Paper List
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GOPHER: Optimization-based Phenotype Randomization for Genome-Wide Association Studies with Differential Privacy
This paper addresses the core challenge of balancing rigorous privacy protection with data utility when releasing full GWAS summary statistics, overco...
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Real-time Cricket Sorting By Sex A low-cost embedded solution using YOLOv8 and Raspberry Pi
This paper addresses the critical bottleneck in industrial insect farming: the lack of automated, real-time sex sorting systems for Acheta domesticus ...
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Training Dynamics of Learning 3D-Rotational Equivariance
This work addresses the core dilemma of whether to use computationally expensive equivariant architectures or faster symmetry-agnostic models with dat...
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Fast and Accurate Node-Age Estimation Under Fossil Calibration Uncertainty Using the Adjusted Pairwise Likelihood
This paper addresses the dual challenge of computational inefficiency and sensitivity to fossil calibration errors in Bayesian divergence time estimat...
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Few-shot Protein Fitness Prediction via In-context Learning and Test-time Training
This paper addresses the core challenge of accurately predicting protein fitness with only a handful of experimental observations, where data collecti...
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scCluBench: Comprehensive Benchmarking of Clustering Algorithms for Single-Cell RNA Sequencing
This paper addresses the critical gap of fragmented and non-standardized benchmarking in single-cell RNA-seq clustering, which hinders objective compa...
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Simulation and inference methods for non-Markovian stochastic biochemical reaction networks
This paper addresses the computational bottleneck of simulating and performing Bayesian inference for non-Markovian biochemical systems with history-d...
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Assessment of Simulation-based Inference Methods for Stochastic Compartmental Models
This paper addresses the core challenge of performing accurate Bayesian parameter inference for stochastic epidemic models when the likelihood functio...
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.