98 research outputs found
Stratus Ocean Reference Station (20˚S, 85˚W), mooring recovery and deployment cruise R/V Revelle cruise dana 03, November 10 - November 26, 2003
The Ocean Reference Station at 20°S, 85°W under the stratus clouds west of northern
Chile and Peru is being maintained to provide ongoing, climate-quality records of surface
meteorology, of air-sea fluxes of heat, freshwater, and momentum, and of upper ocean
temperature, salinity, and velocity variability. The Stratus Ocean Reference Station,
hereafter ORS Stratus, is supported by the National Oceanic and Atmospheric
Administrations (NOAA) Climate Observation Program. It is recovered and redeployed
annually, with cruises that have come in October or November.
During the November 2003 cruise of Scripps Institution of Oceanography's R/V Roger
Revelle to the ORS Stratus site, the primary activities where the recovery of the WHOI
surface mooring that had been deployed in October 2002, the deployment of a new WHOI
surface mooring at that site, the in-situ calibration of the buoy meteorological sensors by
comparison with instrumentation put on board by Chris Fairall of the NOAA
Environmental Technology Laboratory (ETL), and observations of the stratus clouds and
lower atmosphere by NOAA ETL and Jason Tomlinson from Texas A&M.
The ORS Stratus buoys are equipped with two Improved Meteorological systems, which
provide surface wind speed and direction, air temperature, relative humidity, barometric
pressure, incoming shortwave radiation, incoming longwave radiation, precipitation rate,
and sea surface temperature. The IMET data are made available in near real time using
satellite telemetry. The mooring line carries instruments to measure ocean salinity,
temperature, and currents. On some deployments, additional instrumentation is attached to
the mooring to measure rainfall and bio-optical variability. The ETL instrumentation used
during the 2003 cruise included a cloud radar, radiosonde balloons, and sensors for mean
and turbulent surface meteorology.
In addition to this work, buoy work was done in support of the Ecuadorian Navy Institute
of Oceanography (INOCAR) and of the Chilean Navy Hydrographic and Oceanographic
Service (SHOA). The surface buoy, oceanographic instrumentation, and upper 500 m of
an INOCAR surface mooring at 2°S, 84°W that had been vandalized were recovered and
transferred to the Ecuadorian Navy vessel B. A. E. Calicuchima. A tsunami warning
mooring was installed at 75°W, 20°S for SHOA. SHOA personnel onboard were trained
during the cruise by staff from the NOAA Pacific Marine Environmental Laboratory
(PMEL) and National Data Buoy Center (NDBC). The cruise hosted two teachers
participating in NOAA's Teacher at Sea Program, Deb Brice from San Marcos, California
and Viviana Zamorano from Arica, Chile.Funding was provided by the National Oceanic and Atmospheric Administration uncer Contract Number NA17RJ1223
Clinical trial protocol: PRednisolone in early diffuse cutaneous Systemic Sclerosis (PRedSS)
From SAGE Publishing via Jisc Publications RouterHistory: received 2020-05-08, accepted 2020-08-16, epub 2020-09-17Publication status: PublishedFunder: Versus Arthritis; FundRef: https://doi.org/10.13039/501100012041; Grant(s): 21021Background:: Many of the painful, disabling features of early diffuse cutaneous systemic sclerosis have an inflammatory component and are potentially treatable with corticosteroid therapy. These features include painful and itchy skin, fatigue and musculoskeletal involvement. Yet many clinicians are understandably reluctant to prescribe corticosteroids because of the concern that these are a risk factor for scleroderma renal crisis. The aim of PRedSS (PRednisolone in early diffuse cutaneous Systemic Sclerosis) is to evaluate the efficacy and safety of moderate dose prednisolone in patients with early diffuse cutaneous systemic sclerosis, specifically whether moderate dose prednisolone is (a) effective in terms of reducing pain and disability, and improving skin score and (b) safe, with particular reference to renal function. Methods:: PRedSS is a Phase II, multicentre, double-blind randomised controlled trial which aims to recruit 72 patients with early diffuse cutaneous systemic sclerosis. Patients are randomised to receive either prednisolone (dosage approximately 0.3 mg/kg) or placebo therapy for 6 months. The two co-primary outcome measures are the difference in mean Health Assessment Questionnaire Disability Index at 3 months and the difference in modified Rodnan skin score at 3 months. Secondary outcome measures include patient reported outcome measures of itch, hand function, anxiety and depression, and helplessness. Results:: Recruitment commenced in December 2017 and after a slow start (due to delays in opening centres) 25 patients have now been recruited. Conclusion:: PRedSS should help to answer the question as to whether clinicians should or should not prescribe prednisolone in early diffuse cutaneous systemic sclerosis
An Early and Comprehensive Millimetre and Centimetre Wave and X-ray Study of SN 2011dh: a Non-Equipartition Blast Wave Expanding into a Massive Stellar Wind
Only a handful of supernovae (SNe) have been studied in multiwavelengths from the radio to X-rays, starting a few days after the explosion. The early detection and classification of the nearby Type IIb SN 2011dh/PTF 11eon in M51 provides a unique opportunity to conduct such observations. We present detailed data obtained at one of the youngest phase ever of a core-collapse SN (days 3–12 after the explosion) in the radio, millimetre and X-rays; when combined with optical data, this allows us to explore the early evolution of the SN blast wave and its surroundings. Our analysis shows that the expanding SN shock wave does not exhibit equipartition (ϵe/ϵB ∼ 1000), and is expanding into circumstellar material that is consistent with a density profile falling like R−2. Within modelling uncertainties we find an average velocity of the fast parts of the ejecta of 15 000 ± 1800 km s−1, contrary to previous analysis. This velocity places SN 2011dh in an intermediate blast wave regime between the previously defined compact and extended SN Type IIb subtypes. Our results highlight the importance of early (∼1 d) high-frequency observations of future events. Moreover, we show the importance of combined radio/X-ray observations for determining the microphysics ratio ϵe/ϵB
WHOI Hawaii Ocean Timeseries Station (WHOTS) : WHOTS-6 2009 mooring turnaround cruise report
The Woods Hole Oceanographic Institution (WHOI) Hawaii Ocean Timeseries Site
(WHOTS), 100 km north of Oahu, Hawaii, is intended to provide long-term, high-quality air-sea
fluxes as a part of the NOAA Climate Observation Program. The WHOTS mooring also serves
as a coordinated part of the Hawaiian Ocean Timeseries (HOT) program, contributing to the
goals of observing heat, fresh water and chemical fluxes at a site representative of the
oligotrophic North Pacific Ocean. The approach is to maintain a surface mooring outfitted for
meteorological and oceanographic measurements at a site near 22.75°N, 158°W by successive
mooring turnarounds. These observations will be used to investigate air–sea interaction processes
related to climate variability.
The first WHOTS mooring (WHOTS-1) was deployed in August 2004. Turnaround cruises for
successive moorings (WHOTS-2 through WHOTS-5) have typically been in either June or July.
This report documents recovery of the WHOTS-5 mooring and deployment of the sixth mooring
(WHOTS-6). The moorings utilize Surlyn foam buoys as the surface element and are outfitted
with two Air–Sea Interaction Meteorology (ASIMET) systems. Each ASIMET system measures,
records, and transmits via Argos satellite the surface meteorological variables necessary to
compute air–sea fluxes of heat, moisture and momentum. The upper 155 m of the mooring is
outfitted with oceanographic sensors for the measurement of temperature, conductivity and
velocity in a cooperative effort with R. Lukas of the University of Hawaii (UH). A pCO2 system
is installed on the buoy in a cooperative effort with Chris Sabine at the Pacific Marine
Environmental Laboratory. Dr. Frank Bradley, CSIRO, Australia, assisted with meteorological
sensor comparisons. A NOAA “Teacher at Sea” and a NOAA “Teacher in the Lab” participated
in the cruise.
The WHOTS mooring turnaround was done on the University of Hawaii research vessel
Kilo Moana, Cruise KM-09-16, by the Upper Ocean Processes Group of the Woods Hole
Oceanographic Institution in cooperation with UH and NOAA’s Earth System Research
Laboratory, Physical Sciences Division (ESRL/PSD). The cruise took place between 9 and 17
July 2009. Operations began with deployment of the WHOTS-6 mooring on 10 July at
approximately 22°40.0'N, 157°57.0'W in 4758 m of water. This was followed by meteorological
intercomparisons and CTDs at the WHOTS-6 and WHOTS-5 sites. The WHOTS-5 mooring was
recovered on 15 July 2009. The Kilo Moana then moved to the HOT central site (22°45.0'N,
158°00.0'W) for CTD casts. This report describes the cruise operations in more detail, as well as
some of the in-port operations and pre-cruise buoy preparations.Funding was provided by the National Oceanic and Atmospheric Administration
under Grant No. NA17RJ1223 for the Cooperative Institute for Climate and Ocean Research (CICOR)
An Early & Comprehensive Millimeter and Centimeter Wave and X-ray Study of Supernova 2011dh: A Non-Equipartition Blastwave Expanding into A Massive Stellar Wind
Only a handful of supernovae (SNe) have been studied in multi-wavelength from
radio to X-rays, starting a few days after explosion. The early detection and
classification of the nearby type IIb SN2011dh/PTF11eon in M51 provides a
unique opportunity to conduct such observations. We present detailed data
obtained at the youngest phase ever of a core-collapse supernova (days 3 to 12
after explosion) in the radio, millimeter and X-rays; when combined with
optical data, this allows us to explore the early evolution of the SN blast
wave and its surroundings. Our analysis shows that the expanding supernova
shockwave does not exhibit equipartition (e_e/e_B ~ 1000), and is expanding
into circumstellar material that is consistent with a density profile falling
like R^-2. Within modeling uncertainties we find an average velocity of the
fast parts of the ejecta of 15,000 +/- 1800 km/s, contrary to previous
analysis. This velocity places SN 2011dh in an intermediate blast-wave regime
between the previously defined compact and extended SN IIb subtypes. Our
results highlight the importance of early (~ 1 day) high-frequency observations
of future events. Moreover, we show the importance of combined radio/X-ray
observations for determining the microphysics ratio e_e/e_B.Comment: 9 pages, 5 figures, submitted to Ap
Genomic insights into the conservation status of the world’s last remaining Sumatran rhinoceros populations
Highly endangered species like the Sumatran rhinoceros are at risk from inbreeding. Five historical and 16 modern genomes from across the species range show mutational load, but little evidence for local adaptation, suggesting that future inbreeding depression could be mitigated by assisted gene flow among populations. Small populations are often exposed to high inbreeding and mutational load that can increase the risk of extinction. The Sumatran rhinoceros was widespread in Southeast Asia, but is now restricted to small and isolated populations on Sumatra and Borneo, and most likely extinct on the Malay Peninsula. Here, we analyse 5 historical and 16 modern genomes from these populations to investigate the genomic consequences of the recent decline, such as increased inbreeding and mutational load. We find that the Malay Peninsula population experienced increased inbreeding shortly before extirpation, which possibly was accompanied by purging. The populations on Sumatra and Borneo instead show low inbreeding, but high mutational load. The currently small population sizes may thus in the near future lead to inbreeding depression. Moreover, we find little evidence for differences in local adaptation among populations, suggesting that future inbreeding depression could potentially be mitigated by assisted gene flow among populations
Macroevolutionary Dynamics and Historical Biogeography of Primate Diversification Inferred from a Species Supermatrix
Phylogenetic relationships, divergence times, and patterns of biogeographic descent among primate species are both complex and contentious. Here, we generate a robust molecular phylogeny for 70 primate genera and 367 primate species based on a concatenation of 69 nuclear gene segments and ten mitochondrial gene sequences, most of which were extracted from GenBank. Relaxed clock analyses of divergence times with 14 fossil-calibrated nodes suggest that living Primates last shared a common ancestor 71–63 Ma, and that divergences within both Strepsirrhini and Haplorhini are entirely post-Cretaceous. These results are consistent with the hypothesis that the Cretaceous-Paleogene mass extinction of non-avian dinosaurs played an important role in the diversification of placental mammals. Previous queries into primate historical biogeography have suggested Africa, Asia, Europe, or North America as the ancestral area of crown primates, but were based on methods that were coopted from phylogeny reconstruction. By contrast, we analyzed our molecular phylogeny with two methods that were developed explicitly for ancestral area reconstruction, and find support for the hypothesis that the most recent common ancestor of living Primates resided in Asia. Analyses of primate macroevolutionary dynamics provide support for a diversification rate increase in the late Miocene, possibly in response to elevated global mean temperatures, and are consistent with the fossil record. By contrast, diversification analyses failed to detect evidence for rate-shift changes near the Eocene-Oligocene boundary even though the fossil record provides clear evidence for a major turnover event (‘‘Grande Coupure’’) at this time. Our results highlight the power and limitations of inferring diversification dynamics from molecular phylogenies, as well as the sensitivity of diversification analyses to different species concepts
Modulations in the radio light curve of the Type IIb Supernova 2001ig: Evidence for a Wolf-Rayet binary progenitor?
We describe the radio evolution of SN 2001ig in NGC 7424, from 700 days of
multi-frequency monitoring with the Australia Telescope Compact Array (ATCA)
and the Very Large Array (VLA). We find that deviations of the radio light
curves at each frequency from the standard "minishell" model are consistent
with density modulations in the circumstellar medium (CSM), which seem to recur
with a period near 150 days. One possibility is that these are due to enhanced
mass-loss from thermal pulses in an AGB star progenitor. A more likely scenario
however is that the progenitor was a Wolf-Rayet star, whose stellar wind
collided with that from a massive hot companion on an eccentric 100 day orbit,
leading to a regular build-up of CSM material on the required time and spatial
scales. Recent observations of "dusty pinwheels" in Wolf-Rayet binary systems
lend credibility to this model. Since such binary systems are also thought to
provide the necessary conditions for envelope-stripping which would cause the
Wolf-Rayet star to appear as a Type Ib/c supernova event rather than a Type II,
these radio observations of SN 2001ig may provide the key to linking Type Ib/c
SNe to Type IIb events, and even to some types of Gamma-Ray Bursts.Comment: 10 pages, MNRAS, accepte
The origin and evolution of the normal Type Ia SN 2018aoz with infant-phase reddening and excess emission
SN~2018aoz is a Type Ia SN with a -band plateau and excess emission in the
infant-phase light curves 1 day after first light, evidencing an
over-density of surface iron-peak elements as shown in our previous study.
Here, we advance the constraints on the nature and origin of SN~2018aoz based
on its evolution until the nebular phase. Near-peak spectroscopic features show
the SN is intermediate between two subtypes of normal Type Ia: Core-Normal and
Broad-Line. The excess emission could have contributions from the radioactive
decay of surface iron-peak elements as well as ejecta interaction with either
the binary companion or a small torus of circumstellar material. Nebular-phase
limits on H and He~I favour a white dwarf companion, consistent with
the small companion size constrained by the low early SN luminosity, while the
absence of [O~I] and He~I disfavours a violent merger of the progenitor. Of the
two main explosion mechanisms proposed to explain the distribution of surface
iron-peak elements in SN~2018aoz, the asymmetric Chandrasekhar-mass explosion
is less consistent with the progenitor constraints and the observed blueshifts
of nebular-phase [Fe~II] and [Ni~II]. The helium-shell double-detonation
explosion is compatible with the observed lack of C spectral features, but
current 1-D models are incompatible with the infant-phase excess emission,
color, and absence of nebular-phase [Ca~II]. Although
the explosion processes of SN~2018aoz still need to be more precisely
understood, the same processes could produce a significant fraction of Type Ia
SNe that appear normal after 1 day.Comment: Submitted for publication in ApJ. 35 pages, 16 figures, 7 table
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