Scientific articles
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2008
Traditional real-time quantitative polymerase chain reaction protocols cannot be used accurately with symbiotic organisms unless the relative contribution of each symbiotic compartment to the total nucleic acid pool is known. A modified ‘universal reference gene’ protocol was created for reef-building corals and sea anemones, anthozoans that harbour endosymbiotic dinoflagellates belonging to the genus Symbiodinium. Gene expression values are first normalized to an RNA spike and then to a symbiont molecular proxy that represents the number of Symbiodinium cells extracted and present in the RNA. The latter is quantified using the number of genome copies of heat shock protein-70 (HSP70)...
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2007
Indonesia Tsunami Impacts in Aceh Provence and North Sumatra
The huge earthquake and resulting tsunami which occurred on December 26, 2004 off the west coast of Sumatra resulted in regionally variable patterns of impact in and around the Indian Ocean basin. The coast of Sumatra was close to the earthquake epicenter and was the first to be struck, within one hour of the event. A collaborative expedition between the Khaled bin Sultan Living Oceans Foundation, Reef Check International and IUCN (World Conservation Union) to the northwest coast of Sumatra and Aceh Province, Indonesia, was conducted in October 2005....
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2007
Osmoregulation in Anthozoan–Dinoflagellate Symbiosis
Endosymbiosis creates a unique osmotic circumstance. Hosts are not only responsible for balancing their internal osmolarity with respect to the external environment, but they must also maintain a compatible osmotic environment for their endosymbionts, which may themselves contribute to the net osmolarity of the host cell through molecular fluxes and/or exchange. Cnidarian hosts that harbor intracellular dinoflagellates (zooxanthellae) are excellent examples of such a symbiosis. These associations are characterized by the exchange of osmotically active compounds, but they are temporally stable under normal environmental conditions indicating that these osmotically driven exchanges are effectively and rapidly regulated. Although we have...
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2006
Indonesia Coral Reefs: Status of Coral Reefs in Indonesia After the December 2004 Tsunami
The 2004 tsunami was the worst natural disaster in the history of Indonesia. More than 120,000 people died or are still missing; more than 500,000 people lost their homes; and more than 250,000 houses were destroyed or damaged; the total damage bill exceeds US$4.45 billion (approximately 97% of Aceh’s GDP); Seawalls, flood control walls, irrigation canals and jetties have been severely affected with damage estimates in Aceh of US$72.1 million;...
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2004
Coral Cover: The Cover of Living and Dead Corals from Airborne Remote Sensing
Trends in coral cover are widely used to indicate the health of coral reefs but are costly to obtain from field survey over large areas. In situ studies of reflected spectra at the coral surface show that living and recently dead colonies can be distinguished. Here, we investigate whether such spectral differences can be detected using an airborne remote sensing instrument. The Compact Airborne Spectrographic Imager (Itres Research Ltd, Canada) was flown in two configurations: 10 spectral bands with 1-m2 pixels and 6 spectral bands with 0.25-m2 pixels. First, we show that an instrument with 10 spectral bands possesses...
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2003
Seaweed Resistance to Microbial Attack: A Targeted Chemical Defense Against Marine Fungi
Pathogenic microbes can devastate populations of marine plants and animals. Yet, many sessile organisms such as seaweeds and sponges suffer remarkably low levels of microbial infection, despite lacking cell-based immune systems. Antimicrobial defenses of marine organisms are largely uncharacterized, although from a small number of studies it appears that chemical defenses may improve host resistance. In this study, we asked whether the common seaweed Lobophora variegata is chemically defended against potentially deleterious microorganisms. Using bioassayguided fractionation, we isolated and characterized a 22-membered cyclic lactone, lobophorolide (1), of presumed polyketide origin, with sub-M activity against pathogenic and...
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2002
Widespread and Persistent Populations of a Major New Marine Actinomycete Taxon in Ocean Sediments
A major taxon of obligate marine bacteria within the order Actinomycetales has been discovered from ocean sediments. Populations of these bacteria (designated MAR 1) are persistent and widespread, spanning at least three distinct ocean systems. In this study, 212 actinomycete isolates possessing MAR 1 morphologies were examined and all but two displayed an obligate requirement of seawater for growth. Forty-five of these isolates, representing all observed seawater-requiring morphotypes, were partially sequenced and found to share characteristic small-subunit rRNA signature nucleotides between positions 207 and 468 (Escherichia coli numbering). Phylogenetic characterization of seven representative isolates based on almost...