Two studies examined the extent to which the type of triadic interaction pervasive in Western populations (i.e., shared visual attention and ostensive pedagogical cues) was representative of infant-caregiver object exploration in a non-Western indigenous community. Caregivers in the United States and Vanuatu interacted with infants and a novel object for 3 min. In Study 1 (N = 116, Mage  = 29.0...

We call a matrix triadic if it has no more than two nonzero off-diagonal elements in any column. A symmetric tridiagonal matrix is a special case. In this paper we consider LXLT factorizations of symmetric triadic matrices, where L is unit lower triangular and X is diagonal, block diagonal with 1×1 and 2×2 blocks, or the identity with L lower triangular. We prove that with diagonal pivoting, th...

The provision of maternal-infant body contact during a period of maternal separation was examined for its effects on parent-infant and triadic interactions. Participants were 146 three-month-old preterm infants and their parents, half of whom received skin-to-skin contact, or kangaroo care (KC), in the neonatal nursery. Global relational style and micro-patterns of proximity and touch were code...

Motivated by the role of triadic closures in social networks, and the importance of finding a maximum subgraph avoiding a fixed pattern, we introduce and initiate the parameterized study of the Strong F -closure problem, where F is a fixed graph. This is a generalization of Strong Triadic Closure, whereas it is a relaxation of F free Edge Deletion. In Strong F -closure, we want to select a maxi...

Despite its prominent placement between the retina and primary visual cortex in the early visual pathway, the role of the dorsal lateral geniculate nucleus (dLGN) in molding and regulating the visual signals entering the brain is still poorly understood. A striking feature of the dLGN circuit is that relay cells (RCs) and interneurons (INs) form so-called triadic synapses, where an IN dendritic...

This research compares the role of initial individual characteristics to that of patterns of resolution in which successive dominance relationships are established during the formation of triads in the domestic hen. Combining weight, prior victory or defeat in the site of encounter, and comb size, we created three levels of asymmetries on characteristics for triads of hens. The effects of these...

Problem 2. Let A be a central division algebra (of finite dimension) over a field k. Let [A, A] be the k-subspace of A spanned by the elements ab − ba with a, b ∈ A. Show that [A, A] = A. Solution. Let K be the algebraic closure of k, and consider B = A ⊗ k K. Then B ∼ = M n (K) for some n ∈ N, and thus we can understand [B, B] ∼ = [A, A] ⊗ k K. In this case, [B, B] contains only matrices of tr...

We deene the notion of weak relative pseudo-complement, and we show that, for an arbitrary lattice, the property of weak relative pseudo-complementation is strictly weaker than relative pseudo-complementation, but stronger than pseudo-complementation. Our main interest for this notion is in relation with the theory of closure operators. We prove that if a complete lattice L is completely inf-di...