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Analysis of the qualitative signature of fatty acids in tissues of organisms is an increasingly utilized tool in studies of trophic ecology in aquatic and terrestrial ecosystems. Here, we studied a colonial waterbird, the black-headed gull Chroicocephalus ridibundus, nesting in three colonies. We aimed to investigate whether fatty acid composition of its eggs is affected by the location of the colony (reflecting the spatial variation in habitat composition and, in turn, female diet at the time of egg formation), and the egg laying sequence (reflecting the temporal variation in female diet). We found that the composition of fatty acids in eggs of black-headed gulls differed among colonies, but not among subsequent eggs within the clutch. We interpret these results in the context of spatial differences in the diet of females breeding in different colonies and a lack of temporal variation in the diet of individual females. The pattern of the ratio of omega-3 to omega-6 fatty acids reflected the contribution of aquatic/terrestrial prey to their diet, and was consistent with the area of water courses around the colonies. High levels of omega-6:omega-3 can promote inflammation and thus lead to increased susceptibility to antigens. Further studies with prey sampling are required to reconstruct the diet composition of females during egg formation in more detail. [ABSTRACT FROM AUTHOR]

During the last decade, a series of controlled source seismic experiments brought new insight into the crustal and lithospheric structure of the Eastern Alps and their adjacent tectonic provinces. A fragmentation of the lithosphere into three blocks, Europe (EU), Adria (AD), and the new Pannonian fragment (PA), was interpreted and a triple junction was inferred. The goal of this study has been to relate these deep crustal structures to active tectonics. We used elastic plate modeling to reconsider the Moho fragmentation. We interpret subduction of EU below AD and PA from north to south and underthusting of AD mantle below PA from southwest to northeast. The Moho fragmentation correlates well with major upper crustal structures and is supported by gravity, seismic, and geodetic data. An analysis of crustal thickening suggests that active convergence is associated with continued thrusting and lateral extrusion in the central Eastern Alps and thickening of the Adriatic indenter under the Southern Alps. According to the velocity relations at the triple junction, PA moves relative to EU and AD along ENE and SE striking faults, mainly by strike slip. An eastward directed extensional component is compensated by the lateral extrusion of the central Eastern Alps. The Periadriatic (Insubric) line east of the triple junction and the mid-Hungarian fault zone have relatively recently lost their role as first-order active structures. We favor the idea that the Pannonian fragment and the TISZA block merged to a 'soft' microplate surrounded by the Eastern and Southern Alpine, Carpathian, and Dinaric orogens. doi: 10.1029/2009TC002491

The problem of the existence of the asthenosphere for old Precambrian cratons is still discussed. In order to study the seismic lithosphere–asthenosphere boundary (LAB) beneath the Baltic Shield, we used records of nine local earthquakes with magnitudes ranging from 2.7 to 5.9. To model the LAB, original data were corrected for topography and Moho depth using a reference model with a 46-km-thick crust. For two northern events at Spitsbergen and Novaya Zemlya, we observe a low-velocity layer, 60–70-km-thick asthenosphere, and the LAB beneath Barents Sea was found at depth of c. 200 km. Sections for other events show continuous first arrivals of P-waves with no evidence for “shadow zone” in the whole range of registration, which could either be interpreted as the absence of the asthenosphere beneath the central part of the Baltic Shield, or that the LAB in this area occurs deeper (>200 km). The relatively thin low-velocity layer found beneath southern Sweden, 15 km below the Moho, could be interpreted as small-scale lithospheric heterogeneities, rather than asthenosphere. Differentiation of the lower lithosphere velocities beneath the Baltic Shield could be interpreted as regional heterogeneity or as anisotropy of the Baltic Shield lithosphere, with high velocities approximately in the east–west direction, and slow velocities approximately in the south–north direction. [ABSTRACT FROM PUBLISHER]

To perform high-throughput studies on the biological effects of ionizing radiation in vivo, we have implemented a microfluidic tool for microbeam irradiation of Caenorhabditis elegans. The device allows the immobilization of worms with minimal stress for a rapid and controlled microbeam irradiation of multiple samples in parallel. Adapted from an established design, our microfluidic clamp consists of 16 tapered channels with 10-μm-thin bottoms to ensure charged particle traversal. Worms are introduced into the microfluidic device through liquid flow between an inlet and an outlet, and the size of each microchannel guarantees that young adult worms are immobilized within minutes without the use of anesthesia. After site-specific irradiation with the microbeam, the worms can be released by reversing the flow direction in the clamp and collected for analysis of biological endpoints such as repair of radiation-induced DNA damage. For such studies, minimal sample manipulation and reduced use of drugs such as anesthetics that might interfere with normal physiological processes are preferable. By using our microfluidic device that allows simultaneous immobilization and imaging for irradiation of several whole living samples on a single clamp, here we show that 4.5-MeV proton microbeam irradiation induced DNA damage in wild-type C. elegans, as assessed by the formation of Rad51 foci that are essential for homologous repair of radiation-induced DNA damage. [ABSTRACT FROM AUTHOR]

The updated geological and potential fields data on the East European Platform margin in SE Poland confirm the existence of several regional units differing in Ediacaran to Silurian development: the Upper Silesian Block, Małopolska Block and Łysogóry Block. All the blocks are characterized by a distinct crustal structure seen in Vp velocity models obtained from the seismic refraction data of the CELEBRATION 2000 Programme. The first two units are interpreted as exotic terranes initially derived from Avalonia-type crust and ultimately accreted before the late Early Devonian. The Łysogóry Block is probably a proximal terrane displaced dextrally along the Baltica margin. The sutures between the terranes do not precisely match lateral gradients in Vp models. This is partly explained by a limited resolution of refraction seismic data (20 km wide interpretative window). Most of the difference is related, however, to a post-accretionary tectonism, mainly Variscan transtension–transpression. The latter processes took advantage of lithospheric memory recorded earlier as zones of rheological weakness along the former suture zones. The course of the East European Platform margin (= Teisseyre–Tornquist Zone) corresponds most likely to the Nowe Miasto–Zawichost Fault marking the NE boundary of the proximal Łysogóry Terrane. [ABSTRACT FROM AUTHOR]

Presented here is a novel microbeam technology—the Flow-And-ShooT (FAST) microbeam—under development at RARAF. In this system, cells undergo controlled fluidic transport along a microfluidic channel intersecting the microbeam path. They are imaged and tracked in real-time, using a high-speed camera and dynamically targeted, using a magnetic Point and Shoot system. With the proposed FAST system, RARAF expects to reach a throughput of 100 000 cells per hour, which will allow increasing the throughput of experiments by at least one order of magnitude. The implementation of FAST will also allow the irradiation of non-adherent cells (e.g. lymphocytes), which is of great interest to many of the RARAF users. This study presents the design of a FAST microbeam and results of first tests of imaging and tracking as well as a discussion of the achievable throughput. [ABSTRACT FROM PUBLISHER]

The Variscan orogeny is the major Middle to Late Palaeozoic tectonometamorphic event in central Europe, and the Bohemian Massif is the largest exposure of rocks deformed during this orogeny. The Bohemian Massif consists of the Saxothuringian, Barrandian and Moldanubian units. Adjacent to this massif in the southeast, the Western Carpathians form an arc-shaped mountain range related to the Alpine orogeny during the Cretaceous to Tertiary. The complex crustal-scale geological structure of the Variscan Bohemian Massif and the Western Carpathians, and especially their contact, were analysed in this study employing the data of the SUDETES 2003 international seismic refraction experiment. The analysed seismic data were acquired along the 740 km long, NW-SE oriented S04 profile that crossed the Bohemian Massif and the Western Carpathians before terminating in the Pannonian Basin. The data were interpreted by 2-D trial-and-error forward modelling of P waves, and additional constraints on crustal structure were provided by gravity modelling. The complex velocity structure derived in our analysis included low velocities of 5.85 km s−1 at the contact of the Saxothuringian and Barrandian units that reflect the presence of low-density granites. There are distinct lateral variations in deep crustal structure in the transition between the Bohemian Massif and the Western Carpathians. The abrupt change of the crustal thickness in this transition zone may be associated with the Pieniny Klippen Belt, a deep-seated boundary between the colliding Palaeozoic lithospheric plate to the north and the ALCAPA microplate to the south. In the upper crust of this transition, low velocities of 4 km s−1 extend to 6 km and represent the sedimentary fill of the Carpathian Flysch and Foredeep that thins towards the foreland. This basin is also expressed as a pronounced gravity low. The Moho in the Carpathians reaches a depth of 32-33 km. In contrast, in the Pannonian Basin the Moho rises to a depth of 25 km, which corresponds to the Pannonian gravity high. [ABSTRACT FROM AUTHOR]

In this paper, we present results of the 3-D tomographic modelling of the crustal structure and Moho topography applied to data recorded in SE Poland during the CELEBRATION 2000 seismic experiment. The target area covers ca. 500 km × 500 km and represents a complex geological setting from old Precambrian platform (East European Craton, EEC), through the crustal blocks (terranes) that form the Trans-European Suture Zone, to the young Alpine orogen—the Carpathians. We test two different inversion strategies using two different algorithms: (i) coupled inversion of and arrivals to constrain both the crustal velocities and the Moho depths; (ii) decoupled inversion of arrivals only using previously obtained smooth 3-D crustal velocity model. The coupled inversion of and arrivals results in a much smoother crustal velocity field than the one previously obtained by inversion of first arrivals only. Also, the obtained Moho structure is much smoother than the Moho map compiled from the existing 2-D models. Decoupled inversion of the reflections provides Moho structure comparable in resolution to the compiled map. Synthetic tests indicate that with our data set we are able to resolve larger than 100-km-size Moho structures. The modelled Moho is shallowest in the area of the Upper Silesian Block ( ca. 32 km), then it is deepening by ca. 10 km over 100-km-wide zone along the margin of the EEC and finally it reaches up to 48 km depth in the area of the EEC. Our favoured strategy for modelling large refraction/wide-angle reflection data set consists of derivation of a smooth crustal velocity model by a first-arrival tomography and then complementing this model by a decoupled inversion of reflections in order to constrain minimum-structure Moho topography. [ABSTRACT FROM AUTHOR]

We present analysis of lateral variations of density in the upper mantle in the area of contact of the precambrian East European Craton (EEC) and the Palaeozoic Platform (PP) in Poland, obtained by analysis of the gravimetric geoid undulations. A precise 3-D density model of the crust in the study area down to a depth of 50 km, discussed in the first part of this paper ( Majdański et al. , in press) did not explain all features of the observed geoid. This suggests that these features can be due to density inhomogeneities in the upper mantle. To estimate them, we performed inversion of a residual between the observed geoid and undulations caused by the 3-D density distribution in the crust. Basing on the assumption of local isostatic compensation and Pratt–Hayford isostasy model, the density distribution in the upper mantle was parametrized as a 40-km-thick layer located above the assumed compensation depth of 140 km and subdivided into irregular blocks. The boundaries of the blocks were defined according to boundaries of major tectonic units in the study area and position and shape of the most pronounced anomalies in the residual geoid. A series of sensitivity tests calculated for such density heterogeneities in the upper mantle showed that they can produce geoid undulations of the order of several metres. The density values in each unit were taken as model parameters for the inversion procedure, and inverse problem was solved using global optimization with constraints. The density variations in the upper mantle in the final model correlate well with the surface heat flow. This suggests that these variations can be due to diversity in mantle temperature. The Trans-European Suture Zone (TESZ), which is a major suture separating the EEC from the PP, is not observed as a distinct unit in the mantle. Instead, our study suggests continuation of the lithosphere of the EEC beneath the PP and confirms subdivision of the TESZ into terranes with distinctly different evolution. A simple calculation shows that condition of local isostatic equilibrium is almost achieved at the assumed compensation depth, with the exception of several small-scale units. However, different loads and mass deficiencies in the lithosphere are compensated at different depth levels. This proves that the lithosphere is alternation of mechanically strong and weak layers, both in the crust and upper mantle, and that different loads can be compensated at different depth. However, the total compensation of all lithospheric loads occurs in the upper mantle. [ABSTRACT FROM AUTHOR]

The subject of this paper concerns the seismic modelling of the crustal structure in the transition zone from the Bohemian Massif, across the Molasse basin and the Eastern Alps to the Southern Alps, mainly on the territory of Austria. The CEL10/Alp04 profile crosses the triple point of the European plate, Adriatic microplate and the recently identified Pannonian fragment. The seismic data along the presented profile originate from two large experiments: CELEBRATION 2000 and ALP 2002. The wavefield observed in the Eastern Alps is more complex than in the Bohemian Massif. Strong first arrivals ( Pg) are distinct up to 60–90 km offset and are characterized by large variations in apparent velocity and amplitude. The contact between the Molasse basin and the Eastern Alps represents a barrier for seismic waves. Mid-crustal reflections ( Pc) are usually recorded at short distance intervals (20–50 km) and are also characterized by variations in apparent velocity and amplitude. The Moho reflections are usually strong and well correlated, while Pn arrivals are only fragmentarily recorded. Detailed 2-D forward modelling of all refracted, post-critical and reflected phases, identified in the correlation process, was undertaken using a ray-tracing technique. The P-wave velocity in the crystalline upper crust of the Bohemian Massif and Molasse basin is about 6.15 km s−1, which is slightly higher than in the Alpine area (about 6.0 km s−1). Below the northern accretionary wedge of the Eastern Alps low-velocity sediments penetrate towards the southwest (SW) down to about 10 km depth. In the middle crust of the Alpine part, a reflective zone was modelled by a lamellae structure with alternating high and low velocities and thicknesses of about 2–3 km. The lower crust in this part of the model is more homogeneous, with a velocity of about 6.9 km s−1. In the Bohemian Massif, a high-velocity (HV) body ( VP∼ 7 km s−1) of a few kilometres thickness was delineated in the depth interval 18–23 km. The crustal thickness along the CEL10/Alp04 profile changes from about 42–44 km in the SW (Alpine part), to around 40 km in the central part of the profile (Molasse basin), and 38–40 km in the NE (Bohemian Massif). The velocity in the uppermost mantle determined from Pn wave traveltimes is about 8 km s−1 along the whole profile. The interpretation of the seismic wavefield is supplemented by an existing 3-D P-wave velocity model of the area. Main features derived by 2-D modelling (low velocities beneath the accretionary wedge, high velocities in the lower crust of the Bohemian Massif, Moho topography) well correlate with the 3-D model. Furthermore, the 3-D model allows assessing the lateral extent of significant features alongside the CEL10/Alp04 profile. This area is affected by both collision and escape tectonics. The high-reflectivity zone in the middle crust is explained by intermediate to mafic intrusions, rather than by ductile extensional deformation as generally observed in the lower crust. [ABSTRACT FROM AUTHOR]

In this paper, we present results of 3-D first-arrival tomography applied to data recorded in SE Poland during the CELEBRATION 2000 seismic experiment. The target area covers ca. 500 × 500 km2 and represents a complex geological setting from old Precambrian platform (East European Craton, EEC), through the crustal blocks (terranes) that form the Trans-European Suture Zone (TESZ) to the young Alpine orogen—the Carpathians. Contrasting velocity distributions in various geological units makes the tomographic inversion challenging. For this reason, much attention was paid to the inversion methodology. We tested ‘multioffset’ and ‘multiscale’ approaches. By increasing the offset range in the ‘multioffset’ inversion we have independently constrained different depth ranges of our model. We have found that the ‘multiscale’ method, that is, the gradual stepping from bigger to smaller model cells produced the preferred solution. Resolution of the resultant crustal model was determined by performing checkerboard and restoration resolution tests. Lateral resolution of the order of 25 km is inferred down to 10 km depth and 50 km down to 25–30 km depth. We have also applied a quasi-Monte Carlo analysis to determine the absolute errors of model parameters, which to our knowledge, is the first such attempt in case of a 3-D wide-angle data set. The mean uncertainties of our tomographic velocities are 0.1 km s−1, but some anomalies are recovered with larger errors. We also advocate that the results from the central part of the Małopolska Block (MB) are biased by the influence of crustal anisotropy as confirmed by an independent study. The overall picture of the transition from the EEC to the TESZ resembles an Atlantic-type passive margin, with several high velocity bodies occurring along the EEC edge and relatively low velocities ( V P < 6 km s−1) extending down to ca. 20 km. Of the crustal units investigated, the Upper Silesian Block (USB) fully deserves to be called a terrane. It is distinct in terms of seismic velocities and its eastern edge (Kraków–Lubliniec Fault) is clearly visible and continues beneath the Carpathian nappes. The differences between the overall crustal structure of the MB and the Łysogóry Unit (LU) are minor and thus the ‘terrane’ concept does not necessarily apply to them. [ABSTRACT FROM AUTHOR]

Abstract: The extent of the Variscan deformation front is one of the key problems of the regional geology of the Central European Permian Basin system, particularly in its Polish part. Conventional reflection seismics usually fails to produce a satisfactory image of the pre-Permian strata due to the shielding effect of Zechstein (Upper Permian) evaporites. Thus we used a novel seismic acquisition technique to study the base of the Permian complex and its Variscan basement. In the GRUNDY 2003 experiment we combined wide-angle reflection–refraction measurements with the near-vertical reflection seismics by the use of the constant geophone array with dense (100 m) receiver spacing occupying 50-km long profile. 3D design of the experiment, covering 50×10 km area, helped in eliminating the effect of out-of-plane propagations and local inhomogeneities. An effective integration of traveltime tomography, CDP reflection processing and prestack depth migration of wide-angle reflections applied to our data, allowed us to present the model in which we deduced the contact zone of the Variscan overthrust structure (Variscan front) with its molasse-filled foredeep. The latter might be a gas-generation zone, which is of a great importance for hydrocarbons prospecting in this area. [Copyright &y& Elsevier]

CELEBRATION 2000 was a large international experiment that focused on the lithospheric structure in Central Europe. It consisted of several wide-angle reflection and refraction seismic profiles. Profiles CEL01 and CEL04 are located in the transition from the Precambrian and Palaeozoic platforms to the Carpathian orogen. The data were modelled using 2-D tomographic and forward modelling techniques. The profile CEL01 (about 900 km long) extends from the southwestern margin of the East European Craton to the Pannonian basin system. The depth of Moho boundary varies along the profile from 27–33 km under the Pannonian basin system area, 30–39 under the Carpathians and within the TESZ to 40–45 km under the East European Craton. The CEL04 profile (630 km long) starts in the Polish trough (PT) and reaches the Pannonian basin system. Along the CEL04 profile, the Moho interface shallows from 40 km beneath the PT to about 35 km in the Maopolska unit. The crustal thickness is 43 km beneath the Carpathians and 25 km beneath the Pannonian basin system. The results obtained are consistent with a commonly accepted view of the Carpathians, thought to be formed largely due to the interplay between Palaeogene to Middle Miocene subduction of oceanic or suboceanic crust and subsequent collision. A feature that we interpret as the subduction-related orogenic root is at least partially preserved in both profiles and is manifested by a crustal thicknesses of 39 km (CEL01) and 43 km (CEL04). The boundary between the Małopolska unit and the Bruno–Silesian unit is discernible north of the Carpathian frontal thrust along the CEL01 profile, but is not observed farther to the southeast (CEL04) beneath the Carpathians. In the Pannonian basin system, no substantial differences in the crustal structure across the Mid-Hungarian Line were observed. Upper mantle reflections observed along both profiles originate from a north-dipping mantle discontinuity, probably representing a shear zone related to collision and possibly ongoing convergence between the European plate and ALCAPA (Alps-Carpathians–Pannonian). [ABSTRACT FROM AUTHOR]

The Donbas Foldbelt (DF) is the uplifted and deformed part of the up to 20-km-thick Dniepr–Donets Basin (DDB) that formed as the result of rifting of the East European Craton (EEC) in the Late Devonian. Uplift, especially of the southern margin of the basin, occurred in Early Permian times, in a (trans)tensional tectonic stress regime while folding and reverse faulting mainly occurred later—mainly during the Late Cretaceous. A seismic refraction/wide-angle reflection survey was carried out in 1999 (DOBREfraction''99) to complement existing Deep Seismic Sounding (DSS) data from the area that did not record significant Pn phase arrivals because of insufficient maximum offset. DOBREfraction''99 comprised some 245 recording stations along a line of 360 km length with 11 in-line shot points as well as a 100 km away, parallel 190 km long subsidiary fan profile. The main profile runs between the shores of the Azov Sea in the south to the Ukraine–Russia border in the north, across the Azov Massif (Ukrainian Shield), the Foldbelt, and the Voronezh Massif. Particular scientific targets include the nature of the crust–mantle transition and the geometry of crustal–upper mantle structures related to rifting and subsequent basin inversion. Tomographic inversion as well as ray-trace based velocity modelling has been carried out. The velocity signature of the sedimentary basin itself is well resolved, indicating an asymmetric form, with a steeper basement surface in the south than in the north, and a total thickness of about 20 km. A thick (>10 km) high velocity (>6.9 km/s) lower crustal body lies beneath the rift basin itself, offset slightly to the north compared to the main basin depocentre, likely related to the rifting processes. Velocities in the crust below the Ukrainian Shield, south of the Foldbelt, are in general higher than beneath the Voronezh Massif to the north. The Moho displays only slight topography around a depth of 40 km along the profile. [Copyright &y& Elsevier]

Investigates the transition zone between Precambrian and Paleozoic Europe by using seismograms of teleseismic earthquakes recorded by the broad-band Teleseismic Tomography Tornquist (TOR) stations to calculate the receiver functions. Data from the TOR experiment carried out in winter 1996-97 across the Trans-European Suture Zone in Germany, Denmark and Sweden; Time-domain inversion method; S-wave velocities.