Metrics that matter for assessing the ocean biological carbon pump.

The biological carbon pump (BCP) comprises wide-ranging processes that set carbon supply, consumption, and storage in the oceans' interior. It is becoming increasingly evident that small changes in the efficiency of the BCP can significantly alter ocean carbon sequestration and, thus, atmospheric CO and climate, as well as the functioning of midwater ecosystems. Earth system models, including those used by the United Nation's Intergovernmental Panel on Climate Change, most often assess POC (particulate organic carbon) flux into the ocean interior at a fixed reference depth.

Tracking the Fate of Particle Associated Fukushima Daiichi Cesium in the Ocean off Japan.

A three year time-series of particle fluxes is presented from sediment traps deployed at 500 and 1000 m at a site 115 km southeast of Fukushima Daiichi Nuclear Power Plant (FDNPP). Results show a high fraction of lithogenic material and mass flux peaks that do not align between the trap depths, suggesting a lateral source of sediments. Fukushima cesium-137 and cesium-134 were enhanced in flux peaks that, given variations in trap (137)Cs/(210)Pbex ratios, are characteristic of material derived from shelf and slope sediments found from <120 to >500 m.

Spatiotemporal evolution of apoptotic neurodegeneration following traumatic injury to the developing rat brain.

Closed head injury to the developing rat brain causes an acute excitotoxic lesion and axonal disruption at the impact site followed by a delayed pattern of apoptotic damage at various distant sites. Using an electromagnetic impact device to deliver a precisely controlled degree of mechanical deformation to the P7 infant rat skull, we studied the distribution of distant apoptotic lesions and the sequence and time course with which these lesions evolve following relatively mild closed head injury. The first major wave of apoptotic neurodegeneration occurred at 8 h postimpact in the retrosplenial cortex and pre- and parasubiculum.

In vivo imaging of rapid deformation and strain in an animal model of traumatic brain injury.

In traumatic brain injury (TBI) rapid deformation of brain tissue leads to axonal injury and cell death. In vivo quantification of such fast deformations is extremely difficult, but important for understanding the mechanisms of degeneration post-trauma and for development of numerical models of injury biomechanics. In this paper, strain fields in the brain of the perinatal rat were estimated from data obtained in vivo during rapid indentation.