Computerized tomography and skeletal density of coral skeletons

Coral Reefs ◽  
1993 ◽  
Vol 12 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Hemmo Bosscher
Keyword(s):  
Computerized Tomography ◽  
Skeletal Density ◽  
Coral Skeletons

scholarly journals Bioerosion by euendoliths decreases in phosphate-enriched skeletons of living corals

2012 ◽  
Vol 9 (7) ◽  
pp. 2377-2384 ◽  
Author(s):  
C. Godinot ◽  
A. Tribollet ◽  
R. Grover ◽  
C. Ferrier-Pagès
Keyword(s):  
Apical Part ◽  
Skeletal Growth ◽  
Dead Coral ◽  
Skeletal Density ◽  
Stylophora Pistillata ◽  
Thin Sections ◽  
Coral Skeletons ◽  
Effective Expansion ◽  
First Time

Abstract. While the role of microboring organisms, or euendoliths, is relatively well known in dead coral skeletons, their function in live corals remains poorly understood. They are suggested to behave like ectosymbionts or parasites, impacting their host's health. However, the species composition of microboring communities, their abundance and dynamics in live corals under various environmental conditions have never been explored. Here, the effect of phosphate enrichment on boring microorganisms in live corals was tested for the first time. Stylophora pistillata nubbins were exposed to 3 different treatments (phosphate concentrations of 0, 0.5 and 2.5 μmol l−1) during 15 weeks. After 15 weeks of phosphate enrichment, petrographic thin sections were prepared for observation with light microscopy, and additional samples were examined with scanning electron microscopy (SEM). Euendoliths comprised mainly phototrophic Ostreobium sp. filaments. Rare filaments of heterotrophic fungi were also observed. Filaments were densely distributed in the central part of nubbins, and less abundant towards the apex. Unexpectedly, there was a visible reduction of filament abundance in the most recently calcified apical part of phosphate-enriched nubbins. The overall abundance of euendoliths significantly decreased, from 9.12 ± 1.09% of the skeletal surface area in unenriched corals, to 5.81 ± 0.77% and 5.27 ± 0.34% in 0.5 and 2.5 μmol l−1-phosphate enriched corals respectively. SEM observations confirmed this decrease. Recent studies have shown that phosphate enrichment increases coral skeletal growth and metabolic rates, while it decreases skeletal density and resilience to mechanical stress. We thus hypothesize that increased skeletal growth in the presence of phosphate enrichment occurred too fast for an effective expansion of euendolith growth. They could not keep up with coral growth, so they became diluted in the apex areas as nubbins grew with phosphate enrichment. Results from the present study suggest that coral skeletons of S. pistillata will not be further weakened by euendoliths under phosphate enrichment.

scholarly journals Bioerosion by euendoliths decreases in phosphate-enriched skeletons of living corals

2012 ◽  
Vol 9 (3) ◽  
pp. 2425-2444 ◽  
Author(s):  
C. Godinot ◽  
A. Tribollet ◽  
R. Grover ◽  
C. Ferrier-Pagès
Keyword(s):  
Apical Part ◽  
Skeletal Growth ◽  
Metabolic Rates ◽  
Dead Coral ◽  
Skeletal Density ◽  
Thin Sections ◽  
Coral Skeletons ◽  
Host Health ◽  
First Time

Abstract. While the role of microboring organisms, or euendoliths, is relatively well known in dead coral skeletons, their function in live corals remains poorly understood. They are suggested to behave like ectosymbionts or parasites, impacting their host health. However, the species composition of microboring communities, their abundance and dynamics in live corals under various environmental conditions have never been explored. Here, the effect of phosphate enrichment on boring microorganisms in live corals was tested for the first time. S. pistillata nubbins were exposed to 3 different treatments (phosphate enrichments of 0, 0.5 and 2.5 μmol l−1) during 15 weeks. After 15 weeks of phosphate enrichment, petrographic thin sections were prepared for observation with light microscopy, and additional samples were examined with scanning electron microscopy (SEM). Euendoliths comprised mainly autotrophic Ostreobium sp. filaments. Rare filaments of heterotrophic fungi were also observed. Filaments were densely distributed in the central part of nubbins, and less abundant towards the apex. Unexpectedly, there was a visible reduction of filaments abundance in the most recently-calcified apical part of phosphate-enriched nubbins. The overall abundance of euendoliths significantly decreased, from 9.12 ± 1.09% of the skeletal surface area in unenriched corals, to 5.81 ± 0.77% and 5.27 ± 0.34% in 0.5 and 2.5 μmol l−1-phosphate enriched corals respectively. SEM observations confirmed this decrease. Recent studies have shown that phosphate enrichment increases coral skeletal growth and metabolic rates, while it decreases skeletal density and resilience to mechanical stress. We thus hypothesize that increased skeletal growth in the presence of phosphate enrichment occurred too fast for an effective euendolith colonization. They could not keep up with coral growth, so they became diluted in the apex areas as nubbins grew with phosphate enrichment. The possible advantages and downsides of the reduction of euendoliths associated with phosphate eutrophication in live corals are discussed in this article.

1786: Prediction of Differential Renal Function as Determined by Contrasted and non-contrasted Computerized Tomography

2007 ◽  
Vol 177 (4S) ◽  
pp. 593-594
Author(s):  
Shelby N. Morrisroe ◽  
Erin P. Gibbons ◽  
Benjamin R. Stockton ◽  
Kyongtae T. Bae ◽  
Cheng Hong ◽  
...  
Keyword(s):  
Renal Function ◽  
Computerized Tomography ◽  
Differential Renal Function

1573: Flat-Panel Volume Computerized Tomography (VCT) has Decreased Variability in Hounsfield Unit Measurements Compared to Conventional Helical Computerized Tomography

2005 ◽  
Vol 173 (4S) ◽  
pp. 426-426
Author(s):  
Dianne E. Sacco ◽  
Patricio Gargollo ◽  
Gupta Rajiv ◽  
Ijad Madisch ◽  
Ronald Arellano ◽  
...  
Keyword(s):  
Computerized Tomography ◽  
Hounsfield Unit ◽  
Flat Panel
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