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Abstract A facile and efficient two‐step synthesis ofp‐substituted tris(2‐pyridylmethyl)amine (TPMA) ligands to form Cu complexes with the highest activity to date in atom transfer radical polymerization (ATRP) is presented. In the divergent synthesis,p‐Cl substituents in tris(4‐chloro‐2‐pyridylmethyl)amine (TPMA^3Cl) were replaced in one step and high yield by electron‐donating cyclic amines (pyrrolidine (TPMA^PYR), piperidine (TPMA^PIP), and morpholine (TPMA^MOR)) by nucleophilic aromatic substitution. The [Cu^II(TPMA^NR2)Br]⁺complexes exhibited larger energy gaps between frontier molecular orbitals and >0.2 V more negative reduction potentials than [Cu^II(TPMA)Br]⁺, indicating >3 orders of magnitude higher ATRP activity. [Cu^I(TPMA^PYR)]⁺exhibited the highest reported activity for Br‐capped acrylate chain ends in DMF, and moderate activity toward C−F bonds at room temperature. ATRP ofn‐butyl acrylate using only 10–25 part per million loadings of [Cu^II(TPMA^NR2)Br]⁺exhibited excellent control. 

Abstract Drawing on social hierarchy theory, we develop a contingency model of leader–member exchange (LMX) differentiation in which LMX differentiation is positively and negatively related to group cooperation and group social undermining, respectively, when it is based on the group members’ performance, but the relations are reversed (i.e., negative and positive, respectively) when it stems from a leader's personal liking of the members. In addition, we propose that the moderating effects of the performance and personal liking bases of LMX differentiation are magnified by the levels of reward interdependence. Specifically, under a high (vs. low) level of reward interdependence, LMX differentiation based on performance more strongly relates to high group cooperation and low group social undermining, whereas LMX differentiation with a personal liking basis is more likely to decrease group cooperation and increase group social undermining. Group cooperation and social undermining are then hypothesized to convey the three‐way interactive effects of LMX differentiation, its two bases, and reward interdependence on subsequent group performance. Analyses of data from 328 sales groups of a large retailer support the core part of our contingency model of LMX differentiation. 

Abstract Contaminants such as mercury are pervasive and can have immunosuppressive effects on wildlife. Impaired immunity could be important for forecasting pathogen spillover, as many land‐use changes that generate mercury contamination also bring wildlife into close contact with humans and domestic animals. However, the interactions among contaminants, immunity and infection are difficult to study in natural systems, and empirical tests of possible directional relationships remain rare.We capitalized on extreme mercury variation in a diverse bat community in Belize to test association among contaminants, immunity and infection. By comparing a previous dataset of bats sampled in 2014 with new data from 2017, representing a period of rapid agricultural land conversion, we first confirmed bat species more reliant on aquatic prey had higher fur mercury. Bats in the agricultural habitat also had higher mercury in recent years. We then tested covariation between mercury and cellular immunity and determined if such relationships mediated associations between mercury and bacterial pathogens. As bat ecology can dictate exposure to mercury and pathogens, we also assessed species‐specific patterns in mercury–infection relationships.Across the bat community, individuals with higher mercury had fewer neutrophils but not lymphocytes, suggesting stronger associations with innate immunity. However, the odds of infection for haemoplasmas andBartonellaspp. were generally lowest in bats with high mercury, and relationships between mercury and immunity did not mediate infection patterns. Mercury also showed species‐ and clade‐specific relationships with infection, being associated with especially low odds for haemoplasmas inPteronotus mesoamericanusandDermanura phaeotis. ForBartonellaspp., mercury was associated with particularly low odds of infection in the genusPteronotusbut high odds in the subfamily Stenodermatinae.Synthesis and application. Lower general infection risk in bats with high mercury despite weaker innate defense suggests contaminant‐driven loss of pathogen habitat (i.e. anemia) or vector mortality as possible causes. Greater attention to these potential pathways could help disentangle relationships among contaminants, immunity and infection in anthropogenic habitats and help forecast disease risks. Our results also suggest that contaminants may increase infection risk in some taxa but not others, emphasizing the importance of considering surveillance and management at different phylogenetic scales.