Different Effects of Supervisor Positive and Negative Feedback on Subordinate In-Role and Extra-Role Performance: The Moderating Role of Regulatory Focus

As an important tool for supervisors to intervene subordinates’ work and influence their performance, supervisor feedback has gradually become a new academic research hotspot. In this study, we build and verify a theoretical model to explore the different effects of supervisor positive and negative feedback on subordinate in-role and extra-role performance, and the moderating role of regulatory focus in these relationships. With data from pairing samples of 403 Chinese employees and their direct supervisors, the results indicate that supervisor positive feedback is positively related to subordinate in-role and extra-role performance. Supervisor negative feedback is positively related to subordinate in-role performance and negatively related to subordinate extra-role performance. Regulatory focus of subordinate can moderate the influence of supervisor positive feedback on subordinate in-role and extra-role performance, but it cannot moderate the influence of supervisor negative feedback on subordinate in-role and extra-role performance. That means when subordinates have promotion focus, the influence of supervisor positive feedback on their in-role performance and extra-role performance was stronger than those with prevention focus. These results further enrich the research on the relationship between supervisor feedback and subordinate performance, especially the different effects of positive and negative feedback from supervisor on subordinate with different regulatory focus. All conclusions from the analyses above not only further verify and develop some previous points on supervisor feedback and subordinate performance, but also derive certain management implications for promoting subordinate in-role and extra-role performance from the perspective of supervisor positive and negative feedback.

The synaptic organization in the C. elegans neural network suggests significant local compartmentalized computations

Neurons are characterized by elaborate tree-like dendritic structures that support local computations by integrating multiple inputs from upstream presynaptic neurons. It is less clear if simple neurons, consisting of a few or even a single neurite, may perform local computations as well. To address this question, we focused on the compact neural network of C. elegans animals for which the full wiring diagram is available, including the coordinates of individual synapses. We find that the positions of the chemical synapses along the neurites are not randomly distributed, nor can they be explained by anatomical constraints. Instead, synapses tend to form clusters, an organization that supports local compartmentalized computations. In mutually-synapsing neurons, connections of opposite polarity cluster separately, suggesting that positive and negative feedback dynamics may be implemented in discrete compartmentalized regions along neurites. In triple-neuron circuits, the non-random synaptic organization may facilitate local functional roles, such as signal integration and coordinated activation of functionally-related downstream neurons. These clustered synaptic topologies emerge as a guiding principle in the network presumably to facilitate distinct parallel functions along a single neurite, effectively increasing the computational capacity of the neural network.

Killing by Degradation: Regulation of Apoptosis by the Ubiquitin-Proteasome-System

Apoptosis is a cell suicide process that is essential for development, tissue homeostasis and human health. Impaired apoptosis is associated with a variety of human diseases, including neurodegenerative disorders, autoimmunity and cancer. As the levels of pro- and anti-apoptotic proteins can determine the life or death of cells, tight regulation of these proteins is critical. The ubiquitin proteasome system (UPS) is essential for maintaining protein turnover, which can either trigger or inhibit apoptosis. In this review, we will describe the E3 ligases that regulate the levels of pro- and anti-apoptotic proteins and assisting proteins that regulate the levels of these E3 ligases. We will provide examples of apoptotic cell death modulations using the UPS, determined by positive and negative feedback loop reactions. Specifically, we will review how the stability of p53, Bcl-2 family members and IAPs (Inhibitor of Apoptosis proteins) are regulated upon initiation of apoptosis. As increased levels of oncogenes and decreased levels of tumor suppressor proteins can promote tumorigenesis, targeting these pathways offers opportunities to develop novel anti-cancer therapies, which act by recruiting the UPS for the effective and selective killing of cancer cells.

Alternating Positive and Negative Feedback Control Model Based on Catastrophe Theories

In automatic control systems, negative feedback control has the advantage of maintaining a steady state, while positive feedback control can enhance some activities of the control system. How to design a controller with both control modes is an interesting and challenging problem. Motivated by it, on the basis idea of catastrophe theories, taking positive feedback and negative feedback as two different states of the system, an adaptive alternating positive and negative feedback (APNF) control model with the advantages of two states is proposed. By adaptively adjusting the relevant parameters of the constructed symmetric catastrophe function and the learning rule based on error and forward weight, the two states can be switched in the form of catastrophe. Through the Lyapunov stability theory, the convergence of the proposed adaptive APNF control model is proven, which indicates that system convergence can be guaranteed by selecting appropriate parameters. Moreover, we present theoretical proof that the negative feedback system with negative parameters can be equivalent to the positive feedback system with positive parameters. Finally, the results of the simulation example show that APNF control has satisfactory performance in response speed and overshoot.

Interplay of positive and negative feedback loops governs robustness in multistable biological networks

Biological networks are widely reported to be robust to both external and internal perturbations. However, the exact mechanisms and design principles that enable robustness are not yet fully understood. Here we investigated dynamic and structural robustness in biological networks with regards to phenotypic distribution and plasticity. We use two different approaches to simulate these networks: a computationally inexpensive, parameter-independent continuous model, and an ODE-based parameter-agnostic framework (RACIPE), both of which yield similar phenotypic distributions. Using perturbations to network topology and by varying network parameters, we show that multistable biological networks are structurally and dynamically more robust as compared to their randomized counterparts. These features of robustness are governed by an interplay of positive and negative feedback loops embedded in these networks. Using a combination of the number of negative and positive feedback loops weighted by their lengths and sign, we identified a metric that can explain the structural and dynamical robustness of these networks. This metric enabled us to compare networks across multiple sizes, and the network principles thus obtained can be used to identify fragilities in large networks without simulating their dynamics. Our analysis highlights a network topology based approach to quantify robustness in multistable biological networks.

Metabolic homeostasis: it’s all in the timing

Cross-talk between peripheral tissues is essential to ensure the coordination of nutrient intake with disposition during the feeding period, thereby preventing metabolic disease. This Mini-review considers the interactions between the key peripheral tissues that constitute the metabolic clock, each of which is considered in a separate Mini-review in this collation of articles published in Endocrinology in 2020/2021, by: Martchenko et al. (Circadian Rhythms and the Gastrointestinal Tract: Relationship to Metabolism and Gut Hormones); Alvarez et al. (The Microbiome as a Circadian Coordinator of Metabolism); Seshadri et al. (Circadian Regulation of the Pancreatic Beta Cell); McCommis et al. (The Importance of Keeping Time in the Liver); Oosterman et al. (The Circadian Clock, Shift Work, and Tissue-Specific Insulin Resistance); and Heyde et al. (Contributions of White and Brown Adipose Tissues to the Circadian Regulation of Energy Metabolism). The use of positive- and negative-feedback signals, both hormonal and metabolic, between these tissues ensures that peripheral metabolic pathways are synchronized with the timing of food intake, thus optimizing nutrient disposition and preventing metabolic disease. Collectively, these articles highlight the critical role played by the circadian clock in the maintenance of metabolic homeostasis.

Reap what you sow: implementing agencies as strategic actors in policy feedback dynamics

Government agencies responsible for policy implementation have expertise on policy practicability, efficiency and effectiveness, and knowledge which is provided to policymakers as feedback. However, we know very little about the feedback dynamics in which implementing agencies provide different types of feedback with the intention that it is used by policymakers, and the strategic decisions underlying these dynamics. This article connects the literature on policy feedback and knowledge use to develop a typology of implementation feedback which can account for these strategic actions. While existing distinctions between positive and negative feedback lead to confusion when applied to implementation feedback, our typology moves beyond this confusion, by classifying implementation feedback on the basis of two dimensions: preferences of implementing agencies and whether feedback is in response an agenda for change, or existing policy instruments. To illustrate the typology, we look at implementation feedback surrounding the post-2013 reform of the Common Agricultural Policy. We find that implementing agencies engage predominantly in problem-solving and mitigating types of implementation feedback, which are the types of feedback most likely to be used instrumentally by policymakers. Moreover, role perception of implementing agencies limits feedback focused on agenda removal, which is more politically sensitive and contested. These insights are important for our understanding of policy feedback on the level of policy instruments and settings. Moreover, future research can use this typology to structure feedback by other actors.

Negative feedback

Negative feedback is an essential constituent of any control system. It is illustrated for the case of an electronic voltage amplifier. Formal definitions are given of positive and negative feedback. Feedback can be used to adjust the amplifier's frequency response. Distortion, meaning generation of new and unwanted frequencies (harmonics, sums, differences), is reduced by a factor equal to the “return difference”.