Tachykinins Stimulate a Subset of Mouse Taste Cells

The tachykinins substance P (SP) and neurokinin A (NKA) are present in nociceptive sensory fibers expressing transient receptor potential cation channel, subfamily V, member 1 (TRPV1). These fibers are found extensively in and around the taste buds of several species. Tachykinins are released from nociceptive fibers by irritants such as capsaicin, the active compound found in chili peppers commonly associated with the sensation of spiciness. Using real-time Ca2+-imaging on isolated taste cells, it was observed that SP induces Ca2+ -responses in a subset of taste cells at concentrations in the low nanomolar range. These responses were reversibly inhibited by blocking the SP receptor NK-1R. NKA also induced Ca2+-responses in a subset of taste cells, but only at concentrations in the high nanomolar range. These responses were only partially inhibited by blocking the NKA receptor NK-2R, and were also inhibited by blocking NK-1R indicating that NKA is only active in taste cells at concentrations that activate both receptors. In addition, it was determined that tachykinin signaling in taste cells requires Ca2+-release from endoplasmic reticulum stores. RT-PCR analysis further confirmed that mouse taste buds express NK-1R and NK-2R. Using Ca2+-imaging and single cell RT-PCR, it was determined that the majority of tachykinin-responsive taste cells were Type I (Glial-like) and umami-responsive Type II (Receptor) cells. Importantly, stimulating NK-1R had an additive effect on Ca2+ responses evoked by umami stimuli in Type II (Receptor) cells. This data indicates that tachykinin release from nociceptive sensory fibers in and around taste buds may enhance umami and other taste modalities, providing a possible mechanism for the increased palatability of spicy foods

Rubber Clay Nanocomposites

The use of nanofillers allows the development of nanocomposites with improved properties and novel applications. The technological goal is possible due to the new compounding method that allows a particle dispersion in the nanometer scale increasing the specific surface area.Fil: Cova Sánchez, Mariajose. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; ArgentinaFil: Bacigalupe, Alejandro. Universidad Nacional de San Martín. Instituto de Investigación e Ingeniería Ambiental. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigación e Ingeniería Ambiental; Argentina. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; ArgentinaFil: Escobar, Mariano Martin. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Mansilla, Marcela Angela. Instituto Nacional de Tecnología Industrial. Instituto Nacional de Tecnología Industrial - Caucho; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Behavioral genetics and taste

This review focuses on behavioral genetic studies of sweet, umami, bitter and salt taste responses in mammals. Studies involving mouse inbred strain comparisons and genetic analyses, and their impact on elucidation of taste receptors and transduction mechanisms are discussed. Finally, the effect of genetic variation in taste responsiveness on complex traits such as drug intake is considered. Recent advances in development of genomic resources make behavioral genetics a powerful approach for understanding mechanisms of taste

Investigations on delta modulated inverter

Delta modulation offers a number of unique advantages in static PWM inverter applications in variable speed AC drives. The performance of a delta modulator is investigated in this paper for a square wave reference signal. This changeover from sine wave reference signal to square wave reference signal can reduce the cost of the control circuit significantly which is crucial in FHP drive range. The parametric sensitivity of this modulator is studied in this paper.© IEE

Performance of line start permanent magnet synchronous motor with single-phase supply system

The operation of a three-phase induction motor from a single-phase supply with a capacitor in circuit is well known. While detailed investigations on the performance of the induction motor under such operating conditions are well reported in the literature, no such work is reported for the synchronous motor. The fine-start permanent-magnet synchronous motor (LSPMSM) is actively being considered as an energy efficient alternative to the induction motor in general purpose, heavy duty applications. The paper presents an analytical and experimental evaluation on the performance of a three-phase LSPMSM fed from a single-phase supply. This analysis is carried out using symmetrical component theory. A capacitor is connected across two stator phases during starting and running. Estimation of the capacitor value to achieve the desired objectives, such as minimum unbalance, maximum power factor, maximum torque or maximum efficiency, is carried out. Load tests are conducted to validate the simulation results

Synchronous motor using ferrite magnets for general purpose energy efficient drive

A synchronous motor using ferrite magnets has the potential for energy saving in general applications such as fan, pump and compressor drives. A rotor geometry is suggested for this machine which eliminates the drawbacks of the conventionally used rotor geometries and gives higher airgap flux density. The performance of this machine with the proposed rotor geometry is compared with the conventional geometries for the same magnet volume and conductor density, employing field based circuit analysis. The performance of the machine for different operating conditions and asynchronous performance are also presented. The machine is also modified to suit the inverter fed drive.© IEE

EPROM-based modulator for synchronized asymmetric regular-sampled SPWM technique

The objective of sinusoidal PWM technique is to synthesize the motor currents as near to a sinusoid as possible economically. Traditionally, PWM control is accomplished using a natural sampling technique. Though its implementation is simple and in real time, it cannot give good performance in the entire operating range. Microprocessor-based PWM generation can offer significant advantages but suffer from computational time limitations. Moreover, it is not economical for general-purpose variable speed drives. A novel technique of PWM signal generation is addressed in this paper. While different requirements of high performance SPWM are fulfilled, the circuit configuration is reduced compared with conventional circuits. A regular sampled, asymmetric, synchronized SPWM with variable gear ratio and third harmonic injection at higher modulation depth, is realized with much reduced hardware. Such reduction in complexity, cost and space are essential to boost the changeover from constant speed to variable speed drive for energy saving in general applications. This was the motivation of work presented. The technique is well suited even for dedicated implementation using a microcontroller.© IEE

Equivalent circuit of single phase permanent magnet synchronous motor

Growing consumer and legislative pressures are increasing the demand for improved efficiency of fractional horse power motors. The single phase line start permanent magnet synchronous motor has been shown to have potential for high efficiency. An equivalent circuit for this motor is proposed to predict the steady state performance of this machine. Criteria for estimating the value of capacitor required for balanced operation for desired load is outlined. The analysis is analytically validated.© IEE