Read by QxMD icon Read

Mathematical modelling

Ying Chen, Chao He, Jing-Jun Cheng, Wen-Yao Huang, Sheng-Wen Shao, Ya-Ping Jiang, Ling-Feng Dai, Jia-Fa Liu, Yi Song
This study aimed to conduct measurement uncertainty assessment of a new method for determination of Sudan colorants (Sudan I, II, III and IV) in food by high performance liquid chromatography (HPLC). Samples were extracted with organic solvents (hexane, 20% acetone) and first purified by magnesium trisilicate (2MgO·3SiO2). The Sudan colorants (Sudan I-IV) were also initially separated on C8 by gradient elution using acetonitrile and 0.1% (v/v) formic acid aqueous solution as the mobile phases and detected with diode-array detector (DAD)...
October 2016: Journal of Huazhong University of Science and Technology. Medical Sciences
Matthew L Paff, Scott L Nuismer, Andrew D Ellington, Ian J Molineux, Ryan H May, James J Bull
BACKGROUND: We propose, model, and implement a novel system of population-level intervention against a virus. One context is a treatment against a chronic infection such as HIV. The underlying principle is a form of virus 'wars' in which a benign, transmissible agent is engineered to protect against infection by and spread of a lethal virus. In our specific case, the protective agent consists of two entities, a benign virus and a gene therapy vector mobilized by the benign virus. RESULTS: Numerical analysis of a mathematical model identified parameter ranges in which adequate, population-wide protection is achieved...
2016: Journal of Biological Engineering
Sridhar Ravi, Dmitry Kolomenskiy, Thomas Engels, Kai Schneider, Chun Wang, Jörn Sesterhenn, Hao Liu
The natural wind environment that volant insects encounter is unsteady and highly complex, posing significant flight-control and stability challenges. It is critical to understand the strategies insects employ to safely navigate in natural environments. We combined experiments on free flying bumblebees with high-fidelity numerical simulations and lower-order modeling to identify the mechanics that mediate insect flight in unsteady winds. We trained bumblebees to fly upwind towards an artificial flower in a wind tunnel under steady wind and in a von Kármán street formed in the wake of a cylinder...
October 18, 2016: Scientific Reports
Maris S Arcilla, Jarne M van Hattem, Manon R Haverkate, Martin C J Bootsma, Perry J J van Genderen, Abraham Goorhuis, Martin P Grobusch, Astrid M Oude Lashof, Nicky Molhoek, Constance Schultsz, Ellen E Stobberingh, Henri A Verbrugh, Menno D de Jong, Damian C Melles, John Penders
BACKGROUND: International travel contributes to the dissemination of antimicrobial resistance. We investigated the acquisition of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-E) during international travel, with a focus on predictive factors for acquisition, duration of colonisation, and probability of onward transmission. METHODS: Within the prospective, multicentre COMBAT study, 2001 Dutch travellers and 215 non-travelling household members were enrolled...
October 14, 2016: Lancet Infectious Diseases
Boopathy Ramakrishnan, Karthik Viswanathan, Kannan Tharakaraman, Vlado Dančík, Rahul Raman, Gregory J Babcock, Zachary Shriver, Ram Sasisekharan
Broadly neutralizing monoclonal antibodies (bNAbs) for viral infections, such as HIV, respiratory syncytial virus (RSV), and influenza, are increasingly entering clinical development. For influenza, most neutralizing antibodies target influenza virus hemagglutinin. These bNAbs represent an emerging, promising modality for treatment and prophylaxis of influenza due to their multiple mechanisms of antiviral action and generally safe profile. Preclinical work in other viral diseases, such as dengue, has demonstrated the potential for antibody-based therapies to enhance viral uptake, leading to enhanced viremia and worsening of disease...
October 14, 2016: Trends in Microbiology
Issa J Dahabreh, Thomas A Trikalinos, Ethan M Balk, John B Wong
Models and simulations are valuable tools for addressing the uncertainty, tradeoffs, and heterogeneous preferences that complicate research questions in health technology assessment. This article presents recommendations for the conduct and reporting of modeling and simulation studies based on a systematic review of published recommendation statements, a survey of Web sites of international health technology assessment organizations, and input from experts and other stakeholders. The recommendations apply to mathematical models that represent structural relationships among model components and integrate information from multiple sources; they address model identification, estimation, verification, and validation, as well as the conduct of sensitivity, stability, and uncertainty analyses...
October 18, 2016: Annals of Internal Medicine
Ting Zhang, Xuan Ban, Xuelei Wang, Xiaobin Cai, Enhua Li, Zhi Wang, Chao Yang, Qing Zhang, Xiaorong Lu
A two-dimensional (2D) water quality model was established to determine the response of water quality variables and submerged aquatic vegetation biomass to load reduction from watershed inflows and enclosure aquaculture in Honghu Lake in China. Results showed that the total nitrogen (TN) and total phosphorus (TP) loads from upstream discharge were the major external loads in the lake, accounting for 70% and 63% of the total loads, respectively. Scenario simulation results indicated that 93.2% of the lake area in summer (August) and 89...
October 14, 2016: Science of the Total Environment
Richard A Gray, Pras Pathmanathan
Elucidating the underlying mechanisms of fatal cardiac arrhythmias requires a tight integration of electrophysiological experiments, models, and theory. Existing models of transmembrane action potential (AP) are complex (resulting in over parameterization) and varied (leading to dissimilar predictions). Thus, simpler models are needed to elucidate the "minimal physiological requirements" to reproduce significant observable phenomena using as few parameters as possible. Moreover, models have been derived from experimental studies from a variety of species under a range of environmental conditions (for example, all existing rabbit AP models incorporate a formulation of the rapid sodium current, INa, based on 30 year old data from chick embryo cell aggregates)...
October 2016: PLoS Computational Biology
Andriy Temko, Gordon Lightbody
It is now generally accepted that EEG is the only reliable way to accurately detect newborn seizures and, as such, prolonged EEG monitoring is increasingly being adopted in neonatal intensive care units. Long EEG recordings may last from several hours to a few days. With neurophysiologists not always available to review the EEG during unsociable hours, there is a pressing need to develop a reliable and robust automatic seizure detection method-a computer algorithm that can take the EEG signal, process it, and output information that supports clinical decision making...
October 2016: Journal of Clinical Neurophysiology: Official Publication of the American Electroencephalographic Society
Ornella Affinito, Giovanni Scala, Domenico Palumbo, Ermanno Florio, Antonella Monticelli, Gennaro Miele, Vittorio Enrico Avvedimento, Alessandro Usiello, Lorenzo Chiariotti, Sergio Cocozza
DNA methylation is often analyzed by reporting the average methylation degree of each cytosine. In this study, we used a single molecule methylation analysis in order to look at the methylation conformation of individual molecules. Using D-aspartate oxidase as a model gene, we performed an in-depth methylation analysis through the developmental stages of three different mouse tissues (brain, lung, and gut), where this gene undergoes opposite methylation destiny. This approach allowed us to track both methylation and demethylation processes at high resolution...
October 17, 2016: Epigenetics: Official Journal of the DNA Methylation Society
Mark Doyle, Gerald M Pohost, C Noel Bairey Merz, Leslee J Shaw, George Sopko, William J Rogers, Barry L Sharaf, Carl J Pepine, Diane V Thompson, Geetha Rayarao, Lindsey Tauxe, Sheryl F Kelsey, Robert W W Biederman
BACKGROUND: We introduce an algorithmic approach to optimize diagnostic and prognostic value of gated cardiac single photon emission computed tomography (SPECT) and magnetic resonance (MR) myocardial perfusion imaging (MPI) modalities in women with suspected myocardial ischemia. The novel approach: bio-informatics assessment schema (BIAS) forms a mathematical model utilizing MPI data and cardiac metrics generated by one modality to predict the MPI status of another modality. The model identifies cardiac features that either enhance or mask the image-based evidence of ischemia...
October 2016: Cardiovascular Diagnosis and Therapy
Rainer Engelken, Farzad Farkhooi, David Hansel, Carl van Vreeswijk, Fred Wolf
Neuronal activity in the central nervous system varies strongly in time and across neuronal populations. It is a longstanding proposal that such fluctuations generically arise from chaotic network dynamics. Various theoretical studies predict that the rich dynamics of rate models operating in the chaotic regime can subserve circuit computation and learning. Neurons in the brain, however, communicate via spikes and it is a theoretical challenge to obtain similar rate fluctuations in networks of spiking neuron models...
2016: F1000Research
Clark K Ho, Ganesh Sriram, Katrina M Dipple
Mathematical modeling approaches have been commonly used in complex signaling pathway studies such as the insulin signal transduction pathway. Our expanded mathematical model of the insulin signal transduction pathway was previously shown to effectively predict glucose clearance rates using mRNA levels of key components of the pathway in a mouse model. In this study, we re-optimized and applied our expanded model to study insulin sensitivity in other species and tissues (human skeletal muscle) with altered protein activities of insulin signal transduction pathway components...
October 11, 2016: Molecular Genetics and Metabolism
Sihuang Xie, Faisal I Hai, Xinmin Zhan, Wenshan Guo, Hao H Ngo, William E Price, Long D Nghiem
Anaerobic co-digestion (AcoD) is a pragmatic approach to simultaneously manage organic wastes and produce renewable energy. This review demonstrates the need for improving AcoD modelling capacities to simulate the complex physicochemical and biochemical processes. Compared to mono-digestion, AcoD is more susceptible to process instability, as it operates at a higher organic loading and significant variation in substrate composition. Data corroborated here reveal that it is essential to model the transient variation in pH and inhibitory intermediates (e...
October 6, 2016: Bioresource Technology
Sylvie Deuffic-Burban, Jérôme Boursier, Vincent Leroy, Yazdan Yazdanpanah, Laurent Castera, Philippe Mathurin
BACKGROUND AND AIMS: This study quantifies the impact of different rules for access to treatment, ranging from targeted therapy in patients with ⩾F3 in Italy, ⩾ severe F2 in France, and universal therapy in UK, using noninvasive diagnostic tests of fibrosis to determine targeted therapy. METHODS: A country-specific Markov model predicts outcomes with targeted and universal interferon-free therapy vs. no treatment in the three countries. Targeted therapy was initiated in patients ⩾F2 (F2-scenario) or ⩾F3 (F3-scenario) evaluated by noninvasive diagnostic tests according to the real stage of fibrosis...
October 12, 2016: Journal of Hepatology
Alexey Martyushev, Shinji Nakaoka, Kei Sato, Takeshi Noda, Shingo Iwami
Ebola virus (EBOV) causes a severe, often fatal Ebola virus disease (EVD), for which no approved antivirals exist. Recently, some promising anti-EBOV drugs, which are experimentally potent in animal models, have been developed. However, because the quantitative dynamics of EBOV replication in humans is uncertain, it remains unclear how much antiviral suppression of viral replication affects EVD outcome in patients. Here, we developed a novel mathematical model to quantitatively analyse human viral load data obtained during the 2000/01 Uganda EBOV outbreak and evaluated the effects of different antivirals...
October 12, 2016: Antiviral Research
Eric Hermand, François J Lhuissier, Nicolas Voituron, Jean-Paul Richalet
We evaluated the mechanisms responsible for the instability of ventilation control system under simultaneous metabolic (exercise) and environmental (hypoxia) stresses, promoting the genesis of periodic breathing. A model following the main concepts of ventilatory control has been tested, including cardiovascular and respiratory parameters, characteristics of peripheral and central chemoreceptors, at mild exercise in hypoxia (FIO2=0.145). Interaction between O2 and CO2 sensing was introduced following three different modalities...
October 12, 2016: Journal of Theoretical Biology
Gregory Francis
Recent reform efforts in psychological science have led to a plethora of choices for scientists to analyze their data. A scientist making an inference about their data must now decide whether to report a p value, summarize the data with a standardized effect size and its confidence interval, report a Bayes Factor, or use other model comparison methods. To make good choices among these options, it is necessary for researchers to understand the characteristics of the various statistics used by the different analysis frameworks...
October 14, 2016: Behavior Research Methods
David Baca-Carrasco, Jorge X Velasco-Hernández
Since the first major outbreak reported on the island Yap in 2007, the Zika virus spread has alerted the scientific community worldwide. Zika is an arbovirus transmitted by Aedes mosquitoes; particularly in Central and South America, the main vector is the same mosquito that transmits dengue and chikungunya, Aedes aegypti. Seeking to understand the dynamics of spread of the Zika, in this paper, three mathematical models are presented, in which vector transmission of the virus, sexual contact transmission and migration are considered...
October 14, 2016: Bulletin of Mathematical Biology
Jimmy Garnier, Mark A Lewis
Range expansion and range shifts are crucial population responses to climate change. Genetic consequences are not well understood but are clearly coupled to ecological dynamics that, in turn, are driven by shifting climate conditions. We model a population with a deterministic reaction-diffusion model coupled to a heterogeneous environment that develops in time due to climate change. We decompose the resulting travelling wave solution into neutral genetic components to analyse the spatio-temporal dynamics of its genetic structure...
October 14, 2016: Bulletin of Mathematical Biology
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"