Search results for "Matrix"

Evanescent wave approximation for non-Hermitian Hamiltonians

2020

The counterpart of the rotating wave approximation for non-Hermitian Hamiltonians is considered, which allows for the derivation of a suitable effective Hamiltonian for systems with some states undergoing decay. In the limit of very high decay rates, on the basis of this effective description we can predict the occurrence of a quantum Zeno dynamics, which is interpreted as the removal of some coupling terms and the vanishing of an operatorial pseudo-Lamb shift.

Topology testing of phylogenies using least squares methods

2006

[Background] The least squares (LS) method for constructing confidence sets of trees is closely related to LS tree building methods, in which the goodness of fit of the distances measured on the tree (patristic distances) to the observed distances between taxa is the criterion used for selecting the best topology. The generalized LS (GLS) method for topology testing is often frustrated by the computational difficulties in calculating the covariance matrix and its inverse, which in practice requires approximations. The weighted LS (WLS) allows for a more efficient albeit approximate calculation of the test statistic by ignoring the covariances between the distances.

An analytical method for monitoring micro-traces of landfill leachate in groundwater using fluorescence excitation–emission matrix spectroscopy

2016

In this study, we use three-dimensional excitation-emission matrix (EEM) fluorescence spectroscopy for the identification of contamination of natural water bodies by landfill leachate. In particular, EEM was applied to provide information about the presence and quantities of leachate in ground waters. A good linear relationship was found between the fluorescence intensity emission of groundwater spiked with landfill leachate and the volumes of the latter, suggesting that there was no intrinsic fluorescence in the concentration range of 0-1000 μL L-1. The obtained values of the LOD (10 μL L-1; TOC = 34 μg L-1) and LOQ (34 μL L-1; TOC = 114 μg L-1) allow us to detect the presence and the amou…

Fluorescence fingerprinting of bottled white wines can reveal memories related to sulfur dioxide treatments of the must.

2015

For the first time, Excitation Emission Matrix (EEM) fluorescence spectroscopy was combined with parallel factor statistical analysis (PARAFAC) and applied to a set of 320 dry white wines of the Chardonnay grape variety. A four component PARAFAC model (C1, C2, C3 and C4) best explained the variability of fluorescence signatures of white wines. Subtle changes were observed in EEMs of white wines from two different vintages (2006 and 2007), where different concentrations of sulfur dioxide (0, 4, and 8 g·hL(-1)) were added to the grape must at pressing. PARAFAC results clearly indicated that sulfur dioxide added to the must subsequently influenced white wine chemistry into three distinct sulfu…

Expression patterns of matrix genes during human skeletal development.

1994

Extracellular Hsp70 Enhances Mesoangioblast Migration via an Autocrine Signaling Pathway

2016

Mouse mesoangioblasts are vessel-associated progenitor stem cells endowed with the ability of multipotent mesoderm differentiation. Therefore, they represent a promising tool in the regeneration of injured tissues. Several studies have demonstrated that homing of mesoangioblasts into blood and injured tissues are mainly controlled by cytokines/chemokines and other inflammatory factors. However, little is known about the molecular mechanisms regulating their ability to traverse the extracellular matrix (ECM). Here, we demonstrate that membrane vesicles released by mesoangioblasts contain Hsp70, and that the released Hsp70 is able to interact by an autocrine mechanism with Toll-like receptor …

Non-Canonical WNT Signaling Regulates TGF-²1-Induced Extracellular Matrix Production By Airway Smooth Muscle Cells

2012

Stick around: Cell-Cell Adhesion Molecules during Neocortical Development

2020

The neocortex is an exquisitely organized structure achieved through complex cellular processes from the generation of neural cells to their integration into cortical circuits after complex migration processes. During this long journey, neural cells need to stablish and release adhesive interactions through cell surface receptors known as cell adhesion molecules (CAMs). Several types of CAMs have been described regulating different aspects of neurodevelopment. Whereas some of them mediate interactions with the extracellular matrix, others allow contacts with additional cells. In this review, we will focus on the role of two important families of cell-cell adhesion molecules (C-CAMs), classi…

Alterations in the Microstructure of the Anterior Mitral Valve Leaflet Under Physiological Stress

2012

An improved understanding of mitral valve (MV) function remains an important goal for determining mechanisms underlying valve disease and for developing novel therapies. Critical to heart valve tissue homeostasis is the valvular interstitial cells (VICs), which reside in the interstitium and maintain the extracellular matrix (ECM) through both protein synthesis and enzymatic degradation [1]. There is scant quantitative experimental data on the alterations of the MV fiber network reorganization as a function of load, which is critical for implementation of computational strategies that attempt to link this meso-micro scale phenomenon. The observed large scale deformations experienced by VICs…

TALPID3/KIAA0586 regulates multiple aspects of neuromuscular patterning during gastrointestinal development in animal models and human

2021

ABSTRACTTALPID3/KIAA0586 is an evolutionary conserved protein, which plays an essential role in protein trafficking. Its role during gastrointestinal (GI) and enteric nervous system (ENS) development has not been studied previously. Here, we analysed chicken, mouse and human embryonic GI tissues with TALPID3 mutations. The GI tract of TALPID3 chicken embryos was shortened and malformed. Histologically, the gut smooth muscle was mispatterned and enteric neural crest cells were scattered throughout the gut wall. Analysis of the Hedgehog pathway and gut extracellular matrix provided causative reasons for these defects. Interestingly, chicken intra-species grafting experiments and a conditional…