We investigated mesopredator effects on prey availability in the Ross Sea, Antarctica, assessing the reasons why Adélie penguin Pygoscelis adeliae foraging trip duration (FTD) increases and diet changes from krill to fish as numbers of foraging penguins and competing cetaceans increase in the penguins’ foraging area. To investigate penguins’ seasonally...
The results of high-resolution biogeochemical measurements in the upper 200 m of
the Ross Sea, Antarctica, obtained during the AESOPS (U. S. JGOFS) program using the
Lamont Pumping SeaSoar (LPS) are presented. They consist of three west-east transects
from 170°E to 180° longitude along the AESOPS study line at 76.5°S...
The application of a generalized inverse approach for assimilating vessel-mounted acoustic Doppler current profiler (VM-ADCP) data into numerical solutions of barotropic tides is described. The derived estimates of tidal currents can be used to detide the VM-ADCP data and expose underlying mean circulation. The methodology is illustrated with data assimilation...
Increasing paleoclimatic evidence suggests that the Little Ice Age (LIA) was a global climate change event. Understanding the forcings and associated climate system feedbacks of the LIA is made difficult by the scarcity of Southern Hemisphere paleoclimate records. We use a new glaciochemical record of a coastal ice core from...
Body size, mass and condition can affect an organism’s ability to cope with variation in resource availability or metabolic demand, particularly as juveniles reach independence. It follows that changes to parental provisioning efficiency (size and frequency of meals) through intraspecific competition or environmental conditions that affect prey availability may affect...
A technical definition of artisan breads is proposed, based on the concepts of lean formulations, long fermentations, and the use of process as the primary way to adapt to changing flour qualities. The current status of what constitutes refined flour for artisan bread production is presented and a conclusion drawn...
The development of hybrids with enhanced expression of heterosis depends on the genetic background of the source population and the effectiveness of a breeding scheme used to identify and use divergent inbred lines with good combining ability. The present study was conducted to examine the potential of improved tropical reciprocal...
Background and objectives: One hard wheat and one semi-hard wheat were milled on commercial, laboratory, and household-scale flour mills with rotating elements ranging from 0.1 to 1.0 m in diameter and speeds ranging from 65 to 40,000 rpm. The aim of the study was to assess and compare the quality...
Pole-size Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) were inoculated with two fungi (Ophiostoma pseudotsugae (Rumb.) von Arx and Leptographium abietinum (Peck) Wingf.) associated with the Douglas-fir beetle (Dendroctonus pseudotsugae Hopkins) to evaluate their pathogenicity. Pruning the lowermost 30% of the live crown had no
effect on host tree defenses. Inoculation with...
Several efforts have recently been made to relate the displacement of swimming three-link systems over strokes to geometric quantities of the strokes. In doing so, they provide powerful, intuitive representations of the bounds on a system’s locomotion capabilities and the forms of its optimal strokes or gaits. While this approach...
Four species of the sequestrate fungal genus Elaphomyces are reported from New Zealand: Elaphomyces bollardii sp. nov. associated with Leptospermum spp. and Kunzea ericoides, E. luteicrustus sp. nov. associated with Nothofagus menziesii, E. putridus sp. nov. associated with Nothofagus spp., and an unnamed species associated with Nothofagus spp.
Managing for species using current weather patterns fails to incorporate the uncertainty associated with future climatic conditions; without incorporating potential changes in climate into conservation strategies, management and conservation efforts may fall short or waste valuable resources. Understanding the effects of climate change on species in the Great Plains of...
A snowpack model sensitivity study, observed changes of snow cover in the NOAA satellite dataset, and snow cover simulations from the Coupled Model Intercomparison Project phase 3 (CMIP3) multimodel dataset are used to provide new insights into the climate response of Northern Hemisphere (NH) snow cover. Under conditions of warming...
We document the age and extent of late Quaternary glaciofluvial processes in Garwood Valley, McMurdo Dry Valleys, Antarctica, using mapping, stratigraphy, geochronology, and geochemical analysis of sedimentary and ice deposits. Geomorphic and stratigraphic evidence indicates damming of the valley at its Ross Sea outlet by the expanded Ross Sea ice...
An important constraint on mechanisms of past
carbon cycle variability is provided by the stable isotopic
composition of carbon in atmospheric carbon dioxide (δ¹³C-CO₂) trapped in polar ice cores, but obtaining very precise
measurements has proven to be a significant analytical challenge.
Here we describe a new technique to determine...
Combining geometric mechanics theory, laboratory robotic experiment, and numerical simulation, we study the locomotion in granular media of the simplest noninertial swimmer, the Purcell three-link swimmer. Using granular resistive force laws as inputs, the theory relates translation and rotation of the body to shape changes (movements of the links). This...
The range in the projections of future climate warming can be attributed to the inherent uncertainty in the representation of climate model parameters and processes. In this study, we assess the effect of uncertainty in climate sensitivity and ocean heat uptake on the rate of future climate change. We apply...
Leucopis spp. (Diptera: Chamaemyiidae) from the Pacific Northwest previously were identified as potential biological control agents for the hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), in the eastern United States. We collected Leucopis spp. larvae from A. tsugae infested western hemlocks in Oregon and Washington and reared them on...
Microzooplankton grazing impact on phytoplankton in the Bering Sea during spring was assessed in 2008, 2009 and 2010 using two-point dilution assays. Forty-nine experiments were completed in a region encompassing shelf to slope waters, including the 70 m line along the edge of the shelf. A variety of conditions were...