Silencing Orco Impaired the Ability to Perceive Trail Pheromones and Affected Locomotion Behavior in Two Termite Species

2020 ◽  
Vol 113 (6) ◽  
pp. 2941-2949
Author(s):  
Yongyong Gao ◽  
Qiuying Huang ◽  
Huan Xu
Keyword(s):  
Rna Interference ◽  
Angular Velocity ◽  
Olfactory System ◽  
Termite Species ◽  
Turn Angle ◽  
Trail Pheromones ◽  
Pheromone Trails ◽  
Wide Range ◽  
Locomotion Behavior ◽  
Odontotermes Formosanus

Abstract Sophisticated social behaviors in termite colonies are mainly regulated via chemical communication of a wide range of pheromones. Trail pheromones play important roles in foraging behavior and building tunnels and nests in termites. However, it is almost unclear how termites perceive trail pheromones. Here, we cloned and sequenced of olfactory co-receptor (Orco) genes from the two termites Reticulitermes chinensis Snyder (Isoptera: Rhinotermitidae) and Odontotermes formosanus (Shiraki) (Isoptera: Termitidae), and then examined their responses to trail pheromones after silencing Orco through RNA interference (RNAi). We found that Orco knockdown impaired their ability to perceive trail pheromones and resulted in the disability of following pheromone trails in the two termite species. Our locomotion behavior assays further showed that Orco knockdown significantly decreased the distance and velocity in the two termite species, but significantly increased the angular velocity and turn angle in the termite R. chinensis. These findings strongly demonstrated that Orco is essential for termites to perceive their trail pheromones, which provides a potential way to control termite pests by damaging olfactory system.

ESTIMATION OF AERODYNAMIC FORCES AND MOMENTS DERIVATIVES WITH RESPECT TO THE ANGULAR VELOCITY COMPONENTS OF THE AIRCRAFT MODEL IN A WIDE RANGE OF ANGLES OF ATTACK

2018 ◽  
Vol 49 (1) ◽  
pp. 43-64
Author(s):  
Mikhail Alekseyevich Golovkin ◽  
Andrey Aleksandrovich Efremov ◽  
Miroslav Sergeevich Makhnev
Keyword(s):  
Angular Velocity ◽  
Aerodynamic Forces ◽  
Aircraft Model ◽  
Wide Range

scholarly journals The magnetorotational instability prefers three dimensions

2020 ◽  
Vol 476 (2233) ◽  
pp. 20190622
Author(s):  
Jeffrey S. Oishi ◽  
Geoffrey M. Vasil ◽  
Morgan Baxter ◽  
Andrew Swan ◽  
Keaton J. Burns ◽  
...  
Keyword(s):  
Shear Rate ◽  
Angular Velocity ◽  
Laboratory Experiments ◽  
Three Dimensional ◽  
Linear Instability ◽  
Three Dimensions ◽  
Two Dimensional ◽  
Magnetorotational Instability ◽  
Dynamo Action ◽  
Wide Range

The magnetorotational instability (MRI) occurs when a weak magnetic field destabilizes a rotating, electrically conducting fluid with inwardly increasing angular velocity. The MRI is essential to astrophysical disc theory where the shear is typically Keplerian. Internal shear layers in stars may also be MRI-unstable, and they take a wide range of profiles, including near-critical. We show that the fastest growing modes of an ideal magnetofluid are three-dimensional provided the shear rate, S , is near the two-dimensional onset value, S c . For a Keplerian shear, three-dimensional modes are unstable above S  ≈ 0.10 S c , and dominate the two-dimensional modes until S  ≈ 2.05 S c . These three-dimensional modes dominate for shear profiles relevant to stars and at magnetic Prandtl numbers relevant to liquid-metal laboratory experiments. Significant numbers of rapidly growing three-dimensional modes remainy well past 2.05 S c . These finding are significant in three ways. First, weakly nonlinear theory suggests that the MRI saturates by pushing the shear rate to its critical value. This can happen for systems, such as stars and laboratory experiments, that can rearrange their angular velocity profiles. Second, the non-normal character and large transient growth of MRI modes should be important whenever three-dimensionality exists. Finally, three-dimensional growth suggests direct dynamo action driven from the linear instability.

scholarly journals The cell biology of smell

2010 ◽  
Vol 191 (3) ◽  
pp. 443-452 ◽  
Author(s):  
Shannon DeMaria ◽  
John Ngai
Keyword(s):  
Olfactory System ◽  
Cell Biology ◽  
Odorant Receptor ◽  
Large Family ◽  
G Protein Coupled Receptors ◽  
Odorant Receptors ◽  
Chemical Structures ◽  
Wide Range ◽  
G Protein Coupled ◽  
The Brain

The olfactory system detects and discriminates myriad chemical structures across a wide range of concentrations. To meet this task, the system utilizes a large family of G protein–coupled receptors—the odorant receptors—which are the chemical sensors underlying the perception of smell. Interestingly, the odorant receptors are also involved in a number of developmental decisions, including the regulation of their own expression and the patterning of the olfactory sensory neurons' synaptic connections in the brain. This review will focus on the diverse roles of the odorant receptor in the function and development of the olfactory system.

SIFs for Radial Cracks in Annular Discs Under Internal and External Shrinkage Pressure and Constant Angular Velocity

2007 ◽  
Author(s):  
A. Sakhaee-Pour ◽  
A. R. Gowhari-Anaraki ◽  
S. J. Hardy
Keyword(s):  
Finite Element ◽  
Angular Velocity ◽  
Constant Angular Velocity ◽  
Coefficient Of Determination ◽  
Linear Elastic ◽  
Crack Configuration ◽  
Wide Range ◽  
Elastic Fracture ◽  
Radial Cracks

Finite element method has been implemented to predict stress intensity factors (SIFs) for radial cracks in annular discs under constant angular velocity. Effects of internal and external uniform pressure on the SIFs have also been considered. Linear elastic fracture mechanics finite element analyses have been performed and results are presented in the form of crack configuration factors for a wide range of components and crack geometry parameters. These parameters are chosen to be representative of typical practical situations. The extensive range of crack configuration factors obtained from the analyses is then used to develop equivalent prediction equations via a statistical multiple non-linear regression model. The accuracy of this model is measured using a multiple coefficient of determination, R2, where 0 ≤ R2 ≤ 1. This coefficient is found to be greater than or equal to 0.98 for all cases considered in this study, demonstrating the quality of the model fit to the data. These equations for the SIFs enable designers to predict fatigue life of the components easily.

A New Control Strategy to Reduce Steering Torque Without Perceptible Vibration for Vehicles Equipped With Electric Power Steering

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Masahiko Kurishige ◽  
Osamu Nishihara ◽  
Hiromitsu Kumamoto
Keyword(s):  
Angular Velocity ◽  
Electric Power ◽  
Control Strategy ◽  
Steering Wheel ◽  
Velocity Control ◽  
Steering Control ◽  
Electric Power Steering ◽  
Power Steering ◽  
Wide Range ◽  
Steering Torque

This paper proposes a new electric power steering control strategy, which significantly reduces the effort needed to change the steering direction of stationary vehicles. Previous attempts to reduce undesirable steering vibration have failed to reduce the steering torque because high-assist gains tend to produce oscillation or increase noise sensitivity. Herein, to eliminate this vibration, a new control strategy was developed based on pinion angular velocity control using a newly developed observer based on a simplified steering model. Tests yielded excellent estimations of the pinion angular velocity, and this made it possible to eliminate vibration at all steering wheel rotation speeds. Experiments with a test vehicle confirmed significant steering torque reduction, over a wide range of steering wheel speeds, without vibration transmission to the driver. The proposed control strategy allowed use of an assist gain more than three times higher than is conventional. Additionally, the proposed control strategy does not require supplemental sensors.

Particle Resuspension in a Wall-Bounded Turbulent Flow

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
S. C. Fu ◽  
C. Y. H. Chao ◽  
R. M. C. So ◽  
W. T. Leung
Keyword(s):  
Angular Velocity ◽  
Uhlenbeck Process ◽  
Particle Resuspension ◽  
Air Stream ◽  
Safety And Health ◽  
Wide Range ◽  
Resuspension Rate ◽  
Mc Simulation ◽  
Using Data ◽  
Good Agreement

Resuspension is of common occurrence in a wide range of industrial and environmental processes. Excessive resuspension in these processes could have a severe impact on human safety and health. Therefore, it is necessary to develop a practical, yet reasonably accurate model to describe the resuspension phenomenon. It has been identified that rolling is the dominant mechanism for particle resuspension in the presence of an air stream, be it laminar or turbulent. Existing models predict the resuspension rate by regarding particles as being resuspended once they are set in motion; only a few of these models attempt to describe the full scenario, including rolling motion and the effect of turbulence. The objective of this paper is to propose a stochastic model to simulate the resuspension rate in the presence of a near-wall turbulent stream, and where the rolling mechanism is assumed to dominate the resuspension process. The fluctuating part of the angular velocity of a rolling particle is modeled by the Langevin equation (i.e., an Ornstein–Uhlenbeck process); thus, the overall angular velocity is modeled as a diffusion process. A free parameter of the proposed resuspension model is determined using data obtained from a Monte Carlo (MC) simulation of the problem. Once determined, the parameter is found to be universal for different materials and different sizes of particles tested. The modeling results obtained using this parameter are found to be in good agreement with experimental data, and the model performs better compared to other models.

Study on Nozzle Array Structure Fluidic Gyroscope

2012 ◽  
Vol 542-543 ◽  
pp. 727-730
Author(s):  
Chuan Zhi Mei ◽  
Lin Hua Piao ◽  
Quan Gang Yu ◽  
Bao Li Zhang ◽  
Xia Ding ◽  
...  
Keyword(s):  
Angular Velocity ◽  
Sensitive Element ◽  
Impact Resistance ◽  
Measurement Range ◽  
Test Results ◽  
Velocity Difference ◽  
Wide Range ◽  
Array Structure ◽  
The Impact ◽  
Better Than

This paper reports about a nozzle array structure fluidic gyroscope. The gyro used setting sub-nozzle around the main nozzle to inhibit the attenuation which had been caused by the main nozzle jet column spread out and to increase the angular velocity difference of sensitive element in the thermal resistance wire when the jet flow rate had been input, thereby to improve the performance of the jet gyro. The test results showed that: a resolution of better than 0.1°/s nozzle formation jet gyro sensitivity better than 10mv/(0.1°/s), the measurement range is better than ± 60°/s; non-linearity of better than 1%.The impact of the gyroscope impact resistance capability, small size and wide range of applications.

Interpretation of synthetic common‐depth‐point gathers for a single anisotropic layer

Geophysics ◽  
1982 ◽  
Vol 47 (3) ◽  
pp. 323-335 ◽  
Author(s):  
Stuart Crampin ◽  
Barbara J. Radovich
Keyword(s):  
Angular Velocity ◽  
Elastic Constants ◽  
Arrival Time ◽  
Transversely Isotropic ◽  
Orthorhombic Symmetry ◽  
Isotropic Layer ◽  
Anisotropic Layer ◽  
Wide Range ◽  
Velocity Variations ◽  
Anisotropic Layers

Analysis of synthetic traveltime gathers shows that anisotropy may have a large enough effect on P, SH, and SV propagation to alter significantly the interpretation of the subsurface below the anisotropic layers. Consequently, if anisotropy exists below a seismic line, it is important to estimate the anisotropic parameters correctly. We discuss the effects of anisotropy on seismic waves and present a method for estimating the elastic constants of a transversely isotropic layer from P and SH arrival‐time gathers. The technique may be extended to more general anisotropic symmetries by analyzing gathers from several azimuths. To illustrate the possible effect of anisotropy on exploration surveys, P, SH, and SV velocity variations are calculated for several types of anisotropic sedimentary fabrics. Alignments due to bedding, shale lithology, and dry parallel cracks may have similar velocity variations. Fabrics with other configurations of cracks may still possess overall transversely isotropic symmetry, but they have a wide range of angular velocity variations with different polarities and periodicities. Synthetic gather curves are generated for a range of models with an anisotropic layer over an isotropic substrate. They show departures from hyperbolas, and erroneous depth determinations, that depend upon the elastic constants of the anisotropic layer. The elastic constants of the anisotropic layers are estimated from the synthetic gather curves by means of approximate equations for the angular velocity variations, which are linear in the elastic constants. Formulas are developed which relate tangents to the gather curves directly in terms of the elastic constants. These are tested for single‐layer transversely isotropic models and allow the five elastic constants to be estimated by drawing three tangents to P and SH synthetic arrival‐time gathers in [Formula: see text] space. Comparisons of estimated with original elastic constants are good for a number of different types of transversely isotropic fabrics. Gathers are also calculated at two azimuths in an anisotropic layer with orthorhombic symmetry and are analyzed with some success.

scholarly journals SYNTHESIS OF FRACTIONAL ORDER CONTROLLERS FOR MULTI-LUPP CONTROL STRUCTURE OF FIRE LIFT BASKET TURNING

Fire Safety ◽  
2018 ◽  
pp. 65-72
Author(s):  
B. Kopchak ◽  
A. Kushnir ◽  
I. Kravets
Keyword(s):  
Genetic Algorithm ◽  
Control System ◽  
Angular Velocity ◽  
Fractional Order ◽  
Transfer Functions ◽  
High Order ◽  
Nonlinear Load ◽  
Turn Angle ◽  
Transition Functions ◽  
Low Sensitivity

Introduction. The attempt to get the best dynamic and static characteristics of the basket turn angle complicates the tasks performed by the automatic control system (ACS) basket turn drive. The ACS  of the basket turn should meet the following requirements: high speed, smooth acceleration and breaking of the motor, static and dynamic accuracy of the reproduction of tasks trajectories, no overregulation in transition modes, required stability reserve, low sensitivity to coordinate and parametric disturbances, etc. A number of fundamentally different ACSs and methods for their synthesis have been analyzed to provide these requirements. As a result of the analysis, there has been selected a two-loop feedback control system (FCS) of the basket turn with regard to the elastic properties of the arrow, which is synthesized by the method of the generalized characteristic polynomial. Studies have shown that this system allows to provide an aperiodic transition process of the basket turn angle with a given speed and low sensitivity in steady state to the perturbation effect. However, the synthesized FCS transfer functions of the controllers of angular velocity of the motor and the basket have a high order and turned out to be quite complicated in terms of practical implementation. Purpose. In the article it is proposed to replace these controllers, by approximating them through evolutionary methods, with more compact fractional PІλDμ-controllers or fractional order controllers. Results. The studies carried out in this work have shown that fractional order controllers are quite advantageous in comparison with the over classical ones, particularly in the case of their application for optimization of electromechanical systems with the following features of their control objects: two masses, including those with the presence of impact; backlash viscosity of the drive friction; nonlinear load and so on. Replacement of the high-order motor and basket angular speed controllers with more compact PІλDμcontrollers or fractional order controllers has been performed using Optimization Toolbox optimization package in the MATLAB package. This software has been developed for approximation of classical parts with high-order transfer functions by fractional order parts, using a genetic algorithm or a particle swarm optimization for their transition functions. Conclusion. The conducted research on digital models has confirmed the efficiency of the replacement of high-order motor and basket angular velocity controllers with PІλDμ-controllers or fractional order controllers, whose transfer functions are determined by approximating the transition functions of the controllers by the genetic algorithm method.

scholarly journals The Role of RNA Interference in Functional Cure Strategies for Chronic Hepatitis B

2020 ◽  
Vol 19 (4) ◽  
pp. 362-369 ◽  
Author(s):  
Jeremy S Nayagam ◽  
Zillah C Cargill ◽  
Kosh Agarwal
Keyword(s):  
Clinical Trials ◽  
Chronic Hepatitis ◽  
Rna Interference ◽  
Hepatitis B ◽  
Chronic Hepatitis B ◽  
Early Phase ◽  
Safety Data ◽  
Functional Cure ◽  
Wide Range ◽  
Early Phase Clinical Trials

Abstract Purpose of Review Current treatments for chronic hepatitis B (CHB) are associated with low rates of cure. Functional cure has been accepted as a viable treatment end point in CHB. There have been substantial advances in the field of RNA interference (RNAi) therapeutics across a wide range of specialties, and the clinical pipeline now encompasses CHB. This review will highlight some of the challenges in therapeutic development, the data for RNAi in CHB, and future directions for the field. Recent Findings Early phase clinical trials have reported good safety data for RNAi therapies in CHB and demonstrated significant reductions in quantitative HBsAg levels (qHBsAg). Animal models however suggest that in HBeAg-negative individuals, HBsAg may be derived from hepatitis B DNA integrated into the host genome, which cannot be targeted by current RNAi therapies, and may prove to be a limitation. Preliminary data is being presented from combination therapy, which may result in more robust reductions in qHBsAg; however, trials are in the early stages of recruitment. Summary Despite promising data that RNAi may be an effective therapeutic strategy in CHB, it is unlikely to be in the form of monotherapy. The goal for the community will be to find the right combination of RNAi therapy with other antiviral or immunomodulatory agents, to achieve functional cure with a cessation of therapy. Early phase clinical trials are continuing to recruit, and data from combination studies will provide a “pivot point” in determining whether RNAi therapies can provide a backbone to finite duration and curative CHB regimens.

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