A mathematical network analysis of voting patterns and committee memberships in the 107th U.S. House of Representatives suggests that the Select Committee on Homeland Security is among the most partisan committees in the House and that it has close membership ties with the House Rules Committee rather than with the Permanent Select Committee on Intelligence, which is among the least partisan committees in the House.

Mason Porter and colleagues used network analysis to explore data of 101st-108th Houses (1989-2004) and provide detailed examples for the 107th House (2001-2002). The researchers determined a measure of the connection between pairs of House committees and subcommittees by looking at the number of members they share. They then clustered the committees according to strengths of those connections. This led to the finding of close ties between the House Rules Committee and the Select Committee on Homeland Security.

The researchers also analyzed the 990 House roll call votes of the 107th Congress and found that a simple mathematical tool called a singular value decomposition can identify Representatives' partisanship and their degree of cooperativity with the House as a whole.

Using these measures of Representatives' voting records, committees and subcommittees can be categorized according to the partisanship of their constituent members. The paper identifies "extreme" committees, or those whose members are highly partisan. Examples include the Judiciary, the House Rules, and the Homeland Security Committees.

Potential Diabetes Treatment with Transplanted Liver Cells

According to a newly published report, researchers have converted adult human liver (AHL) cells expressing the pancreatic and duodenal homeobox gene-1 (PDX-1) into insulin-producing cells that can be transplanted into mice to treat diabetes.

Cell replacement therapies
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Contact: Leikny Johnson
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202-334-1310
Proceedings of the National Academy of Sciences (PNAS)
16-May-2005