98 research outputs found

    Significant decline of mesospheric water vapor at the NDACC site near Bern in the period 2007 to 2018

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    The middle atmospheric water vapor radiometer MIAWARA is located close to Bern in Zimmerwald (46.88∘&thinsp;N, 7.46∘&thinsp;E; 907 m) and is part of the Network for the Detection of Atmospheric Composition Change (NDACC). Initially built in the year 2002, a major upgrade of the instrument's spectrometer allowed middle atmospheric water vapor to be continuously measured since April 2007. Thenceforward to May 2018, a time series of more than 11 years has been gathered, that makes a first trend estimate possible. For the trend estimation, a robust multilinear parametric trend model has been used. The trend model encompasses a linear term, a solar activity tracker, the El Niño–Southern Oscillation (ENSO) index and the Quasi-Biennial Oscillation (QBO) as well as the annual and semi-annual oscillation. In the time period April 2007 to May 2018 we find a significant decline in water vapor by -0.6±0.2&thinsp;ppm per decade between 61 and 72 km. Below the stratopause level (∼48 km) a smaller reduction of H2O of up to -0.3±0.1&thinsp;ppm per decade is detected.</p

    On the polarimetric backscatter by a still or quasi-still wind turbine

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    Wind turbines negatively affect the performance of weather radars, especially when located in the proximity of a radar site. In March 2019, MeteoSwiss performed a measurement campaign by deploying a mobile X-band radar in Schaffhausen. It proved to be useful for mapping and characterizing the maximum power returns by three wind turbines observed using standard scanning strategies. In March 2020, the campaign was repeated using a more sophisticated scan strategy: ∼ 100 min special sessions of fixed pointing an antenna towards the nacelle of the closest wind turbine (WT) located within a range of 7766 m from the radar, interleaved every 2 h by a scanning protocol identical to that of the March 2019 campaign. Polarimetric radar signatures were derived every 64 ms using 128 radar pulses transmitted every 0.5 ms (pulse repetition frequency (PRF) = 2000 Hz). A thorough overview of the polarimetric signatures of the WT in still or quasi-still conditions has been obtained based on 30 000 polarimetric measurables acquired over 32 min on the first day of the campaign (4 March 2020). During the first 2 min with zero rotor speed, the co-polar correlation coefficient between the orthogonal polarization states, ρHV, was persistently equal to 1, similarly to the signature of a bright scatterer observed by a non-rotating antenna. The changes between two consecutive values of the differential reflectivity and radar reflectivity factor were either 0 dBz or ±0.5 dBz. Due to the absence of precipitation, one could assume that the standard deviation of the differential phase shift, which was as small as 3.0∘, can be entirely attributed to the variability of the differential backscattering phase shift. There were two 10 min periods during which the rotor moved less than 1 revolution. It is worth noting that this slow movement could be associated with a change in the blade pitch angle and the nacelle orientation, which caused extreme changes in the radar reflectivity factor. For instance, two pairs of 64 ms consecutive values reached 78.5 dBz, which is the absolute maximum reached in the whole campaign (4–21 March 2020).</p

    A research agenda on patient safety in primary care. Recommendations by the LINNEAUS collaboration on patient safety in primary care

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    This is the final version of the article. Available from Taylor & Francis via the DOI in this record.BACKGROUND: Healthcare can cause avoidable serious harm to patients. Primary care is not an exception, and the relative lack of research in this area lends urgency to a better understanding of patient safety, the future research agenda and the development of primary care oriented safety programmes. OBJECTIVE: To outline a research agenda for patient safety improvement in primary care in Europe and beyond. METHODS: The LINNEAUS collaboration partners analysed existing research on epidemiology and classification of errors, diagnostic and medication errors, safety culture, and learning for and improving patient safety. We discussed ideas for future research in several meetings, workshops and congresses with LINNEAUS collaboration partners, practising GPs, researchers in this field, and policy makers. RESULTS: This paper summarizes and integrates the outcomes of the LINNEAUS collaboration on patient safety in primary care. It proposes a research agenda on improvement strategies for patient safety in primary care. In addition, it provides background information to help to connect research in this field with practicing GPs and other healthcare workers in primary care. CONCLUSION: Future research studies should target specific primary care domains, using prospective methods and innovative methods such as patient involvement.The research leading to these results has received funding from the European Community’s Seventh Framework Programme FP7/2008–2012 under grant agreement no. 223424

    Long-term observation of midlatitude quasi 2-day waves by a water vapor radiometer

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    A mesospheric water vapor data set obtained by the middle atmospheric water vapor radiometer (MIAWARA) close to Bern, Switzerland (46.88°&thinsp;N, 7.46°&thinsp;E) during October 2010 to September 2017 is investigated to study the long-term evolution and variability of quasi 2-day waves (Q2DWs). We present a climatological overview and an insight on the dynamical behavior of these waves with the occurring spectrum of periods as seen from a midlatitude observation site. Such a large and nearly continuous measurement data set as ours is rare and of high scientific value. The core results of our investigation indicate that the activity of the Q2DW manifests in burst-like events and is higher during winter months (November–February) than during summer months (May–August) for the altitude region of the mesosphere (up to 0.02&thinsp;hPa in winter and up to 0.05&thinsp;hPa in summer) accessible for the instrument. Single Q2DW events reach at most about 0.8&thinsp;ppm in the H2O amplitudes. Further, monthly mean Q2DW amplitude spectra are presented and reveal a high-frequency variability between different months. A large fraction of identified Q2DW events (20&thinsp;%) develop periods between 38 and 40&thinsp;h. Further, we show the temporal evolution of monthly mean Q2DW oscillations continuously for all months and separated for single months over 7 years. The analysis of autobicoherence spectra gives evidence that Q2DWs are sometimes phase coupled to diurnal oscillations to a high degree and to waves with a period close to 18&thinsp;h.</p

    Fisiología del cultivo de yuca en el bosque seco tropical de Sucre – Colombia

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    The species M. esculenta presents great genetic variability that makes its study difficult because it must be evaluated not only for its varietal behavior but also for its response to the environment where it occurs. For this research, the physiological behavior of cassava was evaluatedin three of the most cultivated varieties in the department of Sucre: MCOL 2066 (Chirosa: industrial and edible use), MCOL 2215 (Venezolana: edible use) and M- Tai 8 (M-Tai: industrial use), under the environmental offer of the tropical dry forest, a randomized complete block design with three replications was used. Plant height (AP), stem diameter (DT), number of leaves (NH), diameter of tuberous roots (DR), photosynthesis (PN), stomatal conductance (GS), transpiration (E), accumulation and distribution were evaluated. dry mass and harvest index (CI). The evaluations were carried out at 90, 270, 315 and 360 days after sowing (DDS). The M-Tai variety presented the most favorable results, an earlier growth and development in the first stages of the crop (90 DDS) expressed in a larger size and greater accumulation of biomass with an average of 198.51 gr of dry matter. At crop date 270, 315 and 360 DDS no differences were observed between variables of gas exchange and biomass accumulation and distribution, presenting average values of 130 mmol H2O m-2 s-1, 17.87 µmoles CO2 m-2 s-1 and 1.99 mmol H2O m-2 s-1 for GS, PN and E respectively, and with values around 55% for IC.La especie&nbsp; M. esculenta presenta gran variabilidad genética que dificulta su estudio debido a que debe ser evaluada no solo por su comportamiento varietal sino también por su respuesta al ambiente donde se produce. Para esta investigación se evaluó el comportamiento fisiológico de yuca en tres de las variedades más cultivadas en el departamento de Sucre: MCOL 2066 (Chirosa: uso industrial y comestible), MCOL 2215 (Venezolana: comestible) y M-Tai 8 (M-Tai: uso industrial), bajo la oferta ambiental del bosque seco tropical, se utilizó un diseño en bloques completos al azar con tres repeticiones. Se evaluó altura de planta (AP), diámetro de tallo (DT), número de hojas (NH), diámetro de raíces tuberosas (DR), fotosíntesis (PN), conductancia estomática (GS), transpiración (E) acumulación y distribución de masa seca e índice de cosecha (IC). Las evaluaciones se llevaron a cabo a los 90, 270, 315 y 360 días después de la siembra (DDS). La variedad M-Tai presentó los resultados más favorables un crecimiento y desarrollo más precoz en los primeros estadios del cultivo (90 DDS) expresado en un mayor porte y mayor acumulación de biomasa con una media de 198,51 gr de materia seca. En la fecha de cosecha 270, 315 y 360 DDS no se observó diferencias entre variables de intercambio gaseoso y acumulación y distribución de biomasa, presentando valores promedios de 130 mmol H2O m-2s-1, 17,87 µmoles CO2 m-2 s-1 y 1,99 mmol H2Omm-2 s-1 para GS, PN y E respectivamente, y con valoresalrededor de un 55% para IC

    Drone-based photogrammetry combined with deep learning to estimate hail size distributions and melting of hail on the ground

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    Hail is a major threat associated with severe thunderstorms, and estimating the hail size is important for issuing warnings to the public. For the validation of existing operational, radar-derived hail estimates, ground-based observations are necessary. Automatic hail sensors, for example within the Swiss Hail Network, record the kinetic energy of hailstones to estimate the hail sizes. Due to the small size of the observational area of these sensors (0.2 m2), the full hail size distribution (HSD) cannot be retrieved. To address this issue, we apply a state-of-the-art custom trained deep learning object detection model to drone-based aerial photogrammetric data to identify hailstones and estimate the HSD. Photogrammetric data of hail on the ground were collected for one supercell thunderstorm crossing central Switzerland from southwest to northeast in the afternoon of 20 June 2021. The hail swath of this intense right-moving supercell was intercepted a few minutes after the passage at a soccer field near Entlebuch (canton of Lucerne, Switzerland) and aerial images were taken by a commercial DJI drone, equipped with a 45-megapixel full-frame camera system. The resulting images have a ground sampling distance (GSD) of 1.5 mm per pixel, defined by the focal length of 35 mm of the camera and a flight altitude of 12 m above the ground. A 2-dimensional orthomosaic model of the survey area (750.4 m2) is created based on 116 captured images during the first drone mapping flight. Hail is then detected using a region-based convolutional neural network (Mask R-CNN). We first characterize the hail sizes based on the individual hail segmentation masks resulting from the model detections and investigate the performance using manual hail annotations by experts to generate validation and test data sets. The final HSD, composed of 18 207 hailstones, is compared with nearby automatic hail sensor observations, the operational weather-radar-based hail product MESHS (Maximum Expected Severe Hail Size) and crowdsourced hail reports. Based on the retrieved data set, a statistical assessment of sampling errors of hail sensors is carried out. Furthermore, five repetitions of the drone-based photogrammetry mission within 18.65 min facilitate investigations into the hail-melting process on the ground.</p

    ИССЛЕДОВАНИЕ ИМПРЕГНИРОВАНИЯ ОРГАНИЧЕСКИМИ СОЕДИНЕНИЯМИ ОБОЖЖЕННЫХ АНОДОВ АЛЮМИНИЕВЫХ ЭЛЕКТРОЛИЗЕРОВ

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    The results of the investigation into the impregnation (saturation) of the samples of ready roasted anodes promising for aluminum electrolyzers by organic compounds are presented. A procedure of performing this process including the preliminary evacuation, sub- sequent saturation of the samples with organic compounds under the excess external pressure, and further, high-temperature pyrolysis in the lead–bismuth melt is developed. It is established that the developed modification method allows one to increase the corrosion stability of roasted anodes. Приведены результаты исследований процесса импрегнирования (пропитывания) органическими соединениями образ- цов готовых обожженных анодов, перспективных для алюминиевых электролизеров. Разработана методика проведения данного процесса, включающая предварительное вакуумирование, последующее насыщение образцов органическими соединениями под избыточным внешним давлением и, далее, высокотемпературный пиролиз в расплаве свинец–висмут. Установлено, что разработанный метод модифицирования позволяет увеличить коррозионную стойкость обожженных анодов.

    Stromal transcriptional profiles reveal hierarchies of anatomical site, serum response and disease and identify disease specific pathways

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    Synovial fibroblasts in persistent inflammatory arthritis have been suggested to have parallels with cancer growth and wound healing, both of which involve a stereotypical serum response programme. We tested the hypothesis that a serum response programme can be used to classify diseased tissues, and investigated the serum response programme in fibroblasts from multiple anatomical sites and two diseases. To test our hypothesis we utilized a bioinformatics approach to explore a publicly available microarray dataset including rheumatoid arthritis (RA), osteoarthritis (OA) and normal synovial tissue, then extended those findings in a new microarray dataset representing matched synovial, bone marrow and skin fibroblasts cultured from RA and OA patients undergoing arthroplasty. The classical fibroblast serum response programme discretely classified RA, OA and normal synovial tissues. Analysis of low and high serum treated fibroblast microarray data revealed a hierarchy of control, with anatomical site the most powerful classifier followed by response to serum and then disease. In contrast to skin and bone marrow fibroblasts, exposure of synovial fibroblasts to serum led to convergence of RA and OA expression profiles. Pathway analysis revealed three inter-linked gene networks characterising OA synovial fibroblasts: Cell remodelling through insulin-like growth factors, differentiation and angiogenesis through -3 integrin, and regulation of apoptosis through CD44. We have demonstrated that Fibroblast serum response signatures define disease at the tissue level, and that an OA specific, serum dependent repression of genes involved in cell adhesion, extracellular matrix remodelling and apoptosis is a critical discriminator between cultured OA and RA synovial fibroblasts

    The SPARC water vapor assessment II: intercomparison of satellite and ground-based microwave measurements

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    As part of the second SPARC (Stratosphere–troposphere Processes And their Role in Climate) water vapor assessment (WAVAS-II), we present measurements taken from or coincident with seven sites from which ground-based microwave instruments measure water vapor in the middle atmosphere. Six of the ground-based instruments are part of the Network for the Detection of Atmospheric Composition Change (NDACC) and provide datasets that can be used for drift and trend assessment. We compare measurements from these ground-based instruments with satellite datasets that have provided retrievals of water vapor in the lower mesosphere over extended periods since 1996. We first compare biases between the satellite and ground-based instruments from the upper stratosphere to the upper mesosphere. We then show a number of time series comparisons at 0.46 hPa, a level that is sensitive to changes in H2O and CH4 entering the stratosphere but, because almost all CH4 has been oxidized, is relatively insensitive to dynamical variations. Interannual variations and drifts are investigated with respect to both the Aura Microwave Limb Sounder (MLS; from 2004 onwards) and each instrument's climatological mean. We find that the variation in the interannual difference in the mean H2O measured by any two instruments is typically  ∼  1%. Most of the datasets start in or after 2004 and show annual increases in H2O of 0–1 % yr−1. In particular, MLS shows a trend of between 0.5 % yr−1 and 0.7 % yr−1 at the comparison sites. However, the two longest measurement datasets used here, with measurements back to 1996, show much smaller trends of +0.1 % yr−1 (at Mauna Loa, Hawaii) and −0.1 % yr−1 (at Lauder, New Zealand)

    Overview of ASDEX upgrade results in view of ITER and DEMO

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    Experiments on ASDEX Upgrade (AUG) in 2021 and 2022 have addressed a number of critical issues for ITER and EU DEMO. A major objective of the AUG programme is to shed light on the underlying physics of confinement, stability, and plasma exhaust in order to allow reliable extrapolation of results obtained on present day machines to these reactor-grade devices. Concerning pedestal physics, the mitigation of edge localised modes (ELMs) using resonant magnetic perturbations (RMPs) was found to be consistent with a reduction of the linear peeling-ballooning stability threshold due to the helical deformation of the plasma. Conversely, ELM suppression by RMPs is ascribed to an increased pedestal transport that keeps the plasma away from this boundary. Candidates for this increased transport are locally enhanced turbulence and a locked magnetic island in the pedestal. The enhanced D-alpha (EDA) and quasi-continuous exhaust (QCE) regimes have been established as promising ELM-free scenarios. Here, the pressure gradient at the foot of the H-mode pedestal is reduced by a quasi-coherent mode, consistent with violation of the high-n ballooning mode stability limit there. This is suggestive that the EDA and QCE regimes have a common underlying physics origin. In the area of transport physics, full radius models for both L- and H-modes have been developed. These models predict energy confinement in AUG better than the commonly used global scaling laws, representing a large step towards the goal of predictive capability. A new momentum transport analysis framework has been developed that provides access to the intrinsic torque in the plasma core. In the field of exhaust, the X-Point Radiator (XPR), a cold and dense plasma region on closed flux surfaces close to the X-point, was described by an analytical model that provides an understanding of its formation as well as its stability, i.e., the conditions under which it transitions into a deleterious MARFE with the potential to result in a disruptive termination. With the XPR close to the divertor target, a new detached divertor concept, the compact radiative divertor, was developed. Here, the exhaust power is radiated before reaching the target, allowing close proximity of the X-point to the target. No limitations by the shallow field line angle due to the large flux expansion were observed, and sufficient compression of neutral density was demonstrated. With respect to the pumping of non-recycling impurities, the divertor enrichment was found to mainly depend on the ionisation energy of the impurity under consideration. In the area of MHD physics, analysis of the hot plasma core motion in sawtooth crashes showed good agreement with nonlinear 2-fluid simulations. This indicates that the fast reconnection observed in these events is adequately described including the pressure gradient and the electron inertia in the parallel Ohm’s law. Concerning disruption physics, a shattered pellet injection system was installed in collaboration with the ITER International Organisation. Thanks to the ability to vary the shard size distribution independently of the injection velocity, as well as its impurity admixture, it was possible to tailor the current quench rate, which is an important requirement for future large devices such as ITER. Progress was also made modelling the force reduction of VDEs induced by massive gas injection on AUG. The H-mode density limit was characterised in terms of safe operational space with a newly developed active feedback control method that allowed the stability boundary to be probed several times within a single discharge without inducing a disruptive termination. Regarding integrated operation scenarios, the role of density peaking in the confinement of the ITER baseline scenario (high plasma current) was clarified. The usual energy confinement scaling ITER98(p,y) does not capture this effect, but the more recent H20 scaling does, highlighting again the importance of developing adequate physics based models. Advanced tokamak scenarios, aiming at large non-inductive current fraction due to non-standard profiles of the safety factor in combination with high normalised plasma pressure were studied with a focus on their access conditions. A method to guide the approach of the targeted safety factor profiles was developed, and the conditions for achieving good confinement were clarified. Based on this, two types of advanced scenarios (‘hybrid’ and ‘elevated’ q-profile) were established on AUG and characterised concerning their plasma performance
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