International Liquidity and the Role of the SDR in the International Monetary System

This paper describes how the changed conditions in the international monetary system have undermined the role originally envisaged for the SDR. It argues that the concept of a global stock of international liquidity, which was fundamental to the creation of the SDR, is now no longer relevant. Nonetheless, there are good reasons to satisfy part of the growing demand for international reserves with SDR allocations: (i) there are efficiency gains, as SDRs can be created at zero resource cost, and thus obviate the need for countries to run current account surpluses or engage in expensive borrowing to obtain reserves, and (ii) there would be a reduction in systemic risk, as SDRs would substitute to some extent for borrowed reserves, which are a less reliable and predictable source of reserves, especially in times of crisis. Copyright 2004, International Monetary Fund

The simplest b 2 + ion: determining its structure from its energetics by a direct comparison of the threshold collision-induced dissociation of protonated oxazolone and diketopiperazine

ManuscriptEnergy-resolved collision-induced dissociation of b2 + ions derived from protonated GGG and GAG are compared with that of protonated diketopiperazine (H+DKP). Absolute dissociation cross sections are obtained using a guided ion beam tandem mass spectrometer and analyzed using statistical methods. The fragmentation pattern of the b2 + ion from H+GGG differs significantly from that of H+DKP, although decarbonylation (forming the a2 + ion) is the lowest energy pathway found for both species. The threshold measured for b2 + decarbonylation differs appreciably from that of H+DKP, but both processes have onsets that are consistent with those obtained from quantum chemical calculations, positively identifying the b2 + ion as the protonated 2-aminomethyl-5-oxazolone, H+AMOx. The threshold for the b2 + ion derived from H+GAG has a slightly lower threshold, again consistent with theory. Examination of the higher energy dissociation pathways observed shows that these generally involve subsequent dissociation of the primary a2 + product ion. As a consequence, statistical analysis of these pathways for threshold information is difficult and ultimately provides little agreement with theory. This disagreement is rationalized on the basis of considerable kinetic energy release that has been observed previously by Harrison for these subsequent reactions. The present results are also favorably compared with previous results obtained by Siu and coworkers, although a number of refinements in the analysis and mechanisms are suggested

The simplest b2+ ion: determining its structure from its energetics by a direct comparison of the threshold collision-induced dissociation of protonated oxazolone and diketopiperazine

pre-printEnergy-resolved collision-induced dissociation of b2 + ions derived from protonated GGG and GAG are compared with that of protonated diketopiperazine (H+DKP). Absolute dissociation cross sections are obtained using a guided ion beam tandem mass spectrometer and analyzed using statistical methods. The fragmentation pattern of the b2 + ion from H+GGG differs significantly from that of H+DKP, although decarbonylation (forming the a2 + ion) is the lowest energy pathway found for both species. The threshold measured for b2 + decarbonylation differs appreciably from that of H+DKP, but both processes have onsets that are consistent with those obtained from quantum chemical calculations, positively identifying the b2 + ion as the protonated 2-aminomethyl-5-oxazolone, H+AMOx. The threshold for the b2 + ion derived from H+GAG has a slightly lower threshold, again consistent with theory. Examination of the higher energy dissociation pathways observed shows that these generally involve subsequent dissociation of the primary a2 + product ion. As a consequence, statistical analysis of these pathways for threshold information is difficult and ultimately provides little agreement with theory. This disagreement is rationalized on the basis of considerable kinetic energy release that has been observed previously by Harrison for these subsequent reactions. The present results are also favorably compared with previous results obtained by Siu and coworkers, although a number of refinements in the analysis and mechanisms are suggested

Tensin1 expression and function in chronic obstructive pulmonary disease

open access articleChronic obstructive pulmonary disease (COPD) constitutes a major cause of morbidity and mortality. Genome wide association studies have shown significant associations between airflow obstruction or COPD with a non-synonymous SNP in the TNS1 gene, which encodes tensin1. However, the expression, cellular distribution and function of tensin1 in human airway tissue and cells are unknown. We therefore examined these characteristics in tissue and cells from controls and people with COPD or asthma. Airway tissue was immunostained for tensin1. Tensin1 expression in cultured human airway smooth muscle cells (HASMCs) was evaluated using qRT-PCR, western blotting and immunofluorescent staining. siRNAs were used to downregulate tensin1 expression. Tensin1 expression was increased in the airway smooth muscle and lamina propria in COPD tissue, but not asthma, when compared to controls. Tensin1 was expressed in HASMCs and upregulated by TGFβ1. TGFβ1 and fibronectin increased the localisation of tensin1 to fibrillar adhesions. Tensin1 and α-smooth muscle actin (αSMA) were strongly co-localised, and tensin1 depletion in HASMCs attenuated both αSMA expression and contraction of collagen gels. In summary, tensin1 expression is increased in COPD airways, and may promote airway obstruction by enhancing the expression of contractile proteins and their localisation to stress fibres in HASMCs

Uncertainty Types and Transitions in the Entrepreneurial Process

While judgment has hitherto typically been viewed as a discrete decision process, we propose that it be conceptualized instead as a continuous and dynamic process of reassessment and revision. Adopting this approach, we revisit the nature of entrepreneurial decision making under uncertainty. We begin with a novel typology of uncertainty that defines and delineates different types of uncertain contexts. We then examine the nature of decision making within these distinct contexts, highlighting differences in how entrepreneurs make decisions within different types of uncertainty. We build these insights into a theory of the entrepreneurial process that highlights the transitory nature of uncertainty as entrepreneurs make certain judgments and revise those judgments over time. We discuss how uncertainty transitions throughout the judgment process, how the judgment process continues dynamically even after a judgment is made, and how the nature of uncertainty shifts over time due to endogenous and exogenous change

Complete Boolean algebras are Bousfield lattices

Given a complete Heyting algebra we construct an algebraic tensor triangulated category whose Bousfield lattice is the Booleanization of the given Heyting algebra. As a consequence we deduce that any complete Boolean algebra is the Bousfield lattice of some tensor triangulated category. Using the same ideas we then give two further examples illustrating some interesting behaviour of the Bousfield lattice.Comment: 10 pages, update to clarify the products occurring in the main constructio

Polarized Raman Scattering Studies of Orientational Order in Uniaxial Liquid Crystalline Phases

The measurement of vibrational Raman depolarization ratios has been used to study molecular orientational order in uniaxial single domain nematic and smectic liquid crystal samples. This technique is demonstrated to obtain the same microscopic order parameter $\langle P_2 \rangle =1/2 \langle 3 cos^2\theta −1 \rangle$, where $\theta$ is the angle between a molecular long axis and the uniaxial direction, as other existing methods. In addition, the next higher moment of the orientational distribution function $\langle P_4 \rangle=1/8 \langle 35 cos^4 \theta−30 cos^2 \theta+3 \rangle$ has been measured for the first time. The physical basis, theoretical apparatus, and experimental methods necessary for the application of this technique are thoroughly detailed in this paper. Measurements are presented of the temperature dependence of $\langle P_2 \rangle$ and $\langle P_4 \rangle$ of N‐(p'‐butoxybenzylidene)‐p‐cyanoaniline (BBCA) dissolved in N‐(p'‐methoxybenzylidene)‐p‐cyanoaniline (MBBA) and of pure MBBA in the isotropic and nematic phases, and in the isotropic, nematic, smectic A, and smectic B phases of N‐(p'‐butoxybenzylidene)‐p‐n‐octylaniline (40.8). In the nematic phases the new quantitative information marks significant discrepancies with existing theories of nematic ordering. In the smectic phases the results show unambiguously the anticipated high degree of molecular orientational order.Engineering and Applied Science

Running impact forces: from half a leg to holistic understanding – comment on Nigg et al.

Running impact forces have immediate relevance for the muscle tuning paradigm proposed here and broader relevance for overuse injuries, shoe design and running performance. Here, we consider their mechanical basis. Several studies demonstrate that the vertical ground reaction force-time (vGRFT) impulse, from touchdown to toe-off, corresponds to the instantaneous accelerations of the body’s entire mass (Mb) divided into two or more portions. The simplest, a two-mass partitioning of the body (lower-limb, M1=0.08•Mb; remaining mass, M2=0.92•Mb) can account for the full vGRFT waveform under virtually all constant-speed, level-running conditions. Model validation data indicate that: 1) the non-contacting mass, M2, often accounts for one-third or more of the early “impact” portion of the vGRFT, and 2) extracting a valid impact impulse from measured force waveforms requires only lower-limb motion data and the fixed body mass fraction of 0.08 for M1