An expanded database of Southern Hemisphere surface sediment dinoflagellate cyst assemblages and their oceanographic affinities

Dinoflagellate cyst assemblages present a valuable proxy to infer paleoceanographic conditions, yet factors influencing geographic distributions of species remain largely unknown, especially in the Southern Ocean. Strong lateral transport, sea-ice dynamics, and a sparse and uneven geographic distribution of surface sediment samples have limited the use of dinocyst assemblages as a quantitative proxy for paleo-environmental conditions such as sea surface temperature (SST), nutrient concentrations, salinity, and sea ice (presence). In this study we present a new set of surface sediment samples (n=66) from around Antarctica, doubling the number of Antarctic-proximal samples to 100 (dataset wsi_100) and increasing the total number of Southern Hemisphere samples to 655 (dataset sh_655). Additionally, we use modelled ocean conditions and apply Lagrangian techniques to all Southern Hemisphere sample stations to quantify and evaluate the influence of lateral transport on the sinking trajectory of microplankton and, with that, to the inferred ocean conditions. k-means cluster analysis on the wsi_100 dataset demonstrates the strong affinity of Selenopemphix antarctica with sea-ice presence and of Islandinium spp. with low-salinity conditions. For the entire Southern Hemisphere, the k-means cluster analysis identifies nine clusters with a characteristic assemblage. In most clusters a single dinocyst species dominates the assemblage. These clusters correspond to well-defined oceanic conditions in specific Southern Ocean zones or along the ocean fronts. We find that, when lateral transport is predominantly zonal, the environmental parameters inferred from the sea floor assemblages mostly correspond to those of the overlying ocean surface. In this case, the transport factor can thus be neglected and will not represent a bias in the reconstructions. Yet, for some individual sites, e.g. deep-water sites or sites under strong-current regimes, lateral transport can play a large role. The results of our study further constrain environmental conditions represented by dinocyst assemblages and the location of Southern Ocean frontal systems.</p

Study of ground and excited state decays in N approximate to Z Ag nuclei

4 pags., 4 figs. -- CGS15 – Capture Gamma-Ray Spectroscopy and Related TopicsA decay spectroscopy experiment was performed within the EURICA campaign at RIKEN in 2012. It aimed at the isomer and particle spectroscopy of excited states and ground states in the mass region below the doubly magic 100Sn. The N = Z nuclei 98In, 96Cd and 94Ag were of particular interest for the present study. Preliminary results on the neutron deficient nuclei 93Ag and 94Ag are presented. In 94Ag a more precise value for the half-life of the ground state’s superallowed Fermi transition was deduced. In addition the energy spectra of the mentioned decay could be reproduced through precise Geant4 simulations of the used active stopper SIMBA. This will enable us to extract Qβ values from the measured data. The decay of 93Ag is discussed based on the observed implantation-decay correlation events.This work was carried out at the RIBF operated by RIKEN Nishina Center, RIKEN and CNS, University of Tokyo. We acknowledge the EUROBALL Owners Committee for the loan of germanium detectors and the PreSpec Collaboration for the readout electronics of the cluster detectors. This work was supported by the German BMBF under Contract No. 05P12PKFNE and by the U.S. Department of Energy under grant No. DE-FG02-91ER-40609

The role of core excitations in the structure and decay of the 16+ spin-gap isomer in 96Cd

The first evidence for β-delayed proton emission from the 16+ spin gap isomer in 96Cd is presented. The data were obtained from the Rare Isotope Beam Factory, at the RIKEN Nishina Center, using the BigRIPS spectrometer and the EURICA decay station. βp branching ratios for the ground state and 16+ isomer have been extracted along with more precise lifetimes for these states and the lifetime for the ground state decay of 95Cd. Large scale shell model (LSSM) calculations have been performed and WKB estimates made for ℓ=0,2,4 proton emission from three resonance-like states in 96Ag, that are populated by the β decay of the isomer, and the results compared to the new data. The calculations suggest that ℓ=2 proton emission from the resonance states, which reside ∼5 MeV above the proton separation energy, dominates the proton decay. The results highlight the importance of core-excited wavefunction components for the 16+ state

Davidson on Self‐Knowledge: A Transcendental Explanation

Davidson has attempted to offer his own solution to the problem of self-knowledge, but there has been no consensus between his commentators on what this solution is. Many have claimed that Davidson’s account stems from his remarks on disquotational specifications of self-ascriptions of meaning and mental content, the account which I will call the “Disquotational Explanation”. It has also been claimed that Davidson’s account rather rests on his version of content externalism, which I will call the “Externalist Explanation”. I will argue that not only are these explanations of self-knowledge implausible, but Davidson himself has already rejected them. Thus, neither can be attributed to Davidson as his suggested account of self-knowledge. I will then introduce and support what I take to be Davidson’s official and independent account of self-knowledge, that is, his “Transcendental Explanation”. I will defend this view against certain potential objections and finally against the objections made by William Child

Study of Isomeric States in ^{198,200,202,206}Pb and ²⁰⁶Hg Populated in Fragmentation Reactions

Isomeric states in isotopes in the vicinity of doubly-magic 208Pb were populated following reactions of a relativistic 208Pb primary beam impinging on a 9Be fragmentation target. Secondary beams of 198;200;202;206Pb and 206Hg were isotopically separated and implanted in a passive stopper positioned in the focal plane of the GSI Fragment Separator. Delayed γ rays were detected with the Advanced GAmma Tracking Array (AGATA). Decay schemes were re-evaluated and interpreted with shell-model calculations. The momentum-dependent population of isomeric states in the two-nucleon hole nuclei 206Pb/206Hg was found to differ from the population of multi neutron-hole isomeric states in 198;200;202Pb

Kant's Threefold Synthesis On a Moderately Conceptualist Interpretation

In this chapter I advance a moderately conceptualist interpretation of Kant’s account of the threefold synthesis in the A-Deduction. Often the first version of TD, the A-Deduction, is thought to be less conceptualist than the later B-version from 1787 (e.g. Heidegger 1991, 1995). Certainly, it seems that in the B-Deduction Kant puts more emphasis on the role of the understanding in determining the manifold of representations in intuition than he does in the A-Deduction. It also appears that in the A-Deduction the seemingly pre-conceptual aspects of a priori synthesis, namely those of the synthesis of apprehension and the imagination, are more prominently featured than in the B-Deduction. And the fact that in the A-Deduction judgement does not appear to play any significant role reinforces the view that the A-Deduction is less strongly conceptualist. I believe that Kant is a conceptualist also in the A-Deduction (as much as in the B-Deduction) in the sense that all syntheses, which are expounded in the second section of the A-Deduction, must be seen as involving the categories or the understanding as the seat of the categories. However, despite some apparent strong modal claims regarding apperception in the A-Deduction, I argue that Kant is a moderate conceptualist in the sense that he allows for the real possibility that some representations are apprehended that are not subsumed or subsumable under the categories, or determined or determinable by the understanding as the seat of the categories. Not all representations must be synthesised and hence be conceptualised (by means of the categories), nor are all representations necessarily conceptualisable (by means of the categories). Often it is argued that the application of the categories must be seen as separate from or prior to conceptualisation (that is, employment of concepts in a judgement), so that the categories must be considered to apply to representations at least to the extent that the productive imagination or recognitive synthesis is involved, even if no empirical concepts are applied in an actual judgement. But it is difficult to see how categories can apply outside the context of an actual judgement in which ipso facto empirical concepts are employed, because, after all, categories are nothing but logical functions of judgement (e.g. B143). More in particular, I shall argue for the claims that (1) appearances to the contrary, all three levels of syntheses in the A-Deduction, including the synthesis of recognition, are interdependent and are not to be seen as operating singly or independently of each other, and hence of the categories; (2) ‘mere’ apprehension, or ‘mere’ intuition, is not dependent on the understanding and the application or possible application of the categories; and that (3) ‘mere’ apprehension does not even invoke a priori synthesis of apprehension and hence is as such fully lawless in terms of Kantian a priori laws. In this context, I also address Kant’s argument in the A-Deduction about the role of the imagination in the production of spatial objects and explain his apt use of the example of cinnabar to show that the kind of association that is at issue here concerns the possibility of knowledge, not the possibility of mere association, as is often assumed

Search formixed-symmetry states of nuclei in the vicinity of the double-magic nucleus 208Pb

In this work we present the results from two experiments dedicated to search for quadrupolecollective isovector valence-shell excitation, the states with so-called mixed proton-neutron symmetry (MSS), in nuclei around the doubly magic nucleus 208Pb. 212Po was studied in an α-transfer reaction. 204Hg was studied in an inverse kinematics Coulomb excitation reaction on a carbon target. Both experiments provide indications for existence of one-phonon MSSs. Those are the first experimentally identified MSSs in the mass A ≈ 208 region

Properties of γ-decaying isomers in the 100 Sn region revisited

International audienceThe study of nuclei in the region around the N = Z doubly-magic nucleus 100Sn has been of long standing interest for the nuclear structure and nuclear astrophysics. Recently, Park et al. have reported on properties of γ-decaying isomers and isomeric ratios in the vicinity of 100Sn. That experiment was performed at the Radioactive Ion Beam Factory (RIBF) of the RIKEN Nishina Center in Japan as a part of the EURICA campaign. Neutron-deficient nuclei were produced in a fragmentation reaction of a 124Xe primary beam on a 9Be target at an energy of 345 MeV/A. Secondary ions were separated and identified in the BigRIPS fragment separator and implanted in the silicon detector array WAS3ABi. The data presented here were obtained in another experiment performed at the RIBF using the same reaction but slightly different separator settings. New results of ratios of isomeric population and half-lives of γ-decaying isomers populated in the experiment are presented

Properties of γ-decaying isomers in the Sn 100 region populated in fragmentation of a Xe 124 beam

A systematic study was performed of microsecond γ-decaying isomers around Sn100 produced in a fragmentation reaction of a Xe124 beam at 345 MeV/u at the Radioactive Ion Beam Factory of the RIKEN Nishina Center in Saitama, Japan. Half-lives of isomeric states in that region were remeasured allowing us to improve the currently available experimental information. Reduced transition probabilities were deduced and compared to shell-model calculations in various model spaces. The recently reported low-energy transitions in Rh92 and Ag96 were remeasured with improved precision. Additionally, experimental information on isomeric ratios, including five new ones, were extracted and compared to a previous experimental study and the sharp cutoff model of fragmentation reaction