Mice are used extensively in preclinical diabetes research to model various aspects of blood glucose homeostasis. Careful experimental design is vital for maximising welfare and improving reproducibility of data. Alongside decisions regarding physiological characteristics of the animal cohort (e.g., sex, strain and age), experimental protocols must also be carefully considered. This includes choosing relevant end points of interest and understanding what information they can provide and what their limitations are. Details of experimental protocols must, therefore, be carefully planned during the experimental design stage, especially considering the impact of researcher interventions on preclinical end points. Indeed, in line with the 3Rs of animal research, experiments should be refined where possible to maximise welfare. The role of welfare may be particularly pertinent in preclinical diabetes research as blood glucose concentrations are directly altered by physiological stress responses. Despite the potential impact of variations in experimental protocols, there is distinct lack of standardisation and consistency throughout the literature with regards to several experimental procedures including fasting, cage changing and glucose tolerance test protocol. This review firstly highlights practical considerations with regard to the choice of end points in preclinical diabetes research and the potential for novel technologies such as continuous glucose monitoring and glucose clamping techniques to improve data resolution. The potential influence of differing experimental protocols and in vivo procedures on both welfare and experimental outcomes is then discussed with focus on standardisation, consistency and full disclosure of methods.

Ignition at the surface of a flammable liquid and the subsequent spread of flame occur in three stages: an induction period, in which the liquid burns only within the ignition source; a transition period, in which the flame spreads from the source to the liquid surface; and a propagation period, in which the flame spreads across the liquid surface without reference to the source. An experimental investigation of the first of these stages in a system for one-dimensional flame-spread is described. Changes in the liquid and gas phases during the induction period have been followed and effects of depth, surface dimensions and initial temperature of the liquid on the duration of this period studied. A probable sequence of events determining the end of the induction period is deduced.

The one-dimensional spread of flame along the surface of flammable liquids confined in a parallel-sided channel has been studied and the effects of physical dimensions and initial temperature upon its rate established. When the initial temperature of the liquid is below the closed flash point, flame spread depends upon the transfer of heat to the liquid sufficient to raise its surface temperature to the flash-point value and a qualitative picture of the mechanism by which this takes place is developed. When the initial temperature is above the flash point, flame spread is dependent upon conditions in the gas phase above the liquid and these are defined.

A theoretical model is proposed for the situation in which the rate of spread of flame across the surface of a liquid is controlled by the necessity to preheat the liquid in advance of the flame. In this model the flame is represented by a moving strip source of heat and the liquid by an anisotropic solid. The contributions of convection currents to the preheating of the liquid are represented by ‘effective thermal conductivities’. Heat conduction theory then leads to expressions relating rate of spread of flame and horizontal and vertical temperature variations in the liquid to the characteristics of the flame and the liquid. Several points of qualitative resemblance between the predictions of this theoretical model and relevant experimental data are established, and these are used to determine values of horizontal and vertical ‘effective thermal conductivities’ and of heat flux from the flame to the liquid, the significance of which is discussed. The model predicts a region in which the spread of flame would not be possible because of excessive heat loss. This region was not entered experimentally for reasons which are discussed.

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