Application of the Yale Technology Concordance to the Construction of International Spillover Variables for India

Although there is increased interest in the role of international technology spillovers, empirical studies have been hampered by a host of measurement problems. This paper reviews recent attempts to address two of these problems. First, there are differing degrees of transferability of technology from one region to another. Second, both embodied and disembodied technology are transferred, and these different modes of transfer have distinct implications for both behavior and policy. To deal with the first measurement problem, the Yale Technology Concordance (YTC)—a matrix that maps patents into industries of manufacture and sectors of use—was used to construct indices of relevance of foreign technology to India. To deal with the second measurement problem, the YTC was again used to construct pools of embodied and disembodied international technology. After describing the variable construction, the paper highlights the performance of these variables in equations that predict Indian firms' R&D, technology purchases and output.Yale Technology Concordance, International R&D spillovers, India,

The Effects of R&D, Foreign Technology Purchase, and Domestic and International Spillovers on Productivity in Indian Firms.

Using panel data on Indian firms from 1974-75 to 1981-82, the authors provide estimates of the impact on output of Indian firms' R&D expenditures, their technology purchases, and international and domestic R&D spillovers. The private returns to technology purchases are estimated to be high and statistically significant, while the private returns to firms' own R&D expenditures are somewhat lower and are often insignificant. There is evidence of both international and domestic R&D spillovers. The estimates permit estimation of total factor productivity growth in the period preceding India's industrial liberalization policies. Copyright 1996 by MIT Press.

Biochemical Analysis of HIV-1 Integrase Variants Resistant to Strand Transfer Inhibitors*

In this study, eight different HIV-1 integrase proteins containing mutations observed in strand transfer inhibitor-resistant viruses were expressed, purified, and used for detailed enzymatic analyses. All the variants examined were impaired for strand transfer activity compared with the wild type enzyme, with relative catalytic efficiencies (kp/Km) ranging from 0.6 to 50% of wild type. The origin of the reduced strand transfer efficiencies of the variant enzymes was predominantly because of poorer catalytic turnover (kp) values. However, smaller second-order effects were caused by up to 4-fold increases in Km values for target DNA utilization in some of the variants. All the variants were less efficient than the wild type enzyme in assembling on the viral long terminal repeat, as each variant required more protein than wild type to attain maximal activity. In addition, the variant integrases displayed up to 8-fold reductions in their catalytic efficiencies for 3′-processing. The Q148R variant was the most defective enzyme. The molecular basis for resistance of these enzymes was shown to be due to lower affinity binding of the strand transfer inhibitor to the integrase complex, a consequence of faster dissociation rates. In the case of the Q148R variant, the origin of reduced compound affinity lies in alterations to the active site that reduce the binding of a catalytically essential magnesium ion. Finally, except for T66I, variant viruses harboring the resistance-inducing substitutions were defective for viral integration