Inactive Points Research Articles

LEGENDRE CONDITIONS FOR A VARIATIONAL PROBLEM WITH ONE-SIDED PHASE CONSTRAINTS

This paper is concerned with a variational problem with inequality phase constraints. We present second-order necessary conditions (Legendre condition) for weak minimal solutions of the variational problem. Our optimality conditions give an information about the Hessian of the integrand at not only inactive points but also active points. Since the present constraints do not include x, our conditions differ from the Legendre-Clebsch condition.

Quantitative changes in liver dehydrogenase activity during and after temporary ischemia of the limbs

Experiments were performed on rabbits with electrochemotrodes implanted into the left and right dorsal hippocamp. The evidence was obtained for the first time as to the marked inhibitory effect of acupuncture on epileptogenic foci created by penicillin microinjections into the hippocamp. The most effective was stimulation of the Min-Men point. The antiepileptic effect was potentiated on combined stimulation of the Min-Men and Yao-Yan-Guan points. The efficacy of the procedure was significantly decreased on stimulation of the points of another acupunctural canal. The epileptiform activity was potentiated by affecting the knowingly inactive points. The antiepileptic effect of acupuncture was significantly reduced with an increase in the number of acupunctures. This might be connected with the development of tolerance to enkephalins by which the effect of acupuncture is most likely mediated.

Salt ingestion responses to diencephalic electrical stimulation in the unrestrained conscious sheep

In 20 conscious sheep, evidence was sought for localized brain mechanisms controlling ingestion of sodium salts, using electrical stimulation of diencephalic and neighbouring regions. The sheep lost saliva continuously through parotid fistulae. They were permitted to replace resultant sodium deficits episodically by drinking NaHCO 3 solution (300 mEquiv./l). Focal cathodal stimulation at 40 Hz was delivered through needle electrodes, permanently fixed or roving in depth, when the sheep were behaviourally satiated for available salt, water and food. Response maps were constructed for approximately 1,000 brain loci tested. On stimulation of particular sites in fimbria, fornix columns, perifornical hypothalamus, or medial forebrain bundle, 6 sheep ingested salt specifically, but similar loci in other elicited only licking or arousal. In some sheep, selection between NaHCO 3 and water for elicited drinking was influenced by situational factors. Licking was elicited from widespread loci in the diencephalon, fornix system, preoptic region and strio-pallidum, interspersed with excitatory or inactive points. The results suggest that hypothalamic mechanisms controlling salt ingestion exist, but are not reliably activated at comparable loci in different animals. It is alternatively possible that stimulated ingestion results from interactions between generalized arousal, excitation of unspecific alimentary circuits, and concurrent patterns of afferent input.