2,335 research outputs found
High resolution discharge simulations over Europe and the Baltic Sea catchment
Regional coupled system models require a high-resolution discharge component to couple their atmosphere/land components to the ocean component and to adequately resolve smaller catchments and the day-to-day variability of discharge. As the currently coupled discharge models usually do not fulfill this requirement, we improved a well-established discharge model, the Hydrological Discharge (HD) model, to be globally applicable at 5 Min. resolution. As the first coupled high-resolution discharge simulations are planned over Europe and the Baltic Sea catchment, we focus on the respective regions in the present study. As no river specific parameter adjustments were conducted and since the HD model parameters depend on globally available gridded characteristics, the model is, in principle, applicable for climate change studies and over ungauged catchments. For the validation of the 5 Min. HD (HD5) model, we force it with prescribed fields of surface and subsurface runoff. As no large-scale observations of these variables exist, they need to be calculated by a land surface scheme or hydrology model using observed or re-analyzed meteorological data. In order to pay regard to uncertainties introduced by these calculations, three different methods and datasets were used to derive the required fields of surface and subsurface runoff for the forcing of the HD5 model. However, the evaluation of the model performance itself is hampered by biases in these fields as they impose an upper limit on the accuracy of simulated discharge. 10-years simulations (2000–2009) show that for many European rivers, where daily discharge observations were available for comparison, the HD5 model captures the main discharge characteristics reasonably well. Deficiencies of the simulated discharge could often be traced back to deficits in the various forcing datasets. As direct anthropogenic impact on the discharge, such as by regulation or dams, is not regarded in the HD model, those effects can generally not be simulated. Thus, discharges for many heavily regulated rivers in Scandinavia or for the rivers Volga and Don are not well represented by the model. The comparison of the three sets of simulated discharges indicates that the HD5 model is suitable to evaluate the terrestrial hydrological cycle of climate models or land surface models, especially with regard to the separation of throughfall (rain or snow melt) into surface and subsurface runoff
Life time of soil moisture perturbations in a coupled land-atmosphere simulation
This study evaluates the lifetime of soil moisture perturbations using an atmosphere-land GCM. We find memory of up to 9 months for root zone soil moisture. Interactions with other surface states result in significant but short-lived anomalies in surface temperature and more stable anomalies in leaf carbon content. As these anomalies can recur repeatedly, e.g. due to interactions with a deep-soil moisture reservoir, we conclude that soil moisture initialization may impact climate predictions
HydroPy (v1.0): a new global hydrology model written in Python
Global hydrological models (GHMs) are a useful tool in the assessment of the land surface water balance. They are used to further the understanding of interactions between water balance components and their past evolution as well as potential future development under various scenarios. While GHMs have been part of the hydrologist's toolbox for several decades, the models are continuously being developed. In our study, we present the HydroPy model, a revised version of an established GHM, the Max Planck Institute for Meteorology's Hydrology Model (MPI-HM). Being rewritten in Python, the new model requires much less effort in maintenance, and due to its flexible infrastructure, new processes can be easily implemented. Besides providing a thorough documentation of the processes currently implemented in HydroPy, we demonstrate the skill of the model in simulating the land surface water balance. We find that evapotranspiration is reproduced realistically for the majority of the land surface but is underestimated in the tropics. The simulated river discharge correlates well with observations. Biases are evident for the annual accumulated discharge; however, they can - at least to some extent - be attributed to discrepancies between the meteorological model forcing data and the observations. Finally, we show that HydroPy performs very similarly to MPI-HM and thus conclude the successful transition from MPI-HM to HydroPy
"Re-educating" tumor-associated macrophages by targeting NF-kappaB
The nuclear factor kappaB (NF-kappaB) signaling pathway is important in cancer-related inflammation and malignant progression. Here, we describe a new role for NF-kappaB in cancer in maintaining the immunosuppressive phenotype of tumor-associated macrophages (TAMs). We show that macrophages are polarized via interleukin (IL)-1R and MyD88 to an immunosuppressive "alternative" phenotype that requires IkappaB kinase beta-mediated NF-kappaB activation. When NF-kappaB signaling is inhibited specifically in TAMs, they become cytotoxic to tumor cells and switch to a "classically" activated phenotype; IL-12(high), major histocompatibility complex II(high), but IL-10(low) and arginase-1(low). Targeting NF-kappaB signaling in TAMs also promotes regression of advanced tumors in vivo by induction of macrophage tumoricidal activity and activation of antitumor activity through IL-12-dependent NK cell recruitment. We provide a rationale for manipulating the phenotype of the abundant macrophage population already located within the tumor microenvironment; the potential to "re-educate" the tumor-promoting macrophage population may prove an effective and novel therapeutic approach for cancer that complements existing therapies
Violation and persistence of the K-quantum number in warm rotating nuclei
The validity of the K-quantum number in rapidly rotating warm nuclei is
investigated as a function of thermal excitation energy U and angular momentum
I, for the rare-earth nucleus 163Er. The quantal eigenstates are described with
a shell model which combines a cranked Nilsson mean-field and a residual
two-body interaction, together with a term which takes into account the angular
momentum carried by the K-quantum number in an approximate way. K-mixing is
produced by the interplay of the Coriolis interaction and the residual
interaction; it is weak in the region of the discrete rotational bands (U
\lesim 1MeV), but it gradually increases until the limit of complete violation
of the K-quantum number is approached around U \sim 2 - 2.5 MeV. The calculated
matrix elements between bands having different K-quantum numbers decrease
exponentially as a function of , in qualitative agreement with recent
data.Comment: 29 pages, 7 figure
A simple plating assay for aneuploidy in sexual progeny of Neurospora crassa, and a new allele of mei-1.
We developed a simple ascospore plating assay for aneuploidy, based on identifying disomic progeny that inherit two independently selectable mtr alleles. We validated the assay using a known meiotic mutant, mei-2. We used this assay to demonstrate that elevated frequencies of aneuploidy previously reported to be associated with reduced DNA methylation were not, in fact, due to the methylation deficiencies. A new allele of the mei-1 gene was responsible for some of the high aneuploidy
Calcium-free Solid Solutions in the System Ba7F12Cl2−xBrx (x<1.5), a Single-component White Phosphor Host
We have recently prepared solid solutions of Ba∼6.3Ca∼0.7F12Cl2−xBrx with x ranging from 0 to 2. In this work, the synthesis and single crystal X-ray structure of calcium-free crystals of Ba∼6.9Na∼0.2F12Br0.6Cl1.4 (space group P63/m, a=10.6024(10), c=4.2034(4)Å), Ba∼6.9Na∼0.2F12Br1.4 Cl0.6 (space group P63/m, a=10.6155(9), c=4.2355(4)Å) and Ba∼6.9Na∼0.2Br1.32Cl0.68F12 (space group P63/m, a=10.6218(9), c=4.2284(4)Å) are reported. These crystals systematically present additional electron density at the 0 0 0.25 position which is associated with the presence of small, but significant amounts of Na+ ions in the crysta
Increased breast tissue receptor activator of nuclear factor- κB ligand (RANKL) gene expression is associated with higher mammographic density in premenopausal women
Realising rights:Case studies on state responses to violence against women and children in Europe
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