Impact of river reconstruction on groundwater flow during bank filtration assessed by transient three-dimensional modelling of flow and heat transport

Notice: the article has been corrected and updated. Use this link for up-to-date information: https://doi.org/10.1007/s10040-019-02063-

StratIT – A Framework Describing the Contents of IT Strategies. Background and Approach

Until today no consensus has been found regarding the contents of IT strategies. This results in uncer-tainty when formulating the topical areas of IT strategy documents. The Special Interest Group (SIG) “Strate¬gisches Informationsmanagement (SIM)” (Strategic Information Management) of the “Gesellschaft für Informatik” (German Informatics Society)” addresses this gap by developing a framework that defines generic perspectives, domains, and elements of an IT strategy. Within the group, researchers and practi¬tioners bundle their insights and experiences in the development of the framework named “StratIT”. We report on the current status of work and develop a structured basis for discussion. In addition, we de¬scribe the methodical and scientific foundations and the “modus operandi” of the SIG. Our intent is to communicate the perceived problem, our approach, and the developed artifact to an international audi¬ence, to get feedback and also to exchange ideas

Magnetic field stabilization for high-accuracy mass measurements on exotic nuclides

The magnetic-field stability of a mass spectrometer plays a crucial role in precision mass measurements. In the case of mass determination of short-lived nuclides with a Penning trap, major causes of instabilities are temperature fluctuations in the vicinity of the trap and pressure fluctuations in the liquid helium cryostat of the superconducting magnet. Thus systems for the temperature and pressure stabilization of the Penning trap mass spectrometer ISOLTRAP at the ISOLDE facility at CERN have been installed. A reduction of the fluctuations by at least one order of magnitude downto dT=+/-5mK and dp=+/-50mtorr has been achieved, which corresponds to a relative frequency change of 2.7x10^{-9} and 1.5x10^{-10}, respectively. With this stabilization the frequency determination with the Penning trap only shows a linear temporal drift over several hours on the 10 ppb level due to the finite resistance of the superconducting magnet coils.Comment: 23 pages, 13 figure

An Epigenetic Blockade of Cognitive Functions in the Neurodegenerating Brain

Cognitive decline is a debilitating feature of most neurodegenerative diseases of the central nervous system, including Alzheimer’s disease. The causes leading to such impairment are only poorly understood and effective treatments are slow to emerge. Here we show that cognitive capacities in the neurodegenerating brain are constrained by an epigenetic blockade of gene transcription that is potentially reversible. This blockade is mediated by histone deacetylase 2, which is increased by Alzheimer’s-disease-related neurotoxic insults in vitro, in two mouse models of neurodegeneration and in patients with Alzheimer’s disease. Histone deacetylase 2 associates with and reduces the histone acetylation of genes important for learning and memory, which show a concomitant decrease in expression. Importantly, reversing the build-up of histone deacetylase 2 by short-hairpin-RNA-mediated knockdown unlocks the repression of these genes, reinstates structural and synaptic plasticity, and abolishes neurodegeneration-associated memory impairments. These findings advocate for the development of selective inhibitors of histone deacetylase 2 and suggest that cognitive capacities following neurodegeneration are not entirely lost, but merely impaired by this epigenetic blockade

Simulating future salinity dynamics in a coastal marshland under different climate scenarios

Salinization is a well‐known problem in agricultural areas worldwide. In the last 20–30 yr, rising salinity in the upper, unconfined aquifer has been observed in the Freepsumer Meer, a grassland near the German North Sea coast. For investigating long‐term development of salinity and water balance during 1961–2099, the one‐dimensional Soil–Water–Atmosphere–Plant (SWAP) model was set up and calibrated for a soil column in the area. The model setup involves a deep aquifer as the source of salt through upward seepage. In the vertical salt transport equation, dispersion and advection are included. Six different regional outputs of statistical downscaling methods were used as climate scenarios. These comprise different rates of increasing surface temperature and different trends in seasonal rainfall. The simulation results exhibit opposing salinity trends for topsoil and deeper layers. Although projections of some scenarios entail decreasing salinities near the surface, most of them project a rise in subsoil salinity, with the strongest trends of up to +0.9 mg cm−3 100 yr−1 at −65 cm. The results suggest that topsoil salinity trends in the study area are affected by the magnitude of winter rainfall trends, whereas high subsoil salinities correspond to low winter rainfall and high summer temperature. How these projected trends affect the vegetation and thereby future land use will depend on the future management of groundwater levels in the area

A histone acetylome-wide association study of Alzheimer’s disease identifies disease-associated H3K27ac differences in the entorhinal cortex

We quantified genome-wide patterns of lysine H3K27 acetylation (H3K27ac) in entorhinal cortex samples from Alzheimer’s disease (AD) cases and matched controls using chromatin immunoprecipitation and highly parallel sequencing. We observed widespread acetylomic variation associated with AD neuropathology, identifying 4,162 differential peaks (false discovery rate < 0.05) between AD cases and controls. Differentially acetylated peaks were enriched in disease-related biological pathways and included regions annotated to genes involved in the progression of amyloid-β and tau pathology (for example, APP, PSEN1, PSEN2, and MAPT), as well as regions containing variants associated with sporadic late-onset AD. Partitioned heritability analysis highlighted a highly significant enrichment of AD risk variants in entorhinal cortex H3K27ac peak regions. AD-associated variable H3K27ac was associated with transcriptional variation at proximal genes including CR1, GPR22, KMO, PIM3, PSEN1, and RGCC. In addition to identifying molecular pathways associated with AD neuropathology, we present a framework for genome-wide studies of histone modifications in complex disease

Changing friction at the base of an Alpine glacier

ISSN:2045-232

In-situ Measurements of Stick-Slip Motion at the Bed of an Alpine Glacier

Until recently, observations of sudden frictional processes at the bed of glaciers were limited to monitoring form the glacier surface. We study these processes causing stick-slip motion with a new approach that was applied the first time in a field campaign in summer 2018: We carried out the first in-situ measurements of an active seismogenic fault at a bi- material interface beneath a glacier. Enabled by guided hot water drilling, we targeted borehole experiments to specific glacier bed regions where spatially limited microseismic stick-slip sliding happens and combine them with the recordings of a high-densitiy network of seismometers at the glacier surface. From the various measurements we can determine the subglacial water- and thus pore pressure evolution and its effect on the fault stability. Futhermore the in-situ borehole measurements enable us to study material properties such as the till and ice characteristics within the stick-slip asperities and compare them to off-site reference measurements in seimically non-active regions of the glacier bed. Finally from acceleration, ice deformation measurements, and borehole camera videos from the glacier bed, we can estimate the amount of aseismic and co-seismic sliding, which cannot be obtained remotely from the ice surface. Summed up, with our in-situ measurements of an seismogenically active strike-slip fault beneath an alpine glacier, we open a unique posibility for studying seismogenic stick-slip motion at a bi-material interface in a natural environment

Tagebuch der Blokirung von Stralsund und deren Folgen

TAGEBUCH DER BLOKIRUNG VON STRALSUND UND DEREN FOLGEN Tagebuch der Blokirung von Stralsund und deren Folgen ([1]r) Einband ( - ) Neuer Grundriss der Stadt Stralsund ([1]vgef) Titelseite ([1]r) Tagebuch der Blocade der Festung Stralsund und deren Folgen, geführt von einem unterrichteten Augenzeugen bis zum 19. April 1807. (1) Tagebuch der zweyten Blocade Stralsunds, geführt vom Verfasser des der ersten bis zum 27. September 1807. (44) Ungefähre Stärke der Schwedischen Armee auf Rügen zwischen dem 7. und 27. September 1807. (78) No. 2. Unterthänigster Rapport. (81) No. 3. Unterthänigster Rapport. (88) No. 4. Convention. / Convention. (93) No. 5. Ueber die Französischen Feldarbeiten vor der Festung während der zweyten Blocade. (98

Diurnal expansion and contraction of englacial fracture networks revealed by seismic shear wave splitting

Fractures contribute to bulk elastic anisotropy of many materials in the Earth. This includes glaciers and ice sheets, whose fracture state controls the routing of water to the base and thus large-scale ice flow. Here we use anisotropy-induced shear wave splitting to characterize ice structure and probe subsurface water drainage beneath a seismometer network on an Alpine glacier. Shear wave splitting observations reveal diurnal variations in S-wave anisotropy up to 3%. Our modelling shows that when elevated by surface melt, subglacial water pressures induce englacial hydrofractures whose volume amounts to 1-2 percent of the probed ice mass. While subglacial water pressures decrease, these fractures close and no fracture-induced anisotropy variations are observed in the absence of meltwater. Consequently, fracture networks, which are known to dominate englacial water drainage, are highly dynamic and change their volumes by 90-180 % over subdaily time scales.ISSN:2662-443