Novel Methods for Determining Effective Interactions for the Nuclear Shell Model

The Contractor Renormalization (CORE) method is applied in combination with modern effective-theory techniques to the nuclear many-body problem. A one-dimensional--yet ``realistic''--nucleon-nucleon potential is introduced to test these novel ideas. It is found that the magnitude of ``model-space'' (CORE) corrections diminishes considerably when an effective potential that eliminates the hard-momentum components of the potential is first introduced. As a result, accurate predictions for the ground-state energy of the there-body system are made with relatively little computational effort when both techniques are used in a complementary fashion.Comment: 14 pages, 5 figures and 2 tabl

Attachment, Aggression, and Family Risk in a Low-Income Sample

Attachment security in children\u27s first relationships with their primary caregivers in infancy supports multiple aspects of their social development during childhood. Insecure attachment, in contrast, underlies a wide range of negative outcomes for children, including aggressive behavior toward others. In a sample of 161 low-income families, early attachment insecurity was examined in relation to physical punishment and child aggression at ages two and three in the context of risk and intervention. Families had been randomly assigned either to a comparison group or to an Early Head Start program that provided weekly home visits aimed at increasing positive aspects of parenting behaviors. Children with higher security scores were less likely to be spanked at age three and less likely to be aggressive at ages two and three. Early Head Start made an independent contribution to less spanking at age three, over and above family risk factors, earlier attachment security, or earlier spanking. The results suggest that a secure attachment relationship and a parenting-focused home visiting intervention can reduce the physical punishment associated with child aggression and thereby indirectly reduce early childhood aggression