Reductions in the dietary niche of southern sea otters () from the Holocene to the Anthropocene.

The sea otter () is a marine mammal hunted to near extinction during the 1800s. Despite their well-known modern importance as a keystone species, we know little about historical sea otter ecology. Here, we characterize the ecological niche of ancient southern sea otters () using δC analysis and δN analysis of bones recovered from archaeological sites spanning ~7,000 to 350 years before present ( = 112 individuals) at five regions along the coast of California.

The developmental transition to flowering in Arabidopsis is associated with an increase in leaf chloroplastic lipoxygenase activity.

The developmental transition from vegetative growth to flowering in Arabidopsis is associated with a precipitous decline in the activity of leaf ascorbate peroxidase (APx), an enzymatic scavenger of hydrogen peroxide, and an increase in specific lipid peroxidation leading to the accumulation of 13-hydroperoxy-9,11,15 (Z,E,Z) octadecatrienoic acid (13 HOO-FA). The appearance of this specific isomer suggests that it is of enzymatic origin and may represent the activation of an oxylipin signaling pathway. We thus hypothesized that leaf 13-lipoxygenase (LOX) activity increases at the floral transition and leads to the observed elevation of 13-HOO-FA levels.

Detection of oligonucleotide hybridization at femtomolar level and sequence-specific gene analysis of the Arabidopsis thaliana leaf extract with an ultrasensitive surface plasmon resonance spectrometer.

A flow-injection (FI) device is combined, through the use of a low-volume (4 microl) flow cell, with an ultrasensitive surface plasmon resonance (SPR) spectrometer equipped with a bi-cell photodiode detector. The application of this novel FI-SPR device for sequence-specific ultratrace analysis of oligodeoxynucleotides (ODNs) and polydeoxynucleotides was demonstrated. Self-assembled monolayers of ODN probes are tethered onto Au films with a mercaptohexyl group at the 3' ends.

Paleocoastal marine fishing on the Pacific Coast of the Americas: perspectives from Daisy Cave, California.

Analysis of over 27,000 fish bones from strata at Daisy Cave dated between about 11,500 and 8500 cal B.P. suggests that early Channel Islanders fished relatively intensively in a variety of habitats using a number of distinct technologies, including boats and the earliest evidence for hook-and-line fishing on the Pacific Coast of the Americas.

Oligonucleotide-capped gold nanoparticles for improved atomic force microscopic imaging and enhanced selectivity in polynucleotide detection.

A novel assay for selective determination of polynucleotides using atomic force microscopy in conjunction with the formation of the probe/target/DNA-gold nanoparticle sandwich structure at a gold surface is described. A 17-mer probe was attached to the surface for subsequent hybridization with a polynucleotide target. Due to the flat orientation of the probe-target hybrid with respect to the surface and the spatial obstruction of the unhybridized probes near the hybrids, the AFM images are not clear.