Allocation tradeoffs with the immune system can enforce honesty on sexual signals that act as indicators of individual quality. Such tradeoffs can be brought about by (1) the dual action of testosterone, which stimulates sexual signals but also suppresses immune functions, and/or (2) competition for carotenoids, which can be deposited as ornamental pigments or used as antioxidants in support of immune functions. Recent studies1-3 integrate these two mechanisms by showing that testosterone treatment in male birds upregulates circulating lipoproteins, plasma carriers (...) for carotenoids, and increases bio-availability of carotenoids, which enhances carotenoid-based sexual coloration and immune responsiveness. BioEssays 29:427–430, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

To realize the full potential of solar photovoltaics (PV), PV adopters need to adapt their energy demand to the production of self-generated solar energy as much as possible (i.e., use their PV sustainably). In a longitudinal questionnaire study (N = 74) in the Netherlands, we compared the intention to use PV in a sustainable way before the installation of PV with actual PV use. Wave 1 took place before respondents adopted PV, while Wave 2 took place after they installed PV. (...) We examined whether potential differences between actual sustainable PV use and initial intentions may have implications for how people see themselves and for the motivation they ascribe to their decision to adopt PV. Our results show that the vast majority of people use their PV in a less sustainable way than they anticipated. Furthermore, after the installation of PV, respondents are less likely to see themselves as a sustainable PV user and less likely to believe that PV have positive environmental consequences than before the installation, while environmental self-identity did not differ pre and post-installation of PV. Moreover, the stronger the discrepancy between intended and actual sustainable use of the PV, the less likely people were to see themselves as a sustainable PV user and as a person who acts pro-environmentally in general. These findings suggest that it is important to support people to use their PV in a sustainable way to facilitate them to act upon their intentions. (shrink)

The phrase, "state of nature", has been used over centuries to describe the uncultivated state of lands and animals, nudity, innocence, heaven and hell, interstate relations, and the locus of pre- and supra-political rights, such as the right to resistance, to property, to create and leave polities, and the freedom of religion, speech, and opinion, which may be reactivated or reprioritised when the polity and its laws fail. Combining intellectual history with current concerns, this volume brings together fourteen essays on (...) the past, present and possible future applications of the legal fiction known as the state of nature. Contributors are: Daniel S. Allemann, Pamela Edwards, Ioannis D. Evrigenis, Mary C. Fuller, David Singh Grewal, Francesca Iurlaro, Edward J. Kolla, László Kontler, Grant S. McCall, Tom Sparks, Benjamin Straumann, Karl Widerquist, Sarah Winter, and Simone Zurbuchen. (shrink)