Addressing ethnic disparities in neurological research in the United Kingdom: An example from the prospective multicentre COVID-19 Clinical Neuroscience Study

\ua9 2024 The Author(s). Background: Minority ethnic groups have often been underrepresented in research, posing a problem in relation to external validity and extrapolation of findings. Here, we aimed to assess recruitment and retainment strategies in a large observational study assessing neurological complications following SARS-CoV-2 infection. Methods: Participants were recruited following confirmed infection with SARS-CoV-2 and hospitalisation. Self-reported ethnicity was recorded alongside other demographic data to identify potential barriers to recruitment. Results: 807 participants were recruited to COVID-CNS, and ethnicity data were available for 93.2%. We identified a proportionate representation of self-reported ethnicity categories, and distribution of broad ethnicity categories mirrored individual centres’ catchment areas. White ethnicity within individual centres ranged between 44.5% and 89.1%, with highest percentage of participants with non-White ethnicity in London-based centres. Examples are provided how to reach potentially underrepresented minority ethnic groups. Conclusions: Recruitment barriers in relation to potentially underrepresented ethnic groups may be overcome with strategies identified here

Palaeoclimate interpretation of stable isotope data from lake sediment archives

The isotope composition of authigenic and biogenic carbonates and diatom silica are commonly used as palaeoclimate proxies from lake sediments. This article reviews the controls on the isotope composition of lacustrine skeletal and non-skeletal deposits and illustrates how stable isotope studies contribute to an understanding of changes in temperature, precipitation patterns, evaporation and the carbon cycle. It highlights the differences in the palaeoclimate potential of a wide range of lakes ranging from open to closed lake basins. A large number of the case histories, but not all, are drawn from studies of temperate lakes from Europe. Large closed lake systems, in the tropics and elsewhere, lose water predominantly through evaporation, and contain sediments with variable and generally high δ18O values. Fluctuations in the isotope composition of authigenic or biogenic minerals are mainly a function of long-term changes in the precipitation/evaporation ratio. In contrast small open lakes which have a degree of through-flow typically contain sediments with δ18O values that vary by no more than a few ‰. These variations are generally ascribed to variations in temperature or the isotope composition of precipitation (δp), from which either an annual or seasonally specific signal can be gained. These types of lakes are common in Northern Europe and at high altitudes. The interpretation of isotope data from a lacustrine succession requires a knowledge of the local processes that might control and modify the signal. Their effects need to be quantified, and a robust calibration using the modern lake system is necessary to establish the relationship between the measured signal, the isotopic composition of the host waters, and climate