437 research outputs found

    Extreme variability in Irminger Sea winter heat loss revealed by ocean observatories initiative mooring and the ERA5 reanalysis

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    Author Posting. © American Geophysical Union, 2018. 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 46(1), (2018): 293-302, doi:10.1029/2018GL080956.Ground‐breaking measurements from the ocean observatories initiative Irminger Sea surface mooring (60°N, 39°30′W) are presented that provide the first in situ characterization of multiwinter surface heat exchange at a high latitude North Atlantic site. They reveal strong variability (December 2014 net heat loss nearly 50% greater than December 2015) due primarily to variations in frequency of intense short timescale (1–3 days) forcing. Combining the observations with the new high resolution European Centre for Medium Range Weather Forecasts Reanalysis 5 (ERA5) atmospheric reanalysis, the main source of multiwinter variability is shown to be changes in the frequency of Greenland tip jets (present on 15 days in December 2014 and 3 days in December 2015) that can result in hourly mean heat loss exceeding 800 W/m2. Furthermore, a new picture for atmospheric mode influence on Irminger Sea heat loss is developed whereby strongly positive North Atlantic Oscillation conditions favor increased losses only when not outweighed by the East Atlantic Pattern.We are grateful to Meric Srokosz and the two reviewers for helpful comments on this work. S. J. acknowledges the U.K. Natural Environment Research Council ACSIS programme funding (Ref. NE/N018044/1). M. O. acknowledges support from EU Horizon 2020 projects AtlantOS (grant 633211) and Blue Action (grant 727852). G. W. K. M. acknowledges support from the Natural Sciences and Engineering Research Council of Canada. Support for the Irminger Sea array of the ocean observatories initiative (OOI) came from the U.S. National Science Foundation. Thanks to the WHOI team and ships' officers and crew for the field deployments and to Nan Galbraith for processing the data and computing the air‐sea fluxes. Support for this processing, and making available and sharing the OOI data, came from the National Science Foundation under a Collaborative Research: Science Across Virtual Institutes grant (82164000) to R. A. W. Data used are available from the following sites: NOAA Climate Prediction Center NAO and EAP indices ftp://ftp.cpc.ncep.noaa.gov/wd52dg/data/indices/tele_index.nh, ECMWF Reanalysis 5 (ERA5) https://www.ecmwf.int/en/forecasts/datasets/archive‐datasets/reanalysis/datasets/era5, and ocean observatories initiative Irminger Mooring https://ooinet.oceanobservatories.org/.2019-06-1

    The Potential of TaqMan Array Cards for Detection of Multiple Biological Agents by Real-Time PCR

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    The TaqMan Array Card architecture, normally used for gene expression studies, was evaluated for its potential to detect multiple bacterial agents by real-time PCR. Ten PCR assays targeting five biological agents (Bacillus anthracis, Burkholderia mallei, Burkholderia pseudomallei, Francisella tularensis, and Yersinia pestis) were incorporated onto Array Cards. A comparison of PCR performance of each PCR in Array Card and singleplex format was conducted using DNA extracted from pure bacterial cultures. When 100 fg of agent DNA was added to Array Card channels the following levels of agent detection (where at least one agent PCR replicate returned a positive result) were observed: Y. pestis 100%, B. mallei & F. tularensis 93%; B. anthracis 71%; B. pseudomallei 43%. For B. mallei & pseudomallei detection the BPM2 PCR, which detects both species, outperformed PCR assays specific to each organism indicating identification of the respective species would not be reproducible at the 100 fg level. Near 100% levels of detection were observed when 100 fg of DNA was added to each PCR in singleplex format with singleplex PCRs also returning sporadic positives at the 10 fg per PCR level. Before evaluating the use of Array Cards for the testing of environmental and clinical sample types, with potential levels of background DNA and PCR inhibitors, users would therefore have to accept a 10-fold reduction in sensitivity of PCR assays on the Array Card format, in order to benefit for the capacity to test multiple samples for multiple agents. A two PCR per agent strategy would allow the testing of 7 samples for the presence of 11 biological agents or 3 samples for 23 biological agents per card (with negative control channels)

    Constraining warm dark matter with cosmic shear power spectra

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    We investigate potential constraints from cosmic shear on the dark matter particle mass, assuming all dark matter is made up of light thermal relic particles. Given the theoretical uncertainties involved in making cosmological predictions in such warm dark matter scenarios we use analytical fits to linear warm dark matter power spectra and compare (i) the halo model using a mass function evaluated from these linear power spectra and (ii) an analytical fit to the non-linear evolution of the linear power spectra. We optimistically ignore the competing effect of baryons for this work. We find approach (ii) to be conservative compared to approach (i). We evaluate cosmological constraints using these methods, marginalising over four other cosmological parameters. Using the more conservative method we find that a Euclid-like weak lensing survey together with constraints from the Planck cosmic microwave background mission primary anisotropies could achieve a lower limit on the particle mass of 2.5 keV.Comment: 26 pages, 9 figures, minor changes to match the version accepted for publication in JCA

    Risk factors for delay in symptomatic presentation: a survey of cancer patients

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    Background: Delay in symptomatic presentation leading to advanced stage at diagnosis may contribute to poor cancer survival. To inform public health approaches to promoting early symptomatic presentation, we aimed to identify risk factors for delay in presentation across several cancers. Methods: We surveyed 2371 patients with 15 cancers about nature and duration of symptoms using a postal questionnaire. We calculated relative risks for delay in presentation (time from symptom onset to first presentation >3 months) by cancer, symptoms leading to diagnosis and reasons for putting off going to the doctor, controlling for age, sex and deprivation group. Results: Among 1999 cancer patients reporting symptoms, 21% delayed presentation for >3 months. Delay was associated with greater socioeconomic deprivation but not age or sex. Patients with prostate (44%) and rectal cancer (37%) were most likely to delay and patients with breast cancer least likely to delay (8%). Urinary difficulties, change of bowel habit, systemic symptoms (fatigue, weight loss and loss of appetite) and skin symptoms were all common and associated with delay. Overall, patients with bleeding symptoms were no more likely to delay presentation than patients who did not have bleeding symptoms. However, within the group of patients with bleeding symptoms, there were significant differences in risk of delay by source of bleeding: 35% of patients with rectal bleeding delayed presentation, but only 9% of patients with urinary bleeding. A lump was a common symptom but not associated with delay in presentation. Twenty-eight percent had not recognised their symptoms as serious and this was associated with a doubling in risk of delay. Embarrassment, worry about what the doctor might find, being too busy to go to the doctor and worry about wasting the doctor’s time were also strong risk factors for delay, but were much less commonly reported (<6%). Interpretation: Approaches to promote early presentation should aim to increase awareness of the significance of cancer symptoms and should be designed to work for people of the lowest socioeconomic status. In particular, awareness that rectal bleeding is a possible symptom of cancer should be raised

    Comparison of Eight Methods for the Extraction of Bacillus atrophaeus Spore DNA from Eleven Common Interferents and a Common Swab

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    Eight DNA extraction products or methods (Applied Biosystems PrepFiler Forensic DNA Extraction Kit; Bio-Rad Instagene Only, Bio-Rad Instagene & Spin Column Purification; EpiCentre MasterPure DNA & RNA Kit; FujiFilm QuickGene Mini80; Idaho Technologies 1-2-3 Q-Flow Kit; MoBio UltraClean Microbial DNA Isolation Kit; Sigma Extract-N-Amp Plant and Seed Kit) were adapted to facilitate extraction of DNA under BSL3 containment conditions. DNA was extracted from 12 common interferents or sample types, spiked with spores of Bacillus atropheaus. Resulting extracts were tested by real-time PCR. No one method was the best, in terms of DNA extraction, across all sample types. Statistical analysis indicated that the PrepFiler method was the best method from six dry powders (baking, biological washing, milk, plain flour, filler and talcum) and one solid (Underarm deodorant), the UltraClean method was the best from four liquids (aftershave, cola, nutrient broth, vinegar), and the MasterPure method was the best from the swab sample type. The best overall method, in terms of DNA extraction, across all sample types evaluated was the UltraClean method

    Modulation of σ-Alkane Interactions in [Rh(L2)(alkane)]+ Solid-State Molecular Organometallic (SMOM) Systems by Variation of the Chelating Phosphine and Alkane : Access to η2,η2-σ-Alkane Rh(I), η1-σ-Alkane Rh(III) Complexes, and Alkane Encapsulation

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    Solid/gas single-crystal to single-crystal (SC-SC) hydrogenation of appropriate diene precursors forms the corresponding σ-alkane complexes [Rh(Cy2P(CH2)nPCy2)(L)][BArF 4] (n = 3, 4) and [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(L)][BArF 4] (n = 5, L = norbornane, NBA; cyclooctane, COA). Their structures, as determined by single-crystal X-ray diffraction, have cations exhibiting Rh···H-C σ-interactions which are modulated by both the chelating ligand and the identity of the alkane, while all sit in an octahedral anion microenvironment. These range from chelating η2,η2 Rh···H-C (e.g., [Rh(Cy2P(CH2)nPCy2)(η2η2-NBA)][BArF 4], n = 3 and 4), through to more weakly bound η1 Rh···H-C in which C-H activation of the chelate backbone has also occurred (e.g., [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(η1-COA)][BArF 4]) and ultimately to systems where the alkane is not ligated with the metal center, but sits encapsulated in the supporting anion microenvironment, [Rh(Cy2P(CH2)3PCy2)][COÅBArF 4], in which the metal center instead forms two intramolecular agostic η1 Rh···H-C interactions with the phosphine cyclohexyl groups. CH2Cl2 adducts formed by displacement of the η1-alkanes in solution (n = 5; L = NBA, COA), [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(κ1-ClCH2Cl)][BArF 4], are characterized crystallographically. Analyses via periodic DFT, QTAIM, NBO, and NCI calculations, alongside variable temperature solid-state NMR spectroscopy, provide snapshots marking the onset of Rh···alkane interactions along a C-H activation trajectory. These are negligible in [Rh(Cy2P(CH2)3PCy2)][COÅBArF 4]; in [RhH(Cy2P(CH2)2(CH)(CH2)2PCy2)(η1-COA)][BArF 4], σC-H → Rh σ-donation is supported by Rh → σ∗C-H "pregostic" donation, and in [Rh(Cy2P(CH2)nPCy2)(η2η2-NBA)][BArF 4] (n = 2-4), σ-donation dominates, supported by classical Rh(dπ) → σ∗C-H π-back-donation. Dispersive interactions with the [BArF 4]- anions and Cy substituents further stabilize the alkanes within the binding pocket

    Communication about colorectal cancer screening in Britain:public preferences for an expert recommendation

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    BACKGROUND: Informed decision-making approaches to cancer screening emphasise the importance of decisions being determined by individuals' own values and preferences. However, advice from a trusted source may also contribute to autonomous decision-making. This study examined preferences regarding a recommendation from the NHS and information provision in the context of colorectal cancer (CRC) screening. METHODS: In face-to-face interviews, a population-based sample of adults across Britain (n=1964; age 50–80 years) indicated their preference between: (1) a strong recommendation to participate in CRC screening, (2) a recommendation alongside advice to make an individual decision, and (3) no recommendation but advice to make an individual decision. Other measures included trust in the NHS and preferences for information on benefits and risks. RESULTS: Most respondents (84%) preferred a recommendation (47% strong recommendation, 37% recommendation plus individual decision-making advice), but the majority also wanted full information on risks (77%) and benefits (78%). Men were more in favour of a recommendation than women (86% vs 81%). Trust in the NHS was high overall, but the minority who expressed low trust were less likely to want a recommendation. CONCLUSION: Most British adults want full information on risks and benefits of screening but they also want a recommendation from an authoritative source. An ‘expert' view may be an important part of autonomous health decision-making
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