This paper considers the boundary that separates marketable from non-marketable items. First, it examines the issue of blocked exchanges, that is, exchanges that cannot and/or should not take place. Second, it proposes to synthesise the seemingly separate issues of blocked exchanges from a single perspective based on critical realist ontology. Finally, it tackles some scepticism and criticism that has been levelled against the idea that ontology can be useful in determining a market boundary.

Mediator is a coregulatory complex that plays essential roles in multiple processes of transcription regulation. One of the human Mediator subunits, MED26, has a role in recruitment of the super elongation complex (SEC) to polyadenylated genes and little elongation complex (LEC) to non‐polyadenylated genes, including small nuclear RNAs (snRNAs) and replication‐dependent histone (RDH) genes. MED26‐containing Mediator plays a role in 3′ Pol II pausing at the proximal region of transcript end sites in RDH genes through recruitment of Cajal bodies (CBs) (...) to histone locus bodies (HLBs). This finding suggests that Mediator is involved in the association of CBs with HLBs to facilitate 3′ Pol II pausing and subsequent 3′‐end processing by supplying 3′‐end processing factors from CBs. Thus, we argue the possibility that Mediator is involved in the organization of nuclear bodies to orchestrate multiple processes of gene transcription. (shrink)

Both W9 and OP3‐4 were known to bind the receptor activator of NF‐κB ligand (RANKL), inhibiting osteoclastogenesis. Recently, both peptides were shown to stimulate osteoblast differentiation; however, the mechanism underlying the activity of these peptides remains to be clarified. A primary osteoblast culture showed that rapamycin, an mTORC1 inhibitor, which was recently demonstrated to be an important serine/threonine kinase for bone formation, inhibited the peptide‐induced alkaline phosphatase activity. Furthermore, both peptides promoted the phosphorylation of Akt and S6K1, an upstream molecule (...) of mTORC1 and the effector molecule of mTORC1, respectively. In the in vivo calvarial defect model, W9 and OP3‐4 accelerated BMP‐2‐induced bone formation to a similar extent, which was confirmed by histomorphometric analyses using fluorescence images of undecalcified sections. Our data suggest that these RANKL‐binding peptides could stimulate the mTORC1 activity, which might play a role in the acceleration of BMP‐2‐induced bone regeneration by the RANKL‐binding peptides. (shrink)