459 research outputs found
Real-time environmental Arctic monitoring (R-TEAM) deployment cruise
The R-TEAM mooring was deployed on August 24, 1988 at the coordinates of 79°25'.92N and 06°47'.91 E.
This technical report describes the mooring as set and the deployment procedures.Funding was provided by the Office of Naval Research
through contract Number N00014-86-C-0135
Review of the occupational health and safety of Britain’s ethnic minorities
This report sets out an evidence-based review on work-related health and safety issues relating to black and
minority ethnic groups. Data included available statistical materials and a systematic review of published research
and practice-based reports.
UK South Asians are generally under-represented within the most hazardous occupational groups. They have
lower accident rates overall, while Black Caribbean workers rates are similar to the general population;
Bangladeshi and Chinese workers report lowest workplace injury rates
UK South Asian people exhibit higher levels of limiting long-term illness (LLI) and self reported poor health than the
general population while Black Africans and Chinese report lower levels. Ethnic minority workers with LLI are more
likely than whites to withdraw from the workforce, or to experience lower wage rates.
Some of these findings conflict with evidence of differentials from USA, Europe and Australasia, but there is a
dearth of effective primary research or reliable monitoring data from UK sources.
There remains a need to improve monitoring and data collection relating to black and ethnic minority populations
and migrant workers. Suggestions are made relating to workshops on occupational health promotion programmes
for ethnic minorities, and ethnic minority health and safety 'Beacon' sites
Experimental evaluation of CTD package hydrodynamic behavior and recommendations for improved lowering techniques
This report is the last of a series of three reports on a comprehensive
study of CTD instrument lowering mechanics. The first
report, WHOI 79-81, "A Study of CTD Cables and Lowering Systems",
examines the causes and modes of lowering cable failures, both mechanical
and electrical, and makes recommendations to improve existing instrument
packages and lowering procedures. The second report, WHOI 81-76,
"Hydrodynamics of CTD Instrument Packages", is a theoretical study of
instrument package stability when cable lowered or free falling. The
model is used to predict the hydrodynamic response of CTD packages in
their present or improved configuration. This report, WHOI 83-21, is
more factual. It describes the tests performed on scale models and
actual CTD packages to actually observe and/or measure their hydrodynamic
behavior. Analytical results and experimental data obtained in this
study are used to draw recommendations for CTD package improvement and
future lowering procedures.Prepared for the Office of Naval Research under Contract
N00014-72-C-0019
Large Deletions in the pAtC58 Megaplasmid of Agrobacterium tumefaciens Can Confer Reduced Carriage Cost and Increased Expression of Virulence Genes
The accessory plasmid pAtC58 of the common laboratory strain of Agrobacterium tumefaciens confers numerous catabolic functions and has been proposed to play a role in virulence. Genomic sequencing of evolved laboratory strains of A. tumefaciens revealed the presence of multiple deletion events in the At plasmid, with reductions in plasmid size ranging from 25% to 30% (115–194 kb). Flanking both ends of the sites of these deletions is a short-nucleotide repeat sequence that is in a single copy in the deleted plasmids, characteristic of a phage- or transposon-mediated deletion event. This repeat sequence is widespread throughout the C58 genome, but concentrated on the At plasmid, suggesting its frequency to be nonrandom. In this study, we assess the prevalence of the larger of these deletions in multiple C58 derivatives and characterize its functional significance. We find that in addition to elevating virulence gene expression, this deletion is associated with a significantly reduced carriage cost to the cell. These observations are a clear demonstration of the dynamic nature of the bacterial genome and suggest a mechanism for genetic plasticity of these costly but otherwise stable plasmids. Additionally, this phenomenon could be the basis for some of the dramatic recombination events so ubiquitous within and among megaplasmids
Constitutive Activation of the Src Family Kinase Hck Results in Spontaneous Pulmonary Inflammation and an Enhanced Innate Immune Response
To identify the physiological role of Hck, a functionally redundant member of the Src family of tyrosine kinases expressed in myelomonocytic cells, we generated HckF/F “knock-in” mice which carry a targeted tyrosine (Y) to phenylalanine (F) substitution of the COOH-terminal, negative regulatory Y499-residue in the Hck protein. Unlike their Hck−/− “loss-of-function” counterparts, HckF/F “gain-of-function” mice spontaneously acquired a lung pathology characterized by extensive eosinophilic and mononuclear cell infiltration within the lung parenchyma, alveolar airspaces, and around blood vessels, as well as marked epithelial mucus metaplasia in conducting airways. Lungs from HckF/F mice showed areas of mild emphysema and pulmonary fibrosis, which together with inflammation resulted in altered lung function and respiratory distress in aging mice. When challenged transnasally with lipopolysaccharide (LPS), HckF/F mice displayed an exaggerated pulmonary innate immune response, characterized by excessive release of matrix metalloproteinases and tumor necrosis factor (TNF)α. Similarly, HckF/F mice were highly sensitive to endotoxemia after systemic administration of LPS, and macrophages and neutrophils derived from HckF/F mice exhibited enhanced effector functions in vitro (e.g., nitric oxide and TNFα production, chemotaxis, and degranulation). Based on the demonstrated functional association of Hck with leukocyte integrins, we propose that constitutive activation of Hck may mimic adhesion-dependent priming of leukocytes. Thus, our observations collectively suggest an enhanced innate immune response in HckF/F mice thereby skewing innate immunity from a reversible physiological host defense response to one causing irreversible tissue damage
Modeling acoustic propagation of airgun array pulses recorded on tagged sperm whales (Physeter macrocephalus)
Author Posting. © Acoustical Society of America, 2006. This article is posted here by permission of Acoustical Society of America for personal use, not for redistribution. The definitive version was published in Journal of the Acoustical Society of America 120 (2006): 4100-4114, doi:10.1121/1.2359705.In 2002 and 2003, tagged sperm whales (Physeter macrocephalus) were experimentally exposed to airgun pulses in the Gulf of Mexico, with the tags providing acoustic recordings at measured ranges and depths. Ray trace and parabolic equation (PE) models provided information about sound propagation paths and accurately predicted time of arrival differences between multipath arrivals. With adequate environmental information, a broadband acoustic PE model predicted the relative levels of multipath arrivals recorded on the tagged whales. However, lack of array source signature data limited modeling of absolute received levels. Airguns produce energy primarily below 250 Hz, with spectrum levels about 20–40 dB lower at 1 kHz. Some arrivals recorded near the surface in 2002 had energy predominantly above 500 Hz; a surface duct in the 2002 sound speed profile helps explain this effect, and the beampattern of the source array also indicates an increased proportion of high-frequency sound at near-horizontal launch angles. These findings indicate that airguns sometimes expose animals to measurable sound energy above 250 Hz, and demonstrate the influences of source and environmental parameters on characteristics of received airgun pulses. The study also illustrates that on-axis source levels and simple geometric spreading inadequately describe airgun pulse propagation and the extent of exposure zones.Funding for this work was provided by the Office of Naval
Research, the U.S. Department of the Interior Minerals Management
Service Cooperative Agreements Nos. 1435-01-02-
CA-85186 and NA87RJ0445, and the Industry Research
Funding Coalition. S.L.D.R. was supported by a National
Science Foundation Graduate Research Fellowship
The Triticeae Toolbox: Combining Phenotype and Genotype Data to Advance Small‐Grains Breeding
Evaluation of automated airway morphological quantification for assessing fibrosing lung disease
Abnormal airway dilatation, termed traction bronchiectasis, is a typical feature of idiopathic pulmonary fibrosis (IPF). Volumetric computed tomography (CT) imaging captures the loss of normal airway tapering in IPF. We postulated that automated quantification of airway abnormalities could provide estimates of IPF disease extent and severity. We propose AirQuant, an automated computational pipeline that systematically parcellates the airway tree into its lobes and generational branches from a deep learning based airway segmentation, deriving airway structural measures from chest CT. Importantly, AirQuant prevents the occurrence of spurious airway branches by thick wave propagation and removes loops in the airway-tree by graph search, overcoming limitations of existing airway skeletonisation algorithms. Tapering between airway segments (intertapering) and airway tortuosity computed by AirQuant were compared between 14 healthy participants and 14 IPF patients. Airway intertapering was significantly reduced in IPF patients, and airway tortuosity was significantly increased when compared to healthy controls. Differences were most marked in the lower lobes, conforming to the typical distribution of IPF-related damage. AirQuant is an open-source pipeline that avoids limitations of existing airway quantification algorithms and has clinical interpretability. Automated airway measurements may have potential as novel imaging biomarkers of IPF severity and disease extent
Search for Higgs Bosons in e+e- Collisions at 183 GeV
The data collected by the OPAL experiment at sqrts=183 GeV were used to
search for Higgs bosons which are predicted by the Standard Model and various
extensions, such as general models with two Higgs field doublets and the
Minimal Supersymmetric Standard Model (MSSM). The data correspond to an
integrated luminosity of approximately 54pb-1. None of the searches for neutral
and charged Higgs bosons have revealed an excess of events beyond the expected
background. This negative outcome, in combination with similar results from
searches at lower energies, leads to new limits for the Higgs boson masses and
other model parameters. In particular, the 95% confidence level lower limit for
the mass of the Standard Model Higgs boson is 88.3 GeV. Charged Higgs bosons
can be excluded for masses up to 59.5 GeV. In the MSSM, mh > 70.5 GeV and mA >
72.0 GeV are obtained for tan{beta}>1, no and maximal scalar top mixing and
soft SUSY-breaking masses of 1 TeV. The range 0.8 < tanb < 1.9 is excluded for
minimal scalar top mixing and m{top} < 175 GeV. More general scans of the MSSM
parameter space are also considered.Comment: 49 pages. LaTeX, including 33 eps figures, submitted to European
Physical Journal
A Measurement of the Product Branching Ratio f(b->Lambda_b).BR(Lambda_b->Lambda X) in Z0 Decays
The product branching ratio, f(b->Lambda_b).BR(Lambda_b->Lambda X), where
Lambda_b denotes any weakly-decaying b-baryon, has been measured using the OPAL
detector at LEP. Lambda_b are selected by the presence of energetic Lambda
particles in bottom events tagged by the presence of displaced secondary
vertices. A fit to the momenta of the Lambda particles separates signal from B
meson and fragmentation backgrounds. The measured product branching ratio is
f(b->Lambda_b).BR(Lambda_b->Lambda X) = (2.67+-0.38(stat)+0.67-0.60(sys))%
Combined with a previous OPAL measurement, one obtains
f(b->Lambda_b).BR(Lambda_b->Lambda X) = (3.50+-0.32(stat)+-0.35(sys))%.Comment: 16 pages, LaTeX, 3 eps figs included, submitted to the European
Physical Journal
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