A positive energy theorem for Einstein-aether and Ho\v{r}ava gravity

Energy positivity is established for a class of solutions to Einstein-aether theory and the IR limit of Ho\v{r}ava gravity within a certain range of coupling parameters. The class consists of solutions where the aether 4-vector is divergence free on a spacelike surface to which it is orthogonal (which implies that the surface is maximal). In particular, this result holds for spherically symmetric solutions at a moment of time symmetry.Comment: 4 page

The costs of poor safety in the workplace

Over the last two years we have conducted research on the costs of accidents in the workplace, monitoring 14 firms in the Republic of Ireland (RoI) over a 12 week period in 1995, and 11 firms in Northern Ireland (NI) over a 12 week period in 1996. Using a standard Report Form (Appendix I) which was filled in by the appropriate manager for every accident over the period, we have been able to obtain interesting case study information on the nature of the costs of accidents. In this paper we discuss costs of accidents in general (Section II), then describe our research methodology (Section III). The next section, section IV, presents the information on the costs of accidents arising from the research, in three sub-sections: total costs, direct vs indirect costs, and insured vs uninsured costs. In section V, we briefly summarise some of the recent literature on the prevention of accidents. Finally, section VI provides a brief conclusion

Core-periphery analysis: a tale of two nations

Bias, unreliability and omission have been documented in traditional sources of trade data; the lack of service data in trade statistics is the most frequently cited shortcoming. Current trade liberalization is likely to exacerbate these deficiencies. This paper develops and applies a location quotient based methodology for analysing core-periphery dualism, thus obviating the use of trade data. Our application to the European Union shows agglomeration in core areas of high technology, large scale manufacturing, and producer service industries. Peripheral countries are shown to specialize in agriculture, extractives, low technology manufacturing, and standardized production. Detailed examination of two peripheral economies, Ireland and Denmark, finds that each departs from the mean of peripheral nations. A comparison of proxied trade data to actual trade data indicates that the location quotient method is a statistically viable means of proxying trade patterns

Quantum Gravity Phenomenology and Lorentz Violation

If quantum gravity violates Lorentz symmetry, the prospects for observational guidance in understanding quantum gravity improve considerably. This article briefly reviews previous work on Lorentz violation (LV) and discusses aspects of the effective field theory framework for parametrizing LV effects. Current observational constraints on LV are then summarized, focusing on effects in QED at order E/M_Planck.Comment: 16 pages, Expanded version of a lecture by T. Jacobson, to be published in Particle Physics and the Universe, Proceedings of the 9th Adriatic Meeting, eds. J.Trampetic and J.Wess (Springer-Verlag, 2004

Counting the ions surrounding nucleic acids.

Nucleic acids are strongly negatively charged, and thus electrostatic interactions-screened by ions in solution-play an important role in governing their ability to fold and participate in biomolecular interactions. The negative charge creates a region, known as the ion atmosphere, in which cation and anion concentrations are perturbed from their bulk values. Ion counting experiments quantify the ion atmosphere by measuring the preferential ion interaction coefficient: the net total number of excess ions above, or below, the number expected due to the bulk concentration. The results of such studies provide important constraints on theories, which typically predict the full three-dimensional distribution of the screening cloud. This article reviews the state of nucleic acid ion counting measurements and critically analyzes their ability to test both analytical and simulation-based models

Innovation processes and industrial districts

In this survey, we examine the operations of innovation processes within industrial districts by exploring the ways in which differentiation, specialization, and integration affect the generation, diffusion, and use of new knowledge in such districts. We begin with an analysis of the importance of the division of labour and then investigate the effects of social embeddedness on innovation. We also consider the effect of forms of organization within industrial districts at various stages of product and process life, and we examine the negative aspects of embeddedness for innovation. We conclude with a discussion of the possible consequences of new information and communications technologies on innovation in industrial districts