Multilevel modeling analysis of dyadic network data with an application to Ye'kwana food sharing

Behavioral ecologists have recently begun using multilevel modeling for the analysis of social behavior. We present a multilevel modeling formulation of the Social Relations Model that is well suited for the analysis of dyadic network data. This model, which we adapt for count data and small datasets, can be fitted using standard multilevel modeling software packages. We illustrate this model with an analysis of meal sharing among Ye’kwana horticulturalists in Venezuela. In this setting, meal sharing among households is predicted by an association index, which reflects the amount of time that members of the households are interacting. This result replicates recent findings that interhousehold food sharing is especially prevalent among households that interact and cooperate in multiple ways. We discuss opportunities for human behavioral ecologists to expand their focus to the multiple currencies and cooperative behaviors that characterize interpersonal relationships in preindustrial societies. We discuss possible extensions to this statistical modeling approach and applications to research by human behavioral ecologists and primatologists

Structural determinants of specific DNA-recognition by the THAP zinc finger

Human THAP1 is the prototype of a large family of cellular factors sharing an original THAP zinc-finger motif responsible for DNA binding. Human THAP1 regulates endothelial cell proliferation and G1/S cell-cycle progression, through modulation of pRb/E2F cell-cycle target genes including rrm1. Recently, mutations in THAP1 have been found to cause DYT6 primary torsion dystonia, a human neurological disease. We report here the first 3D structure of the complex formed by the DNA-binding domain of THAP1 and its specific DNA target (THABS) found within the rrm1 target gene. The THAP zinc finger uses its double-stranded β-sheet to fill the DNA major groove and provides a unique combination of contacts from the β-sheet, the N-terminal tail and surrounding loops toward the five invariant base pairs of the THABS sequence. Our studies reveal unprecedented insights into the specific DNA recognition mechanisms within this large family of proteins controlling cell proliferation, cell cycle and pluripotency