Stress: Putting the Brain Back Into Medicine

Throughout the life course stress plays a major role in health and disease. Although it has long been known that the brain orchestrates the many ways that the body responds to these experiences, a gap exists between health care providers who focus from the head up and those who focus on the head down

Chaotic diffusion of the Vesta family induced by close encounters with massive asteroids

We numerically estimate the semi-major axis chaotic diffusion of the Vesta family asteroids induced by close encounters with 11 massive main belt asteroids : (1) Ceres, (2) Pallas, (3) Juno, (4) Vesta, (7) Iris, (10) Hygiea, (15) Eunomia, (19) Fortuna, (324) Bamberga, (532) Herculina, (704) Interamnia. We find that most of the diffusion is due to Ceres and Vesta. By extrapolating our results, we are able to constrain the global effect of close encounters with all the main belt asteroids. A comparison of this drift estimate with the one expected for the Yarkovsky effect shows that for asteroids whose diameter is larger than about 40 km, close encounters dominate the Yarkovsky effect. Overall, our findings confirm the standard scenario for the history of the Vesta family.Comment: 9 pages, 9 figures, 1 Table, submitte

Tidal dissipation and the formation of Kepler near-resonant planets

Multi-planetary systems detected by the Kepler mission present an excess of planets close to first-order mean-motion resonances (2:1 and 3:2) but with a period ratio slightly higher than the resonant value. Several mechanisms have been proposed to explain this observation. Here we provide some clues that these near-resonant systems were initially in resonance and reached their current configuration through tidal dissipation. The argument that has been opposed to this scenario is that it only applies to the close-in systems and not to the farthest ones for which the tidal effect is too weak. Using the catalog of KOI of the Kepler mission, we show that the distributions of period ratio among the most close-in planetary systems and the farthest ones differ significantly. This distance dependent repartition is a strong argument in favor of the tidal dissipation scenario.Comment: 3 pages, 3 figures, submitted for publicatio

An Overview of Federal Support for Housing

The federal government commits substantial resources to support housing and mortgage markets through a combination of spending programs and tax expenditures (that is, subsidies conveyed through reductions in taxes). During the crisis of the past two years, the budgetary commitment expanded—to about $300 billion in fiscal year 2009—from the placement into conservatorship in September 2008 of the Federal National Mortgage Association (Fannie Mae) and the Federal Home Loan Mortgage Corporation (Freddie Mac) and the creation of new housing programs. This Congressional Budget Office (CBO) brief describes, in broad terms, the array of federal activities that support housing and the recent expansion of particular programs.