measures of social capital and trust

Trust and trustworthiness are important components of social capital and much attention has been devoted to the problems of their correct evaluation. Attitudinal survey questions as reported in the EVS – European Value Survey - are often regarded as inefficient indicators of trust, since they lack of behavioural underpinnings (Putnam, 1995) which one might desire when measuring trust. In this paper, we consider alternative measures of trust and trustworthiness, based on behavioural assumptions. We construct two relative behavioural measures of trust (RBM1 and RBM2), both based on the ex post measurement of trust, once individuals are informed on the level of trustworthiness of the social group to which they have been allocated during the experiment. Our main finding is that the relative behavioural measures show that trust strongly varies once the individual is informed on the on the level of trustworthiness of the social group to which he\she has been allocated during the experiment. This difference is higher the higher is the family level of income and the parental education status. As for previous findings (Glaeser et al., 2000, Lazzarini, 2005) which have found no correlation between attitudinal and behavioural measures of trust, we find that relative behavioural measures are not correlated to attitudinal measures but they are strongly correlated to groups’ trustworthiness. We also find that similar social preferences profiles (between Senders and Recipients) tend to enhance the individual level of trust, in the RBM2 context. This result seems to confirm the importance of the homogeneity of the social environment when studying the effects of policy interventions (Alesina and La Ferrara, 2002).social capital, trust, experiments

XIAP upregulates expression of HIF target genes by targeting HIF1 alpha for Lys(63)-linked polyubiquitination

The cellular response to hypoxia is characterised by a switch in the transcriptional program, mediated predominantly by the hypoxia inducible factor family of transcription factors (HIF). Regulation of HIF1 is primarily controlled by post-translational modification of the HIF1α subunit, which can alter its stability and/or activity. This study identifies an unanticipated role for the X-linked inhibitor of apoptosis (XIAP) protein as a regulator of Lys63-linked polyubiquitination of HIF1α. Lys63-linked ubiquitination of HIF1α by XIAP is dependent on the activity of E2 ubiquitin conjugating enzyme Ubc13. We find that XIAP and Ubc13 dependent Lys63-linked polyubiquitination promotes HIF1α nuclear retention leading to an increase in the expression of HIF1 responsive genes. Inhibition of the Lys63-linked polyubiquitination pathway leads to reduced levels of nuclear HIF1α, promoter occupancy, HIF-dependent gene expression and cell viability. Our data reveals an additional and significant level of control of the HIF1 by XIAP, with important implications in understanding the role of HIF1 and XIAP in human disease