101 research outputs found

    Resonance Lifetimes from Complex Densities

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    The ab-initio calculation of resonance lifetimes of metastable anions challenges modern quantum-chemical methods. The exact lifetime of the lowest-energy resonance is encoded into a complex "density" that can be obtained via complex-coordinate scaling. We illustrate this with one-electron examples and show how the lifetime can be extracted from the complex density in much the same way as the ground-state energy of bound systems is extracted from its ground-state density

    'I-I' and 'I-me' : Transposing Buber's interpersonal attitudes to the intrapersonal plane

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    Hermans' polyphonic model of the self proposes that dialogical relationships can be established between multiple I-positions1 (e.g., Hermans, 2001a). There have been few attempts, however, to explicitly characterize the forms that these intrapersonal relationships may take. Drawing on Buber's (1958) distinction between the 'I-Thou' and 'I-It' attitude, it is proposed that intrapersonal relationships can take one of two forms: an 'I-I' form, in which one I-position encounters and confirms another I-position in its uniqueness and wholeness; and an 'I-Me' form, in which one I-position experiences another I-position in a detached and objectifying way. This article argues that this I-Me form of intrapersonal relating is associated with psychological distress, and that this is so for a number of reasons: Most notably, because an individual who objectifies and subjugates certain I-position cannot reconnect with more central I-positions when dominance reversal (Hermans, 2001a) takes place. On this basis, it is suggested that a key role of the therapeutic process is to help clients become more able to experience moments of I-I intrapersonal encounter, and it is argued that this requires the therapist to confirm the client both as a whole and in terms of each of his or her different voices

    HERA Collider Physics

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    HERA, the first electron-proton collider, has been delivering luminosity since 1992. It is the natural extension of an impressive series of fixed-target lepton-nucleon scattering experiments. The increase of a factor ten in center-of-mass energy over that available for fixed-target experiments has allowed the discovery of several important results, such as the large number of slow partons in the proton, and the sizeable diffractive cross section at large Q2Q^2. Recent data point to a possible deviation from Standard Model expectations at very high Q2Q^2, highlighting the physics potential of HERA for new effects. The HERA program is currently in a transition period. The first six years of data taking have primarily elucidated the structure of the proton, allowed detailed QCD studies and had a strong impact on the understanding of QCD dynamics. The coming years will bring the era of electroweak studies and high Q2Q^2 measurements. This is therefore an appropriate juncture at which to review HERA results.Comment: 351 pages, 154 figures, submitted to Reviews of Modern Physic

    Hidden Skewness: On the Difficulty of Multiplicative Compounding Under Random Shocks

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    Multiplicative growth processes that are subject to random shocks often have a skewed distribution of outcomes. In a number of incentivized laboratory experiments we show that a large majority of participants either strongly underestimate skewness or ignore it completely. Participants misperceive the outcome distribution’s spread to be far too narrow-band and they estimate the median to lie too close to the distribution’s center. The observed bias in expectations is irrespective to risk preferences and fairly robust to feedback. It is consistent with a behavioral model in which geometric growth is confused with linear growth. The misperception is a possible explanation of investors’ difficulties with real-world financial products like leveraged ETFs

    RNAi for Treating Hepatitis B Viral Infection

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    Chronic hepatitis B virus (HBV) infection is one of the leading causes of liver cirrhosis and hepatocellular carcinoma (HCC). Current treatment strategies of HBV infection including the use of interferon (IFN)-α and nucleotide analogues such as lamivudine and adefovir have met with only partial success. Therefore, it is necessary to develop more effective antiviral therapies that can clear HBV infection with fewer side effects. RNA interference (RNAi), by which a small interfering RNA (siRNA) induces the gene silence at a post-transcriptional level, has the potential of treating HBV infection. The successful use of chemically synthesized siRNA, endogenous expression of small hairpin RNA (shRNA) or microRNA (miRNA) to silence the target gene make this technology towards a potentially rational therapeutics for HBV infection. However, several challenges including poor siRNA stability, inefficient cellular uptake, widespread biodistribution and non-specific effects need to be overcome. In this review, we discuss several strategies for improving the anti-HBV therapeutic efficacy of siRNAs, while avoiding their off-target effects and immunostimulation. There is an in-depth discussion on the (1) mechanisms of RNAi, (2) methods for siRNA/shRNA production, (3) barriers to RNAi-based therapies, and (4) delivery strategies of siRNA for treating HBV infection

    Exploring the design and perceived benefit of sustainable solutions: a review

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    The demand for more innovative solutions to meet progressively complex consumer requirements is increasingly at the forefront of design practice and research. Coinciding with this is the stipulation for more environmentally, socially and economically sustainable services. Although many approaches towards the design of more systemic and sustainable solutions exist, the terminology to describe them is manifold. Subsequently, confusion surrounding the cross-disciplinary process that stakeholders are required to follow is increasingly apparent. This paper presents a critical review of multiple-design approaches from the perspective of the stakeholders involved and identifies a set of attributes that are common to them. It is concluded that stakeholders could substantially benefit from a supportive framework of common characteristics to enable the integrative design of more systemic and sustainable solutions
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