Biology subjects

Kraus, D.

Publications and source records attributed to Kraus, D..

5 recordsLinked to original sources

bioRxiv2026

Forest biodiversity benefits from warmer microclimate, but only in colder regions

The diversity of many forest-dwelling organisms depends on forest structure, but it remains unknown to which degree this is mediated by microclimatic temperature, and whether microclimatic buffering is universally beneficial for forest biodiversity. In 234 broad-leaved forest plots across nine climatically differing regions in Germany, we measured micro- and macroclimatic temperatures, canopy cover, and deadwood volume after experimental manipulations of forest structure through thinning operations and gap cuts. We surveyed 21 taxonomic groups, representing plants, bacteria, fungi, and animals, to assess how their diversity depended on the predictors. Multi-taxon diversity, and diversity of ten separate taxonomic groups, increased from closed to open canopies. Only necrophagous beetles were more diverse in closed stands. These effects of canopy cover on diversity were partly mediated by microclimatic temperatures. Thereby, diversity responses to microclimatic temperature depended on the macroclimatic context. In regions with colder summers, locally warmer microclimates in canopy gaps had strong positive effects on biodiversity, while these effects were not found in regions with warmer summers. Consequently, management strategies aimed at multi-taxon forest diversity conservation should be chosen based on the regional climate, favoring canopy gaps primarily in colder regions, and taking future climate warming into consideration.

ecology↗

bioRxiv2026

Development of Audiovisual Integration in Beginning Readers: A Longitudinal fMRI Study

Acquiring reading proficiency, unlike spoken language, requires the brain to engage several specialized neural systems to map visual symbols (letters) to their corresponding phonological sounds (audiovisual integration), laying the foundation for fluent reading. This study investigates the neural and behavioral trajectory of developing audiovisual (AV) integration during the first year of learning to read. Thirty-two healthy Hebrew-speaking first-grade children were assessed at 3 time points across the school year: beginning, middle, and end of first grade. Participants underwent behavioral testing and brain fMRI scans while performing a block-design fMRI task involving AV matching or non-matching letters and sounds. Together with improvement in behavioral test scores related to general abilities, working memory, cognitive flexibility, and phonemic abilities, a Drift Diffusion Modeling (DDM) analysis of the accuracy and reaction time across sessions suggested faster and more efficient responses as the year progressed. fMRI results showed a significant increase in activation, from the beginning to the end of the first grade, in the left superior temporal gyrus (STG), frontal cortices and parietotemporal cortices, with a shift towards left-lateralization in the fusiform gyrus at the end of the year. These findings point towards the second half of the first grade as the time window for neural specialization and lateralization to phonological and orthographic information. A significant positive correlation between the fusiform gyrus activation and naming objects and colors scores across all sessions links this neural specialization to cognitive flexibility behavioral skills. Key pointsO_LISignificant increase, predominantly between the middle and end of the first grade, in activation in fusiform, left superior temporal, frontal, and parietotemporal cortices across the first grade. C_LIO_LISignificant left lateralization in the fusiform gyrus at the end of first grade. C_LIO_LIPositive correlation between naming skills and a bilateral fusiform gyrus activation throughout the first grade. C_LI

animal behavior and cognition↗

bioRxiv2024

An adapted typology of tree-related microhabitats including tropical forests

Tree-related microhabitats (TreMs) describe the microhabitats that a tree can provide for a multitude of other taxonomic groups and have been proposed as an important indicator for forest biodiversity (Asbeck et al., 2021). So far, the focus of TreM studies has been on temperate forests, although many trees in the tropics harbour exceptionally high numbers of TreMs. In this study, TreMs in the lowland tropical forests of the Choco (Ecuador) and in the mountain tropical forests of Mount Kilimanjaro (Tanzania) were surveyed. Our results extend the existing typology of TreMs of Larrieu et al. (2018) to include tropical forests and enabled a comparison of the relative recordings and diversity of TreMs between tropical and temperate forests. A new TreM form, Root formations, and three new TreM groups, concavities build by fruits or leaves, dendrotelms, and root formations, were established. In total, 15 new TreM types in five different TreM groups were specified. The relative recordings of most TreMs were similar between tropical and temperate forests. However, ivy and lianas, and ferns were more common in the lowland rainforest than in temperate forests, and bark microsoil, limb breakage, and foliose and fruticose lichens in tropical montane forest than in lowland rainforest. Mountain tropical forests hosted the highest diversity for common and dominant TreM types, and lowland tropical forest the highest diversity for rare TreMs. Our extended typology of tree-related microhabitats can support studies of forest-dwelling biodiversity in tropical forests. Specifically, given the ongoing threat to tropical forests, TreMs can serve as an additional tool allowing rapid assessments of biodiversity in these hyperdiverse ecosystems.

ecology↗

bioRxiv2023

Characterization of regeneration initiating cells during Xenopus laevis tail regeneration

Embryos are regeneration and wound healing masters. They not only rapidly close their wounds, remodel injured tissue without a scar, but also regenerate body parts. Many animal models with variable regenerative capabilities have already been studied. Additionally, with the introduction of high throughput techniques, novel regeneration mechanisms including genes and signaling pathways, and specialized cell types required for regeneration control in spatial and temporal aspects have been identified. Until now our knowledge has been limited to primarily the late phases of regeneration (> 1 day post injury). In this paper, we reveal the critical steps for regeneration initiation. We have discovered Regeneration Initiating Cells (RICs) using single cell and spatial transcriptomic analyses during tail regeneration in Xenopus laevis. RICs are formed transiently from the basal epidermal cells and are critical for the modification of the surrounding extracellular matrix to allow for migration of other cell types such as regeneration organizing cells that further promote regeneration. Absence or deregulation of RICs leads to excessive extracellular matrix deposition and regeneration defects.

developmental biology↗

bioRxiv2019

A Hox code defines spinocerebellar neuron subtype regionalisation

Coordinated body movement requires the integration of many sensory inputs. This includes proprioception, the sense of relative body position and force associated with movement. Proprioceptive information is relayed to the cerebellum via spinocerebellar neurons, located in the spinal cord within a number of major neuronal columns or as various scattered cell populations. Despite the importance of proprioception to fluid movement, a molecular understanding of spinocerebellar relay interneurons is only beginning to be explored, with limited knowledge of molecular heterogeneity within and between columns. Using fluorescent reporter knock-in mice, neuronal tracing and in situ hybridisation, we identify widespread expression of Hox cluster genes, including both protein-coding genes and microRNAs, within spinocerebellar neurons. We reveal a \"Hox code\" based on axial level and individual spinocerebellar column, which, at cervico-thoracic levels, is essential for subtype regionalisation. Specifically, we show that Hoxc9 function is required in most, but not all, cells of the major thoracic spinocerebellar column, Clarkes column, revealing heterogeneity reliant on Hox signatures.

developmental biology↗