907 research outputs found

    Middle atmosphere thermal structure during MAP/WINE

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    Middle atmosphere temperatures were measured during the MAP/WINE campaign by various ground-based techniques, by rocket instruments, and by satellites. Respective data were analyzed for atmospheric thermal mean state as well as for long and short period variations. A brief survey of the results is given. Monthly mean temperatures agree well with the new CIRA model. Long period (planetary) waves frequently exhibit peculiar vertical amplitude and phase structures, resembling those of standing waves. Short period oscillations tend to begin breaking well below the stratosphere

    Global budget of stratospheric trace constituents (GLOBUS). MAP/GLOBUS 1983: A review

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    MAP/GLOBUS 1983 was a project for the study of stratospheric trace gases and dynamics. A respective field campaign was performed in September/October 1983 in Western Europe. A large number of measurements were taken by instruments based on the ground, on airplane, balloons, and satellite. The structure of the campaign is described, and a survey of the results are given

    Sub-mesoscale observations of convective cold pools with a dense station network in Hamburg, Germany

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    From June to August 2020, an observational network of 103 meteorological ground-based stations covered the greater area (50 km × 35 km) of Hamburg (Germany) as part of the Field Experiment on Sub-mesoscale Spatio-Temporal variability at Hanseatic city of Hamburg (FESST@HH). The purpose of the experiment was to shed light on the sub-mesoscale (O(100) m–O(10) km) structure of convective cold pools that typically remain under-resolved in operational networks. During the experiment, 82 custom-built, low-cost APOLLO (Autonomous cold POoL LOgger) stations sampled air temperature and pressure with fast-response sensors at 1 s resolution to adequately capture the strong and rapid perturbations associated with propagating cold pool fronts. A secondary network of 21 weather stations with commercial sensors provided additional information on relative humidity, wind speed, and precipitation at 10 s resolution. The realization of the experiment during the COVID-19 pandemic was facilitated by a large number of volunteers who provided measurement sites on their premises and supported station maintenance. This article introduces the novel type of autonomously operating instruments, their measurement characteristics, and the FESST@HH data set (https://doi.org/10.25592/UHHFDM.10172; Kirsch et al., 2021b). A case study demonstrates that the network is capable of mapping the horizontal structure of the temperature signal inside a cold pool, and quantifying a cold pool's size and propagation velocity throughout its life cycle. Beyond its primary purpose, the data set offers new insights into the spatial and temporal characteristics of the nocturnal urban heat island and variations of turbulent temperature fluctuations associated with different urban and natural environments

    Indications for the Nonexistence of Three-Neutron Resonances near the Physical Region

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    The pending question of the existence of three-neutron resonances near the physical energy region is reconsidered. Finite rank neutron-neutron forces are used in Faddeev equations, which are analytically continued into the unphysical energy sheet below the positive real energy axis. The trajectories of the three-neutron S-matrix poles in the states of total angular momenta and parity J^\pi=1/2 +- and J^\pi= 3/2 +- are traced out as a function of artificial enhancement factors of the neutron-neutron forces. The final positions of the S-matrix poles removing the artificial factors are found in all cases to be far away from the positive real energy axis, which provides a strong indication for the nonexistence of nearby three-neutron resonances. The pole trajectories close to the threshold E=0 are also predicted out of auxiliary generated three-neutron bound state energies using the Pad\'e method and agree very well with the directly calculated ones.Comment: 20 pages, 7 Postscript figures, fig.1 is corrected, uses relax.st

    Use of CRISTA mesopause region temperatures for the intercalibration of gound-based instruments

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    Most available ground-based (GB) techniques for measuring temperatures in the upper mesosphere to lower thermosphere (or mesopause region) have systematic errors that are comparable to those of orbiting instruments. Determining these unknown biasses would normally require colocated observations that are only seldom feasible. Satellite measurements can be used as a ‘‘transfer standard’’ between GB observations that are not colocated. In this context, even with a reproducible or known bias in the satellite data, the comparison is still meaningful. Since Cryogenic Infrared Spectrometers and Telescopes for the Atmosphere (CRISTA) temperatures cover the mesopause region with very good accuracy (statistical errors do not exceed 1.5 K and systematic uncertainties range from about 3–7.5 K), they are quite suitable for this purpose. Because of the nearly constant precision over the height range of interest, also rotational temperatures of airglow emissions from different altitudes like the OH and O2 bands (or the OI 558 nm line) can be successfully compared with each other. In spite of the limited number of overpasses during the relatively short CRISTA missions, the feasibility of such an intercalibration is demonstrated for widely separated GB sites. Here, the results obtained for GB measurements at eight different sites, using CRISTA-1 and CRISTA-2 data, are presented. For OH temperatures, the standard deviation between the different instruments is only 5.4 K, confirming previous estimates.Fil: Scheer, Jurgen. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Reisin, Esteban Rodolfo. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Gusev, O. A.. University of Wuppertal; AlemaniaFil: French, W. J. R.. Australian Antarctic Division; AustraliaFil: Hernandez, G.. University of Washington; Estados UnidosFil: Huppi, R.. State University Of Utah; Estados UnidosFil: Ammosov, P.. Institute of Cosmophysical Research and Aeronomy; RusiaFil: Gavrilyeva, G. A.. Institute of Cosmophysical Research and Aeronomy; RusiaFil: Offermann, D.. University of Wuppertal; Alemani

    Consistent alpha-cluster description of the 12C (0^+_2) resonance

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    The near-threshold 12C (0^+_2) resonance provides unique possibility for fast helium burning in stars, as predicted by Hoyle to explain the observed abundance of elements in the Universe. Properties of this resonance are calculated within the framework of the alpha-cluster model whose two-body and three-body effective potentials are tuned to describe the alpha - alpha scattering data, the energies of the 0^+_1 and 0^+_2 states, and the 0^+_1-state root-mean-square radius. The extremely small width of the 0^+_2 state, the 0_2^+ to 0_1^+ monopole transition matrix element, and transition radius are found in remarkable agreement with the experimental data. The 0^+_2-state structure is described as a system of three alpha-particles oscillating between the ground-state-like configuration and the elongated chain configuration whose probability exceeds 0.9

    Resonances in the three-neutron system

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    A study of 3-body resonances has been performed in the framework of configuration space Faddeev equations. The importance of keeping a sufficient number of terms in the asymptotic expansion of the resonance wave function is pointed out. We investigated three neutrons interacting in selected force components taken from realistic nn forces.Comment: 38 pages, 11 tables, 4 figure

    What factors influence training opportunities for older workers? Three factorial surveys exploring the attitudes of HR professionals

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    The core research questions addressed in this paper are: what factors influence HR professionals in deciding whether to approve training proposals for older workers? What kind of training are they more likely to recommend for older employees and in which organizational contexts? We administered three factorial surveys to 66 HR professionals in Italy. Participants made specific training decisions based on profiles of hypothetical older workers. Multilevel analyses indicated that access to training decreases strongly with age, while highly-skilled older employees with low absenteeism rates are more likely to enjoy training opportunities. In addition, older workers displaying positive performance are more likely to receive training than older workers who perform poorly, suggesting that training late in working life may serve as a reward for good performance rather than as a means of enhancing productivity. The older the HR professional evaluating training proposals, the higher the probability that older workers will be recommended for training. keywords: training; older workers; HR professionals; factorial survey; multilevel model

    Performance of Different Diagnostic PD-L1 Clones in Head and Neck Squamous Cell Carcinoma

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    Background: The approval of immune checkpoint inhibitors in combination with specific diagnostic biomarkers presents new challenges to pathologists as tumor tissue needs to be tested for expression of programmed death-ligand 1 (PD-L1) for a variety of indications. As there is currently no requirement to use companion diagnostic assays for PD-L1 testing in Germany different clones are used in daily routine. While the correlation of staining results has been tested in various entities, there is no data for head and neck squamous cell carcinomas (HNSCC) so far. Methods: We tested five different PD-L1 clones (SP263, SP142, E1L3N, 22-8, 22C3) on primary HNSCC tumor tissue of 75 patients in the form of tissue microarrays. Stainings of both immune and tumor cells were then assessed and quantified by pathologists to simulate real-world routine diagnostics. The results were analyzed descriptively and the resulting staining pattern across patients was further investigated by principal component analysis and non-negative matrix factorization clustering. Results: Percentages of positive immune and tumor cells varied greatly. Both the resulting combined positive score as well as the eligibility for certain checkpoint inhibitor regimens was therefore strongly dependent on the choice of the antibody. No relevant co-clustering and low similarity of relative staining patterns across patients was found for the different antibodies. Conclusions: Performance of different diagnostic anti PD-L1 antibody clones in HNSCC is less robust and interchangeable compared to reported data from other tumor entities. Determination of PD-L1 expression is critical for therapeutic decision making and may be aided by back-to-back testing of different PD-L1 clones
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