The effect of a southward interplanetary magnetic field on St\"ormer's allowed regions

The motion of a charged particle in a magnetic dipole has first been studied by Stormer. The different applications of Stormer's theory to aurorae, cosmic rays and Van Allen radiation belt particles are recalled in an historical perspective. In this paper, we expand the Stormer theory in order to take into account the effects produced by an additional uniform and stationary interplanetary magnetic field (IMF) whose orientation is parallel or antiparallel to the magnetic moment of the dipole. A new expression is derived for the Stormer potential taking into account the additional IMF component. It is shown how Stormer's allowed and forbidden zones are influenced by the implementation of a northward or a southward IMF, and how a southward turning of the IMF orientation makes it easier for Solar Energetic Particle and Galactic Cosmic Rays to enter into the inner part of the geomagnetic field along interconnected magnetic field lines.Comment: 24 Pages; 15 Figures; Tutorial Lecture Presented At The Cospar Colloquium "Plasma Processes In Th Near-Earth Space: Interball And Beyond, Sofia, Bulgaria, 5-10 200

Transformationspfade für eine Kultur der Nachhaltigkeit an deutschen Hochschulen [Pathways of transformation towards a culture of sustainability in German higher education institutions]

Die Hochschulrektorenkonferenz hat sich 2018 für eine ,,Kultur der Nachhaltigkeit“ ausgesprochen. Um dieses neue Leitbild für die Hochschulentwicklung auszugestalten, hat sich das Verbundvorhaben Hochschulen in Gesellschaft ‐ Realexperimente transformativer Lern- und Forschungsprozesse für eine Kultur der Nachhaltigkeit an Hochschulen gegründet. Es will alle relevanten Stakeholder von Hochschulen ansprechen und einen wichtigen Impuls für die Nachhaltigkeitstransformation an Hochschulen setzen

Transformationspfade für eine Kultur der Nachhaltigkeit an deutschen Hochschulen

Die Hochschulrektorenkonferenz hat sich 2018 für eine ,,Kultur der Nachhaltigkeit“ ausgesprochen. Um dieses neue Leitbild für die Hochschulentwicklung auszugestalten, hat sich das Verbundvorhaben Hochschulen in Gesellschaft ‐ Realexperimente transformativer Lern- und Forschungsprozesse für eine Kultur der Nachhaltigkeit an Hochschulen gegründet. Es will alle relevanten Stakeholder von Hochschulen ansprechen und einen wichtigen Impuls für die Nachhaltigkeitstransformation an Hochschulen setzen

The Tri-Trophic Interactions Hypothesis: Interactive Effects of Host Plant Quality, Diet Breadth and Natural Enemies on Herbivores

Several influential hypotheses in plant-herbivore and herbivore-predator interactions consider the interactive effects of plant quality, herbivore diet breadth, and predation on herbivore performance. Yet individually and collectively, these hypotheses fail to address the simultaneous influence of all three factors. Here we review existing hypotheses, and propose the tri-trophic interactions (TTI) hypothesis to consolidate and integrate their predictions. The TTI hypothesis predicts that dietary specialist herbivores (as compared to generalists) should escape predators and be competitively dominant due to faster growth rates, and that such differences should be greater on low quality (as compared to high quality) host plants. To provide a preliminary test of these predictions, we conducted an empirical study comparing the effects of plant (Baccharis salicifolia) quality and predators between a specialist (Uroleucon macolai) and a generalist (Aphis gossypii) aphid herbivore. Consistent with predictions, these three factors interactively determine herbivore performance in ways not addressed by existing hypotheses. Compared to the specialist, the generalist was less fecund, competitively inferior, and more sensitive to low plant quality. Correspondingly, predator effects were contingent upon plant quality only for the generalist. Contrary to predictions, predator effects were weaker for the generalist and on low-quality plants, likely due to density-dependent benefits provided to the generalist by mutualist ants. Because the TTI hypothesis predicts the superior performance of specialists, mutualist ants may be critical to A. gossypii persistence under competition from U. macolai. In summary, the integrative nature of the TTI hypothesis offers novel insight into the determinants of plant-herbivore and herbivore-predator interactions and the coexistence of specialist and generalist herbivores

River ecosystem conceptual models and non‐perennial rivers: A critical review

Conceptual models underpin river ecosystem research. However, current models focus on continuously flowing rivers and few explicitly address characteristics such as flow cessation and drying. The applicability of existing conceptual models to nonperennial rivers that cease to flow (intermittent rivers and ephemeral streams, IRES) has not been evaluated. We reviewed 18 models, finding that they collectively describe main drivers of biogeochemical and ecological patterns and processes longitudinally (upstream-downstream), laterally (channel-riparian-floodplain), vertically (surface water-groundwater), and temporally across local and landscape scales. However, perennial rivers are longitudinally continuous while IRES are longitudinally discontinuous. Whereas perennial rivers have bidirectional lateral connections between aquatic and terrestrial ecosystems, in IRES, this connection is unidirectional for much of the time, from terrestrial-to-aquatic only. Vertical connectivity between surface and subsurface water occurs bidirectionally and is temporally consistent in perennial rivers. However, in IRES, this exchange is temporally variable, and can become unidirectional during drying or rewetting phases. Finally, drying adds another dimension of flow variation to be considered across temporal and spatial scales in IRES, much as flooding is considered as a temporally and spatially dynamic process in perennial rivers. Here, we focus on ways in which existing models could be modified to accommodate drying as a fundamental process that can alter these patterns and processes across spatial and temporal dimensions in streams. This perspective is needed to support river science and management in our era of rapid global change, including increasing duration, frequency, and occurrence of drying.info:eu-repo/semantics/publishedVersio

Native California soils are selective reservoirs for multidrug-resistant bacteria

Soil bacteria can exhibit extensive antibiotic resistomes and act as reservoirs of important antibiotic resistance traits. However, the geographic sources and evolutionary drivers of resistance traits are poorly understood in these natural settings. We investigated the prevalence, spatial structure and evolutionary drivers of multidrug resistance in natural populations of Bradyrhizobium, a cosmopolitan bacterial lineage that thrives in soil and aquatic systems as well as in plant and human hosts. We genotyped > 400 isolates from plant roots and soils across California and assayed 98 of them for resistance traits against 17 clinically relevant antibiotics. We investigated the geographic and phylogenetic structure of resistance traits, and analysed correlations of resistance with strain abundance, host infection capacity and in vitro fitness. We found: (i) multidrug resistance at all sites, (ii) subsets of resistance traits that are spatially structured and (iii) significant associations between resistance traits and increased strain abundance or host infection capacity. Our results highlight multiple selective factors that can result in the spread of resistance traits in native Bradyrhizobium populations

Late 1920s film theory and criticism as a test-case for Benjamin’s generalizations on the experiential effects of editing

This article investigates Walter Benjamin’s influential generalization that the effects of cinema are akin to the hyper-stimulating experience of modernity. More specifically, I focus on his oft-cited 1935/36 claim that all editing elicits shock-like disruption. First, I propose a more detailed articulation of the experience of modernity understood as hyper-stimulation and call for distinguishing between at least two of its subsets: the experience of speed and dynamism, on the one hand, and the experience of shock/disruption, on the other. Then I turn to classical film theory of the late 1920s to demonstrate the existence of contemporary views on editing alternative to Benjamin’s. For instance, whereas classical Soviet and Weimar theorists relate the experience of speed and dynamism to both Soviet and classical Hollywood style editing, they reserve the experience of shock/disruption for Soviet montage. In order to resolve the conceptual disagreement between these theorists, on the one hand, and Benjamin, on the other, I turn to late 1920s Weimar film criticism. I demonstrate that, contrary to Benjamin’s generalizations about the disruptive and shock-like nature of all editing, and in line with other theorists’ accounts, different editing practices were regularly distinguished by comparison to at least two distinct hyper-stimulation subsets: speed and dynamism, and shock-like disruption. In other words, contemporaries regularly distinguished between Soviet montage and classical Hollywood editing patterns on the basis of experiential effects alone. On the basis of contemporary reviews of city symphonies, I conclude with a proposal for distinguishing a third subset – confusion. This is an original manuscript / preprint of an article published by Taylor & Francis in Early Popular Visual Culture on 02 Aug 2016 available online: https://doi.org/10.1080/17460654.2016.1199322

Functional Copy-Number Alterations in Cancer

Understanding the molecular basis of cancer requires characterization of its genetic defects. DNA microarray technologies can provide detailed raw data about chromosomal aberrations in tumor samples. Computational analysis is needed (1) to deduce from raw array data actual amplification or deletion events for chromosomal fragments and (2) to distinguish causal chromosomal alterations from functionally neutral ones. We present a comprehensive computational approach, RAE, designed to robustly map chromosomal alterations in tumor samples and assess their functional importance in cancer. To demonstrate the methodology, we experimentally profile copy number changes in a clinically aggressive subtype of soft-tissue sarcoma, pleomorphic liposarcoma, and computationally derive a portrait of candidate oncogenic alterations and their target genes. Many affected genes are known to be involved in sarcomagenesis; others are novel, including mediators of adipocyte differentiation, and may include valuable therapeutic targets. Taken together, we present a statistically robust methodology applicable to high-resolution genomic data to assess the extent and function of copy-number alterations in cancer

Added Value of Molecular Biological Analysis in Diagnosis and Clinical Management of Liposarcoma: A 30-Year Single-Institution Experience

Biological, physical and clinical aspects of cancer treatment with ionising radiatio

Understanding the relationship between suicidality, current depressed mood, personality, and cognitive factors

Objectives: Links between suicidality and depressed mood are well established. There is, however, little information about the emotional regulation processes that underlie the relationship between suicidality and current low mood, and how these processes differ between groups of never-suicidal (NS), suicidal ideators, and suicide attempters. As suicidality and depression are heterogeneous constructs, this study aimed to conduct within- and between-group comparisons of known suicide risk factors that are associated with emotion regulation (neuroticism, trait aggression, brooding, impulsivity, and overgeneral autobiographical memories). Design: Correlational design using between- and within-group comparisons from self-report measures. Methods: Inter- and intragroup differences were identified using Pearson's correlation coefficients and tests of difference. An analysis of indirect effects was used to investigate whether the relationship between suicidality and current low mood was mediated by neuroticism, trait aggression, brooding, impulsivity, and overgeneral autobiographical memories, and if this relationship varied according to group type. Results:  Brooding appeared to be a consistent feature of all three groups and was closely related to current low mood. Compared to the NS group, the relationship between suicide attempts and current low mood showed greater associations with brooding, trait aggression, and overgeneral autobiographical memories. Compared to the NS group, the suicidal ideation group showed stronger associations with neuroticism and impulsivity, but these factors did not correlate with low mood. Conclusion: These results suggest a need for larger studies to focus on heterogeneity within suicidal populations and consider how different combinations of risk factors may heighten or reduce suicide risk. Practitioner points: * It is well known that the severity and intensity of suicide and depressed presentations vary because of underlying dispositional and contextual factors (Fried & Nesse, ) which, in turn, affect how events are interpreted and responded to. Despite this, there is little research about how these mechanisms operate in different types of suicide groups, and their influence on the relationship between suicidality and current low mood. * Understanding interrelationships that affect current low mood is of clinical significance because past suicidal history and deteriorations in already negative mood are linked to repeated suicide attempts and completion. * Our findings show that ruminative brooding, defined as a tendency to repeatedly think about emotional aspects of an event, consistently correlates with current low mood across different types of suicidal groups (NS, suicidal ideators, and suicide attempters), and across analyses. * Findings also show that suicidal ideation and attempt groups were associated with specific personality characteristics that increased the propensity of emotional responding and interpretation compared to the NS group. The relationship between suicide attempt and current low mood had a higher propensity to be influenced by trait aggression, brooding, and overgenerality compared to the NS group. In contrast, although the suicidal ideation group correlated more strongly with neuroticism and impulsivity, these factors did not influence current low mood. * In terms of clinical practice, these findings imply that specific styles of interpretation and thinking may maintain the relationship between suicidality and current low mood. Given the cross-sectional nature of the study, however, it is not possible to imply causality. Nevertheless, the findings obtained provide some support for transdiagnostic models of cognitive-behavioural processes that could be developed further.PostprintPeer reviewe