Practice under pressure: what neurology can learn from anaesthesia

Performing a stressful task under pressure is challenging. Strategies to optimise our training must focus on learning a skill correctly, and then practising that skill sufficiently to avoid compromising that performance in the cauldron of the clinical environment. This article discusses ways of doing things better, based on practical strategies employed in anaesthesia, but developed primarily in elite sport and the military. It involves taking a skill, practising it until it becomes a habit and over time making it part of normal behaviour. The philosophy is simple (but difficult to apply): control what you can control and always do your best. The best summary of this strategy is: learn it right, practise it right, perform it right

How often should you have dental visits?

Dental diseases are a costly public health issue that disproportionately affect disadvantaged people.1,2 However in Australia, access to oral health care services is determined largely by the ability to pay. In recent years, there has been growing concern about inequities in access to care, with a particular focus on the length of time people are waiting to access state and territory-funded public dental services. In response to these concerns, the Gillard government established a National Advisory Council on Dental Health in 2011. In August 2012, the government announced a new dental reform package that would replace two of its existing dental programs – the Chronic Disease Dental Scheme and Medicare Teen Dental program – both of which provide benefits to patients through the Medicare scheme. In contrast, the new reform package provides more funding to state and territory governments so that they can reduce public dental waiting lists and establish more effective and efficient dental care for low income families and children. To implement the new reform package, policymakers will need to make important decisions about access to publicly-funded dental care: who should be eligible, how often should they be able to access services, and what services should be covered

How to be a resilient doctor: skills to maximize your antifragility

Resilience has become a byword for solving many of the problems in the current NHS caused by years of underfunding and increased workload. This article focuses on individual skills and resources that the reader can use to enhance his/her own performance in life and work

Suspended Sediment Fluxes at an Intertidal Flat: The Shifting Influence of Wave, Wind, Tidal, and Freshwater Forcing

Using in situ, continuous, high frequency (8–16 Hz) measurements of velocity, suspended sediment concentration (SSC), and salinity, we investigate the factors affecting near-bed sediment flux during and after a meteorological event (cold front) on an intertidal flat in central San Francisco Bay. Hydrodynamic forcing occurs over many frequency bands including wind wave, ocean swell, seiching (500–1000 s), tidal, and infra-tidal frequencies, and varies greatly over the time scale of hours and days. Sediment fluxes occur primarily due to variations in flow and SSC at three different scales: residual (tidally averaged), tidal, and seiching. During the meteorological event, sediment fluxes are dominated by increases in tidally averaged SSC and flow. Runoff and wind-induced circulation contribute to an order of magnitude increase in tidally averaged offshore flow, while waves and seiching motions from wind forcing cause an order of magnitude increase in tidally averaged SSC. Sediment fluxes during calm periods are dominated by asymmetries in SSC over a tidal cycle. Freshwater forcing produces sharp salinity fronts which trap sediment and sweep by the sensors over short (∼30 min) time scales, and occur primarily during the flood. The resulting flood dominance in SSC is magnified or reversed by variations in wind forcing between the flood and ebb. Long-term records show that more than half of wind events (sustained speeds of greater than 5 m/s) occur for 3 h or less, suggesting that asymmetric wind forcing over a tidal cycle commonly occurs. Seiching associated with wind and its variation produces onshore sediment transport. Overall, the changing hydrodynamic and meteorological forcing influence sediment flux at both short (minutes) and long (days) time scales

Shear and turbulence production across subtidal channels

Author Posting. © Sears Foundation for Marine Research, 2006. This article is posted here by permission of Sears Foundation for Marine Research for personal use, not for redistribution. The definitive version was published in Journal of Marine Research 64 (2006): 147-171, doi:10.1357/002224006776412359.In intertidal regions with subtidal channels, effects of bathymetry on overlying flow vary greatly with tidal stage. Around low water when mudflats and marsh are exposed, flow is constrained to channels, but when water depths are greater, tidal forcing may not necessarily be aligned with meandering channel axes. Flow across the channel can generate strong shear and turbulence at the elevation of the channel banks and can significantly increase turbulent energy in the middle of the water column. Field observations in a mudflat channel of San Francisco Bay indicate that cross-channel shear regularly occurs there early in ebb tides. With increased freshwater flow, baroclinic forcing can enhance shear by decoupling flow between dense water flooding in the channel and fresher water ebbing above the channel banks. A water column numerical model with κ-ε turbulence closure is modified to represent the cross-channel shear production. Numerical results with uniform density indicate that turbulence production increases with the angle between the barotropic tidal forcing and the channel axis. When a longitudinal salinity gradient is imposed, cross-channel shear production contributes to breakdown of periodic stratification. Turbulence produced at the channel banks locally exceeds dissipation, and the excess energy is either lost to buoyancy or diffuses vertically to lower energy regions near the surface and near the bed. The balance among shear production, buoyancy production, and diffusion of turbulence depends on the flow angle and the strength of the longitudinal salinity gradient.This research was funded by National Institutes of Health grant no. P42ES0475 from the National Institute of Environmental Health Sciences

Tidal and meteorological forcing of sediment transport in tributary mudflat channels

Author Posting. © Elsevier B.V., 2007. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Continental Shelf Research 27 (2007): 1510-1527, doi:10.1016/j.csr.2007.01.010.Field observations of flow and sediment transport in a tributary channel through intertidal mudflats indicate that suspended sediment was closely linked to advection and dispersion of a tidal salinity front. During calm weather when tidal forcing was dominant, high concentrations of suspended sediment advected up the mudflat channel in the narrow region between salty water from San Francisco Bay and much fresher runoff from the small local watershed. Salinity and suspended sediment dispersed at similar rates through each tidal inundation, such that during receding ebbs the sediment pulse had spread spatially and maximum concentrations had decreased. Net sediment transport was moderately onshore during the calm weather, as asymmetries in stratification due to tidal straining of the salinity front enhanced deposition, particularly during weaker neap tidal forcing. Sediment transport by tidal forcing was periodically altered by winter storms. During storms, strong winds from the south generated wind waves and temporarily increased suspended sediment concentrations. Increased discharge down the tributary channels due to precipitation had more lasting impact on sediment transport, supplying both buoyancy and fine sediment to the system. Net sediment transport depended on the balance between calm weather tidal forcing and perturbations by episodic storms. Net transport in the tributary channel was generally off-shore during storms and during calm weather spring tides, and on-shore during calm weather neap tides.The research was funded by National Institutes of Health grant P42ES0475 from the National Institute of Environmental Health Sciences. Reference

Examining egg surface morphology and microbial content of Sceloporus virgatus eggshells

Eggs laid by the Sceloporus virgatus lizard are exposed to a variety of potentially protective microorganisms when passed through the cloaca, the opening at the end of both the reproductive and digestive tracts. Past data have indicated that eggs dissected out of the female before passing through the cloaca often have decreased hatching success, potentially due to the lack of protective bacteria on the dissected eggshell surface. This study examined the microorganisms found on both laid and dissected eggs at 0 weeks of incubation, as well as microbial and fungal content on the eggshells after 3 weeks of incubation in a non-sterile environment. The eggshells were swabbed and plated onto media to observe any visible growth at 0 and 3 weeks of incubation. The morphology of the eggshells was also studied with scanning electron microscopy to determine visual differences in microbial and fungal content between the eggs. A lesser proportion of dissected eggs exhibited microbial growth at 0 weeks of incubation, while at 3 weeks of incubation fungal growth was found on mainly dissected eggs. The results support the claim that laid eggs passed through the cloaca may be exposed to microorganisms that are protective against fungi in the incubation environment

Thermal prestress in composite compliant shell mechanisms

This paper explores the ability to tailor the mechanical properties of composite compliant shell mechanisms, by exploiting the thermal prestress introduced during the composite laminate cure. An extension of an analytical tape spring model with composite thermal analysis is presented, and the effect of the thermal prestress is studied by means of energy landscapes for the cylindrical composite shells. Tape springs that would otherwise be monostable structures become bistable and exhibit greater ranges of low-energy twisting with thermally induced prestress. Predicted shell geometries are compared with finite element (FE) results and manufactured samples, showing good agreement between all approaches. Wider challenges around the manufacture of prestressed composite compliant mechanisms are discussed