International Capital Mobility and the Coordination of Monetary Rules

The paper develops a two-country model with flexible exchange rates and perfect capital mobility, for evaluating the alternative macroeconomic policy rules. Macroeconomic performance is measured in terms of fluctuations in inflation and output. Expectations are rational, and prices are sticky; wagesetting is staggered over time. The countries are linked by aggregate spending effects, relative price effects, and mark-up pricing arrangements. The modelis solved and analyzed through deterministic and stochastic simulation techniques. The results suggest that international capital mobility is not necessarily an impediment to efficient domestic macroeconomic performance. Changes in the expected appreciation or a depreciation of the exchange rate along with differentials between real interest rates in the two countries can permit macroeconomic performance in one country to be relatively independent of the policy rule chosen by the other country. The results depend on the particular parameter values used in the model and suggest the need for further econometric work to determine the size of these parameters.

Constructing Reference Metrics on Multicube Representations of Arbitrary Manifolds

Reference metrics are used to define the differential structure on multicube representations of manifolds, i.e., they provide a simple and practical way to define what it means globally for tensor fields and their derivatives to be continuous. This paper introduces a general procedure for constructing reference metrics automatically on multicube representations of manifolds with arbitrary topologies. The method is tested here by constructing reference metrics for compact, orientable two-dimensional manifolds with genera between zero and five. These metrics are shown to satisfy the Gauss-Bonnet identity numerically to the level of truncation error (which converges toward zero as the numerical resolution is increased). These reference metrics can be made smoother and more uniform by evolving them with Ricci flow. This smoothing procedure is tested on the two-dimensional reference metrics constructed here. These smoothing evolutions (using volume-normalized Ricci flow with DeTurck gauge fixing) are all shown to produce reference metrics with constant scalar curvatures (at the level of numerical truncation error).Comment: 37 pages, 16 figures; additional introductory material added in version accepted for publicatio

Scalar, Vector and Tensor Harmonics on the Three-Sphere

Scalar, vector and tensor harmonics on the three-sphere were introduced originally to facilitate the study of various problems in gravitational physics. These harmonics are defined as eigenfunctions of the covariant Laplace operator which satisfy certain divergence and trace identities, and ortho-normality conditions. This paper provides a summary of these properties, along with a new notation that simplifies and clarifies some of the key expressions. Practical methods are described for accurately and efficiently computing these harmonics numerically, and test results are given that illustrate how well the analytical identities are satisfied by the harmonics computed numerically in this way.Comment: 14 pages, 9 figures, to appear in General Relativity and Gravitatio

Flow cytometric characterization of freshwater crayfish hemocytes for the examination of physiological status in wild and captive animals

Enumeration of invertebrate hemocytes is a potentially powerful tool for the determination of physiological effects of extrinsic stressors, such as hypoxia, disease, and toxicant exposure. A detailed flow cytometric method of broad application was developed for the objective characterization and enumeration of the hemocytes of New Zealand freshwater crayfish Paranephrops planifrons for the purpose of physiological health assessment. Hemocyte populations were isolated by flow cytometric sorting based on differential light scatter properties followed by morphological characterization via light microscopy and software image analysis. Cells were identified as hyaline, semigranular, and granular hemocytes based on established invertebrate hemocyte classification. A characteristic decrease in nuclear size, an increase in granularity between the hyaline and granular cells, and the eccentric location of nuclei in granular cells were also observed. The granulocyte subpopulations were observed to possess varying degrees of granularity. The developed methodology was used to perform total and differential hemocyte counts from three lake populations and between wild and captive crayfish specimens. Differences in total and differential hemocyte counts were not observed among the wild populations. However, specimens held in captivity for 14 d exhibited a significant 63% reduction in total hemocyte count, whereas the relative hemocyte proportions remained the same. These results demonstrate the utility of this method for the investigation of subacute stressor effects in selected decapod crustaceans

A TEST OF ASSET FIXITY IN SOUTHEASTERN U.S. AGRICULTURE

A test for static equilibrium developed by Schankerman and Nadiri is used to evaluate the hypothesis that land and capital in aggregate southeastern U.S. agriculture behave as fixed inputs. Empirical results reject the hypothesis that these two inputs are at their long-run equilibrium levels implied by observed prices. Thus, some degree of asset fixity may be concluded.Financial Economics,

COMPETITIVE PRESSURE AND PRODUCTIVITY GROWTH: THE CASE OF THE FLORIDA VEGETABLE INDUSTRY

The relationship between the degree of competitive market pressure and the rate of productivity growth is empirically investigated with a case study of the Florida fresh winter vegetable industry. The results indicate that crops which faced considerable competitive pressure exhibited significant productivity growth while the crops that faced minimal competitive pressure generally exhibited little growth in productivity. Thus, the hypothesis that competitive pressure is positively related to productivity growth is supported.Productivity Analysis,

Introduction to the Special Issue on Web Archiving

This article serves as an introduction to the Journal of Western Archives Special Issue on Web Archiving. It provides a snapshot of and reflections on the state of the field, as well as an overview of the works that constitute the issue

Hot spots in ammonium nitrate

Ammonium nitrate (AN) is commonly used as an explosive and as a fertilizer. In both roles it is provided as prills or pellets, approximately spherical and a few millimetres in diameter. The microstructures of several commercially-available AN compositions were investigated using environmental scanning electron microscopy (ESEM) and X-ray microtomography. Those intended for explosive use were found to be more porous than those intended for fertilizer use. The pores in explosive prills were also found to form a connected network. The elemental composition of pellets of mixed AN and dolomite was investigated using energy-dispersive X-ray spectroscopy (EDX); the dolomite additive was found to take the form of grains roughly 50 μm in size. The compaction behaviour of confined cylindrical beds of these prills and pellets was studied at strain rates between 4 × 10−4 s−1 and 200 s−1. Quasi-static experiments were performed using a screw-driven instrumented press, while higher-rate experiments used a drop weight, instrumented with a line laser and load cell. The resistance of a bed to compaction was found to depend on the microstructure of its prills in most cases. Denser prills offered greater resistance to compaction. The exception to this rule was a pellet, rather than prill, formulation. Beds were also found to offer more resistance to compaction at higher strain rates. The Kawakita compaction model was found to agree well with the experimental data. A commercial fertilizer, not containing any AN, was assessed for use as an inert mock for AN prills and pellets. Prills of a suitable size for this purpose were found using EDX to consist of P2O5, with a coating of unknown composition. They were supplied mixed with smaller K2CO3 and urea prills. The mixture was found to have comparable compaction behaviour to AN compositions, indicating that it was useful as a mock for those compositions. In a plate impact experiment on a single layer of P2O5 prills, very little light was observed. This indicated that these prills were sufficiently inert for these purposes. The light produced by shocked granular ammonium nitrate beds and single prill layers was investigated using high-speed framing photography, photodiodes and gated visible-light spectroscopy. Framing photography of prill layers suggested that reaction in prill beds was dominated by effects internal to prills. This was further supported by the similarity between photodiode recordings of prill beds and beds of inert prills containing a single reactive prills. Framing photography of drop weight experiments searching for a mechanism for initiation of reaction by interaction between prills found nothing. Decay of the light output of the beds suggested that in both granular and prill beds this light output was due to small regions heated to thousands of kelvin, which then cooled. Spectroscopic study confirmed this. These regions were found to reach a peak temperature of 6660 ± 20 K, well in excess of the approximately 2000 K predicted by a simple chemical model. Investigation of spectral lines observed during this study indicated that the exothermic reaction that led to heating of these emitting regions involved NO