Read by QxMD icon Read

Mathematical model

Royi Jacobovic
The prediction of cancer prognosis and metastatic potential immediately after the initial diagnoses is a major challenge in current clinical research. The relevance of such a signature is clear, as it will free many patients from the agony and toxic side-effects associated with the adjuvant chemotherapy automatically and sometimes carelessly subscribed to them. Motivated by this issue, several previous works presented a Bayesian model which led to the following conclusion: thousands of samples are needed to generate a robust gene list for predicting outcome...
July 14, 2018: Statistical Applications in Genetics and Molecular Biology
Markus Breit, Gillian Queisser
Neuronal calcium signals propagating by simple diffusion and reaction with mobile and stationary buffers are limited to cellular microdomains. The distance intracellular calcium signals can travel may be significantly increased by means of calcium-induced calcium release from internal calcium stores, notably the endoplasmic reticulum. The organelle, which can be thought of as a cell-within-a-cell, is able to sequester large amounts of cytosolic calcium ions via SERCA pumps and selectively release them into the cytosol through ryanodine receptor channels leading to the formation of calcium waves...
July 13, 2018: Journal of Mathematical Neuroscience
Christian Contarino, Eleuterio F Toro
We propose a one-dimensional model for collecting lymphatics coupled with a novel Electro-Fluid-Mechanical Contraction (EFMC) model for dynamical contractions, based on a modified FitzHugh-Nagumo model for action potentials. The one-dimensional model for a deformable lymphatic vessel is a nonlinear system of hyperbolic Partial Differential Equations (PDEs). The EFMC model combines the electrical activity of lymphangions (action potentials) with fluid-mechanical feedback (circumferential stretch of the lymphatic wall and wall shear stress) and lymphatic vessel wall contractions...
July 14, 2018: Biomechanics and Modeling in Mechanobiology
Vinh Q Mai, Tuoi T Vo, Martin Meere
Hyaluronic acid (Hyaluronan) is a linear, high molecular weight polysaccharide that forms an important component of the extracellular matrix. It is an excellent biomaterial, and it is increasingly being used in biotechnology, biomedical applications, and drug delivery. Polymer chains of hyaluronan occur in many different lengths in nature, and can be as large as multiples of ten thousand. Since the biological function of a hyaluronan chain often depends on its molecular weight, it is of value for applications to develop reliable quantitative descriptions of the degradation processes of hyaluronan...
July 10, 2018: Mathematical Biosciences
Nakul Chitnis, Allan Schapira, Christian Schindler, Melissa Penny, Thomas Smith
Malaria and some other tropical diseases are currently targeted for elimination and eventually eradication. Since resources are limited, prioritisation of countries or areas for elimination is often necessary. However, this prioritisation is frequently conducted in an ad hoc manner. Lower transmission areas are usually targeted for elimination first, but for some areas this necessitates long and potentially expensive surveillance programs while transmission is eliminated from neighbouring higher transmission areas...
July 10, 2018: Journal of Theoretical Biology
Pridi Siregar, Nathalie Julen, Peter Hufnagl, George Mutter
In order to understand living organisms, considerable experimental efforts and resources have been devoted to correlate genes and their expressions with cell, tissue, organ and whole organisms' phenotypes. This data driven approach to knowledge discovery has led to many breakthrough in our understanding of healthy and diseased states, and is paving the way to improve the diagnosis and treatment of diseases. Complementary to this data-driven approach, computational models of biological systems based on first principles have been developed in order to deepen our understanding of the multi-scale dynamics that drives normal and pathological biological functions...
July 10, 2018: Bio Systems
Yoshihiro Asano
No abstract text is available yet for this article.
July 10, 2018: EBioMedicine
Nicolas Kunz, Analina R da Silva, Ileana O Jelescu
A two-compartment model of diffusion in white matter, which accounts for intra- and extra-axonal spaces, is associated with two plausible mathematical scenarios: either the intra-axonal axial diffusivity Da,‖ is higher than the extra-axonal De,‖ (Branch 1), or the opposite, i.e. Da,‖  < De,‖ (Branch 2). This duality calls for an independent validation of compartment axial diffusivities, to determine which of the two cases holds. The aim of the present study was to use an intracerebroventricular injection of a gadolinium-based contrast agent to selectively reduce the extracellular water signal in the rat brain, and compare diffusion metrics in the genu of the corpus callosum before and after gadolinium infusion...
July 10, 2018: NeuroImage
Jonathan M Grund, Candice M Chetty-Makkan, Sibuse Ginindza, Reuben Munyai, Helen Kisbey-Green, Mpho Maraisane, Salome Charalambous
BACKGROUND: South Africa introduced medical male circumcision (MMC) to reduce HIV incidence. Mathematical modeling suggested that targeting MMC services to men aged 20-34 years could provide the most immediate impact on HIV incidence. However the majority of MMCs performed have been among males aged ≤25 years. We evaluated an intervention package to increase MMC uptake among men aged 25-49 years. METHODS: We conducted a pre-post study to compare the proportion of men (aged 25-49 years) presenting for MMC during the formative (Phase 1) and intervention (Phase 2) phases in Ekurhuleni, Johannesburg, South Africa...
July 13, 2018: BMC Public Health
Weixing Liu, Dagong Jia, Jing Chao, Hongxia Zhang, Tiegen Liu, Yimo Zhang, Ye Sun
Human skin temperature mapping provides abundant information of physiological conditions of human body, which provides supplementary or alternative indicators for disease monitoring or diagnosis. The existing models of temperature mapping or temperature field distribution of human skin are generally established by finite element method. Due to the complexity of biological systems, it is challenging to achieve high accuracy mathematical models of temperature field of human skin. The goal of this study is to establish human skin temperature 3D mapping platform by integrating optical fibers and improved GA-BP neural network...
July 10, 2018: IEEE Journal of Biomedical and Health Informatics
John S Clemmer, William Andrew Pruett, Robert L Hester, Radu Iliescu, Thomas E Lohmeier
Electrical stimulation of the baroreflex chronically suppresses sympathetic activity and arterial pressure and is currently being evaluated for the treatment of resistant hypertension. The antihypertensive effects of baroreflex activation are often attributed to renal sympathoinhibition. However, baroreflex activation also decreases heart rate, and robust blood pressure lowering occurs even after renal denervation. Because controlling renal sympathetic nerve activity and cardiac autonomic activity cannot be achieved experimentally, we used an established mathematical model of human physiology (HumMod) to provide mechanistic insight into their relative and combined contributions to the cardiovascular responses during baroreflex activation...
July 13, 2018: American Journal of Physiology. Heart and Circulatory Physiology
Ana Vaniqui, Brent van der Heyden, Isabel P Almeida, Lotte Ejr Schyns, Stefan J van Hoof, Frank Verhaegen
This work aims to analyse the effect of respiratory motion on optimal irradiation margins for murine lung tumour models.  Methods: Four-dimensional mathematical phantoms with different lung tumour locations affected by respiratory motion were created. Two extreme breathing curves were adopted and divided into time-points. Each time-point was loaded in a treatment planning system and Monte Carlo (MC) dose calculations were performed for a 360° arc plan. A time-resolved dose was derived, considering the gantry rotation and the breathing motion...
July 13, 2018: British Journal of Radiology
Yao Shen, Yu-Lin Zhao
Gentile statistics, which is famous for its advantages in dealing with composite particle systems, is a kind of fractional statistics. These years, researchers are concentrating on finding real systems that obey Gentile statistics. Five years ago, we discovered that the cyclic hydrocarbon polyenes called N-annulenes in Hückel model had certain correspondence with Gentile oscillators. According to their rotation and dihedral symmetry, these two systems had the same energy levels and partition functions. In this paper, we discuss the specific details of this correspondence...
July 13, 2018: Journal of Physical Chemistry. A
Mudassar Imran, Muhammad Usman, Tufail Malik, Ali R Ansari
The Zika virus is transmitted to humans primarily through Aedes mosquitoes and through sexual contact. It is documented that the virus can be transmitted to newborn babies from their mothers. We consider a deterministic model for the transmission dynamics of the Zika virus infectious disease that spreads in, both humans and vectors, through horizontal and vertical transmission. The total populations of both humans and mosquitoes is assumed to be constant. Our models consist of a system of eight differential equations describing the human and vector populations during the different stages of the disease...
July 9, 2018: Virus Research
Mustafa Evren Ersahin
Anaerobic digestion is one of the most commonly accepted processes applied for the stabilization and treatment of primary sludge generated in municipal wastewater treatment plants enabling energy recovery via biogas production. Understanding and optimizing anaerobic sludge digesters play a key role in sustainability of wastewater treatment plants. Mathematical modeling of biological treatment systems provides several advantages such as better understanding of biochemical processes, interrelations of different biomass types, and impact of environmental conditions on the treatment plant performance...
July 12, 2018: Bioprocess and Biosystems Engineering
Daniel Garcia-Castellanos, Jim E O'Connor
Most current models for the landscape evolution over geological timescales are based on semi-empirical laws that consider riverbed incision proportional to rock erodability (dependent on lithology) and to the work performed by water flow (stream power). However, the erodability values obtained from these models are entangled with poorly known conditions of past climate and streamflow. Here we use the erosion reported for 82 outburst floods triggered by overtopping lakes as a way to estimate the outlet erodability...
July 12, 2018: Scientific Reports
Pilar Manzanares-Lopez, Josemaria Malgosa-Sanahuja, Juan Pedro Muñoz-Gea
In this paper, the concept of SDN ( Software Defined Networking ) is extended to be applied to wireless networks. Traditionally, in a wired SDN environment, the OpenFlow protocol is the communication protocol used to configure the flow table of forwarding elements (i.e., switches and Access Points). However, although in IEEE 802.11 networks there is no concept of forwarding, the SDN paradigm could also be applied to set up the wireless network dynamically, in order to improve the performance. In this case, not only the network elements, that is the Access Points, but also the mobile elements should configure their link and physical layers parameters following the guidelines of a centralized SDN controller...
July 12, 2018: Sensors
Alexandra B Hogan, Peter Winskill, Robert Verity, Jamie T Griffin, Azra C Ghani
BACKGROUND: The RTS,S/AS01 vaccine for Plasmodium falciparum malaria demonstrated moderate efficacy in 5-17-month-old children in phase 3 trials, and from 2018, the vaccine will be evaluated through a large-scale pilot implementation program. Work is ongoing to optimise this vaccine, with higher efficacy for a different schedule demonstrated in a phase 2a challenge study. The objective of our study was to investigate the population-level impact of a modified RTS,S/AS01 schedule and dose amount in order to inform the target product profile for a second-generation malaria vaccine...
July 13, 2018: BMC Medicine
Vishnu Venugopal, Pranesh Padmanabhan, Rubesh Raja, Narendra M Dixit
Direct-acting antiviral agents (DAAs) for hepatitis C treatment tend to fare better in individuals who are also likely to respond well to interferon-alpha (IFN), a surprising correlation given that DAAs target specific viral proteins whereas IFN triggers a generic antiviral immune response. Here, we posit a causal relationship between IFN-responsiveness and DAA treatment outcome. IFN-responsiveness restricts viral replication, which would prevent the growth of viral variants resistant to DAAs and improve treatment outcome...
July 12, 2018: PLoS Computational Biology
Daniel Spitzer, Vincent Marichez, Georges Formon, Pol Besenius, Thomas Hermans
Controlling supramolecular growth at solid surfaces is of great importance to expand the scope of supramolecular materials. Here we describe a dendritic benzene-1,3,5-tricarboxamide peptide conjugate whose assembly can be triggered by a pH jump. Stopped flow kinetics and mathematical modeling provide a quantitative understanding of the nucleation, elongation, and fragmentation behavior in solution. To assemble the molecule at a solid-liquid interface, we use proton diffusion from the bulk. The latter needs to be slower than the lag phase of nucleation in order to progressively grow a hydrogel outwards from the surface...
July 12, 2018: Angewandte Chemie
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"