Study of celestial/inertial test facility Final report

Test facility and equipment for evaluation of optical sensors employed in celestial navigation and guidance system

Coupling planktonic and benthic shifts during a bloom of Alexandrium catenella in southern Chile:Implications for bloom dynamics and recurrence

Cell abundances and distributions of Alexandrium catenella resting cysts in recent sediments were studied along time at two locations in the Chilean Inland Sea exposed to different oceanographic conditions: Low Bay, which is much more open to the ocean than the more interior and protected Ovalada Island. The bloom began in interior areas but maximum cyst concentrations were recorded in locations more open to the ocean, at the end of the Moraleda channel. Our results showed a time lapse of around 3 months from the bloom peak (planktonic population) until the number of resting cysts in the sediments reached a maximum. Three months later, less than 10% of the A. catenella cysts remained in the sediments. Maximum cyst numbers in the water column occurred one month after the planktonic peak, when no cells were present. The dinoflagellate assemblage at both study sites was dominated by heterotrophic cysts, except during the A. catenella bloom. CCA analyses of species composition and environmental factors indicated that the frequency of A. catenella blooms was associated with low temperatures, but not with salinity, chlorophyll a concentration, and predator presence (measured as clam biomass). However, resting cyst distribution was only related to cell abundance and location. The occurrence of A. catenella cysts was also associated with that of cysts from the toxic species Protoceratium reticulatum. By shedding light on the ecological requirements of A. catenella blooms, our observations support the relevance of encystment as a mechanism of bloom termination and show a very fast depletion of cysts from the sediments (<3 months), which suggest a small role for resting cyst deposits in the recurrence of A. catenella blooms in this area.Postprin

Ecosystem Consequences of Contrasting Flow Regimes in an Urban Effects Stream Mesocosm Study 1

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73638/1/j.1752-1688.2009.00336.x.pd

Biogeochemical responses to Holocene catchment-lake dynamics in the Tasmanian World Heritage Area, Australia

Environmental changes such as climate, land use, and fire activity affect terrestrial and aquatic ecosystems at multiple scales of space and time. Due to the nature of the interactions between terrestrial and aquatic dynamics, an integrated study using multiple proxies is critical for a better understanding of climate- and fire-driven impacts on environmental change. Here we present a synthesis of biological and geochemical data (pollen, spores, diatoms, micro X-ray fluorescence scanning, CN content, and stable isotopes) from Dove Lake, Tasmania, allowing us to disentangle long-term terrestrial-aquatic dynamics through the last 12 kyear. We found that aquatic dynamics at Dove Lake are tightly linked to vegetation shifts dictated by regional hydroclimatic variability in western Tasmania. A major shift in the diatom composition was detected at ca. 6 ka, and it was likely mediated by changes in regional terrestrial vegetation, charcoal, and iron accumulation. High rainforest abundance prior ca. 6 ka is linked to increased terrestrially derived organic matter delivery into the lake, higher dystrophy, anoxic bottom conditions, and lower light penetration depths. The shift to a landscape with a higher proportion of sclerophyll species following the intensification of El Niño-Southern Oscillation since ca. 6 ka corresponds to a decline in terrestrial organic matter input into Dove Lake, lower dystrophy levels, higher oxygen availability, and higher light availability for algae and littoral macrophytes. This record provides new insights on terrestrial-aquatic dynamics that could contribute to the conservation management plans in the Tasmanian World Heritage Area and in temperate high-altitude dystrophic systems elsewhere

The Ties That Bind: A Re-examination of the Career of Hugh Gaine, Printer and Bookseller, at the Bible and Crown, in Hanover Square

This thesis re-examines the printing career of Hugh Gaine, an Irish-born and New York-based printer during the second half of the eighteenth century, using the approach of the history of the book. I examine how the colonial printing house developed into a communal space that fostered transatlantic imagined communities with the printer as their facilitator. The role of print as a cultural agent has not gone unnoticed by scholars, but the systems of its production and dissemination remain to be studied in greater depth. Analysis of the development of the colonial American printing house and their printers as facilitators of cultural change allows us to more fully understand the changes in taste and thought that occurred within colonial society during the eighteenth century. The printing house emerged as an intermediate space between colonists’ identity as subjects of the British Empire and an evolving construction of a national American identity