BURNSTOCK, G, DUMSDAY, B & SMYTHE, A 1972, 'Atropine resistant excitation of the urinary bladder: the possibility of transmission via nerves releasing a purine nucleotide', British Journal of Pharmacology, vol. 44, no. 3, pp. 451-461.
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SummaryThe possibility that a purine nucleotide is involved in excitatory transmission to the urinary bladder has been tested. All the purine compounds tested which contained a pyrophosphate bond produced contraction, adenosine triphosphate (ATP) being the most potent. Adenosine and adenosine monophosphate caused relaxation.The response to ATP closely mimicked the nerve‐mediated contraction, both being characterized by a rapid contraction which was not maintained. A lack of sensitivity to ATP was noted in some preparations of the rat urinary bladder.Both nerve‐mediated contractions and contractions caused by ATP were blocked by quinidine, while the response to acetylcholine persisted.Nerve‐mediated responses were depressed during tachyphylaxis produced by high concentrations of ATP. Tachyphylaxis did not occur when low concentrations were used. Possible explanations for these results are discussed.The results are consistent with the hypothesis that non‐cholinergic excitatory nerves to the guinea‐pig bladder release a purine nucleotide, but do not provide critical evidence for it.
BURNSTOCK, G, SATCHELL, DG & SMYTHE, A 1972, 'A comparison of the excitatory and inhibitory effects of non‐adrenergic, non‐cholinergic nerve stimulation and exogenously applied ATP on a variety of smooth muscle preparations from different vertebrate species', British Journal of Pharmacology, vol. 46, no. 2, pp. 234-242.
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Summary. The responses to non‐adrenergic, non‐cholinergic nerve stimulation have been compared with those to exogenously applied ATP on seventeen different tissues from a number of vertebrate classes.. Stimulation of all the mammalian gut preparations studied (with the exception of the guinea‐pig ileum) after blockade of the effects of adrenergic and cholinergic nerve stimulation by guanethidine (3·5 μm) and hyoscine (1–3 μm) caused inhibition; exogenously applied ATP mimicked this inhibitory response.. Stimulation of the guinea‐pig ileum in the presence of hyoscine and guanethidine, usually caused a diphasic response, relaxation followed by contraction; exogenously applied ATP mimicked this response, in contrast to acetylcholine and noradrenaline which caused excitation and relaxation respectively.. Stimulation of preparations of lower vertebrate gut and guinea‐pig bladder in the presence of hyoscine and guanethidine caused contraction; exogenously applied ATP mimicked this contractile response.. In each preparation the time course of the response to ATP was similar or identical to the response to non‐adrenergic, non‐cholinergic nerve stimulation.. The results are consistent with the hypothesis that a purine nucleotide may be the transmitter substance released from non‐adrenergic, non‐cholinergic nerves supplying smooth muscle preparations from a number of vertebrate classes.
Leslie, LM 1972, 'The wake of a finite rotating disc', Journal of the Australian Mathematical Society, vol. 13, no. 3, pp. 291-304.
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When a disc rotates in a fluid at rest, fluid near the disc acquires azimuthal momentum because of the viscous torque of the disc and outwards radial momentum under the action of centrifugal forces. The resultant flow is essentially a swirling jet. Away from the disc continuity requires the existence of an axial flow towards the disc to compensate for the fluid which has been thrown outwards. If the disc is finite there is a discontinuity in the boundary conditions at the edge of the disc where the no-slip condition is suddenly replaced by a condition of zero stress in the plane of the disc. The flow discharged from the edge of the disc is essentially a wake embedded in a swirling radial jet. It appears that no investigation of this wake has yet been made.
Novikov, AA 1972, 'Sequential estimation of the parameters of diffusion processes', Mathematical Notes of the Academy of Sciences of the USSR, vol. 12, no. 5, pp. 812-818.
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For the parameter λ of a diffusion processξ(t), satisfying the stochastic differential equation dξ(t)=λf (t,ξ)dt+dw(l), we propose an effective sequential estimation plan with an unbiased and normally distributed estimate. The proposed sequential plan is discussed in detail for the example of a process ξ(t) having a linear stochastic differential. © 1973 Consultants Bureau.
