An Explanation for the Adiponectin Paradox

The adipokine adiponectin improves insulin sensitivity. Functional signal transduction of adiponectin requires at least one of the receptors AdipoR1 or AdipoR2, but additionally the glycosyl phosphatidylinositol-anchored molecule, T-cadherin. Overnutrition causes a reduction in adiponectin synthesis and an increase in the circulating levels of the enzyme glycosyl phosphatidylinositol-phospholipase D (GPI-PLD). GPI-PLD promotes the hydrolysis of T-cadherin. The functional consequence of T-cadherin hydrolysis is a reduction in adiponectin sequestration by responsive tissues, an augmentation of adiponectin levels in circulation and a (further) reduction in signal transduction. This process creates the paradoxical situation that adiponectin levels are augmented, whereas the adiponectin signal transduction and insulin sensitivity remain strongly impaired. Although both hypoadiponectinemia and hyperadiponectinemia reflect a situation of insulin resistance, the treatments are likely to be different.

The Sensitivity Functional Forms of Earnings: Earnings Functions to Specification

The purpose of this paper is to examine the nature of the latent component in the distribution of earnings. The distribution of earnings can be deconvoluted into a latent and an observable component. The observed component is generated by those measurable characteristics of the individual that are interpreted as indicators of productivity. The latent component is generated by misinformation, discrimination and ignorance on the part of the employer. In this paper we employ the distribution of the residuals of a series of Mincer type equations as the proxy for the distribution of the latent component in earnings. By using various specifications and by computing distributions across occupations we are able to remove the confounding influence of potential specification bias. The residuals are examined using the Bera-Jargue test for normality and Elderton’s Kappa criterion. The results are reported for 34 occupations using the 1990 CPS data.