The five known families of difference sets whose parameters (v,k,>.;n) satisfy the condition gcd(v,n) > 1 are the McFarland, Spence, Davis-Jedwab, Hadamard and Chen families. We survey recent work which ursive techniques to unify these difference set families, placing particular emphasis on examples. This unified approach has also proved useful for studying semi-regular relative difference sets...

BACKGROUND Depressive illness is common. Depression in one family member is associated with an increased incidence of psychopathology in other family members. There are no data on the physical well being of the families of depressed individuals. AIM To compare physical morbidity of family members of depressed patients with that of family members of comparison patients. METHOD A comparative ...

Difference families are traditionally built using groups as their basis. This paper looks at what sort of generalised difference family constructions could be made, using the standard basis of translation and difference. The main result is that minimal requirements on the structure force nothing that groups cannot give, at least in the finite case. Thus all difference families arise from groups.

Domains of unknown function (DUFs) are a large set of uncharacterized protein families that are found in the Pfam database. Here, the scale and growth of functionally uncharacterized families in biological databases are surveyed and the prospects for discovering their function are examined. In particular, the important role that structural genomics can play in identifying potential function is ...

We use the Rosetta de novo structure prediction method to produce three-dimensional structure models for all Pfam-A sequence families with average length under 150 residues and no link to any protein of known structure. To estimate the reliability of the predictions, the method was calibrated on 131 proteins of known structure. For approximately 60% of the proteins one of the top five models wa...

In this paper we formulate the problem of constructing 1-rotational near resolvable difference families as a combinatorial optimization problem where a global optimum corresponds to a desired difference family. Then, we develop an algorithm based on scatter search in conjunction with a tabu search to construct many of these difference families. In particular, we construct three new near resolva...