Intercellular communication controls agonist-induced calcium oscillations independently of gap junctions in smooth muscle cells

In this study, we report the existence of a communication system among human smooth muscle cells that uses mechanical forces to frequency modulate long-range calcium waves. An important consequence of this mechanical signaling is that changes in stiffness of the underlying extracellular matrix can interfere with the frequency modulation of Ca2+ waves, causing smooth muscle cells from healthy human donors to falsely perceive a much higher agonist dose than they actually received. This aberrant sensing of contractile agonist dose on stiffer matrices is completely absent in isolated smooth muscle cells, although the isolated cells can sense matrix rigidity. We show that the intercellular communication that enables this collective Ca2+ response in smooth muscle cells does not involve transport across gap junctions or extracellular diffusion of signaling molecules. Instead, our data support a collective model in which mechanical signaling among smooth muscle cells regulates their response to contractile agonists.

Intercellular communication controls agonist-induced calcium oscillations independently of gap junctions in smooth muscle cells

We report the existence of a unique mode of communication among human smooth muscle cells (SMCs) where they use force to frequency modulate long-range calcium waves. An important consequence of this mechanical signaling is that changes in stiffness of the underlying extracellular matrix can interfere with the frequency modulation of Ca2+ waves causing healthy SMCs to falsely perceive a much higher agonist dose than they actually received. This distorted sensing of contractile agonist dose on stiffer matrices is absent in isolated SMCs, even though the isolated cells can sense matrix rigidity. We show that intercellular communication that enables this collective Ca2+ response does not involve transport across gap junctions or extracellular diffusion of signaling molecules. The aberrant communication between cells that distorts the individual cell's perception of contractile stimulus can explain the sudden, exaggerated narrowing of the lumen when exposed to low dose of inhaled agonists in diseases like asthma.

Multiple Targets Detection and Acceleration Estimation for Intelligent Transport System

For intelligence transportation system,it is necessary to resolve the problems of multiple targets detection and vehicle longitudinal control with high level response capability. False targets can appearance because of mistaking the combination of these beat frequencies of Frequency Modulate continuous wave radar. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. About vehicle longitudinal control, the purpose of this paper is to propose new approach to estimating relative acceleration information for vehicle longitudinal control without inter-vehicle communication. Computer simulation results and theoretical analysis proved that the proposed methods are effective and practical for multiple targets detection and acceleration estimation in intelligence transportation system.

Target Range and Velocity Measurement to Reduce False Targets in FMCW Automotive Anti-Collision Radar

For frequency modulate continuous wave radar, it is necessary and difficult to search the pairs of beat frequencies in an up-chirp mode and a down-chirp mode t o measure range and velocity of multiple targets. However, the inherent problem of FMCW radar is multiple targets detection. False targets can appearance because of mistaking the combination of these beat frequencies. A novel waveform named double-slope symmetrical saw-tooth wave is proposed and its corresponding algorithm is also introduced to resolve the problem of multiple targets detection for automotive anti-collision radar. Computer simulation results and theoretical analysis prove that the method is effective and practical for multiple targets detection in intelligence transportation system.

WAVE HEIGHT MEASURING EQUIPMENT

The equipment was designed to obtain data from sea waves. It was developed by the Organization for Applied Scientific Research at Delft in coordination with the Royal Dutch Navy. The intention of the measurements with the wave height measuring equipment was to establish a correlation between the sea motion and the movements of a ship, which is steaming in that sea. So wave measurements and measurements of the ship movements were always carried out simultaneously. To have the movement of the ship free from the position of the wave meter, a telemetering system was chosen to transmit the data from the wave meter. The receiving and recording instruments are placed on board the ship. The first measurement was made in December 1958. At that moment, the wave meter consisted of a buoy assembly in which was mounted a transmitter coupled with an accelerometer. The accelerometer measured the accelerations of the wave meter in a direction perpendicular to the water surface. The carrier of the transmitter was direct frequency modulated by the signal of the accelerometer. After this measurement it became desirable to gather more data from the sea waves. For that reason the instrumentation of the wave meter was extended with a gyro, which measures the slope of the waves. The slope is determined by the angles of the water surface with respect to the horizontal plane in two directions perpendicular to each other. The angle signals frequency-modulate two subcarriers, which in their turn amplitude-modulated the transmitter carrier . With this more complicated equipment a measurement was made in November 1959. In this paper a description is given of the instrumentation of the wave meter and the receiving and recording equipment as it is at the present with a slightly changed modulating system. As the data from the wave meter could be used to study only the wave motion apart from the ship, it seems reasonable to present this paper at this conference.