989 research outputs found
A deep sea docking station for ODYSSEY class autonomous underwater vehicles
Under subcontract to the Massachusetts Institute of Technology's (MIT) Sea Grant Autonomous Ocean Sampling Network
(AOSN) program, engineers and researchers at the Woods Hole Oceanographic Institution (WHOI) designed, fabricated and
operated a deep sea Docking Station for ODYSSEY-class autonomous underwater vehicles (AUVs). The docking station
provides shelter as well as power transfer and data exchange services for an AUV that is between autonomous midwater
missions. The Station is integrated into the main tension member of a deep sea mooring system. A large subsea flotation
sphere supports the mass of the Station above the seafoor. A surface expression connected by an umbilcal to the Station
was capable of bi-directional satellite or radio frequency communications. Primary subsystems of the Docking Station
described in this report include a dock controller with multi-sensor support, long-duration battery packs, a docking pole with
a moving carage, an inductive link for power and data transfer, and information about how the Station was deployed,
operated and recovered.Funding was provided by the Offce of Naval Research under Grant No. NOOO-14-95-1-1316
Deployment operation procedures for the WHOI Ice-Tethered Profiler
Deployed and fixed to a suitable multi-year ice floe, the Ice-Tethered Profiler (ITP) can
sustain near-real time measurements of upper ocean temperature and salinity for up to three years.
Incorporating a specifically designed winch system and deployment apparatus that is both light
weight and easily assembled or disassembled on a ship or at a deployment site, the ITP can be
deployed in less than four hours by either transporting the gear and field personnel to the
deployment site via aircraft, or by lowering the gear over the side of a ship and hauling on the ice.
Using daily satellite imagery (if available), visual reconnaissance flights, and ice surveying, the
choice of an appropriate ice floe is a necessity to select a site that will sustain the system for a
prolonged period of time (depending upon the instrument sampling rate). If available, the
helicopter is the preferable method for surveying different sites and for deployment operations.
Working from a ship typically limits the distance and selection of ice floes. Pre-deployment
procedures include powering and configuring the ITP instruments and preparing the apparatus
for transport to the deployment site. Specific deployment methods include the assembly and
disassembly of the ITP winch, proper placement of the total ITP deployment apparatus, ‘Yale
Grip’ braiding and slipping techniques, and testing the Iridium and Inductive communication
links. The operations described here provide a safe and efficient manner to easily deploy the
WHOI ITP.Funding was provided by the National Science Foundation under Grant No. OCE-0324233 and by the Office of Polar Programs under award numbers ARC-0519899 and ARC-0631951
Creating and Certifying the Professional Mediator -- Education and Credentialing
Existing and pending law school mediation programs, post-graduate mediator training programs, mentorship programs, credentialing movements, and continuing mediation education were examined by a panel and speakers directly involved in those fields. Are we effectively training new mediators in law schools and post-graduate programs? Should we, and how can we, credential mediators? Do good mediators need to be re-trained? How would continuing mediation educational requirements be implemented
Creating and Certifying the Professional Mediator -- Education and Credentialing
Existing and pending law school mediation programs, post-graduate mediator training programs, mentorship programs, credentialing movements, and continuing mediation education were examined by a panel and speakers directly involved in those fields. Are we effectively training new mediators in law schools and post-graduate programs? Should we, and how can we, credential mediators? Do good mediators need to be re-trained? How would continuing mediation educational requirements be implemented
Continued deceleration of Whillans Ice Stream, West Antarctica
Author Posting. © American Geophysical Union, 2005. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Geophysical Research Letters 32 (2005): L22501, doi:10.1029/2005GL024319.Earlier observations indicated that Whillans Ice Stream slowed from 1973 to 1997. We collected new GPS observations of the ice stream's speed in 2003 and 2004. These data show that the ice stream is continuing to decelerate at rates of about 0.6%/yr2, with faster rates near the grounding line. Our data also indicate that the deceleration extends over the full width of the ice plain. Extrapolation of the deceleration trend suggests the ice stream could stagnate sometime between the middle of the 21st and 22nd Centuries.This work was supported by the National
Science Foundation (NSF-OPP-0229659). IJ’s contribution was supported
by the Cryospheric Sciences Program of NASA’s Earth Science Enterprise
Design and operation of automated ice-tethered profilers for real-time seawater observations in the polar oceans
An automated, easily-deployed Ice-Tethered Profiler (ITP) has been developed for deployment on perennial sea ice in polar oceans to
measure changes in upper ocean temperature and salinity in all seasons. The ITP system consists of three components: a surface
instrument that sits atop an ice floe, a weighted, plastic-jacketed wire-rope tether of arbitrary length (up to 800 m) suspended from the
surface instrument, and an instrumented underwater unit that profiles up and down the wire tether. The profiling underwater unit is
similar in shape and dimension to an ARGO float except that the float's variable-buoyancy system is replaced with a traction drive unit.
Deployment of ITPs may be conducted either from ice caps or icebreakers, utilizing a self contained tripod/winch system that requires no
power. Careful selection of an appropriate multiyear ice floe is needed to prolong the lifetime of the system (up to 3 years depending on
the profiling schedule). Shortly after deployment, each ITP begins profiling the water column at its programmed sampling interval. After
each acquired temperature and salinity profile, the underwater unit (PROCON) transfers the data and engineering files using an inductive
modem to the surface controller (SURFCON). SURFCON also accumulates battery voltages, buoy temperature, and locations from GPS at
specified intervals in status files, and queues that information for transmission at the start of each new day. At frequent intervals, an
Iridium satellite transceiver in the surface package calls and transmits queued status and CTD data files onto a WHOI logger computer,
which are subsequently processed and displayed in near-real time at http://www.whoi.edu/itp. In 2004 and 2005, three ITP prototypes
were deployed in the Arctic Ocean. Each system was programmed with accelerated sampling schedules of multiple one-way traverses per
day between 10 and 750-760 m depth in order to quickly evaluate endurance and component fatigue. Two of the ITPs are continuing to
function after more than 10 months and 1200 profiles. Larger motor currents are observed at times of fast ice floe motion when larger
wire angles develop and drag forces on the profiler are increased. The CTD profile data so far obtained document interesting spatial
variations in the major water masses of the Beaufort Gyre, show the double-diffusive thermohaline staircase that lies above the warm,
salty Atlantic layer, and many mesoscale eddys. Deployed together with CRREL Ice Mass Balance (IMB) buoys, these ITP systems also
operate as part of an Ice Based Observatory (IBO). Data returned from an array of IBOs within an Arctic Observing Network will provide
valuable real time observations, support studies of ocean processes, and facilitate numerical model initialization and validation.Funding was provided by the National Science Foundation under Contract Nos. OCE-0324233 and ARC-0519899
The Sloan Digital Sky Survey Reverberation Mapping Project: Technical Overview
The Sloan Digital Sky Survey Reverberation Mapping project (SDSS-RM) is a
dedicated multi-object RM experiment that has spectroscopically monitored a
sample of 849 broad-line quasars in a single 7 deg field with the SDSS-III
BOSS spectrograph. The RM quasar sample is flux-limited to i_psf=21.7 mag, and
covers a redshift range of 0.1<z<4.5. Optical spectroscopy was performed during
2014 Jan-Jul dark/grey time, with an average cadence of ~4 days, totaling more
than 30 epochs. Supporting photometric monitoring in the g and i bands was
conducted at multiple facilities including the CFHT and the Steward Observatory
Bok telescopes in 2014, with a cadence of ~2 days and covering all lunar
phases. The RM field (RA, DEC=14:14:49.00, +53:05:00.0) lies within the CFHT-LS
W3 field, and coincides with the Pan-STARRS 1 (PS1) Medium Deep Field MD07,
with three prior years of multi-band PS1 light curves. The SDSS-RM 6-month
baseline program aims to detect time lags between the quasar continuum and
broad line region (BLR) variability on timescales of up to several months (in
the observed frame) for ~10% of the sample, and to anchor the time baseline for
continued monitoring in the future to detect lags on longer timescales and at
higher redshift. SDSS-RM is the first major program to systematically explore
the potential of RM for broad-line quasars at z>0.3, and will investigate the
prospects of RM with all major broad lines covered in optical spectroscopy.
SDSS-RM will provide guidance on future multi-object RM campaigns on larger
scales, and is aiming to deliver more than tens of BLR lag detections for a
homogeneous sample of quasars. We describe the motivation, design and
implementation of this program, and outline the science impact expected from
the resulting data for RM and general quasar science.Comment: 25 pages, submitted to ApJS; project website at http://www.sdssrm.or
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Clinical Significance of Bronchodilator Responsiveness Evaluated by Forced Vital Capacity in COPD: SPIROMICS Cohort Analysis.
ObjectiveBronchodilator responsiveness (BDR) is prevalent in COPD, but its clinical implications remain unclear. We explored the significance of BDR, defined by post-bronchodilator change in FEV1 (BDRFEV1) as a measure reflecting the change in flow and in FVC (BDRFVC) reflecting the change in volume.MethodsWe analyzed 2974 participants from a multicenter observational study designed to identify varying COPD phenotypes (SPIROMICS). We evaluated the association of BDR with baseline clinical characteristics, rate of prospective exacerbations and mortality using negative binomial regression and Cox proportional hazards models.ResultsA majority of COPD participants exhibited BDR (52.7%). BDRFEV1 occurred more often in earlier stages of COPD, while BDRFVC occurred more frequently in more advanced disease. When defined by increases in either FEV1 or FVC, BDR was associated with a self-reported history of asthma, but not with blood eosinophil counts. BDRFVC was more prevalent in subjects with greater emphysema and small airway disease on CT. In a univariate analysis, BDRFVC was associated with increased exacerbations and mortality, although no significance was found in a model adjusted for post-bronchodilator FEV1.ConclusionWith advanced airflow obstruction in COPD, BDRFVC is more prevalent in comparison to BDRFEV1 and correlates with the extent of emphysema and degree of small airway disease. Since these associations appear to be related to the impairment of FEV1, BDRFVC itself does not define a distinct phenotype nor can it be more predictive of outcomes, but it can offer additional insights into the pathophysiologic mechanism in advanced COPD.Clinical trials registrationClinicalTrials.gov: NCT01969344T4
Progressive star formation in the young galactic super star cluster NGC 3603
Early release science observations of the cluster NGC3603 with the WFC3 on
the refurbished HST allow us to study its recent star formation history. Our
analysis focuses on stars with Halpha excess emission, a robust indicator of
their pre-main sequence (PMS) accreting status. The comparison with theoretical
PMS isochrones shows that 2/3 of the objects with Halpha excess emission have
ages from 1 to 10 Myr, with a median value of 3 Myr, while a surprising 1/3 of
them are older than 10 Myr. The study of the spatial distribution of these PMS
stars allows us to confirm their cluster membership and to statistically
separate them from field stars. This result establishes unambiguously for the
first time that star formation in and around the cluster has been ongoing for
at least 10-20 Myr, at an apparently increasing rate.Comment: 10 pages, 8 figures, accepted for publication in The Astrophysical
Journa
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