Synchronism of Holocene East Asian monsoon variations and North Atlantic drift-ice tracers (vol 65；pg 443；2006)

IEECAS SKLLQG

The Holocene Asian monsoon: Links to solar changes and North Atlantic climate

IEECAS SKLLQG

Analytical intercomparison results from the 1990 Intergovernmental Oceanographic Commission open-ocean baseline survey for trace metals: Atlantic Ocean

“Dissolved” (< 0.4 μm filtered) and “total dissolvable” (unfiltered) trace element samples were collected using “clean” sampling techniques from four vertical profiles in the eastern Atlantic Ocean on the first IOC Trace Metals Baseline expedition. The analytical results obtained by 9 participating laboratories for Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, and Se on samples from station 4 in the northeast Atlantic have been evaluated with respect to accuracy and precision (intercomparability). The data variability among the reporting laboratories was expressed as 2 × SD for a given element and depth, and was comparable to the 95% confidence interval reported for the NASS seawater reference standards (representing analytical variability only). The discrepancies between reporting laboratories appear to be due to inaccuracies in standardization (analytical calibration), blank correction, and/or extraction efficiency corrections.Several of the sampling bottles used at this station were not adequately pre-cleaned (anomalous Pb results). The sample filtration process did not appear to have been a source of contamination for either dissolved or particulate trace elements. The trace metal profiles agree in general with previously reported profiles from the Atlantic Ocean. We conclude that the sampling and analytical methods we have employed for this effort, while still in need of improvement, are sufficient for obtaining accurate concentration data on most trace metals in the major water masses of the oceans, and to enable some evaluation of the biogeochemical cycling of the metals.

Coal-burning roasted corn and chili as the cause of dental fluorosis for children in southwestern China

To find the pathologic cause of the children's dental fluorosis in southwestern China, diet structure before the age of 6 and prevalence rate of dental fluorosis (DF) of 405 children were investigated, and the fluorine and arsenic content of several materials were determined. The prevalence rate of DF of children living on roasted corn before the age of 6 is 100% with nearly 95% having the mild to severe DF; while that of children living on non-roasted corn or rice is less than 5% with all having very mild DF. The average fluorine and arsenic concentration are 20.26 mg/kg and 0.249 mg/kg in roasted corn, which are about 16 times and 35 times more than in non-roasted corn, respectively. The average fluorine concentration is 78 mg/kg in coal, 1116 mg/kg in binder clay and 313 mg/kg in briquette (coal mixed with clay). The average arsenic concentration of coal is 5.83 mg/kg, the binder clay is 20.94 mg/kg, with 8.52 mg/kg in the briquette. Living on roasted corn and chili is the main pathologic cause of endemic fluorosis in southwestern China. The main source of fluorine and arsenic pollution of roasted corn and chill is the briquette of coal and binder clay. (C) 2010 Elsevier B.V. All rights reserved.

Differences in the rDNA-bearing chromosome divide the Asian-Pacific and Atlantic species of Crassostrea (Bivalvia, Mollusca)

Karyotype and chromosomal location of the major ribosomal RNA genes (rDNA) were studied using fluorescence in situ hybridization (FISH) in five species of Crassostrea: three Asian-Pacific species (C. gigas, C. plicatula, and C. ariakensis) and two Atlantic species (C. virginica and C. rhizophorae). FISH probes were made by PCR amplification of the intergenic transcribed spacer between the 18S and 5.8S rRNA genes, and labeled with digoxigenin-11-dUTP. All five species had a haploid number of 10 chromosomes. The Atlantic species had 1-2 submetacentric chromosomes, while the three Pacific species had none. FISH with metaphase chromosomes detected a single telomeric locus for rDNA in all five species without any variation. In all three Pacific species, rDNA was located on the long arm of Chromosome 10 (10q)-the smallest chromosome. In the two Atlantic species, rDNA was located on the short arm of Chromosome 2 (2p)-the second longest chromosome. A review of other studies reveals the same distribution of NOR sites (putative rDNA loci) in three other species: on 10q in C. sikamea and C. angulata from the Pacific Ocean and on 2p in C. gasar from the western Atlantic. All data support the conclusion that differences in size and shape of the rDNA-bearing chromosome represent a major divide between Asian-Pacific and Atlantic species of Crassostrea. This finding suggests that chromosomal divergence can occur under seemingly conserved karyotypes and may play a role in reproductive isolation and speciation.

Identification of an Atlantic salmon IFN multigene cluster encoding three IFN subtypes with very different expression properties

A cluster of 11 interferon (IFN) genes were identified in the Atlantic salmon genome linked to the growth hormone I gene. The genes encode three different IFN subtypes; IFNa (two genes), IFNb (four genes) and IFNc (five genes), which show 22-32% amino acid sequence identity. Expression of the fish IFNs were studied in head kidney, leukocytes or To cells after stimulation with the dsRNA poly I:C or the imidazoquinoline S-27609. In mammals, poly I:C induces IFN-beta through the RIG-I/MDA5 or the TLR3 pathway, both of which are dependent on NF-kappa B. In contrast, S-27609 induces mammalian IFN-alpha in plasmacytoid dendritic cells through the TLR7 pathway independent of NF-kappa B. The presence of an NF-kappa B site in their promoters and their strong up-regulation by poly I:C, suggest that salmon IFNa1/IFNa2 are induced through similar pathways as IFN-beta. In contrast, the apparent lack of NF-kappa B motif in the promoter and the strong upregulation by S-27609 in head kidney and leukocytes, suggest that IFNb genes are induced through a pathway similar to mammalian IFN-alpha. IFNc genes showed expression patterns different from both IFNa and IFNb. Taken together, salmon IFNa and IFNb are not orthologs of mammalian IFN-beta and IFN-alpha, respectively, but appear to utilize similar induction pathways. (C) 2008 Elsevier Ltd. All rights reserved.

Phylogeography of the Northern Atlantic species Chondrus crispus (Gigartinales, Rhodophyta) inferred from nuclear rDNA internal transcribed spacer sequences

Eighteen isolates of the red algae Chondrus crispus were collected from Northern Atlantic sites, together with C. ocellatus, C. yendoi and C. pinnulatus from the North Pacific. The nuclear rDNA internal transcribed spacer (ITS) was sequenced and compared, spanning both the ITS regions and the 5.8S rRNA gene. Percentage of nucleotide variation for C. crispus ranged from 0.3% to 4.0%. Phylogenetic analyses were performed using maximum parsimony (MP), neighbor-joining (NJ) and minimum evolution methods. They showed that two main clades existed within the C. crispus samples examined and that suggested C. crispus had a single Atlantic origin. The clustering however did not follow the geographic origin. We hypothesized that the current distribution of C. crispus populations might be a result of three main factors: temperature boundaries, paleoclimate and paleoceanography. ITS data exhibited abundant molecular information not only for phylogeographical investigation but also for systematics studies.

Inter-simple sequence repeat (ISSR) analysis of genetic variation of Chondrus crispus populations from North Atlantic

ISSR analysis was used to investigate genetic variations of 184 haploid and diploid samples from nine North Atlantic Chondrus crispus Stackhouse populations and one outgroup Yellow Sea Chondrus ocellatus Holmes population. Twenty-two of 50 primers were selected and 163 loci were scored for genetic diversity analysis. Genetic diversity varied among populations, percentage of polymorphic bands (PPB) ranged from 27.0 to 55.8%, H(Nei's genetic diversity) ranged from 0.11 to 0.20 and I(Shannon's information index) ranged from 0.16 to 0.30. Estimators PPB, H and I had similar values in intra-population genetic diversity, regardless of calculation methods. Analysis of molecular variance (AMOVA) apportioned inter-population and intra-population variations for C crispus, showing more genetic variance (56.5%) occurred in intra-population, and 43.5% variation among nine populations. The Mantel test suggested that genetic differentiation between nine C. crispus populations was closely related with geographic distances (R = 0.78, P = 0.002). Results suggest that, on larger distance scale (ca. > 1000 km), ISSR analysis is useful for determining genetic differentiations of C crispus populations including morphologically inseparable haploid and diploid individuals. (c) 2007 Elsevier B.V. All rights reserved.

Differentiation of the rainbow trout (Oncorhynchus mykiss) from Atlantic salmon (Salmon salar) by the AFLP-derived SCAR

A species-specific SCAR marker for rainbow trout, which was used to detect adulteration and fraudulent labeling in Atlantic salmon products, has been developed based on the AFLP analysis and evaluated in this study. The SCAR marker could be amplified and visualized in 1% agarose gel in all tested rainbow trout samples and absent in all salmon samples. Using DNA admixtures, the detection of 1% (0.5 ng), 10% (5 ng) rainbow trout DNA in Atlantic salmon DNA for fresh and processed samples, respectively was readily achieved. The molecular approach was sensitive and demonstrated to be a rapid and reliable method for identifying frauds in salmon products and could be extended for applications of species identification in food industry.

Sedimentation rates and provenance analysis in the Southwestern Okinawa Trough since the mid-Holocene

As a high-sedimentation rate depocenter along the path of the Kuroshio Current, the southwesternmost part of the Okinawa Trough is a key area to understand the Kuroshio history and sediments transportation. A 34.17-m-long sediment core was obtained by the advanced piston corer of Marco Polo/IMAGES XII MARION DUFRESNE during the May 2005 from the Southern Okinawa Trough at site MD05-2908. The recovered sediments were analyzed by AMS C-14 dating, coarse size fraction (> 63 mu m) extraction and moisture content determination in order to study its sedimentation flux and provenance. The depth-age relationship of core MD05-2908 was well constrained by 17 C-14 dating points. The sediments span across the mid-Holocene (6.8 ka B.P.) and have remarkablely high sedimentation rates between 1.8 and 21-2 m/ka, which is well consistent with the modern observations from sediment traps. We identified five 70-200 a periods of abnormally rapid sedimentation events at 6790-6600 a B.P., 5690-5600 a B.P., 4820-4720 a B.P., 1090-880 a B.P., and 260-190 a B.P., during which the highest sedimentation rate is up to 21-2 m/ka. In general, the lithology of the sediments were dominated by silt and clay, associated with less than 5% coarse size fraction (a parts per thousand << 63 mu m). As the most significant sediment source, the Lanyang River in northeastern Taiwan annually deliver about 10Mt materials to the coastal and offshore region of northeast Taiwan, a portion of which could be carried northward by currents toward the study area. Therefore, we concluded that the 5 abnormally rapid sedimentation events may be related to intensified rainfall in Taiwan and thus increased materials to our study area at that time. However, a few extreme-rapid sedimentation events cannot be explained by normal river runoff alone. The large earthquakes or typhoons induced hyperpycnal discharge of fluvial sediment to the ocean may also act as a potential source supply to the Okinawa Trough.

He, Ne and Ar isotope compositions of fluid inclusions in hydrothermal sulfides from the TAG hydrothermal field, Mid-Atlantic Ridge

Helium, rieon and argon isotope compositions of fluid inclusions have been measured in hydrothermal sulfide samples from the TAG hydrothermal field at the Mid-Atlantic Ridge. Fluid-inclusion He-3/He-4 ratios are 2.2-13.3 times the air value (Ra), and with a mean of 7.2 Ra. Comparison with the local vent fluids (He-3/He-4=7.5-8.2 Ra) and mid-ocean ridge basalt values (He-3/He-4=6-11 Ra) shows that the variation range of He-3/He-4 ratios from sulfide-hosted fluid inclusions is significantly large. Values for Ne-20/Ne-22 are from 10.2 to 11.4, which are significantly higher than the atmospheric ratio (9.8). And fluid-inclusion Ar-40/Ar-36 ratios range from 287 to 359, which are close to the atmospheric values (295.5). These results indicate that the noble gases of fluid inclusions in hydrothermal sulfides are a mixture of mantle- and seawater-derived noble gases; the partial mantle-derived components of trapped hydrothermal fluids may be from the lower mantle; the helium of fluid inclusions is mainly from upper mantle; and the Ne and Ar components are mainly from seawater.

Effect of low-frequency Rossby wave on thermal structure of the upper southwestern tropical Indian Ocean

We investigate the influence of low-frequency Rossby waves on the thermal structure of the upper southwestern tropical Indian Ocean (SWTIO) using Argo profiles, satellite altimetric data, sea surface temperature, wind field data and the theory of linear vertical normal mode decomposition. Our results show that the SWTIO is generally dominated by the first baroclinic mode motion. As strong downwelling Rossby waves reach the SWTIO, the contribution of the second baroclinic mode motion in this region can be increased mainly because of the reduction in the vertical stratification of the upper layer above thermocline, and the enhancement in the vertical stratification of the lower layer under thermocline also contributes to it. The vertical displacement of each isothermal is enlarged and the thermal structure of the upper level is modulated, which is indicative of strong vertical mixing. However, the cold Rossby waves increase the vertical stratification of the upper level, restricting the variability related to the second baroclinic mode. On the other hand, during decaying phase of warm Rossby waves, Ekman upwelling and advection processes associated with the surface cyclonic wind circulation can restrain the downwelling processes, carrying the relatively colder water to the near-surface, which results in an out-of-phase phenomenon between sea surface temperature anomaly (SSTA) and sea surface height anomaly (SSHA) in the SWTIO.

Dynamics of intraseasonal sea level and thermocline variability in the equatorial Atlantic during 2002-03

Satellite and in situ observations in the equatorial Atlantic Ocean during 2002-03 show dominant spectral peaks at 40-60 days and secondary peaks at 10-40 days in sea level and thermocline within the intraseasonal period band (10-80 days). A detailed investigation of the dynamics of the intraseasonal variations is carried out using an ocean general circulation model, namely, the Hybrid Coordinate Ocean Model (HYCOM). Two parallel experiments are performed in the tropical Atlantic Ocean basin for the period 2000-03: one is forced by daily scatterometer winds from the Quick Scatterometer (QuikSCAT) satellite together with other forcing fields, and the other is forced by the low-passed 80-day version of the above fields. To help in understanding the role played by the wind-driven equatorial waves, a linear continuously stratified ocean model is also used. Within 3 degrees S-3 degrees N of the equatorial region, the strong 40-60-day sea surface height anomaly (SSHA) and thermocline variability result mainly from the first and second baroclinic modes equatorial Kelvin waves that are forced by intraseasonal zonal winds, with the second baroclinic mode playing a more important role. Sharp 40-50-day peaks of zonal and meridional winds appear in both the QuikSCAT and Pilot Research Moored Array in the Tropical Atlantic (PIRATA) data for the period 2002-03, and they are especially strong in 2002. Zonal wind anomaly in the central-western equatorial basin for the period 2000-06 is significantly correlated with SSHA across the equatorial basin, with simultaneous/ lag correlation ranging from-0.62 to 0.74 above 95% significance. Away from the equator (3 degrees-5 degrees N), however, sea level and thermocline variations in the 40-60-day band are caused largely by tropical instability waves (TIWs). On 10-40-day time scales and west of 10 degrees W, the spectral power of sea level and thermocline appears to be dominated by TIWs within 5 degrees S-5 degrees N of the equatorial region. The wind-driven circulation, however, also provides a significant contribution. Interestingly, east of 10 W, SSHA and thermocline variations at 10 40- day periods result almost entirely from wind-driven equatorial waves. During the boreal spring of 2002 when TIWs are weak, Kelvin waves dominate the SSHA across the equatorial basin (2 degrees S-2 degrees N). The observed quasi-biweekly Yanai waves are excited mainly by the quasi-biweekly meridional winds, and they contribute significantly to the SSHA and thermocline variations in 1 degrees-5 degrees N and 1 degrees-5 degrees S regions.