Senescence: developmental program or timetable?

A cellular timetable of autumn senescence.

We have studied autumn leaf senescence in a free-growing aspen (Populus tremula) by following changes in pigment, metabolite and nutrient content, photosynthesis, and cell and organelle integrity. The senescence process started on September 11, 2003, apparently initiated solely by the photoperiod, and progressed steadily without any obvious influence of other environmental signals. For example,...

The New Dutch Timetable: The OR Revolution

On April 14, 2008, INFORMS (The Institute for Operations Research and Management Sciences) announced Netherlands Railways to be the winner of the 2008 Franz Edelman Award. In this extended abstract, we give a short summary of both the paper [1] and the presenwe give a short summary of both the paper [1] and the presentation of the winning team.

A fertilization-independent developmental program triggers partial fruit development and senescence processes in pistils of Arabidopsis.

The pistil is the specialized plant organ that enables appropriate pollination and ovule fertilization, after which it undergoes growth and differentiation to become a fruit. However, in most species, if ovules are not fertilized around anthesis the pistil irreversibly loses its growth capacity. We used physiological, molecular, and transcriptomic tools to characterize the post-anthesis develop...

Senescence, Apoptosis or Autophagy?

Many features of aging result from the incapacity of cells to adapt to stress conditions. When damage accumulates irreversibly, mitotic cells from renewable tissues rely on either of two mechanisms to avoid replication. They can permanently arrest the cell cycle (cellular senescence) or trigger cell death programs. Apoptosis (self-killing) is the best-described form of programmed cell death, bu...

Timetable