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1
Salinas, Nelson R., und Damon P. Little. „Electric LAMP: Virtual Loop-Mediated Isothermal AMPlification“. ISRN Bioinformatics 2012 (21.11.2012): 1–5. http://dx.doi.org/10.5402/2012/696758.
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We present eLAMP, a PERL script, with Tk graphical interface, that electronically simulates Loop-mediated AMPlification (LAMP) allowing users to efficiently test putative LAMP primers on a set of target sequences. eLAMP can match primers to templates using either exact (via builtin PERL regular expressions) or approximate matching (via the tre-agrep library). Performance was tested on 40 whole genome sequences of Staphylococcus. eLAMP correctly predicted that the two tested primer sets would amplify from S. aureus genomes and not amplify from other Staphylococcus species. Open source (GNU Public License) PERL scripts are available for download from the New York Botanical Garden's website.
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Clamann, Michael, und David B. Kaber. „Augmenting Fine Motor Skill Training with Haptic Error Amplification“. Proceedings of the Human Factors and Ergonomics Society Annual Meeting 62, Nr. 1 (September 2018): 1547–51. http://dx.doi.org/10.1177/1541931218621350.
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This work compared two methods to augment fine motor skill training using haptic control, including techniques that guide (e.g., virtual fixtures) and challenge the trainee (e.g., error amplification). A prototype system capable of displaying virtual fixtures or error amplification during a writing task was evaluated to determine the extent to which performance in each condition transfers to an unassisted test condition. An experiment comparing training effects was executed in which participants were trained to draw a series of letters from a foreign alphabet with the non-dominant hand. The results showed that task accuracy when training with virtual fixtures did not transfer to an unassisted test condition. Training with error amplification, in contrast, increased accuracy in unaided test trials. These findings suggest that amplifying errors may be used to accelerate fine motor training for unimpaired individuals.
3
Day, Charles. „Yoking real and virtual cells confirms theory of cochlear amplification“. Physics Today 63, Nr. 6 (Juni 2010): 13–15. http://dx.doi.org/10.1063/1.3455242.
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Workman, Michael. „Virtual team culture and the amplification of team boundary permeability on performance“. Human Resource Development Quarterly 16, Nr. 4 (2005): 435–58. http://dx.doi.org/10.1002/hrdq.1149.
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5
Liebhaber, Frank B., Matti Lehtimäki und Klaus Willeke. „Low-Cost Virtual Impactor for Large-Particle Amplification in Optical Particle Counters“. Aerosol Science and Technology 15, Nr. 3 (Januar 1991): 208–13. http://dx.doi.org/10.1080/02786829108959528.
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Berrocal, José Augusto, Marko M. L. Nieuwenhuizen, Luigi Mandolini, E. W. Meijer und Stefano Di Stefano. „Copper(i)-induced amplification of a [2]catenane in a virtual dynamic library of macrocyclic alkenes“. Org. Biomol. Chem. 12, Nr. 32 (2014): 6167–74. http://dx.doi.org/10.1039/c4ob01009d.
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Li, Ping. „Electronic Circuit Teaching Aided by MultiSim Virtual Simulation Software“. Advanced Materials Research 933 (Mai 2014): 703–7. http://dx.doi.org/10.4028/www.scientific.net/amr.933.703.
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MultiSim is a famous electronic designed automation software, which is widely used in circuit teaching, circuit design and SPICE simulation. In this paper, the MultiSim software is introduced into electronic circuit teaching, the three-section teaching pattern and six-step teaching process are proposed, meanwhile, the teaching design examples of three-level amplification circuit and its frequency characteristic analysis are also demonstrated. The research results show the advantages of MultiSim virtual simulation software are to build a learning platform to explore, resolve the difficulty of teaching, and promote students thinking. MultiSim virtual simulation software is a carrier of learning for students, it is the source of the question, it is an effective tool for improving students learning enthusiasm and initiative.
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Kullmann, Paul H. M., Kristine M. Sikora, K. Lyles Clark, Irene Arduini, Mitchell G. Springer und John P. Horn. „HCN hyperpolarization-activated cation channels strengthen virtual nicotinic EPSPs and thereby elevate synaptic amplification in rat sympathetic neurons“. Journal of Neurophysiology 116, Nr. 2 (01.08.2016): 438–47. http://dx.doi.org/10.1152/jn.00223.2016.
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The influence of hyperpolarization-activated cation current (h-current; Ih) upon synaptic integration in paravertebral sympathetic neurons was studied together with expression of hyperpolarization-activated cyclic nucleotide-gated (HCN) subunit isoforms. All four HCN subunits were detected in homogenates of the rat superior cervical ganglion (SCG) using the PCR to amplify reverse-transcribed messenger RNAs (RT-PCR) and using quantitative PCR. Voltage clamp recordings from dissociated SCG neurons at 35°C detected Ih in all cells, with a maximum hyperpolarization-activated cation conductance of 1.2 ± 0.1 nS, half-maximal activation at −87.6 mV, and reversal potential of −31.6 mV. Interaction between Ih and synaptic potentials was tested with virtual fast nicotinic excitatory postsynaptic potentials (EPSPs) created with dynamic clamp. The blocking of Ih with 15 μM ZD7288 hyperpolarized cells by 4.7 mV and increased the virtual synaptic conductance required to stimulate an action potential from 7.0 ± 0.9 nS to 12.1 ± 0.9 nS. In response to stimulation with 40 s long trains of virtual EPSPs, ZD7288 reduced postsynaptic firing from 2.2 to 1.7 Hz and the associated synaptic amplification from 2.2 ± 0.1 to 1.7 ± 0.2. Cyclic nucleotide binding to HCN channels was simulated by blocking native Ih with ZD7288, followed by reconstitution with virtual Ih using a dynamic clamp model of the voltage clamp data. Over a 30-mV range, shifting the half-activation voltage for Ih in 10 mV depolarizing increments always increased synaptic gain. These results indicate that Ih, in sympathetic neurons, can strengthen nicotinic EPSPs and increase synaptic amplification, while also working as a substrate for cyclic nucleotide-dependent modulation.
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Moran, Linda. „Invited reaction: Virtual team culture and the amplification of team boundary permeability on performance“. Human Resource Development Quarterly 16, Nr. 4 (2005): 459–63. http://dx.doi.org/10.1002/hrdq.1150.
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Niu, Jun Hao, und Zhi Li. „Research on Portable Virtual Oscilloscope Based on USB Bus“. Advanced Materials Research 459 (Januar 2012): 114–17. http://dx.doi.org/10.4028/www.scientific.net/amr.459.114.
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A designed method of portable virtual oscilloscope with USB interface is proposed in this paper. The programmable gain amplifier (attenuator) circuit is used to adjust the different range of inputting signal to the A/D converter's. The A/D convert is realized by using ADS830E, which is a chip with maxim 60MHz sample rate and 8-bit data width. CY7C68013A, one chip of EZ-USB FX2 series, is used to achieve the data transfer to computer in block mode. The FPGA is programmed as an external host controller to control the gain amplification and attenuation circuit, and provide the sample clock for high-speed A/D converter ADS830E, and send the data to the Slave-FIFO. Application software is designed with VC++ platform to calculate and display the received data graphically.
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Nie, Cheng, Yue Wang, Wanjun Lei, Tian Li und Shiyuan Yin. „Modeling and Enhanced Error-Free Current Control Strategy for Inverter with Virtual Resistor Damping“. Energies 11, Nr. 10 (20.09.2018): 2499. http://dx.doi.org/10.3390/en11102499.
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In microgrid, the grid-connected inverter current with the LCL (inductor-capacitor-inductor) output filter is amplified at certain frequencies. Using virtual resistor damping method can help suppress the amplification. By choosing an appropriate virtual resistor value, the model of the inverter current control loop is simplified as a 2nd-order lowpass filter. Based on such simplified model, this paper proposes a design method of reference current compensation controller, which does not require decomposition of harmonic components. With the reference compensation, the inverter output current control precision is improved obviously. The simulation and experimental results verify the accuracy of the inverter simplified model and effectiveness of the reference compensation design method.
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Morley, David. „In a Viral Conjuncture“. Cultural Politics 17, Nr. 1 (01.03.2021): 17–27. http://dx.doi.org/10.1215/17432197-8797473.
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Abstract This article offers a conjunctural analysis of the various factors that must be taken into account to explain the development of the COVID-19 pandemic. It offers an interdisciplinary perspective on questions of how virtual and material geographies are enmeshed, paying particular attention to the continuing importance of transport infrastructures. The key concerns are with the politics of differential power over—and access to—mobility, in both its actual and virtual modalities. The COVID-19 crisis is argued to have functioned both as a mode of amplification of many preexisting forms of inequality and as a powerful solvent of the unexamined presumptions of the dominant discourse of globalization.
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Kim, Hyun-Jung, Young Sam Yoo, Kyeongmee Park, Ji-Eun Kwon, Jung Yeon Kim und Federico A. Monzon. „Genomic Aberrations in Salivary Duct Carcinoma Arising in Warthin Tumor of Parotid Gland: DNA Microarray and HER2 Fluorescence In Situ Hybridization“. Archives of Pathology & Laboratory Medicine 135, Nr. 9 (01.09.2011): 1088–91. http://dx.doi.org/10.5858/2010-0428-crr1.1.
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Carcinoma arising from Warthin tumor is extremely rare. A 79-year-old man was admitted for a firm, well-defined, 5-cm left infra-auricular mass. Aspiration cytology showed many lymphohistiocytes and oncocytes in a proteinaceous background, compatible with Warthin tumor. A left superficial parotidectomy showed a solid mass around the cyst wall. The tumor cells of the solid area were arranged as infiltrative ducts with a few foci of malignant transformation. Virtual karyotyping disclosed a complex pattern of genetic aberrations with a focal amplification in 12q14–q21.2. This chromosomal region contains the MDM2 (murine double minute) gene, which regulates p53 inactivation. HER2 fluorescence in situ hybridization showed a focal amplification. Subsequently, the patient underwent total parotidectomy and ipsilateral neck dissection for a recurrence. To our knowledge, this is the first case of salivary duct carcinoma arising from Warthin tumor. The essential molecular pathway has not been reported, we presume an important role of MDM2 amplification–P53 inactivation.
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Workman, Michael. „Rash impulsivity, vengefulness, virtual-self and amplification of ethical relativism on cyber-smearing against corporations“. Computers in Human Behavior 28, Nr. 1 (Januar 2012): 217–25. http://dx.doi.org/10.1016/j.chb.2011.09.003.
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Kim, Wonhee, Chang Mook Kang, Young Seop Son und Chung Choo Chung. „Nonlinear Backstepping Control Design for Coupled Nonlinear Systems under External Disturbances“. Complexity 2019 (07.02.2019): 1–13. http://dx.doi.org/10.1155/2019/7941302.
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A nonlinear backstepping control is proposed for the coupled normal form of nonlinear systems. The proposed method is designed by combining the sliding-mode control and backstepping control with a disturbance observer (DOB). The key idea behind the proposed method is that the linear terms of state variables of the second subsystem are lumped into the virtual input in the first subsystem. A DOB is developed to estimate the external disturbances. Auxiliary state variables are used to avoid amplification of the measurement noise in the DOB. For output tracking and unmatched disturbance cancellation in the first subsystem, the desired virtual input is derived via the backstepping procedure. The actual input in the second subsystem is developed to guarantee the convergence of the virtual input to the desired virtual input by using a sliding-mode control. The stability of the closed-loop is verified by using the input-to-state stable (ISS) property. The performance of the proposed method is validated via numerical simulations and an application to a vehicle system based on CarSim platform.
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Li, Gaixin. „Optimization and Simulation of Virtual Experiment System of Human Sports Science Based on VR“. Complexity 2021 (31.05.2021): 1–10. http://dx.doi.org/10.1155/2021/3872881.
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Virtual reality technology is an emerging technology developed on the basis of information technology. It is widely used in military, medical, mining, entertainment, and other fields. Therefore, many countries have been vigorously conducting research in recent years. As one of the important components of the virtual reality system, the three-dimensional human motion tracking system is of great significance to the research of practical virtual reality systems. It introduces the measurement principle of the spatial three-dimensional coordinate dynamic measurement device and discusses in detail the ultrasonic transmission, reception, amplification, filtering, comparison, shaping circuit, and single-chip interface circuit. This paper introduces the working principle and characteristics of the virtual experiment system and gives the structure diagram, hardware schematic diagram, and software flow diagram of the system. We mainly study the method of tracking human motion by measuring the three-dimensional coordinates of the space point, which lays a good foundation for the research of the actual three-dimensional motion tracking system. At the same time, the three-dimensional human body modeling is discussed, and the interactive movement policy of the human arm is briefly introduced. It has a certain effect on the actual virtual reality human-computer interaction system.
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Jay, Caroline, und Roger Hubbold. „Amplifying Head Movements with Head-Mounted Displays“. Presence: Teleoperators and Virtual Environments 12, Nr. 3 (Juni 2003): 268–76. http://dx.doi.org/10.1162/105474603765879521.
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The head-mounted display (HMD) is a popular form of virtual display due to its ability to immerse users visually in virtual environments (VEs). Unfortunately, the user's virtual experience is compromised by the narrow field of view (FOV) it affords, which is less than half that of normal human vision. This paper explores a solution to some of the problems caused by the narrow FOV by amplifying the head movement made by the user when wearing an HMD, so that the view direction changes by a greater amount in the virtual world than it does in the real world. Tests conducted on the technique show a significant improvement in performance on a visual search task, and questionnaire data indicate that the altered visual parameters that the user receives may be preferable to those in the baseline condition in which amplification of movement was not implemented. The tests also show that the user cannot interact normally with the VE if corresponding body movements are not amplified to the same degree as head movements, which may limit the implementation's versatility. Although not suitable for every application, the technique shows promise, and alterations to aspects of the implementation could extend its use in the future.
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HOLLOWOOD, TIMOTHY J., und GRAHAM M. SHORE. „THE UNBEARABLE BEINGNESS OF LIGHT — Dressingand Undressing Photonsin Black Hole Spacetimes“. International Journal of Modern Physics D 21, Nr. 11 (Oktober 2012): 1241003. http://dx.doi.org/10.1142/s0218271812410039.
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Gravitational tidal forces acting on the virtual e+e- cloud surrounding a photon endow spacetime with a nontrivial refractive index. This has remarkable properties unique to gravitational theories including superluminal low-frequency propagation, in apparent violation of causality, and amplification of the renormalized photon field, in apparent violation of unitarity. Using the geometry of null congruences and the Penrose limit, we illustrate these phenomena and their resolution by tracing the history of a photon as it falls into the near-singularity region of a black hole.
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Papoutsi, Chara, Athanasios Drigas und Charalabos Skianis. „Virtual and Augmented Reality for Developing Emotional Intelligence Skills“. International Journal of Recent Contributions from Engineering, Science & IT (iJES) 9, Nr. 3 (27.09.2021): 35. http://dx.doi.org/10.3991/ijes.v9i3.23939.
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<p>The development and the cultivation of emotional intelligence and of the skills it can offer to the individual are the main elements and pursuits of contemporary research. The enhancement of self-control, the reinforcement of self-criticism and self-awareness and the cultivation of the constant self-development are the most central objectives of all the people and of the scientists since they are the cornerstone for euphoria. The aim of the present study is the review and the critical reproduction of information and conclusions that have been extracted from the international bibliography regarding the issue in question. More specifically, there will be an effort to evaluate and present the significance of the activities of virtual reality and of augmented reality that contribute to the development of emotional intelligence skills. Along the same lines, there will be an important review of the articles that refer to the exploitation of such digital tools, to achieve the same results for the people suffering from autism as well. Besides, the care for all the members of the society with no exceptions, and certainly of those members that suffer from mental retardation, should be of upmost importance. The present article focuses on the role that those tools play for the amplification of the skills in the sphere of emotional intelligence not only as far as the duration of the research is concerned.</p>
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Sturm, Damion. „Fans as e-participants? Utopia/dystopia visions for the future of digital sport fandom“. Convergence: The International Journal of Research into New Media Technologies 26, Nr. 4 (25.02.2020): 841–56. http://dx.doi.org/10.1177/1354856520907096.
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Media technologies and digital practices are reshaping and redefining the future of sport fandom. This article points to some of the utopian and dystopic transformations for fandom presented by (post)television, digital/social media and the anticipated virtual technologies of the future. Specifically, three distinct phases of fan participation are charted around existing and futuristic visions of technology-as-sport. First are the current televisual technologies that attempt to engage and retain traditionally “passive” viewers as spectators through pseudo-participatory perspectives that will carry over to new screens and technologies. Second, the assumed interactive participation afforded by social and digital media is considered, positing the future amplification of connectivity, personalisation and networking across digital fan communities, albeit undercut by further impositions of corporatisation and datafication through illusory forms of “interactivity”. Finally, the fusion, intensification and continual evolution of technology-as-sport is explored, asserting that forms of immersive participation will be significant for future virtual technologies and may ultimately re-position fans as e-participants in their own media-tech sport spectacles. Collectively, it is anticipated that the creation of new virtual worlds, spaces and experiences will amplify and operationalise forms of immersive participation around augmented spectatorship, virtual athletic replication and potentially constitute the sport itself. Indeed, a new model of the fan-as-immersed-e-participant is advanced as such futuristic virtual sporting realms may not only integrate fans into the spectacle but also project them into the event as participant and as the spectacle.
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Fukuwa, Nobuo, Takashi Hirai, Jun Tobita und Kazumi Kurata. „Dynamic Response of Tall Buildings on Sedimentary Basin to Long-Period Seismic Ground Motion“. Journal of Disaster Research 11, Nr. 5 (01.10.2016): 857–69. http://dx.doi.org/10.20965/jdr.2016.p0857.
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Characteristics of long-period seismic ground motion and response of tall buildings are investigated in this paper to promote earthquake proof countermeasures considering the damage caused by the 2011 Tohoku earthquake. 3D finite difference method and the reciprocal theorem are used to examine the effect of sedimentary basin structures on seismic wave amplification. Natural period and damping of tall buildings are evaluated by ambient vibration tests and earthquake response observation during construction or demolition of the buildings. The effects of dynamic soil-structure interaction on response amplification of tall buildings are confirmed applying wave propagation theory to a continuum building model. Finally, a newly built base-isolated building with an isolated rooftop laboratory is introduced for full-scale long-period shaking experiment by installing actuators and jacks. Experience of long-period shaking in the building is also available with virtual reality view of indoor damage, which is effective for promotion of seismic countermeasures such as fixing furniture and safe evacuation.
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Baloi, Alexandru, und Adrian Pana. „Software Solutions for Harmonic Conditions Monitoring and Optimal Placing of Reactive Power Sources in Distributions Networks“. Advanced Engineering Forum 8-9 (Juni 2013): 77–84. http://dx.doi.org/10.4028/www.scientific.net/aef.8-9.77.
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Power factor correction in electrical distribution networks can lead to harmonic risk increase. The paper presents a method to anticipate the amplification of network harmonic conditions based on the equivalent network harmonic impedance which can be monitored using virtual instruments. Based on the values of the harmonic impedance and the required reactive power, a mathematical model is implemented through an algorithm and software classes are developed for the solution regarding the type of the reactive power sources (capacitor banks or filters) and the place where it will be installed.
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Kullmann, Paul H. M., und John P. Horn. „Excitatory Muscarinic Modulation Strengthens Virtual Nicotinic Synapses on Sympathetic Neurons and Thereby Enhances Synaptic Gain“. Journal of Neurophysiology 96, Nr. 6 (Dezember 2006): 3104–13. http://dx.doi.org/10.1152/jn.00589.2006.
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Acetylcholine excites many neuronal types by binding to postsynaptic m1-muscarinic receptors that signal to ion channels through the Gq/11 protein. To investigate the functional significance of this metabotropic pathway in sympathetic ganglia, we studied how muscarinic excitation modulated the integration of virtual nicotinic excitatory postsynaptic potentials (EPSPs) created in dissociated bullfrog B-type sympathetic neurons with the dynamic-clamp technique. Muscarine (1 μM) strengthened the impact of virtual synapses by reducing the artificial nicotinic conductance required to reach the postsynaptic firing threshold from 20.9 ± 5.4 to 13.1 ± 3.1 nS. Consequently, postganglionic action potential output increased by 4–215% when driven by different patterns of virtual presynaptic activity that were chosen to reflect the range of physiological firing rates and convergence levels seen in amphibian and mammalian sympathetic ganglia. In addition to inhibiting the M-type K+ conductance, muscarine activated a leak conductance in three of 37 cells. When this leak conductance was reproduced with the dynamic clamp, it also acted to strengthen virtual nicotinic synapses and enhance postganglionic spike output. Combining pharmacological M-conductance suppression with virtual leak activation, at resting potentials between −50 and −55 mV, produced synergistic strengthening of nicotinic synapses and an increase in the integrated postganglionic spike output. Together, these results reveal how muscarinic activation of a branched metabotropic pathway can enhance integration of fast EPSPs by modulating their effective strength. The results also support the hypothesis that muscarinic synapses permit faster and more accurate feedback control of autonomic behaviors by generating gain through synaptic amplification in sympathetic ganglia.
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Li, Fei, Yang Liu, Ke Xu, Mingyao Ma, Xing Zhang und Lingxiang Wang. „A virtual resistor design method based on voltage harmonic amplification factor for active damper used in DFIG system“. Energy Reports 6 (Dezember 2020): 572–79. http://dx.doi.org/10.1016/j.egyr.2020.11.187.
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Faenov, A. Ya, T. A. Pikuz, S. A. Magnitskiy, N. Nagorskiy, M. Tanaka, M. Ishino, M. Nishikino et al. „X-ray coherent mirage: Generation of phase – matched coherent point source in plasma media by propagated X-ray laser seeded beam“. Laser and Particle Beams 34, Nr. 3 (30.05.2016): 402–11. http://dx.doi.org/10.1017/s0263034616000288.
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AbstractThe overview of the recent results for discovery and investigations of a very exotic phenomenon – optical mirage in the X-ray spectral range – is presented. It was found that the mirage could be created in the form of coherent virtual point source, emerging in the vicinity of the second plasma in two-stage oscillator-amplifier X-ray laser. The X-ray source-mirage, rigidly phased with the initial radiation of generator, occurs only when amplification takes place in the amplifier plasma and leads to the appearance of the interference pattern in the form of concentric rings in the spatial profile of the output X-ray laser beam. The equation describing the emergence of X-ray mirage was found, numerical solution of which shows that its formation is similar to that of the optical mirages observed at propagation of light rays through an inhomogeneously heated air. Obtained results have already demonstrated novel comprehension into the physical nature of amplification of X-ray radiation, opening additional opportunities for X-ray interferometry, holography, and other applications, which require multiple rigidly phased sources of coherent radiation.
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Greenhalgh, Chris, und Steve Benford. „Supporting Rich And Dynamic Communication In Large-Scale Collaborative Virtual Environments“. Presence: Teleoperators and Virtual Environments 8, Nr. 1 (Februar 1999): 14–35. http://dx.doi.org/10.1162/105474699566026.
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We focus on the problem of constructing collaborative virtual environments (CVEs) that scale to large numbers of simultaneous participants and yet which still afford rich and varied possibilities for communication. This is achieved by extending our previously defined spatial model of interaction for CVEs to include third-party objects that provide support for contextual factors in awareness calculations and that enhance scaleability. Third parties can have two effects on awareness: attenuation or amplification of existing awareness relationships, and the introduction of new aggregate awareness relationships. We propose a range of applications for third-party objects including world structuring regions, aggregate views, dynamic crowds of participants, common foci, representational and group services, and dynamic load management. We also discuss how the third-party concept relates to other approaches to structuring virtual environments such as tiles, zones, and locales. We then present an implementation, the MASSIVE-2 system, focusing on its network architecture which is based on a dynamic and selfconfiguring hierarchy of multicast groups. Finally, we describe four demonstration applications that have been developed in MASSIVE-2: an environment for staging a public poetry performance that includes semiprivate zones for social interaction; the Panoptican Plaza, which demonstrates a variety of differently bounded regions; a collaborative 3-D Web browser that groups pages into server regions; and the Arena, a performance space that supports both static and mobile crowd aggregations of groups of participants.
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Courtois, Gilles, Vincent Grimaldi, Hervé Lissek, Philippe Estoppey und Eleftheria Georganti. „Perception of Auditory Distance in Normal-Hearing and Moderate-to-Profound Hearing-Impaired Listeners“. Trends in Hearing 23 (Januar 2019): 233121651988761. http://dx.doi.org/10.1177/2331216519887615.
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The auditory system allows the estimation of the distance to sound-emitting objects using multiple spatial cues. In virtual acoustics over headphones, a prerequisite to render auditory distance impression is sound externalization, which denotes the perception of synthesized stimuli outside of the head. Prior studies have found that listeners with mild-to-moderate hearing loss are able to perceive auditory distance and are sensitive to externalization. However, this ability may be degraded by certain factors, such as non-linear amplification in hearing aids or the use of a remote wireless microphone. In this study, 10 normal-hearing and 20 moderate-to-profound hearing-impaired listeners were instructed to estimate the distance of stimuli processed with different methods yielding various perceived auditory distances in the vicinity of the listeners. Two different configurations of non-linear amplification were implemented, and a novel feature aiming to restore a sense of distance in wireless microphone systems was tested. The results showed that the hearing-impaired listeners, even those with a profound hearing loss, were able to discriminate nearby and far sounds that were equalized in level. Their perception of auditory distance was however more contracted than in normal-hearing listeners. Non-linear amplification was found to distort the original spatial cues, but no adverse effect on the ratings of auditory distance was evident. Finally, it was shown that the novel feature was successful in allowing the hearing-impaired participants to perceive externalized sounds with wireless microphone systems.
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Ionită, Monica Alina, und Cătălin Alexandru. „Control System Design for a Mechatronic Solar Tracker“. Applied Mechanics and Materials 332 (Juli 2013): 248–53. http://dx.doi.org/10.4028/www.scientific.net/amm.332.248.
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This paper presents the optimization of a tracking system for photovoltaic modules, regarding the growth of energetic efficiency. The study takes into consideration the optimization of the control system, which is developed with the commercial DFC (Design for Control) software environment EASY5. The tracking system is approached in mechatronic concept, by integrating the control system and the mechanical device of the solar tracker at the virtual prototype level. The optimization is performed by using parametric design technique, the design variables for optimization being the amplification factors of the controllers. The optimization study leads to the maximization of the incident solar radiation gain by minimizing the tracking errors.
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Ascoli, Giorgio A., Jeffrey L. Krichmar, Slawomir J. Nasuto und Stephen L. Senft. „Generation, description and storage of dendritic morphology data“. Philosophical Transactions of the Royal Society of London. Series B: Biological Sciences 356, Nr. 1412 (29.08.2001): 1131–45. http://dx.doi.org/10.1098/rstb.2001.0905.
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It is generally assumed that the variability of neuronal morphology has an important effect on both the connectivity and the activity of the nervous system, but this effect has not been thoroughly investigated. Neuroanatomical archives represent a crucial tool to explore structure–function relationships in the brain. We are developing computational tools to describe, generate, store and render large sets of three–dimensional neuronal structures in a format that is compact, quantitative, accurate and readily accessible to the neuroscientist. Single–cell neuroanatomy can be characterized quantitatively at several levels. In computer–aided neuronal tracing files, a dendritic tree is described as a series of cylinders, each represented by diameter, spatial coordinates and the connectivity to other cylinders in the tree. This ‘Cartesian’ description constitutes a completely accurate mapping of dendritic morphology but it bears little intuitive information for the neuroscientist. In contrast, a classical neuroanatomical analysis characterizes neuronal dendrites on the basis of the statistical distributions of morphological parameters, e.g. maximum branching order or bifurcation asymmetry. This description is intuitively more accessible, but it only yields information on the collective anatomy of a group of dendrites, i.e. it is not complete enough to provide a precise ‘blueprint’ of the original data. We are adopting a third, intermediate level of description, which consists of the algorithmic generation of neuronal structures within a certain morphological class based on a set of ‘fundamental’, measured parameters. This description is as intuitive as a classical neuroanatomical analysis (parameters have an intuitive interpretation), and as complete as a Cartesian file (the algorithms generate and display complete neurons). The advantages of the algorithmic description of neuronal structure are immense. If an algorithm can measure the values of a handful of parameters from an experimental database and generate virtual neurons whose anatomy is statistically indistinguishable from that of their real counterparts, a great deal of data compression and amplification can be achieved. Data compression results from the quantitative and complete description of thousands of neurons with a handful of statistical distributions of parameters. Data amplification is possible because, from a set of experimental neurons, many more virtual analogues can be generated. This approach could allow one, in principle, to create and store a neuroanatomical database containing data for an entire human brain in a personal computer. We are using two programs, L–NEURON and ARBORVITAE, to investigate systematically the potential of several different algorithms for the generation of virtual neurons. Using these programs, we have generated anatomically plausible virtual neurons for several morphological classes, including guinea pig cerebellar Purkinje cells and cat spinal cord motor neurons. These virtual neurons are stored in an online electronic archive of dendritic morphology. This process highlights the potential and the limitations of the ‘computational neuroanatomy’ strategy for neuroscience databases.
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Kemp, A. R. „Inelastic instability of rectangular and nonrectangular frames“. Canadian Journal of Civil Engineering 26, Nr. 3 (01.06.1999): 282–92. http://dx.doi.org/10.1139/l98-063.
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Proposals are described for extending the elastic amplification approach to frame instability given in the Canadian and South African codes for structural steel design to both nonrectangular frames and material inelasticity. The proposed approach to generalized nonrectangular frames is based on sway equilibrium equations which are derived by the principle of virtual work for each independent mode of sway collapse. The influence of material inelasticity is assessed by idealizing the moment-curvature relationship and the load-deflection behaviour between an effective elastic limit and the formation of the plastic collapse mechanism. A number of examples are given which demonstrate both the simplicity and accuracy of the method.Key words: codes, design, frames, inelastic properties, plastic properties, stability.
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Yang, Jie. „Research on Image Mosaic Algorithm Based on Computer Information Science“. Applied Mechanics and Materials 427-429 (September 2013): 1467–70. http://dx.doi.org/10.4028/www.scientific.net/amm.427-429.1467.
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With the development of the computer information science and technology, image Mosaic technology has been applied to various fields, which including image compression and amplification, synthesis of images and virtual scene of image design . The algorithm of image mosaic technology research is increasing. This paper analyzes the present situation and application of image mosaic technology and proposes the genetic algorithm of image mosaic technology based on computer information theory. It also constructs the image mosaic technology flow chart. This paper simulates image magnification and synthesis technology in order to prove feasibility and reliability of algorithm by the image Mosaic technology cases. This paper puts forward opinions to the deficiency of mosaic technology and provides a theoretical reference for the application and development of image mosaic technology.
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Lu, Lu, Jinfeng Chen, Sofia M. C. Robb, Yutaka Okumoto, Jason E. Stajich und Susan R. Wessler. „Tracking the genome-wide outcomes of a transposable element burst over decades of amplification“. Proceedings of the National Academy of Sciences 114, Nr. 49 (20.11.2017): E10550—E10559. http://dx.doi.org/10.1073/pnas.1716459114.
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To understand the success strategies of transposable elements (TEs) that attain high copy numbers, we analyzed two pairs of rice (Oryza sativa) strains, EG4/HEG4 and A119/A123, undergoing decades of rapid amplification (bursts) of the class 2 autonomous Ping element and the nonautonomous miniature inverted repeat transposable element (MITE) mPing. Comparative analyses of whole-genome sequences of the two strain pairs validated that each pair has been maintained for decades as inbreds since divergence from their respective last common ancestor. Strains EG4 and HEG4 differ by fewer than 160 SNPs and a total of 264 new mPing insertions. Similarly, strains A119 and A123 exhibited about half as many SNPs (277) as new mPing insertions (518). Examination of all other potentially active TEs in these genomes revealed only a single new insertion out of ∼40,000 loci surveyed. The virtual absence of any new TE insertions in these strains outside the mPing bursts demonstrates that the Ping/mPing family gradually attains high copy numbers by maintaining activity and evading host detection for dozens of generations. Evasion is possible because host recognition of mPing sequences appears to have no impact on initiation or maintenance of the burst. Ping is actively transcribed, and both Ping and mPing can transpose despite methylation of terminal sequences. This finding suggests that an important feature of MITE success is that host recognition does not lead to the silencing of the source of transposase.
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Rana, Sindhuprava, und R. Sivaperumal. „Virtual screening and molecular docking of Anti-Antileishmanial for selected pharmacophore for visceral Leishmaniasis“. Journal of Drug Delivery and Therapeutics 8, Nr. 6-s (15.12.2018): 230–35. http://dx.doi.org/10.22270/jddt.v8i6-s.2120.
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Objective: DNA amplification of Cysteine protease of Leishmania donovani and study the interaction of cysteine protease inhibitors, antileishmanial compounds with cysteine protease receptor in various computational programs.
Materials and methods: Cysteine protease DNA of Leishmania donovani was amplified by PCR. The sequence of cysteine protease has been modeled and docked with suitable inhibitors by using various servers and computational tools. The model was designed, compared and validated by DOPE and Verify 3D scores. The model and the compound interaction were studied by LibDock and other programs.
Results: Cysteine protease DNA of Leishmania donovani was successfully amplified by PCR. The structural modeling was done to achieve effective enzyme inhibition, inhibitors block the binding sites of that protein. Homology modeling of cysteine protease has been done and docked with suitable inhibitors by using various servers and computational tools. The model was designed, compared and validated by DOPE and Verify 3D scores by using DSv3.5. Licochalcone-a alone showed 37 LibDock conformations with 6 different poses, were suitably docked at the site 1 with hydrogen bond formation. The study would help to design the novel drugs in respect of resistant one for the treatment of harmful visceral Leishmaniasis.
Conclusion: The molecular interaction of vinyl sulfones, hydrazide derivatives, antileishmanial drugs molecules and carbohydrazide derivatives have exhibited ideal molecular interaction with cathepsin B, a cysteine protease of L. donovani, amino acids such as Cys29, Hisl88 and Asn208 has been found to be active residues. Licochalcone-a and hydrazide derivative may become future antileishmanial compounds, which needs to be tested in in vitro and in vivo.
Keywords: Cysteine Protease, Vinyl Sulfone, Hydrazide, Antileishmanial Drugs, Licochalcone, Visceral Leishmaniasis.
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Xie, Zhen, Lifan Niu und Xing Zhang. „An Enhanced Control Strategy for Doubly-Fed Induction Generators Based on a Virtual Harmonic Resistor and Capacitor under Nonlinear Load Conditions“. Energies 11, Nr. 10 (01.10.2018): 2613. http://dx.doi.org/10.3390/en11102613.
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Harmonic amplification for doubly-fed induction generator wind turbine systems (DFIG WTSs) will occur due to the existence of non-linear loads and reactive power compensation installation, and grid voltage and total grid current at the point of common coupling (PCC) will be distorted. An impedance model is established to analyze the interaction between DFIG WTS, non-linear loads and weak grids. Harmonic current impact factor and harmonic voltage impact factor is proposed to analyze the impact of harmonic current source on total grid current and voltage at the PCC with different control strategies. A virtual harmonic resistor and capacitor method is adopted to reduce the harmonic voltage. An impedance-based analysis method is adopted to analyze the stability of the DFIG system. To achieve optimal control of harmonic voltage and harmonic current, a coordination factor is proposed to adjust the dynamic allocation for harmonic voltage and harmonic current at PCC. The experimental results demonstrate the effectiveness of the proposed control strategy.
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Sahal, A., J. Roger, S. Allgeyer, B. Lemaire, H. Hébert, F. Schindelé und F. Lavigne. „The tsunami triggered by the 21 May 2003 Boumerdès-Zemmouri (Algeria) earthquake: field investigations on the French Mediterranean coast and tsunami modelling“. Natural Hazards and Earth System Sciences 9, Nr. 6 (10.11.2009): 1823–34. http://dx.doi.org/10.5194/nhess-9-1823-2009.
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Abstract. A field survey was organized on the French Mediterranean coasts to investigate the effects of the tsunami induced by the 21 May 2003 Boumerdès-Zemmouri (Algeria) earthquake (Mw=6.9). The results show that eight harbours were affected by important sea level disturbances that caused material loss. Unfortunately, the low sampling rate of the French tide gage records (10 min) does not allow for a proper evaluation of the tsunami wave amplitudes since these amplitudes were probably underestimated in the harbours where these sensors are installed. The survey brings to light regional and local contrasts among the harbours' hydrological responses to the tsunami. To better understand these contrasts, a numerical simulation of the sea level elevations induced by the tsunami was conducted. The simulation showed a certain correlation between the field results and the wave amplification along the coast; however it underestimated the observed phenomena. Another simulation was then conducted using high resolution bathymetric grids (space step of 3 m) centred more specifically on 3 neighbouring harbours, however, again the simulation results did not match the amplitudes recorded through the observations. In order to better understand the wave amplification mechanisms inside each grid, a Gaussian signal was virtually broadcasted from the source to the harbours. Virtual sensors identified the periods which are stimulated – or not – by the arrival of the signal in each grid. Comparing these periods with those previously recorded emphasizes the proper period of each waterbody. This paper evaluates the limitations of such a study, focusing specifically on (1) the importance of having accurate and precise data about the source (the lack of information about the signal amplitude leads to an underestimation of the tsunami, thus reproducing only a fourth to a third of the observed phenomenon), (2) the need for networked tide gages with high resolution records and short sampling rates, and (3) the importance of conducting field studies immediately after a tsunami occurs.
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Kros, Johan M., Karin Huizer, Aurelio Hernández-Laín, Gianluca Marucci, Alex Michotte, Bianca Pollo, Elisabeth J. Rushing et al. „Evidence-Based Diagnostic Algorithm for Glioma: Analysis of the Results of Pathology Panel Review and Molecular Parameters of EORTC 26951 and 26882 Trials“. Journal of Clinical Oncology 33, Nr. 17 (10.06.2015): 1943–50. http://dx.doi.org/10.1200/jco.2014.59.0166.
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Purpose With the rapid discovery of prognostic and predictive molecular parameters for glioma, the status of histopathology in the diagnostic process should be scrutinized. Our project aimed to construct a diagnostic algorithm for gliomas based on molecular and histologic parameters with independent prognostic values. Methods The pathology slides of 636 patients with gliomas who had been included in EORTC 26951 and 26882 trials were reviewed using virtual microscopy by a panel of six neuropathologists who independently scored 18 histologic features and provided an overall diagnosis. The molecular data for IDH1, 1p/19q loss, EGFR amplification, loss of chromosome 10 and chromosome arm 10q, gain of chromosome 7, and hypermethylation of the promoter of MGMT were available for some of the cases. The slides were divided in discovery (n = 426) and validation sets (n = 210). The diagnostic algorithm resulting from analysis of the discovery set was validated in the latter. Results In 66% of cases, consensus of overall diagnosis was present. A diagnostic algorithm consisting of two molecular markers and one consensus histologic feature was created by conditional inference tree analysis. The order of prognostic significance was: 1p/19q loss, EGFR amplification, and astrocytic morphology, which resulted in the identification of four diagnostic nodes. Validation of the nodes in the validation set confirmed the prognostic value (P < .001). Conclusion We succeeded in the creation of a timely diagnostic algorithm for anaplastic glioma based on multivariable analysis of consensus histopathology and molecular parameters.
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Vacarus, Teodor Dan, Cristina Popescu, Adrian Moise und Gabriela Bucur. „Electromyography and Applications Based on the Interpretation of the Electrical Activity Associated with the Depolarization-Repolarization Cycle of the Muscle Fiber Membrane“. Revista de Chimie 71, Nr. 9 (05.09.2020): 325–36. http://dx.doi.org/10.37358/rc.20.9.8343.
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The aim of this paper is to present the implementation of a method for data acquisition, processing and interpretation of the electrical activity associated with the muscle fiber membrane, generated as a result of the ionic pumps� action. By using a biofeedback shield (EKG/EMG shield) for differential amplification and analog signal filtering, an Arduino development board for analog to digital conversion and an external processing unit, a series of experiments were carried out. These referred to medical diagnosis and research, human-machine interfaces (control of a robotic joint which could be used for prosthetic limbs or industrial robots, as well as control of the computer � for video games, virtual reality, interaction with other devices), and monitoring and increasing sports performance. Due to its noninvasive characteristics, this technique, known as surface electromyography, proves to play a significant role in areas such as medical research, rehabilitation, ergonomics, sports etc.
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Hao und Zhu. „Design of a Monolithic Double-Slider Based Compliant Gripper with Large Displacement and Anti-Buckling Ability“. Micromachines 10, Nr. 10 (30.09.2019): 665. http://dx.doi.org/10.3390/mi10100665.
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In a micro-manipulation system, the compliant gripper is used for gripping, handling and assembling of objects. Large displacement and anti-buckling characteristics are desired in the design of the gripper. In this paper, a compliant gripper with these two characteristics is proposed, modelled and verified. The large displacement is enabled by using distributed compliance in a double-slider kinematic mechanism. An inverted flexure arrangement enables the anti-buckling of the gripper when closing the two jaws. A pseudo-rigid-body model (PRBM) method with the help of virtual work principle is employed to obtain several desired analytical relations including the amplification coefficient and kinetostatics. The results of the finite element analysis (FEA) are shown to be consistent with the results of the derived analytical model. An experimental test was carried out through a milling machined aluminium alloy prototype, the results of which verify the good performance of the compliant gripper.
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OGDEN, N. H., P. A. NUTTALL und S. E. RANDOLPH. „Natural Lyme disease cycles maintained via sheep by co-feeding ticks“. Parasitology 115, Nr. 6 (Dezember 1997): 591–99. http://dx.doi.org/10.1017/s0031182097001868.
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We present observational and experimental evidence that cycles of the Lyme disease spirochaete, Borrelia burgdorferi s.l., can be maintained by sheep in the virtual absence of alternative hosts. A 2-year field study in upland moorland habitats of northwest UK established that sheep feed up to 80% of larval, >99% of nymphal and all of the adult female tick (Ixodes ricinus) population. Infection prevalence of B. burgdorferi in questing ticks reaches over 20%, but amplification of infection occurs principally as nymphs (20- to 30-fold), rather than larvae (4- to 7-fold), feed on sheep, and transmission from sheep to ticks occurred only during peak tick abundance in May and September. Experimental transmission studies confirmed that sheep, previously exposed to infected ticks on the moorland site, do not support systemic infections of B. burgdorferi, but they can transmit localized infections from infected to uninfected ticks co-feeding at the same site on the sheep's body.
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Akhtar, Khalid Pervaiz, Muhammad Yussouf Saleem, Sumaira Yousaf, Najeeb Ullah, Ghulam Rasool und Nighat Sarwar. „Occurrence, identification and transmission of the phytoplasma associated with tomato big bud disease and identification of its vector and weed host in Pakistan“. Archives of Phytopathology and Plant Protection 51, Nr. 7 (09.05.2018): 387–98. http://dx.doi.org/10.1080/03235408.2018.1485827.
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Tomato (Solanum lycopersicum L.) plants showing stunting, big bud, leaves yellowing or reddening and witches’-broom symptoms were observed since 2009 in Pakistan. A weed Parthenium hysterophorus grown in and around tomato fields also exhibited witches’-broom like symptoms. Fluorescence light microscopy of hand-cut stem stalk sections treated with Dienes’ stain showed blue areas in the phloem region of both tomato and P. hysterophorus symptomatic plants that indicated the association of phytoplasma with the complex. Amplification of 1.2 kb 16S rDNA fragment in nested PCR confirmed that the symptomatic tomato and P. hysterophorus plants are infected by a phytoplasma. Partial sequencing of 16S rRNA (GenBank accession: LT671581 and LT671583) and virtual restriction fragment length polymorphism confirmed that the phytoplasma associated with both plant species had the greatest homology to 16SrII-D subgroup. Disease was successfully transmitted by grafting and leafhopper Orosius albicinctus in tomato plants. This is the first report of natural occurrence of 16SrII-D phytoplasma in tomatoes and a weed P. hysterophorus in Pakistan.
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Ha, Sung Kyu, Lei Xu, Chao Zhao und Matthias DeMonte. „Progressive failure prediction of short fiber reinforced composites using a multi-scale approach“. Journal of Composite Materials 52, Nr. 27 (22.04.2018): 3785–801. http://dx.doi.org/10.1177/0021998318770252.
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A hybrid multi-scale approach combining a virtual mesoscale volume element (representative volume element) and a microscale finite element representative unit cell is developed, for progressive failure prediction of short fiber reinforced composites. The representative volume element represents the fiber orientation and distribution of the whole composites, from which the global mechanical behavior can be estimated. The representative unit cell captures the local mechanical response of each short fiber by transforming global strains to local strains. The constituent strains of the fiber, matrix, and interface are calculated from local strains using representative unit cell. Correlations between mesoscale local strains and microscale constituent strains are established using strain amplification factors. After computing microscale stresses, a progressive damage model is employed to determine the damage status of all constituents. A homogenization method is employed to eliminate damage localization in the matrix and interface. The predicted stress–strain curves are compared with experimental results, and good agreement is also achieved.
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Yang, Bolei, und Zhe-Min Tan. „The Initiation of Dry Patches in Cloud-Resolving Convective Self-Aggregation Simulations: Boundary Layer Dry-Subsidence Feedback“. Journal of the Atmospheric Sciences 77, Nr. 12 (Dezember 2020): 4129–41. http://dx.doi.org/10.1175/jas-d-20-0133.1.
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AbstractSelf-aggregation of convection can be considered as the simultaneous occurrence of dry patch initiation/amplification and wet patch contraction/intensification from initially uniform moisture and temperature fields. As the twin of wet patches, dry patches play an important role in moisture and energy balance during convective self-aggregation. In this study, the WRF Model is used to study the initiation of dry patches in convective self-aggregation, especially the continuous drying in their boundary layer (BL). In the dry patch BL, increased air density leads to an enhanced high pressure anomaly, which drives an amplifying BL divergent flow and induces an amplifying BL subsidence. The virtual effect of drying by subsidence counteracts warming by subsidence and the BL process, further increasing BL air density. Our analysis indicates the existence of a dry-subsidence feedback, which leads to the initiation of dry patches in convective self-aggregation. This feedback is shown to be important even in very large-scale (3000 km × 9000 km) cloud-resolving convective self-aggregation simulations.
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Zhang, Siqi, Qiaoling Song, Xueting Wang, Zhiqiang Wei, Rilei Yu, Xin Wang und Tao Jiang. „Virtual Screening Guided Design, Synthesis and Bioactivity Study of Benzisoselenazolones (BISAs) on Inhibition of c-Met and Its Downstream Signalling Pathways“. International Journal of Molecular Sciences 20, Nr. 10 (20.05.2019): 2489. http://dx.doi.org/10.3390/ijms20102489.
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c-Met is a transmembrane receptor tyrosine kinase and an important therapeutic target for anticancer drugs. In this study, we designed a small library containing 300 BISAs molecules that consisted of carbohydrates, amino acids, isothiourea, tetramethylthiourea, guanidine and heterocyclic groups and screened c-Met targeting compounds using docking and MM/GBSA. Guided by virtual screening, we synthesised a series of novel compounds and their activity on inhibition of the autophosphorylation of c-Met and its downstream signalling pathway proteins were evaluated. We found a panel of benzisoselenazolones (BISAs) obtained by introducing isothiourea, tetramethylthiourea and heterocyclic groups into the C-ring of Ebselen, including 7a, 7b, 8a, 8b and 12c (with IC50 values of less than 20 μM in MET gene amplified lung cancer cell line EBC-1), exhibited more potent antitumour activity than Ebselen by cell growth assay combined with in vitro biochemical assays. In addition, we also tested the antitumour activity of three cancer cell lines without MET gene amplification/activation, including DLD1, MDA-MB-231 and A549. The neuroblastoma SK-N-SH cells with HGF overexpression which activates MET signalling are sensitive to MET inhibitors. The results reveal that our compounds may be nonspecific multitarget kinase inhibitors, just like type-II small molecule inhibitors. Western blot analysis showed that these inhibitors inhibited autophosphorylation of c-MET, and its downstream signalling pathways, such as PI3K/AKT and MARK/ERK. Results suggest that bensoisoselenones can be used as a scaffold for the design of c-Met inhibiting drug leads, and this study opens up new possibilities for future antitumour drug design.
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Holyaka, R. L., T. A. Marusenkova und D. V. Fedasyuk. „LOGARITHMIC AMPLIFIERS FOR SOFTWARE HARDWARE MAGNETIC TRACKING SYSTEMS“. ELECTRICAL AND COMPUTER SYSTEMS 33, Nr. 109 (22.12.2020): 33–45. http://dx.doi.org/10.15276/eltecs.33.109.2020.4.
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The work deals with the problem of signal conversion in magnetic tracking devices. Magnetic tracking technology is based on computing the spatial position of an object being tracked upon measuring reference magnetic fields in low-frequency electromagnetic radiation spectrum. Magnetic tracking devices are key components of navigation sensors for virtual and augmented reality. It has been shown that the main problem one faces when developing sensory devices for magnetic tracking is the fact that signals should be measured in a wide measurement range. We have analyzed possible ways to solve the stated problem by digital and combined methods. The latter have proven to be more efficient. They consist in signal amplification due to analog compression, which is performed by logarithmic amplifiers whose negative feedback circuits contain components with non-linear volt-ampere characteristics (typically, diodes or bipo- lar transistors are used). It has been shown that the parameters of logarithmic signal compression can be controlled by modified circuits with auxiliary resistance dividers. The resistance dividers scale the logarithmic volt-ampere characteristics of emitter p-n junctions of bipolar n-p-n and p-n-p transistors. A substantial advantage of circuits with resistance dividers is that they provide the possibility to expand the range of the output voltage of logarithmic amplifiers and optimize the transition between the linear and logarithmic amplification regions. The work presents the results of simulation and experimental investigations into a logarithmic amplifier for a magnetic tracking system. Simulation was carried out using SPICE (Simulation Program with Integrated Circuit Emphasis) models. We applied an integrated approach,which provides collections of transient characteristics of logarithmic amplifiers at different sets of the parameters of resistance dividers. The simulation results have been verified using our own software- firmware magnetic tracking tools – Magnetic Tracking System Integrated Development Environment. The signal converter was built upon a programmable system-on-chip PSoC 5LP by Cypress Semiconductor.
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Yadav, A., U. Bhale, V. Thorat und Y. Shouche. „First Report of a New Subgroup 16Sr II-M ‘Candidatus Phytoplasma aurantifolia’ Associated with Witches'-Broom Disease of Tephrosia purpurea in India“. Plant Disease 98, Nr. 7 (Juli 2014): 990. http://dx.doi.org/10.1094/pdis-11-13-1183-pdn.
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Wild indigo (Tephrosia purpurea (L.) Pers.) grows as a common weed throughout the Indian subcontinent. The plant has pinnate leaves, white or purplish flowers, and flat hairy pods, and is cultivated as a green manure crop. The plant extracts contain compounds such as tephrosin, an aromatic ester, prenylated flavonoid, and sesquiterpene (2) that have medicinal properties. The newly recognized disease, Tephrosia purpurea witches' broom (TPWB), was characterized by chlorosis, stunting, and proliferative branching, which were suggestive of phytoplasma infection during a field survey conducted in November 2013. To determine the presence of phytoplasma, 2 g of compound leaves from three symptomatic and asymptomatic plants were used for total DNA extraction using the CTAB method. The phytoplasma 16S rRNA gene was detected in all three symptomatic plants using nested PCR with universal phytoplasma primer pairs, P1/P7 followed by R16F2n/R16R2 (4). No amplification was observed in DNA isolated from asymptomatic plants. PCR fragments (1,246 bp in length) generated from symptomatic T. purpurea plants were sequenced directly using five different primers viz. 343R, 536F, 704F, 907R, and 1103F. TPWB phytoplasma 16S rRNA gene sequence (GenBank Accession No. HG792252) showed 99.12% homology with a ‘Candidatus Phytoplasma aurantifolia’ strain WBDL (U15442) when compared using the EzTaxon 16S rRNA database (3). Virtual restriction fragment length polymorphism (RFLP) analysis was carried out on the obtained sequence using iPhyClassifier (5). The virtual RFLP pattern derived from the HG792252 sequence was different to the reference patterns of previously established 16Sr groups and subgroups. The reference pattern of the 16Sr group II, subgroup C (AJ293216) was most similar with a similarity coefficient of 0.92, which placed it in a new subgroup, 16Sr II-M (1). Furthermore, virtual RFLP results were confirmed by digesting R16F2n/R16R2 amplicon with BstUI, DraI, HinfI, HpaI, and MseI restriction enzymes according to manufacturer's instructions. To our knowledge, this is the first report of a ‘Ca. P. aurantifolia’-related strain associated with witches'-broom disease of T. purpurea in India. References: (1) H. Cai et al. Int. J. Syst. Evol. Microbiol. 58:1448, 2008. (2) A. K. Khalafalah et al. Pharmacognosy Res. 2:72, 2010. (3) O.-S. Kim et al. Int. J. Syst. Evol. Microbiol. 62:716, 2012. (4) C. Smart et al. Appl. Environ. Microbiol. 62:2988, 1996. (5) Y. Zhao et al. Int. J. Syst. Evol. Microbiol. 59:2582, 2009.
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Flôres, Daniela, Ana Paula de Oliveira Amaral Mello, Thays Benites Camargo Pereira, Jorge Alberto Marques Rezende und Ivan Paulo Bedendo. „A novel subgroup 16SrVII-D phytoplasma identified in association with erigeron witches' broom“. International Journal of Systematic and Evolutionary Microbiology 65, Pt_8 (01.08.2015): 2761–65. http://dx.doi.org/10.1099/ijs.0.000274.
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Erigeron sp. plants showing symptoms of witches' broom and stunting were found near orchards of passion fruit in São Paulo state, Brazil. These symptoms were indicative of infection by phytoplasmas. Thus, the aim of this study was to detect and identify possible phytoplasmas associated with diseased plants. Total DNA was extracted from symptomatic and asymptomatic plants and used in nested PCR conducted with the primer pairs P1/Tint and R16F2n/16R2. Amplification of genomic fragments of 1.2 kb from the 16S rRNA gene confirmed the presence of phytoplasma in all symptomatic samples. The sequence identity scores between the 16S rRNA gene of the phytoplasma strain identified in the current study and those of previously reported ‘Candidatus Phytoplasma fraxini’-related strains ranged from 98 % to 99 % indicating the phytoplasma to be a strain affiliated with ‘Candidatus Phytoplasma fraxini’. The results from a phylogenetic analysis and virtual RFLP analysis of the 16S rRNA gene sequence with 17 restriction enzymes revealed that the phytoplasma strain belongs to the ash yellows phytoplasma group (16SrVII); the similarity coefficient of RFLP patterns further suggested that the phytoplasma represents a novel subgroup, designated 16SrVII-D. The representative of this new subgroup was named EboWB phytoplasma (Erigeron bonariensis Witches' Broom).
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Živanović, Dragan, Milan Simić, Zivko Kokolanski, Dragan Denić und Vladimir Dimcev. „Generation of Long-time Complex Signals for Testing the Instruments for Detection of Voltage Quality Disturbances“. Measurement Science Review 18, Nr. 2 (01.04.2018): 41–51. http://dx.doi.org/10.1515/msr-2018-0007.
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Abstract Software supported procedure for generation of long-time complex test sentences, suitable for testing the instruments for detection of standard voltage quality (VQ) disturbances is presented in this paper. This solution for test signal generation includes significant improvements of computer-based signal generator presented and described in the previously published paper [1]. The generator is based on virtual instrumentation software for defining the basic signal parameters, data acquisition card NI 6343, and power amplifier for amplification of output voltage level to the nominal RMS voltage value of 230 V. Definition of basic signal parameters in LabVIEW application software is supported using Script files, which allows simple repetition of specific test signals and combination of more different test sequences in the complex composite test waveform. The basic advantage of this generator compared to the similar solutions for signal generation is the possibility for long-time test sequence generation according to predefined complex test scenarios, including various combinations of VQ disturbances defined in accordance with the European standard EN50160. Experimental verification of the presented signal generator capability is performed by testing the commercial power quality analyzer Fluke 435 Series II. In this paper are shown some characteristic complex test signals with various disturbances and logged data obtained from the tested power quality analyzer.
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Boy, Michael, Erik S. Thomson, Juan-C. Acosta Navarro, Olafur Arnalds, Ekaterina Batchvarova, Jaana Bäck, Frank Berninger et al. „Interactions between the atmosphere, cryosphere, and ecosystems at northern high latitudes“. Atmospheric Chemistry and Physics 19, Nr. 3 (14.02.2019): 2015–61. http://dx.doi.org/10.5194/acp-19-2015-2019.
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Abstract. The Nordic Centre of Excellence CRAICC (Cryosphere–Atmosphere Interactions in a Changing Arctic Climate), funded by NordForsk in the years 2011–2016, is the largest joint Nordic research and innovation initiative to date, aiming to strengthen research and innovation regarding climate change issues in the Nordic region. CRAICC gathered more than 100 scientists from all Nordic countries in a virtual centre with the objectives of identifying and quantifying the major processes controlling Arctic warming and related feedback mechanisms, outlining strategies to mitigate Arctic warming, and developing Nordic Earth system modelling with a focus on short-lived climate forcers (SLCFs), including natural and anthropogenic aerosols. The outcome of CRAICC is reflected in more than 150 peer-reviewed scientific publications, most of which are in the CRAICC special issue of the journal Atmospheric Chemistry and Physics. This paper presents an overview of the main scientific topics investigated in the centre and provides the reader with a state-of-the-art comprehensive summary of what has been achieved in CRAICC with links to the particular publications for further detail. Faced with a vast amount of scientific discovery, we do not claim to completely summarize the results from CRAICC within this paper, but rather concentrate here on the main results which are related to feedback loops in climate change–cryosphere interactions that affect Arctic amplification.
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Panchal, Ishan I., Ashish Shah, Animesh Devgirkar, Umang Shah, Ashish Patel, Alkesh Patel und Dhrubo J. Sen. „In Silico Analysis and Molecular Docking Studies of Novel 6,7-dihydropyrano [2,3-d] pyrimidin-5-one Derivatives as Human Epidermal Growth Factor Receptor 2 (HER2) and Epidermal Growth Factor Receptor (EGFR) Inhibitors“. Current Cancer Therapy Reviews 15, Nr. 3 (16.11.2019): 235–47. http://dx.doi.org/10.2174/1573394715666181129104528.
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Background:: HER2 is a member of the human epidermal growth factor receptor (HER/EGFR-/ERBB) family. Amplification or over-expression of this oncogene has been shown to play a major role in the development and progression of certain destructive types of breast cancer. Several drugs like Trastuzumab, Pertuzumab, Capecitabine, and Letrozole are used in the patients with metastatic breast cancer that overexpress the HER2 receptor. Materials and Methods:: We aimed to investigate, the prevalence, ADME prediction, biological activity prediction of novel HER2/ EGFR mutations in breast cancer. Literature review shows that pyrano pyrimidin scaffold plays important role in the treatment of Brest cancer. So we have to design novel 6,7-Dihydropyrano [2,3-d] pyrimidin-5-one derivatives with virtual screening techniques. Molecular target prediction shows that all derivatives act on tyrosine kinase. Results:: Among all the compounds H11 (-8.8 kcal/mol), H2 (-8.7 kcal/mol), H15 (-8.6 Kcal/mol), and H17 (-8.7 Kcal/mol) had a maximum binding affinity as compared to Cipecitabine (-6.0 kcal/mol), STD1 (-7.2 Kcal/mol) and STD2 (-7.9 Kcal/mol) and other derivatives. Most of the compounds are moderately active and do not cross the blood brain barrier. Conclusion:: The bioactivity prediction shows that all compounds are active to moderately active. These positive results show that it could be further investigated and explored.
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Liu, Yifan, Jinlin Sun, Zhiqiang Pu, Jianqiang Yi und Shiliang Pu. „Robust fuzzy tracking control for flexible air-breathing hypersonic vehicles with measurement noises“. Transactions of the Institute of Measurement and Control 41, Nr. 13 (22.04.2019): 3818–35. http://dx.doi.org/10.1177/0142331219837590.
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Measurement noise is an obstacle to the performance improvement of a flexible air-breathing hypersonic vehicle. This paper explores a robust fuzzy tracking control scheme for the longitudinal dynamics of the hypersonic vehicle, which is constructed by utilizing type-2 fuzzy adaptive technique and dynamic surface control (DSC) approach. The control scheme is comprised of two parts: the state estimators and tracking controllers of velocity and altitude. The state estimators are designed by using the type-2 fuzzy logic system-based approximators, which guarantees the estimation of real states from measurement signals with noises. Furthermore, on the basis of the designed state estimators, the velocity and altitude tracking controllers are constructed by using the adaptive fuzzy DSC approach. On one hand, DSC approach can filter the virtual control law and avoid the amplification of the measurement noise. On the other hand, since the antecedent of the type-2 fuzzy logic system is based on the type-2 fuzzy sets and the consequent parameters are adjusted by an integral calculation in the adaptive law, the type-2 fuzzy adaptive technique in the adaptive fuzzy DSC tracking controller has the ability to further reduce the impact of the measurement noises. A Lyapunov-based stability analysis shows the tracking ability of the proposed control scheme. Nominal and comparison simulation considering the measurement noises are carried out for demonstrating the effectiveness of the proposed method.