Quantum graph wave external triggering: Energy transfer and damping.

The propagation of wave trains resulting from a local external trigger inside a network described by a metric graph is analyzed using quantum graph theory. The external trigger is a finite-time perturbation imposed at one vertex of the graph, leading to a consecutive wave train into the network, supposedly at rest before the applied external perturbation. A complete analytical solution for the induced wave train is found having a specific spectrum as well as mode's amplitudes.

Anomalous Diffusion of Deformable Particles in a Honeycomb Network.

Transport of deformable particles in a honeycomb network is studied numerically. It is shown that the particle deformability has a strong impact on their distribution in the network. For sufficiently soft particles, we observe a short memory behavior from one bifurcation to the next, and the overall behavior consists in a random partition of particles, exhibiting a diffusionlike transport.

Geolocalization of water-waves origin within water distribution networks using time reversal of first event detection.

Drinking water distribution networks in urban areas are daily subject to fast propagating pressure waves resulting from routine operations. These water-hammer waves lead to structural aging and facility damages, the origin of which is not easy to find but are sometimes of high managerial interest. In this contribution, we demonstrate that using a reasonable number of high-frequency pressure detectors distributed within the network combined with a proper post-processing method permits a close geolocalization of the damaging wave origin.

From whole-organ imaging to in-silico blood flow modeling: A new multi-scale network analysis for revisiting tissue functional anatomy.

We present a multi-disciplinary image-based blood flow perfusion modeling of a whole organ vascular network for analyzing both its structural and functional properties. We show how the use of Light-Sheet Fluorescence Microscopy (LSFM) permits whole-organ micro-vascular imaging, analysis and modelling. By using adapted image post-treatment workflow, we could segment, vectorize and reconstruct the entire micro-vascular network composed of 1.

3D analysis of the whole subcutaneous adipose tissue reveals a complex spatial network of interconnected lobules with heterogeneous browning ability.

Adipose tissue, as the main energy storage organ and through its endocrine activity, is interconnected with all physiological functions. It plays a fundamental role in energy homeostasis and in the development of metabolic disorders. Up to now, this tissue has been analysed as a pool of different cell types with very little attention paid to the organization and putative partitioning of cells.

Toward quantitative three-dimensional microvascular networks segmentation with multiview light-sheet fluorescence microscopy.

Three-dimensional (3-D) large-scale imaging of microvascular networks is of interest in various areas of biology and medicine related to structural, functional, developmental, and pathological issues. Light-sheet fluorescence microscopy (LSFM) techniques are rapidly spreading and are now on the way to offer operational solutions for large-scale tissue imaging. This contribution describes how reliable vessel segmentation can be handled from LSFM data in very large tissue volumes using a suitable image analysis workflow.

New objective measurements of semen wave motion are associated with fertility in sheep.

In sheep, wave motion in semen is currently used by AI centres to select ejaculates for insemination. Despite its low cost, convenience and established ability to predict fertility, the subjectivity of this assessment is a limiting factor for its applicability. The aims of the present study were to establish an objective method for the analysis of wave motion and to assess the associations of objective parameters with fertility after cervical insemination.

Symmetry-breaking phase transitions in highly concentrated semen.

New experimental evidence of self-motion of a confined active suspension is presented. Depositing fresh semen sample in an annular shaped microfluidic chip leads to a spontaneous vortex state of the fluid at sufficiently large sperm concentration. The rotation occurs unpredictably clockwise or counterclockwise and is robust and stable.

Regionalization of browning revealed by whole subcutaneous adipose tissue imaging.

Objective: White and brown adipose tissues play a major role in the regulation of metabolic functions. With the explosion of obesity and metabolic disorders, the interest in adipocyte biology is growing constantly. While several studies have demonstrated functional differences between adipose fat pads, especially in their involvement in metabolic diseases, there are no data available on possible heterogeneity within an adipose depot.

Turbulence of swarming sperm.

Collective motion of self-sustained swarming flows has recently provided examples of small-scale turbulence arising where viscous effects are dominant. We report the first observation of universal enstrophy cascade in concentrated swarming sperm consistent with a body of evidence built from various independent measurements. We found a well-defined k^{-3} power-law decay of a velocity field power spectrum and relative dispersion of small beads consistent with theoretical predictions in 2D turbulence.

On the normalization of cerebral blood flow.

Cerebral blood flow (CBF) is the most common parameter for the quantification of brain's function. Literature data indicate a widespread dispersion of values that might be related to some differences in the measurement conditions that are not properly taken into account in CBF evaluation. Using recent high-resolution imaging of the complete cortical microvasculature of primate brain, we perform extensive numerical evaluation of the cerebral perfusion.

Broadband converging plasmon resonance at a conical nanotip.

We propose an analytical theory which predicts that Converging Plasmon Resonance (CPR) at conical nanotips exhibits a red-shifted and continuous band of resonant frequencies and suggests potential application of conical nanotips in various fields, such as plasmonic solar cells, photothermal therapy, tip-enhanced Raman and other spectroscopies. The CPR modes exhibit superior confinement and ten times broader scattering bandwidth over the entire solar spectrum than smooth nano-structures. The theory also explicitly connects the optimal angles and resonant optical frequencies to the material permittivities, with a specific optimum half angle that depends only on the real permittivity for high-permittivity and low-loss materials.

Simple patient-based transmantle pressure and shear estimate from cine phase-contrast MRI in cerebral aqueduct.

From measurements of the oscillating flux of the cerebrospinal fluid (CSF) in the aqueduct of Sylvius, we elaborate a patient-based methodology for transmantle pressure (TRP) and shear evaluation. High-resolution anatomical magnetic resonance imaging first permits a precise 3-D anatomical digitalized reconstruction of the Sylvius's aqueduct shape. From this, a very fast approximate numerical flow computation, nevertheless consistent with analytical predictions, is developed.

Coupling and robustness of intra-cortical vascular territories.

Vascular domains have been described as being coupled to neuronal functional units enabling dynamic blood supply to the cerebral cyto-architecture. Recent experiments have shown that penetrating arterioles of the grey matter are the building blocks for such units. Nevertheless, vascular territories are still poorly known, as the collection and analysis of large three-dimensional micro-vascular networks are difficult.

Electrolyte stability in a nanochannel with charge regulation.

The stability of an electrolyte confined in one dimension between two solid surfaces is analyzed theoretically in the case where overlapping double layers produce nontrivial interactions. Within the Poisson-Boltzmann-Nernst-Planck description of the electrostatic interaction and transport of electrical charges, the presence of Stern layers can enrich the set of possible solutions. Our analytical and numerical study of the stability properties of the trivial state of this system identified an instability to a new antisymmetric state.

Cerebral blood flow modeling in primate cortex.

We report new results on blood flow modeling over large volumes of cortical gray matter of primate brain. We propose a network method for computing the blood flow, which handles realistic boundary conditions, complex vessel shapes, and complex nonlinear blood rheology. From a detailed comparison of the available models for the blood flow rheology and the phase separation effect, we are able to derive important new results on the impact of network structure on blood pressure, hematocrit, and flow distributions.

Attraction between two similar particles in an electrolyte: effects of Stern layer absorption.

When Debye length is comparable or larger than the distance between two identical particles, the overlapping among the particles double-layers can play an important role in their interactions. This paper presents a theoretical analysis of the interaction among two identical particles with overlapped double-layers. We particularly focus on the effect of a Stern electro static condition from linearization of the adsorption isotherm near the isoelectric (neutrality) point in order to capture how polyvalent ion condensation affect sand reverses the surface charge.