Birdsong is a complex vocal behavior, which emerges out of the interaction between a nervous system and a highly nonlinear vocal device, the syrinx. In this work we discuss how low dimensional dynamical systems, interpretable in terms of the biomechanics involved, are capable of synthesizing realistic songs. We review the experimental and conceptual steps that lead to the formulation of low dimensional dynamical systems for the song system and describe the tests that quantify their success. In particular, we show how to evaluate computational models by comparing the responses of highly selective neurons to the bird's own song and to synthetic copies generated mathematically. Beyond testing the hypothesis behind the model's construction, these low dimensional models allow designing precise stimuli in order to explore the sensorimotor integration of acoustic signals.
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http://dx.doi.org/10.3389/fnins.2021.647978 | DOI Listing |
Acta Crystallogr C Struct Chem
January 2025
College of Chemistry and Materials Science, Anhui Normal University, Wuhu, Anhui 241000, People's Republic of China.
A new twofold interpenetrated 3D metal-organic framework (MOF), namely, poly[[μ-aqua-diaqua{μ-2,2'-[terephthaloylbis(azanediyl)]diacetato}barium(II)] dihydrate], {[Ba(CHNO)(HO)]·2HO}, (I), has been assembled through a combination of the reaction of 2,2'-[terephthaloylbis(azanediyl)]diacetic acid (TPBA, HL) with barium hydroxide and crystallization at low temperature. In the crystal structure of (I), the nine-coordinated Ba ions are bridged by two μ-aqua ligands and two carboxylate μ-O atoms to form a 1D loop-like Ba-O chain, which, together with the other two coordinated water molecules and μ-carboxylate groups, produces a rod-like secondary building unit (SBU). The resultant 1D polynuclear SBUs are further extended into a 3D MOF via the terephthalamide moiety of the ligand as a spacer.
View Article and Find Full Text PDFMed Biol Eng Comput
January 2025
School of Medical Engineering, Department of Cardiology of The First Affiliated Hospital of Xinxiang Medical University, Xinxiang Medical University, Xinxiang, 453003, Henan, China.
The research aims to investigate the mechanical response of footfalls at different velocities to understand the mechanism of heel injury and provide a scientific basis for the prevention and treatment of heel fractures. A three-dimensional solid model of foot drop was constructed using anatomical structures segmented from medical CT scans, including bone, cartilage, ligaments, plantar fascia, and soft tissues, and the impact velocities of the foot were set to be 2 m/s, 4 m/s, 6 m/s, 8 m/s, and 10 m/s. Explicit kinetic analysis methods were used to investigate the mechanical response of the foot landing with different speeds to explore the damage mechanism of heel bone at different impact velocities.
View Article and Find Full Text PDFBiomaterials
December 2024
Wenzhou Institute, University of Chinese Academy of Sciences, Wenzhou, Zhejiang, 325011, China. Electronic address:
The effective prevention and treatment of anastomotic leakage after intestinal anastomosis for colorectal diseases is still a major clinical challenge. In order to assist intestinal anastomosis healing and avoid anastomotic leakage caused by high tension, low blood supply or infection, we designed a double-layer nanofiber intestinal anastomosis scaffold, which was composed of electrospun PTMC/PHA nanofibers as the main layer, and electrospun PVA/OHA-Gs nanofibers with antibacterial properties as the antibacterial surface layer. This double-layer scaffold has good toughness, its maximum tensile force value could reach 8 N, elongation could reach 400 %, and it has hydrophilic properties, and its contact angle was about 60°.
View Article and Find Full Text PDFACS Nano
January 2025
State Key Laboratory of Materials Processing and Die & Mould Technology, and School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074, Hubei, P. R. China.
Intensifying the severity of electromagnetic (EM) pollution in the environment represents a significant threat to human health and results in considerable energy wastage. Here, we provide a strategy for electricity generation from heat generated by electromagnetic wave radiation captured from the surrounding environment that can reduce the level of electromagnetic pollution while alleviating the energy crisis. We prepared a porous, elastomeric, and lightweight BiTe/carbon aerogel (CN@BiTe) by a simple strategy of induced in situ growth of BiTe nanosheets with three-dimensional (3D) carbon structure, realizing the coupling of electromagnetic wave absorption (EMA) and thermoelectric (TE) properties.
View Article and Find Full Text PDFPhys Rev Lett
December 2024
School of Physics, Beihang University, Haidian District, Beijing 100191, China.
Massive Dirac fermions, which are essential for realizing novel topological phenomena, are expected to be generated from massless Dirac fermions by breaking the related symmetry, such as time-reversal symmetry in topological insulators or crystal symmetry in topological crystalline insulators. Here, we report scanning tunneling microscopy and angle-resolved photoemission spectroscopy studies of α-Bi_{4}I_{4}, which reveals the realization of massive Dirac fermions in the (100) surface states without breaking the time-reversal symmetry. Combined with first-principles calculations, our experimental results indicate that the spontaneous symmetry breaking engenders two nondegenerate edge states at the opposite sides of monolayer Bi_{4}I_{4} after the structural phase transition, imparting mass to the Dirac fermions after taking the interlayer coupling into account.
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