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Absolute gravity measurements have been regularly performed in the Austrian Eastern Alps since 1985. A gravity increase of 300 nm s-2 has been observed so far. The gravity trend is explained by ablation effects within surrounding glaciers. Ice thickness changes derived from 3 successive glacier inventories of 1969, 1997 and 2006 are used for quantitative 3-D modeling based on rectangular prisms with basis areas of ⩽8m×8 m. Local topographic changes due to man-made mass displacements close to the measuring site are modeled by a polyhedron approach. Two-thirds (2/3) of the observed gravity increase can be explained by the ablation model response and man-made effects. A positive trend of about 100 nm s-2 remains. The origin of the residual trend remains open. Correcting for geodynamical processes like Alpine uplift or postglacial deformation is expected to cause a slight increase of this trend. The observed gravity signal shows seasonal gravity variations as well, which are probably due to snow cover effects but cannot be quantified due to the lack of appropriate snow cover information. [ABSTRACT FROM AUTHOR]

The Vienna Basin at the transition between the Alpine and Carpathian belt hosts a number of large Pleistocene sub-basins forming along an active continental scale strike-slip fault (Vienna Basin strike-slip fault). We utilize first-order derivatives from industrial Bouguer gravity data to unravel the impacts of Pleistocene kinematics on the Vienna Basin and to compensate for the lack of near-surface fault data. Anomalies have been evaluated by independent geophysical and geological data and were integrated to build up a tectonic model. Factors influencing the wavelength and the amplitude of anomalies were additionally investigated by 2-D models to better interpret field data. Subsidence and related accumulation of Quaternary sediments in the Vienna Basin produce significant gravity signals related to the activity of the strike-slip fault. The constrained fault patterns and structures highlight tight and elongated transtensional pull-apart basins with typically associated features like separated depocenters and Riedel fractured sidewalls in an en-echelon alignment. Further Pleistocene basins are highlighted as tectonic grabens developing along branches of the master fault. The Vienna Basin is additionally affected by minor deformation represented by both subsidence along major Miocene sidewalls and NW-SE faulting resulting in distinct topographic features, which manifests kinematics on a regional scale. The clear density contrasts between Miocene marine and Quaternary terrestrial sediments, as well as the exceptional database, provide a unique framework to demonstrate advantages of incorporating gravity derivatives for near-surface fault analysis. [ABSTRACT FROM AUTHOR]

Abstract: The influence of the atmosphere on gravity measurements by Newtonian attraction and vertical displacements due to surface loading is well known and studied especially at frequencies below 1mHz. Less work has been done at the higher seismic frequencies where inertial effects come into play. The sensor mass of a vertical accelerometer responds to several forces caused by the atmosphere, on global, regional and local scales. For the seismic frequencies the atmosphere above the observation site has the largest influence. A simple “Gedankenexperiment” demonstrates that the gravitational effect on one hand and the free air and inertial effects due to deformation on the other have opposite sign. Since the inertial effect is strongly frequency-dependent there should be a crossover-frequency where the pressure admittance to gravity changes sign. Simple analytical models clearly show this property near frequencies of a few mHz and are used here to amplify the variance reduction of the gravity residuals. The crossover-frequency depends on the properties of the models of the atmospheric phenomena and the elasticity of the Earth’s crust. Therefore in reality it must be expected to vary in time and space. We show one extremely clear example of this sign-reversal detected in the gravity data from the superconducting gravimeter GWR-C025 in Vienna among other examples which demonstrate the reality of this effect. [Copyright &y& Elsevier]

BSTRACT [ABSTRACT FROM AUTHOR]

Two accurately calibrated superconducting gravimeters (SGs) provide high quality tidal gravity records in three central European stations: C025 in Vienna and at Conrad observatory (A) and OSG050 in Pecný (CZ). To correct the tidal gravity factors from ocean loading effects we compared the load vectors from different ocean tides models (OTMs) computed with different software: OLFG/OLMP by the Free Ocean Tides Loading Provider (FLP), ICET and NLOADF. Even with the recent OTMs the mass conservation is critical but the methods used to correct the mass imbalance agree within 0.1 nm/s 2 . Although the different software agrees, FLP probably provides more accurate computations as this software has been optimised. For our final computation we used the mean load vector computed by FLP for 8 OTMs (CSR4, NAO99, GOT00, TPX07, FES04, DTU10, EOT11a and HAMTIDE). The corrected tidal factors of the 3 stations agree better than 0.04% in amplitude and 0.02° in phase. Considering the weighted mean of the three stations we get for O1 δ c = 1.1535 ± 0.0001, for K1 δ c = 1.1352 ± 0.0003 and for M2 δ c = 1.1621 ± 0.0003. These values confirm previous ones obtained with 16 European stations. The theoretical body tides model DDW99/NH provides the best agreement for M2 (1.1620) and MATH01/NH for O1 (1.1540) and K1 (1.1350). The largest discrepancy is for O1 (0.05%). The corrected phase α c does not differ significantly from zero except for K1 and S2. The calibrations of the two SG's are consistent within 0.025% and agree with Strasbourg results within 0.05%. [ABSTRACT FROM AUTHOR]

Genetic mouse models based on alpha-synuclein overexpression are particularly compelling because abnormal accumulation of alpha-synuclein occurs in sporadic Parkinson's disease (PD). Our laboratory has characterized a mouse overexpressing wild-type human alpha-synuclein under the Thy1 promoter, which confers broad expression of the transgene in neurons. These mice show progressive sensorimotor anomalies starting at 2 months of age, as well as olfactory and digestive deficits similar to those observed in patients at early stages of PD. Patterns of gene expression examined in nigrostriatal neurons isolated by single-cell laser capture microdissection in these mice at 6 months of age show an upregulation of defence mechanisms including increased levels of genes involved in proteasome and mitochondrial function, as well as cholesterol biosynthesis. At the same time, numerous alterations in genes encoding ion channels suggest that changes in the cellular function of these neurons occur independently of cell death. These data provide information on the early effects--in a mammalian brain--of a mutation known to cause PD, and they identify a number of useful end points for evaluating potential neuroprotective therapies that could interfere with the pathophysiological mechanisms of PD upstream of neuronal cell death. [ABSTRACT FROM AUTHOR]