507 research outputs found

    KAPEX RAFOS float data report 1997-1999 part B : float trajectories at 750 m in the Benguela Current

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    Thirty-two RAFOS floats were launched at the depth of intermediate water, near 750 m, in the Benguela Current along 30S and its extension along 7W. The floats were tracked acoustically for two years during 1997–1999. Seven floats looped in three Agulhas Current rings, which drifted west northwestward at a mean velocity of around 5 cm/sec. Floats not in Agulhas rings tended to drift westward at around 2 cm/sec in the latitude band 22S–35S. North of 22S three floats drifted eastward. This report describes the float trajectories and summarizes the main results. These are the first subsurface long-term Lagrangian data in the Benguela Current.Funding was provided by the National Science Foundation under Grant Nos. OCE-9528574 and OCE-0236654

    North Brazil Current Rings Experiment : surface drifter data report, November 1998-June 2000

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    This data report summarzes 45 surface drifter trajectories collected between November 1998 and June 2000 as part of the North Brazil Current (NBC) Rings Experiment. NBC rings have been proposed as one of several important mechanisms for the transport of South Atlantic upper-ocean water across the equatorial-tropical gyre boundary and into the North Atlantic subtropical gyre. Such transport is required to complete the meridional overturning cell in the Atlantic forced by the high-latitude production and southward export of North Atlantic Deep Water. The goal of this program is to obtain, for the first time, comprehensive observations of the NBC retroflection, the NBC ring formation process, and the physical structure and properties of NBC rings as they translate northwestward along the low-latitude western boundary. A total of 45 drifters were deployed. Twenty-four of these looped anticyclonically within the five rings identified during this experiment. Seven of the looping ring drifters entered the Caribbean, while the rest moved northward along the eastern flank of the Lesser Antiles.Funding was provided by the National Science Foundation under Grant No. OCE-9729765

    SOFAR float trajectories in the tropical Atlantic 1989-1992

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    Neutrally buoyant SOFAR floats at nominal depths of 800 m, 1800 m, and 3300 m were tracked acoustically for 3.7 years in the vicinity of the western boundary and the equator of the Atlantic Ocean. Trajectories and summaries from the whole experiment are shown along with detailed trajectories from the second setting of the listening stations, October 1990 to September 1992. Some highlights are mentioned below. Trajectories at 1800 m revealed a swift narrow southward flowing deep western boundary current (DWBC) extending from 7°N across the equator. Two floats directly crossed the equator in the DWBC and went to 10°S. Two other floats left the DWBC near the equator and drifted eastward. Three floats entered the DWBC from the equatorial current system and drifted southward. No obvious DWBC or swift equatorial currents were observed by the 3300 m floats. The 800 m floats plus some surface drifters measured seven anticyclonic eddies as they translated northwestward along the coast of South America in a band from the equator to 12°N. One of the floats (28) entered the Caribbean where tracking stopped. This float was again tracked as it drifted across the mid-Atlantic Ridge and entered the Canary Basin near 34°N 28°W after a gap of 2.7 years. We infer that this float went westward though the Caribbean and northeastward in the Gulf Stream. Float 17 drifted northward from 10°N to 22°N in an eastern boundary current off the coast of West Africa. Floats between 6°N-6°S (roughly) drifted long distances zonally in the equatorial current system.Funding was provided by the National Science Foundation through Grants Nos. OCE85-21082, OCE85-17375, and OCE91-14656

    A Mediterranean undercurrent seeding experiment (AMUSE) : part II: RAFOS float data report, May 1993-March 1995

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    This is the final data report of all acoustically tracked RAFOS data collected in 1993-1995 during A Mediterranean Undercurrent Seeding Experiment (AMUSE). The overall objective of the program was to observe directly the spreading pathways by which Mediterranean Water enters the North Atlantic. This includes the direct observation of Mediterranean eddies (meddies), which is one mechanism that transports Mediterranean Water to the North Atlantic. The experiment was comprised of a repeated high-resolution expendable bathythermograph (XBT) section and RAFOS float deployments across the Mediterranean Undercurrent south of Portugal near 8.5°W. A total of 49 floats were deployed at a rate of about two floats per week on 23 cruises on the chartered Portuguese-based vessel, Kialoa II, and one cruise on the R/V Endeavor. The floats were ballasted for 1100 or 1200 decibars (db) to seed the lower salinity core of the Mediterranean Undercurrent. The objectives of the Lagrangian float study were (1) to identify where meddies form, (2) to make the first direct estimate of meddy formation frequency, (3) to estimate the fraction of time meddies are being formed, and (4) to determine the pathways by which Mediterranean Water which is not trapped in meddies enters the North Atlantic.Funding was provided by the National Science Foundation through Grant No. OCE-91-01033 to the Woods Hole Oceanographic Institution and Grant No. OCE-91-00724 to Scripps Institution of Oceanography, and by the Luso-American Foundation for Development through Grant No. 54/93 to the University of Lisbon

    North Brazil Current Rings Experiment : RAFOS float data report : November 1998 – June 2000

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    Twenty-one RAFOS floats were tracked at depths of 200-1000 meters in and around several North Brazil Current Rings between November 1998 and June 2000. This was part of an experiment to study the role of these current rings in transporting upper level South Atlantic water across the equatorial-tropical gyre boundary into the North Atlantic subtropical gyre. The float trajectories in combination with surface drifters and satellite imagery reveal the sometimes complex life histories of several rings and their fate as they collide with the Lesser Antilles Islands. This report describes the float trajectories, the velocity, temperature, and depth time series, and a preliminary analysis of the float data.Funding was provided by the National Science Foundation under Grant No. OCE-9729765 and OCE-0136477

    SOFAR float trajectories from an experiment to measure the Atlantic cross equatorial flow (1989-1990)

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    Neutrally buoyant SOFAR floats at nominal depths of 800, 1800, and 3300 m were tracked for 21 months in the vicinity of western boundary currents near 6N and at several sites in the Atlantic near 11N and along the equator. Trajectories at 1800 m show a swift (>50 cm/sec), narrow (100 km wide) southward-flowing Deep Western Boundary Current (DWBC) extending from 7N to the equator. At times (February-March 1989) DWBC water turned eastward and flowed along the equator and at other times (August-September 1990) the DWBC crossed the equator and continued southward. The mean velocity near the equator was eastward from February 1989 to February 1990 and westward from March 1990 to November 1990. Thus the cross-equatorial flow in the DWBC appeared to be linked to the direction of equatorial currents which varied over periods of more than a year. No obvious DWBC nor swift equatorial current was observed by 3300 m floats. Eight-hundred-meter floats revealed a northwestward intermediate level western boundary current although flow patterns were complicated. Three floats that significantly contributed to the northwestward flow looped in anticyclonic eddies that translated up the coast at 8 cm/sec. Six 800 m floats drifted eastward along the equator between 5S and 6N at a mean velocity of 11 cm/sec; one reached 5W in the Gulf of Guinea, suggesting that the equatorial current extended at least 35-40° along the equator. Three of these floats reversed direction near the end of the tracking period, implying low frequency fluctuations.Funding was provided by the National Science Foundation through Grant Nos. OCE-8521082, OCE-8517375, and OCE-9114656

    Understanding factors associated with the translation of cardiovascular research: A multinational case study approach

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    This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited.This article has been made available through the Brunel Open Access Publishing Fund.Background: Funders of health research increasingly seek to understand how best to allocate resources in order to achieve maximum value from their funding. We built an international consortium and developed a multinational case study approach to assess benefits arising from health research. We used that to facilitate analysis of factors in the production of research that might be associated with translating research findings into wider impacts, and the complexities involved. Methods: We built on the Payback Framework and expanded its application through conducting co-ordinated case studies on the payback from cardiovascular and stroke research in Australia, Canada and the United Kingdom. We selected a stratified random sample of projects from leading medical research funders. We devised a series of innovative steps to: minimize the effect of researcher bias; rate the level of impacts identified in the case studies; and interrogate case study narratives to identify factors that correlated with achieving high or low levels of impact. Results: Twenty-nine detailed case studies produced many and diverse impacts. Over the 15 to 20 years examined, basic biomedical research has a greater impact than clinical research in terms of academic impacts such as knowledge production and research capacity building. Clinical research has greater levels of wider impact on health policies, practice, and generating health gains. There was no correlation between knowledge production and wider impacts. We identified various factors associated with high impact. Interaction between researchers and practitioners and the public is associated with achieving high academic impact and translation into wider impacts, as is basic research conducted with a clinical focus. Strategic thinking by clinical researchers, in terms of thinking through pathways by which research could potentially be translated into practice, is associated with high wider impact. Finally, we identified the complexity of factors behind research translation that can arise in a single case. Conclusions: We can systematically assess research impacts and use the findings to promote translation. Research funders can justify funding research of diverse types, but they should not assume academic impacts are proxies for wider impacts. They should encourage researchers to consider pathways towards impact and engage potential research users in research processes. © 2014 Wooding et al.; licensee BioMed Central Ltd.RAND Europe and HERG, with subsequent funding from the NHFA, the HSFC and the CIHR. This research was also partially supported by the Policy Research Programme in the English Department of Health

    Identification of polymorphisms and balancing selection in the male infertility candidate gene, ornithine decarboxylase antizyme 3

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    Abstract Background The antizyme family is a group of small proteins that play a role in cell growth and division by regulating the biosynthesis of polyamines (putrescine, spermidine, spermine). Antizymes regulate polyamine levels primarily through binding ornithine decarboxylase (ODC), an enzyme key to polyamine production, and targeting ODC for destruction by the 26S proteosome. Ornithine decarboxylase antizyme 3 (OAZ3) is a testis-specific antizyme paralog and the only antizyme expressed in the mid to late stages of spermatogenesis. Methods To see if mutations in the OAZ3 gene are responsible for some cases of male infertility, we sequenced and evaluated the genomic DNA of 192 infertile men, 48 men of known paternity, and 34 African aborigines from the Mbuti tribe in the Democratic Republic of the Congo. The coding sequence of OAZ3 was further screened for polymorphisms by SSCP analysis in the infertile group and an additional 250 general population controls. Identified polymorphisms in the OAZ3 gene were further subjected to a haplotype analysis using PHASE 2.02 and Arlequin 2.0 software programs. Results A total of 23 polymorphisms were identified in the promoter, exons or intronic regions of OAZ3. The majority of these fell within a region of less than two kilobases. Two of the polymorphisms, -239 A/G in the promoter and 4280 C/T, a missense polymorphism in exon 5, may show evidence of association with male infertility. Haplotype analysis identified 15 different haplotypes, which can be separated into two divergent clusters. Conclusion Mutations in the OAZ3 gene are not a common cause of male infertility. However, the presence of the two divergent haplotypes at high frequencies in all three of our subsamples (infertile, control, African) suggests that they have been maintained in the genome by balancing selection, which was supported by a test of Tajima's D statistic. Evidence for natural selection in this region implies that these haplotypes may be associated with a trait other than infertility. This trait may be related to another function of OAZ3 or a region in tight linkage disequilibrium to the gene.</p
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