scholarly journals Biomechanics and control of vocalization in a non-songbird

2007 ◽  
Vol 5 (24) ◽  
pp. 691-703 ◽  
Author(s):  
Coen P.H Elemans ◽  
Riccardo Zaccarelli ◽  
Hanspeter Herzel

The neuromuscular control of vocalization in birds requires complicated and precisely coordinated motor control of the vocal organ (i.e. the syrinx), the respiratory system and upper vocal tract. The biomechanics of the syrinx is very complex and not well understood. In this paper, we aim to unravel the contribution of different control parameters in the coo of the ring dove ( Streptopelia risoria ) at the syrinx level. We designed and implemented a quantitative biomechanical syrinx model that is driven by physiological control parameters and includes a muscle model. Our simple nonlinear model reproduces the coo, including the inspiratory note, with remarkable accuracy and suggests that harmonic content of song can be controlled by the geometry and rest position of the syrinx. Furthermore, by systematically switching off the control parameters, we demonstrate how they affect amplitude and frequency modulations and generate new experimentally testable hypotheses. Our model suggests that independent control of amplitude and frequency seems not to be possible with the simple syringeal morphology of the ring dove. We speculate that songbirds evolved a syrinx design that uncouples the control of different sound parameters and allows for independent control. This evolutionary key innovation provides an additional explanation for the rapid diversification and speciation of the songbirds.

2018 ◽  
Vol 2 ◽  
pp. 9-16
Author(s):  
A. Al-Ammouri ◽  
◽  
H.A. Al-Ammori ◽  
A.E. Klochan ◽  
A.M. Al-Akhmad ◽  
...  

The control of movement is essential for animals traversing complex environments and operating across a range of speeds and gaits. We consider how animals process sensory information and initiate motor responses, primarily focusing on simple motor responses that involve local reflex pathways of feedback and control, rather than the more complex, longer-term responses that require the broader integration of higher centers within the nervous system. We explore how local circuits facilitate decentralized coordination of locomotor rhythm and examine the fundamentals of sensory receptors located in the muscles, tendons, joints, and at the animal’s body surface. These sensors monitor the animal’s physical environment and the action of its muscles. The sensory information is then carried back to the animal’s nervous system by afferent neurons, providing feedback that is integrated at the level of the spinal cord of vertebrates and sensory-motor ganglia of invertebrates.


2019 ◽  
Vol 9 (2) ◽  
pp. 252 ◽  
Author(s):  
Ziqian Zhang ◽  
Cihan Gercek ◽  
Herwig Renner ◽  
Angèle Reinders ◽  
Lothar Fickert

This article presents an in-situ comparative analysis and power quality tests of a newly developed photovoltaic charging system for e-bikes. The various control methods of the inverter are modeled and a single-phase grid-connected inverter is tested under different conditions. Models are constituted for two current control methods; the proportional resonance and the synchronous rotating frames. In order to determine the influence of the control parameters, the system is analyzed analytically in the time domain as well as in the frequency domain by simulation. The tests indicated the resonance instability of the photovoltaic inverter. The passivity impedance-based stability criterion is applied in order to analyze the phenomenon of resonance instability. In conclusion, the phase-locked loop (PLL) bandwidth and control parameters of the current loop have a major effect on the output admittance of the inverter, which should be adjusted to make the system stable.


2015 ◽  
Vol 352 (3) ◽  
pp. 776-801 ◽  
Author(s):  
Liang Li ◽  
Yahui Zhang ◽  
Chao Yang ◽  
Xiaohong Jiao ◽  
Lipeng Zhang ◽  
...  

2017 ◽  
Vol 76 (5) ◽  
pp. 1225-1233 ◽  
Author(s):  
M. Schäfer ◽  
I. Hobus ◽  
T. G. Schmitt

In the future, an additional potential of control reserve as well as storage capacities will be required to compensate fluctuating renewable energy availability. The operation of energy systems will change and flexibility in energy generation and consumption will rise to a valuable asset. Wastewater treatment plants (WWTPs) are capable of providing the flexibility needed, not only with their energy generators but also in terms of their energy consuming aggregates on the plant. To meet challenges of the future in regard to energy purchase and to participate in and contribute to such a volatile energy market, WWTPs have to reveal their energetic potential as a flexible service provider. Based on the evaluated literature and a detailed analysis of aggregates on a pilot WWTP an aggregate management has been developed to shift loads and provide a procedure to identify usable aggregates, characteristic values and control parameters to ensure effluent quality. The results show that WWTPs have a significant potential to provide energetic flexibility. Even for vulnerable components such as aeration systems, load-shifting is possible with appropriate control parameters and reasonable time slots without endangering system functionality.


2019 ◽  
Vol 148 ◽  
pp. 157-172 ◽  
Author(s):  
Sriraj Gokarakonda ◽  
Christoph van Treeck ◽  
Rajan Rawal

1966 ◽  
Vol 36 (1) ◽  
pp. 35-51 ◽  
Author(s):  
D. M. VOWLES ◽  
D. HARWOOD

SUMMARY The aggressive and defensive behaviour of the ring dove was studied in response to a model predator and to another member of the same species. During a single breeding cycle defensive behaviour increased rapidly just before laying, reached a second peak at the time of hatching, and declined as the squabs became independent. Cocks showed aggressive behaviour to other doves throughout the cycle, but this response reached a peak soon after laying, and declined at the time of hatching. The effects of seven daily injections of oestrogen, progesterone, progesterone plus oestrogen, testosterone, and prolactin were studied. In both sexes prolactin and progesterone (with and without oestrogen) increased defensive behaviour towards a predator; in hens these hormones also increased defensive behaviour towards other birds. In cocks, however, prolactin had no effect on the response to other doves; progesterone (with and without oestrogen) increased aggressiveness, and oestrogen increased nest-cooing. Single injections of the same hormones produced similar effects, with the exception that testosterone and oestrogen in hens caused a temporary (1–5 hr.) increase in defensive behaviour. The latency of most hormonal effects was 30 min. to 2 hr., although the injections were intramuscular. This suggests a direct effect on central nervous mechanisms. Progesterone had a latency of 12–18 hr., suggesting an indirect effect.


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