Biology subjects

Rasmussen, P.

Publications and source records attributed to Rasmussen, P..

3 recordsLinked to original sources

bioRxiv2026

First characterization of metabolomic and lipidomic exchange over the healthy human brain

The energy turnover and metabolic flexibility of the human brain extend beyond a primary reliance on carbohydrates and oxygen. Building on work in anesthetized patients with cerebrovascular pathology, we quantified trans-cerebral arteriovenous differences in healthy humans to isolate and characterize the most abundant cerebral metabolite and lipid species. We observed a net release of acylcarnitine from the cerebral circulation, indicating that these species are active in mitochondrial fatty acid {beta}-oxidation occurring in the healthy resting brain. Furthermore, a strong association was apparent between variability in the brains respiratory quotient (RQ) and activity within the purine salvage pathway, particularly with the uptake of guanosine monophosphate. In a larger sample size (n = 210), we further established that biological variability around an RQ of 1.0 - typically interpreted as exclusive carbohydrate oxidation - coincides with coordinated arteriovenous shifts in metabolomic and lipidomic pathways. The variability is not only visible through complex omics pathways, but is also strongly related to the oxygen carbohydrate index of the brain, further supporting that energy substrates other than glucose are exchanged and oxidized across the brain. These findings reveal substantial versatility and redundancy in how the healthy brain maintains its high energetic demands through flexible, interconnected metabolic and lipidomic networks.

physiology↗

bioRxiv2024

Randomised Badger Culling Trial lacks evidence for proactive badger culling effect on tuberculosis in cattle: comment on Mills et al. 2024, Parts I & II

Re-evaluation of statistical analysis of the Randomised Badger Culling Trial (RBCT) by Torgerson et al. 2024 was rebutted by Mills et al. 2024 Parts I and II. The rebuttal defended the use of count rather than rate when considering bovine tuberculosis herd incidence. The defence makes biologically implausible use of Information Criterion for appraisal diagnostics; overfits data; and has erroneous Bayesian analyses. It favours goodness of fit over predictive power, for a small data set, when the study was to inform application. Importantly, for total bTB breakdown: ( confirmed (OTF-W) +unconfirmed (OTF-S)), where modern interpretation of the main diagnostic bTB test better indicates the incidence rate of herd breakdown, there is no effect in cull and neighbouring areas, across all statistical models. The RBCT was a small, single experiment with unknown factors. With respect to the paradigm of reproducibility and the FAIR principles, the original RBCT analysis and recent efforts to support it are wholly unconvincing. The 2006 conclusion of the RBCT that "badger culling is unlikely to contribute positively to the control of cattle TB in Britain" is supported, but the route to such a position is revised in the light of modern veterinary understanding and statistical reappraisal.

microbiology↗

bioRxiv2022

Population Genomics of Stone Age Eurasia

Western Eurasia witnessed several large-scale human migrations during the Holocene1-5. To investigate the cross-continental impacts we shotgun-sequenced 317 primarily Mesolithic and Neolithic genomes from across Northern and Western Eurasia. These were imputed alongside published data to obtain diploid genotypes from >1,600 ancient humans. Our analyses revealed a Great Divide genomic boundary extending from the Black Sea to the Baltic. Mesolithic hunter-gatherers (HGs) were highly genetically differentiated east and west of this zone, and the impact of the neolithisation was equally disparate. Large-scale ancestry shifts occurred in the west as farming was introduced, including near-total replacements of HGs in many areas, whereas no substantial ancestry shifts happened east of the zone during the same period. Similarly, relatedness decreased in the west from the Neolithic transition onwards, while east of the Urals relatedness remained high until [~]4,000 BP, consistent with persistence of localised HG groups. The boundary dissolved when Yamnaya-related ancestry spread across western Eurasia around 5,000 BP resulting in a second major turnover that reached most parts of Europe within a 1,000-year span. The genetic origin and fate of the Yamnaya have remained elusive but we demonstrate that HGs from the Middle Don region contributed ancestry to them. Yamnaya-groups later admixed with individuals associated with the Globular Amphora Culture before expanding into Europe. Similar turnovers occurred in western Siberia, where we report new genomic data from a Neolithic steppe cline spanning the Siberian forest steppe to Lake Baikal. These prehistoric migrations had profound and lasting effects on the genetic diversity of Eurasian populations.

evolutionary biology↗