The Steller sea lion (SSL) population west of 144°W longitude experienced a significant population decline. While there appears to be a stable or increasing population trend in rookeries in the Gulf ...of Alaska (GOA) and Southeast Alaska (SEA), some rookeries within the Aleutian Islands (AI) have failed to recover. Previous studies found regional differences in whole blood total mercury concentrations (THg) showing more than 20% of AI pups had THg above critical thresholds for increased risk of immunological effects and other adverse outcomes. Measurements of immune cell-signaling proteins can be used to evaluate the immune status of marine mammals in relation to THg. We compared serum cytokine and chemokine concentrations in pups among regions (AI, eastern GOA, SEA), and examined associations among cytokines, chemokines, white blood cell (WBC) counts, and THg. Considering liver is an important target organ for mercury and immune protein synthesis we additionally examined the relationship of THg with liver-related enzymes serum aspartate (AST) and alanine aminotransferase (ALT). We observed regional differences in cytokine and chemokine measurements and immune protein associations. There was a positive association between total WBC counts and THg in AI pups, whereas a negative association between lymphocytes and THg in SEA pups. These findings may indicate regional variation in proliferation and differentiation of hematopoietic cells, differences in immune system development, and/or a difference in antigenic stimuli. No associations between THg and cytokines, chemokines, AST or ALT were found. Observed regional differences in cytokine and chemokine milieu during gestational and early development in SSL pups could lead to an imbalance in cell differentiation that could impact immunological resiliency in juvenile and adult life stages. We report concentration ranges of a suite of cytokines and chemokines which may prove to be a useful metric for ecotoxicology and risk assessment studies in SSLs and other wildlife.
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•Immune measures were compared with blood mercury in Alaskan Steller sea lion pups.•Serum cytokine and chemokine concentrations differed regionally.•Cytokines and chemokines were associated with select blood cell counts.•Blood mercury was associated with blood cell counts, not cytokines or chemokines.•Cytokine and chemokine profiles may indicate pup immune status differs by region.
Concentrations of achiral and chiral organochlorine contaminants (OCs), including hexachlorocyclohexane isomers (HCH), chlordane congeners (cis‐ and trans‐chlordane, cis‐ and trans‐nonachlor, MC5, ...MC7, and U82), and related metabolites (oxychlordane OXY and heptachlor exo‐epoxide HEPX), were quantified in seawater (100 L; n = 6) and biota from the coastal Beaufort–Chukchi Seas food web near Barrow (AK, USA). The biota included zooplankton (Calanus spp.; n = 5), fish species such as arctic cod (Boreogadus saida; n = 10), arctic char (Salvelinus alpinus; n = 3), and marine mammals including bowhead whales (Balaena mysticetus; liver: n = 23; blubber: n = 40), beluga whales (Delphinapterus leucas; blubber: n = 20), ringed seals (Phoca hispida; blubber: n = 20), and bearded seals (Erignathus barbatus; blubber: n = 7). The food web magnification factors (FWMFs) for HCHs and chlordane compounds ranged from 0.5 (γ‐HCH) to 6.5 (HEPX) and were expected based on known recalcitrance and biotransformation of OCs. The enantiomer fractions (EFs) of all chiral OCs were near racemic (EF = 0.50) in seawater, zooplankton, and all fish analyzed. In contrast, the EFs for most OCs analyzed were nonracemic (EF ≠ 0.50) in the marine mammals blubber (range: 0.09–0.79) because of enantiomer‐specific biotransformation and (or) accumulation. However, EF values were not significantly correlated with isotopically determined trophic level. The EFs for all chiral OCs (except α‐HCH) in bowhead whale liver closely approximated the values in zooplankton, suggesting that the accumulation of chiral OCs from prey into this cetacean is not enantiomer specific. However, the modification of EFs from bowhead liver to blubber suggests that this species has the ability to enantioselectively biotransform and accumulate several chiral OC compounds.
Levels of organochlorine contaminants in blood of northern fur seal (
Callorhinus ursinus) pups and the blood and milk of their dams early in the lactation period are reported here. The contaminants ...included 15 selected individual polychlorinated biphenyl (PCB) congeners and DDT metabolites identified through high-performance liquid chromatography. Congeners CB-77, -81, -126, -169 and -189 were below the limits of detection in milk and blood samples analyzed. Congener-specific concentrations of PCBs in the blood of pups were compared based on the age of their dam (≤5 years or >7 years). Pups of young (presumably primiparous) dams had significantly elevated levels of CBs-101, -118, -128, -138, -153/87, -170/194, and -180 than pups of older (multiparous) dams. Congeners CB-128 and -170/194 were detected in the blood of pups of young dams but not in the blood of pups of older dams nor in any of the dams blood. Additionally, pups had higher blood levels in seven of 10 detected PCB congeners as compared to the levels measured in milk when adjusted for lipid content. Levels of DDT metabolites and toxic equivalency quotients of dioxin-like congeners followed similar trends. Lipid-normalized concentrations of CB-101 and total PCBs were significantly higher in the blood of dams than in their milk. CB-128, -156, -157, -170/194,
p,p′-DDT,
o,p′-DDT,
p,p′-DDD and
o,p′-DDD were not detected in dam blood samples, but were detected in milk samples. Calculation of ‘biomagnification factors’ from milk to pup blood indicated a biomagnification of CB-101, -105, -118, -138, -153/87, and -180. Significant mean accumulation factors ranged from 1.5 to 7.5. Inter-annual differences in exposure levels and specific congener concentrations in both milk and blood were apparent. Northern fur seal pups, especially first-born, have a substantial exposure to organochlorine contaminants at a critical developmental stage.
The increasing number of genetic association studies conducted in multiple populations provides an unprecedented opportunity to study how the genetic architecture of complex phenotypes varies between ...populations, a problem important for both medical and population genetics. Here, we have developed a method for estimating the transethnic genetic correlation: the correlation of causal-variant effect sizes at SNPs common in populations. This methods takes advantage of the entire spectrum of SNP associations and uses only summary-level data from genome-wide association studies. This avoids the computational costs and privacy concerns associated with genotype-level information while remaining scalable to hundreds of thousands of individuals and millions of SNPs. We applied our method to data on gene expression, rheumatoid arthritis, and type 2 diabetes and overwhelmingly found that the genetic correlation was significantly less than 1. Our method is implemented in a Python package called Popcorn.
The availability of inexpensive CMOS technologies that perform well at microwave frequencies has created new opportunities for automated material handling within supply chain management (SCM) that in ...hindsight, be viewed as revolutionary. This article outlines the system architecture and circuit design considerations that influence the development of radio frequency identification (RFID) tags through a case study involving a high-performance implementation that achieves a throughput of nearly 800 tags/s at a range greater than 10 m. The impact of a novel circuit design approach ideally suited to the power and die area challenges is also discussed. Insights gleaned from first-generation efforts are reviewed as an object lesson in how to make RFID technology for SCM, at a cost measured in pennies per tag, reach its full potential through a generation 2 standard.
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