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https://www.readbyqxmd.com/read/28231278/interplay-between-fungicides-and-parasites-tebuconazole-but-not-copper-suppresses-infection-in-a-daphnia-metschnikowia-experimental-model
#1
Ana P Cuco, Nelson Abrantes, Fernando Gonçalves, Justyna Wolinska, Bruno B Castro
Natural populations are commonly exposed to complex stress scenarios, including anthropogenic contamination and their biological enemies (e.g., parasites). The study of the pollutant-parasite interplay is especially important, given the need for adequate regulations to promote improved ecosystem protection. In this study, a host-parasite model system (Daphnia spp. and the microparasitic yeast Metschnikowia bicuspidata) was used to explore the reciprocal effects of contamination by common agrochemical fungicides (copper sulphate and tebuconazole) and parasite challenge...
2017: PloS One
https://www.readbyqxmd.com/read/28230845/dynamic-models-of-large-scale-brain-activity
#2
REVIEW
Michael Breakspear
Movement, cognition and perception arise from the collective activity of neurons within cortical circuits and across large-scale systems of the brain. While the causes of single neuron spikes have been understood for decades, the processes that support collective neural behavior in large-scale cortical systems are less clear and have been at times the subject of contention. Modeling large-scale brain activity with nonlinear dynamical systems theory allows the integration of experimental data from multiple modalities into a common framework that facilitates prediction, testing and possible refutation...
February 23, 2017: Nature Neuroscience
https://www.readbyqxmd.com/read/28230844/network-neuroscience
#3
REVIEW
Danielle S Bassett, Olaf Sporns
Despite substantial recent progress, our understanding of the principles and mechanisms underlying complex brain function and cognition remains incomplete. Network neuroscience proposes to tackle these enduring challenges. Approaching brain structure and function from an explicitly integrative perspective, network neuroscience pursues new ways to map, record, analyze and model the elements and interactions of neurobiological systems. Two parallel trends drive the approach: the availability of new empirical tools to create comprehensive maps and record dynamic patterns among molecules, neurons, brain areas and social systems; and the theoretical framework and computational tools of modern network science...
February 23, 2017: Nature Neuroscience
https://www.readbyqxmd.com/read/28230793/dynamic-fluid-in-a-porous-transducer-based-angular-accelerometer
#4
Siyuan Cheng, Mengyin Fu, Meiling Wang, Li Ming, Huijin Fu, Tonglei Wang
This paper presents a theoretical model of the dynamics of liquid flow in an angular accelerometer comprising a porous transducer in a circular tube of liquid. Wave speed and dynamic permeability of the transducer are considered to describe the relation between angular acceleration and the differential pressure on the transducer. The permeability and streaming potential coupling coefficient of the transducer are determined in the experiments, and special prototypes are utilized to validate the theoretical model in both the frequency and time domains...
February 21, 2017: Sensors
https://www.readbyqxmd.com/read/28230725/towards-a-semantic-web-of-things-a-hybrid-semantic-annotation-extraction-and-reasoning-framework-for-cyber-physical-system
#5
Zhenyu Wu, Yuan Xu, Yunong Yang, Chunhong Zhang, Xinning Zhu, Yang Ji
Web of Things (WoT) facilitates the discovery and interoperability of Internet of Things (IoT) devices in a cyber-physical system (CPS). Moreover, a uniform knowledge representation of physical resources is quite necessary for further composition, collaboration, and decision-making process in CPS. Though several efforts have integrated semantics with WoT, such as knowledge engineering methods based on semantic sensor networks (SSN), it still could not represent the complex relationships between devices when dynamic composition and collaboration occur, and it totally depends on manual construction of a knowledge base with low scalability...
February 20, 2017: Sensors
https://www.readbyqxmd.com/read/28230525/inference-and-forecast-of-h7n9-influenza-in-china-2013-to-2015
#6
Ruiyun Li, Yuqi Bai, Alex Heaney, Sasikiran Kandula, Jun Cai, Xuyi Zhao, Bing Xu, Jeffrey Shaman
The recent emergence of A(H7N9) avian influenza poses a significant challenge to public health in China and around the world; however, understanding of the transmission dynamics and progression of influenza A(H7N9) infection in domestic poultry, as well as spillover transmission to humans, remains limited. Here, we develop a mathematical model-Bayesian inference system which combines a simple epidemic model and data assimilation method, and use it in conjunction with data on observed human influenza A(H7N9) cases from 19 February 2013 to 19 September 2015 to estimate key epidemiological parameters and to forecast infection in both poultry and humans...
February 16, 2017: Euro Surveillance: Bulletin Européen sur les Maladies Transmissibles, European Communicable Disease Bulletin
https://www.readbyqxmd.com/read/28230285/modeling-lung-surfactant-interactions-with-benzo-a-pyrene
#7
Jacek Korchowiec, Anna Stachowicz-Kusnierz, Sonia Trojan, Lukasz Cwiklik, Beata Korchowiec
By reducing surface tension of the air-water interface in alveoli, lung surfactant (LS) is crucial for proper functioning of the lungs. It also forms the first barrier against inhaled pathogens. In this study we inspect the interactions of LS models with a dangerous air pollutant, benzo[a]pyrene (BaP). DPPC, POPC and their 1:1 mixture are used as LS models. Pressure-area isotherms are employed to study macroscopic properties of the monolayers. We find that addition of BaP has a condensing effect, manifested by lowering the values of surface pressure and shifting the isotherms to smaller areas...
February 23, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28230239/common-evolutionary-trends-underlie-the-four-bar-linkage-systems-of-sunfish-and-mantis-shrimp
#8
Yinan Hu, Nathan Nelson-Maney, Philip S L Anderson
Comparative biomechanics offers an opportunity to explore the evolution of disparate biological systems that share common underlying mechanics. Four-bar linkage modelling has been applied to various biological systems such as fish jaws and crustacean appendages to explore the relationship between biomechanics and evolutionary diversification. Mechanical sensitivity states that the functional output of a mechanical system will show differential sensitivity to changes in specific morphological components. We document similar patterns of mechanical sensitivity in two disparate four-bar systems from different phyla: the opercular four-bar system in centrarchid fishes and the raptorial appendage of stomatopods...
February 23, 2017: Evolution; International Journal of Organic Evolution
https://www.readbyqxmd.com/read/28230127/theory-of-chaotic-orbital-variations-confirmed-by-cretaceous-geological-evidence
#9
Chao Ma, Stephen R Meyers, Bradley B Sageman
Variations in the Earth's orbit and spin vector are a primary control on insolation and climate; their recognition in the geological record has revolutionized our understanding of palaeoclimate dynamics, and has catalysed improvements in the accuracy and precision of the geological timescale. Yet the secular evolution of the planetary orbits beyond 50 million years ago remains highly uncertain, and the chaotic dynamical nature of the Solar System predicted by theoretical models has yet to be rigorously confirmed by well constrained (radioisotopically calibrated and anchored) geological data...
February 22, 2017: Nature
https://www.readbyqxmd.com/read/28228754/proofreading-of-peptide-mhc-complexes-through-dynamic-multivalent-interactions
#10
REVIEW
Christoph Thomas, Robert Tampé
The adaptive immune system is able to detect and destroy cells that are malignantly transformed or infected by intracellular pathogens. Specific immune responses against these cells are elicited by antigenic peptides that are presented on major histocompatibility complex class I (MHC I) molecules and recognized by cytotoxic T lymphocytes at the cell surface. Since these MHC I-presented peptides are generated in the cytosol by proteasomal protein degradation, they can be metaphorically described as a window providing immune cells with insights into the state of the cellular proteome...
2017: Frontiers in Immunology
https://www.readbyqxmd.com/read/28228546/a-minimal-actomyosin-based-model-predicts-the-dynamics-of-filopodia-on-neuronal-dendrites
#11
Olena O Marchenko, Sulagna Das, Ji Yu, Igor L Novak, Vladimir I Rodionov, Nadia Efimova, Tatyana Svitkina, Charles W Wolgemuth, Leslie M Loew
Dendritic filopodia are actin-filled dynamic subcellular structures that sprout on neuronal dendrites during neurogenesis. The exploratory motion of the filopodia is crucial for synaptogenesis but the underlying mechanisms are poorly understood. To study the filopodial motility, we collected and analyzed image data on filopodia in cultured rat hippocampal neurons. We hypothesized that mechanical feedback among the actin retrograde flow, myosin activity and substrate adhesion gives rise to various filopodial behaviors...
February 22, 2017: Molecular Biology of the Cell
https://www.readbyqxmd.com/read/28228022/electron-nuclear-wave-packet-dynamics-through-a-conical-intersection
#12
Kilian Hader, Julian Albert, E K U Gross, Volker Engel
We investigate the coupled electron-nuclear dynamics in a model system showing a conical intersection (CoIn) between two excited state potential energy surfaces. Within the model, a single electron and nucleus move in two dimensions in an external static field. It is demonstrated that the nuclear density conserves its initial Gaussian shape when directly passing the CoIn, whereas the electronic density remains approximately constant. This is in sharp contrast to the picture which evolves from an analysis within the basis of adiabatic electronic states...
February 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28227964/cross-entropy-optimization-for-neuromodulation
#13
Harleen K Brar, Yunpeng Pan, Babak Mahmoudi, Evangelos A Theodorou, Harleen K Brar, Yunpeng Pan, Babak Mahmoudi, Evangelos A Theodorou, Yunpeng Pan, Harleen K Brar, Babak Mahmoudi, Evangelos A Theodorou
This study presents a reinforcement learning approach for the optimization of the proportional-integral gains of the feedback controller represented in a computational model of epilepsy. The chaotic oscillator model provides a feedback control systems view of the dynamics of an epileptic brain with an internal feedback controller representative of the natural seizure suppression mechanism within the brain circuitry. Normal and pathological brain activity is simulated in this model by adjusting the feedback gain values of the internal controller...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227890/in-vitro-identification-of-shoulder-joint-and-muscle-dynamics-based-on-motion-capture-and-musculoskeletal-computation
#14
Akihiko Murai, Yusuke Kawano, Ko Ayusawa, Mitsunori Tada, Noboru Matsumura, Takeo Nagura, Akihiko Murai, Yusuke Kawano, Ko Ayusawa, Mitsunori Tada, Noboru Matsumura, Takeo Nagura
Dynamics properties of shoulder joint and muscle are experimentally identified under different musculoskeletal conditions for a digital human model with accurate dynamics. Passive swing motions of scapula and upper limb bones in cadaveric specimen with and without muscles are measured by an optical motion capture system. External forces that are applied to the scapula bone are simultaneously measured by a force plate. The dynamics identification process consists of 3 steps: 1) identify the inertial parameters of the cadaveric specimen with and without muscles respectively, 2) identify the viscosity of the glenohumeral joint from the specimen without muscles, and 3) identify the viscosity of the shoulder muscles from the specimen with muscles and the identified joint viscosity...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227778/hybrid-automata-models-of-cardiac-ventricular-electrophysiology-for-real-time-computational-applications
#15
Sidharta Andalam, Harshavardhan Ramanna, Avinash Malik, Parthasarathi Roop, Nitish Patel, Mark L Trew, Sidharta Andalam, Harshavardhan Ramanna, Avinash Malik, Parthasarathi Roop, Nitish Patel, Mark L Trew, Nitish Patel, Avinash Malik, Parthasarathi Roop, Harshavardhan Ramanna, Mark L Trew, Sidharta Andalam
Virtual heart models have been proposed for closed loop validation of safety-critical embedded medical devices, such as pacemakers. These models must react in real-time to off-the-shelf medical devices. Real-time performance can be obtained by implementing models in computer hardware, and methods of compiling classes of Hybrid Automata (HA) onto FPGA have been developed. Models of ventricular cardiac cell electrophysiology have been described using HA which capture the complex nonlinear behavior of biological systems...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227773/whole-heart-modeling-spatiotemporal-dynamics-of-electrical-wave-conduction-and-propagation
#16
Hui Yang, Yun Chen, Fabio M Leonelli, Hui Yang, Yun Chen, Fabio M Leonelli, Hui Yang, Fabio M Leonelli, Yun Chen
Cardiac electrical activities are varying in both space and time. Human heart consists of a fractal network of muscle cells, Purkinje fibers, arteries and veins. Whole-heart modeling of electrical wave conduction and propagation involves a greater level of complexity. Our previous work developed a computer model of the anatomically realistic heart and simulated the electrical conduction with the use of cellular automata. However, simplistic assumptions and rules limit its ability to provide an accurate approximation of real-world dynamics on the complex heart surface, due to sensitive dependence of nonlinear dynamical systems on initial conditions...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227754/brain-heart-linear-and-nonlinear-dynamics-during-visual-emotional-elicitation-in-healthy-subjects
#17
G Valenza, A Greco, C Gentili, A Lanata, N Toschi, R Barbieri, L Sebastiani, D Menicucci, A Gemignani, E P Scilingo, G Valenza, A Greco, C Gentili, A Lanata, N Toschi, R Barbieri, L Sebastiani, D Menicucci, A Gemignani, E P Scilingo, A Lanata, A Gemignani, E P Scilingo, A Greco, D Menicucci, L Sebastiani, C Gentili, N Toschi, R Barbieri, G Valenza
This study investigates brain-heart dynamics during visual emotional elicitation in healthy subjects through linear and nonlinear coupling measures of EEG spectrogram and instantaneous heart rate estimates. To this extent, affective pictures including different combinations of arousal and valence levels, gathered from the International Affective Picture System, were administered to twenty-two healthy subjects. Time-varying maps of cortical activation were obtained through EEG spectral analysis, whereas the associated instantaneous heartbeat dynamics was estimated using inhomogeneous point-process linear models...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227752/multiscale-analysis-of-information-dynamics-for-linear-multivariate-processes
#18
Luca Faes, Alessandro Montalto, Sebastiano Stramaglia, Giandomenico Nollo, Daniele Marinazzo, Luca Faes, Alessandro Montalto, Sebastiano Stramaglia, Giandomenico Nollo, Daniele Marinazzo, Alessandro Montalto, Luca Faes, Sebastiano Stramaglia, Giandomenico Nollo, Daniele Marinazzo
In the study of complex physical and physiological systems represented by multivariate time series, an issue of great interest is the description of the system dynamics over a range of different temporal scales. While information-theoretic approaches to the multiscale analysis of complex dynamics are being increasingly used, the theoretical properties of the applied measures are poorly understood. This study introduces for the first time a framework for the analytical computation of information dynamics for linear multivariate stochastic processes explored at different time scales...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227357/experimental-evaluation-of-the-accuracy-at-the-c-arm-pose-estimation-with-x-ray-images
#19
Sabine Thurauf, Florian Vogt, Oliver Hornung, Mario Korner, M Ali Nasseri, Alois Knoll, Sabine Thurauf, Florian Vogt, Oliver Hornung, Mario Korner, M Ali Nasseri, Alois Knoll, Sabine Thurauf, Alois Knoll, Mario Korner, Florian Vogt, Oliver Hornung, M Ali Nasseri
C-arm X-ray systems need a high spatial accuracy for applications like cone beam computed tomography and 2D/3D overlay. One way to achieve the needed precision is a model-based calibration of the C-arm system. For such a calibration a kinematic and dynamic model of the system is constructed whose parameters are computed by pose measurements of the C-arm. Instead of common measurement systems used for a model-based calibration for robots like laser trackers, we use X-ray images of a calibration phantom to measure the C-arm pose...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227209/high-speed-in-vivo-imaging-of-retinal-hemodynamics-in-a-rodent-model-of-hypertension
#20
Mahdieh Rezaeian, Dana Georgevsky, S Mojtaba Golzan, Stuart L Graham, Mahdieh Rezaeian, Dana Georgevsky, S Mojtaba Golzan, Stuart L Graham, Dana Georgevsky, Mahdieh Rezaeian, S Mojtaba Golzan, Stuart L Graham
The eye is the only organ through which microcirculation can be visualized non-invasively. This unique feature makes the eye and specifically retinal vasculature an excellent target area to monitor and study micro-vascular damage in systemic diseases. Dynamic (real-time) changes of retinal vessels have been shown to be more specific to the disease in comparison with static measurements. In this study we utilize high speed imaging (i.e. 125 fps) to study and derive dynamic changes of retinal vessels in a rat model of hypertension...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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