Variations in the Fine-Scale Composition of a Central Pacific Ferromanganese Crust: Paleoceanographic Implications

1992 ◽  
Vol 7 (1) ◽  
pp. 63-77 ◽  
Author(s):  
James R. Hein ◽  
Wendy A. Bohrson ◽  
Marjorie S. Schulz ◽  
Marlene Noble ◽  
David A. Clague
Keyword(s):  
Ferromanganese Crust ◽  
Fine Scale ◽  
Central Pacific ◽  
Scale Composition

scholarly journals No Population Genetic Structure of Skipjack Tuna (Katsuwonus pelamis) in the Tropical Western and Central Pacific Assessed Using Single Nucleotide Polymorphisms

2020 ◽  
Vol 7 ◽  
Author(s):  
Giulia Anderson ◽  
Monal Lal ◽  
Brian Stockwell ◽  
John Hampton ◽  
Neville Smith ◽  
...  
Keyword(s):  
Pacific Ocean ◽  
Population Size ◽  
Population Genomics ◽  
Biological Significance ◽  
Fine Scale ◽  
Skipjack Tuna ◽  
Central Pacific ◽  
Katsuwonus Pelamis ◽  
Central Pacific Ocean ◽  
Basin Scale

Skipjack tuna (Katsuwonus pelamis) has historically been considered panmictic at the ocean basin scale because of the species’ life history and substantial absolute population size. However, recent advances in population genomics have enabled scientists to demonstrate population structure in other species that were likewise traditionally assumed to be panmictic. Accordingly, we used DArTseq, a proprietary platform of reduced-representation genome sequencing developed by Diversity Arrays Technology (DArTech) to genotype 222 skipjack tuna from 9 sample groups collected across 6 exclusive economic zones (EEZs) and over 6 years in the tropical Western and Central Pacific Ocean. This is one of the most fine-scale population genetics assessments of skipjack tuna to date. We found several statistically significant pairwise FST comparisons using purportedly neutral loci, but very little indication of structure based on observed and expected heterozygosity, effective population size, a Mantel test, AMOVA, numerous genetic clustering and population assignment tests, and exploration of correlation with oceanographic features. Significant pairwise FST values were often shallow and resulted in uncertainty about their biological significance. Furthermore, a test of the hypothesis that the geographic and temporal distribution of the potentially adaptive genetic diversity may depict cryptic fine scale structure using two different outlier detection methods, could not reject panmixia based on estimates of fixation indices and two clustering software. Our results support the presence of a single population of skipjack tuna in the tropical Western and Central Pacific Ocean, but highly recommend the expansion of the study area, in latitude, longitude, and seasonality, before drawing any global conclusions.

scholarly journals Farnella Cruise F7-86-HW, cobalt-rich ferromanganese crust data report for Karin Ridge and Johnston Island, Central Pacific

1987 ◽  
Author(s):  
J.R. Hein ◽  
W.C. Schwab ◽  
D.G. Foot ◽  
Yoshio Masuda ◽  
Akira Usui ◽  
...  
Keyword(s):  
Ferromanganese Crust ◽  
Central Pacific

Os isotopic compositions of a cobalt-rich ferromanganese crust profile in Central Pacific

2005 ◽  
Vol 50 (18) ◽  
pp. 2106-2112 ◽  
Author(s):  
Yazhou Fu ◽  
Jiantang Peng ◽  
Wenjun Qu ◽  
Ruizhong Hu ◽  
Xuefa Shi ◽  
...  
Keyword(s):  
Ferromanganese Crust ◽  
Central Pacific ◽  
Isotopic Compositions ◽  
Crust Profile

High Resolution Stereography of Complementary Freeze-Fracture Replicas Reveals the Presence of Depressions Opposite Membrane Associated Particles of Split Membranes

1971 ◽  
Vol 29 ◽  
pp. 442-443
Author(s):  
Russell L. Steere
Keyword(s):  
High Resolution ◽  
Cardiac Muscle ◽  
Electron Micrographs ◽  
Chromic Acid ◽  
Freeze Fracture ◽  
Distilled Water ◽  
Fine Scale ◽  
Acid Cleaning ◽  
Cleaning Solution

Complementary replicas have revealed the fact that the two common faces observed in electron micrographs of freeze-fracture and freeze-etch specimens are complementary to each other and are thus the new faces of a split membrane rather than the original inner and outer surfaces (1, 2 and personal observations). The big question raised by published electron micrographs is why do we not see depressions in the complementary face opposite membrane-associated particles? Reports have appeared indicating that some depressions do appear but complementarity on such a fine scale has yet to be shown.Dog cardiac muscle was perfused with glutaraldehyde, washed in distilled water, then transferred to 30% glycerol (material furnished by Dr. Joaquim Sommer, Duke Univ., and VA Hospital, Durham, N.C.). Small strips were freeze-fractured in a Denton Vacuum DFE-2 Freeze-Etch Unit with complementary replica tooling. Replicas were cleaned in chromic acid cleaning solution, then washed in 4 changes of distilled water and mounted on opposite sides of the center wire of a Formvar-coated grid.

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