keyword
MENU ▼
Read by QxMD icon Read
search

Differential equation

keyword
https://www.readbyqxmd.com/read/28231313/a-stochastic-hybrid-systems-based-framework-for-modeling-dependent-failure-processes
#1
Mengfei Fan, Zhiguo Zeng, Enrico Zio, Rui Kang, Ying Chen
In this paper, we develop a framework to model and analyze systems that are subject to dependent, competing degradation processes and random shocks. The degradation processes are described by stochastic differential equations, whereas transitions between the system discrete states are triggered by random shocks. The modeling is, then, based on Stochastic Hybrid Systems (SHS), whose state space is comprised of a continuous state determined by stochastic differential equations and a discrete state driven by stochastic transitions and reset maps...
2017: PloS One
https://www.readbyqxmd.com/read/28231156/a-computational-study-of-amensalistic-control-of-listeria-monocytogenes-by-lactococcus-lactis-under-nutrient-rich-conditions-in-a-chemostat-setting
#2
Hassan Khassehkhan, Hermann J Eberl
We study a previously introduced mathematical model of amensalistic control of the foodborne pathogen Listeria monocytogenes by the generally regarded as safe lactic acid bacteria Lactococcus lactis in a chemostat setting under nutrient rich growth conditions. The control agent produces lactic acids and thus affects pH in the environment such that it becomes detrimental to the pathogen while it is much more tolerant to these self-inflicted environmental changes itself. The mathematical model consists of five nonlinear ordinary differential equations for both bacterial species, the concentration of lactic acids, the pH and malate...
September 9, 2016: Foods (Basel, Switzerland)
https://www.readbyqxmd.com/read/28230090/advanced-retarded-differential-equations-in-quantum-photonic-systems
#3
Unai Alvarez-Rodriguez, Armando Perez-Leija, Iñigo L Egusquiza, Markus Gräfe, Mikel Sanz, Lucas Lamata, Alexander Szameit, Enrique Solano
We propose the realization of photonic circuits whose dynamics is governed by advanced-retarded differential equations. Beyond their mathematical interest, these photonic configurations enable the implementation of quantum feedback and feedforward without requiring any intermediate measurement. We show how this protocol can be applied to implement interesting delay effects in the quantum regime, as well as in the classical limit. Our results elucidate the potential of the protocol as a promising route towards integrated quantum control systems on a chip...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28229357/experimental-determination-and-theoretical-calculation-of-the-eutectic-composition-of-cefuroxime-axetil-diastereomers
#4
Namita Dalal, Ira S Buckner, Peter L D Wildfong
Cefuroxime axetil (CFA), an ester prodrug of cefuroxime exists as a pair of diastereoemers, namely isomer A and isomer B. To enable phase diagram construction, crystallization of the diastereomers of CFA from the commercially available amorphous drug substance was carried out. Isomer A was separated with a purity approaching 100% whereas the maximum purity of isomer B was 85% as confirmed by solution state proton NMR spectroscopy. The crystalline forms of isomer A and isomer B were confirmed as forms AI and BI, respectively, based on differential scanning calorimetry (DSC) analysis and powder X-ray diffraction...
February 22, 2017: AAPS PharmSciTech
https://www.readbyqxmd.com/read/28228546/a-minimal-actomyosin-based-model-predicts-the-dynamics-of-filopodia-on-neuronal-dendrites
#5
Olena O Marchenko, Sulagna Das, Ji Yu, Igor L Novak, Vladimir I Rodionov, Nadia Efimova, Tatyana Svitkina, Charles W Wolgemuth, Leslie M Loew
Dendritic filopodia are actin-filled dynamic subcellular structures that sprout on neuronal dendrites during neurogenesis. The exploratory motion of the filopodia is crucial for synaptogenesis but the underlying mechanisms are poorly understood. To study the filopodial motility, we collected and analyzed image data on filopodia in cultured rat hippocampal neurons. We hypothesized that mechanical feedback among the actin retrograde flow, myosin activity and substrate adhesion gives rise to various filopodial behaviors...
February 22, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/28228465/prognostic-value-of-residual-urine-volume-gfr-by-24-hour-urine-collection-and-egfr-in-patients-receiving-dialysis
#6
Mi Jung Lee, Jung Tak Park, Kyoung Sook Park, Young Eun Kwon, Hyung Jung Oh, Tae-Hyun Yoo, Yong-Lim Kim, Yon Su Kim, Chul Woo Yang, Nam-Ho Kim, Shin-Wook Kang, Seung Hyeok Han
BACKGROUND AND OBJECTIVES: Residual kidney function can be assessed by simply measuring urine volume, calculating GFR using 24-hour urine collection, or estimating GFR using the proposed equation (eGFR). We aimed to investigate the relative prognostic value of these residual kidney function parameters in patients on dialysis. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Using the database from a nationwide prospective cohort study, we compared differential implications of the residual kidney function indices in 1946 patients on dialysis at 36 dialysis centers in Korea between August 1, 2008 and December 31, 2014...
February 22, 2017: Clinical Journal of the American Society of Nephrology: CJASN
https://www.readbyqxmd.com/read/28226780/modeling-of-coupled-differential-equations-for-cellular-chemical-signaling-pathways-implications-for-assay-protocols-utilized-in-cellular-engineering
#7
George D O'Clock, George D O'Clock, George D O'Clock
Cellular engineering involves modification and control of cell properties, and requires an understanding of fundamentals and mechanisms of action for cellular derived product development. One of the keys to success in cellular engineering involves the quality and validity of results obtained from cell chemical signaling pathway assays. The accuracy of the assay data cannot be verified or assured if the effect of positive feedback, nonlinearities, and interrelationships between cell chemical signaling pathway elements are not understood, modeled, and simulated...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226658/on-an-analogue-signal-processing-circuit-in-the-nematode-c-elegans
#8
Roghieh Skandari, Yuichi Iino, Jonathan H Manton, Roghieh Skandari, Yuichi Iino, Jonathan H Manton, Roghieh Skandari, Yuichi Iino, Jonathan H Manton
In this work we will work on analogue signal processing in the neural circuit of C. elegans which is able to detect the analogue signals from the environment and produce locomotive behaviours which are in accordance with experiments. The signals in C. elegans are processed in a purely analogue procedure, since no action potential has been recorded in its neural activity. We aim to show how signal processing can be executed in analogue domain in a living creature. In order to do that we will model two different behaviours of C...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28225811/automated-numerical-simulation-of-biological-pattern-formation-based-on-visual-feedback-simulation-framework
#9
Mingzhu Sun, Hui Xu, Xingjuan Zeng, Xin Zhao
There are various fantastic biological phenomena in biological pattern formation. Mathematical modeling using reaction-diffusion partial differential equation systems is employed to study the mechanism of pattern formation. However, model parameter selection is both difficult and time consuming. In this paper, a visual feedback simulation framework is proposed to calculate the parameters of a mathematical model automatically based on the basic principle of feedback control. In the simulation framework, the simulation results are visualized, and the image features are extracted as the system feedback...
2017: PloS One
https://www.readbyqxmd.com/read/28225128/analysis-of-charging-induced-structural-damage-in-electrochemical-systems
#10
Fuqian Yang
Electrochemical charging of an electrochemical system results in Maxwell stress and a variation in the surface energy of the electrode. The charging-induced variation in the surface energy of the electrode and Maxwell stress introduce mechanical deformation and create stresses in the electrode. To relax the strain energy stored in the electrode, surface cracking and buckling can occur. Under the condition that the charging-induced change in the surface energy is the dominant factor controlling the in-plane deformation of a planar electrode, i...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28223172/a-simple-model-of-cardiac-muscle-for-multiscale-simulation-passive-mechanics-crossbridge-kinetics-and-calcium-regulation
#11
Fyodor A Syomin, Andrey K Tsaturyan
A simple model of cardiac muscle was designed for multiscale simulation of heart mechanics. Relaxed cardiac muscle was described as a transversally isotropic hyperelastic material. Active tension caused by actin-myosin crossbridges depends on the ensemble averaged strain of myosin heads bound to actin. Calcium activation was modeled by Ca(2+) binding to troponin-C. To account for the dependence of troponin affinity for Ca(2+) on myosin heads strongly bound to actin, the kinetics of troponin binding to Ca(2+) in the overlap zone of the thin and thick filaments and outside it were separated...
February 18, 2017: Journal of Theoretical Biology
https://www.readbyqxmd.com/read/28220955/profiles-of-adolescent-religiousness-using-latent-profile-analysis-implications-for-psychopathology
#12
Gregory S Longo, Bethany C Bray, Jungmeen Kim-Spoon
Prior research has documented robust associations between adolescent religiousness/spirituality (R/S) and psychopathology outcomes including externalizing and internalizing symptomatology, yet no previous studies have examined these associations with adolescent R/S profiles using a person-centred approach. We examined whether there are identifiable subgroups characterized by unique multidimensional patterns of R/S experiences and how these experiences may be related to externalizing and internalizing symptomatology...
March 2017: British Journal of Developmental Psychology
https://www.readbyqxmd.com/read/28220893/general-planar-transverse-domain-walls-realized-by-optimized-transverse-magnetic-field-pulses-in-magnetic-biaxial-nanowires
#13
Mei Li, Jianbo Wang, Jie Lu
The statics and field-driven dynamics of transverse domain walls (TDWs) in magnetic nanowires (NWs) have attracted continuous interests because of their theoretical significance and application potential in future magnetic logic and memory devices. Recent results demonstrate that uniform transverse magnetic fields (TMFs) can greatly enhance the wall velocity, meantime leave a twisting in the TDW azimuthal distribution. For application in high-density NW devices, it is preferable to erase the twisting so as to minimize magnetization frustrations...
February 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28220467/emergent-dynamical-properties-of-the-bcm-learning-rule
#14
Lawrence C Udeigwe, Paul W Munro, G Bard Ermentrout
The Bienenstock-Cooper-Munro (BCM) learning rule provides a simple setup for synaptic modification that combines a Hebbian product rule with a homeostatic mechanism that keeps the weights bounded. The homeostatic part of the learning rule depends on the time average of the post-synaptic activity and provides a sliding threshold that distinguishes between increasing or decreasing weights. There are, thus, two essential time scales in the BCM rule: a homeostatic time scale, and a synaptic modification time scale...
December 2017: Journal of Mathematical Neuroscience
https://www.readbyqxmd.com/read/28220211/competitive-association-binding-kinetic-assays-a-new-tool-to-detect-two-different-binding-orientations-of-a-ligand-to-its-target-protein-under-distinct-conditions
#15
Hans-Joachim Wittmann, Andrea Strasser
Within the last years, for several ligands, binding to G protein-coupled receptors or other target proteins, a binding of the ligand in two different orientations is described. One appropriate experimental technique to detect two different binding orientations is the crystallization of the ligand-protein-complex, but crystallization and subsequent X-ray analysis do not belong to the routine methods. By traditional competitive radioligand equilibrium binding assays, it is not possible to detect or to distinguish between two different binding orientations, but there is a possibility to identify two different binding orientations by performing kinetic competitive radioligand-binding assays...
February 20, 2017: Naunyn-Schmiedeberg's Archives of Pharmacology
https://www.readbyqxmd.com/read/28220053/simulation-study-on-effects-of-order-and-step-size-of-runge-kutta-methods-that-solve-contagious-disease-and-tumor-models
#16
Wang Z, Wang Q, Klinke Dj
Biological processes such as contagious disease spread patterns and tumor growth dynamics are modelled using a set of coupled differential equations. Experimental data is usually used to calibrate models so they can be used to make future predictions. In this study, numerical methods were implemented to approximate solutions to mathematical models that were not solvable analytically, such as a SARS model. More complex models such as a tumor growth model involve high-dimensional parameter spaces; efficient numerical simulation techniques were used to search for optimal or close-to-optimal parameter values in the equations...
September 2016: Journal of Computer Science and Systems Biology
https://www.readbyqxmd.com/read/28219373/a-new-efficient-approach-to-fit-stochastic-models-on-the-basis-of-high-throughput-experimental-data-using-a-model-of-irf7-gene-expression-as-case-study
#17
Luis U Aguilera, Christoph Zimmer, Ursula Kummer
BACKGROUND: Mathematical models are used to gain an integrative understanding of biochemical processes and networks. Commonly the models are based on deterministic ordinary differential equations. When molecular counts are low, stochastic formalisms like Monte Carlo simulations are more appropriate and well established. However, compared to the wealth of computational methods used to fit and analyze deterministic models, there is only little available to quantify the exactness of the fit of stochastic models compared to experimental data or to analyze different aspects of the modeling results...
February 20, 2017: BMC Systems Biology
https://www.readbyqxmd.com/read/28216295/finite-volume-schemes-for-the-numerical-simulation-of-tracer-transport-in-plants
#18
Jonas Bühler, Gregor Huber, Eric von Lieres
Compartmental models can be used for inverse modeling of long distance tracer transport experiments in plants. Such transport models describe axial convection and diffusion as well as exchange between compartments, and are defined by partial differential equations (PDEs). Since for inverse modelling, the forward simulation needs to be evaluated frequently, a fast PDE solver is required. Here, we compare several different finite volumes schemes up to fifth order for spatial discretization with respect to accuracy, computation time and numerical oscillations...
February 16, 2017: Mathematical Biosciences
https://www.readbyqxmd.com/read/28213682/mathematical-modelling-of-cytokines-mmps-and-fibronectin-fragments-in-osteoarthritic-cartilage
#19
Michelle Baker, Bindi S Brook, Markus R Owen
Osteoarthritis (OA) is a degenerative disease which causes pain and stiffness in joints. OA progresses through excessive degradation of joint cartilage, eventually leading to significant joint degeneration and loss of function. Cytokines, a group of cell signalling proteins, present in raised concentrations in OA joints, can be classified into pro-inflammatory and anti-inflammatory groups. They mediate cartilage degradation through several mechanisms, primarily the up-regulation of matrix metalloproteinases (MMPs), a group of collagen-degrading enzymes...
February 17, 2017: Journal of Mathematical Biology
https://www.readbyqxmd.com/read/28212412/a-mathematical-model-of-aortic-aneurysm-formation
#20
Wenrui Hao, Shihua Gong, Shuonan Wu, Jinchao Xu, Michael R Go, Avner Friedman, Dai Zhu
Abdominal aortic aneurysm (AAA) is a localized enlargement of the abdominal aorta, such that the diameter exceeds 3 cm. The natural history of AAA is progressive growth leading to rupture, an event that carries up to 90% risk of mortality. Hence there is a need to predict the growth of the diameter of the aorta based on the diameter of a patient's aneurysm at initial screening and aided by non-invasive biomarkers. IL-6 is overexpressed in AAA and was suggested as a prognostic marker for the risk in AAA. The present paper develops a mathematical model which relates the growth of the abdominal aorta to the serum concentration of IL-6...
2017: PloS One
keyword
keyword
81171
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"