keyword
MENU ▼
Read by QxMD icon Read
search

mathematical modeling

keyword
https://www.readbyqxmd.com/read/28719607/stress-induced-mutagenesis-stress-diversity-facilitates-the-persistence-of-mutator-genes
#1
Marta Lukačišinová, Sebastian Novak, Tiago Paixão
Mutator strains are expected to evolve when the availability and effect of beneficial mutations are high enough to counteract the disadvantage from deleterious mutations that will inevitably accumulate. As the population becomes more adapted to its environment, both availability and effect of beneficial mutations necessarily decrease and mutation rates are predicted to decrease. It has been shown that certain molecular mechanisms can lead to increased mutation rates when the organism finds itself in a stressful environment...
July 18, 2017: PLoS Computational Biology
https://www.readbyqxmd.com/read/28718662/prediction-of-porosity-of-food-materials-during-drying-current-challenges-and-future-directions
#2
Mohammad U H Joardder, C Kumar, M A Karim
Pore formation in food samples is a common physical phenomenon observed during dehydration processes. The pore evolution during drying significantly affects the physical properties and quality of dried foods. Therefore, it should be taken into consideration when predicting transport processes in the drying sample. Characteristics of pore formation depend on the drying process parameters, product properties and processing time. Understanding the physics of pore formation and evolution during drying will assist in accurately predicting the drying kinetics and quality of food materials...
July 18, 2017: Critical Reviews in Food Science and Nutrition
https://www.readbyqxmd.com/read/28717995/ovomucin-nanoparticles-promising-carriers-for-mucosal-delivery-of-drugs-and-bioactive-compounds
#3
Ali Akbari, Jianping Wu
Ovomucin, with a similar structure to mucin and gelation ability at room temperature, is a potential mucosal carrier. To evaluate this potential, the mucoadhesive property of ovomucin was studied by the tensile strength and rheology methods, and compared with three known mucoadhesive polymers, chitosan, polyacrylic acid (PAA), and alginate. Ovomucin particles were basically spherical in shape with an average size of ~572, 235 and 54 nm prepared at pH 5, 6.5, and 9, respectively. The absolute value of the zeta potential increased from ~ -51 mV at pH 5 to ~ -59 and -91 mV at pH 6...
July 17, 2017: Drug Delivery and Translational Research
https://www.readbyqxmd.com/read/28717163/titin-mediated-thick-filament-activation-through-a-mechanosensing-mechanism-introduces-sarcomere-length-dependencies-in-mathematical-models-of-rat-trabecula-and-whole-ventricle
#4
Lorenzo Marcucci, Takumi Washio, Toshio Yanagida
Recent experimental evidence in skeletal muscle demonstrated the existence of a thick-filament mechanosensing mechanism, acting as a second regulatory system for muscle contraction, in addition to calcium-mediated thin filament regulation. These two systems cooperate to generate force, but the extent to which their interaction is relevant in physiologically contracting muscle was not yet assessed experimentally. Therefore, we included both regulatory mechanisms in a mathematical model of rat trabecula and whole ventricle...
July 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28717156/patterned-arrangements-of-olfactory-receptor-gene-expression-in-zebrafish-are-established-by-radial-movement-of-specified-olfactory-sensory-neurons
#5
Xalid Bayramli, Yiğit Kocagöz, Uğurcan Sakizli, Stefan H Fuss
Spatial restriction of olfactory receptor (OR) gene expression in peripheral sense organs is a common phenomenon across species, suggesting that zonal OR expression somehow contributes to olfactory function. In zebrafish OR expression patterns reminiscent of zones occur as concentric domains with preferred diameters for different ORs. However, the function and the developmental origin of the pattern are unknown. Here we investigate olfactory sensory neuron (OSN) neurogenesis in the adult zebrafish olfactory epithelium (OE) to understand how the zonally organized OR pattern is established and maintained during the lifetime of the animal...
July 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28717042/modeling-the-kinetics-of-the-permeation-of-antibacterial-agents-into-growing-bacteria-and-its-interplay-with-efflux
#6
Wright W Nichols
A mathematical model of the passive permeation of a novel solute into bacteria is developed that explicitly accounts for intracellular dilution through growth. A bacterial cell envelope permeability coefficient of >10(-8) cm(2)s(-1) approx., is predicted to ensure passive permeation into rapidly replicating bacterial cells. The relative importance of the permeability coefficients of the cytoplasmic and outer membranes of Gram-negative bacteria in determining the overall envelope permeability coefficient is analyzed quantitatively...
July 17, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28716945/evaluating-optimal-therapy-robustness-by-virtual-expansion-of-a-sample-population-with-a-case-study-in-cancer-immunotherapy
#7
Syndi Barish, Michael F Ochs, Eduardo D Sontag, Jana L Gevertz
Cancer is a highly heterogeneous disease, exhibiting spatial and temporal variations that pose challenges for designing robust therapies. Here, we propose the VEPART (Virtual Expansion of Populations for Analyzing Robustness of Therapies) technique as a platform that integrates experimental data, mathematical modeling, and statistical analyses for identifying robust optimal treatment protocols. VEPART begins with time course experimental data for a sample population, and a mathematical model fit to aggregate data from that sample population...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716938/dynamic-responses-of-the-adrenal-steroidogenic-regulatory-network
#8
Francesca Spiga, Eder Zavala, Jamie J Walker, Zidong Zhao, John R Terry, Stafford L Lightman
The hypothalamic-pituitary-adrenal axis is a dynamic system regulating glucocorticoid hormone synthesis in the adrenal glands. Many key factors within the adrenal steroidogenic pathway have been identified and studied, but little is known about how these factors function collectively as a dynamic network of interacting components. To investigate this, we developed a mathematical model of the adrenal steroidogenic regulatory network that accounts for key regulatory processes occurring at different timescales...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716917/diverse-continuum-of-cd4-t-cell-states-is-determined-by-hierarchical-additive-integration-of-cytokine-signals
#9
Inbal Eizenberg-Magar, Jacob Rimer, Irina Zaretsky, David Lara-Astiaso, Shlomit Reich-Zeliger, Nir Friedman
During cell differentiation, progenitor cells integrate signals from their environment that guide their development into specialized phenotypes. The ways by which cells respond to complex signal combinations remain difficult to analyze and model. To gain additional insight into signal integration, we systematically mapped the response of CD4(+) T cells to a large number of input cytokine combinations that drive their differentiation. We find that, in response to varied input combinations, cells differentiate into a continuum of cell fates as opposed to a limited number of discrete phenotypes...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716716/fiber-tractography-using-machine-learning
#10
Peter F Neher, Marc-Alexandre Côté, Jean-Christophe Houde, Maxime Descoteaux, Klaus H Maier-Hein
We present a fiber tractography approach based on a random forest classification and voting process, guiding each step of the streamline progression by directly processing raw diffusion-weighted signal intensities. For comparison to the state-of-the-art, i.e. tractography pipelines that rely on mathematical modeling, we performed a quantitative and qualitative evaluation with multiple phantom and in vivo experiments, including a comparison to the 96 submissions of the ISMRM tractography challenge 2015. The results demonstrate the vast potential of machine learning for fiber tractography...
July 14, 2017: NeuroImage
https://www.readbyqxmd.com/read/28716193/epidemiological-features-and-financial-loss-due-to-clinically-diagnosed-haemorrhagic-septicemia-in-bovines-in-karnataka-india
#11
G Govindaraj, P Krishnamoorthy, K R Nethrayini, R Shalini, H Rahman
The epidemiological features and financial losses due to Haemorrhagic Septicemia (HS) in bovines were studied in Karnataka state using the primary data collected from 133 clinically diagnosed HS affected farms. The various losses due to HS and the Benefit- Cost of the vaccination programme in cattle and water buffaloes were studied using mathematical models. The number of HS outbreaks were higher during the year 2002 and peaked during 2005 and thereafter declined due to targeted vaccination against HS. The morbidity and mortality risks were lower in large farms than medium and small farms, and lower in indigenous cattle compared to high yielding crossbred cattle and water buffaloes...
September 1, 2017: Preventive Veterinary Medicine
https://www.readbyqxmd.com/read/28716140/modelling-infectious-diseases-with-relapse-a-case-study-of-hsv-2
#12
Jinliang Wang, Xiaoqing Yu, Heidi L Tessmer, Toshikazu Kuniya, Ryosuke Omori
BACKGROUND: Herpes Simplex Virus Type 2 (HSV-2) is one of the most common sexually transmitted diseases. Although there is still no licensed vaccine for HSV-2, a theoretical investigation of the potential effects of a vaccine is considered important and has recently been conducted by several researchers. Although compartmental mathematical models were considered for each special case in the previous studies, as yet there are few global stability results. RESULTS: In this paper, we formulate a multi-group SVIRI epidemic model for HSV-2, which enables us to consider the effects of vaccination, of waning vaccine immunity, and of infection relapse...
July 17, 2017: Theoretical Biology & Medical Modelling
https://www.readbyqxmd.com/read/28715244/small-sample-methods-for-multilevel-modeling-a-colloquial-elucidation-of-reml-and-the-kenward-roger-correction
#13
Daniel McNeish
Studies on small sample properties of multilevel models have become increasingly prominent in the methodological literature in response to the frequency with which small sample data appear in empirical studies. Simulation results generally recommend that empirical researchers employ restricted maximum likelihood estimation (REML) with a Kenward-Roger correction with small samples in frequentist contexts to minimize small sample bias in estimation and to prevent inflation of Type-I error rates. However, simulation studies focus on recommendations for best practice, and there is little to no explanation of why traditional maximum likelihood (ML) breaks down with smaller samples, what differentiates REML from ML, or how the Kenward-Roger correction remedies lingering small sample issues...
July 17, 2017: Multivariate Behavioral Research
https://www.readbyqxmd.com/read/28715130/average-glandular-dose-coefficients-for-pendant-geometry-breast-ct-using-realistic-breast-phantoms
#14
Andrew M Hernandez, John M Boone
PURPOSE: To design volume-specific breast phantoms from breast CT (bCT) data sets and estimate the associated normalized mean glandular dose coefficients for breast CT using Monte Carlo methods. METHODS: A large cohort of bCT data sets (N=215) was used to evaluate breast volume into quintiles (plus the top 5%). The average radius profile was then determined for each of the six volume-specific groups and used to both fabricate physical phantoms and generate mathematical phantoms (V1-V6; "V" denotes classification by volume)...
July 17, 2017: Medical Physics
https://www.readbyqxmd.com/read/28715121/analytical-solutions-of-three-dimensional-contaminant-transport-models-with-exponential-source-decay
#15
Ombretta Paladino, Arianna Moranda, Marco Massabò, Gary A Robbins
Despite the availability of numerical models, interest in analytical solutions of multidimensional advection-dispersion systems remains high. Such models are commonly used for performing Tier I risk analysis and are embedded in many regulatory frameworks dealing with groundwater contamination. In this work, we develop a closed-form solution of the three-dimensional advection-dispersion equation with exponential source decay, first-order reaction, and retardation, and present an approach based on some ease of use diagrams to compare it with the integral open form solution and with earlier versions of the closed-form solution...
July 17, 2017: Ground Water
https://www.readbyqxmd.com/read/28714956/the-uncertainty-of-crop-yield-projections-is-reduced-by-improved-temperature-response-functions
#16
Enli Wang, Pierre Martre, Zhigan Zhao, Frank Ewert, Andrea Maiorano, Reimund P Rötter, Bruce A Kimball, Michael J Ottman, Gerard W Wall, Jeffrey W White, Matthew P Reynolds, Phillip D Alderman, Pramod K Aggarwal, Jakarat Anothai, Bruno Basso, Christian Biernath, Davide Cammarano, Andrew J Challinor, Giacomo De Sanctis, Jordi Doltra, Elias Fereres, Margarita Garcia-Vila, Sebastian Gayler, Gerrit Hoogenboom, Leslie A Hunt, Roberto C Izaurralde, Mohamed Jabloun, Curtis D Jones, Kurt C Kersebaum, Ann-Kristin Koehler, Leilei Liu, Christoph Müller, Soora Naresh Kumar, Claas Nendel, Garry O'Leary, Jørgen E Olesen, Taru Palosuo, Eckart Priesack, Ehsan Eyshi Rezaei, Dominique Ripoche, Alex C Ruane, Mikhail A Semenov, Iurii Shcherbak, Claudio Stöckle, Pierre Stratonovitch, Thilo Streck, Iwan Supit, Fulu Tao, Peter Thorburn, Katharina Waha, Daniel Wallach, Zhimin Wang, Joost Wolf, Yan Zhu, Senthold Asseng
Increasing the accuracy of crop productivity estimates is a key element in planning adaptation strategies to ensure global food security under climate change. Process-based crop models are effective means to project climate impact on crop yield, but have large uncertainty in yield simulations. Here, we show that variations in the mathematical functions currently used to simulate temperature responses of physiological processes in 29 wheat models account for >50% of uncertainty in simulated grain yields for mean growing season temperatures from 14 °C to 33 °C...
July 17, 2017: Nature Plants
https://www.readbyqxmd.com/read/28714585/mathematical-model-of-collective-cell-migrations-based-on-cell-polarity
#17
Masakazu Akiyama, Takamichi Sushida, Sumire Ishida, Hisashi Haga
Individual cells migrate toward the direction of the cell polarity generated by interior or exterior factors. Under situations without guides such as chemoattractants, they migrate randomly. On the other hand, it has been observed that cell groups lead to systematic collective cell migrations. For example, Dictyostelium discoideum and Madin-Darby canine kidney (epithelial) cells exhibit typical collective cell migration patterns such as uniformly directional migration and rotational migration. In particular, it has been suggested from experimental investigations that rotational migrations are intimately related to morphogenesis of organs and tissues in several species...
July 17, 2017: Development, Growth & Differentiation
https://www.readbyqxmd.com/read/28713795/a-new-approach-to-predict-the-fish-fillet-shelf-life-in-presence-of-natural-preservative-agents
#18
Alessandro Giuffrida, Filippo Giarratana, Davide Valenti, Daniele Muscolino, Roberta Parisi, Alessio Parco, Stefania Marotta, Graziella Ziino, Antonio Panebianco
Three data sets concerning the behaviour of spoilage flora of fillets treated with natural preservative substances (NPS) were used to construct a new kind of mathematical predictive model. This model, unlike other ones, allows expressing the antibacterial effect of the NPS separately from the prediction of the growth rate. This approach, based on the introduction of a parameter into the predictive primary model, produced a good fitting of observed data and allowed characterising quantitatively the increase of shelf-life of fillets...
April 13, 2017: Italian Journal of Food Safety
https://www.readbyqxmd.com/read/28713420/modeling-the-metabolism-of-arabidopsis-thaliana-application-of-network-decomposition-and-network-reduction-in-the-context-of-petri-nets
#19
Ina Koch, Joachim Nöthen, Enrico Schleiff
Motivation:Arabidopsis thaliana is a well-established model system for the analysis of the basic physiological and metabolic pathways of plants. Nevertheless, the system is not yet fully understood, although many mechanisms are described, and information for many processes exists. However, the combination and interpretation of the large amount of biological data remain a big challenge, not only because data sets for metabolic paths are still incomplete. Moreover, they are often inconsistent, because they are coming from different experiments of various scales, regarding, for example, accuracy and/or significance...
2017: Frontiers in Genetics
https://www.readbyqxmd.com/read/28713308/predictive-relation-between-early-numerical-competencies-and-mathematics-achievement-in-first-grade-portuguese-children
#20
Lilia Marcelino, Óscar de Sousa, António Lopes
Early numerical competencies (ENC) (counting, number relations, and basic arithmetic operations) have a central position in the initial learning of mathematics, and their assessment is useful for predicting later mathematics achievement. Using a regression model, this study aims to analyze the correlational and predictive evidence between ENC and mathematics achievement in first grade Portuguese children (n = 123). The children's ENC were examined at the point of school entry. Three criterion groups (low, moderate, and high ENC) were formed based on the results of the early numerical brief screener and mathematics achievement measured at the end of first grade...
2017: Frontiers in Psychology
keyword
keyword
8568
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"