4,015 research outputs found

    Market liquidity and banking liquidity: linkages, vulnerabilities and the role of disclosure.

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    During the course of 2007, global financial markets went through noticeable periods of turbulence. In particular, complex credit markets suffered a marked set-back. Oddly, turmoil in these fairly new markets contributed to severe liquidity shortages in short-term money and interbank markets, triggering repeated large-scale monetary interventions by central banks worldwide. Recent events have thus demonstrated that banks are considerably intertwined in fi nancial markets; dependent on and exposed to them as regards liquidity. The aim of this article is to better understand this complex relationship and to frame relevant aspects of the latest fi nancial market turmoil accordingly. In particular, we explore the mechanics of a market liquidity crisis and its impact on individual banks’ liquidity, as well as possible spillovers to other banks. These dynamics of course raise a number of policy issues. Here, we focus on the role that greater disclosure to markets on banks’ liquidity situation itself could play as a market-stabilising device. In summary, global banks have increasingly integrated into capital markets and in terms of both funding and asset liquidity rely considerably on functioning, liquid financial markets. This is particularly visible in the shift towards secured lending transactions; growth of the securitisation market; the broadening of collateral to encompass complex products with shifting levels of market liquidity; and the rise in committed credit or liquidity lines to sponsored special purpose vehicles (SPVs) and corporates. While some of the recent developments in fi nancial market liquidity can be attributed to technological progress, importantly, more temporary factors resulting from an environment of low interest rates have accelerated market liquidity beyond sustainable levels. While, per se, banks’ ability to “liquify” assets represents a positive development which should help mitigate the fundamental liquidity risk that banks face, increased sensitivity with respect to market liquidity risk has also created new vulnerabilities with respect to sudden reversals of market liquidity. Importantly, adverse circumstances could trigger a combined increase in demands on liquid assets via margin requirements and activation of credit lines and reduced liquidity of assets and related market funding sources. The severe loss of liquidity in asset-backed securities markets and its repercussions on global interbank markets during 2007 provide a vivid illustration of the channels that link market liquidity to banks’ funding and asset liquidity and of the wider externalities of idiosyncratic liquidity shocks. How can these risks be addressed? Together with active liquidity management, disclosure may represent one tool through which such vulnerability may be reduced. A large literature exists on the merits of transparency in banking. Greater transparency should alleviate refi nancing frictions related to asymmetric information. When information problems are however deeper and concern aggregate uncertainty, improved disclosure on credit fundamentals may be less effective to restore confidence. Instead, better information on liquidity itself may be necessary. We explore the current availability of information on banks’ liquidity and funding risks. Overall, information appears to be limited –failing to disclose in a comprehensive and comparable way the underlying dynamics of liquidity demands and funding sources. But liquidity is volatile and banks are subject to inherent liquidity mismatches. Can greater disclosure in this area ever be a useful tool to reinforce market discipline in a systemically stabilising fashion? While this question merits serious reflection, the 2007 market events have shown that current information gaps are large and need addressing.

    Quantum initial condition sampling for linearized density matrix dynamics: Vibrational pure dephasing of iodine in krypton matrices

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    This paper reviews the linearized path integral approach for computing time dependent properties of systems that can be approximated using a mixed quantum-classical description. This approach is applied to studying vibrational pure dephasing of ground state molecular iodine in a rare gas matrix. The Feynman-Kleinert optimized harmonic approximation for the full system density operator is used to sample initial conditions for the bath degrees of freedom. This extremely efficient approach is compared with alternative initial condition sampling techniques at low temperatures where classical initial condition sampling yields dephasing rates that are nearly an order of magnitude too slow compared with quantum initial condition sampling and experimental results.Comment: 20 pages and 8 figure

    Grain - A Java Analysis Framework for Total Data Readout

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    Grain is a data analysis framework developed to be used with the novel Total Data Readout data acquisition system. In Total Data Readout all the electronics channels are read out asynchronously in singles mode and each data item is timestamped. Event building and analysis has to be done entirely in the software post-processing the data stream. A flexible and efficient event parser and the accompanying software framework have been written entirely in Java. The design and implementation of the software are discussed along with experiences gained in running real-life experiments.Comment: Submitted to NIM

    Molecular Dipolar Crystals as High Fidelity Quantum Memory for Hybrid Quantum Computing

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    We study collective excitations of rotational and spin states of an ensemble of polar molecules, which are prepared in a dipolar crystalline phase, as a candidate for a high fidelity quantum memory. While dipolar crystals are formed in the high density limit of cold clouds of polar molecules under 1D and 2D trapping conditions, the crystalline structure protects the molecular qubits from detrimental effects of short range collisions. We calculate the lifetime of the quantum memory by identifying the dominant decoherence mechanisms, and estimate their effects on gate operations, when a molecular ensemble qubit is transferred to a superconducting strip line cavity (circuit QED). In the case rotational excitations coupled by dipole-dipole interactions we identify phonons as the main limitation of the life time of qubits. We study specific setups and conditions, where the coupling to the phonon modes is minimized. Detailed results are presented for a 1D dipolar chain

    Non-adiabatic Effects in the Dissociation of Oxygen Molecules at the Al(111) Surface

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    The measured low initial sticking probability of oxygen molecules at the Al(111) surface that had puzzled the field for many years was recently explained in a non-adiabatic picture invoking spin-selection rules [J. Behler et al., Phys. Rev. Lett. 94, 036104 (2005)]. These selection rules tend to conserve the initial spin-triplet character of the free O2 molecule during the molecule's approach to the surface. A new locally-constrained density-functional theory approach gave access to the corresponding potential-energy surface (PES) seen by such an impinging spin-triplet molecule and indicated barriers to dissociation which reduce the sticking probability. Here, we further substantiate this non-adiabatic picture by providing a detailed account of the employed approach. Building on the previous work, we focus in particular on inaccuracies in present-day exchange-correlation functionals. Our analysis shows that small quantitative differences in the spin-triplet constrained PES obtained with different gradient-corrected functionals have a noticeable effect on the lowest kinetic energy part of the resulting sticking curve.Comment: 17 pages including 11 figures; related publications can be found at http://www.fhi-berlin.mpg.de/th/th.htm

    Ana Mendieta, the Iowa Years: A Critical Study, 1969 through 1977

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    This dissertation investigates the artistic development of Ana Mendieta (born Cuba, 1948; died United States, 1985) from 1969 to 1977 when she lived in Iowa City, attended the University of Iowa, worked as an art teacher, and established herself as an artist. Mendieta is known for her early performance pieces and earth-body sculptures. From the late 1980s her work has been increasingly included in the contexts of feminist art history, performance, photography, work in nature, body art, self-representation, Cuban art, and transcultural identity. Collected by major museums throughout the United States, her work has begun to be included in surveys of world art. Her approach to earth-body art differed significantly from the new forms of conceptual art of the 1960s and early 1970s. By 1974 the artist had begun to produce ephemeral body-earth pieces in Iowa and Mexico that endowed nature with a human form, personifying it and evoking nature\u27s lifecycle. That work evolved from both painting and performance-oriented work that layered multiple references, with sources as diverse as her autobiography, everyday life, transcultural myths, Catholic subjects, and Western and non-Western art and archaeology. This study begins with Mendieta\u27s exile from Cuba and relocation in Iowa, then examines her evolution as a graduate student in painting (1969–1972), a Multimedia student (1972–1977), and an elementary art school teacher (1973–1975). Mendieta. developed during a period of intense collaboration between the university\u27s Multimedia area and the Center for New Performing Art, two unique programs that encouraged interdisciplinary, experimental performance work. In contextualizing that innovative period, I investigate the artist\u27s learning environment and studio practice. I also examine works that have not yet been written about, elaborate the circumstances of their creation, identify the sites and the assistance the artist had in making or performing them, incorporate her written sketchbook notations for them, and relate the substance of her comments regarding intentions for specific pieces. This study incorporates oral histories from previous instructors, colleagues, friends, and acquaintances and discusses the artist\u27s responses in her work to well-known visiting artists such as Robert Wilson, Vito Acconci, and Scott Burden, who performed and lectured at the university. Mendieta\u27s early and middle production has not been examined in the literature within the larger artistic milieu at the university. This study remedies this omission and presents a contextual reading of the artist\u27s work, thereby locating her practice within contemporary art history wherein performance, body work, and earth art were key expressive modes

    NSAIDs for analgesia in the era of COVID-19

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    Globally, non-steroidal anti-inflammatory drugs (NSAIDs) are highly used to treat pain. With the rise of the COVID-19 pandemic, the safety of NSAIDs use has been called into question. These concerns are worthy of review. At present, there is no compelling data showing that NSAIDs worsen the severity of COVID-19 symptoms or increase one\u27s likelihood of contracting the illness. For patients in pain and without symptoms that could potentially be attributed to COVID-19 (cough, fevers/chills, lethargy, myalgias, anosmia and so on), NSAIDs should continue to remain a viable option to provide analgesia to patients in need

    Water vapor at a translational temperature of one kelvin

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    We report the creation of a confined slow beam of heavy-water (D2O) molecules with a translational temperature around 1 kelvin. This is achieved by filtering slow D2O from a thermal ensemble with inhomogeneous static electric fields exploiting the quadratic Stark shift of D2O. All previous demonstrations of electric field manipulation of cold dipolar molecules rely on a predominantly linear Stark shift. Further, on the basis of elementary molecular properties and our filtering technique we argue that our D2O beam contains molecules in only a few ro-vibrational states.Comment: 4 pages, 4 figures, 1 tabl

    Detection of interstellar CH_3

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    Observations with the Short Wavelength Spectrometer (SWS) onboard the {\it Infrared Space Observatory} (ISO) have led to the first detection of the methyl radical CH3{\rm CH_3} in the interstellar medium. The ν2\nu_2 QQ-branch at 16.5 μ\mum and the RR(0) line at 16.0 μ\mum have been unambiguously detected toward the Galactic center SgrA^*. The analysis of the measured bands gives a column density of (8.0±\pm2.4)×1014\times10^{14} cm2^{-2} and an excitation temperature of (17±2)(17\pm 2) K. Gaseous CO{\rm CO} at a similarly low excitation temperature and C2H2{\rm C_2H_2} are detected for the same line of sight. Using constraints on the H2{\rm H_2} column density obtained from C18O{\rm C^{18}O} and visual extinction, the inferred CH3{\rm CH_3} abundance is (1.3+2.20.7)×108(1.3{{+2.2}\atop{-0.7}}) \times 10^{-8}. The chemically related CH4{\rm CH_4} molecule is not detected, but the pure rotational lines of CH{\rm CH} are seen with the Long Wavelength Spectrometer (LWS). The absolute abundances and the CH3/CH4{\rm CH_3/CH_4} and CH3/CH{\rm CH_3/CH} ratios are inconsistent with published pure gas-phase models of dense clouds. The data require a mix of diffuse and translucent clouds with different densities and extinctions, and/or the development of translucent models in which gas-grain chemistry, freeze-out and reactions of H{\rm H} with polycyclic aromatic hydrocarbons and solid aliphatic material are included.Comment: 2 figures. ApJL, Accepte

    C_2 in Peculiar DQ White Dwarfs

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    White dwarfs (WDs) with carbon absorption features in their optical spectra are known as DQ WDs. The subclass of peculiar DQ WDs are cool objects (T_eff<6000 K) which show molecular absorption bands that have centroid wavelengths ~100-300 Angstroms shortward of the bandheads of the C_2 Swan bands. These "peculiar DQ bands" have been attributed to a hydrocarbon such as C_2H. We point out that C_2H does not show strong absorption bands with wavelengths matching those of the peculiar DQ bands and neither does any other simple molecule or ion likely to be present in a cool WD atmosphere. The most straightforward explanation for the peculiar DQ bands is that they are pressure-shifted Swan bands of C_2. While current models of WD atmospheres suggest that, in general, peculiar DQ WDs do not have higher photospheric pressures than normal DQ WDs do, that finding requires confirmation by improved models of WD atmospheres and of the behavior of C_2 at high pressures and temperatures. If it is eventually shown that the peculiar DQ bands cannot be explained as pressure-shifted Swan bands, the only explanation remaining would seem to be that they arise from highly rotationally excited C_2 (J_peak>45). In either case, the absorption band profiles can in principle be used to constrain the pressure and the rotational temperature of C_2 in the line-forming regions of normal and peculiar DQ WD atmospheres, which will be useful for comparison with models. Finally, we note that progress in understanding magnetic DQ WDs may require models which simultaneously consider magnetic fields, high pressures and rotational excitation of C_2.Comment: ApJ in press. 8 pages emulateapj style, 1 figur
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