Sediment contamination of an urban canal—a case study approach for an integrated assessment of organic sediment contamination

Purpose The pesticide DDT and its metabolites represent a contamination risk for the aquatic environment, especially the polar metabolite DDA. The study provides a quantitative assessment of long-term pollution risks from sedimentary DDT residues with a special focus on DDA. It presents an overview of the contamination range of different DDX compounds in the sediments of a canal in Berlin (Germany), resulting from a former industrial point source that has implications for drinking water resources in the nearby area. The comprehensive analysis scheme provides information on free accessible and potentially metabolized precursors also in the non-extractable residues. This allows a quantitative assessment of the DDA pollution potential derived from the sedimentary DDT residues. Materials and methods The area was investigated for fine-grained sediment by means of a geo-electric mapping. Twelve sediment cores were taken in four areas (three in each section). A wider range of precursor metabolites has been included due to their transformation potential to the polar metabolite DDA. The sediments were analysed quantitatively for extractable and easily releasable fractions by application of a variety of degradation techniques as well as a dispersion extraction procedure on the sediment samples. These extracts were fractionated and subsequently analysed by GC-MS. Results and discussion Concentrations were obtained for extractable and bound metabolites. Different scenarios for the calculation of the amount of contaminated sediment are displayed as a tool for contamination assessment. The formation potential of DDA as the water-soluble metabolite is presented. Several precursor metabolites, e.g. DDD and DDMS, extractable from the sediment organic matter, revealed a high potential for a long-term formation of DDA, especially in the easily releasable fraction (via hydrolysis) with a mean concentration of up to 11,000 mu g g(-1)dry sediment. The resulting DDA contamination potential represents a significant pollution risk for the groundwater from a downstream waterworks area and by remobilisation into the whole ecosystem and adjacent rivers. Conclusions The application of the presented methods provides a tool for a quantitative assessment of the long-term release potential of DDA under different scenarios by a comprehensive analysis of contaminated sediments (and soils). This approach can be transferred to pollutants that are also characterized by a complex metabolism accompanied by bound residue formation

THE STRATEGIC UTILITY OF SOF IN GREAT POWER COMPETITION: A NATO PERSPECTIVE

NATO needs to discuss whether, why, and how Special Operations Forces (SOF) contribute to the “fight” in Great Power Competition. NATO’s security strategy traditionally relies on a deterrence posture with conventional and nuclear capabilities. The new NATO 2022 Strategic Concept validates the necessity to research the question: What is the strategic utility of SOF for NATO in Great Power Competition, and how can this strategic utility be enhanced? This study uses a qualitative methodology. At the core is a comparative analysis of two scenarios in the Black Sea and Arctic regions, both developed through a systematic process and enriched with imagination to contain useful vignettes. The analysis suggests that SOF have strategic utility, albeit in changing manifestations in different phases of the conflict continuum, in Great Power Competition. SOF expands the strategic options available to political and military leaders—expansion of choice—to anticipate and respond, especially in an early stage of a crises below the threshold of armed conflict. SOF also achieve significant results with limited forces—economy of force—when conventional formations are not available or capable. It is not about what SOF can and should do; the heart of the matter is what makes the strategic difference—expansion of choice and economy of force—that defines the future of SOF.Majoor, Royal Netherlands ArmyOberstleutnant, German ArmyApproved for public release. Distribution is unlimited

Organogenesis: Cutting to the Chase

AbstractGonad morphogenesis in Caenorhabditis elegans requires two secreted proteases. Recent studies show that alterations of the extracellular matrix component fibulin-1 rescue gonadogenesis in the absence of these proteases. This finding is a critical step toward understanding the role of extracellular matrix in organogenesis

Depositional environment and source rock potential of Cenomanian and Turonian sedimentary rocks of the Tarfaya Basin, Southwest Morocco

Detailed organic and inorganic geochemical analyses were used to assess the depositional environment and source rock potential of the Cenomanian and Turonian oil shale deposits in the Tarfaya Basin. This study is based on core samples from the Tarfaya Sondage-4 well that penetrated over 300m of Mid Cretaceous organic matter-rich deposits. A total of 242 samples were analyzed for total organic and inorganic carbon and selected samples for total sulfur and major elements as well as for organic petrology, Rock-Eval pyrolysis, Curie-Point-pyrolysis-gaschromatography-Mass-Spectrometry and molecular geochemistry of solvent extracts. Based on major elements the lower Cenomanian differs from the other intervals by higher silicate and lower carbonate contents. Moreover, the molecular geochemistry suggests anoxic bottom marine water conditions during the Cenomanian-Turonian Boundary Event (CTBE; Oceanic Anoxic Event 2: OAE2). As a proxy for the Sorg/Corg ratio, the ratio total thiophenes/total benzenes compounds was calculated from pyrolysate compositions. The results suggest that Sorg/ Corg is low in the lower Cenomanian, moderate in the upper Cenomanian, very high in the CTBE (CenomanianTuronian Boundary Event) and high in the Turonian samples. Rock-Eval data reveal that the lower Cenomanian is a moderately organic carbon-rich source rock with good potential to generate oil and gas upon thermal maturation. On the other hand, the samples from the upper Cenomanian to Turonian exhibit higher organic carbon content and can be classified as oil-prone source rocks. Based on Tmax data, all rocks are thermally immature. The microscopic investigations suggest dominance of submicroscopic organic matter in all samples and different contents of bituminite and alginite. The lower Cenomanian samples have little visible organic matter and no bituminite. The upper Cenomanian and CTBE samples are poor in bituminite and have rare visible organic matter, whereas the Turonian samples change from bituminite-fair to bituminite-rich and to higher percentages of visible organic matter towards the younger interval. These differences in the organic matter type are attributed to i) early diagenetic kerogen sulfurization and ii) the upwelling depositional environment. Moreover, kerogen sulfurization was controlled by the relationship between carbonate, iron and sulfur as well as the organic matter. Thus, the organic carbon-rich deposits can be grouped into: i) low Sorg and moderately organic matter-rich oil prone source rocks, ii) moderate Sorg and organic-carbon-rich oil prone source rocks, iii) high Sorg and organic carbon-rich oil prone source rocks and iv) very high Sorg and organic carbon-rich oil prone source rocks, the latter representing the CTBE interval. Types 2 to 4 will generate sulfur-rich petroleum upon maturation or artificial oil shale retorting. This integrated organic and inorganic approach sheds light on the various processes leading to the development of the world-class oil shales deposited through the Cenomanian to Turonian. In addition, this study shows how the changes in the depositional environment might have controlled kerogen sulfurization and organic matter preservation and structure. This detailed approach provides a better understanding on source rock development during the Cenomanian to Turonian in a global context, as many of the geochemical features were identified worldwide for deposits related to OAE2

Depositional environment and source rock potential of Cenomanian and Turonian sedimentary rocks of the Tarfaya Basin, Southwest Morocco

Detailed organic and inorganic geochemical analyses were used to assess the depositional environment and source rock potential of the Upper Albian to Turonian oil shale deposits in the Tarfaya Basin. This study is based on core samples from the Tarfaya Sondage-4 well that penetrated over 300m of Mid Cretaceous organic matter-rich deposits. A total of 242 samples were analyzed for total organic and inorganic carbon and selected samples for total sulfur and major elements as well as for organic petrology, Rock-Eval pyrolysis, Curie-Point-pyrolysis-gas-chromatography-Mass-Spectrometry and molecular geochemistry of solvent extracts. Based on major elements the Albian and Lower Cenomanian differ from the other intervals by higher silicate and lower carbonate contents. Moreover, the molecular geochemistry suggests marine anoxic bottom water conditions during the Cenomanian-Turonian boundary event (CTBE; oceanic anoxic event 2: OAE2). As a proxy for the Sorg/Corg ratio, the ratio total thiophenes/total benzenes compounds was calculated from pyrolysate compositions. The results suggest that Sorg/Corg is low in the Albian, moderate in the Cenomanian, very high in the CTBE and high in the Turonian samples.  Rock-Eval data reveal that the Albian is a moderately organic carbon-rich source rock with good potential to generate oil and gas upon thermal maturation. On the other hand, the samples from the Cenomanian to the Turonian exhibit higher organic carbon contents and can be classified as oil-prone source rocks. Based on Tmax data, all rocks are thermally immature.The microscopic investigations suggest dominance of submicroscopic organic matter in all samples and different contents of bituminite and alginite. The Albian samples have little visible organic matter and no bituminite. The Cenomanian and CTBE samples are poor in bituminite and have rare visible organic matter, whereas the Turonian samples change from bituminite-fair to bituminite-rich and to higher percentages of visible organic matter towards the younger interval. These differences in the organic matter type are attributed to 1) early diagenetic kerogen sulfurization and 2) the upwelling depositional environment. Moreover, kerogen sulfurization was controlled by the relationship between carbonate, iron and sulfur as well as the organic matter. Thus, the organic carbon-rich deposits can be grouped into: 1) low Sorg and moderately organic matter-rich oil prone source rocks, 2) moderate Sorg and organic-carbon-rich oil prone source rocks, 3) high Sorg and organic carbon-rich oil prone source rocks and 4) very high Sorg and organic carbon-rich oil prone source rocks, the latter being represented by the CTBE. Types 2 to 4 will generate sulfur-rich petroleum upon maturation or artificial oil shale retorting

Sequential effects of propofol on functional brain activation induced by auditory language processing: an event‐related functional magnetic resonance imaging study

Background. We have investigated the effect of propofol on language processing using event‐related functional magnetic resonance imaging (MRI). Methods. Twelve healthy male volunteers underwent MRI scanning at a magnetic field strength of 3 Tesla while performing an auditory language processing task. Functional images were acquired from the perisylvian cortical regions that are associated with auditory and language processing. The experiment consisted of three blocks: awake state (block 1), induction of anaesthesia with 3 mg kg-1 propofol (block 2), and maintenance of anaesthesia with 3 mg kg-1 h-1 propofol (block 3). During each block normal sentences and pseudo‐word sentences were presented in random order. The subjects were instructed to press a button to indicate whether a sentence was made up of pseudo‐words or not. All subjects stopped responding during block two. The data collected before and after the subjects stopped responding during this block were analyzed separately. In addition, propofol plasma concentrations were measured and the effect‐site concentrations of propofol were calculated. Results. During wakefulness, language processing induced brain activation in a widely distributed temporofrontal network. Immediately after unresponsiveness, activation disappeared in frontal areas but persisted in both temporal lobes (block 2 second half, propofol effect‐site concentration: 1.51 µg ml-1). No activation differences related to the task were observed during block 3 (propofol effect‐site concentration: 4.35 µg ml-1). Conclusion. Our findings suggest sequential effects of propofol on auditory language processing networks. Brain activation firstly declines in the frontal lobe before it disappears in the temporal lobe. Br J Anaesth 2004; 92: 641-5

Paläofluide in störungskontrollierten Bruchsystemen der Aachener Geothermie-Bohrung

In der vorliegenden Arbeit werden geologische Prozesse im Untergrund des linksrheinischen Rhenoherzynikums und deren Verhältnis zum regionaltektonischen Rahmen anhand der Proben aus der Aachener Geothermie- Bohrung mit dem Schwerpunkt des Fluid- und Stofftransportes untersucht. Die methodische Vorgehensweise basiert auf einer systematischen und detaillierten Bestandsaufnahme der Paläofluide in Form von Flüssigkeitseinschlüssen an Kernmaterial der Bohrung. Im Aachener Raum wurden Untersuchungen von Flüssigkeitseinschlüssen hauptsächlich an postvariszischen Pb-Zn-Gangvorkommen durchgeführt. Die Homogenisierungstemperaturen (Th) von NaCl-CaCl2-Lösungen unterschiedlicher Salinität liegen zwischen 70°C und maximal 190°C (Redecke 1992, Stroink 1993, Muchez et al. 1994, Glasmacher 1995). Für die tektonischmetallogentische Entwicklung des Rheinischen-Schiefergebirges können generell zwei Fluid-Aktivitätsperioden unterschieden werden (Behr et al. 1993). Die im Zuge der variszischen Gebirgsbildung synkinematische Defluidisierung des Orogenkörpers generierte das Fluid-System der ‚Tectonic Brines‘ (1). Diese sind Na-(K)-Cl-betonte Lösungen geringer Salinität mit CO2, CH4 und N2 sowie durch Th < 350°C gekennzeichnet. Im Gegensatz dazu wurden die meisten postvariszischen Ganglagerstätten des Rheinischen- Schiefergebirges durch ‚Basement Brines‘ (2) gebildet. Diese sind Ca- Na-Cl-Lösungen hoher Salinität mit Th < 250°C (Behr et al. 1993).conferenc

Some Evidence on the Relevance of the Chain-reaction Theory in Selected Countries

In this paper we challenge the traditional labour market view, which argues that unemployment is determined in the long-term by its equilibrium rate, which in turn is affected by permanent shocks of some exogenous variables. In our empirical approach we decompose the dynamics of employment and labour force into transitory and permanent components. We estimated a small labour market model using VAR techniques. By simulating the model we are able to quantify the relative importance of the permanent and transitory components for the movements of the unemployment rate in four countries (Austria, France, UK, and USA). We find that the transitory component has a significant impact on unemployment only in the US. In contrast to that the permanent component appear to influence unemployment significantly in all included countries. In combination with the observation that labour market dynamics differ between countries, this may have powerful policy implications.Unemployment, Natural rate hypothesis, Labour markets, Employment, Adjustment costs