804 research outputs found

    Observational evidence for the convective transport of dust over the central United States

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    Bulk aerosol composition and aerosol size distributions measured aboard the DC-8 aircraft during the Deep Convective Clouds and Chemistry Experiment mission in May/June 2012 were used to investigate the transport of mineral dust through nine storms encountered over Colorado and Oklahoma. Measurements made at low altitudes (\u3c5 km mean sea level (MSL)) in the storm inflow region were compared to those made in cirrus anvils (altitude \u3e 9 km MSL). Storm mean outflow Ca2+ mass concentrations and total coarse (1 µm \u3c diameter \u3c 5 µm) aerosol volume (Vc) were comparable to mean inflow values as demonstrated by average outflow/inflow ratios greater than 0.5. A positive relationship between Ca2+, Vc, ice water content, and large (diameter \u3e 50 µm) ice particle number concentrations was not evident; thus, the influence of ice shatter on these measurements was assumed small. Mean inflow aerosol number concentrations calculated over a diameter range (0.5 µm \u3c diameter \u3c 5.0 µm) relevant for proxy ice nuclei (NPIN) were ~15–300 times higher than ice particle concentrations for all storms. Ratios of predicted interstitial NPIN (calculated as the difference between inflow NPIN and ice particle concentrations) and inflow NPIN were consistent with those calculated for Ca2+ and Vc and indicated that on average less than 10% of the ingested NPIN were activated as ice nuclei during anvil formation. Deep convection may therefore represent an efficient transport mechanism for dust to the upper troposphere where these particles can function as ice nuclei cirrus forming in situ

    Sea salt reactivity over the northwest Atlantic: an in-depth look using the airborne ACTIVATE dataset

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    Chloride (Cl−) displacement from sea salt particles is an extensively studied phenomenon with implications for human health, visibility, and the global radiation budget. Past works have investigated Cl− depletion over the northwest Atlantic (NWA); however, an updated, multi-seasonal, and geographically expanded account of sea salt reactivity over the region is needed. This study uses chemically resolved mass concentrations and meteorological data from the airborne Aerosol Cloud meTeorology Interactions oVer the western ATlantic Experiment (ACTIVATE) to quantify seasonal, spatial, and meteorological trends in Cl− depletion and to explore the importance of quantifying (1) non-sea salt sources of Na+ and (2) mass concentrations of lost Cl− (instead of relative amounts displaced). Lost Cl− mass concentrations are lowest in December–February and March, moderate around Bermuda in June, and highest in May (median losses of 0.04, 0.04, 0.66, and 1.76 µg m−3, respectively), with losses in May that are high enough to potentially accelerate tropospheric oxidation rates. Inorganic acidic species can account for all Cl− depletion in December–February, March, and June near Bermuda but none of the lost Cl− in May, suggesting that organic acids may be of importance for Cl− displacement in certain months. Contributions of dust to Na+ are not important seasonally but may cause relevant overestimates of lost Cl− in smoke and dust plumes. Higher percentages of Cl− depletion often do not correspond to larger mass concentrations of lost Cl−, so it is highly recommended to quantify the latter to place depletion reactions in context with their role in atmospheric oxidation and radiative forcing.</p

    The future of hospital at home: a qualitative interview study of healthcare staff

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    PurposeHospital at Home (HaH) services are expanding to provide acute multidisciplinary care in an individual's home. In this pilot study, we interviewed HaH staff to understand challenges and opportunities for service development. MethodsWe conducted 23 semi-structured interviews with multidisciplinary staff working across three HaH services in Scotland. Questions focussed on service strengths and challenges. ResultsFour themes emerged: raising referral awareness, service design and efficiency, staff security on home visits and sustainability. HaH staff described Emergency Department posters, experience days for non-HaH staff, and daily communication of virtual bed capacity to raise awareness for referrals. Ideas for maximising clinician time were prioritised to improve service efficiency, and investment in electric vehicles was strongly supported to mitigate climate impact. ConclusionWe found high job satisfaction and engagement amongst HaH staff. Our interviews suggest enthusiasm for further development of HaH while raising important challenges to address during service expansion. <br/

    From policy to pedagogy: widening the discourse and practice of the learning society in the European Union

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    This paper explores the policy turn of the learning society, and how the academic world is responding to new social and political demands. It highlights some of the criticisms levelled at the learning society, as well as the voices of support. The paper also showcases the European Language Portfolio and the Transferable Skills project as two examples of good practice. Cet article examine le tournant de la politique de la socie´te´ du savoir ainsi que la re´ponse du monde intellectuel face aux nouvelles exigences sociales et politiques. Il met en lumie`re certaines des critiques souleve´es par la socie´te´ du savoir ainsi que par les voix favorables. L’article s’appuie sur deux exemples pratiques, a` savoir le Portfolio Europe´en des Langues et le Project des Compe´tences Transmissibles

    Aircraft Engine Particulate Matter Emissions from Sustainable Aviation Fuels: Results from Ground-Based Measurements during the NASA/DLR Campaign ECLIF2/ND-MAX

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    The use of alternative jet fuels by commercial aviation has increased substantially in recent years. Beside the reduction of carbon dioxide emission, the use of sustainable aviation fuels (SAF) may have a positive impact on the reduction of particulate emissions. This study summarizes the results from a ground-based measurement activity conducted in January 2018 as part of the ECLIF2/ND-MAX campaign in Ramstein, Germany. Two fossil reference kerosenes and three different blends with the renewable fuel component HEFA-SPK (Hydroprocessed Esters and Fatty Acids Synthetic Paraffinic Kerosene) were burned in an A320 with V2527-A5 engines to investigate the effect of fuel naphthalene/aromatic content and the corresponding fuel hydrogen content on non-volatile particle number and mass emissions. Reductions up to 70% in non-volatile particle mass emission compared to the fossil reference fuel were observed at low power settings. The reduction trends to decrease with increasing power settings. The fuels showed a decrease in particle emission with increasing fuel hydrogen content. Consequently, a second fossil fuel with similar hydrogen content as one of the HEFA blends featured similar reduction factors in particle mass and number. Changes in the fuel naphthalene content had significant impact on the particle number emission. A comparison to in-flight emission data shows similar trends at cruise altitudes. The measurements highlight the importance of individual fuel components in regulating engine emissions, particularly at the low thrust settings typically employed during ground operations (e.g. during idle and taxi). Therefore, when selecting and mixing SAF blends to meet present fuel-certification standards, attention should be paid to minimizing complex aromatic content to achieve the greatest possible air quality and climate benefits

    Detection of MCM5 as a novel non-invasive aid for the diagnosis of endometrial and ovarian tumours

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    From Springer Nature via Jisc Publications RouterHistory: received 2020-05-02, accepted 2020-09-28, registration 2020-09-29, online 2020-10-15, pub-electronic 2020-10-15, collection 2020-12Publication status: PublishedFunder: Arquer Diagnostics Ltd; Grant(s): n/aAbstract: Background: MCM5 is a protein involved in DNA replication, facilitating cell proliferation. In normal epithelium MCM5 expression is restricted to the cells in the basal proliferative compartments, however in the presence of a tumour MCM5 positive cells are present at the surface epithelium and are shed into bodily fluids. The aim of this study was to determine the sensitivity of MCM5 as a biomarker for the detection of endometrial and ovarian cancer. Methods: Patients with known ovarian or endometrial cancers, or known benign gynaecological conditions, were enrolled. Informed consent was obtained prior to the collection of full void urine, and either a vaginal tampon (worn for 6–8 h), or a vaginal swab. Vaginal secretions were extracted from the tampon or swab, centrifuged and lysed. Urine samples were centrifuged and lysed. MCM5 levels were determined by MCM5-ELISA (Arquer Diagnostics Ltd). Results: 125 patients completed the study protocol, 41 patients had endometrial cancer, 26 ovarian cancer, and 58 benign controls. All patients provided a urine sample and either a tampon or vaginal swab sample. Urine MCM5 levels were higher in cancer patients than controls (p < 0.0001), there was no significant difference in levels between tampon samples or vaginal swab samples in cancer patients when compared to controls. Performance of MCM5 to discriminate cancer from benign disease was high with an area under the ROC curve of 0.83 for endometrial cancer and 0.68 for ovarian cancer. Using a cut off of 12 pg/mL, overall sensitivity for endometrial cancer was 87.8, and 61.5% for ovarian cancer with a specificity of 75.9%. Conclusions: MCM5 is a novel sensitive and specific biomarker for the detection of ovarian and endometrial tumours in urine samples, which is likely to have clinical utility as a diagnostic aid

    Assessing potential indicators of aerosol wet scavenging during long-range transport

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    As one of the dominant sinks of aerosol particles, wet scavenging greatly influences aerosol lifetime and interactions with clouds, precipitation, and radiation. However, wet scavenging remains highly uncertain in models, hindering accurate predictions of aerosol spatiotemporal distributions and downstream interactions. In this study, we present a flexible, computationally inexpensive method to identify meteorological variables relevant for estimating wet scavenging using a combination of aircraft, satellite, and reanalysis data augmented by trajectory modeling to account for air mass history. We assess the capabilities of an array of meteorological variables to predict the transport efficiency of black carbon (TEBC) using a combination of nonlinear regression, curve fitting, and k-fold cross-validation. We find that accumulated precipitation along trajectories (APT) – treated as a wet scavenging indicator across multiple studies – does poorly when predicting TEBC. Among different precipitation characteristics (amount, frequency, intensity), precipitation intensity was the most effective at estimating TEBC but required longer trajectories (&gt;48 h) and including only intensely precipitating grid cells. This points to the contribution of intense precipitation to aerosol scavenging and the importance of accounting for air mass history. Predictors that were most able to predict TEBC were related to the distribution of relative humidity (RH) or the frequency of humid conditions along trajectories, suggesting that RH is a more robust way to estimate TEBC than APT. We recommend the following alternatives to APT when estimating aerosol scavenging: (1) the 90th percentile of RH along trajectories, (2) the fraction of hours along trajectories with either water vapor mixing ratios &gt;15 g kg−1 or RH &gt;95 %, and (3) precipitation intensity along trajectories at least 48 h along and filtered for grid cells with precipitation &gt;0.2 mm h−1. Future scavenging parameterizations should consider these meteorological variables along air mass histories. This method can be repeated for different regions to identify region-specific factors influencing wet scavenging.</p

    Aircraft-Engine Particulate Matter Emissions from Conventional and Sustainable Aviation Fuel Combustion: Comparison of Measurement Techniques for Mass, Number, and Size

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    Sustainable aviation fuels (SAFs) have different compositions compared to conventional petroleum jet fuels, particularly in terms of fuel sulfur and hydrocarbon content. These differences may change the amount and physicochemical properties of volatile and non-volatile particulate matter (nvPM) emitted by aircraft engines. In this study, we evaluate whether comparable nvPM measurement techniques respond similarly to nvPM produced by three blends of SAFs compared to three conventional fuels. Multiple SAF blends and conventional (Jet A-1) jet fuels were combusted in a V2527-A5 engine, while an additional conventional fuel (JP-8) was combusted in a CFM56-2C1 engine. We evaluated nvPM mass concentration measured by three real-Time measurement techniques: photoacoustic spectroscopy, laser-induced incandescence, and the extinction-minus-scattering technique. Various commercial instruments were tested, including three laser-induced incandescence (LII) 300s, one photoacoustic extinctiometer (PAX), one micro soot sensor (MSS+), and two cavity-Attenuated phase shift PMSSA (CAPS PMSSA) instruments. Mass-based emission indices (EIm) reported by these techniques were similar, falling within 30ĝ€¯% of their geometric mean for EIm above 100ĝ€¯mg per kg fuel (approximately 10ĝ€¯μgĝ€¯PMĝ€¯m-3 at the instrument); this geometric mean was therefore used as a reference value. Additionally, two integrative measurement techniques were evaluated: filter photometry and particle size distribution (PSD) integration. The commercial instruments used were one tricolor absorption photometer (TAP), one particle soot absorption photometer (PSAP), and two scanning mobility particle sizers (SMPSs). The TAP and PSAP were operated at 5ĝ€¯% and 10ĝ€¯% of their nominal flow rates, respectively, to extend the life of their filters. These techniques are used in specific applications, such as on board research aircraft to determine particulate matter (PM) emissions at cruise. EIm reported by the alternative techniques fell within approximately 50ĝ€¯% of the mean aerosol-phase EIm. In addition, we measured PM-number-based emission indices using PSDs and condensation particle counters (CPCs). The commercial instruments used included TSI SMPSs, a Cambustion differential mobility spectrometer (DMS500), and an AVL particle counter (APC), and the data also fell within approximately 50ĝ€¯% of their geometric mean. The number-based emission indices were highly sensitive to the accuracy of the sampling-line penetration functions applied as corrections. In contrast, the EIm data were less sensitive to those corrections since a smaller volume fraction fell within the size range where corrections were substantial. A separate, dedicated experiment also showed that the operating laser fluence used in the LII 300 laser-induced incandescence instrument for aircraft-engine nvPM measurement is adequate for a range of SAF blends investigated in this study. Overall, we conclude that all tested instruments are suitable for the measurement of nvPM emissions from the combustion of SAF blends in aircraft engines

    Lost in reviews:Looking for the involvement of stakeholders, patients, public and other non-researcher contributors in realist reviews

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    The involvement of non‐researcher contributors (eg, stakeholders, patients and the public, decision and policy makers, experts, lay contributors) has taken a variety of forms within evidence syntheses. Realist reviews are a form of evidence synthesis that involves non‐researcher contributors yet this practice has received little attention. In particular, the role of patient and public involvement (PPI) has not been clearly documented. This review of reviews describes the ways in which contributor involvement, including PPI, is documented within healthcare realist reviews published over the last five years. A total of 448 papers published between 2014 and 2019 were screened, yielding 71 full‐text papers included in this review. Statements about contributor involvement were synthesized across each review using framework analysis. Three themes are described in this article including nomenclature, nature of involvement, and reporting impact.Papers indicate that contributor involvement in realist reviews refers to stakeholders, experts, or advisory groups (ie, professionals, clinicians, or academics). Patients and the public are occasionally subsumed into these groups and in doing so, the nature and impact of their involvement become challenging to identify and at times, is lost completely. Our review findings indicate a need for the realist review community to develop guidance to support researchers in their future collaboration with contributors, including patients and the public
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