2,137 research outputs found

    Dynamic equilibrium correction modelling of yen Eurobond credit spreads

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    Understanding the long term relationship between the yields of risky and riskless bonds is a critical task for portfolio managers and policy makers. This study specifies an equilibrium correction model of the credit spreads between Japanese Government bonds (JGBs) and Japanese yen Eurobonds with high quality credit ratings. The empirical results indicate that the corporate bond yields are cointegrated with the otherwise equivalent JGB yields, with the spread defining the cointegration relation. In addition the results indicate that the equilibrium correction term is highly statistically significant in modelling credit spread changes. Another important factor is the risk-free interest rate with the negative sign, while there is little evidence of the contribution of the asset return to the behaviour of spreads.

    Foreign Bond Markets and Financial Market Development: International Perspectives

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    The domestic bond markets of the Asia and Pacific region have grown considerably since the Asian financial crisis of 1997, although they remain undeveloped relative to the region's weight in the world economy. This paper proposes that in order to encourage further development of these markets, regulators should make them more accessible to foreign borrowers. To that end we offer insights into the nature and mechanics of foreign bond issuance by investigating the key characteristics of 3,132 foreign bonds issued in 14 countries (other than the United States) between July 1928 and June 2009. We found that the foreign borrowers that tap domestic markets are overwhelmingly of high credit quality and comprise sovereigns, supranationals, and major financial institutions. There is a preference for simple fixed-rate payment structures, which can then be swapped into the currency and coupon type of choice using currency and interest rate derivatives. On the whole, the long-term viability of foreign bond markets appears linked to the presence of highly liquid foreign exchange and derivatives markets that facilitate risk management and transformation, enabling regulation that facilitates cooperation with market participants, the presence of benchmark issues, and competitive pricing between alternate market segments.bond markets; financial market development; foreign bonds

    On the joint moments of the characteristic polynomials of random unitary matrices

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    We establish the asymptotics of the joint moments of the characteristic polynomial of a random unitary matrix and its derivative for general real values of the exponents, proving a conjecture made by Hughes in 2001. Moreover, we give a probabilistic representation for the leading order coefficient in the asymptotic in terms of a real-valued random variable that plays an important role in the ergodic decomposition of the Hua-Pickrell measures. This enables us to establish connections between the characteristic function of this random variable and the σ\sigma-Painlev\'{e} III' equation.Comment: Minor revision according to referee reports. To appear IMR

    Observations of Transient Active Region Heating with Hinode

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    We present observations of transient active region heating events observed with the Extreme Ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode. This initial investigation focuses on NOAA active region 10940 as observed by Hinode on February 1, 2007 between 12 and 19 UT. In these observations we find numerous examples of transient heating events within the active region. The high spatial resolution and broad temperature coverage of these instruments allows us to track the evolution of coronal plasma. The evolution of the emission observed with XRT and EIS during these events is generally consistent with loops that have been heated and are cooling. We have analyzed the most energetic heating event observed during this period, a small GOES B-class flare, in some detail and present some of the spectral signatures of the event, such as relative Doppler shifts at one of the loop footpoints and enhanced line widths during the rise phase of the event. While the analysis of these transient events has the potential to yield insights into the coronal heating mechanism, these observations do not rule out the possibility that there is a strong steady heating level in the active region. Detailed statistical analysis will be required to address this question definitively

    Macrostructural analysis : unravelling polyphase glacitectonic histories

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    Many Pleistocene glacial profiles look extremely simple, comprising till, or glacitectonite, overlying older sediments or bedrock (Figure 4.1). In more complex sequences the till may itself be overlain by younger sediments laid down as the ice retreated or during a completely separate, later phase of advance. Macroscopically, subglacial traction tills (Evans et al., 2007) are typically massive, unstructured deposits suggesting that it should be relatively straightforward to unravel the glacitectonic deformation history recorded by the sequence. Many reconstructions do indeed look very simple, slabs of sediment have been tilted and stacked and then overridden by the glacier to cap the structure with till. Added to this is the use of vertical exaggeration which makes the whole structure look like alpine tectonics (for an example see fig. 5 in van Gijssel, 1987). Dropping the exaggeration led to the recognition that actually we were looking at much more horizontal structures, i.e. overriding nappes and not imbricated slabs (van der Wateren, 1987). Traditionally (van der Meer, 1987) glaciotectonics was thought to relate to large structures like big push moraines and not to smaller structures like drag structures underneath tills (Figure 4.2), let alone to the tills themselves. With the notion that deforming bed tills are tectonically and not sedimentologically structured and could be regarded as tectomicts (Menzies et al., 2006), comes the realisation that glacitectonics happens across a wide range of scales, from the microscopic to tens of kilometres. Only by realising the full range of glaciotectonic scales can we hope to understand the processes

    Non-Gaussian Scatter in Cluster Scaling Relations

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    We investigate the impact of non-Gaussian scatter in the cluster mass-observable scaling relation on the mass and redshift distribution of clusters detected by wide area surveys. We parameterize non-Gaussian scatter by incorporating the third and forth moments (skewness and kurtosis) into the distribution P(Mobs|M). We demonstrate that for low scatter mass proxies the higher order moments do not significantly affect the observed cluster mass and redshift distributions. However, for high scatter mass indicators it is necessary for the survey limiting mass threshold to be less than 10^14 h^-1 Msol to prevent the skewness from having a significant impact on the observed number counts, particularly at high redshift. We also show that an unknown level of non-Gaussianity in the scatter is equivalent to an additional uncertainty on the variance in P(Mobs|M) and thus may limit the constraints that can be placed on the dark energy equation of state parameter w. Furthermore, positive skewness flattens the mass function at the high mass end, and so one must also account for skewness in P(Mobs|M) when using the shape of the mass function to constrain cluster scaling-relations.Comment: 6 Pages, 3 Figures, to be submitted to ApJ Letter

    A Leptin-regulated Circuit Controls Glucose Mobilization During Noxious Stimuli

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    Adipocytes secrete the hormone leptin to signal the sufficiency of energy stores. Reductions in circulating leptin concentrations reflect a negative energy balance, which augments sympathetic nervous system (SNS) activation in response to metabolically demanding emergencies. This process ensures adequate glucose mobilization despite low energy stores. We report that leptin receptor–expressing neurons (LepRb neurons) in the periaqueductal gray (PAG), the largest population of LepRb neurons in the brain stem, mediate this process. Application of noxious stimuli, which often signal the need to mobilize glucose to support an appropriate response, activated PAG LepRb neurons, which project to and activate parabrachial nucleus (PBN) neurons that control SNS activation and glucose mobilization. Furthermore, activating PAG LepRb neurons increased SNS activity and blood glucose concentrations, while ablating LepRb in PAG neurons augmented glucose mobilization in response to noxious stimuli. Thus, decreased leptin action on PAG LepRb neurons augments the autonomic response to noxious stimuli, ensuring sufficient glucose mobilization during periods of acute demand in the face of diminished energy stores

    A comparison of precipitation and filtration-based SARS-CoV-2 recovery methods and the influence of temperature, turbidity, and surfactant load in urban wastewater

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    Wastewater-based epidemiology (WBE) has become a complimentary surveillance tool during the SARS-CoV-2 pandemic. Viral concentration methods from wastewater are still being optimised and compared, whilst viral recovery under different wastewater characteristics and storage temperatures remains poorly understood. Using urban wastewater samples, we tested three viral concentration methods; polyethylene glycol precipitation (PEG), ammonium sulphate precipitation (AS), and CP select™ InnovaPrep® (IP) ultrafiltration. We found no major difference in SARS-CoV-2 and faecal indicator virus (crAssphage) recovery from wastewater samples (n = 46) using these methods, PEG slightly (albeit non-significantly), outperformed AS and IP for SARS-CoV-2 detection, as a higher genome copies per litre (gc/l) was recorded for a larger proportion of samples. Next generation sequencing of 8 paired samples revealed non-significant differences in the quality of data between AS and IP, though IP data quality was slightly better and less variable. A controlled experiment assessed the impact of wastewater suspended solids (turbidity; 0–400 NTU), surfactant load (0–200 mg/l), and storage temperature (5–20 °C) on viral recovery using the AS and IP methods. SARS-CoV-2 recoveries were >20% with AS and 0.05), whilst surfactant and storage temperature combined were significant negative correlates (p < 0.001 and p < 0.05, respectively). In conclusion, our results show that choice of methodology had small effect on viral recovery of SARS-CoV-2 and crAssphage in wastewater samples within this study. In contrast, sample turbidity, storage temperature, and surfactant load did affect viral recovery, highlighting the need for careful consideration of the viral concentration methodology used when working with wastewater samples
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