“Engelmann Told Me...”: On the Aesthetic Relevance of a Certain Remark by Wittgenstein

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Modification of the Size of Supported Clusters by Coadsorption of an Organic Compound: Gold and l-Cysteine on Rutile TiO(2)(110).

Using X-ray photoelectron spectroscopy we studied the coadsorption of the amino acid l-cysteine and gold on a rutile TiO(2)(110) surface under ultrahigh vacuum conditions. Irrespective of the deposition order, i.e., irrespective of whether l-cysteine or gold is deposited first, the primary interaction between l-cysteine and the gold clusters formed at the surface takes place through the deprotonated thiol group of the molecule. The deposition order, however, has a profound influence on the size of the gold clusters as well as their location on the surface. If l-cysteine is deposited first the clusters are smaller by a factor two to three compared to gold deposited onto the pristine TiO(2)(110) surface and then covered by l-cysteine. Further, in the former case the clusters cover the molecules and thus form the outermost layer of the sample. We also find that above a minimum gold cluster size the gold cluster/l-cysteine bond is stronger than the l-cysteine/surface bridging oxygen vacancy bond, which, in turn, is stronger than the gold cluster/vacancy bond

Water and sediment pollution of intensively used surface waters during a drought period — a case study in Central Northern Namibia

Semiarid regions are often affected by water scarcity and poor water quality. Seasonal changes in precipitation and drought events increase the pressure of use on water bodies and their pollution. In Central Northern Namibia, a high seasonal intra- and inter-annual variability of precipitation caused a 5-year lasting drought period. In the semiarid region, ephemeral channels and water pans represent the main water source, besides the institutionalized water supply. No systematic analysis of its quality has been conducted so far. The states of the surface waters at the end of the dry season in 2017 and the end of the rainy seasons in 2018 and 2019 were characterized by the analysis of physical–chemical parameters, focusing on usability. The first results show coarse contamination of the waters, which results in high turbidity values. Salt concentrations, such as Ca2+ and Na+, greatly increased due to evaporation. Al is present in high concentrations in solid and liquid phases, which indicates direct anthropogenic pollution. Spatial differences are evident in the study area and based on the precipitation gradient, land use, and population density. The waters cannot be used as drinking water without prior treatment

GNSS mobile road dam surveying for TanDEM-X correction to improve the database for floodwater modeling in northern Namibia

The aim of this study is the improvement of the TanDEM-X elevation model for future floodwater modeling by implementing surveyed road dams and the use of filter algorithms. Modern satellite systems like TanDEM-X deliver high-resolution images with a high vertical and horizontal accuracy. Nevertheless, regarding special usage they sometimes reach their limits in documenting important features that are smaller than the grid size. Especially in the context of 2D-hydrodynamic flood modelling, the features that influence the runoff processes, e.g. road dams and culverts, have to be included for precise calculations. To fulfil the objective, the main road dams were surveyed, especially those that are blocking the flood water flowing from south Angola to the Etosha Pan in northern Namibia. First, a Leica GS 16 Sensor was installed on the roof of a car recording position data in real time while driving on the road dams in the Cuvelai Basin. In total, 532 km of road dams have been investigated during 4 days while driving at a top speed of 80 km/h. Due to the long driving distances, the daily regular adjustment of the base station would have been necessary but logistically not possible. Moreover, the lack of reference stations made a RTK and Network-RTK solution likewise impossible. For that reasons, the Leica SmartLink function was used. This method is not dependent on classic reference stations next to the GNSS sensor but instead works with geostationary satellites sending correction data in real time. The surveyed road dam elevation data have a vertical accuracy of 4.3 cm up to 10 cm. These precise measurements contribute to rectifying the TanDEM-X elevation data and thus improve the surface runoff network for the future floodwater model and should enhance the floodwater prediction for the Cuvelai Basin

Targeting tachykinin receptors in neuroblastoma

Neuroblastoma is the most common extracranial tumor in children. Despite aggressive multimodal treatment, high-risk neuroblastoma remains a clinical challenge with survival rates below 50%. Adding targeted drugs to first-line therapy regimens is a promising approach to improve survival in these patients. TACR1 activation by substance P has been reported to be mitogenic in cancer cell lines. Tachykinin receptor (TACR1) antagonists are approved for clinical use as an antiemetic remedy since 2003. Tachykinin receptor inhibition has recently been shown to effectively reduce growth of several tumor types. Here, we report that neuroblastoma cell lines express TACR1, and that targeting TACR1 activity significantly reduced cell viability and induced apoptosis in neuroblastoma cell lines. Gene expression profiling revealed that TACR1 inhibition repressed E2F2 and induced TP53 signaling. Treating mice harboring established neuroblastoma xenograft tumors with Aprepitant also significantly reduced tumor burden. Thus, we provide evidence that the targeted inhibition of tachykinin receptor signaling shows therapeutic efficacy in preclinical models for high-risk neuroblastoma

Position-Dependent Dysfunction of Deep Brain Stimulation in Tourette Syndrome: Diagnostic Clues

Background: Detection of defective deep brain stimulation (DBS) contacts/electrodes is sometimes challenging. Case Report: We report a patient with Tourette syndrome (TS), who presented with abrupt tic increase and mild generalized headache 9 years after DBS implantation. On the suspicion of a hardware defect, a fracture of the DBS electrode and extension lead was ruled out by radiography and standard implantable pulse generator readouts. Further investigation revealed position-dependent modifiable therapeutic impedances, suggesting an impaired contact of the extension lead/adaptor. After replacement normal impedances were recorded, and the patient fully recovered. Discussion: In DBS dysfunction with inconspicuous hardware check, position-dependent defects might be suspected

Pyridine Adsorption on Single-Layer Iron Phthalocyanine on Au(111)

The adsorption of pyridine on monolayers of well-ordered, flat-lying iron phthalocyanine molecules on Au(111) is investigated by X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and density functional theory. It is found that pyridine both coordinates to the iron site of iron phthalocyanine and binds weakly to other sites. The iron coordination causes significant changes in the electronic structure of the iron phthalocyanine compound, with the implication of a change of the spin properties of the iron atoms due to the strong ligand field created by the pyridine axial ligand. Both low coverages and multilayer coverages of pyridine are considered. At low doses, the pyridine molecules are ordered, whereas in multilayers, no preferred orientation is observed. The orientation of the FePc molecules with respect to the Au(111) surface is not affected by the adsorption of pyridine

Ammonia adsorption on iron phthalocyanine on Au(111): Influence on adsorbate-substrate coupling and molecular spin.

The adsorption of ammonia on Au(111)-supported monolayers of iron phthalocyanine has been investigated by x-ray photoelectron spectroscopy, x-ray absorption spectroscopy, and density functional theory calculations. The ammonia-induced changes of the x-ray photoemission lines show that a dative bond is formed between ammonia and the iron center of the phthalocyanine molecules, and that the local spin on the iron atom is quenched. This is confirmed by density functional theory, which also shows that the bond between the iron center of the metalorganic complex and the Au(111) substrate is weakened upon adsorption of ammonia. The experimental results further show that additional adsorption sites exist for ammonia on the iron phthalocyanine monolayer

Natural Pans as an Important Surface Water Resource in the Cuvelai Basin - Metrics for Storage Volume Calculations and Identification of Potential Augmentation Sites

Numerous ephemeral rivers and thousands of natural pans characterize the transboundary Iishana-System of the Cuvelai Basin between Namibia and Angola. After the rainy season, surface water stored in pans is often the only affordable water source for many people in rural areas. High inter- and intra-annual rainfall variations in this semiarid environment provoke years of extreme flood events and long periods of droughts. Thus, the issue of water availability is playing an increasingly important role in one of the most densely populated and fastest growing regions in southwestern Africa. Currently, there is no transnational approach to quantifying the potential storage and supply functions of the Iishana-System. To bridge these knowledge gaps and to increase the resilience of the local people’s livelihood, suitable pans for expansion as intermediate storage were identified and their metrics determined. Therefore, a modified Blue Spot Analysis was performed, based on the high-resolution TanDEM-X digital elevation model. Further, surface area–volume ratio calculations were accomplished for finding suitable augmentation sites in a first step. The potential water storage volume of more than 190,000 pans was calculated at 1.9 km3. Over 2200 pans were identified for potential expansion to facilitate increased water supply and flood protection in the future