All posts under category "Quantitative Biology / Q-Bio.TO"
The innumerable shapes of plant leaves present a challenge to the explanatory power of biophysical theory. A model is needed that can produce these shapes with a small set of parameters. This paper presents a simple model of leaf shape based on a growth algorithm, which governs the growth rate of le
We study the interplay between traveling action potentials and spatial inhomogeneities in the FitzHugh-Nagumo model to investigate possible mechanisms for the occurrence of fibrillatory states in the atria of the heart. Different dynamical patterns such as ectopic foci, localized and meandering spir
Micropropagation of three genotypes of Indian mustard [textit{Brassica juncea} (L.) Czern.] using 7-days old seedling-derived transverse thin cell layer (tTCL) explants was accomplished. The genotype, explant source and addition of silver nitrate to the medium significantly influenced shoot bud in
Since laws of physics exist in nature, their possible relationship to terrestial growth is introduced. By considering the human body as a dynamic system of variable mass (and volume), growing under a gravity field, it is shown how natural laws may influence the vertical growth of humans. This approa
A new type of diode that is made entirely of electrically excitable muscle cells and nonexcitable fibroblast cells is designed, fabricated, and characterized. These two cell types in a rectangular pattern allow the signal initiated on the excitable side to pass to the nonexcitable side, and not in t
Prostaglandin E2 (PGE2), is a major prostanoid produced by the activity of cyclooxygenases (COX) in response to various physiological and pathological stimuli. PGE2 exerts its effects by activating four specific E-type prostanoid receptors (EP1, EP2, EP3, and EP4). In the present study, we analyzed
Analytical study of results of experimental and theoretical works on pathogenesis of psoriatic disease was conducted. Psoriasis is dermal implication of systemic psoriatic process (SPP). New SPP model explaining results of clinical and laboratory experiments was formulated. According to Y-model ther
Classification of vertebral compression fractures (VCF) having osteoporotic or neoplastic origin is fundamental to the planning of treatment. We developed a fracture classification system by acquiring quantitative morphologic and bone density determinants of fracture progression through the use of a
With the National Toxicology Program issuing its final report on cancer, rats and cell phone radiation, one can draw the following conclusions from their data. There is a roughly linear relationship between gliomas (brain cancers) and schwannomas (cancers of the nerve sheaths around the heart) with
A model of pattern formation in living systems is presented. The pattern is achieved by the sequential interaction of two signaling pathways. The coupling of the pattern to the (thick) epithelial sheet changes is given, when the Gauss curvature'K'enters. The model suggests a novel point-like placeme
A number of studies showed association of mental status with heart rate variability. This work discovered a feature of frequency structure of heart rate variability that is associated with mental readiness. In three independent groups of 64, 39, and 19 volunteers by the factor analysis of heart rate
Pathologists routinely classify breast tumors according to recurring patterns of nuclear grades, cytoplasmic coloration, and large-scale morphological formations (i.e. streams of spindle cells, adenoid islands, etc.). The fact that there are large-scale morphological formations suggest that tumor ce
We study a simplified stochastic model for the vascularization of a growing tumor, incorporating the formation of new blood vessels at the tumor periphery as well as their regression in the tumor center. The resulting morphology of the tumor vasculature differs drastically from the original one. We
Numerical simulations of the behavior of the osteonal structure are more and more acute and an important parameter is the pressure of the bony fluid. Haversian and Volkmann canals contain blood vessels that transport oxygen and nutrients necessary for the cellular activity. The pressure in these ves
Shape is one of the important characteristics for the structures observed in living organisms. Whereas biologists have proposed models where the shape is controlled on a molecular level [1], physicists, following Turing [2] and d'Arcy Thomson [3], have developed theories where patterns arise spontan
The automatic extraction of retinal vascular biomarkers from color fundus images (CFI) is essential for large-scale studies of the retinal vasculature. We present VascX, an open-source Python toolbox designed for the automated extraction of biomarkers from artery and vein segmentations. The VascX wo
Micro-sized cold atmospheric plasma (uCAP) has been developed to expand the applications of CAP in cancer therapy. In this paper, uCAP devices with different nozzle lengths were applied to investigate effects on both brain (glioblastoma U87) and breast (MDA-MB-231) cancer cells. Various diagnostic t
The eye lens is the most characteristic example of mammalian tissues exhibiting complex colloidal behaviour. In this paper we briefly describe how dynamics in colloidal suspensions can help addressing selected aspects of lens cataract which is ultimately related to the protein self-assembly under pa
During fast locomotion - gallop, half bound - of quadruped mammals, the ground contact of the limbs in each pair do not alternate symmetrically. Animals using such asymmetrical gait thus choose whether the left or the right limb will contact the ground first, and this gives rise to limb preference.
Chondrocytes are described as one cell population in different cartilage types. The auricular cartilage in mouse and rat contains unique chondrocytes similar in morphology to white adipocytes and known as lipochondrocytes. Lipochondrocytes were not mentioned in other species. The current study aimed
We present a portable, simple-to-operate, point-of-use analyte surface localization device. We take advantage of a set of hydrodynamic design features and components that achieve passive analyte localization by means of a single vacuum input. The vacuum source can be supplied by mechanical or batter
We apply three optical coherence tomography (OCT) image analysis techniques to extract morphometric information from OCT images obtained on peripheral nerves of rat. The accuracy of each technique is evaluated against histological measurements accurate to +/-1 um. The three OCT techniques are: 1) av
Computational models of the respiratory central pattern generator (rCPG) are usually based on biologically-plausible Hodgkin Huxley neuron models. Such models require numerous parameters and thus are prone to overfitting. The HH approach is motivated by the assumption that the biophysical properties
A mathematical model for fluid transport in peritoneal dialysis is constructed. The model is based on a three-component nonlinear system of two-dimensional partial differential equations for fluid, glucose and albumin transport with the relevant boundary and initial conditions. Non-constant steady-s
Flow-induced shear stresses have been found to be a stimulatory factor in pre-osteoblastic cells seeded in 3D porous scaffolds and cultured under continuous flow perfusion. However, due to the complex internal structure of the scaffolds, whole scaffold calculations of the local shear forces are comp
Multiple Myeloma (MM) is a blood cancer implying bone marrow involvement, renal damages and osteolytic lesions. The skeleton involvement of MM is at the core of the present paper, exploiting radiomics and artificial intelligence to identify image-based biomarkers for MM. Preliminary results show tha
In this study, we investigated the effects of specific low frequency electromagnetic fields sequences on U937 cells, an in vitro model of human monocyte/macrophage differentiation. U937 cells were exposed to electromagnetic stimulation by means of the SyntheXer system using two similar sequences, XR
Umbilical cord blood (UBC) can be viewed as the most promising source of stem cells, in which collection cost is minimal and its benefits are immense. The cord blood is used to treat malignant and nonmalignant diseases; this is due to its progenitor characteristics know as stem cells.Its properties
A total of 293 women treated at Tomsk Cancer Research Institute were examined. HPV type 16 had the highest incidence rate (45.0%) followed by HPV 31-17,0%, HPV 56/33-15,0%, HPV 51/18/52-13,0%, HPV 58/35/39/45-7,0%, HPV 59-5,0%. Persistent infection was detected in 35.7% of primarily HPV-positive cas
Ischemia leading to heart attacks and strokes is the major cause of deaths in the world. Whether an occlusion occurs or not, depends on the ability of a growing thrombus to resist forces exerted on its structure. This manuscript provides the first known in vivo measurement of the stresses that clots
The aim of this paper is to develop a multiscale hierarchical hybrid model based on finite element analysis and neural network computation to link mesoscopic scale (trabecular network level) and macroscopic (whole bone level) to simulate bone remodelling process. Because whole bone simulation consid
A mathematical model of a drug transport after rapid injection is given. It takes into account three processes: - drug plasma protein binding in central compartment - transport processes between the central compartment and the peripheral compartment - elimination of a drug from the central compartme
Some inconsistencies in the passive pharmacokinetics has been observed many years ago. It is possible these inconsistencies result from the lack of proper evolution equations. In this communication, this possibility is illustrated on the example of an evolution equation for an one compartment model.
Blood system functions are very diverse and important for most processes in human organism. One of its primary functions is matter transport among different parts of the organism including tissue supplying with oxygen, carbon dioxide excretion, drug propagation etc. Forecasting of these processes un
The dynamic patterning of the plant hormone auxin and its efflux facilitator the PIN protein are the key regulator for the spatial and temporal organization of plant development. In particular auxin induces the polar localization of its own efflux facilitator. Due to this positive feedback auxin flo
During the development of an organism, cells must coordinate and organize to generate the correct shape, structure, and spatial patterns of tissues and organs, a process known as morphogenesis. The morphogenesis of embryonic tissues is supported by multiple processes that induce the precise physical
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