Circulation, hydrography, and transport over the summit of Axial Seamount, a deep volcano in the Northeast Pacific

Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 122 (2017): 5404–5422, doi:10.1002/2016JC012464.A numerical model of ocean flow, hydrography, and transport is used to extrapolate observations of currents and hydrography and infer patterns of material flux in the deep ocean around Axial Seamount, a destination node of NSF's Ocean Observatories Initiative's Cabled Array. Using an inverse method, the model is made to approximate measured deep ocean flow around this site during a 35 day time period in the year 2002. The model is then used to extract month-long mean patterns and examine smaller-scale spatial and temporal variability around Axial. Like prior observations, model month-long mean currents flow anticyclonically around the seamount's summit in toroidal form with maximum speeds at 1500 m depth of 10–11 cm/s. As a time mean, the temperature (salinity) anomaly distribution takes the form of a cold (briny) dome above the summit. Passive tracer material continually released at the location of the ASHES vent field exits the caldera primarily through its southern open end before filling the caldera. Once outside the caldera, the tracer circles the summit in clockwise fashion, fractionally reentering the caldera over lower walls at its north end, while gradually bleeding southwestward during the modeled time period into the ambient ocean. A second tracer release experiment using a source of only 2 day duration inside and near the CASM vent field at the northern end of the caldera suggests a residence time of the fluid at that locale of 8–9 days.WHOI as a postdoctoral scholar2018-01-0

Defining the word “seamount”

Author Posting. © Oceanography Society, 2010. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 23, 1 (2010): 20-21.The term seamount has been defined many times (e.g., Menard, 1964; Wessel, 2001; Schmidt and Schmincke, 2000; Pitcher et al., 2007; International Hydrographic Organization, 2008; Wessel et al., 2010) but there is no “generally accepted” definition. Instead, most definitions serve the particular needs of a discipline or a specific paper

Seamount sciences : quo vadis?

Author Posting. © Oceanography Society, 2010. This article is posted here by permission of Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 23, 1 (2010): 212-213.Seamounts are fascinating natural ocean laboratories that inform us about fundamental planetary and ocean processes, ocean ecology and fisheries, and hazards and metal resources. The more than 100,000 large seamounts are a defining structure of global ocean topography and biogeography, and hundreds of thousands of smaller ones are distributed throughout every ocean on Earth

The prediction, verification, and significance of flank jets at mid-ocean ridges

Author Posting. © The Oceanography Society, 2012. This article is posted here by permission of The Oceanography Society for personal use, not for redistribution. The definitive version was published in Oceanography 25, no. 1 (2012): 277–283, doi:10.5670/oceanog.2012.26.One aspect of ocean flow over mid-ocean ridges that has escaped much attention is the capacity of a ridge to convert oscillatory flows into unidirectional flows. Those unidirectional flows take the form of relatively narrow jets hugging the ridge's flanks. In the Northern Hemisphere, the jets move heat and dissolved and particulate matter poleward on the west and equatorward on the east of north-south trending ridges. Recent measurements and a model of flow at the East Pacific Rise at 9–10°N show that these ridge-parallel flows can extend 10–15 km horizontally away from the ridge axis, reach from the seafloor to several hundreds of meters above ridge crest depth, and have maximum speeds in their cores up to 10 cm s–1. Because of their along-ridge orientation and speed, the jets can significantly affect the transport of hydrothermal vent-associated larvae between vent oases along the ridge crest and, possibly, contribute to the mesoscale stirring of the abyssal ocean. Because jet-formation mechanisms involve oscillatory currents, ocean stratification, and topography, the jets are examples of "stratified topographic flow rectification." Ridge jets have parallels in rectified flows at seamounts and submarine banks.JWL is supported by the National Oceanic and Atmospheric Administration (NOAA) Pacific Marine Environmental Laboratory and by NOAA Vents Program. The work of other authors has been supported by National Science Foundation through grants OCE-0424953 and OCE-0425361, LADDER (LArval Dispersion along the Deep East pacific Rise)

Active positioning of vent larvae at a mid-ocean ridge

Author Posting. © The Author(s), 2013. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 92 (2013): 46-57, doi:10.1016/j.dsr2.2013.03.032.The vertical position of larvae of vent species above a mid-ocean ridge potentially has a strong effect on their dispersal. Larvae may be advected upward in the buoyant vent plume, or move as a consequence of their buoyancy or active swimming. Alternatively, they may be retained near bottom by the topography of the axial trough, or by downward swimming. At vents near 9°50’N on the axis of the East Pacific Rise, evidence for active larval positioning was detected in a comparison between field observations of larvae in the plankton in 2006 and 2007 and distributions of non-swimming larvae in a two-dimensional bio-physical model. In the field, few vent larvae were collected at the level of the neutrally buoyant plume (~75 m above bottom); their relative abundances at that height were much lower than those of simulated larvae from a near-bottom release in the model. This discrepancy was observed for many vent species, particularly gastropods, suggesting that they may actively remain near bottom by sinking or swimming downward. Near the seafloor, larval abundance decreased from the ridge axis to 1000 m off axis much more strongly in the observations than in the simulations, again pointing to behavior as a potential regulator of larval transport. We suspect that transport off axis was reduced by downward-moving behavior, which positioned larvae into locations where they were isolated from cross-ridge currents by seafloor topography, such as the walls of the axial valley – which are not resolved in the model. Cross-ridge gradients in larval abundance varied between gastropods and polychaetes, indicating that behavior may vary between taxonomic groups, and possibly between species. These results suggest that behaviorally mediated retention of vent larvae may be common, even for species that have a long planktonic larval duration and are capable of long-distance dispersal.We gratefully acknowledge the support of NSF grants OCE-0424953 and OCE-0525361, which funded the Larval Dispersal on the Deep East Pacific Rise (LADDER) project. WHOI provided additional support to LSM as an Ocean Life Fellow, to DJM as the Holger Jannasch Chair for Excellence in Oceanography, and to JRL as the Edward W. and Betty J. Scripps Senior Scientist Chair. JWL was supported by the National Oceanic and Atmospheric Administration’s (NOAA) Vents Program and by NOAA’s Pacific Marine Environmental Laboratory

Dendritic Cell-Mediated, DNA-Based Vaccination Against Hepatitis C Induces the Multi-Epitope-Specific Response of Humanized, HLA Transgenic Mice

Hepatitis C virus (HCV) is the etiologic agent of chronic liver disease, hepatitis C. Spontaneous resolution of viral infection is associated with vigorous HLA class I- and class II-restricted T cell responses to multiple viral epitopes. Unfortunately, only 20% of patients clear infection spontaneously, most develop chronic disease and require therapy. The response to chemotherapy varies, however; therapeutic vaccination offers an additional treatment strategy. To date, therapeutic vaccines have demonstrated only limited success. Vector-mediated vaccination with multi-epitope-expressing DNA constructs alone or in combination with chemotherapy offers an additional treatment approach. Gene sequences encoding validated HLA-A2- and HLA-DRB1-restricted epitopes were synthesized and cloned into an expression vector. Dendritic cells (DCs) derived from humanized, HLA-A2/DRB1 transgenic (donor) mice were transfected with these multi-epitope-expressing DNA constructs. Recipient HLA-A2/DRB1 mice were vaccinated s.c. with transfected DCs; control mice received non-transfected DCs. Peptide-specific IFN-γ production by splenic T cells obtained at 5 weeks post-immunization was quantified by ELISpot assay; additionally, the production of IL-4, IL-10 and TNF-α were quantified by cytokine bead array. Splenocytes derived from vaccinated HLA-A2/DRB1 transgenic mice exhibited peptide-specific cytokine production to the vast majority of the vaccine-encoded HLA class I- and class II-restricted T cell epitopes. A multi-epitope-based HCV vaccine that targets DCs offers an effective approach to inducing a broad immune response and viral clearance in chronic, HCV-infected patients

Imaging of CO₂ bubble plumes above an erupting submarine volcano, NW Rota-1, Mariana Arc

NW Rota-1 is a submarine volcano in the Mariana volcanic arc located ~100 km north of Guam. Underwater explosive eruptions driven by magmatic gases were first witnessed there in 2004 and continued until at least 2010. During a March 2010 expedition, visual observations documented continuous but variable eruptive activity at multiple vents at ~560 m depth. Some vents released CO₂ bubbles passively and continuously, while others released CO₂ during stronger but intermittent explosive bursts. Plumes of CO₂ bubbles in the water column over the volcano were imaged by an EM122 (12 kHz) multibeam sonar system. Throughout the 2010 expedition numerous passes were made over the eruptive vents with the ship to document the temporal variability of the bubble plumes and relate them to the eruptive activity on the seafloor, as recorded by an in situ hydrophone and visual observations. Analysis of the EM122 midwater data set shows: (1) bubble plumes were present on every pass over the summit and they rose 200-400 m above the vents but dissolved before they reached the ocean surface, (2) bubble plume deflection direction and distance correlate well with ocean current direction and velocity determined from the ship’s acoustic doppler current profiler, (3) bubble plume heights and volumes were variable over time and correlate with eruptive intensity as measured by the in situ hydrophone. This study shows that midwater multibeam sonar data can be used to characterize the level of eruptive activity and its temporal variability at a shallow submarine volcano with robust CO₂ output.Keywords: multibeam sonar, carbon dioxide degassing, submarine eruption, seamoun

Defining the word "Seamount"

Reading through this issue of Oceanography, it will become apparent that researchers in different disciplines see their seamounts in quite different ways. The term seamount has been defined many times (e.g., Menard, 1964; Wessel, 2001; Schmidt and Schmincke, 2000; Pitcher et al., 2007; International Hydrographic Organization, 2008; Wessel et al., 2010) but there is no “generally accepted” definition. Instead, most definitions serve the particular needs of a discipline or a specific paper. Inconsistencies are common among different publications and, most notably, differ from the recommendations of the International Hydrographic Organization and International Oceanographic Commission (International Hydrographic Organization, 2008). It is not the goal of this note to arbitrate or remedy these inconsistencies. However, as seamount researchers begins to coalesce into one broad, multidisciplinary research community, it is important to: (1) have a simple definition that explains which features are included under the umbrella of seamount research and which are not, providing an essential condition for defining the seamount research community, and (2) respect and be aware of differences among disciplinary definitions, as they may stand in the way of consistently applying one disciplinary data set to another

Comparison of the efficacy of four drug combinations for immobilization of wild pigs

Field immobilization of native or invasive wild pigs (Sus scrofa) is challenging. Drug combinations commonly used often result in unsatisfactory immobilization, poor recovery, and adverse side effects, leading to unsafe handling conditions for both animals and humans. We compared four chemical immobilization combinations, medetomidine–midazolam–butorphanol (MMB), butorphanol–azaperone–medetomidine (BAM™), nalbuphine–medetomidine–azaperone (NalMed-A), and tiletamine– zolazepam–xylazine (TZX), to determine which drug combinations might provide better chemical immobilization of wild pigs. We achieved adequate immobilization with no post-recovery morbidity withMMB. Adequate immobilization was achieved with BAM™; however, we observed post-recovery morbidity. Both MMB and BAM™ produced more optimal results relative to body temperature, recovery, and post-recovery morbidity and mortality compared to TZX. Adequate immobilization was not achieved with NalMed-A. Of the four drug combinations examined, we conclude that MMB performed most optimally for immobilization and recovery of wild pigs

Limited Liability Companies in Kentucky, Second Edition

The Kentucky Limited Liability Company Act, KRS Chapter 275, went into effect July 15, 1994, allowing Kentuckians to conduct business under the LLC form. With over 10,000 LLCs formed in the Commonwealth since the Act\u27s inception, this flexible business entity has become the most popular way to conduct business in Kentucky. The LLC has become so pervasive that business law practitioners, accountants, tax advisors and estate planners must all be well-versed in the myriad of issues and creative applications that accompany this business entity. With flexible tax-treatment and the liability protection of a traditional corporation this entity is utilized not only for business formation and practice but also for business succession and estate planning, the structuring of joint ventures and strategic alliances, as venture capital vehicles, and as tax planning tools. The goal of this monograph is to provide the practitioner with a concise and comprehensive approach to the tools necessary for lawyers to counsel and advise clients on this complex and efficient business entity form. Succinct chapters take the reader through an overview of the LLC entity and the Kentucky LLC Act; choice of entity considerations (both tax and non-tax); the formation, operation and statutory transaction issues which arise for the entity; as well as the new single-member LLC; the professional LLC; the use of the LLC in tax-exempt organizations; wealth transfer planning with LLCs; and securities law, commercial law and benefit issues arising under the LLC entity. Each chapter is set forth in separately numbered paragraphs, present running headers for easy access, and are cross-referenced to other relevant chapters and paragraphs contained in the monograph. Summary and comparative charts, a table of authorities and a statutory appendix are also presented. Finally, a comprehensive index has been created to aid the user in finding relevant subject treatments