Vasopressins are evolutionarily conserved peptide hormones. Mammalian vasopressin functions systemically as an antidiuretic and regulator of blood and cardiac flow essential for adapting to terrestrial environments. Moreover, vasopressin acts centrally as a neurohormone involved in social and parental behavior and stress response. Vasopressin synthesis in several cell types, storage in intracellular vesicles, and release in response to physiological stimuli are highly regulated and mediated by three distinct G protein coupled receptors. Other receptors may bind or cross-bind vasopressin. Vasopressin is regulated spatially and temporally through transcriptional and post-transcriptional mechanisms, sex, tissue, and cell-specific receptor expression. Anomalies of vasopressin signaling have been observed in polycystic kidney disease, chronic heart failure, and neuropsychiatric conditions. Growing knowledge of the central biological roles of vasopressin has enabled pharmacological advances to treat these conditions by targeting defective systemic or central pathways utilizing specific agonists and antagonists.

Summary This paper investigates the tracking problem for a class of uncertain switched nonlinear delayed systems with nonstrict‐feedback form. To address this problem, by introducing a new common Lyapunov function (CLF), an adaptive neural network dynamic surface control is proposed. The state‐dependent switching rule is designed to orchestrate which subsystem is active at each time instance. In order to compensate unknown delay terms, an appropriate Lyapunov‐Krasovskii functional is considered in the constructing of the CLF. In addition, a novel switched neural network–based observer is constructed to estimate system states through the output signal. To maintain the tracking error performance within a predefined bound, a prescribed performance bound approach is employed. It is proved that by the proposed output‐feedback control, all the signals of the closed‐loop system are bounded under the switching law. Moreover, the transient and steady‐state tracking performance is guaranteed by the prescribed performance bound. Finally, the effectiveness of the proposed method is illustrated by two numerical and practical examples.

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An experiment was conducted to evaluate the effect of zinc (Zn) rates and vermicompost levels on distribution of Zn forms of a calcareous soil. After incubation periods, soil samples were air dried, and a sequential extraction scheme was used to fractionate Zn into soluble and exchangeable, bound to carbonate, organically bound, bound to manganese (Mn) oxide, bound to amorphous iron (Fe) oxide, bound to crystalline Fe oxide, and residual forms. In untreated soil, Zn was mainly in the residual fraction. Increasing rates of applied Zn significantly increased all forms of Zn. Carbonate and residual forms showed the greatest increase. Application of vermicompost significantly increased all fractions except Mn-oxide form. This increase was more pronounced for organically bound, soluble, and exchangeable forms, indicating an increase in bioavailability of soil Zn. Incubation time significantly decreased soluble, exchangeable, and organically bound forms but increased other forms of Zn, meaning a significant reduction in Zn phytoavailability in soil with time.

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