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https://www.readbyqxmd.com/read/29351554/field-data-based-mathematical-modeling-by-bode-equations-and-vector-fitting-algorithm-for-renewable-energy-applications
#1
A H Sabry, W Z W Hasan, M Z A Ab Kadir, M A M Radzi, S Shafie
The power system always has several variations in its profile due to random load changes or environmental effects such as device switching effects when generating further transients. Thus, an accurate mathematical model is important because most system parameters vary with time. Curve modeling of power generation is a significant tool for evaluating system performance, monitoring and forecasting. Several numerical techniques compete to fit the curves of empirical data such as wind, solar, and demand power rates...
2018: PloS One
https://www.readbyqxmd.com/read/29351477/mathematical-analysis-of-circadian-disruption-and-metabolic-re-entrainment-of-hepatic-gluconeogenesis-the-intertwining-entraining-roles-of-light-and-feeding
#2
Seul-A Bae, Ioannis P Androulakis
The circadian rhythms influence the metabolic activity from molecular level to tissue, organ, and host level. Disruption of the circadian rhythms manifest to the host's health as metabolic syndromes including obesity, diabetes, and elevated plasma glucose, eventually leading to cardiovascular diseases. Therefore, it is imperative to understand the mechanism behind the relationship between circadian rhythms and metabolism. To start answering this question, we propose a semi-mechanistic mathematical model to study the effect of circadian disruption on hepatic gluconeogenesis in humans...
January 9, 2018: American Journal of Physiology. Endocrinology and Metabolism
https://www.readbyqxmd.com/read/29351421/increased-insulin-clearance-in-mice-with-double-deletion-of-glucagon-like-peptide-1-and-glucose-dependent-insulinotropic-polypeptide-receptors
#3
Andrea Tura, Roberto Bizzotto, Yuichiro Yamada, Yutaka Seino, Giovanni Pacini, Bo Ahren
To establish whether incretin hormones affect insulin clearance, the aim of this study was to assess insulin clearance in mice with genetic deletion of receptors for both glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP), so called double incretin receptor knockout mice (DIRKO). DIRKO (n=31) and wild-type (WT) C57BL6J mice (n=45) were intravenously injected with D-glucose (0.35 g/kg). Blood was sampled for 50 minutes and assayed for glucose, insulin and C-peptide. Data were modeled to calculate insulin clearance; C-peptide kinetics was established after human C-peptide injection...
January 3, 2018: American Journal of Physiology. Regulatory, Integrative and Comparative Physiology
https://www.readbyqxmd.com/read/29351275/a-mathematical-model-for-il-6-mediated-stem-cell-driven-tumor-growth-and-targeted-treatment
#4
Fereshteh Nazari, Alexander T Pearson, Jacques Eduardo Nör, Trachette L Jackson
Targeting key regulators of the cancer stem cell phenotype to overcome their critical influence on tumor growth is a promising new strategy for cancer treatment. Here we present a modeling framework that operates at both the cellular and molecular levels, for investigating IL-6 mediated, cancer stem cell driven tumor growth and targeted treatment with anti-IL6 antibodies. Our immediate goal is to quantify the influence of IL-6 on cancer stem cell self-renewal and survival, and to characterize the subsequent impact on tumor growth dynamics...
January 19, 2018: PLoS Computational Biology
https://www.readbyqxmd.com/read/29351028/female-and-male-differences-in-academic-achievement-in-individuals-with-cleft-a-population-based-register-study
#5
Martin Persson, Magnus Becker, Amy L Conrad, Henry Svensson
OBJECTIVE: The focus of this study was to determine if there is any significant difference in academic achievement for girls and boys with a cleft compared to the general population of Swedish students at graduation from compulsory school. DESIGN: A retrospective population-based study using data obtained from the Swedish Medical Birth Register that was linked to the Swedish School-Grade Register. PARTICIPANTS: Two hundred seventy girls and 241 boys with cleft palate (CP), 222 girls and 429 boys with cleft lip (CL), and 299 girls and 531 boys with cleft lip and palate (CLP) were compared with the compulsory school population comprising 609,397 girls and 640,007 boys...
February 2018: Cleft Palate-craniofacial Journal
https://www.readbyqxmd.com/read/29350688/laws-of-physics-help-explain-capillary-non-perfusion-in-diabetic-retinopathy
#6
E Stefánsson, Y K Chan, T Bek, S H Hardarson, D Wong, D I Wilson
The purpose is to use laws of physics to elucidate the mechanisms behind capillary non-perfusion in diabetic retinopathy. In diabetic retinopathy, loss of pericytes weakens capillary walls and the vessel dilates. A dilated capillary has reduced resistance to flow, therefore increased flow in that vessel and decreased in adjoining capillaries. A preferential shunt vessel is thus formed from the dilated capillary and the adjacent capillaries become non-perfused. We apply the laws of Laplace and Hagen-Poiseuille to better understand the phenomena that lead to capillary non-perfusion...
January 19, 2018: Eye
https://www.readbyqxmd.com/read/29350049/targeted-and-off-target-bystander-and-abscopal-effects-of-radiation-therapy-redox-mechanisms-and-risk-benefit-analysis
#7
Jean-Pierre Pouget, Alexandros G Georgakilas, Jean-Luc Ravanat
Radiation therapy (from external beams to unsealed and sealed radionuclide sources) takes advantage of the detrimental effects of the clustered production of radicals and reactive oxygen species (ROS). Research has mainly focused on the interaction of radiation with water, which is the major constituent of living beings, and with nuclear DNA, which contains the genetic information. This led to the so-called "target" theory according to which cells have to be hit by ionizing particles to elicit an important biological response, including cell death...
January 19, 2018: Antioxidants & Redox Signaling
https://www.readbyqxmd.com/read/29349826/low-performance-on-mathematical-tasks-in-preschoolers-the-importance-of-domain-general-and-domain-specific-abilities
#8
H M Costa, B Nicholson, C Donlan, J Van Herwegen
BACKGROUND: Different domain-specific and domain-general cognitive precursors play a key role in the development of mathematical abilities. The contribution of these domains to mathematical ability changes during development. Primary school-aged children who show mathematical difficulties form a heterogeneous group, but it is not clear whether this also holds for preschool low achievers (LAs) and how domain-specific and domain-general abilities contribute to mathematical difficulties at a young age...
January 19, 2018: Journal of Intellectual Disability Research: JIDR
https://www.readbyqxmd.com/read/29349685/solute-transport-in-the-bone-lacunar-canalicular-system-lcs
#9
REVIEW
Liyun Wang
PURPOSE OF REVIEW: Solute transport in the lacunar-canalicular system (LCS) plays important roles in osteocyte metabolism and cell-cell signaling. This review will summarize recent studies that establish pericellular matrix (PCM), discovered inside the LCS, as a crucial regulator of solute transport in bone. RECENT FINDINGS: Utilizing confocal imaging and mathematical modeling, recent studies successfully quantified molecular diffusion and convection in the LCS as well as the size-dependent sieving effects of the PCM, leading to the quantification of the effective PCM fiber spacing (10 to 17 nm) in murine adult bones...
January 18, 2018: Current Osteoporosis Reports
https://www.readbyqxmd.com/read/29349627/modeling-and-simulation-of-enzymatic-gluconic-acid-production-using-immobilized-enzyme-and-cstr-pftr-circulation-reaction-system
#10
Can Li, Jianqun Lin, Ling Gao, Huibin Lin, Jianqiang Lin
OBJECTIVES: Production of gluconic acid by using immobilized enzyme and continuous stirred tank reactor-plug flow tubular reactor (CSTR-PFTR) circulation reaction system. RESULTS: A production system is constructed for gluconic acid production, which consists of a continuous stirred tank reactor (CSTR) for pH control and liquid storage and a plug flow tubular reactor (PFTR) filled with immobilized glucose oxidase (GOD) for gluconic acid production. Mathematical model is developed for this production system and simulation is made for the enzymatic reaction process...
January 18, 2018: Biotechnology Letters
https://www.readbyqxmd.com/read/29349609/caspase-1-mediated-pyroptosis-of-the-predominance-for-driving-cd4-formula-see-text-t-cells-death-a-nonlocal-spatial-mathematical-model
#11
Wei Wang, Tongqian Zhang
Caspase-1-mediated pyroptosis is the predominance for driving CD4[Formula: see text] T cells death. Dying infected CD4[Formula: see text] T cells can release inflammatory signals which attract more uninfected CD4[Formula: see text] T cells to die. This paper is devoted to developing a diffusive mathematical model which can make useful contributions to understanding caspase-1-mediated pyroptosis by inflammatory cytokines IL-1[Formula: see text] released from infected cells in the within-host environment. The well-posedness of solutions, basic reproduction number, threshold dynamics are investigated for spatially heterogeneous infection...
January 18, 2018: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/29349467/lysine-derived-ph-sensitive-and-biodegradable-poly-beta-aminoester-urethane-networks-and-their-local-drug-delivery-behaviour
#12
Yasemin Tamer, Biqiong Chen
In this study, a series of covalently crosslinked, l-lysine based poly(beta-aminoester urethane) (LPBAEU) networks with good biodegradability and pH sensitivity was reported. The effect of hydrophilic/hydrophobic characteristics and diacrylate/amine molar ratio on the structure, swelling and degradation behaviour of the networks was investigated. The water transport mechanism and dynamic swelling behavior of the LPBAEU networks were strongly affected by medium pH, and swelling amounts up to 252.2% and 148.7% were observed at pH 5...
January 19, 2018: Soft Matter
https://www.readbyqxmd.com/read/29349296/unlocking-data-sets-by-calibrating-populations-of-models-to-data-density-a-study-in-atrial-electrophysiology
#13
Brodie A J Lawson, Christopher C Drovandi, Nicole Cusimano, Pamela Burrage, Blanca Rodriguez, Kevin Burrage
The understanding of complex physical or biological systems nearly always requires a characterization of the variability that underpins these processes. In addition, the data used to calibrate these models may also often exhibit considerable variability. A recent approach to deal with these issues has been to calibrate populations of models (POMs), multiple copies of a single mathematical model but with different parameter values, in response to experimental data. To date, this calibration has been largely limited to selecting models that produce outputs that fall within the ranges of the data set, ignoring any trends that might be present in the data...
January 2018: Science Advances
https://www.readbyqxmd.com/read/29348634/a-biosensor-based-framework-to-measure-latent-proteostasis-capacity
#14
Rebecca J Wood, Angelique R Ormsby, Mona Radwan, Dezerae Cox, Abhishek Sharma, Tobias Vöpel, Simon Ebbinghaus, Mikael Oliveberg, Gavin E Reid, Alex Dickson, Danny M Hatters
The pool of quality control proteins (QC) that maintains protein-folding homeostasis (proteostasis) is dynamic but can become depleted in human disease. A challenge has been in quantitatively defining the depth of the QC pool. With a new biosensor, flow cytometry-based methods and mathematical modeling we measure the QC capacity to act as holdases and suppress biosensor aggregation. The biosensor system comprises a series of barnase kernels with differing folding stability that engage primarily with HSP70 and HSP90 family proteins...
January 18, 2018: Nature Communications
https://www.readbyqxmd.com/read/29348418/a-novel-modeling-in-mathematical-biology-for-classification-of-signal-peptides
#15
Asma Ehsan, Khalid Mahmood, Yaser Daanial Khan, Sher Afzal Khan, Kuo-Chen Chou
The molecular structure of macromolecules in living cells is ambiguous unless we classify them in a scientific manner. Signal peptides are of vital importance in determining the behavior of newly formed proteins towards their destined path in cellular and extracellular location in both eukaryotes and prokaryotes. In the present research work, a novel method is offered to foreknow the behavior of signal peptides and determine their cleavage site. The proposed model employs neural networks using isolated sets of prokaryote and eukaryote primary sequences...
January 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29348204/tumor-suppressor-apc-is-an-attenuator-of-spindle-pulling-forces-during-c-elegans-asymmetric-cell-division
#16
Kenji Sugioka, Lars-Eric Fielmich, Kota Mizumoto, Bruce Bowerman, Sander van den Heuvel, Akatsuki Kimura, Hitoshi Sawa
The adenomatous polyposis coli (APC) tumor suppressor has dual functions in Wnt/β-catenin signaling and accurate chromosome segregation and is frequently mutated in colorectal cancers. Although APC contributes to proper cell division, the underlying mechanisms remain poorly understood. Here we show that Caenorhabditis elegans APR-1/APC is an attenuator of the pulling forces acting on the mitotic spindle. During asymmetric cell division of the C. elegans zygote, a LIN-5/NuMA protein complex localizes dynein to the cell cortex to generate pulling forces on astral microtubules that position the mitotic spindle...
January 18, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29347760/anomalies-in-the-equilibrium-and-nonequilibrium-properties-of-correlated-ions-in-complex-molecular-environments
#17
Sathiya Mahakrishnan, Subrata Chakraborty, Amrendra Vijay
Emergent statistical attributes, and therefore the equations of state, of an assembly of interacting charge carriers embedded within a complex molecular environment frequently exhibit a variety of anomalies, particularly in the high-density (equivalently, the concentration) regime, which are not well understood, because they do not fall under the low-concentration phenomenologies of Debye-Hückel-Onsager and Poisson-Nernst-Planck, including their variants. To go beyond, we here use physical concepts and mathematical tools from quantum scattering theory, transport theory with the Stosszahlansatz of Boltzmann, and classical electrodynamics (Lorentz gauge) and obtain analytical expressions both for the average and the frequency-wave vector-dependent longitudinal and transverse current densities, diffusion coefficient, and the charge density, and therefore the analytical expressions for (a) the chemical potential, activity coefficient, and the equivalent conductivity for strong electrolytes and (b) the current-voltage characteristics for ion-transport processes in complex molecular environments...
November 2017: Physical Review. E
https://www.readbyqxmd.com/read/29347582/estimation-of-the-degree-of-dynamical-instability-from-the-information-entropy-of-symbolic-dynamics
#18
Takaya Miyano, Hiroshi Gotoda
A positive Lyapunov exponent is the most convincing signature of chaos. However, existing methods for estimating the Lyapunov exponent from a time series often give unreliable estimates because they trace the time evolution of the distance between a pair of initially neighboring trajectories in phase space. Here, we propose a mathematical method for estimating the degree of dynamical instability, as a surrogate for the Lyapunov exponent, without tracing initially neighboring trajectories on the basis of the information entropy from a symbolic time series...
October 2017: Physical Review. E
https://www.readbyqxmd.com/read/29347568/impact-of-environmental-colored-noise-in-single-species-population-dynamics
#19
Tommaso Spanio, Jorge Hidalgo, Miguel A Muñoz
Variability on external conditions has important consequences for the dynamics and the organization of biological systems. In many cases, the characteristic timescale of environmental changes as well as their correlations play a fundamental role in the way living systems adapt and respond to it. A proper mathematical approach to understand population dynamics, thus, requires approaches more refined than, e.g., simple white-noise approximations. To shed further light onto this problem, in this paper we propose a unifying framework based on different analytical and numerical tools available to deal with "colored" environmental noise...
October 2017: Physical Review. E
https://www.readbyqxmd.com/read/29347567/kinetics-of-biochemical-sensing-by-single-cells-and-populations-of-cells
#20
David B Saakian
We investigate the collective stationary sensing using N communicative cells, which involves surface receptors, diffusive signaling molecules, and cell-cell communication messengers. We restrict the scenarios to the signal-to-noise ratios (SNRs) for both strong communication and extrinsic noise only. We modified a previous model [Bialek and Setayeshgar, Proc. Natl. Acad. Sci. USA 102, 10040 (2005)PNASA60027-842410.1073/pnas.0504321102] to eliminate the singularities in the fluctuation correlations by considering a uniform receptor distribution over the surface of each cell with a finite radius a...
October 2017: Physical Review. E
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