509 research outputs found

    Mysteries, philosophy, and self-representation in imperial Rome : Plutarch, Apuleius, and Vettius Agorius Praetextatus

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    In my dissertation, I explore the use of mystery cults in three separate authors -- Plutarch of Chaeronea, Apuleius of Madauros, and Vettius Agorius Praetextatus -- and analyze how these writers use mystery cults to self-referential ends. This study is not primarily concerned with the actual rituals and the objects used in mystery cults, but rather explores how these writers present these elements in their works. Through writing about mystery cults, I argue, these authors intentionally construct significant facets of their public iamges built around claims to erudition and the possession of a paideia that includes knowledge of Greek philosophy (often explicitly Platonic). Further, these constructed images are colored by traditionalism and antiquarianism. I argue that these texts are (auto)biographical in nature because each author shapes his personal experience and his ideas about religious practice in calculated ways that aims for a particular type of self-presentation. Through discussion of mystery cults, that is, these three authors present themselves in a way that address both reading and listening audiences. I chart the elements consistent between each author and also explore how specific historical contexts and contemporary intellectual currents shaped what it meant to write about mystery cults over a span of nearly three hundred years. Plutarch's On Superstition and On Isis and Osiris, Apuleius' Apology and Golden Ass, and Praetextatus' funerary monument in conjunction with Macrobius' Saturnalia all show that elite authors intimately connect participation in mystery cults with erudition and the possession of philosophical knowledge, which is Greek and Platonic in nature. More particularly, Plutarch and Apuleius make strong connections between themselves and the Greek past, emphasizing their connections to Platonic thought. Although Praetextatus' funerary monument contains some vague Platonic resonances, it primarily emphasizes his connection with traditional religion practices of the Roman senatorial aristocracy that consciously separate the senator from the Christian element in Roman high society. Ultimately, philosophy and religion are nearly synonymous in these texts. In short, each author intellectualizes popular religious forms in order to highlight in some manner the difference between the social elite and the common people. Writing about mysteries is also self-writing.Includes bibliographical reference

    On the Subgroup Distance Problem

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    We investigate the computational complexity of finding an element of a permutation group H subset S_n with a minimal distance to a given pi in S_n , for different metrics on S_n . We assume that H is given by a set of generators, such that the problem cannot be solved in polynomial time by exhaustive enumeration. For the case of the Cayley Distance, this problem has been shown to be NP-hard, even if H is abelian of exponent two Pinch, 2006. We present a much simpler proof for this result, which also works for the Hamming Distance, the l\_p distance, Lee's Distance, Kendall's tau, and Ulam's Distance. Moreover, we give an NP-hardness proof for the l\_oo distance using a different reduction idea. Finally, we settle the complexity of the corresponding fixed-parameter and maximization problems

    Ultra precise characterization of LCLS hard X ray focusing mirrors by high resolution slope measuring deflectometry

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    We present recent results on the inspection of a first diffractionlimited hard X ray Kirkpatrick Baez KB mirror pair for the Coherent Xray Imaging CXI instrument at the Linac Coherent Light Source LCLS . The full KB system mirrors and holders was under inspection by use of high resolution slope measuring deflectometry. The tests confirmed that KB mirrors of 350mm aperture length characterized by an outstanding residual figure error of lt;1 nm rms has been realized. This corresponds to the residual figure slope error of about 0.05 amp; 956;rad rms, unprecedented on such long elliptical mirrors. Additional measurements show the clamping of the mirrors to be a critical step for the final shape preserving installation of such outstanding optic

    Coatings for FEL optics preparation and characterization of B4C and Pt

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    Large X ray mirrors are required for beam transport at both present day and future free electron lasers FELs and synchrotron sources worldwide. The demand for large mirrors with lengths up to 1 m single layers consisting of light or heavy elements has increased during the last few decades. Accordingly, surface finishing technology is now able to produce large substrate lengths with micro roughness on the sub nanometer scale. At the Helmholtz Zentrum Geesthacht HZG , a 4.5 m long sputtering facility enables us to deposit a desired single layer material some tens of nanometers thick. For the European XFEL project, the shape error should be less than 2 nm over the whole 1 m X ray mirror length to ensure the safe and efficient delivery of X ray beams to the scientific instruments. The challenge is to achieve thin film deposition on silicon substrates, benders and gratings without any change in mirror shape. Thin films of boron carbide and platinum with a thickness in the range 30 100 nm were manufactured using the HZG sputtering facility. This setup is able to cover areas of up to 1500 mm x120 mm in one step using rectangular sputtering sources. The coatings produced were characterized using various thin film methods. It was possible to improve the coating process to achieve a very high uniformity of the layer thickness. The movement of the substrate in front of the sputtering source has been optimized. Avariation in B4C layer thickness below 1 nm peak to valley was achieved at a mean thickness of 51.8 nm over a deposition length of 1.5 m. In the case of Pt, reflectometry and micro roughness measurements were performed. The uniformity in layer thickness was about 1 nm peak to valley . The micro roughness of the Pt layers showed no significant change in the coated state for layer thicknesses of 32 nm and 102 nm compared with the uncoated substrate state. The experimental results achieved will be discussed with regard to current restrictions and future development

    Internal Transcribed Spacer 2 (nu ITS2 rRNA) Sequence-Structure Phylogenetics: Towards an Automated Reconstruction of the Green Algal Tree of Life

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    L). Some have advocated the use of the nuclear-encoded, internal transcribed spacer two (ITS2) as an alternative to the traditional chloroplast markers. However, the ITS2 is broadly perceived to be insufficiently conserved or to be confounded by introgression or biparental inheritance patterns, precluding its broad use in phylogenetic reconstruction or as a DNA barcode. A growing body of evidence has shown that simultaneous analysis of nucleotide data with secondary structure information can overcome at least some of the limitations of ITS2. The goal of this investigation was to assess the feasibility of an automated, sequence-structure approach for analysis of IT2 data from a large sampling of phylum Chlorophyta.Sequences and secondary structures from 591 chlorophycean, 741 trebouxiophycean and 938 ulvophycean algae, all obtained from the ITS2 Database, were aligned using a sequence structure-specific scoring matrix. Phylogenetic relationships were reconstructed by Profile Neighbor-Joining coupled with a sequence structure-specific, general time reversible substitution model. Results from analyses of the ITS2 data were robust at multiple nodes and showed considerable congruence with results from published phylogenetic analyses.Our observations on the power of automated, sequence-structure analyses of ITS2 to reconstruct phylum-level phylogenies of the green algae validate this approach to assessing diversity for large sets of chlorophytan taxa. Moreover, our results indicate that objections to the use of ITS2 for DNA barcoding should be weighed against the utility of an automated, data analysis approach with demonstrated power to reconstruct evolutionary patterns for highly divergent lineages

    Attachment-specific speech patterns induce dysphoric mood changes in the listener as a function of individual differences in attachment characteristics and psychopathology

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    Objectives Early childhood experiences influence cognitive-emotional development, with insecure attachment predisposing to potential psychopathologies. We investigated whether narratives containing attachment-specific speech patterns shape listeners’ emotional responses and social intentions. Design First, 149 healthy participants listened to three narratives characteristic for secure, insecure-preoccupied, and insecure-dismissing attachment. Following each narrative, the wellbeing and interpersonal reactivity as a particular aspect of emotional reactivity of the listener were assessed. Likewise, psychopathological aspects of personality were evaluated. A follow-up study compared 10 psychosomatic patients with a current depressive episode and/or personality disorder with distinct depressive symptoms and 10 age- and gender-matched healthy controls. Methods Effects of narratives on listeners’ mental state were tested with repeated-measures AN(C)OVA. Mediating effects in the listener (attachment characteristics in the context of personality traits) were explored. Narrative effects were compared between patients and controls. Results Listening to insecure attachment narratives reduced wellbeing in controls. Nevertheless, tendency for social interaction was highest following the insecure-preoccupied narrative. Importantly, listeners’ individual attachment characteristics mediated the relationship between wellbeing/interpersonal reactivity following the insecure-preoccupied narrative and levels of psychopathology. Furthermore, compared with healthy participants, patients showed higher emotional reactivity following exposure to the insecure-preoccupied narrative, represented by lower wellbeing and lower estimation of friendliness towards the narrator. Conclusions Exposure to attachment-specific speech patterns can result in dysphoric mood changes. Specifically, the insecure-preoccupied narrative influenced the listeners’ emotional state, which was further mediated by the individual attachment patterns and psychopathological personality characteristics. This deepens the understanding of interpersonal processes, especially in psychotherapeutic settings

    Cells' Flow and Immune Cell Priming under alternating g-forces in Parabolic Flight

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    Gravitational stress in general and microgravity (mu g) in particular are regarded as major stress factors responsible for immune system dysfunction in space. To assess the effects of alternating mu g and hypergravity (hyper-g) on immune cells, the attachment of peripheral blood mononuclear cells (PBMCs) to adhesion molecules under flow conditions and the antigen-induced immune activation in whole blood were investigated in parabolic flight (PF). In contrast to hyper-g (1.8 g) and control conditions (1 g), flow and rolling speed of PBMCs were moderately accelerated during mu g-periods which were accompanied by a clear reduction in rolling rate. Whole blood analyses revealed a "primed" state of monocytes after PF with potentiated antigen-induced pro-inflammatory cytokine responses. At the same time, concentrations of anti-inflammatory cytokines were increased and monocytes displayed a surface molecule pattern that indicated immunosuppression. The results suggest an immunologic counterbalance to avoid disproportionate immune responses. Understanding the interrelation of immune system impairing and enhancing effects under different gravitational conditions may support the design of countermeasures to mitigate immune deficiencies in space

    Evolutionary distances in the twilight zone -- a rational kernel approach

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    Phylogenetic tree reconstruction is traditionally based on multiple sequence alignments (MSAs) and heavily depends on the validity of this information bottleneck. With increasing sequence divergence, the quality of MSAs decays quickly. Alignment-free methods, on the other hand, are based on abstract string comparisons and avoid potential alignment problems. However, in general they are not biologically motivated and ignore our knowledge about the evolution of sequences. Thus, it is still a major open question how to define an evolutionary distance metric between divergent sequences that makes use of indel information and known substitution models without the need for a multiple alignment. Here we propose a new evolutionary distance metric to close this gap. It uses finite-state transducers to create a biologically motivated similarity score which models substitutions and indels, and does not depend on a multiple sequence alignment. The sequence similarity score is defined in analogy to pairwise alignments and additionally has the positive semi-definite property. We describe its derivation and show in simulation studies and real-world examples that it is more accurate in reconstructing phylogenies than competing methods. The result is a new and accurate way of determining evolutionary distances in and beyond the twilight zone of sequence alignments that is suitable for large datasets.Comment: to appear in PLoS ON

    A Generalization of the Directed Graph Layering Problem

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    The Directed Layering Problem (DLP) solves a step of the widely used layer-based layout approach to automatically draw directed acyclic graphs. To cater for cyclic graphs, classically a preprocessing step is used that solves the Feedback Arc Set Problem (FASP)to make the graph acyclic before a layering is determined. Here, we present the Generalized Layering Problem (GLP) which solves the combination of DLP and FASP simultaneously, allowing general graphs as input. We show GLP to be NP- complete, present integer programming models to solve it, and perform thorough evaluations on different sets of graphs and with different implementations for the steps of the layer- based approach. We observe that GLP reduces the number of dummy nodes significantly, can produce more compact drawings and improves on graphs where DLP yields poor aspect ratios
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