Biology subjects

Finnegan, S.

Publications and source records attributed to Finnegan, S..

4 recordsLinked to original sources

bioRxiv2026

Nineteenth-century emergence of a seafloor ecosystem beyond late Quaternary limits

Mismatches between ecological time and geologic time complicate our ability to effectively compare contemporary ecosystem changes with those of the past. We amassed sub-decadal paleoecological data from the California Current System (CCS) to examine how benthic ecosystem structure evolved over the past 34,000 years in the Santa Barbara Basin across the glacial-to-interglacial transition. Our results indicate that even deep-sea ecosystems of the anthropocene sensu lato - the past few centuries characterized by outsized human impacts - are distinct compared to any point in the last 34,000 years. Novel ecosystem states and heightened variability began in the early 1800s AD, suggesting that colonial-era human land-use drove the emergence of a novel ecosystem state more than a century before global climate warming began in earnest.

paleontology↗

bioRxiv2022

Breathlessness in a virtual world: An experimental paradigm testing how discrepancy between VR visual gradients and pedal resistance during stationary cycling affects breathlessness perception.

IntroductionThe sensation of breathlessness is often attributed to perturbations in cardio-pulmonary physiology, leading to changes in afferent signals. New evidence suggests that these signals are interpreted in the light of prior "expectations". A misalignment between afferent signals and expectations may underly unexplained breathlessness. Using a novel immersive virtual reality (VR) exercise paradigm, we investigated whether manipulating an individuals expectation of effort (determined by a virtual hill gradient) may alter their perception of breathlessness, independent from actual effort (the physical effort of cycling). MethodsNineteen healthy volunteers completed a single experimental session where they exercised on a cycle ergometer while wearing a VR headset. We created an immersive virtual cycle ride where participants climbed up 100 m hills with virtual gradients of 4%, 6%, 8%, 10% and 12%. Each virtual hill gradient was completed twice: once with a 4% cycling ergometer resistance and once with a 6% resistance, allowing us to dissociate expected effort (virtual hill gradient) from actual effort (physical effort of pedalling). At the end of each hill, participants reported their perceived breathlessness. Linear mixed effects models were used to examine the independent contribution of actual effort and expected effort to ratings of breathlessness (0-10 scale). ResultsExpectation of effort (effect estimate {+/-} std. error, 0.63 {+/-} 0.11, p<0.001) and actual effort (0.81 {+/-} 0.21, p<0.001) independently explained subjective ratings of breathlessness, with comparable contributions of 19% and 18%, respectively. Additionally, we found that effort expectation accounted for 6% of participants physical effort of pedalling and was a significant, independent predictor (0.09 {+/-} 0.03; p=0.001). ConclusionsAn individuals expectation of effort is equally important for forming perceptions of breathlessness as the actual effort required to cycle. A new VR paradigm enables this to be experimentally studied and could be used to re-align breathlessness and enhance training programmes.

neuroscience↗

bioRxiv2020

The Filter Detection Task for measurement of breathing-related interoception and metacognition

The study of the brains processing of sensory inputs from within the body ( interoception) has been gaining rapid popularity in neuroscience, where interoceptive disturbances are thought to exist across a wide range of chronic physiological and psychological conditions. Here we present a task and analysis procedure to quantify specific dimensions of breathing-related interoception, including interoceptive sensitivity (accuracy), decision bias, metacognitive bias, and metacognitive performance. Two major developments address some of the challenges presented by low trial numbers in interoceptive experiments: (i) a novel adaptive algorithm to maintain task performance at 70-75% accuracy; (ii) an extended hierarchical metacognitive model to estimate regression parameters linking metacognitive performance to relevant (e.g. clinical) variables. We demonstrate the utility of the task and analysis developments, using both simulated data and three empirical datasets. This methodology represents an important step towards accurately quantifying interoceptive dimensions from a simple experimental procedure that is compatible with clinical settings.

neuroscience↗

bioRxiv2019

Adaptive maintenance of fertility in the face of meiotic drive

Selfish genetic elements that gain a transmission advantage through the destruction of sperm have grave implications for drive male fertility. In the X-linked SR meiotic drive system of a stalk-eyed fly, we found that drive males have greatly enlarged testes and maintain high fertility despite the destruction of half their sperm, even when challenged with fertilising large numbers of females. Conversely, we observed reduced allocation of resources to the accessory glands that probably explains the lower mating frequency of SR males. Body size and eyespan were also reduced, which are likely to impair viability and pre-copulatory success. We discuss the potential evolutionary causes of these differences between drive and standard males.

evolutionary biology↗