Feeding Monsters – A Study of Active Galaxies

We present new interferometric observations of the molecular gas distribution and kinematics in the nuclei of different active galaxies at high angular resolution and high sensitivity carried out with the IRAM Plateau de Bure interferometer (PdBI). The observations cover galaxies in a redshift range of 0.03–1.4. We have so far observed five different active galaxies: NGC3718, NGC1068, HE1029–1831, 3C48 and Q0957+561. The first two objects belong to the NUGA (NUclei of GAlaxies) project – an international collaboration mainly between Spain, France and Germany – containing about 30 Seyfert and LINER galaxies. Both are at the same distance of 14Mpc and show a warped gas and dust disk. The new mosaic map of NGC3718 corrected for short-spacing effects with IRAM 30 m observations well demonstrates the existence of the warped gas disk with several secondary maxima in the projected gas distribution caused by orbit crowding effects. Based on these new data we have improved recent simulations of the warped disk in NGC3718. HE1029–1831 and 3C48 are nearby QSOs. HE1029–1831 is taken out of the Cologne nearby QSO sample. The maps of the integrated CO(1–0) and CO(2–1) emission clearly show that the molecular gas is mostly related to the central bulge with a non-negligible fraction distributed along the bar known from optical observations. Our new CO data of 3C48 unveil new information about the kinematics of its molecular gas complementing and improving further studies based on previous infrared observations and detailed multi-particle simulations. Finally, new measurements of the CO(1–0) line in Q0957+561 – a highly-red-shifted, gravitationally lensed quasar – will be presented as a link to earlier evolutionary stages of active galaxies and their hosts.     

Palaeovariations in the East-Asian Monsoon Regime Geochemically Recorded in Varved Sediments of Lake Sihailongwan (Northeast China, Jilin Province). Part 1: Hydrological Conditions and Dust Flux

The varved sediments of the dimictic Lake Sihailongwan (Long Gang mountain area, Jilin Province, Northeast China) represent a palaeoclimatic archive which documents the local precipitation frequency during the summer monsoon, and variations in the aeolian flux of dust with their remote sources in the arid and semi-arid regions of inner Asia. Based on a detailed discussion of sediment genesis in Lake SHL, dust flux rates and palaeohydrological conditions were reconstructed on a decadal scale over the past 220 years. The aeolian influx by dry and wet deposition was quantified and characterised in its chemical composition. Photosynthetic production in the lake is positively correlated with the inflow of nutrient-rich groundwater. The groundwater discharge largely reflects the strength of the summer monsoon. Net accumulation rates for biogenic silica were determined for annually laminated sediments from the centre of the U-shaped lake basin based on sediment data. In a Si-balance model of the modern lake, the depositional flux of biogenic silica could be independently quantified on the base of hydrochemical monitoring data. Comparison of the both estimates allowed to asses the focussing of the particle flux in the lake. Though water retention in Lake SHL is rather high (ca. 30 years), changes in the hydrological conditions are sensitively recorded in the sediments because (i) nutrient-rich groundwater discharges into the productive zone of the lake, (ii) a substantial proportion of the total dissolved Si-inventory of the mixed lake (ca. 30%) is annually consumed by diatom growth, and (3) sediment accumulation is substantially focussed towards the flat bottom of the lake basin. The bulk siliciclastic sediment fraction (ca. 75 wt.%) largely originates from influx of dust of remote provenance. In sediment thin-sections, the dry-deposited dust fraction is microscopically identifiable as seasonal silt layer. Aeolian input by wet-deposition shows a distinctly higher variability than the influx of dust by dry-deposition. As diatom production, wet-deposition of dust is positively correlated with the rainfall during the summer monsoon. The inferred positive correlation between rainfall and dust flux during the summer monsoon implies that dust deposition is determined by the out-wash efficiency of mineral particles for a permanent high atmospheric dust concentration over Northeast China in the last 220 years.     

Climate change effects on winter chill for tree crops with chilling requirements on the Arabian Peninsula

Fruit production systems that rely on winter chill for breaking of dormancy might be vulnerable to climatic change. We investigated decreases in the number of winter chilling hours (0–7.2°C) in four mountain oases of Oman, a marginal area for the production of fruit trees with chilling requirements. Winter chill was calculated from long-term hourly temperature records. These were generated based on the correlation of hourly temperature measurements in the oases with daylength and daily minimum and maximum temperatures recorded at a nearby weather station. Winter chill was estimated for historic temperature records between 1983 and 2008, as well as for three sets of synthetic 100-year weather records, generated to represent historic conditions, and climatic changes likely to occur within the next 30 years (temperatures elevated by 1°C and 2°C). Our analysis detected a decrease in the numbers of chilling hours in high-elevation oases by an average of 1.2–9.5 h/year between 1983 and 2008, a period during which, according to the scenario analysis, winter chill was sufficient for most important species in most years in the highest oasis. In the two climate change scenarios, pomegranates, the most important tree crop, received insufficient chilling in 13% and 75% of years, respectively. While production of most traditional fruit trees is marginal today, with trees barely fulfilling their chilling requirements, such production might become impossible in the near future. Similar developments are likely to affect other fruit production regions around the world.     

GETEMME—a mission to explore the Martian satellites and the fundamentals of solar system physics

GETEMME (Gravity, Einstein??s Theory, and Exploration of the Martian Moons?? Environment), a mission which is being proposed in ESA??s Cosmic Vision program, shall be launched for Mars on a Soyuz Fregat in 2020. The spacecraft will initially rendezvous with Phobos and Deimos in order to carry out a comprehensive mapping and characterization of the two satellites and to deploy passive Laser retro-reflectors on their surfaces. In the second stage of the mission, the spacecraft will be transferred into a lower 1500-km Mars orbit, to carry out routine Laser range measurements to the reflectors on Phobos and Deimos. Also, asynchronous two-way Laser ranging measurements between the spacecraft and stations of the ILRS (International Laser Ranging Service) on Earth are foreseen. An onboard accelerometer will ensure a high accuracy for the spacecraft orbit determination. The inversion of all range and accelerometer data will allow us to determine or improve dramatically on a host of dynamic parameters of the Martian satellite system. From the complex motion and rotation of Phobos and Deimos we will obtain clues on internal structures and the origins of the satellites. Also, crucial data on the time-varying gravity field of Mars related to climate variation and internal structure will be obtained. Ranging measurements will also be essential to improve on several parameters in fundamental physics, such as the Post-Newtonian parameter ?? as well as time-rate changes of the gravitational constant and the Lense-Thirring effect. Measurements by GETEMME will firmly embed Mars and its satellites into the Solar System reference frame.     

PCB-containing paint and plaster caused extreme PCB-concentrations in biota from the Sørfjord (Western Norway)--a case study

The Sørfjord (Western Norway) has a long history of industry and pollution, and has been monitored for several decades. The environmental monitoring has comprised analyses of different contaminants in sea water, mussel, fish, seaweed and sediments. Measurements of polychlorinated biphenyls (PCBs) in blue mussels (Mytilus edulis) some 17 years ago indicated a local source. In 2001 severe concentrations were measured in blue mussels and further investigations disclosed the primary source of PCBs in the Sørfjord. In 2002, extreme PCB-concentrations were found in cod (Gadus morhua) from the same area. However, no induction of EROD activity was detected, indicating the limitations of this assay as marker for PCB contamination. A future scientific challenge will be to understand the specific mechanisms and effects of such PCB accumulation in fish.     

‘Box‐Profile’ Ion Implants as Geochemical Reference Materials for Electron Probe Microanalysis and Secondary Ion Mass Spectrometry

Although electron probe microanalysis and secondary ion mass spectrometry are widely used analytical techniques for geochemical and mineralogical applications, metrologically rigorous quantification remains a major challenge for these methods. Secondary ion mass spectrometry (SIMS) in particular is a matrix‐sensitive method, and the use of matrix‐matched reference materials (RMs) is essential to avoid significant analytical bias. A major problem is that the number of available RMs for SIMS is extremely small compared with the needs of analysts. One approach for the production of matrix‐specific RMs is the use of high‐energy ion implantation that introduces a known amount of a selected isotope into a material. We chose the more elaborate way of implanting a so‐called ‘box‐profile’ to generate a quasi‐homogeneous concentration of the implanted isotope in three dimensions, which allows RMs not only to be used for ion beam analysis but also makes them suitable for EPMA. For proof of concept, we used the thoroughly studied mineralogically and chemically ‘simple’ SiO₂ system. We implanted either ⁴⁷Ti or ⁴⁸Ti into synthetic, ultra‐high‐purity silica glass. Several ‘box‐profiles’ with mass fractions between 10 and 1000 μg g^?1 Ti and maximum depths of homogeneous Ti distribution between 200 nm and 3 μm were produced at the Institute of Ion Beam Physics and Materials Research of Helmholtz‐Zentrum Dresden‐Rossendorf. Multiple implantation steps using varying ion energies and ion doses were simulated with Stopping and Range of Ions in Matter (SRIM) software, optimising for the target concentrations, implantation depths and technical limits of the implanter. We characterised several implant test samples having different concentrations and maximum implantation depths by means of SIMS and other analytical techniques. The results show that the implant samples are suitable for use as reference materials for SIMS measurements. The multi‐energy ion implantation technique also appears to be a promising procedure for the production of EPMA‐suitable reference materials.     

Predicting Soil-Water and Soil-Air Transport Properties and Their Effects on Soil-Vapor Extraction Efficiency

Accurate prediction of water and air Iran sport parameters in variably saturated soil is necessary for modeling of soil-vapor extraction (SVE) at soil sites contaminated with volatile organic chemicals (VOCs). An expression for predicting saturated water permeability (k_l,s) in undisturbed soils from the soil total porosity and the field capacity soil-water content was developed by fitting a tortuous-tube fluid flow model to measured water permeability and gas diffusivity data. The new k_l,s expression gave accurate predictions when tested against independent k_l,s data. The k_l,s expression was implemented in the Campbell relative water permeability model to yield a predictive model for water permeability in variably saturated, undisturbed soil. The water permeability model, together with recently developed predictive equations for gas permeability and gas diffusivity, was used in a two-dimensional numerical SVE model that also included non-equilibrium mass transfer of VOC from a separate phase (nonaqueous phase liquid [NAPL]) to the air phase. SVE: calculations showed that gas permeability is likely the most important factor controlling VOC migration and vapor extraction efficiency. Water permeability and gas diffusivity effects became significant at water contents near and above field capacity. The NAPL-air mass transfer coefficient also had large impacts on simulated vapor extraction efficiency. The calculations suggest that realistic SVE models need to include predictive expressions for both conveciive, diffusive. and phase-partitioning processes in natural, undisturbed soils.     

Effects of Dredging Activities on Growth of Laminaria saccharina

Abstract. The possible effects of fine-grained deposits on the photosynthesis, growth, and nutrient uptake of Laminaria have been studied in field and laboratory experiments. Some of the plants were treated with fine-grained material for two hours and then transplanted in rows together with untreated plants. At two-week intervals the treatment was repeated and samples collected. The macroalgae were analyzed for growth as well as chlorophyll a , nitrogen, and phosphorus content. In the laboratory experiments, plants of a uniform size were incubated in Plexiglas containers after leaf-marking and treatment in a sediment suspension. At weekly intervals, photosynthesis, growth, chlorophyll a , and nutrients were analyzed.
The field study showed that Laminaria growth was significantly affected by the fine-grained material. The growth in the control experiment was 20% higher than in the treated plants. The chlorophyll a concentrations in the treated plants were significantly lower than in the control experiment, and the results indicated a reduced nutrient uptake in the treated plants. In the laboratory experiments the growth of the treated plants was only 30% of the controls, but no differences in photosynthetic capacities were detected. Nitrogen uptake was reduced in the treated plants, but no effects were observed on phosphorus uptake. Thick layers of fine-grained material caused direct harmful effects and rotting.
The results are discussed in relation to dredging activities; it is concluded that in heavy sedimentation areas, Laminaria growth may be significantly reduced beyond the indirect effect of shading from suspended material in the water.     

Variations in bottom water activity at the southern Argentine margin: indications from a seismic analysis of a continental slope terrace

Continental slope terraces at the southern Argentine margin are part of a significant contourite depositional system composed of a variety of drifts, channels, and sediment waves. Here, a refined seismostratigraphic model for the sedimentary development of the Valentin Feilberg Terrace located in ~4.1?km water depth is presented. Analyzing multichannel seismic profiles across and along this terrace, significant changes in terrace morphology and seismic reflection character are identified and interpreted to reflect variations in deep water hydrography from Late Miocene to recent times, involving variable flow of Antarctic Bottom Water and Circumpolar Deep Water. A prominent basin-wide aggradational seismic unit is interpreted to represent the Mid-Miocene climatic optimum (~17?C14?Ma). A major current reorganization can be inferred for the time ~14?C12?Ma when the Valentin Feilberg Terrace started growing due to the deposition of sheeted and mounded drifts. After ~12?Ma, bottom water flow remained vigorous at both margins of the terrace. Another intensification of bottom flow occurred at ~5?C6?Ma when a mounded drift, moats, and sediment waves developed on the terrace. This may have been caused by a general change in deep water mass organization following the closure of the Panamanian gateway, and a subsequent stronger southward flow of North Atlantic Deep Water.     

The BEEP project in the Baltic Sea: overview of results and outline for a regional biological effects monitoring strategy

Field studies in the framework of the EU funded BEEP project (Biological Effects of Environmental Pollution in Marine Coastal Ecosystems, 2001-2004) aimed at validating and intercalibrating a battery of biomarkers of contaminant exposure and effects in selected indicator species in the Mediterranean, the North Atlantic and the Baltic Seas. Major strategic goals of the BEEP project were the development of a sensitive and cost-efficient biological effects monitoring approach, delivery of information and advice to end-user groups, and the implementation of a network of biomarker researchers around Europe. Based on the main results obtained in the Baltic Sea component of the BEEP the present paper summarises and assesses the applicability of biomarkers for different regions and species in this sea area. Moreover, a general strategy and some practical considerations for the monitoring of biological effects in the Baltic Sea are outlined.