2,474 research outputs found

    Probabilistic prediction of rupture length, slip and seismic ground motions for an ongoing rupture: implications for early warning for large earthquakes

    Get PDF
    Earthquake EarlyWarning (EEW) predicts future ground shaking based on presently available data. Long ruptures present the best opportunities for EEW since many heavily shaken areas are distant from the earthquake epicentre and may receive long warning times. Predicting the shaking from large earthquakes, however, requires some estimate of the likelihood of the future evolution of an ongoing rupture. An EEW system that anticipates future rupture using the present magnitude (or rupture length) together with the Gutenberg-Richter frequencysize statistics will likely never predict a large earthquake, because of the rare occurrence of ‘extreme events’. However, it seems reasonable to assume that large slip amplitudes increase the probability for evolving into a large earthquake. To investigate the relationship between the slip and the eventual size of an ongoing rupture, we simulate suites of 1-D rupture series from stochastic models of spatially heterogeneous slip. We find that while large slip amplitudes increase the probability for the continuation of a rupture and the possible evolution into a ‘Big One’, the recognition that rupture is occurring on a spatially smooth fault has an even stronger effect.We conclude that anEEWsystem for large earthquakes needs some mechanism for the rapid recognition of the causative fault (e.g., from real-time GPS measurements) and consideration of its ‘smoothness’. An EEW system for large earthquakes on smooth faults, such as the San Andreas Fault, could be implemented in two ways: the system could issue a warning, whenever slip on the fault exceeds a few metres, because the probability for a large earthquake is high and strong shaking is expected to occur in large areas around the fault. A more sophisticated EEW system could use the present slip on the fault to estimate the future slip evolution and final rupture dimensions, and (using this information) could provide probabilistic predictions of seismic ground motions along the evolving rupture. The decision on whether an EEW system should be realized in the first or in the second way (or in a combination of both) is user-specific

    RNAi-based anti-cancer strategies - targeting the proto-oncogene PIM1 and oncogenic miRNAs

    Get PDF
    Cancer is a chronic disease caused by a degeneration of somatic cells due to mutations. In general cells grow erratic and under certain conditions this leads to an infiltration of even healthy tissues. To date cancer is the second most common cause of death in the Western world and belongs to one of the most important epidemiological diseases of our society. Besides traditional methods in cancer treatment such as resection of tumor tissue, chemo or immunotherapy, the development of novel therapeutic strategies is of the highest importance. One therapeutic option would include the use of small non coding regulatory RNAs such as miRNAs. MiRNAs are involved in the regulation of crucial biological processes such as development, differentiation or proliferation due to the control of the cell’s gene expression via RNA interference. Since the discovery of miRNAs, evidence has emerged that they can exert either tumor suppressive or oncogenic functions. Thus miRNAs are not only applied as diagnostic or prognostic biomarkers of cancerous tissues, but can also function as therapeutics. In miRNA replacement therapy a loss or downregulation of a tumor suppressive miRNA is adjusted with addition of this single miRNA. On the contrary an antisense therapy approach mediates the inhibition of oncogenic miRNAs by antisense oligonucleotides. Safe and efficient delivery of the oligonucleotides has to be guaranteed for both approaches. Currently the development of such efficient delivery systems is the critical and limiting factor upon miRNA based therapy designs. In this thesis the proto oncogene PIM1 was considered regarding a putative RNA based anti cancer strategy. Overexpression of PIM1 kinase usually is associated with severe forms of cancers with bad prognosis in several solid tumors or malign degenerations of the hematopoietic system. In vitro studies revealed a specific reduction of PIM1 protein levels in human leukemia and colon carcinoma cell lines due to a miRNA with tumor suppressive potential, namely miR 33a. Additionally this decrease in PIM1 resulted in an inhibition of proliferation. Successful delivery with nanoparticle complexes composed of miR 33a oligonucleotides and a non toxic branched polyethylenimine (PEI F25 LMW) showed an anti tumor effect in mouse colon carcinoma models that was obtained through a reduction in tumor size. These in vitro and in vivo studies provide evidence for the first time that the proto oncogene PIM1 is a promising target for miRNA replacement therapy. The second project dealt with the development of novel LNA based miRNA inhibitors, termed LNA antiseeds, composed of single stranded RNA oligonucleotides with locked nucleic acid (LNA) modifications and a natural phosphodiester backbone. In general an LNA design enhances the resistance of oligonucleotides against cellular degradation by nucleases. Furthermore affinity of the molecule to the miRNA of interest is increased. Cellular functions of the targeted oncogenic miRNAs are silenced due to complementary binding to the inhibitor. A use of minor amounts of LNA antiseeds already revealed an almost complete inhibition of miRNAs of the miR 106b family in human cancer cell lines which was connected to an endogenous derepression of the tumor suppressor P21. Successful complex formation of the novel LNA antiseeds with the branched polyethylenimine PEI F25 LMW has been proven. Furthermore in vitro experiments confirmed a functional delivery of the resulting nanoparticles into human cancer cell lines. Application of PEI F25 LMW complexed LNA antiseed miRNA inhibitors could now be tested as a promising antisense therapy approach in xenograft tumor mouse models. The third topic addressed the transcriptional regulation of the oncogenic miRNA cluster miR 17 92. Overexpression of this miRNA cluster is associated with enhanced proliferation, sustained angiogenesis and reduced apoptosis in several hematopoietic malignancies and solid tumors. Transcription of human miR 17 92 is significantly regulated by the oncogene MYC. In vitro experiments in human cancer cell lines confirmed that miR 17 92 belongs to one of those 20 % of MYC regulated genes which transcription is controlled by a synergism of MYC and PIM1. Further investigations regarding transcriptional control of miRNA promoters could provide profound evidences for a better understanding of a connection between miRNA expression levels and the development of cancer

    Employer Branding: Kritische WĂŒrdigung eines personalwirtschaftlichen Gestaltungsansatzes

    Full text link
    In der personalwirtschaftlichen Praxis hat sich das Konzept des Employer Branding mittlerweile als ein wesentlicher Bestandteil modernen Personalmanagements mehr oder weniger fest etabliert. Die Entwicklung, Implementierung und Kommu-nikation einer unverwechselbaren Arbeitgebermarke gilt vielen Unternehmen in-zwischen als bedeutsame Voraussetzung, um sich auf den strategisch bedeutsamen ArbeitsmĂ€rkten fĂŒr Fach- und FĂŒhrungskrĂ€fte erfolgreich behaupten zu können. Anhand einer Sichtung einschlĂ€giger Standardwerke, LehrbĂŒcher und Praxisratgeber zum Thema unterzieht der vorliegende Beitrag die inhaltliche Substanz des Employer Branding-Konzepts einer kritischen WĂŒrdigung. Dabei treten einige fun-damentale SchwĂ€chen, WidersprĂŒchlichkeiten und "blinde Flecken" zutage, die nicht bloß als argumentative UnzulĂ€nglichkeiten einzelner Publikationen abgetan werden können, sondern die postulierte LeistungsfĂ€higkeit des Employer Branding-Ansatzes ganz grundsĂ€tzlich in Frage stellen. Im Endergebnis gelangen die Autoren zu der Schlussfolgerung, dass es sich beim Employer Branding ledig-lich um eine zeitgeistgemĂ€ĂŸ aufbereitete Neuauflage des hinlĂ€nglich bekannten Themas "Personalmarketing" handelt

    Geopolitics and Renewable Energy: A Study on the Implications of the Energy Transition

    Get PDF
    This thesis investigates the potential geopolitical implications of the transition to renewable energy for the USA, EU, Russia, and China, addressing the question: "To what extent can the transition to renewable energy be described as a 'game changer' in geopolitics?". Utilizing a document analysis approach, the study reviews relevant theoretical frameworks and literature on the geopolitics of renewable energy, examining themes of winners-losers, direct-indirect influences, and conflict-peace. In addition, the thesis offers an analysis of Scholten et al. (2020) work on the six clusters of implications related to the geopolitics of renewables. The conclusion reveals that in the long-term, the transition to renewable energy may be considered a "game-changer" in geopolitics, particularly in energy geopolitics. The USA and the EU are likely to emerge as winners, while Russia may become a loser due to its heavy reliance on fossil fuel exports. China, with its commitment to renewables and clean technology manufacturing, may also emerge as a winner. The transition is poised to reshape global power structures, creating new sources of conflict and challenges. However, the continued dependence on fossil fuels in the short to medium term tempers the immediate impact of renewable energy on global geopolitical dynamics

    Real-time Finite Fault Rupture Detector (FinDer) for large earthquakes

    Get PDF
    To provide rapid estimates of fault rupture extent during large earthquakes, we have developed the Finite Fault Rupture Detector algorithm, ‘FinDer’. FinDer uses image recognition techniques to detect automatically surface-projected fault ruptures in real-time (assuming a line source) by estimating their current centroid position, length L, and strike ξ. The approach is based on a rapid high-frequency near/far-source classification of ground motion amplitudes in a dense seismic network (station spacing <50 km), and comparison with a set of pre-calculated templates using ‘Matching by Correlation’. To increase computational efficiency, we perform the correlation in the wavenumber domain. FinDer keeps track of the current dimensions of a rupture in progress. Errors in L are typically on the same order as station spacing in the network. The continuously updated estimates of source geometries as provided by FinDer make predicted shaking intensities more accurate and thus more useful for earthquake early warning, ShakeMaps, and related products. The applicability of the algorithm is demonstrated for several recorded and simulated earthquakes with different focal mechanisms, including the 2009 M_w 6.3 L’Aquila (Italy), the 1999 M_w 7.6 ChiChi (Taiwan) and the M_w 7.8 ShakeOut scenario earthquake on the southern San Andreas Fault (California)

    The young binary HD 102077: Orbit, spectral type, kinematics, and moving group membership

    Full text link
    The K-type binary star HD 102077 was proposed as a candidate member of the TW Hydrae Association (TWA) which is a young (5-15 Myr) moving group in close proximity (~50 pc) to the solar system. The aim of this work is to verify this hypothesis by different means. We first combine diffraction-limited observations from the ESO NTT 3.5m telescope in SDSS-i' and -z' passbands and ESO 3.6m telescope in H-band with literature data to obtain a new, amended orbit fit, estimate the spectral types of both components, and reanalyse the Hipparcos parallax and proper motion taking the orbital motion into account. Moreover, we use two high-resolution spectra of HD 102077 obtained with the fibre-fed optical echelle spectrograph FEROS at the MPG/ESO 2.2m telescope to determine the radial velocity and the lithium equivalent width of the system. The trajectory of HD 102077 is well constrained and we derive a total system mass of 2.6±0.8 2.6 \pm 0.8\, M⊙_{\odot} and a semi-major axis of 14.9±1.6 14.9 \pm 1.6\,AU. From the i'-z' colours we infer an integrated spectral type of K2V, and individual spectral types of K0 +/- 1 and K5 +/- 1. The radial velocity corrected for the orbital motion of the system is 17.6±2 17.6 \pm 2\,km/s. Even though the parallax determination from the Hipparcos data is not influenced by the orbital motion, the proper motion changes to Όα∗cos⁥(ÎŽ)=−137.84±1.26 \mu_\alpha*\cos(\delta) = -137.84 \pm 1.26\, mas/yr and ΌΎ=−33.53±1.45 \mu_\delta = -33.53 \pm 1.45 \,mas/yr. With the resultant space motion, the probability of HD 102077 being a member of TWA is less than 1%. Furthermore, the lithium equivalent width of 200±4 200 \pm 4\,m\AA  \, is consistent with an age between 30 Myr and 120 Myr and thus older than the predicted age of TWA. In conclusion, HD 102077's age, galactic space motion, and position do not fit TWA or any other young moving group

    A Synthesized Perspective on Privacy and Transparency in the Digital Workplace

    Get PDF
    The pandemic crisis has made the digitalization of workplaces imperative for many organizations. Besides reorganizing work, rapid advances in technologies also enhance organizational efficiency and enable remote work. Having to work completely digitally imposes unprecedented transparency on employees. A major consequence of the transparent workplace is the emergence of employees’ privacy concerns. Even though the concepts of transparency and privacy are closely related, there is a research gap regarding the relationship between the two. Based on a conceptual approach and a systematic literature review, we postulate a synthesis of transparency and privacy in the digital workplace, and outline directions for future research. We discuss what makes the relationship between the two constructs double-edged by introducing the privacy-transparency paradox. This study therefore adds to the literature on privacy and transparency in the digital workplace and forms the basis for further studies

    VLT Spectroscopy of Globular Cluster Systems, I. The Photometric and Spectroscopic Dataset

    Get PDF
    We present Lick line-index measurements of extragalactic globular clusters in seven early-type galaxies (NGC 1380, 2434, 3115, 3379, 3585, 5846, and 7192) with different morphological types (E-S0) located in field and group/cluster environments. High-quality spectra were taken with the FORS2 instrument at ESO's Very Large Telescope. About 50% of our data allow an age resolution dt/t ~ 0.3 and a metallicity resolution ~0.25-0.4 dex, depending on the absolute metallicity. Globular cluster candidates are selected from deep B, V, R, I, K FORS2/ISAAC photometry with 80-100% success rate inside one effective radius. Using combined optical/near-infrared colour-colour diagrams we present a method to efficiently reduce fore-/background contamination down to <10%. We find clear signs for bi-modality in the globular cluster colour distributions of NGC 1380, 3115, and 3585. The colour distributions of globular clusters in NGC 2434, 3379, 5846, and 7192 are consistent with a broad single-peak distribution. For the analysed globular cluster systems the slopes of projected radial surface density profiles, of the form Sigma(R) ~ R^-Gamma, vary between ~0.8 and 2.6. Using globular clusters as a tracer population we determine total dynamical masses of host galaxies out to large radii (~1.6 - 4.8 Reff). For the sample we find masses in the range ~8.8*10^10 Msolar up to ~1.2*10^12 Msolar. The line index data presented here will be used in accompanying papers of this series to derive ages, metallicities and abundance ratios. A compilation of currently available high-quality Lick index measurements for globular clusters in elliptical, lenticular, and late-type galaxies is provided and will serve to augment the current data set. [abridged]Comment: A&A accepted, 42 page

    More self-organization, more control — or even both? Inverse transparency as a digital leadership concept

    Get PDF
    Digital innovations drive an organization's digital transformation. While numerous studies focus on digital product and service innovation, digital process innovation and novel business models, management and leadership concepts are primarily investigated as enabling framing conditions in previous contributions. However, management and leadership concepts have changed dramatically in the digital era. The rise of digital technologies has led to companies acquiring large amounts of data. Moreover, novel technical solutions facilitate the analysis and processing of this data, leading to an increase in organizational transparency. Traditional leadership theories fail to explain the influence of digitalization and increasing transparency of leadership. In a digitized world, managers often face a trade-off when using data for management purposes. On the one hand, transparency leads to decreasing information asymmetries, allowing managers to monitor employees' actions at low cost. On the other hand, employees demand self-organization and empowerment. In this context, new forms of control and employee engagement need to be designed. With our conceptual paper, we aim to provide a solution to the challenges of using transparency in leadership in a mutually beneficial way for managers and employees by introducing the concept of "inverse transparency." We develop the concept building on the existing literature on transparency and leadership. We see inverse transparency as the basis for a new type of digital innovation, which we introduce as digital leadership innovation. Thus, we enhance current research on leadership approaches and digital innovation and create a theoretical basis for further research
    • 

    corecore