Feedback effective

The main relationships between the agitation intensity of the dispersion and the total mass-transfer rate are summarized qualitatively for constant gas flow rate by Fig. 1 (G9) wherein interaction effects among the bubbles are indicated by dashed lines. Intermediate phenomena not shown, such as the direct and feedback effects between coalescence and mass transfer (G5, G9), should also be considered. 

Block the inhibitory feedback effect of released DA on terminal autoreceptors. 

In Chapter 3 the steady-state hydrodynamic aspects of two-phase flow were discussed and reference was made to their potential for instabilities. The instability of a system may be either static or dynamic. A flow is subject to a static instability if, when the flow conditions change by a small step from the original steady-state ones, another steady state is not possible in the vicinity of the original state. The cause of the phenomenon lies in the steady-state laws hence, the threshold of the instability can be predicted only by using steady-state laws. A static instability can lead either to a different steady-state condition or to a periodic behavior (Boure et al., 1973). A flow is subject to a dynamic instability when the inertia and other feedback effects have an essential part in the process. The system behaves like a servomechanism, and knowledge of the steady-state laws is not sufficient even for the threshold prediction. The steady-state may be a solution of the equations of the system, but is not the only solution. The above-mentioned fluctuations in a steady flow may be sufficient to start the instability. Three conditions are required for a system to possess a potential for oscillating instabilities ... 

Delay and feedback effects in relationships among flow rate, density, pressure drops... 

Computer codes Because of the computer s ability to handle the complicated mathematics, most of the compounded and feedback effects are built into computer codes for analyzing dynamic instabilities. Most of these codes can analyze one or more of the following instabilities density wave instability, compound dynamic instabilities such as BWR instability and parallel-channel instability, and pressure drop oscillations. 

Cortisol is an important component of the body s response to physical and psychological stress. Nervous signals regarding stress are transmitted to the hypothalamus and the release of CRH is stimulated. The resulting increase in cortisol increases levels of glucose, free fatty acids, and amino acids in the blood, providing the metabolic fuels that enable the individual to cope with the stress. A potent inhibitor of this system is cortisol itself. This hormone exerts a negative-feedback effect on the hypothalamus and the adenohypophysis and inhibits the secretion of CRH and ACTH, respectively. 

The beams are backreflected by the cube corner prisms which are fixed, respectively, on the sample and on the sample holder. Since the cube corner prisms are able to make reflected beam exactly parallel to incident beam, this interferometer is tilt independent. The reflected beams get back to the beam splitter through the same path, but shifted by about 2 mm in the vertical direction. The beam splitter lets a part of the two beams go towards the photodiode sensor and lets the other part of beams reach the laser source (off axis, therefore giving no feedback effect). 

Chongthammakun S, Teresawa E (1993) Negative feedback effects of estrogen on luteinizinghormone-releasinghormone release occur in pubertal, but not prepubertal, ovariectomized female rhesus monkeys. Endocrinology 132 735-743... 

A particular pulmonary irritant may alter air or mucus flow, and this in turn is one of the factors determining the local tissue dosage of the irritant. Such positive or negative feedback effects should also be incorporated into a dynamic model. 

Section IV explains a new approach to high resolution spectroscopy based on various kinds of saturation effects. Some of the experiments are performed inside the laser resonator, which implies the presence of coupling phenomena between the absorbing molecules under investigation and the laser oscillation itself. These feedback effects can be used for high-precision frequency stabilization and to measure frequency shifts and line profiles with an accuracy never... 

Why weeds reduce crop yields cannot be adequately answered. Considerable data have accumulated which relate duration of weed presence and weed density to crop yield. However, such data provide little explanation for why crop yields are reduced. The objectives of this paper are to 1) provide an overview of the time relationship of competition for growth factors and of allelopathy as factors in crop yield reduction and 2) suggest a direct feedback effect on reproduction in response to light as a possible third direct factor in explaining effects of weeds on crop yield. 

Autonomic and hormonal control of cardiovascular function. Note that two feedback loops are present the autonomic nervous system loop and the hormonal loop. The sympathetic nervous system directly influences four major variables peripheral vascular resistance, heart rate, force, and venous tone. It also directly modulates renin production (not shown). The parasympathetic nervous system directly influences heart rate. In addition to its role in stimulating aldosterone secretion, angiotensin II directly increases peripheral vascular resistance and facilitates sympathetic effects (not shown). The net feedback effect of each loop is to compensate for changes in arterial blood pressure. Thus, decreased blood pressure due to blood loss would evoke increased sympathetic outflow and renin release. Conversely, elevated pressure due to the administration of a vasoconstrictor drug would cause reduced sympathetic outflow, reduced renin release, and increased parasympathetic (vagal) outflow. 

Since FSH and LH are involved in spermatogenesis, hypothalamic control of their release by the pituitary is important for testicular function. Both FSH and LH are secreted in a pulsatile fashion from the pituitary. Inhibin produced by Sertoli cells has the most important negative feedback effect on FSH secretion, while testosterone exerts negative feedback effects on secretion of GnRH by the hypothalamus, thus regulating secretion of LH and, to a lesser extent, FSH. 

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