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Munsky B - - 2010
Owing to the inherently random and discrete nature of genes, RNAs and proteins within living cells, there can be a wide range of variability both over time in a single cell and from cell to cell in a population of genetically identical cells. Different mechanisms and reaction rates help shape ...
Haeger J-D - - 2011
Introduction: In this study, we aimed to form spheroids with the bovine placental trophoblast cell line F3. Spheroids are 3-dimensional culture models which can be used to conduct versatile in vitro and in vivo experiments. Materials and Methods: The spheroids were generated using the hanging drop technique, 25% methocel and ...
Fong Eileen - - 2010
The processes of wound healing and collective cell migration have been studied for decades. Intensive research has been devoted to understanding the mechanisms involved in wound healing, but the role of cell-substrate interactions is still not thoroughly understood. Here we probe the role of cell-substrate interactions by examining in vitro ...
Tamulonis Carlos - - 2011
The gastrulation of Nematostella vectensis, the starlet sea anemone, is morphologically simple yet involves many conserved cell behaviors such as apical constriction, invagination, bottle cell formation, cell migration and zippering found during gastrulation in a wide range of more morphologically complex animals. In this article we study Nematostella gastrulation using ...
Neilson Matthew P - - 2010
In this paper we present a computational tool that enables the simulation of mathematical models of cell migration and chemotaxis on an evolving cell membrane. Recent models require the numerical solution of systems of reaction-diffusion equations on the evolving cell membrane and then the solution state is used to drive ...
Ratcliff William C - - 2010
The expression of phenotypic variability can enhance geometric mean fitness and act as a bet-hedging strategy in unpredictable environments. Metazoan bet hedging usually involves phenotypic diversification among an individual's offspring, such as differences in seed dormancy. Virtually all known microbial bet-hedging strategies, in contrast, rely on low-probability stochastic switching of ...
Coskun Hasan - - 2011
Cell motility is an essential phenomenon in almost all living organisms. It is natural to think that behavioral or shape changes of a cell bear information about the underlying mechanisms that generate these changes. Reading cell motion, namely, understanding the underlying biophysical and mechanochemical processes, is of paramount importance. The ...
Or-Tzadikario Shira - - 2011
This communication extends the recently reported cell-specific finite element (FE) method in Slomka and Gefen (2010) in which geometrically realistic FE cell models are created from confocal microscopy scans for large deformation analyses. The cell-specific FE method is extended here in the following aspects: (i) we demonstrate that cell-specific FE ...
Poulos Sylvia P - - 2010
In vitro models have been invaluable in determining the mechanisms involved in adipocyte proliferation, differentiation, adipokine secretion and gene/protein expression. The cells presently available for research purposes all have unique advantages and disadvantages that one should be aware of when selecting cells. Established cell lines, such as 3T3-L1 cells, are ...
Xiong Yuan - - 2010
Cells have an internal compass that enables them to move along shallow chemical gradients. As amoeboid cells migrate, signaling events such as Ras and PI3K activation occur spontaneously on pseudopodia. Uniform stimuli trigger a symmetric response, whereupon cells stop and round up; then localized patches of activity appear as cells ...
Norman Leann L - - 2010
Cells remodel their plasma membrane and cytoskeleton during numerous physiological processes, including spreading and motility. Morphological changes require the cell to adjust its membrane tension on different timescales. While it is known that endo- and exocytosis regulate the cell membrane area in a timescale of 1 h, faster processes, such ...
Wolgemuth Charles W - - 2010
Eukaryotic cell crawling is a highly complex biophysical and biochemical process, where deformation and motion of a cell are driven by internal, biochemical regulation of a poroelastic cytoskeleton. One challenge to building quantitative models that describe crawling cells is solving the reaction-diffusion-advection dynamics for the biochemical and cytoskeletal components of ...
Lidstrom Mary E - - 2010
As the ability to analyze individual cells in microbial populations expands, it is becoming apparent that isogenic microbial populations contain substantial cell-to-cell differences in physiological parameters such as growth rate, resistance to stress and regulatory circuit output. Subpopulations exist that are manyfold different in these parameters from the population average, ...
Huang Yao-Xiong - - 2011
We developed a technique using quantum dot (QD) as a sensor for quantitative visualization of the surface charge on biological cells with nano-scale resolution. The QD system was designed and synthesized using amino modified CdSe/ZnS nanoparticles. In a specially designed buffer solution, they are positively charged and can homogeneously disperse ...
Hillen Thomas - - 2010
Classical expressions for the tumor control probability (TCP) are based on models for the survival fraction of cancer cells after radiation treatment. We focus on the derivation of expressions for TCP from dynamic cell population models. In particular, we derive a TCP formula for a generalized cell population model that ...
Dingli David - - 2010
Cancer is the consequence of sequential acquisition of mutations within somatic cells. Mutations alter the relative reproductive fitness of cells, enabling the population to evolve in time as a consequence of selection. Cancer therapy itself can select for or against specific subclones. Given the large population of tumor cells, subclones ...
Golubev A - - 2010
Several recent experiments related to fundamental aspects of cell behaviour, such as passing of the restriction point of cell cycle, which are generally interpreted in accordance with the dynamic paradigm implying the use of differential equations operating with the concentrations of cellular components and rate constants of their interactions, are ...
Goh Fernie F School of Chemical & Biomolecular Engineering, Georgia Institute of Technology, 315 Ferst Dr., Atlanta, GA 30332, - - 2010
Due to the high solubility of oxygen in perfluorocarbons (PFCs), these compounds have been explored for improved cell and tissue oxygenation. The goal of this study is to investigate the effects of a PFC emulsion on cellular growth and function in a tissue engineered construct. A perfluorotributylamine (PFTBA) emulsion was ...
Rolf Julia J Laboratory of Lymphocyte Signalling and Development, Babraham Institute, Cambridge, United - - 2010
The generation of high-affinity Abs is essential for immunity and requires collaboration between B and T cells within germinal centers (GCs). By using novel mouse models with a conditional deletion of the p110δ catalytic subunit of the PI3K pathway, we established that p110δ is required in T cells, but not ...
Goodman Rachel M - - 2010
Among ectotherms, individuals raised in cooler temperatures often have larger body size and/or larger cell size. The current study tested whether geographic variation in cell size and plasticity for cell size exist in a terrestrial, ectothermic vertebrate, Anolis carolinensis Voigt, 1832. We demonstrated temperature-induced plasticity in erythrocytes and epithelial cells ...
Barik Debashis D Department of Biological Sciences, Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, - - 2010
In order for the cell's genome to be passed intact from one generation to the next, the events of the cell cycle (DNA replication, mitosis, cell division) must be executed in the correct order, despite the considerable molecular noise inherent in any protein-based regulatory system residing in the small confines ...
Grote Mathias - - 2010
The term 'cell', in addition to designating fundamental units of life, has also been applied since the nineteenth century to technical apparatuses such as fuel and galvanic cells. This paper shows that such technologies, based on the electrical effects of chemical reactions taking place in containers, had a far-reaching impact ...
Sriyudthsak Kansuporn - - 2010
A number of recent research studies have focused on theoretical and experimental investigation of a bottleneck in a metabolic reaction network. However, there is no study on how the bottleneck affects the performance of a fermentation process when a product is highly toxic and remarkably influences the growth and death ...
Costigliola Nancy - - 2010
When microtubules are depolymerized in spreading cells, they experience morphological oscillations characterized by a period of about a minute, indicating that normal interactions between the microfilament and microtubule systems have been significantly altered. This experimental system provides a test bed for the development of both fine- and coarse-grained models of ...
Turner C - - 2010
Under the cancer stem cell (CSC) hypothesis, sustained metastatic growth requires the dissemination of a CSC from the primary tumour followed by its re-establishment in a secondary site. The epithelial-mesenchymal transition (EMT), a differentiation process crucial to normal development, has been implicated in conferring metastatic ability on carcinomas. Balancing these ...
O'Malley Maureen A - - 2010
The eukaryote cell is one of the most radical innovations in the history of life, and the circumstances of its emergence are still deeply contested. This paper will outline the recent history of attempts to reveal these origins, with special attention to the argumentative strategies used to support claims about ...
Tasoglu Savas - - 2010
The impact and spreading of a compound viscous droplet on a flat surface are studied computationally using a front-tracking method as a model for the single cell epitaxy. This is a technology developed to create two-dimensional and three-dimensional tissue constructs cell by cell by printing cell-encapsulating droplets precisely on a ...
Skorkina M Yu - - 2010
We propose and tested a method for studies of native blood cells by atomic-force microscopy in a humid chamber preserving viability, size, and shape of biological objects. The method has some advantages over scanning in a liquid cell: it allows studying non-fixed blood samples in the form of suspension of ...
Gowthaman Uthaman - - 2010
The germinal center (GC) reaction supports the processes of affinity maturation and class switching in B cells that result in long-lasting humoral immunity. CD4(+) T follicular helper cells (Tfh) participate in the GC reaction to help B cells. However, recent studies highlight the heterogeneity of CD4(+) T cells in GCs, ...
Wong Ieong - - 2010
Significance of single cell measurements stems from the substantial temporal fluctuations and cell-cell variability possessed by individual cells. A major difficulty in monitoring surface non-adherent cells such as bacteria and yeast is that these cells tend to aggregate into clumps during growth, obstructing the tracking or identification of single-cells over ...
Hölttä Teemu - - 2010
Cambial growth was modelled as a function of detailed levelled physiological processes for cell enlargement and water and sugar transport to the cambium. Cambial growth was described at the cell level where local sugar concentration and turgor pressure induce irreversible cell expansion and cell wall synthesis. It was demonstrated how ...
Teka Wondimu W Department of Mathematics, Florida State University, Tallahassee, - - 2011
Bursting electrical activity is ubiquitous in excitable cells such as neurons and many endocrine cells. The technique of fast/slow analysis, which takes advantage of time scale differences, is typically used to analyze the dynamics of bursting in mathematical models. Two classes of bursting oscillations that have been identified with this ...
Khmelinskii Anton - - 2010
During mitosis in Saccharomyces cerevisiae, senescence factors such as extrachromosomal ribosomal DNA circles (ERCs) are retained in the mother cell and excluded from the bud/daughter cell. Shcheprova et al. proposed a model suggesting segregation of ERCs through their association with nuclear pore complexes (NPCs) and retention of pre-existing NPCs in ...
Ling Hong - - 2010
We investigate the robustness and the behaviours of the critical proteins under parameter perturbations of G1/S checkpoint pathways with different levels of DNA-damage, based on a mathematical model of the pathways. We identify the peak times (PTs) of two key proteins as the in silico biomarkers based on the currently ...
Lee Byunghong - - 2010
A series of experiments have been carried out to study the effects of materials quality, surface and interfacial modification, and photon confinement on standard dye-sensitized solar cells. For these studies, both physical and optical characterization of the materials has been performed in detail. In addition, DC and AC impedance measurements ...
Munson Mark E - - 2010
Investigating the response of cells to specific agonists may involve the use of cell tracking dyes to assess the extent of stimulated proliferation, frequently reported as the proliferation index (PI). Calculation of PI uses a model for cell division that expects the cell number to double as cells proliferate through ...
Enikeeva Farida N FN Institute for Information Transmission Problems, the Kharkevich Institute of RAS, Bolshoi Karetny pereulok 19, GSP-4, Moscow 127994, Russia. - - 2010
The success of a phage that infects a bacterial cell possessing a restriction-modification (R-M) system depends on the activities of the host methyltransferase and restriction endonuclease, and the number of susceptible sites in the phage genome. However, there is no model describing this dependency and linking it to observable parameters ...
Besser Achim - - 2010
Mechanical cues like the rigidity of the substrate are main determinants for the decision-making of adherent cells. Here we use a mechano-chemical model to predict the cellular response to varying substrate stiffnesses. The model equations combine the mechanics of contractile actin filament bundles with a model for the Rho-signaling pathway ...
Jiang Hongyuan H Department of Mechanical Engineering and Whitaker Biomedical Engineering Institute, Johns Hopkins University, Baltimore, Maryland 21218, - - 2010
Bacterial cells utilize a living peptidoglycan network (PG) to separate the cell interior from the surroundings. The shape of the cell is controlled by PG synthesis and cytoskeletal proteins that form bundles and filaments underneath the cell wall. The PG layer also resists turgor pressure and protects the cell from ...
Cramer Louise P - - 2010
Directed cell migration requires the breaking of cell symmetry to generate a cell front and a cell rear along an axis approximately aligned with the direction of locomotion. In most cell types, regulated actin polymerization promotes initial cell front formation and its subsequent persistent protrusion, whereas myosin II-based forces are ...
Doinikov Alexander A - - 2010
There are numerous experimental investigations on sonoporation, while the theoretical background of this phenomenon still is in its infancy. One of the suggested mechanisms of sonoporation is linked to shear stress exerted on the cell membrane by acoustic microstreaming generated by a contrast microbubble pulsating nearby a cell. Currently, the ...
Detzel Christopher J - - 2010
An increasing demand for products such as tissues, proteins, and antibodies from mammalian cell suspension cultures is driving interest in increasing production through high-cell density bioreactors. The centrifugal bioreactor (CCBR) retains cells by balancing settling forces with surface drag forces due to medium throughput and is capable of maintaining cell ...
Schuster Stefan - - 2010
The engineering of microorganisms to produce a variety of extracellular enzymes (exoenzymes), for example for producing renewable fuels and in biodegradation of xenobiotics, has recently attracted increasing interest. Productivity is often reduced by "cheater" mutants, which are deficient in exoenzyme production and benefit from the product provided by the "cooperating" ...
Solow Andrew R - - 2010
There is growing interest in predicting the abundance of a species in a region from the occupancy of cells in a uniform grid overlaid on the region. When the number of individuals in each cell follows a negative binomial distribution, prediction is in general not possible from the number of ...
Morata Gines - - 2010
We have generated wing disc compartments that contain marked fast growing M+ clones surrounded by slow dividing M/+ cells. Under these conditions the interactions between fast and slow dividing cells at the clone borders frequently lead to cell competition. However, our assay suppressing apoptosis indicates that cell competition plays no ...
Boczko Erik M EM Department of Biomedical Informatics, Vanderbilt University, Nashville, - - 2010
Biologists have long observed periodic-like oxygen consumption oscillations in yeast populations under certain conditions, and several unsatisfactory explanations for this phenomenon have been proposed. These ‘autonomous oscillations’ have often appeared with periods that are nearly integer divisors of the calculated doubling time of the culture. We hypothesize that these oscillations ...
Tay SavaƟ S Department of Bioengineering, Stanford University, Stanford, California 94305, - - 2010
Cells operate in dynamic environments using extraordinary communication capabilities that emerge from the interactions of genetic circuitry. The mammalian immune response is a striking example of the coordination of different cell types. Cell-to-cell communication is primarily mediated by signalling molecules that form spatiotemporal concentration gradients, requiring cells to respond to ...
Dokukina Irina V - - 2010
To function efficiently in the body, the biological cells must have the ability to sense the external environment. Mechanosensitivity toward the extracellular matrix was identified as one of the sensing mechanisms affecting cell behavior. It was shown experimentally that a fibroblast cell prefers locomoting over the stiffer substrate when given ...
Kim Min-Cheol - - 2010
To successfully perform biological experiments on bacteria in microfluidic devices, control of micron-scale cell motion in the chip-sized environment is essential. Here we describe a new method for simulating the motion of individual bacterial cells in a microfluidic device using a one-way coupling Lagrangian approach combined with rigid body theory. ...
Stamatakis Michail - - 2010
Several approaches have been used in the past to model heterogeneity in bacterial cell populations, with each approach focusing on different source(s) of heterogeneity. However, a holistic approach that integrates all the major sources into a comprehensive framework applicable to cell populations is still lacking. In this work we present ...
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