Publications by authors named "Rebecca Asch"

Substantial interannual variability in marine fish recruitment (i.e., the number of young fish entering a fishery each year) has been hypothesized to be related to whether the timing of fish spawning matches that of seasonal plankton blooms.

View Article and Find Full Text PDF

Photosynthesis fuels marine food webs, yet differences in fish catch across globally distributed marine ecosystems far exceed differences in net primary production (NPP). We consider the hypothesis that ecosystem-level variations in pelagic and benthic energy flows from phytoplankton to fish, trophic transfer efficiencies, and fishing effort can quantitatively reconcile this contrast in an energetically consistent manner. To test this hypothesis, we enlist global fish catch data that include previously neglected contributions from small-scale fisheries, a synthesis of global fishing effort, and plankton food web energy flux estimates from a prototype high-resolution global earth system model (ESM).

View Article and Find Full Text PDF

Anchovy and sardine populated productive ocean regions over hundreds of thousands of years under a naturally varying climate, and are now subject to climate change of equal or greater magnitude occurring over decades to centuries. We hypothesize that anchovy and sardine populations are limited in size by the supply of nitrogen from outside their habitats originating from upwelling, mixing, and rivers. Projections of the responses of anchovy and sardine to climate change rely on a range of model types and consideration of the effects of climate on lower trophic levels, the effects of fishing on higher trophic levels, and the traits of these two types of fish.

View Article and Find Full Text PDF

Climate change has prompted an earlier arrival of spring in numerous ecosystems. It is uncertain whether such changes are occurring in Eastern Boundary Current Upwelling ecosystems, because these regions are subject to natural decadal climate variability, and regional climate models predict seasonal delays in upwelling. To answer this question, the phenology of 43 species of larval fishes was investigated between 1951 and 2008 off southern California.

View Article and Find Full Text PDF

A large fraction of the carbon dioxide added to the atmosphere by human activity enters the sea, causing ocean acidification. We show that otoliths (aragonite ear bones) of young fish grown under high CO2 (low pH) conditions are larger than normal, contrary to expectation. We hypothesize that CO2 moves freely through the epithelium around the otoliths in young fish, accelerating otolith growth while the local pH is controlled.

View Article and Find Full Text PDF

Objective: Regionalization has been proposed as a method to improve outcomes for patients with critical illness. We sought to determine intensivist physician attitudes and potential barriers to the regionalization of adult critical care.

Design: Mail survey.

View Article and Find Full Text PDF

Background: Regionalization of adult critical care services may improve outcomes for critically ill patients. We sought to develop a framework for understanding clinician attitudes toward regionalization and potential barriers to developing a tiered, regionalized system of care in the United States.

Methods: We performed a qualitative study using semi-structured interviews of critical care stakeholders in the United States, including physicians, nurses and hospital administrators.

View Article and Find Full Text PDF

We have established human B-lineage (BLIN) acute lymphoblastic leukemia cell lines that retain a dependency on fibroblast monolayers for survival and proliferation. Eight hours following removal from adherent cell contact BLIN cells undergo a decrease in mitochondrial transmembrane potential and an increase in annexin V binding. Unexpectedly, the caspase-9 inhibitor (C9i) benzyloxycarbonyl-Leu-Glu-His-Asp-fluoromethylketone enhanced the appearance of apoptotic cells within 8 hours following removal of BLIN cells from fibroblast monolayers.

View Article and Find Full Text PDF