LmbU, a Cluster-Situated Regulator for Lincomycin, Consists of a DNA-Binding Domain, an Auto-Inhibitory Domain, and Forms Homodimer

Few studies were reported about the regulatory mechanism of lincomycin biosynthesis since it was found in 1962. Although we have proved that a cluster-situated regulator (CSR) LmbU (GenBank Accession No. ABX00623.1) positively modulates lincomycin biosynthesis in Streptomyces lincolnensis NRRL 2936, the molecular mechanism of LmbU regulation is still unclear. In this study, we demonstrated that LmbU binds to the target lmbAp by a central DNA-binding domain (DBD), which interacts with the binding sites through the helix-turn-helix (HTH) motif. N-terminal of LmbU includes an auto-inhibitory domain (AID), inhibiting the DNA-binding activity of LmbU. Without the AID, LmbU variant can bind to its own promoter. Interestingly, compared to other LmbU homologs, the homologs within the biosynthetic gene clusters (BGCs) of known antibiotics generally contain N-terminal AIDs, which offer them the abilities to play complex regulatory functions. In addition, cysteine 12 (C12) has been proved to be mainly responsible for LmbU homodimer formation in vitro. In conclusion, LmbU homologs naturally exist in hundreds of actinomycetes, and belong to a new regulatory family, LmbU family. The present study reveals the DBD, AID and dimerization of LmbU, and sheds new light on the regulatory mechanism of LmbU and its homologs

Common and distinct equity preferences in children and adults

Fairness plays a crucial role in children’s social life and has garnered considerable attention. However, previous research and theories primarily examined the development of children’s fairness behaviors in the conflict between self-interest motivation and fairness-complying motivation, neglecting the influence of advantage-seeking motivation. Moreover, despite the well-established role of gain/loss frame in human decision-making, it remains largely unclear whether the framing effect modulates fairness behaviors in children. It was hypothesized that children would exhibit advantage-seeking motivation resulting in more selfish behaviors in the loss context. To examine the hypothesis, we combined an adapted dictator game and computational modeling to investigate various motivations underlying fairness behaviors of children in both loss and gain contexts and to explore the developmental directions by contrasting children and adults. In addition, the current design enabled the dissociation between fairness knowledge and behaviors by asking participants to decide for themselves (the first-party role) or for others (the third-party role). This study recruited a total of 34 children (9–10 years, Mage = 9.82, SDage = 0.38, 16 females) and 31 college students (Mage = 19.81, SDage = 1.40, 17 females). The behavioral results indicated that children behaved more selfishly in first-party and more fairly in third-party than adults, without any significant framing effects. The computational results revealed that both children and adults exhibited aversion to advantageous and disadvantageous inequity in third-party. However, they showed distinct preferences for advantageous inequity in first-party, with advantage-seeking preferences among children and aversion to advantageous inequity among adults. These findings contribute to a deeper understanding of children’s social preferences and their developmental directions

Stimulating the Right Temporoparietal Junction with tDCS Decreases Deception in Moral Hypocrisy and Unfairness

Self-centered and other-regarding concerns play important roles in decisions of deception. To investigate how these two motivations affect deception in fairness related moral hypocrisy, we modulated the brain activity in the right temporoparietal junction (rTPJ), the key region for decision making involved in self-centered and other-regarding concerns. After receiving brain stimulation with transcranial direct current stimulation (tDCS), participants finished a modified dictator game. In the game, they played as proposers to make allocations between themselves and recipients and had a chance to deceive by misreporting their totals for allocations. Results show that deception in moral hypocrisy was decreased after anodal stimulation than sham and cathodal stimulation, only when participants know that their reported totals (appearing fair) would be revealed to recipients rather than being unrevealed. Anodal stimulation also increased offers to recipients than cathodal stimulation regardless of the revelation of reported totals. These findings suggest that enhancing the activity of rTPJ decreased deception caused by impression management rather than self-deception in moral hypocrisy and unfairness through facilitating other-regarding concerns and weakening non-material self-centered motivations. They provide causal evidence for the role of rTPJ in both other-regarding concerns and non-material self-centered motivations, shedding light on the way to decrease moral hypocrisy

Social evaluation boosts cooperation by enhancing guilt aversion: an effect diminished in primary psychopathic traits

The association between primary psychopathic traits and non-cooperative behaviors is well-identified. There is a lack of studies on how to motivate cooperative behaviors in individuals with primary psychopathic traits. This study investigated the effects of mone- tary incentives and social incentives on promoting cooperation in healthy adults with vary- ing primary psychopathic traits. Participants played a one-shot public goods game (PGG) with other anonymous players in three different contexts: a social incentives context where participants’ decisions would be judged by others, a monetary incentives context where participants’ decisions would result in winning or losing money depending on their con- tributions, and a control condition where no additional incentives were implemented. We found that, compared to the control condition, both monetary and social incentives sig- nificantly improved participants’ contributions to the public project—an indicator of cooperative behavior. However, the association between higher primary psychopathic traits and less cooperation was only observed in the context of social incentives. Computa- tional modeling further revealed that this effect can be explained by the diminishing guilt aversion when participants deliberately violated their inferred expectations of themselves from others’ perspectives. This study found that social incentives can encourage coopera- tive behaviors in non-clinical psychopathy, and identified the mental processes navigating this effect

Research on Influence Factors and Acceleration Methods of Current Commutation

The vacuum interrupter is widely used due to the advantages of no arc-extinguishing medium and high insulation strength. However, the arc voltage generated by the commonly used CuCr contacts is low. In hybrid DC circuit breakers (DCCB), hybrid automatic transfer switches (ATS), medium voltage compound switches and other fields, it is difficult to rely on vacuum arc to complete natural commutation, which restricts the development of hybrid switches. In order to understand the current commutation process deeply, the influence of internal and external factors on the current commutation is analyzed by experiments. The coupling mathematical model of arc-commutated branch is established. The criterion for the success of current commutation is summarized. The parameters of the arc model are reconstructed through repeated breaking experiments to explore the influence of internal factors on the arc characteristics. Based on this, the influence law of arc current, contacts gap and transverse magnetic field (TMF) is analyzed. An acceleration method of current commutation is proposed. A prototype for accelerating experiments with an electromagnetic repulsion mechanism and TMF is developed. The commutated branch equivalent to practical applications is built. The experimental results show that the commutation time is effectively shortened and meets the requirements of practical applications through the acceleration method, which provides new thought for the development of hybrid switches

Early distinction between shame and guilt processing in an interpersonal context

Shame and guilt have been compared in many behavioral and functional magnetic resonance imaging studies. However, the time course of shame and guilt processing remains unknown. We conducted an event-related potential (ERP) study to investigate the temporal dynamics of shame and guilt in an interpersonal context. Behaviorally, participants reported &quot;shame&quot; when their wrong advice was correctly rejected by a confederate, whereas reported &quot;guilt&quot; when their wrong advice resulted in economic loss of a confederate. The ERP results showed significant difference between the shame and guilt conditions in the early P2 component (140-220 ms) over the frontal region and the alpha oscillations (240-1000 ms) over the parietal region. No significant difference was found between the shame and guilt conditions in the N2, P3, and theta oscillations. These results supported previous findings that shame compared to guilt involves more self-referential processing, whereas guilt compared to shame involves more empathetic processing, and provided evidence that the distinction between shame and guilt could occur in an early stage.</p

Investigation of the Structure and Allergic Potential of Whey Protein by Both Heating Sterilization and Simulation with Molecular Dynamics

As the main allergens in milk, whey proteins are heat-sensitive proteins and are widespread in dairy products and items in which milk proteins are involved as food additives. The present work sought to investigate the effect of heating sterilization on the allergenicity of &alpha;-lactalbumin (&alpha;-LA) and &beta;-lactoglobulin (&beta;-LG), the main composite and allergen in whey protein isolate (WPI), by combining molecular dynamics with experimental techniques for detecting the spatial structure and IgE binding capacity. The structure of WPI was basically destroyed at heat sterilization conditions of 95 &deg;C for 5 min and 65 &deg;C for 30 min by SDS-PAGE analysis and spectroscopic analysis. In addition, &alpha;-lactalbumin (&alpha;-LA) may be more sensitive to temperature, resulting in exposure to allergic epitopes and increasing the allergic potential, while the binding capacity of &beta;-lactoglobulin (&beta;-LG) to IgE was reduced under 65 &deg;C for 30 min. By the radius of gyration (Rg) and root-mean-square deviation (RMSD) plots calculated in molecular dynamics simulations, &alpha;-LA was less structurally stable at 368 K, while &beta;-LG remained stable at higher temperatures, indicating that &alpha;-LA was more thermally sensitive. In addition, we observed that the regions significantly affected by temperatures were associated with the capacity of allergic epitopes (&alpha;-LA 80&ndash;101 and &beta;-LG 82&ndash;93, 105&ndash;121) to bind IgE through root-mean-standard fluctuation (RMSF) plots, which may influence the two major allergens. We inferred that these regions are susceptible to structural changes after sterilization, thus affecting the allergenicity of allergens