Determining military expenditures: arms races and spill-over effects in cross-section and panel data

This paper considers the determinants of military spending, building on an emerging literature that estimates military expenditure demand functions in cross-section and panel data, incorporating ‘arms-race’ type effects. It updates Dunne and Perlo-Freeman (2003b) using the SIPRI military expenditure database for the period 1988-2003, finding broadly similar results. It also shows differences in results across panel methods, particularly the within and between estimates and illustrates the importance of recognising and modelling dynamic processes within panel data. Heterogeneity is also found to be an important issue and when countries are broken up into groups on the basis of per capita income there is no obvious systematic pattern in the results. This is seen to imply that the demand for military spending, even between two mutually hostile powers, may depend on the whole nature of the relationship between them (and other countries and events in the region), and not simply Richardsonian action-reaction patterns

A note on the effect of post-mortem maturation on colour of bovine Longissimus dorsi muscle

peer-reviewedFinancial support to P.G. Dunne was provided under the Walsh Fellowship programme of Teagasc.Fifteen heifers were housed and fed a concentrate diet while 54 counterparts grazed at pasture for 90 days at which stage six heifers from each group were slaughtered. The remaining animals in the pasture group were then housed and offered either: concentrate only; concentrate plus grass silage with silage accounting for either 20% or 50% of the total dry matter offered; or zero-grazed grass plus concentrate with grass accounting for 83% of the dry matter offered. Heifers (3/diet) were slaughtered 28, 56, 91 and 120 days thereafter. Colour characteristics of M. longissimus dorsi (LD) were measured at 48 h post mortem. The LD was then vacuum-packaged and stored at between 0 and 4 °C in darkness for 12 days, when colour characteristics were again measured. Maturation of LD resulted in meat that had higher redness values (‘a’ value; P<0.001) and a more intense red colour (higher ‘C’ value; P<0.001) at 14 days post mortem than at 2 days, regardless of diet/duration of feeding. Maturation also resulted in a brighter colour (higher ‘L’ value; P<0.001) but this difference was greatest when cattle were slaughtered the day-56 time point

Complex Saddles in Two-dimensional Gauge Theory

We study numerically the saddle point structure of two-dimensional (2D) lattice gauge theory, represented by the Gross-Witten-Wadia unitary matrix model. The saddle points are in general complex-valued, even though the original integration variables and action are real. We confirm the trans-series/instanton gas structure in the weak-coupling phase, and identify a new complex-saddle interpretation of non-perturbative effects in the strong-coupling phase. In both phases, eigenvalue tunneling refers to eigenvalues moving off the real interval, into the complex plane, and the weak-to-strong coupling phase transition is driven by saddle condensation.Comment: 4+4 pages RevTeX, 9 figures; v2: version published in PR

Hopf instantons, Chern-Simons vortices, and Heisenberg ferromagnets

The dimensional reduction of the three-dimensional fermion-Chern-Simons model (related to Hopf maps) of Adam et el. is shown to be equivalent to (i) either the static, fixed--chirality sector of our non-relativistic spinor-Chern-Simons model in 2+1 dimensions, (ii) or a particular Heisenberg ferromagnet in the plane.Comment: 4 pages, Plain Tex, no figure

Exotic galilean symmetry and the Hall effect

The ``Laughlin'' picture of the Fractional Quantum Hall effect can be derived using the ``exotic'' model based on the two-fold centrally-extended planar Galilei group. When coupled to a planar magnetic field of critical strength determined by the extension parameters, the system becomes singular, and ``Faddeev-Jackiw'' reduction yields the ``Chern-Simons'' mechanics of Dunne, Jackiw, and Trugenberger. The reduced system moves according to the Hall law.Comment: Talk given by P. A. Horvathy at the Joint APCTP- Nankai Symposium. Tianjin (China), Oct.2001. To appear in the Proceedings, to be published by Int. Journ. Mod. Phys. B. 7 pages, LaTex, IJMPB format. no figure

Exotic plasma as classical Hall Liquid

A non-relativistic plasma model endowed with an ``exotic'' structure associated with the two-parameter central extension of the planar Galilei group is constructed. Introducing a Chern-Simons statistical gauge field provides us with a self-consistent system; when the magnetic field takes a critical value determined by the extension parameters, the fluid becomes incompressible and moves collectively, according to the Hall law.Comment: 11 pages, LaTex, no figures. Revised version: Some details better explained. To appear in Int. Journ. Mod. Phys.

Determining Military Expenditures: Arms Races and Spill-Over Effects in Cross-Section and Panel Data

This paper considers the determinants of military spending, building on an emerging literature that estimates military expenditure demand functions in cross-section and panel data, incorporating ‘arms-race’ type effects. It updates Dunne and Perlo-Freeman (2003b) using the SIPRI military expenditure database for the period 1988-2003, finding broadly similar results. It also shows differences in results across panel methods, particularly the within and between estimates and illustrates the importance of recognising and modelling dynamic processes within panel data. Heterogeneity is also found to be an important issue and when countries are broken up into groups on the basis of per capita income there is no obvious systematic pattern in the results. This is seen to imply that the demand for military spending, even between two mutually hostile powers, may depend on the whole nature of the relationship between them (and other countries and events in the region), and not simply Richardsonian action-reaction patterns.Military Spending; Demand; Arms races; Spillovers; Panel data

A Note on Schwinger Mechanism and a Nonabelian Instability in a Nonabelian Plasma

We point out that there is a nonabelian instability for a nonabelian plasma which does not allow both for a net nonzero color charge and the existence of field configurations which are coherent over a volume $v$ whose size is determined by the chemical potential. The basic process which leads to this result is the Schwinger decay of chromoelectric fields, for the case where the field arises from commutators of constant potentials, rather than as the curl of spacetime dependent potentials. In terms of the fields, instability is obtained when Tr(DF)^2 > 0.Comment: 14 pages, 6 figure

The effects of scopolamine upon control of attention and memory in humans

Research into the effects of scopolamine hydrobromide, a post­synaptic cholinergic receptor blocking drug, upon cognition in humans has been conducted for at least two decades. In that time, a distinct pattern of effects has emerged. Within a dose range of 0.3 to 1.2 mg (oral), scopolamine has been found to impair the acquisition of new information in verbal and spatial learning tasks, to reduce stimulus sensitivity in tests of vigilance and to impair selective attention. Generally it is thought that information retrieval, both of newly learned and autobiographical material, is unaffected by this drug. A primary reason for research interest in scopolamine is that the effects have been found to resemble the pattern of impairment found in advanced age, and particularly in Alzheimer's Disease (AD). This is often referred to as the 'Scopolamine model of dementia'. Coupled with the observation of extensive damage to CNS cholinergic neurons in AD, the hypothesis has emerged that acetylcholine activity influences many important cognitive processes. Recent theoretical analyses of cognitive loss in AD have proposed that there is a selective impairment to effortful (i.e. active, conscious) processes, whereas the more automatic (i.e. reflexive, unconscious) aspects of cognition remain intact. If the scopolamine model is to remain valid in this perspective, then it should be possible to show that, in normal humans, the effects of the drug are specific to effortful cognitive control processes. This thesis describes six experiments designed to test this prediction. It is presented in three parts. In Part I, two experiments examined the effects of O. 6mg and O. 9mg oral scopolamine upon the control of attention to targets in visual space. Results confirmed the prediction that the ability to detect stimuli in high probability locations on a VDU is impaired, while detection of stimuli in low probability locations is enhanced. It was argued that the drug broadened the attentional focus, and that this is due to a general reduction in cognitive control. In Part II, two studies sought to find evidence that the drug impairs the active selection of information from semantic memory. Here, subjects were not provided with material to learn, but rather were asked to sustain the retrieval of items from natural semantic categories for extended periods (8 to 12 min). In the second study of this pair, subjects were also constrained as to the type of retrieval strategy they could use. Results failed to confirm the prediction. The drug had no main or interactive effects on active control over semantic memory retrieval. In Part III, two studies tested the prediction that scopolamine would selectively impair the more difficult, controlled aspects of encoding and retrieval following presentation of verbal material (i.e. an episodic memory task) in two sensory modalities (auditory and visual). Subjects were required to recall lists of words, and to actively group their recall on the basis of the items' sensory modality. The first study found that the drug impaired recall, but not recognition, and did not have an effect on more automatic phenomena such as word priming effects and the recall advantage for auditory material. In addition, there was some evidence from statistical interactions that the drug impaired subjects' ability to actively cluster the presented material on the basis of input modality. The second experiment examined effects of scopolamine upon list learning and modality clustering when subjects were given five attempts to recall the same i terns. This experiment introduced two levels of task difficulty, by varying the extent to which item input modality was consistent across learning trials. Pilot testing (non-drug) revealed that list learning and clustering ability were significantly impaired in the variable, as compared to consistent, modality condition. In the full experiment, scopolamine impaired total recall but not recognition. The drug did not directly effect subjects' ability to group items on the basis of modality, and the size of the drug effect on immediate recall was similar for both the easy (i.e. consistent modality) and difficult (i.e. variable modality) learning trials. There were some interactions between drug and task variables which indicated a weak effect upon attention Taken together, these six experiments show the following pattern. Control over visual attention is impaired by scopolamine, and this agrees with some previous research. However, this reduction in cognitive control appears to be specific, rather than general, since the attempts to find an effect of the drug on active control of retrieval from semantic memory and the conscious organisation of material in episodic memory were unsuccessful. In theoretical terms, this series of experiments does not support the view that anticholinergic drug effects are specific to effortful processing. It was argued that the pattern of drug effects observed here is not simply due to low potency of a O. 9mg oral dose. Numerous previous experiments have observed subtle effects of scopolamine 0.9mg oral (and lower doses) on various measures of cognitive function. It was concluded that a low to moderate dose of oral scopolamine does have selective effects on different cognitive processes, but that this selectivity is not related to the amount of cognitive effort involved in the tasks. This work has identified some important limits to the scopolamine model of dementia, and extended research with this drug into several domains of human memory not previously examined. The implications for future research are discussed