Progress in the measurement of salinity and oxygen at the Woods Hole Oceanographic Institution

Improvements in the measurement of salinity and dissolved oxygen during the past few years at WHOI have increased the accuracy of salinity observations to +/- 0.001 ppt and that of dissolved oxygen determinations to +/- 0.04 ml/1. These improvements are attributable to the careful maintenance of the sample collection and analysis equipment, the construction of portable, sea going laboratories in which the temperature is constant to +/- 1 degree C and the skillful use of an Autosal 8400-A salinometer and a Metrohm Titroprocessor by well trained technicians. An automated data logging system eliminates transcription errors and facilitates the timely calibration of the CTD sensors.Funding was provided by the National Science Foundation under grant Nos. OCE 85-15642 and OCE 82-13967

Automated oxygen titration and salinity determination

This report describes a newly developed automated Winkler titration system for dissolved oxygen in seawater which is presently in use at the Woods Hole Oceanographic Institution. This amperometric, calculated, endpoint system was compared with two different automated and one manual Winkler method during a recent cruise. The four different methods agreed to within about 0.04 ml/l. The system described here measures the titrant needed to reach the endpoint with a resolution better than 0.001 ml. The standard deviation of replicate samples is 0.005 ml/l and the accuracy is about 0.02 ml/l. A technique to automatically acquire conductivity ration measurements and calculate salinity using a Guildline Autosal Salinometer is also described.Funding was provided by the National Science Foundation through Grant No. OCE88-22542

Deep Caribbean inflow through the Anegada -- Jungfern Passage

The Jungfem Passage Sill at a depth of 1815 meters is the controlling sill for the deepest water exchange between the Atlantic Ocean and the Venezuelan Basin of the Caribbean Sea. Data from moored current meters and temperature recorders, STD\u27s and hydrographic stations obtained during March and April 1972 are interpreted as indicating an average net flow of 56 × 103 m3 sec-1 of deep Atlantic water into the Caribbean Sea. Current speeds as high as 32 cm sec-1 were recorded on the sill near the axis of the inflow, and the average velocity during 38 days was 20 cm sec-1...

Cruise summaries of Oceanus cruises 205, leg 8, and 216

A study of the upper ocean thermal and density structure in the northwestern Atlantic in 1989 compared temperature and density measurements made with Expendable Bathythermograph (XBT) and Conductivity-Temperature-Depth instruments with current data from an acoustic Doppler current profiler and satellite infrared imagery and altimetry. Two cruises were made in the spring and winter of 1989 with the goal of directly measuring the upper ocean currents and variabilty of the Gulf Stream. The XBT observations were used to extend the measured velocities geostrophically from the near-surface region to depths of 750 meters, thereby allowing transport estimates to be made for the upper ocean. In April the measurments were compared and used with the GEOSAT altimeter which, unfortunately, was not operating during the December cruise.Funding was provided by the National Science Foundation through Grant No. OCE-SS-1769S

Correlations between FEV1 and patient-reported outcomes: A pooled analysis of 23 clinical trials in patients with chronic obstructive pulmonary disease.

BACKGROUND: In clinical trials of inhaled bronchodilators, chronic obstructive pulmonary disease (COPD) guidelines recommend that patient-reported outcomes (PROs) are assessed alongside lung function. How these endpoints are related is unclear. METHODS: Pooled longitudinal data from 23 randomised controlled COPD studies were analyzed (N = 23,213). Treatments included long-acting β2 agonists, long-acting muscarinic antagonists (LABAs or LAMAs) and the LABA/LAMA combination QVA149. Outcome measures were Transition Dyspnoea Index (TDI) and St. George's Respiratory Questionnaire (SGRQ) scores, COPD exacerbation frequency and rescue medication use. Relationships between changes in trough forced expiratory volume in one second (ΔFEV1) and outcomes following treatment were assessed using correlations of data summaries and model-based analysis: generalized linear mixed-effect regression modeling to determine if ΔFEV1 could predict patient outcomes with different treatments. RESULTS: Mean age was 64 years, 73% were male, and most had moderate (45%) or severe (52%) disease. Statistically significant correlations were observed between ΔFEV1 and each outcome measure (exacerbations Rs = 0.05; rescue medication, SGRQ, TDI, r = 0.11-0.16; all p < .001). Patients with greater improvements in trough FEV1 had on average better SGRQ and TDI scores, fewer exacerbations, and used less rescue medication. For SGRQ and TDI scores, minimal clinically important differences were observed over the range of pooled ΔFEV1 values. Model-based predictions confirmed the treatment effect was partly explained by changes in FEV1 from baseline with improvements in PROs observed across all treatments when trough FEV1 improved. Across all endpoints active treatments were better than placebo (p < .0001), and LABA/LAMA treatment resulted in numerically better treatment outcomes than either monocomponent. CONCLUSIONS: These data suggest that FEV1 improvements post-bronchodilation correlate with PRO improvements. Further improvements in patient outcomes may be expected by maximizing lung function improvements. TRIAL REGISTRATION: Registration details for the 23 randomised controlled studies used in this pooled analysis are supplied in Additional File 4

The vacuum bubbles in de Sitter background and black hole pair creation

We study the possible types of the nucleation of vacuum bubbles. We classify vacuum bubbles in de Sitter background and present some numerical solutions. The thin-wall approximation is employed to obtain the nucleation rate and the radius of vacuum bubbles. With careful analysis we confirm that Parke's formula is also applicable to the large true vacuum bubbles. The nucleation of the false vacuum bubble in de Sitter background is also evaluated. The tunneling process in the potential with degenerate vacua is analyzed as the limiting cases of the large true vacuum bubble and false vacuum bubble. Next, we consider the pair creation of black holes in the background of bubble solutions. We obtain static bubble wall solutions of junction equation with black hole pair. The masses of created black holes are uniquely determined by the cosmological constant and surface tension on the wall. Finally, we obtain the rate of pair creation of black holes.Comment: 3 figures, minor including errors and typos corrected, and refs. adde

The extremely collimated bipolar H_2O jet from the NGC 1333-IRAS 4B protostar

We have performed observations of water maser emission towards a sample of low-mass protostars, in order to investigate the properties of jets associated with the earliest stages of star formation and their interaction with the surrounding medium. The main aim is to measure the absolute positions and proper motions of the H_2O spots in order to investigate the kinematics of the region from where the jet is launched. We imaged the protostars in the nearby region NGC 1333-IRAS 4 in the water maser line at 22.2 GHz by using the VLBA in phase-reference mode at the milliarcsecond scale over four epochs, spaced by one month to measure proper motions. Two protostars (A2 and B) were detected in a highly variable H_2O maser emission, with an active phase shorter than four weeks. The H_2O maps allow us to trace the fast jet driven by the B protostar: we observed both the red- and blue-shifted lobes very close to the protostar, =< 35 AU, moving away with projected velocities of ~10-50 km/s. The comparison with the molecular outflow observed at larger scale suggests a jet precession with a 18'/yr rate. By measuring the positional spread of the H_2O spots we estimate a jet width of ~2 AU at a distance of ~12 AU from the driving protostar.Comment: 9 pages, 8 figures, A&A accepte