Feasibility of an automated interview grounded in multiple mini interview (MMI) methodology for selection into the health professions: an international multimethod evaluation.

OBJECTIVES: Global, COVID-driven restrictions around face-to-face interviews for healthcare student selection have forced admission staff to rapidly adopt adapted online systems before supporting evidence is available. We have developed, what we believe is, the first automated interview grounded in multiple mini-interview (MMI) methodology. This study aimed to explore test-retest reliability, acceptability and usability of the system. DESIGN, SETTING AND PARTICIPANTS: Multimethod feasibility study in Physician Associate programmes from two UK and one US university during 2019-2020. PRIMARY, SECONDARY OUTCOMES: Feasibility measures (test-retest reliability, acceptability and usability) were assessed using intraclass correlation (ICC), descriptive statistics, thematic and content analysis. METHODS: Volunteers took (T1), then repeated (T2), the automated MMI, with a 7-day interval (±2) then completed an evaluation questionnaire. Admission staff participated in focus group discussions. RESULTS: Sixty-two students and seven admission staff participated; 34 students and 4 staff from UK and 28 students and 3 staff from US universities. Good-excellent test-retest reliability was observed at two sites (US and UK2) with T1 and T2 ICC between 0.65 and 0.81 (p<0.001) when assessed by individual total scores (range 80.6-119), station total scores 0.6-0.91, p<0.005 and individual site (≥0.79 p<0.001). Mean test re-test ICC across all three sites was 0.82 p<0.001 (95% CI 0.7 to 0.9). Admission staff reported potential to reduce resource costs and bias through a more objective screening tool for preselection or to replace some MMI stations in a 'hybrid model'. Maintaining human interaction through 'touch points' was considered essential. Users positively evaluated the system, stating it was intuitive with an accessible interface. Concepts chosen for dynamic probing needed to be appropriately tailored. CONCLUSION: These preliminary findings suggest that the system is reliable, generating consistent scores for candidates and is acceptable to end users provided human touchpoints are maintained. Thus, there is evidence for the potential of such an automated system to augment healthcare student selection.

Effect of extracellular polymeric substances on the mechanical properties of Rhodococcus.

The mechanical properties of Rhodococcus RC291 were measured using force spectroscopy equipped with a bacterial cell probe. Rhodococcal cells in the late growth stage of development were found to have greater adhesion to a silicon oxide surface than those in the early growth stage. This is because there are more extracellular polymeric substances (EPS) that contain nonspecific binding sites available on the cells of late growth stage. It is found that EPS in the late exponential phase are less densely bound but consist of chains able to extend further into their local environment, while the denser EPS at the late stationary phase act more to sheath the cell. Contraction and extension of the EPS could change the density of the binding sites, and therefore affect the magnitude of the adhesion force between the EPS and the silicon oxide surface. By treating rhodococcal EPS as a surface-grafted polyelectrolyte layer and using scaling theory, the interaction between EPS and a solid substrate was modelled for the cell approaching the surface which revealed that EPS possess a large capacity to store charge. Changing the pH of the surrounding medium acts to change the conformation of EPS chains.

Reduced curvilinear velocity of boar sperm on substrates with increased hydrophobicity.

The curvilinear velocity (VCL) of boar spermatozoa between standard microscopy glassware decreases when the slides are coated with the hydrophobic polymer polystyrene (PS) compared with the less hydrophobic poly(methyl methacrylate) (PMMA) coating. Sperm from three boars were observed and analyzed using particle tracking software. The VCL did not differ significantly between coatings of different thickness, indicating no penetration of the sperm into the coating and that only the surface layer of the polymer film interacts with the sperm and buffer medium. The VCL of sperm between PS-coated surfaces was significantly reduced compared with PMMA surfaces (P < 0.0001), and this was attributed to a stronger hydrophobic effect between PS and water. The size of this effect varied between different boars, perhaps as a consequence of variations in hydrophobicity of sperm from different boars or different ejaculates. The modification of surface properties in this way may improve our understanding of sperm behavior and may provide improvements to assisted conception techniques as animal or human sperm used in assisted conception are frequently manipulated in laboratory plastics as part of diagnostic procedures (e.g., semen analysis) or before injection into an oocyte or during the co-incubation with the oocyte in IVF. Controlling the velocity of sperm using the interaction properties of inert polymer coatings could lead to new sperm selection procedures for clinical use or the development of model systems to better understand sperm-surface interactions.

Single macromolecule diffusion in confined environments.

We consider the behaviour of single molecules on surfaces and, more generally, in confined environments. These are loosely split into three sections: single molecules in biology, the physics of single molecules on surfaces and controlled (directed) diffusion. With recent advances in single molecule detection techniques, the importance and mechanisms of single molecule processes such as localised enzyme production and intracellular diffusion across membranes has been highlighted, emphasising the extra information that cannot be obtained with techniques that present average behaviour. Progress has also been made in producing artificial systems that can control the rate and direction of diffusion, and because these are still in their infancy (especially in comparison to complex biological systems), we discuss the new physics revealed by these phenomena.