The temporal response of microdialysis probes in vivo was followed with 1-min sampling. The response under four conditions was examined: in vitro sampling of dopamine (DA), in vitro perfusion of DA, in vivo perfusion of DA, and in vivo perfusion of cocaine. The temporal response of the probe in a stirred solution at 37 degrees C for both sampling mode and perfusion mode was determined using a flow rate of 1.6 microL/min. As expected, the rate of gain or loss of DA in these two cases rapidly stabilized. The in vivo response to a step change in perfusate concentration was also examined. The rate of loss of DA into the tissue rapidly reached a steady state so that the dialysate DA concentration stabilized within 2 min. To examine the in vivo response of DA to a step change in drug concentration, dialysis probes in the striata of anesthetized rats were perfused with artificial cerebrospinal fluid interchanged with 20 microM cocaine. The increase in DA caused by its uptake inhibition by cocaine rapidly reached a maximum level in 2-4 min and then gradually decreased. After the cocaine was removed, the dialysate concentration of DA fell rapidly with some tailing, suggesting the presence of residual cocaine in the tissue. These results suggest that relatively fast changes in DA levels in tissue can be followed by microdialysis probes. The rapid stabilization also suggests that the DA concentration profile does not extend very far from the probe.

A major shift from skilled to unskilled workers was one of the many changes caused by the Industrial Revolution, when the switch to machines contributed to decline in the social and economic status of artisans, whose skills were dismembered into discrete actions by factory-line workers. We consider what may be an analogous computing technology: the recent introduction of AI-generated art software. AI art generators such as Dall-E and Midjourney can create fully rendered images based solely on a user's prompt, just at the click of a button. Some artists fear if the cheaper price and conveyorbelt speed that comes with AI-produced images is seen as an improvement to the current system, it may permanently change the way society values/views art and artists. In this article, we consider the implications that AI art generation introduces through a post-industrial revolution historical lens. We then reflect on the analogous issues that appear to arise as a result of the AI art revolution, and we conclude that the problems raised mirror those of industrialization, giving a vital glimpse into what may lie ahead.

The temporal and concentration response of microdialysis probes in vivo was characterized. The temporal response was monitored using step changes in dopamine (DA) concentration which were followed with one minute sampling using smallbore HPLC. The response under three conditions was examined: in vitro sampling of DA, in vitro infusion of DA, and local infusion of DA. The dialysate DA concentration stabilized within two minutes after each change. These results suggest that relatively fast changes in DA levels in tissue can be followed by microdialysis probes. The rapid stabilization also suggests that the DA concentration profile does not extend very far from the probe. To characterize the concentration response, the linearity of the gain or loss of DA diffusing between the probe and tissue was determined. The difference in the inflow and outflow concentrations was plotted as a function of the inflow concentration. The correlation coefficient of the linear regression curve was 0.99. The zero point intercept, the extracellular concentration of DA, was 3.8 nM and the slope, or recovery, was 63.4%. There was no break at the zero point which is indicative of symmetrical diffusion into and out of the probe.

We prove that $164\, 634\, 913$ is the smallest positive integer that is a sum of two rational sixth powers, but not a sum of two integer sixth powers. If $C_{k}$ is the curve $x^{6} + y^{6} = k$ , we use the existence of morphisms from $C_{k}$ to elliptic curves, together with the Mordell–Weil sieve, to rule out the existence of rational points on $C_{k}$ for various k.

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