Fluctuating Atlantic inflows modulate Arctic atlantification

Enhanced warm, salty subarctic inflows drive high-latitude atlantification, which weakens oceanic stratification, amplifies heat fluxes, and reduces sea ice. In this work, we show that the atmospheric Arctic Dipole (AD) associated with anticyclonic winds over North America and cyclonic winds over Eurasia modulates inflows from the North Atlantic across the Nordic Seas. The alternating AD phases create a “switchgear mechanism.” From 2007 to 2021, this switchgear mechanism weakened northward inflows and enhanced sea-ice export across Fram Strait and increased inflows throughout the Barents Sea. By favoring stronger Arctic Ocean circulation, transferring freshwater into the Amerasian Basin, boosting stratification, and lowering oceanic heat fluxes there after 2007, AD+ contributed to slowing sea-ice loss. A transition to an AD− phase may accelerate the Arctic sea-ice decline, which would further change the Arctic climate system.acceptedVersio

Increasing nutrient fluxes and mixing regime changes in the eastern Arctic Ocean

Primary productivity in the Arctic Ocean is experiencing dramatic changes linked to the receding sea ice cover. The vertical transport of nutrients from deeper water layers is the limiting factor for primary production. Here, we compare coincident profiles of turbulence and nutrients from the Siberian Seas in 2007, 2008, and 2018. In all years, the water column structure in the upstream region of the Arctic Boundary Current promotes upward nutrient transport, in contrast to the regions further downstream, and there are first indications for an eastward progression of these conditions. In summer 2018, strongly enhanced vertical nitrate flux and primary production above the continental slope were observed, likely related to a remote storm. The estimated contribution of these elevated fluxes above the slope to the Pan-Arctic vertical nitrate supply is comparable with the basin-wide transport, and is predicted to increase with declining sea ice cover in the future

Circulating Concentrations of Vitamin B6 and Kidney Cancer Prognosis: A Prospective Case-Cohort Study

Prospective cohort studies have found that prediagnostic circulating vitamin B6 is inversely associated with both risk of kidney cancer and kidney cancer prognosis. We investigated whether circulating concentrations of vitamin B6 at kidney cancer diagnosis are associated with risk of death using a case-cohort study of 630 renal cell carcinoma (RCC) patients. Blood was collected at the time of diagnosis, and vitamin B6 concentrations were quantified using LC-MS/MS. Hazard ratios (HR) and 95% confidence intervals (CI) were calculated using Cox regression models. After adjusting for stage, age, and sex, the hazard was 3 times lower among those in the highest compared to the lowest fourth of B6 concentration (HR4vs1 0.33, 95% CI [0.18, 0.60]). This inverse association was solely driven by death from RCC (HR4vs1 0.22, 95% CI [0.11, 0.46]), and not death from other causes (HR4vs1 0.89, 95% CI [0.35, 2.28], p-interaction = 0.008). These results suggest that circulating vitamin B6 could provide additional prognostic information for kidney cancer patients beyond that afforded by tumour stage

Weakening of cold halocline layer exposes sea ice to oceanic heat in the eastern Arctic Ocean

A 15-yr duration record of mooring observations from the eastern (>70°E) Eurasian Basin (EB) of the Arctic Ocean is used to show and quantify the recently increased oceanic heat flux from intermediate-depth (~150–900 m) warm Atlantic Water (AW) to the surface mixed layer and sea ice. The upward release of AW heat is regulated by the stability of the overlying halocline, which we show has weakened substantially in recent years. Shoaling of the AW has also contributed, with observations in winter 2017–18 showing AW at only 80 m depth, just below the wintertime surface mixed layer, the shallowest in our mooring records. The weakening of the halocline for several months at this time implies that AW heat was linked to winter convection associated with brine rejection during sea ice formation. This resulted in a substantial increase of upward oceanic heat flux during the winter season, from an average of 3–4 W m−2 in 2007–08 to >10 W m−2 in 2016–18. This seasonal AW heat loss in the eastern EB is equivalent to a more than a twofold reduction of winter ice growth. These changes imply a positive feedback as reduced sea ice cover permits increased mixing, augmenting the summer-dominated ice-albedo feedback

Vitamin D Pathway Genes, Diet, and Risk of Renal Cell Carcinoma

Mediated by binding to the high-affinity vitamin D receptor (VDR), vitamin D forms a heterodimer complex with the retinoid-X-receptor (RXR). Variation in both genes has been shown to modify renal cell carcinoma (RCC) risk. Therefore, we investigated whether VDR and RXRA polymorphisms modify associations between RCC risk and frequency of dietary intake of vitamin D and calcium rich foods, and occupational ultraviolet exposure among 777 RCC case and 1035 controls from Central and Eastern Europe. A positive association was observed in this population between increasing dietary intake frequency of yogurt, while an inverse association was observed with egg intake frequency. RXRA polymorphisms, located 3′ of the coding sequence, modified associations between specific vitamin D rich foods and RCC risk, while RXRA polymorphisms, located in introns 1 and 4, modified associations with specific calcium rich foods. Results suggest that variants in the RXRA gene modified the associations observed between RCC risk and calcium and vitamin D intake

Publisher Correction: Carbon dioxide sink in the Arctic Ocean from cross-shelf transport of dense Barents Sea water

In the version of this article initially published, author Cora Hörstmann was wrongly listed with a second affiliation with the Department of Ecoscience–Applied Marine Ecology and Modelling, Aarhus University rather than the Mediterranean Institute of Oceanography (MIO), Marseille, France. Furthermore, references 83–97, now found in the Supplementary Tables caption, were wrongly cited in the Data Availability section. The errors have been corrected in the HTML and PDF versions of the article

An analysis of growth, differentiation and apoptosis genes with risk of renal cancer

We conducted a case-control study of renal cancer (987 cases and 1298 controls) in Central and Eastern Europe and analyzed genomic DNA for 319 tagging single-nucleotide polymorphisms (SNPs) in 21 genes involved in cellular growth, differentiation and apoptosis using an Illumina Oligo Pool All (OPA). A haplotype-based method (sliding window analysis of consecutive SNPs) was used to identify chromosome regions of interest that remained significant at a false discovery rate of 10%. Subsequently, risk estimates were generated for regions with a high level of signal and individual SNPs by unconditional logistic regression adjusting for age, gender and study center. Three regions containing genes associated with renal cancer were identified: caspase 1/5/4/ 12(CASP 1/5/4/12), epidermal growth factor receptor (EGFR), and insulin-like growth factor binding protein-3 (IGFBP3). We observed that individuals with CASP1/5/4/12 haplotype (spanning area upstream of CASP1 through exon 2 of CASP5) GGGCTCAGT were at higher risk of renal cancer compared to individuals with the most common haplotype (OR:1.40, 95% CI:1.10-1.78, p-value = 0.007). Analysis of EGFR revealed three strong signals within intron 1, particularly a region centered around rs759158 with a global p = 0.006 (GGG: OR:1.26, 95% CI:1.04-1.53 and ATG: OR:1.55, 95% CI:1.14-2.11). A region in IGFBP3 was also associated with increased risk (global p = 0.04). In addition, the number of statistically significant (p-value 0.05) SNP associations observed within these three genes was higher than would be expected by chance on a gene level. To our knowledge, this is the first study to evaluate these genes in relation to renal cancer and there is need to replicate and extend our findings. The specific regions associated with risk may have particular relevance for gene function and/or carcinogenesis. In conclusion, our evaluation has identified common genetic variants in CASP1, CASP5, EGFR, and IGFBP3 that could be associated with renal cancer risk

Nutrient and Silicon Isotope Dynamics in the Laptev Sea and Implications for Nutrient Availability in the Transpolar Drift

Realistic prediction of the near-future response of Arctic Ocean primary productivity to ongoing warming and sea ice loss requires a mechanistic understanding of the processes controlling nutrient bioavailability. To evaluate continental nutrient inputs, biological utilization and the influence of mixing and winter processes in the Laptev Sea, the major source region of the Transpolar Drift, we compare observed with preformed concentrations of dissolved inorganic nitrogen (DIN), phosphorus (DIP), silicic acid (DSi) and silicon isotope compositions of DSi (δ30SiDSi) obtained for two summers (2013, 2014) and one winter (2012). In summer, preformed nutrient concentrations persisted in the surface layer of the southeastern Laptev Sea, while diatom-dominated utilization caused intense northward drawdown and a pronounced shift in δ30SiDSi from +0.91 to +3.82 ‰. The modeled Si isotope fractionation suggests that DSi in the northern Laptev Sea originated from the Lena River during the spring freshet, while in the southeastern Laptev Sea it was continuously supplied by it during the summer. Primary productivity fueled by river-borne nutrients was enhanced by admixture of DIN- and DIP-rich Atlantic-sourced waters to the surface, either by convective mixing during the previous winter or by occasional storm-induced stratification breakdowns in late summer. Substantial enrichments of DSi (+240 %) and DIP (+90 %) beneath the Lena River plume were caused by sea ice-driven redistribution and remineralization. Predicted weaker stratification on the outer Laptev shelf will enhance DSi utilization and removal through greater vertical DIN supply, which will limit DSi export and reduce diatom-dominated primary productivity in the Transpolar Drift. Key Points - Surface DIN, DIP, DSi and Si isotope dynamics are controlled by marine and riverine inputs and uptake by phytoplankton - Strong DIP and DSi enrichments beneath the Lena River plume are due to sea ice-driven nutrient redistribution and remineralization - Enhanced DSi utilization in the Laptev Sea will lead to a reduced diatom-dominated primary productivity in the Transpolar Drif

Von Hippel-Lindau (VHL) inactivation in sporadic clear cell renal cancer: Associations with germline VHL polymorphisms and etiologic risk factors

Renal tumor heterogeneity studies have utilized the von Hippel-Lindau VHL gene to classify disease into molecularly defined subtypes to examine associations with etiologic risk factors and prognosis. The aim of this study was to provide a comprehensive analysis of VHL inactivation in clear cell renal tumors (ccRCC) and to evaluate relationships between VHL inactivation subgroups with renal cancer risk factors and VHL germline single nucleotide polymorphisms (SNPs). VHL genetic and epigenetic inactivation was examined among 507 sporadic RCC/470 ccRCC cases using endonuclease scanning and using bisulfite treatment and Sanger sequencing across 11 CpG sites within the VHL promoter. Case-only multivariate analyses were conducted to identify associations between alteration subtypes and risk factors. VHL inactivation, either through sequence alterations or promoter methylation in tumor DNA, was observed among 86.6% of ccRCC cases. Germline VHL SNPs and a haplotype were associated with promoter hypermethylation in tumor tissue (OR = 6.10; 95% CI: 2.28-16.35, p = 3.76E-4, p-global = 8E-5). Risk of having genetic VHL inactivation was inversely associated with smoking due to a higher proportion of wild-type ccRCC tumors [former: OR = 0.70 (0.20-1.31) and current: OR = 0.56 (0.32-0.99); P-trend = 0.04]. Alteration prevalence did not differ by histopathologic characteristics or occupational exposure to trichloroethylene. ccRCC cases with particular VHL germline polymorphisms were more likely to have VHL inactivation through promoter hypermethylation than through sequence alterations in tumor DNA, suggesting that the presence of these SNPs may represent an example of facilitated epigenetic variation (an inherited propensity towards epigenetic variation) in renal tissue. A proportion of tumors from current smokers lacked VHL alterations and may represent a biologically distinct clinical entity from inactivated cases