Critical transcription factors, notably OCT4, SOX2, and NANOG, are necessary to maintain self-renewal and pluripotency, two properties characteristic of embryonic stem (ES) cells. By analyzing the genome-wide localization of these factors at promoter regions in human ES cells, Boyer et al. (2005) demonstrate frequent promoter co-occupancy at numerous target genes. As they discuss in this issue ...

Abstract. River rocks round through the process of impact attrition, whereby energetic collisions during bed-load transport induce chipping grain surface. This is also important for bedrock erosion. Although previous work has shown that energy, lithology, and shape are controlling factors attrition rates, functional dependence among these quantities not settled. Here we examine using a double-p...

A regional assessment of the ecological effects of chipping and mastication fuels reduction and forest restoration treatments. Project Title: A regional assessment of the ecological effects of chipping and mastication fuels reduction and forest restoration treatments. ABSTRACT: Over the past several years, fire managers have increased their use of mastication treatments, the on-site disposal of...

Vibratory sensation thresholds of ten fingertips of each person were measured by each of the three frequencies in groups using three kinds of vibrating tools and the control groups. The subject groups were using leg-drill (n=37), chipping-hammer (n=25) and chain-saw (n=19). The control groups were engaged in desk work or outdoor work in a bureau of forest management (n=24), a local forest offic...

We reexamine a simple lattice model of aggregation in which masses diffuse and coalesce upon contact with rate 1 and every nonzero mass chips off a single unit of mass and adds it to a randomly chosen neighbor with rate w. The dynamics conserves the average mass density rho and in the stationary state the system undergoes a nonequilibrium phase transition in the (rho-w) plane across a critical ...