End-to-end models were constructed to examine and compare the trophic structure and energy flow in coastal shelf ecosystems of four US Global Ocean Ecosystem Dynamics (GLOBEC) study regions: the Northern California Current, the Central Gulf of Alaska, Georges Bank, and the Southwestern Antarctic Peninsula. High-quality data collected on system components...
Although it is generally assumed that the intensifying abiotic environment is the primary effect of drought on aquatic organisms, drought-induced top predator extinctions may be an important underlying mechanism. I used manipulative experiments to disentangle the impacts of drying and top predator extinctions on arid-land aquatic invertebrate communities. I then...
dependence and regulation of relatively large local populations? If so, what are the causative mechanisms and their implications? We conducted an eight-year multigeneration study of population dynamics of bicolor damselfish (Stegastes partitus) inhabiting four large coral reefs in the Bahamas. After a four-year baseline period, it was clear that two...
Fe25Co25Ni25Cr25-XMoX High Entropy Alloys were fabricated in mini arc-melter and then cast into 4mm diameter cylinders by injection casting technique and 1cm diameter cylinders by water quenching technique. Heat transfer modeling during solidification of FeCoNiCr HEA was simulated. Combining X-Ray Diffraction, Optical Microscopy, Scanning Electron Microscope, Energy Dispersive X-ray analysis,...
The Type-II dilemma zone refers to the segment of roadway approaching an
intersection where drivers have difficulty deciding to stop or proceed through at
the onset of the circular yellow (CY) indication. Signalized intersection safety can
be improved when the dilemma zone is correctly identified and steps are taken to...
Solid solution alloying was employed in an attempt to produce some
relatively ductile form of beryllium. If the c/a ratio could be significantly
altered, it was felt new or different slip systems could be activated. The
following elements were selected on the basis of atomic size, melting point,
crystal structure...
The majority of the world's breeding population of northern fur seals (Callorhinus ursinus) is found on the Pribilof Islands (St. Paul and St. George) in the Bering Sea, Alaska. Pup production on these islands experienced an irregular but overall decline since the early 1970's. Between 1998 and 2010, pup production...
Greater sage-grouse (Centrocercus urophasianus) populations declined range wide during the past 50 years. Grouse populations were 2-3 times larger than the current population as recently as the early 1970's. In addition to habitat loss and fragmentation, declines were attributed habitat degradation that caused reduced productivity. Because chick survival remains the...
In 1997, the Eskimo Walrus Commission (EWC) and the U.S. Fish and Wildlife Service (USFWS) established a formal cooperative agreement for the conservation and management of Pacific walrus (Odobenus rosmarus divergens). This arrangement facilitates the transfer of funds from Section 119 of the Marine Mammal Protection Act via the USFWS...
The aim of this research was to provide forest managers and researchers with a better understanding of individual tree defenses and tree responses to disturbances, within a Collaborative Forest Landscape Restoration Program area. Forest restoration often aims to increase stand-level resistance to uncharacteristic changes, and stand-level resistance begins with tree-level...