440 research outputs found
Bodenkundliche Sondierung ausgewählter Standorte im Roßlauer Oberluch und bei Klieken
Die bodenkundliche Sondierung von 24 Standorten im Roßlauer Oberluch und 12 Probeflächen im Referenzgebiet bei Klieken dient der Standortcharakterisierung ausgewählter Untersuchungsflächen in der Elbeaue. Sie stellt die Grundlage für begleitende faunistische und floristische Untersuchungen dar, die im Zuge der Deichrückverlegung im Roßlauer Oberluch durchgeführt werden. Die Untersuchungsflächen befinden sich in der rezenten Elbeaue und im Rückdeichungsgebiet des Roßlauer Oberluchs sowie in der Altaue (historischen Aue) bei Klieken. Durch die Deichrückverlegung gehört nun wieder das gesamte Roßlauer Oberluch zum aktiven Überflutungsbereich. Die Untersuchungsflächen bei Klieken liegen in der eingedeichten holozänen Aue, geschützt vor Hochwasser und Sedimenteintra
The Impact of Medicare's Prospective Payment System on Psychiatric Patients Treated in Scatterbeds
Medicare's Prospective Payment System (PPS) for hospitals was phased-in during the 1884 Federal Fiscal Year. While many providers of psychiatric inpatient care were exempted from PPS patients treated in general hospital beds outside of psychiatric units (scatterbeds) were not. This allows for an initial assessment of the impact of PPS on psychiatric patients. We use a single equation model of hospital length of stay to estimate the impact of PPS. We allow for the possibility of both anticipating behavior and slow adjustment to the new payment scheme. The results indicate a substantial response to PPS over the first year of implementation. The estimated response includes sizable anticipatory and slow adjustment components. The findings suggest that policy discussions may be weighted too heavily in the direction of concern over hospital financial status given the ability of hospitals to change their behavior.
Enriched Galerkin method for the shallow-water equations
This work presents an enriched Galerkin (EG) discretization for the two-dimensional shallow-water equations. The EG finite element spaces are obtained by extending the approximation spaces of the classical finite elements by discontinuous functions supported on elements. The simplest EG space is constructed by enriching the piecewise linear continuous Galerkin space with discontinuous, element-wise constant functions. Similarly to discontinuous Galerkin (DG) discretizations, the EG scheme is locally conservative, while, in multiple space dimensions, the EG space is significantly smaller than that of the DG method. This implies a lower number of degrees of freedom compared to the DG method. The EG discretization presented for the shallow-water equations is well-balanced, in the sense that it preserves lake-at-rest configurations. We evaluate the method’s robustness and accuracy using various analytical and realistic benchmarks and compare the results to those obtained using the DG method. Finally, we briefly discuss implementation aspects of the EG method within our MATLAB / GNU Octave framework FESTUNG
The Diurnal Rhythm of Brassica napus L. Influences Contents of Sulfur-Containing Defense Compounds and Occurrence of Vascular Occlusions during an Infection with Verticillium longisporum
Reduction in atmospheric sulfur and intensified agriculture have led to sulfur deficiency, often correlated with a higher susceptibility to pathogens. The spread of fungal pathogens, such as the soil-born Verticillium longisporum, was observed. Defense responses of infected plants are linked to sulfur-containing compounds including glucosinolates (GSLs). Some pathogens infect their hosts at specific time periods during the day. To investigate the relation of sulfur-containing metabolites with diurnal effects of infection time points, Brassica napus plants cultivated at two different sulfur supplies, were infected with V. longisporum at four different time points during the day. It was demonstrated that 3, 7 and 14 days after inoculation the infected plants differed in their infection rate depending on the time point of infection. Additionally, infected plants had higher contents of sulfur-containing metabolites, such as specific GSLs, in comparison to non-infected plants. Sufficient sulfur fertilization was always reflected in higher contents of sulfur-containing compounds as well as a lower rate of infection compared to sulfur-deprived plants. On the microscopic level vascular occlusions in the hypocotyl were visible and the amount was dependent on the time point of infection. The results might be used to optimize sulfur fertilization to reduce susceptibility to V. longisporum
Mehr als nur Rohstofflieferant
Mit der Transformation zu einer biobasierten Wirtschaft bieten sich auch über die Rohstoffbereitstellung hinaus Entwicklungsmöglichkeiten für den ländlichen Raum. Diese in einer nachhaltigen Art und Weise zu fördern, ist eine Zukunftsaufgabe von Politik, Wirtschaft, Wissenschaft und Zivilgesellschaft
A review on the wettability of dental implant surfaces I: Theoretical and experimental aspects
The surface wettability of biomaterials determines the biological cascade of events at the biomaterial/ host interface. Wettability is modulated by surface characteristics, such as surface chemistry and surface topography. However, the design of current implant surfaces focuses mainly on specific micro- and nanotopographical features, and is still far from predicting the concomitant wetting behavior. There is an increasing interest in understanding the wetting mechanisms of implant surfaces and the role of wettability in the biological response at the implant/bone or implant/soft tissue interface. Fundamental knowledge related to the influence of surface roughness (i.e. a quantification of surface topography) on titanium and titanium alloy surface wettability, and the different associated wetting regimes, can improve our understanding of the role of wettability of rough implant surfaces on the biological outcome. Such an approach has been applied to biomaterial surfaces only in a limited way. Focusing on titanium dental and orthopaedic implants, the present study reviews the current knowledge on the wettability of biomaterial surfaces, encompassing basic and applied aspects that include measurement techniques, thermodynamic aspects of wetting and models predicting topographical and roughness effects on the wetting behavior.The surface wettability of biomaterials determines the biological cascade of events at the biomaterial/ host interface. Wettability is modulated by surface characteristics, such as surface chemistry and surface topography. However, the design of current implant surfaces focuses mainly on specific micro- and nanotopographical features, and is still far from predicting the concomitant wetting behavior. There is an increasing interest in understanding the wetting mechanisms of implant surfaces and the role of wettability in the biological response at the implant/bone or implant/soft tissue interface. Fundamental knowledge related to the influence of surface roughness (i.e. a quantification of surface topography) on titanium and titanium alloy surface wettability, and the different associated wetting regimes, can improve our understanding of the role of wettability of rough implant surfaces on the biological outcome. Such an approach has been applied to biomaterial surfaces only in a limited way. Focusing on titanium dental and orthopaedic implants, the present study reviews the current knowledge on the wettability of biomaterial surfaces, encompassing basic and applied aspects that include measurement techniques, thermodynamic aspects of wetting and models predicting topographical and roughness effects on the wetting behavior
Fluorescence excitation spectrum, lifetimes and photoisomerization of jet-cooled conformers of 1,1 '- bi(benzocyclobutylidene)
First measurements of fluorescence excitation spectra of the recently synthesized rigid stilbene analogue 1,1'- bi(benzocyclobutylidene) in a supersonic jet expansion show that, in contrast to the parent compound, both the trans- and the cis-conformer fluoresce under these conditions. The excitation energy dependence of fluorescence lifetimes indicates the onset of an efficient non-radiative decay channel above energy thresholds of 1340 cm(-1) and 990 cm(-1) for the trans- and cis-form, respectively, which is assigned to photoisomerization in the singlet state. From an RRKM analysis of the microcanonical rate coefficients an estimate of the high pressure limit of the thermal photoisomerization rate coefficient is obtained and compared with photoisomerization rate coefficients measured in low viscosity solution and in thermal vapor. There are strong indications that for this compound there are no dynamic or static solvent induced effects that lead to an anomalous acceleration of the reaction in solution
Three-Dimensional Shapes of Spinning Helium Nanodroplets
A significant fraction of superfluid helium nanodroplets produced in a
free-jet expansion have been observed to gain high angular momentum resulting
in large centrifugal deformation. We measured single-shot diffraction patterns
of individual rotating helium nanodroplets up to large scattering angles using
intense extreme ultraviolet light pulses from the FERMI free-electron laser.
Distinct asymmetric features in the wide-angle diffraction patterns enable the
unique and systematic identification of the three-dimensional droplet shapes.
The analysis of a large dataset allows us to follow the evolution from
axisymmetric oblate to triaxial prolate and two-lobed droplets. We find that
the shapes of spinning superfluid helium droplets exhibit the same stages as
classical rotating droplets while the previously reported metastable, oblate
shapes of quantum droplets are not observed. Our three-dimensional analysis
represents a valuable landmark for clarifying the interrelation between
morphology and superfluidity on the nanometer scale
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