Building a window to the sea : Ocean Research Interactive Observatory Networks (ORION)

Author Posting. © Oceanography Society, 2004. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 17, 2 (2004): 113-120.For centuries, oceanographers have relied on data and observations about the ocean and the seafloor below gathered from ships during cruises of limited duration. This expeditionary research approach has resulted in major advances in understanding global ocean circulation, the energy associated with mesoscale circulation, plate tectonics, global ocean productivity, and climate-ocean coupling. These and many other successes have expanded our view of Earth and ocean processes, and have demonstrated a need for sampling strategies spanning temporal and spatial scales not effectively carried out using ships. To address this observational gap, community efforts in the United States consistently have recommended that funding agencies support development of the capability to maintain a continuous sampling and monitoring presence in the ocean.MKT is grateful for support from a WHOI Deep Ocean Exploration Institute fellowship

Laboratory experiments on two coalescing axisymmetric turbulent plumes in a rotating fluid

Author Posting. © The Author(s), 2011. This is the author's version of the work. It is posted here by permission of American Institute of Physics for personal use, not for redistribution. The definitive version was published in Physics of Fluids 23 (2011): 056601, doi:10.1063/1.3584134.We investigate the early-time coalescence of two co-flowing axisymmetric turbulent plumes and the later-time flow of the induced vortices in a rotating, homogeneous fluid using laboratory experiments. The experiments demonstrate the critical importance of the rotation period Tf = 2π/f, where f is the Coriolis parameter of the background rotation. We find that if the plumes’ sources are sufficiently “close” for the plumes to merge initially at an “early time” tm≲tr = 3Tf/4, the experimentally observed merging height zme agrees well with the non-rotating theoretical relationship of zmt ≈ (0.44/α)x0tr, however, the flow dynamics are substantially more complicated, as the flow becomes significantly affected by rotation. The propagation and entrainment of the plumes becomes strongly affected by the vortices induced by the entrainment flow in a rotating environment. Also, the plume fluid itself starts to interact with these vortices. If the plumes have already initially merged by the time t = tr, a single vortex (initially located at the midpoint of the line connecting the two plume sources) develops, which both advects and modifies the geometry of the merging plumes. Coupled with the various suppressing effects of rotation on the radial plume entrainment, the “apparent” observed height of merger can vary substantially from its initial value. Conversely, for more widely separated “distant” plumes, where x0>xc = (25α/2)F01/4f-3/4, the plumes do not merge before the critical time tr when rotation becomes significant in the flow dynamics and two vortices are observed, each located over a plume source. The combined effect of these vortices with the associated suppression of entrainment by rotation thus significantly further delays the merger of the two plumes, which apparently becomes possible only through the merger of the induced vortices.This work was supported by the Center for Planetary Science

The Guaymas Basin Hiking Guide to Hydrothermal Mounds, Chimneys, and Microbial Mats: Complex Seafloor Expressions of Subsurface Hydrothermal Circulation

The hydrothermal mats, mounds, and chimneys of the southern Guaymas Basin are the surface expression of complex subsurface hydrothermal circulation patterns. In this overview, we document the most frequently visited features of this hydrothermal area with photographs, temperature measurements, and selected geochemical data; many of these distinct habitats await characterization of their microbial communities and activities. Microprofiler deployments on microbial mats and hydrothermal sediments show their steep geochemical and thermal gradients at millimeter-scale vertical resolution. Mapping these hydrothermal features and sampling locations within the southern Guaymas Basin suggest linkages to underlying shallow sills and heat flow gradients. Recognizing the inherent spatial limitations of much current Guaymas Basin sampling calls for comprehensive surveys of the wider spreading region

Tawney and the third way

From the 1920s to the 1950s R. H. Tawney was the most influential socialist thinker in Britain. He articulated an ethical socialism at odds with powerful statist and mechanistic traditions in British socialist thinking. Tawney's work is thus an important antecedent to third way thinking. Tawney's religiously-based critique of the morality of capitalism was combined with a concern for detailed institutional reform, challenging simple dichotomies between public and private ownership. He began a debate about democratizing the enterprise and corporate governance though his efforts fell on stony ground. Conversely, Tawney's moralism informed a whole-hearted condemnation of market forces in tension with both his concern with institutional reform and modern third way thought. Unfortunately, he refused to engage seriously with emergent welfare economics which for many social democrats promised a more nuanced understanding of the limits of market forces. Tawney's legacy is a complex one, whose various elements form a vital part of the intellectual background to current third way thinking

Crying with laughter: adapting the tickling protocol to address individual differences among rats in their response to playful handling

International audienc

Variable morphologic expression of volcanic, tectonic, and hydrothermal processes at six hydrothermal vent fields in the Lau back-arc basin

Author Posting. © American Geophysical Union, 2008. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geochemistry Geophysics Geosystems 9 (2008): Q07022, doi:10.1029/2008GC002047.Ultrahigh-resolution bathymetric maps (25 cm grid) are used to quantify the physical dimensions of and spatial relationships between tectonic, volcanic, and hydrothermal features at six hydrothermal vent fields in the Lau back-arc basin. Supplemented with near-bottom photos, and nested within regional DSL-120A side-scan sonar data, these maps provide insight into the nature of hydrothermal systems along the Eastern Lau Spreading Center (ELSC) and Valu Fa Ridge (VFR). Along-axis transitions evident in localized volcanic morphology and tectonic characteristics include a change from broad low-relief volcanic domes (hundreds of meters wide, <10 m tall) that are dominated by pillow and lobate lava morphologies and are cut by faults and fissures to higher aspect ratio volcanic domes (tens of meters wide, tens of meters tall) dominated by aa-type lava morphologies, with finger-like flows, and few tectonic structures. These along-axis differences in localized seafloor morphology suggest differences in hydrothermal circulation pathways within the shallow crust and correlate with regional transitions in a variety of ridge properties, including the large-scale morphology of the ridge axis (shallow axial valley to axial high), seafloor lava compositions, and seismic properties of the upper crust. Differences in morphologic characteristics of individual flows and lava types were also quantified, providing an important first step toward the remote characterization of complex terrains associated with hydrothermal vent fields.Support for field and laboratory studies was provided by the National Science Foundation under grant OCE02-41796 (M.K.T.). Additional support for data analysis and integration was provided by the National Science Foundation under grant OCE03-28117 (S.M.C.)

Minimum follow-up time required for the estimation of statistical cure of cancer patients: verification using data from 42 cancer sites in the SEER database

BACKGROUND: The present commonly used five-year survival rates are not adequate to represent the statistical cure. In the present study, we established the minimum number of years required for follow-up to estimate statistical cure rate, by using a lognormal distribution of the survival time of those who died of their cancer. We introduced the term, threshold year, the follow-up time for patients dying from the specific cancer covers most of the survival data, leaving less than 2.25% uncovered. This is close enough to cure from that specific cancer. METHODS: Data from the Surveillance, Epidemiology and End Results (SEER) database were tested if the survival times of cancer patients who died of their disease followed the lognormal distribution using a minimum chi-square method. Patients diagnosed from 1973–1992 in the registries of Connecticut and Detroit were chosen so that a maximum of 27 years was allowed for follow-up to 1999. A total of 49 specific organ sites were tested. The parameters of those lognormal distributions were found for each cancer site. The cancer-specific survival rates at the threshold years were compared with the longest available Kaplan-Meier survival estimates. RESULTS: The characteristics of the cancer-specific survival times of cancer patients who died of their disease from 42 cancer sites out of 49 sites were verified to follow different lognormal distributions. The threshold years validated for statistical cure varied for different cancer sites, from 2.6 years for pancreas cancer to 25.2 years for cancer of salivary gland. At the threshold year, the statistical cure rates estimated for 40 cancer sites were found to match the actuarial long-term survival rates estimated by the Kaplan-Meier method within six percentage points. For two cancer sites: breast and thyroid, the threshold years were so long that the cancer-specific survival rates could yet not be obtained because the SEER data do not provide sufficiently long follow-up. CONCLUSION: The present study suggests a certain threshold year is required to wait before the statistical cure rate can be estimated for each cancer site. For some cancers, such as breast and thyroid, the 5- or 10-year survival rates inadequately reflect statistical cure rates, and highlight the need for long-term follow-up of these patients

Mineralogical and geochemical features of sulfide chimneys from the 49°39′E hydrothermal field on the Southwest Indian Ridge and their geological inferences

© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Chinese Science Bulletin 56 (2011): 2828-2838, doi:10.1007/s11434-011-4619-4.During January–May in 2007, the Chinese research cruise DY115-19 discovered an active hydrothermal field at 49°39′E/37°47′S on the ultraslow spreading Southwest Indian Ridge (SWIR). This was also the first active hydrothermal field found along an ultraslow-spreading ridge. We analyzed mineralogical, textural and geochemical compositions of the sulfide chimneys obtained from the 49°39′E field. Chimney samples show a concentric mineral zone around the fluid channel. The mineral assemblages of the interiors consist mainly of chalcopyrite, with pyrite and sphalerite as minor constitunets. In the intermediate portion, pyrite becomes the dominant mineral, with chalcopyrite and sphalerite as minor constitunets. For the outer wall, the majority of minerals are pyrite and sphalerite, with few chalcopyrite. Towards the outer margin of the chimney wall, the mineral grains become small and irregular in shape gradually, while minerals within interstices are abundant. These features are similar to those chimney edifices found on the East Pacific Rise and Mid-Atlantic Ridge. The average contents of Cu, Fe and Zn in our chimney samples were 2.83 wt%, 45.6 wt% and 3.28 wt%, respectively. The average Au and Ag contents were up to 2.0 ppm and 70.2 ppm respectively, higher than the massive sulfides from most hydrothermal fields along mid-ocean ridge. The rare earth elements geochemistry of the sulfide chimneys show a pattern distinctive from the sulfides recovered from typical hydrothermal fields along sediment-starved mid-ocean ridge, with the enrichment of light rare earth elements but the weak, mostly negative, Eu anomaly. This is attributed to the distinct mineralization environment or fluid compositions in this area.This work was supported by the China Ocean Mineral Resources Research and Development Association Program (DY115- 02-1-01) and the State Oceanic Administration Youth Science Fund (2010318)

Formation of Zn- and Fe-sulfides near hydrothermal vents at the Eastern Lau Spreading Center: implications for sulfide bioavailability to chemoautotrophs

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens