Lifespan-increasing drug nordihydroguaiaretic acid inhibits p300 and activates autophagy.

Aging is characterized by the progressive loss of physiological function in all organisms. Remarkably, the aging process can be modulated by environmental modifications, including diet and small molecules. The natural compound nordihydroguaiaretic acid (NDGA) robustly increases lifespan in flies and mice, but its mechanism of action remains unclear. Here, we report that NDGA is an inhibitor of the epigenetic regulator p300. We find that NDGA inhibits p300 acetyltransferase activity in vitro and suppresses acetylation of a key p300 target in histones (i.e., H3K27) in cells. We use the cellular thermal shift assay to uniquely demonstrate NDGA binding to p300 in cells. Finally, in agreement with recent findings indicating that p300 is a potent blocker of autophagy, we show that NDGA treatment induces autophagy. These findings identify p300 as a target of NDGA and provide mechanistic insight into its role in longevity

Mineralogy and sand surface morphology of selected andisols from west Sumatra

Andisols from Mt. Marapi and Mt. Pasaman in west Sumatra, Indonesia were studied to characterize their mineralogy and the surface morphology of the sand grains. The minerals in the sand grains included quartz, plagioclase, hornblende, augite, hypersthene, olivine and volcanic glass having different surface morphology. The morphology surface features present are bubbles, pitted, curve platy and sponge-like. Some of the sand grains are coated with amorphous materials. Halloysite is confirmed by the presence of strong peaks of Si and Al and a weak peak of Fe on the SEM-EDX spectra. The clay fraction is composed mainly of allophane, cristobalite, feldspars and halloysite. Soils from the Mt. Pasaman have some gibbsite, while those of the Mt. Marapi have opaline silica in the surface horizons. The abundance of opaline silica tends to decrease with the age of the volcanic ash soils

Fungi used for pest management in crop production

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Scaling of Traction Forces with Size of Cohesive Cell Colonies

To understand how the mechanical properties of tissues emerge from interactions of multiple cells, we measure traction stresses of cohesive colonies of 1-27 cells adherent to soft substrates. We find that traction stresses are generally localized at the periphery of the colony and the total traction force scales with the colony radius. For large colony sizes, the scaling appears to approach linear, suggesting the emergence of an apparent surface tension of order 1E-3 N/m. A simple model of the cell colony as a contractile elastic medium coupled to the substrate captures the spatial distribution of traction forces and the scaling of traction forces with the colony size.Comment: 5 pages, 3 figure