Estimating Exchange Rate Exposures: Some "Weighty" Issues

From a sample of 910 U.S. firms over the period 1977 1996, we find that structure of the empirical model has significant impacts on resulting estimates of exchange rate exposures from equity returns. While lengthening the return horizon has minimal impact on exposure estimates, the inclusion of a market portfolio in the specification results in significant changes to the exposure estimates. We further demonstrate that different definitions of the market portfolio result in important differences in the overall distribution of exposure estimates and the interpretations of the sign, size, and significance of many firms' exposures. The source of the exposure differences across market portfolios is due to a strong size-exposure relation for U.S. firms. Surprisingly, this size-exposure relation does not appear to be driven by an underlying correlation between size and foreign cash flow position of the firms. An alternative model specification using matched CRSP capital-based size portfolios as controls for market movements in the exposure model produces firm-level exposures with a stronger relation to foreign cash flows and less of a correlation with firm size.

Oil quality in diesel engines with on line oil cleaning using a heated lubricating oil recycler

A method of cleaning the oil on line was investigatedusing a bypass fine particulate filter followed by an infra red heater to remove water and light diesel fractions in the oil. This was tested on a range of on road vehicles and a Ford 1.8 litre IDI passenger car engine on a test bed. Comparison was made with the oil quality on the same vehicles and engines without the on-line recycler. Test times were from 200 to 1500 hours of oil ageing and some of the tests showed that the oil quality was still good after 4 times the normal oil life. The results showed that the on line oil recycler cleaning system reduced the rate of fall of the TBN and rate of increase of the TAN. There was a very significant reduction in the soot in oil and the fuel dilution. There was also a consistent reduction in all the wear metals apart from copper and a decrease in the rate of reduction of oil additives. There was also measured on the Ford IDI engine a 5% reduced fuel consumption. Many of these effects were attributed to an influence of the cleaner oil on reduced engine deposits

Oil quality in diesel engines with on line oil cleaning using a heated lubricating oil recycler

A method of cleaning the oil on line was investigatedusing a bypass fine particulate filter followed by an infra red heater to remove water and light diesel fractions in the oil. This was tested on a range of on road vehicles and a Ford 1.8 litre IDI passenger car engine on a test bed. Comparison was made with the oil quality on the same vehicles and engines without the on-line recycler. Test times were from 200 to 1500 hours of oil ageing and some of the tests showed that the oil quality was still good after 4 times the normal oil life. The results showed that the on line oil recycler cleaning system reduced the rate of fall of the TBN and rate of increase of the TAN. There was a very significant reduction in the soot in oil and the fuel dilution. There was also a consistent reduction in all the wear metals apart from copper and a decrease in the rate of reduction of oil additives. There was also measured on the Ford IDI engine a 5% reduced fuel consumption. Many of these effects were attributed to an influence of the cleaner oil on reduced engine deposits

In situ rheological measurements of the external gelation of alginate

Direct mixing of alginate and divalent cations such as Ca2+ generally produces heterogeneous gels that form almost instantaneously. Therefore, is particularly difficult to measure the rheological properties of this gelation event due to the rapid gelation kinetics. In this study, the gelation of alginate when exposed to a solution of CaCl2 was measured by using a modified rheometer. This modification involved attaching a petri dish to the lower plate of the rheometer into which, filter paper impregnated with CaCl2 solution was added. A semi-permeable membrane was then placed above the filter paper as a barrier to prevent the filter paper imbibing the gel. Samples of 4%w/w alginate were loaded onto the semi-permeable membrane and measurements were taken using 55mm parallel plate geometry. Measurements of G′ and Gʺ were determined as a function of time to monitor gelation. Once gelation was complete the filter paper was removed and replaced with filter paper impregnated with calcium chelators (EDTA, sodium citrate) to assess the degradation of the gel. The results showed that this technique was suitable for analysing the external gelation of alginate with a sharp increase in G′ in the first three minutes which then plateaued over the remainder of the test. It was also shown that gel stiffness reduced to a greater extent on exposure to EDTA compared with sodium citrate. This method is not only suitable for measuring rapid gelation kinetics on exposure to cross-linkers, but has potential applications in modelling the in situ gelation behaviour in simulated physiological environments

Bistability and macroscopic quantum coherence in a BEC of ^7Li

We consider a Bose-Einstein condensate (BEC) of $^7Li$ in a situation where the density undergoes a symmetry breaking in real space. This occurs for a suitable number of condensed atoms in a double well potential, obtained by adding a standing wave light field to the trap potential. Evidence of bistability results from the solution of the Gross-Pitaevskii equation. By second quantization, we show that the classical bistable situation is in fact a Schr\"odinger cat (SC) and evaluate the tunneling rate between the two SC states. The oscillation between the two states is called MQC (macroscopic quantum coherence); we study the effects of losses on MQC.Comment: 8 pages, 11 figures. e-mail: [email protected]

[Accepted Manuscript] Optimizing tubal ligation service delivery: a prospective cohort study to measure the task-sharing experience of Marie Stopes International Ethiopia.

The Ethiopian government implements a progressive task-sharing policy for health services as a strategy to address shortages of highly skilled providers and increase access to critical services, such as family planning. Since 2009, Marie Stopes International Ethiopia has trained health officers to provide tubal ligations, a permanent method of family planning, as part of its task-sharing strategy. The objectives of this research were to evaluate task-sharing tubal ligations to health officers at Marie Stopes International Ethiopia, specifically: (a) to investigate safety, as measured by the proportion of major adverse events; (b) to evaluate the feasibility, as measured by adherence to the standard tubal ligation procedure protocol and (c) to investigate acceptability to clients of the tubal ligation procedure provided by health officers. We established a prospective cohort of women aged  ≥18 years presenting for tubal ligation at Marie Stopes International Ethiopia sites in three regions in Ethiopia (March-May 2014). Data on adverse events (incomplete procedure, pain, bleeding, infection, perforation) were collected intra-operatively; peri-operatively (1-h post-procedure); and post-operatively (7 days post-procedure). To measure feasibility, 65% of procedures were selected for 'audit', where a nurse observed and scored health officers adherence to standard protocol using an 18-item checklist. To assess acceptability, women were asked about their satisfaction with the procedure. In total, 276 women were enrolled in the study. 97.5% of procedures took place in rural settings. All participants were followed up 7 days post-procedure (100% response rate). The overall proportion of major adverse events was 3% (95% CI 1-6%). The most frequent adverse event was 'failure to complete the TL' (2.2%, n = 6). The average score on protocol adherence was 96.9%. Overall, 98.2% (n = 271) of clients would recommend the procedure to a friend. Findings from this study, indicating safety, feasibility and acceptability, are consistent with the existing literature, which indicate safety and acceptability for task-sharing tubal ligations, and other methods of contraception with non-physician health providers. This study adds to scant literature on task-sharing tubal ligations in rural and low-resource settings.<br/

Effect of nanoparticle morphologies on signal strength in photoacoustic sensing

Spherical gold nanoparticles with a plasmonic extinction peak at 532 nm and two sizes of star shaped gold nanoparticles with plasmonic extinction peaks at 532 nm and 600 nm were synthesised and introduced into tissue phantoms as exogenous absorbers. The photoacoustic signals generated from the three different nanoparticle morphologies embedded in tissue the phantoms is compared. The effect of nanoparticle concentration on the generated photoacoustic signal strength was also investigated for the spherical nanoparticles. At an excitation laser wavelength of 532 nm, the spherical gold nanoparticles were shown to produce the greatest photoacoustic response

Self-consistent model of ultracold atomic collisions and Feshbach resonances in tight harmonic traps

We consider the problem of cold atomic collisions in tight traps, where the absolute scattering length may be larger than the trap size. As long as the size of the trap ground state is larger than a characteristic length of the van der Waals potential, the energy eigenvalues can be computed self-consistently from the scattering amplitude for untrapped atoms. By comparing with the exact numerical eigenvalues of the trapping plus interatomic potentials, we verify that our model gives accurate eigenvalues up to milliKelvin energies for single channel s-wave scattering of $^{23}$Na atoms in an isotropic harmonic trap, even when outside the Wigner threshold regime. Our model works also for multi-channel scattering, where the scattering length can be made large due to a magnetically tunable Feshbach resonance.Comment: 7 pages, 4 figures (PostScript), submitted to Physical Review

Impacts of Climate Change on indirect human exposure to pathogens and chemicals from agriculture

Objective: Climate change is likely to affect the nature of pathogens and chemicals in the environment and their fate and transport. Future risks of pathogens and chemicals could therefore be very different from those of today. In this review, we assess the implications of climate change for changes in human exposures to pathogens and chemicals in agricultural systems in the United Kingdom and discuss the subsequent effects on health impacts. Data sources: In this review, we used expert input and considered literature on climate change ; health effects resulting from exposure to pathogens and chemicals arising from agriculture ; inputs of chemicals and pathogens to agricultural systems ; and human exposure pathways for pathogens and chemicals in agricultural systems. Data synthesis: We established the current evidence base for health effects of chemicals and pathogens in the agricultural environment ; determined the potential implications of climate change on chemical and pathogen inputs in agricultural systems ; and explored the effects of climate change on environmental transport and fate of different contaminant types. We combined these data to assess the implications of climate change in terms of indirect human exposure to pathogens and chemicals in agricultural systems. We then developed recommendations on future research and policy changes to manage any adverse increases in risks. Conclusions: Overall, climate change is likely to increase human exposures to agricultural contaminants. The magnitude of the increases will be highly dependent on the contaminant type. Risks from many pathogens and particulate and particle-associated contaminants could increase significantly. These increases in exposure can, however, be managed for the most part through targeted research and policy changes

Resonance Kondo Tunneling through a Double Quantum Dot at Finite Bias

It is shown that the resonance Kondo tunneling through a double quantum dot (DQD) with even occupation and singlet ground state may arise at a strong bias, which compensates the energy of singlet/triplet excitation. Using the renormalization group technique we derive scaling equations and calculate the differential conductance as a function of an auxiliary dc-bias for parallel DQD described by SO(4) symmetry. We analyze the decoherence effects associated with the triplet/singlet relaxation in DQD and discuss the shape of differential conductance line as a function of dc-bias and temperature.Comment: 11 pages, 6 eps figures include