A methodologically sound systematic review is characterized by transparency, replicability, and a clear inclusion criterion. However, little attention has been paid to reporting the details of interrater reliability (IRR) when multiple coders are used to make decisions at various points in the screening and data extraction stages of a study. Prior research has mentioned the paucity of information on IRR including number of coders involved, at what stages and how IRR tests were conducted, and how disagreements were resolved. This article examines and reflects on the human factors that affect decision-making in systematic reviews via reporting on three IRR tests, conducted at three different points in the screening process, for two distinct reviews. Results of the two studies are discussed in the context of IRR and intrarater reliability in terms of the accuracy, precision, and reliability of coding behavior of multiple coders. Findings indicated that coding behavior changes both between and within individuals over time, emphasizing the importance of conducting regular and systematic IRR and intrarater reliability tests, especially when multiple coders are involved, to ensure consistency and clarity at the screening and coding stages. Implications for good practice while screening/coding for systematic reviews are discussed.

The pathologic self-assembly of proteins is associated with typically late-onset disorders such as Alzheimer's disease, Parkinson's disease, and type 2 diabetes. Important mechanistic details of the self-assembly are unknown, but there is increasing evidence supporting the role of transient α-helices in the early events. Islet amyloid polypeptide (IAPP) is a 37-residue polypeptide that self-assembles into aggregates that are toxic to the insulin-producing β cells. To elucidate early events in the self-assembly of IAPP, we used limited proteolysis to identify an exposed and flexible region in IAPP monomer. This region includes position 20 where a serine-to-glycine substitution (S20G) is associated with enhanced formation of amyloid fibrils and early onset type 2 diabetes. To perform detailed biophysical studies of the exposed and flexible region, we synthesized three peptides including IAPP(11-25)WT (wild type), IAPP(11-25)S20G, and IAPP(11-25)S20P. Solution-state NMR shows that all three peptides transiently populate the α-helical conformational space, but the S20P peptide, which does not self-assemble, transiently samples a broken helix. Under similar sample conditions, the WT and S20G peptides populate the α-helical intermediate state and β-sheet end state, respectively, of fibril formation. Our results suggest a mechanism for self-assembly that includes the stabilization of transient α-helices through the formation of NMR-invisible helical intermediates followed by an α-helix to β-sheet conformational rearrangement. Furthermore, our results suggest that reducing intermolecular helix-helix contacts as in the S20P peptide is an attractive strategy for the design of blockers of peptide self-assembly.

Recent political contests across Europe and North America have been propelled by a wave of populist, anti-immigrant resentment, and it was widely expected that these populist victories would further fan the flames of xenophobia. This article reports the results of an experiment around the Brexit referendum, designed to test how populist victories shape anti-immigrant attitudes. The study finds that anti-immigrant attitudes actually softened after the Brexit referendum, among both Leave and Remain supporters, and these effects persisted for several months. How could a right-wing, populist victory soften anti-immigrant attitudes? The authors use causal mediation analysis to understand this ‘populist paradox’. Among Leavers, a greater sense of control over immigration channelled the effects of the Brexit outcome onto anti-immigrant attitudes. Individuals' efforts to distance themselves from accusations of xenophobia and racism explains the softening of attitudes towards immigration observed among both Leavers and Remainers.

While the UNHCR promotes voluntary repatriation as the preferred solution to refugee situations, there is little understanding of variation in refugees’ preferences regarding return. We develop a theoretical framework suggesting two mechanisms influencing refugees’ preferences. First, refugees’ lived experiences in their country of origin prior to displacement and in their new host country create a trade-off in feelings of being anchored to their origin or host country. Second, firsthand exposure to traumas of war provides some refugees with a sense of competency and self-efficacy, leading them to prefer to return home. We test these relationships with data from a survey among Syrian refugees hosted in Lebanon. We find refugees exposed to violence during the war have a sense of attachment to Syria and are most likely to prefer return. Refugees who have developed a detachment from Syria or an attachment to Lebanon are less likely to prefer return.