Opioids inhibit the rapid eye movement (REM) phase of sleep and decrease acetylcholine (ACh) release in medial pontine reticular formation (mPRF) regions contributing to REM sleep generation. It is ...not known whether opioids decrease ACh release by acting on cholinergic cell bodies or on cholinergic axon terminals. This study used in vivo microdialysis to test the hypothesis that opioids decrease ACh levels at cholinergic neurons in the laterodorsal tegmental nuclei (LDT) and LDT axon terminals in the mPRF.
Nine male cats were anesthetized with halothane, and ACh levels within the mPRF or LDT were assayed using microdialysis and high-pressure liquid chromatography (HPLC). ACh levels were analyzed in response to dialysis of the mPRF and LDT with Ringer's solution (control), followed by dialysis with Ringer's solution containing morphine sulfate (MSO4) or naloxone. ACh in the mPRF also was measured during either dialysis delivery or intravenous infusion of remifentanil and during dialysis delivery of fentanyl.
Compared with dialysis of Ringer's solution, microdialysis with MSO4 decreased ACh by 23% in the mPRF and by 30% in the LDT. This significant decrease in ACh was antagonized by naloxone. MSO4 and fentanyl each caused a dose-dependent decrease in mPRF ACh when delivered by dialysis. Remifentanil delivered by continuous intravenous infusion or by dialysis into the mPRF did not alter mPRF ACh.
Morphine inhibits ACh at the cholinergic cell body region (LDT) and the terminal field in the mPRF. ACh in the mPRF was not altered by remifentanil and was significantly decreased by fentanyl. Thus, MSO4 and fentanyl disrupt cholinergic neurotransmission in the LDT-mPRF network known to modulate REM sleep and cortical electroencephalographic activation. These data are consistent with the possibility that inhibition of pontine cholinergic neurotransmission contributes to arousal state disruption by opioids.
The blind decades Askenazy, Philippe
2014., 20141128, 2014, 2014-11-26
eBook
France is often described as one of the last Western economies unable to reform itself in the face of globalization. Yet its economy has not fallen by the wayside and has even resisted the great ...recession that began in 2008. By interlinking historical, economic, and political factors and by comparing France with other nations, this book explains the puzzle presented by the development of France. Understanding France's economy requires downplaying the usual policy injunctions—demands for less state control and less rigidity in the labor market—and instead stressing the importance of constructing a long-term industrial strategy.
Final-state Control for a Long Span Motion HIRATA, Mitsuo; KIDOKORO, Takahiro
Keisoku Jidō Seigyo Gakkai ronbunshū,
2009, 2009-00-00, Volume:
45, Issue:
12
Journal Article
Open access
We have proposed a design method of feedforward input that does not excite high frequency resonance modes based on a final-state control (FSC). However, for a long span motion, the number of steps of ...feedforward input tends to be higher, and the final-state control method may not produce a correct solution because of numerical conditions. In this paper, we propose a new design method of the final-state control for the long span motion. The amount of calculation is reduced to have time intervals in which the feedforward input is a constant or zero. The effectiveness is shown by simulations.
Purpose
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Reviews the latest management developments across the globe and pinpoints practical implications from cutting-edge research and case studies.
Design/methodology/approach
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This briefing is ...prepared by an independent writer who adds their own impartial comments and places the articles in context.
Findings
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Expansion into international markets has become one of the main growth strategies for many organizations. The blueprint is straightforward enough. Identify untapped potential and exploit the opportunities provided. Build a strong market position and reap lucrative rewards. If only it was that simple. Entering any new territory in the home nation is invariably demanding enough. Factor in the additional challenges inherent in any oversea venture and the difficulty soars to even greater heights. In any market, companies are subject to both technical and institutional demands which increase the complexity of decisions firms have to make. Pressures differ in each environment, so reacting in an appropriate manner is a must. Negotiating these demands effectively can go a considerable way in determining whether organizations ultimately succeed or fail.
Practical implications
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Provides strategic insights and practical thinking that have influenced some of the world's leading organizations.
Originality/value
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The briefing saves busy executives and researchers hours of reading time by selecting only the very best, most pertinent information and presenting it in a condensed and easy-to digest format.
Purpose - The purpose of this paper is to show the link between human error and marine accidents.Design methodology approach - The authors carried out field research and also used empirical ...evidence.Findings - Until 1998, the human side has been neglected, for centuries, in favor of the technical side. Even after 1998 improper focus did not eliminate marine accidents.Research limitations implications - Lack of data between human error and marine accidents.Practical implications - The paper is addressed to the maritime community and its safety administration in the EU and IMO, to eliminate human error.Social implications - There is potential for reduction of human injuries, deaths and marine pollution.Originality value - The paper is of value as no prior research, in depth, has been done to see what is behind the standard etiquette "human error" in marine accidents.
This article discusses the enforcement of shipping standards, with a particular focus on Part XII of UNCLOS. Section 6 of Part XII contains the only comprehensive set of vessel-related enforcement ...provisions in the Convention, but the Part’s scope is limited to “the preservation and protection of the marine environment.” Therefore, not all shipping standards fall clearly within Part XII’s ambit, including those centered on safety, security, and crewing considerations. The enforcement provisions of Section 6 are favorable to flag states and their vessels, and Section 7 contains a number of safeguards for their benefit, so it is in the interests of these parties to have coastal state enforcement governed by Part XII. However, the ability of coastal states to establish and enforce shipping standards that apply within the territorial sea extends to more than just environmental matters. The result is that different standards give rise to different enforcement powers, depending on the maritime zone in which a vessel is located, even if those standards arise from the same international agreement. It is suggested that to remedy these problems, UNCLOS would need to be amended in order to provide a comprehensive enforcement regime for the enforcement of shipping standards.
Prevailing ecological control theory is based on predation phenomena, it implies that a symbiotic ecosystem results from the predator imposing on prey a low, stable equilibrium. Mathematically, such ...dynamic model, like prevailing control equations, stresses directly regulating the state of prey, the controlled population, while the input variable of the control is state variable of the predator population. However, predation relation is not unique theorem to explain every kind of interaction between populations, the interactions without energy or biomass exchange are scarcely depicted by the dynamic models which depict the interaction based on principle of predation. How to model the interrelation deals with how to comprehend the interaction mechanism. Many researchers have recognized that some interactions work in indirect ways, regulating state of a population via imposing on its ecological/physiological trait is also one mode of interaction between the populations. These phenomena broadly exist in ecosystems. If coefficients of state equation of the regulated population are defined in terms of their ecological trait, regulating the coefficients to vary the population state may implement a kind of particular control processes, namely, trait control.
Expressed by differential dynamic equations, as well known, an ecosystem may exhibit different formal solutions by regulating coefficients of the equations, and each solution corresponds to an ecological pattern. This is theoretic basis of ecological trait control. Introduced trait control function by means of coefficient regulation, the dynamic model can depict many indirect effects caused by biotic or abiotic ecological factors, and explain more complex phenomena in ecosystems. For instance, the environmental factors can be considered as variables imposing on the trait of the ecosystem.
This paper applies Life Energy System dynamic model (LESM) to illustrate the principle and analysis approach of energy trait control; possible energy trait control modes are proposed according to different interaction between populations in an ecosystem. It was found that the trait control could realize distinct control effect from that depicted by traditional biological control models. With the trait control function, the dynamic model is able to interpret more complex ecological structures and potential evolutionary mechanism. Such exploration may provide further research on complexity of ecosystem with theoretical basis.
Mesopontine cholinergic neurons have long been thought to play a key role in behavioral state control. In particular, they have been implicated in the process of EEG desynchrony and in the generation ...of rapid eye movement (REM) sleep. However, the behavioral profile of identified mesopontine cholinergic neurons has not been unequivocally demonstrated. In an attempt to address this issue, in vivo microdialysis was used to monitor acetylcholine (ACh) release across behavioral state in the rat thalamus, a major projection site of mesopontine cholinergic neurons. Because REM periods in rats are of short duration, a method was developed to collect and accumulate sufficiently large samples from each of the individual states of wake, slow-wave sleep, and REM sleep to permit off-line analysis via (HPLC-ECD). Probe placement and the source of cholinergic innervation to the vicinity of the microdialysis probe were verified using retrograde tracing combined with ChAT immunohistochemistry. Finally, the sodium and calcium dependence of ACh measured in the thalamus were tested using TTX and calcium-free dialysates. The results showed that (1) extracellular ACh concentrations in the thalamus are high during both wake and REM sleep and significantly lower during slow-wave sleep, (2) the majority of cholinergic projections to the vicinity of the dialysis probes originate in the mesopontine tegmentum, and (3) ACh release in the thalamus is due to sodium- and calcium-dependent mechanisms. In contrast to predictions of some previous hypotheses, these results demonstrate that mesopontine cholinergic neurons are active during both wake and REM sleep.
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