6,306 research outputs found
RRS Discovery Cruise DY039, 17 Oct - 01 Dec 2015, Southampton, UK to Nassau, Bahamas. RAPID moorings cruise report
This cruise report covers scientific operations conducted during RRS Discovery Cruise DY039. The purpose of the cruise was the refurbishment of an array of moorings spanning the latitude of 26.5°N from the Bahamas to the Canary Islands. Cruise DY039 departed from Southampton, UK on Saturday 17 October 2015, calling at Tenerife, Spain and Nassau, Bahamas before ending in Nassau, Bahamas on 21 November 2015.
The moorings are part of a purposeful Atlantic wide mooring array for monitoring the Atlantic Meridional Overturning Circulation and the associated heat transport. The array is a joint UK- US programme and is known as the RAPID-MOCHA array.
During DY039 moorings were serviced at sites: EBH4, EBH4L, EBH3, EBH2, EBH1, EBH1L, EBHi, EB1, EB1L, MAR3, MAR3L, MAR2, MAR1, MAR1L, MAR0, WB6, WB4, WB4L, WBH2, WB2, WB2L, WB1, WBADCP and WBAL. Sites with suffix âLâ denote landers fitted with bottom pressure recorders.
RAPID-AMOC continues the measurements at 26°N started with the RAPID and RAPID-WATCH programmes and through the ABC Fluxes project extends the measurements to include biological and chemical measurements in order to determine AMOC links to climate and the ocean carbon sink on interannual-to-decadal time scales. This is the first deployment of the ABC Fluxes biogeochemical samplers and sensors to the array (aside from initial oxygen sensors that were deployed in 2014).
The ABC Fluxes sensors include pCO2 sensors, pH sensors, additional oxygen sensors and autonomous water samplers to collect samples for nutrient and carbonate chemistry analysis following mooring recovery.
Additionally the RAPID telemetry MkIII system was deployed for the first time on the array at EBHi with 6 data pods set to release over the 18-month deployment period. 24 temperature sensors and 2 75kHz ADCPs were also added to mooring WB1 for the MerMEED project.
Mooring EB1L was not able to be recovered but a replacement was deployed. A sediment trap mooring NOGST was also recovered and redeployed for the Ocean Biogeochemistry and Ecosystems Group at the NOCS.
CTD stations were conducted throughout the cruise for purposes of providing pre- and post- deployment calibrations for mooring instrumentation (including oxygen and carbonate chemistry sampling) and for testing mooring releases prior to deployment.
Shipboard underway measurements were systematically logged, processed and calibrated, including: surface meteorology, 5m depth sea temperatures and salinities, water depth, and navigation. Water velocity profiles from 15 m to approximately 800 m depth were obtained using the two vessel mounted Acoustic Doppler Current Profilers (one 75 kHz and one 150 kHz)
RRS Discovery Cruise DY039, 17 Oct - 01 Dec 2015, Southampton, UK to Nassau, Bahamas. RAPID moorings cruise report
This cruise report covers scientific operations conducted during RRS Discovery Cruise DY039. The purpose of the cruise was the refurbishment of an array of moorings spanning the latitude of 26.5°N from the Bahamas to the Canary Islands. Cruise DY039 departed from Southampton, UK on Saturday 17 October 2015, calling at Tenerife, Spain and Nassau, Bahamas before ending in Nassau, Bahamas on 21 November 2015.The moorings are part of a purposeful Atlantic wide mooring array for monitoring the Atlantic Meridional Overturning Circulation and the associated heat transport. The array is a joint UK- US programme and is known as the RAPID-MOCHA array.During DY039 moorings were serviced at sites: EBH4, EBH4L, EBH3, EBH2, EBH1, EBH1L, EBHi, EB1, EB1L, MAR3, MAR3L, MAR2, MAR1, MAR1L, MAR0, WB6, WB4, WB4L, WBH2, WB2, WB2L, WB1, WBADCP and WBAL. Sites with suffix âLâ denote landers fitted with bottom pressure recorders. RAPID-AMOC continues the measurements at 26°N started with the RAPID and RAPID-WATCH programmes and through the ABC Fluxes project extends the measurements to include biological and chemical measurements in order to determine AMOC links to climate and the ocean carbon sink on interannual-to-decadal time scales. This is the first deployment of the ABC Fluxes biogeochemical samplers and sensors to the array (aside from initial oxygen sensors that were deployed in 2014).The ABC Fluxes sensors include pCO2 sensors, pH sensors, additional oxygen sensors and autonomous water samplers to collect samples for nutrient and carbonate chemistry analysis following mooring recovery.Additionally the RAPID telemetry MkIII system was deployed for the first time on the array at EBHi with 6 data pods set to release over the 18-month deployment period. 24 temperature sensors and 2 75kHz ADCPs were also added to mooring WB1 for the MerMEED project.Mooring EB1L was not able to be recovered but a replacement was deployed. A sediment trap mooring NOGST was also recovered and redeployed for the Ocean Biogeochemistry and Ecosystems Group at the NOCS.CTD stations were conducted throughout the cruise for purposes of providing pre- and post- deployment calibrations for mooring instrumentation (including oxygen and carbonate chemistry sampling) and for testing mooring releases prior to deployment.Shipboard underway measurements were systematically logged, processed and calibrated, including: surface meteorology, 5m depth sea temperatures and salinities, water depth, and navigation. Water velocity profiles from 15 m to approximately 800 m depth were obtained using the two vessel mounted Acoustic Doppler Current Profilers (one 75 kHz and one 150 kHz)
A note on the CMH general association statistic and square contingency tables
In this expository note a simplified formula for the CMH general association statistic applicable to repeated categorical response data is given and applied to three-way square contingency tables
Recommended from our members
Antimicrobial resistance and biological governance: explanations for policy failure
The paper reviews the state of policy on antimicrobial use and the growth of antimicrobial resistance (AMR). AMR was anticipated at the time of the first use of antibiotics by their originators. For decades, reports and scientific papers have expressed concern about AMR at global and national policy levels, yet the problem, first exposed a half-century ago, worsened. The paper considers the explanations for this policy failure and the state of arguments about ways forward. These include: a deficit of economic incentivisation; complex interventions in behavioural dynamics; joint and separate shifts in medical and animal health regimes; consumerism; belief in technology; and a narrative that in a âwar on bugsâ nature can be beaten by human ingenuity. The paper suggests that these narratives underplay the biological realities of the human-animal-biosphere being in constant flux, an understanding which requires an ecological public health analysis of AMR policy development and failure. The paper suggests that effective policy change requires simultaneous actions across policy levels. No single solution is possible, since AMR is the result of long-term human intervention which has accelerated certain trends in the evolution of a microbial ecosystem shared by humans, animals and other biological organism inhabiting that ecosystem. Viewing the AMR crisis today through an ecological public health lens has the advantage of reuniting the social-ecological and bio-ecological perspectives which have been separated within public health
FeH Absorption in the Near-Infrared Spectra of Late M and L Dwarfs
We present medium-resolution z-, J-, and H-band spectra of four late-type
dwarfs with spectral types ranging from M8 to L7.5. In an attempt to determine
the origin of numerous weak absorption features throughout their near-infrared
spectra, and motivated by the recent tentative identification of the E 4\Pi- A
^4\Pi system of FeH near 1.6 microns in umbral and cool star spectra, we have
compared the dwarf spectra to a laboratory FeH emission spectrum. We have
identified nearly 100 FeH absorption features in the z-, J-, and H-band spectra
of the dwarfs. In particular, we have identified 34 features which dominate the
appearance of the H-band spectra of the dwarfs and which appear in the
laboratory FeH spectrum. Finally, all of the features are either weaker or
absent in the spectrum of the L7.5 dwarf which is consistent with the weakening
of the known FeH bandheads in the spectra of the latest L dwarfs.Comment: accepted by Ap
Time transfer between the Goddard Optical Research Facility and the U.S. Naval Observatory using 100 picosecond laser pulses
A horizontal two-way time comparison link in air between the University of Maryland laser ranging and time transfer equipment at the Goddard Optical Research Facility (GORF) 1.2 m telescope and the Time Services Division of the U.S. Naval Observatory (USNO) was established. Flat mirrors of 25 cm and 30 cm diameter respectively were placed on top of the Washington Cathedral and on a water tower at the Beltsville Agricultural Research Center. Two optical corner reflectors at the USNO reflect the laser pulses back to the GORF. Light pulses of 100 ps duration and an energy of several hundred microjoules are sent at the rate of 10 pulses per second. The detection at the USNO is by means of an RCA C30902E avalanche photodiode and the timing is accomplished by an HP 5370A computing counter and an HP 1000 computer with respect to a 10 pps pulse train from the Master Clock
Cations Affect the Rate of Gating Charge Recovery in Wild-type and W434F Shaker Channels through a Variety of Mechanisms
In this study we examine the effects of ionic conditions on the gating charge movement in the fast inactivationâremoved wild-type Shaker channel and its W434F mutant. Our results show that various ionic conditions influence the rate at which gating charge returns during repolarization following a depolarizing pulse. These effects are realized through different mechanisms, which include the regulation of channel closing by occupying the cavity, the modulation of transitions into inactivated states, and effects on transitions between closed states via a direct interaction with the channel's gating charges. In generating these effects the cations act from the different binding sites within the pore. Ionic conditions, in which conducting wild-type channels close at different rates, do not significantly affect the rate of charge recovery upon repolarization. In these conditions, channel closing is fast enough not to be rate-limiting in the charge recovery process. In the permanently P-inactivated mutant channel, however, channel closing becomes the rate-limiting step, presumably due to weakened ionâion interactions inside the pore and a slower intrinsic rate of gate closure. Thus, variations in closing rate induced by different ions are reflected as variations in the rate of charge recovery. In 115 mM internal Tris+ and external K+, Cs+, or Rb+, low inward permeation of these ions can be observed through the mutant channel. In these instances, channel closing becomes slower than in Tris+O//Tris+I solutions showing resemblance to the wild-type channel, where higher inward ionic fluxes also retard channel closing. Our data indicate that cations regulate the transition into the inactivated states from the external lock-in site and possibly the deep site. The direct action of barium on charge movement is probably exerted from the deep site, but this effect is not very significant for monovalent cations
- âŠ