380 research outputs found
Observations of current rings in the Antarctic Zone at Drake Passage
Time series of current velocity and temperature from several depths at a site near the center of Drake Passage show features that can plausibly be interpreted as current rings. Between June 1975 and January 1976, five cyclonic rings from the Continental Water Boundary and one anticyclonic ring from the Polar Front passed over the site. The diameters of the rings varied from 30 km to 130 km, and all of them extended vertically to a depth of at least 2500 m. The rings exhibited maximum spin velocities of about 20 cm sec−1 at 1000 m depth and 10 cm sec−1 at 2500 m. Their translatory motion, which was toward the north at about 4 cm sec−1, contained a westward component relative to the ambient flow. The magnitude of the westward component suggests that it may have resulted from an interaction between rings and the sea floor, which slopes downward to the northeast at the mooring site. The total available mechanical energy of the rings (kinetic plus potential) varied from 6.2 × 1013 j in the smallest ring to 9.9 × 1014 in the largest. The available heat, relative to the Antarctic Zone, was several orders of magnitude larger: −3.0 × 1017 j for the smallest ring and −3.6 × 1018 j for the largest. The numbers indicate that current rings may play an important role in dissipating the kinetic energy of the circumpolar fronts and that they may be responsible for a significant poleward flux of heat in the Southern Ocean
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An analysis of upwelling off the south-east Arabian coast during the summer monsoon
A method is described for determining the absolute dynamic
topography of the sea surface. Using hydrographic and wind data obtained
in 1963, the surface topography and the horizontal and vertical
mass transports off the southeast Arabian coast during the summer
monsoon are calculated. As indicated by the calculations, upwelling
occurs throughout a region extending at least 400 km offshore and
paralleling the Arabian coast for over 1000 km. Upwelling is most
intense in a narrow band adjacent to the coast. Because of the great
breadth of the upwelling zone, the upwelled water is supplied from
levels considerably deeper than those observed elsewhere in coastal
upwelling areas
On the Choquet multiple criteria preference aggregation model: theoretical and practical insights from a real-world application
We consider the use of the Choquet integral for evaluating projects or actions in a real-world application starting from the case of the re-qualification of an abandoned quarry. Despite the Choquet integral being a very well-known preference model for which there is a rich and well developed theory, its application in a multiple criteria decision aiding perspective requires some specific methodological developments. This led us to work out and implement, in practice, two new procedures: A first procedure to build interval scales with the objective of assigning utility values on a common scale to the criteria performances, and a second one to construct a ratio scale for assigning numerical values to the capacities of the Choquet integral. This article discusses the strengths and weaknesses of the Choquet integral as appearing in the case study, proposing as well insights related to the interaction of the experts within a focus grou
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A compilation of observations from moored current meters. Vol. 13. Currents, temperature and pressure southeast of New Zealand, April 1978-May 1980
Observations were made southeast of New Zealand from April 1978 to May 1980 with the objectives of investigating the dynamics of low-frequency motions and their effects on the Antarctic Circumpolar Current; and the formation of subantarctic mode water on Campbell Plateau. Self-recording instruments were deployed during a 7-month period from April to November 1978, and during an 18-month period from November 1978 to May 1980. The 7-month array consisted of 15 Aanderaa current meters and 5 Aanderaa thermistor chains. The 18-month array consisted of 3 Aanderaa current meters. Measurements from these instruments are summarized in this report through statistical tables, progressive vector diagrams, real time plots, rotary and standard spectra, and stick figures
Correlation of intestinal histopathologic findings with mucosa-attached bacteria, clinical disease activity, and clinical outcome in dogs with chronic enteropathies
Peer reviewe
HCV reinfection incidence and spontaneous clearance rates in HIV-positive men who have sex with men in Western Europe
BACKGROUND & AIMS: Moderate cure rates of acute hepatitis C virus (HCV) infections with pegylated interferon and ribavirin have been described in the last decade in men who have sex with men (MSM), who are also coinfected with the human immunodeficiency virus (HIV). However, a subsequent high incidence of HCV reinfections has been reported regionally in men who both clear the infection spontaneously or who respond to treatment. METHODS: Retrospective analysis of reinfections in HIV infected MSM in eight centers from Austria, France, Germany, and the UK within the NEAT network between May 2002 and June 2014. RESULTS: Of 606 individuals who cleared HCV spontaneously or were successfully treated, 149 (24.6%) presented with a subsequent HCV reinfection. Thirty out of 70 (43%) who cleared again or were successfully treated, presented with a second reinfection, 5 with a third, and one with a fourth reinfection. The reinfection incidence was 7.3/100 person-years (95% CI 6.2-8.6). We found a trend for lower incidence among individuals who had spontaneously cleared their incident infection than among individuals who were treated (Hazard ratio 0.62, 95% CI 0.38-1.02, p=0.06). Spontaneous clearance of reinfection was associated with ALT levels >1000IU/ml and spontaneous clearance of a prior infection. CONCLUSIONS: HCV reinfection is an issue of major concern in HIV-positive MSM. Prevention strategies are needed for high risk groups to reduce morbidity and treatment costs. HIV-positive MSM with a prior HCV infection should be tested every 3 to 6months for reinfection. Those who had achieved a reinfection should be tested every 3months. LAY SUMMARY: We evaluated the occurrence of HCV reinfection in HIV-positive men who have sex with men. We found an alarming incidence of 7.3/100 person-years. Prevention measures need to address this specific subgroup of patients at high risk for HCV
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A compilation of observations from moored current meters. Vol. VIII. Wind, currents and temperature off Northwest Africa along 21°40' N during JOINT-1
Current meters, moored during JOINT-I in the coastal upwelling area off Northwest Africa along 21°40'N measured current speed and direction, temperature and, in some cases, conductivity and pressure. In addition, surface buoy meterological stations were installed at some current meter strings to record wind speed and direction, as well as air and water temperature.
The sampling intervals of the instruments were 5 and 10 minutes. The data have been filtered and are shown here by means of pertinent statistics, real time plots, progressive vector diagrams and rotary spectra of hourly values
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A Compilation of observations from moored current meters. Vol. VII. Oregon continental shelf, July-August 1973
Aanderaa recording current meters, moored off the Oregon coast at fixed depths measured water temperature, current speed, current direction and for some meters, conductivity and pressure. In addition to these subÂsurface meters, surface meteorological buoys were installed to measure wind speed, wind direction, air and water temperature. Data from each current meter string are shown by means of pertinent statistics, real time plots of hourly values, progressive vector diagrams, and rotary spectra
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A Compilation of observations from moored current meters. Vol. 6. Oregon continental shelf, April-October 1972
Aanderaa recording current meters, moored in CUE-I off the Oregon coast at specific depths along both the Newport hydrographic line and perpendicular to the isobaths off Depoe Bay, were set to measure water temperature, current speed, current direction and, in some cases, pressure. In addition, surface buoy meteorological stations were moored at points along these same lines to measure wind speed, direction and air and water temperature. Data from
each current meter string are shown by means of pertinent statistics, real time plots of hourly values, progressive vector diagrams and rotary spectra. The appendices describe the actual operation of the Aanderaa current meter and the methods used to process the data
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A compilation of observations from moored current meters. Vol. 11. Currents, temperature and pressure in the Drake Passage during F DRAKE 76 : February 1976-January 1977
Self-recording instruments were installed in Drake
Passage in February 1976 and recovered in January 1977.
The instrument array consisted of eleven Aanderaa current
meters on seven moorings and two tide gauges. The data
were sampled at one hour intervals.
In this report the measurements are summarized through
pertinent statistics, progressive vector diagrams, real
time plots, stick figures, and rotary spectra
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