Biology subjects

Kainerstorfer, J.

Publications and source records attributed to Kainerstorfer, J..

3 recordsLinked to original sources

bioRxiv2025

Head-related transfer function predictions reveal dominant sound transmission mechanisms in a dolphin head

Toothed whales possess specialized anatomical structures in the head, including thin, excavated lower mandible embedded in mandibular fat bodies, complex skull morphology fused with the upper jaw, and extensive air spaces surrounding the middle ears and beneath the skull. In this study, we use finite element modeling to investigate how these structures influence the transmission of water-borne sounds to the ears. The models are based on volumetric representations derived from computed tomography (CT) scans of a live bottlenose dolphin (Tursiops truncatus). We iteratively modify the anatomical structures included in the model and use the predicted head-related transfer functions (HRTFs) as a proxy for comparison. Our results show that the mandibular fat bodies, which support a lower sound speed than the surrounding tissues, significantly enhance the forward receiving directionality at echolocation frequencies through refraction, in a manner similar to the melon in shaping the dolphins highly directional transmission beams. Additionally, we show that, in the frequencies encompassing dolphin communication signals, the air volumes help block the otherwise complex sound transmission through the bones. These findings highlight convergent evolutionary solutions in toothed whale anatomy to create strong directionality in both sound emission and reception governed by the same physical principles.

biophysics↗

bioRxiv2021

In Situ Volumetric Imaging and Analysis of FRESH 3D Bioprinted Constructs Using Optical Coherence Tomography

As 3D bioprinting has grown as a fabrication technology, so too has the need for improved analytical methods to characterize these engineered constructs. This is especially challenging for soft tissues composed of hydrogels and cells as these materials readily deform, posing a barrier when trying to assess print fidelity and other properties non- destructively. Indeed, given the importance of structure-function relationships in most tissue types, establishing that the 3D architecture of the bioprinted construct matches its intended anatomic design is critical. Here we report development of a multimaterial bioprinting platform with integrated optical coherence tomography (OCT) for in situ volumetric imaging, error detection, and 3D reconstruction. While generally applicable to extrusion-based 3D bioprinting, we also report improvements to the Freeform Reversible Embedding of Suspended Hydrogels (FRESH) bioprinting process through new collagen bioink compositions, support bath optical clearing, and machine pathing. This enables high-fidelity 3D volumetric imaging with micron scale resolution over centimeter length scales, the ability to detect a range of print defect types within a 3D volume, and real-time imaging of the printing process at each print layer. These advances provide FRESH and other extrusion-based 3D bioprinting approaches with a comprehensive methodology for quality assessment that has been absent in the field to date, paving the way for translation of these engineered tissues to the clinic and ultimately to achieving regulatory approval. TeaserTransparent FRESH support bath enables in situ 3D volumetric imaging and validation of patient-derived tissue constructs.

bioengineering↗

bioRxiv2020

A Paradigm for Measuring Resting State Functional Connectivity in Young Children Using fNIRS and Freeplay

Resting state functional connectivity (RSFC) reflects the organization of functional networks in the brain. Functional networks measured during "resting", or task-absent, state are correlated with cognitive function, and much development of these networks occurs between infancy and adulthood. However, RSFC research in the intermediate years (especially between ages 3 and 5 years) has been limited, mainly due to a paucity of child-appropriate neural measures and behavioral paradigms. This paper presents a new paradigm to measure RSFC in young children, utilizing functional near-infrared spectroscopy (fNIRS) and Freeplay, a simple behavioral setup designed to approximate resting state in children. In Experiment 1, we recorded fNIRS data from children aged 3-8 years and adults aged 18-21 years and examined feasibility and validity of our measure of RSFC, and compared measures across the two groups. In Experiment 2, we recorded longitudinal data at two points (approximately 3 months apart) from children aged 3-5 years, and examined reliability under a variety of measures. In both experiments, all children were able to complete testing and provide usable data, a significant improvement over fMRI-based RSFC measurement in children. Results suggest this paradigm is practical and has good construct validity and test-retest reliability, and may contribute towards increasing the availability of reliable data on resting state networks in early childhood. In particular, these are some of the first positive results on the feasibility of reliably measuring functional connectivity in children aged 3-5 years.

neuroscience↗