50 research outputs found

    The Sum of Its Parts: The Lawyer-Client Relationship in Initial Public Offerings

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    This Article examines the impact of the quality of a lawyer\u27s working relationship with his or her client on one of the most important types of capital markets deal in a company\u27s existence: its initial public offering (IPO). Drawing on data from interviews with equity capital markets lawyers at major law firms, and analyzing data from IPOs in the United States registered with the Securities and Exchange Commission between June 1996 and December 2010, this study finds a strong association between several measures of IPO performance and the familiarity between the lead underwriter and its counsel, as measured by the number of times a particular law firm serves as counsel to a managing underwriter within a relatively short time period. Performance is gauged according to a stock\u27s opening day returns, price performance over thirty, sixty, and ninety trading days, correct price revision, litigation rates, and the speed at which deals are completed. I also analyze the relationships between the lawyers for the lead underwriter and the lawyers for the issuer. The analysis shows some benefits from familiarity, albeit generally smaller than those associated with the underwriter-lawyer relationship. In all cases, the positive effects of repeated interaction diminish the further back in time the previous collaborations occurred. To rule out selection and reverse causality, I perform a number of tests using smaller subsets of the data to remove observations that are plausibly selection driven. I also show that the relationships between familiarity and deal quality occur independently of the level of the lawyers\u27 experience. These findings support the conclusion that lawyers\u27 relational skill can positively influence deal outcomes, independent even of substance and process knowledge. I hypothesize that the core advantage of repeated interaction is the formation of more effective lawyer-client team dynamics

    Spatio-temporal coupling of attosecond pulses

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    The shortest light pulses produced to date are of the order of a few tens of attoseconds, with central frequencies in the extreme ultraviolet range and bandwidths exceeding tens of eV. They are often produced as a train of pulses separated by half the driving laser period, leading in the frequency domain to a spectrum of high, odd-order harmonics. As light pulses become shorter and more spectrally wide, the widely-used approximation consisting in writing the optical waveform as a product of temporal and spatial amplitudes does not apply anymore. Here, we investigate the interplay of temporal and spatial properties of attosecond pulses. We show that the divergence and focus position of the generated harmonics often strongly depend on their frequency, leading to strong chromatic aberrations of the broadband attosecond pulses. Our argumentation uses a simple analytical model based on Gaussian optics, numerical propagation calculations and experimental harmonic divergence measurements. This effect needs to be considered for future applications requiring high quality focusing while retaining the broadband/ultrashort characteristics of the radiation

    Regulatory T cells control the Th1 immune response in murine crescentic glomerulonephritis

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    Crescentic glomerulonephritis is mediated by inappropriate humoral and cellular immune responses toward self-antigens that may result from defects in central and peripheral tolerance. Evidence now suggests that regulatory T cells (Tregs) may be of pathophysiological importance in proliferative and crescentic forms of glomerulonephritis. To analyze the role of endogenous Tregs in a T cell-dependent glomerulonephritis model of nephrotoxic nephritis, we used ‘depletion of regulatory T cell' (DEREG) mice that express the diphtheria toxin receptor under control of the FoxP3 (forkhead box P3) gene promoter. Toxin injection into these mice efficiently depleted renal and splenic FoxP3+ Treg cells as determined by fluorescent-activated cell sorting (FACS) and immunohistochemical analyses. Treg depletion exacerbated systemic and renal interferon-γ (IFNγ) expression and increased recruitment of IFNγ-producing Th1 cells into the kidney without an effect on the Th17 immune response. The enhanced Th1 response, following Treg cell depletion, was associated with an aggravated course of glomerulonephritis as measured by glomerular crescent formation. Thus, our results establish the functional importance of endogenous Tregs in the control of a significantly enhanced systemic and renal Th1 immune response in experimental glomerulonephritis

    Sleep Loss Produces False Memories

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    People sometimes claim with high confidence to remember events that in fact never happened, typically due to strong semantic associations with actually encoded events. Sleep is known to provide optimal neurobiological conditions for consolidation of memories for long-term storage, whereas sleep deprivation acutely impairs retrieval of stored memories. Here, focusing on the role of sleep-related memory processes, we tested whether false memories can be created (a) as enduring memory representations due to a consolidation-associated reorganization of new memory representations during post-learning sleep and/or (b) as an acute retrieval-related phenomenon induced by sleep deprivation at memory testing. According to the Deese, Roediger, McDermott (DRM) false memory paradigm, subjects learned lists of semantically associated words (e.g., “night”, “dark”, “coal”,…), lacking the strongest common associate or theme word (here: “black”). Subjects either slept or stayed awake immediately after learning, and they were either sleep deprived or not at recognition testing 9, 33, or 44 hours after learning. Sleep deprivation at retrieval, but not sleep following learning, critically enhanced false memories of theme words. This effect was abolished by caffeine administration prior to retrieval, indicating that adenosinergic mechanisms can contribute to the generation of false memories associated with sleep loss

    Repression of the genome organizer SATB1 in regulatory T cells is required for suppressive function and inhibition of effector differentiation

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    Regulatory T cells (T(reg) cells) are essential for self-tolerance and immune homeostasis. Lack of effector T cell (T(eff) cell) function and gain of suppressive activity by T(reg) cells are dependent on the transcriptional program induced by Foxp3. Here we report that repression of SATB1, a genome organizer that regulates chromatin structure and gene expression, was crucial for the phenotype and function of T(reg) cells. Foxp3, acting as a transcriptional repressor, directly suppressed the SATB1 locus and indirectly suppressed it through the induction of microRNAs that bound the SATB1 3' untranslated region. Release of SATB1 from the control of Foxp3 in T(reg) cells caused loss of suppressive function, establishment of transcriptional T(eff) cell programs and induction of T(eff) cell cytokines. Our data support the proposal that inhibition of SATB1-mediated modulation of global chromatin remodeling is pivotal for maintaining T(reg) cell functionality.Marc Beyer... Timothy Sadlon...Simon C Barry... et al

    Investigation of Ultrafast Molecular Dynamics via Covariance Mapping -A Tool for Intense XUV Light Sources

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    The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. Ultrashort laser pulses have become established as a viable tool for probing femtosecond dynamics by irradiating the target for only extremely short times. This allows snapshots of the motion to be obtained. However, extreme ultraviolet (XUV) or soft X-ray wavelengths are required to generate attosecond pulses. Two light sources that produce ultrashort XUV pulses were used during the work presented in this thesis: the free electron laser in Hamburg (FLASH) and the high-order harmonic generation-based light source at the High-Intensity XUV Beamline in Lund.This thesis describes the application of covariance mapping and pump-probe spectroscopy as tools to investigate molecular dynamics at these XUV light sources. A covariance mapping scheme was implemented in conjunction with a double-sided velocity map imaging spectrometer at the High-Intensity XUV Beamline. Its capabilities were demonstrated in a proof-of-principle experiment on molecular nitrogen. The scheme was subsequently applied to more complex molecules, and results from photoion-photoion covariance mapping of adamantane (C10H16) are presented. The photodissociation behavior of halomethane molecules was investigated with infrared - ultraviolet and ultraviolet - soft X-ray pump-probe schemes during several measurement campaigns at FLASH. While these time-resolved experiments probed dynamics mainly on the picosecond timescale, efforts were made at the High-Intensity XUV Beamline towards attosecond precision XUV-XUV pump-probe experiments. After demonstrating the ability to induce two-photon processes with XUV light, the XUV wavefronts were studied over several experimental campaigns. These campaigns led to a significant reduction of aberrations in the XUV wavefronts. The size and quality of the XUV focal spot as well as the XUV generation yield were improved

    Investigation of Ultrafast Molecular Dynamics via Covariance Mapping : A Tool for Intense XUV Light Sources

    No full text
    The study of molecular dynamics involves observations of the motion of nuclei and electrons. While nuclear motion is usually on the picosecond or femtosecond timescale, attosecond precision is necessary to directly observe the motion of electrons. Ultrashort laser pulses have become established as a viable tool for probing femtosecond dynamics by irradiating the target for only extremely short times. This allows snapshots of the motion to be obtained. However, extreme ultraviolet (XUV) or soft X-ray wavelengths are required to generate attosecond pulses. Two light sources that produce ultrashort XUV pulses were used during the work presented in this thesis: the free electron laser in Hamburg (FLASH) and the high-order harmonic generation-based light source at the High-Intensity XUV Beamline in Lund.This thesis describes the application of covariance mapping and pump-probe spectroscopy as tools to investigate molecular dynamics at these XUV light sources. A covariance mapping scheme was implemented in conjunction with a double-sided velocity map imaging spectrometer at the High-Intensity XUV Beamline. Its capabilities were demonstrated in a proof-of-principle experiment on molecular nitrogen. The scheme was subsequently applied to more complex molecules, and results from photoion-photoion covariance mapping of adamantane (C10H16) are presented. The photodissociation behavior of halomethane molecules was investigated with infrared - ultraviolet and ultraviolet - soft X-ray pump-probe schemes during several measurement campaigns at FLASH. While these time-resolved experiments probed dynamics mainly on the picosecond timescale, efforts were made at the High-Intensity XUV Beamline towards attosecond precision XUV-XUV pump-probe experiments. After demonstrating the ability to induce two-photon processes with XUV light, the XUV wavefronts were studied over several experimental campaigns. These campaigns led to a significant reduction of aberrations in the XUV wavefronts. The size and quality of the XUV focal spot as well as the XUV generation yield were improved
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