Tubular agglutinated foraminifera as indicators of organic carbon flux

The dimensions of tubular agglutinated foraminifera such as Rhizammina and Rhabdammina respond in a predictable manner to changes in the flux of organic carbon to the sea floor. In both the modern western North Atlantic and in an ancient example (the K/T boundary in Gubbio), the slender, finely-grained tubes (<100 μm diameter) dominate in oligotrophic regimes, whereas in eutrophic regimes the abundance of tubes is higher, and the mean and standard deviation of the tube diameter increases. Large tubes (> 500 μm) are present only when organic flux is comparatively high. Although our observations are at present not directly calibrated to primary productivity levels, we maintain that the potential for using tubular agglutinated foraminifera does exist

What, if anything, is a Paratrochamminoides? A key to the morphology of the Cretaceous to Cenozoic species of Conglophragmium and Paratrochamminoides (Foraminifera)

We present a review of the current taxonomical status of the genus Paratrochamminoides Soliman, 1972. We recognise five main subgroups of this genus based upon the following modes of coiling: trochospiral, streptospiral, glomospiral, triloculine or milioline, and thalmannamminiform. Species that display streptospiral coiling and an interiomarginal aperture are placed in the genus Conglophragmium Bermúdez & Rivero, 1963, whereas the genus Paratrochamminoides is here understood to encompass all other coiling modes. The morphological characters of 23 named and unnamed species that we recognise as belonging to Paratrochamminoides and Conglophragmium are presented in tabular form. Of these, 22 are considered here to be valid species. Emended descriptions are provided for both genera, and diagnoses are given for each of the species

Bowker's Test for Symmetry and Modifications within the Algebraic Framework

Categorical data occur in a wide range of statistical applications. If the data are observed in matched pairs, it is often of interest to examine the differences between the responses. We concentrate on tests of axial symmetry in two-way tables. A commonly used procedure is the Bowker test which is a generalization of the McNemar test. The test decision is based on a x2-approximation which might not be adequate, for example if the table is sparse. Therefore modifications of the test statistic have been proposed. We suggest a test of symmetry based on Bowker's test and Markov Chain Monte Carlo methods following the algorithm of Diaconis and Sturmfels (1998). We carry out a simulation study to determine and com- pare the performance of the simulation test, the Bowker test and two modifications. --Computational commutative algebra,Diaconis-Sturmfels algorithm,matched-pairs data,MCMC,Metropolis-Hastings algorithm,test for symmetry

Upper Cretaceous, K/T boundary, and Paleocene agglutinated foraminifers from Hole 959D (Côte d'Ivoire-Ghana Transform Margin)

Upper Cretaceous agglutinated foraminifer assemblages from Hole 959D of Ocean Drilling Program (ODP) Leg 159, Côte d’Ivoire-Ghana Transform Margin, reflect the subsidence history and paleoceanography of the widening equatorial Atlantic gateway. Five benthic foraminifer assemblage types are recognized: (1) Santonian and the lowermost Campanian assemblages (Cores 159-959D-65R and 64R) are characterized by the occurrence of bathyal calcareous benthic foraminifers with an increasing proportion of agglutinated foraminifers. The disappearance of calcareous foraminifers and assemblages exclusively composed of organically cemented agglutinated forms in Section 159-959D-65R-3 reflects the subsidence of the seafloor below the calcite compensation depth (CCD); (2) lower Campanian "biofacies B" assemblages (Cores 159-959D-63R through 61R) are exclusively composed of low-diversity agglutinated foraminifers, accompanied by abundant and occasionally well-preserved radiolarian assemblages; (3) middle Campanian to upper Maastrichtian deposits (Cores 159-959D-59R through 49R) contain an exclusively agglutinated Rzehakina epigona biofacies, which is well-known from middle to deep bathyal sites along the North Atlantic margins; (4) a change in agglutinated foraminifer assemblage composition toward morphologies commonly observed in present infaunal habitats and the common occurrence of the presumably infaunal genus Spiroplectammina are observed in Core 159-959D-48R. This change in agglutinated foraminifer assemblages corresponds to the Tethyan early Paleocene "Spiroplectammina event;" (5) a diversified Paleocene "Lizard Springs type" assemblage is characterized by several diverse Rzehakina, Saccamina, and Haplophragmoides species. Assemblages from Cores 159-959D-48R through 44R display high species diversity and reflect the deepest (lower bathyal to upper abyssal) paleobathymetry. Ranges of agglutinated foraminifer marker species and occurrences of paleoceanographic events within this biostratigraphic framework are almost identical to those observed in the North Atlantic, in the Western Tethys, and along the conjugate Brazilian margin. These observations lead us to confirm that a deep-water circulation system common to the North and South Atlantic has been active at least since the Santonian

Cool episodes in the Late Cretaceous - exploring the effects of physical forcing on Antarctic snow accumulation

Until recently it was assumed that the major modern ice sheets on Antarctica became established around the Eocene-Oligocene boundary about 34 Ma ago. But new evidence (e.g. Miller et al., 2008) indicates that continental ice may have been present much earlier, some of it probably even since the greenhouse times of the Late Cretaceous. Deep sea drilling data suggest changes in sea-level during the Late Cretaceous that could have been caused by the melting and freezing of vast ice sheets on Antarctica. Using a GCM approach to test the whether it would be possible to generate the described high-amplitude sealevel falls is one additional way to test this vigorously discussed issue. As shown above, our numerical approach indicates the possibility of a substantial Antarctic glaciation by changing the physical boundary conditions, eccentricity, pCO2, and elevation within reasonable Late Cretaceous ranges. Our simulations suggest that simulated snowfall and consecutive ice formation on Antarctica might yield sufficient volumes to account for the documented rapid, low-amplitude Cretaceous sea-level fluctuations. Based on cautious assumptions and possible errors the model results show that ice build-up could take place in realistic time spans and in accordance with the proxy records. Thus, the possibility of an Antarctic ice shield build-up large enough to drive sea level fluctuations on the order of tens of meters within 20,000-220,000 years is supported. The initial snow accumulation and following growth of Antarctic ice-sheets in the Cretaceous can be attributed to changes in southern hemisphere summer insolation due to reduced orbital eccentricity. Alternatively and/or additionally, declining atmospheric CO2 values caused further coolin

Agglutinated foraminifera from neritic to bathyal facies in the Palaeogene of Spitsbergen and the Barents Sea

Late Palaeocene to Early Eocene foraminiferal assemblages have been analysed from an exploratory well (7119/7-1) drilled in the Tromsø Basin (southwestern Barents Sea) and from two onshore sections, Basilikaelva and Kovalskifjella, exposed in the Central Tertiary Basin of Spitsbergen. The assemblages reveal marked differences in taxonomic composition and diversity, reflecting inner neritic to middle bathyal conditions. Within this depth range, four foraminiferal biofacies (FB) are distinguished: FB 1 occurs in the Kolthoffberget Member (of the Firkanten Formation, Late Palaeocene) sampled in the Basilikaelva section. The member consists of interbedded shales, siltstones and sandstones deposited in a transitional delta front - prodelta environment, according to current sedimentological interpretation. The foraminiferal assemblages are entirely agglutinated, show extremely low species diversities and strong dominance of Reticulophragmium arcticum followed by Labrospira aff. turbida. FB 2 is recognised in the Basilika Formation (Late Palaeocene) exposed in the Kovalskifjella section. The formation consists of silty claystones deposited in a prodelta shelf setting. The foraminiferal assemblages show an increased species diversity, and consist mainly of agglutinated taxa with a strongly subordinate calcareous component. The two most abundant species are R. arcticum and L. aff. turbida. Species of Verneuilinoides and Trochammina occur in significant numbers while tubular taxa are rare. FB 3 is found in the Lower Eocene clay interval composing the upper part of the Torsk Formation in well 7119/7-1. It contains entirely agglutinated assemblages with comparatively high diversities. The dominant species are Recurvoides aff. turbinatus and Budashevaella multicamerata, while Reticulophragmium amplectens is typical and common in these strata. Tubular forms referred to Rhizammina occur locally in significant quantities. The diversity and composition of the assemblages suggest an outer neritic to upper bathyal environment. FB 4 is developed in Palaeocene claystones comprising the lower part of the Torsk Formation in well 7119/7-1. In this interval the species diversity, as well as the frequency of tubular forms (referred to Rhizammina, Bathysiphon and Hyperammina) attains maximum values. Other common to dominant taxa include Spiroplectammina spectabilis, Haplophragmoides walteri, Ammosphaeroidina pseudopauciloculata, and Recurvoides sp. These wholly agglutinated assemblages are interpreted as reflecting upper to middle bathyal conditions

Holistic Temporal Situation Interpretation for Traffic Participant Prediction

For a profound understanding of traffic situations including a prediction of traf- fic participants’ future motion, behaviors and routes it is crucial to incorporate all available environmental observations. The presence of sensor noise and depen- dency uncertainties, the variety of available sensor data, the complexity of large traffic scenes and the large number of different estimation tasks with diverging requirements require a general method that gives a robust foundation for the de- velopment of estimation applications. In this work, a general description language, called Object-Oriented Factor Graph Modeling Language (OOFGML), is proposed, that unifies formulation of esti- mation tasks from the application-oriented problem description via the choice of variable and probability distribution representation through to the inference method definition in implementation. The different language properties are dis- cussed theoretically using abstract examples. The derivation of explicit application examples is shown for the automated driv- ing domain. A domain-specific ontology is defined which forms the basis for four exemplary applications covering the broad spectrum of estimation tasks in this domain: Basic temporal filtering, ego vehicle localization using advanced interpretations of perceived objects, road layout perception utilizing inter-object dependencies and finally highly integrated route, behavior and motion estima- tion to predict traffic participant’s future actions. All applications are evaluated as proof of concept and provide an example of how their class of estimation tasks can be represented using the proposed language. The language serves as a com- mon basis and opens a new field for further research towards holistic solutions for automated driving

Light-induced charge-transfer dynamics in Ruthenium-polypyridine complexes

Die Arbeit beinhaltet die photophysikalische Charakterisierung verschiedener Ruthenium-polypyridyl-Komplexe mit Fokus auf dem lichtinduzierten Ladungstransfer ausgehend vom Ru-zentrum. Dabei wurden die Techniken der Absorptions-, Emissions- und Ultrakurzzeit-Pump-Probe-Spektroskopie verwendet, um die Abhängigkeit dieses Ladungstransfers von Umgebungsparametern und Substitutionen an den Polypyridyl-Liganden zu untersuchen