A balanced part ternary design (BPTD) is a balanced ternary design (BTD) with a specified number of blocks, say b2, each having repeated elements. We prove some necessary conditions on b2 and show the existence of some particular BPTDs. We also give constructions of infinite families of BPTDs with b1 = 0, including families of ternary t-designs with t ≥ 3.

Scholars have been slow to test welfare state theories on the extensive subnational variation in the United States during the recent period of retrenchment. We assess institutional politics theories, literature on race and social policy, and public opinion arguments relative to levels of support in states' Aid to Families Dependent Children programs from 1982 until its elimination in 1996. Pool...

The study of microbial pangenomes relies on the computation of gene families, i.e. the clustering of coding sequences into groups of essentially similar genes. There is no standard approach to obtain such gene families. Ideally, the gene family computations should be robust against errors in the annotation of genes in various genomes. In an attempt to achieve this robustness, we propose to clus...

What is the effect of the AFDC-Unemployed Parent (UP) program on two-parent families? This question has become particularly relevant following the passage of the Family Support Act (FSA) of 1988, effective October 1990, which extended the previously state-optional AFDC-Unemployed Parent program to all states. This study clarifies what is meant by "two-parent" family in the federal legislation a...

We document a negative association between nonmarital childbearing and the subsequent likelihood of first marriage in the United States, controlling for a variety of potentially confounding influences. Nonmarital childbearing does not appear to be driven by low expectations of future marriage. Rather, it tends to be an unexpected and unwanted event, whose effects on a woman's subsequent likelih...

While the number of solved 3D protein structures continues to grow rapidly, the structural rules that distinguish protein-protein interactions between different structural families are still not clear. Here, we classify and analyse the secondary structural features and promiscuity of a comprehensive non-redundant set of domain family binding sites (DFBSs) and hetero domain-domain interactions (...

Workfare, reciprocal obligations, parental responsibility, and the need to balance opportunities with mandates have been prominent in the current lexicon of welfare reform, replacing the emphasis on entitlements and incentives familiar from an earlier era. This article discusses why the debate has shifted toward work strategies and summarizes what we know about the feasibility and success of th...

This research seeks to reevaluate the relationship between AFDC and fertility by focusing on births to women through the age of twenty-three using data from the National Longitudinal Survey of Youth (NLSY). Using discrete time hazard models, I examine the impact of AFDC on births directly associated with AFDC, on out-of-wedlock births, and on all births. I also examine the importance of AFDC on...

Introduction