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Single-cell approaches to cell competition: high-throughput imaging, machine learning and simulationsMar 25 2019Cell competition is a quality control mechanism in tissues that results in the elimination of less fit cells. Over the past decade, the phenomenon of cell competition has been identified in many physiological and pathological contexts, driven either by ... More
Cellular reproduction number, generation time and growth rate differ between human- and avian-adapted influenza strainsMar 19 2019When analysing in vitro data, growth kinetics of influenza strains are often compared by computing their growth rates, which are sometimes used as proxies for fitness. However, analogous to mechanistic epidemic models, the growth rate can be defined as ... More
Computational Astrocyence: Astrocytes encode inhibitory activity into the frequency and spatial extent of their calcium elevationsMar 18 2019Deciphering the complex interactions between neurotransmission and astrocytic $Ca^{2+}$ elevations is a target promising a comprehensive understanding of brain function. While the astrocytic response to excitatory synaptic activity has been extensively ... More
From individual-based mechanical models of multicellular systems to free-boundary problemsMar 15 2019In this paper we present an individual-based mechanical model that describes the dynamics of two contiguous cell populations with different proliferative and mechanical characteristics. An off-lattice modelling approach is considered whereby: (i) every ... More
Antibody-mediated cross-linking of gut bacteria hinders the spread of antibiotic resistanceMar 13 2019The body is home to a diverse microbiota, mainly in the gut. Resistant bacteria are selected for by antibiotic treatments, and once resistance becomes widespread in a population of hosts, antibiotics become useless. Here, we develop a multiscale model ... More
Effects of Local Concentration Gradients of Monocyte Chemoattractant Protein-1 on Monocytes Adhesion and Transendothelial Migration in a Three-Dimensional In Vitro Vascular Tissue ModelMar 12 2019Objective: The main objective of this study was to investigate the formation of MCP-1 concentration gradients within the subendothelial extracelluar matrix (ECM) and determine the effect on monocytes migration in response to inflammation. To meet this ... More
Biomechanics of Collective Cell Migration in Cancer Progression -- Experimental and Computational MethodsMar 12 2019Cell migration is essential for regulating many biological processes in physiological or pathological conditions, including embryonic development and cancer invasion. In vitro and in silico studies suggest that collective cell migration is associated ... More
Modeling fungal hypha tip growth via viscous sheet approximationMar 08 2019In this paper we present a new model for single-celled, non-branching hypha tip growth. The growth mechanism of hypha cells consists of transport of cell wall building material to the cell wall and subsequent incorporation of this material in the wall ... More
Collective ECM remodeling organizes 3D collective cancer invasionMar 08 2019Tumor metastasis, traditionally considered as random spreading of individual cancer cells, has been shown to also involve coordinated collective invasion in the tissue space. Here we demonstrate experimentally and computationally that physical interactions ... More
Universal voter model emergence in genetically labeled homeostatic tissuesMar 07 2019Recent experiments in adult mammalian tissues have found scaling relations of the voter model in the dynamics of the genetically labeled population of stem cells. Yet, the reason for this seemingly robust appearance of the voter model remains unexplained. ... More
Stochastic nonlinear model for somatic cell population dynamics during ovarian follicle activationMar 04 2019In mammals, female germ cells are sheltered within somatic structures called ovarian follicles, which remain in a quiescent state until they get activated, all along reproductive life. We investigate the sequence of somatic cell events occurring just ... More
Convergence of solutions in a mean-field model of go-or-grow type with reservation of sites for proliferation and cell cycle delayMar 03 2019We consider the mean-field approximation of an individual-based model describing cell motility and proliferation, which incorporates the volume exclusion principle, the go-or-grow hypothesis and an explicit cell cycle delay. To utilise the framework of ... More
Principles of efficient chemotactic pursuitFeb 27 2019In chemotaxis, cells are modulating their migration patterns in response to concentration gradients of a guiding substance. Immune cells are believed to use such chemotactic sensing for remotely detecting and homing in on pathogens. Considering that an ... More
A physical mechanism of heterogeneity in stem cell, cancer and cancer stem cellFeb 27 2019Heterogeneity is ubiquitous in stem cells (SC), cancer cells (CS), and cancer stem cells (CSC). SC and CSC heterogeneity is manifested as diverse sub-populations with self-renewing and unique regeneration capacity. Moreover, the CSC progeny possesses ... More
ABM of osteoblast's mechanotransduction pathway: time patterns of critical eventsFeb 23 2019Background: Mechanotransduction in bone cells plays a pivotal role in osteoblast differentiation and bone remodelling. Mechanotransduction provides the link between modulation of the extracellular matrix and intracellular actions. By controlling the balance ... More
Cell pelotons: a model of early evolutionary cell sorting, with application to slime mold D. discoideumFeb 20 2019A theoretical model is presented for early evolutionary cell sorting within cellular aggregates. The model involves an energy-saving mechanism and principles of collective self-organization analogous to those observed in bicycle pelotons (groups of cyclists). ... More
Generalized Rayleigh-Plesset Theory for Cell Size Maintenance in Viruses and BacteriaFeb 19 2019The envelopes covering bacterial cytoplasm possess remarkable elastic properties. They are rigid enough to resist large pressures while being flexible enough to adapt to growth under environmental constraints. Similarly, the virus shells play an important ... More
The Essential Role of Thermodynamics in metabolic network modeling: physical insights and computational challengesFeb 19 2019Quantitative studies of cell metabolism are often based on large chemical reaction network models. A steady state approach is suited to analyze phenomena on the timescale of cell growth and circumvents the problem of incomplete experimental knowledge ... More
Metabolic basis of brain-like electrical signalling in bacterial communitiesFeb 17 2019Information processing in the mammalian brain relies on a careful regulation of the membrane potential dynamics of its constituent neurons, which propagates across the neuronal tissue via electrical signalling. We recently reported the existence of electrical ... More
Reassessment of the basis of cell size control based on analysis of cell-to-cell variabilityFeb 13 2019Fundamental mechanisms governing cell size control and homeostasis are still poorly understood. The relationship between sizes at division and birth in single cells is used as a metric to categorize the basis of size homeostasis [1-3]. Cells dividing ... More
Model-based assessment of the Role of Uneven Partitioning of Molecular Content on Heterogeneity and Regulation of Differentiation in CD8 T-cell Immune ResponsesFeb 07 2019Activation of naive CD8 T-cells can lead to the generation of multiple effector and memory subsets. Multiple parameters associated with activation conditions are involved in generating this diversity that is associated with heterogeneous molecular contents ... More
Aggregation dynamics of active cells on non-adhesive substrateFeb 06 2019Cellular self-assembly and organization are fundamental steps for the development of biological tissues. In this paper, within the framework of a cellular automata model, we address how an ordered tissue pattern spontaneously emerges from a randomly migrating ... More
Stick-Slip Dynamics of Migrating Cells on Viscoelastic SubstratesFeb 06 2019Stick-slip motion, a common phenomenon observed during crawling of cells, is found to be strongly sensitive to the substrate stiffness. Stick-slip behaviours have previously been investigated typically using purely elastic substrates. For a more realistic ... More
A general model of focal adhesion orientation dynamics in response to static and cyclic stretchFeb 03 2019Understanding cellular response to mechanical forces is immensely important for a plethora of biological processes. Focal adhesions are multi-molecular protein assemblies that connect the cell to the extracellular matrix and play a pivotal role in cell ... More
Condensation of nucleoid in Escherichia coli cell as a result of prolonged starvationJan 31 2019Electron microscopy and X-ray diffraction studies of dormant E. coli cells revealed several forms of nucleoid condensation: quasi - nanocrystalline, quasi -liquid crystalline (or spore-like) and folded nucleosome - like structure. Of particular interest ... More
\textit{C. elegans} collectively forms dynamical networksJan 30 2019Understanding physical rules underlying collective motions requires perturbation of controllable parameters in self-propelled particles. However, controlling parameters in animals is generally not easy, which makes collective behaviours of animals elusive. ... More
Quantitative Measurement of Heritability in the Pre-RNA WorldJan 22 2019Long ago, life obtained nucleotides in the course of evolution and became a vehicle for them. Before assembly with nucleotides, in the pre-RNA era, what system dominated heredity? What was the subject of survival competition? Is it still a subject of ... More
Phosphorylation by the stress-activated MAPK Slt2 down-regulates the yeast TOR complex 2Jan 21 2019Saccharomyces cerevisiae target of rapamycin (TOR) complex 2 (TORC2) is an essential regulator of plasma membrane lipid and protein homeostasis. How TORC2 activity is modulated in response to changes in the status of the cell envelope is unclear. Here ... More
Tracking yeast pheromone receptor Ste2 endocytosis using fluorogen-activating protein taggingJan 21 2019To observe internalization of the yeast pheromone receptor Ste2 by fluorescence microscopy in live cells in real time, we visualized only those molecules present at the cell surface at the time of agonist engagement (rather than the total cellular pool) ... More
Horizontal transfer between loose compartments stabilizes replication of fragmented ribozymesJan 21 2019The emergence of replicases that can replicate themselves is a central issue in the origin of life. Recent experiments suggest that such replicases can be realized if an RNA polymerase ribozyme is divided into fragments short enough to be replicable by ... More
Predicting Growth Rate from Gene ExpressionJan 15 2019Growth rate is one of the most important and most complex phenotypic characteristics of unicellular microorganisms, which determines the genetic mutations that dominate at the population level, and ultimately whether the population will survive. Translating ... More
Competition for Stem Cell Fate Determinants as a Mechanism for Tissue HomeostasisJan 12 2019Jan 20 2019Stem cells maintain tissues by generating differentiated cell types while simultaneously self-renewing their own population. The mechanisms that allow stem cell populations to function collectively to control their density, maintain robust homeostasis ... More
A population dynamics model of cell-cell adhesion incorporating population pressure and density saturationJan 09 2019We discuss several continuum cell-cell adhesion models based on the underlying microscopic assumptions. We propose an improvement on these models leading to sharp fronts and intermingling invasion fronts between different cell type populations. The model ... More
Microglial memory of early life stress, epigenetic mechanisms and susceptibility to neurodegeneration in adulthoodJan 01 2019In this review we present a concept that, despite mounting evidence, received little attention so far: susceptibility to adult neurodegenerative diseases may be programmed in utero and early postnatal preventive measures may reduce the risk. We delineate ... More
A new model for the emergence of blood capillary networksDec 24 2018We propose a new model for the emergence of blood capillary networks. We assimilate the tissue and extra cellular matrix as a porous medium, using Darcy's law for describing both blood and intersticial fluid flows. Oxygen obeys a convection-diffusion-reaction ... More
Cell-cell and Cell-noise Interactions of Bacterial Cells in a Shallow Circular Pool and Transitions of Collective MotionsDec 18 2018We have experimentally investigated the transitions of collective motions of bacterial cells in a shallow circular pool using the bacterial species $Bacillus$ $subtilis$. In our previous paper, we reported that the collective motions were classified into ... More
Topological and geometrical quantities in active cellular structuresDec 17 2018Topological and geometrical properties and the associated topological defects find a rapidly growing interest in studying the interplay between mechanics and the collective behavior of cells on the tissue level. We here test if well studied equilibrium ... More
α7 nicotinic acetylcholine receptor signaling modulates ovine fetal brain astrocytes transcriptome in response to endotoxin: comparison to microglia, implications for prenatal stress and development of autism spectrum disorderDec 17 2018Dec 31 2018Neuroinflammation in utero may result in lifelong neurological disabilities. Astrocytes play a pivotal role, but the mechanisms are poorly understood. No early postnatal treatment strategies exist to enhance neuroprotective potential of astrocytes. We ... More
Bridging the gap between individual-based and continuum models of growing cell populationsDec 14 2018Dec 18 2018Continuum models for the spatial dynamics of growing cell populations have been widely used to investigate the mechanisms underpinning tissue development and tumour invasion. These models consist of nonlinear partial differential equations that describe ... More
Geometry of epithelial cells provides a robust method for image based inference of stress within tissuesDec 11 2018Cellular mechanics plays an important role in epithelial morphogenesis, a process wherein cells reshape and rearrange to produce tissue-scale deformations. However, the study of tissue-scale mechanics is impaired by the difficulty of direct measurement ... More
Bacterial growth: a statistical physicist's guideDec 11 2018Bacterial growth presents many beautiful phenomena that pose new theoretical challenges to statistical physicists, and are also amenable to laboratory experimentation. This review provides some of the essential biological background, discusses recent ... More
Oscillations in a white blood cell production model with multiple differentiation stagesDec 05 2018In this work we prove occurrence of a super-critical Hopf bifurcation in a model of white blood cell formation structured by three maturation stages. We provide an explicit analytical expression for the bifurcation point depending on model parameters. ... More
Run-and-tumble motion with step-like responses to a stochastic inputDec 03 2018Jan 04 2019We study a simple run-and-tumble random walk whose switching frequency from run mode to tumble mode and the reverse depend on a stochastic signal. We consider a particularly sharp, step-like dependence, where the run to tumble switching probability jumps ... More
Cell-based model of the generation and maintenance of the shape and structure of the multi-layered shoot apical meristem of Arabidopsis thalianaDec 02 2018One of the central problems in animal and plant developmental biology is deciphering how chemical and mechanical signals interact within a tissue to produce organs of defined size, shape and function. Cell walls in plants impose a unique constraint on ... More
On the Analysis of Bacterial Cooperation with a Characterization of 2D Signal PropagationDec 01 2018The exchange of small molecular signals within microbial populations is generally referred to as quorum sensing (QS). QS is ubiquitous in nature and enables microorganisms to respond to fluctuations of living environments by working together. In this ... More
Both cellular ATP level and ATP hydrolysis free energy determine energetically the calcium oscillation in pancreatic $β$-cellNov 28 2018Nov 29 2018In pancreatic $\beta$-cells, calcium oscillation signal is the core part of glucose-stimulated insulin secretion. Intracellular calcium concentration oscillates in response to the intake of glucose, which triggers the exocytosis of insulin secretory granules. ... More
Free Energy of ATP hydrolysis manipulates the cellular calcium signalsNov 25 2018In living cells, oscillation of the concentration of cytosolic Ca2+ is an important and pervasive signal for the intercellular and intracellular information conduction. To generate the oscillation, the hydrolysis of ATP is always needed. Many recent studies ... More
Balance of Mechanical Forces Drives Endothelial Gap Formation and May Facilitate Cancer and Immune-Cell ExtravasationNov 22 2018The formation of gaps in the endothelium is a crucial process underlying both cancer and immune cell extravasation, contributing to the functioning of the immune system during infection, the unfavorable development of chronic inflammation and tumor metastasis. ... More
Field induced cell proliferation and death in a thick epitheliumNov 09 2018We study the dynamics of a thick polar epithelium subjected to the action of both an electric and a flow field in a planar geometry. We develop a generalized continuum hydrodynamic description and describe the tissue as a two component fluid system. The ... More
A chemotaxis-based explanation of spheroid formation in 3D cultures of breast cancer cellsOct 31 2018Three-dimensional cultures of cells are gaining popularity as an in vitro improvement over 2D Petri dishes. In many such experiments, cells have been found to organize in aggregates. We present new results of three-dimensional in vitro cultures of breast ... More
Adapting a plant tissue model to animal development: introducing cell sliding into VirtualLeafOct 29 2018Cell-based, mathematical modeling of collective cell behavior has become a prominent tool in developmental biology. Cell-based models represent individual cells as single particles or as sets of interconnected particles, and predict the collective cell ... More
Graphene oxide upregulates the homeostatic functions of primary astrocytes and modulates astrocyte-to-neuron communicationOct 24 2018Graphene-based materials are the focus of intense research efforts to devise novel theranostic strategies for targeting the central nervous system. In this work, we have investigated the consequences of long-term exposure of primary rat astrocytes to ... More
Origin of soft glassy rheology in the cytoskeletonOct 18 2018Dynamically crosslinked semiflexible biopolymers such as the actin cytoskeleton govern the mechanical behavior of living cells. Semiflexible biopolymers stiffen nonlinearly in response to mechanical loads, whereas the crosslinker dynamics allow for stress ... More
Optimal cell transport in straight channels and networksOct 18 2018Flux of rigid or soft particles (such as drops, vesicles, red blood cells, etc.) in a channel is a complex function of particle concentration, which depends on the details of induced dissipation and suspension structure due to hydrodynamic interactions ... More
Active tuning of synaptic patterns enhances immune discriminationOct 14 2018Immune cells learn about their antigenic targets using tactile sense: during recognition, a highly organized yet dynamic motif, named immunological synapse, forms between immune cells and antigen-presenting cells (APCs). Via synapses, immune cells selectively ... More
Traction force microscopy with optimized regularization and automated Bayesian parameter selection for comparing cellsOct 13 2018Adherent cells exert traction forces on to their environment, which allows them to migrate, to maintain tissue integrity, and to form complex multicellular structures. This traction can be measured in a perturbation-free manner with traction force microscopy ... More
Multiscale Modelling of Fibres Dynamics and Cell Adhesion within Moving Boundary Cancer InvasionOct 01 2018Oct 10 2018Cancer cell invasion is recognised as one of the hallmarks of cancer and involves several inner-related multiscale processes that ultimately contribute to its spread into the surrounding tissue. In order to gain a deeper understanding of the tumour invasion ... More
Control of cell colony growth by contact inhibitionOct 01 2018We investigate the dynamics of a colony of crawling, proliferating cells with a minimal, mechanical cell model. The cells consist of two disks, modelling the cell body and a pseudopod, connected by a finite extensible spring. The cells exhibit locomotion ... More
Mechanics of tissue competition: Interfaces stabilize coexistenceSep 28 2018Mechanical forces influence the dynamics of growing tissues. Computer simulations are employed to study the importance of interfacial effects in tissue competition. It was speculated that mechanical pressure determines the competition, where the determining ... More
Modelling cell-cell collision and adhesion with the Filament Based Lamellipodium ModelSep 20 2018We extend the live-cell motility Filament Based Lamellipodium Model to incorporate the forces exerted on the lamellipodium of the cells due to cell-cell collision and cadherin induced cell-cell adhesion. We take into account the nature of these forces ... More
Emergent oscillations in dense adaptive cell populationsSep 19 2018Sep 27 2018Dynamical quorum sensing is one of the simplest group behaviours in cell populations, where collective oscillations emerge via mutual signaling beyond a critical cell density. Although many examples are documented, no unifying principle has yet been proposed. ... More
An In Vitro Vascularized Tumor Platform for Modeling Breast Tumor Stromal Interactions and Characterizing the Subsequent ResponseSep 17 2018Tumor stromal interactions have been shown to be the driving force behind the poor prognosis associated with aggressive breast tumors. These interactions, specifically between tumor and the surrounding ECM, and tumor and vascular endothelium, promote ... More
A coupled bulk-surface model for cell polarisationSep 12 2018Several cellular activities, such as directed cell migration, are coordinated by an intricate network of biochemical reactions which lead to a polarised state of the cell, in which cellular symmetry is broken, causing the cell to have a well defined front ... More
Deciphering the dynamics of Epithelial-Mesenchymal Transition and Cancer Stem Cells in tumor progressionAug 28 2018Nov 06 2018Purpose of review: The epithelial-Mesenchymal Transition (EMT) and the generation of Cancer Stem Cells (CSC) are two fundamental aspects contributing to tumor growth, acquisition of resistance to therapy, formation of metastases, and tumor relapse. Recent ... More
Artificial neural networks for immunological recognitionAug 10 2018Adaptive immunity is analogous to machine learning as the immune system learns about dangerous pathogens and discriminates them from safe self-molecules. Each immune cell has a unique receptor for specific immunological recognition. The binding affinity ... More
Cooperation of dual modes of cell motility promotes epithelial stress relaxation to accelerate wound healingAug 06 2018Collective cell migration in cohesive units is vital for tissue morphogenesis, wound repair, and immune response. While the fundamental driving forces for collective cell motion stem from contractile and protrusive activities of individual cells, it remains ... More
Morphology and Motility of Cells on Soft SubstratesAug 01 2018Aug 03 2018Recent experiments suggest that the interplay between cells and the mechanics of their substrate gives rise to a diversity of morphological and migrational behaviors. Here, we develop a Cellular Potts Model of polarizing cells on a visco-elastic substrate. ... More
Advances in computational modeling approaches in pituitary gonadotropin signalingAug 01 2018Pituitary gonadotropins play an essential and pivotal role in the control of human and animal reproduction within the hypothalamic-pituitary-gonadal (HPG) axis. The computational modeling of pituitary gonadotropin signaling encompasses phenomena of different ... More
A stochastic model for protrusion activityAug 01 2018In this work we approach cell migration under a large-scale assumption, so that the system reduces to a particle in motion. Unlike classical particle models, the cell displacement results from its internal activity: the cell velocity is a function of ... More
Crawling migration under chemical signalling: a stochastic particle modelAug 01 2018Cell migration is a fundamental process involved in physiological phenomena such as the immune response and morphogenesis, but also in pathological processes, such as the development of tumor metastasis. These functions are effectively ensured because ... More
Pulling in models of cell migrationJul 31 2018There are numerous scenarios in which populations of cells migrate in crowded environments. Typical examples include wound healing, cancer growth and embryo development. In these crowded environments cells are able to interact with each other in a variety ... More
The morphodynamics of 3D migrating cancer cellsJul 27 2018Cell shape is an important biomarker. Previously extensive studies have established the relation between cell shape and cell function. However, the morphodynamics, namely the temporal fluctuation of cell shape is much less understood. We study the morphodynamics ... More
Regulation of T cell expansion by antigen presentation dynamicsJul 25 2018An essential feature of the adaptive immune system is the proliferation of antigen-specific lymphocytes during an immune reaction to form a large pool of effector cells. This proliferation must be regulated to ensure an effective response to infection ... More
A simple device for microinjections, manipulations and measurements using an electromorphological chip under microinterferometric control of the interface and membrane processes at the thickness range of 5-1000 nm at different anglesJul 23 2018Micromanipulations, perfusions and measurements performed using glass microelectrodes filled with an electrolyte is a conventional technique for experimental morphological and membrane electrophysiological studies at a single cell and membrane surface ... More
Methods of electron microscopy of biological and abiogenic structures in artificial gas atmospheresJul 23 2018This paper reviews opportunities for using electron microscopy in various gas atmospheres for the analysis and morpho-physiological modification of biological structures. The approaches that allow varying the gaseous phase content, as well as temperature, ... More
Loss of vimentin intermediate filaments decreases peri-nuclear stiffness and enhances cell motility through confined spacesJul 17 2018The migration of cells through tight constricting spaces or along fibrous tracks in tissues is important for biological processes, such as embryogenesis, wound healing, and cancer metastasis, and depends on the mechanical properties of the cytoskeleton. ... More
Dynamics of the brain extracellular matrix governed by interactions with neural cellsJul 16 2018Neuronal and glial cells release diverse proteoglycans and glycoproteins, which aggregate in the extracellular space and form the extracellular matrix (ECM) that may in turn regulate major cellular functions. Brain cells also release extracellular proteases ... More
Enhancement of chemotherapy using oncolytic virotherapy: Mathematical and optimal control analysisJul 11 2018Oncolytic virotherapy (OV) has been emerging as a promising novel cancer treatment that may be further combined with the existing therapeutic modalities to enhance their effects. To investigate how OV could enhance chemotherapy, we propose an ODE based ... More
Etude de la composition chimique et du potentiel pharmacologique associ{é} de Phyllanthus amarus Schum et Thonn (1827)Jul 03 2018In August 2013, the French pharmacopoeia was enriched with 43 plants used in French overseas territories, including 15 proposed by APLAMEDAROM association of Guadeloupe. However, for most of them, no data on the chemical composition, qualitatively and ... More
Orchestral: a lightweight framework for parallel simulations of cell-cell communicationJun 28 2018We develop a modeling and simulation framework capable of massively parallel simulation of multicellular systems with spatially resolved stochastic kinetics in individual cells. By the use of operator-splitting we decouple the simulation of reaction-diffusion ... More
Mathematical models for chemotaxis and their applications in self-organisation phenomenaJun 22 2018Jun 25 2018Chemotaxis is a fundamental guidance mechanism of cells and organisms, responsible for attracting microbes to food, embryonic cells into developing tissues, immune cells to infection sites, animals towards potential mates, and mathematicians into biology. ... More
Gradient Sensing via Cell CommunicationJun 19 2018The chemotactic dynamics of cells and organisms that have no specialized gradient sensing organelles is not well understood. In fact, chemotaxis of this sort of organism is especially challenging to explain when the external chemical gradient is so small ... More
Stochastic and deterministic modelling of cell migrationJun 18 2018Aug 15 2018Mathematical models are vital interpretive and predictive tools used to assist in the understanding of cell migration. There are typically two approaches to modelling cell migration: either micro-scale, discrete or macro-scale, continuum. The discrete ... More
Transient drift of Escherichia coli under diffusing Step nutrient profileJun 09 2018Bacteria such as Escherichia coli (E. coli) exhibit biased motion if kept in a spatially non-uniform chemical environment. Here, we bring out unique time-dependent characteristics of bacterial chemotaxis, in response to a diffusing spatial step ligand ... More
The invasion speed of cell migration models with realistic cell cycle time distributionsJun 08 2018Cell proliferation is typically incorporated into stochastic mathematical models of cell migration by assuming that cell divisions occur after an exponentially distributed waiting time. Experimental observations, however, show that this assumption is ... More
Modeling of drug diffusion in a solid tumor leading to tumor cell deathJun 05 2018It has been shown recently that changing the fluidic properties of a drug can improve its efficacy in ablating solid tumors. We develop a modeling framework for tumor ablation, and present the simplest possible model for drug diffusion in a spherical ... More
A diffuse interface framework for modelling the evolution of multi-cell aggregates as a soft packing problem driven by the growth and division of cellsJun 04 2018Jan 08 2019We present a model for cell growth, division and packing under soft constraints that arise from the deformability of the cells as well as of a membrane that encloses them. Our treatment falls within the framework of diffuse interface methods, under which ... More
Cell Motility Dependence on Adhesive WettingJun 04 2018Feb 04 2019Adhesive cell-substrate interactions are crucial for cell motility and are responsible for the necessary traction that propels cells. These interactions can also change the shape of the cell, analogous to liquid droplet wetting on adhesive substrates. ... More
Random Walker Models for DurotaxisJun 01 2018Motile biological cells in tissue often display the phenomenon of durotaxis, i.e. they tend to move towards stiffer parts of substrate tissue. The mechanism for this behavior is not completely understood. We consider simplified models for durotaxis based ... More
Boundary behaviours of Leishmania mexicana: a hydrodynamic simulation studyJun 01 2018Nov 16 2018It is well established that the parasites of the genus Leishmania exhibit complex surface interactions with the sandfly vector midgut epithelium, but no prior study has considered the details of their hydrodynamics. Here, the boundary behaviours of motile ... More
A Hybrid Multiscale Model for Cancer Invasion of the Extracellular MatrixMay 26 2018The ability to locally degrade the extracellular matrix (ECM) and interact with the tumour microenvironment is a key process distinguishing cancer from normal cells, and is a critical step in the metastatic spread of the tumour. The invasion of the surrounding ... More
A Two-Phase Model of Early Fibrous Cap Formation in AtherosclerosisMay 18 2018Atherosclerotic plaque growth is characterised by chronic inflammation that promotes accumulation of cellular debris and extracellular fat in the inner artery wall. This material is highly thrombogenic, and plaque rupture can lead to the formation of ... More
Continuum models of collective cell migrationMay 16 2018Dec 05 2018Collective cell migration plays a central role in tissue development, morphogenesis, wound repair and cancer progression. With the growing realization that physical forces mediate cell motility in development and physiology, a key biological question ... More
Rigidity controls human desmoplastic matrix anisotropy to enable pancreatic cancer invasion via extracellular signal-regulated kinase 2May 07 2018Jul 01 2018Only about 8 percent of patients with pancreatic ductal adenocarcinoma, PDAC, live up to 5 years following diagnosis; by 2020 PDAC will become the second most lethal cancer in the United States. PDAC includes an anisotropic fibrous-like stroma, desmoplasia, ... More
The same strain of Piscine orthoreovirus (PRV-1) is involved with the development of different, but related, diseases in Atlantic and Pacific Salmon in British ColumbiaMay 03 2018Piscine orthoreovirus Strain PRV-1 is the causative agent of heart and skeletal muscle inflammation (HSMI) in Atlantic salmon (Salmo salar). Given its high prevalence in net pen salmon, debate has arisen on whether PRV poses a risk to migratory salmon, ... More
Cell membrane disruption by vertical nanopillars: the role of membrane bending and traction forcesApr 27 2018Gaining access to the cell interior is fundamental for many applications, such as electrical recording, drug and biomolecular delivery. A very promising technique consists of culturing cells on nano/micro pillars. The tight adhesion and high local deformation ... More
Optimal segregation of proteins: phase transitions and symmetry breakingApr 24 2018Asymmetric segregation of key proteins at cell division -- be it a beneficial or deleterious protein -- is ubiquitous in unicellular organisms and often considered as an evolved trait to increase fitness in a stressed environment. Here, we provide a general ... More
Rapid behavioral transitions produce chaotic mixing by a planktonic microswimmerApr 23 2018Despite their vast morphological diversity, many invertebrates have similar larval forms characterized by ciliary bands, innervated arrays of beating cilia that facilitate swimming and feeding. Hydrodynamics suggests that these bands should tightly constrain ... More
Spatial heterogeneities shape collective behavior of signaling amoeboid cellsApr 18 2018We present novel experimental results on pattern formation of signaling Dictyostelium discoideum amoeba in the presence of a periodic array of millimeter-sized pillars. We observe concentric cAMP waves that initiate almost synchronously at the pillars ... More
Emergent three-dimensional sperm motility: Coupling calcium dynamics and preferred curvature in a Kirchhoff rod modelApr 12 2018Changes in calcium concentration along the sperm flagellum regulates sperm motility and hyperactivation, characterized by an increased flagellar bend amplitude and beat asymmetry, enabling the sperm to reach and penetrate the ovum (egg). The signaling ... More