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https://www.readbyqxmd.com/read/28343335/a-new-infant-hybrid-respiratory-simulator-preliminary-evaluation-based-on-clinical-data
#1
Barbara Stankiewicz, Krzysztof J Pałko, Marek Darowski, Krzysztof Zieliński, Maciej Kozarski
A new hybrid (numerical-physical) simulator of the respiratory system, designed to simulate spontaneous and artificial/assisted ventilation of preterm and full-term infants underwent preliminary evaluation. A numerical, seven-compartmental model of the respiratory system mechanics allows the operator to simulate global and peripheral obstruction and restriction of the lungs. The physical part of the simulator is a piston-based construction of impedance transformer. LabVIEW real-time software coordinates the work of both parts of the simulator and its interaction with a ventilator...
March 25, 2017: Medical & Biological Engineering & Computing
https://www.readbyqxmd.com/read/28342844/a-system-dynamics-modelling-approach-to-assess-the-impact-of-launching-a-new-nicotine-product-on-population-health-outcomes
#2
Andrew Hill, Oscar M Camacho
In 2012 the US FDA suggested the use of mathematical models to assess the impact of releasing new nicotine or tobacco products on population health outcomes. A model based on system dynamics methodology was developed to project the potential effects of a new nicotine product at a population level. A model representing traditional smoking populations (never, current and former smokers) and calibrated using historical data was extended to a two-product model by including electronic cigarettes use statuses. Smoking mechanisms, such as product initiation, switching, transition to dual use, and cessation, were represented as flows between smoking statuses (stocks) and the potential effect of smoking renormalisation through a feedback system...
March 22, 2017: Regulatory Toxicology and Pharmacology: RTP
https://www.readbyqxmd.com/read/28342418/dynamics-of-runoff-and-sediment-trapping-performance-of-vegetative-filter-strips-run-on-experiments-and-modeling
#3
Daili Pan, Xiaodong Gao, Miles Dyck, Yaqian Song, Pute Wu, Xining Zhao
Vegetative filter strips (VFSs) are a labor-saving and cost-effective agricultural best management practice to trap water runoff and sediment from the source areas. They also provide forage and/or fuel and are therefore potentially profitable for land owners. VFSs are however a dynamic system: the runoff delivery ratio (RDR) and sediment delivery ratio (SDR) vary with growth stage and vegetation types. The impacts of vegetation characteristics as well as soil physical properties modified by vegetation growth, on the RDR and SDR of VFS were evaluated by a flume experiment...
March 22, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28340243/finite-time-parametric-identification-for-the-model-representing-the-metabolic-and-genetic-regulatory-effects-of-sequential-aerobic-respiration-and-anaerobic-fermentation-processes-in-escherichia-coli
#4
Alfonso Sepúlveda-Gálvez, Jesús Agustín Badillo-Corona, Isaac Chairez
Mathematical modelling applied to biological systems allows for the inferring of changes in the dynamic behaviour of organisms associated with variations in the environment. Models based on ordinary differential equations are most commonly used because of their ability to describe the mechanisms of biological systems such as transcription. The disadvantage of using this approach is that there is a large number of parameters involved and that it is difficult to obtain them experimentally. This study presents an algorithm to obtain a finite-time parameter characterization of the model used to describe changes in the metabolic behaviour of Escherichia coli associated with environmental changes...
March 17, 2017: Mathematical Medicine and Biology: a Journal of the IMA
https://www.readbyqxmd.com/read/28339682/the-effects-of-interleukin-2-on-immune-response-regulation
#5
Ryan S Waters, Justin S A Perry, SunPil Han, Bibiana Bielekova, Tomas Gedeon
The immune system has many adaptive and dynamic components that are regulated to ensure appropriate, precise and rapid response to a foreign pathogen. A delayed or inadequate immune response can lead to prolonged disease, while an excessive or under-regulated response can lead to autoimmunity. The cytokine, interleukin-2 (IL-2) and its receptor IL-2R play an important role in maintaining this balance.The IL-2 receptor transduces pSTAT5 signal through both the intermediate and high affinity receptors, which differ from each other by the presence of CD25 chain in IL-2 receptor...
February 20, 2017: Mathematical Medicine and Biology: a Journal of the IMA
https://www.readbyqxmd.com/read/28339279/trade-off-between-speed-and-cost-in-shortcuts-to-adiabaticity
#6
Steve Campbell, Sebastian Deffner
Achieving effectively adiabatic dynamics is a ubiquitous goal in almost all areas of quantum physics. Here, we study the speed with which a quantum system can be driven when employing transitionless quantum driving. As a main result, we establish a rigorous link between this speed, the quantum speed limit, and the (energetic) cost of implementing such a shortcut to adiabaticity. Interestingly, this link elucidates a trade-off between speed and cost, namely, that instantaneous manipulation is impossible as it requires an infinite cost...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339252/helical-floquet-channels-in-1d-lattices
#7
Jan Carl Budich, Ying Hu, Peter Zoller
We show how dispersionless channels exhibiting perfect spin-momentum locking can arise in a 1D lattice model. While such spectra are forbidden by fermion doubling in static 1D systems, here we demonstrate their appearance in the stroboscopic dynamics of a periodically driven system. Remarkably, this phenomenon does not rely on any adiabatic assumptions, in contrast to the well known Thouless pump and related models of adiabatic spin pumps. The proposed setup is shown to be experimentally feasible with state-of-the-art techniques used to control ultracold alkaline earth atoms in optical lattices...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339221/open-systems-with-error-bounds-spin-boson-model-with-spectral-density-variations
#8
F Mascherpa, A Smirne, S F Huelga, M B Plenio
In the study of open quantum systems, one of the most common ways to describe environmental effects on the reduced dynamics is through the spectral density. However, in many models this object cannot be computed from first principles and needs to be inferred on phenomenological grounds or fitted to experimental data. Consequently, some uncertainty regarding its form and parameters is unavoidable; this in turn calls into question the accuracy of any theoretical predictions based on a given spectral density. Here, we focus on the spin-boson model as a prototypical open quantum system, find two error bounds on predicted expectation values in terms of the spectral density variation considered, and state a sufficient condition for the strongest one to apply...
March 10, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28339071/direct-interaction-between-caffeic-acid-phenethyl-ester-and-human-neutrophil-elastase-inhibits-the-growth-and-migration-of-panc-1-cells
#9
Jianhui Duan, Yilixiati Xiaokaiti, Shengjun Fan, Yan Pan, Xin Li, Xuejun Li
Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal malignant tumors of the digestive system, but the mechanisms of its development and progression are unclear. Inflammation is thought to be fundamental to pancreatic cancer development and caffeic acid phenethyl ester (CAPE) is an active component of honey bee resin or propolis with anti-inflammatory and anticancer activities. We investigated the inhibitory effects of CAPE on cell growth and migration induced by human neutrophil elastase (HNE) and report that HNE induced cancer cell migration at low doses and growth at higher doses...
March 21, 2017: Oncology Reports
https://www.readbyqxmd.com/read/28338970/woody-plant-ecosystems-under-climate-change-and-air-pollution-response-consistencies-across-zonobiomes
#10
R Matyssek, A R Kozovits, G Wieser, J King, H Rennenberg
Forests store the largest terrestrial pools of carbon (C), helping to stabilize the global climate system, yet are threatened by climate change (CC) and associated air pollution (AP, highlighting ozone (O3) and nitrogen oxides (NOx)). We adopt the perspective that CC-AP drivers and physiological impacts are universal, resulting in consistent stress responses of forest ecosystems across zonobiomes. Evidence supporting this viewpoint is presented from the literature on ecosystem gross/net primary productivity and water cycling...
March 14, 2017: Tree Physiology
https://www.readbyqxmd.com/read/28338931/evolutionary-dynamics-of-pathoadaptation-revealed-by-three-independent-acquisitions-of-the-virb-d4-type-iv-secretion-system-in-bartonella
#11
Alexander Harms, Francisca H I D Segers, Maxime Quebatte, Claudia Mistl, Pablo Manfredi, Jonas Körner, Bruno B Chomel, Michael Kosoy, Soichi Maruyama, Philipp Engel, Christoph Dehio
The α-proteobacterial genus Bartonella comprises a group of ubiquitous mammalian pathogens that are studied as a model for the evolution of bacterial pathogenesis. Vast abundance of two particular phylogenetic lineages of Bartonella had been linked to enhanced host adaptability enabled by lineage-specific acquisition of a VirB/D4 type IV secretion system (T4SS) and parallel evolution of complex effector repertoires. However, the limited availability of genome sequences from one of those lineages as well as other, remote branches of Bartonella has so far hampered comprehensive understanding of how the VirB/D4 T4SS and its effectors called Beps have shaped Bartonella evolution...
March 7, 2017: Genome Biology and Evolution
https://www.readbyqxmd.com/read/28338127/phonon-bottleneck-and-long-lived-excited-states-in-%C3%AF-conjugated-pyrene-hoop
#12
Ricardo Franklin-Mergarejo, Tammie Nelson, Sergei Tretiak, Sebastian Fernandez-Alberti
In the last decade, recent synthetic advances have launched carbon-based π-conjugated hoops to the forefront of theoretical and experimental investigation not only for their potential use as bottom-up templates for carbon nanotube (CNT) growth, but also for the interesting excitonic effects arising from the cyclic geometry, unique π-system orientation, and unusual electronic interactions and couplings. In particular, cyclic materials based on pyrene, a common component in organic electronics, are popular candidates for the future design of π-conjugated nanorings for optoelectronic applications...
March 24, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28338079/dissecting-mirna-gene-repression-on-single-cell-level-with-an-advanced-fluorescent-reporter-system
#13
Nicolas Lemus-Diaz, Kai O Böker, Ignacio Rodriguez-Polo, Michael Mitter, Jasmin Preis, Maximilian Arlt, Jens Gruber
Despite major advances on miRNA profiling and target predictions, functional readouts for endogenous miRNAs are limited and frequently lead to contradicting conclusions. Numerous approaches including functional high-throughput and miRISC complex evaluations suggest that the functional miRNAome differs from the predictions based on quantitative sRNA profiling. To resolve the apparent contradiction of expression versus function, we generated and applied a fluorescence reporter gene assay enabling single cell analysis...
March 24, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28337675/an-ontology-based-search-engine-for-digital-reconstructions-of-neuronal-morphology
#14
Sridevi Polavaram, Giorgio A Ascoli
Neuronal morphology is extremely diverse across and within animal species, developmental stages, brain regions, and cell types. This diversity is functionally important because neuronal structure strongly affects synaptic integration, spiking dynamics, and network connectivity. Digital reconstructions of axonal and dendritic arbors are thus essential to quantify and model information processing in the nervous system. NeuroMorpho.Org is an established repository containing tens of thousands of digitally reconstructed neurons shared by several hundred laboratories worldwide...
March 23, 2017: Brain Informatics
https://www.readbyqxmd.com/read/28337601/the-cortisol-awakening-response-mediates-the-relationship-between-acculturative-stress-and-self-reported-health-in-mexican-americans
#15
Antonio F Garcia, Kristin Wilborn, Deborah L Mangold
BACKGROUND: The assessment of acculturative stress as synonymous with acculturation level overlooks the dynamic, interactive, and developmental nature of the acculturation process. An individual's unique perception and response to a range of stressors at each stage of the dynamic process of acculturation may be associated with stress-induced alterations in important biological response systems that mediate health outcomes. Evidence suggests the cortisol awakening response (CAR) is a promising pre-clinical biomarker of stress exposure that may link acculturative stress to self-reported health in Mexican Americans...
March 23, 2017: Annals of Behavioral Medicine: a Publication of the Society of Behavioral Medicine
https://www.readbyqxmd.com/read/28337138/motor-skill-learning-in-an-insect-inspired-neuro-computational-control-system
#16
Eleonora Arena, Paolo Arena, Roland Strauss, Luca Patané
In nature, insects show impressive adaptation and learning capabilities. The proposed computational model takes inspiration from specific structures of the insect brain: after proposing key hypotheses on the direct involvement of the mushroom bodies (MBs) and on their neural organization, we developed a new architecture for motor learning to be applied in insect-like walking robots. The proposed model is a nonlinear control system based on spiking neurons. MBs are modeled as a nonlinear recurrent spiking neural network (SNN) with novel characteristics, able to memorize time evolutions of key parameters of the neural motor controller, so that existing motor primitives can be improved...
2017: Frontiers in Neurorobotics
https://www.readbyqxmd.com/read/28336861/modified-continuum-mechanics-modeling-on-size-dependent-properties-of-piezoelectric-nanomaterials-a-review
#17
REVIEW
Zhi Yan, Liying Jiang
Piezoelectric nanomaterials (PNs) are attractive for applications including sensing, actuating, energy harvesting, among others in nano-electro-mechanical-systems (NEMS) because of their excellent electromechanical coupling, mechanical and physical properties. However, the properties of PNs do not coincide with their bulk counterparts and depend on the particular size. A large amount of efforts have been devoted to studying the size-dependent properties of PNs by using experimental characterization, atomistic simulation and continuum mechanics modeling with the consideration of the scale features of the nanomaterials...
January 26, 2017: Nanomaterials
https://www.readbyqxmd.com/read/28336538/effects-of-dobutamine-on-intestinal-microvascular-blood-flow-heterogeneity-and-oxygen-extraction-during-septic-shock
#18
Gustavo Adolfo Ospina-Tascón, Alberto Federico García Marín, Gabriel J Echeverri, William Fernando Bermúdez, Humberto José Madriñán Navia, Juan David Valencia, Edgardo Quiñones, Fernando Rodríguez, Angela Marulanda, César Augusto Arango Davila, Alejandro Bruhn, Glenn Hernández, Daniel De Backer
Derangements of microvascular blood flow distribution might contribute to disturbing oxygen extraction by peripheral tissues. We evaluated the dynamic relationships between the mesenteric oxygen extraction ratio (mes-ERO2) and the heterogeneity of microvascular blood flow at the gut and sublingual mucosa, during the development and resuscitation of septic shock in a swine model of fecal peritonitis. Jejunal-villi and sublingual microcirculation were evaluated using a portable intravital-microscopy technique...
March 23, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28336531/vasopressin-induced-serine-269-phosphorylation-reduces-sipa111-signal-induced-proliferation-associated-1-like-1-mediated-aquaporin-2-endocytosis
#19
Po-Jen Wang, Shu-Ting Lin, Shao-Hsuan Liu, Kuang-Ting Kuo, Chun-Hua Hsu, Mark A Knepper, Ming-Jiun Yu
The abundance of integral membrane proteins in the plasma membrane is determined by a dynamic balance between exocytosis and endocytosis, which can often be regulated by physiological stimuli. Here, we describe a mechanism that accounts for the ability of the peptide hormone vasopressin to regulate water excretion via a phosphorylation-dependent modulation of the PDZ domain-ligand interactions involving the water channel protein aquaporin-2. We discovered that the PDZ domain-containing protein Sipa1l1 (signal-induced proliferation-associated 1 like 1) binds to the cytoplasmic PDZ-ligand motif of aquaporin-2 and accelerates its endocytosis in the absence of vasopressin...
March 23, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28336062/integrated-strategies-to-gain-a-systems-level-view-of-dynamic-signaling-networks
#20
Robert H Newman, Jin Zhang
In order to survive and function properly in the face of an ever changing environment, cells must be able to sense changes in their surroundings and respond accordingly. Cells process information about their environment through complex signaling networks composed of many discrete signaling molecules. Individual pathways within these networks are often tightly integrated and highly dynamic, allowing cells to respond to a given stimulus (or, as is typically the case under physiological conditions, a combination of stimuli) in a specific and appropriate manner...
2017: Methods in Enzymology
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