150 research outputs found
Ice-Ocean Environmental Buoys (IOEB) : technology and deployment in 1991-1992
Based upon the 1987-88 Arctic Environmental Drifting Buoy (AEDB), the Ice-Ocean Environmental Buoy (IOEB) was developed to
acquire and telemeter in near real-time inter-relatable time-series data on atmospheric, oceanographic and ice physics in ice-covered oceans
during all seasons. Two IOEBs were successfully deployed in two Arctic Sea Basin Stations in April, 1992. Since then, although some
sensors malfunctioned, for 18 continuous months, they have been sending massive amounts of information. In this report we describe the
technology which was developed for the 1991 IOEB. Mechanically, the IOEB consists of an extremely durable surface flotation package
and an underwater mooring line of instruments and sensors. The apex contains data loggers for air, ice and engineering measurements,
microcontroller modules for accumulating the data from all the instruments, and ARGOS platform transmit terminals (PTTs) for
broadcasting the data. Extending above the surface float, a mast supports a wind monitor and air temperature probe, which along with a
barometer provides meteorological data. Thermistor strings, vibrating wire stress sensors, and a thickness gauge are installed in the ice
surrounding the buoy, and are interrogated by the modules inside the apex. In the ocean, 110m of conducting strength cable passes the
data from conductivity/temperature recorders, an Acoustic Doppler Current Profier and data compression module, a dissolved oxygen
sensor, a transmissometer and fluorometers to the PTT microcontrollers. Furthermore, a suspended particle collector and sediment trap
transmit status information along the two-wire multidrop network cable. Because the IOEB differs from the AEDB by telemetering the
majority of the scientific data, a complicated compression scheme is incorporated to broadcast the data from the 103 variables within the
allowable 256-bit ARGOS data stream. Via Service ARGOS, this data currently becomes available to scientists in several countries within
eight hours of transmission.
In April 1992, two IOEBs were deployed at separate ice camps in the Arctic Ocean with battery power adequate to sustain the systems for
over two years. One was deployed 115 miles from the North Pole in the center of the Transpolar Drift sea-ice current, and the other off of
the coast of Alaska along the edge of the Beaufort Gyre. Airplanes capable of landing on ice were used for the transportation of the systems
to their final destination. Simultaneously, a third, reduced version of the IOEB was deployed in the Weddell Sea by the Scott Polar
Research Institute.Funding was provided by the Office of Naval Research, Arlington, Virginia, USA
and
Japan Marine Science and Technology Center, Yokosuka, Japan
Water samplers for open ocean tracer release experiments
Conventional "spot" sampling of patchy distributions of oceanic constituents can lead to sampling errors. Interpretation of results
based on data of disparate temporal or spatial resolution can be difficult or impossible. Ths report discusses the design and
performance of two water sampling devices which attempt to minimize these problems. The devices were created for open ocean
tracer release experiments, but can be used for other experiments where inhomogeneity is anticipated. The first sampler is a
mechancally-operated, variable-rate integrating water sampler which acquires a time-averaged sample. The sampler incorporates
featues of both the spring-driven and the hydraulically-driven samplers described by Ledwell et al., 1991. The second sampler is a
multichamber sampling system incorporating a battery powered pump and valve system made by McLane Research, Inc., of
Falmouth, Massachusett. The system consists of a micro-gear pump, a 50-port valve with programmable controller, and
carousels contaning fifty glass sampling syringes. It can be programmed to sample on a variety of schedules allowing the user
flexibilty in the field to adapt to changing requirements. A general description, operational instructions, and performance analysis
are provided for each sampler system.Funding was provided by National Science Foundation under
grant numbers OCE-9020492 and OCE-9415598
Design and evaluation of a directional antenna for ocean buoys
A system concept has been developed by Viasat, Inc. and Woods Hole Oceanographic Institution for improving the data
telemetry bandwidth available on ocean buoys. This concept utilizes existing communications satellites as data relay
stations and mechanically steered antenna arrays to achieve increased data rates and improved power efficiency needed for
ocean applications.
This report describes an initial feasibility and design study to determine if a mechanically steered antenna array can
meet the requirements of open ocean buoy applications. To meet the system requirements, an 18-element microstrip
antenna (9-element transmit, 9-element receive) was designed and fabricated under subcontract by Seavey Engineering
Associates, Inc. It operates in the 4-6GHz frequency band (C-band) and provides 14 dB of gain. The 1/2 power beamwidth
is +-t5° in azimuth and elevation. This antenna design, in conjunction with a simple rotating mount, was used to evaluate
the potential of this approach to keep a geostationary satellite in view when mounted on an ocean buoy. The evaluation is
based on laboratory measurements using a magnetic compass and a small stepper motor to maintain antenna orientation
while the complete assembly was rotated and tilted at speeds similar to what would be expected on an offshore buoy
equipped with a stabilizing wind vane.
The results are promising, but less than conclusive because of limitations in the experimental test setup. The recent
introduction of several commercially available mechanically steered antennas designed for use on small boats may provide
a viable alternative to the approach described here with appropriate modification to operate at C-band.Funding was provided by Viasat, Inc., under subcontract No. SC95001 and by a
Cecil H. and Ida M. Green Technology Innovation Award
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
Autonomous Microbial Sampler (AMS), a device for the uncontaminated collection of multiple microbial samples from submarine hydrothermal vents and other aquatic environments
Author Posting. © Elsevier B.V., 2006. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part I: Oceanographic Research Papers 53 (2006): 894-916, doi:10.1016/j.dsr.2006.01.009.An Autonomous Microbial Sampler (AMS) is described that will obtain uncontaminated and
exogenous DNA-free microbial samples from most marine, fresh water and hydrothermal
ecosystems. Sampling with the AMS may be conducted using manned submersibles, Remotely
Operated Vehicles (ROVs), Autonomous Underwater Vehicles (AUVs), or when tethered to a
hydrowire during hydrocast operations on research vessels. The modular device consists of a
titanium nozzle for sampling in potentially hot environments (>350°C) and fluid-handling
components for the collection of six independent filtered or unfiltered samples. An onboard
microcomputer permits sampling to be controlled by the investigator, by external devices (e.g.,
AUV computer), or by internal programming. Temperature, volume pumped and other
parameters are recorded during sampling. Complete protection of samples from microbial
contamination was observed in tests simulating deployment of the AMS in coastal seawater,
where the sampling nozzle was exposed to seawater containing 1x106 cells ml-1 of a red
pigmented tracer organism, Serratia marinorubra. Field testing of the AMS at a hydrothermal
vent field was successfully undertaken in 2000. Results of DNA destruction studies have
revealed that exposure of samples of the Eukaryote Euglena and the bacterium S. marinorubra to
0.5 N sulfuric acid at 23°C for 1 hour was sufficient to remove Polymerase Chain Reaction
(PCR) amplifiable DNA. Studies assessing the suitability of hydrogen peroxide as a sterilizing
and DNA-destroying agent showed that 20 or 30% hydrogen peroxide sterilized samples of
Serratia in 1 hr and destroyed the DNA of Serratia, in 3 hrs, but not 1 or 2 hrs. DNA AWAYâą
killed Serratia and destroyed the DNA of both Serratia and the vent microbe (GB-D) of the
genus Pyrococcus in 1 hour.This work was supported by a DOC/NOAA Small Business Innovative Research Award,
Contract No. 50-DKNA-9-90116 awarded to McLane Research Laboratories, Inc. and (via
subcontract) to the Woods Hole Oceanographic Institution. Some of the microbial testing work
was also supported by the National Science Foundation, Grant No. IBN-0131557 and the Woods
Hole Oceanographic Inst. Deep Ocean Exploration Institute Grant No. 25051131
Novel Genetic Variants for Cartilage Thickness and Hip Osteoarthritis
Osteoarthritis is one of the most frequent and disabling diseases of the elderly. Only few genetic variants have been identified for osteoarthritis, which is partly due to large phenotype heterogeneity. To reduce heterogeneity, we here examined cartilage thickness, one of the structural components of joint health. We conducted a genome-wide association study of minimal joint space width (mJSW), a proxy for cartilage thickness, in a discovery set of 13,013 participants from five different cohorts and replication in 8,227 individuals from seven independent cohorts. We identified five genome-wide significant (GWS, Pâ€5·0Ă10â8) SNPs annotated to four distinct loci. In addition, we found two additional loci that were significantly replicated, but results of combined meta-analysis fell just below the genome wide significance threshold. The four novel associated genetic loci were located in/near TGFA (rs2862851), PIK3R1 (rs10471753), SLBP/FGFR3 (rs2236995), and TREH/DDX6 (rs49654
LSST: from Science Drivers to Reference Design and Anticipated Data Products
(Abridged) We describe here the most ambitious survey currently planned in
the optical, the Large Synoptic Survey Telescope (LSST). A vast array of
science will be enabled by a single wide-deep-fast sky survey, and LSST will
have unique survey capability in the faint time domain. The LSST design is
driven by four main science themes: probing dark energy and dark matter, taking
an inventory of the Solar System, exploring the transient optical sky, and
mapping the Milky Way. LSST will be a wide-field ground-based system sited at
Cerro Pach\'{o}n in northern Chile. The telescope will have an 8.4 m (6.5 m
effective) primary mirror, a 9.6 deg field of view, and a 3.2 Gigapixel
camera. The standard observing sequence will consist of pairs of 15-second
exposures in a given field, with two such visits in each pointing in a given
night. With these repeats, the LSST system is capable of imaging about 10,000
square degrees of sky in a single filter in three nights. The typical 5
point-source depth in a single visit in will be (AB). The
project is in the construction phase and will begin regular survey operations
by 2022. The survey area will be contained within 30,000 deg with
, and will be imaged multiple times in six bands, ,
covering the wavelength range 320--1050 nm. About 90\% of the observing time
will be devoted to a deep-wide-fast survey mode which will uniformly observe a
18,000 deg region about 800 times (summed over all six bands) during the
anticipated 10 years of operations, and yield a coadded map to . The
remaining 10\% of the observing time will be allocated to projects such as a
Very Deep and Fast time domain survey. The goal is to make LSST data products,
including a relational database of about 32 trillion observations of 40 billion
objects, available to the public and scientists around the world.Comment: 57 pages, 32 color figures, version with high-resolution figures
available from https://www.lsst.org/overvie
BRCA2 polymorphic stop codon K3326X and the risk of breast, prostate, and ovarian cancers
Background: The K3326X variant in BRCA2 (BRCA2*c.9976A>T; p.Lys3326*; rs11571833) has been found to be associated with small increased risks of breast cancer. However, it is not clear to what extent linkage disequilibrium with fully pathogenic mutations might account for this association. There is scant information about the effect of K3326X in other hormone-related cancers.
Methods: Using weighted logistic regression, we analyzed data from the large iCOGS study including 76 637 cancer case patients and 83 796 control patients to estimate odds ratios (ORw) and 95% confidence intervals (CIs) for K3326X variant carriers in relation to breast, ovarian, and prostate cancer risks, with weights defined as probability of not having a pathogenic BRCA2 variant. Using Cox proportional hazards modeling, we also examined the associations of K3326X with breast and ovarian cancer risks among 7183 BRCA1 variant carriers. All statistical tests were two-sided.
Results: The K3326X variant was associated with breast (ORw = 1.28, 95% CI = 1.17 to 1.40, P = 5.9x10- 6) and invasive ovarian cancer (ORw = 1.26, 95% CI = 1.10 to 1.43, P = 3.8x10-3). These associations were stronger for serous ovarian cancer and for estrogen receptorânegative breast cancer (ORw = 1.46, 95% CI = 1.2 to 1.70, P = 3.4x10-5 and ORw = 1.50, 95% CI = 1.28 to 1.76, P = 4.1x10-5, respectively). For BRCA1 mutation carriers, there was a statistically significant inverse association of the K3326X variant with risk of ovarian cancer (HR = 0.43, 95% CI = 0.22 to 0.84, P = .013) but no association with breast cancer. No association with prostate cancer was observed.
Conclusions: Our study provides evidence that the K3326X variant is associated with risk of developing breast and ovarian cancers independent of other pathogenic variants in BRCA2. Further studies are needed to determine the biological mechanism of action responsible for these associations
Effects of Transport Inhibitors on the Cellular Uptake of Carboxylated Polystyrene Nanoparticles in Different Cell Lines
Nanotechnology is expected to play a vital role in the rapidly developing field of nanomedicine, creating innovative solutions and therapies for currently untreatable diseases, and providing new tools for various biomedical applications, such as drug delivery and gene therapy. In order to optimize the efficacy of nanoparticle (NP) delivery to cells, it is necessary to understand the mechanisms by which NPs are internalized by cells, as this will likely determine their ultimate sub-cellular fate and localisation. Here we have used pharmacological inhibitors of some of the major endocytic pathways to investigate nanoparticle uptake mechanisms in a range of representative human cell lines, including HeLa (cervical cancer), A549 (lung carcinoma) and 1321N1 (brain astrocytoma). Chlorpromazine and genistein were used to inhibit clathrin and caveolin mediated endocytosis, respectively. Cytochalasin A and nocodazole were used to inhibit, respectively, the polymerisation of actin and microtubule cytoskeleton. Uptake experiments were performed systematically across the different cell lines, using carboxylated polystyrene NPs of 40 nm and 200 nm diameters, as model NPs of sizes comparable to typical endocytic cargoes. The results clearly indicated that, in all cases and cell types, NPs entered cells via active energy dependent processes. NP uptake in HeLa and 1321N1 cells was strongly affected by actin depolymerisation, while A549 cells showed a stronger inhibition of NP uptake (in comparison to the other cell types) after microtubule disruption and treatment with genistein. A strong reduction of NP uptake was observed after chlorpromazine treatment only in the case of 1321N1 cells. These outcomes suggested that the same NP might exploit different uptake mechanisms to enter different cell types
Telomere structure and maintenance gene variants and risk of five cancer types.
Telomeres cap chromosome ends, protecting them from degradation, double-strand breaks, and end-to-end fusions. Telomeres are maintained by telomerase, a reverse transcriptase encoded by TERT, and an RNA template encoded by TERC. Loci in the TERT and adjoining CLPTM1L region are associated with risk of multiple cancers. We therefore investigated associations between variants in 22 telomere structure and maintenance gene regions and colorectal, breast, prostate, ovarian, and lung cancer risk. We performed subset-based meta-analyses of 204,993 directly-measured and imputed SNPs among 61,851 cancer cases and 74,457 controls of European descent. Independent associations for SNP minor alleles were identified using sequential conditional analysis (with gene-level p value cutoffs â€3.08 Ă 10-5 ). Of the thirteen independent SNPs observed to be associated with cancer risk, novel findings were observed for seven loci. Across the DCLRE1B region, rs974494 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Across the TERC region, rs75316749 was positively associated with colorectal, breast, ovarian, and lung cancers. Across the DCLRE1B region, rs974404 and rs12144215 were inversely associated with prostate and lung cancers, and colorectal, breast, and prostate cancers, respectively. Near POT1, rs116895242 was inversely associated with colorectal, ovarian, and lung cancers, and RTEL1 rs34978822 was inversely associated with prostate and lung cancers. The complex association patterns in telomere-related genes across cancer types may provide insight into mechanisms through which telomere dysfunction in different tissues influences cancer risk.Funding for the iCOGS infrastructure came from: the European Communityâs Seventh Framework Programme under grant agreement n° 223175 (HEALTH-F2-2009-223175) (COGS), Cancer Research UK (C1287/A10118, C1287/A 10710, C12292/A11174, C1281/A12014,
C5047/A8384, C5047/A15007, C5047/A10692, C8197/A16565), the National Institutes of Health (CA128978) and Post-Cancer GWAS initiative (1U19 CA148537, 1U19 CA148065 and 1U19 CA148112 â the GAME-ON initiative), the Department of Defense (W81XWH-10-1-0341), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer, Komen Foundation for the Cure, the Breast Cancer Research Foundation, and the Ovarian Cancer Research Fund.This is the author accepted manuscript. The final version is available from Wiley via http://dx.doi.org/10.1002/ijc.3028
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