Ableism and Ageism: Insights from Disability Studies for Aging Studies

[This piece is written for those working in social gerontology and aging studies, with the aim of bringing insights from disability studies and philosophy of disability to bear on enduring debates in those fields.] The guiding question of humanistic age-studies—What does it mean to grow old?—cannot be answered without reflecting on disability. This is not simply because growing old invariably means becoming impaired in various ways, but also because the discriminations and stigmas involved in ageism are often rooted in ableism. We here draw on research in the philosophy of disability as well as the interdisciplinary field of disability studies to explore the relationship between ageism and ableism

A brain atlas of axonal and synaptic delays based on modelling of cortico-cortical evoked potentials

International audienceAbstract Epilepsy presurgical investigation may include focal intracortical single-pulse electrical stimulations with depth electrodes, which induce cortico-cortical evoked potentials at distant sites because of white matter connectivity. Cortico-cortical evoked potentials provide a unique window on functional brain networks because they contain sufficient information to infer dynamical properties of large-scale brain connectivity, such as preferred directionality and propagation latencies. Here, we developed a biologically informed modelling approach to estimate the neural physiological parameters of brain functional networks from the cortico-cortical evoked potentials recorded in a large multicentric database. Specifically, we considered each cortico-cortical evoked potential as the output of a transient stimulus entering the stimulated region, which directly propagated to the recording region. Both regions were modelled as coupled neural mass models, the parameters of which were estimated from the first cortico-cortical evoked potential component, occurring before 80 ms, using dynamic causal modelling and Bayesian model inversion. This methodology was applied to the data of 780 patients with epilepsy from the F-TRACT database, providing a total of 34 354 bipolar stimulations and 774 445 cortico-cortical evoked potentials. The cortical mapping of the local excitatory and inhibitory synaptic time constants and of the axonal conduction delays between cortical regions was obtained at the population level using anatomy-based averaging procedures, based on the Lausanne2008 and the HCP-MMP1 parcellation schemes, containing 130 and 360 parcels, respectively. To rule out brain maturation effects, a separate analysis was performed for older (>15 years) and younger patients (<15 years). In the group of older subjects, we found that the cortico-cortical axonal conduction delays between parcels were globally short (median = 10.2 ms) and only 16% were larger than 20 ms. This was associated to a median velocity of 3.9 m/s. Although a general lengthening of these delays with the distance between the stimulating and recording contacts was observed across the cortex, some regions were less affected by this rule, such as the insula for which almost all efferent and afferent connections were faster than 10 ms. Synaptic time constants were found to be shorter in the sensorimotor, medial occipital and latero-temporal regions, than in other cortical areas. Finally, we found that axonal conduction delays were significantly larger in the group of subjects younger than 15 years, which corroborates that brain maturation increases the speed of brain dynamics. To our knowledge, this study is the first to provide a local estimation of axonal conduction delays and synaptic time constants across the whole human cortex in vivo, based on intracerebral electrophysiological recordings

Aetiology of invasive bacterial infection and antimicrobial resistance in neonates in sub-Saharan Africa: a systematic review and meta-analysis in line with the STROBE-NI reporting guidelines

Background: Aetiological data for neonatal infections are essential to inform policies and programme strategies at various levels, but such data are scarce from sub-Saharan Africa. We therefore conducted a systematic review and meta-analysis of available data from the African continent since 1980, with a focus on regional differences in aetiology and antimicrobial resistance (AMR) in the last decade (2008 – 2018). Methods: We included data for microbiologically confirmed invasive bacterial infection including meningitis and AMR among neonates in sub-Saharan Africa and assessed the quality of scientific reporting according to Strengthening the Reporting of Observational Studies in Epidemiology for Newborn Infection (STROBE-NI) checklist. We calculated pooled proportions for reported bacterial isolates and AMR. Findings: We included 151 studies comprising data from 84534 neonates from 26 countries, almost all of which were hospital-based. Of the 82 studies published between 2008 and 2018, insufficient details were reported regarding most STROBE-NI items. Regarding culture positive bacteraemia/sepsis, S aureus, Klebsiella spp and E coli accounted for 25% (95% CI 21 – 29%) 21%, (16 – 27%) and 10% (8 – 10%) respectively. For meningitis, the predominant identified causes were Group B streptococcus 25% (16 – 33%), S pneumoniae 17% (9 – 26%), and S aureus 12% (3 – 25%). Resistance to WHO recommended β-lactams was reported in >68% of 904 cases and to aminoglycosides in 27% of 1176 cases. Interpretation: Hospital-acquired neonatal infections and AMR are a major burden in Africa, and improved surveillance is required. More population-based neonatal infection studies are also needed, and all studies should be reported according to standardised reporting guidelines, such as STROBE-NI to aid comparability and reduce research wastage