Crystallization, optimization and preliminary X-ray characterization of a metal-dependent PI-PLC from Streptomyces antibioticus

A recombinant metal-dependent phosphatidylinositol-specific phospholipase C (PI-PLC) from Streptomyces antibioticus has been crystallized by the hanging-drop method with and without heavy metals. The native crystals belonged to the orthorhombic space group P222, with unit-cell parameters a = 41.26, b = 51.86, c= 154.78 A. The X-ray diffraction results showed significant differences in the crystal quality of samples soaked with heavy atoms. Additionally, drop pinning, which increases the surface area of the drops, was also used to improve crystal growth and quality. The combination of heavy-metal soaks and drop pinning was found to be critical for producing high-quality crystals that diffracted to 1.23 A resolution.

Public Attitudes Toward Social Spending in the United States: The Differences Between Direct Spending and Tax Expenditures

This paper uses a survey experiment to examine differences in public attitudes toward 'direct' and 'indirect' government spending. Federal social welfare spending in the USA has two components: the federal government spends money to directly provide social benefits to citizens, and also indirectly subsidizes the private provision of social benefits through tax expenditures. Though benefits provided through tax expenditures are considered spending for budgetary purposes, they differ from direct spending in several ways: in the mechanisms through which benefits are delivered to citizens, in how they distribute wealth across the income spectrum, and in the visibility of their policy consequences to the mass public. We develop and test a model explaining how these differences will affect public attitudes toward spending conducted through direct and indirect means. We find that support for otherwise identical social programs is generally higher when such programs are portrayed as being delivered through tax expenditures than when they are portrayed as being delivered by direct spending. In addition, support for tax expenditure programs which redistribute wealth upward drops when citizens are provided information about the redistributive effects. Both of these results are conditioned by partisanship, with the opinions of Republicans more sensitive to the mechanism through which benefits are delivered, and the opinions of Democrats more sensitive to information about their redistributive effects.