Paper List
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SpikGPT: A High-Accuracy and Interpretable Spiking Attention Framework for Single-Cell Annotation
This paper addresses the core challenge of robust single-cell annotation across heterogeneous datasets with batch effects and the critical need to ide...
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Unlocking hidden biomolecular conformational landscapes in diffusion models at inference time
This paper addresses the core challenge of efficiently and accurately sampling the conformational landscape of biomolecules from diffusion-based struc...
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Personalized optimization of pediatric HD-tDCS for dose consistency and target engagement
This paper addresses the critical limitation of one-size-fits-all HD-tDCS protocols in pediatric populations by developing a personalized optimization...
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Realistic Transition Paths for Large Biomolecular Systems: A Langevin Bridge Approach
This paper addresses the core challenge of generating physically realistic and computationally efficient transition paths between distinct protein con...
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Consistent Synthetic Sequences Unlock Structural Diversity in Fully Atomistic De Novo Protein Design
This paper addresses the core pain point of low sequence-structure alignment in existing synthetic datasets (e.g., AFDB), which severely limits the pe...
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MoRSAIK: Sequence Motif Reactor Simulation, Analysis and Inference Kit in Python
This work addresses the computational bottleneck in simulating prebiotic RNA reactor dynamics by developing a Python package that tracks sequence moti...
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On the Approximation of Phylogenetic Distance Functions by Artificial Neural Networks
This paper addresses the core challenge of developing computationally efficient and scalable neural network architectures that can learn accurate phyl...
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EcoCast: A Spatio-Temporal Model for Continual Biodiversity and Climate Risk Forecasting
This paper addresses the critical bottleneck in conservation: the lack of timely, high-resolution, near-term forecasts of species distribution shifts ...
Countershading coloration in blue shark skin emerges from hierarchically organized and spatially tuned photonic architectures inside skin denticles
City University of Hong Kong | Max Planck Institute of Colloids and Interfaces | University of Salzburg | B CUBE – Center for Molecular Bioengineering | Elasmobranch Research Belgium (ERB) | Medical University Innsbruck | AZTI, Basque Research and Technology Alliance (BRTA) | Hong Kong Polytechnic University
30秒速读
IN SHORT: This paper solves the core problem of how blue sharks achieve their striking dorsoventral countershading camouflage, revealing that coloration originates not from dermal pigments but from hierarchical photonic architectures within individual skin denticles.
核心创新
- Biology Identifies denticles as the primary optical units ('pixels') for shark skin coloration, overturning the assumption that coloration originates from underlying dermal chromatophores.
- Methodology Establishes a multi-scale correlative imaging pipeline (optical, μCT, histology, FIB-SEM, TEM) to link nanoscale crystal organization with macroscopic color gradients.
- Biology Demonstrates a spatial gradient in photonic architecture: from ordered purine-crystal stacks (blue) to disordered assemblies (white), coupled with systematic changes in chromatophore composition and pulp cavity volume (25% in blue zone vs. 17% in white zone).
主要结论
- Blue shark countershading originates from denticle-embedded photonic architectures, not dermal pigments, with pulp cavity volume decreasing from 25% (blue) to 17% (white).
- Color variation is organized hierarchically: at the microscale, blue denticles contain a tessellated reflector-absorber system (iridophores + melanophores), while white denticles lack melanophores entirely.
- At the nanoscale, ordered purine-crystal stacks (~10-60 nm features) generate narrowband blue reflection, whereas disordered assemblies produce broadband white scattering, directly linking crystal organization to optical output.
摘要: The blue shark (Prionace glauca) exhibits a striking dorsoventral color gradient, transitioning from vibrant blue dorsally to silver and white ventrally—a pattern widely interpreted as pelagic countershading. Despite its ecological significance, the physical basis of this coloration remains unresolved. Here we show that this color system does not arise from dermal chromatophores, as in most vertebrates, but from a previously unrecognised photonic architecture housed within the pulp cavity of individual dermal denticles that cover the skin. Optical imaging reveals discrete color domains within denticle crowns, while external denticle morphology remains similar across color zones. Using spectroscopy, micro-computed tomography, histology and correlative electron microscopy, we demonstrate that color variation is organized across coupled micro- and nanoscale architectures. In blue denticles, iridophores and melanophores form a densely packed tessellated reflector–absorber system within an expanded crown-restricted pulp cavity. Transition-zone denticles exhibit partial cellular layering, whereas white denticles lack melanophores and contain only reflective cells. At the nanoscale, ordered purine-crystal stacks generate narrowband blue reflection, whereas disordered assemblies produce broadband white scattering. Together, these results reveal denticles as mechanically protected optical “pixels” whose hierarchical cellular and nanocrystal organization generates the shark’s countershaded coloration.