A feeding trial with growing sheep was conducted on mixed roughage-supplement diets, to test whether roughage intake could be estimated from a known intake of a supplement and an alkane-based estimate of the supplement and roughage proportions in the diet (diet composition) without the need for separate dosing with external marker alkanes. Diets consisted of chaffed Trifolium subterraneum hay (SC), or a mix of SC and beeswax-labelled cottonseed meal (CSM) in the proportions of 7: 1, 6: 2, 5: 3 and 4: 4 (air-dry matter basis). Six sheep were given the pure SC diet and three sheep were given each of the mixed diets. Additionally, the CSM was also labelled with octatriacontane (C38) to investigate its use for labelling supplements. Due to unexpectedly low recoveries, C38 was not included in any estimation of diet composition or digestibility.

The inclusion of beeswax-labelled CSM in a SC diet resulted in lower faecal alkane recoveries (as proportions of alkane ingested; P ≤ 0·05). Within mixed diets, recoveries decreased significantly with increasing proportion of CSM, but this effect was significant (P < 0·05) only for alkanes consisting of 25, 26, 27 and 29 carbon-atoms. Estimates of diet composition were close to measured values. Daily SC intake and organic matter digestibility (OMD) differed by −3·7 to 7·2% and −2·0 to 5·7% from measured values if a mean faecal recovery, across diets, was applied for each alkane. Accuracy increased greatly if estimates were based upon faecal alkane recoveries for individual diets, instead of mean recoveries across diets (−0·3 to 0·9% and −0·2 to 0·0% for SC intake and OMD, respectively).

The results indicate that roughage intake can be estimated from a combination of known supplement intake and an estimate of diet composition, which obviates the need for separate alkane dosing to estimate intake. The method should be applicable in situations in which animals either normally receive supplements (e.g., dairy cows) or could readily be given supplements.

A more accurate estimate of the number of ambulances needed at disasters prevents vehicles from being withdrawn unnecessarily from their “normal” duties, thereby curtailing needless expense and helping to ensure that disaster sites are not overcrowded with emergency workers impeding each other's effectiveness. This article discusses a formula for determining the number of ambulances needed at a disaster.

For more than two decades, emergency medical services (EMS) systems have proliferated primarily based upon governmental impetus and funding at the federal, state, and local levels. Although many of the foundations of patient care rendered in these systems have been based upon intuitive logic, the understanding of the impact on patient outcome is poor, at best. The reasons for the current status are varied, but five issues are preeminent:

1) The authority for the development of these medical systems has been based primarily in political and bureaucratic institutions which have little or no medical expertise;

2) Little attention has been paid to system evaluation, particularly in the area of cost-effectiveness;

3) Few academic medical institutions have become involved in EMS research;

4) Traditional approaches to medical research primarily are disease-specific and are not multidisciplinary. Thus these are not useful for evaluating and understanding the highly complex and uncontrolled environmental interactions that typify EMS systems; and

5) The process of efficiently and reliably collecting accurate data in the prehospital setting is extremely difficult.