Aging at the interface of stem cell renewal, apoptosis, senescence, and cancer

The aging-related research field has focused on the detection of genetic factors that affect the aging process, but more recently scientists have started to shift their attention to novel and more integrative ways of studying cellular and organismal function. Such approaches allow them to uncover and explore unexpected patterns and themes, resulting in a more comprehensive knowledge of the complex regulatory pathways and networks involved in aging and age-related diseases. Eventually, this knowledge will lead to a systems-level understanding of aging. The third "Functional Genomics of Aging" conference held in Palermo, Italy, in March/April 2006 highlighted some of the more exciting work in this area.     

Cross-Cultural Differences in Risk Perception: A Model-Based Approach

The present study assessed cross-cultural differences in the perception of financial risks. Students at large universities in Hong Kong, Taiwan, the Netherlands, and the U.S., as well as a group of Taiwanese security analysts rated the riskiness of a set of monetary lotteries. Risk judgments differed with nationality, but not with occupation (students vs. security analysts) and were modeled by the Conjoint Expected Risk (CER) model.⁽¹⁾ Consistent with cultural differences in country uncertainty avoidance,⁽²⁾ CER model parameters of respondents from the two Western countries differed from those of respondents from the two countries with Chinese cultural roots: The risk judgments of respondents from Hong Kong and Taiwan were more sensitive to the magnitude of potential losses and less mitigated by the probability of positive outcomes.     

Dimensions of Risk Perception for Financial and Health Risks

This study of 29 MBA students compares two models of risk perception for both financial and health risk stimuli. The first, inspired by Luce and Weber's Conjoint Expected Risk (CER) model, uses five dimensions: probability of gain, loss and status quo, and expected benefit and harm. The second, inspired by the Sovic et al. psychometric model, employs seven dimensions: voluntariness, dread, control, knowledge, catastrophic potential, novelty, and equity. The CER-type model provided a better fit for most subjects and stimuli. Adding the psychological risk dimensions from the Slovic et al. model explained only modestly more variance. Relationships between the dimensions of the two models are described and the construction of a hybrid model explored.     

Correcting expected utility for comparisons between alternative outcomes: A unified parameterization of regret and disappointment

A unified parameterization of an expected utility model corrected for regret and disappointment effects is presented, constrained to conform to a well-known choice pattern, the common consequence effect, a special case of the Allais paradox. For choices subject to regret and disappointment effects to be consistent with this choice pattern, the function that corrects the utility of the obtained outcome has to have a positive second derivative for its regret component and a negative second derivative for its disappointment component. These hypothesized functional forms make predictions about the relative effect that small vs. large differences between obtained and alternative outcomes should have on people’s experiences of regret or disappointment.

Asymmetric discounting of gains <Emphasis Type="Italic">and</Emphasis> losses: A query theory account

People discount delayed gains (where the default is to receive a smaller gain sooner) more than accelerated gains (where the default is to receive a larger gain later). For losses, the pattern reverses—people discount delayed losses less than accelerated losses. In Study 1, confirming a Query Theory process account, this sign by direction interaction is mediated by the prominence of thoughts in favor of the default. Thoughts in favor of the smaller, sooner amount are more prominent in delay scenarios than acceleration scenarios, and this increases discounting for gains and decreases discounting for losses. Study 2 confirms the causal role of the order of option consideration. Participants considering thoughts in the natural order (pro-default thoughts first) replicate the sign by direction interaction, whereas participants considering thoughts in the opposite, unnatural order (pro-alternative thoughts first) do not. Reversing the order of option consideration eliminates the sign by direction interaction.