On the turbulent co-spectrum of two scalars and its effect on acoustic scattering from oceanic turbulence

Author Posting. © Cambridge University Press, 2004. This article is posted here by permission of Cambridge University Press for personal use, not for redistribution. The definitive version was published in Journal of Fluid Mechanics 514 (2004): 107-119, doi:10.1017/S0022112004000126.While acoustic scatter from oceanic turbulence is sensitive to temperature–salinity covariations, there are unfortunately no published measurements of the turbulent temperature–salinity co-spectrum. Several models have been proposed for the form of the co-spectrum of two scalars in turbulence, but they all produce unsatisfactory results when applied to the turbulent scattering equations (either predicting negative scattering cross-sections in some regimes or predicting implausible levels of correlation between temperature and salinity at some scales). A new model is proposed and shown to give physically plausible scattering predictions in all density regimes. High-frequency acoustic data illustrate the importance of the co-spectrum for acoustic scattering, but were collected in a density regime where there is little difference between the co-spectrum models.This work was supported by NSERC and by ONR under grant #N00014-93-1-0362

Integration of a RSI microstructure sensing package into a Seaglider

Seagliders are a type of propeller-less AUV that glide through the water by changing their buoyancy. They have become mainstream collectors of standard oceanographic data (conductivity, temperature, pressure, dissolved oxygen, fluorescence and backscatter) and are increasingly used as trucks to carry a wide variety of hydrographic and bio-geochemical sensors. The extended sensor capability enhances the utility of the gliders for oceanographic observations. Seagliders are designed and optimized for long-term missions (up to 10 months) and deep sea profiling (up to 1000 m). They provide high resolution oceanographic data with very good temporal and spatial density, in near real-time, at a fraction of the cost of ship collected data. These performance parameters are sometimes at odds with the physical dimensions and electrical requirements of the hydrographic and bio-geochemical sensors scientists want installed in gliders. However, as the acceptance of gliders as an integral component of the oceanographic suite of measurement tools grows so do the efforts of sensor vendors to develop products that meet the size, weight and power requirements for successful glider integration. Turbulence microstructure sensors are one measurement system that scientists desired on Seagliders but that until recently did not fit the glider footprint. In collaboration with Rockland Scientific, Inc., a suite of RSI turbulence microstructure sensors was recently integrated into a Seaglider and the system’s performance validated during field tests in Puget Sound near Seattle, WA and in Loch Linnhe on the west coast of Scotland. Ocean turbulence controls the mixing of water masses, biogeochemical fluxes within them, and facilitates ocean-atmosphere gas exchange. As a result, turbulence impacts global ocean circulation, polar ice melt rates, drawdown of atmospheric carbon dioxide and carbon deposition, coastal and deep ocean ecology, commercial fisheries, and the dispersion of pollutants. Turbulent mixing is also recognized as a key parameter in global climate models, used for understanding and predicting future climate change. Seagliders equipped with turbulence microstructure sensors will allow scientists to map the geographical distribution and temporal variability of mixing in the ocean on scales not possible with ship-based measurements. This presentation discusses the technical aspects of the integration of the turbulence sensor suite on a Seaglider with an emphasis on achieving high data quality, while retaining the performance characteristics of the Seaglider. We will also describe applications for this sensor suite, examine the turbulence measurement data already collected by the Seaglider and discuss future deployment plans

Adding epoetin alfa to intense dose-dense adjuvant chemotherapy for breast cancer : randomized clinical trial

BACKGROUND: The AGO-ETC trial compared 5-year relapse-free survival of intense dose-dense (IDD) sequential chemotherapy with epirubicin (E), paclitaxel (T), and cyclophosphamide (C) (IDD-ETC) every 2 weeks vs conventional scheduled epirubicin/cyclophosphamide followed by paclitaxel (EC→T) (every 3 weeks) as adjuvant treatment in high-risk breast cancer patients. The objective of this study was to evaluate the safety and efficacy of epoetin alfa in a second randomization of the intense dose-dense arm. METHODS: One thousand two hundred eighty-four patients were enrolled; 658 patients were randomly assigned to the IDD-ETC treatment group. Within the IDD-ETC group, 324 patients were further randomly assigned to the epoetin alfa group, and 319 were randomly assigned to the non-erythropoiesis-stimulating agent (ESA) control group. Primary efficacy endpoints included change in hemoglobin level from baseline to Cycle 9 and the percentage of subjects requiring red blood cell transfusion. Relapse-free survival, overall survival, and intramammary relapse were secondary endpoints estimated with Kaplan-Meier and Cox regression methods. Except for the primary hypothesis, all statistical tests were two-sided. RESULTS: Epoetin alfa avoided the decrease in hemoglobin level (no decrease in the epoetin alfa group vs -2.20g/dL change for the control group; P < .001) and statistically significantly reduced the percentage of subjects requiring red blood cell transfusion (12.8% vs 28.1%; P < .0001). The incidence of thrombotic events was 7% in the epoetin alfa arm vs 3% in the control arm. After a median follow-up of 62 months, epoetin alfa treatment did not affect overall survival, relapse-free survival, or intramammary relapse. CONCLUSIONS: Epoetin alfa resulted in improved hemoglobin levels and decreased transfusions without an impact on relapse-free or overall survival. However, epoetin alfa had an adverse effect, resulting in increased thrombosis

Patient’s Anastrozole Compliance to Therapy (PACT) Program: Baseline Data and Patient Characteristics from a Population-Based, Randomized Study Evaluating Compliance to Aromatase Inhibitor Therapy in Postmenopausal Women with Hormone-Sensitive Early Breast Cancer

BACKGROUND: The Patient's Anastrozole Compliance to Therapy (PACT) program is a large randomized study designed to assess whether the provision of educational materials (EM) could improve compliance with aromatase inhibitor therapy in postmenopausal women with early, hormone receptor-positive breast cancer. PATIENTS AND METHODS: The PACT study presented a large, homogeneous dataset. The baseline analysis included patient demographics and initial treatments and patient perceptions about treatment and quality of life. RESULTS: Overall, 4,923 patients were enrolled at 109 German breast cancer centers/clinics in cooperation with 1,361 office-based gynecologists/oncologists. 4,844 women were randomized 1:1 to standard therapy (n = 2,402) or standard therapy plus EM (n = 2,442). Prior breast-conserving surgery and mastectomy had been received by 76% and 24% of the patients, respectively. Radiotherapy was scheduled for 85% of the patients, adjuvant chemotherapy for 38%. Reflecting the postmenopausal, hormone-sensitive nature of this population, only 285 patients (7%) had received neoadjuvant chemotherapy. CONCLUSIONS: A comparison with epidemiological data from the West German Breast Center suggests that the patients in the PACT study are representative of a general postmenopausal early breast cancer population and that the findings may be applicable to ‘real-world’ Germany and beyond. Compliance data from PACT are eagerly anticipated

Heated anemometry and thermometry in water

The characteristics of several types of heated sensors used for measuring oceanic turbulence have been examined. The author measured the steady heat flux from glass coated ellipsoidal microbead thermistors, computed numerically the unsteady heat flux from an ideal constant temperature flat plate, and analyzed the steady flow calibration data of a paralene-c coated plate thermistor as well as the steady and unsteady calibration data of two conical constant temperature hot film anemometers. In order to understand the behaviour of probes alone, thermal models of these sensors have been developed. The models incorporate a Nusselt number governed steady heat flux from the wetted surface and the thermal effects of a surface coating and a supportive substrate. Derived functional relationships between the steady heat flux and the flow rate agree favourably with the available calibration data. The quasi-steady sensitivity of these probes when used as anemometers or thermometers as well as their signal contamination by temperature or velocity are calculated using the functional heat flux relationships. The substrate and the coating reduce the sensitivity to temperature and to speed as well as the ratio of speed-to-temperature sensitivity. The response of sensors is not governed by the Nusselt number when the boundary layer is unsteady. The unsteady response of a sensor to velocity oscillations is governed by its unsteady viscous boundary layer and may increase with increasing frequency over some frequency ranges. The response bandwidth is wider for velocity than for temperature. The ratio of unsteady temperature-to-velocity sensitivity is highest at zero frequency. Frequency response calibrations methods must realistically simulate the sensor's unsteady viscous boundary layer.Science, Faculty ofEarth, Ocean and Atmospheric Sciences, Department ofGraduat

投棄型微細構造プロファイラによる海洋の乱流直接観測

http://www.godac.jamstec.go.jp/darwin/cruise/mirai/mr11-08_leg2/

Turbulence Measurements with a submarine

Measurements of small-scale velocity and temperature fluctuations have been made from the research submarine Dolphin in the open ocean off San Diego, California. The important contribution of the submarine is that it collects horizontal profiles. The submarine can depth-cycle to obtain a quasi-vertical profile of the fluctuations along a horizontal path. The noise level depends on the configuration of the instrumentation and the operating conditions of the vessel. Expressed in terms of energy dissipation, it is approximately 10−7 W m−3, comparable to that of free-fall vertical profilers. Much of the small-scale velocity and temperature data are similar to those collected with free-fall vertical profilers. A major difference is that the horizontal transects are aligned with the temperature gradient of salt fingers, which are not well detected by vertical profilers. Fingers were seen beneath the saline upper layer at values of Rρ between 2 and 4. Off San Diego, the velocity signal from the fingers was below the noise level of the velocity probes. More than 80% of our estimates of the local rate of dissipation of kinetic energy from a nighttime convecting surface layer are distributed log-normally. There is a deficit of large values and an excess of small values, as in atmospheric boundary layers.APL/JHUOffice of Naval Researc

ATOMIX benchmark datasets for dissipation rate measurements using shear probes

Turbulent mixing in the ocean, lakes and reservoirs facilitates the transport of momentum, heat, nutrients, and other passive tracers. Turbulent fluxes are proportional to the rate of turbulent kinetic energy dissipation per unit mass, ε. A common method for ε measurements is using microstructure profilers with shear probes. Such measurements are now widespread, and a non-expert practitioner will benefit from best practice guidelines and benchmark datasets. As a part of the Scientific Committee on Oceanographic Research (SCOR) working group on “Analysing ocean turbulence observations to quantify mixing” (ATOMIX), we compiled a collection of five benchmark data of ε from measurements of turbulence shear using shear probes. The datasets are processed using the ATOMIX recommendations for best practices documented separately. Here, we describe and validate the datasets. The benchmark collection is from different types of instruments and covers a wide range of environmental conditions. These datasets serve to guide the users to test their ε estimation methods and quality-assurance metrics, and to standardize their data for archiving