Search results for "cell behavior"
showing 10 items of 91 documents
Retrieving infinite numbers of patterns in a spin-glass model of immune networks
2013
The similarity between neural and immune networks has been known for decades, but so far we did not understand the mechanism that allows the immune system, unlike associative neural networks, to recall and execute a large number of memorized defense strategies {\em in parallel}. The explanation turns out to lie in the network topology. Neurons interact typically with a large number of other neurons, whereas interactions among lymphocytes in immune networks are very specific, and described by graphs with finite connectivity. In this paper we use replica techniques to solve a statistical mechanical immune network model with `coordinator branches' (T-cells) and `effector branches' (B-cells), a…
Collective Cell Migration in a Fibrous Environment: A Hybrid Multiscale Modelling Approach
2021
International audience; The specific structure of the extracellular matrix (ECM), and in particular the density and orientation of collagen fibres, plays an important role in the evolution of solid cancers. While many experimental studies discussed the role of ECM in individual and collective cell migration, there are still unanswered questions about the impact of nonlocal cell sensing of other cells on the overall shape of tumour aggregation and its migration type. There are also unanswered questions about the migration and spread of tumour that arises at the boundary between different tissues with different collagen fibre orientations. To address these questions, in this study we develop …
Interaction of C 60 fullerenes with asymmetric and curved lipid membranes: a molecular dynamics study
2015
Interaction of fullerenes with asymmetric and curved DOPC/DOPS bicelles is studied by means of coarse-grained molecular dynamics simulations. The effects caused by asymmetric lipid composition of the membrane leaflets and the curvature of the membrane are analyzed. It is shown that the aggregates of fullerenes prefer to penetrate into the membrane in the regions of the moderately positive mean curvature. Upon penetration into the hydrophobic core of the membrane fullerenes avoid the regions of the extreme positive or the negative curvature. Fullerenes increase the ordering of lipid tails, which are in direct contact with them, but do not influence other lipids significantly. Our data sugges…
Efficient and reproducible experimental infections of rats with Blastocystis spp.
2018
Although Blastocystis spp. infect probably more than 1 billion people worldwide, their clinical significance is still controversial and their pathophysiology remains poorly understood. In this study, we describe a protocol for an efficient and reproducible model of chronic infection in rats, laying the groundwork for future work to evaluate the pathogenic potential of this parasite. In our experimental conditions, we were unable to infect rats using vacuolar forms of an axenically cultivated ST4 isolate, but we successfully established chronic infections of 4 week-old rats after oral administration of both ST3 and ST4 purified cysts isolated from human stool samples. The infection protocol …
"Table 25" of "Multiplicity dependence of K*(892)$^{0}$ and $\phi$(1020) production in pp collisions at $\sqrt{s}$ = 13 TeV"
2020
$\phi$ transverse momentum spectrum - V0M multiplicity class VII
Artificial Neural Networks and Linear Discriminant Analysis: A Valuable Combination in the Selection of New Antibacterial Compounds
2004
A set of topological descriptors has been used to discriminate between antibacterial and nonantibacterial drugs. Topological descriptors are simple integers calculated from the molecular structure represented in SMILES format. The methods used for antibacterial activity discrimination were linear discriminant analysis (LDA) and artificial neural networks of a multilayer perceptron (MLP) type. The following plot frequency distribution diagrams were used: a function of the number of drugs within a value interval of the discriminant function and the output value of the neural network versus these values. Pharmacological distribution diagrams (PDD) were used as a visualizing technique for the i…
Anergy in self-directed B lymphocytes from a statistical mechanics perspective
2012
The ability of the adaptive immune system to discriminate between self and non-self mainly stems from the ontogenic clonal-deletion of lymphocytes expressing strong binding affinity with self-peptides. However, some self-directed lymphocytes may evade selection and still be harmless due to a mechanism called clonal anergy. As for B lymphocytes, two major explanations for anergy developed over three decades: according to "Varela theory", it stems from a proper orchestration of the whole B-repertoire, in such a way that self-reactive clones, due to intensive interactions and feed-back from other clones, display more inertia to mount a response. On the other hand, according to the `two-signal …
Transient frailty induced by cell division. Observation, reasons and implications
2021
We know that stress-factors, e.g. X-rays, have an effect on cells that is more lethal in rapid exponential growth than in stationary phase. It is this effect which makes radiotherapy effective in cancer treatment. This stress effect can be explained in two ways: (a) more vulnerability in the growth phase, (b) improved protection capacity and repair mechanisms in the stationary phase. Although the two explanations do not exclude each other, they are very different in the sense that (a) is a general mechanism whereas (b) is strain and stress-factor dependent. In this paper we explore major facets of (a). Firstly, we emphasize that (a) can account for known experimental stress-factor evidence.…
Is there an infant mortality in bacteria?
2021
This manuscript proposes a significant step in our long-run investigation of infant mortality across species. Since 2016 (Berrut et al. 2016) a succession of studies (Bois et al. 2019) have traced infant mortality from organisms of high complexity (e.g. mammals) down to unicellular organisms. Infant mortality may be considered as a filtering process through which organisms with potentially lethal congenital defects are eliminated. Such defects may have many causes but here we focus particularly on mishaps resulting from non-optimal conditions in the production of proteins, enzymes and other crucial macromolecules. The statistical signature of infant mortality consists in a falling age-speci…
XPO1E571K Mutation Modifies Exportin 1 Localisation and Interactome in B-cell Lymphoma
2020
The XPO1 gene encodes exportin 1 (XPO1) that controls the nuclear export of cargo proteins and RNAs. Almost 25% of primary mediastinal B-cell lymphoma (PMBL) and classical Hodgkin lymphoma (cHL) cases harboured a recurrent XPO1 point mutation (NM_003400, chr2:g61718472C>