Coincidence of Small-scale Spatial Discontinuities in Leaf Morphology and Nuclear Microsatellite Variation of Quercus petraea and Q. robur in a Mixed Forest

Background and Aims The taxon complex comprising Quercus petraea and Q. robur shows distinct morphologies and ecological preferences, but mostly low differentiation in various types of molecular markers at a broad spatial range. Local, spatially explicit analyses may reveal patterns induced by microevolutionary processes operating mainly over short distances. However, no attempts have been made to date to explore the potential of spatial analyses combining morphological and genetic data of these oaks. Methods A mixed oak stand was studied to elucidate the small-scale population genetic structure. All adult individuals were classified and putative hybrids were identified using multivariate discrimination analysis of leaf morphological characters. Likewise, all trees were genotyped with five nuclear microsatellites, and a Bayesian assignment method was applied based on maximum likelihood of multilocus genotypes for taxon and putative hybrid classification. Key Results Multivariate analyses of leaf morphological data recognized two groups with few individuals as putative hybrids. These groups were significantly differentiated at the five microsatellites, and genetic taxon assignment coincided well with morphological classification. Furthermore, most putative hybrids were assigned to the taxon found in their spatial neighbourhood. When grouping trees into clusters according to their spatial positions, these clusters were clearly dominated by one taxon. Discontinuities in morphological and genetic distance matrices among these clusters showed high congruence. Conclusions The spatial-genetic analyses and the available literature led to the assumption that reproductive barriers, assortative mating, limited seed dispersal and microsite-induced selection in favour of the locally adapted taxon at the juvenile stage may reinforce taxon-specific spatial aggregation that fosters species separation. Thus, the results tend to support the hypothesis that Q. petraea and Q. robur are distinct taxa which share a recent common ancestry. Occasional hybrids are rarely found in adults owing to selection during establishment of juvenile

The PREVENT dementia programme: baseline demographic, lifestyle, imaging and cognitive data from a midlife cohort study investigating risk factors for dementia

PREVENT is a multi-centre prospective cohort study in the UK and Ireland that aims to examine midlife risk factors for dementia and identify and describe the earliest indices of disease development. The PREVENT dementia programme is one of the original epidemiological initiatives targeting midlife as a critical window for intervention in neurodegenerative conditions. This paper provides an overview of the study protocol and presents the first summary results from the initial baseline data to describe the cohort. Participants in the PREVENT cohort provide demographic data, biological samples (blood, saliva, urine and optional cerebrospinal fluid), lifestyle and psychological questionnaires, undergo a comprehensive cognitive test battery and are imaged using multi-modal 3-T MRI scanning, with both structural and functional sequences. The PREVENT cohort governance structure is described, which includes a steering committee, a scientific advisory board and core patient and public involvement groups. A number of sub-studies that supplement the main PREVENT cohort are also described. The PREVENT cohort baseline data include 700 participants recruited between 2014 and 2020 across five sites in the UK and Ireland (Cambridge, Dublin, Edinburgh, London and Oxford). At baseline, participants had a mean age of 51.2 years (range 40–59, SD ± 5.47), with the majority female (n = 433, 61.9%). There was a near equal distribution of participants with and without a parental history of dementia (51.4% versus 48.6%) and a relatively high prevalence of APOEɛ4 carriers (n = 264, 38.0%). Participants were highly educated (16.7 ± 3.44 years of education), were mainly of European Ancestry (n = 672, 95.9%) and were cognitively healthy as measured by the Addenbrookes Cognitive Examination-III (total score 95.6 ± 4.06). Mean white matter hyperintensity volume at recruitment was 2.26 ± 2.77 ml (median = 1.39 ml), with hippocampal volume being 8.15 ± 0.79 ml. There was good representation of known dementia risk factors in the cohort. The PREVENT cohort offers a novel data set to explore midlife risk factors and early signs of neurodegenerative disease. Data are available open access at no cost via the Alzheimer’s Disease Data Initiative platform and Dementia Platforms UK platform pending approval of the data access request from the PREVENT steering group committee

APOE ɛ4 exacerbates age-dependent deficits in cortical microstructure

The apolipoprotein E ɛ4 allele is the primary genetic risk factor for the sporadic type of Alzheimer’s disease. However, the mechanisms by which apolipoprotein E ɛ4 are associated with neurodegeneration are still poorly understood. We applied the Neurite Orientation Dispersion Model to characterize the effects of apolipoprotein ɛ4 and its interactions with age and education on cortical microstructure in cognitively normal individuals. Data from 1954 participants were included from the PREVENT-Dementia and ALFA (ALzheimer and FAmilies) studies (mean age = 57, 1197 non-carriers and 757 apolipoprotein E ɛ4 carriers). Structural MRI datasets were processed with FreeSurfer v7.2. The Microstructure Diffusion Toolbox was used to derive Orientation Dispersion Index maps from diffusion MRI datasets. Primary analyses were focused on (i) the main effects of apolipoprotein E ɛ4, and (ii) the interactions of apolipoprotein E ɛ4 with age and education on lobar and vertex-wise Orientation Dispersion Index and implemented using Permutation Analysis of Linear Models. There were apolipoprotein E ɛ4 × age interactions in the temporo-parietal and frontal lobes, indicating steeper age-dependent Orientation Dispersion Index changes in apolipoprotein E ɛ4 carriers. Steeper age-related Orientation Dispersion Index declines were observed among apolipoprotein E ɛ4 carriers with lower years of education. We demonstrated that apolipoprotein E ɛ4 worsened age-related Orientation Dispersion Index decreases in brain regions typically associated with atrophy patterns of Alzheimer’s disease. This finding also suggests that apolipoprotein E ɛ4 may hasten the onset age of dementia by accelerating age-dependent reductions in cortical Orientation Dispersion Index

Fluency training in medical education: Improving competence in IV fluid therapy knowledge and skills

Objectives: Intravenous fluid (IV) therapy is an important component of care for many hospital patients, especially in perioperative and acute care settings. However, errors in fluid composition and dosing can be life-threatening. To achieve competent professional performance, i.e., accurate and fluent, it is vitally important that medical students receive effective training in IV fluid therapy. Methods: In this study, we explored how Precision Teaching (PT), a behaviour analytic teaching method, can enhance outcomes of usual medical education techniques. A total of 178 third-year medical students participated in the study during the IV fluid therapy training week. All students completed a multiple-choice test pre- and post-training. In addition to standard IV fluid therapy teaching, the experimental intervention group (n=83 students) used SAFMEDS (Say All Fast MinuteEvery Day Shuffled) cards approximately 3-5 times per day for 5 days. The other 95 students (control group) received teaching as usual, but did not undergo the additional training. Results: Results show that the SAFMEDS boosted performance of the intervention group on the MCQ by 20 percentage points when compared to the control group. Fluency (accuracy and speed) of performance on SAFMED trials increased markedly during the intervention week and there was evidence that weaker students benefitted in particular. Conclusions: Implications for medical education are outlined

Fluency training in medical education: Improving competence in IV fluid therapy knowledge and skills

Objectives: Intravenous fluid (IV) therapy is an important component of care for many hospital patients, especially in perioperative and acute care settings. However, errors in fluid composition and dosing can be life-threatening. To achieve competent professional performance, i.e., accurate and fluent, it is vitally important that medical students receive effective training in IV fluid therapy. Methods: In this study, we explored how Precision Teaching (PT), a behaviour analytic teaching method, can enhance outcomes of usual medical education techniques. A total of 178 third-year medical students participated in the study during the IV fluid therapy training week. All students completed a multiple-choice test pre- and post-training. In addition to standard IV fluid therapy teaching, the experimental intervention group (n=83 students) used SAFMEDS (Say All Fast MinuteEvery Day Shuffled) cards approximately 3-5 times per day for 5 days. The other 95 students (control group) received teaching as usual, but did not undergo the additional training. Results: Results show that the SAFMEDS boosted performance of the intervention group on the MCQ by 20 percentage points when compared to the control group. Fluency (accuracy and speed) of performance on SAFMED trials increased markedly during the intervention week and there was evidence that weaker students benefitted in particular. Conclusions: Implications for medical education are outlined