1,521 research outputs found
Genesis and dating of Late Pleistocene-Holocene soil sediment sequences from the Lüneburg Heath, Northern Germany
Während in den Lössgebieten Mitteleuropas die Lössstratigraphie und die menschliche Besiedlung der Lössgebiete sowohl eiszeitlich wie auch im Holozän gut bekannt sind, liegen zu den Sandlössgebieten der Altmoränengebiete keine neueren Erkenntnisse zur zeitlichen Stellung der Sedimente oder zur Siedlungsgeschichte und zum Einfluss auf die Bodenentwicklung vor. In der Arbeit werden aus einem Sandlössgebiet in der Lüneburger Heide zwei Bodenprofile vorgestellt deren Gliederung einen Einblick in die Genese der vergangenen 10 000 Jahre erlaubt. Die Profile wurden sedimentologisch, pedologisch und palynologisch untersucht und charakterisiert. Die Datierung der Profile erfolgte mittels optisch stimulierter Lumineszenz (OSL) und Radiokarbondatierung. Die Ergebnisse legen einen menschlichen Einfluss auf die Böden ab dem späten Neolithikum nahe. Darunter sind Erosions- und Akkumulationsprozesse und insbesondere eine Anreicherung mit organischem Material zu fassen. Erstmals können mit dieser Studie Datierungen von Sedimenten und Böden des Altmoränengebietes präsentiert werden.researc
Development of a New Method to Support a Participatory Planning for Piped Water Supply Infrastructure in Informal Settlements
For decades, infrastructure planning in informal settlements has been a major challenge for urban planners and engineers. In particular, the planning process for the rapidly changing heterogeneous structures in these areas usually require individual and non-sustainable solutions. In this report, a method for the sustainable and practical planning of a piped water distribution system (WDS) that generates different expansion variants as a planning support tool is presented. In this tool, all real-world routing options are included in the decision-making process, based on the existing infrastructure, settlement structure, and identifiable open spaces. Additionally, proposals for the localization of the future public water points are supported by methods from Logistics. The consideration of the existing settlement structure and real route lengths (pedestrian walking distance) to a potential water point location lead to very practical and realizable results. The principle of participatory planning was considered, to easily include individual adjustments at any given timeframe. At the same time, automated processes generate fast results. The method is modular and linked to a geographic information system (GIS) to directly visualize the impacts and effects of the planning and decision-making process
Combined Districting and Main Line Routing — A Method to Implement a Basic Drinking Water Supply Infrastructure in Informal Settlements
The upgrading of large informal settlement areas takes place in sections for technical, economic and social reasons. On one hand, planning is faced with the challenge of taking individual structural and social conditions into account when dividing up the districts. On the other hand, the routing of the mains of a pipe-based infrastructure (water supply) must be selected in the context of the entire area under consideration and integrated into a superordinate network layout. In this paper, a method that combines these contrasting approaches is presented. Potential district boundaries are identified based on existing infrastructure and development patterns, as well as considering the routing requirements of a piped drinking water supply. Thereby, social factors can be considered in the decision-making process. Subsequently, an area subdivision is performed by a recursive partitioning algorithm. The choice and combination of different compactness measures influence the shape of the districts and, thus, the spatial organization. The geodetic height is integrated into the algorithm via an admissibility condition, so that the subsequent development of a district can take place via one pressure zone. By means of variations in the input parameters of the zoning, different planning levels can be generated, which finally lead successively to the upgrading of an informal settlement area
Detailed comparison of the pp -> \pi^+pn and pp -> \pi^+d reactions at 951 MeV
The positively charged pions produced in proton-proton collisions at a beam
momentum of 1640 MeV/c were measured in the forward direction with a high
resolution magnetic spectrograph. The missing mass distribution shows the bound
state (deuteron) clearly separated from the continuum. Despite the very
good resolution, there is no evidence for any significant production of the
system in the spin-singlet state. However, the cross section ratio is about twice as large as
that predicted from -wave final-state-interaction theory and it is suggested
that this is due to -state effects in the system.Comment: 8 pages, 3 figure
The Novel Atypical Dopamine Uptake Inhibitor (S)-CE-123 Partially Reverses the Effort-Related Effects of the Dopamine Depleting Agent Tetrabenazine and Increases Progressive Ratio Responding
Animal studies of effort-based choice behavior are being used to model effort-related
motivational dysfunctions in humans. With these procedures, animals are offered a choice
between high-effort instrumental actions leading to highly valued reinforcers vs. low effort/
low reward options. Several previous studies have shown that dopamine (DA) uptake
inhibitors, including GBR12909, lisdexamfetamine, methylphenidate, and PRX-14040,
can reverse the effort-related effects of the vesicular monoamine transport blocker
tetrabenazine, which inhibits DA storage. Because many drugs that block DA transport
act as major stimulants that also release DA, and produce a number of undesirable
side effects, there is a need to develop and characterize novel atypical DA transport
inhibitors. (S)-CE-123 ((S)-5-((benzhydrylsulfnyl) methyl)thiazole) is a recently developed
analog of modafnil with the biochemical characteristics of an atypical DA transport
blocker. The present paper describes the enantioselective synthesis and initial chemical
characterization of (S)-CE-123, as well as behavioral experiments involving effort-based
choice and microdialysis studies of extracellular DA. Rats were assessed using the fxed
ratio 5/chow feeding choice test. Tetrabenazine (1.0 mg/kg) shifted choice behavior,
decreasing lever pressing and increasing chow intake. (S)-CE-123 was coadministered
at doses ranging from 6.0 to 24.0 mg/kg, and the highest dose partially but signifcantly
reversed the effects of tetrabenazine, although this dose had no effect on fxed ratio
responding when administered alone. Additional experiments showed that (S)-CE-123
signifcantly increased lever pressing on a progressive ratio/chow feeding choice task and
that the effective dose (24.0 mg/kg) increased extracellular DA in nucleus accumbens core.
In summary, (S)-CE-123 has the behavioral and neurochemical profle of a compound
that can block DA transport, reverse the effort-related effects of tetrabenazine, and
increase selection of high-effort progressive ratio responding. This suggests that (S)-CE-
123 or a similar compound could be useful as a treatment for effort-related motivational
dysfunction in humans
Dilepton production in heavy ion collisions at intermediate energies
We present a unified description of the vector meson and dilepton production
in elementary and in heavy ion reactions. The production of vector mesons
() is described via the excitation of nuclear resonances ().
The theoretical framework is an extended vector meson dominance model (eVMD).
The treatment of the resonance decays with arbitrary spin is
covariant and kinematically complete. The eVMD includes thereby excited vector
meson states in the transition form factors. This ensures correct asymptotics
and provides a unified description of photonic and mesonic decays. The
resonance model is successfully applied to the production in
reactions. The same model is applied to the dilepton production in elementary
reactions (). Corresponding data are well reproduced. However, when
the model is applied to heavy ion reactions in the BEVALAC/SIS energy range the
experimental dilepton spectra measured by the DLS Collaboration are
significantly underestimated at small invariant masses. As a possible solution
of this problem the destruction of quantum interference in a dense medium is
discussed. A decoherent emission through vector mesons decays enhances the
corresponding dilepton yield in heavy ion reactions. In the vicinity of the
-peak the reproduction of the data requires further a substantial
collisional broadening of the and in particular of the meson.Comment: 32 pages revtex, 19 figures, to appear in PR
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