An intermediate-depth source of hydrothermal 3He and dissolved iron in the North Pacific

We observed large water column anomalies in helium isotopes and trace metal concentrations above the Loihi Seamount. The 3He/4He of the added helium was 27.3 times the atmospheric ratio, clearly marking its origin to a primitive mantle plume. The dissolved iron to 3He ratio (dFe:3He) exported to surrounding waters was 9.3 ± 0.3 × 106. We observed the Loihi 3He and dFe “signal” at a depth of 1100 m at several stations within ∼100 – 1000 km of Loihi, which exhibited a distal dFe:3He ratio of ∼4 × 106, about half the proximal ratio. These ratios were remarkably similar to those observed over and near the Southern East Pacific Rise (SEPR) despite greatly contrasting geochemical and volcanictectonic origins. In contrast, the proximal and distal dMn:3He ratios were both ∼ 1 × 106, less than half of that observed at the SEPR. Dissolved methane was minimally enriched in waters above Loihi Seamount and was distally absent. Using an idealized regional-scale model we replicated the historically observed regional 3He distribution, requiring a hydrothermal 3He source from Loihi of 10.4 ± 4.2 mola−1, ∼2% of the global abyssal hydrothermal 3He flux. From this we compute a corresponding dFe flux of ∼40 Mmola−1. Global circulation model simulations suggest that the Loihi-influenced waters eventually upwell along the west coast of North America, also extending into the shallow northwest Pacific, making it a possibly important determinant of marine primary production in the subpolar North Pacific

Perspectives in visual imaging for marine biology and ecology: from acquisition to understanding

Durden J, Schoening T, Althaus F, et al. Perspectives in Visual Imaging for Marine Biology and Ecology: From Acquisition to Understanding. In: Hughes RN, Hughes DJ, Smith IP, Dale AC, eds. Oceanography and Marine Biology: An Annual Review. 54. Boca Raton: CRC Press; 2016: 1-72

An Intermediate-Depth Source of Hydrothermal \u3csup\u3e3\u3c/sup\u3eHe and Dissolved Iron In the North Pacific

We observed large water column anomalies in helium isotopes and trace metal concentrations above the Loihi Seamount. The 3He/4He of the added helium was 27.3 times the atmospheric ratio, clearly marking its origin to a primitive mantle plume. The dissolved iron to 3He ratio (dFe:3He) exported to surrounding waters was 9.3 ± 0.3 × 106. We observed the Loihi 3He and dFe “signal” at a depth of 1100 m at several stations within ∼100 – 1000 km of Loihi, which exhibited a distal dFe:3He ratio of ~4 × 106, about half the proximal ratio. These ratios were remarkably similar to those observed over and near the Southern East Pacific Rise (SEPR) despite greatly contrasting geochemical and volcanic-tectonic origins. In contrast, the proximal and distal dMn:3He ratios were both ~1 × 106, less than half of that observed at the SEPR. Dissolved methane was minimally enriched in waters above Loihi Seamount and was distally absent. Using an idealized regional-scale model we replicated the historically observed regional 3He distribution, requiring a hydrothermal 3He source from Loihi of 10.4 ± 4.2 mol a−1, ∼2% of the global abyssal hydrothermal 3He flux. From this we compute a corresponding dFe flux of ∼40 Mmol a−1. Global circulation model simulations suggest that the Loihi-influenced waters eventually upwell along the west coast of North America, also extending into the shallow northwest Pacific, making it a possibly important determinant of marine primary production in the subpolar North Pacific

Developing credible vulnerability indicators for climate adaptation policy assessment

We address the issue of how to develop credible indicators of vulnerability to climate change that can be used to guide the development of adaptation policies. We compare the indicators and measures that five past national-level studies have used and examine how and why their approaches have differed. Other relevant indicator studies of social facets of society as well as vulnerability studies at sub-national level are also examined for lessons regarding best practice. We find that the five studies generally emphasise descriptive measures by aggregating environmental and social conditions. However, they vary greatly both in the types of indicators and measures used and differ substantially in their identification of the most vulnerable countries. Further analysis of scientific approaches underlying indicator selection suggests that the policy relevance of national-level indicators can be enhanced by capturing the processes that shape vulnerability rather than trying to aggregate the state itself. Such a focus can guide the selection of indicators that are representative even when vulnerability varies over time or space. We find that conceptualisation regarding how specific factors and processes influencing vulnerability interact is neither given sufficient consideration nor are assumptions transparently defined in previous studies. Verification has been neglected, yet this process is important both to assess the credibility of any set of measures and to improve our understanding of vulnerability. A fundamental lesson that emerges is the need to enhance our understanding of the causes of vulnerability in order to develop indicators that can effectively aid policy development

Proposed diagnostic criteria and nosology of acute transverse myelitis

Acute transverse myelitis (ATM) is a focal inflammatory disorder of the spinal cord, resulting in motor, sensory, and autonomic dysfunction. A set of uniform diagnostic criteria and nosology for ATM is proposed to avoid the confusion that inevitably results when investigators use differing criteria. This will ensure a common language of classification, reduce diagnostic confusion, and lay the groundwork necessary for multicenter clinical trials. In addition, a framework is suggested for evaluation of individuals presenting with signs and symptoms of ATM. Best treatment often depends on a timely and accurate diagnosis. Because acute transverse myelopathies are relatively rare, delayed and incomplete work-ups often occur. Rapid and precise diagnosis will ensure not only that compressive lesions are detected and treated but also that idiopathic ATM is distinguished from ATM secondary to a known underlying disease. Identification of etiologies may suggest medical treatment, whereas no clearly established medical treatment currently exists for idiopathic ATM. Establishment of a diagnostic algorithm will likely lead to improved care, although it is recognized that the entire evaluation may not be performed for each patient

Replication of genetic loci for ages at menarche and menopause in the multi-ethnic Population Architecture using Genomics and Epidemiology (PAGE) study

STUDY QUESTION: Do genetic associations identified in genome-wide association studies (GWAS) of age at menarche (AM) and age at natural menopause (ANM) replicate in women of diverse race/ancestry from the Population Architecture using Genomics and Epidemiology (PAGE) Study? SUMMARY ANSWER: We replicated GWAS reproductive trait single nucleotide polymorphisms (SNPs) in our European descent population and found that many SNPs were also associated with AM and ANM in populations of diverse ancestry. WHAT IS KNOWN ALREADY: Menarche and menopause mark the reproductive lifespan in women and are important risk factors for chronic diseases including obesity, cardiovascular disease and cancer. Both events are believed to be influenced by environmental and genetic factors, and vary in populations differing by genetic ancestry and geography. Most genetic variants associated with these traits have been identified in GWAS of European-descent populations. STUDY DESIGN, SIZE, DURATION: A total of 42 251 women of diverse ancestry from PAGE were included in cross-sectional analyses of AM and ANM. MATERIALS, SETTING, METHODS: SNPs previously associated with ANM (n = 5 SNPs) and AM (n = 3 SNPs) in GWAS were genotyped in American Indians, African Americans, Asians, European Americans, Hispanics and Native Hawaiians. To test SNP associations with ANM or AM, we used linear regression models stratified by race/ethnicity and PAGE sub-study. Results were then combined in race-specific fixed effect meta-analyses for each outcome. For replication and generalization analyses, significance was defined at P < 0.01 for ANM analyses and P < 0.017 for AM analyses. MAIN RESULTS AND THE ROLE OF CHANCE: We replicated findings for AM SNPs in the LIN28B locus and an intergenic region on 9q31 in European Americans. The LIN28B SNPs (rs314277 and rs314280) were also significantly associated with AM in Asians, but not in other race/ethnicity groups. Linkage disequilibrium (LD) patterns at this locus varied widely among the ancestral groups. With the exception of an intergenic SNP at 13q34, all ANM SNPs replicated in European Americans. Three were significantly associated with ANM in other race/ethnicity populations: rs2153157 (6p24.2/SYCP2L), rs365132 (5q35/UIMC1) and rs16991615 (20p12.3/MCM8). While rs1172822 (19q13/BRSK1) was not significant in the populations of non-European descent, effect sizes showed similar trends. LIMITATIONS, REASONS FOR CAUTION: Lack of association for the GWAS SNPs in the non-European American groups may be due to differences in locus LD patterns between these groups and the European-descent populations included in the GWAS discovery studies; and in some cases, lower power may also contribute to non-significant findings. WIDER IMPLICATIONS OF THE FINDINGS: The discovery of genetic variants associated with the reproductive traits provides an important opportunity to elucidate the biological mechanisms involved with normal variation and disorders of menarche and menopause. In this study we replicated most, but not all reported SNPs in European descent populations and examined the epidemiologic architecture of these early reported variants, describing their generalizability and effect size across differing ancestral populations. Such data will be increasingly important for prioritizing GWAS SNPs for follow-up in fine-mapping and resequencing studies, as well as in translational research. STUDY FUNDING/COMPETING INTEREST(S): The Population Architecture Using Genomics and Epidemiology (PAGE) program is funded by the National Human Genome Research Institute (NHGRI), supported by U01HG004803 (CALiCo), U01HG004798 (EAGLE), U01HG004802 (MEC), U01HG004790 (WHI) and U01HG004801 (Coordinating Center), and their respective NHGRI ARRA supplements. The authors report no conflicts of interest

Mikromekaaninen oskillaattori

Tässä diplomityössä tutustuttiin kapasitiivisesti kytketyllä mikromekaanisella resonaattorilla stabiloidun sähkömekaanisen oskillaattorin teoriaan: resonaattorin mekaniikkaan ja vahvistimen elektroniikkaan. Esitetyn teorian pohjalta suunniteltiin ja rakennettiin sähkömekaaninen 500 kHz:n Pierce-oskillaattori. Prototyypin toiminta demonstroitiin mittauksin. Prototyypin mittauksissa todennettiin mikromekaanisen oskillaattorin värähtelytaajuuden ja -amplitudin riippuvuus resonaattorin biasjännitteestä; mittaustulokset olivat ennusteiden mukaiset. Oskillaattorin värähtelytarkkuutta kuvaava vaihekohina mitattiin tarkoitukseen suunnitellulla laitteistolla. Mitattu vaihekohina oli -123dBc@SkHz. Prototyypissä käytettiin palkkiresonaattoria, jonka epälineaarisuuden seurauksena oskillaattorin ulostulo oli säröytynyt. Työssä pohdittiin myös fysikaalisia rajoja palkkiresonaattoriin perustuvan mikromekaanisen oskillaattorin suorituskyvylle