164 research outputs found

    High density of ice krill (Euphausia crystallorophias) in the Amundsen sea coastal polynya, Antarctica

    Get PDF
    High densities of ice krill Euphausia crystallorophias were observed along six acoustic transects within the Amundsen Sea Coastal Polynya, Antarctica. Two-frequency acoustic backscatter data was examined in the austral summers of January 2011 and February 2012. A dB identification window (Sv120−38) identified ice krill dominating the acoustic backscatter. The density of ice krill, calculated with the stochastic distorted-wave born approximation model, ranged between 4.5 and 30 g wet mass m−2 for each transect (a mean of 16 g wet mass m−2 for all transects), these high values are an order of magnitude higher than recorded previously in the Ross Sea Polynya. High densities were detected along the ice shelf and near the boundary between pack ice and coastal polynya, and we postulate that these could be important habitats for ice krill. The high densities observed along the transects make ice krill a potentially important, but poorly known contributor to these high-latitude shelf food webs

    Zooplankton and micronekton respond to climate fluctuations in the Amundsen Sea polynya, Antarctica

    Get PDF
    The vertical migration of zooplankton and micronekton (hereafter 'zooplankton') has ramifications throughout the food web. Here, we present the first evidence that climate fluctuations affect the vertical migration of zooplankton in the Southern Ocean, based on multi-year acoustic backscatter data from one of the deep troughs in the Amundsen Sea, Antarctica. High net primary productivity (NPP) and the annual variation in seasonal ice cover make the Amundsen Sea coastal polynya an ideal site in which to examine how zooplankton behavior responds to climate fluctuations. Our observations show that the timing of the seasonal vertical migration and abundance of zooplankton in the seasonally varying sea ice is correlated with the Southern Annular Mode (SAM) and El Nino Southern Oscillation (ENSO). Zooplankton in this region migrate seasonally and overwinter at depth, returning to the surface in spring. During +SAM/La Nina periods, the at-depth overwintering period is shorter compared to -SAM/El Nino periods, and return to the surface layers starts earlier in the year. These differences may result from the higher sea ice cover and decreased NPP during +SAM/La Nina periods. This observation points to a new link between global climate fluctuations and the polar marine food web

    Effects of Arctic commercial shipping on environments and communities : context, governance, priorities

    Get PDF
    Increasing shipping traffic in the Arctic Ocean creates an emerging need to understand the consequences of maritime operations on the Arctic environment and coastal Indigenous and non-Indigenous communities, as well as potential governance responses. To address this need, we examine recent shipping trends and assess their impact on Arctic environments and communities. Our arguments are novel, and are built around contemporary empirical investigations and published scientific studies, reports, and government documents. The paper concludes that the environmental and community impacts vary across the Arctic and that greater international coordination is needed to learn from experience, to share assets and capacities, and to guide responsible and sustainable development of Arctic shipping. Given the possibility for opening of the Transpolar Sea Route within the coming decades, further proactive steps, such as developing a governance framework, could help Arctic shipping avoid rather than attempt to correct problems. Shipping Arctic routes Indigenous peoples Local communities Social and environmental concerns RiskspublishedVersio

    Depression and suicide risk prediction models using blood-derived multi-omics data

    Get PDF
    More than 300 million people worldwide experience depression; annually, ~800,000 people die by suicide. Unfortunately, conventional interview-based diagnosis is insufficient to accurately predict a psychiatric status. We developed machine learning models to predict depression and suicide risk using blood methylome and transcriptome data from 56 suicide attempters (SAs), 39 patients with major depressive disorder (MDD), and 87 healthy controls. Our random forest classifiers showed accuracies of 92.6% in distinguishing SAs from MDD patients, 87.3% in distinguishing MDD patients from controls, and 86.7% in distinguishing SAs from controls. We also developed regression models for predicting psychiatric scales with R2 values of 0.961 and 0.943 for Hamilton Rating Scale for Depression???17 and Scale for Suicide Ideation, respectively. Multi-omics data were used to construct psychiatric status prediction models for improved mental health treatment

    A multicenter phase II study of everolimus in patients with progressive unresectable adenoid cystic carcinoma

    Get PDF
    BACKGROUND: The aim of this study was to examine the efficacy and safety of everolimus in patients with progressive unresectable adenoid cystic carcinoma (ACC). METHODS: Histologically confirmed ACC patients with documented disease progression within 12 months prior to the study entry were eligible. Everolimus was given at a dose of 10 mg daily until progression or occurrence of unacceptable toxicities. The primary endpoint was a 4-month progression-free survival (PFS). RESULTS: A total of 34 patients were enrolled. The 4-month PFS probability was 65.5% (95% one-sided confidence interval [CI], 47.7 to infinity). Median PFS duration was 11.2 months (95% CI, 3.6 to 15.8). Complete or partial response was not achieved. Twenty-seven (79.4%, 95% CI, 63.2 to 89.6) patients showed stable disease (SD). Tumor shrinkage within SD criteria was observed in 15 patients (44.1%) and SD lasting 6 months was observed in 13 patients (38.2%). Four patients had disease progression. Among the 18 patients with both pre- and post-treatment (at 8 weeks) FDG-PET scans available, 8 patients (44.4%) showed a partial metabolic response, defined as a ≥25% reduction in maximum standardized uptake values (SUVmax). The most common adverse events were stomatitis, anemia, asthenia, and leukopenia. No unexpected everolimus related toxicities were reported. CONCLUSIONS: Everolimus showed promising efficacy and good tolerability in progressive unresectable ACC. TRIAL REGISTRATION: ClinicalTrials.gov identifier, NCT0115284

    Cox-2 and IL-10 Polymorphisms and Association with Squamous Cell Carcinoma of The Head and Neck in a Korean Sample

    Get PDF
    Cyclooxygenase-2 (COX-2) is involved in inflammation and carcinogenesis. Interleukin-10 (IL-10) is also regarded as anti-inflammatory factors with the multi-functional ability to positively and negatively influence functional immunity and tumor development. Genetic polymorphisms of COX-2 and IL-10 might contribute to the development of squamous cell carcinoma of the head and neck (SCCHN). The purpose of this study was to evaluate the association of COX-2 and IL-10 single nucleotide polymorphisms (SNPs) with the risk of SCCHN in a Korean sample. We analyzed the COX-2 SNPs, -1329A>G, +1266C>T, and +6365T>C, and the IL-10 SNPs, -1082A>G, +920T>G, and +3917T>C, in 290 Korean SCCHN patients and 358 healthy controls. There was no significant association between the risk of SCCHN and the three COX-2 or three IL-10 SNPs. We analyzed three haplotypes (ht1, ht2, ht3) for COX-2 and found that COX-2 ht3+/+ was associated with a decreased risk of SCCHN in a Korean sample, compared with the COX-2 ht3 -/- genotype (P=0.03). Two haplotypes (ht1, ht2) of IL-10 were analyzed and there was no statistical significance in the distribution of haplotypes. Based on these results, the COX-2 haplotype ht3 can be used as a molecular biomarker to predict low risk groups of SCCHN in a Korean sample
    corecore