Biology subjects

Bolton, P.

Publications and source records attributed to Bolton, P..

3 recordsLinked to original sources

bioRxiv2024

Test-Retest Reliability and repeatability of Behavioral and Electrophysiological Markers in an Eriksen Flanker Task

Cognitive control processes, specifically interference control and error monitoring, are often impaired across neuropsychiatric disorders and have been proposed as transdiagnostic markers of psychopathology and important treatment targets. Accurately probing them, however, requires understanding the psychometric properties of the measures used to assess cognitive control, including their intra- and interindividual stability over time. Using an Eriksen Flanker Task, we tested behavioral and electrophysiological readouts of cognitive control in 36 healthy individuals (26 female, 10 male, M age{+/-}SD=33.18{+/-}14.49, range=19-68) and evaluated their test-retest reliability across 48 hours by calculating Pearson correlations and Intraclass Correlation Coefficients (ICCs) to assess group-level stability. Moreover, we assessed repeatability through Coefficients of Variation (CVs) and Bland-Altman statistics, to investigate the degree of change in participants absolute scores. We found satisfactory-to-excellent test-retest reliability for most cognitive control measures, with condition-specific metrics generally being more reliable than difference scores. Regarding repeatability, we observed considerable intraindividual variability in absolute scores over time, which differed widely between participants. These results demonstrate that measurements of cognitive control may display substantial intraindividual variability across sessions despite demonstrating high test-retest reliability and vice versa. Our findings expand the current literature by providing novel information about the stability of behavioral and physiological markers of cognitive control over time. Moreover, they may have important implications for the application and evaluation of clinical interventions by highlighting the usefulness of considering repeatability measures in addition to the more commonly reported test-retest reliability metrics, when tracking changes over time in clinically relevant processes within single individuals.

neuroscience↗

bioRxiv2021

Mapping differences in mammalian distributions and diversity using environmental DNA from rivers

AimFinding more efficient ways to monitor, and estimate the diversity of, mammalian communities is a major step towards their management and conservation. Environmental DNA (eDNA) from river water has recently been shown to be a viable method for biomonitoring mammalian communities. Yet, most of the studies to date have focused on the potential for eDNA to detect individual species, with little focus on describing patterns of community diversity and structure. In this study, we focus on the sampling effort required to reliably map the diversity and distribution of semi-aquatic and terrestrial mammals and allow inferences of community structure surrounding rivers. LocationSoutheastern England MethodsWe used eDNA metabarcoding on water samples collected along two rivers and a beaver enclosure over two days, targeting terrestrial and semi-aquatic mammals. Mammalian community diversity and composition was assessed based on species richness and {beta}-diversity. Differences between river communities were calculated and partitioned into nestedness and turnover, and the sampling effort required to rapidly detect semi-aquatic and terrestrial species was evaluated based on species accumulation curves and occupancy modelling. ResultseDNA metabarcoding efficiently detected 25 wild mammal species from five orders in two days of sampling, representing the vast majority (82%) of the species expected in the area. The required sampling effort varied between orders, with common species (generally rodents, deer and lagomorph species) more readily detected, with carnivores detected less frequently. Measures of species richness differed between rivers (both overall and within each mammalian order) and patterns of {beta}-diversity revealed the importance of species replacement in sites within each river, against a pattern of species loss between the two rivers. Main conclusionseDNA metabarcoding demonstrated its capability to rapidly detect mammal species, allowing inferences of community composition that will better inform future sampling strategies for this Class. Importantly, this study highlights the potential use of eDNA data for investigating mammalian community dynamics over different spatial scales.

ecology↗

bioRxiv2017

Sex Chromosome Dosage Effects On Gene Expression In Humans

A fundamental question in the biology of sex-differences has eluded direct study in humans: how does sex chromosome dosage (SCD) shape genome function? To address this, we developed a systematic map of SCD effects on gene function by analyzing genome-wide expression data in humans with diverse sex chromosome aneuploidies (XO, XXX, XXY, XYY, XXYY). For sex chromosomes, we demonstrate a pattern of obligate dosage sensitivity amongst evolutionarily preserved X-Y homologs, and update prevailing theoretical models for SCD compensation by detecting X-linked genes whose expression increases with decreasing X- and/or Y-chromosome dosage. We further show that SCD-sensitive sex chromosome genes regulate specific co-expression networks of SCD-sensitive autosomal genes with critical cellular functions and a demonstrable potential to mediate previously documented SCD effects on disease. Our findings detail wide-ranging effects of SCD on genome function with implications for human phenotypic variation.\n\nSIGNIFICANCE STATEMENTSex chromosome dosage (SCD) effects on human gene expression are central to the biology of sex differences and sex chromosome aneuploidy syndromes, but challenging to study given the co-segregation of SCD and gonadal status. We address this obstacle by systematically modelling SCD effects on genome wide expression data from a large and rare cohort of individuals with diverse SCDs (XO, XX, XXX, XXXX, XY, XXY, XYY, XXYY, XXXXY). Our findings update current models of sex chromosome biology by (i) pinpointing a core set of X- and Y-linked genes with \"obligate\" SCD sensitivity, (ii) discovering several non-canonical modes of X-chromosome dosage compensation, and (iii) dissecting complex regulatory effects of X-chromosome dosage on large autosomal gene networks with key roles in cellular functioning.

genomics↗