keyword

# Systems dynamics model

keyword
#1
Leila Shahriyary, Gholamhossein Riazi, Mohammad Reza Lornejad, Mansoureh Ghezlou, Bahareh Bigdeli, Behdad Delavari, Fatemeh Mamashli, Shayan Abbasi, Jamshid Davoodi, Ali Akbar Saboury
Alteration in permeability of blood-brain barrier (BBB) is of immense importance in the pathogenesis of diabetes-related central nervous system disorders. Considering the presence of glycated insulin in plasma of type 2 diabetic patients, we hypothesized that glycated insulin could induce changes in paracellular permeability in BBB. Therefore, the authors decided to study the effect of glycated insulin on paracellular permeability in a BBB model. Furthermore, the change induced in insulin conformation upon glycation was studied...
February 11, 2018: Archives of Biochemistry and Biophysics
#2
Alexander Blanke, Manuel Pinheiro, Peter J Watson, Michael J Fagan
Insect head shapes are remarkably variable but the influences of these changes on biomechanical performance are unclear. Among "basal" winged insects, such as dragonflies, mayflies, earwigs, and stoneflies, some of the most prominent anatomical changes are the general mouthpart orientation, eye size and the connection of the endoskeleton to the head. Here, we assess these variations as well as differing ridge and sclerite configurations using modern engineering methods including multibody dynamics modelling and finite element analysis in order to quantify and compare the influence of anatomical changes on strain in particular head regions and the whole head...
February 14, 2018: Journal of Evolutionary Biology
#3
Dominik K Großkinsky, Syahnada Jaya Syaifullah, Thomas Roitsch
The study of senescence in plants is complicated by diverse levels of temporal and spatial dynamics as well as the impact of external biotic and abiotic factors and crop plant management. Whereas the molecular mechanisms involved in developmentally regulated leaf senescence are very well understood, in particular in the annual model plant species Arabidopsis, senescence of other organs such as the flower, fruit, and root is much less studied as well as senescence in perennials such as trees. This review addresses the need for the integration of multi-omics techniques and physiological phenotyping into holistic phenomics approaches to dissect the complex phenomenon of senescence...
February 12, 2018: Journal of Experimental Botany
#4
Yang Ni
In this paper, we present a new logarithmic pixel design currently under development at New Imaging Technologies SA (NIT). This new logarithmic pixel design uses charge domain logarithmic signal compression and charge-transfer-based signal readout. This structure gives a linear response in low light conditions and logarithmic response in high light conditions. The charge transfer readout efficiently suppresses the reset (KTC) noise by using true correlated double sampling (CDS) in low light conditions. In high light conditions, thanks to charge domain logarithmic compression, it has been demonstrated that 3000 electrons should be enough to cover a 120 dB dynamic range with a mobile phone camera-like signal-to-noise ratio (SNR) over the whole dynamic range...
February 14, 2018: Sensors
#5
Eunwoo Kim, Sungjoon Choi, Songhwai Oh
This paper considers two important problems for autonomous robot navigation in a dynamic environment, where the goal is to predict pedestrian motion and control a robot with the prediction for safe navigation. While there are several methods for predicting the motion of a pedestrian and controlling a robot to avoid incoming pedestrians, it is still difficult to safely navigate in a dynamic environment due to challenges, such as the varying quality and complexity of training data with unwanted noises. This paper addresses these challenges simultaneously by proposing a robust kernel subspace learning algorithm based on the recent advances in nuclear-norm and l 1 -norm minimization...
February 14, 2018: Sensors
#6
Pablo G Jambrina, Marta Menendez, Alexandre Zanchet, Ernesto Garcia, F Javier Aoiz
This work present scattering calculations for the O($^3P$) + N$_2$($^1\Sigma$) $\rightarrow$ NO($^2\Pi$) + N($^4$S) and for the O($^3P$) + HCl($^1\Sigma$) $\rightarrow$ OH($^2\Pi$) + Cl($^2$P) reactions with the focus on the prediction of the $\Lambda$-doublet populations in which NO and OH are produced. Both reactions can take place on two competing potential energy surfaces of symmetries $^3A'$ and $^3A''$ that correlate reagents with products but with very distinct topographies. As a result, they exhibit very different dynamical behaviors and total reactivity...
February 14, 2018: Journal of Physical Chemistry. A
#7
Sandra B Lemke, Frank Schnorrer
Muscles together with tendons and the skeleton enable animals including humans to move their body parts. Muscle morphogenesis is highly conserved from animals to humans. Therefore, the powerful Drosophila model system can be used to study concepts of muscle-tendon development that can also be applied to human muscle biology. Here, we describe in detail how morphogenesis of the adult muscle-tendon system can be easily imaged in living, developing Drosophila pupae. Hence, the method allows investigating proteins, cells and tissues in their physiological environment...
February 6, 2018: Journal of Visualized Experiments: JoVE
#8
Melva Suarez Muñoz, Davide Confalonieri, Heike Walles, Elisabeth M W M van Dongen, Gudrun Dandekar
Tissue engineering is a promising field, focused on developing solutions for the increasing demand on tissues and organs regarding transplantation purposes. The process to generate such tissues is complex, and includes an appropriate combination of specific cell types, scaffolds, and physical or biochemical stimuli to guide cell growth and differentiation. Microcarriers represent an appealing tool to expand cells in a three-dimensional (3D) microenvironment, since they provide higher surface-to volume ratios and mimic more closely the in vivo situation compared to traditional two-dimensional methods...
February 7, 2018: Journal of Visualized Experiments: JoVE
#9
Maria Cuenca Cambronero, Luisa Orsini
Long-term studies enable the identification of eco-evolutionary processes that occur over extended time periods. In addition, they provide key empirical data that may be used in predictive modelling to forecast evolutionary responses of natural ecosystems to future environmental changes. However, excluding a few exceptional cases, long-term studies are scarce because of logistic difficulties associated with accessing temporal samples. Temporal dynamics are frequently studied in the laboratory or in controlled mesocosm experiments with exceptional studies that reconstruct the evolution of natural populations in the wild...
January 19, 2018: Journal of Visualized Experiments: JoVE
#10
Michael Everett Rule, Carlos E Vargas-Irwin, John P Donoghue, Wilson Truccolo
Previous studies on the origin and properties of spatial patterns in motor cortex beta local field potential (β-LFP) oscillations have focused on planar traveling waves. However, it is unclear (a) whether β-LFP waves are limited to plane waves, or even (b) whether they are propagating waves of excito-excitatory activity, i.e. primarily traveling waves in excitable media; they could reflect, instead, reorganization in the relative phases of transient oscillations at different spatial sites. We addressed these two problems in β-LFPs recorded via microelectrode arrays implanted in three adjacent motor-cortex areas of non-human primates during steady-state movement preparation...
February 14, 2018: Journal of Neurophysiology
#11
Sheila Flanagan, Tudor-Cătălin Zorilă, Yannis Stylianou, Brian C J Moore
Auditory processing disorder (APD) may be diagnosed when a child has listening difficulties but has normal audiometric thresholds. For adults with normal hearing and with mild-to-moderate hearing impairment, an algorithm called spectral shaping with dynamic range compression (SSDRC) has been shown to increase the intelligibility of speech when background noise is added after the processing. Here, we assessed the effect of such processing using 8 children with APD and 10 age-matched control children. The loudness of the processed and unprocessed sentences was matched using a loudness model...
January 2018: Trends in Hearing
#12
Juan A Arias Del Angel, Ana E Escalante, León Patricio Martínez-Castilla, Mariana Benítez
Myxococcus xanthus is a myxobacterium that exhibits aggregation and cellular differentiation during the formation of fruiting bodies. Therefore, it has become a valuable model system to study the transition to multicellularity via cell aggregation. Although there is a vast set of experimental information for the development on M. xanthus, the dynamics behind cell-fate determination in this organism's development remain unclear. We integrate the currently available evidence in a mathematical network model that allows to test the set of molecular elements and regulatory interactions that are sufficient to account for the specification of the cell types that are observed in fruiting body formation...
February 13, 2018: Development, Growth & Differentiation
#13
Lee Harten, Yasmin Matalon, Naama Galli, Hagit Navon, Roi Dor, Yossi Yovel
Social foraging theory suggests that group-living animals gain from persistent social bonds, which lead to increased tolerance in competitive foraging and information sharing. Bats are among the most social mammals, often living in colonies of tens to thousands of individuals for dozens of years, yet little is known about their social foraging dynamics. We observed three captive bat colonies for over a year, quantifying >13,000 social foraging interactions. We found that individuals consistently used one of two foraging strategies, either producing (collecting) food themselves or scrounging it directly from the mouth of other individuals...
#14
David J Harris, Shawn D Taylor, Ethan P White
Biodiversity forecasts are important for conservation, management, and evaluating how well current models characterize natural systems. While the number of forecasts for biodiversity is increasing, there is little information available on how well these forecasts work. Most biodiversity forecasts are not evaluated to determine how well they predict future diversity, fail to account for uncertainty, and do not use time-series data that captures the actual dynamics being studied. We addressed these limitations by using best practices to explore our ability to forecast the species richness of breeding birds in North America...
2018: PeerJ
#15
Wenya Yu, Yipeng Lv, Chaoqun Hu, Xu Liu, Haiping Chen, Chen Xue, Lulu Zhang
Objectives: Emergency medical system for mass casualty incidents (EMS-MCIs) is a global issue. However, China lacks such studies extremely, which cannot meet the requirement of rapid decision-support system. This study aims to realize modeling EMS-MCIs in Shanghai, to improve mass casualty incident (MCI) rescue efficiency in China, and to provide a possible method of making rapid rescue decisions during MCIs. Methods: This study established a system dynamics (SD) model of EMS-MCIs using the Vensim DSS program...
#16
Justin D Finkle, Jia J Wu, Neda Bagheri
Accurate inference of regulatory networks from experimental data facilitates the rapid characterization and understanding of biological systems. High-throughput technologies can provide a wealth of time-series data to better interrogate the complex regulatory dynamics inherent to organisms, but many network inference strategies do not effectively use temporal information. We address this limitation by introducing Sliding Window Inference for Network Generation (SWING), a generalized framework that incorporates multivariate Granger causality to infer network structure from time-series data...
February 12, 2018: Proceedings of the National Academy of Sciences of the United States of America
#17
James G Burchfield, Melkam A Kebede, Christopher C Meoli, Jacqueline Stöckli, P Tess Whitworth, Amanda L Wright, Nolan J Hoffman, Annabel Y Minard, Xiuquan Ma, James R Krycer, Marin E Nelson, Shi-Xiong Tan, Belinda Yau, Kristen C Thomas, Natalie K Y Wee, Ee-Cheng Khor, Ronaldo F Enriquez, Bryce Vissel, Trevor J Biden, Paul A Baldock, Kyle L Hoehn, James Cantley, Gregory J Cooney, David E James, Daniel J Fazakerley
Obesity is associated with metabolic dysfunction, including insulin resistance and hyperinsulinemia, and with disorders such as cardiovascular disease, osteoporosis, and neurodegeneration. Typically, these pathologies are examined in discrete model systems and with limited temporal resolution, and whether these disorders co-occur is therefore unclear. To address this question, we examined multiple physiological systems in male C57BL/6J mice following prolonged exposure to a high-fat/high-sucrose diet (HFHSD)...
February 13, 2018: Journal of Biological Chemistry
#18
MuhChyi Chai, Tsukasa Sanosaka, Hironobu Okuno, Zhi Zhou, Ikuko Koya, Satoe Banno, Tomoko Andoh-Noda, Yoshikuni Tabata, Rieko Shimamura, Tetsutaro Hayashi, Masashi Ebisawa, Yohei Sasagawa, Itoshi Nikaido, Hideyuki Okano, Jun Kohyama
Multiple congenital disorders often present complex phenotypes, but how the mutation of individual genetic factors can lead to multiple defects remains poorly understood. In the present study, we used human neuroepithelial (NE) cells and CHARGE patient-derived cells as an in vitro model system to identify the function of chromodomain helicase DNA-binding 7 (CHD7) in NE-neural crest bifurcation, thus revealing an etiological link between the central nervous system (CNS) and craniofacial anomalies observed in CHARGE syndrome...
February 9, 2018: Genes & Development
#19
REVIEW
Scott D Adams, Abbas Z Kouzani, Susannah J Tye, Kevin E Bennet, Michael Berk
Dynamic feedback based closed-loop medical devices offer a number of advantages for treatment of heterogeneous neurological conditions. Closed-loop devices integrate a level of neurobiological feedback, which allows for real-time adjustments to be made with the overarching aim of improving treatment efficacy and minimizing risks for adverse events. One target which has not been extensively explored as a potential feedback component in closed-loop therapies is mitochondrial function. Several neurodegenerative and psychiatric disorders including Parkinson's disease, Major Depressive disorder and Bipolar disorder have been linked to perturbations in the mitochondrial respiratory chain...
February 13, 2018: Journal of Neuroengineering and Rehabilitation
#20
Zhi Li, Alexandre Tkatchenko, Ignacio Franco
We propose a computationally efficient strategy to accurately model non-reactive molecule-surface interactions that adapts density-functional theory calculations with the Tkatchenko-Scheffler scheme for van der Waals interactions into a simple classical force field. The resulting force field requires just two adjustable parameters per atom type that are needed to capture short-range and polarization interactions. The developed strategy allows for classical molecular dynamics simulation of molecules on surfaces with the accuracy of high-level electronic structure methods but for system sizes (10$^3-10^7$ atoms) and timescales ($\sim \mu$s) that go well beyond what can be achieved with first-principles methods...
February 13, 2018: Journal of Physical Chemistry Letters
keyword
keyword
54333
1
2
Fetch more papers »
Fetching more papers...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.

### Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign