Rostral Hypothalamic Differentiation With Minimal Exogenous Signals in Human Naive Induced Pluripotent Stem Cells

Familial neurohypophyseal diabetes insipidus (FNDI) is a degenerative disease of vasopressin (AVP) neurons. Studies in mouse in vivo models indicate that accumulation of mutant AVP prehormone is associated with FNDI pathology. However, studying human FNDI pathology in vivo is technically challenging. Therefore, an in vitro human model needs to be developed. When exogenous signals are minimized in the early phase of differentiation in vitro, mouse embryonic stem cells (ESCs) differentiate into AVP neurons, whereas human ESCs/induced pluripotent stem cells (iPSCs) die. Human ES/iPSCs are generally more similar to mouse epiblast stem cells compared to mouse ESCs, which are termed as primed and naive, respectively. In this study, we converted human FNDI-specific iPSCs from primed to naive cells, and found improved cell survival under minimal exogenous signals and differentiation into rostral hypothalamic organoids. Overall, this method provides a simple and straightforward differentiation direction, which may improve the efficiency of hypothalamic differentiation.

Sliding repetitive control with adaptive bound estimation for motion systems liable to periodic exogenous signals

Periodic exogenous signals often exist in motion systems, especially those involving one or more rotating elements. These periodic exogenous signals deteriorate the performance of motion systems, and these adverse effects cannot be practically eliminated by straightforwardly increasing feedback control gains due to sensor noise, actuator saturation, and unmodeled plant dynamics. This paper describes a sliding repetitive controller for motion systems subject to periodic exogenous signals. Moreover, an adaptive law for bound estimation is devised to ensure the presence of a sliding motion for both repetitive learning and disturbance observation. The tracking motion system of a disk drive is considered in practice, and a traditional repetitive controller is also implemented for performance comparisons with the proposed scheme. Experimental results are reported in this paper, showing the efficacy of the proposed scheme.

Bureaucrats' processing of organizational reputation signals

Notwithstanding the significance of a positive bureaucratic reputation, the average bureau functions amidst deep-rooted public hostility. Bureaucracy bashing presumably weakens public sector employees' commitment to their bureaus, which is known to undermine public sector performance. Motivated by these concerns, this paper investigates whether exogenous signals regarding a bureau's reputation affect the organizational attachment - identification and commitment - of its employees, and the variation in employee responses. Employing an experiment at an Israeli welfare bureaucracy, we show that the organizational attachment of employees who feel central and influential within the bureau is unshaken, and even reinforced, in response to negative reputation signals. Conversely, employees who feel marginal and powerless are receptive to both negative and positive reputation signals. The implications of these findings are that public organizations can buffer their employees from the detrimental effects of negative reputation signals, yet by so doing they may shut out justified scrutiny and demands for change.