Biology subjects

Aberg, K. C.

Publications and source records attributed to Aberg, K. C..

4 recordsLinked to original sources

bioRxiv2026

Biological signatures of history: Examination of composite biomes and Y chromosome analysis from da Vinci-associated cultural artifacts

Cultural heritage objects can accumulate DNA from materials, environments, and repeated human contact, but biomolecular profiling of such items is constrained by nondestructive sampling requirements, ultra-low biomass, and high contamination risk. Here we present a minimally invasive workflow that integrates gentle swab collection, low- input whole-metagenome sequencing, taxonomic profiling, and Y-chromosome analyses to recover "biological signatures of history" from Renaissance-era artwork and archival correspondence associated with ancestors of Leonardo da Vinci. Across artifacts, we recovered heterogeneous mixtures of microbial and eukaryotic DNA (including bacteria, fungi, plants, and viruses) consistent with composite "biomes" that reflect differences in substrate, storage, conservation treatments, and handling. Multivariate comparisons show reproducible sample-to-sample separations. In parallel, we assessed human Y-chromosome signal using a panel of [~]90,000 phylogenetically informative markers and partial Y-STR profiling where feasible. Across multiple independent swabs from Leonardo da Vinci-associated items, the obtained Y chromosome marker data suggested assignments withing the broader E1b1/E1b1b clade. However, the control samples also indicate mixed contributions consistent with modern handling and other sources. Together, these data demonstrate the feasibility as well as limitations of combining metagenomics and human DNA marker analysis for cultural heritage science, providing a baseline workflow for future conservation science studies and hypothesis-driven investigations of provenance, authentication and handling history.

genomics↗

bioRxiv2024

Inhibitory mechanisms in the prefrontal-cortex differentially mediate Putamen activity during valence-based learning

Learning from appetitive and aversive stimuli involves interactions between the prefrontal cortex and subcortical structures. Preclinical and theoretical studies indicate that inhibition is essential in regulating the relevant neural circuitry. Here, we demonstrate that GABA, the main inhibitory neurotransmitter in the central nervous system, differentially affects how the dACC interacts with subcortical structures during appetitive and aversive learning in humans. Participants engaged in tasks involving appetitive and aversive learning, while using functional magnetic resonance spectroscopy (MRS) at 7T to track GABA concentrations in the dACC, alongside whole-brain fMRI scans to assess BOLD activation. During appetitive learning, dACC GABA concentrations were negatively correlated with learning performance and BOLD activity measured from the dACC and the Putamen. These correlations were absent during aversive learning, where dACC GABA concentrations negatively correlated with the connectivity between the dACC and the Putamen. Our results show that inhibition in the dACC mediates appetitive and aversive learning in humans through distinct mechanisms.

neuroscience↗

bioRxiv2024

Sampling Techniques and Genomic Analysis of Biological Material from Artworks

The genomic analysis of biological material obtained from artwork or cultural heritage artifacts can be used to guide curation, preservation and restoration. However, the recovery of biological samples from artworks is dependent on the sampling technique used and the media from which the biological materials are recovered. The ideal sampling method should be non-invasive, yet robust. Only rare examples of direct comparisons among sampling techniques have been reported. To develop a framework for the recovery of biological samples for subsequent microbial DNA analysis, we studied five artworks on paper and compared three sampling methods, each with increasing degrees of invasiveness. Minimally invasive swabbing techniques collect samples from the surface, whereas more aggressive techniques such as wet vacuuming were expected to yield more biological material from within the support media. We report a comparison of collection techniques to generate microbial DNA sequence data from artworks on paper. We observed that wet vacuuming resulted in higher DNA recovery than double swabbing and core punches; however, all three techniques yielded satisfactory microbial DNA sequences. Diverse microbial populations existed to varying degrees on the corners and centers of the five artworks studied, but the distribution of the total biomass was relatively even across the surfaces of the works sampled. Studies of peripheral regions, where sampling is less likely to cause alterations to the artwork, could thus yield useful results in microbiome studies. These results provide a framework for sampling artworks on paper to obtain biological material for microbial genomic analysis. The methods described may provide microbiome identification to facilitate restoration and preservation, and might also contribute to the determination of provenance.

genetics↗

bioRxiv2020

Behavioral elements and neural circuits underlying exploratory decisions in normative anxiety

Exploration reduces uncertainty about the environment and improves the quality of future decisions, but at the cost of provisional uncertain and suboptimal outcomes. Although anxiety promotes intolerance to uncertainty, it remains unclear whether and by which mechanisms anxiety modulates exploratory decision-making. We use a dynamic three-armed-bandit task and find that higher trait-anxiety increases exploration, which in turn harms overall performance. We identify two distinct behavioral sources: first, decisions made by anxious individuals were guided towards reduction of uncertainty; and second, decisions were less guided by immediate value gains. Imaging (fMRI) revealed that anxiety correlated negatively with the representation of expected-value in the dorsal-anterior-cingulate-cortex, and in contrast, positively with the representation of uncertainty in the anterior-insula. Moreover, the findings were similar in both loss and gain domains, and demonstrated that affective trait modulates exploration and results in an inverse-U-shaped relationship between anxiety and overall performance. We conclude that a shift in balance towards representation of uncertainty in the insula prevails over reduced value representation in the dACC, and entails maladaptive decision-making in individuals with higher normal-range anxiety.

neuroscience↗