Inhibition of free radical-induced DNA damage by uric acid

AbstractSingle-strand DNA breaks were produced in isolated rat liver nuclei incubated with 3 separate oxygen free radical generating systems: xanthine oxidase-acetaldehyde plus Fe(II); hematin-R(H)OOH; Fe(II)-H2O2. Uric acid inhibited the induction of damage in the first two systems only. At concentrations below those found in human plasma, it was particularly effective against strand breaks produced by hematin-cumene hydroperoxide. These results offer additional evidence that uric acid may function as a cellular protective agent against Superoxide and hydroperoxyl free radical-induced cytotoxicity toxicity

Earthquake Monitoring and Response from Space: The TREMOR Concept

Earthquakes and their after-effects claim thousands of lives and cause enormous property damage each year. Early warning of impending seismological events has the potential to reduce human suffering and physical damage resulting from these natural disasters. Reliable earthquake precursors have yet to be identified, but some research is currently being performed into phenomena that could be observable from space. Satellites have been unquestionably beneficial in the response to earthquakes, providing essential communication and remote sensing support. The Technological Resources for Earthquake MOnitoring and Response (TREMOR) concept was initially developed as a team project at the 2007 International Space University Summer Session Program. It recommends the establishment of an international non-governmental organization that can more efficiently co-ordinate space-based and ground-based resources for the protection of human lives and property. The TREMOR concept is explored further here, concentrating on its use of space technology to minimize the economic and human impact of earthquakes. Updated cost estimates for TREMOR satellite mission concepts are also presented

Perceptual Learning in the Absence of Task or Stimulus Specificity

Performance on most sensory tasks improves with practice. When making particularly challenging sensory judgments, perceptual improvements in performance are tightly coupled to the trained task and stimulus configuration. The form of this specificity is believed to provide a strong indication of which neurons are solving the task or encoding the learned stimulus. Here we systematically decouple task- and stimulus-mediated components of trained improvements in perceptual performance and show that neither provides an adequate description of the learning process. Twenty-four human subjects trained on a unique combination of task (three-element alignment or bisection) and stimulus configuration (vertical or horizontal orientation). Before and after training, we measured subjects' performance on all four task-configuration combinations. What we demonstrate for the first time is that learning does actually transfer across both task and configuration provided there is a common spatial axis to the judgment. The critical factor underlying the transfer of learning effects is not the task or stimulus arrangements themselves, but rather the recruitment of commons sets of neurons most informative for making each perceptual judgment