, increases the activity of the plasma renin and the amount of aldosterone and ANG II in both paced and unpaced states. The inhibition of the plasma arginine vasopressin activity and a decrease in the left ventricular systolic and arterial pressure are seen only in the paced state.

Short term ouabain treatment does not change the plasma concentration of vasoactive hormones or pressor responsivesness in healthy males. Ouabain treatment decreases heart rate and enhances pulse pressure, but has no influence on pressor responsiveness to either norepinephrine or angiotensin II. Ouabain also does not influence the circulating quantities of renin, epinephrine norepinephrine, aldosterone, angiotensin II, brain natriuretic peptide and atrial natriuretic peptide.

Phase equilibria and isothermal, constant-rate decompression experiments conducted on a hawaiite from the Crater Flat volcanic zone near Yucca Mountain, Nevada, provide insight into the dynamics of magma transport for this magmatic province. H2O contents up to 4.6 wt% in melt inclusions, the lack of plagioclase phenocrysts, and the presence of amphibole all suggest that phenocrysts and melt in the Crater Flat volcanic zone were equilibrated at near-water-saturated conditions during ascent. Comparison of decompression-induced crystallization of plagioclase microlites in experiments with natural tephra implies that magma ascent rates for the region are >0.04 m/s if the magmas are water saturated. Estimates of minimum ascent rates increase if the magmas are water undersaturated. A two-stage process is needed to generate reaction rims found on natural amphibole, suggesting that small batches of magma were briefly stored (3-5 days) at depths as shallow as 800 m prior to eruption. [ABSTRACT FROM AUTHOR]

Examines a mathematical model that facilitates daily production scheduling in a tobacco processing plant, to minimize the number of machines used in the production process. Details on the model; Aspects that are relevant when dealing with daily and monthly time intervals; Information on a heuristic for daily production sequencing suggested; In-depth look at the production process; Conclusion based on the findings.

Examines the effect of stilboestrol on sodium balance, cardiac state and renin-angiotensin-aldosterone activity in prostatic carcinoma in England. Evidence of sodium retention; Increase in plasma volume; Mechanism of cardiac complications.